Civil Engineering

Things to remember during Concrete Mix Design

2012-01-02T16:45:00.001-08:00

Good quality concrete starts with the quality of materials, cost effective designs is actually a by-product of selecting the best quality material and good construction practices. Following are 10 Things to remember during Concrete Mix Design and Concrete Trials.
1. ACI and other standards only serves as a guide, initial designs must be confirmed by laboratory trial and plant trial, adjustments on the design shall be done during trial mixes. Initial design “on paper” is never the final design.

2. Always carry out trial mixes using the materials for actual use.

3. Carry out 2 or 3 design variations for every design target.

4. Consider always the factor of safety, (1.125, 1.2, 1.25, 1.3 X target strength)

5. Before proceeding to plant trials, always confirm the source of materials to be the same as the one used in the laboratory trials.

6. Check calibration of batching plant.

7. Carry out full tests of fresh concrete at the batching plant, specially the air content and yield which is very important in commercial batching plants.

8. Correct quality control procedures at the plant will prevent future concrete problems.

9. Follow admixture recommendations from your supplier (of course Sika)

10. Check and verify strength development, most critical stage is the 3 and 7 days strength.

Important note:

Technical knowledge is an advantage for batching plant staff, even if you have good concrete design but uncommon or wrong procedures are practiced it will eventually result to failures.

RCC Mix Design

2012-01-02T16:44:00.001-08:00

Mix design proportioning methods for Roller Compacted Concrete RCC:

ACI 207.5R (chapter 2.4) and ACI 211.3R extensively described the mix design proportioning methods for no slump concrete applicable for Roller Compacted Concrete RCC

Materials Used in RCC mix design
a) Cementitious materials:
Cement content is generally low (typically 70 to 130 kg/m3). Any kind of Portland Cement (but low heat cement is a preferred type when its is available)

Fly Ash: Class F pozzolans are preferred. When used pozzolans, may replace up to 80 % of cement content.

b) Aggregates:
Selection of aggregates and control of aggregates quality is essential. Aggregates shall meet ASTM C33 standard.

Coarse aggregates:
Most of project use a coarse aggregates with a Nominal Maximal Size Aggregate (NMSA) between 37.5 and 75mm. The thickness of placement layer shall be more than 3 times the NMSA.

Fine aggregates:
The grading of fine aggregates strongly influence paste requirements and compactibility of RCC. It also affects water and cementitious material requirements needed to fill the aggregates voids and coat aggregate particles.

Other aggregates: Fines (crusher fines…):
In low cement content mixtures, supplements fines (material passing 0.075 mm sieve) are usually required. Fines quantities is generally 5% of total aggregates

c) Admixtures:
Admixtures for RCC needed mostly for set retardation (and plasticizing) effect. Water Reducer Type D (WR + retarder)
WR use is beneficial for strength gain, and retardation which can be required very extended. Main Sika Product for RCC: Plastiment TM 25 specifically designed for RCC.

Mix design considerations:
a) Workability / Consistency:
Measured with a Vebe vibrating table (ASTM C 1170).
The test principle is to measure the time for the concrete to be consolidated by vibrating in a cylindrically shaped mold. The longer the time, the drier/lesser workable is the concrete. Vebe times of RCC mixtures is generally from 10 to 40 seconds. Comparison of concrete consistency measured by slump and Vebe apparatus. ACI 211.3R

Consistency Slump (mm) Vebe (s)
Extremely dry - 32 to 18
Very Stiff - 18 to 10
Stiff 0 to 25 10 to 5
Stiff Plastic 25 to 75 5 to 3
Plastic 75 to 125 3 to 0
Very plastic 125 to 190 -

b) Strength:
Design strength of RCC dam is often based on long term strength (90 days, 120 days or even 1 year!). The strength of RCC is a function of w/c ratio only for mixture with Vebe time of ~ 15 to 20 sec. range. For drier mix, the strength is more controlled by the moisture-density relationship.

If water content is less than optimum => voids in structure, poorly compacted concrete with loss in density and strengths.

Compressive strength of RCC is usually measured by testing cylinder (15cm diameter, 30cm long).

Strength measured on cores is also possible.

d) Segregation:
It is necessary to produce mixture with minimum tendency to segregate => Aggregates (especially with NSMA > 37.5mm) shall be well graded.

Higher cement content mixture are generally more cohesive => less tendency to segregate.

e) Permeability
Mixture with paste volume of 18 to 22% by mass shall provide suitable level of impermeability. Higher cementitious content or high workability mixes that bond well to fresh lift joints will produce watertightness.

For lower cementitious content mix, and/or low workability mix, a bedding mortar between lifts may be needed.

f) Heat Generation:
It is an important factor considering the massive structures. Limitation of cement content, and/or use of fly ash is helping reduce heat generation.

g) Durability:
RCC should be free of damaging effects of alkali-aggregate reactivity

Quality control of RCC concrete:
Vebe Consistency Test
Density and air voids tests.
Moisture/water content tests.
Cement content evaluation
Temperature monitoring
Test (cylinders) specimens:
- Using modified Vebe apparatus (generally for mix with Vebe up to 20 seconds),

- Using of special vibrating hammers

Beware, because of low early strength of concrete specimens are “fragile”.

Lift-Joint sealing systems:
Lift joints shall be kept moist before placing next lift and normally do not require special treatment. In some cases, it is required to apply a “flowable” bedding mortar which need to be retarded with admixtures.

Concrete Mix Design Secrets

2012-01-02T16:43:00.001-08:00

In order to make a concrete mix design that works, you should master all the concrete theories in combination with experiences of concreting at work. Here is some important things you need to know when design concrete mixes.

A. What do you need to know before designing concrete?
1. What are the strength requirements?

- Compressive (on cube or cylinder specimen) strength

- Flexural strength

- Tensile strength

2. What is the placing method? By pump or direct pouring?

3. How far is the job site from the batching plant?

4. What is the structure for casting? Pavement, foundation, elevated slab, etc.

5. What are the projects specification?

- Maximum or minimum cement contents

- Maximum water/cement ratio

- Slump or consistency limit

- Minimum Strength requirement @28 days

- Material specifications (what is the maximum size of aggregate?)

6. Latest testing results of materials is needed in the preliminary selection of materials and design calculation

B. What are Design Precautions and Things to Remember when design concrete mixes?
1. Increasing the sand/total aggregate ratio, increases the water requirement at the same consistency.

2. Increasing the water/cement ratio decreases the strength of concrete at the same cement content.

3. Remember that adding 5 liters of water per cubic meter increases the slump by 2.5cm.

4. Remember that adding 5 liters of water per cubic meter decreases strength by approximately 4%.

5. Always follow recommended admixture dosage.

6. Always have “control” when performing trial mixes, always perform trial mixes with another mix using the same materials. This data can be useful in diagnostics if a problem occurs.

7. Always adjust batching quantities to the actual moisture condition of the aggregates.

8. Volume tolerance for 1m3 concrete is 1 ± 0.2m3.

9. Range of normal weight concrete is from 2,200 kg/m3 to 2,400 kg/m3

9 Questions Before Making Shotcrete Mix Design

2012-01-02T16:42:00.001-08:00

Before making a mix design for shotcrete or sprayed concrete, it is needed to get sufficient information from the clients. Adequate support information will be resulted in technically and economically effect for the work. A proper mix design assure a successful trial and thus, successful application on site.

Hereafter is a list of 9 questions to the ask the clients prior to making a shocrete mix design:

1. The location of shotcrete to be applied? Slope stabilization, overhead and wall in tunnel
2. Wet or Dry process will be applied? Normally, dry process for slope stabilization, wet process for tunnel lining.
3. The requirement of early strength (8 hours, 72 hours, 7 days, 28 days) and the final strength at each location.
4. Slump requirement (for wet process only)
5. What accelerator admixture to be used? Please note that it would be better to use liquid admixture in rainy season.
6. What is the concrete spraying machine to be used? Rotor Machine (for both wet and dry process) or Pump Machine (wet process only)
7. What kind and type of cement to be used (cement should be super fine. Blain Surface fineness is greater than 4000 square centimeter per gram) PC cement is most suitable for early strength requirement.
8. A dispenser system need to be installed in case wet process is used. Is such liquid dosing unit available?
9. Any other information is helpful in designing shotcrete mix?

Once these question get answered, the mix designing process can be started. For shotcrete or sprayed concrete, trial is a must be prior to the issue of mix design for actual application.

What is shotcrete?

2012-01-02T16:40:00.001-08:00

Shotcrete or gunite was invented by Mr. Carl Ethan Akeley (1864-1926) in 1910. For attractions of a park, this American Architect was mandated to realize in concrete the reproduction of a dinosaur. Considering the sizes of the structure, he had the idea to develop a “cement gun” machine allowing the spraying of a cementitious mortar. Shotcrete was created!

Probably a symbolic coincidence, but the same year, Mr. Kaspar Winkler founded Sika. Since that time Sika has greatly contributed to the development of the shotcrete technology. By shotcrete technology development, we mean the continuous development of chemical additives and admixtures for shotcrete and as well the development of spraying equipments.

Fields of shotcrete application
Shotcrete is mainly used in Underground construction projects as preliminary or permanent structural support. By Underground constructions, we mean the construction of structures like road-rail tunnel, hydropower plant, mines, parking, subway, metro, storage area etc.
However shotcrete is as well as an economical tool to realize stabilization work (slope), swimming pools, waterways, concrete repairs, inner lining and architectural structures. About 90% of the shotcrete applied goes into Underground construction projects. Total volume of shotcrete worldwide applied yearly is more than 12 millions cubic meters

What is shotcrete?
As per the American Concrete Institute (ACI), shotcrete can be defined as a mortar or concrete, pneumatically projected at high velocity through a pressure resistant conveying line onto a surface, where it is compacted on impact.

Cement, sand, aggregate, water, additives and admixtures are the components entering in the production of the shotcrete mix.

Compared to normal concrete, shotcrete differs mainly from three points:

The maximal size of the aggregate used.
The way to place it.
The mixture of shotcrete can be dry or wet.
Regarding terminology we can describe Gunite as sprayed mortar while Shotcrete as a sprayed concrete.
By gunite we means a cementitious mixture of which the particles size is limited to 8 mm.
For shotcrete we consider the use of aggregates of which the maximal size is 16 mm. However, in the last 10 years there is a tendency to limit the maximal aggregate size to 12 mm.

Shotcrete development can be summarized from its start to nowadays as follows:
Dry process –> dry process with powder accelerator –> wet process with Alkali liquid accelerator –> wet process with Alkali free accelerator.

Shotcrete mix design and proportion

2012-01-02T16:39:00.001-08:00

Aggregate

Aggregates for shotcrete my contain river sand, crushed sand and crushed stone with particle sizes up to 16mm, normally up to 9.5mm.

Here after is a typical and recommended gradation of combined aggregates for shotcrete that will resulted in perfect mix design.:

Water Cement Ratio

The water-cement ratio for wet shotcrete normally falls within a range of by weight and 0.40 to 0.55 for wet-mix shotcrete.

Dry mix design shall only include water content enough for the hydration process of cement needed for strength development.

In dry-mix shotcrete, the moisture content of the fine and coarse aggregates should be such that the aggregate-cement mixture will flow at a uniform rate, without slugging or hose plugging. The optimum moisture content is generally within the range of 3 to 6 percent. The sand should be dried or wetted as required to bring the moisture content within that range. Large fluctuations in moisture content should be avoided.

A crude but effective test for determining proper predampening is the “ball-in-hand” test. A small amount of mix is placed in the hand and squeezed tightly. When the hand is opened, the mixture may crumble into discrete particles which indicates too little predampening moisture and is usually light gray. If the material holds together, or cracks but remains essentially whole, there is enough moisture. If moisture comes off on the hand, there is too much moisture in the mix.

Unit Weight of Concrete

The unit weight of good shotcrete is usually between 2230 to 2390 kg/m3, about the same as conventional concrete.

Cement Content

OPC cement with surface Blaine above 4500 cm2/gr is most suitable for shotcrete. Typical and recommended cement contents is:

* It is in the best interest of the end user to perform trial mixes and shotcrete trial to determine the suitable cement content, to meet other parameters, above table is used only as a guide in preliminary design and shall be decided in the results of trial mixes and trial application.

Proportioning

Shotcrete design for wet process can be designed like conventional concrete but these mixes contains higher volume of fine aggregate and cement. Shotcrete process can be designed by absolute volume method or by weight.

Shotcrete design for dry process is designed using the bulk densities of the materials, usually the water content is not included in the calculation.

Application of sprayed concrete or shotcrete

2012-01-02T16:38:00.001-08:00

Uses of sprayed concrete (or shotcrete)
Over the past century, sprayed concrete has replaced the traditional methods of lining tunnel profiles and has become very important in stabilizing the excavated tunnel section. Sprayed concrete is a single term that describes various component of a complete technology:

the material sprayed concrete
the sprayed concreting process
the sprayed concrete system
Sprayed concrete construction is used in many different types of project. The flexibility and economy comes to the fore in above-ground and underground buildings, tunneling and special underground construction, in fact throughout the construction industry. The following uses are widespread:

excavation stabilization in tunnelling and underground construction
tunnel and underground chamber lining
stabilization in mine and gallery construction
concrete repair (concrete replacement and strengthening)
restoration of historic buildings (stone structure)
sealing works
trenching stabilization
slope stabilization
protective lining
wearing courses
special lightweight load-bearing structures
creative applications
In terms of importance, tunnelling, mining and concrete repair head the list. In tunneling and mining, the main uses are for excavation stabilization, temporary and permanent arch lining. Sprayed concrete is also used fir all other appropriate concrete works. Large cavities are often spray filled, for instance. Spray concrete has confirmed and strengthen its position alongside tunnel segment lining (tubbing) and interior ring concrete as the main concreting method. The limits on its use lie in the technical and economic interfaces with the other concreting process and/or construction methods.

Types of construction using sprayed concrete (shotcrete)
Sprayed concrete is used in all areas of tunneling construction – for road or rail tunnels, water drainage and underground military structures, in addition to slope stabilization. Whether tunneling under a building or driving through an obstruction, the construction method is determined by the weight-bearing properties and stability of the substrate tunneled through. The main distinction is between full excavation of the entire section in one operation and partial excavation in many different forms and methods. If full excavation is not possible due to the rock stability, the final profile is often excavated is several phases.

In underground construction, because high stresses would often be exerted on the newly places excavation stabilization and lining. Predetermined deformation of the excavated section is often allowed and only then is the stabilization given a non-positive seal. This causes the stress to be distributed around the excavation section and in the area around the excavation face.

Keep reading next coming post: Sprayed concrete for stabilization and lining.

Fibre Reinforced Concrete

2012-01-02T16:37:00.001-08:00

Conventional concrete containing discontinuous discrete fibres is called fibre-reinforced concrete. Fibers of various shape and size produced from steel, plastic, glass, carbon and natural materials have been used.
However for any reinforcement to be effective, it must be stiffer than the concrete matrix that is reinforcing. Generally the less stiff fibres (made from plastic and natural materials) only offer benefits in improving the tensile strength of plastic and semi-hardened concrete and are therefore mainly used to reduce plastic shrinkage and plastic settlement cracking. The stiffer fibres improve both the tensile strength and the toughness of harden concrete.

The most widely used stiff fibre is steel. Low volume fractions of fibres (less than 1%) are used to reduce shrinkage cracking. Moderate volume fractions (between 1% to 2%) increase flexural strength, fracture toughness and impact resistance. High volume fractions (greater than 2%) lead to strain hardening of the composites. The shape and length of the fibres also play a role in the fibres’ effectiveness in improving the properties of the concrete. The use of fibres in concrete can have a marked effect on the workability of the concrete and this need to be taken into account in the mix proportion of fibre-reinforced concrete.

Currently a great deal of research is being undertaken into the use of ultra-high-performance fibre-reinforced composites. One of the benefits of these materials is extremely high ductility. Fibre-reinforced concrete has been used for precast panels, airfield and highway pavements, industrial floors and in spraying concrete for slope stability and underground mining applications.

Concrete Countertops for your Home

2012-01-02T16:36:00.000-08:00

The biggest reason you could have to choose concrete countertops over any other kind would be to take advantage of the inexpensive nature of the material. Nothing could be simpler and more readily available than poured concrete. Of course, no one likes the drab gray of plain concrete. Anyone who wants something more colorful can easily use staining – a method that is both cheap and simple.

The great thing about deciding to use a concrete for a countertop is that the material does lend itself well to DIY projects – even by novices who have little experience with it. Any investment you put into concrete is repaid well too – there’s quite nothing like concrete even among materials that last. Even used in places where it is exposed to the elements, concrete tends to last for at least a half-century once properly laid.

So concrete is cheap, durable and easy to work with. Isn’t there anything that works against it as a material of choice to use on countertops? Well, you could consider the cost of the sealing material that you need to use on top of laid concrete that would actually make it suitable for use as a countertop. Since countertops need to be buttery smooth in a way concrete just isn’t, you really need to consider finishing a countertop after you’ve laid it. The sealer makes the surface smooth enough and stain-proofed enough, for everyday use. If you don’t feel that you’re up to the task of building a concrete countertop yourself, having a professional come in and do it for you can turn out to be a somewhat expensive service to buy too.

If you do take the plunge and decide to get your feet wet, learning how to put down a concrete slab yourself, if you aren’t careful, you might find yourself in in a little too deep. Wrongly done, concrete can cure unevenly and developed cracks. And concrete countertops, even if you do succeed in installing them properly, do present quite a challenge when you need to to install a sink or something. The material is one of the hardest known to man, and cutting an even opening without damaging everything can be a serious problem. You also need to consider how concrete ages. While the structural integrity of the material can be untouchable for centuries, the glossy sealer overlay can have a finite life.

Concrete happens to be a material that’s easy to achieve mediocre results with, and difficult to finish with perfection. If you can afford to call in a professional, or if you can afford to take the time to learn really well how it is done in the DIY method, it could be the right material for your home.

Specification for Placing of Concrete

2012-01-02T16:34:00.001-08:00

Concrete shall be deposited as nearly as possible to its final position and shall be placed in layers not more than 30 cm thick. Concrete shall be placed at such a rate that it is at all times plastic and will flow readily around reinforcement and embedded parts. Once placing is started, it shall be a continuous operation until the lift is completed. The area of placement shall not be more than that which can be completed in one pour in compliance with this specification.

The time between placing of successive layers forming a lift shall be short enough to permit a vibrator to penetrate the lower layer while the upper layer is being compacted. The minimum time between completion of a lift and the commencement of placing of a succeeding lift shall be 72 hours.

Pneumatic placing and pumping of concrete may only be used with the approval of client. In such a case, discharge lines shall be horizontal or inclined upwards. The discharge end shall not be more than 3m from the point of placement and shall supply a continuous stream of concrete without air pockets. Aluminum piping shall not be used.

During hot weather, special precautions, as directed or approved by the owner, shall be taken to ensure that the temperature of the concrete when it is placed does not exceed 30 degrees Centigrade. These may include, but shall not be limited to, the use of chilled mixing water, cooling of aggregate or working at night.

Concrete shall not be placed in exposed areas during rain and, should it rain while placing is in progress, the placed concrete shall be covered with vinyl or other impervious sheets. Placing may be resumed only when rain stops well before initial set of the placed concrete occurs. Otherwise, placing operations shall cease and the boundaries of the pour shall be prepared as specified for construction joints.

Concrete shall not be placed under water except when specifically directed and authorized in writing by the owner. In such a case, placing shall be done from a bottom?discharging watertight bucket or by termite pipe penetrating the previously placed concrete so that fresh concrete is always deposited below the surface and the operation is continuous until completion of the pour.

Compaction

Concrete shall be compacted by mechanical vibrators electrically or pneumatically driven. Immersion vibrators shall operate, when fully immersed, at speeds of not less than 7,000 impulses per minute for vibrating heads of less than 10 cm diameter and 6,000 impulses per minute for heads 10 cm or greater in diameter. They shall be slowly immersed and withdrawn vertically at spacing of 30 cm to 50 cm, with vibration periods of 10 to 15 seconds for each penetration, and shall penetrate into the layer below. Vibrators shall not come into contact with reinforcement or embedded parts.

Where immersion vibrators cannot be used, the concrete shall be compacted by form vibrators, rigidly attached to the outside of the form, operating at not less than 8,000 impulses per minute.

Curing

Concrete surfaces shall be kept continuously moist for at least 14 days after placing and until the concrete temperature produced by heat of hydration of the cement has peaked and fallen at least 10 centigrade degrees. Initial curing of exposed surfaces shall be performed by atomized water spray positioned so that all surfaces to be cured are constantly moist, or by a continuous layer of burlap kept constantly wet. Hand sprinkling shall not be used except in conjunction with the burlap alternative.

Forms capable of moisture loss, such as plywood forms, shall be regularly sprinkled with water to avoid loss of moisture from formed surfaces of the concrete.

Self-healing Electronics Could Work Longer and Reduce Waste

2012-01-01T23:39:00.001-08:00

When one tiny circuit within an integrated chip cracks or fails, the whole chip -- or even the whole device -- is a loss. But what if it could fix itself, and fix itself so fast that the user never knew there was a problem? A team of University of Illinois engineers has developed a self-healing system that restores electrical conductivity to a cracked circuit in less time than it takes to blink. Led by aerospace engineering professor Scott White and materials science and engineering professor Nancy Sottos, the researchers published their results in the journal Advanced Materials.

"It simplifies the system," said chemistry professor Jeffrey Moore, a co-author of the paper. "Rather than having to build in redundancies or to build in a sensory diagnostics system, this material is designed to take care of the problem itself."

As electronic devices are evolving to perform more sophisticated tasks, manufacturers are packing as much density onto a chip as possible. However, such density compounds reliability problems, such as failure stemming from fluctuating temperature cycles as the device operates or fatigue. A failure at any point in the circuit can shut down the whole device.

