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Title: TEMPERATURE PROFILES THROUGH THE SHELL IN EGGS HEATED BY INFRARED ENERGY
Creator: Guo, Jingxin
Date: 2012-07-30, 2012-07
Description: Infrared heating is an effective method for surface pasteurization of shell eggs. As the external temperature reaches the inactivation...
Show moreInfrared heating is an effective method for surface pasteurization of shell eggs. As the external temperature reaches the inactivation temperature, internal temperatures could become great enough to denature albumen. However, the internal temperature of albumen at the shell cannot be measured directly. The purpose of this study is to use experimental data to understand the response of the albumen temperature at the shell to infrared radiation impinging at its outer surface. Fresh eggs were obtained from a local producer and refrigerated until needed. They were prepared for each experiment by overnight equilibration with ambient conditions. Each egg was placed on a metal stage over which an infrared lamp was positioned. The stage allowed a K-type thermocouple to be inserted through a small hole in the shell opposite of the shell area facing the lamp. The thermocouple was pushed into the egg such that the tip was against the inner surface of the shell just underneath the exposed area. The external temperature of this area was measured by an infrared pyrometer. Variables for these experiments were temperature of the IR lamp (277°C, 329°C, 391°C and 452°C), distance between shell egg and IR lamp (3.13 cm – 15.83 cm), and treatment time. All experiments share the same initial lag around 30s, suggested that the initial lag did not vary with changing of lamp-egg distances and lamp temperatures. After the initial lag, internal and external temperatures were found to increase at the same rate regardless of experimental parameters, indicating and equilibrium between the infrared energy impinging on the surface and its dissipation in the interior of the egg. The difference of temperature distributes between 10°C to 20°C. However, lowering lamp temperatures or increasing distances did not change this difference significantly. Moreover, the temperature gap sustains the same temperature after initial lag. The results showed that the internal temperature could be inferred via measuring external temperature. This is valuable in processing to maximize external surface temperature while protecting heat sensitive albumen. Future work will involve modeling the heating phenomenon to determine if knowing only the lamp temperature and distance is sufficient for predicting internal temperature.
M.S. in Food Processing Engineering, July 2012
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Title: SURVIVAL OF SALMONELLA ON CHAMOMILE, PEPPERMINT AND GREEN TEA DURING STORAGE RELATED TO TEMPERATURE AND HUMIDITY
Creator: Chen, Zhengzai
Date: 2013-04-24, 2013-05
Description: Botanical/herbal teas may contain antimicrobial compounds that will affect the survival and persistence of the native as well as contaminant...
Show moreBotanical/herbal teas may contain antimicrobial compounds that will affect the survival and persistence of the native as well as contaminant microflora. Although Salmonella are known for their ability to survive in low water activity environments, their survival on dry botanical/herbal teas has not been examined. The purpose of this work is to determine the survival of Salmonella on three types of teas, chamomile peppermint, and green tea under different storage conditions. In addition, the ability of Salmonella to grow in tea brewed with contaminated product was examined. A cocktail of four Salmonella serovars was inoculated onto 1 g samples of chamomile, peppermint, and green tea to give a starting cell population of approximately 10 log cfu/g. The inoculum was allowed to dry prior to storage at 25 °C and 35 °C and at low (<30% RH) and high (> 90% RH) humidity levels. At different time intervals up to 6 months, triplicate samples at each condition were evaluated for surviving Salmonella populations. In addition, samples were used to produce a low-temperature (sun) brewed tea and inoculated. Growth was assessed after 24 hr. Under the four storage conditions tested, survival followed the order 25°C/low RH > 35°C/low RH > 25°C/high RH > 35°C/high RH. Salmonella losses at 25°C/low RH occurred primarily during drying, after which populations showed little declines over 6 months. In contrast Salmonella decreased below detection after 45 days at 35°C and high RH in all teas tested. All teas tested supported the growth of Salmonella after brewing. Storage conditions significantly impact the survival of Salmonella in dried herbal teas. If Salmonella survives after storage, it may also survive and grow after a home brewing process.
M.S. in Food Safety and Technology, May 2013
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Title: IN VITRO STUDIES OF VIRULENCE SUPPRESSION ON P. AERUGINOSA BY PHOSPHATE / POLYPHOSPHATE-LOADED NANOPARTICLES
Creator: Yin, Yushu
Date: 2015, 2015-07
Description: Critically ill patients harbor multi-drug resistant pathogens that can activate their virulence in the response to low nutrient conditions and...
