Indian boffin creates camera with invisible flash that takes pics sans the glare

London: An Indian researcher along with a colleague has developed a camera that takes photos with an invisible flash of infrared and ultraviolet light points to a smarter way to take photos in the dark.

Dilip Krishnan and Rob Fergus at New York University made the camera to do away with intrusive regular flashes.

In order to make their 'dark flash' camera, the researchers modified a flashbulb to emit light over a wider range of frequencies and filter out visible light.

They also had to remove the filters which usually prevent a camera's silicon image sensor detecting IR and UV rays, reports New Scientist.

Krishnan and Fergus used colour information from a brief, flash-free photograph of the same scene taken quickly after the dark flash image to give the pictures more normal hues.

Krishnan and Fergus will present their work at the Siggraph conference in New Orleans in August.

New mechanism may double a planet's lifespan

Washington : A team of scientists from the California Institute of Technology (Caltech) has come up with a mechanism that doubles the future lifespan of the biosphere of a planet, while also increasing the chance that advanced life will be found elsewhere in the universe.
As the sun has matured over the past 4.5 billion years, it has become both brighter and hotter, increasing the amount of solar radiation received by Earth, along with surface temperatures.
Earth has coped by reducing the amount of carbon dioxide in the atmosphere, thus reducing the warming effect.
According to Joseph L. Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology at Caltech, the problem is that “we’re nearing the point where there’s not enough carbon dioxide left to regulate temperatures following the same procedures.”
Kirschvink and his collaborators Yuk L. Yung, a Caltech professor of planetary science, and graduate students King-Fai Li and Kaveh Pahlevan, say that the solution is to reduce substantially the total pressure of the atmosphere itself, by removing massive amounts of molecular nitrogen, the largely nonreactive gas that makes up about 78 percent of the atmosphere.
This would regulate the surface temperatures and allow carbon dioxide to remain in the atmosphere, to support life, and could tack an additional 1.3 billion years onto Earth’s expected lifespan.
Increasing the lifespan of our biosphere, from roughly 1 billion to 2.3 billion years, has intriguing implications for the search for life elsewhere in the universe.
The length of the existence of advanced life is a variable in the Drake equation, astronomer Frank Drake’s famous formula for estimating the number of intelligent extraterrestrial civilizations in the galaxy.
Doubling the duration of Earth’s biosphere effectively doubles the odds that intelligent life will be found elsewhere in the galaxy.
“It didn’t take very long to produce life on the planet, but it takes a very long time to develop advanced life,” said Yung.
On Earth, this process took four billion years.
“Adding an additional billion years gives us more time to develop, and more time to encounter advanced civilizations, whose own existence might be prolonged by this mechanism. It gives us a chance to meet,” said Yung.

Sperm-like nano-devices may revolutionise drug delivery inside the body

London: A team of scientists, including an Indian-origin researcher, are working on remote-controlled nano-devices that look like sperm that may one day deliver drugs to where they are needed in the body.
Peer Fischer of The Rowland Institute at Harvard University has revealed that the nanopropellers will mimic the corkscrew motion of flagella, the structures some bacteria use to swim through water.
He and his colleague Ambarish Ghosh have revealed that their nanopropellers are made of glass.
The researchers further revealed that each of them has a spherical head 200 to 300 nanometres across and a corkscrew-shaped tail 1 to 2 micrometres long - less than one-tenth the length of a human sperm.
Ghosh and Fischer covered a silicon wafer with glass beads to make these propellers, before depositing a vapour of silicon dioxide onto them.
While doing so they spun the wafer, causing the silicon dioxide to form corkscrew-shaped tails on each bead. Finally, once the silicon dioxide had solidified they covered one side of the nanopropellers with cobalt.
Ghosh and Fischer say that the nanopropellers can be steered precisely.
"We control the coils that give rise to the magnetic field. By changing the magnetic field in three dimensions we can steer and propel the propellers," New Scientist quoted Fischer as saying.
The team have shown that a nanopropeller can push a silica bead over 1000 times larger than itself. They believe that their work may revolutionise drug delivery to specific areas of the body via the bloodstream, or even to conduct surgery.

