Digital Commons Network^™

Microstructure And Mechanical Properties Of Silicon Carbide-Titanium Diboride Ceramic Composites, Derek Scott King

Masters Theses

"The microstructure, hardness, fracture toughness, Young's modulus, strength and Weibull modulus of silicon carbide-titanium diboride (SiC-TiB₂) ceramics were studied. First, SiC-TiB₂ ceramics with 15 vol.% TiB₂ particles were processed using two green processing methods, spray drying (ST) and ball milling (SiC-15TiB₂). In addition, SiC-TiB2 ceramics with TiB₂ contents ranging from 0 to 100 vol.% were produced to determine a TiB₂ content that produced the best combination of mechanical properties. From spray drying, segregation of the TiB₂ particles in ST led to a granule-like microstructure and spontaneous microcracking in the final ceramic. In ceramics containing 20 and 40 vol.% TiB₂, the …

Advanced Moisture Modeling Of Polymer Composites, Nathan Robert Roe

Masters Theses

"Composite materials absorb moisture from the environment and over time this moisture absorption affects the mechanical performance of the material. In order to determine the long-term moisture effects on the component, representative parts must be tested after having been exposed to an accelerated moisture-conditioning environment. This accelerated environment simulates the worst-case exposure conditions that a part might experience. Currently accepted methodologies for analyzing the time required to condition specimens are limited, only allowing simple geometry and an assumption that diffusivity rates are independent of the flow path or direction. Therefore, a more advanced finite element method is desired. In the …

A Novel Cantilever For Bi-Harmonic Atomic Force Microscopy, Muthukumaran Loganathan

Masters Theses

"Tapping mode (TM) AFM is a popularly used AFM technique in which an oscillating sharp tip mounted on a micro cantilever is used to probe the surface of interest with nanoscale resolution by making intermittent (tapping) contact with the surface. Any change in surface profile affects the tip amplitude, and is detectable only if it results in an amplitude change that is significant enough to be measured by the laser detector. Hence, it is desirable to have a micro cantilever that is sensitive to surface changes so as to provide sharper images and better surface resolution.

In the first part …

A Study Of The Integration Of An Inlet Noise Radiation Code With The Aircraft Noise Prediction Program, Devin Kyle Boyle

Masters Theses

"A numerical method has been developed in order to study the effect of turbofan inlet acoustic treatment on the resulting cumulative noise heard by observers on the ground. The approach to creating the tool was to combine the capabilities of the NASA-developed Aircraft Noise Prediction Program (ANOPP) with the fan noise propagation and radiation code developed at Missouri University of Science and Technology. ANOPP can be used to predict the noise metrics resulting from a typical commercial aircraft with turbofan engines on several different flight profiles, including takeoff, approach/landing and a steady (constant altitude/airspeed) flyover. These capabilities are valuable for …

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 …

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 …

Effects Of High Volumes Of Fly Ash On Cement Paste, Karl Wehking Beckemeier

Masters Theses

"The study of high-volume fly ash (HVFA) concrete mixtures has become popular due to the significant environmental and economic benefits which the material may provide. By including fly ash at 50 percent or greater replacement levels, substantial benefits could be obtained. However, the inclusion of fly ash can have negative effects, including incompatibilities between constituents of a mixture. As the fly ash replacement level increases, the degree and likelihood of these problems increases.

In this study, paste mixtures were made, as part of a larger HVFA concrete study, in order to determine the degree to which varying levels of fly …

Stochastic Model For Solar Sensor Array Data, Faris Alfaris

Masters Theses

Statistical approaches are often used in time series analysis, for example, to predict the future trend of a time series. Trend forecasting can be applied in many time related parameters such as: solar radiation, generation of electricity and other variables related to time series to improve the efficiency and to set the design requirements. Since the design of any solar energy system requires knowledge of the availability of solar radiation data at the location of interest. Therefore, this research seeks the application of a statistical model to fit the solar radiation time series and predict the future values. There are …

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 …

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 …

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 …

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 …

Hot Channel Determination And Burnup Analysis Of Missouri University Of Science And Technology Research Nuclear Reactor, Kelly Christopher Rogers O'Bryant

Masters Theses

"A burnup analysis has been performed on the Missouri University of Science and Technology (Missouri S&T) Research Nuclear Reactor (MSTR). With use of the Monte Carlo neutronics depletion code MCNPX, burned material was input into a neutronics model (burned model) in order better simulate MSTR core characteristics. Simulated burnup values of ²³⁵U for the past twenty years of MSTR operations totaled 14.266 grams, slightly less than the 14.527 grams reported by the reactor staff. A distribution of ²³⁵U was simulated and a burnup map was developed.

