Digital Commons Network^™

Shear Behavior Of Reinforced Fly Ash-Based Geopolymer Concrete, Noor S. Yacob

Masters Theses

"The geopolymerisation of aluminosilicate materials such as fly ash has been a radical change in construction material's chemistry and composition, compared to the portland cement-based concrete calcium silicate-hydrate chemistry. The adoption of fly ash in concrete industry is a good use of by-product ashes to reduce emissions of the greenhouse gas implicitly. However, in this research, the replacement of portland cement by fly ash is 100%, which makes it a zero-cement concrete with no proprietary chemical additives.

Geopolymer concrete (GC) is a revolutionary synthetic material that combines sustainability and high engineering properties, and it is relatively cost-effective compared to portland …

Biodegradable Electronic And Optical Devices Toward Temporary Implants, Md Shihab Adnan

Masters Theses

"Implantable biomedical devices have a high potential to revolutionize health care technologies in near future. Implantable devices can be classified as permanent prosthetic devices such as pacemakers or nerve stimulants and temporary devices for intermediate monitoring and control scenario which are still in research phase. In contrast to permanent device, temporary implants lose functionality and become unnecessary after intended operational lifetime which may pose serious electromagnetic and biomedical safety concern, latent complications at the implanted sites and possible ethical issues if not removed from body by an additional surgical operation.

The first paper of this thesis focuses on exploring the …

Mitigation Of Glass Weave Skew Using A Combination Of Low Dk Spread Glass, Multi-Ply Dielectric And Routing Direction, Kartheek Nalla

Masters Theses

"As the data rates increase into the multi-gigabit range, the bit periods fall in the range of few tens of picoseconds. At above few Gbps, it becomes very important to reduce skew between differential pairs as it can adversely impact the signal eye and thereby increase bit error rate. The goal of this study is to mitigate the skew contributed by woven glass fabric of PCB dielectrics.

The glass weave skew between differential pairs in a PCB occurs due to the difference in dielectric constants (DK) of glass and resin. This thesis aims to mitigate the skew by reducing the …

A Comprehensive Study Of Lost Circulation With Application In The South Rumaila Field, Iraq, Abo Taleb Tuama Al-Hameedi

Masters Theses

“Drilling mud losses and problems associated with lost circulation while drilling account for a major expense in drilling oil and gas wells. By industry estimates, more than 2 billion USD is spent annually to combat and mitigate this problem (Ali et al., 2015).

The South Rumaila field in Iraq is one of the largest oilfields in the world. Wells drilled in this field are highly susceptible to lost circulation problems when drilling through the Dammam, Hartha and Shuaiba formations. Lost circulation events range from seepage losses to complete loss of the borehole and are a critical issue in field development. …

Behavior Of Hollow-Core Composite Columns Under Torsion Loading, Sujith Anumolu

Masters Theses

"The effect of torsional loads could be significant along with axial and flexural loads on bridge columns during earthquake excitations. The present study presents the torsional behavior of hollow-core steel-concrete-steel columns (HC-SCS) and hollow-core fiber reinforced polymer-concrete-steel columns (HC-FCS). The HC-SCS comprises of sandwiched concrete shell between two steel tubes whereas in HC-FCS column, the outer steel tube of HC-SCS column was replaced by the FRP tube. Both columns have stay-in place permanent form-work to the concrete shell in the form of outer and inner tubes. The steel tubes serve as longitudinal and shear reinforcement to the column. Finite element …

Paleogeogra Detrital Zircon Geochronology Of Upper Cambrian To Lower Mississippian Siliciclastic Strata Of The Ozark Dome And Vicinity, Bing Li

Masters Theses

"Siliciclastic strata exposed in the Ozark Dome provide Late Cambrian to Late Cretaceous snapshots of an evolving paleogeology and regional to far-field tectonic events. U-Pb ages of detrital zircons from the arkosic base of the Upper Cambrian Lamotte Formation reflect first cycle derivation from the adjacent ca. 1.31-1.48 Ga Granite-Rhyolite province, with subsidiary input from ca. 1.6-1.7 Ga Mazatzal basement. Feldspathic arenites near the top of the Lamotte Sandstone also contain significant quantities of detrital zircon grains of these ages, with additional peaks centered at ca. 2.7 and ca. 1.1 Ga, signaling the onset of extra-regional detrital input most likely …

