2007 Richard Barrett Scholarships
Charles Farmer, Peter Larson, Jeremy Matt, Karen Sentoff and Iliana M. Vazquez-Spickers were the summer 2007 Barrett Scholars.
- Charles Farmer, Civil Engineering
- Peter Larson, Civil Engineering
- Jeremy Matt, Civil Engineering
- Karen Sentoff, Civil Engineering with environmental focus
- Iliana M. Vazquez-Spickers, Civil Engineering with an environmental option
Microbially Induced Calcite Precipitation (MICP) for Civil and Environmental Engineering Applications
"This is a new area of research with limitless possibilities for application," says Farmer. "The most promising is in increasing soil strength for all kinds of civil and environmental engineering, including creating stability in earthquake-prone areas and protecting roadways from flooding streams."
The Microbially Induced Calcite Precipitation (MICP) method involves using bacteria to alter the chemistry of subsurface soils to promote the precipitation of calcite, or limestone. This has applications in both enhancing the stability of soils and in sequestering pollutants such as highly toxic or radioactive metals, and could be a useful in-situ technology for many engineering applications.
"The idea is to grab pollutants at the surface to protect groundwater from contamination," Farmer explains. Farmer will test whether the MICP method can be used to fixate arsenic and chromium, two toxic metals, to assess possible field remediation applications of the technology.
Structural Assessment of Shelburne Farms Breeding Barn Using Accelerometers
Advisor: Jean-Guy Beliveau
"In today's changing environment, it is more important than ever to preserve unique historical structures such as the Breeding Barn at Shelburne Farms. Built in 1891, it was the largest unsupported open space in North America until the Chicago World's Fair in the 1940s," says Jean-Guy Beliveau, professor of structural engineering and faculty advisor for the project.
A noninvasive method to determine the stiffness and loads of the truss members in the Breeding Barn will be used with wireless accelerometers from Micro-Strain, in Williston, VT. These measurements will help determine if additional renovations are necessary for the barn roof, in particular for snow loads. Should wireless accelerometers prove to be an accurate method for determining the member loads in the structure, the technique could be used to assess other historical buildings and/or bridges for quantitative assessment of structures.
"The Barrett project allows me to do the two things I enjoy most working on structures and historical buildings," says Larson, who plans to become a structural engineer. "I will be working with a graduate student, Nathan Maille, and will attach wireless accelerometers to the trusses to induce vibrations. This allows us to measure resonant frequencies and determine in-situ axial loads."
Applications of Neural Network Analysis: Pollutant Contamination and Leaf Wetness
Matt will work to create a computer-automated system to analyze applications ranging from quantifying leaf wetness for crop disease forecasts to tracking the transport of contaminants through building materials due to a chemical attack or spill.
"Computers are great at picking up edges and by identifying edges in pictures, we can identify such things as the number of water droplets on a single leaf to determine how wet a leaf actually is or the depth of chemical penetration in a building material," says Matt. Using neural network adaptive programs provides feedback on how well each specific task is being done, which in turn allows the program to adjust and improve results.
In many cases, it is cheaper to simply tear down and rebuild contaminated buildings than to decontaminate them, but this is not an option for buildings with high levels of cultural or historic significance. If a contaminated building cannot be demolished and rebuilt, then restoration is costly and time consuming. Understanding how quickly and to what extent various contaminants can penetrate common building materials is important because this knowledge allows for more efficient decontamination.
The goal of this project is to develop methods to automatically analyze CT scans of building materials and photographs of plants and/or fields. The CT scans will be processed and combined into a three-dimensional sample model of the building material. An artificial neural network (ANN) will be used quantify the contaminant transport characteristics of the sample.
Stream Temperature as an Indicator of Aquatic Habitat Quality for Coldwater Fish
The ability of fish populations to survive and thrive is directly linked to the temperature of the water body they inhabit. Slightly increasing water temperature inflicts stress on fish species local to Vermont streams, particularly during the summer season during low flows. As water temperature changes due to a variety of influences, the fish quality of life is compromised. A main objective of the Vermont Fish and Wildlife Department (VTFW) is to identify and prevent such distress on the natural and stocked fish communities by protecting and conserving their ecological habitat. A quantitative measure of the habitat quality of Vermont streams, based on stream temperature, would assist in gauging the progress of the VTFW in their mission.
Ryan Butryn, a graduate student in Natural Resources, will work together with Karen Sentoff on determining stream temperature variability. Data on fish counts from the VTFW will be used together with water temperature data in specific locations.
"I'm excited to have the opportunity to work with a graduate student, because I plan to continue in grad school after graduation," says Sentoff. "And working outside in nature this summer is also going to be a blast!"
Iliana M. Vazquez-Spickers
Role of Fuel Additives in Light Duty Vehicle Tailpipe Emissions
Advisor: Britt Holmén (firstname.lastname@example.org)
Vehicle emissions contribute to air quality issues and there are important factors involved in assessing the vehicles that produce these emissions, such as vehicle type, fuel type and operation purposes. Light duty vehicle (LDV) engines are rather inefficient and result in incomplete fuel combustion releasing pollutants. The broad focus of this study is to understand how LDV tailpipe emissions affect air quality.
Vazquez-Spickers chose this project because she's concerned about air quality issues. "We cannot live without air air quality is as important as water quality," says Vazquez-Spickers. "It's all linked to global warming and we need every nation to work together to reach the ultimate goal of saving the environment for future generations."
Vazquez-Spickers would like to educate others from the University of Puerto Rico so that they will be inspired to make the necessary changes as well. "We collectively need to walk, use buses, all of which will improve air quality," she says. "By using fuel additives, systems would be cleaner and better for the environment, producing fewer tailpipe emissions and reducing greenhouse gases."