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Title: IDENTIFY AND IMPROVE OBSTACLE AVOIDANCE CAPABILITY OF UNMANNED GROUND VEHICLE
Creator: Nie, Chenghui
Date: 2015, 2015-05
Description: An Unmanned Ground Vehicle (UGV), incorporating a high level of obstacle avoidance capability, benefits from field operations. Such a UGV...
Show moreAn Unmanned Ground Vehicle (UGV), incorporating a high level of obstacle avoidance capability, benefits from field operations. Such a UGV would be better able to travel at a high average speed to quickly finish tasks, as well as quickly alter its trajectory to avoid getting into hostile situation. However, avoiding obstacles at high speed is challenging, since the danger of collisions with obstacle is increased with vehicle speed. This thesis developed novel metrics to mathematically identify the obstacle avoidance capability of ground vehicles. The theory is applied to demonstrate the characteristics of the obstacle avoidance capability of generalized rigid bodies and three types of wheeled ground vehicles: Ackermann steered, differential steered and omni-directional vehicle. The design guidelines are provided in the final chapters to improve obstacle avoidance capabilities of these three types of wheeled ground vehicles. I demonstrated in this thesis that the Ackermann steered vehicle's obstacle avoidance capability is related to the location of its center of mass. I utilized the obstacle avoidance theory to create a novel Variable Inertial Vehicle (VIV), an unmanned ground vehicle with a capability to control the location of its center of mass during locotion. Experimental results are presented to demonstrate the improved obstacle avoidance capability at the end. This thesis also experimental evaluates the characteristics of the obstacle avoidance capability of an omni-directional unmanned ground vehicle. This omnidirectional vehicle is comprised of four independent differential steered units, Active Split Offset Caster (ASOC). Both the characteristics of the vehicle system and ASOC kinematics are demonstrated. Experimental results are presented at the end to validate its distinct obstacle avoidance capability in challenging outdoor terrains.
Ph.D. in Mechanical and Aerospace Engineering, May 2015
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Title: INVESTIGATING DIRECTED EVOLUTION AND GENETIC ENGINEERING WITH VITREOSCILLA HEMOGLOBIN TO PRODUCE CULTURES FOR LOW AERATION BIOLOGICAL WASTEWATER TREATMENT
Creator: Kunkel, Stephanie
Date: 2014, 2014-07
Description: The dominance of hemoglobin (Hb)-expressing bacteria in biological wastewater treatment systems could improve oxygen utilization under low...
Show moreThe dominance of hemoglobin (Hb)-expressing bacteria in biological wastewater treatment systems could improve oxygen utilization under low dissolved oxygen (DO) conditions. Hb-proteins are versatile molecules that have several biological functions. Here, Nitrosomonas europaea has been transformed with various plasmids; of particular interest is a recombinant plasmid bearing the constitutive Amo1 promoter and the gene (vgb) encoding the hemoglobin from the bacterium Vitreoscilla. Expression of VHb was assayed using various visible spectral methods, and VHb production seen in this recombinant strain. There were several positive effects on N. europaea metabolism related to VHb expression that were seen, specifically the ability of cultures to convert ammonia to nitrite at a slightly higher rate as well as higher specific oxygen uptake rates (SOUR) at both high (near saturation, 7 mg O2/ L) and low (< 2 mg O2/L) dissolved oxygen (DO) conditions. In parallel to this, two activated sludge cultures from the same source were cultivated using synthetic wastewater seeded with activated sludge from the same source and were operated at high DO (near saturation) and low DO (0.25 mg O2/L) concentrations for 370 days. There were significant changes in the bacterial species and phyla present in each of the cultures at various time points during the 370 day operational period. In the low DO culture, over time, there was a much greater expression of single domain and truncated Hbs which may enhance utilization and delivery of oxygen to various enzymes as well as to the respiratory chain. A larger increase in heme b was also observed which coincides with this observation. By the end of the acclimation period, the SOUR values were about 30% greater in the low DO culture compared to the high DO culture. This indicated the successful adaption of the low DO culture to respire more efficiently and eventually outperform the high DO culture.
Ph.D. in Biology, July 2014
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Title: COMPARATIVE ANALYSIS OF GROWTH KINETICS OF LISTERIA MONOCYTOGENES LINEAGES I AND II IN CHOPPED RED CABBAGE AND CUCUMBER USING PRIDICTIVE MODELING
Creator: Qi, Yan
Date: 2015, 2015-07
Description: Recently, outbreaks oflisteriosis assoc iated with cons umption of contaminated fresh produce by Listeria monocytogenes have increased....
