http://hdl.handle.net/1903/9070 2013-05-19T07:20:29Z 2013-05-19T07:20:29Z Agarwal, Arsh Bradford, Allie Cheng, Kerry Dewan, Ramita Disla, Enrique Goodley, Addison Lim, Nathan Liu, Lisa Place, Lucas Ramadorai, Raevathi Shankar, Jaishri Wellen, Michael Ye, Diane Yu, Edward http://hdl.handle.net/1903/13888 2013-05-02T02:37:40Z 2013-01-01T00:00:00Z

Title: INTERACTIVE EFFECTS OF PLANT SPECIES AND ORGANIC CARBON ON NITRATE REMOVAL IN CHESAPEAKE BAY TREATMENT WETLANDS Authors: Agarwal, Arsh; Bradford, Allie; Cheng, Kerry; Dewan, Ramita; Disla, Enrique; Goodley, Addison; Lim, Nathan; Liu, Lisa; Place, Lucas; Ramadorai, Raevathi; Shankar, Jaishri; Wellen, Michael; Ye, Diane; Yu, Edward Abstract: Nitrate from agricultural runoff are a significant cause of algal blooms in estuarine ecosystems such as the Chesapeake Bay. These blooms block sunlight vital to submerged aquatic vegetation, leading to hypoxic areas. Natural and constructed wetlands have been shown to reduce the amount of nitrate flowing into adjacent bodies of water. We tested three wetland plant species native to Maryland, Typha latifolia (cattail), Panicum virgatum (switchgrass), and Schoenoplectus validus (soft-stem bulrush), in wetland microcosms to determine the effect of species combination and organic amendment on nitrate removal. In the first phase of our study, we found that microcosms containing sawdust exhibited significantly greater nitrate removal than microcosms amended with glucose or hay at a low nitrate loading rate. In the second phase of our study, we confirmed that combining these plants removed nitrate, although no one combination was significantly better. Furthermore, the above-ground biomass of microcosms containing switchgrass had a significantly greater percentage of carbon than microcosms without switchgrass, which can be studied for potential biofuel use. Based on our data, future environmental groups can make a more informed decision when choosing biofuel-capable plant species for artificial wetlands native to the Chesapeake Bay Watershed.

2013-01-01T00:00:00Z Connolly, Jason Fries, Kevin Biswas, Sougata Grant, Christopher Hwang, Kevin Kang, Hoyoung Motabar, Donna http://hdl.handle.net/1903/13887 2013-05-02T02:34:29Z 2013-01-01T00:00:00Z

Title: Laminar Free Convection from a Vertically-Oriented Concentrated Photovoltaic Cell with Uniform Surface Heat Flux Authors: Connolly, Jason; Fries, Kevin; Biswas, Sougata; Grant, Christopher; Hwang, Kevin; Kang, Hoyoung; Motabar, Donna Abstract: This research project uses field measurements to investigate the cooling of a triple-junction, photovoltaic cell under natural convection when subjected to various amounts of insolation. The team built an experimental apparatus consisting of a mirror and Fresnel lens to concentrate light onto a triple-junction photovoltaic cell, mounted vertically on a copper heat sink. Measurements were taken year-round to provide a wide range of ambient conditions. A surface was then generated, in MATLAB, using Sparrow’s model for natural convection on a vertical plate under constant heat flux. This surface can be used to find the expected operating temperature of a cell at any location, given the ambient temperature and insolation. This research is an important contribution to the industry because it utilizes field data that represents how a cell would react under normal operation. It also extends the use of a well-known model from a one-sun environment to a multi-sun one.

2013-01-01T00:00:00Z Brumback, Shelby Byun, Jamie Cohen, Jacob Huang, Feili Kango, Ghazal Latushko, Anastasiya Lin, Michael Mamunes, Alexander Modric, Marko Rosenberg, Kenneth Sun, Oliver Thomas, Christina http://hdl.handle.net/1903/13886 2013-05-02T02:38:13Z 2013-01-01T00:00:00Z

Title: THE EFFECT OF DIET-INDUCED OBESITY AND SUBSEQUENT WEIGHT LOSS ON BODY COMPOSITION, GLUCOSE CLEARANCE, METABOLITE PROFILE AND LIVER AMP-ACTIVATED PROTEIN KINASE IN MICE Authors: Brumback, Shelby; Byun, Jamie; Cohen, Jacob; Huang, Feili; Kango, Ghazal; Latushko, Anastasiya; Lin, Michael; Mamunes, Alexander; Modric, Marko; Rosenberg, Kenneth; Sun, Oliver; Thomas, Christina Abstract: Obesity, currently an epidemic, is a difficult disease to combat because it is marked by both a change in body weight and an underlying dysregulation in metabolism, making consistent weight loss challenging. We sought to elucidate this metabolic dysregulation resulting from diet-induced obesity (DIO) that persists through subsequent weight loss. We hypothesized that weight gain imparts a change in “metabolic set point” persisting through subsequent weight loss and that this modification may involve a persistent change in hepatic AMP-activated protein kinase (AMPK), a key energy-sensing enzyme in the body. To test these hypotheses, we tracked metabolic perturbations through this period, measuring changes in hepatic AMPK. To further understand the role of AMPK we used AICAR, an AMPK activator, following DIO. Our findings established a more dynamic metabolic model of DIO and subsequent weight loss. We observed hepatic AMPK elevation following weight loss, but AICAR administration without similar dieting was unsuccessful in improving metabolic dysregulation. Our findings provide an approach to modeling DIO and subsequent dieting that can be built upon in future studies and hopefully contribute to more effective long-term treatments of obesity.

2013-01-01T00:00:00Z Bowers, Maureen Freyman, Neal McLellan, Elizabeth Paxton, Brian Spiegel, Jeremy http://hdl.handle.net/1903/13885 2013-05-02T02:33:25Z 2013-01-01T00:00:00Z

Title: ONLINE AND TRADITIONAL LECTURES: EVALUATING EFFECTS OF SOCIAL PRESENCE AND LEARNER CONTROL Authors: Bowers, Maureen; Freyman, Neal; McLellan, Elizabeth; Paxton, Brian; Spiegel, Jeremy Abstract: Online courses are rapidly replacing traditional, face-to-face lectures in American universities (Allen & Seaman, 2011). As technology improves, this trend will likely continue and accelerate. Researchers must evaluate the impact of online courses compared to their traditional counterparts. This two-part study quantifies the effect of two variables – social presence and learner control – on students’ recall, application and perceived learning levels in different lecture formats. Students in introductory courses at a four-year, public, American university were randomly assigned into three groups to view distinct lecture formats, one in a traditional classroom and two via the Internet. Upon viewing the single lecture, the students were asked to fill out a test and survey to quantify teacher immediacy, recall and application, and perceived learning levels across lecture formats. The study found that different levels of social presence and learner control affected students’ perceived learning levels but did not impact recall or application.

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