February 5, 2007, 9:39 PM CT

Hafnium Oxide Helps Make Chips Smaller And Faster

Intel and IBM have announced that they will use dramatically different materials to build smaller, faster transistors for their next generation of chips.

Traditionally fashioned out of silicon, transistors are simple on/off switches that process the ones and zeros of digital electronic data. The faster its transistors switch (known as the clock speed) the more efficient the chip. Making them smaller, cheaper, faster and more energy-efficient has helped the industry to stick to Intel's co-founder Gordon Moore prediction that the number of transistors on a chip would double roughly every two years.

Microprocessors now consist of millions of transistors connected together by specific patterns of copper wires. But using current silicon technology, there are limits to the continued fulfilment of 'Moore's Law'.

In transistors, current flows between two terminals, called 'source' and 'drain'. This current is controlled by the voltage at a third terminal, the 'gate' (see diagram). For a transistor to switch efficiently, the gate needs to be isolated from source and drain by a thin piece of insulating silica, known as the dielectric. As transistors shrink, so the silica gate insulator has thinned to just a few atomic layers. This allows quantum tunnelling of electrons, leading to current leakage across the dielectric, producing a lot of heat and poor chip performance.........

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February 5, 2007, 6:31 PM CT

Volcanism with Under-Ocean Sensors

Earthquakes and volcanic activity occur when the tectonic plates that make up Earth's surface move apart or converge. While this activity is relatively easy to observe on land, it's more difficult to observe under the ocean, where most of it occurs. A University of Missouri-Columbia researcher will soon undertake a study to learn more about this process by placing sensors on a mid-ocean ridge called the East Pacific Rise.

"Right now, we can only listen from land using seismometers, or in the oceans using hydrophones, and try to find out when there is activity in a mid-ocean ridge," said Marie-Helene Cormier, assistant professor of geological sciences in MU¿s College of Arts and Science. "We might not know for a few days, and then it might take at least a week to get a ship to the site. If we want to study what's happening, it's very difficult to get accurate and timely information. Our goal is to put sensors in place so that we can record activity as it is happening. When we recover our sensors, we'll be able to study what was happening during those moments."

In mid February, Cormier and her colleagues, Spahr Webb and Roger Buck of Columbia University, will place sensors on the seafloor in multiple positions along the East Pacific Rise southwest of Mexico. The sensors will measure and record changes in the pressure of the water column above them. Cormier said the pressure of the water is expected to decrease during ridge activity because magma flows up between the two plates, creating new seafloor and raising the height of the sensors by a few inches. She and her team will collect data from the sensors while they are in place until they are removed from the ocean floor in 2009 or 2010. MU undergraduate students are expected to accompany Cormier on the research mission to learn more about geology and marine research. ........

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February 5, 2007, 6:10 PM CT

Different Protein Building Blocks

Chemists at Yale have done what Mother Nature chose not to make a protein-like molecule out of non-natural building blocks, as per a report featured early online in the Journal of the American Chemical Society.

Nature uses alpha-amino acid building blocks to assemble the proteins that make life as we know it possible. Chemists at Yale now report evidence that nature could have used a different building block beta-amino acids and show that peptides assembled from beta-amino acids can fold into structures much like natural protein.

"The x-ray structure featured in the report shows a molecule that shares many of the structural characteristics of natural proteins," said principal author Alanna Schepartz, the Milton Harris '29 Ph.D. Professor of Chemistry at Yale and a Howard Hughes Medical Institute Professor. "Related studies show that the physical properties of the molecule are also remarkably similar to natural proteins. In other words, the beta-peptide assembly looks and acts a lot like a real protein".

The ability to mimic natural proteins makes beta-peptides powerful new tools for basic research and drug discovery. Like a taped recording, their greatest value may be in their difference from a live performance.

"Since beta-peptides are not processed in the cell like natural peptides or proteins, it may be possible in the future to design beta-peptides that perform better or in more locations than current protein drugs," said Schepartz. "They also may have unique properties as biomaterials".........