Show moreRecently, outbreaks oflisteriosis assoc iated with cons umption of contaminated fresh produce by Listeria monocytogenes have increased. However, we know little about L. monocytogenes persistence and growth in fresh-cut produce items . The two main human foodbome outbreak lineages ofL. monocytogenes are LI and LB. Strains in LI (including serotypes 1/2b and 4b) are most likely to be isolated from human with listeriosis and Strains in LII (including serotypes 1/2a and 1/2c) are most likely to be isolated from food products and the natural environment. In order to determine the comparative survival and growth kinetics of these two lineages in chopped red cabbage and cucumber, samples of produce were chopped into 100 grams quantities and inoculated with 104 CFU/g of a cocktail of either LI (F2365, H7858, R2-502) or LII (LS814, JI-I 01, J1-067) antibiotic resistant strains. Samples were stored in deli-style containers at 5 or 10°C for 14 days, or 25°C for 7 days. At various intervals, samples were stomached and plated onto PCA with appropriate antibiotics. Data were modeled using DMFit from ComBase and statistical analyses were performed with GraphPad InStat. A p -value less than 0.05 was considered significant. The res ults for the grow th rates ((logIOCFU/g)/h) of the L. monocytogenes LI cocktail in red cabbage were significantly higher at 5°C (0.006±0.003), 10°C (0.017±0.004), and 25°C (0.051±0.017) than the LII cocktail ; and L. monocytogenes LI cocktail in cucumber were significantly lower at 25°C (0.098±0.00 84). Secondary models using the Ratkowsky equation presented r 2 values of 0.9866 for LI in red cabbage whereas presenting / values of 0.9998 and 0.9997 for LI and LII in cucumber, respectively. No significant difference between two lineages was seen in red cabbage and cucumber during ambient temperature display. Finally, the behavior of L. monocy togenes LI and LII on red cabbage and cucumber after potential consumer temperature abuse was determined. In red cabbage, LI grew steadily. However, the growth of L1I in red cabbage was more dynamic. In cucumber, there was no significant difference between LI and LII. The result s from this study will aid in comparing the growth and survival kinetics of Ll and L1l of L. monocytogenes and will provide guidance to both customers and the food industry.
M.S. in Food Safety and Technology, July 2015
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Title: REGULATION OF THE CELL DEATH SIGNALING PATHWAY IN ANDROGEN-INDEPENDENT PROSTATE CANCER CELLS
Creator: Lin, Yuting
Date: 2012-04-16, 2012-05
Description: Prostate cancer is the 2nd leading cause of cancer death in American men, mainly due to therapy-resistance in the advanced stage, androgen...
Show moreProstate cancer is the 2nd leading cause of cancer death in American men, mainly due to therapy-resistance in the advanced stage, androgen-independent prostate cancer (AIPCa). One major defect is that the cancer cells are insensitive to apoptosis induced by androgen ablation, chemotherapy or radiation therapy. However, the underline molecular mechanism still remains unclear. In this thesis, we focused on cell death signaling regulation in the development of AIPCa cells. We first show that up-regulation of Bcl-2, an anti-apoptotic oncogene, is required for the transition of prostate cancer cells from an androgen-dependent to an androgen-independent growth stage. Knockdown Bcl-2 impairs the transition process and blocks androgen-independent prostate tumor formation in vivo. Second, we show that Androgen-receptor (AR), which is generally considered as a survival factor in prostate cancer, promotes stress-induced apoptosis in AIPCa cells. AR promotes apoptosis through augmenting the mitochondrial translocation of Bax, a pro-death family member of Bcl-2. Finally, we show that AR can execute both pro-death and pro-survival events in same AIPCa cells. The AR pro-survival role is transcription-dependent, while its pro-death activity is transcription-independent. Interestingly, the AR exerts both functions through regulating p21 and JNK signaling pathways. These findings will help us to understand the dynamic survival signaling process in the development and progression of AIPCa. The key molecules identified here also provides potential therapeutic targets for the treatment of prostate cancer.
Ph.D. in Biology, May 2012
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Title: GALLIUM NITRIDE NANOSTRUCTURED POWER SEMICONDUCTOR DEVICES
Creator: Sabui, Gourab
Date: 2017, 2017-05
Description: Gallium nitride (GaN) has emerged as a promising material for development of power semiconductor devices owing to its superior material...
Show moreGallium nitride (GaN) has emerged as a promising material for development of power semiconductor devices owing to its superior material characteristics. Fabricated GaN power devices have started to outperform its silicon (Si) counterpart with low conduction and switching losses and holds the key to extremely low-loss and high efficiency power delivery circuits of the future. However, GaN power devices have been plagued with several inherent drawbacks preventing an ubiquitous adoption of GaN as the material of choice for power switches. The most critical trade-o↵ has been the choice of substrate for the growth of GaN epitaxy: a high performance, high-cost native substrate or a low-cost, non-native substrate with reliability issues. In order for GaN to thrive as a superior successor to Si, a low cost, high performance epitaxy with improved reliability is expected moving forward. A novel nanostructured approach to GaN power devices is proposed in this dissertation. The nano-GaN power devices theoretically has the potential to bypass the reliability concerns associated with a non-native substrate but still deliver comparable performance. A comprehensive model is proposed for TCAD modeling of bulk GaN power devices to accurately model the nano-GaN devices. Through extensive modeling and simulations, design guidelines for Schottky barrier diodes and field effect transistors based on the nano-GaN concept is laid out to extract the best performance out of this architecture. Dielectric and semiconductor interaction is also exploited to push these devices to perform beyond the unipolar material limit of GaN. The simulated and fabricated nano-GaN power devices show the potential to deliver equivalent or superior performance to present state of the art GaN devices but with improved reliability, ruggedness and low cost.
Ph.D. in Electrical Engineering, May 2017
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Title: INVESTIGATION AND MODELING OF PRESSURE DEPENDENT YIELD BEHAVIOR OF 3D STOCHASTIC AND PERIODIC FOAMS
Creator: Ayyagari Venkata S, Ravi Sastri
Date: 2013, 2013-07
Description: With growing potential of cellular solids in a multitude of diverse engineering applications including but not limited to automotive,...
