Digital Commons Network^™

Rapid Simulation Of The Statistical Variation Of Crosstalk In Cable Harness Bundles, Xiang Li

Masters Theses

"Accurate assessment of crosstalk problems in cable harnesses requires simulation methods that account for the statistical variation of harness parameters. Methods are proposed to determine the influence of the statistical variation in wire positions, the rate that wires change position (i.e. "twist"), harness height, harness density (i.e. how closely wires are packed) and circuit loads. Methods use a combination of simulation and probability theory. Simulations use the T-parameter method, a rapid simulation technique for harness bundles. Simulation time is further improved by using the mean and variance of crosstalk estimated for fixed harness parameter values to estimate the mean and …

Mutation Of The Hof1 Pest Domain Affects Cytokinesis In Budding Yeast, Katherine E. Stockstill

Masters Theses

"Cytokinesis is the division of a cell into two daughter cells. Cytokinesis failure results in polyploidy, which may contribute to tumorigenesis or cause cell death. The Saccharomyces cerevisiae protein Hof1, which is required for efficient cytokinesis, is phosphorylated during mitosis. The hypothesis that MEN (mitotic exit network) dependent phosphorylation regulates Hof1 degradation, triggering completion of cytokinesis was tested. Hof1 contains a PEST sequence, which is rich in proline, glutamic acid, serine, and threonine, and is believed to be involved in protein degradation. To test the hypothesis, we created two non-phosphorylatable mutants of the Hof1 PEST domain tagged with GFP. The …

Contrast Enhancement Of Digital Mammography Based On Multi-Scale Analysis, Muhammad Imran Khan Abir

Masters Theses

"A contrast enhancement algorithm is developed for digital mammograms aiming to assist radiologists in discerning early breast cancer easily. The algorithm is based on a Laplacian pyramid framework image processing technique. The mammogram is decomposed into three frequency sub-bands, low, mid, and high frequency sub-band images. The lower sub-band image contains very fine details and higher level contains coarser features. In this method contrast enhancement is achieved from high and mid sub-bands by decomposing the image based on multi-scale Laplacian pyramid and enhance contrast by image processing. Several mapping functions are applied on sub-band images based on experimental analysis. After …

Location Privacy Policy Management System, Arej Awodha Muhammed

Masters Theses

"The advance in wireless communication and positioning systems has permitted development of a large variety of location-based services that, for example, can help people easily locate family members or find nearest gas station or restaurant. As location-based services become more and more popular, concerns are growing about the misuse of location information by malicious parties. In order to preserve location privacy, many efforts have been devoted to preventing service providers from determining users' exact locations. Few works have sought to help users manage their privacy preferences; however management of privacy is an important issue in real applications. This work developed …

Numerical Simulation Of Relative Permeability Modifier Effect On Oil And Water Production, Murad Mohammedahmed Abdulfarraj

Masters Theses

"Excess water production is one of the most prevalent operational problems that oil companies are facing. Polymers and polymer gels have been used widely to control excess water production for mature oilfields. It is well known that polymers/gels can reduce the permeability to water (Krw) much more than that to oil (Kro). This phenomenon is called disproportionate permeability reduction (DPR) and the polymers or gels that exhibit this behavior are called relative permeability modifier (RPM). When RPMs are placed in reservoir, reduced permeability to water can lead to decreased water production, and sometimes increased hydrocarbon production, therefore prolonging the useful …

Hardened Concrete Properties And Durability Assessment Of High Volume Fly Ash Concrete, Kyle Marie Marlay

Masters Theses

"Concrete is produced more than any other material in the world. Sustainable construction is extremely important in today's industry and fly ash is the leading material for sustainable concrete design. The addition of fly ash improves many fresh and hardened concrete properties. However, the slow hydration process associated with fly ash makes the use of the material in large amounts undesirable in conventional construction. This study evaluated the hardened concrete and durability performance of several high-volume fly ash (HVFA) concrete mixes. The various HVFA concrete mixes evaluated within this study consisted of 70 percent replacement of portland cement by weight …

