September 29, 2008, 10:15 PM CT

Sounds travel farther underwater

It is common knowledge that the world's oceans and atmosphere are warming as humans release more and more carbon dioxide into the Earth's atmosphere. However, fewer people realize that the chemistry of the oceans is also changing-seawater is becoming more acidic as carbon dioxide from the atmosphere dissolves in the oceans. As per a paper would be published this week by marine chemists at the Monterey Bay Aquarium Research Institute, these changes in ocean temperature and chemistry will have an unexpected side effect-sounds will travel farther underwater.

Conservative projections by the Intergovernmental Panel on Climate Change (IPCC) suggest that the chemistry of seawater could change by 0.3 pH units by 2050 (see below for background information on pH and ocean acidification). In the October 1, 2008 issue of Geophysical Research Letters, Keith Hester and his coauthors calculate that this change in ocean acidity would allow sounds to travel up to 70 percent farther underwater. This will increase the amount of background noise in the oceans and could affect the behavior of marine mammals.

Ocean chemists have known for decades that the absorption of sound in seawater changes with the chemistry of the water itself. As sound moves through seawater, it causes groups of atoms to vibrate, absorbing sounds at specific frequencies. This involves a variety of chemical interactions that are not completely understood. However the overall effect is strongly controlled by the acidity of the seawater. The bottom line is the more acidic the seawater, the less low- and mid-frequency sound it absorbs......... Posted by: Kevin      Read more         Source

September 25, 2008, 10:16 PM CT

MIT solves 100-year-old engineering problem

As a car accelerates up and down a hill then slows to follow a hairpin turn, the airflow around it cannot keep up and detaches from the vehicle. This aerodynamic separation creates additional drag that slows the car and forces the engine to work harder. The same phenomenon affects airplanes, boats, submarines, and even your golf ball.

Now, in work that could lead to ways of controlling the effect with potential impacts on fuel efficiency and more, MIT researchers and his colleagues have reported new mathematical and experimental work for predicting where that aerodynamic separation will occur.

The research solves "a century-old problem in the field of fluid mechanics," or the study of how fluids -- which for researchers include gases and liquids -- move, said George Haller, a visiting professor in the Department of Mechanical Engineering. Haller's group developed the new theory, while Thomas Peacock, the Atlantic Richfield Career Development Associate Professor in the same department, led the experimental effort.

Papers on the experiments and theory are being reported in the Sept. 25 issue of the Journal of Fluid Mechanics and in the recent issue of Physics of Fluids, respectively.

Fluid flows affect everything in our world, from blood flow to geophysical convection. As a result, engineers constantly seek ways of controlling separation in those flows to reduce losses and increase efficiency. One recent accomplishment: the sleek, full-body swimsuits used at the Beijing Olympics......... Posted by: Kevin      Read more         Source

September 18, 2008, 9:14 PM CT

From Sugar to Gasoline

Following independent paths of investigation, two research teams are announcing this month that they have successfully converted sugar-potentially derived from agricultural waste and non-food plants-into gasoline, diesel, jet fuel and a range of other valuable chemicals.

Chemical engineer Randy Cortright and colleagues at Virent Energy Systems of Madison, Wisc., a National Science Foundation (NSF) Small Business Innovation Research awardee, and scientists led by NSF-supported chemical engineer James Dumesic of the University of Wisconsin at Madison are now announcing that sugars and carbohydrates can be processed like petroleum into the full suite of products that drive the fuel, pharmaceutical and chemical industries.

"NSF and other federal funding agencies are advocating the new paradigm of next generation hydrocarbon biofuels," said John Regalbuto, director of the Catalysis and Biocatalysis Program at NSF and chair of an interagency working group on biomass conversion. "Even when solar and wind, in addition to clean coal and nuclear, become highly developed, and cars become electric or plug-in hybrid, we will still need high energy-density gasoline, diesel and jet fuel for planes, trains, trucks, and boats. The processes that these teams developed are superb examples of pathways that will enable the sustainable production of these fuels"......... Posted by: Kevin      Read more         Source

September 14, 2008, 10:06 PM CT

Slicing solar power costs

University of Utah engineers devised a new way to slice thin wafers of the chemical element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by reducing the waste and breakage of the brittle semiconductor.

