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Title: INTEGRATION OF TANGENTIAL FLOW FILTRATION AND IMMUNOMAGNETIC SEPARATION FOR RAPID DETECTION OF ESCHERICHIA COLI 0157:H7 IN PRODUCE WASH WATER
Creator: Ren, Yan
Date: 2011-12-12, 2011-12
Description: Escherichia coli O157:H7 is one of the most commonly reported pathogens associated with microbial contamination of leafy greens. Since washing...
Show moreEscherichia coli O157:H7 is one of the most commonly reported pathogens associated with microbial contamination of leafy greens. Since washing is a major postharvest processing step, microbial testing of spent wash water has been suggested as a good marker to determine the contamination status of the products. In this study, the efficiency of four commercial rapid methods (BAX®, IQ-Check, Reveal® and mini-VIDAS®) for detection of E.coli O157:H7 in lettuce wash water was evaluated in comparison with the FDA BAM method. The improvement of the detection sensitivity of these tests by immunomagnetic separation (IMS) technology and sample pre-concentration by Tangential Flow Filtration (TFF) was determined. Twenty-five ml of lab prepared lettuce wash water samples were spiked with 0, 1, 10, 100 CFU of E.coli O157:H7, and subjected to enrichment protocols recommended by each of the methods. The presence of E.coli O157:H7 in the enriched samples were then assayed by the test kits, either directly or after IMS (IMS-Pathatrix ™ or IMS-Dynabeads™) treatments. All four test kits and BAM were able to detect E.coli O157:H7 at levels as low as 1 CFU/25ml of wash water. IMS treatments did not lead to further improvement in detection sensitivity. Experiments were also performed to determine the feasibility of incorporating IMS and sample pre-concentration to achieve culture-free detection. Fifty ml of wash water samples were inoculated with E.coli O157:H7 at levels of 0 to 107 CFU and analyzed by the test kits either directly or after IMS-Pathatrix™ treatment. Additionally, 10 L of wash water either prepared in the lab or collected from a commercial fresh-cut processing facility were inoculated with 0 – 106 CFU of the pathogen and subjected to TFF concentration prior to IMS or test kit analyses. IQ-Check showed the highest sensitivity with a detection limit as low as 103 CFU/50ml, and, with IMS, achieved a sensitivity of 100 CFU/50ml. Combining TFF concentration and IMS, 10 L of lab prepared wash water can be tested with IQ-Check and achieve a detection limit of approx. 100 CFU/10 L within 6 hours. For 10L of industry spent wash water, IQ-check also showed the highest sensitivity but the results lacked consistency and required additional evaluations.
M.S. in Food Safety and Technology, December 2011
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Title: INCORPORATING INVARIANCE INTO SUPPORT VECTOR MACHINE FOR DETECTION OF MICROCALCIFICATIONS
Creator: Yang, Yan
Date: 2011-11-16, 2011-12
Description: In this thesis, we explore methods for incorporating invariance into a support vector machine (SVM) classifier in detection of clustered...
Show moreIn this thesis, we explore methods for incorporating invariance into a support vector machine (SVM) classifier in detection of clustered microcalcifications (MC) in mammogram images. Unlike standard SVM, both virtual SVM and tangent vector SVM can include prior information into a trained model. We formulate MC detection as a two-class classification problem and apply these three types of SVM classifiers to this problem. The issue of dimensional reduction is considered in the tangent vector SVM, which has influence on the computational cost and complexity of the algorithm. We test and compare their performance on a set of 200 clinical mammogram images which contain a total of 5,115 MCs. In the experiments these classifiers are optimized with a training procedure for model selection. We evaluate the detection performance using both receiver operating characteristic (ROC) curves and free-response operating characteristic (FROC) curves. The results show that both virtual SVM and tangent vector SVM can outperform the standard SVM. The use of dimensional reduction in tangent vector SVM can effectively reduce the computational cost.
M.S. in Electrical Engineering, December 2011
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Title: APPLICATION-AWARE OPTIMIZATIONS FOR BIG DATA ACCESS
Creator: Yin, Yanlong
Date: 2014, 2014-07
Description: Many High-Performance Computing (HPC) applications spend a significant portion of their execution time in accessing data from les and they are...
