Science and Technology: News & Views

Discussion in 'Members Corner' started by RPK, Aug 18, 2009.

  1. RPK

    RPK Indyakudimahan Senior Member

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    BBC NEWS | Science & Environment | Upwards lightning caught on film

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    Scientists have photographed "upwards lightning", a rarely-seen phenomenon where electricity from storms flows into the upper atmosphere.

    During last year's Tropical Storm Cristobal, lightning reached more than 60km (40 miles) up.

    Also known as "gigantic jets", these events are just as powerful as cloud-to-ground lightning bolts.

    The US team of researchers also took radio measurements of the electrical charge.

    The phenomenon was photographed from a field site near Duke University in Durham, North Carolina.

    Their work, published in Nature Geoscience, gives scientists a better understanding of this form of lightning.

    Gigantic jets do not occur during every storm and scientists do not yet know what types of storm are conducive to their formation.

    Substantial charge

    Lead author Professor Steven Cummer, from Duke, told BBC News: "What we were able to conclusively show is that these are not just sparks that come out of the thunderstorm and travel upward and tickle the upper atmosphere.

    "They actually deliver to the upper atmosphere as much electric charge as the very strong lightning strokes to ground."

    The jets discharge a comparable amount of electricity to conventional lightning but the charge travels further and faster because the thinner air between the clouds and the ionosphere provides less resistance.

    Gigantic jets are rarely photographed because they happen so quickly that cameras have to be trained on them exactly when they occur.

    Professor Cummer caught the images of the event by chance. He had trained his camera on the sky above the storm, hoping to photograph another phenomenon known as "sprites". These are blue or red electrical discharges above storm clouds.

    He is planning to install a low-light, high speed camera to capture colour images of gigantic jets, which could provide information about chemical processes and temperatures.

    He said: "In fact, this one that we reported came from a tropical storm - not quite a hurricane.

    "There is another hurricane bearing down on us that is about to hit the eastern seaboard of the US. You can be sure that we will be training our cameras on that, just in case we are lucky."
     
  2. RPK

    RPK Indyakudimahan Senior Member

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    Wikipedia tightens editing policy to prevent online vandalism- Hindustan Times

    Online collaborative encyclopedia Wikipedia announced a tightening of its editing rules on Wednesday aimed at preventing vandalism, as it becomes an increasingly important source of information.

    The new guidelines will require that all edits to articles about living people be approved by authorised editors. The rules represent the most far-reaching changes ever undertaken by the user-written encyclopedia, which had previously allowed anyone to contribute articles or revise information on existing articles.

    Founded in 2001, Wikipedia currently boasts more than 13 million articles, including three million in English, and is one of the top 10 sites on the web. But because of its open source nature it is often not considered an authoritative source, and has been hit by numerous high profile cases of vandalism.

    The changes, called "flagged revisions", apply to the English version of the site and were announced on Wednesday on the Wikipedia blog.

    Under the new policy, articles edited by new contributors will be reviewed by regular contributors, whose comments on the revisions will be posted with the article. Readers will have the option of seeing the article before the changes were made.

    In a small percentage of cases, edited articles will have to be reviewed before they are posted, Wikipedia said. The rule will apply to articles at high risk of vandalism, such as biographies of controversial living people.

    "It's a very thoughtful proposal that attempts to balance the desire for higher quality, and more systematic assessment thereof, with the immediacy of Wikipedia as it exists today, and was supported by a large majority of interested Wikipedia editors," Erik Moeller, deputy director of the Wikimedia Foundation, said in the blog.

    More conservative review policies are in place in other versions of Wikipedia. For example, any edit on German Wikipedia by a new or unregistered user must be reviewed before it is visible to readers.

    The new changes are expected to be fully implemented within two to three months, following testing.
     
  3. RPK

    RPK Indyakudimahan Senior Member

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    domain-b.com : Australian researchers set new record for solar cell efficiency

    A team of Australian and US researchers has set a new solar cell efficiency record when their multi-cell array achieved an efficiency of 43 per cent beating the previous record by 0.3 per cent.

    Professor Martin Green of the University of New South Wales, leading the record breaking effort, said that only a fraction of the energy from the sunlight that falls on the cell is converted to electricity.

    He said that sunlight is made up of small particles of light with different energy. To create electricity each photon of light must have enough energy to free an electron inside the solar cell, however if the energy of the photon is low, no electrical current is created as the photon just bounces off the cell, he added.

    He added that a standard cell can respond to photons only above an energy threshold.

    Silicon has a low energy threshold which allows most wavelengths of energy to free an electron, but at the same time silicon cells are not efficient in converting short wavelengths such as blue light, he said.

    However, cells made of material with lower threshold are not as efficient converters are cells that are matched to that colour, according to Green.

    To achieve a higher rate of conversion, the researchers used five types of solar cells than individually matched different wavelengths of light with each cell having the maximum efficiency to a particular colour.

    With the use of filters, the researchers split the incoming light into different wavelength bands which were then used with different cells.

    The researchers developed a cell that efficiently coverts red light into electricity which they combined with cells that had worked well for other wavelength ranges. With this configuration they were able to significantly improve the overall efficiency of conversion.

    The other four cells were developed in the US by the National Renewable Energy Laboratory and Emcore Corporation.

    The previous world record of 42.7 per cent was set using the four cells in combination with a cell developed at the University of Delaware.

    Though the new design is very efficient, the flip side is it is expensive to produce.

    Green who is next focusing on improving the efficiency of single silicon cells says there will always be a trade off with the cost of efficient electricity conversion and commercial efficiency.

    He added the job of researchers is to improve the efficiency of silicon cells as single cells work out cheaper than five cells.
     
