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October 14, 2010, 7:51 AM CT

Electrified nano filter for clean drinking water

Electrified nano filter  for clean drinking water
With almost one billion people lacking access to clean, safe drinking water, researchers are reporting development and successful initial tests of an inexpensive new filtering technology that kills up to 98 percent of disease-causing bacteria in water in seconds without clogging. A report on the technology appears in Nano Letters, a monthly American Chemical Society journal.

Yi Cui and his colleagues explain that most water purifiers work by trapping bacteria in tiny pores of filter material. Pushing water through those filters requires electric pumps and consumes a lot of energy. In addition, the filters can get clogged and must be changed periodically. The new material, in contrast, has relatively huge pores, which allow water to flow through easily. And it kills bacteria outright, rather than just trapping them.

The researchers knew that contact with silver and electricity can destroy bacteria, and decided to combine both approaches. They spread sub-microscopic silver nanowires onto cotton, and then added a coating of carbon nanotubes, which give the filter extra electrical conductivity. Tests of the material on E. coli-tainted water showed that the silver/electrified cotton killed up to 98 percent of the bacteria. The filter material never clogged, and the water flowed through it very quickly without any need for a pump. "Such technology could dramatically lower the cost of a wide array of filtration technologies for water as well as food, air, and pharmaceuticals where the need to frequently replace filters is a large cost and difficult challenge," their report states.........

Posted by: Nora      Read more         Source


September 25, 2010, 8:23 AM CT

"Coreshine" sheds light on the birth of stars

The molecular cloud CB 244 in the constellation Cepheus, 650 light-years from Earth. In such clouds, the Milky Way's light is scattered in different ways: Visible light is predominantly scattered by small grains of dust in the cloud's outer regions ("cloudshine"). The false-colour image shows mid-infrared light scattered by larger grains of dust in the interior of the cloud, the newly discovered "coreshine".
Stars are formed as the dense core regions of cosmic clouds of gas and dust ("molecular clouds") collapse under their own gravity. As a result, matter in these regions becomes ever denser and hotter until finally nuclear fusion is ignited: a star is born. This is how our own star, the Sun, came into being; the fusion processes are responsible for the Sun's light, on which life on Earth depends. The dust grains contained in the collapsing clouds are the raw material out of which an interesting by-product of star formation is made: solar systems and Earth-like planets.

What happens during the earliest phases of this collapse is largely unknown. Enter an international team of astronomers led by Laurent Pagani (LERMA, Observatoire de Paris) and Jürgen Steinacker (Max Planck Institute for Astronomy, Heidelberg, Gera number of), who have discovered a new phenomenon which promises information about the crucial earliest phase of the formation of stars and planets: "coreshine", the scattering of mid-infrared light (which is ubiquitous in our galaxy) by dust grains inside such dense clouds. The scattered light carries information about the size and density of the dust particles, about the age of the core region, the spatial distribution of the gas, the prehistory of the material that will end up in planets, and about chemical processes in the interior of the cloud.........

Posted by: Edwin      Read more         Source


September 11, 2010, 9:11 AM CT

The Precious Commodity of Water

The Precious Commodity of Water
Water is a valuable resource, which is why the Fraunhofer Alliance SysWasser is demonstrating how we can extract precious drinking water from air, discover a leak in pipeline systems and even effectively clean sewage water at the IFAT/Entsorga fair (September 13-17 in Munich, Gera number of).

As the General Assembly of the UN resolved on July 28 of this year, clean drinking water and basic sanitary provision are human rights. Unfortunately, there are more than one billion people all over the world who do not have access to drinking water, while as a number of as 2.6 billion people live without any sanitary systems at all - that is well over one-third of the world's population.

Not only that, water is a pre-eminent economic factor because agriculture and industry consume more than four-fifths of this precious commodity these days. A study by the UN indicates that in future water will be more important in strategic terms than petroleum. This is the reason why 14 Fraunhofer institutes have joined forces in the Fraunhofer Alliance SysWasser to come up with sustainable water system technologies. They will be unveiling "Research for Tomorrow's Water Utilization" in hall A4, stand 201/302 at the IFAT/Entsorga fair.

Drinking Water from the Air.

Drinking water can be extracted from the humidity in the air even in the desert or in the middle of a megacity, which is made possible by a technology developed by Fraunhofer. The principle behind it is a salt solution that runs down from a tower-shaped system and absorbs water from the air. The hygroscopic brine is then pumped into a tank that stands a couple of meters high and contains a vacuum. Then, energy from solar collectors heats up the brine and the evaporated salt-free water condenses over a distillation bridge. The brine concentrates again and flows down on the surface of the tower to absorb humidity in the air.........

Posted by: Nora      Read more         Source


Sat, 28 Aug 2010 05:07:55 GMT

Orobanche californica

Orobanche californica
It"s been a while since BPotD has featured a contribution from frequent commenter Eric in SF@Flickr, so here"s one from his weekend trip to Point Reyes, California (original image via the Botany Photo of the Day Flickr Pool). If you"re a relatively recent reader of BPotD, you may not know that Eric also runs orchidphotos.org. Thanks again!