Show moreMany High-Performance Computing (HPC) applications spend a significant portion of their execution time in accessing data from les and they are becoming increasingly data-intensive. For them, I/O performance is a significant bottleneck leading to wastage of CPU cycles and the corresponding wasted energy consumption. Various optimization techniques exist to improve data access performance. However, the existing general-purpose optimization techniques are not able to satisfy diverse applications' demands. On the other hand, the application-specific optimization pro- cess is usually a difficult task due to the complexity involved in understanding the parallel I/O system and the applications' I/O behaviors. To address these challenges, this thesis proposes an application-aware data access optimization framework and claims that it is feasible and useful to utilize applications' characteristics to improve the performance and efficiency of the parallel I/O system. Under this framework, an optimization may consist of several basic but challenging steps, including capturing the application's characteristics, identifying the causality of I/O performance degra- dation, and delivering optimization solutions. To make these steps easier, we design and implement the IOSIG toolkit as an essential system support for the default par- allel I/O system. The toolkit is able to pro le the applications' I/O behaviors and then generate comprehensive characteristics through trace analysis. With the help of IOSIG, we design several optimization techniques on data layout optimization, data reorganization, and I/O scheduling. The proposed framework has significant poten- tial to boost application-aware I/O optimization. The results prove that the proposed optimization techniques can significantly improve the data access performance.
Ph.D. in Computer Science, July 2014
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Title: THERMAL RESISTANCE OF SALMONELLA ENTERICA AND ESCHERICHIA COLI 0157:H7 IN PEANUT BUTTER
Creator: He, Yingshu
Date: 2014, 2014-05
Description: Salmonella enterica is a frequent food contaminant and the leading cause of foodborne bacterial illnesses in the United States. Our study...
Show moreSalmonella enterica is a frequent food contaminant and the leading cause of foodborne bacterial illnesses in the United States. Our study demonstrated that a 5-strain S. enterica cocktail displayed increased heat resistance in peanut butter of low water activity (aw). Significant differences (P < 0.05) were found between the survival rates of Salmonella enterica and Escherichia coli O157:H7 in peanut butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment. Furthermore, we also compared the relative heat resistance of three individual strains of S. enterica representing serotypes Typhimurium, Enteritidis and Tennessee and the 3-strain cocktail treated at both 90oC and 126oC in two different peanut butter formulations with varied fat and carbohydrate contents and adjusted water activities (aw from 0.2 to 0.8). When treated at 90oC, increased water activity in peanut butter significantly (P < 0.05) reduced the heat resistance of desiccation-stressed S. enterica cells. Differences in heat resistance were also detected among the three S. enterica serotypes and between the two peanut butter formulations. When treated at 126oC, the differences in bacterial heat resistance among serotypes and adjusted water activities were less notable (P > 0.05). Based on the Weibull model, an average of 52 to 132 min was required to achieve a 5-log reduction of the 3-strain cocktail at 90oC in peanut butter with an aw of 0.2. When aw was increased to 0.6, to achieve the same 5-log reduction required only 23-27 min. At aw of 0.8, S. enterica could be completely killed in less than 10 min in peanut butter with a fat content of 48.49%. Using scanning electron microscopy, we observed minor morphological changes xiii of S. enterica cells during desiccation and rehydration processes in peanut oil, which was used as a surrogate for peanut putter. Results from this study collectively suggest that water activity plays a critical role in determining S. enterica heat resistance in peanut butter. The variability that exists among the heat resistance of different S. enterica serotypes in different peanut butter formulations should also be taken into consideration for developing and validating effective intervention and mitigation strategies in peanut butter production.
PH.D in Biology, May 2014
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Title: EFFECTS OF THERMAL TREATMENTS ON ELISA DETECTION OF MILK PROTEINS
Creator: Lu, Yingshuang
Date: 2011-07-27, 2011-07
Description: Cow’s milk allergy is one of the most prevalent food allergies in the United States. Commercial ELISA test kits, based on antigen-antibody...
