Digital Commons Network^™

Developing An Idealistic Model To Characterize And Optimize A Photovoltaic Battery Systems, Pavani Reddy Nalladimmu

Masters Theses

"Solar energy is one of the most abundant and clean energy sources of renewable energy. Due to its unsteady nature, most photovoltaic systems require a solar storage system. Ultracapacitors have proven to be an effective solar energy storage component due to their wide range of input voltages and high power density. This research focuses on characterizing the performance of a PV/UCAP hybrid storage system to meet required household loads at various locations throughout the US as a backup energy source. A calibrated empirical model was developed to characterize system performance. A load profile was designed based on a typical 2 …

Intensity Control Of Dielectric Barrier Discharge Filaments, Matthew Crawford Paliwoda

Masters Theses

"When operated in a filamentary mode, a volume dielectric barrier discharge (DBD) is known to produce patterned plasma structures. These structures are currently being explored for reconfigurable metamaterial applications. In this work the presence and intensity of a single filament, within an array of filaments, was controlled by adjusting the voltage to that filament's individual needle electrode. The current, voltage, and time-averaged normalized light intensity were measured while varying the voltage of the needle through a self-biasing resistance. For a 7.5 kV, 3.2 kHz DBD in air, the needle-controlled filament intensity varies from that of the surrounding filaments to zero …

Characterization Of Insertion Sequence Is605 In Halanaerobium Hydrogeniformans, Michael C. Sadler

Masters Theses

"Insertion sequences are the smallest prokaryotic transposable elements. These genes play a significant evolutionary role by promoting genome plasticity. Insertion sequences are highly diverse elements that have largely been uncharacterized. As such, the ability to accurately identify, annotate, and infer genomic impact of insertion sequences is lacking. The study of new insertion sequences contributes knowledge to their annotation and evolution. Halanaerobium hydrogeniformans is a unique organism with an abnormally high number of insertion sequences. A family of insertion sequences, IS200/605, showed several interesting distinctions from other elements in the genome, including severe open reading frame degradation, and was characterized in …

Understanding User Experience In Gaming, Sri Chaitanya Sanaboina

Masters Theses

"This research examines the effect of virtual reality gaming versus desktop based gaming on spatial presence, social presence, and intention to play. It draws on cognitive theory of presence, social presence theory, and theory of reasoned action to generate the research hypotheses and explain the observed phenomenon. A within-subject experimental design (N=53) was used to evaluate the effects of virtual reality versus desktop based gaming. The results suggest that both spatial presence and social presence were significantly enhanced in the virtual reality gaming environment while intention to play was significantly greater in the desktop based gaming environment"--Abstract, page iii.

Assessment Of Online Information Literacy Learning Objects For First Year Community College English Composition, Mara Bordignon, Alana Otis, Adele Georgievski, Jennifer Peters, Gail Strachan, Joy Muller, Rana Tamin

All Works

© 2016 Bordignon, Otis, Georgievski, Peters, Strachan, Muller, and Tamin. Objective - The main objective was to determine whether information literacy (IL) learning objects (LOs) impact student IL competency, specifically in a foundational first year English composition course. The primary research question was: What is the effectiveness of IL LOs compared to face-to-face instruction in terms of students' skill acquisition? Methods - The methods involved testing student IL competency through a multiple-choice test given pre- and post-IL intervention. Effectiveness was measured by assessing whether IL competency improves after exposure to one of two interventions: online IL LOs or face-to-face librarian-led …

Artificial Neural Network Approach To Predict Blast-Induced Ground Vibration, Airblast And Rock Fragmentation, Raymond Ninnang Tiile

Masters Theses

"Blasting has been widely used as an economical and cheap way of rock breakage in mining and civil engineering applications. An optimal blast yields the best fragmentation in a safe, economic and environmentally friendly manner. The degree of fragmentation is vital as it determines to a large extent the utilization of equipment, productivity and mill throughput. Explosive energy, besides rock fragmentation, creates health and safety issues such as ground vibration, air blast, fly rock, and back breaks among others. As a result, the explosive energy impacts structures and buildings located in the vicinity of the blasting operation, and causes human …