"In general there's not much avenue for manual repair," Sottos said. "Sometimes you just can't get to the inside. In a multilayer integrated circuit, there's no opening it up. Normally you just replace the whole chip. It's true for a battery too. You can't pull a battery apart and try to find the source of the failure."

Most consumer devices are meant to be replaced with some frequency, adding to electronic waste issues, but in many important applications -- such as instruments or vehicles for space or military functions -- electrical failures cannot be replaced or repaired.

UCLA Neuroscientists Demonstrate Crucial Advances İn 'Brain Reading'

2012-01-01T23:38:00.001-08:00

At UCLA's Laboratory of Integrative Neuroimaging Technology, researchers use functional MRI brain scans to observe brain signal changes that take place during mental activity. They then employ computerized machine learning (ML) methods to study these patterns and identify the cognitive state -- or sometimes the thought process -- of human subjects. The technique is called "brain reading" or "brain decoding." In a new study, the UCLA research team describes several crucial advances in this field, using fMRI and machine learning methods to perform "brain reading" on smokers experiencing nicotine cravings.

The research, presented last week at the Neural Information Processing Systems' Machine Learning and Interpretation in Neuroimaging workshop in Spain, was funded by the National Institute on Drug Abuse, which is interested in using these method to help people control drug cravings.

In this study on addiction and cravings, the team classified data taken from cigarette smokers who were scanned while watching videos meant to induce nicotine cravings. The aim was to understand in detail which regions of the brain and which neural networks are responsible for resisting nicotine addiction specifically, and cravings in general, said Dr. Ariana Anderson, a postdoctoral fellow in the Integrative Neuroimaging Technology lab and the study's lead author.

"We are interested in exploring the relationships between structure and function in the human brain, particularly as related to higher-level cognition, such as mental imagery," Anderson said. "The lab is engaged in the active exploration of modern data-analysis approaches, such as machine learning, with special attention to methods that reveal systems-level neural organization."

For the study, smokers sometimes watched videos meant to induce cravings, sometimes watched "neutral" videos and at sometimes watched no video at all. They were instructed to attempt to fight nicotine cravings when they arose.

New Technique Makes İt Easier To Etch Semiconductors

2012-01-01T23:36:00.000-08:00

Creating semiconductor structures for high-end optoelectronic devices just got easier, thanks to University of Illinois researchers. The team developed a method to chemically etch patterned arrays in the semiconductor gallium arsenide, used in solar cells, lasers, light emitting diodes (LEDs), field effect transistors (FETs), capacitors and sensors. Led by electrical and computer engineering professor Xiuling Li, the researchers describe their technique in the journal Nano Letters.

A semiconductor's physical properties can vary depending on its structure, so semiconductor wafers are etched into structures that tune their electrical and optical properties and connectivity before they are assembled into chips.

Semiconductors are commonly etched with two techniques: "Wet" etching uses a chemical solution to erode the semiconductor in all directions, while "dry" etching uses a directed beam of ions to bombard the surface, carving out a directed pattern. Such patterns are required for high-aspect-ratio nanostructures, or tiny shapes that have a large ratio of height to width. High-aspect-ratio structures are essential to many high-end optoelectronic device applications.

While silicon is the most ubiquitous material in semiconductor devices, materials in the III-V (pronounced three-five) group are more efficient in optoelectronic applications, such as solar cells or lasers.

Unfortunately, these materials can be difficult to dry etch, as the high-energy ion blasts damage the semiconductor's surface. III-V semiconductors are especially susceptible to damage.

To address this problem, Li and her group turned to metal-assisted chemical etching (MacEtch), a wet-etching approach they had previously developed for silicon. Unlike other wet methods, MacEtch works in one direction, from the top down. It is faster and less expensive than many dry etch techniques, according to Li. Her group revisited the MacEtch technique, optimizing the chemical solution and reaction conditions for the III-V semiconductor gallium arsenide (GaAs).

The process has two steps. First, a thin film of metal is patterned on the GaAs surface. Then, the semiconductor with the metal pattern is immersed in the MacEtch chemical solution. The metal catalyzes the reaction so that only the areas touching metal are etched away, and high-aspect-ratio structures are formed as the metal sinks into the wafer. When the etching is done, the metal can be cleaned from the surface without damaging it.

Pitt Researchers Propose New Model To Design Better Flu Shots

2012-01-01T23:35:00.000-08:00

The flu shot, typically the first line of defense against seasonal influenza, could better treat the U.S. population, thanks to University of Pittsburgh researchers. New research that focuses on the composition and timing of the shot design was published in the September-October issue of Operations Research by Pitt Swanson School of Engineering faculty members Oleg Prokopyev, an assistant professor, and Professor Andrew Schaefer, both in the Department of Industrial Engineering, and coauthors Osman Ozaltin and Mark Roberts, professor and chair in Pitt's Department of Health Policy and Management. Ozaltin, who is now an assistant professor of engineering at the University of Waterloo in Ontario, did his research for the study as a Pitt graduate student in the Swanson School; he earned his Pitt PhD degree in industrial engineering earlier this year.

The exact composition of the flu shot is decided every year by the Food and Drug Administration (FDA), and the decision is complicated.

"The flu's high rate of transmission requires frequent changes to the shot," said Prokopyev. "Different strains can also cocirculate in one season, which gives us another challenge for figuring out the composition."

The Pitt researchers used powerful optimization methods from engineering to examine whether they could improve the yearly decisions made regarding what strains of influenza should be included in the current year's vaccine. The strains of flu that will be most likely to appear in the regular flu season are not known with certainty, but waiting longer to finalize the composition of the vaccine and observing what strains are occurring in other parts of the world improves the accuracy of the selection. However, the longer the FDA waits to make the decision, the more likely it is that there will be insufficient vaccine produced by the start of flu season. The model developed by the Pitt researchers balances these two important characteristics of the flu selection decision and integrates the composition and timing decisions of the flu shot design.

The model allows examination of the effect of many changes to the design and production of the vaccine, such as how many strains to include in the shot, when to make the final decision, how many times the FDA should meet to re-examine the current information concerning strains in other parts of the world, and the potential benefits from improved production methods.

"With this model, several policy questions can be addressed," said Schaefer. "For example, incorporating more than three strains might increase the societal benefit substantially, particularly under more severe flu seasons."

New Device Could Bring Optical İnformation Processing

2012-01-01T23:34:00.000-08:00

Researchers have created a new type of optical device small enough to fit millions on a computer chip that could lead to faster, more powerful information processing and supercomputers. The "passive optical diode" is made from two tiny silicon rings measuring 10 microns in diameter, or about one-tenth the width of a human hair. Unlike other optical diodes, it does not require external assistance to transmit signals and can be readily integrated into computer chips.

The diode is capable of "nonreciprocal transmission," meaning it transmits signals in only one direction, making it capable of information processing, said Minghao Qi (pronounced Chee), an associate professor of electrical and computer engineering at Purdue University.

"This one-way transmission is the most fundamental part of a logic circuit, so our diodes open the door to optical information processing," said Qi, working with a team also led by Andrew Weiner, Purdue's Scifres Family Distinguished Professor of Electrical and Computer Engineering.

The diodes are described in a paper to be published online Dec. 22 in the journal Science. The paper was written by graduate students Li Fan, Jian Wang, Leo Varghese, Hao Shen and Ben Niu, research associate Yi Xuan, and Weiner and Qi.

Although fiberoptic cables are instrumental in transmitting large quantities of data across oceans and continents, information processing is slowed and the data are susceptible to cyberattack when optical signals must be translated into electronic signals for use in computers, and vice versa.

"This translation requires expensive equipment," Wang said. "What you'd rather be able to do is plug the fiber directly into computers with no translation needed, and then you get a lot of bandwidth and security."

Go To Work On A Christmas Card

2012-01-01T23:33:00.002-08:00

If all the UK's discarded wrapping paper and Christmas cards were collected and fermented, they could make enough biofuel to run a double-decker bus to the moon and back more than 20 times, according to the researchers behind a new scientific study. The study, by scientists at Imperial College London, demonstrates that industrial quantities of waste paper could be turned into high grade biofuel, to power motor vehicles, by fermenting the paper using microorganisms. The researchers hope that biofuels made from waste paper could ultimately provide one alternative to fossil fuels like diesel and petrol, in turn reducing the impact of fossil fuels on the environment.

According to some estimates 1.5 billion cards and 83 square kilometres of wrapping paper are thrown away by UK residents over the Christmas period. They currently go to landfill or are recycled in local schemes. This amount of paper could provide 5-12 million litres of biofuel, say the researchers, enough to run a bus for up to 18 million km.

"If one card is assumed to weigh 20g and one square metre of wrapping paper is 10g, then around 38,300 tonnes of extra paper waste will be generated at Christmas time," said study author Dr Richard Murphy from the Department of Life Sciences at Imperial College London. "Our research shows that it would be feasible to build waste paper-to-biofuel processing plants that give energy back as transport fuel."

Co-author and PhD student Lei Wang, also from Imperial's Department of Life Sciences, said: "The fermentation process could even cope with festive paper and card which has been 'contaminated' with the likes of glitter and sellotape. The cellulose molecules in sellotape would be broken down into glucose sugars and then fermented into ethanol fuel, just like the paper itself. Insoluble items like glitter are easy to filter out as part of the process."

Dr Murphy added: "People should not stop recycling their discarded paper and Christmas cards because at the moment there is no better solution. However, if this technology can be developed further, waste paper might ultimately provide a great, environmentally friendly alternative to fossil fuels. There's more work to do to assess the effectiveness and benefits of the technology, but we think it has significant potential."

Shearing Triggers Odd Behavior İn Microscopic Particles

2012-01-01T23:33:00.001-08:00

Microscopic spheres form strings in surprising alignments when suspended in a viscous fluid and sheared between two plates -- a finding that will affect the way scientists think about the properties of such wide-ranging substances as shampoo and futuristic computer chips. A team of scientists at Cornell University and the University of Chicago have imaged this behavior and have explained the forces causing it for the first time. Its findings appear in the Dec. 19-23 early edition of the Proceedings of the National Academy of Sciences.

"The experimental breakthrough revealed that these string structures were perpendicular to the shear instead of parallel to it, contrary to what many in the field were expecting," said Aaron Dinner, associate professor in chemistry at UChicago and a study co-author.

The experiment was led by Itai Cohen, associate professor of physics at Cornell, who custom-built a device that would enable him simultaneously to exert shearing forces on suspended colloids (the spheres) and image the resulting motion at 100 frames per second with a confocal microscope. Imaging speed was critical to the experiment because the string-like structures appear only at certain shear rates.

"This issue of strings has been pretty controversial. I'm not sure that we've solved all the controversies associated with them, but at least we've made a step forward," Cohen said.

Shearing forces affect the dynamic behavior of paint, shampoo and other viscous household products, but an understanding of these and related phenomena at the microscopic level has largely eluded a detailed scientific understanding until the last decade, Dinner noted.

Futuristically speaking, these forces potentially could be harnessed to produce microscopic patterns on computer chips or biosensors via special paints that flow easily when layered in one direction, but becomes hard when layered in another direction.

Cohen's objective was more scientifically immediate: to devise an experiment that would overcome the technical difficulties associated with measuring the mechanical properties of the colloidal strings while also imaging their formation. "The holy grail is to be able to understand how the structure leads to the mechanical properties and then to be able to control the mechanical properties by influencing the structure," Cohen explained.

Sunlight and Bunker Oil A Fatal Combination For Pacific Herring

2012-01-01T23:32:00.000-08:00

The 2007 Cosco Busan disaster, which spilled 54,000 gallons of oil into the San Francisco Bay, had an unexpectedly lethal impact on embryonic fish, devastating a commercially and ecologically important species for nearly two years, reports a new study by the University of California, Davis, and the National Oceanic and Atmospheric Administration. The study, to be published the week of Dec. 26 in the early edition of the Proceedings of the National Academy of Sciences, suggests that even small oil spills can have a large impact on marine life, and that common chemical analyses of oil spills may be inadequate.

"Our research represents a change in the paradigm for oil spill research and detecting oil spill effects in an urbanized estuary," said Gary Cherr, director of the UC Davis Bodega Marine Laboratory and a study co-author.

On the foggy morning of Nov. 7, 2007, when the container ship collided with the San Francisco-Oakland Bay Bridge, bunker oil contaminated spawning habitats for the largest U.S. coastal population of Pacific herring -- a month before spawning season.

The new study, which analyzed Pacific herring embryos following the spill, highlights the effects of bunker oil on fish embryos in shallow water, the potential significance of sunlight interacting with oil compounds, and the extreme vulnerability of fish in early life stages to spilled oil.

Specifically, the study found that components of Cosco Busan bunker oil accumulated in naturally spawned herring embryos, then interacted with sunlight during low tides to kill the embryos. Laboratory-fertilized eggs, caged in deeper waters, were protected from the lethal combination of sunlight and oil, but still showed less severe abnormalities associated with oil exposure.

Crude oil is naturally occurring, liquid petroleum. Bunker oil is a thick fuel oil distilled from crude oil and burned on ships to fuel their engines. It is contaminated with various, sometimes unknown, substances.

The study builds on research following the 1989 Exxon Valdez spill, which released up to 32 million gallons of crude oil into the comparatively pristine environment of Prince William Sound, Alaska. That research established a new paradigm for understanding the effects of oil toxicity on fish at early life stages.

Irikaitz Archaeological Site Host To A 25,000-year-old Pendant

2012-01-01T23:31:00.000-08:00

The recent discovery of a pendant at the Irikaitz archaeological site in Zestoa (in the Basque province of Gipuzkoa) has given rise to intense debate: it may be as old as 25,000 years, which would make it the oldest found to date at open-air excavations throughout the whole of the Iberian Peninsula. This stone is nine centimetres long and has a hole for hanging it from the neck although it would seem that, apart from being adornment, it was used to sharpen tools. This is one of a number of interesting findings made by the team led by Álvaro Arrizabalaga at this location: "Almost every year some archaeological artefact of great value is discovered; at times, even 8 or 10. It is a highly fruitful location."

Irikaitz lies behind the bath spa in Zestoa, on the other side of the river Urola, 14 metres from the river bank. The archaeologist from the University of the Basque Country (UPV/EHU) has been carrying out excavations here summer after summer, together with students and researchers from this and other universities and in cooperation with Aranzadi Science Society. Since 1998 they have uncovered 32 square metres; nothing compared to the eight hectares (at least) that this "gigantic" open-air site covers. This is archaeology, demanding a lot of patience, but the results are worth it: "You feel as if you have found something that has been waiting to fall into your hands for 200,000 years."

It is like a lottery

The tasks pertaining to an archaeological site are complex and lengthy in any case, but particularly so at Irikaiz. To start with, because it is in the open air. In the case of caves, it is known that they served as refuges for our ancestors and, once their location is identified, it is highly possible that archaeological treasures are found there. Open air archaeological sites, on the other hand, are discovered when some civil engineering infrastructure has to be built, and it is difficult to predict what will be found. Moreover, in Zestoa there are remains from the Lower Paleolithic, when there are hardly any references from this period in the Basque Country. According to Mr Arrizabalaga, when they started, "it was like a lottery. We did not know what to expect -- either about its chronology or about the kinds of remains likely to be uncovered."

Precisely because of this lack of references, they were fascinated when they came across "totally exotic" raw material: volcanic stones. "In the first dig, we thought at first that someone may have brought the rocks there when they were building the Urola railway, to use them as ballast. It was all so surprising and incredible," said the archaeologist. But no; this phenomenon had another logical explanation: "It is a geological rarity. In the Urola River valley there is a layer of volcanic stones; the river cut through these, took them to the surface and brought them to this place. This is why humans from prehistory came here -- there was no other place in the Basque Country with stones like these."

Brain's Connective Cells Are Much More Than Glue

2012-01-01T23:29:00.000-08:00

Glia cells, named for the Greek word for "glue," hold the brain's neurons together and protect the cells that determine our thoughts and behaviors, but scientists have long puzzled over their prominence in the activities of the brain dedicated to learning and memory. Now Tel Aviv University researchers say that glia cells are central to the brain's plasticity -- how the brain adapts, learns, and stores information. According to Ph.D. student Maurizio De Pittà of TAU's Schools of Physics and Astronomy and Electrical Engineering, glia cells do much more than hold the brain together. A mechanism within the glia cells also sorts information for learning purposes, De Pittà says. "Glia cells are like the brain's supervisors. By regulating the synapses, they control the transfer of information between neurons, affecting how the brain processes information and learns."

De Pittà's research, led by his TAU supervisor Prof. Eshel Ben-Jacob, along with Vladislav Volman of The Salk Institute and the University of California at San Diego and Hugues Berry of the Université de Lyon in France, has developed the first computer model that incorporates the influence of glia cells on synaptic information transfer. Detailed in the journal PLoS Computational Biology, the model can also be implemented in technologies based on brain networks such as microchips and computer software, Prof. Ben-Jacob says, and aid in research on brain disorders such as Alzheimer's disease and epilepsy.

Regulating the brain's "social network"

The brain is constituted of two main types of cells: neurons and glia. Neurons fire off signals that dictate how we think and behave, using synapses to pass along the message from one neuron to another, explains De Pittà. Scientists theorize that memory and learning are dictated by synaptic activity because they are "plastic," with the ability to adapt to different stimuli.

But Ben-Jacob and colleagues suspected that glia cells were even more central to how the brain works. Glia cells are abundant in the brain's hippocampus and the cortex, the two parts of the brain that have the most control over the brain's ability to process information, learn and memorize. In fact, for every neuron cell, there are two to five glia cells. Taking into account previous experimental data, the researchers were able to build a model that could resolve the puzzle.

The brain is like a social network, says Prof. Ben-Jacob. Messages may originate with the neurons, which use the synapses as their delivery system, but the glia serve as an overall moderator, regulating which messages are sent on and when. These cells can either prompt the transfer of information, or slow activity if the synapses are becoming overactive. This makes the glia cells the guardians of our learning and memory processes, he notes, orchestrating the transmission of information for optimal brain function.

Market Research Salary

2011-12-09T12:59:00.001-08:00

Individuals that work in market research analyze what ideals and desires frequently motivate consumers to buy certain goods and avoid other goods. They often use sales statistics, feedback from consumer reports and surveys. This information helps companies design effective public relation campaigns, advertising and to choose only highly effective media. The results of the research can estimate the success of a product or a product line and help determine how a new product is designed.

Salary Overview

Salaries are affected by several factors such as the state and metropolitan location and what industry the company is part of. Generally, cities will pay more than towns in rural areas. The applicant’s level of education and training, professional certifications and membership to associations also can make an impact on how an employee is paid. For example, a market analyst that has a master’s degree is more likely to start at a higher salary than one with a bachelor’s or associate’s degree.

The US Bureau of Labor Statistics reported the following salary information as of May in 2009.

A market research analyst’s median annual salary was $61,580. Individuals that worked in the scientific, technical and management consulting services earned highest pay of $64,360.

Individuals employed as marketing managers earned a median salary of $110,030. Managers of securities and commodity exchanges made the highest mean wage of $153, 060.

The median salary for survey researchers was $35,380. Those that worked in the science research and development service made the highest industrial wage of $62,280.

Job Description and Outlook

A market research analyst is responsible for determining the potential sales of a service or product. They analyze the statistical information of sales history to estimate future sales and then give management the data required to make an informed decision on how a service or product is created, priced, promoted and distributed.

A marketing manager supervises the design and development of a company’s general strategy for marketing. Their duties include keeping an eye the on progress of research performed externally and internally, how marketing promotions are used, designing new products for specific demographics and implementing advertising strategies. Often, marketing managers supervise market research analysts and other research employees. They also work with various managers to ensure a coordinated strategy for producing new items and promoting current products to consumers.

Business Administration Salary

2011-12-09T12:58:00.002-08:00

Business administration managers direct, coordinate and plan a variety of services that allow companies to operate in an efficient manner. They often coordinate facilities maintenance, space allocation and property procurement. They may also supervise centralized operation to ensure that the meet the needs and standards of different department within the organization. Business administration managers may also supervise telecommunications management, security and transportation services for the organization.

The duties for business administration managers tend to vary from company to company, depending on the size of the organization and the industry in which it works. Smaller companies may have only one business administration manager, which is called an office manager, while larger companies may have a team of business administration managers dividing the work load and specializing in different areas according to their level of expertise.

Salary Overview

Specific wages of business administration managers may vary greatly depending on the industry they work in, their specialty and the geographical area in which the business is located. Median income salaries of business administration managers in 2010 were $73,520. The middle fifty percent earned between $52,320 and $98,990. The bottom ten percent earned less than $38,460 per year and the upper ten percent earner more than $129,770 per year.

Business administration managers who managed corporations had a median income of $85,980 per year, those who managed hospitals had a median income of $77,860 per year and those who worked for local governments had a median income of $74,458 per year. Business administration managers who were employed by professional schools or universities had a median income of $72,460 per year, while those working for state governments had a median income of $65,690 per year.

Job Description and Outlook

Business administrators spend the majority of their days in an office environment, but may be required to make inspections around the building or grounds to supervise facilities that fall under their management duties. Half of business administrators work a forty hour work week, with the other half working considerably longer hours. In many cases, uncompensated overtime is expected of the business administrator in order to ensure that deadlines are met.

The exact duties of the business administrator may vary as significantly as the range of administrative services that they are expected to execute for the organization. Business administrators may serve as contract administrators, construction administrators or supply administrators depending on the organization where they are employed.

Employment in this field is expected to grow at the national average for most positions. Growth for the upper level jobs in this field will grow at a slower pace due to stiff competition. For the middle-tier positions, competition is lower so employment prospects will continue to look good for this level for the next ten years. Business administrators who specialize in facility management have the best employment prospects. Business administrators who are engaged in management consulting should also have a significant increase in their employment prospects due to companies outsourcing routine managerial duties.

