Search results

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
Show less

Title: GENOME ANNOTATION AND PHYLOGENETIC ANALYSIS OF 27 SALMONELLA STRAINS BASED ON BIOINFORMATIC ANALYSIS OF RESPECTIVE GENOMES AND THREE GENES
Creator: Li, Xinyue
Date: 2013-04-15, 2013-05
Description: Salmonella is the most common food-borne bacterial infectious pathogen worldwide. Different serovars of Salmonella are capable of infecting...
Show moreSalmonella is the most common food-borne bacterial infectious pathogen worldwide. Different serovars of Salmonella are capable of infecting different kinds of hosts, such as humans, mice, pigs, chickens, and can also lead to different syndromes, such as enterica fever, enterocolitis and diarrhea, bacteremia and chronic asymptomatic carriage. Although Salmonella strains are quite diverse, strains within the same serovar usually infect the same host and cause similar symptoms. Thus, it is important, especially in food-borne disease outbreaks, to know which type of Salmonella is present. The current method of typing Salmonella is based on the Kaufmann-White scheme and MLEE, which are laborious and expensive. Although the reliability of this method has not been previously verified, the evolutionary relationship reflected by phylogenetic trees can be a possible alternative to the way of typing the Salmonella strains; this method would be less labor intensive and more economical. MLST is considered as a “gold standard” of typing for many species includes Salmonella. And genome sequence, which certainly reflects the evolutionary relationship of strains, is the most ideal data to construct a more reliable phylogenetic tree; however, genome sequencing is also a laborious and expensive process. Thus, conserved and ubiquitous gene data, which can be accessed with little effort, are generally used to minimize cost. Using16s rRNA is the most widely used method. In this study, 27 Salmonella genome sequences are annotated with RAST, and phylogenetic trees are constructed using three software, (phylip3.69, MEGA5.1, and CVTree). And MLST is also used to construct phylogenetic tree in this study, and the result is used to be compared with genome phylogenetic tree to find a more reliable reference tree. Although Neighbor-Joining method is the only algorithms x available in CVTree, phylip3.69 and MEGA5.1 are capable to use three separate algorithms(Maximum Parsimony, Maximum Likelihood, and Neighbor-Joining, respectively). Finally, these trees are compared in an effort to find a good alternative to replace the reference phylogenetic tree. In this study, it was determined that the groEL gene would be the best replacement.
M.S. Biological and Chemical Sciences, May 2013
Show less

Title: INCORPORATING REACTIVE POWER MARKET INTO THE DAY-AHEAD ELECTRICITY MARKET
Creator: Al Ghamdi, Mohammed
Date: 2012-05-29, 2012-07
Description: The research work presented in this thesis proposes the incorporation of the reactive power market into the day-ahead electricity market in...
Show moreThe research work presented in this thesis proposes the incorporation of the reactive power market into the day-ahead electricity market in order to compensate generation companies (GENCOs) and independent power producers (IPPs) for providing any additional reactive power support, which varies on an hourly basis based on the load demand, transmission network configuration, and any contingencies that might occur. This proposal would minimize the total payment burden on the independent system operator (ISO), which is related to the reactive power dispatch. The proposed model achieves the main objective of an ISO in a competitive electricity market, which is to provide the required reactive power support from generators at minimum cost while ensuring the secure operation of the power system. In this research, the reactive power price is the bidding-based price that is submitted by the GENCOs and IPPs to the ISOs during the day-ahead market. The proposal takes into the account both the technical and economic aspects associated with the active power and reactive power dispatch in the context of the new operating paradigms in competitive electricity markets. In this research, the Security Constrained Unit Commitment (SCUC) based on AC power flow modeling is considered as the drive engine for clearing the day-ahead electricity market based on the amount of information provided by the market participants. This proposed framework would provide appropriate reactive power support from service providers at minimum cost, while ensuring the secure and reliable operation of the electrical power system. In the research, the PQ capability curves of the generating units are modeled to ensure the practically of the SCUC solutions that are obtained. This proposal would be an essential step toward a fair electricity market while increasing the security of the power system and reducing transmission congestions. Also, it would pave the road for various renewable energy resources since the penetration of renewable energy resources would impact the commitment of the generating units. This would impact the available reactive power reserve margin and security of the network. In addition, incorporating the reactive power market into the day-ahead market would provide a clear signal for optimal private investment in the reactive power capacity. The framework that has been developed is general in nature and can be used for any electricity market structure.
Ph.D. in Electrical Engineering, July 2012
Show less