The expensive solar cells now are used mainly on spacecraft, but with the improved wafer-slicing method, "the idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor," especially for solar power on Earth, says Eberhard "Ebbe" Bamberg, an assistant professor of mechanical engineering. "You want to do it on your roof".

Dinesh Rakwal, a doctoral student in mechanical engineering, adds: "We're coming up with a more efficient way of making germanium wafers for solar cells to reduce the cost and weight of these solar cells and make them defect-free".

Bamberg and Rakwal are publishing their findings in the Journal of Materials Processing Technology Their study has been accepted, and a final version will be published online late this month or in early October, and in print in 2009.

Brass-coated, steel-wire saws now are used to slice round wafers of germanium from cylindrical single-crystal ingots. But the brittle chemical element cracks easily, requiring broken pieces to be recycled, and the width of the saws means a significant amount of germanium is lost during the cutting process. The sawing method was developed for silicon wafers, which are roughly 100 times stronger......... Posted by: Kevin      Read more         Source

September 10, 2008, 6:48 PM CT

First beam for Large Hadron Collider

An international collaboration of researchers today sent the first beam of protons zooming at nearly the speed of light around the 17-mile-long underground circular path of the Large Hadron Collider (LHC), the world's most powerful particle accelerator, located at the CERN laboratory near Geneva, Switzerland.

The researchers also accelerated a second beam of protons through the path in the opposite direction, the goal being head-on collisions of protons that can offer clues to the origin of mass and new forces and particles in the universe. The second beam made one turn around the LHC.

Celebrations across the United States and around the world mark the LHC's first circulating beams, an occasion more than 15 years in the making. An estimated 10,000 people from 60 countries have helped design and build the accelerator and its massive particle detectors, including more than 1,700 scientists, engineers, students and technicians from 94 U.S. universities and laboratories supported by the U.S. Department of Energy Office of Science and the National Science Foundation.

UCR faculty Robert Clare, John Ellison, J. William Gary, Gail Hanson and Stephen Wimpenny, along with postdoctoral researchers and graduate students are involved in the LHC's Compact Muon Solenoid (CMS) experiment, a large particle-capturing detector whose discoveries are expected to help answer questions such as: Are there undiscovered principles of nature? What is the origin of mass? Do extra dimensions exist? What is dark matter? How can we solve the mystery of dark energy? And how did the universe come to be?........ Posted by: Kevin      Read more         Source

September 2, 2008, 7:28 PM CT

Scientists grow 'nanonets' able to snare added energy transfer

Using two abundant and relatively inexpensive elements, Boston College chemists have produced nanonets, a flexible webbing of nano-scale wires that multiplies surface area critical to improving the performance of the wires in electronics and energy applications.

Scientists grew wires from titanium and silicon into a two-dimensional network of branches that resemble flat, rectangular netting, Assistant Professor of Chemistry Professor Dunwei Wang and his team report in the international edition of the German Chemical Society journal Angewandte Chemie

By creating nanonets, the team conquered a longstanding engineering challenge in nanotechnology: creating a material that is extremely thin yet maintains its complexity, a structural design large or long enough to efficiently transfer an electrical charge.

"We wanted to create a nano structure unlike any other with a relatively large surface area," said Wang. "The goal was to increase surface area and maintain the structural integrity of the material without sacrificing surface area and thereby improving performance".