Show moreCritically ill patients harbor multi-drug resistant pathogens that can activate their virulence in the response to low nutrient conditions and host stress derived factors. It was recently shown that the oversupply of inorganic phosphate to bacterial environment can profoundly suppress the virulence of pathogens. Here we hypothesized that phosphateand/ or polyphosphate-loaded nanoparticles can present a tool to deliver and slowly release phosphate in pathogen-rich niche, thereby suppressing bacterial virulence. In this work, a designed study on effect of different phosphate levels (including the phosphate released from hydrogel nanoparticles) on virulence of P. aeruginosa is addressed. In this work, we developed formulations for preparing hexametaphosphate-loaded nanoparticles on the basis of that for phosphate loaded nanoparticles. We utilized inverse miniemulsion polymerization in the synthesis of these nanoparticles. Polyethylene glycol diacrylate (PEGDA, moleculat weight of 575 Da) and N-vinyl pyrrolidone (molecular weight: 111.14 Da ) were chosen to be the initial monomers because the main crosslinker, polyethylene glycol is a kind of biocompatible material that has been approved by the U.S. Food and Drug Administration (FDA). Several parameter could be adjusted among the experiment. We selected the monomer mole fraction of PEGDA-575 as our parameter. After the synthesis, a nanoparticle size distribution between 110 nm and 150 nm was obtained. And these nanoparticles were proved to be able to release phosphate and hexametaphosphate as drug molecules. Although there were release bursts in the test of release kinetics, the crosslink density could be adjusted in following researches. The second part of this study is to test the virulence suppression effect of the nanoparticles in in vitro experiment on a kind of opportunistic pathogen, P. aeruginosa. This kind of gram-negative bacteria is one of the common intestinal microbial communities. We presented the strategy of suppressing virulence while containing rather than killing the bacteria. As a result, polyphosphate loaded nanoparticles showed to be the most effective one among several experiment groups. This result gave this study a promising future in further research in several aspects, such as in vivo test in biomedical and biomedical engineering.
M.S. in Chemical Engineering, July 2015
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Title: DETECTION OF SUPEROXIDE ANION RADICALS IN ANION EXCHANGE MEMBRANE FUEL CELLS USING IN-SITU FLUORESCENCE SPECTROSCOPY
Creator: Zhang, Yunzhu
Date: 2016, 2016-07
Description: Anion exchange membrane (AEM) stability is a long-standing challenge that has limited the widespread development and adoption of AEM fuel...
Show moreAnion exchange membrane (AEM) stability is a long-standing challenge that has limited the widespread development and adoption of AEM fuel cells. It is essential to understand the mechanism of AEM degradation during fuel cell operation. There are multiple modes of AEM degradation, broadly classified as chemical, mechanical and thermal degradation. Chemical degradation is among the most destructive modes, and can be further sub-divided into nucleophilic degradation (induced by the hydroxide ion), and oxidative degradation (induced by reactive oxygen species). While the former has been extensively studied, there is minimal work on oxidative AEM degradation. The reactive oxygen chemical species produced during the operation of an AEM fuel cell have hitherto not been detected during operation. Given the high pH, it is postulated that superoxide anion radicals (𝑂2∙−), as opposed to hydroxyl radicals, are primarily involved in the degradation progress. The objective of this study was to confirm the 𝑂2∙− formation during AEM fuel cell operation and to monitor in real-time the rate of 𝑂2∙− generation in an operating fuel cell using in-situ fluorescence spectroscopy. 1,3-diphenlisobenzofuran (DPBF) was chosen as the fluorescence probe, the sensitivity of which towards 𝑂2∙− was evaluated by performing ex-situ experiments in a semi-batch reactor. We demonstrate that the fluorescence intensity of this dye selectively decreased upon exposing 𝑂2∙−. DPBF was then incorporated into an AEM (membrane was solution cast after mixing the dye with the casting solution), which was assembled into a fuel cell. 𝑂2∙− generation in an operating AEM fuel cell was then monitored via in-situ fluorescence spectroscopy using a bifurcated optical probe, when the cell was operated in H2/O2 mode. To confirm the impact of 𝑂2∙− on AEM degradation, independent experiments (without dye) were performed under identical conditions, under both H2/O2 and N2/N2 modes, and the ionic conductivity and ion exchange capacity were monitored to estimate degradation extent. From our in-situ fluorescence studies, we were able to estimate the rate constants and activation energy for oxidative AEM degradation in an operating AEM fuel cell.