Show moreCow’s milk allergy is one of the most prevalent food allergies in the United States. Commercial ELISA test kits, based on antigen-antibody reactions, are increasingly used by food manufacturers to detect the presence of allergen residues. Milk is a common ingredient used in a variety of foods that are subjected to different degrees of cooking. How thermal processing may affect the quantitative analysis of milk allergens by ELISA test kits needs to be determined. This study first examined the performance of four total protein assays (Pierce 660nm, Modified Lowry, Coomassie, BCA) for quantification of protein residues in thermally processed milk. BCA and Lowry assays were affected by lactose and its Maillard reaction byproducts resulting in the overestimation of protein concentrations in the samples. Pierce 660 nm assay was not affected and therefore was picked as the method for total protein analysis when evaluating commercial ELISA kits. Performances of four ELISA test kits (Veratox for Total Milk Allergen, BioKits BLG Assay Kits, ELISA SYSTEMS Casein and Beta-Lactoglobulin Residue assays) in comparison with the Pierce 660 nm assay for detection of thermally treated milk samples was also evaluated. NIST non-fat milk powder standard reference material 1549 and Backpacker’s Pantry Powdered Whole Milk were either heated in water at 60◦C, 63◦C, boiled, or autoclaved for 10 or 30 min, dry-heated in a mini-oven at 100 - 232◦C for 10 min, or fried in corn oil at 150◦C or 180◦C for 3 min in a deep fryer. Milk proteins in the oil samples were analyzed either directly or after extraction with phosphate-buffered saline with 0.05% Tween (PBST) followed by partitioning in hexane to remove residual oil. The results show that all four ELISA test kits were able to accurately quantify the amount of milk proteins in uncooked oils. Inclusion of the PBST/hexane extraction step prior to test kit analyses did not improve the detection. Elevated heat resulted in a lower level of proteins extracted. While the amount of protein residues determined by Veratox and ELISA SYSTEMS Casein kits were similar to those obtained by the Pierce assay, the BioKits BLG kits registered the highest amount of proteins in samples. On the other hand, ELISA SYSTEMS Beta-Lactoglobulin assay registered the lowest level of proteins in these samples. These results suggest that heat treatment could affect the solubility and possibly the antigenic properties of proteins. Depending on the test kits used, these changes could result in over- or underestimation of protein residues in thermally treated foods.
M.S. in Food Safety and Technology, July 2011
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Title: LICENSE PLATE RECOGNITION SYSTEM USING K NEAREST NEIGHBOR ALGORITHM
Creator: Xia, Yong
Date: 2012-12-03, 2012-12
Description: License Plate Recognition (LPR) is an image-processing technology, also known as Automatic Number Plate Recognition (ANPR). This technology is...
Show moreLicense Plate Recognition (LPR) is an image-processing technology, also known as Automatic Number Plate Recognition (ANPR). This technology is very popular in fighting crime, locating stolen car, identifying parking-ticket and so on. In LPR system, the image is taken of the front or rear of the car and its quality needs to be enhanced for further process. With this enhanced image, first license plate region is located and extracted. Then character segmentation is performed on extracted license plate image. In this thesis, we use K Nearest Neighbor (KNN) algorithm to recognize these segmented characters. Keywords: LPR, Plate location, character segmentation, Image Processing, KNN
M.S.in Electrical Engineering, December 2012
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Title: FUNCTIONAL ANALYSIS OF POTENTIAL PHOSPHORYLATION SITES IN BAXΔ2 UNIQUE OLIGOPEPTIDE
Creator: Tsai, Yu-tseng
Date: 2014, 2014-07
Description: The tumor suppressor gene, Bax, plays a critical role in tumor progression through regulating cell apoptosis. Mutations on the BAX gene often...
Show moreThe tumor suppressor gene, Bax, plays a critical role in tumor progression through regulating cell apoptosis. Mutations on the BAX gene often result in silencing its expression and the loss of pro-death ability. However, there is a unique Bax isoform, BaxΔ2, recently discovered in these Bax mutated cancer cells. BaxΔ2 isoform shows higher pro-apoptotic activity than Baxα. Unlike the parental Baxα, BaxΔ2 does not target mitochondria and forms aggregates in cytosol. There is a unique 10-amino-acid peptide in the N-terminus of BaxΔ2 protein possible function as a special signal. Two serines in this region are predicted as potential phosphorylation sites for regulation of the protein activity. To test this hypothesis, we mutated both serines (SS) into non-phosphorylatable alanines (AA) by site-directed mutagenesis approach. Both BaxΔ2 wild type (BaxΔ2-SS) and mutants (BaxΔ2-AA) were tagged with GFP, which allows us to monitor the protein expression and cellular localization in live cells. Here, we found that the distribution patterns of BaxΔ2-AA and BaxΔ2-SS were similar and appeared as aggregates in cytosol. BaxΔ2-AA mutant also possessed the similar pro-apoptotic activity with BaxΔ2-SS wild type. These results suggested that the two serines in BaxΔ2 unique oligopeptide might not play a critical role in BaxΔ2 localization and pro-death activity under the current ectopic expression conditions. Further study is needed to have better understanding of phosphorylation in contribution to unique behavior of BaxΔ2.
M.S. in Biology, July 2014
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Title: REAL-TIME FACEDETECTION ANDRECOGNITION SYSTEM INCOMPLEX BACKGROUNDS
Creator: Zhang, Xin
Date: 2015, 2015-07
Description: This report provides a fast and reliable system for real-time face detection and recognition in complex backgrounds. Most current face...