Late Ordovician Tectonism In The North American Midcontinent: Constraints From U-Pb Detrital Zircon Geochronology, Daniel Nathan Meehan I

Masters Theses

"Numerous sandstone filled depressions hosted in upper Cambrian to Middle Ordovociain dolostones in south-central Missouri have historically been identified as Pennsylvanian paleokarst structures. U-Pb detrital zircon geochronology is at odds the time of formation and sedimentological evidence challenges their classification. "Filled sink" deposits yield primary zircon age populations of 2.8-2.6 Ga (~50% of all analyzed grains), 1.2-1.1 Ga (~25%), 1.8-1.6 Ga (~15%) and 1.5-1.3 Ga (~10%). These zircon populations most likely originated from the Superior Craton and Midcontinent Rift and/or Grenville orogen, respectively. The Warrensburg and Moberly channel-fill sandstones of central Missouri were identified as good candidates for Pennsylvanian aged …

Pricing Of Geometric Asian Options In General Affine Stochastic Volatility Models, Johannes Ruppert

Masters Theses

"In this thesis, we look at the general affine pricing model introduced in [11]. This model allows to price geometric Asian options, which are of big interest due to their lower volatility in comparison to, for example, European options. Because of their structure and in order to be able to price these options, we look at the basic theory of Lévy processes and stochastic calculus. Furthermore, we provide the detailed description of the parameters of the pricing formulas for some popular specific single-factor stochastic volatility models with jumps and generalize the approach of [11] to multi-factor models"--Abstract, page iii.

Factors Influencing The Adoption Of Smart Wearable Devices, Apurva Adapa

Masters Theses

"This study aims to examine the factors and issues in adoption of smart wearable devices. Wearable devices have many functions to offer which make them very useful in our daily lives. However, factors influencing the adoption of these devices are not well understood. This research explores the inhibiting and contributing factors influencing the adoption of wearable devices by employing the laddering approach. Qualitative data were collected through in-depth interviews using the laddering technique in order to understand these factors. Wearable devices that were examined include the Smart Glass (Google Glass) and the Smart Watch (Sony Smart Watch 3). After the …

2d Seismic Data And Gas Chimney Interpretation In The South Taranaki Graben, New Zealand, Taqi Talib Alzaki

Masters Theses

"The Taranaki Basin is one of the major oil and gas producing basins offshore New Zealand. The study area covers an area of 10,000 km² in the basin, and includes 171 2D seismic lines and six wells, which are provided by the New Zealand Petroleum & Minerals. Some previous studies refer to the study area as the South Taranaki Graben.

This thesis provides detailed mapping and interpreted subsurface stratigraphy and structure of five horizons, i.e. basement top, Pakawau Group top, Kapuni Group top, Wai-iti Group top, and seafloor. It undertakes studies of the relation between the basin evolution, faults, …

Effect Of Cooperation On Players' Immersion And Enjoyment, Lakshmi Sushma Daggubati

Masters Theses

"This research examines the effect of cooperative versus non-cooperative game play on immersion and enjoyment in online games. It draws on the self-determination theory to generate the research hypotheses and explain the observed phenomenon. A within-subject experimental design (N=38) was used to evaluate the effects of cooperative versus non-cooperative game play on enjoyment and immersion by having participants play in a manipulated game mode in a controlled gaming environment. The participants' subjective responses were assessed to understand their user experience in cooperative and non-cooperative gaming environments. The results suggest that both immersion and enjoyment were significantly enhanced in cooperative game …

Aspen Simulation Of Oil Shale And Biomass Process, Anand Alembath

Masters Theses

"This thesis focuses on design and analysis of two major chemical processes using computer simulation which performs a steady state computation. The objective is to design processes using Aspen simulation to establish optimum operating conditions by performing various simulation runs which are challenging to execute at lab scale.