Using the updated fuel material, the hot channel of the current configuration of the …

Pulmonary Fluid Dynamics And Aerosol Drug Delivery In The Upper Tracheobronchial Airways Under Mechanical Ventilation Conditions, Timothy Andrew Van Rhein

Masters Theses

"The effects of mechanical ventilation conditions on fluid flow and particle deposition were studied in a computer model of the human airways. The frequency with which aerosolized drugs are delivered to mechanically ventilated patients demonstrates the importance of understanding the effects that ventilation parameters have on particle deposition in the human airways. Past studies that modeled particle deposition in silico frequently used an idealized geometry with steady inlet conditions. With recent advancements in computational power and medical imaging capabilities, studies have begun to use more realistic geometries or unsteady inlet conditions that model normal breathing. This study focuses specifically on …

Implementation And Evaluation Of Spatial Audio Recording And Rendering Techniques, Jayasecha Raghavendra Nimmala

Masters Theses

"The thesis is divided into two main sections. First half describes the implementation of different adaptive beamforming techniques. Adaptive beamforming techniques are widely used in many real world applications like teleconferencing, speech recognition, devices for the hearing impaired, radar, sonar, etc. The beamformer is an array of sensors which can be electronically steered to any particular direction to enhance the signal in the direction of interest while at the same time suppressing interference or jammers coming from other directions.

In our experiment, we implement both the regularized minimum variance distortionless receiver (MVDR) and the generalized sidelobe canceller (GSC). The beamforming …

Development Of A Shared Earth Model To Investigate Potential For Carbon Dioxide Sequestration In The Springfield Area, Mo, Imowo Celestine Akpan

Masters Theses

"Carbon dioxide (C0₂) sequestration has been extensively implemented and explored predominantly in depleted oil reservoirs and deep saline aquifers where the C0₂ is stored under supercritical conditions. A lesser explored option with great potential is based on injection into shallow reservoirs where the C0₂ may not always be in its denser supercritical state. The research evaluates the potential for injecting C0₂ into saline aquifers at depths of ~550-650 meters and formation temperatures of -22⁰C.

To evaluate injectivity and cap rock integrity, reservoir and geomechanical simulations need to be conducted separately and subsequently coupled. A Shared Earth Model is developed utilizing …

Wavelet Based Contrast Limited Histogram Equalization For Contrast Enhancement Of Digital Mammography, Ashish Vighnahar Avachat

Masters Theses

"Mammography has been the most efficient tool for screening of microcalcification and cancer tissues; however, the raw images produced by mammography systems are usually of poor contrast. In order to use these raw images for early diagnosis; their contrast, sharpness and noise need to be enhanced. Among these important enhancement parameters contrast enhancement is critical. A novel algorithm is introduced which blends wavelet transforms with Contrast Limited Adaptive Histogram Equalization (CLAHE) for contrast enhancement. In this algorithm, the input image is decomposed to its low frequency and high frequency components in wavelet domain. Decomposed coefficients from different bands are then …

A Three-Dimensional Transient Simulation Of An Electrochemical Magnetohydrodynamics Cell With Micro And Millielectrode: A Unified Reconciliation Of Theory And Experiment, Cajon Gonzales

Masters Theses

"Even though electrochemically induced magnetohydrodynamic (MHD) convection is a straightforward inexpensive method for moving fluids in confined spaces as for example during electrodeposition, stripping voltammetry, or in microfluidics, efficient quantitative models only recently have begun to appear. This is traced to complex mathematics that have prevented development of analytical expressions, e.g., for mass-transfer limited currents in analogy to the well-known Levich equation for the rotating electrode. Thus, related literature expressions remain mainly phenomenological concerning particular cell geometries or applications. Here, using such reports as points of departure, we validate a computationally rigorous description of the magnetoelectrochemical problem and define the …

Modeling Supply Chain Network Resiliency In The Aftermath Of An Extreme Event, Varun Ramachandran

Masters Theses

"Failure of infrastructure elements due to an extreme event adversely affects the supply chain networks in any urban environment. This study models the resiliency of a supply chain network by integrating geospatial data with critical supply chain elements and graph theory. This model can then be combined with an extreme event simulation to calculate resiliency. Resiliency refers to the time required for services and select economic indicators to approach pre-event levels (in this study, a return to 80% of the pre-event capacity). This research proposes an interdisciplinary approach to develop a comprehensive framework for resiliency modeling. This approach includes the …

Gray Gas Analysis Of Radiative Preheating Effects On Shock Induced Combustion, Pratibha Raghunandan

Masters Theses

"The use of detonations in combustors has been receiving increased attention in recent times. The presence of shock waves in such combustors invariably poses the existence of two domains that present different physics for the flow processes. The variation of upstream temperature due to radiative heating by the products of combustion was given particular attention in the present study. The modeling of heat transfer across a normal shock wave of negligible thickness was done by considering the reactants and the products of combustion to be in radiative equilibrium with each other. The quantification of emissivity of the products of combustion …