'Smart turbine blades' to improve wind power

Washington: In a new research, scientists have developed a technique that uses sensors and computational software to constantly monitor forces exerted

on wind turbine blades, a step towardimproving efficiency by adjusting for rapidly changing wind conditions.
The research, by engineers at Purdue University and Sandia National Laboratories, is part of an effort to develop a smarter wind turbine structure
"The ultimate goal is to feed information from sensors into an active control system that precisely adjusts components to optimize efficiency," said Purdue doctoral student Jonathan White, who is leading the research with Douglas Adams, a professor of mechanical engineering

and director of Purdue's Center for Systems Integrity.
The system also could help improve wind turbine reliability by providing critical real-time information to the control system to prevent catastrophic wind turbine damage from high winds.
The engineers embedded sensors called uniaxial and triaxial accelerometers inside a wind turbine blade as the blade was being built.
The blade is now being tested on a research wind turbine at the US Department of Agriculture's Agriculture Research Service laboratory in Bushland, Texas.
Such sensors could be instrumental in future turbine blades that have "control surfaces" and simple flaps like those on an airplane's wings to change the aerodynamic characteristics of the blades for better control.
Because these flaps would be changed in real time to respond to changing winds, constant sensor data would be critical.
Research findings show that using a trio of sensors and "estimator model" software developed by White accurately reveals how much force is being exerted on the blades.
"You want to be able to control the generator or the pitch of the blades to optimize energy capture by reducing forces on the components in the wind turbine during excessively high winds and increase the loads during low winds. In addition to improving efficiency, this should help improve reliability," said Adams.
"We envision smart systems being a potentially huge step forward for turbines," said Sandia's Rumsey.
"There is still a lot of work to be done, but we believe the payoff will be great. Our goal is to provide the electric utility industry with a reliable and efficient product. We are laying the groundwork for the wind turbine of the future," he added.
Purdue and Sandia have applied for a provisional patent on the technique.

Biofuel crops can become invasive pests in tropical areas

Washington: In a new research, scientists have concluded that biofuel crops proposed for use in the Hawaiian Islands are two to four times more likely to become invasive pests in Hawaii and other tropical areas when compared to a random sample of other introduced plants.
The research was done by scientists with the University of Hawaii Pacific Cooperative Studies Unit, who examined the impact of unregulated planting of biofuel crops for their potential invasiveness and raised concerns about their impacts on Hawaii's environment.
Recent spikes in energy costs and political instability in many oil-rich regions of the world are driving a search for homegrown alternatives to traditional fossil fuels, such as coal, oil and natural gas.
Biofuel crops are often touted as a 'green' solution to U.S. dependence on foreign oil and have been promoted for stimulus package 'green jobs'.
Despite the potential benefits, researchers say biofuel crops actually might be aggressive invasive plants grown under the guise of beneficial crops.
The researchers used a weed risk assessment that examines a plant's biology, geographic origin, pest status elsewhere, and published information on its behavior in Hawaii to identify plants with a high risk of becoming invasive pests in Hawaii or other Pacific islands.
Despite these findings, researchers say some high risk biofuel crops could be grown if measures are implemented that reduce their risk of spreading out of control and causing unintended problems.
According to Christopher Buddenhagen, co-author of the study, 'By identifying the species with the highest risk, and pushing for planting guidelines and precautionary measures prior to widespread planting, we hope to spare the Hawaiian Islands and similar tropical ecosystems from future economic and environmental costs of the worst invaders while encouraging and promoting the use of lower risk alternative crops.'

Higher Performance Electrical and Optical Integrated Circuits come closer to Reality

