Digital Commons Network^™

Determination Of Linear Attenuation Coefficients Of Chemically Bonded Phosphate Ceramics, Jason Joseph Pleitt

Masters Theses

"Chemically Bonded Phosphate Ceramics (CBPCs) is a composite based material formed in a manner similar to cements. CBPCs have shown to be a good structural material with excellent thermal resistance properties. They have also been shown to have potential as a radiation shield. By incorporating various powders into the ceramic the improvement in its radiation shielding properties are examined. The method for obtaining the linear attenuation coefficients for CBPCs as well as MCNP simulated results for gamma and neutrons are presented"--Abstract, page iv.

Effect Of Lipid Composition On The Physical Properties Of Liposomes: A Light Scattering Study, Rajiv Kumar Yandrapati

Masters Theses

"The aim of this study was to investigate the effect of lipid composition on the physical properties of liposomes. Eight different types of liposomes were prepared for this study. Liposomes consisting of phosphatidylcholine (PC) and cholesterol were prepared in three different compositions 80/20, 50/50 and 20/80 respectively. Similarly liposomes consisting of PC and negatively charged phosphatidylserine (PS) were also prepared in three different compositions 80/20, 50/50 and 20/80 respectively. Two liposomes with the compositions 2:2:1:1 (cholesterol:PC:phosphatidylglycerol (PG): phosphatidylethanolamine (PE) ) which resembles the myelin membrane and 10:5:7.5:16 (PC:PE:PS:cholesterol) which mimics rat's neural membranes were also prepared. The liposomes were prepared …

Unified Knowledge Model For Stability Analysis In Cyber Physical Systems, Tamal Paul

Masters Theses

"The amalgamation and coordination between computational processes and physical components represent the very basis of cyber-physical systems. A diverse range of CPS challenges had been addressed through numerous workshops and conferences over the past decade. Finding a common semantic among these diverse components which promotes system synthesis, verification and monitoring is a significant challenge in the cyber-physical research domain. Computational correctness, network timing and frequency response are system aspects that conspire to impede design, verification and monitoring. The objective of cyber-physical research is to unify these diverse aspects by developing common semantics that span each aspect of a CPS. The …

Operation Of The Aerodynamic Plasma Actuator At High Altitude, Timothy Glen Nichols

Masters Theses

"A plasma actuator was operated at altitudes from 0 to 18288 meters to determine the mechanisms leading to decreased force production at low pressures. The actuator was driven with a 5 kHz sine wave and a peak to peak voltage of 13.4 kV at pressures of 760, 429, 321, 226, and 88 Torr. A passive measurement technique called the capacitive V-dot probe was adapted to the actuator in order to resolve the spatiotemporal evolution of the surface potential and electric field on the dielectric surface. At low pressures up to 20 times more plasma is present than at atmospheric conditions. …

A Digitally Implemented Practical Photovoltaic Simulator With A Double Current Mode Controller, Jie Ang Zhao

Masters Theses

"This thesis presents a microcontroller- and DC-DC converter-based photovoltaic (PV) simulator which emulates the output characteristic of a PV module. The current-voltage (IV) characteristic of a PV module is implemented as a look-up-table that generates an output reference current based on a measured output voltage. The control mechanism is based on a double current mode controller that consists of a predictive current mode controller and a proportional-integral (PI) controller arranged in an inner loop and outer loop configuration. The PI controller is designed based on classical phase margin and gain margin criteria to ensure system stability. The performance of the …

How Should Plastic-Packaging Companies Apply Artificial Proofs And Topics Of Invention To Communicate Sustainability? : A Heuristic Developed On The Basis Of Rhetorical Analysis, Shristy Bashyal

Masters Theses

"This study examines how the ten plastic-packaging companies use artificial proofs and topics of invention to communicate sustainability-related information. The objective of this study was to answer the following research questions:

(i) Do plastic-packaging companies define sustainability on their website?

(ii) What are the strengths and weaknesses of the arguments in these companies' sustainability-related communications?

(iii) What invention strategies should technical marketing communicators use to communicate company's sustainable practices?

To answer these questions, I analyzed the sustainability-related documents available on the websites of the ten companies. On the basis of this analysis, I developed an invention heuristic that can be …

Investigation Of The Effects Of Shrinkage, Creep, And Abrasion On Self-Consolidating Concrete And High Volume Fly Ash Concrete For Use In Transportation Related Infrastructure, Brian Timothy Tucker

Masters Theses

"Concrete specimens were fabricated for shrinkage, creep, and abrasion resistance testing. Variations of self-consolidating concrete (SCC), high volume fly ash concrete (HVFA), and conventional concrete were studied. The results were compared to previous similar testing programs and used to determine the adequacy of the materials for use in practice. These two concrete variations offer significant benefits when used as replacements to conventional concrete. Because of the respective properties of both types of concrete, both economic and environmental benefits are achieved with the use of both. The lower labor costs of SCC and the lower material cost of HVFA lead to …

