Copyright (c) 2013 Utah State University All rights reserved. http://digitalcommons.usu.edu/ncur Recent documents in NCUR en-us Thu, 02 May 2013 13:05:13 PDT 3600 http://digitalcommons.usu.edu/ncur/2 http://digitalcommons.usu.edu/ncur/2 Mon, 04 Feb 2013 08:05:26 PST Samples that were part of the Materials International Space Station Experiment (MISSE) experienced varying effects whilst exposed to the space environment; perhaps the most intriguing effect was the crater created by a micrometeoroid impact into a thin film of Vapor Deposited Aluminum (VDA) coated Mylar. Approximately 180 samples of various materials used in space-component design were flown on MISSE-6 and spent 18 months suspended off the side of the International Space Station. The Utah State University SUSpECS project was a unique student experiment that allowed for pre- and post-flight analysis of these material samples which were returned in pristine condition after exposure to the space environment. Despite micrometeoroids being a common occurrence, there is a significant lack of data pertaining to the effects of micrometeoroids on space components. Further examination of the micrometeoroid impact sample will allow us to determine the impact velocity, mass, and composition of the micrometeoroid and its influence on materials in space. Micrometeoroids pose a serious threat to space operations and in turn require constant observation. It is of particular interest to note that Mylar is a major component in the construction of astronaut suits; the knowledge gained from our evaluation of this meteoroid will allow us to determine the mass required to penetrate through a spacesuit.

]]> Kelby T. Peterson et al. http://digitalcommons.usu.edu/ncur/1 http://digitalcommons.usu.edu/ncur/1 Tue, 17 Apr 2012 07:18:55 PDT Fire blight caused by the bacterium Erwinia amylovora results in millions of dollar in losses worldwide. It is the most important disease problem for apple and pear growers in Utah. Currently the only effective management strategy is application of the antibiotic streptomycin. In 2006, resistant isolates were detected in an apple orchard in Utah County. To determine the distribution of resistant isolates, samples collected in 2006, 2007, 2010 and 2011 from orchards across Utah were tested for resistance to streptomycin. Isolates were screened at 0, 100 and 1000ppm of streptomycin. Bacteria were spread on LB agar. A hole was punched from the agar and the streptomycin solution was pipetted into the well. After 24 hours a bacteria-free zone around the well was observed for sensitive isolates but not for resistant isolates. The majority of resistant isolates were found in Utah County where most orchards are located. The resistance in most Utah isolates is caused by a mutation in the rpsL gene but at least one isolate acquired a plasmid containing streptomycin resistance genes.

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