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Nanotechnology To Improve Solar Cells
Researchers at the NanoPower Research Labs at Rochester Institute of Technology, led by director Ryne Raffaelle, are using nanotechnology to explore this possibility through a project funded by an $847,109 grant from the U.S. Department of Defense. The project aims to take current state-of-the-art solar cells used for space power to the next level by developing nanostructured materials and, ultimately, by producing nanostructured cells. The program may extend to three and half years, with total funding reaching $3 million. "If successful, the results of this program will improve current solar array and satellite technology, and lay the foundation for long-term improvement in our ability to use solar energy," Raffaelle says. Unique to this project is the ability to exploit the fundamental behavior of nanoscale crystals, also known as quantum dots, which alter the way a solar cell absorbs light and converts it into electricity. As per Raffaelle, the electrical, optical, mechanical and even thermal properties of nanomaterials can be controlled by changing the particle size, making them highly useful in semiconductor device development. Today's current solar-cell technology used for space power relies upon three individual photovoltaic junctions used in a series. These so-called triple-junction solar cells-consisting of the chemical compounds, germanium, gallium arsenide and indium gallium phosphide-are grown latticed-matched on top of one another. Raffaelle's team will augment the middle cell in the three-layered sandwich with a quantum dot array to enhance its short-circuit current and improve the overall efficiency of the triple junction cell......... Posted by: Kevin Permalink Source Making Cleaner Gasoline
The Delft-based PhD student Xander Dupain has investigated a method which produces cleaner petrol using the method of 'catalytic cracking'. Catalytic cracking, with a worldwide processing capacity of over 500 million tonnes of oil per year, is one of the most important processes applied in modern oil refineries and the prime method for making petrol from oil. In addition it is an important way of producing diesel blends and valuable products such as propene and butene. The disadvantage of catalytic cracking is that a further expensive process (hydrotreatment) is often mandatory to render the petrol and diesel sufficiently clean and bring it into line with the necessary specifications. The core of Dupain's method is a combination of catalytic cracking with the Fischer-Tropsch Synthesis process. This chemical process was invented in the 1920s by the German scientists Franz Fischer and Hans Tropsch and further developed in Gera number of during the Second World War for the production of synthetic fuels from coal. Due to the relatively low oil prices in the period following the Second World War this method then mostly went out of fashion, with the exception of South Africa where - prompted by the international oil embargo - it was applied by the Sasol company to meet fuel demands. In recent years, as oil prices rise, the process has been experiencing a revival: with the activities of Shell in Malaysia and Qatar, for instance. It is now primarily being applied to obtain relatively clean synthetic diesel from natural gas and to make a series of other products which contain extremely low concentrations of sulphur, nitrogen and aromatics. Dupain believes it can be economically and environmentally interesting to catalytically crack the fairly 'heavy' faction (waxes) which is created by the Fischer-Tropsch Synthesis process. At the moment this cracking is still done using expensive hydrocracking that focuses mainly on the production of diesel and that also involves high consumption of hydrogen......... Posted by: Kevin Permalink Source March 8, 2006, 11:42 PM CT Selective Laser Melting : 3D Printing in MetalMCP Group’s MCP Realizer takes 3D printing / rapid prototyping into the world of metals. MCP uses a technique called SLM (Selective Laser Melting) which uses ordinary metal powders (bronze, zinc, stainless steel, tool steel, titanium, cobalt-chrome alloys) and a laser to melt thin layers of geometry repeatedly to produce finished parts. more> Treehugger
MCP Group’s MCP Realizer takes 3D printing / rapid prototyping into the world of metals. MCP uses a technique called SLM (Selective Laser Melting) which uses ordinary metal powders (bronze, zinc, stainless steel, tool steel, titanium, cobalt-chrome alloys) and a laser to melt thin layers of geometry repeatedly to produce finished parts. more> Treehugger Source low-density, environmentally friendly foam