Show moreThis report provides a fast and reliable system for real-time face detection and recognition in complex backgrounds. Most current face recognition systems identify faces under constrained conditions, such as constant lighting condition, the same background. In the real world, people need to be recognized in complex backgrounds under different conditions, such as tilted head poses, various facial expressions, dark or strong lighting conditions. Meanwhile, because of large amounts of real-time applications for face recognition, such as intelligent robot, unmanned vehicle, security monitor, the fast face recognition rate needs to be satisfied for the real-time requirement. In this project, a fast and reliable system is designed to real-time detect and recognize faces under various conditions. Frames are obtained directly from VGA camera. Image preprocessing and face detection, collection, recognition are sequentially implemented on the frames. Local binary patterns and Haar features are used for face detection and eye detection. Local binary pattern encodes every pixel of the image for texture extraction, which is several times faster than Haar feature detection. Adaptive boosting algorithm is used for selecting the best weak classifiers and cascading method divides the extracted best classifiers into several stages to enhance detection rate. Affine transformation is implemented to unify the size of detected facial images and align two eyes to the desired position for improving recognition accuracy. 3􀁵3 Gaussian filter is designed to remove noises of the pre-processed facial images. Principal component analysis (PCA) is used for face recognition, which is fast to identify high-dimensional faces with few principal components.
M.S. in Electrical Engineering, July 2015
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Title: ANTENNA LOCATION DESIGN IN DOWNLINK DISTRIBUTED ANTENNA SYSTEM
Creator: Zhang, Peng
Date: 2015, 2015-07
Description: In recent years, Wireless cellular network design with distributed antenna system (DAS) has received much attention for its ability to extend...
Show moreIn recent years, Wireless cellular network design with distributed antenna system (DAS) has received much attention for its ability to extend the cell coverage, improve spectral efficiency and increase the system capacity. Instead of locating all antennas at the cell center in the centralized antenna systems (CAS), distributed antenna basements in the DAS are separated geographically, which has been wide implemented to cover the dead spots and improve the system efficiency in wireless communication systems The mainly purpose of this research is to find optimal antenna locations that maximize the cell average ergodic capacity for the distributed-antenna system in downlink applied condition. Squared distance criterion (SDC) will be considered to offer an object function to maximize the lower bound of the cell average ergodic capacity. Existed analyses for location design in distributed antenna system are based on the uniform distribution without considering other cell interference. Considering other cell interference, I derive the analytical antenna location position for the infinite uniform distribution linear cell. For multi-cell applied condition implementation, I get reasonable locations of the applied condition by applying K-means algorithm to generating the initial values and find the optimal location. In order to solve the multi-cell scenario considering other-cell interference, I change the existed algorithm and simulation results show the performance of the obtained antenna location with changed algorithm offer a higher performance than the original one. I propose a circle initial setup to generate the initial points for relative location and converge fitting. The simulation has showed the initial setup I proposed significant reduce the computation in the antenna location design in applied downlink scenario.
M.S. in Electrical Engineering, July 2015
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Title: THE EVALUATION OF THERMAL INACTIVATION OF COXIELLA BURNETII NINE MILE PHASE II IN BOVINE AND NON-BOVINE MILKS BY MOST PROBABLE NUMBER-POLYMERASE CHAIN REACTION (MPN-PCR) ASSAY
Creator: Zhang, Cheng
Date: 2016, 2016-05
Description: As non-bovine milks become popular for human consumption, ensuring that standard bovine milk pasteurization conditions provide enough...
Show moreAs non-bovine milks become popular for human consumption, ensuring that standard bovine milk pasteurization conditions provide enough treatment for non-bovine milks is significant for food safety. Coxiella burnetii, an obligate intracellular bacterium, has been used as the reference microorganism for defining milk pasteurization conditions. To evaluate C. burnetii thermal inactivation in bovine and non-bovine milks at commercial pasteurization temperature, an MPN-PCR assay was developed to quantitate viable C. burnetii in milk. Using this assay, the thermal inactivation of C. burnetii and a potential nonpathogenic surrogate, Micrococcus luteus, was tested in bovine, buffalo, camel and goat milks. Milk in sealed glass vials was pre-heated in a water bath at 72°C and inoculated via a syringe with C. burnetii and M. luteus at a final concentration of ~6.5 log10 ge/mL (CFU/mL) each. The inoculated milk was heat-treated at 72°C for up to 16 sec, cooled in a crushed ice bath and serially diluted. Viable M. luteus was quantitated by plating on BHIA plates. For C. burnetii detection, 1 mL of each dilution was inoculated into 9 mL Acidified Citrate Cysteine Medium-2 (ACCM-2) in triplicate T-25 flasks to produce a 3- flask Most Probable Number (MPN) assay. Viability of C. burnetii was considered positive if an increase of ≥0.5 log10 ge/mL was detected by qPCR after 14 d growth in ACCM-2 media. The numbers of positive flasks at each dilution were used to calculate the remaining viable C. burnetii by MPN method. The average D-values for 72°C inactivation were 1.99 ± 0.21 sec, 0.79 ± 0.28 sec, 1.43 ± 0.30 sec, and 2.06 ± 0.71 sec for C. burnetii, and 5.47 ± 0.94 sec, 3.65 ± 0.45 sec, 3.48 ± 0.83 sec and 5.34 ± 1.54 sec for M. luteus in bovine, buffalo, camel and goat milks, respectively. For C. burnetii, D-values in camel and goat milks were not significantly different (p>0.05) from bovine milk, but the D-value in buffalo milk was significantly lower (p<0.05). These results indicate that non-bovine milks may not be a safety concern under standard milk pasteurization conditions, and M. luteus could be a good surrogate for C. burnetii thermal inactivation in milk.
