August 29, 2007, 9:47 PM CT

Greece Suffers More Fires In 2007

Greece has experienced more wildfire activity this August than other European countries have over the last decade, as per data from ESA satellites. The country is currently battling an outbreak of blazes, which began last Thursday, that have spread across the country killing more than 60 people.

ESA's ERS-2 and Envisat satellites continuously survey fires burning across the Earth's surface with onboard sensors - the Along Track Scanning Radiometer (ATSR) and the Advanced Along Track Scanning Radiometer (AATSR) respectively, known as the ATSR Word Fire Atlas, which is available to users online in near-real time.

The ATSR World Fire Atlas is the longest worldwide fire atlas available. Even if the atlas is not supposed to pick up all fires due to satellite overpass constraints and cloud coverage, it is statistically representative from one month to the other and from one year to the other.

Working like thermometers in the sky, the sensors measure thermal infrared radiation to take the temperature of Earth's land surfaces. Temperatures exceeding 308ºK at night are classed as burning fires. Data gathered from July 1996 to 28 August 2007 was used to plot the number of fires occurring monthly and show Greece has had four times the number of fires this August in comparison to its July and August 1998 records......... Posted by: Tyler      Read more         Source

August 28, 2007, 9:40 PM CT

Greenhouse caused the US warmth in 2006

Greenhouse gases likely accounted for over half of the widespread warmth across the continental United States in 2006, according to a new study that will be published 5 September in Geophysical Research Letters, a publication of the American Geophysical Union. Last year's average temperature was the second highest since recordkeeping began in 1895. The team found that it was very unlikely that the 2006 El Nino played any role, though other natural factors likely contributed to the near-record warmth.

When average annual temperature in the United States broke records in 1998, a powerful El Nino was affecting climate around the globe. Scientists widely attributed the unusual warmth in the United States to the influence of the ongoing El Nino. El Nino is a warming of the surface of the east tropical Pacific Ocean.

The research team, led by Martin Hoerling at the National Oceanic And Atmospheric Administration (NOAA) Earth System Research Lab in Boulder, Colorado, also found that greenhouse gas increases in Earth's atmosphere enhanced the probability of U.S. temperatures breaking a record in 2006 by approximately 15-fold compared to pre-industrial times. The authors also estimate that there is a 16 percent chance that 2007 will bring record-breaking warmth.

"We wanted to find out whether it was pure coincidence that the two warmest years on record both coincided with El Nino events," Hoerling said. "We decided to quantify the impact of El Nino and compare it to the human influence on temperatures through greenhouse gases"......... Posted by: Tyler      Read more         Source

August 28, 2007, 9:37 PM CT

simpler method for analyzing radium in water

A simpler technique for testing public drinking water samples for the presence of the radioactive element radium can dramatically reduce the amount of time required to conduct the sampling required by federal regulations. The U.S. Environmental Protection Agency (EPA) has approved use of the new testing method.

The technique developed by Bernd Kahn, director of the Georgia Tech Research Institutes (GTRI) Environmental Radiation Center (ERC), and GTRI senior research scientist Robert Rosson became advantageous when the EPA established new radionuclide drinking water standards in 2000.

While radium is found at low concentrations in soil, water, plants and food, the greatest potential for human exposure to radium is through drinking water. Research shows that inhalation, injection, ingestion or body exposure to relatively large amounts of radium can cause cancer and other disorders. Since radium is chemically similar to calcium, it has the potential to cause harm by replacing calcium in bones.

As a result, drinking water systems are now required to sample and report on the amounts of two isotopes, radium-226 and radium-228, that are sometimes found in drinking water supplies.

The Georgia Department of Natural Resources recognized the applicability and benefits of our method because of the new rules and proposed it to the EPA in 2002, said Kahn......... Posted by: Kevin      Read more         Source

August 27, 2007, 9:17 PM CT

Hot Spots And Fires From Space

Hot spots across Southeastern Europe from 21 to 26 August have been detected with instruments aboard ESA satellites, which have been continuously surveying fires burning across the Earth's surface for a decade.

Working like thermometers in the sky, the Along Track Scanning Radiometer (ATSR) on ESA's ERS-2 satellite and the Advanced Along Track Scanning Radiometer (AATSR) on ESA's Envisat satellite measure thermal infrared radiation to take the temperature of Earth's land surfaces.