Increasing energy needs and decline of global oil prices has shifted our focus on commercially developing unconventional and renewable resources. Commercialization of any process relies on developing a process model that identifies different process parameters by performing a steady state mass and heat balance. Aspen simulation is considered an effective process modeling …

Tracking Silver, Gold, And Titanium Dioxide Nanoparticles Through Drinking Water Systems By Single Particle - Inductively Coupled Plasma - Mass Spectrometry, Ariel Renee Donovan

Masters Theses

"Single particle (SP)-ICP-MS methods were developed to characterize and quantify Ti-containing, titanium dioxide, silver, and gold NP concentration, size, size distribution and dissolved metal element concentration in surface water and treated drinking water. The effectiveness of conventional drinking water treatments (including lime softening, alum coagulation, filtration, and disinfection) to remove NPs from surface water was evaluated using six-gang stirrer jar test simulations. Six-gang stirrers were used to simulate drinking water treatments including lime softening, alum coagulation, powdered activated carbon sorption, filtration, and disinfection by free chlorine. Lime softening effectively removed most nanoparticles added. Source and drinking waters from three large …

Phytoforensics Tools: The Degradation And Detection Of Chlorinated Solvents In Integrated Systems, Tommy J. Goodwin Jr.

Masters Theses

"Due to decades of mismanaged pollutants entering groundwater, subsurface pollution of various compounds has become a widespread challenge. Chlorinated solvents are the most common groundwater contaminants that persist in aquifers, and remediation of these wide-spread plumes is difficult. Bioremediation, permeable reactive barriers, and phytoremediation are remedial technologies that have been developed and applied to chlorinated solvents in groundwater systems. This study integrates these technologies in different combinations to demonstrate the remediation potential of this approach. Zerovalent iron (ZVI) and bioaugmentation with a Dehalococcoides sp. (DHC) culture were applied separately and in combination for degradation of perchloroethene (PCE). Salix pentandra were …

Caseload/Workload Study Of Speech Language Pathologists In Missouri Public Schools, Jinyu Du

Masters Theses

"A survey was distributed to speech-language pathologists (SLPs) in Missouri public schools to obtain statewide information regarding caseload number, workload related activities and SLPs' level job satisfaction on various aspects of their job. An online questionnaire was sent to school-based SLPs in Missouri to solicit factual information on average monthly caseload numbers, factors that impact caseload assignments and the percentage of time spent on various professional responsibilities and job satisfaction ratings. Results indicated that 24% of the respondents had caseloads that exceeded the maximum state regulated caseload number for SLPs. Respondents were also largely unaware of the maximum caseload regulation …

Experimental Evaluations Of Selected Sealants To Remediate Co₂ Leakage, Aaron Jeffrey Blue

Masters Theses

"Carbon Dioxide (CO₂) sequestration into porous and permeable brine-filled aquifers is seen as one of the most feasible solutions for reducing the amount of greenhouse gases released into the atmosphere from coal-fired power plants. To safely store the CO₂, it must be trapped under an impermeable rock acting as a seal. One of the concerns with CO₂ sequestration is the generation of new fractures or reopening of existing fractures caused by CO₂ injection in the sealing formation. This project evaluates the potential of sealing these fractures by injecting sealing materials into them. These sealing …

An Imu-Based Spacecraft Navigation Architecture Using A Robust Multi-Sensor Fault Detection Scheme, Samuel J. Haberberger

Masters Theses

"Redundant sensor networks of inertial measurement units (IMUs) provide inherent robustness and redundancy to a navigation solution obtained by dead reckoning the fused accelerations and angular velocities sensed by the IMU. However, IMUs have been known to experience faults risking catastrophic mission failure creating large financial setbacks and an increased risk of human safety. Different fusion methods are analyzed for a multi-sensor network using cost effective IMUs, including direct averaging and covariance intersection. Simulations of a spacecraft in low Earth orbit are used to baseline a typical expensive IMU and compare the navigation solution obtained from a network of several …

The Mantle Transition Zone Beneath South America From Stacking Of P-To-S Receiver Functions, B. A. Goetze

Masters Theses

"The Mantle Transition Zone (MTZ) beneath South America is investigated with stacking of Receiver Functions (RFs) of converted P-to-S phases from the velocity discontinuities at 410 km (d410) and 660 km (d660). A total of 785 seismic stations provided 22,235 high quality RFs, allowing 1,717 MTZ thickness measurements in circular bins of 2⁰ radius. An apparent MTZ structure is derived using the IASP91 reference model, where the d410 mean depth is 409.1 km and the d660 is 661.5 km, and the mean MTZ thickness is 251.8 km. This model presents coherent depressions and uplifts of the discontinuities matching well known …