M.S. in Food Safety and Technology, May 2016
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Title: SURVIVAL AND ATTACHMENT OF SALMONELLA ENTERICA ON SELECT LOW MOISTURE NUT SURFACES
Creator: Zhang, Bo
Date: 2017, 2017-07
Description: Salmonella can contaminate various nuts and lead to human foodborne disease outbreaks and related product recalls in the United States. Nuts...
Show moreSalmonella can contaminate various nuts and lead to human foodborne disease outbreaks and related product recalls in the United States. Nuts have been identified as an increasingly common vector for human salmonellosis. The objective of this study was to evaluate the influence of environmental factors and Salmonella enterica serotypes on the survival and attachment of this pathogen on the surface of low moisture, raw in shell nuts. Two S. enterica strains (Enteritidis and Typhimurium) were individually tested on three different food samples (almonds, hazelnuts and black peppers) at 4°C or 25°C for up to 14 days. The storage relative humidity was maintained at 20±2% throughout the study. Nut samples were collected at 0, 1, 3, 7 and 14 days. The population of bacteria was calculated based on the plate count data. The results showed that S. Typhimurium attached and survived better than S. Enteritidis on almonds, hazelnuts and black peppers at both 4 and 25°C. A lower storage temperature led to a better survival of Salmonella on raw nuts during storage. The surface characteristics of hazelnuts resulted in the least Salmonella attachment compared to almond and black pepper.
M.S. in Food Safety and Technology, July 2017
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Title: FUNCTIONAL ANALYSIS OF UBIQUITIN-LIKE PROTEIN 4A
Creator: Zhao, Yu
Date: 2015, 2015-12
Description: Ubiquitin-like protein 4A (Ubl4A) was identified as a housekeeping gene at X chromosome. It involves in the guided entry of tail-anchored (GET...
Show moreUbiquitin-like protein 4A (Ubl4A) was identified as a housekeeping gene at X chromosome. It involves in the guided entry of tail-anchored (GET) protein pathway in which tail-anchored (TA) proteins are transported to endoplasmic reticulum (ER). However, Ubl4A also involves other functions not related to GET pathway, such as tumor suppression and DNA damage-mediated apoptosis. Up to date, the function of Ubl4A in mammals is still largely unknown. We found that either overexpression or knockdown of Ubl4A promoted cell death in cell culture system. Using an in vivo genetic knockout system, we found that Ubl4A knockout mice displayed a high neonatal mortality and had a defect in glycogen synthesis, which is mainly controlled by a key protein kinase Akt. Loss of Ubl4A resulted in the impairment of insulin-induced Akt translocation to the plasma membrane, an essential step for Akt activation. We demonstrated that Ubl4A directly interacted with actin-related protein 2/3 (Arp2/3) complex, further accelerated Arp2/3 complex-dependent actin branching, thereby bringing Akt to proximity into the plasma membrane for activation. Furthermore, we showed that Ubl4A-mediated actin branching also played important roles in other cellular activities, such as formations oflamellipodia and filopodia, macrophage phagocytosis, wound healing, and neutrophil chemotaxis. These findings provide us a new insight into understanding the roles of Ubl4A in cellular function and a molecular basis for treatment of related human diseases.
Ph.D. in Biology, December 2015
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Title: HIGH PERFORMANCE, HIGH STABILITY AND LOW POWER SRAM DESIGN BY USING CARBON NANOTUBE FIELD EFFECT TRANSISTORS
Creator: Wang, Wei
Date: 2012-07-07, 2012-07
Description: As the feature size of silicon semiconductor devices scales down to nanometer range, planar bulk CMOS design and fabrication encounter...
