Digital Commons Network^™

Integrated Circuits For Programming Flash Memories In Portable Applications, Mir Mohammad Navidi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Smart devices such as smart grids, smart home devices, etc. are infrastructure systems that connect the world around us more than before. These devices can communicate with each other and help us manage our environment. This concept is called the Internet of Things (IoT). Not many smart nodes exist that are both low-power and programmable. Floating-gate (FG) transistors could be used to create adaptive sensor nodes by providing programmable bias currents. FG transistors are mostly used in digital applications like Flash memories. However, FG transistors can be used in analog applications, too. Unfortunately, due to the expensive infrastructure required for …

Laser And 3-Dimensional Printers: Characterizing Emissions And Occupational Exposures, Alyson R. Johnson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: Toxicology and epidemiology studies have observed an association between ultrafine particles (UFPs) and respiratory, cardiovascular, and neurological health effects. While there is a paucity of data in the literature on the potential toxicity and health effects from indoor UFP exposure, more exposure assessment studies and research evaluating the efficacy of controls is merited. An increased demand for efficiency, productivity, and manufacturing has led to conception of laser and 3- dimmensional (3-D) printers in various indoor workplaces. The indoor environment is one of the most important determinants of personal exposure. Introducing laser and 3-D printers to indoor workplaces, introduces a …

The Principles And Rhetoric Of Autarky: Debate And Decision-Making In Early Colonial Kenya, Ian Michael Ferguson

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study seeks to understand the decision-making process of the colonial government of the East Africa Protectorate by articulating the principles of autarky: financial independence, development, and effective occupation. The principles of autarky, which are both goal and process for the colonial government, strove to bring that government to a state of self-sufficiency, or autarky. These principles created their own rhetoric within official correspondence which dominated the decision-making process. By looking at three different periods, Foreign Office control, the transition to Colonial Office responsibility, and the Soldier Settlement Scheme of 1919, the importance of the principles and rhetoric of autarky …

Cortactin Phosphorylation By Casein Kinase 2 Regulates Actin Related Protein 2/3 Complex Activity And Invadopodia Function, Steven Michael Markwell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Malregulation of the actin cytoskeleton enhances tumor cell motility and invasion. The actin-binding protein cortactin facilitates branched actin network formation through activation of the actin-related protein (Arp) 2/3 complex. Arp2/3 complex activation is responsible for driving increased migration and extracellular matrix (ECM) degradation by governing invadopodia formation and activity. While cortactin-mediated activation of Arp2/3 complex and invadopodia regulation has been well established, signaling pathways responsible for governing cortactin binding to Arp2/3 are unknown. In this dissertation we identify casein kinase (CK) 2α phosphorylation of cortactin as a negative regulator of Arp2/3 binding. CK2α directly phosphorylates cortactin at a conserved threonine …

Explanatory And Causality Analysis In Software Engineering, Yasser Ali Alshehri

Graduate Theses, Dissertations, and Problem Reports (ETD)

Software fault proneness and software development efforts are two key areas of software engineering. Improving them will significantly reduce the cost and promote good planning and practice in developing and managing software projects. Traditionally, studies of software fault proneness and software development efforts were focused on analysis and prediction, which can help to answer questions like `when’ and `where’. The focus of this dissertation is on explanatory and causality studies that address questions like `why’ and `how’.

First, we applied a case-control study to explain software fault proneness. We found that Bugfixes (Prerelease bugs), Developers, Code Churn, and Age of …

Instrumentation And Inertial Navigation Systems Design For Tensegrity Robot Implementations, Scott Edward Harper

Graduate Theses, Dissertations, and Problem Reports (ETD)

One of the major challenges faced when developing missions for the exploration of planetary bodies is the risk these terrains pose on the science platform when using a traditional lander or wheeled rover. One means of developing platforms to traverse these harsh terrains is to utilize mobility systems comprised of tensegrity structures. These structures have the capacity to distribute loads across a network of axially loaded members such that they can be constructed in a very lightweight manner and morph their geometries when required. In literature, there has been significant progress in simulated environments to utilize tensegrity structures as mobility …