The Origin Of Quartz Glomerocrysts: Insights From The Rhyolite Dike At Medicine Park, Ok, Sedeg Ahmed E. Ahmed

Masters Theses

"The origin of quartz glomerocrysts a distinctive petrographic feature of the rhyolite dike in Medicine Park, Oklahoma, was investigated using transmitted light and cathodoluminescence microscopy to determine if quartz glomerocrysts formed during quartz crystallization or during quartz dissolution. Quartz glomerocrysts are typically comprised of two to six individual phenocrysts of quartz and commonly exhibit subhedral partially embayed crystal forms with very rare euhedral phenocrysts in both glomerocrysts and individual quartz phenocrysts. The size range of the individual quartz phenocrysts are 0.08mm to 1.7mm while the size range is 0.08mm to 3.25mm for quartz glomerocrysts . Cathodoluminescence revealed that individual quartz …

Evaluating The Effectiveness Of Multi-Spectral Remote Sensing Data For Lithological Mapping In Arid Regions: A Quantitative Approach With Examples From The Makkah Neoproterozoic Region, Saudi Arabia, Nawwaf Awad Al Muntshry

Masters Theses

"This work quantitatively evaluates the effectiveness of multi-spectral remote sensing data for geological mapping in arid regions. For this, Landsat Thematic Mapper (TM) data covering part of the Neoproterozoic Arabian Shield around the Makkah region in Saudi Arabia are used. The Makkah region is dominated by a variety of layered and intrusive rocks covered by unconsolidated sediments. The Landsat TM data have six spectral bands in the visible and near infrared (VNIR) and shortwave infrared (SWIR) with thirty meters spatial resolution.

The Optimum Index Factor (OIF) has been computed to determine the best Red-Green-Blue (RGB) band combination emerging from the …

Eyes Don't Lie: Understanding Users' First Impressions On Website Design Using Eye Tracking, Sirjana Dahal

Masters Theses

"Websites are becoming more prevalent these days. They need to create a favorable first impression on the users during initial exposure. After allocating their attention to stimuli, users form a cognitive representation of the visual information leading to first impression. Hence, first impression is important to evaluate the effectiveness of a website. This research tries to examine the amount of exposure time needed to form first impression; identify the web design factors that influence the formation of users' first impression; study the emotional responses of users on website design; and finally understand the relationship between first impression and eye movement. …

Influence Of Particle Size And Specimen Preparation On The Iowa Pore Index, Christopher Paul Davis

Masters Theses

"This study was performed in order to identify a size correction that would allow aggregate of different sizes, other than the standard 1/2-3/4-inch fraction, to be used in the Iowa Pore Index (IPI) test. This size correction would allow for the IPI to be determined for aggregate gradations of material that have a nominal maximum size (NMS) smaller than 3/4-inch. The interest in a size correction for the IPI developed from its use in a Durability Factor (DF) estimation equation. The estimation equation was developed with the use of 19 different DF from Missouri aggregate sources, where eight aggregates had …

Design Of A Current Probe For Measuring Ball-Grid-Array Packaged Devices, Tianqi Li

Masters Theses

"A current probe to measure BGA ball currents via magnetic induction has been designed. The probe is manufactured on a 4 layer flex circuit and has been validated by full wave simulations and measurements. The feature size of the probe is very tiny that it almost pushes the limit of flex-circuit technology. Several critical manufacturing problems were happened, and they have been solved now. The probe allows measuring currents of a 1 mm pitch BGA ball directly. Its operating frequency stretched from tens of MHz up to 3GHz. The BGA probe's mutual inductance is approximately 11 pH, and with amplifiers …

Thermomechanics Of Curves In Space, Pavan Krishna Kanchi

Masters Theses

"Several biological molecules are known to form helices and coiled structures, such as DNA, collagen, bacterial flagella, and proteins. The backbones of such molecules may be modeled as a curve in three dimensions. A variational problem for the functional of the total free energy required to perturb moving curves in space is considered. The total energy of a curve in three dimensions is minimized y with a general intensive energy, which is a function of position, and the invariants, curvature and torsion. Three types of moduli are identified: stretching, bending and torsional moduli. As a result, three independent force balances …