M.S. in Chemical Engineering, July 2016
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Title: SUSTAINABLE NEW CITY MENTOUGOU, CHINA
Creator: Yin, Lu
Date: 2013-04-30, 2013-05
Description: This thesis will demonstrate one of the first urban models for the future of China’s growth. The Urban Operating System and GPS make the smart...
Show moreThis thesis will demonstrate one of the first urban models for the future of China’s growth. The Urban Operating System and GPS make the smart city smarter by linking up networks of billions of distributed sensors, systems, and intelligence across urban environments via city-scale operating systems. Personal Rapid Transit system runs everywhere and it is accessed and ordered by smart phone. Green belt is the medium that links all the natural area and parks in the city which become the core element in the city because it plays the most important role. Two types of transportation system including the Meglev for 10 minute access to Beijing and the PRT system for all internal urban mobility. The population of the new city is 80000. 80% of the people live here and work here, 20% of the people live here but work in Beijing. 30% of the people will use PRT system everyday. All the city blocks are mixed-use blocks. There are several types of residential buildings including mid-rise, high-rise and Beijing traditional courtyard house. This sustainable new city provides quality of lift to all the people live in the city.
M.S. in Architecture, May 2013
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Title: STRUCTURAL CHARACTERIZATION OF THE FLIGHT MUSCLE OF MANDUCA SEXTA
Creator: Cheng, Yu-shu
Date: 2013-04-22, 2013-05
Description: There are several properties of the flight muscle Manduca sexta that are interesting. In its physiological characteristics, like mammalian...
Show moreThere are several properties of the flight muscle Manduca sexta that are interesting. In its physiological characteristics, like mammalian skeletal and cardiac striated muscle, it is a synchronous muscle. However, it is much more similar structurally to the more widely known asynchronous insect flight muscles of Drosophila and Lethocerus. The goal of the thesis is to study the structural characteristics and perform mechanical studies of dorsal and ventral muscle of Manduca flight muscle. In pursuit of this goal, a secondary purpose was to develop better storage conditions for skinned insect muscle which can maintain muscle structure and function. Maximum active force as a function of time in storage was compared for storing at 4℃ without glycerol and storing at -80℃ with 75% glycerol. The maximum force values were almost the same during days 0-4. However, the muscle stored at -80℃ with 75% glycerol gave higher active force in high calcium (pCa 4.5) solution over a longer time in storage than muscle stored at 4℃. Both ventral and dorsal muscles can deliver 40-50% of original active force for up to 21 days in storage. X-ray diffraction experiments were done to compare the response of chemically skinned Manduca flight muscle to temperature and to the induction of rigor. The lattice spacing (d10) decreased and intensity ratio I20/I10 increased when the temperature of the relaxing solution bathing the solution increased from 10℃ to 40℃. Lattice spacing (d10) decreased, but the I20/I10 intensity ratio increased slightly while concentration of dextran increased from 1% to 6%. Six percent dextran was insufficient to restore the in vivo lattice spacing.
M.S. in Molecular Biochemistry and Biophysics, May 2013
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Title: MODELING OF A DCFC ANODE IN CONNECTION WITH THE EXPERIMENTAL RESEARCH ON THE WETTING BEHAVIOR OF A GRAPHIC ROD IN MOLTEN CARBONATE
Creator: Li, Yue
Date: 2013, 2013-12
Description: Not available
M.S. in Civil Engineering, July 2013

Title: INVESTIGATION OF THE EFFICACY OF REACTIVE OXYGEN SPECIES GENERATED BY BOVINE AORTIC ENDOTHELIAL CELLS FOR INITIATING FREE-RADICAL POLYMERIZATION
Creator: Lu, Chenlin
Date: 2013, 2013-12
Description: Reactive oxygen species are reported to be generated by bovine aortic endothelial cells during ischemia followed by reperfusion. This...