Tests showed an improved performance in the material's ability to conduct electricity through high quality connections of the nanonet, which suggest the material could lend itself to applications from electronics to energy-harvesting, Wang said. Titanium disilicide (TiSi2) has been proven to absorb light across a wide range of the solar spectrum, is easily obtained, and is inexpensive. Metal silicides are also found in microelectronics devices......... Posted by: Kevin      Read more         Source

Sat, 30 Aug 2008 15:23:28 GMT

Samsung Messager for Texting Freaks

The Samsung Messager is a perfect messaging device for all the testing freaks out there. It comes with a full QWERTY Keyboard, 2.1 inch display (176 x 220 pixels), 1.3 megapixel camera, Bluetooth, Advanced Voice Recognition, Speakerphone, microSD memory slot, MP3 player, IM and Email. It also comes with some Pre Installed Applications/Games including Rabble Social Networking, Are You Smarter Than a 5th Grader and Street Fighter II Champion Edition.

It is available in Navy blue and Green colors in Cricket's retail stores for $199.99. It is also available online on MetroPCS website.

Source: Into Mobile Posted by: Umair Khalid      Read more     Source

August 20, 2008, 6:32 PM CT

Creating unconventional metals

The semiconductor silicon and the ferromagnet iron are the basis for much of mankind's technology, used in everything from computers to electric motors. In this week's issue of the journal Nature (August 21st) an international group of scientists, including academic and industrial scientists from the UK, USA and Lesotho, report that they have combined these elements with a small amount of another common metal, manganese, to create a new material which is neither a magnet nor an ordinary semiconductor. The paper goes on to show how a small magnetic field can be used to switch ordinary semiconducting behaviour (such as that seen in the electronic-grade silicon which is used to make transistors) back on.

The new material exists in a quantum halfway house between magnet and semiconductor - in the same way that much more complex materials such as ceramics which exhibit high temperature superconductivity exist in quantum halfway houses between metals and magnetic insulators. The research is of fundamental importance because it demonstrates, for the first time, a simple recipe for reaching this halfway house, whilst also suggesting new mechanisms for controlling electrical currents and magnetism in semiconductor devices.

Professor J.F. DiTusa of Louisiana State University and a co-author of the paper said: "It's amazing that something which was thought to exist theoretically in mathematical physics could actually be found in an alloy which was simply formed by melting together a few common elements"......... Posted by: Sarah      Read more         Source

August 20, 2008, 1:34 AM CT

Controlling the behavior of quantum dots

Scientists from the National Institute of Standards and Technology (NIST) and the Joint Quantum Institute (JQI), a collaborative center of the University of Maryland and NIST, have reported a new way to fine-tune the light coming from quantum dots by manipulating them with pairs of lasers. Their technique, published in Physical Review Letters,* could significantly improve quantum dots as a source of pairs of entangled photons, a property with important applications in quantum information technologies. The accomplishment could accelerate development of powerful advanced cryptography applications, projected to be a key 21st-century technology.

Entangled photons are a peculiar consequence of quantum mechanics. Tricky to generate, they remain interconnected even when separated by large distances. Merely observing one instantaneously affects the properties of the other. The entanglement can be used in quantum communication to pass an encryption key that is by its nature completely secure, as any attempt to eavesdrop or intercept the key would be instantly detected. One goal of the NIST-JQI team is to develop quantum dots as a convenient source of entangled photons.

Quantum dots are nanoscale regions of a semiconductor material similar to the material in computer processors but with special properties due to their tiny dimensions. Though they can be composed of tens of thousands of atoms, quantum dots in a number of ways behave almost as if they were single atoms. Unfortunately, almost is not good enough when it comes to the fragile world of quantum cryptography and next-generation information technologies. When energized, a quantum dot emits photons, or particles of light, just as a solitary atom does. But imperfections in the shape of a quantum dot cause what should be overlapping energy levels to separate. This ruins the delicate balance of the ideal state mandatory to emit entangled photons......... Posted by: Kevin      Read more         Source

July 17, 2008, 9:23 PM CT

"Nanosculpture" Could Enable New Types of Heat Pumps

A new technique for growing single-crystal nanorods and controlling their shape using biomolecules could enable the development of smaller, more powerful heat pumps and devices that harvest electricity from heat.