Insurance Agent Salary

2011-12-09T12:58:00.001-08:00

Insurance Agents are important for people who are looking to purchase life insurance. Life insurance plays an important role in a families financial future. In most households, it takes two people to bring in a sufficient income to help take care of a family. Life insurance can ease the minds of many people who work for a living to provide for their family. If anything happens to them, it could cause financial devastation to their families. Purchasing life insurance will ensure that if anything happens to them, their families will be well taken care of. Becoming a life insurance agent can be a rewarding career when a person knows that they are having a direct impact on helping to ease the minds of their clients. The salary for a life insurance agent can vary depending on the type of agent they are, and which company they work for. Many agents can make up to $45,000 a year.

Salary Overview

Insurance agents who work for a single Insurance carrier are called captive agents who work under contract. Captive agents can make up to $39,000 a year. Broker agents are freelance Insurance Agents who can work for several insurance carriers. They are mostly paid on commission depending on how much insurance they sell. They can make anywhere from $39,000 and up to $68,000 a year. Independent Insurance Sales Agents will also work on commission, and can make $26,000 a year or more. Depending on how much life insurance they sell, they can earn up to $110,000 a year. Much of the salary for independent agents rely on job performance. The person is in control of their own earning potential.

Job Description and Outlook

Life insurance will always be needed and counted on as long as there are people in the world. There will always be a high need for Insurance Agents. Insurance Agents sell several different life insurance policies to individuals and families who are looking for the right kind of coverage at a price that they can afford. The types of insurance that an agent can sell are life, long-term care, disability, health, and property and casualty insurance. Insurance Agents are also known as “producers,” and as producers of insurance, they must have skills and knowledge on how to present their material to potential clients that will create an interest for them to purchase insurance from them. Insurance can be sold to individuals, families, and businesses. The insurance will help to protect people from disasters, such as fires, theft, storms, vehicle accidents, and large financial losses from damage to property. For most businesses, the insurance can cover employees who have been injured on the job, medical malpractice, and liability claims.

An Insurance Agent will also be responsible for all of the paperwork, reports, and record keeping involved, as well as gaining new clients. Insurance Agents are also responsible for the clients they already have. If a client experiences a financial loss, they must help them to settle their claims.

Retail Marketing Salary

2011-12-09T12:57:00.002-08:00

Retail marketing is the process of determining the value and demand for a product and the act of advertising a brand, product, or store to the general public. Candidates who work in retail marketing can be in either one of two categories: entry level or mid level account coordinators and account executives or higher level marketing account managers.

Employees in this industry coordinate research, develop marketing and advertising plans, assist with product development and assist with public relations duties and responsibilities. Retail Marketing candidates can either be employed directly by a large company, or work for a smaller firm under the direction of a VP candidate or other supervisor.

Salary Overview

In general, Retail marketing and associated industries has the potential to be a very lucrative business to work in. Entry Level and Mid level account coordinators, account executives and marketing specialists can make anywhere between $27,000 annually to $35,000 annually depending on the company or size of firm. In addition companies and firms or agencies also offer quarterly bonuses for excellent performance.

Marketing managers, due to extensive experience and amount of education can make anywhere between $50,000 and upwards to $80,000 or more annually with the possibility of also making commission, and quarterly bonuses.

Both Marketing managers, and marketing account coordinators, executives or specialists will also receive benefits such as medical, vacation, paid time off, sick leave and retirement options. Publicly traded companies may also offer stock purchase options to employees who can set aside a percentage of their net pay to purchase company stock at a discounted rate.

Job Description and Outlook

Retail marketing managers often take full direction of planing a company or client’s marketing strategy. Like lower and mid level employees, marketing managers conduct research, analyze return on investment or ROI data, respond to request for proposals and other tasks. Retail marketing manager are also given the task of delegating work to account coordinators, account executives or specialists. Entry level and mid level marketing specialists should have good computer skills as they may be required to constantly pull monthly expenditure reports, or conduct research on previous marketing campaigns.

Advertising Copywriter Salary

2011-12-09T12:57:00.001-08:00

A career as an advertising copywriter is rewarding in many ways, including financially, personally, and professionally. Advertising copywriters enjoy some of the most diverse and sometimes relaxed work environments of any career, although, the competition and stress level can be extremely high in certain markets. While the traditional hubs of the entertainment industry have been the hot spots for high paying advertising jobs, advances in technology and mobile communications have opened up the market on a global scale. Over a third of all freelance writers are now self-employed and all signs point to the numbers rising steadily of the next eight to ten years.

Advertising copywriters can occupy a wide range of fields including fashion, television, radio, internet, films, and even sporting events. Copywriters can always look forward to demand in their field; the outlook for copywriters has steadily risen over several years to meet its average prediction, even during the recent troubling economic times. Unfortunately, with demand so high, the competition is fierce for many of the higher paying opportunities which require skill, creativity, and a great deal of experience.

Salary Overview

Entry level advertising copywriters can expect to begin their careers in the twenty-five to thirty-five thousand dollar a year range for their first few years on the job. While this is quite fine for an entry level position, the pay scale does grow quite rapidly commensurate with experience and education level. According to the Bureau of Labor Statistics or BLS, the average pay for a salaried writer fluctuates between fifty thousand and seventy thousand dollars per year, and the high end of the pay scale is over one hundred thousand dollars per year. When combined with the growth predictions of the BLS, it all adds up to great pay now and well into the future.

Job Description and Outlook

An advertising copywriter’s career usually starts as an internship, assistant copywriter, or as a junior copywriter. As they learn the business, the latest techniques, and prove themselves by researching, editing, proofreading, and performing other tasks assisting the writing staff, they can move on to become a full copywriter. Advertising copywriters typically work with development teams composed of executives, graphic designers, art directors, and writers.

Accountant Salary

2011-12-09T12:56:00.000-08:00

The role of an accountant is very important to the overall success of a firm, whether it is large or small. Their primary concern is to keep accurate records of a firm’s financial position. Accountants are primarily employed by corporations, small businesses, sole proprietors, and government agencies. The four major fields within the accounting industry are public accounting, internal auditing, management accounting, and government accounting.

The challenging workload and love for numbers draw many individuals into the accounting field. Accountants can work in a range of roles that span from broad to very specific. Depending on the role, there are different educational and work experience requirements. Accounting jobs that are more specialized tend to have greater requirements.

Salary Overview

In calculating an accountant’s salary, there are many factors that come into play. One of the major factors is education and experience. Accountants who hold graduate degrees are likely to earn more than those with only an undergraduate degree. Certified Public Accountants tend to earn the highest salaries.

Geographical location is also a determining factor when calculating the average salary of an accountant. The states that employ the most accountants are the District of Columbia, Delaware, Colorado, and New York.

According to the Bureau of Labor Statistics, the median salary for accountants was $59,430 in 2008. The top 10% earned more than $102,380. The middle half of accountants earned between $45,900 and $78,210. The bottom 10% of accountants earned less than $36,720.

The National Association of Colleges and Employers conducted a survey and reported that in 2009 the average starting salary for candidates with bachelor’s degrees was $48,993 and $49,786 for candidates with master’s degrees.

Accountants typically receive standard health, medical, and life insurance benefits. They also receive standard 401(k) and annual leave benefits. Accountants in high-level senior positions usually receive additional benefits, such as an expense account and the use of a company car.

Job Description and Outlook

Accountants are responsible for ensuring that a firm’s financial records are properly accounted for and that taxes are paid properly and on time. Majority of accounting work involves analyzing and reporting financial data.

Civil Engineer Salary

2011-12-09T12:55:00.000-08:00

Civil engineering is one of the oldest of the engineering professions. Civil engineers are responsible for designing and overseeing the construction of infrastructure systems, highways, bridges, dams, water supply and sewage systems, airports, tunnels, and other projects. As current infrastructure needs replacement, there will be increasing demand for civil engineers. Areas of specialty may include environmental, highway systems, architectural, structural, marine, and geo-technical. Requiring at least a bachelor degree, civil engineers are well paid, with average salaries of above $70,000.

Civil engineering professionals are usually based in metropolitan centers, near the hubs of government, industry, and commerce. Job projects frequently involve travel and field work. Using the principles of civil engineering, they must take into accounts such variables as the materials involved in construction of the projects and local conditions including earthquakes, hurricanes, and climate and geologic variables.

Salary Overview

According to the Bureau of Labor Statistics (BLS) Occupational Employment Statistics from May 2009, the median salary for civil engineers is $76,590 or $36.82 per hour. In the lower 10th percentile, the annual salary is $49,620 and below, and in the top 10th percentile it is above $118,320.

Salary is based on education level with a bachelor degree being the minimum requirement. A 2009 survey indicated that an average entry-level position for a civil engineer with a bachelor degree is $52,000. Having a master degree or doctorate will increase the beginning salary. As experience is gained in the position, promotions to supervisory levels will have accompanying increases in salaries.

Salaries vary depending on the agency or company that the civil engineer is employed by. According to the BLS, the highest annual mean salaries are in the oil and gas extraction industries and other pipeline transportation industries with mean salaries at $107,430. The natural gas pipeline transportation industry has a mean salary of $96,690. Civil engineers working for state governments average $75,870, while federal positions average $88,040. Regional salaries vary with the District of Columbia, California, Texas, New Jersey, and Louisiana having the highest mean wages.

Training and Education Requirements

A minimum of a bachelor degree is required for entry-level civil engineering positions. Engineering programs at four year colleges require a strong basis in mathematics and science. Physics, geology, engineering science, and chemistry, along with supporting mathematics emphasizing geometry, statistics, trigonometry, and calculus are part of the core curriculum. The real-world application of the sciences and math will be used to solve specific problems related to commerce, industry, and infrastructure.

In addition to science and math, a strong emphasis on written and oral communication and technical writing is required. Engineers generally work on a team, deal with clients, and the public, requiring excellence in interpersonal communication skills, technical reports, and project presentation. Computer abilities are essential, with familiarity in drafting and schematics necessary. Consideration should be given to whether the graduate will immediately enter the workforce or continue in post-graduate studies.

Types Of Swimming Pool Covers

2011-12-09T12:50:00.000-08:00

All across the United States, thousand and thousands of people own swimming pools. A swimming pool can provide a lot of fun and excitement, although it can also be dangerous. As many of us already know, it only takes a few seconds for a child to drown. To stop this from happening, you should use a pool cover to cover your swimming pool.
Along with protecting your swimming pool, covers have other uses as well. You can get solar powered pool covers, which will help to keep your water warm from the heat of the sun and protect your pool at the same time. For those looking for the best in protection, there are hard top swimming pool covers out there that are very sturdy and can keep just about anything out of your pool.
If you live in a warm climate area, you may want to get a basic plastic cover for your pool, which will keep it clean and protected. These covers will keep dust, dirt, and leaves out of your pool when you aren’t using it. Depending on where you live and what needs you have, the cover you need will vary.
Covers for your swimming pool come in several different choices as well, such as net, mesh, vinyl, and so on. Mesh pool covers are very popular, as they offer a tight fitting barrier which helps to keep your pool clean and free of debris, reduce maintenance, reduce evaporation, and keep your pool from unauthorized access.
Vinyl pool covers on the other hand, provide an amazing source of security. These pool covers operate via key, and help to keep debris out of your pool. They are also great for insulating and retaining heat, along with reducing any loss of chemicals. Vinyl is a very popular type of pool cover, being used by hundreds of thousands of pool owners.
No matter what type of pool cover you select, you can rest assured that it will do a lot in protecting your swimming pool. They don’t cost you a lot of money, yet they can go a long way in helping to prevent a child from accidental drowning. Depending on the type of swimming pool you have, the type of covers you have to choose from will vary.
From above ground pools to in ground pools, a swimming pool cover is something that you absolutely must have. There are many different types available, designed to fit all swimming pools. Before you buy a swimming pool cover you should first look at the package and make sure that it will work with your swimming pool. Some types of swimming pool covers may not work with your swimming pool – which makes it all the more important to double check.

Solutions for Swimming Pools

2011-12-09T12:49:00.000-08:00

Outdoor Swimming Pools
Two basic alternatives are available for outdoor swimming pools: in-ground pools and above-ground pools. In-ground pools are set into the ground, thus requiring ground excavation. Only solutions for in-ground pools are presented here.
Main Components of in-ground Swimming Pools
The main components are:
Structure: floor / foundation; walls
Waterproofing element
Decorative finishing
Equipment and accessories
The structure itself is usually not sufficiently watertight, and therefore a waterproofing element is needed. In case of a conventionally built structure, this waterproofing element consists of a cementitious coating. It serves at the same time as a substrate for the decorative finish which is made up of ceramic tiles (or mosaic) or a decorative coating. Sheet membranes offer an alternative solution, combining the waterproofing and finishing function in a single element.
“Membranes”, consisting of thicker and more robust sheets, are installed in the traditional way, by cutting and seam welding on site. By contrast, “liners”, consisting of thinner sheets, are completely prefabricated to the size of each pool and then installed simply by attaching them onto profiles on the pool edge. They can also be easily replaced at the end of their service life.
Design Swimming Pools
Swimming pools must be designed by specialists in accordance with the state of the art, as well as standards and regulations in force.
Requirements for Swimming Pools
Esthetic Requirements
Free pool geometry
Wide choice of esthetic design possibilities (colours and patterns of pool surface)
Colour stability
Economical Requirements
Favorable investment cost
Ease of cleaning
Easy and cost-effective renewal possibilities
Durability Requirements
Mechanical (impact) resistance
Resistance to substrate cracking and movement
Frost resistance
Resistance to (chlorine; ozone) treated water
Resistance to sun cream
Resistance to algae and mold growth

Testing Concrete Aggregates

2011-12-09T12:47:00.001-08:00

Here after is the specification for concrete aggregate testing in a hi-rise building construction.

General

Samples of the fine and coarse aggregates approved by the Engineer shall be kept on the Site and shall give a fair indication of the approved quality of the aggregate for comparison with the aggregate delivered during the course of the works.

Should a sample fail to comply with any of tests, the Engineer may at his own discretion reject the batch from which sample was taken, or order it to be washed and/or screened, or permit such to be used with variations in the proportions of the concrete mixes specified, all a the Contractor’s expense. Any batch of aggregate rejected by the Engineer shall be removed from the site forthwith and replaced entirely at the Contractor’s expense.

All sample and testing of aggregates shall be carried out in accordance with ASTM C33.

Preliminary Aggregate Tests

As soon as the source of supply of aggregate have been approved, the Contractor shall instruct the testing agency to carry out the following tests for compliance with “Specification of Concrete Aggregates” (ASTM C33).

Sieve analysis
Tests for clay, silt and dust content
Tests for organic impurities
Tests for salt content (chloride and sulfate ions)
The results of these tests shall be submitted for approval as soon as available. Test (1) and (2) with tests for the moisture content of each aggregate shall be carried out on the sample used for each trial mix.

Testing sampling of Aggregates

The contractors shall carry out such tests on aggregate samples as are necessary for the production of the specified concrete. The minimum incremental frequency of tests on each type of concrete used for the works shall be:

Sieve analysis: at least once weekly
Moisture content: at least once weekly
Tests for clay, silt and dust content: at least once fortnightlu
Tests for organic impurities: at least once monthly
Tests for salt content (chloride and sulfate ions): for every 500 cubic meters of concrete placed.
If for any reason the Engineer is not satisfied with the works concrete, he may instruct the Contractor to further increase the rate of sampling. Conversely, the rate of sampling may be reduce by the Engineer when consistent high quality been well established.

Hydropower financing:current trends and key issues

2011-12-09T12:43:00.000-08:00

In the late 2000s the power sector in many countries experienced a major revolution. The old vertically-integrated, nationally owned power utilities were unbundled and the concept of freestanding independent power generating companies (IPPs) was established. This trend was part of a wider process of encouraging more private participation in the ownership and development of infrastructure, including hydropower and multi-purpose water projects. With this arrangement most projects were developed using the BOOT model (build-own-operate-transfer) under which a special purpose private company finances the scheme (usually on a non-recourse basis) and assumes virtually all of the project risks. In return it owns the infrastructure for the duration of the concession.
While this formula worked well for the thermal power sector, it quickly became apparent that the situation is more complicated when it comes to major water resources projects. In general the experience with projects such as large hydropower schemes has not been favourable, with many MOUs being signed between governments and prospective private developers, but few schemes actually reaching the construction stage. In many cases the main problem has been an inability to finance the project.
A number of Case Studies have been undertaken by the author. Although each is different, it is possible to detect certain overriding issues which dominate the private financing scene. They are:
1. RISKS dominate the availability and cost of finance, and are tending to migrate back to the public sector.
2. TARIFFS tend to be higher (than the public sector alternative) due to high soft costs, the layering of risk, and heavy debt service obligations.
3. FINANCIAL viability tends to compete with wider economic considerations, and it can distort the optimisation.
4. The PUBLIC SECTOR has yet to find a workable model for attracting private participation.
Faced with these problems, there is an increasing tendency to move towards something that is often referred to as a “Pubic-Private Partnership” – although this term has no clear definition and can mean different things to different people. The objective is to move towards come half-way project structure that preserves the best of both the traditional public sector model and the perceived benefits of private sector participation through a BOOT type of arrangement.
The structuring of a project (in terms of ownership, risk sharing, etc.) is often dominated by financing considerations. There is no single generic solution that can be applied to all projects, but the paper will discuss some of the key issues that arise in selecting the most appropriate financing model for a particular project.

Broadcast Flooring

2011-12-09T12:42:00.000-08:00

Scope of work for broadcast flooring
The specified system of broadcast flooring shall provide a wearing surface with waterproofing properties.
The system is based on a solvent free epoxy, which has a good resistance to wear and chemicals.
Advantages of broadcast epoxy flooring
Good impact resistance
Skid-resistant finish
Good chemical resistance
Suitable for wet process area
High wear and abrasion resistance
System build-up for broadcast system
1.If needed, moisture barrier (if > 4% pbw moisture content into the substrate)
Epocem Primer ( Primer coat) 1 x Epocem Primer Approximately 0.15 Kg/m²
Moisture barrier (Body coat) 1 x Sikafloor 81 Epocem (2 mm minimum): 2.1 kg/m²/mm
2. Primer + levelling broadcast course
Wearing course 1 mm (Levelling layer) Sikafloor 161+ Silica Flour :Approx. 1,2 Kg/m²/mm + 0.3 Kg/m²/mm
Broadcast onto fresh resin (Broadcast) Quartz sand from 0.3 – 0.8 mm or 0.6 – 1.2 mm 4 – 5 kg/m²
Sealing coat (Coloured coat) Sikafloor 264 0.7 kg/m² (minimum)
(Approx. system thickness from 3 mm, without moisture barrier)
Application of broadcast epoxy flooring system
Primer and leveling broadcasted course: Apply Sikafloor 161 and Silica Flour on a 1 mm thickness.
Broadcast the surface of the resin to excess to achieve the desired degree of slip resistance. Next day remove all excess by brush and vacuum.
Sealing coat: Apply a sealing coat of Sikafloor264 by roller or squeegee.
[NB. Certain colors may require a slightly increased consumption applied in two coats].

Using Solar Energy for your Home Power

2011-12-09T12:41:00.001-08:00

What we get from the sun? Heat and light as we all see. Another saying is sun’s energy or solar energy. The power from the sun is the most abundant form of energy available on earth. The sun has been one of the biggest factors dictating every living being’s stay on the earth. If we go the right path, we can harness more from the solar energy, like generating home power for daily use.
Advantages of home power taken from Solar Energy
The solar energy solution is gaining popularity amongst the alternate energy solutions.
• Green energy solution: When you look at the solar energy solution, you will realize that it uses absolutely no fuel other than the sun’s light. Moreover, it does not release into the atmosphere anything harmful.
• Cheapest power solution: First, the energy comes free. Then, the installation cost is a one-time cost. Finally, the investment is recovered within a few years of installation, making the power generated by solar energy absolutely free.
• Convenience of storage: You cannot store conventional power but you can store solar power for future use. The sun’s energy comes to rescue even in the times of darkness! Storing it also ensures a 24×7 supply of power, thus saving you from any power outage.
• Low on maintenance: The solar energy systems are easy to maintain. They do not involve high costs or too much effort, thus letting you reap the benefits of the solution comfortably.
How can solar energy be used for home power?
Solar power can be used as home power in our everyday lives by adopting the following solar power systems:
• Solar cooking system: Solar cooking is about cooking without lighting a fire or using electricity! Before you wonder, let me tell you that solar cooking is not about bland food. You can cook in more ways than one – boil, roast, or bake, cook the way you want! The only demand that solar cooking makes of you is being patient; it is a matter of more than a few minutes. However, it is not asking for too much given that you will get tasteful and healthy food without worrying about paying your gas or electricity bill.
• Solar lighting system: You can now light up the entire house, use every electrical appliance without thinking about cutting down bills. The solar lighting system lights up your house even in the nights, thanks to the power storage feature it has.
• Solar heating system: You can keep your house cozy and warm using the solar heating system without worrying about costs.
You can make your own home power system energy to eliminate your power bill. Make it easy by visiting

Project Management Methodology

2011-12-09T12:39:00.000-08:00

Projects are usually split into phases often along the lines of initiation, control and closure. During each phase a number of documents are produced as part of the project control process.

Initiating a Project

All projects start with an idea for a product, service, new capability or other desired outcome. The idea is communicated to the project sponsor using the mandate. The mandate provides a structured approach to proposing a project and contains the project’s business case.

Once the mandate has been approved a further document is prepared that explains the project in greater detail. The project definition report is used to provide this information. This document is used as a key part of the assessment when deciding whether the project should be undertaken.

In particular it outlines the goals, objectives, scope, deliverables, assumptions, constraints, risks, issues, key people, benefits, costs and duration.