Optimal Control Of A Helicopter Unmanned Aerial Vehicle (Uav), David John Nodland

Masters Theses

"This thesis addresses optimal control of a helicopter unmanned aerial vehicle (UAV). Helicopter UAVs may be widely used for both military and civilian operations. Because these helicopters are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This thesis presents an optimal controller design via both state and output feedback for trajectory tracking of a helicopter UAV using a neural network (NN). The state and output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers while the output feedback approach uses an observer in addition to these controllers. The online approximator-based dynamic controller learns the …

Synthesis And Toxicity Studies Of Imidazolium-Based Ionic Liquids, Ninu Madria

Masters Theses

"There is a considerable recent interest in the applications of room temperature ionic liquids (RTILs) as green solvents in organic synthesis and as nonvolatile electrolytes in lithium ion batteries. A variety of commercially available imidazolium based RTILs have been used for these applications, mainly due to their negligible vapor pressures, high thermal stabilities, wide liquid range, wide electrochemical windows and high anodic stability. The state of the art lithium ion batteries require the use of electrolytes that have relatively low viscosities at temperatures as low as -35°C. This thesis describes the synthesis of novel oxygenated and fluorinated imidazolium based RTILs …

Novel Transparent Conductive Materials: Understanding And Prediction, Yaou Song

Masters Theses

"Transparent conductive oxides (TCOs) such as doped In₂O₃, ZnO, SnO₂ or CdO are highly attractive due to their special properties, which are electrical conductivity and optical transparency. The lack of complete understanding of the fundamentals behind this unique phenomena and rapidly increasing commercial demand draw a lot of interest in investigating this kind of materials. More efficient, environmentally friendly and less expensive transparent conductive materials are needed for a variety of applications, and a general understanding of the origins of the unusual behavior would help further search for potential transparent conductive (TC) candidates. Understanding the basic properties of conventional TCOs …

Driven Pile Load Test Data For Load And Resistance Factor Design In Missouri, Joseph Ronson Cravens

Masters Theses

"The Missouri Department of Transportation (MoDOT) has recently migrated from allowable stress design (ASD) to load and resistance factor design (LRFD) of driven piles. This transition was initiated when the Federal Highway Administration (FHWA) issued a policy stating that all new bridge designs shall be designed in accordance with the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications to eliminate the difference in design methodologies for bridge superstructures and bridge substructures. However, the resistance factors for driven piles specified in the AASHTO LRFD specifications are based on nationwide pile data, consisting of a wide range …

The History Of Technical Communication Instruction At Missouri University Of Science And Technology: The Evolution Of A Curriculum, Elizabeth Marie Roberson

Masters Theses

"This thesis provides a written record of the history of technical communication instruction at Missouri University of Science and Technology (Missouri S&T). Beginning with the school's inception in 1871 as the Missouri School of Mines and Metallurgy (MSM) through to the year 2005, I have examined course catalogs and department files and conducted interviews to provide an overview of the evolution of technical communication instruction at this institution. To better understand this evolution, I have also provided a framework for the development of the English department from a single course in 1871 to the current Department of English and Technical …

Shaker Table Vibration Testing Of A Microsatellite, Tonya Michelle Sanders

Masters Theses

"In the satellite development process, structural testing is a means to gain confidence in analytical models and ultimately support qualification of the spacecraft for flight. Vibration testing, in particular, is motivated by the safety considerations of crew or launch personnel, the survivability of delicate hardware and electronics, and the avoidance of large stresses that cause structural fatigue or failure. The subject of this thesis is concerned with the shaker table vibration testing of a microsatellite pair designed and built by students at the Missouri University of Science and Technology in Rolla, Missouri. A finite element model (FEM) used in structural …

Educational Robotics: Using The Lego Mindstorms Nxt Platform For Increasing High School Stem Education, Matthew Aaron Strautmann