Show moreWith growing potential of cellular solids in a multitude of diverse engineering applications including but not limited to automotive, aerospace, naval and biomed- ical industries as lightweight alternatives and space lling cores in sandwich struc- tures, need for predictive yield/failure criteria for these load bearing members under multiaxial stress states becomes critical. Although there exist several yield criteria proposed in the literature for highly porous solid foams, they are all phenomenolog- ical in nature, rely on relatively long list of model parameters that require di cult experimentation not readily available to end user, and none of them can handle the anisotropy observed in the majority of commercially available solid foams. Further, it is by now well established that, unlike commonly used engineering bulk solids, the yield behavior of highly porous solid foams is signi cantly in uenced by the hydro- static component of stress. In majority of phenomenological yield criteria proposed for solid foams this dependence is expressed by a quadratic pressure term. The scope of this study is quite comprehensive in the sense that it integrates analytical and computational investigation of yield behavior in solid foams along with extensive validation by recent experimental results produced in our lab. Present study proposes a physics based approach by hypothesizing that the yielding of stochastic foams is governed by the total elastic strain energy density, which leads to an energy based yield criterion for transversely isotropic foams and also provides a physical basis for the quadratic pressure dependence commonly adopted in existing phenomenolog- ical models. An added bene t of the analytical framework proposed in this work is that it introduces new scalar measures of stress and strain, which are referred to as characteristic stress and characteristic strain, that function in an analogous way to e ective (von Mises) stress and strain commonly used in analyzing the yield and post- yield behavior of bulk metals. Besides accommodating anisotropy, this energy-based xii yield criterion renders a unique advantage by relying only on the elastic properties and uniaxial yield strengths of the material, which makes the proposed yield criterion extremely practical for end user. Results from experimental data obtained from multiaxial testing of Divinycell H100 and H130 foams (Sha q, 2009; Ehaab, 2011) as well as a series of extensive com- putational simulations performed in this study on: a) periodic Kelvin foam models (both isotropic and transversely isotropic) of varying relative densities, b) stochastic Voronoi foams (both isotropic and transversely isotropic), point out to an additional linear pressure dependence in the yield behavior of solid foams, from a load-sharing viewpoint. This dependence is observed to be more pronounced at lower relative den- sities. A simple quantitative technique which is based on the partition of elastic strain energy into bending and stretch components is used to identify the distribution of deformation modes at microstructural level, along with its in uence on load sharing as a function of stress path. Furthermore, a plasticity model that incorporates a ow rule and hardening law are presented which allows the analysis of inelastic deforma- tions in solid foams in a continuum framework. Such models facilitate development of user de ned material model (UMAT) that allow evaluating the performance of proposed yield criterion under complex loading scenarios, such as indentation and punch loading.
PH.D in Mechanical and Aerospace Engineering, July 2013
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Title: ENHANCEMENT OF DESULFURIZATION BY DIRECTED EVOLUTION UTILIZING THE SULPEPTIDE AND CHLORAMPHENICOL RESISTANCE GENES
Creator: Yu, Qingfei
Date: 2013, 2013-12
Description: With the increasing demand of upgrading the quality of petroleum, optimizing the efficiency of biodesulfurization (BDS) is necessary. R....
Show moreWith the increasing demand of upgrading the quality of petroleum, optimizing the efficiency of biodesulfurization (BDS) is necessary. R. erythropolis 5F [pRESX dszABC] encodes the enzymes of the 4S pathway (on the dszABC operon) which catalyze the conversion of dibenzothiophene (DBT) to hydroxybiphenyl (2-HBP) plus sulfite. Our research attempts to increase the nutritional requirement of the cell for sulfur and to use selective pressure to obtain improved desulfurization. The genetic engineering strategy involves inserting the sulpeptide 1 (S1) gene, which encodes a sulfur-rich polypeptide, between dszA and dszBC in the dszABC operon to increase sulfur demand and force the strain into a spiral of ever increasing dszABC expression and thus desulfurization ability. Insertion of the chloramphenicol resistance (Cm) gene between dszAS1 and dszBC provides an additional method to select strains with higher desulfurization ability by their increasing resistance to chloramphenicol. We completed directed evolution for 22 passages for all three strains (those containing pRESX dszABC, pRESX dszAS1BC, or pRESX dszAS1CmBC transformed into strain 5F) and measured the desulfurization activity at selected passages. The results show that directed evolution did improve the desulfurization abilities in the first ten passages in the strains expressing dszABC and dszAS1CmBC, but reduced the desulfurization ability in the strain expressing dszAS1BC. For all three strains and all passages tested, the highest desulfurization activity was 83.6 μmol DBT/g DCW/hour in the dszABC bearing strain. Thus, the presence of S1 had a negative effect on the rate of desulfurization. A possible explanation for these results is that mutations occurring during the selection process enhance the efficiency of sulfur utilization and S1 alone can thus not force the strains to improve desulfurization.
M.S. in Biology, December 2013
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Title: THE EFFECT OF SURGICAL DECISION MAKING ON QUALITY OF LIFE IN ADOLESCENTS WITH CRANIOFACIAL CONDITIONS
Creator: Sokolowski Ruta, Caroline M.
Date: 2011-07, 2011-07
Description: Previous research concerning the delivery of medical services to adolescents, specifically the extent to which young people are involved in...