If authorisation to proceed is given, the contract is used to obtain formal agreement from the project sponsor and budget holder to start the project. This signifies the end of the initiation phase.

Controlling a Project

The control phase involves managing and tracking the project. To do this a project plan is developed. The project plan is most commonly expressed in the form of a Gantt chart and identifies the stages, tasks, timeline and resources. A good plan will include regular milestones that act as a measure of progress and keep the project team focused on short-term goals. Project plans may also include information about costs and dependent projects. A tracking Gantt chart can be used to monitor progress.

Once you have planned the project it is important to identify any factors that could have an impact on it. This is done using the issues log and risk log. The issues log is used to record issues and a plan to address them. The risk log is used to record and grade risks with an associated action plan to mitigate them. Often confused, risks and issues are defined as follows:

Risk: The likelihood of the occurrence of an event, usually a negative one that may adversely affect the successful completion of a project.

Issue: A concern raised by any stakeholder that needs to be addressed, either immediately or during a project.

Key to good project management and a successful project outcome is effective communication. The progress report is used to communicate progress on a regular basis, typically weekly or monthly, to all stakeholders of the project.

The control phase ends once the project has achieved its goals and objectives as detailed in the project definition report. A project may be stopped prior to completion for a variety of reasons, including changes within a business, lack of resources or higher priorities.

Closing a Project

Project closure is an important aspect of project management that is often overlooked. A project that is not closed will continue to consume resources, albeit slowly.

To receive acknowledgment from the customer that the project has ended the customer acceptance form is used. Once signed off the project team is disbanded and no more work is carried out.

At this point it is important to know whether the project has achieved its goals and objectives. This is done using the project closure report. This document communicates how well the project has performed against its original business case, quality criteria, costs, duration and tolerances.

Testing of Concrete Blocks

2011-12-09T12:36:00.002-08:00

NTRODUCTION
Concrete can be converted into precast masonry units such as Hollow and Solid normal and light weight concrete blocks of suitable size to be used for load and non-load bearing units for wallings. Use of such concrete blocks are more appropriate in region where soil bricks are costly, poor in strength and are not available. Depending upon the structural requirements of masonry unit, concrete mixes can be designed using ingredients available locally or if not found suitable then with in the most economical distance. The concrete mix used for normal hollow and solid blocks shall not be richer than one part by volume of cement to 6 parts by volume of combined room dry aggregates before mixing. Hollow concrete blocks for normal work used in masonry when reinforced is used shall not be leaner than 1 part cement to 8 parts room dry sand by volume. The mixes are designed with the available materials to give overall economy and the required properties of the products. The hollow load bearing concrete blocks of the standard size 400 x 200 x 200 mm will weight between 17 and 26 kg (1063 to 1625 kg/m3) when made with normal weight aggregates. Normal weight blocks are made with cement, sand, gravel, crushed stone and air-cooled slag. The grading for sand used in Hollow concrete block shall be as given below:

I.S. Sieve Size

Percentage Passing

4.75 mm

98-100

2.36 mm

80-100

1.18 mm

60-80

600 Micron

40-65

300 Micron

10-40

150 Micron

0-10

The aggregates for solid blocks shall be sand as per IS : 383-1970 and well graded aggregate of suitable maximum size as per the dimensions of the block. The mixes are properly designed as per standard practice. Concrete admixtures may be used in both Hollow and Solid concrete blocks.

SPECIMENS
20 full size units shall be measured for length, width and height. Cored units shall also be measured for minimum thickness of face, shells and webs. From these 3 blocks are to be tested for block density, 8 blocks for compressive strength, 3 blocks for water absorption and 3 blocks for drying shrinkage and moisture movement.

DETERMINATION OF BLOCK DENSITY
Three blocks shall be dried to constant mass in a suitable oven heated to approximately 1000C. After cooling the blocks to room temperature, the dimensions of each block shall be measured in centimeters to the nearest millimeter and the overall volume computed in cubic centimeters. The blocks shall then be weighted in kilograms to the nearest 10 gm. The density of each block calculated as follows:

Density in kg/m3 = Mass of block in kg/Mass of block in cm2 * 106

DETERMINATION OF WATER ABSORPTION
Three full size blocks shall be completely immersed in clean water at room temperature for 24 hours. The blocks shall then be removed from the water and allowed to drain for one minute by placing them on a 10 mm or coarser wire mesh, visible surface water being removed with a damp cloth, the saturated and surface dry blocks immediately weighed. After weighing all blocks shall be dried in a ventilated oven at 100 to 1150C for not less than 24 hours and until two successive weighing at intervals of 2 hours show an increment of loss not greater than 0.2 percent of the last previously determined mass of the specimen. The water absorption calculates as given below:
Absorption, percent =(A-B)/B * 100

Where,
A = wet mass of unit in kg.
B = dry mass of unit in kg.

TESTING BLOCKS FOR COMPRESSIVE STRENGTH
COMPRESSIN TESTING MACHINE (CTM)
The compression testing machine should be as per IS : 516-1959 and I.S : 14858-2000. The load capacity, platens sizes, vertical space between platens and horizontal space between machine columns shall be as per the requirements of the specimens to be tested.

However, IS : 2185 (pert-I) – 1979 specified that when the bearing area of the steel blocks is not sufficient to cover the bearings area of the blocks, steel bearing plates shall be placed between the bearing blocks and the capped specimen after the centroid of the masonry bearing surface has been aligned with the centre of thrust of the bearing blocks. It is desirable that the bearing faces of blocks and plates used for compression testing of concrete masonry have hardness of not less than 60 (HRC).

When steel plates are employed between the steel bearing blocks and the masonry specimen, the plates shall have thickness equal to at least one-third of the distance from the edge of the bearing block to the most distant corner of the specimen. In no case shall the plate thickness be less than 12 mm.

ASTM : C 140-03 specified that when the bearing area of the upper platen or lower platen is not sufficient to cover the area of the specimen, a single steel bearing plate with a thickness equal to at least the distance from the edge of the platen to the most distant corner of the specimen shall be placed between the platen and the capped specimen. The length and width of the steel plate shall be at least 6.3 mm grater than the length and width of the unit. The surface of the platen or plate hardness shall be not less than HRC 60 (BHN 620).

Thickness of bearing plates has a significant effect on the tested compressive strength of masonry units when the bearing area of the platen is not sufficient to cover the area of the specimen. Tested compressive strength will typically increase with increased plate thickness and with reduce distance to the further corner of the specimen. Accordingly the CTM platens shall have the required dimensions with respect to the specimens to be tested on it.

TEST SPECIMENS
Eight full size units shall be tested with in 72 hours after delivery to the laboratory, during which time they shall be stored continuously in normal room air.

For the purpose of acceptance, age of testing the specimens shall be 28 days. The age shall be reckoned from the time of the addition of water to the dry ingredients.

CAPPING TEST SPECIMENS
The bearing surfaces of units shall be capped by gypsem. The gypsem and water paste shall be spread evenly on a non-absorbent surface that has been lightly coated with oil. The surface of the unit to be capped shall be brought into contact with the capping paste. The average thickness of the cap shall be not more than 3 mm. The caps shall be aged for at least 2 hours before the specimens are tested.

PROCEDURE
Specimens shall be tested with the centroid of their bearing surfaces aligned vertically with the centre of thrust of the spherically seated steel bearing blocks of the testing machine.
The load up to one-half of the expected maximum load may be applied at any convenient rate, after which the control of the machine shall be adjusted as required to give a uniform rate of travel of the moving head such that the remaining load is applied in not less than one nor more than two minutes.

The compressive strength of a concrete masonry unit shall be taken as the maximum load in Newtones divided by the gross cross sectional area of the unit in square millimeters. Report to the nearest 0.1 N/mm2 separately for each unit and the average for the 8 full units.

Note:- The Gross area is : The total area occupied by a block on its bedding face, including areas of the cavities and end recesses.

REFERENCES
1.IS : 2185 (part-I)1979 1987 1998 – Specifications for concrete masonry. Units part-I Hollow and Solid Concrete Blocks (Second Revision).
2. IS : 2185 (part-II)- 1985
Super seeding IS : 3590-1966 Specifications for concrete masonry units part-II Hollow and Solid light weight concrete blocks (First Revision)
3. IS : 2572-1963 Reaffirmed 1997 Code of practice for construction of hollow concrete block masonry.
4. IS : 383-1970 Specification for coarse and fine aggregates from natural sources for concrete (Second Revision)
5. ASTM : C 140-03 Standard test methods for sampling and testing concrete masonry units and related units.

We are thankful to Sir Kaushal Kishore for publishing his unpublished research paper here on the website. This would be of great use to all the civil engineers who work are looking for information regarding Testing of Concrete Blocks .

Mix Proportion designations

2011-12-09T12:36:00.001-08:00

he common method of expressing the proportions of ingredients of a concrete mix is in the terms of parts or ratios of cement, fine and coarse aggregates. For e.g., a concrete mix of proportions 1:2:4 means that cement, fine and coarse aggregate are in the ratio 1:2:4 or the mix contains one part of cement, two parts of fine aggregate and four parts of coarse aggregate. The proportions are either by volume or by mass. The water-cement ratio is usually expressed in mass

Factors to be considered for mix design

ð The grade designation giving the characteristic strength requirement of concrete.

ð The type of cement influences the rate of development of compressive strength of concrete.

ð Maximum nominal size of aggregates to be used in concrete may be as large as possible within the limits prescribed by IS 456:2000.

ð The cement content is to be limited from shrinkage, cracking and creep.

ð The workability of concrete for satisfactory placing and compaction is related to the size and shape of section, quantity and spacing of reinforcement and technique used for transportation, placing and compaction.

Types of Mixes

2011-12-09T12:34:00.002-08:00

Types of Mixes

1. Nominal Mixes

In the past the specifications for concrete prescribed the proportions of cement, fine and coarse aggregates. These mixes of fixed cement-aggregate ratio which ensures adequate strength are termed nominal mixes. These offer simplicity and under normal circumstances, have a margin of strength above that specified. However, due to the variability of mix ingredients the nominal concrete for a given workability varies widely in strength.

2. Standard mixes

The nominal mixes of fixed cement-aggregate ratio (by volume) vary widely in strength and may result in under- or over-rich mixes. For this reason, the minimum compressive strength has been included in many specifications. These mixes are termed standard mixes.

IS 456-2000 has designated the concrete mixes into a number of grades as M10, M15, M20, M25, M30, M35 and M40. In this designation the letter M refers to the mix and the number to the specified 28 day cube strength of mix in N/mm2. The mixes of grades M10, M15, M20 and M25 correspond approximately to the mix proportions (1:3:6), (1:2:4), (1:1.5:3) and (1:1:2) respectively.

3. Designed Mixes

In these mixes the performance of the concrete is specified by the designer but the mix proportions are determined by the producer of concrete, except that the minimum cement content can be laid down. This is most rational approach to the selection of mix proportions with specific materials in mind possessing more or less unique characteristics. The approach results in the production of concrete with the appropriate properties most economically. However, the designed mix does not serve as a guide since this does not guarantee the correct mix proportions for the prescribed performance.

For the concrete with undemanding performance nominal or standard mixes (prescribed in the codes by quantities of dry ingredients per cubic meter and by slump) may be used only for very small jobs, when the 28-day strength of concrete does not exceed 30 N/mm2. No control testing is necessary reliance being placed on the masses of the ingredients.

Factors affecting the choice of mix proportions

The various factors affecting the mix design are:

1. Compressive strength

It is one of the most important properties of concrete and influences many other describable properties of the hardened concrete. The mean compressive strength required at a specific age, usually 28 days, determines the nominal water-cement ratio of the mix. The other factor affecting the strength of concrete at a given age and cured at a prescribed temperature is the degree of compaction. According to Abraham’s law the strength of fully compacted concrete is inversely proportional to the water-cement ratio.

2. Workability

The degree of workability required depends on three factors. These are the size of the section to be concreted, the amount of reinforcement, and the method of compaction to be used. For the narrow and complicated section with numerous corners or inaccessible parts, the concrete must have a high workability so that full compaction can be achieved with a reasonable amount of effort. This also applies to the embedded steel sections. The desired workability depends on the compacting equipment available at the site.

3. Durability

The durability of concrete is its resistance to the aggressive environmental conditions. High strength concrete is generally more durable than low strength concrete. In the situations when the high strength is not necessary but the conditions of exposure are such that high durability is vital, the durability requirement will determine the water-cement ratio to be used.

4. Maximum nominal size of aggregate

In general, larger the maximum size of aggregate, smaller is the cement requirement for a particular water-cement ratio, because the workability of concrete increases with increase in maximum size of the aggregate. However, the compressive strength tends to increase with the decrease in size of aggregate.

IS 456:2000 and IS 1343:1980 recommend that the nominal size of the aggregate should be as large as possible.

5. Grading and type of aggregate

The grading of aggregate influences the mix proportions for a specified workability and water-cement ratio. Coarser the grading leaner will be mix which can be used. Very lean mix is not desirable since it does not contain enough finer material to make the concrete cohesive.

The type of aggregate influences strongly the aggregate-cement ratio for the desired workability and stipulated water cement ratio. An important feature of a satisfactory aggregate is the uniformity of the grading which can be achieved by mixing different size fractions.

6. Quality Control

The degree of control can be estimated statistically by the variations in test results. The variation in strength results from the variations in the properties of the mix ingredients and lack of control of accuracy in batching, mixing, placing, curing and testing. The lower the difference between the mean and minimum strengths of the mix lower will be the cement-content required. The factor controlling this difference is termed as quality control.

Mix Design M-50 Grade

2011-12-09T12:34:00.001-08:00

The mix design M-50 grade (Using Admixture –Sikament) provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.

Parameters for mix design M50

Grade Designation = M-50
Type of cement = O.P.C-43 grade
Brand of cement = Vikram ( Grasim )
Admixture = Sika [Sikament 170 ( H ) ]
Fine Aggregate = Zone-II

Sp. Gravity
Cement = 3.15
Fine Aggregate = 2.61
Coarse Aggregate (20mm) = 2.65
Coarse Aggregate (10mm) = 2.66

Minimum Cement (As per contract) =400 kg / m3
Maximum water cement ratio (As per contract) = 0.45

Mix Calculation: -

1. Target Mean Strength = 50 + ( 5 X 1.65 ) = 58.25 Mpa

2. Selection of water cement ratio:-
Assume water cement ratio = 0.35

3. Calculation of water: -
Approximate water content for 20mm max. Size of aggregate = 180 kg /m3 (As per Table No. 5 , IS : 10262 ). As plasticizer is proposed we can reduce water content by 20%.

Now water content = 180 X 0.8 = 144 kg /m3

4. Calculation of cement content:-
Water cement ratio = 0.35
Water content per cum of concrete = 144 kg
Cement content = 144/0.35 = 411.4 kg / m3
Say cement content = 412 kg / m3 (As per contract Minimum cement content 400 kg / m3 )
Hence O.K.

5. Calculation for C.A. & F.A.: [ Formula's can be seen in earlier posts]-

Volume of concrete = 1 m3
Volume of cement = 412 / ( 3.15 X 1000 ) = 0.1308 m3
Volume of water = 144 / ( 1 X 1000 ) = 0.1440 m3
Volume of Admixture = 4.994 / (1.145 X 1000 ) = 0.0043 m3
Total weight of other materials except coarse aggregate = 0.1308 + 0.1440 +0.0043 = 0.2791 m3

Volume of coarse and fine aggregate = 1 – 0.2791 = 0.7209 m3
Volume of F.A. = 0.7209 X 0.33 = 0.2379 m3 (Assuming 33% by volume of total aggregate )

Volume of C.A. = 0.7209 – 0.2379 = 0.4830 m3

Therefore weight of F.A. = 0.2379 X 2.61 X 1000 = 620.919 kg/ m3

Say weight of F.A. = 621 kg/ m3

Therefore weight of C.A. = 0.4830 X 2.655 X 1000 = 1282.365 kg/ m3

Say weight of C.A. = 1284 kg/ m3

Considering 20 mm: 10mm = 0.55: 0.45
20mm = 706 kg .
10mm = 578 kg .
Hence Mix details per m3
Increasing cement, water, admixture by 2.5% for this trial

Cement = 412 X 1.025 = 422 kg
Water = 144 X 1.025 = 147.6 kg
Fine aggregate = 621 kg
Coarse aggregate 20 mm = 706 kg
Coarse aggregate 10 mm = 578 kg
Admixture = 1.2 % by weight of cement = 5.064 kg.

Water: cement: F.A.: C.A. = 0.35: 1: 1.472: 3.043

Observation: -
A. Mix was cohesive and homogeneous.
B. Slump = 120 mm
C. No. of cube casted = 9 Nos.
7 days average compressive strength = 52.07 MPa.
28 days average compressive strength = 62.52 MPa which is greater than 58.25MPa
Hence the mix accepted.

We are thankful to Er Gurjeet Singh for this valuable information.

Concrete Mix Design M-60

2011-12-09T12:33:00.002-08:00

(a) DESIGN STIPULATION:-
Target strength = 60Mpa
Max size of aggregate used = 12.5 mm
Specific gravity of cement = 3.15
Specific gravity of fine aggregate (F.A) = 2.6
Specific gravity of Coarse aggregate (C.A) = 2.64
Dry Rodded Bulk Density of fine aggregate = 1726 Kg/m3
Dry Rodded Bulk Density of coarse aggregate = 1638 Kg/m3

Step-1
Calculation for weight of Coarse Aggregate:
From ACI 211.4R Table 4.3.3 Fractional volume of oven dry Rodded C.A for 12.5mm size aggregate is 0.68m3
Weight of C.A = 0.68*1638 = 1108.13 Kg/m3

Step-2
Calculation for Quantity of Water:
From ACI 211.4R Table 4.3.4
Assuming Slump as 50 to 75mm and for C.A size 12.5 mm the Mixing water = 148 ml
Void content of FA for this mixing water = 35%
Void content of FA (V)
V = {1-(Dry Rodded unit wt / specific gravity of FA*1000)}*100
= [1-(1726/2.6*1000)]*100
= 34.62%

Adjustment in mixing water = (V-35)* 4.55
= (34.62 – 35)*4.55
= -1.725 ml
Total water required = 148 + (-1.725) = 146.28 ml
Step-3
Calculation for weight of cement
From ACI 211.4R Table 4.3.5(b)
Take W / C ratio = 0.29
Weight of cement = 146.28 / 0.29 = 504.21 kg/m3

Step-4
Calculation for weight of Fine Aggregate:

Cement = 504.21 / 3.15*1000= 0.1616
Water = 146.28 / 1*1000= 0.1462
CA = 1108.13 / 3*1000= 0.3690
Entrapped Air = 2 / 100= 0.020
Total = 0.7376m3
Volume of Fine Aggregate= 1-0.7376
Weight of Fine Aggregate= 0.2624*2.6*1000= 683.24 kg/m3

Step-5
Super plasticizer:
For 0.8% = (0.8 / 100)*583.53 = 4.668 ml

Step-6
Correction for water:
Weight of water (For 0.8%) =146.28 – 4.668 =141.61 kg/m3

Requirement of materials per Cubic meter
Cement = 504.21 Kg/m3
Fine Aggregate = 683.24 Kg/m3
Coarse Aggregate = 1108.13 Kg/m3
Water = 141.61 Kg/ m3
Super plasticizers = 4.6681 / m3

So the final ratio becomes
Cement : Fine agg (kg/m3) : Coarse agg (kg/m3) : Water (l/m3): Superplasticizer (l/m3)

1: 1.35 :2.19 :0.29 :0.8

This concrete mix design has been submitted to us by Natarajan. We are thankful to him for this valuable contribution.

Concrete Mix Design – M 20 Grade Of Concrete

2011-12-09T12:33:00.001-08:00

1. REQUIREMENTS
a) Specified minimum strength = 20 N/Sq mm

b) Durability requirements
i) Exposure Moderate
ii) Minimum Cement Content = 300 Kgs/cum

c) Cement
(Refer Table No. 5 of IS:456-2000)
i) Make Chetak (Birla)
ii) Type OPC
iii) Grade 43

d) Workability
i) compacting factor = 0.7

e) Degree of quality control Good

2. TEST DATA FOR MATERIALS SUPPLIED
a) CEMENT
i) Specific gravity = 3.05
ii) Avg. comp. strength 7 days = 46.5 more than 33.0 OK
28 days = 55.0 more than 43.0 OK

b) COARSE AGGREGATE
i) 20mm Graded
Type Crushed stone aggregate
Specific gravity = 2.68
Water absorption = 1.46
Free (surface) moisture = 0

Mix Design For M35 Grade Of Concrete

2011-12-09T12:32:00.000-08:00

he mix design for M35 Grade Of Concrete for pile foundations provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.

Grade of Concrete : M35
Characteristic Strength (Fck) : 35 Mpa
Standard Deviation : 1.91 Mpa*
Target Mean Strength : T.M.S.= Fck +1.65 x S.D.
(from I.S 456-2000) = 35+ 1.65×1.91
= 38.15 Mpa

Test Data For Material:
Aggregate Type : Crushed
Specific Gravity
Cement : 3.15
Coarse Aggregate : 2.67
Fine Aggregate : 2.62

Water Absorption:
Coarse Aggregate : 0.5%
Fine Aggregate : 1.0 %

MIX DESIGN

Take Sand content as percentage of total aggregates = 36%

Select Water Cement Ratio = 0.43 for concrete grade M35

(From Fig 2. of I.S. 10262- 1982)

Select Water Content = 172 Kg

(From IS: 10262 for 20 mm nominal size of aggregates Maximum Water Content = 186 Kg/ M3 )

Hence, Cement Content= 172 / 0.43 = 400 Kg / M3

Formula for Mix Proportion of Fine and Coarse Aggregate:

1000(1-a0) = {(Cement Content / Sp. Gr. Of Cement) + Water Content +(Fa / Sp. Gr.* Pf )}

1000(1-a0) = {(Cement Content / Sp. Gr. Of Cement) + Water Content +Ca / Sp. Gr.* Pc )}

Where Ca = Coarse Aggregate Content

Fa = Fine Aggregate Content

Pf = Sand Content as percentage of total Aggregates

= 0.36

Pc = Coarse Aggregate Content as percentage of total Aggregates.