Show moreReactive oxygen species are reported to be generated by bovine aortic endothelial cells during ischemia followed by reperfusion. This biological response, believed to be the cause of post-ischemic reperfusion injury, inspired us to investigate the possibility of coupling it with the initiation of free-radical polymerization to produce polymer hydrogels for cell encapsulation. In this work, the generation of reactive oxygen species during ischemia and reperfusion was examined by fluorescence detection and the feasibility of initiating free-radical polymerization by generated reactive oxygen species was investigated in two sets of experiments. The generation of reactive oxygen species by bovine aortic endothelial cells when subjected to anoxia followed by reoxygenation was investigated in both attached and suspended cells. Both intracellular and extracellular generations of ROS appeared to occur in the experiments of attached cells. Cell viability experiments demonstrated that the generation of ROS was sufficient to cause cell damage and death. The feasibility of initiating free-radical polymerization by reactive oxygen species generated by bovine aortic endothelial cells subjected to anoxia followed by reoxygenation was investigated in two sets of experiments. One set involved the linear polymerization of NVP which allowed us to quantify the extent of polymerization and characterization of the weight conversion of PVP polymer. The other set involved the formation of PEGDA hydrogels which were characterized by imaging and staining methods. To our knowledge this is the first evidence of cell induced polymerization initiated by reactive oxygen species and gelation which can be used for a variety of biomedical applications.
M.S. in Chemical and Biological Engineering, December 2013
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Title: EVALUATION OF COXIELLA BURNETII NINE MILE PHASE II INACTIVATION IN WHOLE MILK AFTER THERMAL TREATMENT BY INTEGRATED CELL CULTURE-PCR ASSAY
Creator: Ma, Songchuan
Date: 2013-04-30, 2013-05
Description: Coxiella burnetii, the etiologic agent of Q fever, is a Gram-negative, obligate intracellular coccobacillus, which has been used as the...
Show moreCoxiella burnetii, the etiologic agent of Q fever, is a Gram-negative, obligate intracellular coccobacillus, which has been used as the reference organism for defining milk pasteurization conditions. A developed Integrated Cell Culture-PCR (ICC-PCR) assay may be helpful for evaluating C. burnetii inactivation by thermal process in whole milk products. The purpose of this research was to characterize and optimize an ICCPCR assay in whole milk and evaluate this assay by thermal process. Coxiella burnetii was diluted into whole milk from FDA stock and treated by thermal process. Samples were sealed in glass vials and placed in ice-water to obtain a consistent starting temperature. Cooled vials were heated in a shaking waterbath at 60 °C, 62 °C and 64 °C in for various times. Thermally treated samples were diluted by RPMI+1% FBS and inoculated on Vero cell culture monolayers with PBS, incubated for 48 hours to infect the Vero cells, and then incubated for another 9 days to allow propagation. The propagated C. burnetii mix was subjected to freeze-thaw followed by DNA extraction with Autogen DNA Tissue Kit by using Quickgene Mini80. Extracted DNA was amplified by using TaqMan-MGB based qPCR targeting published primers for the IS1111a transposase gene to verify C. burnetii growth. For detection limit determination, serial dilutions of C. burnetii were mixed independently in whole milk and 1% FBS+RPMI. The mix was overlaid on confluent Vero cells for 2 days and 11 days. The DNA extractions were followed using DNA tissue kit by Quickgene Mini80 and PCR. At least duplicate trials using 3 replicates per trial were completed for each time/temperature condition.
M.S. in Food Safety and Technology, May 2013
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Title: MODEL-BASED EXPLORATION OF THE FEASIBILITY OF CREATING MULTIPLE PROPERTY GRADIENT IN CROSSLINKED POLYMER FILMS IN CONTROLLED LIVING POLYMERIZATION
Creator: Qin, Zikai
Date: 2014, 2014-05
Description: The functional gradient materials have been widely used in chemical engineering, biomedical engineering and tissue engineering since they have...
Show moreThe functional gradient materials have been widely used in chemical engineering, biomedical engineering and tissue engineering since they have been reported because of their admirable mechanical, physical and chemical properties. Several traditional methods of synthesis gradient materials are known to all. Here we introduced a new mathematical model of designing and producing crosslinked polymeric films with target multiple gradients. We derive our model from batch reactor system and explore how each condition of the system affects the gradient of the polymer film. Then we extend to semi-batch reactor to control the gradient in crosslink density and set up different strategies to make the target multiple gradient crosslink density accomplish. With any given target gradient crosslinked polymer film, we can make an exact similar film in our model.