  4. RPK

    RPK Indyakudimahan Senior Member

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    domain-b.com : Robots swim with the fishes

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    New robots mimic fish's swimming, could be used in underwater exploration, writes Anne Trafton, MIT News Office

    Borrowing from Mother Nature, a team of MIT researchers has built a school of swimming robo-fish that slip through the water just as gracefully as the real thing, if not quite as fast.

    Mechanical engineers Kamal Youcef-Toumi and Pablo Valdivia Y Alvarado have designed the sleek robotic fish to more easily maneuver into areas where traditional underwater autonomous vehicles can't go. Fleets of the new robots could be used to inspect submerged structures such as boats and oil and gas pipes; patrol ports, lakes and rivers; and help detect environmental pollutants.


    Pablo Valdivia Y Alvarado, a research affiliate in the Department of Mechanical Engineering, works in his lab on a robotic fish he created with Professor Kamal Youcef-Toumi. The robot is designed to more easily maneuver into areas where traditional underwater autonomous vehicles cannot go. Photo / Patrick Gillooly/MIT News Office
    "Given the (robotic) fish's robustness, it would be ideal as a long-term sensing and exploration unit. Several of these could be deployed, and even if only a small percentage make it back there wouldn't be a terrible capital loss due to their low cost," says Valdivia Y Alvarado, a recent MIT PhD recipient in mechanical engineering.

    Robotic fish are not new: In 1994, MIT ocean engineers demonstrated Robotuna, a four-foot-long robotic fish. But while Robotuna had 2,843 parts controlled by six motors, the new robotic fish, each less than a foot long, are powered by a single motor and are made of fewer than 10 individual components, including a flexible, compliant body that houses all components and protects them from the environment. The motor, placed in the fish's midsection, initiates a wave that travels along the fish's flexible body, propelling it forward.

    The robofish bodies are continuous (i.e., not divided into different segments), flexible and made from soft polymers. This makes them more maneuverable and better able to mimic the swimming motion of real fish, which propel themselves by contracting muscles on either side of their bodies, generating a wave that travels from head to tail.

    "Most swimming techniques can be copied by exploiting natural vibrations of soft structures," says Valdivia Y Alvarado.

    As part of his doctoral thesis, Valdivia Y Alvarado created a model to calculate the optimal material properties distributions along the robot's body to create a fish with the desired speed and swimming motion. The model, which the researchers initially proposed in the journal Dynamic Systems Measurements and Control (ASME), also takes into account the robot's mass and volume. A more detailed model is described in Valdivia Y Alvarado's thesis and will soon be published along with new applications by the group.

    Other researchers, including a team at the University of Essex, have developed new generations of robotic fish using traditional assembly of rigid components to replicate the motions of fish, but the MIT team is the only one using controlled vibrations of flexible bodies to mimic biological locomotion.

    "With these polymers, you can specify stiffness in different sections, rather than building a robot with discrete sections," says Youcef-Toumi. "This philosophy can be used for more than just fish" - for example, in robotic prosthetic limbs.
    Mimicking fish

    With motors in their bellies and power cords trailing as they swim, the robo-fish might not be mistaken for the real thing, but they do a pretty good fish impersonation.

    The team's first prototypes, about five inches long, mimic the carangiform swimming technique used by bass and trout. Most of the movement takes place in the tail end of the body. Fish that use this type of motion are generally fast swimmers, with moderate maneuverability.

    Later versions of the robo-fish, about eight inches long, swim like tuna, which are adapted for even higher swimming speeds and long distances. In tuna, motion is concentrated in the tail and the peduncle region (where the tail attaches to the body), and the amplitude of body motions in this region is greater than in carangiform fish.

    Real fish are exquisitely adapted to moving through their watery environment, and can swim as fast as 10 times their body length per second. So far, the MIT researchers have gotten their prototypes close to one body length per second - much slower than their natural counterparts but faster than earlier generations of robotic fish.

    The new robo-fish are also more durable than older models - with their seamless bodies, there is no chance of water leaking into the robots and damaging them. Several four-year-old prototypes are still functioning after countless runs through the testing tank, which is filled with tap water.

    Current prototypes require 2.5 to 5 watts of power, depending on the robot's size. That electricity now comes from an external source, but in the future the researchers hope to power the robots with a small internal battery.

    Later this fall, the researchers plan to expand their research to more complex locomotion and test some new prototype robotic salamanders and manta rays.

    "The fish were a proof of concept application, but we are hoping to apply this idea to other forms of locomotion, so the methodology will be useful for mobile robotics research - land, air and underwater - as well," said Valdivia Y Alvarado.
     
  5. RPK

    RPK Indyakudimahan Senior Member

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    domain-b.com : Scientists succeed in decoding complex HIV genome structure

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    A team of US scientists has suceeded in decoding the structure of an entire HIV genome for the first time, which will give the world a better insight into the viruses that causes AIDS in humans.

    Researchers at the University of North Carolina at Chapel Hill decoded the complex HIV genome, the results of which, will have widespread implications for understanding how exactly the virus infects humans.

    The study, published in Nature, also opens the door for further research for accelerating the development of antiviral drugs.

    Kevin Weeks, Ph.D., a professor of chemistry in UNC's College of Arts and Sciences who led the study, said prior to this new work researchers had modeled only small regions of the HIV RNA genome. The HIV RNA genome is very large, composed of two strands of nearly 10,000 nucleotides each.

    By mapping the genetic structure of the virus, scientists will be able to develop more effective drugs to treat HIV, said Weeks. If replication of the virus is stopped or curtailed, there may be a possibility to even attack the virus before it gets an opportunity of sitting idle in the human body.

    HIV, like the viruses that cause influenza, hepatitis C and polio, carries its genetic information as single-stranded RNA rather than double-stranded DNA.