Show morePrevious research concerning the delivery of medical services to adolescents, specifically the extent to which young people are involved in the planning of their care, is lacking. This study investigated the importance of the decision-making process in adolescents with craniofacial conditions (CFCs) and whether their involvement in surgical decision-making has an effect on their perceived surgical outcome. Additionally, the study explored whether resilience factors such as positive self-concept, freedom from depression, coping abilities, and positive views of CFCs positively influence surgical outcome. Results demonstrated that coping abilities and positive views of CFCs predicted positive surgical outcome. Active participation in the decision-making process also predicted positive surgical outcome, though the effect size was trivial. Lastly, adolescent psychological health did not have an influence on surgical outcome. Limitations and areas for future research are discussed.
M.S. in Psychology, July 2011
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Title: Expanding the Magic Circle and the Self: Integrating Discursive Topics into Games
Creator: da Rosa Faller, Roberto
Date: 2020
Description: This study focuses on games for self-development and how they communicate ideas, challenge established assumptions, cause reflection, and...
Show moreThis study focuses on games for self-development and how they communicate ideas, challenge established assumptions, cause reflection, and provoke change. It explores the integration of discursive topics – specifically those perceived as difficult, political, philosophical, taboo, or controversial – into games, and how to manage player exposure to these topics through design while avoiding player disengagement to achieve self-development goals. Using a Research Through Design approach, this study was conducted in two phases. The first exploratory phase resulted in an analytical framework with four distinct lenses: engaging play experience; player’s emotional investment; the friction points of discursive topics; and, controlled exposure to the topic. During the second phase, this framework was used to analyze eight case studies and three prototypes. The resultant insights from analysis revealed five categories – topic depiction, emotional climate, emotional anchors, topic delivery, and exposure timing – that form the Discursive Topic Integration Framework for self-development. This framework offers a new theoretical perspective for design scholars and practicing designers about how to manipulate the “magic circle” (a safe temporary space for the act of play), by intentionally designing for discursive topics and their friction points. It contributes strategies about when, how, how frequently, and with what intensity discursive topics may be introduced and abstracted in games. It frames the discursive topic, creates the emotional climate, and anchors the player inside the magic circle of the game so that they feel engaged, motivated, and curious without becoming overwhelmed. This study also generated two additional frameworks, including: the Self-Development Opportunity Matrix that can be used to generate or evaluate self-development goals; and, the Five Categories of Transitional and Traumatic Experiences that can assist in the design of games and other experiences that build a person’s capacity, self-determination, and commitment to positive change.
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Title: A Multi-level Data Integration Approach for the Convergence of HPC and Big Data Systems
Creator: Feng, Kun
Date: 2020
Description: HPC is moving towards exascale (10^18 operations per second) following the trend that has continued for over half a century. Such an extremely...
Show moreHPC is moving towards exascale (10^18 operations per second) following the trend that has continued for over half a century. Such an extremely compelling computing power brings huge opportunities for scientists to explore their problems with larger sizes and finer granularity. As a result, the data volume produced and consumed by extreme-scale computing has increased dramatically. To gain useful scientific insights, scientists analyze tremendous amounts of data, which stresses the storage systems and requires efficient data access. Besides the data volume increase, the variety of I/O subsystems grows as well to meet the drastically different, often conflicting I/O requirements of numerous applications. HPC and BD, as two major camps of extreme-scale computing, have been developed separately for a long time and diverged from computing and storage paradigms. However, recent developments have proven the convergence of them leads to more efficient scientific output. Hence, unification between these ecosystems is necessary to accelerate extreme-scale computing with the collaboration of applications from both camps. Therefore, integrated I/O has become a major issue that needs to be addressed as the extreme computing community moves forward.This study explores improvement by proposing a new integrated data access system for extreme-scale computing. We enhance the BD framework to adapt to the change of integrated data access requirement by enabling direct processing of scientific data from PFS at the HPC site. Our framework can perform up to 8x faster than the state-of-the-art solutions in representative workloads. We design a new advanced I/O middleware service to utilize data aggregation resources to facilitate integrated data access in scientific workflows with both HPC and BD applications. Our middleware service can reach up to 10x speedup against the default solution and 133% better performance than existing solutions. We propose a novel storage integration solution on the storage side to unite all the storage resources, to unify the namespace across all the storage systems, and provide an ultimate integrated data access service. The integrated solution can speed up a real workflow with integrated data access requirements by up to 6.86x over existing solutions. The three-level integration at the application level, middleware level, and storage level provide us a systematic hierarchical I/O integration. Our implementation results show that the three-level optimized design and implementation is feasible and effective. It improves the state-of-the-art solutions and helps us to achieve an enhanced I/O system towards extreme-scale computing to support both HPC and BD applications.
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Title: BAXΔ2: FROM FUNCTIONAL DOMAINS TO CANCER CORRELATION
Creator: MaÑas NÚÑez, Adriana
Date: 2018, 2018-05
Description: BaxΔ2 is a functional pro-apoptotic Bax isoform, originally identified in cancer patients with microsatellite instability. Here we performed...