Resilience Modeling Of Surface Transportation System In Mixed Traffic Environment, Shofiq Ahmed

Graduate Theses, Dissertations, and Problem Reports (ETD)

Large-scale natural disasters challenge the resilience of surface transportation system. The objective of this research was to develop a resilience model of surface transportation system in mixed-traffic environment considering varying Connected and Automated Vehicle (CAV) penetration scenarios. As deployment of CAVs are expected to improve traffic operations, a resilience model was developed in this research to evaluate the resilience performance of a transportation system with several CAV penetration levels (0%, 25%, 50%, 75% and 100%) for a given budget and recovery time. The proposed resilience quantification model was applied on a roadway network considering several disaster scenarios. The network capacity …

Integrating Microscale Enzyme And Lectin Reactions Using Nanogel Assisted Capillary Electrophoresis, Srikanth Gattu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Protein glycosylation is one of the most prevalent post-translational modifications which plays an important role in determining the structure, stability, and function of proteins. Changes in glycosylation patterns are a hallmark of cancer and other diseases. Characterizing glycosylation is difficult because these structures vary in their linkage and monomer sequence, which gives rise to vast microheterogenity that could affect the function of the molecule. A novel method using capillary gel electrophoresis by integrating microscale enzymes and lectin reactions in the capillary was developed to verify glycan structure by analyzing monosaccharides. Capillary electrophoresis (CE) improves upon conventional methods of glycan structure …

Development Of Oxide-Dispersion-Strengthened Nickel-Based Super Alloy Powders For Additive Manufacturing, Sizhe Huang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Oxide-Dispersion-Strengthened (ODS) Nickel-Based superalloy has been drawn a huge attention and developed with good oxidation resistance, corrosion resistance and high creep strength. It has been considered as critical materials for Additive Manufacturing (AM). The quality and the efficiency of fabrication methods of ODS limits the performance of itself on AM. The development of new type of ODS, new methodologies and evaluation techniques are required if the enhanced quality of ODS and enhanced efficiency of fabrication are to be achieved. Of the current fabrication techniques for AM, Gas Atomization (GA) is widely used since they can generate spherical powders with high …

Midterm 2018 And Targeting Latino Community Through Misinformation And Disinformation Online, Manjul Shrestha

Graduate Theses, Dissertations, and Problem Reports (ETD)

How has the Latino community been targeted by digital propaganda during the 2018 midterm elections in the US? How might this affect their involvement in and around the election? This thesis starts to answer these questions through a data analysis on two of the most prominent and popular social media platforms for political discussion: Twitter and Reddit. This study analyzed people’s posting patterns over time, the digital traces of the individuals pushing the majority and most popular content, and Latino candidates’ interaction on Twitter. This research provides evidence that on Twitter there are two main actors discussing Latinos and politics: …

On Designing An Ecg-Based Intelligent System: Utilizing The Heart’S Electrical Activity To Recognize Humans And Detect Arrhythmia, Sara Saeed Abdeldayem

Graduate Theses, Dissertations, and Problem Reports (ETD)

The electrocardiogram (ECG) signal is the bioelectrical signal that reflects the heart's activity. It has been extensively used as a diagnostic tool since it holds information about the cardiac health condition. However, recent researches have shown that it exhibits an inter-subject variability property. Therefore, it can be used as a biometric-based modality for either identification or verification purposes. Nevertheless, some of the challenges are faced while employing such a signal. For instance, ECG signal is prone to noise, accordingly, noise filters should be designed to remove the noise while keeping the signal properties. Moreover, factors such as medications, health condition, …

An Experimental Investigation Of The Cooling System For A Free Piston Stirling Engine, Akshay Milind Gupte

Graduate Theses, Dissertations, and Problem Reports (ETD)

Free-Piston Stirling Engine (FPSE) has been identified as a good candidate for combined heat and power application (CHP). FPSE being highly efficient and environmentally friendly promises to facilitate the increasing demand in waste heat energy recovery systems. FPSE system consists of three important components: (1) hot side heat exchanger; (2) regenerator; and (3) cold side heat exchanger. The cold side heat exchanger is a crucial part as it enables to maintain an optimal temperature of the working fluid by rejecting heat.