Temperatures exceeding 312ºK (38.85ºC) are classed as burning fires by AATSR, which is capable of detecting fires as small as gas flares from industrial sites because of their high temperature. Worldwide fire maps based on this data are available to users online in near-real time through ESA's ATSR World Fire Atlas (WFA).

Smoke from some of the fires included in the WFA fire map was detected during the same period by Envisat's Medium Resolution Imaging Spectrometer (MERIS) optical instrument. While working in Full Resolution mode to provide a spatial resolution of 300 metres, MERIS captured smoke plumes arising from fires raging across Greece's southern Peloponnese peninsula, where fires have claimed the lives of at least 60 people since they began four days ago.

These images are available on ESA's MIRAVI website, which gives access to Envisat's most recently acquired images. MIRAVI, short for MERIS Images RApid VIsualisation, tracks Envisat - the world's largest Earth Observation satellite - around the globe, generates images from the raw data collected by MERIS and provides them online within two hours. MIRAVI is free and requires no registration......... Posted by: Brooke      Read more         Source

August 27, 2007, 8:24 PM CT

Perfecting hydrogen-generating technology

Scientists at Purdue University have further developed a technology that could represent a pollution-free energy source for a range of potential applications, from golf carts to submarines and cars to emergency portable generators.

The technology produces hydrogen by adding water to an alloy of aluminum and gallium. When water is added to the alloy, the aluminum splits water by attracting oxygen, liberating hydrogen in the process. The Purdue scientists are in the process of developing a method to create particles of the alloy that could be placed in a tank to react with water and produce hydrogen on demand.

The gallium is a critical component because it hinders the formation of an aluminum oxide skin normally created on aluminum's surface after bonding with oxygen, a process called oxidation. This skin commonly acts as a barrier and prevents oxygen from reacting with aluminum. Reducing the skin's protective properties allows the reaction to continue until all of the aluminum is used to generate hydrogen, said Jerry Woodall, a distinguished professor of electrical and computer engineering at Purdue who invented the process.

Since the technology was first announced in May, scientists have developed an improved form of the alloy that contains a higher concentration of aluminum......... Posted by: Sarah      Read more         Source

August 27, 2007, 8:21 PM CT

Long-term increase in rainfall seen in tropics

NASA researchers have detected the first signs that tropical rainfall is on the rise with the longest and most complete data record available.

Using a 27-year-long global record of rainfall assembled by the international scientific community from satellite and ground-based instruments, the researchers observed that the rainiest years in the tropics between 1979 and 2005 were mainly since 2001. The rainiest year was 2005, followed by 2004, 1998, 2003 and 2002, respectively.

"When we look at the whole planet over almost three decades, the total amount of rain falling has changed very little. But in the tropics, where nearly two-thirds of all rain falls, there has been an increase of 5 percent," says lead author Guojun Gu, a research scientist at Goddard Space Flight Center in Greenbelt, Md. The rainfall increase was concentrated over tropical oceans, with a slight decline over land.

Climate researchers predict that a warming trend in Earth's atmosphere and surface temperatures would produce an accelerated recycling of water between land, sea and air. Warmer temperatures increase the evaporation of water from the ocean and land and allow air to hold more moisture. Eventually, clouds form that produce rain and snow.

"A warming climate is the most plausible cause of this observed trend in tropical rainfall," says co-author Robert F. Adler, senior scientist at Goddard's Laboratory for Atmospheres. Adler and Gu are now working on a detailed study of the relationship between surface temperatures and rainfall patterns to further investigate the possible link. The study appears in the Aug. 1, 2007, issue of the American Meteorological Society's Journal of Climate......... Posted by: Tyler      Read more         Source

August 26, 2007, 10:55 AM CT

Toxic Byproducts of Carbon Nanotube Manufacturing

A new analysis of by-products discharged to the environment during production of carbon nanotubes (CNTs) -- expected to become the basis of multibillion-dollar industries in the 21st Century -- has identified cancer-causing compounds, air pollutants, and other substances of concern, scientists reported here today at the 234th national meeting of the American Chemical Society.