    The information encoded in DNA is almost entirely in the sequence of its building blocks, which are called nucleotides. But the information encoded in RNA is more complex, RNA is able to fold into intricate patterns and structures. These structures are created when the ribbon-like RNA genome folds back on itself to make three-dimensional objects.

    Weeks, who is also a member of the UNC Lineberger Comprehensive Cancer Center, and Joseph M. Watts, a chemistry postdoctoral fellow supported by the Lineberger Center, used technology developed by Weeks' lab to analyse the architecture of HIV genomes isolated from infectious cultures containing trillions of viral particles that were grown by Robert Gorelick, Ph.D., and Julian Bess of the National Cancer Institute.

    They then teamed up with UNC researchers in the College and the School of Medicine for further analysis. Christopher Leonard in the department of chemistry; Kristen Dang, Ph.D., from biomedical engineering; Ron Swanstrom, Ph.D., a professor of microbiology and immunology at UNC Lineberger; and Christina Burch, Ph.D., an associate professor of biology. They found that the RNA structures influence multiple steps in the HIV infectivity cycle.

    ''There is so much structure in the HIV RNA genome that it almost certainly plays a previously unappreciated role in the expression of the genetic code,'' Weeks said.
    Swanstrom and Weeks note that the study is the key to unlocking additional roles of RNA genomes that are important to the lifecycle of these viruses in future investigations.

    ''One approach is to change the RNA sequence and see if the virus notices,'' Swanstrom said. ''If it doesn't grow as well when you disrupt the virus with mutations, then you know you've mutated or affected something that was important to the virus.''

    ''We are also beginning to understand tricks the genome uses to help the virus escape detection by the human host,'' said Weeks.

    The study was supported by the National Institutes of Health and the National Cancer Institute.

    Hashim Al-Hashimi of the University of Michigan, Ann Arbor noted in an article in News and Views that structural biologists usually ''cut out'' the motifs formed by RNA and then ''zoom in to determine their three-dimensional structures in an attempt to further understand their function. However, Watts zoom out and provide an 'aerial view' of the secondary structure of the entire HIV-1 genome
     
  6. RPK

    RPK Indyakudimahan Senior Member

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    domain-b.com : US unveils world's most powerful laser

    The Lawrence Livermore National Laboratory in the US unveiled the world's most powerful laser last week, setting into motion the move into next stage of one of the country's greatest scientific assets.

    Costing about $4 billion, which is nearly four times the original estimate, construction of the powerful laser, known as the National Ignition Facility, began in 1997 and is designed to safeguard the country's nuclear weapons stockpile and also study the heavens.

    The NIF, which is housed in a 10-storey building covering three football fields, is the world's highest-energy laser system, consisting of 192 laser beams that will focus nearly two million joules of energy and create temperatures and pressures that exist in the cores of stars and giant planets.

    By harnessing the massive power generated by its lasers, NIF will be able to create conditions and conduct a wide range of experiments never before possible on earth.

    Funded by the US Department of Energy's National Nuclear Security Administration, the NIF was commissioned with three scientific missions in mind. Its first mission is to serve as a key component of the National Nuclear Security Administration's Stockpile Stewardship Program to ensure the safety and reliability of the nation's nuclear deterrent without the need for nuclear testing.

    NIF also offers the possibility of groundbreaking scientific discoveries in planetary science and astrophysics. By creating the conditions that exist in supernovas, in the event horizons of black holes and in the cores of giant planets, NIF will help unlock the secrets of the cosmos.

    A large majority of these experiments will be unclassified and will provide a rich source of previously unobtainable data to the world-wide research community.
    NIF's third mission, 'energy dependence' is considered the most exciting to global scientists.

    Global energy demand, driven by population growth and the aspirations of the developing world, already is straining the planet's existing energy resources. Global demand for electricity is expected to double from its current level by 2030 and then double again by the end of the century.

    At such a pace, as many as 10,000 new power plants will have to be built to keep up with this demand. Many of these plants will burn non-renewable fossil fuels - coal, oil and natural gas - and in the process release more carbon dioxide into the environment.

    As part of the global race to satisfy the world's thirst for energy, NIF will advance a new form of green energy and is scheduled to begin ignition experiments in 2010 that will focus its lasers on a very tiny target filled with isotopes of hydrogen. The heat and pressures created by NIF's lasers will force the hydrogen nuclei to collide and produce a controlled fusion reaction similar to that found in the sun.

    ''More energy will be produced by this 'ignition' process than the amount of laser energy required to start it. This is the long-sought goal of 'energy gain' that has been the goal of fusion researchers for more than half a century.

    NIF's success will be a scientific breakthrough of historic significance - the first demonstration of fusion ignition in a laboratory setting, duplicating on Earth the processes that power the stars,'' said Edward Moses, director, National Ignition Facility.

    If the laser works in the field energy dependence, then it will radically reduce the dependence on oil as the current main source energy, which is controlled by a handful of nations.

    One cubic kilometre of sea water has the fusion energy equivalent of whole world's oil reserves compared to the oil reserves sitting underground either on land or sea of some nations.

    ''This laser system is an incredible success not just for California, but for our country and our world,'' said California Governor Arnold Schwarzenegger. ''NIF has the potential to revolutionise our energy system - teaching us a new way to harness the energy of the sun to power our cars and homes. California was the home of the first working laser, so it is no surprise that the Golden State has produced the world's largest and most powerful one.''

    Although the US is not a signatory to the Comprehensive Test-Ban Treaty, it had pledged in 1992 to suspend testing nuclear weapons.

    But with this new super laser, the US will be able to conduct subcritical tests without any nuclear detonations and computer simulations to determine the results from a real life explosion.