M.S. in Chemical Engineering, May 2014
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Title: AGENT-BASED MODELING OF ANGIOGENESIS: EXPLORATION OF THE EFFECTS OF VEGF DELIVERY STRATEGIES ON PROMOTING ANGIOGENESIS
Creator: Xiao, Nan
Date: 2015, 2015-05
Description: This is a dissertation about three-dimensional agent-based modeling (ABM) of angiogenesis within porous scaffold. Tissue engineering...
Show moreThis is a dissertation about three-dimensional agent-based modeling (ABM) of angiogenesis within porous scaffold. Tissue engineering technology provides great benefits for humanity in maintaining healthy tissue formation and disease rehabilitation. However, biomedical experiments, especially animal experiments, are very costly, timeconsuming and high technological level of equipment required. The computational modeling can provide an efficient alternative to biomedical experiments in strategy design and assist clinical research. To simulate the angiogenesis process, an agent-based model was developed using java-based Repast toolkit. The purpose of this research is to explore the effects of different Vascular Endothelial Growth Factor (VEGF) delivery methods in promoting angiogenesis. The work here includes four parts: a) model verification by comparing simulation results with experimental results; b) exploration of different VEGF delivery methods by changing total dose and release rate; c) exploration of the effects of prevascularized strategies; d) development of a tissue cell VEGF secretion model. The simulation results showed that: angiogenesis can be promoted by increasing VEGF total dose or decreasing releasing rate; prevascularized scaffolds can improve new vascular network formation and result in better invasion depth; pre-seeded tissue cells in the scaffold can provide a continuous source of VEGF and promote angiogenesis. This ABM can provide a good reference for the design of biomedical applications.
M.S. in Chemical Engineering, May 2015
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Title: EFFECT OF REACTANT CONCENTRATIONS AND AGING EFFECT IN THE SYNTHESIS OF SILVER NANORODS
Creator: Wang, Guan
Date: 2016, 2016-05
Description: In the recent years, anisotropic metallic nanoparticles have drawn much attention because of their unique optical properties. Particularly,...
Show moreIn the recent years, anisotropic metallic nanoparticles have drawn much attention because of their unique optical properties. Particularly, gold and silver nanorods show great potential in extensive applications such as health care, food storage, drug delivery, biosensor, and cancer treatment. Among a variety of nanorods synthesis methods, the seed-mediated growth approach stands out due to its mild and convenient experimental conditions. However, there exist two defects of this method, the poor reproducibility and low yield of nanorods. In order to create nanoparticle systems of reproducible quality in high yields, a deeper understanding of the mechanism of nanorods formation as well as identifying the more important variables is necessary. In this study, the original seed-mediated growth method has been modified to promote the reproducibility and yield of nanorods. Effects of CTAB concentration and ages of growth solution have been investigated in the nanorods formation process. The results suggest that a high concentration of CTAB is not necessary for the growth process and the age of growth solution can affect the optical performance of nanorods. In a brief survey on the stability property of nanorods, it shows that the degradation rate decreases with increasing concentrations of CTAB.
M.S. in Chemical Engineering, May 2016
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Title: MODELING, CONTROL, AND DESIGN OF HYBRID FUEL CELL VEHICLES
Creator: Ahmed, Syed
Date: 2011-12, 2011-12
Description: The Polymer Electrolyte Membrane Fuel Cell (PEMFC) has been projected to be the fuel cell of choice for future automotive applications. Among...
Show moreThe Polymer Electrolyte Membrane Fuel Cell (PEMFC) has been projected to be the fuel cell of choice for future automotive applications. Among the challenging aspects of this application is maintaining highly efficient operation of the fuel cell. The key component of the PEMFC, the Nafion Membrane, can reach two critical states: drying and flooding. In drying, high resistance prevents normal operation of the fuel cell. In flooding, reactants are prevented from reaching reaction sites and there is a reduction of performance of the fuel cell. To address the first point, a spatially distributed along the plane membrane model was developed and tested with proportional-integral control of voltage and temperature. To analyze the occurrence of severe and frequent changes in power demand, a model aimed at mimicking the load expected in a fuel cell vehicle, including a DC motor, DC-DC converters and a rechargeable battery for peak-shaving and regenerative braking was developed. The model includes rotational and translational inertia as well as a simple wind resistance model for a vehicle. In contrast to simple lab-focused loads where load impendence is directly manipulated, the manipulated variable within this load is the DC-DC converter gain. Based on this model a control system architecture was developed consisting of a number of low level regulatory loops, a power distributor for peak-shaving and finally a high level loop for tracking vehicle speed. After understanding the load demands to a fuel cell vehicle with only a battery, the issue of multiple energy storage technologies is addressed. Designing a vehicle with these technologies poses an optimization problem. A high-level model of a fuel cell vehicle with two storage technologies, a battery and super-capacitor was developed. The model accounted for the constraints of each component and a drive cycle characterized the power demand. An economic-based optimization problem xv was posed whereas its objective was to minimize the capital cost of the system, while meeting power demand and keeping the technologies within their constraints. The result of the optimization provided a controller from which a high-level power coordination unit can be developed for the fuel cell vehicle.
