Past Projects‎ > ‎

2010-11

 
Emily Alper and 
Ellie Haeg - CATEGORY

Salmonella is the number one food-borne pathogen in the United States, which has been demonstrated in recent Salmonella outbreaks. Previously, dangerous serovars of Salmonella have been eliminated by eradication of the entire serovar. This is problematic because an empty ecological niche can be filled with a more virulent serovar. Recently, S. Kentucky filled an empty niche and has become one of the most prominent serovars in processed chicken breasts and potentially poses a serious human health risk. The goals of our project were to see if eighteen pre-identified genes specific to only one strain of S. Kentucky were specific to all strains of S. Kentucky, and to see if these genes were present in five other common serovars: S. Enteritidis, S. Typhimurium, S. Worhtington, S. Schwarzengrund. To do this we used multiplex PCR and gel electrophoresis. Results showed that the genes were completely present in all strains of S. Kentucky and mostly absent in other serovars. The one exception we had was eleven of the genes were 100% present in S. Worthington. This indicates that if Salmonella continues to be eliminated through traditional ways of complete eradication S. Worthington is in position to fill the ecological niche of S. Kentucky. 

John Culliton
 - CATEGORY

Hybrid vehicles have gained a great deal of attention in past years because they use conventional methods of propulsion coupled with electric power to reduce fuel consumption and emissions. I engineered an inexpensive fuel-displacement device that saved the hydraulic-hybrid vehicle team at the University of Minnesota thousands of dollars because they did not have to purchase a fuel-flow meter to measure fuel consumption. My device measured fuel consumption of a 1.13-L Perkins diesel engine used in a hydraulic-hybrid Polaris Ranger utility vehicle. My fuel-displacement device provided benefits over commercially available flow meters by allowing the engine to warm up to operating temperature while using fuel from the fuel tank prior to testing and then switching fuel flow to an incremented container during testing. After testing fuel consumption using my device, I used a Willans line method in MatLab to develop engine maps by extrapolating fuel consumption and efficiency of test data, using a least squares fit. Then, I compared maps of test data to data in a second set of engine maps that I developed using five consumption points measured by the engine manufacturer (Perkins Engine Company) at wide open throttle and while the engine was being used as a generator. By comparing efficiency maps, I determined that the most efficient operating range of the 1.13-L Perkins diesel engine in the hybrid vehicle is between 2200 and 2600 RPM and at torque outputs between 50 and 60 Nm. Using my findings, vehicle controls for the powertrain in the hydraulic-hybrid Polaris Ranger will be modified to run the engine within the range of peak efficiency at all times.

Samarth Damania 
- CATEGORY

My study was an extension of the HaloFit Project, which studies aspects of player and team performance in professional Halo 3, a first-person shooter video game. I used the database of the HaloFit Project to mine relevant player and team statistics from the 2008 and 2009 seasons for professional Halo 3 to determine impact of change in team composition on player and team performance, and to use past performance to predict future success of players and teams. I used PivotTables in Excel to sort player classifications (professional and amateur), player change (how often a player moves to a new team), team change (how often new players join a team), and performance measures of teams and players (kill/death ratio and assist ratio for individual performance and win ratio for team performance). I then used MySQL to aggregate data into PivotTables and used Waikato Environment for Knowledge Analysis to execute prediction of performance. Results showed that while individual success is not as greatly affected by switching teams, team performance is significantly affected. While I was unable to predict future performance from the dataset, the innovation of my research lies in that it is a data-driven approach to investigating a social science phenomenon.

Tom Erdmann 
- CATEGORY

The goal of my study was to synthesize 2-methoxy-9,10-bis(4-methoxyphenyl)indenotetracene, a novel indene derivative, for implementation in organic photovoltaic devices. I began by synthesizing a starting material (5,6,11,12-tetrachlorotetracene) using a procedure outlined by Yagodkin et al. (2009). Next, I synthesized the Grignard reagent (4-methoxyphenyl)magnesium bromide. I combined those two compounds with a PEPPSI-iPr catalyst in a Kumada cross-coupling reaction to produce the methoxylated indene derivative. To purify the derivative, I used two techniques: wet column chromatography and recrystalization. To optimize the purification procedure for wet column chromatography, I tested various ratios of hexanes to methylene chloride, finding that a 2:1 ratio (v/v) was the most effective solvent system. When thin-layer chromatography tests showed impurities after wet column purification, I tested various solvent systems, finding that a 2:2:1 ratio (v/v) of toluene, isopropanol, and methanol eliminated impurities. 1H NMR showed that purification of the methoxylated indene derivative was highly successful; therefore, I concentrated on scaling-up the reaction, which allowed the targeted indene derivative to be synthesized in quantities large enough for implementation in an organic photovoltaic device.