    The laser will be able to do real life nuclear test and give their scientists enough information in the field of nuclear weapons but still be out of the pledge given by it to not carry out any nuclear test.

    Founded in 1952, Lawrence Livermore National Laboratory is America's national security laboratory, with a mission to ensure national security and apply science and technology to the important issues.

    Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the US Department of Energy's National Nuclear Security Administration
     
  7. RPK

    RPK Indyakudimahan Senior Member

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    Scientists record first ever image of molecule’s structure

    Washington, Aug 29 (IANS) Scientists have recorded the first ever image of a molecule’s “anatomy” with unprecedented clarity, using a complex technique known as non-contact atomic force microscopy.
    The results could greatly impact the field of nanotechnology, which seeks to understand and control some of the tiniest known objects.

    “If you think about how a doctor uses an X-ray to image bones and organs inside the human body, we are using the atomic force microscope (AFM) to image the atomic structures that are the backbones of individual molecules,” said IBM researcher Gerhard Meyer.

    “Scanning probe techniques offer amazing potential for prototyping complex functional structures and for tailoring and studying their electronic and chemical properties on the atomic scale,” he added.

    The team’s current study follows on the heels of another experiment published in the June 12 issue of Science, where IBM scientists measured the charged states of atoms using an AFM.

    These breakthroughs will open new possibilities for investigating how charge transmits through molecules or molecular networks.

    Understanding the charge distribution at the atomic scale is essential for building smaller, faster and more energy-efficient computing components than today’s processors and memory devices, said an IBM release.

    These findings were reported in the Friday issue of Science.
     
  8. RPK

    RPK Indyakudimahan Senior Member

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    World's smallest semiconductor laser @ The Hindu

    Shortly after the world’s smallest laser that is 10 times smaller than the wavelength of light was produced by researchers at Norfolk State University in Virginia, researchers from the University of California, Berkeley have created the world's smallest semiconductor laser, capable of generating visible light in a space smaller than a single protein molecule.

    This marks a major milestone in laser physics, and heralds a new era in the field of optics.

    What makes the latest advancement important is that researchers not only squeezed light into such a tight space but also succeeded in finding a novel way to keep that light energy from dissipating as it moved along, thereby achieving laser action. The results were published online in the journal Nature.

    The two achievements shatter the traditional notion of laser limits: an electromagnetic wave cannot be focused beyond the size of half its wavelength.

    Researchers have tried to break the laser limit by compressing light down to dozens of nanometers by binding it to the electrons that oscillate collectively at the surface of metals. This interaction between light and oscillating electrons is known as surface plasmons.

    Researchers from Norfolk State University created lasing action through plasmons by using gold nanoparticles immersed in a dye. The dye coupled to the gold spheres generated surface plasmons when exposed to light.

    But the biggest problem encountered by scientist working on plasmon lasers is in achieving the buildup of the electromagnetic field necessary for lasing. The resistance inherent in metals caused an almost immediate dissipation of surface plasmons.

    Xiang Zhang, who led the team that worked on semiconductor laser, found a way to overcome this problem. He used a novel approach by to stem the loss of light energy by pairing a cadmium sulfide nanowire — 1,000 times thinner than a human hair — with a silver surface separated by an insulating gap of only 5 nanometers, the size of a single protein molecule. In this structure, the gap region stores light within an area 20 times smaller than its wavelength. Because light energy is largely stored in this tiny non-metallic gap, loss is significantly diminished.

    There are several applications of plasmons: nanolasers that can probe, manipulate and characterize DNA molecules; optics-based telecommunications many times faster than current technology; and optical computing in which light replaces electronic circuitry with a corresponding leap in speed and processing power.
     
  9. RPK

    RPK Indyakudimahan Senior Member

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    BBC NEWS | Science & Environment | Single molecule's stunning image

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    The detailed chemical structure of a single molecule has been imaged for the first time, say researchers.

    The physical shape of single carbon nanotubes has been outlined before, using similar techniques - but the new method even shows up chemical bonds.

    Understanding structure on this scale could help in the design of many things on the molecular scale, particularly electronics or even drugs.

    The IBM researchers report their findings in the journal Science.

    It is the same group that in July reported the feat of measuring the charge on a single atom.

    Fine tuning

    In both cases, a team from IBM Research Zurich used what is known as an atomic force microscope or AFM.

    Their version of the device acts like a tiny tuning fork, with one of the prongs of the fork passing incredibly close to the sample and the other farther away.

    When the fork is set vibrating, the prong nearest the sample will experience a minuscule shift in the frequency of its vibration, simply because it is getting close to the molecule.

    Comparing the frequencies of the two prongs gives a measure of just how close the nearer prong is, effectively mapping out the molecule's structure.


    The microscope must be kept under high vacuum and exceptionally cold
    The measurement requires extremes of precision. In order to avoid the effects of stray gas molecules bounding around, or the general atomic-scale jiggling that room-temperature objects experience, the whole setup has to be kept under high vacuum and at blisteringly cold temperatures.

    However, the tip of the AFM's prong is not well-defined and isn't necessarily sharp on the scale of single atoms. The effect of this bluntness is to blur the instrument's images.

    The researchers have now hit on the idea of deliberately picking up just one small molecule - made of one atom of carbon and one of oxygen - with the AFM tip, forming the sharpest, most well-defined tip possible.

    Their measurement of a pentacene molecule using this carbon monoxide tip shows the bonds between the carbon atoms in five linked rings, and even suggests the bonds to the hydrogen atoms at the molecule's periphery.

    Tip of the iceberg

    Lead author of the research Leo Gross told BBC News that the group is aiming to combine their ability to measure individual charges with the new technique, characterising molecules at a truly unprecedented level of detail.

    That will help in particular in the field of "molecular electronics", a potential future for electronics in which individual molecules serve as switches and transistors.