Scientists at Rensselaer Polytechnic Institute have discovered how to direct the growth of nanorods made up of two single crystals using a biomolecular surfactant. The scientists were also able to create "branched" structures by carefully controlling the temperature, time, and amount of surfactant used during synthesis.

"Our work is the first to demonstrate the synthesis of composite nanorods with branching, wherein each nanorod consists of two materials - a single-crystal bismuth telluride nanorod core encased in a hollow cylindrical shell of single-crystal bismuth sulfide," said G. Ramanath, professor of materials science and engineering at Rensselaer and director of the university's Center for Future Energy Systems, who led the research project. "Branching and core-shell architectures have been independently demonstrated, but this is the first time that both features have been simultaneously realized through the use of a biomolecular surfactant".

Most nanostructures comprised of a core and a shell generally require more than one step to synthesize, but these new research results demonstrate how to synthesize such nanorods in only one step......... Posted by: Kevin      Read more         Source

July 15, 2008, 9:36 PM CT

For toy-like NASA robots in Arctic, ice research is child's play

Several snowmobiles navigated speedily over arctic ice and snow in Alaska's outback in late June. This scene might seem ordinary except that the recently unveiled snowmobiles are unmanned, autonomous, toy-size robots called SnoMotes the first prototype network of their kind envisioned to rove treacherous areas of the Arctic and Antarctic capturing more accurate measurements that will help researchers better understand what is causing the well-documented melting of ice in those regions.

Ayanna Howard, an associate professor in the School of Electrical and Computer Engineering at the Georgia Institute of Technology in Atlanta, worked with researchers at Pennsylvania State University in State College, Pa., to create the toy-like robots. The robots are designed to traverse terrain often too dangerous for scientists, in pursuit of barometric pressure, temperature, and relative humidity measurements that will help researchers improve climate models. Howard, a former member of NASA's Mars technology program team who developed SmartNav, an autonomous, next-generation Mars rover, believed that science-driven robotics could be just as useful of a vehicle to new discoveries on Earth as it has been in the quest to learn more about Mars.

"After working with robots for the Mars technology program, I thought a similar type of rover could be used to collect multiple science measurements on this planet," said Howard. She is lead on the SnoMotes project funded by the Advanced Information Systems Technology program in NASA's Earth Science Technology Office, a NASA Headquarters office located at Goddard Space Flight Center in Greenbelt, Md......... Posted by: Kevin      Read more         Source

July 14, 2008, 4:42 PM CT

Physicists tweak quantum force

Cymbals don't clash of their own accord - in our world, anyway.

But the quantum world is bizarrely different. Two metal plates, placed almost infinitesimally close together, spontaneously attract each other.

What seems like magic is known as the Casimir force, and it has been well-documented in experiments. The cause goes to the heart of quantum physics: Seemingly empty space is not actually empty but contains virtual particles linked to fluctuating electromagnetic fields. These particles push the plates from both the inside and the outside. However, only virtual particles of shorter wavelengths - in the quantum world, particles exist simultaneously as waves - can fit into the space between the plates, so that the outward pressure is slightly smaller than the inward pressure. The result is the plates are forced together.

Now, University of Florida physicists have found they can reduce the Casimir force by altering the surface of the plates. The discovery could prove useful as tiny "microelectromechanical" systems - so-called MEMS devices that are already used in a wide array of consumer products - become so small they are affected by quantum forces.

"We are not talking about an immediate application," says Ho Bun Chan, an assistant professor of physics and the first author of a paper on the findings that appears today in the online edition of the journal Physical Review Letters......... Posted by: Kevin      Read more         Source

July 10, 2008, 8:26 PM CT

A Colorful Approach to Solar Energy

Revisiting a once-abandoned technique, engineers at the Massachusetts Institute of Technology (MIT) have successfully created a sophisticated, yet affordable, method to turn ordinary glass into a high-tech solar concentrator.