Title: USE OF AQUEOUS DISPERSIONS OF SDS MICELLES TO REMOVE BACTERIAL CONTAMINATION FROM FRESH PRODUCE AND FOOD CONTACT SURFACES
Creator: Han, Yibin
Date: 2013-04-30, 2013-05
Description: The current trend of increased consumption of fresh produce has coincided with an increase in foodborne illness resulting from fresh produce...
Show moreThe current trend of increased consumption of fresh produce has coincided with an increase in foodborne illness resulting from fresh produce consumption, which in turn has increased the amount of research directed at understanding the interactions between microbial pathogens and fresh produce. This dissertation examines the removal and inactivation of Escherichia coli O157:H7 and E. coli K12 from Romaine lettuce leaves and a model hydrophobic surface (polyvinyl chloride, PVC) using a nanofluid (a fluid containing nanometer-sized particles - in this case, sodium dodecyl sulfate, SDS) and its combinations with organic acids. A novel mechanism previously proposed by Wasan and Nikolov (D. T. Wasan & Nikolov, 2003) was used as the basis to explore the removal of bacteria from these surfaces by the aqueous dispersion of SDS micelles, and to explain how SDS plus levulinic acid at pH<3 improves inactivation of these bacteria. Examination of the bactericidal effect of levulinic acid, SDS, and their combination on E. coli O157:H7 attached to Romaine lettuce leaves revealed that using levulinic acid or SDS alone cannot effectively wash the bacterial cells from the surface or cause inactivation. However, combining them increased the effectiveness of the solution. The most effective combination of SDS plus acid for bacteria removal and inactivation among those we tested was found to be 0.06 mol/L SDS + 0.25 mol/L levulinic acid. This combination, which has a pH of 2.9, inactivated more than 5.2-log E. coli O157:H7 on a leaf surface, and similar results were achieved for E. coli K12 on a leaf surface, and for both E. coli O157:H7 and E. coli K12 on the surface of PVC. Surface and interface measurements, including x surface tension and contact angle, of washing solutions indicated that solutions containing SDS had a lower work of adhesion than those without the surfactant, which shows that a significant role of SDS in the inactivation mechanism is a weakening of the forces of attraction between the bacteria and the surface being cleaned. Our experiments also confirm that SDS likely plays a secondary role which depends on the solution pH. When the presence of an organic acid lowers the pH of the washing solution to below 2.6, the surface charge of E. coli O157:H7 changes from negative to positive (the pH is lower than the bacteria’s isoelectric point). In this case, we hypothesize that negatively-charged SDS molecules attach to the cells’ surfaces and inactivate the bacteria. This work provides additional insight into the complex nature of bacterial detachment from solid surfaces. Our work with aqueous dispersions of SDS micelles indicates how and why bacterial inactivation is increased through a combination treatment of SDS and an organic acid.
M.S. in Food Safety and Technology, May 2013
Show less

Title: HOW HOSTILE CRITICISM RELATES TO HEALTH FUNCTIONING AND MARITAL ADJUSTMENT IN PATIENTS WITH CARDIOVASCULAR DISEASE AND THEIR PARTNERS
Creator: Hicks Iii, R. Elliott
Date: 2012-04-30, 2012-05
Description: Destructive communication and hostile interactions between spouses has been found to elicit large increases in systolic blood pressure, heart...
Show moreDestructive communication and hostile interactions between spouses has been found to elicit large increases in systolic blood pressure, heart rate, and cardiac output in patients (Nealey-Moore et al., 2007; Smith et al., 2009). This negatively impacts the cardiovascular health of the receiving partner. The present study was designed to assess the relationship between hostile criticism and patient report of marital satisfaction, physical health, and depressive symptomatology in a sample of couples participating in a cardiac risk reduction intervention. The current study uses archival data obtained during the Partners for Life cardiac risk reduction intervention for couples (Sher et al., 2002). Additionally, further observationally coded data was collected from video taped conversations recorded for the purposes of the Partners for Life study. Pearson correlation analyses indicate moderate negative relationships between Criticism and Marital Adjustment. Implications of these and other results are discussed.
M.S. in Clinical Psychology, May 2012
Show less

