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NEWS ABOUT SCIENCE, TECHNOLOGY AND ENGINEERING AT IOWA STATE UNIVERSITY
X-rays in the Fields
A study funded by the U.S. Department of Energys (DOE) Ames Laboratory shows that x-ray technology can provide on-the- spot, accurate measurement of grain yields. Feyzi Inanc, a member of the x-ray group at ISUs Center for Nondestructive Evaluation (CNDE), and Joe Gray, an Ames Lab scientist who also heads CNDEs x-ray group, devised a system that allows x-ray equipment to be mounted on harvesters and grain elevators. As the grain passes through a low-energy x-ray beam on the way to the collection bin, information is relayed to a computer and translated into yield data. Corn was used in the feasibility study, but the technique will also work with other crops.
Inanc and Gray believe their approach has greater accuracy and fewer drawbacks than other yield measurement systems. Also, Inanc explained, the technique is insensitive to the differing moisture content of the grain, which can be affected by the weather or time at which the harvesting is done. The $19,500 feasibility study was funded through the Laboratory Directed Research and Development Grant program at Ames Lab. "This project allows us to go beyond our traditional scientific boundaries and fund research in agriculture, an area in which we would like to play a larger role," said Ames Lab Director Tom Barton.
Stayin Alive! Stayin Alive!
The Iowa poultry breeding industry annually exports millions of baby chicks through commercial airlines. But when 2,500 to 5,000 chicks per shipment end up dead from suffocation, dehydration and/or starvation, it can be costly to the industry. Hongwei Xin, associate professor of agricultural and biosystems engineering at Iowa State, researched ways producers could reduce the mortality rate and weight loss of breeding stock chicks, which cost about $50 each.
Xin (pronounced "shin") and his colleagues found that the longer the transportation time, the higher the mortality rate. But transport time cannot be predicted due to flight delays, customs problems, biosecurity procedures and various travel times to the destination farms, so Xin took a different approach. Each 18- by 24- by 7-inch cardboard box, with circular holes cut out for air flow, typically contains 88 chicks. Xin improved air flow characteristics of the boxes by replacing the cardboard lid with plastic mesh and increasing the space between boxes from one inch to three inches.
During flight and ground transportation water and feed were not available to the chicks, because of international regulations. Xin combined commercially available Aqua-Jel_, a gelatin-type product containing 93 per cent water, with a nutritional supplement. "The combination has done a good job in alleviating stress in the chicks and maintaining their body weight," Xin said. The largest U.S. layer breeder exporter, which is based in Iowa, implemented his recommendations and is pleased with the results, he said. "Now other companies are starting to get interested and were expanding this research into broiler chicks and piglet exporting industries."
Photonic band gap filters show promise
Distant galaxies may come into sharper focus for astronomers thanks to a new photonic band gap (PBG) device developed by Iowa State researchers. A group of photonics researchers at ISU has successfully demonstrated that a PBG filter can operate at 10 THz, the far infrared region of the electromagnetic spectrum.
"PBGs are basically electromagnetic filters that we can use to modify or control the flow of electromagnetic waves in a certain frequency range," said Gary Tuttle, an electrical and computer engineering associate professor. "At 10 THz, astronomers will be able to have more of the desired light come through and a greater rejection of the light they dont want."
Although other filters can accomplish the same result, Tuttle says the PBG filter his group developed will be less expensive than those currently available and is expected to perform better. PBGs also show great promise for use in certain microwave devices, cell phones, radar antennas, GPS systems, and high-efficiency lasers. Tuttles research group is one of only a handful worldwide involved in the design and fabrication of PBG devices. They are the first to demonstrate operating a PBG at 10 THz. The new filter should be fabricated by the end of the year. "It will be exciting for us if this helps astronomers do their work," Tuttle said.
Capturing an elusive pollutant
Iowa State University scientists are working on ways to capture an elusive air pollutant released during coal burning. Robert Brown and Glenn Norton will lead a team of researchers in the study of mercury emissions from coal burning. Brown is director of ISUs Center for Coal and the Environment, an ISU professor and an Ames Laboratory program director. Norton is a scientist at the Coal Center and Ames Lab.
The two will head an investigation of the changes in mercury as it is released during coal burning. The $400,000 federally funded research project will lead to strategies to effectively trap mercury in the wide variety of coals used for power generation.
With the 1990 amendments to the Clean Air Act, mercury was one of 189 compounds designated as a hazardous air pollutant. Coal, which emits mercury during burning, is the most commonly used fuel to generate electricity worldwide. But capturing mercury is a challenge -- the substance is highly volatile and remains largely vaporized during coal burning. As a result, its efficient removal depends on the form of mercury present. The current initiative, which includes researchers from the University of North Dakota and the University of Maryland-Eastern Shore, will look at the chemistry and properties of mercury in the coal burning environment.
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