The technology, which uses dye-coated glass to collect and channel photons otherwise lost from a solar panel's surface, could eventually enable an office building to draw energy from its tinted windows as well as its roof.

Electrical engineer Marc Baldo, his graduate students Michael Currie, Jon Mapel and Timothy Heidel, and postdoctoral associate Shalom Goffri, announced their findings in the July 11 issue of Science.

"We think this is a practical technology for reducing the cost of solar power," said Baldo.

The scientists coated glass panels with layers of two or more light-capturing dyes. The dyes absorbed incoming light and then re-emitted the energy into the glass, which served as a conduit to channel the light to solar cells along the panels' edges. The dyes can vary from bright colors to chemicals that are mostly transparent to visible light.

Because the edges of the glass panels are so thin, far less semiconductor material is needed to collect the light energy and convert that energy into electricity......... Posted by: Kevin      Read more         Source

July 9, 2008, 9:19 PM CT

Controlling the Size of Nanoclusters

Scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and Stony Brook University have developed a new instrument that allows them to control the size of nanoclusters - groups of 10 to 100 atoms - with atomic precision. They created a model nanocatalyst of molybdenum sulfide, the first step in developing the next generation of materials to be used in hydrodesulfurization, a process that removes sulfur from natural gas and petroleum products to reduce pollution.

As published in the July 9, 2008 online edition of the Journal of Physical Chemistry C, the researchers made size-selected molybdenum sulfide nanoclusters as gaseous ions, and then gently deposited the clusters on a gold surface. The nanoclusters interact weakly with the gold support and therefore remain intact.

"With this new instrument, we can control how a number of and what type of atoms are in a nanocluster," said Brookhaven chemist Michael White, the principal author of the paper. "This knowledge enables us to make nanoclusters with predetermined size, structure and chemical composition, all which are important for the design of new catalysts."

Currently, molybdenum sulfide nanoparticles are used for hydrodesulfurization and other chemical processes, but it is not known what size is most active or how the reactions occur on small particles. The ability to make model nanocatalysts containing molybdenum sulfide particles of variable size and chemical makeup will allow White and coworkers to understand how current catalysts work and help design the next generation of catalysts......... Posted by: Kevin      Read more         Source

June 26, 2008, 8:50 PM CT

New Nano Technique Significantly Boosts Boiling Efficiency

Whoever penned the old adage "a watched pot never boils" surely never tried to heat up water in a pot lined with copper nanorods.

A new study from scientists at Rensselaer Polytechnic Institute shows that by adding an invisible layer of the nanomaterials to the bottom of a metal vessel, an order of magnitude less energy is mandatory to bring water to boil. This increase in efficiency could have a big impact on cooling computer chips, improving heat transfer systems, and reducing costs for industrial boiling applications.

"Like so a number of other nanotechnology and nanomaterials breakthroughs, our discovery was completely unexpected," said Nikhil A. Koratkar, associate professor in the Department of Mechanical, Aerospace, and Nuclear Engineering at Rensselaer, who led the project. "The increased boiling efficiency seems to be the result of an interesting interplay between the nanoscale and microscale surfaces of the treated metal. The potential applications for this discovery are vast and exciting, and we're eager to continue our investigations into this phenomenon."

Bringing water to a boil, and the related phase change that transforms the liquid into vapor, requires an interface between the water and air. In the example of a pot of water, two such interfaces exist: at the top where the water meets air, and at the bottom where the water meets tiny pockets of air trapped in the microscale texture and imperfections on the surface of the pot. Even though most of the water inside of the pot has reached 100 degrees Celsius and is at boiling temperature, it cannot boil because it is surrounded by other water molecules and there is no interface - i.e., no air - present to facilitate a phase change......... Posted by: Kevin      Read more         Source

June 26, 2008, 8:42 PM CT

Quantum computing breakthrough

The odd behavior of a molecule in an experimental silicon computer chip has led to a discovery that opens the door to quantum computing in semiconductors.