Ph.D. in Chemical Engineering, December 2011
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Title: UNDERSTANDING THE MEMBRANE ACTIVITY OF ACYL LYSINE OLIGOMERS
Creator: Lingaraju, Mahesh
Date: 2012-07-10, 2012-07
Description: In the past two decades, Antimicrobial peptides (AMPs) have attracted considerable interest because of their potential therapeutic use as...
Show moreIn the past two decades, Antimicrobial peptides (AMPs) have attracted considerable interest because of their potential therapeutic use as antibiotics, antivirals, and antitumoural drugs. However, there are a number of serious challenges on the way toward bringing AMPs onto the market which include their rapid in vivo degradation, high production costs, reduced activity in physiological conditions, etc. To overcome these problems and yet to capitalize on the immense potential of AMPs, extensive efforts to develop their non-natural mimics have been recently made. A better understanding of the structure-activity relationships of AMPs is essential to the creation of a successful peptidomimetic compound. It has been widely accepted that AMPs kill pathogens by disrupting the cell membrane or invading the cytoplasm and inhibiting core metabolic functions. Thus, the pathogenic membrane plays a crucial role either as an immediate target or as a barrier that must be traversed. Herein, we have investigated the role of charge and hydrophobicity in the interplay between membrane-active molecules (Oligomers of acyl lysine) and model bacterial or host cell membranes using constant-pressure insertion assays, synchrotron X-ray reflectivity (XR) and grazing incident-angle X-ray diffraction (GIXD). The outer surface of a membrane was approximated by a planar lipid monolayer at the air-liquid interface, whose composition was modified in accordance with the cell being modelled. The presented results have helped us to arrive at a general mechanism by which the OAKs seem to interact with lipids which is strongly dependent upon the charge density of the monolayer, charge and hydrophilicity of the molecule and presence of freely accessible hydrophobic regions. The results indicate the molecules fail to interact with the acyl chains when they poorly negotiate with the head group or when they lack accessible hydrophobic regions. Overall, presented results advance current understanding of the mechanism of action of flexible AMP mimics on bacterial membranes and will no doubt aid in the rational design and optimization of non-natural mimics of antimicrobial peptides that will be effective against multidrug resistant bacteria and cancer cells. Nevertheless, future work is required to further understand the critical factors leading to potent anti-infective activity of antimicrobials.
M.S. in Molecular Biochemistry and Biophysics, July 2012
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Title: YIELD STRESS MEASUREMENTS USING NOVEL SQUEEZING FLOWS
Creator: Ward, Daniel
Date: 2015, 2015-12
Description: Techniques for measuring the yield stress of materials are numerous, but often plagued with diffculties and uncertainties in measurement. The...
Show moreTechniques for measuring the yield stress of materials are numerous, but often plagued with diffculties and uncertainties in measurement. The primary methods include shear rheometry and, more recently, squeezing ow. Shear rheometry requires care on the part of the experimentalist to generate uniform flow fields and avoid shear banding or wall slip which may interfere with measurements. Squeezing fow tests are often performed with poorly controlled boundary conditions creating complicated flow fields. Further, the effects of the experimental modifications made to produce these boundary conditions in measurements are often not investigated and simply ignored. The main objective of this study was to develop a novel measuring technique to study the yield stress behavior of a model material, Carbopol. First attempts were made towards a novel lubricant injection squeezing (LIS) ow technique based on the continuous lubricated squeezing ow (CLSF) setup, as well as a novel lubricant film squeezing (LFS) technique which will allow measurement of the yield stress without the complicated treatment of either the sample or experimental setup required by currently favored methods. The novel techniques were developed and validated by direct comparison with shear measurements, the current gold standard for determining yield stress. Common squeezing techniques for characterizing yield stress fluids were also compared and found to be inadequate and inconsistent when compared to the shear measurements. The results from this study showed that the LIS and LFS methods are able to qualitatively determine a yield stress, but further investigation is required before they can be achieve their full potential as viable methods for determine yield stress.