Title: VITREOSCILLA HEMOGLOBIN: STRUCTURE-FUNCTION AND GENETIC ENGINEERING STUDIES
Creator: Li, Xiaodong
Date: 2014, 2014-05
Description: Paenibacillus strains 32O-W and 32O-Y were attempted to be transformed by electroporation with constructed plasmid pNW33N-vgb, modified to...
Show morePaenibacillus strains 32O-W and 32O-Y were attempted to be transformed by electroporation with constructed plasmid pNW33N-vgb, modified to contain the vgb gene which can be expressed as Vitreoscilla hemoglobin. Only attempts with 32O-Y were successful. Transformed 32O-Y/pNW33N-vgb was grown in CDM medium with dibenzothiophene (DBT) as the sole source of sulfur at different temperatures. Dramatic variability was observed in culture at different temperatures, so only the data at 45 °C was analyzed. The growth assay showed that the 32O-Y/pNW33N-vgb strain grew slower than untransformed 32O-Y, although Gibbs assay showed improvements in utilizing ability of DBT of 32O-Y/pNW33N-vgb compared to untransformed 32O-Y. This finding indicated that genetic engineering of introducing vgb into 32O-Y may cause deterioration in cell growth rate but improvement in desulfurization activities. Plasmid pUC-vgb-M2 was transformed into E. coli DH5α. The transformed DH5α/M2-vgb was cultured along with DH5α/pUC8:16, bearing plasmid pUC8:16 that was previously constructed in our lab and can be expressed to produce wild type VHb, and untransformed DH5α. CO-difference spectra were performed with the lysed cultures for the detection of VHb expression. As a result, DH5α/M2-vgb was confirmed to lack the ability to express functional VHb.
M.S. in Biology, May 2014
Show less

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
Show less

Title: MANAGING STOCHASTIC WIND POWER GENERATION BY INCORPORATING DEMAND RESPONSE IN DAY-AHEAD SCHEDULING
Creator: Al Hassan, Hassan
Date: 2015, 2015-05
Description: This thesis proposes a stochastic algorithm for managing the variability of wind energy by incorporating hourly demand response in the day...
Show moreThis thesis proposes a stochastic algorithm for managing the variability of wind energy by incorporating hourly demand response in the day-ahead scheduling in power systems. Monte Carlo simulation with Latin hypercube sampling technique is applied to represent the uncertainties of wind energy via different wind scenarios. Demand response has several physical and operating constraints to be considered into the stochastic security-constrained unit commitment (SCUC) for economic, reliability, and security purposes. Benders decomposition method is applied to decompose the large-scale complex stochastic SCUC problem into several tractable problems. Different case studies are analyzed in this thesis to demonstrate the benefits of applying DR to the proposed day-ahead scheduling model with variable wind energy.
M.S. in Electrical Engineering, May 2015
Show less

Title: BIO-COMPOSITE NANOMATERIALS; CHARACTERIZATION, MANIPULATION AND APPLICATION
Creator: Kim, Taeyoung
Date: 2013, 2013-05
Description: Biomaterials are any matter or material which interacts with biological system which were present on natural or synthetic nonviable materials....
Show moreBiomaterials are any matter or material which interacts with biological system which were present on natural or synthetic nonviable materials. An ideal biomaterial must physically and chemically compatible for biological applications to avoid toxicity and immune reaction. Collagen is a widely abundant, robust biopolymer that is found in the extracellular matrix (ECM) of many tissues. In terms of its structure and organization, collagen is a bio-nano material. The use of collagen in stem cell differentiation is particularly enticing since it is now evident that the extracellular matrix (ECM) proteins can regulate the cell’s fate and growth by their molecular and physical properties. In this thesis research, we have characterized the physical and structural properties of collagen and its composite materials. We found collagen interacts with NaCl and other nano-materials, such as carbon nanotube (CNT) and TiO2 nanotube, resulting in the modification of collagen structure and increase of its stiffness. In particular, CNT has changed collagen structure at both the molecular level and the higher organizational level. The effects of the matrices on cell growth and development were studied. It was found that collagen/CNT matrix specify and accelerate the stem cell differentiation toward neural cells. Since neurons form the foundation of biological circuit, manipulation of neurons in growth has the potential to form desired biological circuit. We also examined collagen in vaginal wall connective tissues, and found that alteration of collagen properties in clinical tissues is correlated to the onset of pelvic organ prolapse.
PH.D in Chemistry, May 2013
Show less