Including all of its five subspecies, Orobanche californica (or California broomrape) is native from British Columbia to Baja California, extending as far east as Montana. Subspecies californica, however, is restricted to coastal areas of British Columbia, Washington, Oregon and California where it parasitizes the roots of species of Grindelia (Asteraceae). Other subspecies are typically associated with different genera in the Asteraceae.

This subspecies of California broomrape reaches 5-27cm (2 to 10.5in) in height. Its coastal requirements mean that it is typically found in sandy or heavy soils below 150m (500ft.) in elevation (when it is found -- it is uncommon throughout its range).

Additional photographs are available from Eric in S.F. or the Burke Museum: Orobanche californica.

Botany / photography resource link: local BPotD reader Verity G. sent along the following link for your interest: X-rays of Flowers by Hugh Turvey from the UK"s Telegraph. More of Hugh"s (non-flower) images can be seen at gustoimages.

Posted by: Daniel Mosquin      Read more     Source


August 26, 2010, 11:19 PM CT

Single-Spin Magnetoelectronics

Single-Spin Magnetoelectronics
The integration of single-spin magnetoelectronics into standard silicon technology may soon be possible, if experiments confirm a new theoretical prediction by physicists at the Naval Research Laboratory and the University of Wisconsin-Madison. The scientists predict that a family of well-known silicon surfaces, stabilized by small amounts of gold atoms, is intrinsically magnetic despite having no magnetic elements. None of these surfaces has yet been investigated experimentally for magnetism, but the new predictions are already supported indirectly by existing data. The complete findings of the study are reported in the August 24, 2010, issue of the journal Nature Communications.

Silicon provides a unique entry point for combining magnetoelectronics based on single spins with standard electronics technology. If a single-spin device can be built on a silicon wafer, input and output electronics can be directly integrated with the magnetic part of the device. This has been an obstacle for current spintronics approaches. For example, spin injection from a metal into silicon is very inefficient unless the metal/semiconductor interface is carefully optimized.

These latest results have the advantage that nature itself guides, by a self-assembly process, the formation of long chains of polarized electron spins with atomically precise structural order. "This integration of structural and magnetic order is crucial for future technologies based on single spins at the atomic level" said Dr. Steven Erwin, a physicist at NRL and lead theorist on the project.........

Posted by: John      Read more         Source


August 26, 2010, 11:00 PM CT

Two Planets Transiting Same Star

Two Planets Transiting Same Star
This artist's concept illustrates the two Saturn-sized planets discovered by NASA's Kepler mission. The star system is oriented edge-on, as seen by Kepler, such that both planets cross in front of, or transit, their star. This is the first star system found to have multiple transiting planets.
Credit: NASA/Ames/JPL-Caltech
NASA's Kepler Mission has discovered the first confirmed planetary system with more than one planet transiting the same star.

Today's announcement of the discovery of the two planets, Kepler 9b and 9c, is based on seven months of observations of more than 156,000 stars being monitored for subtle brightness changes as part of an ongoing search for Earth-like planets outside our solar system. Researchers designated the sun-like star Kepler-9.

The inner world, Kepler 9-b, orbits its star every 19.2 days at a distance of 13 million miles, while the outer world orbits once in 38.9 days at a distance of 21 million miles. (In comparison, Mercury has an orbital period of 88 days.) They orbit nearly in resonance, with the inner planet completing two orbits for every one of the outer planet. Both are Saturn-sized gas giants, with the inner world weighing in at 0.25 Jupiter mass (80 Earths) while the outer world is a slimmer 0.17 Jupiter mass (54 Earths).

"This is the first confirmed system of more than one planet transiting the same star," said Matthew Holman, a Kepler Mission scientist from the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. Researchers confirmed the multiple transits with radial velocity observations conducted at the W.M Keck Observatory in Hawaii.........

Posted by: Edwin      Read more         Source


August 26, 2010, 7:06 AM CT

Why are sunspots a source of radio emissions?

Why are sunspots a source of radio emissions?
Why sunspots are a strong source of radio emissions and what information those emissions carry will be the focus of an invited talk by NJIT Research Professor Jeongwoo Lee.

Credit: New Jersey Institute of Technology
Why sunspots are a strong source of radio emissions and what information those emissions carry will be the focus of an invited talk by NJIT Research Professor Jeongwoo Lee tomorrow at the International Astronomical Union Symposium on the Physics of Sun and Star Spots in Ventura, CA. http://www.csun.edu/physicsandastronomy/IAUS273/ The event numbers among the top gatherings in the U.S. for people studying sunspots and related phenomena.

Lee, who will speak Aug. 26, 2010, will highlight Owens Valley Solar Array (OVSA), one of the two unique frequency-agile radio telescopes in the world. NJIT has managed and operated the facility since 1997. Research opportunities there coupled with Lee's earlier article-- "Radio Emissions from Solar Active Regions" Space Science Reviews, Vol. 133, 73-102 http://www.springerlink.com/content/6533674378432313/ --will be the foundation for the talk.

