http://hdl.handle.net/1813/110 2013-05-25T03:18:54Z 2013-05-25T03:18:54Z Powers, Siobhan http://hdl.handle.net/1813/33243 2013-05-17T05:01:52Z 2013-05-16T00:00:00Z

Title: Nitrate Reductiona nd Phosphate Uptake in Lab-Scale Denitrifying Bioreactors with Woodchip and Biochar Media Authors: Powers, Siobhan Abstract: High nutrient loads in agricultural-field-adjacent waterways results in ecosystem-debilitating hypoxic zones. One potential solution for this problem is a denitrifying bioreactor, which intercepts the high nutrient (usually phosphate and nitrate from fertilizer) water from artificial drainage. This study aimed at modeling a denitrifying bioreactor in a laboratory setting, with woodchip media acting as a carbon source, and further amended by biochar in some of the experimental reactors. Water spiked with nitrate and phosphate was fed through the reactors and the concentrations were measured at both the inflows and outflows. The predicted pathway for nitrogen reduction was denitrification and the phosphate was expected to be adsorbed by the biochar. Both woodchip and biochar-mix (10% biochar, 90% woodchip by mass), had levels of nitrogen reduction above 30% with an inflow of about 5 mg Nitrate-N/L, with the biochar-mix achieving higher levels of reduction than the plain woodchip media. The phosphate uptake was no different between the woodchip and biochar-mix bioreactors across various inflow concentrations, however these influents were higher than intended for the purpose of this study. Thus, in these experiments, both woodchip and woodchip-biochar mix bioreactors decreased the nitrate concentration between inflow and outflow, but with different pathways- denitrification for woodchip and most likely adsorption for biochar-mix. Phosphate adsorption did not occur more within the biochar-mix reactors. In this study, though biochar as a bioreactor amendment was not useful in enhanced phosphate concentration reduction, its presence was indicative of higher nitrate removal so an in-situ bioreactor might benefit from subsisting of both biochar and woodchips to decrease the probability of eutrophication in adjacent waters.

2013-05-16T00:00:00Z Xu, Yitian http://hdl.handle.net/1813/33233 2013-05-16T05:09:24Z 2013-05-15T00:00:00Z

Title: Monitoring host response to Mycobacterium Tuberculosis infection Authors: Xu, Yitian Abstract: Mycobacterium tuberculosis (Mtb) is a widespread pathogenic bacterial species which causes 1.5 million people death every year in the world (1-3). Moreover, M. tuberculosis infected about one third of world population, 5-10% of which developed acute clinical disease (4). To find a cure for this pathogen we need to understand how Mtb infects human beings and how the host environment responds to Mtb infection. Through lipid metabolism, Mtb can manipulate host gene expression to benefit its own sustention. Among those lipids, Trehalose 6,6'-dimycolate (TDM) is a cell wall glycolipid is proved to induce host response which is most similar to Mtb infection (6, 7). Therefore, we built reporter cell lines that can sense TDM induction, enabling us to monitor the progression by examing the GFP and luciferase expression.

2013-05-15T00:00:00Z Vasudevan, Divya http://hdl.handle.net/1813/33215 2013-05-09T06:14:38Z 2013-05-08T00:00:00Z

Title: Upgrading dilute ethanol from syngas fermentation to n-caproate with reactor microbiomes Authors: Vasudevan, Divya Abstract: Fermentation of synthesis gas (syngas, which is a gas mixture including CO, H2, and CO2) from a renewable biomass source is gaining momentum. However, energy-intensive distillation of ethanol at dilute concentrations of 2-4% (w/w), which are anticipated for syngas fermentation with carboxydotrophic bacteria, is one impediment towards widespread adaptation. n-Caproic acid is a carboxylic acid with a chain length of six carbon atoms, and can be extracted more easily compared to ethanol. This because of its hydrophilic nature and its charge as n-caproate beyond a pKa of 4.88 while ethanol is completely miscible due to its short 2-carbon chain and hydrogen-bonding interactions. n-Caproic acid can be produced from ethanol in an anaerobic open culture (reactor microbiome) by chain elongation via the reversed β oxidation pathway. Here, we show a proof-of-concept to utilize diluted ethanol and acetic acid in real syngas fermentation effluent as the sole substrate for chain elongation into the product n-caproic acid. This concept, therefore, integrates the syngas platform and the carboxylate platform within a biorefinery. We observed with a bioreactor study that lowering the pH to slightly acidic conditions was necessary to shift the metabolic flux from production of methane to production of n-caproic acid. The highest concentration of n-caproic acid of ~ 1 g L-1 was produced at pH 5.44.