Show moreAs the feature size of silicon semiconductor devices scales down to nanometer range, planar bulk CMOS design and fabrication encounter significant challenges. This situation is exacerbated when it comes to SRAM, as SRAM takes a large part of power consumption and area overhead in modern VLSI processor designs. To achieve higher performance, stability and lower power consumption, carbon nanotube (CNT) has been introduced to SRAM design as an alternative material. The semiconducting single-walled CNTs are promising candidates for the channel material of CMOS devices because of two advantages over the other semiconductor materials: high ON current, leading to high speed and low OFF current, leading to less leakage power. In this research work, characterizing work of technology parameters for 6T carbon nanotube field effect transistor (CNFET) SRAM cell is performed for basic understanding of the relationship between SRAM delay/power and CNFET technology parameters. Stability issue is studied by investigating the diameter and transistor ratio impacts on the SRAM static noise margin (SNM). A stability-optimized 6T CNFET SRAM cell achieves 38.88% reading delay reduction, 21.61% writing delay reduction, 85.65% reading power reduction, 5.88% writing power reduction, 97.80% leakage power reduction, 41.41% SNM increment, 91.23% reading power-delay product (PDP) reduction and 26.23% writing PDP reduction, compared with conventional silicon MOSFET SRAM cell. To mitigate major CNT imperfection impacts on CNFET circuits, a misalignment immune SRAM design method is proposed to eliminate CNT misalignment problem by using etching region defined in circuit layout; and a diameter variation sensing and compensating system is designed to mitigate the negative impacts of CNT diameter variation on SRAM delay and power consumption. A hybrid silicon/CNT 4T SRAM cell design is proposed for low-power high-density cache application, which is better than conventionally used 6T SRAM in terms of power consumption and circuit area. Finally, a design flow of high performance, high stability and low power SRAM is summarized.
Ph.D. in Electrical Engineering, July 2012
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Title: Investigation of Fresh Produce Washing on E. Coli O157:H7 and Murine Norovirus with Peroxyacetic Acid and High Power Ultrasound
Creator: Yuan, Wen
Date: 2011-12-05, 2011-12
Description: E. coli O157:H7 and norovirus have each been responsible for outbreaks of foodborne illness involving fresh leafy green vegetables....
Show moreE. coli O157:H7 and norovirus have each been responsible for outbreaks of foodborne illness involving fresh leafy green vegetables. Peroxyacetic acid (POAA) has the potential to be an effective sanitizer during commercial fresh-cut produce washing. The addition of high power ultrasound (HPU) to the washing system may enhance the POAA efficacy. The purpose of this study was to reduce E. coli O157:H7 and norovirus contamination during commercial fresh-cut lettuce washing using POAA and HPU. Fresh-cut romaine lettuce leaves were inoculated with E. coli O157:H7 or murine norovirus (MNV, a surrogate for the human norovirus) and washed by POAA and HPU. Cross-contamination was tested by washing clean leaves in contaminated processing water where pre-inoculated leaves were washed previously. A high level of cross-contamination (4.5-log CFU/g E. coli) occurred after uninoculated leaves were rinsed in contaminated wash water for 2 min. A subsequent 2 min wash in POAA alone or in combination with HPU reduced counts by approximately 1.2-log and 2.3-log, respectively. More than 2-log norovirus was removed from washing 2 min in either DI water or POAA. However infectious MNV washed from leaves was not detected in wash water containing POAA. Those results implied a high possibility of cross-contamination during freshproduce washing, and indicate that adding POAA and HPU in addition to washing water in wash water can reduce cross-contamination rate.
M.S. in Food Safety and Technology, December 2011
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Title: DIFFERENTIAL SENSITIVITY OF BAXΔ2 POSITIVE AND NEGATIVE CELLS TO ANTI-TUMOR AGENT BORTEZOMIB IN COLON CANCER
Creator: Chen, Wenjing
Date: 2015, 2015-05
Description: Tumor suppressor BaxΔ2 is a functional Bax isoform that is found in microsatellite unstable (MSI) colon cancer. However, BaxΔ2 proteins are...