Washington: Scientists at the University of Illinois have moved a step closer to realising higher speed electronics and higher performance electrical and optical integrated circuits, for they have successfully created a microwave signal mixer made from a tunnel-junction transistor laser.
The researchers have revealed that their mixing device accepts two electrical inputs, and produces an optical signal that was measured at frequencies of up to 22.7 gigahertz.
They say that the frequency range was limited by the bandwidth of the detector employed in the measurements, not by the transistor device.
"In addition to the usual current-modulation capability, the tunnel junction provides an enhanced means for voltage-controlled modulation of the photon output of the transistor laser. This offers new capabilities and a much greater sensitivity for unique signal-mixing and signal-processing applications," said Nick Holonyak Jr., a John Bardeen Chair Professor of Electrical and Computer Engineering and Physics.
For making the device, the research team placed a quantum well inside the base region of a transistor laser, and then created a tunnel junction within the collector region.
"Within the transistor laser, the tunnelling process occurs predominantly through a process called photon-assisted absorption," said Milton Feng, the Holonyak Chair Professor of Electrical and Computer Engineering.
According to Feng, the tunnelling process begins in the quantum well, where electrons and holes combine and generate photons, which are then reabsorbed to create new pairs of electrons and holes used for voltage modulation.
"The tunnel junction makes it possible to annihilate an electron in the quantum well, and then tunnel an electron out to the collector by the tunnel contact," Feng said.
The transistor output is sensitive to third-terminal voltage control because of the electrons tunneling from the base to the collector, which also creates an efficient supply of holes to the quantum well for recombination.
"We are using the photon internally to modify the electrical operation and make the transistor itself a different device with additional properties," said Holonyak, who also is a professor in the university's Center for Advanced Study, one of the highest forms of campus recognition.
According to the researchers, high-speed signal mixing is made possible by the nonlinear coupling of the internal optical field to the base electron-hole recombination, minority carrier emitter-to-collector transport, and the base-to-collector electron tunneling at the collector junction.
The sensitivity of the tunnel-junction transistor laser to voltage control enables the device to be directly modulated by both current and voltage.
The researchers say that this flexibility facilitates the design of new non-linear signal processing devices for improved optical power output.
"The metamorphosis of the transistor is not yet complete. We're still working on it, and the transistor is still changing," Holonyak said.
The fabrication and operation of the mixing device has been described in the journal Applied Physics Letters.

85,500 Solar Jobs Possible in Florida:
By Susan Salisbury

Harnessing solar energy in the Sunshine State has always seemed to make a lot of sense. Well, now a grass-roots group wants to put that to the test.
The San Francisco-based The Vote Solar Initiative, focused on advancing solar energy development in the U.S., estimates that 85,500 jobs -- from construction to engineering to marketing -- could be created if Florida adopts a proposed requirement that 20 percent of the state's electricity comes from renewable sources by 2020.
By May, the Florida Legislature is expected to consider the 20 percent renewable standard recommended by the Florida Public Service Commission. Now, about 2 percent of the state's energy comes from renewable sources.
Gwen Rose, deputy director of The Vote Solar Initiative, said the jobs estimate comes from a study by Navigant Consulting that showed more than 3,800 megawatts of solar power could be generated if the state goes to the 20 percent standard. According to Navigant, with each megawatt yielding 15 to 30 direct jobs, that translates into 57,000 to 114,000 direct jobs -- 85,500 is the mid-range.
Today, Vote Solar placed a job listing in the Classifieds section of newspapers around the state, including The Palm Beach Post, stating: "HELP WANTED: 85,000 electricians, engineers, sales to staff the new solar energy economy. Apply at Legislature. Ask for strong solar energy policies." "The nice thing about solar is that it is flexible, modular and quick to market," Rose said. "You get projects in on the ground really fast. If the renewable portfolio standard passes and the rules are in place, you could see development really accelerate by 2010." She said solar is flexible because solar power plants can be large enough to power a community, or small enough to be installed on the rooftops of a house.
Indeed, several South Florida companies are finding a market in rooftop photovoltaic power systems, as well as the more typical solar hot water and pool heaters.
Yann Brandt, vice president of Advanced Green Technologies in Fort Lauderdale, said a typical residential solar power system costs from $30,000 to $40,000 to install, but that the homeowner receives $25,000 to $30,000 in federal tax incentives and state rebates. Among the company's projects were 26-kilowatt systems at the Publix Super Markets Greenwise stores in Boca Raton and Palm Beach Gardens.
"Solar is the infrastructure project of the 21st century. ... It offers us the most shovel-ready projects of all," Brandt said. "We have the roof space and solar is readily available." Brian Betron agreed. The solar energy consultant for Jupiter-based Abundant Energy said the company recently installed the town's first photovoltaic system.
For Jupiter homeowners Brian and Emily O'Mahoney, having the system installed about a month ago was all about being green. Emily O'Mahoney, a landscape architect, is LEED certified.
"We calculated it for a size where it should offset our electrical usage completely," Brian O'Mahoney said. "I don't actually believe that will happen. (But) it will definitely save us quite a bit." Betron agrees that the solar industry would be boosted if the state adopted the 20 percent standard.
"There is so much potential here in the state of Florida," he said "For just the residential facilities, or homes, only half of 1 percent have any type of solar installed."