David Fuad
 - CATEGORY

The goal of my project was to find a surface coating that would prevent microalgae build-up on walls and tubing of photobioreactors that are used to grow microalgae for biofuel production. I applied the following non-stick products that are currently on the market to a pilot plexiglass photobioreactor: TDL Dry Lube, Silicone Lube, NanoSafeguard Sealant, and Easy On Bottom Coating. I found that Easy On Bottom Coating and TDL Dry Lube worked best, significantly reducing microalgae buildup on the pilot photobioreactor (p < 0.05). Easy On Bottom Coating worked almost as well as TDL Dry Lube when the plexiglass had been roughed with sandpaper before being coated (p = 0.001). Furthermore, my results suggest that agitation significantly reduces microalgae build-up on photobioreactors (p < 0.05). While my study did identify an important problem in biofuel production using microalgae, results did not suggest a commercially viable method of reducing microalgae build-up on photobioreactor.

 
Matthew Hackner
 - CATEGORY

Matthew worked in the Chemistry Engineering Department at the University of Minnesota under the supervision of Dr. David Blank. Matthew researched the interaction of a new type of plastic called regiorandom P3HT with regioregular P3HT, which is already used in solar cells. Regioregular is currently used in solar cells because it absorbs light and outputs usable energy well. Regiorandom also absorbs light but does not output usable energy because it fluoresces. Using absorption spectroscopy and fluorimetry, Matthew found that regioregular almost completely quenches fluorescence of regiorandom. His results suggest that adding regioregular to regiorandom could harness the fluorescent energy of regiorandom to increase electrical output organic solar cells. 

Cara Kowalchyk 
Rebecca Southern - CATEGORY

Cara and Rebecca collaborated on a project, working in the Microbiology Department at the University of St. Thomas under the supervision of Dr. Jayna Ditty. The goal of Cara and Rebecca’s study was to determine if the bacteria P. putida Fu1 can be used in bioremediation of furan compounds that are toxic, possibly carcinogenic agricultural byproducts. They used capillary assays to measure responses of mutant strains of P. putida Fu1 to furan com- pounds, showing that P. putida Fu1 does sense these compounds. They also used agarose plug assays to determine if mutant strains of P. putida Fu1 (P. putida PSF2 and P. putida PSF9) respond to 2-furoic acid. Their results suggested that the gene (psfb) in P. putida PSF2 may be involved in regulating chemotaxis to 2-furoic acid, but results did not support that the gene in P. putida PSF9 is involved in repressing the trigger for chemotactic response of P. putida Fu1. 

Caleb Kumar 
- CATEGORY

Caleb worked at Access Genetics under the supervision of Dr. Ron McGlennen and Stephen Trusheim (class of 2009). Caleb designed a neural network using Java programming that selectively identifies cancerous human bladder cells. The neual network analyzes morphometric characteristics of bladder cells in a way that simulated the process that a pathologist follows to examine cell characteristics in order to detect abnormalities. The program that Caleb designed will enable diagnoses to be done more specifically, more quickly, and at a lower cost than diagnoses done by pathologists, so treatments can commence earlier. 

Michael Portu 
- CATEGORY

Michael worked at Medtronic, Inc., under the supervision of Dr. Tim Laske. Michael
determined how the heart is affected by impacts to the chest, specifically during athletic participation. He used a combination of a crash-test dummy and a chest model he engineered to measure the forces that are placed on the chest and heart during athletic impacts. His results showed that a heart can experience up to 20 pounds of force during athletic impacts. Engineers will use Michael’s results to develop heart valves and stents that can withstand forces athletes experience during practices and games. 

Roshny Vijayakar and 
Aris Prince - CATEGORY

Roshny and Aris collaborated on a project, working in the Department of Horticultural Science at the University of Minnesota under the supervision of Dr. Gary Gardner. Roshny and Aris grew wild Arabidopsis seeds collected from locations with different altitudes and latitudes around the world. They then exposed the Arabidopsis seedlings to UV-B radiation. Results showed that plant sensitivity to UV-B did not depend on alti- tude or latitude of the sites where the seeds were collected; however, they found a surprising result that suggests plants from Japan have developed decreased sensitivity to UV-B nuclear radiation. The next step is to determine if plants from other sites that have been exposed to nuclear radiation also show altered UV-B sensitivity.

Addison Weiler 
- CATEGORY

Addison worked in the Chemical Engi- neering and Materials Science Department at the University of Minnesota under the supervision of Dr. Russell Holmes. Addison engineered a new type of organic solar cell using organic materials that absorb infrared radiation in order to more effi- ciently convert radiation from the sun to usable electrical energy. He tested different concentra- tions of the organic materials in varying architec- tures, finding that laying copper phthalocyanine in a planar architecture with lead phthalocyanine and carbon fullerene 60 gives a power conversion efficiency of 1.53%. This is the highest efficiency ever achieved for organic solar cells that use similar chemicals and architectures. 

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