Show moreTumor suppressor BaxΔ2 is a functional Bax isoform that is found in microsatellite unstable (MSI) colon cancer. However, BaxΔ2 proteins are not stable and are prone to be degraded by proteasomes in tumor cells. Bortezomib, a proteasome inhibitor, is an FDA approved anti-cancer drug mainly used for the treatment of myeloma and lymphoma. We tested if Bortezomib can block BaxΔ2 degradation and potentially be beneficial for the treatment of BaxΔ2 positive colon cancer. In this project, we compared the efficacy of Bortezomib-induced cell death in BaxΔ2-positive and BaxΔ2-negative colon cancer cells. We found that BaxΔ2-positive cells were highly sensitive to Bortezomib-induced cell death in comparison with that in BaxΔ2-negative cells. The half maximal inhibitory concentration (IC50) of cell viability for BaxΔ2-positive cells is 11.1 nM, while it is 453.8 nM for BaxΔ2-negative cells. The results indicate that Bortezomib has a selectivity towards BaxΔ2-expressive cells and could be a drug candidate for the treatment of BaxΔ2-positive colon cancer.
M.S. in Biology, May 2015
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Title: FIELD AND PHOTO-EMISSION IN A SHORT-PULSE, HIGH-CHARGE CESIUM TELLURIDE RF PHOTOINJECTOR
Creator: Wisniewski, Eric E.
Date: 2014, 2014-05
Description: A new high-charge RF gun is now operating at the Argonne Wakefield Accelerator (AWA) facility at Argonne National Laboratory (ANL). The 1.5...
Show moreA new high-charge RF gun is now operating at the Argonne Wakefield Accelerator (AWA) facility at Argonne National Laboratory (ANL). The 1.5 cell 1.3 GHz gun uses a Cesium telluride photocathode driven with a 248 nm laser to provide short-pulse, high charge electron beams for the new 75 MeV drive beamline. The high-gradient RF gun (peak field on the cathode > 80MV/m) is a key piece of the facility upgrade. The large Cs2Te photocathode (diameter > 30 mm) was fabricated in-house. The photo-injector will be used to generate high-charge, short pulse, single bunches (Q > 100 nC) and bunch-trains (Q>1000 nC) for wakefield experiments, typically involving dielectric-loaded accelerating structures. Details of the photocathode fabrication process and the results of associated diagnostic measurements are presented, including QE measurements and work function measurements performed with a Kelvin probe. Field-emitted dark current from the Cs2Te cathode was measured during RF conditioning and characterized. Fowler-Nordheim plots of the data are presented and compared to similar measurements made using a copper cathode in the initial phase of conditioning. The results for cesium telluride exhibited non-linear regions within the Fowler-Nordheim plots similar to previous experimental results for other p-type semiconductors. Results of quantum efficiency (QE) studies are presented with the cathode operating in both single and bunch-train modes. QE uniformity and lifetime studies are presented. During commissioning, the cesium telluride photocathode produced bunch-charge of 100 nC, breaking the previous record. No evidence of bunch-train position-dependence of QE was found when generating four-bunch trains with total charge up to 200 nC.
PH.D in Physics, May 2014
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Title: INDUSTRIAL UPGRADING IN KOREA
Creator: Woosiklee
Date: 2014, 2014-05
Description: One of the most difficult obstacles facing non-western nations is the issue of technology transfer. The main objective of this dissertation is...
Show moreOne of the most difficult obstacles facing non-western nations is the issue of technology transfer. The main objective of this dissertation is to analyze the how South Korea has succeeded through industrial upgrading through technology transfer in achieving the Han River Miracle- making it in 2011, the fourth largest economy in Asia and the 9th largest in the world. From 1910 to 1945, Korean modernization was continuously developed under the Japanese war economy and its military policy. Japanese capital, technology and entrepreneurs were transferred to Korea due to supplement the shortages of Japanese industries or to take advantage of the low labor costs in Korea in order to prepare for the Sino-Japanese War in 1936 and the Pacific War in 1941. There is no doubt that President Chung-Hee Park (1961-1979) was the architect of the Korean economic miracle. During his authoritarian regime, the government had played an important role in the creation and financing of the modern Korean industrial groupings, called the Chaebols. The government also intervened directly in the formation of their policies. In the 1980s, when the country embarked on financial liberalization, the degree of intervention started to decrease. And finally, the 1997 crisis will be examined, with special attention on the introduction of reforms required by the International Monetary Fund (IMF). In the industrial arena, the focus will be on the rationalization policies undertaken to increase the total factor productivity (TFP). It will cover the currently important industries of steel, automobiles and semiconductors, as well as those promising industries which have led the development of South Korea's knowledge-intensive economy. An integral part of the xi ii analysis will study the repercussions of the 1997 financial reforms on both the large and small and medium-size industries. Conventional wisdom assumes that it was under President Park's rule that South Korea had its first experience with industrialization. This assumption, however, ignores the significant industrialization that took place during the colonial period. It also does not take into account the admittedly limited industrial development that took place during the time before the 1961 coup d'état, when civilian governments were in charge. The dissertation would shed light on these overlooked periods.