Show moreBaxΔ2 is a functional pro-apoptotic Bax isoform, originally identified in cancer patients with microsatellite instability. Here we performed an extensive study on BaxΔ2, covering the structure-function relationship, the clinical potential, and the human tissue expression profile. Unlike Baxa, BaxΔ2 forms aggregates and triggers non-mitochondrial cell death through caspase 8. However, the functional domain(s) responsible for BaxΔ2 unique behavior were elusive. Here we show that disruption of helix α1 makes Baxα mimic BaxΔ2, but other alterations in the N-terminus have no significant impact. We found that the core region is key for aggregation, but is not sufficient to trigger cell death. The Cterminal helical conformation, not its primary sequence, appears to be critical for caspase 8 activation. As BaxΔ2 shares core and C-terminal with most Bax isoforms, our results indicate an intrinsic potential for aggregate-mediated caspase 8-dependent cell death in other Bax family members. BaxΔ2 has been shown to sensitize cancer cells to chemotherapy, but it is a very unstable protein. Therefore, we screened a panel of proteasome inhibitors in colorectal cancer cells with different Bax statuses. We found that proteasome inhibitors can block BaxΔ2 degradation without affecting the levels of Baxa or Bcl-2. Among the inhibitors tested, bortezomib and carfilzomib were able to induce significantly higher cell death in BaxΔ2-positive cells than in cells with Baxa or no Bax. Furthermore, bortezomib-induced cell death in BaxΔ2-positive cells was predominantly dependent on the caspase 8/3 pathway. These results suggest that BaxΔ2 can selectively sensitize cancer cells to proteasome inhibitors. As many cancers have microsatellite mutations, we screened BaxΔ2 protein expression in 1090 samples of tumor and healthy tissues from several organs. We found that BaxΔ2 is expressed in 1% to 5% of cells in most organs, predominantly in healthy tissues. Production of BaxΔ2 requires a guanine deletion in the microsatellite region, but the great majority of BaxΔ2-positive tissues contained no mutation at genomic or transcript levels. Therefore, we tested Programed Ribosomal Frameshift (PRF) as a possible BaxΔ2 expression mechanism, using a double tagged construct with no mutation. We found that, though rare, PRF can lead to expression of BaxΔ2. In conclusion, BaxΔ2 can be expressed without a genetic mutation. In conclusion, BaxΔ2 is a unique isoform whose expression is the product of the extreme plasticity of the Bax gene and the biochemical circumstances in the cell. As an example of non-traditional expression, it opens the door to a whole new proteome expressed by alternative mechanisms both under physiological and pathological conditions.
Ph.D. in Biology, May 2018
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Title: HIGH TEMPERATURE GRAIN BOUNDARY ENGINEERING OF POWDER PROCESSED NICKEL BASED SUPERALLOYS
Creator: Mccarley, Joshua B.
Date: 2018, 2018-05
Description: The concept of grain boundary engineering (GBE) has been effectively utilized to improve the properties of polycrystalline Nickel based...
Show moreThe concept of grain boundary engineering (GBE) has been effectively utilized to improve the properties of polycrystalline Nickel based superalloys via triggering the formation of special High-angle grain boundaries which are highly coherent. Current processing routes which implement GBE often require multiple iterations of room temperature deformation also characterized as cold work, followed by short annealing cycles whereby each applied iteration results in limited to modest enhancements in the fraction of the aforementioned special grain boundaries. As such, a substantial number of iterations are required to obtain fractions large enough (>50%) to effectively yield improved resistance to corrosion, creep, and fatigue. The current application of GBE on high-strength materials is not suitable for the production of large, complex-shaped structures, and has also been noted to increase manufacturing lead time and cost. In this investigation, alternative processing routes which utilize GBE at elevated temperatures for powder processed Nickel based superalloys used as turbine discs in gas turbine engines manufactured by Rolls-Royce. The material which serves as the central focus of the forthcoming investigation is an experimental low stacking fault energy Nickel based superalloy containing a cobalt concentration of 24 wt.%. A preliminary study which focused on the effects of hot deformation parameters similar to typical industrial applications revealed the materials ability to enhance its Σ3 twin boundary length fraction from 21% to 53% following a single deformation/anneal cycle. Subsequently, the investigated deformation parameters displayed a near consistent triggering of dislocation based plasticity mechanisms which promoted the formation of annealing twin boundaries. Although the experimental Nickel based superalloy exhibited the ability to promote extensive fractions of annealing twins, the resultant grain boundary characters produced via hot deformation displayed varying magnitudes of dynamically recrystallized grains which are generally considered to be detrimental in GBE practices. Mechanisms which assist in optimizing the formation of Σ3 twin boundaries during high-temperature GBE were further investigated. The enhanced cobalt concentration possessed by the experimental alloy was observed to have effectively enhanced the materials ability to rapidly store high magnitudes of strain energy upon hot deformation when compared to a commercially available Nickel based superalloy possessed a lower Co. concentration. Reducing the volume fraction of primary gamma prime precipitates present in the experimental alloys microstructure was noted to have effectively slowed the onset of dynamic recrystallization, while still promoting favorable fractions of annealing twins. A critical strain was later identified at which the onset of dynamic recrystallization was predominately avoided in the experimental alloy during hot deformation, and the strain induced boundary migration mechanism was effectively triggered which promoted the largest observed length fractions of Σ3 twin boundaries. A final investigation which considered what effect distinct microstructural features have on the kinetics which drive twin formation was also performed to assist in providing insight on optimizing applications related to GBE for advanced turbine engines.
Ph.D. in Materials Science and Engineering, May 2018
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Title: TRANSFER MECHANISM AND TRANSCRIPTOMIC PROFILING OF SALMONELLA IN FRESH-CUT FRUITS
Creator: Chen, Ruixi
Date: 2018, 2018-05
Description: Salmonella has been recognized as an increasing concern for food safety of fresh fruits because of their constant involvement in associated...