Effect Of Timing And Source Of Online Product Recommendations: An Eye-Tracking Study, Qing Zeng

Masters Theses

"Online retail business has become an emerging market for almost all business owners. Online recommender systems provide better services to the consumers as well as assist consumers with their decision making processes. In this study, a controlled lab experiment was conducted to assess the effect of recommendation timing (early, mid, and late) and recommendation source (expert reviews vs. consumer reviews) on e-commerce users' interest and attention. Eye-tracking data was extracted from the experiment and analyzed. The results suggest that users show more interest in recommendation based on consumer reviews than recommendation based on expert reviews. Earlier recommendations do not receive …

A Linear Matrix Inequality-Based Approach For The Computation Of Actuator Bandwidth Limits In Adaptive Control, Daniel Robert Wagner

Masters Theses

"Linear matrix inequalities and convex optimization techniques have become popular tools to solve nontrivial problems in the field of adaptive control. Specifically, the stability of adaptive control laws in the presence of actuator dynamics remains as an important open control problem. In this thesis, we present a linear matrix inequalities-based hedging approach and evaluate it for model reference adaptive control of an uncertain dynamical system in the presence of actuator dynamics. The ideal reference dynamics are modified such that the hedging approach allows the correct adaptation without being hindered by the presence of actuator dynamics. The hedging approach is first …

Mitigation Of Wellbore Instability In Deviated Wells By Using Geomechanical Models And Mpd Technique, Husam Raad Abbood

Masters Theses

"During drilling operations for the E oilfield in the Mishrif formation in southern Iraq, stuck pipe presents a significant wellbore stability problem for deviated wells. In this study, two solutions are utilized to address this problem. The first approach is a 1-D Geomechanical model of the Mishrif formation compiled based on the state of stress and rock strength parameters. It is utilized to assess the contribution of borehole collapse leading to the stuck pipe problems. The results of this study show that wells characterized by stuck pipe are drilled along azimuths which promote wellbore collapse. Three different failure criteria, the …

Design And Analysis Of An Axisymmetric Aerospike Supersonic Micro-Nozzle For A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Abdalla Ali Bani

Masters Theses

"The cold-gas propulsion system being developed by M-SAT requires improvements to its original nozzle design. This study documents the research, design, and analysis of a supersonic plug nozzle concept that could be integrated to the refrigerant-based cold-gas propulsion system to possibly improve its performance. As documented in this thesis, CFD analysis showed that the outlined nozzle design method resulted in a feasible nozzle concept that has the ability to out-perform a conventional nozzle of the same area ratio. The flow-fields and thrust of the aerospike nozzle, for the full and truncated nozzles, were investigated. The purpose of this study is …

Design, Scale-Up, Six Sigma In Processing Different Feedstocks In A Fixed Bed Downdraft Biomass Gasifier, Sai Chandra Teja Boravelli

Masters Theses

"This thesis mainly focuses on design and process development of a downdraft biomass gasification processes. The objective is to develop a gasifier and process of gasification for a continuous steady state process. A lab scale downdraft gasifier was designed to develop the process and obtain optimum operating procedure.

Sustainable and dependable sources such as biomass are potential sources of renewable energy and have a reasonable motivation to be used in developing a small scale energy production plant for countries such as Canada where wood stocks are more reliable sources than fossil fuels. This thesis addresses the process of thermal conversion …

Voltage Control In A Distribution System Using Active Power Loads, Mounika Chava

Masters Theses

"High penetration of renewable energy resources such as rooftop solar photovoltaic (PV) systems is exacerbating violations of the voltage limits in power distribution networks. Existing solutions to these over-/under-voltage issues include tap-changing transformers and shunt capacitors. However, tap changers only allow voltage changes in discrete steps and shunt capacitors cannot handle over-voltage situations. To overcome these problems, this thesis proposes voltage control in a distribution system by adjusting active power loads. The proposed solution can be used for both under- and over-voltage cases at any levels of voltage adjustment. First, the active power that needs to be adjusted at selected …

An Investigation Of Plugging And Increasing Oil Recovery In Sandstone Porous Media By Micrometer-Size Particle Gel, Haifeng Ding

Masters Theses

"Micrometer-size particle gel (microgel) has been developed and successfully applied to improve conformance in mature reservoirs. However, quite few researches have been published to address on their effect on oil recovery and rock permeability modification.