PH.D in Management Science, May 2014
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Title: Large Scale Integration of Sustainable Energy and Congestion Management in Western Interconnection
Creator: Aflaki Khosrosha, Kaveh
Date: 2012-07-12, 2012-07
Description: Large scale sustainable energy like wind and solar energy integration to the bulk grid could introduce inevitable challenges to regional...
Show moreLarge scale sustainable energy like wind and solar energy integration to the bulk grid could introduce inevitable challenges to regional transmission and generation systems. The most important challenges for transmission system are the congestion management and planning for transmission expansion to transfer the zero cost generated electricity. Another big challenge is competition of current fuel based generation units in the electricity market with zero cost sustainable energy. In this dissertation all these challenges identified and analyzed for large scale grid. This thesis brings a new method used to study transmission congestions in Western Interconnection of the United States. The process involved Security-Constrained Unit Commitment (SCUC) formulation applying its results for analysis of transmission congestion. This thesis also presents results and findings in simulation of the system operation in the Western Interconnection of the United States with the inclusion of large scale wind and solar energy integration for year 2030. High level of wind and solar energy with the forecasted wind and solar time series profiles were integrated to the Western Interconnection grid. Their impact on different existing types of generation plants is studied. The sensitivity of the fuel prices, wind turbine power output, load volatility and demand side management as well as carbon tax are analyzed in different possible scenarios. In order to incorporate large scale of sustainable energy into a bulk electricity grid footprint, planned transmission expansion showed need to take place. Transmission expansion reduces grid congestion and balances Locational Marginal Prices (LMP). This thesis explores the advancements in high-performance computing and visual analytics of economic-based transmission expansion in the Western Electricity Coordinating Council (WECC). This expansion is based on 2018 and 2029 forecasted data. It identifies transmission congestions and average of LMP for each area, and expands the transmission system while accommodating large scale wind and solar energy to achieve the Department of Energy’s renewable energy vision for year 2030. An iterative transmission expansion analysis, based on the average LMP for each area, is used to identify the minimum WECC transmission lines required. All results are visualized on the Geographical Information System (GIS) format map of North America.
Ph.D. in Electrical Engineering, July 2012
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Title: CHARACTERIZATION OF A NOVEL TUMOR SUPPRESSOR BAX
Creator: Wang, Xin
Date: 2013-04-16, 2013-05
Description: Bax is a pro-death tumor suppressor. The loss of functional Bax expression can enhance the tumor growth. Recently we discovered a new family...
Show moreBax is a pro-death tumor suppressor. The loss of functional Bax expression can enhance the tumor growth. Recently we discovered a new family of functional Bax isoforms generated specifically in certain tumors; one of them is Bax 2 . In this thesis, I characterized the properties of Bax 2 protein by comparing with the parental Bax 2. Bax 2 was cloned into a GFP mammalian expression vector and transfected into the bax knockout cells. I examined Bax 2 expression, cellular distribution, and ability to induce cell death. The results show that the Bax 2 protein aggregated as granules around the nucleus in cytoplasm and induced more cell death than that from previously studied Bax 2. The results implicate that cancer patients with Bax 2 isoform might have better prognosis or response to treatment.
M.S. in Biology, May 2013
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Title: INFLUENCE OF FOUR BACILLUS SP. STRAINS ON GROWTH AND DESULFURIZATION ABILITY OF MYCOBACTERIUM STRAIN U
Creator: Tian, Fangzhou
Date: 2016, 2016-05
Description: Desulfurization is an important step in crude oil processing and is commonly achieved through a chemical process known as hydrodesulfurization...
Show moreDesulfurization is an important step in crude oil processing and is commonly achieved through a chemical process known as hydrodesulfurization (HDS). Because this process is expensive and produces H2S as a by-product, the alternative of biodesulfurization (BDS) has been investigated for many years. The most potentially useful biodesulfurization process is the 4S pathway, which is found in a number of bacterial species, including Mycobacterium Strain U, which was isolated in our lab. To reach the requirement of BDS for use in an actual industrial-scale process, U has to survive at temperatures approaching 60 OC. In work in our lab, natural selection methods have been introduced for improving the U strain. During this natural selection, four contaminant strains, identified by 16S rDNA sequencing as Bacillus sp., were isolated from extraordinary U cultures which have BDS activity at 54 OC. Meanwhile the BDS activity of U on its own was found to have an upper temperature limitation of 53 OC. Additional experiments proved that all four Bacillus strains interact with U and improve its BDS ability.
M.S. in Biology, May 2016
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