Sandia is a National Nuclear Security Administration (NNSA) laboratory. TufFoam- was originally conceived by Sandia materials researchers for NNSA as an encapsulant material to protect sensitive electronic and mechanical structures from harsh weapons environments. It is a water-blown, closed-cell, rigid polyurethane foam that features formulations as low as 2 lbs.-per-cubic foot density. But beyond its use as a structural material, the foam likely has other applications. "It can be used for thermal and electrical insulation, and as a core material for the automobile and aerospace industries," said Scott Vaupen, a business associate at Sandia, which is actively pursuing licensing and commercialization partners. "TufFoam- might not only be ideal for surfboards, but also for car bumpers and airplane wings. The potential market could be staggering." manufacturer of foam for surfboard construction, unexpectedly closed its doors late last year because of the impact of ever-tightening environmental regulations on the manufacturing of their polyurethane surfboard blanks. The move has led to near-panic, especially in California, by manufacturers and sellers of surfboards who fear they will not be able to find the high strength-to-weight ratio surfboard blanks necessary to make the boards. Surf historian Matt Warshaw, in an article in the Santa Barbara NewsPress, said "it's the equivalent of removing lumber from the housing industry"......... Posted by: Kevin Permalink Source Z Machine Produces Ultra High Temperature
The unexpectedly hot output, if its cause were understood and harnessed, could eventually mean that smaller, less costly nuclear fusion plants would produce the same amount of energy as larger plants. The phenomena also may explain how astrophysical entities like solar flares maintain their extreme temperatures. The very high radiation output also creates new experimental environments to help validate computer codes responsible for maintaining a reliable nuclear weapons stockpile safely and securely - the principal mission of the Z facility. "At first, we were disbelieving," says Sandia project lead Chris Deeney. "We repeated the experiment a number of times to make sure we had a true result and not an 'Ooops'!". The results, recorded by spectrometers and confirmed by computer models created by John Apruzese and his colleagues at Naval Research Laboratory, have held up over 14 months of additional tests. A description of the achievement, as well as a possible explanation by Sandia consultant Malcolm Haines, well-known for his work in Z pinches at the Imperial College in London, appeared in the Feb. 24 Physical Review Letters......... Posted by: Kevin Permalink Source Tougher Electronic Components
Alexander Goncharov of the Carnegie Institution's Geophysical Laboratory and his colleagues* have used extreme temperatures and pressures to make two durable compounds called noble metal nitrides; they are the first to succeed in making one of them, and the first to accurately determine the chemical formula of the other. Both nitrides possess a diamond-like hardness, and some compositions might have very low, nearly superconductive electrical resistance-a blend that could prove quite valuable to industry. The two nitrides-one containing iridium and another containing platinum-could eventually replace the titanium nitrides currently valued by the semiconductor industry as surface coatings because of their strength and durability. The scientists believe iridium and platinum nitrides might be even more durable. The group's work is presented in the March 3, 2006, issue of the journal Science. Like several other metals such as gold, silver, and palladium, platinum and iridium are noble metals. Such metals are resistant to corrosion and oxidation, and do not easily form compounds with other elements unless coaxed to do so under very high temperatures and pressures. Goncharov and colleagues used a special tool called a diamond anvil cell to compress the samples to nearly half a million times the atmospheric pressure at sea level. Then they used a focused laser to heat the samples to over 3000 degrees Fahrenheit, or roughly the temperature of a steel mill blast furnace. Under such extreme pressure and temperature the rules of chemistry begin to change, and noble metals can be made to form compounds with other elements such as nitrogen, as in the case of iridium and platinum nitrides......... Posted by: Kevin Permalink Source Robots Would Slash Farm Labour Costs
Mushroom picking robot
