RENO, Nev. — The baking soda–volcano experiment is as ancient as a rotary phone for today’s teens.
Thousands of high school students spent May 13 manning their booths and explaining the research that won each a spot at the Intel International Science and Engineering Fair. Projects included devices to improve gas mileage in today’s cars and to protect against fraud in the credit cards of tomorrow. One student spent hours investigating the light reflected by the moon, another delved into the genetic signature of colorectal cancer.
Energy was on the minds of several students, including Ryan Alexander, a sophomore from Plano, Texas. (Alexander will be skipping the next two grades and heading right to college in the fall). He developed a simple windmill that can be made out of bamboo or other plant materials and about one dollar’s worth of magnets, copper wire and alligator clips.
While playing the violin, Alexander noticed that the strings vibrated quite a bit without much energy input. Inventor and engineer Nikola Tesla noticed this “aeroelastic flutter,” Alexander said, which “could take down an entire building.” So Alexander’s windmill doesn’t bother with blades. Instead it is shaped like a long narrow box with four sides but no top or bottom. A thin material that will flutter in a breeze (such as a long, stiff leaf or a thin plastic strip) “floats” in the center of the box, attached at the ends to magnets and coils. When the thin material oscillates in the wind, the magnets move, generating an electric field. Alexander built a small, standard turbine windmill with blades and also built five oscillator models. In tests with various wind speeds, the oscillator-based models produced between 180 and 819 percent more power than the turbine model. He also created a kit with the basic materials and a pictorial instruction manual that could be used in developing regions to create electricity. “The true breakthrough was using bamboo and leaves,” he said. “It’s the world’s first natural and cheapest windmill that can be made.”
Jingwen Huang, a senior from Guangzhou, China, found inspiration in the polluted grounds near a lead battery factory. She noticed that Lantana plants were thriving in the fields around the factory. Lantana that had been parasitized by Cuscuta (dodder), a twining plant that barely photosynthesizes and gloms onto other plants for food, were doing especially well. Huang tested levels of lead in the plants and soil using flame atomic absorption spectrometry. She found that Lantana is quite good at removing lead from the soil, and the metal mostly accumulates in the plant’s roots. Parasitized Lantana does even better. “I think when it is parasitized the Cuscuta absorbs nutrients, so the Lantana takes even more nutrition and other things from the soil.”
Other projects dealt with loftier problems. Fatimah Alkhunaizi developed a skydiving suit that inflates with helium if the parachute doesn’t open. Outfitted with an accelerometer and a programmable device, the suit inflates if the skydiver drops to an altitude of 600 meters and is still traveling at a constant velocity. Once inflated with helium, the area of the skydiver’s body doubles with only a slight increase in weight, Alkhunaizi’s calculations show. The decrease in velocity and increase in drag greatly reduces the force with which the person hits the ground. “It’s automatic,” said Alkhunaizi of Khobar, Saudi Arabia. “If they faint or get a heart attack, they won’t have to worry.”
No science fair would be complete without projects that involve slicing up worms. Amy Van Scoyoc a senior from East Hampton, N.Y., investigated whether chemical tags attach to the flatworm Dugesia tigrina’s DNA. These tags, called epigenetic marks, have been shown in mammals to influence how much the tagged genes are turned on or off. Environmental factors such as stress from pollution can influence where these tags are attached, and the patterns of tagging can be passed on to offspring. The process has not been as thoroughly investigated in invertebrates as it has in other animals and plants.
Van Scoyoc treated the DNA of her flatworms with an enzyme that recognizes methyl groups, a common chemical tag. Sure enough, her results suggest that her flatworm’s DNA had methyl groups attached to it. After figuring out the best experimental protocol for the flatworms, Van Scoyoc then developed a prototype of a field kit that uses the flatworms to investigate environmental stressors such as acid rain or residues of pharmaceutical drugs. She’s teamed up with researchers at Brookhaven National Laboratory in Upton, N.Y., to do further research. But the thrill of the initial lab work remains. “These flatworms are pretty awesome,” she said. “You can cut them in half and they regenerate into identical copies. You can use one as the control, the other as the variable.”