Statistical And Predictive Modeling Of Automated Meter Reading System Outages, Prasad Prabhakar Shinde

Masters Theses

"An Automated Meter Reading (AMR) system is a metering technology that enables power utility companies to receive customers' energy usage data centrally over a communication network. The installed automated meters also provide a daily log of outage events for each customer. A utility company can greatly benefit by using this information for outage management and to improve reliability. However, outage data is frequently corrupted and the outage flags registered by the customers' meters do not necessarily reflect true outages. This thesis focuses on developing methods to analyze outage data and building a model to identify good data versus spurious indications. …

Hydraulic Fracturing Experiments To Investigate Circulation Losses, Maximiliano Liberman

Masters Theses

"In recent years the oil and gas industry has been drilling more challenging wells due to long deviated wells, drilling through already depleted reservoirs, sub salt wells and increasing water depth. A major challenge these wells create is to prevent fluid loss into the formation and wellbore breakouts by having accurately determined the mud weight operational window. In addition to accurately determine the fracture gradient, additives in the drilling fluid have been used to enhance the fracture gradient in an industry process named wellbore strengthening. In order to study the phenomenon of fracture gradient alteration, a hydraulic fracturing apparatus was …

Thermal Modeling And Analysis Of Polymer Electrolyte Membrane Open Cathode Fuel Cells, Blanca Ollero Loranca

Masters Theses

"In the past decade renewable energies have increasingly become a commodity in everyday life. Because of their high power densities and their application versatility, fuel cells have stood out among other sources of renewable energy. In order to improve this technology as the needs for it increases, thermal modeling is an essential step. Researchers in the past have investigated the effect that temperature has on fuel cells. However, not much work has been done on the thermal dynamics of these devices and no one, to the authors knowledge, has studied the speed of response in thermal changes as a function …

Control Oriented Thermal Modeling Of Lithium Ion Batteries, Derek Brown

Masters Theses

"Lithium ion batteries have been widely used in consumer electronics and are beginning to move to the forefront of the automotive and power grid industries. Lithium ion batteries are desirable in these applications because they are high energy density and high specific energy cells, while remaining inexpensive and lightweight. Safety is a concern in every consumer application; therefore, in order for lithium ion battery use to continue growing, advances in battery management systems are needed. Thermal management of lithium ion batteries is currently a critical issue. Applications are becoming more dependent on active liquid thermal management systems. The development of …

Abel Dynamic Equations Of The First And Second Kind, Sabrina Heike Streipert

Masters Theses

"In this work, we study Abel dynamic equations of the first and the second kind. After a brief introduction to time scales, we introduce the Abel differential equations of the first and the second kind, as well as the canonical Abel form in the continuous case. Using the existing information, we derive novel results for time scales. We provide formulas for the Abel dynamic equations of the second kind and present a solution method. We furthermore achieve a special class of Abel equations of the first kind and discuss the canonical Abel equation. We get relations between common dynamic equations …

Electromagnetic Compatibility Of Integrated Circuit Clock Design, Vijay Kanagachalam

Masters Theses

"With advancements in technology, transistor sizes are shrinking resulting in reduced power supply voltage and thereby reduced noise margin which makes the devices susceptible to electromagnetic noises. The trend of integrating more circuits on a single die at ever growing operating frequency increases interference among circuits and with the outside world. In order to make circuits electromagnetically compatible, it is essential to reduce emissions from the circuit and understand the causes of failure due to interference of noise from other sources coupling into the circuit so that a robust design can be created.

Two topics are explored in this thesis. …

Investigation Of Geosteering In Non-Trivial Geological Settings, Anuroop Pandey

Masters Theses

"The well placement technology has advanced to a stage where we can explore small tolerance targets such as thin reservoirs. Well placement with geosteering, which is the real time adjustment of the well path based on the geological responses to place and maintain the well within the best part of the reservoir, is the technology that has made this progress possible. Geosteering however can get very complex with the increasing heterogeneities of the formations and there is no fixed methodology to devise a steering strategy in such complex geological settings. To accommodate this challenge, we investigated three methods to verify …

Surfactant Enhanced Oil Recovery By Wettability Alteration In Sandstone Reservoirs, Omar Elmofty

Masters Theses

"Recovering more oil from existing oil reservoirs using enhanced oil recovery methods holds the key for meeting future energy demands. Even though wettability is a cornerstone in oil recovery, few studies have focused on increasing oil recovery in sandstone reservoirs through wettability alteration. The objective of this thesis is to prove that altering the wettability of a sandstone rock to preferentially water-wet condition will reduce the remaining oil saturation and thus increase the percentage of recovered oil.