= 0.64

a0 = Percentage air content in concrete (As per IS :10262 for 20 mm nominal size of

aggregates air content is 2 %) = 0.02

Hence, 1000(1-0.02) = {(400 /3.15) + 172 +(Fa / 2.62 x 0.36)}

Fa = 642 Kg/ Cum

As the sand is of Zone II no adjustment is required for sand.

Sand Content = 642 Kg/ Cum

1000(1-0.02) = {(400 /3.15) + 172 +(Ca / 2.67 x 0.64)}

Hence, Ca = 1165 Kg/ Cum

From combined gradation of Coarse aggregates it has been found out that the proportion of 53:47 of 20 mm & 10 mm aggregates produces the best gradation as per IS: 383.

Hence, 20 mm Aggregates = 619 Kg

And 10 mm Aggregates = 546 Kg

To obtain slump in the range of 150-190 mm water reducing admixture brand SP430 from Fosroc with a dose of 0.3 % by weight of Cement shall be used.

Mix Design M-40 Grade

2011-12-09T12:31:00.000-08:00

The mix design M-40 grade for Pier (Using Admixture – Fosroc) provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.

Parameters for mix design M40

Grade Designation = M-40
Type of cement = O.P.C-43 grade
Brand of cement = Vikram ( Grasim )
Admixture = Fosroc ( Conplast SP 430 G8M )
Fine Aggregate = Zone-II
Sp. Gravity Cement = 3.15
Fine Aggregate = 2.61
Coarse Aggregate (20mm) = 2.65
Coarse Aggregate (10mm) = 2.66
Minimum Cement (As per contract) = 400 kg / m3
Maximum water cement ratio (As per contract) = 0.45

Mix Calculation: -

1. Target Mean Strength = 40 + (5 X 1.65) = 48.25 Mpa

2. Selection of water cement ratio:-
Assume water cement ratio = 0.4

3. Calculation of cement content: -
Assume cement content 400 kg / m3
(As per contract Minimum cement content 400 kg / m3)

4. Calculation of water: -
400 X 0.4 = 160 kg Which is less than 186 kg (As per Table No. 4, IS: 10262)
Hence o.k.

5. Calculation for C.A. & F.A.: – As per IS : 10262 , Cl. No. 3.5.1

V = [ W + (C/Sc) + (1/p) . (fa/Sfa) ] x (1/1000)

V = [ W + (C/Sc) + {1/(1-p)} . (ca/Sca) ] x (1/1000)

Where

V = absolute volume of fresh concrete, which is equal to gross volume (m3) minus the volume of entrapped air ,

W = mass of water ( kg ) per m3 of concrete ,

C = mass of cement ( kg ) per m3 of concrete ,

Sc = specific gravity of cement,

(p) = Ratio of fine aggregate to total aggregate by absolute volume ,

(fa) , (ca) = total mass of fine aggregate and coarse aggregate (kg) per m3 of
Concrete respectively, and

Sfa , Sca = specific gravities of saturated surface dry fine aggregate and Coarse aggregate respectively.

As per Table No. 3 , IS-10262, for 20mm maximum size entrapped air is 2% .

Assume F.A. by % of volume of total aggregate = 36.5 %

0.98 = [ 160 + ( 400 / 3.15 ) + ( 1 / 0.365 ) ( Fa / 2.61 )] ( 1 /1000 )

=> Fa = 660.2 kg

Say Fa = 660 kg.

0.98 = [ 160 + ( 400 / 3.15 ) + ( 1 / 0.635 ) ( Ca / 2.655 )] ( 1 /1000 )

=> Ca = 1168.37 kg.

Say Ca = 1168 kg.

Considering 20 mm : 10mm = 0.6 : 0.4

20mm = 701 kg .
10mm = 467 kg .

Hence Mix details per m3

Cement = 400 kg
Water = 160 kg
Fine aggregate = 660 kg
Coarse aggregate 20 mm = 701 kg
Coarse aggregate 10 mm = 467 kg
Admixture = 0.6 % by weight of cement = 2.4 kg.
Recron 3S = 900 gm

Water: cement: F.A.: C.A. = 0.4: 1: 1.65: 2.92

Observation: -
A. Mix was cohesive and homogeneous.
B. Slump = 110mm
C. No. of cube casted = 12 Nos.
7 days average compressive strength = 51.26 MPa.
28 days average compressive strength = 62.96 MPa which is greater than 48.25MPa

Hence the mix is accepted.

We are thankful to Er Gurjeet Singh for this valuable information.

What is the principle of Asphalt Mix Design?

2011-12-09T12:30:00.002-08:00

The main objective of asphalt mix design is to achieve a mix with economical blending of aggregates with asphalt to achieve the following :

(i) workability to facilitate easy placement of bituminous materials without experiencing segregation;
(ii) sufficient stability so that under traffic loads the pavement will not undergo distortion and displacement;
(iii) durability by having sufficient asphalt;
(iv) sufficient air voids

In asphalt mix design, high durability is usually obtained at the expense of low stability. Hence, a balance has to be stricken between the durability and stability requirements.

This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.

What is Marshall Mix Design for Bituminous Materials?

2011-12-09T12:30:00.001-08:00

The Marshall Mix Design method was originally developed by Bruce Marshall of the Mississippi Highway Department in 1939. The main idea of the Marshall Mix Design method involves the selection of the asphalt binder content with a suitable density which satisfies minimum stability and range of flow values.

The Marshall Mix Design method consists mainly of the following steps:

(i) Determination of physical properties, size and gradation of aggregates.

(ii) Selection of types of asphalt binder.

(iii) Prepare initial samples, each with different asphalt binder content.
For example, three samples are made each at 4.5, 5.0, 5.5, 6.0 and 6.5 percent asphalt by dry weight for a total of 15 samples. There should be at least two samples above and two below the estimated optimum asphalt content.

(iv) Plot the following graphs:

(a) Asphalt binder content vs. density
(b) Asphalt binder content vs. Marshall stability
(c) Asphalt binder content vs. flow
(d) Asphalt binder content vs. air voids
(e) Asphalt binder content vs. voids in mineral aggregates
(f) Asphalt binder content vs voids filled with asphalt

(v) Determine the asphalt binder content which corresponds to the air void content of 4 percent

(vi) Determine properties at this optimum asphalt binder content by reference with the graphs. Compare each of these values against design requirements and if all comply with design requirements, then the selected optimum asphalt binder content is acceptable. Otherwise, the mixture should be redesigned.

What is the purpose of conducting load test for piling works?

2011-12-09T12:25:00.001-08:00

Pile load test provides information on ultimate bearing capacity but not settlement behavior. In essence, it can determine if the load is taken up by the stratum designed or if the centre of resistance is at the design location in piles as suggested by Robert D. Chellis (1961).

After conducting load tests, the curve of movement of pile head (Settlement against load) and the curve of plastic deformation can be plotted. By subtracting the curve of plastic deformation from the curve of pile head movement at each load, the curve of elastic deformation can be obtained. For piles of end-bearing type unrestrained by friction, the theoretical elastic deformation can be calculated from e=RL/AE where e is
elastic deformation, L is pile length, A is area of pile, E is Young’s Modulus of pile material and R is the reaction load on pile. By substituting e in the formula, the elastic deformation read from the curve of elastic deformation, L can be obtained which shows the location of the centre of resistance corresponding to that load.

Laterally Loaded Vertical Piles

2011-12-09T12:24:00.002-08:00

When ever we are studying about a vertical pile, we need to understand that the flexural stiffness of the shaft and stiffness of the bearing soil in the upper 4D to 6D length of shaft are the two main factors on which the resistance to lateral loads of vertical pile depends.

Nondimensional solutions of Reese and Matlock help us plot the lateral-load vs. pile-head deflection relationship but the basic assumption with this is that the soil modulus K increases linearly with depth z

K= nhz
where nh coefficient of horizontal subgrade reaction.

A characteristic pile length T is given by
T=(EI/nh)1/2
where
EI= pile stiffness.

Now when a pile with free head is subjected to a lateral load Pt and moment Mt applied at the ground line, The lateral deflection y of a pile is given by

y=AyPtT3/EI+ByMtT2/EI

where
Ay and By are nondimensional coefficients.

For positive moment,
M=Am Pt T+Bm Mt

Percentage of load Transmitted To Rock Socket, Estimated by interpretation of finite-element solution for Poisson’s ratio 0.26.

Er /Ep

Er /Ep

Er /Ep

Ls /ds

0.25

1.0

4.0

0.5

54

48

44

1.0

31

23

18

1.5

17

12

8

2.0

13

8

4

Their is a negative moment imposed at the pile head either due to pile cap or another structural restraint, this can be calculated as a function of the head slope (rotation) from this equation

where
theta rad represents the counterclockwise ( + ) rotation of the pile head and Atheta and Btheta are coefficients .

This value of Mt is put in previous equations to find the influence of the degrees of fixity of the pile head.

When we have a fixed-head case, the formula becomes

What should be the Roof slope to prevent Ponding?

2011-12-09T12:24:00.001-08:00

As per standards, the Roof beams should have a continuous upward slope equivalent to 1/4 in/ft ( 20.8 mm/m) between a drain and the high point of a roof, in addition to minimum recommended camber to avoid ponding.

In case of insufficient slope that is less than 20.8mm/m, it should be noted that the stiffness of supporting members acting 5lb/ft2 or 239.4 N/mm2 load should not cause more than 1/2 inch or 12.7mm deflection.

Coltman Precast Concrete Streamlines Production Of Precast Concrete Hollowcore Slab Products

2011-12-09T07:56:00.001-08:00

To further streamline production of its precast concrete hollowcore slab products, Coltman Precast Concrete has continued its ongoing investment programme with the acquisition of two of the latest Prensoland moulding machines.

The two EV-6 moulders, the first of their type to be bought by a UK manufacturer, represent an investment in excess of £350,000. They enable Coltman to produce hollowcore slab products that meet the requirements of the latest European Codes of Practice, which cover the manufacture of precast concrete.

A profile change can be achieved with the machines in five minutes. This allows for a wide flexibility in the range and size of products that Coltman can produce, increasing its manufacturing efficiency still further.

The EV-6 has a maximum working speed of up to 3m/min and at 17 kW is extremely energy efficient, delivering the twin benefits of lower maintenance costs and more efficient use of raw materials. The two new moulding machines are now jointly producing 5,000 sq m of prestressed concrete hollowcore floor slabs each week.

Said Coltman director, Nigel Gilbert: "The EV-6 is at the forefront of precast concrete production technology. Our management team worked very closely with Prensoland engineers over several months on the specifications for the two machines, which were then manufactured to our specific individual requirements."

Added co-director, Ian Gould: "Having the two new moulding machines gives us a major advantage as we are now supplying precast concrete products conforming to the very latest industry standards. As the machines are completely enclosed they deliver important health and safety benefits, and with their advanced design they are also extremely easy to maintain."

Coltman's product range include prestressed hollowcore wide slab and solid prestressed wide slab for flooring and roofing. Staircases, landings, balconies, terracing and wall units are also available as bespoke products.

Customers include some of the leading names in architecture, construction, civil engingeering, house building and property development. The company has been involved in numerous prestige projects, ranging from multi-million pound city centre redevelopments and quality housing, to civic cultural centres and premier sports arenas.

Caterpillar İncreases Manufacturing Capacity İn India

2011-12-09T07:55:00.001-08:00

As part of its strategic plan to increase its manufacturing footprint in the rapidly growing Asia-Pacific region, Caterpillar Inc. has announced a four-year, $200 million investment to increase manufacturing capacity in India. The announcement to increase engine and machinery production in India was made during a visit to Caterpillar's India facilities by Caterpillar Chairman and Chief Executive Officer Jim Owens.

"Caterpillar machines and engines are being used by our customers in India to drive sustainable development and to support economic growth in the areas of infrastructure development, commercial and residential construction, mining, power generation and energy production," Owens said. "We are pleased to continue contributing to the growth and development of India. This additional investment demonstrates Caterpillar's commitment to customers in India and the importance of such emerging markets as we build our proven global business model across the Asia-Pacific region, an area that is critical to Caterpillar's 2010 and Vision 2020 goals."

Caterpillar will invest to significantly increase production for off highway trucks made at its facility near Chennai. Those Caterpillar trucks are used for coal and other mining applications in India. The company also plans to expand engine production at its facility in Hosur, adding production of the Caterpillar 3508 engine. The 3508 engines will be used primarily in off highway trucks produced by Caterpillar in India.

The company is also investing in increased India production capability for backhoe loaders. The backhoe loader is the most widely used construction machine in India, and Caterpillar has already more than quadrupled production of backhoe loaders in country in recent years. The company is also studying increasing its range of products made in India, with the possibility of building additional manufacturing facilities to meet demand for other earth-moving products.

"This increased capacity will help Caterpillar serve customers in India and Asia-Pacific with world-class machines and engines produced in the region and serviced by our unmatched dealer organization," said Tom Bluth, Caterpillar vice president with responsibility for Asia-Pacific manufacturing operations. "For the industries we serve, Caterpillar already has the widest base of operations and product support in the world, and we will continue to invest in our business in the rapidly growing Asia-Pacific region to meet the needs of our expanding customer base in these critical markets."

Hill Engineering Supplies Auto-Loc Excavator Quick Hitch To Woods Equipment Company

2011-12-09T07:54:00.000-08:00

Hill Engineering Ltd has signed an agreement to supply its 'Safety First' Auto-Loc excavator quick hitch to Woods Equipment Company, one of the USA's largest independent manufacturers and suppliers of construction and agricultural equipment attachments.

Woods Equipment Company provides customers in the USA and Canada with a large selection of attachments for excavators, wheel loaders, tractor loader backhoes and skid steer loaders. Auto-Locs are now being manufactured by Hill and delivered to Woods for sale in the United States. All hitches are produced at Hill Engineering's factory in Newry, Co. Down, Ireland. Invest Northern Ireland has helped Hill Engineering to ramp up its overseas marketing capability, as well as significantly improve productivity and efficiency at its Newry factory.

The supply deal was signed by Hill Engineering's founder and Managing Director, Ian Hill, and representatives of Woods Equipment Company at the CONEXPO 2008 event in Las Vegas.

Ian Hill said, "There is no American-made quick hitch with the unique safety features to be found in the Auto-Loc, which is why Woods Equipment Company has decided to take it on board. The sales agreement represents a major breakthrough for us as it gives us inroads into Woods' vast distribution network of more than 2,000 construction equipment dealers across North America and Canada."

Woods Equipment Company’s Chairman, President & CEO, Fred Korndorf, said: "The Auto-Loc is fully automatic, with a visible safety mechanism, so there is no need for the operator to leave the excavator cab to remove or insert a safety pin when changing from one attachment to another. This rules out the risk of a safety pin being inserted incorrectly or not being inserted at all, which is why we consider it to be the safest and best engineered quick hitch on the market today."

Graham Davis, Invest NI's Director of Regional Economic Development, said: "The high quality and innovative nature of Hill Engineering's product has differentiated the company from its competitors and is indicative of the high level of technical expertise shown by Northern Ireland engineering manufacturers. Having identified a commercial opportunity, the company has successfully brought its products to market and is performing strongly, adding significant value to the local economy."

"This deal with Woods Equipment Company is an indicator of the high esteem in which Hill Engineering's products are held in the market. I wish both companies every success with their working relationship going forward."

Deutz New Hybrid Drive Can Reduce Fuel Consumption By 30%

2011-12-09T07:53:00.002-08:00

DEUTZ has developed a unique hybrid power unit for construction equipment that is designed to reduce fuel consumption and CO2 emissions. DEUTZ claim that their new hybrid drive has the potential to reduce fuel consumption by as much as 30%.

The drive unit is the mild hybrid type, consisting of a DEUTZ four-cylinder diesel engine, an electric motor, a battery and a control unit. The electric drive serves to assist the main diesel engine drive.

Constantly energised when the engine is running, the system creates electrical energy that is stored within a lithium ion battery pack when asked to operate as a generator. In response to high engine loads, the system reverses its operating mode and turns into an electric motor. Doing so enables the system to supplement diesel power by taking stored battery power to assist the engine in driving the machine's hydrostatic transmission.

The electrical system provides a nominal 15kW output, with a peak capacity of up to 30kW, almost doubling the power of the DEUTZ engine.

The hybrid drive has been developed in conjunction with Heinzmann, a well-known manufacturer of engine control systems and a long-term DEUTZ partner and supplier.

A prototype unit has already been fitted to an Atlas Weyhausen wheel loader. While the standard AR65 loader is powered by a 68hp DEUTZ TCD 2011 diesel engine, the hybrid version has been replaced by a smaller 50hp D 2011 non-turbo-charged oil cooled version.

Unlikely to reach full commercial production until 2010, the electric motor/generator is situated where the engine's flywheel and flywheel housing is normally located.

The hybrid power unit has the following functions:
* Start and stop: automatic engine stop during idling phases, automatic engine start in the case of continued operation, the usual starter is omitted.
* Power boost: in the case the power peaks, the electric unit is cut in.
* Battery charging: if the diesel engine has excess power, the electric unit can charge the battery while operating as a generator.
* Recuperation: part of the braking energy is refed into the battery by the electric unit.

The hybrid drive is easy to fit, can be integrated with different types of DEUTZ engines and retrofitted to existing systems.

Currently, all functions on the Weyhausen loader's equipment side are still hydraulically driven. The next step will be to power the loader totally by a full hybrid drive system, delivering eventual emission-free operation.

Torcup Launches Raptor Pneumatic Torque Wrench

2011-12-09T07:53:00.001-08:00

TorcUP has announced a pneumatic wrench with continuous and repeatable torque and an accuracy of +/- 5%. Light and fast, the Raptor is ready to accommodate your torque needs from 120 ft/lbs to 6,000 ft/lbs.

The Raptor works with a variety of applications making it the ideal tool for any pneumatic wrench need. Ranging in five sizes from the RP-500 to the RP-6000, the Raptor will give you the torque you need when you need it, quickly, reliably and dependably.

The Raptor has a patented gear technology which creates greater durability, lower operational temperatures and increased efficiency. Each Raptor meets stringent quality control standards before leaving the warehouse and with TorcUP’s 13 month warranty on all tools, so you can worry about the job at hand and not the tool.

With a sealed housing and ergonomic grip, the Raptor ensures the comfort of the operator and safe operation. After studying issues with typical pneumatic wrenches, TorcUP saw that other pneumatics allow water into the body of the wrench; this creates rust and friction which are the primary causes of pneumatic wrench failure. The Raptor has been sealed to keep the grease in and the water out. The benefit to the operator is less down time with fewer repairs.

Turbine Business Park Construction Started

2011-12-09T07:52:00.001-08:00

The £70 million Turbine Business Park has now been granted reserved matters planning and construction has started. The 55 acre scheme is strategically located between Sunderland and Washington, on land fronting the A1231 adjacent to the junction with the A19, and will incorporate a prestigious 715,000 sq ft business park with office space, light industrial units, a hotel and car showroom and ancillary retail.

Barmston Developments, a joint venture partnership between Wilton Developments and Clugston Developments, has appointed contractor Hall Construction to carry out the first phase of infrastructure work on the 55 acre scheme, which includes 0.75km of the new access road known as Turbine Way, with completion due this autumn.

Jason Stowe, director of Wilton Developments, said: "We've worked closely with Sunderland City Council to create a masterplan for the site that we hope will generate in excess of 4,000 new jobs.

"Now that we have secured reserved matters planning we are keen to make a start on the scheme as swiftly as possible. A number of occupiers have already expressed their interest in space on the busines park and we are likely to be able to report our first deal very soon, prior to any serious marketing of the scheme."

Bob Culliford, managing director of Clugston Developments Ltd, added: "I am pleased to see the masterplan that we have all worked so hard on becoming a reality, in spite of the current economic climate.

"Our commitment and the commitment of our investors to the scheme has remained unwavering and we are looking forward to delivering a vibrant mixed use scheme that will appeal to those looking for a foothold in the North East, as well as meeting local occupier needs."

Sunderland City Council Leader, Paul Watson, concluded: "Turbine Business Park is a real indicator of the economic resilience and strength of the region.

Construction Underway For Derwenthaugh EcoParc Autoclave Recycling Plant

2011-12-09T07:51:00.002-08:00

Derwenthaugh EcoParc will be one of the world’s largest steam autoclave recycling plants on the banks of the River Tyne in Gateshead. This £50 million investment will offer a large waste recycling plant capable of treating 320,000 tonnes of municipal solid wastes and commercial wastes, and will divert more than 80 per cent of input wastes from landfill.

The EcoParc will act as the blueprint for all future sites and comprises four key areas - municipal solid waste/ commercial waste reception; steam treatment and reception; separation plant; light waste, despatch and green waste transfer station. Additional office and floor space will be created for future development. The waste processing buildings will feature the latest UV odour treatment technology and be held at a negative pressure to prevent the release of any odour.

Procured via a negotiated partnering arrangement, the project team comprises process engineers and contractors to ensure a seamless solution to the construction process. Browne Smith Baker, the architects, drew up plans for the Derwenthaugh development and prepared the masterplan.

Clugston Construction, the main contractor on the development, commenced negotiations with Graphite Resources in 2004 and started work on site in May this year. Clugston is carrying out extensive site infrastructure works and will construct an extensive range of buildings on the site. Erection of structural steelwork will commence in the autumn.