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February 4, 2007, 8:23 PM CT

Sophisticated ESA space weather tool

If a satellite encounters high-energy particles or other 'space weather' phenomena before ground controllers can take action, on-board electronics could be disrupted, scientific instruments damaged and, in very rare and extreme cases, spacecraft may even be lost. A sophisticated tool in development at ESOC promises to provide effective monitoring and forecasting for any type of mission.

But since early 2005, SEISOP (Space Environment Information System for Operations), a space-weather monitoring and forecasting tool under development at ESA's Space Operations Centre, has been successfully providing near-real-time space weather reports for Integral, ESA's gamma-ray space observatory.

Solar activity influences the entire solar system in several ways, including generating streams of fast-moving energetic particles and sudden bursts of damaging X-rays during solar flares.

Energetic cosmic rays from elsewhere in the galaxy also penetrate into our solar system. These phenomena are some of the major sources of abnormal behaviour and aging for spacecraft and their sensitive scientific instruments.

"SEISOP can potentially provide warning services to space agencies worldwide, since space weather can affect any spacecraft."

Space Weather affects spacecraft in a number of ways.........

Posted by: Tyler      Read more         Source

February 4, 2007, 8:15 PM CT

Climate Change only one Symptom of a Stressed Planet Earth

In releasing its latest comprehensive report, the Intergovernmental Panel on Climate Change (IPCC) focuses an important spotlight on the current state of the Earth's climate.

Climate change is just one of the a number of symptoms exhibited by a planet under pressure from human activities. "Global environmental change, which includes climate change, threatens to irreversibly alter our planet," says Kevin Noone, Executive Director of the International Geosphere-Biosphere Programme (IGBP).

Global studies by IGBP show that human-driven environmental changes are affecting a number of parts of the Earth's system, in addition to its climate. For example:.

• Half of Earth's land surface is now domesticated for direct human use.

• 75 percent of the world's fisheries are fully or over-exploited.

• The composition of today´s atmosphere is well outside the range of natural variability the Earth has maintained over the last 650,000 years.

• The Earth is now in the midst of its sixth great extinction event.

"The IPCC report, with its interdisciplinary approach to climate change, is a clear example of how the Earth needs to be considered as a coupled system in order to understand global environmental change," says Noone. "The study of the Earth as a system, looking not only at climate but also at changes in the oceans and on land, how those changes affect each other, and the role of humans as part of that system is a crucial approach to managing a sustainable planet," he says.........

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February 2, 2007, 4:56 AM CT

Good Times Using GPS and the Internet

International time coordination is improving throughout the Americas thanks to a low-cost system relying on Global Positioning System (GPS) satellites and the Internet, which enables much faster time comparisons and gives small countries the opportunity to evaluate easily their measurements in relation to others and to world standards.

The time and frequency network of the Sistema Interamericano de Metrologia (SIM), or Inter-American Metrology System, began operation in 2005. The system includes national metrology institutes in member nations of the Organization of American States (OAS). The SIM network currently compares time and frequency measurements made in Brazil, Canada, Mexico, Panama and the United States. Costa Rica and Columbia are expected to join the network soon, and additional OAS members have expressed interest.

As the U.S. civilian timekeeper, the National Institute of Standards and Technology (NIST) participates in the SIM network and also calibrates other members' equipment, which consists of a computer-based measurement system and a GPS receiver provided by OAS. Institutes simultaneously compare their time scales to clocks on the same GPS satellites, and then automatically compare their results over the Internet. Time differences can be viewed on the Web by all laboratories in the network, with updates every 10 minutes.........

Posted by: Tyler      Read more         Source

February 2, 2007, 4:51 AM CT

Improved Nanodots

The massive global challenge of storing digital data-storage needs reportedly double every year-may be met with a tiny yet powerful solution: magnetic particles just a few billionths of a meter across. This idea is looking better than ever now that scientists at the National Institute of Standards and Technology (NIST) and collaborators have made nanodot arrays that respond to magnetic fields with record levels of uniformity. The work enhances prospects for commercially viable nanodot drives with at least 100 times the capacity of today's hard disk drives.

A nanodot has north and south poles like a tiny bar magnet and switches back and forth (or between 0 and 1) in response to a strong magnetic field. Generally, the smaller the dot, the stronger the field mandatory to induce the switch. Until now scientists have been unable to understand and control a wide variation in nanodot switching response. As described in a new paper,* the NIST team significantly reduced the variation to less than 5 percent of the average switching field and also identified what is thought to bethe key cause of variability-the design of the multilayer films that serve as the starting material for the nanodots.

