High-quality white light produced by four-color laser source

The human eye is as comfortable with white light generated by diode lasers as with that produced by increasingly popular light-emitting diodes (LEDs), according to tests conceived at Sandia National Laboratories.

Both technologies pass electrical current through material to generate light, but the simpler LED emits lights only through spontaneous emission. Diode lasers bounce light back and forth internally before releasing it.

The finding is important because LEDs — widely accepted as more efficient and hardier replacements for century-old tungsten incandescent bulb technology — lose efficiency at electrical currents above 0.5 amps. However, the efficiency of a sister technology — the diode laser — improves at higher currents, providing even more light than LEDs at higher amperages.

“What we showed is that

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Scientists take fresh look at 'faster-than-light' experiment

Scientists who threw down the gauntlet to physics by reporting particles that broke the Universe's speed limit said on Friday they were revisiting their contested experiment.

"The new test began two or three days ago," said Stavros Kasavenas, deputy head of France's National Institute for Nuclear Physics and Particle Physics, also called the IN2P3.

"The criticism is that the results we had were a statistical quirk. The test should help (us) address this," he told AFP.

On September 23, the team stunned particle physicists by saying they had measured neutrinos that travelled around six kilometres (3.75 miles) per second faster than the velocity of light, determined by Einstein to be the highest speed possible.

The neutrinos had been measured along a 732-kilometre (454-mile)

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IR Remote Control Jammer

Don't like your little brother's TV channel selection? Hate the volume your wife sets the stereo at? Want to just annoy someone? This circuit does all that and more by jamming most IR remote signals. The circuit releases a flood of pulsing IR light that confuses the reciever by corrupting the data stream. And hence, you jammed the remote control.

Part Total Qty. Description Substitutions R1 1 100K 1/4W Resistor   R2 1 150K 1/4W Resistor   R3 1 10K 1/4W Resistor   R4 1 1K 1/4W Resistor   R5 1 22 Ohm 1/4W Resistor See "Notes" C1 1 10nF Ceramic Disc Capacitor   C2 1 1uF Electrolytic Capacitor   D1, D2, D3 3 High Output IR LED   Q1 1 2N4403 PNP Transistor   Q2 1 2N4401 NPN Transistor   S1 1 Normally Open Momentary Push Botton   B1 1 4.5V Battery (Three "AA"'s In Series)   MISC 1 Wire, Case, Board  

Notes:

1. Email Carl with questions, comments, etc.

2. You may need to adjust the value of R3 for the right

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Fire Alarm

With the onset of summer, chances of fire accidents increase. Such fire accidents can be prevented if timely alarms are available. The circuit presented here warns the user against such fire accidents. The circuit should be placed in fire-prone areas such as a kitchen. Everyone is aware that when anything catches fire, smoke is produced. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and the voltage at pin 2 of IC 555 goes below 1/3 Vcc, thus triggering IC 555 which is used here in bistable mode. As a result the voltage of pin 3 goes high. This high voltage (approximately

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Researchers build transparent, super-stretchy skin-like sensor

Imagine having skin so supple you could stretch it out to more than twice its normal length in any direction - repeatedly - yet it would always snap back completely wrinkle-free when you let go of it. You would certainly never need Botox.

 

That enviable elasticity is one of several new features built into a new transparent skin-like pressure sensor that is the latest sensor developed by Stanford's Zhenan Bao, associate professor of chemical engineering, in her quest to create an artificial "super skin." The sensor uses a transparent film of single-walled carbon nanotubes that act as tiny springs, enabling the sensor to accurately measure the force on it, whether it's being pulled like taffy or squeezed like a sponge.

"This sensor

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Engineers at Yale develop new type of mechanical memory

Research engineers at Yale University have succeeded in building a mechanical memory switch that is controlled and then read by lasers. In their paper published in Nature Nanotechnology, the team, led by professor Hong X. Tang, describe how they were able to use a laser to excite a small strand of solid silicon such that its bending properties that hold steady after the laser is turned off can be used as a memory device.

o create the new memory switch, the team began with an ordinary silicon-on-insulator wafer which they fashioned into an oval waveguide to serve as an optical cavity. They then shaved away some of the wafer beneath the waveguide to create a sort of a tiny bridge made

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Robotic bug gets wings, sheds light on evolution of flight

A six-legged, 25 gram robot has been fitted with flapping wings in order to gain an insight into the evolution of early birds and insects.

When engineers at the University of California, Berkeley, outfitted a six-legged robotic bug with wings in an effort to improve its mobility, they unexpectedly shed some light on the evolution of flight.

Even though the wings significantly improved the running performance of the 10-centimeter-long robot – called DASH, short for Dynamic Autonomous Sprawled Hexapod – they found that the extra boost would not have generated enough speed to launch the critter from the ground. The wing flapping also enhanced the aerial performance of the robot, consistent with the hypothesis that flight originated in gliding tree-dwellers.

The research team,

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