This research contributes to the design of heat exchanger test rig and experimental measurement of cooling heat exchanger. The …

Design And Evaluation Of Novel Attitude Estimation System Using Mems Sensors For Indoor Uas, Joshua Bruce Milam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Most small unmanned aerial systems in use today, employ extended Kalman filter sensor fusion algorithms in order to provide accurate estimations of attitude or orientation. These complex algorithms use measurements from GPS receivers and magnetometer sensors that can be rendered useless in GPS denied environments or areas of significant magnetic interference, such as inside buildings or other structures. The complexity of these algorithms makes them inaccessible for some researchers and hobbyists who wish to code their own attitude estimation algorithms. This complexity is also computationally expensive and requires processors that are powerful enough to operate the algorithms along with any …

Parametric Study Of Coal Liberation Behavior Using Silica Grinding Media, Adewale Wasiu Adeniji

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study evaluates the coal liberation behavior using silica as the grinding media by assessing the effects of four operating factors including nominal feed size, media size, shaft speed and grinding time, each of three levels on two response variables, the product P₈₀ and the specific energy. The coal material used in this study was mixed-phase particles commonly referred to as middlings, sampled from dense medium circuit at the Leatherwood preparation plant in Kentucky. One-third fractional factorial design of resolution III was implemented. Since silica was obtained in three standard size ranges as per manufacturer’s design, media size was …

Thermal-Fatigue And Thermo-Mechanical Equivalence For Transverse Cracking Evolution In Laminated Composites, Javier Cabrera Barbero

Graduate Theses, Dissertations, and Problem Reports (ETD)

Carbon fiber reinforced plastics (CFRP) are potential materials for many aerospace and aeronautical applications due to their high specif strength/weight and a low coeffcient of thermal expansion (CTE) resulting in a high long-term stability. Among candidate structures, the re-entry reusable launch vehicles (RLV), the fuel oxidant storage and transportation at cryogenic temperature, space satellites, and aircraft structure (frame, wings, etc...) can be highlighted. However, CFRP are prone to internal damage as a result of high residual stresses and thermal fatigue loading. In this study, micro-cracking damage evolution in laminated composites subjected to monotonic cooling and thermal cyclic loads is developed …

Investigation Of Combustion Characteristics Of A Heavy-Duty Diesel Engine Retrofitted To Natural Gas Spark Ignition Operation, Jinlong Liu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The conversion of existing diesel engines to natural-gas spark ignition operation by adding a gas injector in the intake manifold for fuel delivery and replacing the diesel fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. As the conventional diesel combustion chamber (i.e., flat head and bowl-in-piston) creates high turbulence, the engine can operate leaner, which would increase its efficiency and reduce emissions. However, natural gas combustion in such retrofitted engines presents differences compared to that in conventional spark ignited engines. Subsequently, the main goal …

Characteristics Of Activated Carbons Produced From Herbaceous Biomass Feedstock, Oluwatosin Jerry Oginni

Graduate Theses, Dissertations, and Problem Reports (ETD)

Energy security and environmental protection are at the forefront of research due to the forecasted depletion of fossil fuel reserves and the growing concern of its adverse environmental impacts. The use of renewable sources for energy applications has centered on the use of biomass feedstocks and this include from herbaceous, woody, agricultural waste, forest residues and municipal wastes. The thermochemical conversion (pyrolysis) of these biomass feedstocks has potential to produce liquid fuel, a solid residue (biochar) and non-condensable gas. The biochar is primarily composed of renewable porous carbon and other inorganic compounds. The biochar is used for soil amendment, adsorption …

Differentiating Human Populations Based On K-Mer Classification Of Hand Bacteria, Thrisha Doppala

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bacterial communities found in and on the human body are not only used in studying human health conditions but are also effective in differentiating individuals due to their distinct profiles. Human palm regions harbor relatively more diverse bacterial communities and are indicative of population groups, life styles, geographic locations, age groups and health conditions. Sequences extracted from hypervariable region V3 of the 16S rRNA bacterial gene of hand bacterial samples from 9 different population groups were classified into Operational Taxonomic Units (OTU) with GreenGenes reference taxonomy using RDP (Ribosomal Database Project) classifier. Frequencies of identified OTUs were used to study …