Richard Greenwood, Project Manager for Clugston said: “Derwenthaugh EcoParc is an exciting opportunity, not just for Gateshead but for the North East region as a whole. It is a prestige project and a symbol of success for all those involved.”

William Thompson, executive director of Graphite Resources said: “This is an important project; we want to be working with the best people and resources to help deliver a scheme the North East can be proud of. The development is all about quality and with our construction team on board, this is an excellent start to attaining that objective.”

Mott MacDonald, the project management and engineering consultants to Graphite, provided pre-contract technical advice and technical contract drafting, and are continuing to provide formal project management and contract administration services throughout the construction and commissioning phases.

Quantity surveyor Henry Riley was involved with the feasibility, cost planning and contractual negotiations.

William Thompson said: “It is our stated aim to develop one of the leading EcoParcs in Europe, in terms of quality environment and technology as well as creating sustainable employment for the long-terms benefits of a local workforce.”

iCrete Concrete Used İn Prestige High-rise Projects İn Manhattan

2011-12-09T07:51:00.001-08:00

The iCrete(TM) System offers record strength as well as dramatic environmental benefits and cost efficiencies when used in all major construction applications, including commercial, residential, and infrastructure projects.

The iCrete System has already been chosen for a variety of Manhattan's most prestigious high-rise projects, including:
- Freedom Tower, designed by architects Daniel Libeskind and David Childs.
- Beekman Tower, designed by legendary architect Frank Gehry.
- The Harrison, designed by the renowned architect Robert A. M. Stern.
- 11 Times Square, designed by Fox & Fowle, New York's premier office tower architects

The iCrete System, which is being poured right now at Freedom Tower as it rises at the former World Trade Center site in lower Manhattan, delivers a reduction of up to 40 percent in green house gases, advanced mix designs, plus higher performance and quality control.

The concrete designed by iCrete for Freedom Tower is the highest strength concrete ever poured in the history of New York. Less than one year after iCrete was introduced at Freedom Tower, it has already been poured at more than 30 construction sites in the Greater New York Metropolitan Area, including Midtown, the Upper West Side, Lower Manhattan and Tribeca and beyond.

"There's concrete. And now there's iCrete," says Juan Carlos Terroba, Chief Executive Officer of iCrete. "This represents the first major shift in 100 years in the way concrete is prepared. And the iCrete System is available worldwide - the rising costs of materials, labor and concrete itself have no geographic borders."

Chief Construction Officer Needed To Tackle The Problem Of The Fragmentation Of Construction Policy

2011-12-09T07:50:00.000-08:00

The construction industry provides employment for more than 2.8 million people. The sector contributed 8.7% of the UK economy's gross value-added (GVA) in 2006, and generated some £10 billion of exports. The public sector is the industry's biggest customer, accounting for around a third of output.

The Business and Enterprise Committee has published its Report, Construction Matters (HC 127-1), a major strategic review of the UK's construction industry. It calls on the Government to create a new post of "Chief Construction Officer" to tackle the problem of the fragmentation of construction policy and procurement across government, and to set the industry on the right footing to tackle the major challenges it faces both in the short and long term.

"Acting at a senior level as 'champion' of the sector, the postholder would provide a single point of engagement between the industry and the public sector, having operational involvement in policy and regulatory matters across departments," the report recommends.

Peter Luff MP, Chairman of the Committee said: "When the committee began its work on the construction industry its commercial position was strong. Now industry, and particularly the house building sector, is facing a major downturn, yet it still generates over £100 billion of value-added for the UK economy-more than twice that of the energy, automotive and aerospace sectors combined. The public sector is by far its largest client and can drive change across the industry.

"We need to take action to address the issues identified in this report, irrespective of the business climate in which the industry is operating. We agree with the industry that coordination on policy between the many Government departments that engage with and impact upon this vital industry is patchy and ineffective. We believe the appointment of a Chief Construction Officer would provide a single point of engagement between the industry and the public sector and so give this vital industry a stronger and clearer presence in government."

Bachy Soletanche Shows Off İts Piling Work At Birmingham Cube Site

2011-12-09T07:49:00.000-08:00

It’s quite rare for Bachy Soletanche Limited to properly show off its work, but at one site in Birmingham the firm’s £1.7M piling work has certainly seen some exposure. In fact BuildAbility’s ‘The Cube’ site excavation is so large that it was fast becoming Birmingham’s newest tourist attraction.

Bachy Soletanche designed and delivered a contiguous piled retaining wall around the perimeter of the site for the project. The piles were to support the surrounding buildings, roads and canal so that the site could be excavated up to 19m in depth. Using the large diameter auger (LDA) piling technique, Bachy Soletanche installed 226, 900mm diameter piles at 1050mm spacings. These were drilled up to a depth of 24m.

Other piling works included a minipile wall consisting of 24, 273mm diameter minipile installations for a car lift in the southwest corner of the site and another 54 minipiles to the west of the site alongside the LDA piles to add further support to the adjacent building. Thirty king post piles were also constructed to provide foundations for a ramp running down the centre of the site. Each king post pile was formed in a 900mm diameter pile, with a 400mm square steel column concreted into the toe of the pile.

Bachy Soletanche also installed to construct 12 temporary anchors to hold back the retaining piles on the east side of the site.

GK Systems To Distribute Sioux Water Heating Equipment İn The UK

2011-12-08T06:31:00.000-08:00

GK Systems (Europe) LLP, part of the Killoughery group of companies, has won a contract with water heater company Sioux to distribute its products in the UK.

The concrete technology specialists will supply market leader Sioux’s wide range of water heaters to the construction industry, which includes mobile units, static units and both hot and cold water pressure washers.

Hot water is essential for cold weather concrete production, and is widely considered a more effective method than heating aggregate – thus making for more profitable operations. Sioux is the biggest name in water heating equipment in the USA.

The company expects the market to find the M-415 model of particular interest – it can be fitted to mobile mixers and used in the production of rapid set concrete, both standard and foam, which can greatly accelerate the reinstatement process.

GKS also supplies washing equipment including hot and cold water pressure washers, mobile mixing units, foam generators and foam concrete.

Requirements For Civil Engineering Staff Remain Strong

2011-12-08T06:30:00.000-08:00

This year has been yet another booming period for UK civil engineering firms. The latest figures from Hays Civil & Structural indicate that far from the stories of doom and gloom, civils is a resilient market due to much of the work being publicly funded and all of the top civils firms are continuing to look for staff.

Projects such as the 2012 Olympics sites and Crossrail which is worth £16billion, combined with Ruth Kelly’s announcement that £6billion will be invested in the nation’s transport system, highlight the opportunity for civil engineering jobs - particularly those who are qualified and are working towards Chartered status.

Hays Specialist Recruitment has re-launched its civil engineering business under the title of Hays Civil & Structural to reflect its renewed focus in this area. This new division benefits from specialist staff in nationwide offices, who have a comprehensive understanding of employers in the sector and specific job requirements.

Greg Lettington, Director of Hays Civil & Structural, commented: "Client requirements for civils staff remain strong because order books are still full. It is one of the key areas which is managing to successfully buck the downward trends, which other sectors are facing due to the credit crunch. Given that there is such a shortage of qualified engineers in general anyway, we can certainly say with confidence that good workers will remain in demand."

Kayleigh Plant Hire Opts For The Latest Volvo Equipment

2011-12-08T06:29:00.000-08:00

Kayleigh Plant Hire, of Tottenham North London, has taken delivery of fourteen Volvo compact excavators and one fourteen tonne EC140C crawler excavator from Volvo Construction Equipment.

Kayleigh Plant Hire Ltd was established in 1993 to complement the main activities of the O’Donovan Group which specialises in waste recycling, waste disposal, material and aggregates recycling. The original business started back in the 1930s and today the Group is managed by the second generation of the O’Donovan family. Since moving into general plant, the Company has grown substantially offering both operated and non operated machines for hire throughout London and the south east of England.

“We pride ourselves in offering our customers a first class service and we expect the same from our suppliers,” said Michael O’Donovan, Managing Director of Kayleigh Plant Hire. “We’ve had a good relationship with Volvo CE since we purchased a BL71 backhoe three years ago, so when it came time to replace some of our older compact equipment we decided to opt for the latest Volvo equipment.”

And the machines in question are five ECR88 Plus (eight point eight tonnes); seven of the recently introduced five tonne ECR48C; two EC25s (two and a half tonnes) compact models together with the larger fourteen tonne EC140C. These are the first Volvo excavators to join Kayleigh’s fleet which totals approximately 100 units.

Features include a variable flow power control hydraulic system for precise control under all load conditions and safety features such as Roll Over Protection Structure (ROPS), Tip Over Protection Structure (TOPS) and Falling Objects protection Structure (FOPS) contribute to outstanding operator safety.

Caterpillar İntroduces PL61 Pipelayer

2011-12-08T06:27:00.000-08:00

Caterpillar has introduced the PL61 Pipelayer at the small end of the Caterpillar pipelayer range, providing a machine with 40,000 pounds (18 145 kg) of lift-capacity and the capability to meet the pipeline contractor’s requirements for precision control, transportability, operator comfort, visibility and durability.

The PL61, shares many common components with the Caterpillar D6K tractor, featuring a Cat® C6.6 ACERTTM engine, closed-loop hydrostatic drive system, oval-track SystemOne™ undercarriage and an electronically enhanced operator station. Complementing this technology are premium features retained from the design of the predecessor model, the 561N, including hydrostatic draw-works, two-speed load line and extendible counterweight.

Available with either a canopy or an optional enclosed cab, the PL61 operator station features a pair of seat-mounted, electro-hydraulic joysticks designed for intuitive control of travel and lifting functions. The operator station provides clear lines of sight to all work areas, including the boom and upper block, which are visible through a new roof-mounted skylight. For added control, a combination decelerator/brake pedal can be configured to slow the machine with or without a reduction in engine speed.

The 18-foot (5.5 m) boom is constructed of high-tensile-strength steel, allowing a robust box-section design that is durable, yet lightweight to optimize payload capacity. The hook and cable-controlled boom are raised and lowered by independent hydraulic winches designed for smooth operation and infinite speed adjustment through their working range. Two-speed operation of the load-line winch provides high speeds for overall productivity, but lower speeds for precise positioning. Oil-disc brakes in the winches positively retain selected boom and hook positions.

The Benefits Of Precast Concrete Flooring

2011-12-08T06:24:00.002-08:00

Over the past 40 years or so there has been an increasing shift to concrete flooring - particularly in commercial and industrial buildings. Some of the key reasons for this continuing growth can be summed up as sustainability, innovation and health & safety.

Sustainability

Sustainability is in many ways an obvious feature since it is one of the principal features of concrete as a material. Its 'shelf life' can be measured in decades rather than years and, what’s more, it can be broken up when no longer required and recycled in a variety of ways; including use as an aggregate for new concrete.

Innovation

In terms of innovation, there are now many variations, each offering particular benefits for specific individual applications.

Health & Safety

Last, but certainly by no means least, there is health & safety - a vitally important area that is at the heart of the work of the Precast Flooring Federation.

Whilst product developments and innovation still continue, there are currently three main generic types of precast concrete floor: hollowcore, beam & block and lattice girder.

Of these it is hollowcore which is proving the most popular for commercial buildings. Hollowcore flooring consists of concrete elements cored along their length, with units generally available as 1,200mm wide - although some manufacturers produce up to 1,500mm, or as narrower units of 600-750mm width. Depths are 100-400mm, depending on the span and loading conditions; providing efficient, flexible solutions across all markets for most building types.

An often over-looked benefit of concrete floors is the improved acoustic performance. With today's generally increasing environmental noise, any such improvements are most welcome.

Concrete floors are also more cost-effective than timber and enable thinner floor zones, as well as longer spans. In addition, they provide a safe working platform for ongoing construction work.

Add to that their intrinsic one hour minimum fire resistance and compatibility with other precast concrete components such as stairs and balconies and it is easy to see why the technique continues to gain ground.

Another more obvious plus for concrete floors is the ability to vary room layouts without worrying about floor loadings. This feature applies particularly at first floor level and above, avoiding any concern about the positions of supporting walls. For the designer this flexibility and adaptability provide yet more factors in favour of concrete.

Tom Prichard Contracting Continues To İnvest İn Volvo Excavators

2011-12-08T06:24:00.001-08:00

Tom Prichard started his business as an agricultural contractor in 1997 when he was eighteen. He diversified into general plant hire in 2001 and his Company became Limited in 2005. Now, with its head office, yard and comprehensive workshops based in Llantrisant, Tom Prichard Contracting Ltd undertakes a whole variety of earthmoving projects throughout South Wales and the south west corner of England. This includes bulk excavations, remediation work and haulage with the Company’s fleet of tipper wagons.

Tom Prichard Contracting Ltd of Llantrisant, South Wales has taken a further selection of Volvo Construction Equipment products for its plant fleet. The most recent additions to Mr Prichard’s fleet include two compact reduced swing excavators – namely an ECR28 and ECR88; two twenty one tonne EC210C’s, and EC240C and the recently released C series version of the fourteen tonne EC140. Accompanying the excavator additions the Company has also taken delivery of its first DD24 tandem roller in full Volvo livery.

These recent arrivals bring the number of Volvo branded products to fourteen out of a total fleet of 110 items of plant. “We are continuing to invest with Volvo machines for the fleet for two main reasons,” comments managing Director Tom Prichard. “Firstly Volvo provides us with a first class support and service back up and secondly, the products and especially the excavators are robust and have proven reliability.”

Opportunities For The UK Construction Sector İn South Africa

2011-12-08T06:23:00.001-08:00

According to a report released by the UK Trade & Investment, British construction firms are being encouraged to take advantage of the multi billion pound infrastructure opportunities in South Africa.

The report, titled ‘Building South Africa: Opportunities for the UK Construction Sector’, highlights infrastructure opportunities in both the public and private sectors stemming from the Government’s £33billion infrastructure plans and events like the 2010 World Cup.

UK Trade & Investment Chief Executive Officer Andrew Cahn said: “South Africa is a fast growth economy with infrastructure plans to match. With investment opportunities in both private and public sectors, coupled with a severe skills shortage now is the time for UK companies to take advantage of the construction boom.”

“The Government’s infrastructure spending plan is set to accelerate the annual growth of the economy between 4.5 per cent and 6.0 per cent. Its ambitious plans for mass transport, water projects, prisons, hospital and prison upgrades provide plenty of opportunities for UK companies.

“This investment and events like the 2010 Football World Cup are acting as a catalyst for growth in the private construction sector. Opportunities include hotel and residential development as well as urban regeneration projects. By establishing a business in South Africa, UK companies can gain a foothold into sub-Saharan Africa.”

This latest report follows on from recent research by UK Trade & Investment which revealed South Africa to be one of tomorrow’s most exciting investment destinations. In recent research South Africa was ranked as number eight in the top ten list of ‘new wave’ markets. The Tomorrow’s Markets report gives new insights into where companies will go next in emerging markets and why. The results are based on the opinions of global business leaders headquartered all over the world and gives credible insights into their future business plans.

New 3-D Transistors Promising Future Chips,Lighter Laptops

2011-12-08T06:17:00.001-08:00

Researchers from Purdue and Harvard universities have created a new type of transistor made from a material that could replace silicon and have a 3-D structure instead of conventional flat computer chips. The approach could enable engineers to build faster, more compact and efficient integrated circuits and lighter laptops that generate less heat than today's. The transistors contain tiny nanowires made not of silicon, like conventional transistors, but from a material called indium-gallium-arsenide.

The device was created using a so-called "top-down" method, which is akin to industrial processes to precisely etch and position components in transistors. Because the approach is compatible with conventional manufacturing processes, it is promising for adoption by industry, said Peide "Peter" Ye, a professor of electrical and computer engineering at Purdue.

A new generation of silicon computer chips, due to debut in 2012, will contain transistors having a vertical structure instead of a conventional flat design. However, because silicon has a limited "electron mobility" -- how fast electrons flow -- other materials will likely be needed soon to continue advancing transistors with this 3-D approach, Ye said.

Indium-gallium-arsenide is among several promising semiconductors being studied to replace silicon. Such semiconductors are called III-V materials because they combine elements from the third and fifth groups of the periodic table.

"Industry and academia are racing to develop transistors from the III-V materials," Ye said. "Here, we have made the world's first 3-D gate-all-around transistor on much higher-mobility material than silicon, the indium-gallium-arsenide."

Solar Power Much Cheaper To Produce Than Most Analysts Realize,Study Finds

2011-12-08T06:16:00.001-08:00

The public is being kept in the dark about the viability of solar photovoltaic energy, according to a study conducted at Queen's University. "Many analysts project a higher cost for solar photovoltaic energy because they don't consider recent technological advancements and price reductions," says Joshua Pearce, Adjunct Professor, Department of Mechanical and Materials Engineering. "Older models for determining solar photovoltaic energy costs are too conservative."

Dr. Pearce believes solar photovoltaic systems are near the "tipping point" where they can produce energy for about the same price other traditional sources of energy.

Analysts look at many variables to determine the cost of solar photovoltaic systems for consumers, including installation and maintenance costs, finance charges, the system's life expectancy, and the amount of electricity it generates.

Dr. Pearce says some studies don't consider the 70 per cent reduction in the cost of solar panels since 2009 . Furthermore, he says research now shows the productivity of top-of-the-line solar panels only drops between 0.1 and 0.2 percent annually, which is much less than the one per cent used in many cost analyses.

Equipment costs are determined based on dollars per watt of electricity produced. One 2010 study estimated the this cost at $7.61, while a 2003 study set the amount at $4.16. According to Dr. Pearce, the real cost in 2011 is under $1 per watt for solar panels purchased in bulk on the global market, though he says system and installation costs vary widely.

Dr. Pearce has created a calculator program available for download online that can be used to determine the true costs of solar energy.

Computer Simulations Shed Light On The Physics Of Rainbows

2011-12-08T06:14:00.000-08:00

Computer scientists at UC San Diego, who set out to simulate all rainbows found in nature, wound up answering questions about the physics of rainbows as well. The scientists recreated a wide variety of rainbows -- primary rainbows, secondary rainbows, redbows that form at sunset and cloudbows that form on foggy days -- by using an improved method for simulating how light interacts with water drops of various shapes and sizes. Their new approach even yielded realistic simulations of difficult-to-replicate "twinned" rainbows that split their primary bow in two. UC San Diego alumnus Iman Sadeghi, who did the work while a Ph.D. student at the Jacobs School of Engineering, his advisor, computer science professor Henrik Wann Jensen, and scientists from Spain, England and Switzerland, will publish their findings in ACM Transactions on Graphics in December of this year.

"This goes beyond computer graphics," Jensen said. "We now have an almost complete picture of how rainbows form."

Jensen is no stranger to advances in computer graphics. He earned an Academy Award in 2004 for research that brought life-like skin to animated characters. He has worked on a number of Hollywood blockbusters, including James Cameron's "Avatar."

Jensen, Sadeghi and colleagues originally set out to simulate rainbows to better understand how spherical water drops interact with light, resulting in the bright, multi-colored arcs that we are used to seeing when rain stops or in tropical, humid weather. They were hoping to improve techniques used in animated movies and video games.

"You usually don't get the opportunity to study such beautiful phenomena while working on your Ph.D. thesis," said Sadeghi, who is now a software engineer in the graphics division of Google in Santa Monica. "There is a lot more to rainbows than meets the eye."

As they started running various simulations, the scientists realized that the interaction of light with spherical drops could not explain some kinds of rainbows, such as twinned rainbows. Scientists turned to research showing that, as a water drop falls, air pressure flattens the bottom of it and shapes it like a burger.

Safety and Security For Construction, Quarrying and Mining With Sıck Outdoor Scanners

2011-12-07T06:56:00.000-08:00

Safety and security scanning for all external environments from large construction and civil engineering sites to conveyors and other heavy moving plant above or below ground is now available with SICK’s IP67 rated / PLd and SIL 2 certificated OS2000 laser scanner.

Developed by SICK, the OS2000 enables a high reliability, electronic safety and security screen to be maintained outdoors despite the harshest conditions and exposure. The system is ideal for the detection of movement of people, vehicles and objects for safety, security and collision avoidance, including emergency stops and machine control.

The OS2000 is easy to install and set up, yet capable of sophisticated and multi-sensor deployment with its intelligent BUS connections. Its versatility allows it to be used for a wide variety of situations and applications, vertically or horizontally, and reconfiguration to meet changed conditions is easy.

The OS2000 is believed to be the first scanner of its type to be CE certificated to performance Level d (EN ISO 13849-1) and SIL2 (EN162061), which allow it to be used where safety demands are critical.

Use of high reliability electronics and with self testing and system status indication capability ensure its operability in situations where mechanically based safety systems might fail or not offer the flexibility and controllability required.

New Approach To İndustrial Noise Measurement

2011-12-07T06:55:00.002-08:00

Cirrus Environmental has launched the MK:427 Noise Sensor, a self-contained outdoor noise meter that connects directly to SCADA systems. The sensor allows noise level data to be incorporated into Process Measurement and Control systems with unparalleled ease. The data can be stored to provide a complete record of a plant's noise activities, and can also be used to control noisy processes in real time. For example: a pump or fan can be throttled back when the noise it generates reaches an excessive level at the site boundary.

Unlike a conventional Sound Level Meter, the Noise Sensor simply converts the noise level in decibels into standard 4-20mA and linear DC outputs. The pure-analogue electronics are highly reliable and operate without any user intervention. No specialist acoustic knowledge is required – simply power-up the Noise Sensor and the measured noise level is continuously fed to the output. With the 4-20mA output, very long cable lengths can be used without reducing the accuracy of noise measurements.

The Noise Sensor incorporates a 1.2 meter microphone pole, allowing the microphone to be positioned in free space, well away from any obstructions. A variety of mounting methods make the device simple to fit on any building or structure. The sensor hardware is based on a well-established Cirrus design that has been proven in harsh weather conditions around the world for many years.