Show moreSalmonella has been recognized as an increasing concern for food safety of fresh fruits because of their constant involvement in associated foodborne outbreaks. However, knowledge is relatively limited about the transfer pattern of this particular pathogen from contaminated to uncontaminated fruits, nor do we know about the molecular mechanisms incorporated by it to address the environment of fresh fruits. In this study, we investigated the transfer mechanism of Salmonella enterica serovars Newport and Typhimurium between fresh gala apples and cantaloupes, respectively, via consecutive fresh cuttings and the subsequent survival of the strains in juice and cube fruit products under 4oC for up to 7 days. We also used RNA-seq and bioinformatics approaches to explore the transcriptome of Salmonella Newport in cantaloupe in comparison with 0.1% BPW (control group). Our results demonstrated fresh cutting as a practical way for bacterial transfer from contaminated to up to 4 uncontaminated fruits, and the transfer rate decreased drastically as the number of fresh cuts increased. The relative distribution of Salmonella cells in the 1st un-inoculated cantaloupe sample was significantly higher than the corresponding gala apple sample (p ≤0.05), while the transfer rate to the following un-inoculated samples in the cantaloupe group was visibly lower than the gala apple group. In general, cantaloupe, rather than gala apple, was capable to at least maintain a constant level of bacterial population during the 7 days storage at 4oC, with juice sample being even more supportive than cube sample (p ≤0.05). Moreover, Salmonella Typhimurium had a better adaptation in cantaloupe environment than Salmonella Newport. According to the results of transcriptome analysis, metabolism activities were promoted for essential nutrient requirements including carbon, energy, nitrogen, phosphorus, iron and zinc comparing to the control group, while suppressed for others such as lipid and fatty acids (FDR ≤0.05, |log2 FoldChange| ≥1). The differential regulation of the corresponding genes of the biological processes was possibly achieved in a time much less than 1 hour.
M.S. in Food Safety and Technology, May 2018
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Title: RISE OF A SINGLE BUBBLE IN A VERTICAL TUBE FILLED WITH NANOFLUIDS
Creator: Cho, Heon Ki
Date: 2018, 2018-05
Description: The motion of air bubbles in tubes filled with nanofluids is of practical interests. Thus, this study focuses on the dynamics of air bubbles...
Show moreThe motion of air bubbles in tubes filled with nanofluids is of practical interests. Thus, this study focuses on the dynamics of air bubbles rising in tubes in nanofluids. Many authors experimentally and analytically proposed the rising air bubble velocity in vertical tubes in common liquids when Capillary number is large. We report here a systematic study of an air bubble rising in vertical tube filled with nanofluids when the Capillary number is small. The presence of the nanoparticles creates a significant change in the bubble velocity compared with the bubble rising in the common liquids. We observed a novel phenomenon of a step-wise decreases in the bubble rising velocity vs. bubble length for small Capillary number. The step-wise velocity increases is attributed to the nanoparticles self-layering phenomenon in the film adjacent to the tube wall. The effect of volume fraction of the nanoparticles and the tube diameters are investigated. Also, we measured the film thickness and calculated the film structural energy isotherm vs. the film thickness from the film meniscus contact angle measurement using the reflected light interferometric method. Based on the experimental measurement of the film thickness and the calculated values of the film structural energy barrier, we estimated the structural film viscosity vs. the number of nanoparticles/micelles. Due to thenanoparticle film self-layering phenomenon, we observed a gradual increasing the film viscosity with the decrease in the film thickness. But, we found a significant increase in the film viscosity accompanied by a step-wise decrease in the bubble velocity when the number of nanoparticles/micelles decreased from three to two particle layers due to the structural transition in the film. Bretherton analyzed the rise of a single long air bubble at a very small Capillary number under the effect of gravity in a vertical tube filled with common liquids with a thick and stable film. However, Bretherton equation cannot accurately predict the rate of the rise of the slow-moving long bubble in the vertical tube in nanofluids because it is valid only for very thick films and uses the bulk viscosity of the fluid. But, we demonstrate that the Bretherton equation can indeed be used for predicting the rate of the rise of the long single bubble through the vertical tube filled with the nanofluids by simply replacing the bulk viscosity with the proper structural nanofilm viscosity of the fluid.
Ph.D. in Chemical Engineering, May 2018
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Title: OPTIMAL SCHEDULING OF ELECTRIC VEHICLE'S CHARGING/DISCHARGING
Creator: Guo, Dalong
Date: 2018, 2018-05
Description: The advent of Electric Vehicles (EVs) demonstrates the effort and determination of humans to protect the environment. However, as the number...