    Although the approach can trace out the ethereal bonds that connect atoms, it cannot distinguish between atoms of different types.

    The team aims to use the new technique in tandem with a similar one known as scanning tunnelling microscopy - in which a tiny voltage is applied accross the sample - to determine if the two methods in combination can deduce the nature of each atom in the AFM images.

    That would help the entire field of chemistry, in particular the synthetic chemistry used for drug design.

    The results are of wide interest to others who study the nano-world with similar instruments. For them, implementing the same approach is as simple as picking up one of these carbon monoxide molecules with their AFM before taking a measurement
     
  10. RPK

    RPK Indyakudimahan Senior Member

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    New laser tech makes it possible to turn light into sound

    Washington: A team of scientists has developed a new laser technology
    that has made it possible to turn light into sound.


    Developed by scientists at the Naval Research Laboratory, US, the technology has the potential to expand and improve both Naval and commercial underwater acoustic applications, including undersea communications, navigation and acoustic imaging.

    According to a report in Live Science, this process is made possible by the compression of laser pulses.

    Various colors of a laser travel at different speeds in water. These colors can be arranged so that the laser pulse compresses in time as it moves through water, which concentrates the light.

    To convert light into sound, a laser pulse is compressed to ionize a small amount of water (give the water molecules a charge).

    The ionized water then absorbs the laser energy and heats up. The result is a small explosion of steam that generates a 220-decibel pulse of sound.

    A laser pulse can travel through either air or water, but the concentration effects are much stronger in water.

    A well-tuned laser can travel many hundreds of meters (yards) through air, then quickly compress once it enters the water, making it possible for aircraft to send messages underwater.
     
  11. RPK

    RPK Indyakudimahan Senior Member

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    Bacteria `to convert waste into power`

    Washington: Scientists have claimed that bacteria which generate significant amounts of electricity can be used in microbial fuel cells to convert waste into power as well as provide electricity in remote environments.


    A team, led by Prof Derek Lovley from the University of Massachusetts, isolated bacteria with large numbers of tiny projections, called pili, which were efficient at transferring electrons to generate power in fuel cells than bacteria with a smooth surface.

    In their experiment, the scientists isolated a strain of Geobacter sulfurreducens which they called KN400 that grew prolifically on the graphite anodes of fuel cells.

    The bacteria formed a thick biofilm on the anode surface, which conducted electricity. They found large quantities of pilin, a protein that makes the tiny fibres that conduct electricity through the sticky biofilm.

    "The filaments form microscopic projections called pili that act as microbial nanowires using this bacterial strain in a fuel cell to generate electricity would greatly increase the cell's power output," Prof Lovley said.
     
  12. RPK

    RPK Indyakudimahan Senior Member

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    You can generate electricity from a tree

    Washington: There's enough power in trees to run an electronic circuit, says a new study.


    A study last year led by the Massachusetts Institute of Technology (MIT) found that plants generate up to 200 millivolts when one electrode is placed in a plant and the other in the surrounding soil.

    "As far as we know this is the first peer-reviewed paper of someone powering something entirely by sticking electrodes into a tree," University of Washington (UW) associate professor of electrical engineering and study co-author Babak Parviz said.

    The researchers have since started a company developing forest sensors that exploit this new power source. The UW team sought to do further academic research in the field of tree power by building circuits to run off that energy. They successfully ran a circuit solely off tree power for the first time.

    Co-author Carlton Himes, UW undergraduate student, spent last summer exploring likely sites. Hooking nails to trees and connecting a voltmeter, he found that bigleaf maples, common on the UW campus, generate a steady voltage of up to a few hundred millivolts.

    The UW team next built a device that could run on available power. Co-author Brian Otis, UW assistant professor of electrical engineering, led the development of a boost converter, a device that takes a low incoming voltage and stores it to produce a greater output.

    His team's custom boost converter works for input voltages of as little as 20 millivolts (a millivolt is a thousandth of a volt), an input voltage lower than any existing such device. It produces an output voltage of 1.1 volts, enough to run low-power sensors.

    The UW circuit is built from parts measuring 130 nanometres and it consumes on average just 10 nanowatts of power during operation (a nanowatt is one billionth of a watt).

    "Normal electronics are not going to run on the types of voltages and currents that we get out of a tree. But the nanoscale is not just in size, but also in the energy and power consumption," Parviz said, according to an UW release.

    Tree power is unlikely to replace solar power for most applications, Parviz admits. But the system could provide a low-cost option for powering tree sensors that might be used to detect environmental conditions or forest fires. The electronic output could also be used to gauge a tree's health.

    These results are slated for publication in the Institute of Electrical and Electronics Engineers' Transactions on Nanotechnology.
     
  13. RPK

    RPK Indyakudimahan Senior Member

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    domain-b.com : Virtually waterless washing machine heralds cleaning revolution

    Xeros Ltd, a University of Leeds spin-out, is commercialising a cleaning technology that needs less than 2 per cent of water and energy a conventional washing machine uses.

    Researchers at the University of Leeds have developed a new way of cleaning clothes using less than 2 per cent of the water and energy of a conventional washing machine. The revolutionary technology will provide alternatives to both domestic washing and dry cleaning, heralding the world's first ''virtually waterless'' washing system.

    Xeros Ltd, a University of Leeds spin-out, is commercialising the technology with some of the biggest names in the washing and dry-cleaning industries.

    The process is based on the use of plastic granules (or chips) which are tumbled with the clothes to remove stains. A range of tests, carried out according to worldwide industry protocols to prove the technology performs to the high standards expected in the cleaning industry, show the process can remove virtually all types of everyday stains as effectively as existing processes whilst leaving clothes as fresh as normal washing. In addition, the clothes emerge from the process almost dry, reducing the need for tumble-dryers.