The scientists from the University of Warwick's horticultural arm, Warwick HRI, and its manufacturing engineering section, Warwick Manufacturing Group, are working on many robotics and automation products that will vastly reduce the labour costs of farmers and growers. Those projects include: A robotic mushroom picker: the robot uses a charged coupled camera to spot and select only mushrooms of the exact size mandatory for picking achieving levels of accuracy far in excess of human labour. The mushroom(s) are then picked by a suction cup on the end of a robotic arm. Whilst the speed of picking is currently just over half that of a human - the mushrooms and the robot can be set to pick 24 hours a day right through the night without the need for any sort of break. The scientists also hope to increase the speed of picking to much closer to that of a human worker. Inflatable Conveyor Belt: The Warwick Manufacturing Group and Warwick HRI scientists have helped an agricultural machinery company "Aeropick" to develop a revolutionary group of inflatable aids to harvesting which provide huge savings on labour costs. The inflatable conveyor system can be driven into an open field or covered growing area. Within minutes up to 100 metres of powered conveyor belt can be deployed allowing crops to be processed at high speed straight to cool storage, or washing, or simply sorted and graded while still in the field......... Posted by: Kevin Permalink Source Liquid crystals and embryonic stem cells
Differentiation is the process by which embryonic stem cells gradually turn into function-specific types of adult cells or so-called "cell lineages," including skin, heart or brain cells. The main challenge facing stem cell research is that of guiding differentiation along these well-defined, controlled lineages. Stem cells grown in the laboratory tend to differentiate in an uncontrolled manner, resulting in a mixture of cells of little medical use. Now, UW-Madison researchers at the NSF-funded Materials Research Science and Engineering Center (MRSEC) have shown that by straining mechanically the cells as they grow, it is possible to reduce significantly and almost eliminate the uncontrolled differentiation of stem cells. In an article in the recent issue of Advanced Functional Materials, the team reports on a liquid crystal-based cell culture system that promises new ways of achieving real-time control over interactions between synthetic materials and human embryonic stem cells, including the possibility of straining embryonic stem cells as they grow......... Posted by: Kevin Permalink Source Carbon Fiber Cars To Efficiency
First, however, scientists at the Department of Energy's Oak Ridge National Laboratory, working as part of a consortium with Ford, General Motors and DaimlerChrysler, must figure out how to lower the cost of carbon fiber composites. If they are successful in developing high-volume renewable sources of carbon fiber feedstocks, ORNL's Bob Norris believes they will be on the road to success. "Whereas today the cost to purchase commercial-grade carbon fiber is between $8 and $10 per pound, the goal is to reduce that figure to between $3 and $5 per pound," said Norris, leader of ORNL's Polymer Matrix Composites Group. At that price, it would become feasible for automakers to use more than a million tons of composites - approximately 300 pounds of composites per vehicle - annually in the manufacturing of cars. The big advantage of carbon fiber is that it is one-fifth the weight of steel yet just as strong and stiff, which makes it ideal for structural or semi-structural components in automobiles. Replacing half the ferrous metals in current automobiles could reduce a vehicle's weight by 60 percent and fuel consumption by 30 percent, as per some studies. The resulting gains in fuel efficiency, made in part because smaller engines could be used with lighter vehicles, would also reduce greenhouse gas and other emissions by 10 percent to 20 percent......... Posted by: Kevin Permalink More Practicality Of Superconductivity
Schilling, a professor of physics in Arts and Sciences at Washington University in St. Louis, collaborated with recent doctoral graduate Takahiro Tomita and scientists at Argonne (Ill.) National Laboratory to determine whether one region in superconductors, called grain boundaries (GB), are oxygen deficient. Such oxygen deficiency impairs superconductor performance. Their paper, titled "Enhancement of the Critical Current Density of YBa2Cu3Ox Superconductors under Hydrostatic Pressure," is published in the Feb. 24 issue of the highly regarded journal Physical Review Letters. A superconductor is a solid material that conducts electricity without resistance when it is cooled to certain subzero temperatures. Because there is no resistance, current uniquely travels through superconductors without losing energy. Their study involves the newer, so-called "high-temperature" ceramic superconductors. They superconduct at less frigid temperatures than other superconductors, although still in the subzero realm. The superconducting material used in this study was a ceramic compound consisting of millions of microscopic crystals (grains). The WUSTL/Argonne team specifically developed a technique to determine whether a desired maximum number of possible sites are filled with oxygen in the GB, which surrounds every crystalline grain. The GB is a region of misfit between the grains and usually is only a few atoms wide......... Posted by: Kevin Permalink Source |
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