Extracting Top Honors

Leveraging work done in their capstone senior design course, a UT team has won the open division of the Gunlogson Student Environmental Design Competition in Ottawa, Canada with their Representative Volume Extraction System (RVES).

The team from the Biosystems Engineering & Environmental Science (BEES) department took first place in this student design competition at the 2004 International meeting of ASAE, the Society for Engineering in Agricultural, Food, and Biological Systems. Student team members Aaron Crenshaw, Mark Bacon, and Matt Rice were advised by faculty member Daniel Yoder.

According to Dr. Yoder, "many environmental sampling projects involve large samples of mixed water and sediment, which are very time-consuming and expensive to analyze as a whole." Scientists would like to extract a representative sample of about a liter from each five-gallon sample. However, it is very difficult to obtain a small representative sample that has the correct amount of sediment, and the correct particle size distribution, because the sediment is constantly settling even as it is mixed. The RVES accomplishes this by extracting ever-smaller fractions of a constantly-mixed sample that cascades through the system. Because the flow is divided as it moves vertically downward, any effects of sediment settling are negligible.

The RVES appears to work relatively well, though it needs fine-tuning. The students overcame design difficulties, typical problems with manufacturing, unexpected tolerance issues, and physical effects that they had not originally considered -- making this a very successful senior design project in terms of the learning process.

The team has good ideas for a second-generation model, and there is the possibility of further refinement, perhaps as a graduate student project. The RVES may someday become a valued tool for researchers, including those that are already using a related BEES-developed research plot sampling system.

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