    Xeros' technology uses as little as a cup of water in each wash cycle and could also bring benefits to other industrial processes such as wastewater treatment and metal degreasing.

    According to Waterwise, a UK NGO focused on decreasing water wastage in the UK, washing machine use has risen by 23 per cent in the past 15 years, up from three times a week in 1990 to an average of four times a week per household today. The average UK household uses almost 21 litres of water each day on clothes washing - 13 per cent of daily household water consumption. This accounts for approximately 455 million litres of water daily, enough water to fill 145 Olympic size swimming pools.

    Tests are currently underway in the dry-cleaning market with a view to replacing certain solvents that are currently used in dry-cleaning. Some of these solvents are potentially harmful, having been linked with certain types of cancer and some are now facing a ban in various states in the US. The company believes that its new proprietary technology would eradicate the need for these solvents from dry-cleaning providing safety and monetary incentives for the dry cleaning industry.

    The new technology could be on the UK market as early as 2009. Xeros has recently received funding of £500,000 from the University's intellectual property commercialisation partnership with IP Group, subject to certain milestones being met. The IP Group specialises in commercialising university technology.

    Xeros was established in February 2007, after 30 years of research, to commercialise a new patented washing method invented and developed in the School of Design at the University of Leeds.

    Company founder, Professor Stephen Burkinshaw, is an internationally-recognised expert in the science of textiles and dyeing who has created considerable intellectual property in the area.

    Professor Burkinshaw, professor of textile chemistry and director of Xeros, said, ''The performance of the Xeros process in cleaning clothes has been quite astonishing. We've shown that it can remove all sorts of everyday stains including coffee and lipstick whilst using a tiny fraction of the water used by conventional washing machines. The investment from IP Group will help us to accelerate the commercialisation of the technology and I look forward to seeing new washing and dry-cleaning machines that use the Xeros technology.''

    A typical washing machine uses about 35kg of water for every kg of clothes that are washed - as well as large amounts of energy to heat the water and to dry the clothes afterwards. With environmental concerns becoming increasingly urgent and water becoming an increasingly scarce resource, there is an urgent need to reduce the amount of water and energy used for washing clothes.

    In designing the Xeros cleaning process, Professor Burkinshaw harnessed the property of polymers to transform under humid conditions and become absorbent. He said, ''Dirt is not just attracted to the surface, it is locked into the centre. This is exactly what happens when Xeros nylon beads are gently tumbled with dampened garments.''

    Dr Rob Rule, managing director of Techtran Ltd, IP Group's Leeds business, and a director of Xeros, said: ''This is one of the most surprising and remarkable technologies I've encountered in recent years. Xeros has the ability to save billions of litres of water per year and, we believe, the potential to revolutionise the global laundry market. ''

    The potential revenues for machines based on the Xeros technology are considerable as over two million washing machines are sold in the UK annually, valuing the UK market alone at around £1 billion.

    GreenEarth partnership
    In a deal which heralds the next stage in the company's evolution, Xeros announced in June 2009 a partnership with US dry cleaning technology group GreenEarth.

    The deal with GreenEarth will result in Xeros' laundry cleaning technology being distributed to the retail dry cleaning industry.

    GreenEarth, which currently licenses its patented silicone-based dry cleaning technology around the world, will have exclusive rights to distribute the technology throughout North America to retail dry cleaners.

    Bill Westwater, Xeros' chief executive officer, said, ''Our partnership with GreenEarth is a critical piece of this project. They are not only experts in licensing and marketing environmentally sound technologies, they stand apart in the dry cleaning community as a company genuinely committed to creating solutions and new opportunities.''

    Xeros was developed and patented after 30 years of research by world-class polymer scientists at Leeds, led by Stephen Burkinshaw, Professor of Textile Chemistry. The company has received funding from the University's commercialisation partner, IP Group. Professor Burkinshaw said: ''Stains behave just like dyes and nylon polymers have an inherent polarity that attracts stains. Picture how white nylon garments can get dingy over time as dirt builds up on the surface despite repeated washing.''

    In designing the Xeros cleaning process, Professor Burkinshaw harnessed the property of polymers to transform under humid conditions and become absorbent. He said, ''Dirt is not just attracted to the surface, it is locked into the centre. This is exactly what happens when Xeros nylon beads are gently tumbled with dampened garments.''

    The tiny nylon polymer beads are designed to gently but fully penetrate into a large wash load. Only a small amount of water is required to dampen the garments, loosen stains and create the water vapour that activates the ''molecular magic'' of the beads. The beads are then tumbled with the clothes, allowing the polarizing properties of polymer to attract and absorb dirt. Once diffused into the bead itself, stains are locked away from the garment, preventing re-deposition.

    Ron Benjamin, GreenEarth Cleaning Managing Director, said: ''We honestly believe Xeros will change the way we launder clothes while helping to conserve our fresh water supply. What a remarkable concept-wet cleaning that no longer sends water down the drain.''

    GreenEarth Cleaning will be the exclusive licensor of the patented Xeros technology to retail dry cleaners in North America; it will also have the right to license to existing GreenEarth Affiliates in every country around the world.
     
  14. RPK

    RPK Indyakudimahan Senior Member

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    Scientists confirm existence of superheavy element 114

    Washington, September 25 (ANI): Researchers in Berkeley Lab’s Nuclear Science Division and UC Berkeley have made a step forward in the quest to achieve an ‘Island of Stability’ among notoriously short-lived artificial elements, by confirming the production of the superheavy element 114.

    The announcement comes ten years after a group in Russia at the Joint Institute for Nuclear Research in Dubna first claimed to have made the element.