Title: TENSIWALL
Creator: Chiu, Mark A.
Date: 2011-12-10, 2011-12
Description: A facade is the interface between building and environment, between indoor and outdoor; therefore it has a functional quality – protection of...
Show moreA facade is the interface between building and environment, between indoor and outdoor; therefore it has a functional quality – protection of the interior spaces, inhabitants, and services from the forces of the exterior surrounding environment. The facade is also the first component to be seen of any building; therefore it has a certain aesthetic quality that it needs to achieve. Currently, most facades are constructed of relatively heavy materials, requiring more structural material usage; and opaque materials, depriving the interior occupants of natural light. A textile facade, however, can provide a lightweight, lighttransmissive, and highly insulative exterior wall, while also offering versatility in the aesthetics. Although they are usually not considered to be a facade material, textiles can create a highly advanced alternative to the current facade solutions. Therefore, the thesis topic is to develop a future exterior wall system with advanced physical properties based on a textile facade.
M.S. in Architecture, December 2011
Show less

Title: "NEW HORIZON" - SUSTAINABLE NEW CITY, DAHEJ, GUJARAT, INDIA
Creator: Suthar, Bhumika
Date: 2013, 2013-07
Description: The purpose of this thesis is to develop an ideal environment for developing new cities, that are not just green and clean but also self...
Show moreThe purpose of this thesis is to develop an ideal environment for developing new cities, that are not just green and clean but also self-sustainable. Current cities in world supports great infrastructure and accommodates approximately 6-7 Million people. According to UN, the population growth in next 15 years would be 10-15 million people will be living in the cities and that would increase loads on existing cities infrastructure. To avoid these inevitable circumstances we need new sustainable cities. In last two decades rapid urbanization and industrialization has caused indelible effects on our ecosystem. This thesis will provide in-depth insight on current urban problems and present a solution in form of new sustainable city. A holistic approach has been taken towards developing a new city at Dahej in Gujarat, India, which will be a prototype for new sustainable community development in future. It focuses on creating a perfect balance between environmental, social and economic sustainability. This new city will provide quality of life and environment. This thesis is a sincere approach to provide a strategic solution for post-carbon world and qualitative phenomena of the sustainable low-carbon future.
M.S. in Architecture, July 2013
Show less

Title: Analysis of Maltese Cross Specimens to Determine Three-Dimensional Yield Surfaces
Creator: Chaudesaygues, Ludwig
Date: 2011-11-29, 2011-12
Description: Yield behavior of extremely porous solid foams under multiaxial states of stress is of significant importance because, unlike pressure...
Show moreYield behavior of extremely porous solid foams under multiaxial states of stress is of significant importance because, unlike pressure independent yield response of the majority of engineering materials, solid foams exhibit quadratic as well as linear dependence on hydrostatic stress component in their yield behavior. Therefore, there exists a critical need to analyze and use specimen geometries that allow biaxial and triaxial experiments through which yield surface can be probed under varying amounts of mean stress. This study investigates, through FE analysis, the feasibility of Maltese-Cross (MC) specimen geometry as a potential candidate for using in biaxial and triaxial experiments. Although solid foams have a pressure dependent yield behavior, the current study adopted a linear elastic-hardening J2 flow rule to keep the analysis reasonably simple and focus on the fundamental effect of specimen geometry on strain field and, more importantly, the extraction of yield point from multiaxial force-displacement data. One must recognize that in multiaxial experiments, particularly in triaxial loading, forces and displacements experienced by the nominal gage section cannot be directly measured for practical reasons. Instead, far field forces and displacements have to be used to calculate average measures of stress and strain within the gage section. This study shows through FE analyses that MC specimens can be used to determine the onset of macroscopic yielding under varying amount of mean stress component, provided that certain stress/strain paths, which cause premature deformation localization out of the gage section, are avoided.
M.S. in Mechanical and Aerospace Engineering, December 2011
Show less

