Crystals grown in space may hold an important key for the improvement and development of the next generation of computers and communication systems. "Better crystals would improve LEDs, photo detectors, lasers, and wireless devices," says John Walker, a professor of mechanical and industrial engineering at the University of Illinois. He is one of several engineers and scientists working with the Marshall Space Flight Center—NASA's lead center for microgravity research in materials science that is developing alloy crystals. Alloy crystals are blends of germanium and silicon that have highly desirable thermoelectric and electro-optic properties, according to Walker. He explains that NASA, for example, is interested in the crystals for use as solar panels. "The only problem with alloy crystals is that they are so far impossible to grow on Earth because of the effects of gravity. Germanium generally sinks to the bottom of the melt in the crucible because it's three time heavier than silicon," explains Walker. He says that gravity destroys the homogeneous concentration in the crystal. "On Earth, gravity presses the liquid against the walls of the container, resulting in the formation of faults, dislocations, and contact stresses in the growing crystal." The ingredients do not separate in the absence of gravity, which is why Walker proposes growing the crystals on the International Space Station. The pencil-thin crystals would be grown in special ampules within the magnetic damping furnaces on the space station. Walker wants to reproduce them on Earth. Contact Walker at (217) 333-7979.
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.