M.S. in Chemical Engineering, December 2015
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Title: MODELING AND NUMERICAL SIMULATION OF WIND TURBINE PERFORMANCE IN RAINY CONDITIONS USING A MULTIPHASE FLOW APPROACH
Creator: Cai, Ming
Date: 2012-04-25, 2012-05
Description: Wind energy is becoming one of the key renewable sources of energy in the United States and the world due to its environmental and economic...
Show moreWind energy is becoming one of the key renewable sources of energy in the United States and the world due to its environmental and economic advantages and absence of water requirements. The performance of a wind turbine is largely affected by surrounding environments and the total power output of a wind farm is closely related to meteorological phenomena such as rain and icing. Investigating the effects of these phenomena is necessary to improve the design and performance of the wind turbines. In this research, we focused on the study of wind turbine performance in rainy conditions as the stepping stone to the future study of icing. We applied Computational Fluid Dynamics (CFD) technology to investigate the impact of rain on wind turbines. A novel model coupling the Lagrangian method with the Eulerian method was developed. The rain droplet was tracked in the Lagrangian frame due to its discrete nature, and the film formed on the wind turbine was simulated with the Eulerian Volume of Fluid Model (VOF). The performance loss and impact on the flow field were also studied. Numerical studies have been conducted on 2-Dimensional S809 airfoils and 3- Dimensional Horizontal Axial Wind Turbines (HAWT). The performance loss under heavy rain conditions was observed and the flow field was analyzed. The impact of air moisture content on wind turbine performance was also studied using our 3-D model. Due to the lack of experimental data on wind turbine performance under heavy rain conditions, our coupled two phase flow model was applied to a NACA 64-210 airfoil to compare with the experimental data in rainy conditions. Simulation results using our model showed good agreement with the experimental data.
M.S. in Chemical and Biological Engineering, May 2012
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Title: SMART GRID COORDINATION OF A CENTRALIZED POWER AND COOLING FOR AN URBAN COMMUNITY
Creator: Franco, Diego Pacheco
Date: 2016, 2016-05
Description: Because the world’s fossil fuel reserves are finite, it is essential to substantially improve the efficiency of all energy consumers. Heating,...
Show moreBecause the world’s fossil fuel reserves are finite, it is essential to substantially improve the efficiency of all energy consumers. Heating, ventilating and air conditioning (HVAC) accounts for 45% of energy consumption in residential buildings. Thus, this project studied and proposed solutions to improve the efficiency of such systems. The project begins with an analysis of a cooling system using electric chillers for a new hypothetical residential community in the Chicago area. Then, two new hybrid configurations were proposed: the utilization of electric and absorption chillers and then this system was augmented with a Thermal Energy Storage (TES) system. A simulation environment based on Matlab/Simulink®, using the concepts of Economic Model Predictive Control (EMPC) was developed to evaluate the performance of these configurations. The main benefits found were the increasing energy efficiency, the environmental impacts reduction and a reduction of more than 70% in operating costs (in some cases, profit was generated).
M.S. in Chemical Engineering, May 2016
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Title: Ease of Contamination and Subsequent Sanitation of Food Contact Surfaces Using Salmonella Contaminated Nut Butters
Creator: Kamineni, Prashanthi
Date: 2012-07-23, 2012-07
Description: Salmonella species can survive and or persist for long periods of time in low moisture foods and on food contact surfaces. Understanding...