Title: LASER MICROMACHINING, SINTERING, AND LASER-INDUCED PLASMA DEBURRING
Creator: Gao, Yibo
Date: 2013, 2013-12
Description: Lasers can provide non-mechanical-contact, localized and concentrated energy input to materials with controlled durations and high spatial...
Show moreLasers can provide non-mechanical-contact, localized and concentrated energy input to materials with controlled durations and high spatial resolutions down to a few microns or less. Therefore, lasers have more and more applications in manufacturing and materials processing, such as laser micromachining (which is to create micro-scale features through laser-induced material removal) and laser sintering. Despite the previous research work in the literature, many laser-based manufacturing and materials processing areas still require lots of further research work. Specifically, the following topics will be investigated in the research work in this thesis: nanosecond-pulsed laser ablation of silicon carbide at an infrared wavelength, nanosecond laser-induced plasma deburring, two-step nanosecond laser surface texturing, and the fabrication of carbon nanotube (CNT)-ceramic composites through the laser sintering process.
PH.D in Mechanical and Aerospace Engineering, December 2013
Show less

Title: BIOLOGICAL STRATEGIES FOR ENHANCEMENT OF LIQUID FUELS: SULFUR REMOVAL FROM PETROLEUM AND BIOETHANOL PRODUCTION
Creator: Wang, Jia
Date: 2013, 2013-12
Description: Rhodococcus baikonurensis CW25 was transformed with the Rhodococcus erythropolis strain IGTS8 desulfurization operon (dszABC, which encodes...
Show moreRhodococcus baikonurensis CW25 was transformed with the Rhodococcus erythropolis strain IGTS8 desulfurization operon (dszABC, which encodes the enzymes of the “4S” desulfurization pathway) or this operon modified to contain a synthetic cysteine-methionine rich “sulpeptide” gene (S1) (dszAS1BC). The two CW25 derivatives were subjected to directed evolution to select faster growing cells using the key 4S pathway substrate dibenzothiophene (DBT) as the sole source of sulfur. Data of cell doubling times verified the success of selection of cultures with increasingly rapid growth. The desulfurization activities of resting cells of early passages demonstrated improvements, and the highest activity of the dszAS1BC-bearing CW25 derivative was 115% higher than that of the CW25 derivative without S1. In addition, a trend of initial high activity was followed by a decrease in subsequent passages. Rates of DBT metabolism of growing cells demonstrated a different trend, probably because the activity of growing cells concurrently reflects the activity of DszABC enzymes and the growth rates of the recombinants. Dry cell weights fluctuated during the evolution process, probably because of variations in the efficiency of the conversion of the sulfur in DBT into sulfite, then into sulfate or biomass, or, for the S1-bearing cells, because the secretion of the S1 peptide from cells might have variable efficiency. A mixed culture of two Paenibacillus species (“W” and “Y”) was isolated that can metabolize DBT at temperatures up to 54 ºC. Strain Y is the only one of the two with desulfurization activity, while strain W enhances the desulfurization ability of Y. The W-Y culture may be a useful starting point for selection of desulfurization cultures with even greater thermal stability. xiii Ethanologenic Escherichia coli strain FBR5 was compared with Vitreoscilla hemoglobin (VHb)-expressing FBR5 (TS3) regarding the concentrations of ATP, NAD+, NADH, NAD+/NADH ratio; and growth and ethanol production at various points during growth. The significant finding was that the NAD+/NADH ratio for TS3 was lower in early growth, but higher in later growth compared to that for FBR5. This is probably because more NADH was required by TS3 for its enhanced ethanol production and VHb-related increased respiration under microaeration conditions.
PH.D in Biology, December 2013
Show less

Title: MIN- AREA RETIMING UNDER WIRE-DELAY MODEL
Creator: Luo, Tianchen
Date: 2011-05-09, 2011-05
Description: Retiming is a powerful optimization technique for synchronize sequential circuits that relocates delay unit without changing the circuit’s...
Show moreRetiming is a powerful optimization technique for synchronize sequential circuits that relocates delay unit without changing the circuit’s input-output functionality. Wire delay is significant and can no longer be ignored in deep sub-micrometer technologies. Existing algorithms solve the problem of min-area and min-period either optimal or heuristically without taking wire delay into consideration. However, those techniques cannot be applied directly to circuit with wire delay. Recent work solved the min-period problem under wire delay model. This paper proposes an algorithm that solves the problem of min-area wire retiming under fixed clock period optimally and efficiently.
M.S. in Electrical and Computer Engineering, May 2011
Show less