This work conducted a series of core flooding experiments to investigate the injectivity, plugging efficiency and improving oil recovery potentials of a couple of microgels synthesized in our lab.

First, this work studied the impact of permeability and crosslinker concentration on PAM type microgel treatment. Results shows that microgel treatment would have a less plugging efficiency in lower permeability rocks, which could be caused by …

Sensitivity Analysis Of Geomechanical Parameters In A Two-Way Coupling Reservoir Simulation, Hector Gabriel Donoso

Masters Theses

"Currently reservoir simulators model geomechanical effects such as compaction, subsidence, fault reactivation, breach of the seal integrity, etc. using only the rock compressibility to change the pore volume. However, rock compressibility as a scalar quantity is unfit to represent the true rock mechanics in the reservoir. In order to accurately represent geomechanical effects in a reservoir simulation, a two-way coupling simulation of the stress analyzer and the reservoir simulator was done. Based on the poroelasticity theory during the production or depletion of the reservoir the porosity and permeability changed due to the stress or pore pressure changes.

A sensitivity analysis …

Characterization Of Electric Solid Propellant Pulsed Microthrusters, Matthew Scott Glascock

Masters Theses

"Electric solid propellants are an attractive option for space propulsion because they are ignited by applied electric power only. In this work, the behavior of pulsed microthruster devices utilizing such a material is investigated. These devices are similar in function and operation to the pulsed plasma thruster, which typically uses Teflon as propellant. A Faraday probe, Langmuir triple probe, residual gas analyzer, pendulum thrust stand and high speed camera are utilized as diagnostic devices. These thrusters are made in batches, of which a few devices were tested experimentally in vacuum environments. Results indicate a plume electron temperature of about 1.7 …

Single Phase Gas Flow Response Of Fractured Horizontal And Vertical Wells To Repeated Production, Divya Kandlakunta

Masters Theses

"Historically, the conventional approach to well production has been to produce continuously, minimizing interruptions to flow insofar as possible. Yet some operators have observed improved well flow rates and ultimate recovery after a significant well shut-in periods. These production increases have not been documented. This study investigates the production impact of cyclic production/shut-in on fractured vertical and horizontal gas well performance.

A numerical reservoir model in Stimplan software was used to model production in fracture stimulated vertical and horizontal gas wells. Reservoir permeability is varied over a range of 0.0001 md to 1 md, and the shut-in period was varied …

Studies On Flocculation Of Fine Mineral Tailings Using Novel Polyacrylamide Based Polymer, Simin Khatibi

Masters Theses

"One of the important features in managing or treating sulfide fine tailings is separating solids from liquid by settling test. This thesis presents results of studied conducted on flocculation of Kaolin suspensions (a model tailings) and sulfide mineral tailings. Two polymers (PAM and Al-PAM) were tested as flocculants. The zeta potential value of slurries was measured by Nano Zetasizer device.

Al-PAM was found to be more effective for flocculation of kaolinite samples and also sulfide samples while PAM with used concentration was not. This study represents the power of flocculation as a possible solution to deal with industrial tailings"--Abstract, page …

Using Eye-Tracking To Understand User Behavior In Deception Detection System Interaction, Prashanth Kumar Lakkapragada

Masters Theses

"This research presents the analysis of data collected using eye-tracking devices on user interaction with a deception detection system. The differences between two groups of subjects, namely Innocent and Guilty, were compared, where Innocent subjects did not carry any explosive and hence, had nothing to hide in declaring objects that they were carrying whereas Guilty subjects had to lie to deceive the system. The results indicate that there is no significant difference in pupil dilation between the Innocent and Guilty subjects. However, the amount of fixations on the empty spaces of slides containing an explosive image can be used to …