Show moreThe advent of Electric Vehicles (EVs) demonstrates the effort and determination of humans to protect the environment. However, as the number of EVs increases, charging those EVs consume large amount of energy that may cause more pressure on Grid. On the other hand, the smart grid enables two-way energy flow which gives EVs the potential to serve as distributed storage system that may help mitigate the pressure of fluctuation brought by Renewable Energy Sources (RES) and reinforce the stability of power systems. Therefore, establishing efficient management mechanism to properly schedule EV charging/discharging behavior becomes imperative. In this thesis, we consider that EVs have one charging mode, Grid-to-Vehicle (G2V), and two discharging modes, Vehicle-to- Grid (V2G) and Vehicle-to-Home (V2H). In V2G, EVs send back their surplus power to grid, while in V2H, EVs supply the power for appliances in a house. We aim to design optimal algorithms to schedule the EV’s operations. We first consider an individual residential household with a single EV, where the EV can operate at all three modes. When the EV works in G2V mode, the owner pays the cost to utility company based on the real-time price (RTP). When the EV works in V2G mode, the owner earns the reward based on the market price from utility companies. In V2H, the owner uses the EV battery to provide power to appliances in the house rather than purchasing from the utility. We propose a linear optimization algorithm to schedule the EV’s operations based on the RTP and market price subject to a set of constraints. The objective is to minimize the total cost. The results show that in general the EV chooses G2V when the RTP is low, responding to demand response. When the RTP is high, the EV tends to work as V2H to avoid buying from the utility. When the market price is high, the EVs will perform V2G to obtain more revenue. Noting that it is not practical for a single EV to perform V2G, we further consider a different scenario in which a group of EVs is aggregated and managed by an aggregator. One example is a parking lot for an enterprise. Initially only V2G is considered, that is, EVs work as energy supplies and the aggregator collects the energy from all connected EVs and then transfers the aggregated energy to the grid. Each EV needs to decide how much energy to discharge to the aggregator depending on its battery capacity, remaining energy level, and etc. To facilitate the energy collection process, we model it as a virtual energy “trading” process by using a hierarchical Stackelberg Game approach. We define the utility functions for aggregator and EVs. To start the game, the aggregator (Leader) announces a set of purchasing prices to EVs and each EV determines how much energy to sell to the aggregator by maximizing its utility based on the announced price and sends that number to the aggregator. Then the aggregator adjusts the purchasing prices by maximizing its utility based on the optimal energy values collected from the EVs and the game process repeats till it converges to an equilibrium point, where the prices and the amounts of energy become fixed values. The proposed game is an uncoordinated game. We also consider power losses during energy transmission and battery degradation caused by additional charging-discharging cycles. Simulation results show the effectiveness and robustness of our game approach. At last, we extend the game to include G2V as well for the aggregated EV group scenario. That is, EVs may charge their batteries according to the RTP so that they can sell more to the aggregator to increase the profit when the purchasing price from the aggregator is attractive. We propose a SG-DR algorithm to combine the game model for V2G and the demand response (DR) for G2V. Specifically, we adjust the utility function for EVs and then update the constraints of the game to include the DR. Subject to the duration of parking period, we solve this optimization problem using our combined SG-DR algorithm and generate EVs’ corresponding hourly charging/discharging pattern. Results show that our algorithm can increase up to 50% utility for EVs compared with the pure game model. Finally, in conclusion, we summarize our work under different scenarios. Then we analyze the potential risk and propose the future trend of EV’s development in Smart Grid.
Ph.D. in Electrical Engineering, May 2018
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Title: Design and Prototyping Information Tools for High Performance IPRO Teams, IPRO 373
Creator: Newman, Catherine, Roche, Jacqueline, Oluwagembi, Williams, Liu, Janet, Abu Amara, Lama, Sahel, Adam, Fotso, Kevin, Bendas, Paul, Posch, Matthew, Rajgor, Yash, Salas, Raul
Date: 2012-06-15, 2012-07
Description: The purpose of this IPRO project is to develop a single, consolidated, interactive information resource for IPRO teams that replaces...
Show moreThe purpose of this IPRO project is to develop a single, consolidated, interactive information resource for IPRO teams that replaces information currently found at the IPRO web site.
Sponsorship: IPRO Office
Project plan for IPRO 373: Design and Prototyping Information Tools for High Performance IPRO Teams, the summer 2012 semester
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Title: Sensor Systems in the Transportation Industry (Spring 2001) IPRO 353
Creator: Boitor, Andrei, Lauzze, Kevin, Pendleton, Ryan, Volberding, Beth
Date: 2001, 2001-05
Description: The prototypes for a railroad tank car monitoring system have been developed in prior IPRO projects. The prototypes now need to be developed...
Show moreThe prototypes for a railroad tank car monitoring system have been developed in prior IPRO projects. The prototypes now need to be developed into potential product form, beta tested, and evaluated both technically and from a market perspective. A patent application has been outlined. A business plan needs to be written that gathers the information required to decide on a commercial product offering to Union Tank Car as the first customer. A market survey should define the potential market within the railroad industry, the economics of such a business, and its potential in other related market segments, such as trucking. At the end of this Entrepreneurial IPRO, we should have beta tested the potential product. If the results are successful, manufacturers and suppliers should be identified to bring the product to market. A first sale offering should be made to Union Tank Car, assuming beta testing is successful. The possibility to formulate a successful business together with our first customer, Union Tank Car, will be evaluated. The team required to execute the business plan will be identified; and the.potential for financing will also be addressed. This entrepreneurial team would ideally consist of chemistry and chemical engineering students for sensor development work; mechanical and electrical engineering students for product engineering and production setup; business school and law school students to support business plan development, market analysis and patenting for the business.
Sponsorship: Union Tank Car Company, a member of The Marmon Group of companies.
Project Plan for IPRO 353: Sensor Systems in the Transportation Industry for the Spring 2001 semester
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Title: Innovation in Spirometry (Spring 2001) IPRO 360
Creator: Coffey, Jessica, Lamm, Adrienne, Nilsson, Lina, Ottem, Tisha, Serrahn, Sean, Wilson, Nicole
Date: 2001, 2001-05
Description: IIT has developed and patented technology for the precise metering of flow for the natural gas industry. This technology may have important...