2013-05-08T00:00:00Z Williams, Matthew http://hdl.handle.net/1813/33209 2013-05-04T14:25:52Z 2013-05-03T00:00:00Z

Title: Energy requirement for continuous ethanol extraction via pervaporation and/or distillation at low concentrations Authors: Williams, Matthew Abstract: Syngas fermentation, or synthesis gas fermentation, is a microbial process that uses hydrogen, carbon dioxide, and carbon monoxide to produce fuel. The effluent in this process contains low concentration ethanol, which often ranges from 2 to 6 wt% ethanol. To make this ethanol usable, it must be concentrated to >95 wt% to be considered fuel grade ethanol. Most commonly, distillation is used to produce fuel grade ethanol, however this requires too much energy for low concentration ethanol feed streams. Therefore, there exists a need for an energy efficient process for converting low concentration ethanol feed streams to fuel grade ethanol. A model was made for a system that produces an ethanol-water effluent from a syngas fermenter that uses distillation alone to produce 95 wt% ethanol in the distillate. Then, a model was made for a system where the syngas fermentation effluent is first concentrated via a pervaporation module and then distilled. The flow rates in both models was calculated to find the amount of ethanol recovered in grams per hour. Then, the amount of energy required per hour was calculated for both models and an analysis was done to compare the energy required to recover a gram of ethanol for various feed stream concentrations.

2013-05-03T00:00:00Z Nelson, Brittany http://hdl.handle.net/1813/33205 2013-05-04T05:03:43Z 2013-05-03T00:00:00Z

Title: Measurements of Cayuga Lake Production Authors: Nelson, Brittany Abstract: This study aims to compare estimates of primary productivity in Cayuga Lake based on in situ measurements of dissolved carbon dioxide (CO2) and dissolved oxygen (DO). Historically, productivity was estimated using the light/dark bottle method. More recent procedures have used in situ DO measurements. However, DO is a by-product of production. Directly using CO2 to determine productivity could offer a faster and more accurate result. Four locations at the southern end of Cayuga Lake were sampled between July 3, 2012 and October 9, 2012. Free aqueous CO2 was measured using an OxyGuard Dissolved CO2 meter. Citric acid was added to the water sample to lower the pH to the range of 3-4, so that most of the inorganic carbon would be in the CO2 form. Additionally, DO readings were taken using a Hydrolab DS 5. Average diel differences in CO2 and DO were found at each of the four sampling sites. To evaluate production, diel DO concentrations were corrected for atmospheric diffusion. In addition, diel CO2 differences were assumed to be adequate measures of production. Direct ambient CO2 concentration differences were found to have a strong, linear relationship with net ecosystem production.

2013-05-03T00:00:00Z Webster, Dylan http://hdl.handle.net/1813/33204 2013-05-04T05:02:33Z 2013-05-03T00:00:00Z

Title: An arsenic-specific biosensor with genetically engineered Shewanella oneidensis in a bioeletrochemical system Authors: Webster, Dylan Abstract: Genetically-engineered microbial biosensors have yet to realize commercial success in environmental applications, due in part to difficulties associated with transducing and transmitting traditional bioluminescent information. The use of bioelectrochemical systems (BESs) in biosensing applications allows for a direct electronic output that can be more easily incorporated into devices for remote environmental monitoring. Herein, we describe the first BES-based biosensor with genetically encoded specificity for a toxic metal. By placing an essential element of the metal reduction (Mtr) pathway of Shewanella oneidensis MR-1 under the control of an arsenic-sensitive promoter, we have engineered a strain that produces increased current in response to arsenic when inoculated into an BES. When operated as a chemostat with a hydraulic retention time of 7 h, our BES-based biosensor has a response time of 24 h and a lower detection limit on the order of 100 μM arsenite. To heighten the sensor's sensitivity to arsenic, we have begun characterizing an alternative sensing strain with improved translational efficiency. This ability to tune analyte sensitivity—along with the reliability of our continuous assay and the simplicity of the transcriptional circuit required for BES-based biosensing—suggests that similar sensing systems may be readily developed for both environmental deployment and on-line process control.

2013-05-03T00:00:00Z Anderson, Caitlin E http://hdl.handle.net/1813/30794 2012-12-19T21:18:04Z 2012-12-19T00:00:00Z