Title: Thermal Resistance of Salmonella in Desiccation and Rehydration
Creator: Ahuja, Rameet
Date: 2011-12-06, 2011-12
Description: Transfer of salmonellae from a desiccated existence in dry food ingredients or processing environments to food products having higher water...
Show moreTransfer of salmonellae from a desiccated existence in dry food ingredients or processing environments to food products having higher water activities (e.g., peanut butter used in pie, chocolate in cake) leads to partial or full re-hydration of the bacteria. This study characterized the thermal behavior of Salmonella in response to desiccation and the subsequent rehydration. The thermal resistance of the desiccated S. enterica ser Tennessee was inversely correlated to aw: for example, desiccation at 11 to 97% equilibrated relative humidity (ERH) resulted in 0.5 to 3.3 log reduction, respectively, after 60ºC treatment for 10 min. Cells stored at lower ERH showed a lower survival rate, but higher thermal resistance. Once cells established their initial physiological response to desiccation, continual storage at 11% ERH up to three weeks did not further change the thermal resistance of Salmonella. Rehydration of the desiccated cells (11% ERH) to higher ERH conditions (84 to 97%) led to greater than 5 log reduction after heating cells at 60ºC for 10 min, in contrast, the same heat treatment resulted in approximate 3 log reduction for cells stored constantly at 84-97% ERH. There was no significant difference in regard to thermal sensitivity between cells rehydrated from 11% ERH to 33-55% ERH and that stored constantly at each ERH, only about 0.3-0.5 log CFU reduction in both cases. The study showed that rehydration moderately reduced cell viability, but greatly increased thermal sensitivity when a drastic aw shift occurred.
M.S. in Food Safety and Technology, December 2011
Show less

Title: EBSD CHARACTERIZATION OF LOW TEMPERATURE DEFORMATION MECHANISMS IN MODERN ALLOYS
Creator: Kozmel, Thomas S Ii
Date: 2015, 2015-05
Description: For structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and...
Show moreFor structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and fracture toughness. Through control of the thermo-mechanical processing parameters, dynamic recrystallization mechanisms were used to produce microstructures consisting of sub-micron grains in 9310 steel, 4140 steel, and Ti-6Al-4V. In both 9310 and 4140 steel, the distribution of carbides throughout the microstructure a ected the ability of the material to dynamically recrystallize and determined the size of the dynamically recrystallized grains. Processing the materials at lower temperatures and higher strain rates resulted in ner dynamically recrystallized grains. Microstructural process models that can be used to estimate the resulting microstructure based on the processing parameters were developed for both 9310 and 4140 steel. Heat treatment studies performed on 9310 steel showed that the sub-micron grain size obtained during deformation could not be retained due to the low equilibrium volume fraction of carbides. Commercially available aluminum alloys were investigated to explain their high strain rate deformation behavior. Alloys such as 2139, 2519, 5083, and 7039 exhibit strain softening after an ultimate strength is reached, followed by a rapid degradation of mechanical properties after a critical strain level has been reached. Microstructural analysis showed that the formation of shear bands typically preceded this rapid degradation in properties. Shear band boundary misorientations increased as a function of equivalent strain in all cases. Precipitation behavior was found to greatly in uence the microstructural response of the alloys. Additionally, precipitation strengthened alloys were found to exhibit similar ow stress behavior, whereas solid solution strengthened alloys exhibited lower ow stresses but higher ductility during dynamic loading. Schmid factor maps demonstrated that shear band formation behavior was in uenced by texturing in these alloys.
Ph.D. in Materials Science and Engineering, May 2015
Show less