Nanodots, as small as 50 nanometers (nm) wide, were fabricated using electron beam lithography to pattern multilayer thin films. The key was to first lay down a tantalum "seed layer" just a few nanometers thick when making a multilayer film of alternating layers of cobalt and palladium on a silicon wafer. The seed layer can alter the strain, orientation or texture of the film. By making and comparing different types of multilayer stacks, the scientists were able to isolate the effects of different seed layers on switching behavior. They also were able to eliminate factors previously suspected to be critical, such as lithographic variations, nanodot shape or crystal grain boundaries.........

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February 2, 2007, 4:38 AM CT

Algae Toxin And The Fish-kill Mystery

A team of scientists from the Hollings Marine Laboratory in Charleston, S.C., has uncovered a subtle chemical pathway by which normally inoffensive algae, Pfiesteria piscicida, can suddenly start producing a lethal toxin. The discovery, reported last week in Environmental Science and Technology,* could resolve a long-standing mystery surrounding occasional mass fish kills on the East Coast.

Pfiesteria has been implicated for years in a series of otherwise unexplained episodes of mass fish death throughout its range from roughly Delaware to Alabama, especially in the Neuse River in North Carolina and the Chesapeake Bay. The single-cell organism can experience explosive growth resulting in algae blooms in coastal waters. While it has been suspected not only in fish kills but in incidents of human memory loss and other environmental and health-related effects, no one has ever conclusively identified the actual mechanism. Attempts to grow lethal Pfiesteria in the laboratory have had inconsistent results.

The Hollings Marine Laboratory is a joint institution of the National Oceanic and Atmospheric Administration (NOAA), the National Institute of Standards and Technology (NIST), the South Carolina Department of Natural Resources, the College of Charleston, and the Medical University of South Carolina (MUSC). Lead researcher Peter Moeller of NOAA suspected that the presence or absence of heavy metals might be the missing factor accounting for Pfiesteria's lethality, and put together a multidisciplinary research team to identify the actual toxin and the conditions under which it is produced.........

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February 2, 2007, 4:19 AM CT

Human Link To Global Warming

Evidence presented in the first phase of the Intergovernmental Panel on Climate Change's 4th Assessment Report, released recently in Paris, paints the clearest picture yet that human-derived greenhouse gases are playing a significant role in observed global warming, says a Duke University scientist who co-authored one of the report's main chapters.

"We are now seeing, not merely predicting, effects of greenhouse warming on a scale and in ways that were not observable before," said Gabriele Hegerl, associate research professor at Duke's Nicholas School of the Environment and Earth Sciences, who also co-authored a summary of the report for policymakers.

"When you look at the changes in temperature, circulation, ocean warming, arctic sea ice reduction and glacial retreat together, it paints a much clearer picture that external drivers, especially greenhouse gases, are playing a key role," she said. "As a result, we can be much more confident that 20th century climate changes were not just associated with natural variability".

Hegerl was a coordinating lead author of the IPCC report's chapter on "Understanding and Attributing Climate Change." Francis Zwiers of the Canadian Centre of Climate Modeling and Analysis was also a coordinating lead author of the chapter.........

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February 1, 2007, 8:11 PM CT

Apex USB battery charger

Think of all those consumer electronics we power with disposable batteries. Now think about how all those batteries find themselves in the dumpster, headed for land fills. Rechargeable is definitely the way to go. With the Apex USB charger, four batteries can charge in four hours by plugging into your computer's USB port.

The unit is small, just four inches square and one inch high, perfect for traveling. However, unlike the USB cell batteries, which have gotten a lot of attention lately, they do not have a USB port directly attached to the battery case. Not as cool perhaps, but probably more useful, since most laptops tend to have only one or two USB ports, and you get to choose whether to charge AA or AAA batteries in the pack. Not only that, it makes a great carrying case for your spare set of batteries; as you use one set, the other can be charging nicely or stowed and ready-to-go.........

Posted by: Kevin      Read more         Source