Title: The Quantification of Liposome Signals Using Nanofiber-Based Microfluidic Devices Authors: Anderson, Caitlin E Abstract: Microfluidic paper-based analytical diagnostics have allowed for a diversification of analytical tools by enabling the development of inexpensive and portable devices that build upon existing detection strategies. Taking advantage of existing quantification techniques is an important strategy to ensure that these novel paper-based systems find use and application in the diagnostics world. For more than 50 years high-throughput assays have been developed using polymeric microtiter plates in which signals are quantified using specific absorbance, fluorescence, and luminescence readers. Here, we studied the novel idea of integrating a paper-based analytical assay with a microtiter plate reader. Specifically, electrospun nanofiber mats were designed to match dimensions and criteria of microtiter plate readers. Dye-encapsulating liposomes were used as a model analyte and quantified using absorbance and fluorescence detection strategies. Initially, positively charged poly(vinyl alcohol) (PVA) and polylactic acid (PLA) nanofibers were electrospun and functionalized in specific locations with anti-streptavidin antibodies. Additionally, streptavidin-conjugated liposomes were synthesized to encapsulate sulforhodamine B (SRB) (absorbance wavelength of 488 nm, and a fluorescence excitation and emission wavelengths of 540 nm and 590 nm respectively). Liposomes were then applied and flowed through the nanofiber mats under various conditions to investigate their selective capture, concentration, and detection. Primary investigations demonstrated the ability of PLA as an immobilization matrix to selectively bind streptavidin conjugated liposomes through the use of absorbance measurements. Fluorescence allowed subsequently for accurate readings without the interference of any of the assay materials. The ability to specifically quantify the capture of liposomes using the microtiter plate reader allowed for quantitative optimization of all involved assay steps and buffer systems to increase the reliability of the assay. In the end, the quantification of signals was achieved with a testing volume of 10 µL of SRB encapsulating liposomes, a wash step using 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)-sucrose-saline buffer, and 2 µL of detergent for liposome lysis at a concentration of 50 mM. Thus, through the use of streptavidin-conjugated liposomes as a model analyte, it was demonstrated that a PLA nanofiber-based microtiter plate could successfully detect and differentiate between different concentrations of analytes with a detection limit of 0.5 mM and a sensitivity of 4023 Fluorescence units/mM.

2012-12-19T00:00:00Z Georgescu, Andrei http://hdl.handle.net/1813/29646 2012-08-10T05:01:45Z 2012-08-09T00:00:00Z

Title: Rapid and efficient mixing in low Reynolds number microfluidic systems via short-distance flow through an electrospun nanofiber mat: A computational analysis Authors: Georgescu, Andrei Abstract: This report presents the development of a comprehensive method by which electrospun nanofibers and their mixing effects may be modeled with a combination of custom scripts and ANSYS 14.0 software. A customizable and entirely automated workflow is realized, through which accurate models and results may be generated without requiring in-depth understanding of the underlying computational fluid dynamics principles. The automation process spans all simulation phases, starting with realistic fiber modeling via a custom script and followed by input specifications, automatic generation of the necessary geometry, export of the resulting computational mesh into ANSYS Fluent, control of computational solvers governing fluid flow and species mixing models, and ending with the automation of ANSYS CFD-Post to output solution data. This method is presented in a step-by-step manner through a case study of a Y-shaped microfluidic channel with an embedded electrospun nanofiber mat, the mixing performance of which is determined in this report's conclusion.

2012-08-09T00:00:00Z Licitra, Johnathan http://hdl.handle.net/1813/29620 2012-08-05T05:00:26Z 2012-08-03T00:00:00Z

Title: West King Road Stormwater Rehabilitation Project Authors: Licitra, Johnathan Abstract: The Town of Ithaca’s Public Works Department mission is to maintain the road infrastructure for commerce throughout the town. Part of this maintenance includes providing proper conveyance of stormwater—one such area that needs rehabilitation is along the intersection of West King Rd and Stone Quarry Rd in Ithaca, NY. This report discusses the background, hydrology, and 3 potential engineering solutions for the current erosion problem. After engineering capacity calculations and a material cost comparison, a weir and armored channel approach is recommended.

2012-08-03T00:00:00Z Sani, Khadeejah http://hdl.handle.net/1813/29619 2012-08-03T13:24:13Z 2012-08-03T00:00:00Z

Title: Evaluating the Impact of Energy Savings Technologies in The Statler Hotel Authors: Sani, Khadeejah Abstract: On average, hotels in America spend $2,196 per available room yearly on energy. In efforts to reduce energy costs, The Statler Hotel permitted Schneider Electric to test Cassia™, its energy management system. Cassia™ is an in-room energy solution based on sensors that detects room status and triggers temperature setbacks in heating and cooling units. In this study, a four-room test bed was used to evaluate potential energy savings associated with Cassia™. Statistical analyses were conducted to determine parameters’ influence in reducing energy units’ runtime. Results show that Cassia™ reduced runtime by 18%. While the average energy savings reported by Schneider Electric is 25-44%, this range includes savings from lighting, which was out of the scope of this study. By extrapolating savings from August-February 2012, a total of $7,829 would have been saved given a Cassia™ installation throughout the Hotel, while $3,003 saved solely based on vacancies during an unrented status.

2012-08-03T00:00:00Z