Detection Of Buried Non-Metallic (Plastic And Frp Composite) Pipes Using Gpr And Irt, Jonas Kavi

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research investigated alternative strategies for making buried non-metallic pipes (CFRP, GFRP, and PVC) easily locatable using Ground Penetrating Radar (GPR). Pipe diameters up to 12" and buried with up to 4 ft. of soil cover were investigated. The findings of this study will help address the detection problem of non-metallic pipelines and speed the adoption of composite pipes by the petroleum and natural gas industry. The research also investigated the possibility of locating buried pipes transporting hot fluids using Infrared Thermography (IRT).

Results from the study have shown that, using carbon fabric and aluminum tape overlay on non‑metallic pipes …

Roofing Practices And Fall Prevention In The Construction Industry, Hadi A. Shishtar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Roofing is an important profession in the construction industry yet there is a lack of understanding of its safeness. It is generally believed that roofing is an occupation that can be easily practiced by anyone. However, there are many key factors that are associated with roofing, which may impact the lives of roofers who often face major risks at work. According to the Occupational Safety and Health Administration (OSHA), roofing is one of the leading causes of falling deaths among construction workers. The Bureau of labor statistics has reported that roofers are highly exposed to non-fatal injuries. They have also …

The Determination Of The Concrete Tensile Creep At Early Age Using The Ring Test, Tadamon Mohammed

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, the modified double power law (MDPL) model is used to determine the tensile creep of concrete at an early age based on the ASTM C1581 restrained shrinkage ring test. Three concrete mixes using Ordinary Portland Cement (OPC) were tested. The three concrete mixes were cast, and each underwent the ring tests up to cracking. Mechanical properties of concrete at the age of 1, 3, 7, 14, and 28 days were tested to find the compressive strength, tensile strength and Young’s Modulus of concrete. The strength tests results were obtained from both 4x8 inch and 6x12 inch cylinders. …

Habitat Suitability Of Restored Wetlands And An Investigation Of Sampling Bias For Freshwater Turtles In West Virginia, Alissa L. Gulette

Graduate Theses, Dissertations, and Problem Reports (ETD)

Loss and drainage of wetlands in the United States has been remediated in part by wetland restoration on agricultural lands through the Agricultural Conservation Easement Program (ACEP), operated by the Natural Resources Conservation Service. Freshwater turtles are important components of wetland ecosystems, where they contribute to nutrient cycling, storage, and transfer between terrestrial and aquatic systems, and function as apex predators. In 2016 and 2017, we investigated use of wetlands restored through the ACEP program in West Virginia by two common freshwater turtle species, snapping turtles (Chelydra serpentina) and painted turtles (Chrysemys picta), and obtained comparative data from reference wetlands. …

Effects Of Reinforcement Rate On The Aversive Function Of Timeout From Positive Reinforcement, Cory Whirtley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Although the use of timeout from positive reinforcement is widespread and has been shown to be an effective punisher in clinical settings, the factors responsible for its effectiveness are not fully understood. The present experiment was designed to evaluate one of these factors, the reinforcement rate underway during periods of time-in. Rats’ lever pressing was maintained on variable-interval schedules of food reinforcement in a multiple schedule with two components. In one component, no timeouts were delivered. In the other component, when a variable-ratio schedule was met, lever presses were followed by a 30-s timeout during which a tone sounded, the …

Remotely Sensed Hydroclimatic Variability For Water Security In An Agricultural Basin, Ashish Kondal

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Indus Basin has supported agricultural practices since the Harappan civilization (3000-1500 BC). Abundance of water has always supported agriculture in the region and built the Indus Basin as one of the major agriculture based economies of the world. The obvious dependency of agriculture on weather and the vagaries of climate emphasizes the necessity of a comprehensive hydro-climate study of the region. The role of climate change in the Indus Basin has always been a contentious issue. Groundwater depletion is evident in the region, and its steady and alarmingly declining rate has brought concerns for the future of agriculture in …