Protection Of A 138/34.5 Kv Transformer Using Sel 387-6 Relay, Aamani Lakkaraju

Masters Theses

"Schweitzer Engineering laboratories (SEL) donated the SEL 387, SEL 311L, and SEL 351S relays and the SEL AMS to Missouri University of Science and Technology. This thesis documents the demonstration approach to set the SEL 387 relay to protect a grounded wye-grounded wye transformer and then test these settings by injecting fault currents into the relay using the SEL AMS. This thesis explains the approach to set the differential element of the SEL 387 relay to protect a transformer against internal faults and the overcurrent element of the SEL 387 relay to protect transformer against external faults. A radial power …

Periclinal Folding In Ozark Plateau: A Record Of Local Karst Collapse Or Regional Tectonic Forces?, Chao Liu

Masters Theses

"The Ordovician Rubidoux Formation of the Ozark Plateau, Missouri is typically identified as mechanically competent sub-horizontal beds of medium grained sandstone. North of Licking, MO, the Rubidoux Formation was deformed into a series of dome-and-basin shaped buckle folds, exposed in road cuts over a distance of ~10 km. Such folds are highly unusual within the Ozark Plateau and their origin remains controversial. Three major hypotheses have been proposed based on field observations and stereographic analysis. Given the pervasive distribution of karst collapse throughout Missouri, one hypothesis to explain these folds is that the Roubidoux Formation sagged into collapsed caverns. A …

Study And Development Of Robust Preformed Particle Gels For Conformance Control, Yifu Long

Masters Theses

"To improve the oil recovery of mature reservoirs, technologies referring to conformance control have been widely developed and implemented. Among various technologies, preformed particle gel (PPG) treatment has attracted increasing attentions. PPGs, as a kind of deformable plyometric superabsorbent, could be pumped through injection wells as plugging agents to block the fracture or high-permeability zone in a reservoir.

In decade usage of PPGs, an intensively employed material is poly(acrylamide) (PAM) based hydrogel. However, conventional PAM gel did reveal deficient in formidable conditions, such as formations with high temperature and high salinity. Therefore, a novel PPG based on starch-grafting-poly(acrylamide)/nano-composite (SAC) hydrogel …

Origin Of Lacustrine Carbonate-Dominated Clinoforms In The Lower-Permian Lucaogou Low-Order Cycle, Southern Bogda Mountains, Nw China, Yiran Lu

Masters Theses

"Lacustrine carbonate clinoforms deposit can reflect ancient lake condition like paleoclimate and lake type. Complex lithofacies of a carbonate-dominated clinoform package in lower Permian Lucaogou low order cycle, Bogda Mountains, NW China, provide clues on clinoform-forming processes in a half-graben lake. The clinoform package is ~5.2 m thick, prograding from S to N for ~200 m with a maximum 15o dip angle, and spans ~4 km laterally. A clinoform consists of a lower siliciclastic-rich and an upper carbonate-rich beds, forming a clinoform cycle. Results of petrographic study of 30 thin sections suggest that the clinoform package is composed of mixed …

Hidden Markov Model Based Non-Intrusive Load Monitoring Using Active And Reactive Power Consumption, Paulomi Nandy

Masters Theses

"This work presents a residential appliance disaggregation technique to help achieve the fundamental goal in Non-Intrusive Load Monitoring (NILM) problem i.e. simple breakdown of energy consumption based on the appliance type in a household. The appliances are modeled using Hidden Markov Model by utilizing both their active and reactive power consumption data. The data was recorded by attaching Power Standards Lab PQube measurement device to the appliances. Granularity of the power readings of the disaggregated appliance matches with that of the reading collected for individual device. The accuracy of the model is compared with other models developed using only active …

Surface Modification Of Tin Oxide Nanoparticles By Atomic Layer Deposition For Enhanced Electrochemical Performance, Sai Abhishek Palaparty

Masters Theses

"Atomic Layer Deposition is a robust technique used to deposit high quality, conformal, and size-tunable ultrathin films on a substrate. This technique can be used to coat protective films on battery anode and cathode materials for enhanced performance. In the case of cathodes, the ultrathin film provides a protective barrier preventing cationic dissolution. In the case of anodes, the film acts as a supporting matrix reducing strain caused by volume expansions. In these study, we use this technique to coat an optimally thick conductive iron oxide film on tin oxide particles to improve its electrochemical performance at high current densities …