Two commercial surfactants were selected after studying both the phase behavior and the interfacial properties of 30 surfactants with oil and 1.00% sodium …

Process Simulation And Inclusion Characterization In Stainless Steel Ingot Casting, Jun Ge

Masters Theses

"For the ingot casting process, fluid flow of steel plays an important role in quality control and industrial operations. Using CFD software (FLUENT), this study overviews the fluid flow pattern in the bottom-teeming ingot filling process with three different swirl-modified upgate designs. Turbulent flow and mass transfer are considered main factors in controlling the process. The motion of the slag phase was also considered. In addition to the modeling studies, inclusions in stainless steel poured into ingots with a traditional and a swirl-modified upgate system were investigated using an optical microscope, SEM-EDS and ASPEX automated feature analysis technology. The main …

Analysis Of A Wound-Induced Gene Family In Glycine Max, Gena Robertson

Masters Theses

Gene families in plants are important in understanding genome evolution indicating when and where genome duplications and segmental duplications occurred as well as subsequent divergence and subfunctionalization. A gene family in Glycine max that encodes a WI12 protein, wound-induced protein, was found to consist of ten genes on five chromosomes. Wound-induced proteins are activated in response to wounding in plants, and the WI12 protein in particular is thought to be involved in cell wall modifications at the wound site. A variety of bioinformatics tools have been used to analyze the expansion of this family in soybean as well as identify …

Modeling Forward Base Camps As Complex Adaptive Sociotechnical Systems, Lori Ann Miller

Masters Theses

Work for this thesis focuses on managing complexity within complex adaptive sociotechnical systems by using model based systems engineering and virtual engineering tools. The hypothesis of the work is that integrated virtual models can be used to increase the understanding of these complex adaptive sociotechnical systems, resulting in a reduction in the perceived complexity. This was tested by the use of a two factor survey given to experts of a system (the customer and members of the model design team) and to a target user-group. This group received a demonstration and had hands on experience with a preliminary model of …

Path Planning For General Mazes, Grant Gilbert Arthur Rivera

Masters Theses

Path planning is used in, but not limited to robotics, telemetry, aerospace, and medical applications. The goal of the path planning is to identify a route from an origination point to a destination point while avoiding obstacles. This path might not always be the shortest in distance as time, terrain, speed limits, and many other factors can affect the optimality of the path. However, in this thesis, the length, computational time, and the smoothness of the path are the only constraints that will be considered with the length of the path being the most important. There are a variety of …

Semantic Preserving Text Tepresentation And Its Applications In Text Clustering, Michael Howard

Masters Theses

Text mining using the vector space representation has proven to be an valuable tool for classification, prediction, information retrieval and extraction. The nature of text data presents several issues to these tasks, including large dimension and the existence of special polysemous and synonymous words. A variety of techniques have been devised to overcome these shortcomings, including feature selection and word sense disambiguation. Privacy preserving data mining is also an area of emerging interest. Existing techniques for privacy preserving data mining require the use of secure computation protocols, which often incur a greatly increased computational cost. In this paper, a generalization-based …

The Effects Of Water On Sympathetic Detonation And Dead Pressing Of Dynamite And Emulsions, Adam Michael Doerfler

Masters Theses

Dynamite and emulsions are very effective explosives in blasting; however they do have some shortcomings. Dynamite is prone to sympathetic detonation whereas emulsions are prone to dead pressing. While this does not happen all the time, the conditions in which the explosives are used do have an effect on whether or not they will sympathetically detonate or dead press.

Numerous researchers have investigated sympathetic detonation for a relationship between the distance between charges, hole separation distance, and size of explosive. This research aimed to look at how hole separation distance was affected when water was introduced into the boreholes for …

Verification Of A Monte Carlo Model Of The Missouri S&T Reactor, Brad Paul Richardson

Masters Theses

The purpose of this research is to ensure that an MCNP model of the Missouri S&T reactor produces accurate results so that it may be used to predict the effects of some desired upgrades to the reactor. The desired upgrades are an increase in licensed power from 200 kW to 400kW, and the installation of a secondary cooling system to prevent heating of the pool. This was performed by comparing simulations performed using the model with experiments performed using the reactor. The experiments performed were, the approach to criticality method of predicting the critical control rod height, measurement of the …

Self-Consolidating Concrete For Infrastructure Elements Shear Characteristics, Eric B. Sells

Masters Theses

"Because of its unique ability to maintain high flow-ability and remain homogeneous, self-consolidating concrete (SCC) has the potential to significantly reduce the costs associated with civil infrastructure; however, the use of higher paste and lower coarse aggregate volumes than non-SCC concretes raises concerns about shear strength of SCC mixes. This research focused on the components that contribute to the concrete's ability to provide shear by aggregate interlock. Variables investigated by push-off tests included concrete compressive strength, coarse aggregate type , and volumetric content level of the coarse aggregate portion . Post-failure digital imaging software was used to confirm fresh concrete …