Masters Theses

"The field of educational robotics (ER) seeks to use the building and programming of robots to engage and educate the next generation of college freshman entering science and engineering majors. To increase the rate of application to science and engineering degree programs as well as the rate of retention, students must be engaged in high school. They must acquire the knowledge and interest to pursue these career choices. This research explores the use of robotics to interest high school students in science, technology, engineering, and math (STEM) and to improve their knowledge of these subjects. The case study developed instructional …

Microcontroller-Based Multiple-Input Multiple-Output Transmitter Systems, Balaji Madapuci Kanday

Masters Theses

"Multiple-Input Multiple_output (MIMO) Systems use multiple antennas at both the transmitter and receiver to increase data throughput and/or system reliability. An MIMO transmitter can be implemented using a variety of approaches. This work describes some of the approaches that can be used to generate the transmitted waveforms, and discuss the features and limitation of each. In particular, it shows haw a microcontroller-based system can be used for applications which require low power consumption. This thesis also describes the high-level design of a microcontroller-based MIMO transmitter. The computational speed of the microcontroller, as compared to Field-programmable Gate Array (FPGA) and Digital …

Risk-Sensitive Preventive Maintenance Policies Using Semivariance, Venkata Manojramam Tirumalasetty

Masters Theses

"Preventive maintenance is an important tool that increases the reliability of the production system by reducing downtime due to failures. In the literature, maintenance and replacement policies for productions systems have been widely studied and modeled. Traditionally preventive maintenance has focused only on minimizing expected costs without considering variability in costs. Cost variability is also commonly known as risk. In a 2003 paper, Chen and Jin used variance of costs as a measure of risk for formulating preventive maintenance policies. The variance criterion that they used ignored the probability of costs exceeding monthly or yearly budgets provided to managers. The …

Grid Frequency And Voltage Support Using Photovoltaic Systems With Energy Storage Assist, Ravi Bhatt

Masters Theses

"An optimized operating scheme for a grid-connected community based photovoltaic (PV) system is described. The system can participate in grid ancillary services like frequency and voltage regulation functions based on the Smart Grid framework. The proposed model comprises of a PV plant with Li-ion batteries coupled to the grid by means of a three-phase inverter. A two-way communication between the PV plant and the grid is assumed. The PV/storage plant provides constant updates on its current kW/kVar capability and the grid transmits the demand for specific amounts of power and for specific lengths of time. The battery charging energy can …

Inherent And Model-Form Uncertainty Analysis For Cfd Simulation Of Synthetic Jet Actuators, Daoru Frank Han

Masters Theses

"A mixed aleatory (inherent) and epistemic (model-form) uncertainty quantification (UQ) analysis method was applied to a computational fluid dynamics (CFD) modeling problem of synthetic jet actuators. A test case, (Case 3, flow over a hump model with synthetic jet actuator control) from the CFDVAL2004 workshop was selected to apply the Second-Order Probability framework implemented with a stochastic response surface obtained from Quadrature-Based Non-Intrusive Polynomial Chaos (NIPC). Three uncertainty sources were considered: (1) epistemic uncertainty in turbulence model, (2) aleatory uncertainty in free stream velocity and (3) aleatory uncertainty in actuation frequency. Uncertainties in both long-time averaged and phase averaged quantities …

The Sorption Of Chemical And Nuclear Contaminants From Soil And Water Using Nanosize Particles Of Hydroxyapatite, Chyrene Joseph

Masters Theses

"High surface area (>200 m²/g) crystals composed of nanosize (30-50nm) hydroxyapatite; (Ca₅(PO₄)₃OH) particles are being investigated as an alternative in cleaing [sic] contaminated groundwater and soil by removing toxic wastes and radionuclides. Static batch tests were carried out at 2, 4, 8, 24 and 120 hour time periods by reacting hydroxyapatite with individual solutions prepared with specific elements to evaluate the applicability of hydroxyapatite in removing potential contaminants. Chemical analyses on leachant solutions, leachate solutions, and post-reaction digested solids were conducted by Inductively Coupled Plasma-Mass Spectroscopy to determine the extent of ion removal. Removal of these ions is expected …