To ensure that the sensitive microphone transducer is always in good condition, it is fitted with an electrostatic actuator calibrator. This can be used to make regular fixed-point calibrations of the entire measuring chain, thus verifying data integrity. The device can be set to measure Fast or Slow time-weighted Sound Pressure Level with “A”, “C” or “Z” frequency weighting to Class 1 standards. A unique prescaling calibration system allows any 65dB span in the range 20 to 130dB to be selected by the user.

Kubota Machines Now Carry 3 Year Warranty As Standard

2011-12-07T06:55:00.001-08:00

Kubota has announced that all their new machines will now carry a full 3 year warranty as standard. The new 3 year warranty will apply to all models across the entire Kubota range. Most other manufacturers currently offer a maximum 2 year standard warranty period.

Richard Harrison, Sales & Marketing Manager, Kubota (UK) - Construction Equipment Division, said: "The decision to extend the standard warranty to 3 years (or 3,000 hours) is another industry first for Kubota and shows our confidence in the quality, reliability, durability and superiority of our machines."

"With their outstanding performance, versatility and excellent residual values, plus our unique key-based 'ANTI-THEFT' security system which also comes as standard, Kubota minis provide unbeatable value for money."

"The addition of an extra year's warranty, our in-built security system, and the legendary Kubota quality and performance characteristics, combined with outstanding dealer support, are all vitally important considerations for customers buying or hiring machines in today's challenging business climate," concluded Richard Harrison.

L Lynch Plant Hire adds Heavier Volvo Excavators To İts Fleet

2011-12-07T06:54:00.001-08:00

Since opting for Volvo branded excavators for the first time in 2004, L Lynch Plant Hire has added a further twenty five Volvo’s to its operating fleet of two hundred, predominantly Volvo badged excavators. At the same time, the Company has recognized the need to be able to offer larger machines for hire to high profile projects and blue chip contractors working on some of the most prestigious construction projects currently being undertaken around the U.K.

Other projects include long term quarrying and landfill contracts in the Midlands and south of England. To this end Lynch included twenty nine tonne EC290C’s and thirty six tonne EC360C’s in the recent package along with a mix of fourteen and twenty one tonne excavators.

Commenting on the deal, Lynch’s Sales and Marketing Manager Rob Lynch said; “There are two main reasons why we prefer operating Volvo excavators in our fleet. Firstly, we take great store in the opinions, advice and feedback from our machine operators and their assessment of the Volvo product is very high indeed. Naturally, operator comfort comes top on the list, but also the performance and power of the Volvo machines is considered superior over their competitors. Our other reason for choosing machines from Volvo is their ability to support the product 100% from their support centres. Their ‘Yes –can do’ approach exactly mirrors our own ethos with our customers,” he continued.

Inspicio Acquires Pile Testing Specialists Precision Monitoring and Control

2011-12-07T06:53:00.000-08:00

Inspicio has announced the acquisition of the independent pile testing specialists Precision Monitoring and Control Ltd (PMC).

PMC is the UK's leading independent pile testing specialist, operating nationwide in the construction sector, primarily on infrastructure projects. Its capability in diagnostic foundation engineering is complementary to Inspicio's Soil Mechanics business and will provide opportunities to cross sell between the businesses.

This latest acquisition will fit into the Inspicio Environment Division headed up by Alex Sleeth. Alex joined Inspicio on 1 October 2008 having spent the previous 20 years in various roles within National Britannia culminating in his role as Chief Executive Officer. The existing PMC management team will remain in place and the two founding directors will continue with the business on a consultancy basis.

Mark Silver, CEO Inspicio said: “After more than 20 years in the business, PMC has built up an enviable reputation in the market and is a valued addition to the Inspicio Environment Division. This is our eighth acquisition this year and clearly demonstrates the support 3i, our major shareholder since February, offers to the Group. The acquisition of PMC will enable us to expand our offerings in the Environment market both throughout the UK and internationally.”

Vibro Projects İs Having A Successful Run İn France

2011-12-07T06:52:00.000-08:00

The Dourges site, situated 20km south of Lille on the main A1 motorway, is for a 55,000m2 logistics platform warehouse. To improve the bearing capacity and stability of the ground, the Vibro team was contracted to install 7,400no. stone columns to an average depth of 4.5m.

Vibro Projects Limited has proven to be a ‘European Champion’ when it comes to vibro ground improvement after going head to head with German and French rigs on a project in Dourges, France. The firm was working on the £750,000 contract on behalf of Soletanche Bachy where it produced over 500m of stone columns per shift; easily making the UK based Vibro Projects top of the league.

Speaking of the contract, Vibro Projects’ Mark Henry explained: “It was the use of pre-auger assistance which allowed Vibro Projects to produce far more stone columns in a shift compared to the other rigs, proving how efficient our system of stone column bottom feed really is. Our high production rates really impressed our fellow Vibro technicians and also Soletanche Bachy, which is extremely positive for Vibro Projects’ future on international projects.”

The most efficient way of completing this was to mobilise one of its bottom feed rigs complete with a larger 600mm diameter tube and a Jean Lutz recorder on site. This new 600mm diameter tube guarantees a 600mm diameter clean stone column from top to bottom. The Lutz recorder, installed in the bottom feed rig, provides information on depth pressures, installation and stone quality used; details which are essential to the sub-contractors, main contractors and client.

Chinese Construction Machinery Manufacturer Sany To İnvest 100 Million Euros İn North Rhine-Westphalia

2011-12-07T06:51:00.000-08:00

SANY Heavy Industry is one of the world's largest manufacturers of concrete pumps. SANY is a globally operating company which at present generates 20 percent of its sales outside China. New plants are currently being built in Pune/India and Atlanta, Georgia/USA. The company now employs more than 28,000 people and generated sales of around 1.35 billion euros in 2007. The company from Changsha, Hunan Province, has been listed on the Shanghai Stock Exchange since 2003.

The Chinese construction machinery manufacturer SANY Heavy Industry Co., Ltd. opened its European headquarters in Cologne in May 2008. By establishing Sany Germany GmbH and setting up its head office in Cologne, the Chinese construction machinery manufacturer took its first steps into the European market.

SANY is now consistently expanding its commitment in Europe by investing 60 million euros in the new location in North Rhine-Westphalia in a first step. By doing so, the company is creating several hundred jobs in the coming years. After intensive negotiations between the investor, the state of North Rhine-Westphalia, the towns of Bedburg and Bergheim and the commercial zone owner, RWE Power AG, NRW.INVEST succeeded in winning the Chinese investor for the attractive location Bedburg/Bergheim Mühlenerft in the city triangle Cologne – Düsseldorf – Aachen.

The planned investment will become one of the largest new business establishments of a Chinese company in Germany and in Europe. Besides production, a research and development center is to be built, as well as a training facility for newly arrived SANY employees, mainly from Europe.

"With the settlement of SANY we can continue to increase the attractiveness of North Rhine-Westphalia for major Chinese investments," stressed Economics Minister Christa Thoben. "We will do everything to ensure that North Rhine-Westphalia becomes the top location for Chinese companies in Europe in the medium term."

NRW.INVEST has been supporting the settlement of the Chinese investor since May 2007. "With our continuous service and the quality of our location we were able to assert ourselves in the face of strong competition from all over Europe and other locations in Germany", explained Petra Wassner, Managing Director of NRW.INVEST.

"The key factors influencing our decision in favor of the 'Mühlenerft' commercial zone were its proximity to Cologne, the excellent connections to the seaports, the sufficient supply of qualified staff, the professional and personal commitment in the town administrations of Bedburg and Bergheim, and the outstanding service of the state agency NRW.INVEST. Negotiations with all those involved have shown that we are very welcome in this region", said Xingliang Feng, Managing Director of Sany Germany GmbH, explaining the decision. He added: "We continue to welcome applications from engineers for our research and development."

Mainland Plant Looks Forward To A Positive Future Under İts New Owner

2011-12-07T06:50:00.000-08:00

The plant hire division of the Mainland Construction Group has been saved - less than a week after Bridge Business Recovery, joint administrators of the company, set out to find a buyer. The fast-paced sale will see the new entity trading as Mainland Plant.

“We are delighted to have found a buyer for the plant hire side business of Mainland Construction in such a short time,” says Matt Evans, Partner with Bridge Business Recovery. “It is encouraging that, in these challenging economic times, this part of the business has been saved – as have the jobs of everyone working there.”

Founded over 20 years ago, until recently Mainland Construction Group employed over 150 people across three main areas – construction, civil engineering and plant hire from its base in Northamptonshire. While the construction and civil engineering divisions of the company have been closed and the contracts sold as a result of the administration, its plant hire operation continued to operate.

Mainland Plant operates a wide range of equipment from five tonne mini diggers to 40 tonne excavators and dozers. It has a policy of using the latest machinery available, the majority of which is new or under two years old, and comes either with a CPCS trained operator or as a self-drive option.

“Like many companies operating in construction, Mainland has struggled financially in the wake of the general economic slowdown, resulting in the closure of several areas of its business,” says Matt Evans. “However, its plant hire division has continued to operate as normal and, under its new owner, can hopefully look forward to a positive future.”

Launched earlier this year, Bridge Business Recovery specialises in providing hands-on, pragmatic solutions to business reviews, corporate restructurings and insolvency assignments across a wide-range of sectors. It currently has offices in London and the South East and employs in excess of 25 people.

Subsurface Utility Engineering İs A Cost-effective Method Of Underground Utility Mapping and Detection

2011-12-07T06:46:00.000-08:00

Research carried out by universities in U.S. and Canada suggests Subsurface Utility Engineering (SUE), brought to the UK by TBE (UK) Limited, provides substantial cost savings down the construction line. Ultimately, SUE is a highly recommended pre-design, underground utility mapping solution to the industry.

In the current economic climate, where 'tightening the belt' has become a prerequisite of construction budgets, TBE's alternative to underground utility mapping and detection is widely known for its accuracy, eliminating not only unexpected costs, but project risk.

However in general terms, the cost saving benefits of SUE surveys is particularly subjective. Therefore to identify and demonstrate just how valuable it can be to a construction project, two separate research studies were conducted and showed significant results.

The Federal Highway Administration (FHWA) in America has encouraged the use of SUE on major highway construction projects for several years. It believes that when information on the horizontal and vertical location of underground utilities is obtained early in a project's development, projects can be designed around the utilities, avoiding costly utility conflicts and relocations. Knowing just how beneficial SUE is to a project, the FHWA commissioned a study in 2000 which was conducted by Purdue University researchers. It found that project owners could save, on average, $4.62 for every dollar spent on SUE.

In a similar study in Canada from 2005 and commissioned by the Ontario Sewer and Watermain Construction Association, the University of Toronto's Centre for Information Systems in Infrastructure and Construction discovered an average savings of $3.41 (Canadian) for every dollar spent on SUE.

Hill International Opens New Office İn Dusseldorf To Expand İn Central Europe

2011-12-07T06:45:00.000-08:00

As part of a global expansion strategy, US risk management consultancy Hill International is expanding its presence in Central Europe by opening a new office in Dusseldorf.

The new office will offer project management and claims consultancy services to construction and energy-related businesses across western Germany and Central Europe.

It will be headed by Thomas Hofbauer, Vice President at Hill's Munich office, who brings to the new branch extensive claims experience on projects worth up to $11.5 billion, and contract management experience on tunnels, bridges, roads, railways, commercial and residential buildings, power plants and sewerage systems.

Hill’s European expansion strategy has seen the company establish five new offices in the UK and Germany over the last 12 months. It has also acquired four European companies including UK-based companies Knowles and Shreeves, project management consultancy Euromost in Poland, and a controlling interest in Gerens in Spain.

Volvo Construction Equipment To Present Hybrid Wheel Loader At Intermat

2011-12-06T06:47:00.000-08:00

At Intermat, Volvo Construction Equipment will present several new models, including the hybrid wheel loader. The expanded road machinery range will also be unveiled for the first time at a major European show, now wearing Volvo’s familiar yellow and grey livery.

Volvo Construction Equipment will use its 3,800m2 (40,700ft2) of stand space to show how ‘more care’ is expressed in smart product design, fuel efficient engine technology, flexible financing – combined with a well trained, experienced and committed dealer network – makes Volvo a solid partner through good times and bad.

The company will also convey how Volvo innovations have a high performance impact on customer profitability – everything from advanced engineering solutions to mobile high-tech diagnostics that allow customers to accurately calculate their costs.

A wide range of products and services will be shown; including several new machines such as the ECR 305CL short swing excavator and the L45F and L50F mid-sized wheel loaders. Another highlight of Volvo’s participation at Intermat will be the company’s new-look road machinery product range, now marketed in the corporate livery of yellow/grey and carrying the Volvo brand.

In the Innovation area, one of the industry’s most talked about products will be on show – the prototype Volvo L220F Hybrid wheel loader. This machine’s diesel-electric hybrid drive system is the first iteration of Volvo’s ongoing development process – but its improved performance and reduced emissions and fuel consumption are impressive indicators of the potential environmental and economic benefits such hybrid systems offer.

Bachy Soletanche Acquires Piling Contractor Simplex Foundations

2011-12-06T06:46:00.001-08:00

Bachy Soletanche Limited has announced that it has purchased the northeast based piling contractor, Simplex Foundations Limited for an undisclosed sum. Bachy Soletanche has purchased the firm from Northwest Holst, gaining an increased rig fleet and its skilled, experienced engineers.

The company will continue to trade as Simplex and will stay in the local area, sharing Bachy Soletanche's new northeast office with the anchors, grouting and mini-pile division in Wakefield, West Yorkshire. Its plant will move to Bachy Soletanche's Burscough depot in Lancashire.

Speaking of the acquisition, Martin Pratt, Managing Director at Bachy Soletanche Limited, commented: "The acquisition will take advantage of the synergy between the two companies. As such, it will expand the capacity of Simplex Foundations and for Bachy Soletanche will provide the extra plant equipment and engineers when required. The arrangement benefits everyone concerned and we are pleased to have Simplex on board."

Bonal Technologies Achieves Excellent Customer Satisfaction Rating

2011-12-06T06:45:00.001-08:00

Bonal International, Inc. has announced the results of a recent blind Customer Satisfaction survey performed by an independent consulting firm on its three product lines – Meta-Lax, Pulse Puddle Arc Welding and Black Magic from customers acquiring equipment over a 16-month period.

The overall satisfaction rating in the three areas surveyed reached excellent satisfaction rating percentages. The overall rating for the equipment was 98% and sales and service was 98%. The satisfaction rating reached an outstanding level of 93% for overall results of using Meta-Lax technology.

One customer commented on their overall results, “We are seeing higher quality repairs with a faster, cheaper process that allows us to avoid moving large parts to the furnace.” Another customer summed up their experience this way, “I think they do an excellent job and cannot think of any way that our experience could have been better.”

Companies involved in the survey represented a wide range of demographics, from small machine shops to large organizations, from 10 different countries and a variety of different industries including fabricating, machining, aerospace, mining, mold making, gunsmithing, high performance racing and specialty metals producing.

Volvo İntroduces EW230C Wheeled Excavator With Superior Stability İn Heavier Lift Operations

2011-12-06T06:44:00.000-08:00

The EW230C from Volvo Construction Equipment is built around a new, more robust platform, which is designed to ensure the stability needed to manage bigger loads, for heavy lifting applications, such as laying big pipe for drainage projects, or hard digging.

Following the recent launch of the EW210C, a benefit of this platform for a machine in this 20t weight class, is that its design ensures that the rear axle weight, when fitted with the standard counterweight, is below 12t – making it approved for road travel between sites. A heavier counterweight is also available for applications not requiring the machine to be moved on the road.

With the standard counterweight, the EW230C weighs 21.6-24.3t, depending on machine configuration. (23.1-25.6t with the heavier counterweight.) A choice of 5.7m mono or optional articulated two-piece boom is available.

The EW230C is powered by a Volvo D6E EHE3 diesel engine, developing 125 kW/168hp net at 2,000 rpm, delivering power where it is needed. When required for mass excavation work, or in heavy lifting applications, the EW230C has a lift capacity among the best in its class, optimising performance and productivity. The EW230C on display at Intermat 2009 is fitted with Volvo’s automatic lubrication system, which not only ensures correct lubrication, but also reduces lubricant use by 50%.

Sharp Fall İn Orders İn The Construction İndustry

2011-12-06T06:41:00.000-08:00

According to the British Office for National Statistics, orders in the construction industry in the three months to December 2008 fell by 9 per cent compared with the previous three month period. Orders in the 12 months to December 2008 fell 16 per cent compared with the previous 12 months and orders in three months to December 2008 fell by 26 per cent compared with the same period a year earlier.

In the three months to December 2008 compared with the same period a year earlier, private housing orders fell by 57 per cent and public and housing association housing orders fell by 28 per cent.

Commenting on the ONS data on new construction orders, which saw new orders drop almost 9% in Q4 2008 compared with Q3 and 25% from the same period of 2007, RICS Chief economist Simon Rubinsohn says: "With new orders falling sharply, it is only a matter of time before this is reflected in a steep decline in the level of construction output and more job losses in the sector. This highlights the need for the government to ensure effective delivery of its enhanced capital spending programme."

He added: "Bringing forward capital funding for vital projects will have the advantage of delivering much needed housing and infrastructure but will also go someway to preventing an employment crisis in the industry. As the UK enters a recession it is essential that skills are not lost to the construction sector as people leave and retrain to take up other jobs."

Private and public housing

Private housing orders in the three months to December 2008 fell by 3 per cent compared with the previous three month period, and fell by 57 per cent compared with the same three month period a year earlier. Private housing orders in the year to December 2008 fell by 43 per cent compared with those in the previous 12 months.

Marine Predators İn Trouble: UBC Researchers

2011-12-06T06:40:00.002-08:00

Iconic marine predators such as sharks, tunas, swordfish, and marlins are becoming increasingly rare under current fishing trends, say University of British Columbia researchers. In half of the North Atlantic and North Pacific waters under national jurisdiction, fishing has led to a 90-per-cent decrease in top predators since the 1950s, and the impacts are now headed south of the Equator, according to a new study published online December 5 in the journal Marine Ecological progress Series.

Funded by the Pew Charitable Trusts, the Natural Sciences and Engineering Research Council of Canada (NSERC), and the French Consulate-General in Vancouver, researchers from UBC's Fisheries Centre modeled the impact of fishing around the world using global databases of fisheries catches from 1950 to 2006 and satellite images of phytoplankton, which are used to map where predators should be, based on food availability.

The scientists found that the exploitation of marine predators first occurred in coastal areas of northern countries, then expanded to the high seas and to the southern hemisphere. The decline of top-of-the-food-chain predators also means widespread and fundamental changes to both the structure and function of marine systems.

"Species such as tuna have been seriously exploited because of high market demand," says Laura Tremblay-Boyer, a PhD student at UBC Fisheries Centre and lead author of the study.

"A constant theme throughout our study of global marine ecosystems is that these top predators are today prey for human beings, assisted by some serious technology," says Tremblay-Boyer. "Top marine predators are more intrinsically vulnerable to the effects of fishing due to their life histories. Bluefin tuna, for instance, cannot reproduce until age nine."

Scientists Discover How Brain Corrects Bumps To Body

2011-12-06T06:40:00.001-08:00

Researchers have identified the area of the brain that controls our ability to correct our movement after we've been hit or bumped -- a finding that may have implications for understanding why subjects with stroke often have severe difficulties moving. The fact that humans rapidly correct for any disturbance in motion demonstrates the brain understands the physics of the limb -- scientists just didn't know what part of the brain supported this feedback response -- until now.

Several pathways and regions of the central nervous system could contribute to our response to external knocks to the body, but researchers only recently discovered that the pathway through the primary motor cortex provides this knowledge of the physics of the limb.

"To say this process is complex is an understatement," says Stephen Scott, a neuroscience professor and motor behavior specialist in the Department of Biomedical and Molecular Sciences. "Voluntary movement is really, really hard in terms of the math involved. When I walk around, the equations of my motion are like a small book. The best physicists can't solve these complicated equations, but your brain can do it incredibly quickly."

The corrective movement pathway works by limiting and correcting the domino effect of involuntary bodily movement caused by an external blow. For example, a blow to the shoulder that causes the whole arm to swing about may require the brain to quickly turn on muscles in the shoulder, bicep, forearm and hand in order to regain control of the limb. Likewise, a football player who collides with an opponent during a game has to respond quickly to correct the movement and remain upright.

Strokes that take place in the primary motor cortex may cause varying levels of damage to this corrective movement pathway. This varying damage may explain why some stroke patients are able to improve their movement skills in rehabilitation and why some patients remain uncoordinated and unsteady

Proton Beam Experiments Open New Areas Of Research

2011-12-06T06:38:00.000-08:00

By focusing proton beams using high-intensity lasers, a team of scientists have discovered a new way to heat material and create new states of matter in the laboratory. Researchers from Lawrence Livermore National Laboratory; Jacobs School of Engineering at the University of California, San Diego; Los Alamos National Laboratory; Hemoltz-Zentrum Dresden-Rossendorf of Germany; Technische Universitat Darmstadt of Germany, and General Atomics of San Diego unveiled new findings about how proton beams can be used in myriad applications.

Using the Trident sub-picosecond laser at Los Alamos, the team generated and focused a proton beam using a cone-shaped target. The protons were found to have unexpectedly curved trajectories due to the large electric fields in the beam. A sheath electric field also channeled the proton beam through the cone tip, substantially improving the beam focus.

"These results agree well with our particle simulations and provide the physics basis for many future applications," said Mark Foord, one of the LLNL scientists on the team.