Show moreIIT has developed and patented technology for the precise metering of flow for the natural gas industry. This technology may have important application in the healthcare and sports medicine field. More specifically, this precision flow meter may offer a better way to monitor the respiration of people with asthma and other respiratory conditions that require careful monitoring and periodic evaluation. It may also be a useful tool to calibrate various inhalation and breathing control devices used by individuals or used under controlled research circumstances. This could include the study of athletes, workers in specialized environments, etc. The purpose of this entrepreneurial IPRO project is twofold. First, it is important to explore the full market potential of a device based on this precision flow meter. This includes a profile of user application segments; driving forces for demand by individuals, researchers and the health care delivery community; and the regulatory environment and process that must be followed (including issues of efficacy for various users, safety, and pathways to trial, approval and market diffusion). In addition, the appropriate pathways to obtaining research and commercialization funding will be identified and evaluated, including SBIR applications. Part of this process involves developing an understanding of the application niche(s) that represent the greatest market opportunity to attract commercial investment, those that represent the earliest market opportunity to stimulate interest and purchase commitment, and those that represent the most viable opportunity to attract research support. A second important purpose is to design, build and test a prototype flow meter and associated electronics. The prototype design will respond to the identified market opportunities. It will include data acquisition and processing systems and user interfaces to provide useful information to the user, physician, researcher or regulatory body. Addressing both purposes can shape the business opportunity based on the precision flow metering technology. This project team may also coordinate with other another planned Spring 2001 IPRO projects IPRO 320, because of its potential focus on asthma incidence and general air quality monitoring in Bronzeville
Sponsorship: IIT Internal R&D
Project Plan for IPRO 360: Innovation in Spirometry for the Spring 2001 semester
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Title: Hybrid Cars with Ultra Capacitor Augmentation (Spring 2003) IPRO 314
Creator: Akdeniz, Hakan, Batra, Saurav, Davis, Josh, Gonzalez, Israel, Hunter, Ben, Lee, Toh Chu, Lugo, Benito, Radwanski, Luke, Stano, Jeffery, Stone, Karen, Tudor, Rafael, Ufot, Ima
Date: 2003, 2003-05
Description: This IPRO is a continuation of the work of the IPRO 314, which is focusing on improving the efficiency of gasoline and hybrid vehicles through...
Show moreThis IPRO is a continuation of the work of the IPRO 314, which is focusing on improving the efficiency of gasoline and hybrid vehicles through the use of ultra capacitors. The goal is to actually develop a hybrid electric vehicle with ultra capacitor augmentation. The need to improve the efficiency for vehicles using internal combustion engines is critical in order to reduce oil consumption and pollution in United States. Hybrid vehicles (e.g., those that use a combination of gas and electric power) also need to reduce cost and improve battery efficiency. The use of ultra capacitor technology in conjunction with electric generators and motors can assist in powering electrical equipment, braking operations, and charging batteries. This hands-on project will afford students the opportunity to research an apply concepts of mechanical, electrical, power, computer, economics, environmental, and materials engineering to hybrid vehicle technology
Sponsorship: IIT Collaboratory for Interprofessional Studies
Project Plan for IPRO 314: Hybrid Cars with Ultra Capacitor Augmentation for the Spring 2003 semester
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Title: Innovations in Spirometry (Spring 2002) ENPRO 357
Creator: Attupurath, Reji, Chen, Steven, Choie, Albert, Gannavarapu, Bhargava, Goossens, Zachary, Huske, Jacob, Jayarajan, Senthil, Panchal, Adit, Patel, Ankur, Shim, Jooman, Shye, Michael, Nicole, Nicole
Date: 2002, 2002-05
Description: IIT has developed and patented technology for the precise metering of flow for the natural gas industry. This technology may have important...
Show moreIIT has developed and patented technology for the precise metering of flow for the natural gas industry. This technology may have important application in the healthcare and sports medicine field. More specifically, this precision flow meter may offer a better way to monitor the respiration of people with asthma and other respiratory conditions that require careful monitoring and periodic evaluation. It may also be a useful tool to calibrate various inhalation and breathing control devices used by individuals or used under controlled research circumstances. This could include the study of athletes, workers in specialized environments, etc. The purpose of this entrepreneurial IPRO project is twofold. First, it is important to explore the full market potential of a device based on this precision flow meter. This includes a profile of user application segments; driving forces for demand by individuals, researchers and the health care delivery community; and the regulatory environment and process that must be followed (including issues of efficacy for various users, safety, and pathways to trial, approval and market diffusion). In addition, the appropriate pathways to obtaining research and commercialization funding will be identified and evaluated, including SBIR applications. Part of this process involves developing an understanding of the application niche(s) that represent the greatest market opportunity to attract commercial investment, those that represent the earliest market opportunity to stimulate interest and purchase commitment, and those that represent the most viable opportunity to attract research support. A second important purpose is to design, build and test a prototype flow meter and associated electronics. The prototype design will respond to the identified market opportunities. It will include data acquisition and processing systems and user interfaces to provide useful information to the user, physician, researcher or regulatory body. Addressing both purposes can shape the business opportunity based on the precision flow metering technology.
Sponsorship: Irving and Sylvia Footlik Foundation
Project Plan for ENPRO 357: Innovations in Spirometry for the Spring 2002 semester
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