Synthesis Of Nickel Nanoparticles By Gamma-Radiation And Femtosecond Laser Ablation, Vivek Murlidhar Rao

Masters Theses

"Nickel nanoparticles were synthesized by gamma-radiation and femtosecond laser ablation. Aqueous precursors were prepared by uniformly dispersing nickel chloride in a 2:1 ratio of water and isopropanol. Stabilizers employed were Sodium Dodecyl Sulfate (SDS) and Poly Vinyl Pyrrolidone (PVP). Gamma-ray radiolysis of aqueous nickel precursors was investigated as a reducing agent for nickel cations to form atomic seeds for nucleation on multi-walled carbon nanotubes (MWCNTs). 30-60kGy was the dosage used in increments of 10kGy, at a rate of 10kGy/hr. Isopropanol was added to consume the excess of oxidizing species produced by irradiation and form stable secondary radicals. The influence of …

Use Of High Volume Fly Ash-Wood Fiber And Polyurea Layers For Blast Mitigation, Anthony Francis Wulfers

Masters Theses

"This project is a continuation of research done by Natalia Carey and John Myers. The first part of Natalia's research was to develop and characterize an e-glass discrete fiber-reinforced polyurea (DFRP) system for infrastructure applications. She then recommended two polyurea systems (A and B) be further examined. These polyurea systems were then applied to plain reinforced concrete and steel fiber reinforced concrete panels (SFRC). Carey found that the SFRC panels sustained less overall damage. For this project SFRC was used as the base layer in combination with the DFRP systems. In addition to the DFRP and SFRC a high-volume fly …

A Novel Membrane Bioreactor Configuration For Nitrogen Removal, Timothy Harrison Canter

Masters Theses

"Population growth in the U.S. and abroad has led to a need for increased treatment of wastewater to limit the effects of additional pollution loadings on bodies of water. Additionally, this need is complicated by limitation on energy inputs. The solution is treatment reactors that are robust, simple to operate, effective in treatment, and energy efficient. This research will compare a traditional membrane bioreactor configuration with a design meant to address these issues.

The proposed configuration used differences in hydraulic head to move liquor from a pre-anoxic zone to the aerobic zone and return a portion of it to the …

A Study Of Wavelet-Based Noise Reduction Techniques In Mammograms, Varun Shah

Masters Theses

"Breast cancer is one of the most common cancers and claims over one thousand lives every day. Breast cancer turns fatal only when diagnosed in late stages, but can be cured when diagnosed in its early stages. Over the last two decades, Digital Mammography has served the diagnosis of breast cancer. It is a very powerful aid for early detection of breast cancer. However, the images produced by mammography typically contain a great amount noise from the inherent characteristics of the imaging system and the radiation involved. Shot noise or quantum noise is the most significant noise which emerges as …

Laminate Dielectric And Foil Characterization For Signal Integrity On Printed Circuit Board, Aleksandr Yakubovich Gafarov

Masters Theses

"Accurate characterization of laminate dielectrics as substrates of printed circuit boards (PCB) over a wide frequency range (from tens megahertz to tens gigahertz) is important from a signal integrity (SI) point of view. Accurate knowledge of dielectric constants (DK) and dissipation factors (DF), or loss tangents, of laminate dielectrics, as well as loss in conductors, as functions of frequency over a wide frequency range, are needed to the designers of high-speed digital electronics.

An "in situ" wideband traveling-wave technique based on measuring S-parameters of the PCB test vehicles with auxiliary "through-reflect-line" (TRL) calibration patterns has been developed. This technique has …

Direct Shear Testing Of Fractured Rocks From Missouri Used To Evaluate Potential Fault Reactivation Induced By Carbon Dioxide Sequestration, Ishan Kumar

Masters Theses

"Geological storage projects of CO₂ are designed to maintain secure storage for thousands of years. Carbon Capture and Storage has been identified as one of the methods which is used to reduce global emission of CO₂ and achieve lower concentration of CO₂ in the atmosphere by capturing the CO₂ from the flue gases and storing it in underground formations. Potential leakage of injected CO₂ from the reservoir to the surface is caused by the reactivation of pre-existing faults and fractures which is caused by the change in the state of stresses and the pore pressure. To avoid damage to the …

Parametric Moment Closure For Non-Linear State Dependent Stochastic Systems, Ritesh Arora

Masters Theses

"This research highlights the use of moment closure approximation techniques to provide analytical approximations to nonlinear state dependent systems. Nonlinear systems are often difficult to solve and often approximated through the use of simulation. However, Moment Closure has the capability to derive an approximate solution by making a closed form solution out of open set of differential equations representing nonlinear system behavior in both transient and equilibrium state. It is this capability of approximating the closed form solution to complex systems that draws interest in the use of this method within systems engineering. This research further extends to the stability …