A small laser could be the key to increasing the amount of data storage on compact disks if Peidong Yang, a professor of chemistry at the University of California in Berkeley, has his way. His laser, which is one thousand times thinner than a human hair, is also said to be an alternative to today’s solid state lasers made from gallium arsenide and gallium nitride. Instead, Yang uses zinc oxide. He paints a gold catalyst onto a sapphire and places it in zinc oxide. The gold forms the crystal wires, which are hexagonal in cross section. The arrays of wire resemble hairbrush bristles. They emit UV light from their flat tips, which act like mirrors. The ends attached to the semiconductor also act like mirrors. Light emitted by the zinc oxide bounces back and forth, causing emission and amplification of the light. Yang uses optical pumping for exciting the zinc-oxide molecules. “Optical pumping uses a conventional laser for exciting our nanowire sample, so that stimulated emission can be generated from the nanowires,” explains Yang. “One of the next steps in commercializing the nanolaser is its successful integration as a miniaturized light source in optoelectronic applications,” he says. For more information, contact Yang at (510) 643-1545 or go to www.cchem.berkeley.edu.
What makes this movie stand out from the typical high school sports story is that the teenagers are undocumented immigrants, and the big game is a NASA-sponsored marine robotics competition. Like many other Hollywood movies, however, Spare Parts only tells part of the story. What the film shows -- and doesn’t show -- raises important issues affecting STEM education in the US.
Instead of sifting through huge amounts of technical data looking for answers to assembly problems, engineers can now benefit from 3M's new initiative -- 3M Assembly Solutions. The company has organized its wealth of adhesive and tape solutions into six typical application areas, making it easier to find the best products to solve their real-world assembly and bonding problems.
Load dump occurs when a discharged battery is disconnected while the alternator is generating current and other loads remain on the alternator circuit. If left alone, the electrical spikes and transients will be transmitted along the power line, leading to malfunctions in individual electronics/sensors or permanent damage to the vehicle’s electronic system. Bottom line: An uncontrolled load dump threatens the overall safety and reliability of the vehicle.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.