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. …

Evaluation Of The Reagan And Lamotte Sandstones In Southwestern Missouri For Carbon Dioxide Sequestration, Todd Jeffrey Miller

Masters Theses

"Carbon dioxide sequestration has been proposed as a way to reduce anthropogenic carbon dioxide emissions. Several characteristics are required in order for a geologic formation to be suitable for sequestration. There must be an impermeable confining layer to restrain CO₂ migration toward the surface, the porosity and permeability must be high enough to allow for long term injection and substantial storage capacity, and the formation must be strong enough for long term injection to occur without inducing fractures. In this work, The Reagan and Lamotte Sandstones near Springfield, Missouri were evaluated for the potential for carbon dioxide sequestration. The Derby-Doe …

Signal-To-Noise Ratio Of Augmentative And Alternative Communication Devices Across Educational Settings, Hope Elizabeth Lorenz

Masters Theses

The use of augmentative and alternative communication (AAC) devices is important for individuals whose natural speech is inadequate for communication. Research conducted to make improvements to AAC devices has included exploring the effectiveness of color-coding symbols, linguistically based arrangement of symbols, and intelligibility of the devices. However, little attention has been given to the volume adequacy of AAC devices in a variety of educational settings. It is hypothesized that volume levels of AAC devices are often inappropriate for adequate communication when compared to noise levels in the classroom. The present study measured the volume output level of AAC devices compared …

The Lee Silverman Voice Treatment Delivered Via Distance Therapy, Kate Harrington

Masters Theses

The purpose of this study was to determine the efficacy of the Lee Silverman Voice Treatment (LSVT) on improving the vocal loudness in patients with Parkinson's disease when delivered via distance therapy. This study utilized a non-concurrent multiple baseline across subjects research design. Subjects were recruited through local Parkinson's Support Groups. A total of five subjects participated in the study and each subject received the standard LSVT techniques which included focus on using correct breath control to project voice, projecting a range of high to low notes, and speaking written sentences and words as loud as possible.

Three subjects received …

"I Am Not Minor": Characters' Apparent Autonomy In J.M. Coetzee's Fiction, Brigid Erin O'Malley

Masters Theses

J.M. Coetzee's most recent works of fiction have become increasingly experimental with form (e.g., metafiction, diary, fictionalized memoir). These various forms illuminate the subject-object split present in Coetzee's recent work and its transcendence of race and gender. Indeed, the gender and racial tensions present in his novels seem to be mere representations of the subject-object split at work - the split that exists between those with power and those without. Thus, I believe Coetzee is attempting to make a more universal, even spiritual statement regarding the body and soul ( our corporeal selves representing the objective self and our soul …

Incremental Predictive Validity Of The Wechsler Intelligence Scale For Children, Fourth Edition: Predicting Academic Achievement With Wisc-Iv Fsiq And Index Scores, Shannon Hollinger

Masters Theses

The purpose of this thesis was to replicate the incremental predictive validity study of observed Wechsler Intelligence Scales for Children- Fourth Edition (WISC-IV) factor index scores in predicting reading and mathematics achievement in a sample of referred children from a Midwestern community. Taken from an archival data set, the sample was composed of 298 students who were evaluated as part of special education referrals ranging from kindergarten through 9th grade. Hierarchical multiple regression analyses were used to assess proportions of reading and mathematics achievement obtained from the Wechsler Individual Achievement Test- Second Edition (WIAT-II) and the Woodcock-Johnson Tests of Achievement-Third …

School Psychologist Training And Diagnosis Of Attention Deficit/Hyperactivity Disorder, Katharine M. Zwolinski

Masters Theses

Attention deficit hyperactive disorder (ADHD) is a developmental disorder that is characterized by inattention, impulsivity, and hyperactivity. ADHD is commonly diagnosed in childhood and one of the most frequent referral concerns brought to the attention of school psychologists, yet it is often misdiagnosed (Cotuono, 1993; Des granges, Des granges, & Karsky, 1995). The goal of this study is to explore ADHD training among specialist level school psychologists, assessment procedures they were exposed to during training, the information they rely on when determining if a child meets ADHD diagnostic criteria, and the accuracy of the diagnosis. It was hypothesized that the …

Ruthenium Polypyridyl Complexes That Utilize Azo-Dyes To Enhance Absorption Of Visible Photons, Akram Hazeen

Masters Theses

Research in the field of dye sensitized solar cells has been growing rapidly. The challenge in this field is to prepare molecules that absorb in the visible region. An azo dye ligand based on l,0-phenanthroline, "phen-azo-phenol", was prepared and found to absorb at 380 nm in MeOH. UV-Vis spectra of this ligand were recorded in different solvents and in the presence of added acid or base and it appeared that the spectra were shifted to longer wavelength (around 500 nm) in the presence of base and/or basic solvents. This was attributed to deprotonation of the phenol portion of the ligand. …