Imaging Reinforced Concrete: A Comparative Study Of Ground Penetration Radar And Rebarscope, Abhishek Kodi

Masters Theses

"Geophysical techniques have been playing a very vital role in subsurface imaging in the recent past. Technology has been making it both reliable and convenient to utilize non-destructive geophysics techniques like Ground Penetration Radar, Induction current based Rebarscope, Seismic methods, ERT, etc. The applications range from shallow subsurface investigation of Bridge decks to old tunnels, mapping of rabars in a pre-existing construction and analyzing the concrete strength.

The thesis constitutes of a comparative study and analysis of a Ground Penetration Radar system and a Rebarscope. Individual parameters obtained directly from the study and obtained indirectly from the study shall be …

Silicone Hollow Fiber Membrane Bioreactors For Mixed Aerobic And Anaerobic Treatment Of Gas Phase Toluene And Trichloroethylene, Alexander Lee Korff

Masters Theses

"Volatile Organic Compounds (VOCs) are common in effluent waste streams from many sectors of industry and low-cost emission control technologies have the potential to mitigate long-term impacts on the environment. Federal Regulations, such as the Clean Air Act and National Emission Standards for Hazardous Air Pollutants (NESHAPS), as well as state regulations are imposing stricter requirements on point-source emissions, with an emphasis on toxic VOCs. Trichloroethylene (TCE) and tetrachloroethylene (PCE), which are toxic VOCs, have been used since the 1920's for a variety of industrial applications like: degreasing, paint and printing operations, as extraction solvents, and for cleaning and drying …

Iron Phosphide Nanostructures As An Efficient Bifunctional Catalysts For Water Splitting, Nikitaa Ashokan

Masters Theses

"The first part of this thesis work focuses on developing a bifunctional catalyst for electrochemical water splitting encompassing both oxygen and hydrogen evolution. A highly efficient catalyst is necessary to improve kinetics of the sluggish four electron process for oxygen evolution reaction (OER) and two-electron process for hydrogen evolution reaction (HER). Recently, transition metal phosphides have gained increasing interest in this field because of their good electrical conductivity properties as well as better catalytic activity. Many transition-metal phosphides are being considered for this application and iron phosphide (FeP) has proved to be a good HER catalyst. In this work, we …

A Meta-Architecture Analysis For A Coevolved System-Of-Systems, George Anthony Muller Iv

Masters Theses

"Modern engineered systems are becoming increasingly complex. This is driven in part by an increase in the use of systems-of-systems and network-centric concepts to improve system performance. The growth of systems-of-systems allows stakeholders to achieve improved performance, but also presents new challenges due to increased complexity. These challenges include managing the integration of asynchronously developed systems and assessing SoS performance in uncertain environments.

Many modern systems-of-systems must adapt to operating environment changes to maintain or improve performance. Coevolution is the result of the system and the environment adapting to changes in each other to obtain a performance advantage. The complexity …

On The Double Chain Ladder For Reserve Estimation With Bootstrap Applications, Larissa Schoepf

Masters Theses

"To avoid insolvency, insurance companies must have enough reserves to fulfill their present and future commitment-refer to in this thesis as outstanding claims towards policyholders. This entails having an accurate and reliable estimate of funds necessary to cover those claims as they are presented. One of the major techniques used by practitioners and researchers is the single chain ladder method. However, though most popular and widely used, the method does not offer a good understanding of the distributional properties of the way claims evolve. In a series of recent papers, researchers have focused on two potential components of outstanding claims, …

Effect Of Sparse-Build Internal Structure On Performance Of Fused Deposition Modeling Parts, Shixuan Meng

Masters Theses

"Fused deposition modeling (FDM) technology has been used in additive manufacturing for years and is able to significantly reduce both manufacturing time and cost for production tooling and end-use parts. Autoclave molding is one of the conventional tools used to produce composite parts. In autoclave molding, the soft composite material is positioned on the molding tool, and then subjected to vacuum and elevated temperatures to facilitate the curing of the resin. With additive manufacturing (AM), it is possible to fabricate the molding tool with a sparse internal structure, thereby reducing the fabrication time and cost compared to a solid tool. …