In a Nature Physics journal paper currently online, the scientists describe how they have created a new, hybrid molecule in which its quantum state can be intentionally manipulated - a mandatory step in the building of quantum computers.

"Up to now large-scale quantum computing has been a dream," says Gerhard Klimeck, professor of electrical and computer engineering at Purdue University and associate director for technology for the national Network for Computational Nanotechnology.

"This development may not bring us a quantum computer 10 years faster, but our dreams about these machines are now more realistic".

The workings of traditional computers haven't changed since they were room-sized behemoths 50 years ago; they still use bits of information, 1s and 0s, to store and process information. Quantum computers would harness the strange behaviors found in quantum physics to create computers that would carry information using quantum bits, or qubits. Computers would be able to process exponentially more information.

If a traditional computer were given the task of looking up a person's phone number in a telephone book, it would look at each name in order until it found the right number. Computers can do this much faster than people, but it is still a sequential task. A quantum computer, however, could look at all of the names in the telephone book simultaneously......... Posted by: Kevin      Read more         Source

June 26, 2008, 8:25 PM CT

3-D Nanostructures with Magnetic Materials

Materials researchers at the National Institute of Standards and Technology (NIST) have developed a process to build complex, three-dimensional nanoscale structures of magnetic materials such as nickel or nickel-iron alloys using techniques compatible with standard semiconductor manufacturing. The process, described in a recent paper,* could enable whole new classes of sensors and microelectromechanical (MEMS) devices.

The NIST team also demonstrated that key process variables are associated with relatively quick and inexpensive electrochemical measurements, pointing the way to a fast and efficient way to optimize the process for new materials.

The NIST process is a variation of a technique called "Damascene metallization" that often is used to create complicated three-dimensional copper interconnections, the "wiring" that links circuit elements across multiple layers in advanced, large-scale integrated circuits. Named after the ancient art of creating designs with metal-in-metal inlays, the process involves etching complex patterns of horizontal trenches and vertical "vias" in the surface of the wafer and then uses an electroplating process to fill them with copper. The high aspect ratio features may range from tens of nanometers to hundreds of microns in width. Once filled, the surface of the disk is ground and polished down to remove the excess copper, leaving behind the trench and via pattern......... Posted by: Kevin      Read more         Source

June 23, 2008, 8:01 PM CT

A look into the nanoscale

Lawrence Livermore National Laboratory scientists have captured time-series snapshots of a solid as it evolves on the ultra-fast timescale.

Using femtosecond X-ray free electron laser (FEL) pulses, the team, led by Anton Barty, is able to observe condensed phase dynamics such as crack formation, phase separation, rapid fluctuations in the liquid state or in biologically relevant environments.

Other Livermore researchers include Michael Bogan, Stafan Hau-Riege, Stefano Marchesini, Matthias Frank, Bruce Woods, former Livermore researcher Saša Bajt and former LLNL scientist Henry Chapman, who is now at the Centre for Free Electron Laser Science, DESY, in Hamburg, Gera number of.

"The ability to take images in a single shot is the key to studying non-repetitive behavior mechanisms in a sample," Barty said.

As the femtosecond laser blasts the sample, it is destroyed, but not before the researchers created images with a 50-nanometer spatial resolution, and a 10-femtosecond shutter speed. (A femtosecond is one billionth of one millionth of a second. For context, a femtosecond is to a second as a second is to about 32 million years.).