Owens Valley Solar Array features an uncommonly large number of frequencies (up to 86) in the range of 118 GHz, which can exploit the unique sensitivity of the gyroresonant spectrum to coronal magnetic fields. The imaging spectroscopy (a technique for constructing spectrum in every spatial point of interest) of sunspots implemented with the OVSA is one of the best examples for unambiguous observational determination of the coronal magnetic field and temperature.........

Posted by: Edwin      Read more         Source


August 25, 2010, 7:04 AM CT

Origin of Large Underwater Hydrocarbon Plume

Origin of Large Underwater Hydrocarbon Plume
Sentry criss-crossed the plume in deep Gulf waters to help determine its size and shape.
Researchers funded by the National Science Foundation (NSF) and affiliated with the Woods Hole Oceanographic Institution (WHOI) have detected a plume of hydrocarbons at least 22 miles long and more than 3,000 feet below the surface of the Gulf of Mexico, a residue of the BP Deepwater Horizon oil spill.

The 1.2-mile-wide, 650-foot-high plume of trapped hydrocarbons was detected during a ten day subsurface sampling effort from June 19-28, 2010 near the wellhead. The results provide a snapshot of where the oil has gone as surface slicks shrink and disappear.

"These results create a clearer picture of where the oil is in the Gulf," said Christopher Reddy, a WHOI marine geochemist and one of the authors of a paper on the results that appears in this week's issue of the journal Science.

The study--which was enabled by three rapid response grants from NSF's chemical oceanography program, with additional funding from the U.S. Coast Guard and NOAA through the Natural Resource Damage Evaluation Program--confirms once again that a continuous plume was found "at petroleum hydrocarbon levels that are noteworthy and detectable," Reddy said.

The scientists measured petroleum hydrocarbons in the plume and, using them as an investigative tool, determined that the source of the plume could not have been natural oil seeps but had to have come from the Deepwater Horizon blowout at the Macondo well.........

Posted by: Nora      Read more         Source


July 8, 2010, 6:59 AM CT

New system to reduce heating costs in cold climates

New system to reduce heating costs in cold climates
Frederick Welck, at left, an intern from Institut für Technische Chemie in Clausthal-Zellerfeld, Germany, and mechanical engineering doctoral student Christian Bach work with an experimental setup for testing valves as part of research led by Purdue University to develop more efficient heat pumps. The improved efficiency could allow residents in cold climates to cut their heating bills in half, in research funded by the California Energy Commission. A follow-up project, funded by the US Department of Energy, will build on this and previous work that began about five years ago at Purdue's Ray W. Herrick Laboratories.

Credit: Purdue University photo/Mark Simons

A new type of heat pump being developed at Purdue University could allow residents in cold climates to cut their heating bills in half.

The research, funded by the U.S. Department of Energy, builds on prior work that began about five years ago at Purdue's Ray W. Herrick Laboratories, said James Braun, a professor of mechanical engineering.

Heat pumps provide heating in winter and cooling in summer but are not efficient in extreme cold climates, such as Minneapolis winters.

"With this technology we can maintain the efficiency of the heat pump even when it gets pretty cold outside," said Eckhard Groll, a professor of mechanical engineering who is working on the project with Braun and W. Travis Horton, an assistant professor of civil engineering.

The innovation aims to improve efficiency in general but is particularly practical for boosting performance in cold climates. The new heat pumps might be half as expensive to operate as heating technologies now used in cold regions where natural gas is unavailable and residents rely on electric heaters and liquid propane.

"We'll be able to extend the geographical range where heat pumps can apply," Horton said. "So this could open up a whole new market".

Scientists expect to complete a prototype by the end of the three-year, $1.3 million project. The research, which also involves three doctoral students, is a partnership with Emerson Climate Technologies Inc. and Carrier Corp. Emerson will work with scientists to create the prototype heat pump, and Carrier will integrate the new heat pump into a complete system.........

Posted by: Nora      Read more         Source


June 24, 2010, 11:02 PM CT

How the first step affects

How the first step affects
These are scientists Dr. Stefanie Tschierlei and Dr. Michael Schmitt working in a spectroscopy laboratory of Jena University.

Credit: Photo: FSU

Energy from hydrogen researchers from all over the world work on this solution to overcome the energy crisis. Amongst other things they try to use the sunlight as driving force for the splitting of water into hydrogen and oxygen. In trying to copy the photosynthesis in the laboratory a team of researchers of the Universities of Jena and Erlangen-Nrnberg and of the Institute of Photonic Technology (IPHT) in Jena (Gera number of) made a huge step forward. The physiccists and chemists were able to prove in their tests, that the first step already affects the efficiency of hydrogen generation. "This is as if you would decide about where youre going to by turning the ignition key in the car," says PD Dr Michael Schmitt from the Institute of Physical Chemistry (IPC) of the University of Jena. To put it scientifically: "The Franck-Cordon-point has to be created in such a way that the initial process of transferring electrons already points into the direction of the catalytic active centre." The results were reported in the science journal Angewandte Chemie Int. Ed".

In their tests for a more efficient energy conversion the researchers focus on chemical photo catalysts. With this light is being used to let electrons "jump" well-directed from one subunit of the molecule to the other or to transport them over a ligand, which is a "bridge".........

Posted by: Nora      Read more         Source


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