Title: UNDERGROUND AIRPORT
Creator: Kim, Churl Jong
Date: 2014, 2014-12
Description: The idea of this project is to investigate the possibility of an underground airport with passenger facilities below and aircrafts above with...
Show moreThe idea of this project is to investigate the possibility of an underground airport with passenger facilities below and aircrafts above with minimum over-ground space. An important advantage is the possibility of loading and unloading passengers at two or more aircraft entrances thereby shortening the turn-around time of aircrafts. This accessibility can be more easily managed when approached from below. Furthermore, an underground facility is expected to provide several additional advantages: 1) greater freedom for aircrafts to get into position to efficiently load and unload; 2) potential for aircrafts to power-in and power-out of gate areas omitting the need for towing; 3) shorter walking distances for passengers due to greater compactness; 4) potential for an effective and efficient Automated People Mover (APM) system; 5) greater potential for systematic airport expansion when needed; 6) potentially reduced operating cost for ventilation, heating, and cooling. These advantages will answer many of the difficulties that current airports are experiencing today. However, in order to achieve these advantages, there are many important practical questions such as the spatial, environmental, structural aspects that need to be most carefully addressed. This project endeavored to investigate these important aspects as thoroughly as time and resources permit.
M.S. in Architecture, December 2014
Show less

Title: ADULTS WITH SICKLE CELL DISEASE: THE DISEASE'S IMPACT ON PAIN NEUROPSYCHOLOGICAL DYSFUNCTION AND QUALITY OF LIFE
Creator: Vernale Iii, Michael A.
Date: 2013, 2013-07
Description: The primary aim of this study is to address the neuropsychological functioning of adults with Sickle Cell Disease (SCD) by examining the...
Show moreThe primary aim of this study is to address the neuropsychological functioning of adults with Sickle Cell Disease (SCD) by examining the association of illness-related and psychosocial factors with cognition. The neuropsychological functioning of adults with SCD will be compared to that of controls matched on gender, race, and age. There is considerable evidence for neuropsychological complications associated with SCD (Anie, 2005; Schatz, 2004). Much of the cognitive deficits are thought to be the result of cerebrovascular accidents commonly suffered by this population. Studies of cognition in children with SCD suggest that cognitive complications tend to increase with age. Particularly implicated are deficits in attention, concentration, and executive functioning. Although the specific neuropsychological morbidity is not as clearly understood for adults with SCD as it is for children, global cognitive impairment within this population has been documented. In addition, pain negatively affects cognitive functioning in both children and adults (Libon et al., 2010). The pattern of impairment was suggested to be the result of additional demands on attentional capacity. However, the relationship between pain and cognitive performance in adults with sickle cell disease is less clear. As a result of frequent pain, individuals with SCD often report a low evaluation of quality of life particularly as a result of health complaints (Anie, 2005). Thus, the inter-dynamic of health -related quality of life, pain , and cognitive dysfunction is not entirely clear within the sickle cell population and therefore warrants examination.
PH.D in Psychology, July 2013
Show less

Title: SUPPORT VECTOR MACHINE BASED CLASSIFICATION FOR TRAFFIC SIGNS AND ULTRASONIC FLAW DETECTION
Creator: Virupakshappa, Kushal
Date: 2015, 2015-12
Description: The use of machine learning techniques for the advanced signal and image processing applications is gaining importance due to performance...
Show moreThe use of machine learning techniques for the advanced signal and image processing applications is gaining importance due to performance increases in accuracy and robustness. Support Vector Machine (SVM) is a machine learning method used for classification and regression analysis of complex real-world problems that may be difficult to analyze theoretically. In this dissertation, the use of SVM for the application of ultrasonic flaw detection and traffic sign classification has been investigated and new methods are introduced. For traffic sign detection, Bag of visual Words technique has been implemented on Speeded Up Robust Feature (SURF) descriptors of the traffic signs and later the sturdy classifier SVM is used to categorize the traffic signs to its respective groups. Experimental results demonstrate that the proposed method of implementation can reach an accuracy of 95.2 % . For ultrasonic aw detection, subband decomposition filters are used to generate the necessary feature vectors for the SVM classifier. Experimental results, using A-scan data measurements from a steel block, show that a very high classification accuracy can be achieved. Robust performance of the classifier is due to proper selection of frequency-diverse feature vectors and successful training. SVM has also been used for regression analysis to locate and amplify the aw by suppressing the clutter noise. The results show that the use of SVM is reliable and achievable for both the applications.
M.S. in Electrical Engineering, December 2015
Show less

repository.iit

Search the repository

Pages

Pages