"This experiment opens the door to a new regime of time-resolved experiments in mesoscopic dynamics," Barty said. "This technique could be extended to a few nanometers spatial and a few tens of femtoseconds temporal resolution"......... Posted by: Kevin      Read more         Source

June 23, 2008, 7:19 PM CT

Light-Driven Reversible Nanoswitches

The ability to see is based on molecules in the eye that flip from one conformation to another when exposed to visible light. Now, a new technique for attaching light-sensitive organic molecules to metal surfaces allows the molecules to be switched between two different configurations in response to exposure to different wavelengths of light. Because the configuration changes are reversible and can be controlled without direct contact, this technique could enable applications that can be controlled at the molecular scale.

The technology has been suggested as a possible basis for molecular motors, artificial muscles, and molecular electronics. The research results, obtained by a team led by Paul S. Weiss, distinguished professor of chemistry and physics at Penn State University and James M. Tour, Chao professor of chemistry at Rice University, are published in the June 2008 issue of the journal Nano Letters.

Until now, progress was impeded because, when such molecules were attached to surfaces, they no longer could be switched back and forth, as they could be when they were in solution. The new technique uses a change in the shape of an azobenzene molecule in response to light to provide two different states. The azobenzene molecule consists of a bridge of two nitrogen atoms attached to one another by a double bond, with each nitrogen atom also bound to a benzene ring. The two benzene rings can be on the same side of the molecule (cis configuration) or on opposite sides (trans configuration). When the molecule absorbs energy, in the form of light, it can change between cis and trans configurations in a process called photoisomerization. "This mechanism is essentially the same that we use in our eyes for vision," said Weiss. "The molecule responds to light by making a change that can be harnessed. In the eye, the change causes a neural impulse"......... Posted by: Kevin      Read more         Source

June 9, 2008, 8:43 PM CT

Interfering with the Global Positioning System

You can't always trust your GPS gadget. As researchers have long known, perplexing electrical activity in the upper atmospheric zone called the ionosphere can tamper with signals from GPS satellites.

Now, new research and monitoring systems are clarifying what happens to disruptive clouds of electrons and other electrically charged particles, known as ions, in the ionosphere. The work may lead to regional predictions of reduced GPS reliability and accuracy.

One team of scientists has recently observed Earth's aurora, which is a prominent manifestation of ionospheric electrical activity, in the act of disrupting GPS equipment. Other researchers have successfully tested a way to forecast GPS disturbances for marine users, with likely extension to users on land.

Some research groups are turning the tables and employing GPS receivers as tools with which to conduct basic research on the electrical-current structures of the ionosphere.

The scientific reports on these and other recent developments are available in a special section of Space Weather: The International Journal of Research and Applications, a publication of the American Geophysical Union, or AGU.

A magazine-style article that introduces the section was posted online Friday, June 6. It summarizes past research and operational developments regarding ionospheric effects on GPS, and discusses potential future improvements in the field......... Posted by: Jim      Read more         Source

June 4, 2008, 10:49 PM CT

Prototype Hydrogen Storage Tank

A cryogenic pressure vessel developed and installed in an experimental hybrid vehicle by a Lawrence Livermore National Laboratory research team can hold liquid hydrogen for six days without venting any of the fuel.

Unlike conventional liquid hydrogen (LH2 tanks in prototype cars, the LLNL pressure vessel was parked for six days without venting evaporated hydrogen vapor.

The LLNL development has significantly increased the amount of time it takes to start releasing hydrogen during periods of long-term parking, as in comparison to today's liquid hydrogen tanks capable of holding hydrogen for merely two to four days.

LH2 tanks hold super-cold liquid hydrogen at around -420 Fahrenheit. Like water boiling in a tea kettle, pressure builds as heat from the environment warms the hydrogen inside. Current automotive LH2 tanks must vent evaporated hydrogen vapor after being parked three to four days, even when using the best thermal insulation available (200 times less conductive than Styrofoam insulation).

In recent testing of its prototype hydrogen tank onboard a liquid hydrogen (LH2) powered hybrid, LLNL's tank demonstrated a thermal endurance of six days and the potential for as much as 15 days, helping resolve a key challenge facing LH2 automobiles......... Posted by: Sarah      Read more         Source