    Heino Nitsche, head of the Heavy Element Nuclear and Radiochemistry Group in Berkeley Lab’s Nuclear Science Division (NSD) and a professor of chemistry at the University of California at Berkeley, and Ken Gregorich, a senior staff scientist in NSD, led the team that independently confirmed the production of the new element, which was first published by the Dubna Gas Filled Recoil Separator group.

    Using an instrument called the Berkeley Gas-filled Separator (BGS) at Berkeley Lab’s 88-Inch Cyclotron, the researchers were able to confirm the creation of two individual nuclei of element 114, each a separate isotope having 114 protons but different numbers of neutrons, and each decaying by a separate pathway.

    “By verifying the production of element 114, we have removed any doubts about the validity of the Dubna group’s claims,” said Nitsche. “This proves that the most interesting superheavy elements can in fact be made in the laboratory,” he added.

    To create a superheavy nucleus requires shooting one kind of atom at a target made of another kind; the total protons in both projectile and target nuclei must at least equal that of the quarry.

    Confirming the Dubna results meant aiming a beam of 48Ca ions - calcium whose nuclei have 20 protons and 28 neutrons - at a target containing 242Pu, the plutonium isotope with 94 protons and 148 neutrons.

    The 88-Inch Cyclotron’s versatile Advanced Electron Cyclotron Resonance ion source readily created a beam of highly charged calcium ions, atoms lacking 11 electrons, which the 88-Inch Cyclotron then accelerated to the desired energy.

    According to Gregorich, “The high beam intensities from the 88-Inch Cyclotron, together with the efficient background suppression of the BGS, allow us to look for nuclear reaction products with very small cross-sections - that is, very low probabilities of being produced. In the case of element 114, that turned out to be just two nuclei in eight days of running the experiment almost continuously.” (ANI)



    Read more: Scientists confirm existence of superheavy element 114
     
  15. RPK

    RPK Indyakudimahan Senior Member

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    fullstory

    Hydrogen-making algae's 'Achilles heel' discovered

    STAFF WRITER 16:20 HRS IST
    London, Sep 29 (PTI) Scientists have discovered how oxygen stops green algae from producing hydrogen. The findings could help those working towards 'solar H2-farms' in which microorganisms produce hydrogen fuel from sunlight and water.

    An international team of scientists from Oxford University and universities in Germany reported their results in two papers published this week.

    For years, scientists have been interested in how we could, potentially, produce hydrogen from just sunlight and water to power vehicles and other devices. One option is to use photosynthetic microorganisms that are able to produce hydrogen as well as starch.

    Green algae are one of the microorganisms that many have suggested could be turned into living hydrogen factories
     
  16. RPK

    RPK Indyakudimahan Senior Member

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    SAfrican mine discovers massive 507 carat white diamond

    Johannesburg, Sept 29 (AFP) Mining group Petra Diamonds has discovered a 507.55 carat white diamond at South Africa's Cullinan mine, one of the largest high-quality rough diamonds ever found, the firm said today.

    "This spectacular gemstone was recovered on Thursday and is currently with experts for analysis," said a statement released by the London-listed company which operates mainly in Africa.

    Initial examinations of the diamond which weighs just over 100 grams (3.5 ounces), have shown it to be of exceptional colour and clarity.

    The diamond is undergoing colour grading, but is believed to be a rare Type II diamond, with very low traces of nitrogen -- considered an impurity -- making them among the most transparent and colourless of the gems.

    "The Cullinan mine has again given the world a spectacularly beautiful and important diamond...
     
  17. RPK

    RPK Indyakudimahan Senior Member

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    Researchers identify bacteria that makes gold!

    Washington, Oct 9 (PTI) Scientists have discovered a bacteria species that forms metallic gold -- but it's unlikely to make anyone rich.

    An international team has found that the bacterium Cupriavidus metallidurans catalyses the biomineralisation of gold by transforming toxic gold compounds to their metallic form using active cellular mechanism.

    According to the scientists, they have found evidence indicating that there may be a biological reason for the presence of these bacteria on gold grain surfaces.

    "A number of years ago we discovered that the metal-resistant bacterium Cupriavidus metallidurans occurred on gold grains from two sites in Australia. The sites are 3500 km apart, in southern New South Wales and northern Queensland, so when we found the same organism on grains from both sites we thought we were onto something.

    "It made us wonder why these organisms live in this particular environment.
     
  18. RAM

    RAM The southern Man Senior Member

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    Energy-autonomous sensors for aircraft

    Aircraft maintenance will be easier in future, with sensors monitoring the aircraft skin. If they discover any dents or cracks they will send a radio message to a monitoring unit. The energy needed for this will be obtained from temperature difference.
    If a bird collides with a plane the consequences can be fatal, not only for the creature itself. The impact can deform the structure of the aircraft fuselage, causing stresses in the material which can later turn into cracks. In future, sensors in the aircraft skin will detect such damage at an early stage and simplify maintenance and repair work. The sensors are light – they don’t need any cables or batteries. They draw their energy from the temperature difference between the outside air (about minus 20 to minus 50 degrees Celsius) and the passenger cabin (about 20 degrees Celsius). Because there are no batteries to change, the sensors can be located at inaccessible places on the aircraft.
    EADS Innovation Works heads the development consortium. Researchers at the Fraunhofer Institute for Physical Measurement Techniques IPM in Freiburg are developing the energy supply system for the sensors. “We use thermoelectric generators, developed in cooperation with Micropelt GmbH, and adapt them so that they work efficiently,” explains Dr. Dirk Ebling, scientist at the IPM. Thermoelectric materials are semiconductors which generate electric power under the influence of a temperature difference. If a number of these thermoelectric elements are connected in series, enough energy is produced to power small sensors as well as a radio device transmitting the measurement results to a central unit. “We are also optimizing the heat flow,” the research scientist continues. A key question is how to couple the thermoelectric generator to the warm and cold environments so that it transports enough heat. To obtain the answer the scientists set up a climate chamber in which the temperature profile of the aircraft fuselage is simulated. The first optimized prototypes have already been built. Development of a prototype of the entire system including the sensor, thermoelectric generator, energy storage device, charging electronics and signal transmission module is scheduled for completion in about three years’ time, hopefully enabling the system to enter series production.
    The applications for energy-autonomous sensors are numerous. In automobiles they could help to reduce weight by removing the need for heavy cable assemblies. They would also be useful in old buildings, where they could be easily affixed to walls e.g. to monitor dampness. Their use in the medical sector is feasible too. A sensor system integrated in a running shirt could monitor an athlete’s pulse during training, and hearing aids could obtain their energy from body heat.