Development And Testing Of A Fracture Energy-Based Model Of Explosive Asteroid Deflection, James A. Veerkamp

Masters Theses

"While asteroid deflection has been studied for the past half century, efforts have generally been directed towards methods that attempt to minimize disruption of the rock body. In order to widen the base of research, a fracture energy-based model of asteroid fragmentation was developed and applied to both asteroid scale and lab testable scale cases. Modeling of the orbital case suggests the capability to deflect a 100 meter diameter asteroid on a 10 year timescale. The model's predicted energy transfer is then compared to laboratory testing using a ballistic pendulum. The results of this testing suggest that the model as …

Data Analysis For Driving Pattern Identification And Driver's Behavior Modeling In A Freeway Work Zone, Hari Narayanan Vijaya Raghavan Nadathur

Masters Theses

"A variety of methods are used by Departments of Transportation (DOT) for informing drivers about upcoming work zones. One such method is work zone signage configuration. Signage plays an important role in work zones to provide guidance to drivers when conditions on the road vary from normal. Therefore, it is necessary to evaluate the effectiveness of different configurations, by law, before implementation of new signage designs that deviate from the national standards.

The Manual on Uniform Traffic Control Devices (MUTCD) is a compilation of national standards for all traffic control devices, including road markings, highway signs, and traffic signals. In …

Design Of An Adaptive Force And Stiffness Controlled Compliant Device For Robotic Polishing, Mohammad Masud Parvez

Masters Theses

"Polishing is a repetitive task done in an unhealthy environment. Often more than half of the manufacturing time is required to polish a die. The manual polishing process is a tedious work actively rely on a skilled human worker. Industrial Robot has replaced the human in performing these tasks. For robotic polishing to control the polishing force, an active compliant device is used. Due to the compressibility of air, a pneumatic system is preferred as the actuator of the device. The force of the actuator is controlled by regulating air pressure in both chambers of the cylinder. However, to improve …

Reduction Of Emi Due To Common Mode Current Using Common Mode Filter Or Lossy Material, Qian Liu

Masters Theses

"This thesis consists of four papers. In the first paper, two new common mode filter structures were designed, fabricated, and measured. A "sandwich-type" EBG structure that resonates at the desired filter frequency is designed to suppress common mode filter on differential signals. The new filters are placed on top of the PCB as a surface-mount component, instead of being implemented within the PCB stackup. The total radiated power (TRP) of the implemented filter is investigated and discussed. RF absorbing material and traditional shielding are considered to reduce the TRP.

In the second paper and third paper, new PCB-embedded common mode …

Knowing When Not To Fight, David Luban

Georgetown Law Faculty Publications and Other Works

Should military personnel (“soldiers”) become selective conscientious objectors to an unjust war? This chapter argues, first, that in most cases the fog of war and politics makes it unreasonable to expect soldiers to make fact-intensive judgments about whether the war is just. Second, it argues that even a justwar tribunal, of the sort proposed by Jeff McMahan, will not do the job. It will inevitably lack the legitimacy and fact-finding capacity necessary to reassure soldiers in such a weighty decision. Third, the moral importance of maintaining civilian control of the military means that soldiers should generally obey orders to deploy. …

Pay It Forward? Law And The Problem Of Restricted-Spending Philanthropy, Brian Galle

Georgetown Law Faculty Publications and Other Works

American foundations and other philanthropic giving entities hold about $1 trillion in investment assets, and that figure continues to grow every year. Even as urgent contemporary needs go unmet, philanthropic organizations spend only a tiny fraction of their wealth each year, mostly due to restrictive terms in contracts between donors and firms limiting the rate at which donations can be distributed. Law has played a critical role in underwriting and encouraging this build-up of philanthropic wealth. For instance, contributors can typically take a full tax deduction for the value of their contribution today, no matter when the foundation spends their …