Show moreSalmonella species can survive and or persist for long periods of time in low moisture foods and on food contact surfaces. Understanding parameters of transfer and survival can provide information required for successful control of this foodborne microorganism. This study investigated the recovery of Salmonella from food contact surfaces (stainless steel, Delrin, polyethylene, polyurethane) as well as their transfer from nut butters onto the contact surfaces. S. Tennessee and S. Oranienburg were grown overnight to stationary phase, harvested and inoculated separately into peanut butter and almond butter. One gram of inoculated nut butter was applied to each of the three separate 4 X 4 cm areas on the materials and stored at room temperature. The nut butters were removed after 1, 7, and 14 day intervals to leave a visually clean surface. Surfaces were swabbed and/or tested with contact plates to determine the population of any remaining cells. Using contaminated peanut butter, highest numbers of S. Tennessee of about 4.27 ± 0.30 per cm2 were recovered from stainless steel surface after 1 day of contact time. Both serovars were recovered at low numbers over time. However, when contaminated almond butter was used, lower recovery was obtained with both serovars. Visually clean surfaces were also treated with various sanitizers to determine efficiency of treatments. Of the three sanitizers, isopropanol proved most effective overall in reducing Salmonella contamination whereas chlorine was least effective. BDD and isopropanol gave best efficiency on stainless steel with a reduction of about 2.5 logs and least on polyurethane surface with a reduction of only about 1 log (p<0.05). Results were similar for both the serovars tested. In general, sanitizers were most effective on stainless steel while polyurethane surface was the most difficult to sanitize. These studies contribute to a better understanding of the behavior of S. Tennessee and S. Oranienburg in nut butters and on food contact surfaces. Estimation of contamination levels may be determined from transfer rates for Salmonella from contaminated to uncontaminated foods and food contact surfaces.
M.S. in Food Safety and Technology, July 2012
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Title: MODELING AND SIMULATION OF DIRECT CARBON FUEL CELL ANODE IN CONNECTION WITH ANALYSIS AND CHARACTERIZATION OF WETTED CARBON ROD IN MOLTEN CARBONATE
Creator: Peng, Feng
Date: 2013, 2013-07
Description: Not available
M.S. in Chemical Engineering, July 2013

Title: INVESTIGATION OF OXYGEN GENERATION DURING THE OPERATION OF LITHIUM-ION CELLS USING IN-SITU FLUORESCENCE SPECTROSCOPY
Creator: Li, Mo
Date: 2016, 2016-07
Description: An ex-situ fluorescence spectroscopy system was set up and utilized to study the interaction of fluorescent dyes with an oxygen quencher. The...
Show moreAn ex-situ fluorescence spectroscopy system was set up and utilized to study the interaction of fluorescent dyes with an oxygen quencher. The Stern-Volmer relationship was obtained and fitted to correlate the partial pressure of oxygen to the dye fluorescence intensity. The oxygen quenching constant α for 30 μM 9,10-dimethylanthracene_(DMA) dissolved in the mixture of ethylene carbonate_(EC) and dimethyl carbonate_(DMC) (1:1 volume ratio) were 0.69/0.62 at high/low partial pressure of oxygen. Operation of the self-made pouch cells with LiCoO2 as the cathode material was examined by charging/discharging at C/10. The discharge capacities were 107 and 104 mAh/g for the pouch cell both with and without the optical probe, which indicates that the optical probe did not significantly affect the performance and capacity of the cell. The optical probe was inserted into the pouch cell to measure the fluorescence intensity of the dye that was dissolved in the electrolyte. Time series experiments before charging demonstrated that the fluorescence intensity was stable for at least 24 hours. However, the fluorescence intensity decreased abruptly as the voltage of the pouch cell increased during the initial stages of charging, which means that the dye (DMA) could not be employed to detect the oxygen generated in the cell. Both the real-time fluorescence spectroscopy and the cyclic voltammetry illustrated that this dye was not suitable for the in-situ fluorescence tests. The electrochemical stability at room temperature of different dyes such as anthracene, Palladium (II) meso-tetrakis (pentafluorophenyl porphyrin)_(PTTFPP) and Platinum octaethylporphyrin_(PtOEP) were examined in the organic solvents used in the electrolytes in Li-ion cells. Cyclic voltammograms of anthracene and PTTFPP showed oxidation peaks at 2V and reduction peaks at around 1V, with the possible formation of the radical anion causing spectral changes. The chemical compound 1-hexyl-3- methylimidazolium bis (trifluormethylsulfonyl)imide_(HMIM BTI) was electrochemically stable, but the fluorescence intensity was too low (5% of dye DMA) to be used in the in-situ detection of oxygen. As a result, more work must be performed in the future to find a suitable dye. Keywords: fluorescence spectroscopy, in-situ Li-ion cell operation, quencheroxygen, the Stern-Volmer relationship
M.S. in Chemical Engineeering, July 2016
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