Co-author of study Desiree L. Plata and his colleagues described their work as "totally new," noting that past analyses of the environmental impact of the emerging nanomaterials industry have been based on the toxicity of ingredients used in the recipes, rather than the actual pollutants formed during CNT manufacture. While expressing concern about the possible health and environmental effects of nanotechnology by-products, Plata said the new data may be crucial as the nanotechnology industry seeks to avoid the kind of unanticipated health and environmental problems that have accompanied emergence of other new technology.

Scientists said, for instance, that they foresee developing, in collaboration with the CNT industry, "green chemical" reactions and filtration systems to substitute for those with potentially hazardous by-products and other ways of manufacturing carbon nanotubes that minimize potentially adverse impacts......... Posted by: Kevin      Read more         Source

August 26, 2007, 10:52 AM CT

Solar Cells May Bring Cheaper Green Power

Researchers are researching new ways of harnessing the sun's rays which could eventually make it cheaper for people to use solar energy to power their homes.

The experts at Durham University are in the process of developing light-absorbing materials for use in the production of thin-layer solar photovoltaic (PV) cells which are used to convert light energy into electricity.

The four-year project involves experiments on a range of different materials that would be less expensive and more sustainable to use in the manufacturing of solar panels.

Thicker silicon-based cells and compounds containing indium, a rare and expensive metal, are more usually used to make solar panels today.

The research, funded by the Engineering and Physical Sciences Research Council (EPSRC) SUPERGEN Initiative, focuses on developing thin-layer PV cells using materials such as copper indium diselenide and cadmium telluride.

Right now the project is entering a new phase for the development of cheaper and more sustainable variants of these materials.

The Durham team is also working on manipulating the growth of the materials so they form a continuous structure which is essential for conducting the energy trapped by solar panels before it is turned into usable electricity. This will help improve the efficiency of the thin-layer PV cells......... Posted by: Kevin      Read more         Source

August 26, 2007, 10:49 AM CT

New Finding Bubbles To Surface

Chemical engineers have discovered a fundamental flaw in the conventional view of how liquids form bubbles that grow and turn into vapors, which takes place in everything from industrial processes to fizzing champagne.

The findings cast into doubt some aspects of a theory dating back to the 1920s that attempts to describe the underlying molecular mechanism behind a phenomenon called "homogeneous nucleation," said David S. Corti, an associate professor of chemical engineering at Purdue University.

The research could lead to a more precise understanding of the "phase transition" that takes place when bubbles form, grow and then become a vapor, which could, in turn, have implications for industry and research, Corti said.

In the conventional view, a liquid boiling and turning into a vapor takes place in a systematic process known as "nucleation and growth." The liquid first forms tiny "nuclei," or microscopic bubbles, that eventually grow as they pick up particles like a snowball gaining size as it rolls down a hillside. This conventional view is described by "classical nucleation theory," which was originally proposed in the 1920s.

"Our findings indicate that this is not what's going on," Corti said. "The bubble grows via a mechanism very different from classical nucleation theory"......... Posted by: Kevin      Read more         Source

August 26, 2007, 10:40 AM CT

Martian Soil Samples Could Have Biological Origin

A new interpretation of data from NASA's Viking landers indicates that 0.1% of the Martian soil tested could have a biological origin.

Dr Joop Houtkooper of the University of Giessen, Gera number of, believes that the subfreezing, arid Martian surface could be home to organisms whose cells are filled with a mixture of hydrogen peroxide and water. In a presentation at the European Planetary Science Congress in Potsdam on Friday 24th August, Dr Houtkooper will describe how he has used data from the Gas Exchange (GEx) experiment, carried by NASA's Viking landers, to estimate the biomass in the Martian soil.

Dr Houtkooper said, "The GEx experiment measured unexplained rises in oxygen and carbon dioxide levels when incubating samples. If we assume these gases were produced during the breakdown of organic material together with hydrogen peroxide solution, we can calculate the masses needed to produce the volume of gas measured. From that, we can estimate the total biomass in the sample of Martian soil. It comes out at little more than one part per thousand by weight, comparable to what is found in some permafrost in Antarctica. This might be detectable by instruments on the Phoenix lander, which will arrive at Mars in May next year".

Dr Houtkooper and his colleague, Dr Schulze-Makuch from Washington State University, suggest that a hydrogen peroxide-water based organism would be quite capable of surviving in the harsh Martian climate where temperatures rarely rise above freezing and can reach -150 degrees Celsius at the poles......... Posted by: Brooke      Read more         Source