Other Livermore researchers include lead author Teresa Bartal (also a UCSD Ph.D student and Lawrence scholar), Claudio Bellei, Michael Key, Pravesh Patel, Drew Higginson and Harry McLean. The research appears in the Dec. 4 issue of the journal Nature Physics.

Bartal said the experiments provide a new understanding of the physics involved in proton focusing, which affects how proton beams can be used in the future -- from heating material to creating new types of matter that couldn't be made by any other means, to medical applications and insights into planetary science.

Supertech Launches 'Supernova' at Sector 94, Noida

2011-12-06T06:37:00.001-08:00

After the successful launch of North India's tallest residential development, North Eye, Supertech Limited has announced the launch of yet another one of its kind, grandeur project, 'Supernova', which is North India's biggest mixed-use development spread across 5 million sq. ft. of area. The project has five towers amongst which 'Spira' - The Iconic Tower is India's tallest mixed-use development having 80 floors which stand at 300 meters.

Supernova being a mixed use development project has residences, service apartments, hotels, shopping malls, office spaces and recreational centers. The benefit of mixed use development redefines Supernova as an epicenter. The project unveils opulence, luxury and elegance, with the world class luxurious modern conveniences.

On the occasion of the launch of Supernova, Mr. RK Arora, Chairman & Managing Director of Supertech Limited said, "With the dream of providing a world class architectural masterpiece, we are launching this spectacular project, which has five state-of-the-art world class towers including the India's tallest mixed use development that has 80 floors, which stands 300 meters high".

"The international standard project is designed in such manner that I hope, it will give a larger than life experience to our valued customers", added Mr. RK Arora.

"After the successful launch of North Eye, we are very ecstatic to launch yet another landmark project, which will redefine the living, shopping and working lifestyles of people. To make this project a complete world class project, we have associated with the best brands and companies in the respective verticals" said Mr. Mohit Arora, Director of Supertech Limited.

Liverpool Waste Site Expands Fleet With Finlay Central

2011-12-06T06:36:00.000-08:00

North West based CCC Waste has taken delivery of two new Terex Finlay machines from Finlay Central – taking its fleet to 10 machines operating across the company’s four depots.

The introduction of the Terex Finlay J-1175+ Jaw Crusher and the Terex Finlay 694+ Supertrak from Finlay Central at CCC Waste’s Liverpool site – based in Kirkby – means the facility is now well-placed to deliver industry-leading recycling targets.

The company, which has four bases around Merseyside and the surrounding area, recycles 100 per cent of demolition materials and 99 per cent of skip hire materials.

At the Kirkby site, the J-1175+ is working in tandem with the 694+ screen, to crush waste material before it can be fed through the triple deck screen, with the 694+ producing clean material at minus 4,10mm and 20mm. This is then stockpiled and sold for pipe bedding.

The Terex Finlay J-1175+, incorporates a heavy duty crusher and undercarriage, with exceptional on site mobility. The machine also includes a new Tier 4 engine, which helps CCC Waste in its ongoing goal to reduce its carbon footprint.

Along with quick set up times and ease of transport, the crusher includes a
heavy duty vibrating grizzly feeder with automatic control to regulate the feed, plus a hydrostatic drive and reverse crushing action to assist in clearing blockages.

The machine’s automatic variable speed also ensures continuous choke feeding of the crushing chamber for optimal productivity.

Established in 1986 by Ian Munroe - who started out in business with one tipping truck – CCC Waste is now run by Ian’s son Sean.
It is one of the largest waste recycling centres in the UK, supplying 15,000 tonnes of recycled crushed brick, concrete, soil and sand a week to Blue Chip clients operating in the utilities sector.

Unusual Rigging Designs and Constructs Garsington Opera Pavilion

2011-12-04T23:01:00.000-08:00

Garsington Opera has moved to the estate of Wormsley in the Chiltern Hills, home of the Getty family, after 22 years at Garsington Manor. It is an established country estate with easy access from both Oxford and London. The surrounding landscaped park at Wormsley is both beautiful and peaceful, yet has extremely good access with ample parking facilities.

Unusual Rigging had completed the project management of a temporary 600 seat pavilion housing the month long run of performances by Garsington Opera. Garsington Opera instructed architect Robin Snell and, following a competitive tendering process, appointed Unusual Rigging, as main contractor, to manage this design and build project, including fabrication and construction of the pavilion. At the end of the opera season, the pavilion will be dismantled and loaded by crane onto some 40 trucks to be taken away for storage, ready for return next year.

Lifted above the ground to give an appearance of ‘floating’ over the landscape, Snell’s design takes its cue from a traditional Japanese pavilion in its use of sliding screens, extended platforms, verandas and bridges to link it to the landscape.

Project manager for Unusual Rigging, Mark Priestley, says: “We won the project in October, then had until April to coordinate the design and build and manage the logistics, including all ground preparation works. The pavilion sits on 100 permanent concrete foundation bases, each of which measures up to 3 sq m and has an adaptor plate to which the steelwork connects, ensuring an accurate and repeatable set-out each year. The pavilion has a modular steel frame and an overall expected 15 year life span; it will return to the same position each year, enabling the company to make this investment in demountability.

“Construction of the primary structure and fabric roof took a month, with a further month of electrical, timber and seating fit out. Up to 15 of our people were on site at any one time, working with a 65 ton crane. In addition to the supply of rigging, lighting trusses and chain hoists, which is our regular ‘bread and butter’, we supplied, cut and fitted all the timber – 3km of oak panelling and 13km of balau for the hardwood decking, held together with 70,000 screws.

TPS Delivers Civil and Structural Engineering Services To Bristol's Southmead Hospital

2011-12-04T23:00:00.000-08:00

Upon its completion in 2014, Southmead Hospital’s main building will have a wide range of specialist regional services, which include A&E, neurosciences, plastic surgery, orthopaedics, pathology, and renal services, to which they will receive referrals from all over the UK and overseas. Located approximately two kilometres north of Bristol city centre, the new hospital will provide world-class healthcare services to a local population of around half a million residents.

The new 800-bed state-of-the-art Acute Hospital, complete with an integrated community hospital, is to be situated on a 27 hectares brown-field site within the restricted limits of the existing Southmead Hospital.

TPS is helping to transform healthcare in and around Bristol, North Somerset and South Gloucestershire by delivering civil and structural engineering services to Bristol’s major Southmead Hospital redevelopment project.

As Structural and Civil Engineers for the project, TPS has provided engineering support services to Carillion, the main contractor, from the project’s conception in August 2007, as well as being the CDM Co-ordinator.

TPS worked with Carillion and the design in the early stages to phase the construction in order to allow the new hospital facilities to be occupied ahead of demolishing the remainder of the existing hospital. TPS’s Associate Director, Jack Mitchell explains:

“The local community’s huge dependence on the existing hospital facilities meant we were responsible for delivering a solution that met the needs of all the hospital’s stakeholders, not just the client’s requirements. We have subsequently taken great care in coordinating the structural design to enable the building to be extended at a later date whilst we organise the temporary works and construction logistics to suit the phase building.”

Devereux Architects Specify Pictura Fibre Cement Overclad Solution For Darlington Memorial Hospital

2011-12-04T22:59:00.000-08:00

County Durham and Darlington NHS Foundation Trust commissioned the refurbishment of the Darlington Memorial Hospital because it wanted to reduce maintenance requirements, improve thermal efficiency and enhance the aesthetic appearance of the dated building.

Marley Eternit's Pictura fibre cement overclad solution has helped boost thermal efficiency, improve aesthetics and reduce maintenance requirements for Darlington Memorial Hospital. Pictura in Grey was specified to replace the existing opaque glass panels, which required regular cleaning and maintenance.

The hospital’s thermal performance was improved by fitting composite insulated panels onto the wall-mounted vertical aluminium frame system between floor levels and then overcladding it with Pictura to create a rainscreen cladding insulation solution.

Pictura was specified by Devereux Architects, who had investigated alternative materials for the infill panels, including PVC-U, timber, GRP and glass. Each of these was rejected because of its appearance, cost, durability or maintenance requirements.

Peter Churchill of Devereux Architects explains: “We had no hesitation in specifying fibre cement Pictura as an overclad solution because it overcame all the issues presented by the other materials. We then talked to Marley Eternit’s technical advisory team about the various fixing systems available and eventually decided on stainless steel screws."

Pictura offers a hard, smooth, silky matt surface that is smooth and easy to clean. Its UV cured top layer also provides protection against graffiti by aerosol and other paints, which can be eliminated with common graffiti removers. Pictura is also available in a range of colours, has an installed life expectancy of at least 50 years and has excellent weather resistance as well as being resistant to insects, mould growth and fungi.

New Business Centre At Harton Staithes Nearing Completion

2011-12-04T22:56:00.000-08:00

Tom de le Motte, Managing Director, Miller Construction, has invited The Rt Hon Eric Pickles, MP, Secretary of State for Communities and Local Government; Martin Swales Chief Executive of South Tyneside Council, and Neil Rogers, President of Government and Health, BT Global Services, to join him in creating a ceremonial brick, to mark the construction of the new business centre in South Shields.

The new £10.5 million business centre at Harton Staithes, being built by Miller Construction on behalf of South Tyneside Council, has taken a further step closer to completion, following a ceremony, to celebrate the progress being made. The new 43,000 sq ft building will house BT operations from many lines of business, providing workspace for up to 500 staff.

The progress celebration was commemorated by an ancient Persian ritual, believed to be 500 years old, in which symbolic elements are added to a concrete pour to ensure the prosperity and success of the development. The Persian ritual consists of a number of different elements being added to the ceremonial brick. Wine – to bring fertility and wisdom; oil – to preserve liberty; corn – for the property to ripen in abundance; salt – added as a sign of purity and hospitality and the final ingredient, a Yew branch, is added to ward off evil spirits.

Mr Eric Pickles was invited to begin proceedings by adding wine, followed by Martin Swales who added the oil, symbolising the regeneration of the riverside at South Shields. The corn was added by Neil Rogers of BT, representing the continued success of BT and its staff as they move into their new building in the North East. Tom de la Motte added salt, illustrating Miller Construction’s hospitality and the purity of their partnership with South Tyneside Council. Garry Hope, Operations Director, North, Miller Construction, added the Yew branch to complete the ceremony.

Desso AirMaster Helps İmprove İnterior Air Quality At Kıa Speed Skating Academy

2011-12-04T22:54:00.002-08:00

The KIA Speed Skating Academy in Inzell has space for 35 athletes housed in a converted hospital, and has incorporated Desso AirMaster® in corridors and bedrooms to provide the best-possible interior air quality.

The world-class training facility for elite athletes from around the world has opened in Germany, with carpeting specifically designed to clean indoor air, named by the World Health Organisation as one of the major hazards of the modern world.

The World Health Organisation has warned that it can be particularly hazardous to inhale particulate matter. Miniscule dust particles settle in the lungs, and the smallest particles can end up in the bloodstream – with potentially serious consequences.

The newly-opened facility, which is expected to become an international focus for the sport, will take in speed skaters from around the world and offer them the best-possible training and residential facilities, with everything designed to develop their full potential as athletes.

AirMaster® was launched last year and is already finding applications across multiple markets in, for example, hospitals, schools and offices. This is the first occasion it has been specified in an elite sports environment – and underlines how the issue of indoor air quality affects us all.

According to The United Nations Environment Programme: “The state of the environment can have significant impacts on sport. Sportsmen and women can be affected by environmental conditions such as air and water quality and exposure to harmful substances.”

Kier Southern Renovates Historic Secret Wartime Tunnels Beneath Dover Castle

2011-12-04T22:54:00.001-08:00

The ‘Operation Dynamo: Rescue from Dunkirk’ visitor experience at Dover Castle will reconstruct the drama of the Dunkirk evacuation in the same historic tunnels in which the desperate rescue operation – codenamed Operation Dynamo – was masterminded. The important army operations rooms have been recreated to look as they appeared during WWII and include the plotting tables for enemy movements and telephone exchanges.

Kier Southern recently completed the refurbishment and renovation of the historic secret wartime tunnels beneath Dover Castle to help create a major new visitor attraction for client English Heritage. The works carried out by Kier Southern included the reconfiguration of the existing entrance and exit to provide a new visitor holding area and refurbishment works to create a new visitor exhibition experience with interactive displays. In addition, the existing shop, café and toilet facilities were upgraded to make for a full and pleasant visitor experience.

Within the tunnels, a new ventilation system, designed to horseshoe around the existing wartime system, along with new electrical systems and the installation of a new mobility lift between the ground and mezzanine levels, were all part of Kier Southern’s renovation works. Redecoration and alterations were also carried out, including new floor finishes, and an existing spiral staircase was repaired and redecorated with the provision of a number of newly handcrafted stone steps.

BioWayste Reactors Are Generating Biogas At The Bruichladdich Distillery

2011-12-04T22:53:00.001-08:00

Two high-rate 60m3 BioWayste reactors are generating biogas and achieving over 95% COD removal at the Bruichladdich distillery on the Hebredian island of Islay.

In a first for the whisky industry, the biogas and treated wastewater sets the distillery apart from other whisky producers in an industry that has long been one of the highest energy users and biggest waste producers.

“In just a few weeks”, said Bruichladdich’s Managing Director Mark Reynier, “the BioWayste process has proved that it is absolutely ideal for pot ale and spent lees – almost completely destroying the COD – as well as achieving over 90% copper removal”.

He added: “BioWayste have provided us with a beautifully simple yet highly effective and environmentally sound solution. The reactors are also extremely resilient to the stop-start nature of our process. When the feed comes back on after a break, gas levels are recovered very quickly indeed”.

Unlike today’s typical industrial-scale anaerobic digestion (AD) plants, which take around 30 days to break down a single tanker of waste, the modular, small footprint BioWayste process takes just 12-24 hours.

Webinar Explains The Key steps To A Successful Green Building Project

2011-12-04T22:49:00.000-08:00

An upcoming webinar will urge attendees to ensure that their next projects consider green building strategies and responsibilities at key stages, leaving no opportunity for cost-savings or innovation behind, while keeping building owners on board the entire time.

WPL Publishing will hold the 90-minute webinar that is designed to help various professionals in the construction community understand the key steps to a successful green building project, including Leadership in Energy and Environmental Design (LEED)-registered projects. The event is scheduled for Thursday, May 19, 2011 at 1:00 p.m. (EDT).

Attendees are expected to leave the webinar with a much better understanding of how to best manage a successful design process while incorporating cost-acceptable green strategies along the way.

The webinar, entitled “The Successful LEED/Green Design Process,” will help attendees do the following:
Prepare a successful green building project plan.
Identify key places in the plan to measure green building benchmarks of the project throughout the building process.
Analyze design goals, construction challenges, and green process obstacles.
Prepare a building owner for the green building process and keep that owner informed.

Addressing attendees will be Bill Bobenhausen, president of Sustainable Design Collaborative Llc. He has served as an environmental architect/author/educator for more than 30 years and has consulted on more than 400 high-performance-building projects.

Carillion Scale Up The MSite Solution On The Whitechapel Project For Crossrail

2011-12-04T22:48:00.000-08:00

The enabling works are well under way at the Carillion Whitechapel site, which will facilitate the new Whitechapel station to be built as part of the crossrail project. The project started in January 2011 with work being carried out a 3 locations, the management of the employees on such a high profile project has been made possible with the installation of Human Recognition Systems MSite workforce management solution.

With the project having such tight deadlines and budgets, Carillion chose MSite to ensure that site access and attendance and incidents were reported against and subsequently managed effectively and efficiently. The initial requirement of the project team and therefore the installation of the MSite solution was double turnstile system aimed at managing up to 400 employees, this was deployed in a 24ft x 10ft security cabin. Carillion where guaranteed that all access and attendance, health and safety and workforce management information was correct and that all employees on site had the correct credentials and accreditation to be on site.

The first installation at the site compound was such a success that Carillion approached the HRS team in March and requested an additional access control point to be added to the existing system. The aim of the additional system was to control access and egress to the build part of the project and ensure that only employees with the correct credentials were allowed to leave the compound to work on the project. HRS also added an extra layer of identification with the installation of a photo id card printing application for all site employees, giving Carillion an extra level of security for all project staff.

“The Whitechapel project is an indication of MSite’s ability to scale even mid project. This was also the first opportunity for HRS to work with Carillion Infrastructure team and highlight the benefits of deploying a solution such as MSite on large high value infrastructure projects” commented Rob Cummerson, Carillion Account Manager

Block Of Bedsits İn County Durham Transformed With Marley Eternit's Pictura Fibre Cement Rainscreen Cladding

2011-12-04T22:37:00.000-08:00

Marley Eternit's Pictura - in three shades of grey - has been specified by architects Blake Hopkinson as part of an environmentally sustainable modern redesign for Haven House. The dated 1960s block of bedsits in Consett, County Durham, has been transformed into a Constructing Excellence award winner with help from Marley Eternit’s Pictura fibre cement rainscreen cladding.

Haven House was awarded the Constructing Excellence North East 2010 award for innovation, which recognised both the design and Blake Hopkinson’s collaborative approach to procurement which ensured that maximum value was achieved within the project’s fixed £1.2m budget.

Pictura has a hard, smooth, silky matt surface with a UV cured top layer that offers good protection against many types of staining including graffiti produced by common aerosol and mechanical damage during construction.

Pictura in Grey was used to replace existing UPVC cladding around windows at ground level to add interest to feature walls. This helped to break up the uniformity of the original brickwork facade, which the residents had raised as an issue with the existing building.

Varying widths of 800mm high Pictura panels in the three shades of grey were then fixed as a ribbon overclad system around roof eaves to add visual interest and counteract the building’s lack of height by drawing the eye upwards.

Marley Eternit fibre cement cladding panels can achieve an A+ rating as defined in the BRE Green Guide to Specification based on generic rating for autoclaved fibre cement single sheet - (Element Ref: 80623042, 806230422, 806230447, 806230450).

Pictura is available in a range of colours and has an installed life expectancy of at least 50 years. It has excellent weather resistance as well as being resistant to insects, mould growth and fungi.

Masternaut Prevents Theft Of Local Authorities' Expensive Construction Equipment and Vehicles

2011-12-03T07:17:00.000-08:00

Using Masternaut’s web-based real-time technology Councils are saving money on vehicle purchase and leasing as well as running costs and administration, while making better use of existing fleet and human resources and delivering higher levels of service.

Vehicle tracking and mobile resource management solutions from Masternaut are helping Local Authorities reduce costs to meet the government’s 25 per cent budget cuts. Masternaut is also helping to reduce the cost of third party claims against Councils and improve the safety and security of lone workers. The system has Thatcham Category 5 approval and actively prevents theft of expensive equipment and vehicles and makes recovery easy.

"We are very pleased with the results we are getting from the Masternaut system. It has given us visibility of our fleets across the two districts [Hambleton and Richmondshire]. We know precisely where our vehicles are at any time and where they have been thanks to its automatic reporting features. We have full information on driving behaviour such as speed and idling reports so that we can monitor vehicle use and fuel usage," said John Proud, Street Scene Manager, Hambleton & Richmondshire District Councils.

Mark Hurst, Streetscene Officer, Crawley Borough Council, said: "The Masternaut system gives us a live view of our fleet activities. It has improved our productivity through better use of our resources and this has saved money on fuel usage - our annual mileage per vehicle has dropped to an average of 5200 miles from about 6000 miles, consequently this saves the Council around 11 per cent per vehicle."

Number Of Planning Applications On The İncrease

2011-12-03T07:16:00.001-08:00

Barbour ABI reports on 100% of planning applications. Their core business is supplying construction industry professionals with analysis, trends and construction leads.

Barbour ABI data has revealed that the number of plan applications being submitted to Local Authorities in England, Scotland and Wales continues to recover and is likely to exceed 600k in 2011. However most of this recovery is driven by homeowner and other small applications.

Adam Valentine, Content Director, says: “The recovery seen in planning application volumes in 2010 has continued into 2011, largely driven by homeowners choosing to stay put and develop their own homes rather than move. The effects of this increase in plan application volumes are even greater when you consider that the changes to permitted development in 2008 effectively removed some home developments from the planning system. Allowing for this adjustment to the figures we’re seeing pre-recession levels of plans being submitted, which is obviously great news for the industry.”

New Affordable Housing Development Benefits From Marley Eternit's Natura Fibre Cement Rainscreen Cladding

2011-12-03T07:15:00.001-08:00

Marley Eternit's Natura fibre cement rainscreen cladding offers a sustainable and low maintenance façade that combines excellent aesthetics with durability and impact resistance.

A mixed tenure housing project close to London's Canary Wharf has been given an award-winning visual identity thanks in part to Natura. Natura was installed by MPG Facades as part of a rainscreen cladding insulation solution, with the walls achieving a U-value of 0.25 W/m2K. The development achieves an Eco Homes Very Good rating and secured The London Evening Standard’s award for The Best New Affordable Housing Development.

Topaz, Coral and Ivory coloured Natura was specified by the architects for Phoenix Heights at Mastmaker Road in East London as part of an ‘appealing, human scaled aesthetic’. The challenge this posed for the architects was how to bridge the shift in scale between the low rise buildings in the west and the high rise glass fronted Millennium Quarter to the east.

The issue was addressed both by graduating the height of the 199 homes over three to seven storeys, and by the use of the Natura in three colours to visually reduce the scale of the building and make it appear less imposing.

Topaz coloured Natura was used for the high level sunshade canopies, whilst Coral was specified as infill panels and privacy screens on the roof terraces. Insulated render to the main body of the building was then matched with Ivory coloured Natura on the large high level balconies, which proved to be much lighter and easier to apply than render.

Project Architect for the development Andrew Carr said: “We specified Natura in collaboration with Ballymore, the developer, from a range of alternatives which fitted within their budget. Whilst meeting the necessary technical requirements Natura was primarily chosen on appearance and colour. We did consider some alternative cladding materials which did not have the appearance we were looking for or could not provide certification to satisfy UK building control.”