Spatial And Temporal Analysis Of Surface Water Quality In Relation To Marcellus Shale Gas Development In The Northern Panhandle Of West Virginia, Rachel Yesenchak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pre-existing water chemistry data available from the West Virginia Department of Environmental Protection were used to examine temporal changes in surface water quality related to the onset of Marcellus Shale gas drilling activity in the state of West Virginia. Drilling is concentrated in the northwestern portion of the state. Watersheds were delineated for twelve discrete stream sampling locations in the Upper Ohio-Wheeling HUC-8 sub-basin, where shale gas drilling is prevalent. Kruskal-Wallis tests were deployed to compare pre- and post-drilling concentrations of conductivity, chloride, and total suspended solids for each location. Increased concentrations of these parameters are associated with surface water …

Analysis Of The Gas Production From Marcellus Shale Horizontal Wells Using Decline Curves, Dalal Alsaadoun

Graduate Theses, Dissertations, and Problem Reports (ETD)

Many challenges present themselves when production is being forecasted in ultra-low permeability unconventional reservoir systems. Some of the major challenges are the lack of understanding of the interaction among the fluid flow, the hydraulic fracturing, the reservoir characteristics in these complex systems, and the limited production history. Therefore, the production performance of the shale gas wells over the longer time periods has not been established. A familiar technique for predicting the future production rates, when the only available data are past production rates, is Decline Curve Analysis (DCA). Several DCA methods have been proposed for shale wells, but their application …

Design And Optimization Of A 1 Kw Stirling Engine, Garrett Tyler Rinker

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stirling engines are often overlooked as a means of energy conversion, though its versatility offers many advantages. Since it is an external combustion engine, it can be supplied with heat through the combustion of a variety of fuels. Its maintenance- and degradation-free aspects, as well as its excellent turn down ratio, make it a suitable candidate for applications such as remote power generation, combined heat and power (CHP), cryogenics, solar power, and even space exploration. The continual advancement of additive manufacturing (AM) offers opportunity to potentially further improve the already efficient Stirling cycle. This dissertation presents the design and optimization …

Application Of Artificial Intelligent Predictive Modeling For Completion Optimization And Refracture Candidacy, Daniel Yingling

Graduate Theses, Dissertations, and Problem Reports (ETD)

Unconventional reservoirs are full of uncertainty when dealing with conventional methods of modeling and analysis. The objective of this work is to use a trained artificial intelligent (AI) model to compare actual production data to AI predicted possible well production. Data-driven models based on AI are efficient tools for optimizing the production, stimulation, and completion design of wells and can be very beneficial when determining the success or failure of wells based on production. An AI model for production predictions require both native and design parameters, which include well characteristics, completion design, and stimulation design parameters.;Data from over 100 Marcellus …

Three-Dimensional Numerical Modeling Encompassing The Stability Of A Vertical Gas Well Subjected To Longwall Mining Operation - A Case Study, Bonaventura Alves Mangu Bali

Graduate Theses, Dissertations, and Problem Reports (ETD)

Longwall mining has been one of the prominent underground mining methods for extracting coal in the United States for many years due to its production efficiency. However, the method itself can possibly cause problems to surface structures, i.e. gas wells, buildings, roads, etc., that are built or located nearby mining operations. In recent years, significant gas resources have been identified to be located underlying coal deposits, particularly in Southwestern Pennsylvania, West Virginia, and Ohio. As a result, within the time frame of the last 10 years, more than 800 gas well have been drilled through active and future underground longwall …

Wetland Characteristics And Wintering Passerellidae Occupancy On Agricultural Conservation Easement Program Wetlands In West Virginia, Katharine Lewis

Graduate Theses, Dissertations, and Problem Reports (ETD)

Wetland ecosystems are unique, important sources of numerous services such as wildlife habitat. Their widespread loss due to drainage and development in North America has promoted the creation of many programs and policies to try to reverse the damage done. One such program is the Agricultural Conservation Easement Program (ACEP). ACEP is administered through the Natural Resources Conservation Service (NRCS) and provides landowners with technical and financial assistance to restore wetlands on private agricultural land. One of the primary objectives of ACEP is to provide wildlife habitat while restoring wetlands in agricultural areas. It is important to monitor conservation practices …