The Impact Of Heat Exchanging Internals On Hydrodynamics Of Bubble Column Reactor, Ahmed Jasim

Masters Theses

"In this study, the impact of configuration and size of vertical heat exchanging internals in bubble columns on gas holdup, specific gas-liquid interfacial area, bubble chord length, and bubble rise velocity were investigated. Three different configurations of internals, each covering 25% of the column's cross-sectional area, were used to simulate the heat exchanging tubes utilized in the F-T process. The First configuration is a circular-like arrangement of 0.5 inch diameter vertical rods, whereas the second is a hexagonal-like arrangement of 0.5 inch diameter vertical rods. The third configuration is also a circular arrangement but of 1 inch diameter vertical rods …

Effect Of Build Parameters On Mechanical Properties Of Ultem 9085 Parts By Fused Deposition Modeling, Krishna Prasanth Motaparti

Masters Theses

"Additive manufacturing is a fabrication technique that is used to build components by depositing material in a layer-by-layer manner. Fused Deposition Modeling (FDM) is one of the additive manufacturing techniques which is widely used for prototyping and production applications of thermoplastic components. In load bearing applications, the flexural and compression forces often coexist. In order to avoid failure under these loads, it is essential to study the mechanical properties of the components fabricated by FDM. The main focus of this research is to study the mechanical properties of the fabricated components and to comprehend their dependence on various build parameters. …

Yik Yak Posts: A Discourse Analysis, Snehal Ravindra Shirke

Masters Theses

"Anonymity and geolocation create a unique environment for users to communicate with each other. Discourse analysis was conducted to study the posts made on Yik Yak, an anonymous social networking mobile application to understand the communication patterns on an anonymous platform and the posts about taboo topics. The posts were analyzed specifically for patterns on taboo topics and how students interact on the anonymous platform on a particular campus (Missouri S&T campus). Student research assistants coded the collected posts into the pre-defined taboo categories namely sexual activity, non-sexual bodily functions, sexual orientation, mental/emotional health, and "other" taboo topics. I found …

Esd Related Soft Error Detection And Root Cause Analysis, Suyu Yang

Masters Theses

"In this article, several methods are outlined for detecting functional changes in an IC due to external interference such as ESD or EMI. The goal is to provide diagnostic tools for detection of potential soft failure susceptibilities of complex systems during the hardware design stage without the aid of any complex software. After the soft errors are found, circuit modeling techniques are used to characterize the DUT. By running the circuit model, the soft error threshold can be predicted and the circuit model can be used to evaluate the performance of other ESD protection methods. In the end several methods …

Variable Stress Orientations In The Offshore Nile Delta: The Role Of Salt As A Mechanical Detachment Horizon, Weicheng Zhang

Masters Theses

"The offshore Nile Delta is characterized by variations of the maximum horizontal stress orientation in subsalt and supra-salt sequences. Margin-parallel SH, typical for tertiary deltas, is observed for regions that are below or do not contain evaporites. In sequences underlain by evaporates pre-dominantly margin-normal SH is observed. This observation yielded the first conclusive in situ evidence that salt acts as a mechanical detachment layer. In this study, 3D finite element analysis (FEA) is used to simulate the total stress distribution in the offshore Nile Delta featuring evaporate sequences. Several parameters such as different salt sequence geometries, friction coefficient on faults, …

Automated Channel Emulator Based On Mems Switch And Improvement Of Signal Transition, Jingdong Sun

Masters Theses

"Channel Emulator, which is widely used in communication system development, is an instrument that emulates the real-world signal propagation environment between transmitter and. [sic] To overcome the disadvantages of traditional channel emulator, we propose a novel structure of the automated channel emulator in Section 1, which can be controlled by software and integrated into auto-testing system. MEMS switch, with good RF performance, is used to connect and isolate multiple channels.

In Section 2, we divide the whole channel emulator system into Channel, Support, and Controller Board, and provide detailed design procedures with critical parameters of each board. The well-designed high …