    Courtesy- Energy-autonomous sensors for aircraft - Research News 10-2009-Topic 1 ? Fraunhofer-Gesellschaft
     
  19. gokulakannan

    gokulakannan Regular Member

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    BT brinjal technology is safe, says Dr. Gosal of Punjab Agriculture University

    Ludhiana, Oct. 20 (ANI): Contrary to apprehensions of voluntary organisations over the ill effects of Bt technology for brinjals, a distinguished professor with the Punjab Agriculture University (PAU) has said that genetically modified brinjal (Bt brinjal) is not harmful and added that it’s a safe technology.

    Dr. Satbir Singh Gosal, Additional Director Research Agriculture in Punjab Agriculture University, said the technology would produce vegetables with much less insecticide level.

    “When insecticide is put on plants, it kills insecticide and also harmful for the consumers but this technology will kill the insects but not harmful to the humans. There is fear in the mind of people about the harmful effects of the technology but the vegetables grown through this technology will have less quantity of insecticides,” says Dr. Gosal of Punjab Agricultural University.

    The commercialisation of genetically modified Bt brinjal approved by Genetic Engineering Approval Committee (GEAC), the biotechnology regulator on Wednesday (October 14), has met with serous concerns by various organisations.

    India allowed commercial cultivation of Bt cotton in 2002, sparking protests from activists who contended that genetically altered crops are a health hazard, spoil soil texture and above all, harm the environment.

    The vegetable consumed by the masses will be the first genetically altered food crop to be commercially launched in India, which has so far permitted commercial cultivation of only one genetically engineered crop-bacillus thuringiensis or Bt cotton.

    Bt brinjal is a transgenic vegetable, which carries a gene called ‘Bt’ from a bacterium, which releases toxin to kill fruit and shoot borer insects.

    BT brinjal technology is safe, says Dr. Gosal of Punjab Agriculture University | National
     
  20. RAM

    RAM The southern Man Senior Member

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    Sensing Disasters From Space


    Tel Aviv University's "Earth Binoculars" see our planet through an astral lens

    One small step for mankind is now a leap for averting natural and man-made disasters on earth.

    New Tel Aviv University technology combines sophisticated sensors in orbit with sensors on the ground and in the air to create a “Hyperspectral Remote Sensor” (HRS). It can give advance warnings about water contamination after a forest fire, alert authorities of a pollution spill long before a red flag is raised on earth, or tell people in China where a monsoon will strike.

    Prof. Eyal Ben-Dor of TAU's Department of Geography describes his team’s HRS technology as a combination of physical, chemical and optical disciplines. “When a devastating forest fire hits the Hollywood Hills, for example, we can see from space how the mineralogy of the soil has changed,” he explains. “Because of these changes, the next rainstorm may wash out all the buildings or leach contaminants into the soil. With our new tool, we can advise on how to contain the pollutants after the fire, and warn if there is a risk for landslides.”

    Details on new applications of this technology were presented recently in several leading journals including Soil Science Society of America Journals, Soil Science Journal and the International Journal of Remote Sensing.

    Putting a price on dirt

    HRS provides information useful to property developers as well. It can offer a soil profile map with detailed information for contractors, farmers or vintners interested in making major land purchase deals or managing existing ones. It can also indicate where water runoff should be directed and what minerals may be lacking in a given parcel of land.

    “Water is an expensive commodity today,” says Prof. Ben Dor. “Knowing how to better manage water resources is a top priority for states like California, and our new tool could help them do that.”

    Today, it can take years before authorities can detect chemicals that can compromise our health. For example, about 90% of all gas stations leak contaminants into the soil, says Prof. Ben-Dor. His new HRS can monitor gas stations and identify problematic areas. “Our space sensors combined with ground measurements and GPS data will be able to detect and map hydrocarbon contamination in real time. Within a year, we’ll be able to identify these problematic areas far more quickly than with traditional methods,” he says.

    Seeing where Earth takes the heat

    The HRS simultaneously acquires hundreds of optical images, each from a different frequency, that enable a “spectral assessment” from distances high in the air via airplanes and in orbit using satellites. This raw data is then processed by Prof. Ben Dor and his team to yield sophisticated thematic maps. “These are not regular maps at all,” says Prof. Ben-Dor. “We are combining properties from the physical, chemical and optical worlds, using all the latest technologies available from these fields. Ours is one of a few leading teams in the world exploring this novel way of mapping earth.”

    These “soil maps” supply a bigger picture. Water bodies and sediment runoff in California. A small soil patch in a California forest after a fire. Impending monsoons and floods in China. Contaminants surrounding a factory. All these can literally be “seen” from space with the HRS.

    Previous research by Prof. Ben-Dor, which focused on mapping urban heat islands from space, is now regularly used by cities and urban planners to develop projects such as “green” roofs or new parks.

    courtesy: Sensing Disasters From Space - Space News - redOrbit
     

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