Continuous Low Thrust For Small Spacecraft Proximity Operations, James Harris Meub

Masters Theses

"Recently, both DoD and NASA have demonstrated increased interest in the development of close proximity operations for space systems. AFRL's Advanced Sciences and Technology Research Institute for Astrodynamics (ASTRIA) has defined several key research topics relevant to military priorities, with one area of critical importance being the inspection and observation of low Earth orbit resident space objects (RSOs). This study investigates the feasibility of using a low-thrust cold-gas propulsion system to effectively and accurately facilitate resident space object inspection. Specifically, this study focuses on the Missouri S&T Satellite mission (M-SAT) as a means to demonstrate autonomous RSO inspection. This paper …

Effect Of Initial Conditions On Molecular Mixing In A High Schmidt-Number Rayleigh-Taylor Mixing Layer, Lakshmi Ayyappa Raghu Mutnuri

Masters Theses

"Characterizing molecular mixing in Rayleigh-Taylor instability (RTI) driven flows where the density and velocity fields are coupled is essential for developing exacting predictive models. Sensitivity of the Rayleigh Taylor mixing layer to initial conditions is a topic that is being explored extensively in interests of accurate turbulent mix model development and its direct consequence in various applications like design of inertial confinement fuel capsule and atmospheric modeling. As part of the current work, an experimental investigation of the effect of initial conditions on molecular mixing in a low Atwood number(~7.5 x 10⁻⁴), high Schmidt number(~1000), RTI driven mixing layer is …

Relaxation Imaging To Characterize Lightweight Polymer-Crosslinked Aerogels, Emmalou T. Satterfield

Masters Theses

"Silica aerogels are three-dimensional assemblies of silica nanoparticles with extremely low densities. In some instances, the internal void volume is more than 90% of the total volume. The highly porous structure of the aerogels leads to attractive properties for thermal and noise insulation, due to very low thermal conductivity and very high acoustic impedance. The strength of silica aerogels has been substantially improved by casting a thin conformal polymer coating over the entire internal porous surfaces of the nanostructure. The coating reinforces the interparticle connections without significantly compromising the internal void space. To analyze and compare the properties of several …

A Framework For Transparent Depression Classification In College Settings Via Mining Internet Usage Patterns, Raghavendra Kotikalapudi

Masters Theses

Depression is a serious mental health problem affecting the mind and body of people in our society. As of today, depression affects about 5 to 7% of the American population, which roughly translates to 14 million people! A particularly worrying concern these days is the increasing incidence of depression among college students. The problem is so severe that many US campuses have dedicated centers with mental health professionals catering to students needs. Although there are very effective treatments for depression, studies report that ~80% of depressed students do not seek any help due to the lack of perception of the …

Bi-Harmonic Atomic Force Microscopy, Santosh R. Kodandarama

Masters Theses

"In tapping mode atomic force microscopy, surface features are measured indirectly via the amplitude of the tapping cantilever. A change in surface profile is detectable only if it results in an amplitude change that is significant enough to be measured by the optics. Previous works have focused on improving sensitivity through the system's Q-factor, either by changing physical cantilever properties or using feedback control, but those approaches undesirably slow down the dynamic response. In this work we take a novel approach to sensitivity amplification by reshaping the tapping trajectory. By shaping the trajectory so that the probe spends a greater …

At The Edge Of Two Worlds: Mary Slessor And Gender Roles In Scottish African Missions, Sarah Marcia Lennon

Masters Theses

Mary Mitchell Slessor, a missionary to Calabar, West Africa in modern-day Nigeria from 1876 until 1915, was a transitional character, combining traditional feminine roles with more masculine roles during her time as a missionary. Though many biographers focus on Slessor's eccentricities and use her life as an example of the exceptional Victorian woman, this study disagrees with that assessment and instead views her caught between two worlds, part of the previous generational thinking regarding women's work, but also progressing toward what would be considered normal in the early decades of the twentieth century. Comparing Slessor to other women working in …