Digital Commons Network^™

Synthesis, Characterization And Mechanistic Studies Of Biomimetic Dinuclear Copper(Ii) Complexes, Millaniyage Nuwanthaka Prasad Jayaweera

Masters Theses

Dinuclear copper complexes are significant synthetic targets due to their use as model compounds for the active sites of type 3 copper proteins like catechol oxidase. A distinct class of ligands used in these studies are built on a phenol core to witch various donor side-arms were appended at the 2 and 6 positions of the arene ring. In our quest to quantify the influence of electron donating or withdrawing groups attached to the central arene ring, we have designed a set of ligands that, upon coordination to copper(II) centers, would produce complexes of the general structure. During this research …

Developing A Basket-Shaped Host Molecule Based On P-Tert-Butylcalix[4]Arene Featuring Urea Groups For Encapsulating Volatile Guest Molecules, Lokugama Widanelage Vidula Priyadarshana

Masters Theses

Molecular baskets are a group of synthetic host molecules which are designed to govern the inclusion of small guest molecules. The basic structural features of basket-shaped host molecules are a cavity for holding a much smaller guest molecule and tunable gates for keeping the guest molecule inside. These types of gates can be tuned by changing temperature, concentration, pH, etc. In this research group's previous study, a molecular basket of cal ix[ 4]arene with carboxylic acid groups was synthesized by functionalizing calix[4]arene's phenol hydroxyl groups with benzyl bromide building blocks. In the study detailed here, 1 , l '-((5-(bromomethyl)-1,3-phenylene)bis(methylene))bis(3-isopropylurea) was …

The Transcriptional Response Of Phanerochaete Chrysosporium And Trametes Versicolor To Growth On Stems Of Helianthus Argophyllus (Silverleaf Sunflower), Nadh Hamoud Alsubaie

Masters Theses

Traditional physicochemical and physicomechanical pretreatment technologies have improved the deconstruction of lignocellulose, but often require high energy inputs and added chemical reagents. Recent studies have demonstrated the use of white-rot fungi as alternative biological pretreatment agents that can mitigate these concerns. Although, white-rot fungi have been shown to grow on a variety of non-woody substrates, they have not been explored with respect to sunflower, which has the potential to provide raw materials for both biodiesel and bioethanol. In the present study, Silverleaf sunflower stems (Helianthus argophyllus) were used as substrates for the white-rot fungi Phanerochaete chrysosporium and Trametes …

Studying Carbon Dioxide Solvent Properties By Microwave Spectroscopic Investigations Of Vinyl Fluoride/Carbon Dioxide Clusters And Developing New Approaches To Decode Rotational Spectra, Prashansa Kannangara

Masters Theses

Supercritical carbon dioxide (sc-C0₂) is an excellent green solvent, but its properties are not thoroughly understood. For example, fluorinated compounds have higher than expected solubility in sc-C0₂. Microwave spectroscopy is one way to learn more about sc-C0₂ because it can be used to determine detailed structures of small clusters of molecules. The purpose of this investigation was to study weak hydrogen bonding interactions in complexes of fluorinated ethylene (solute) with carbon dioxide (C0₂, solvent). Investigations on dimers with one C0₂ molecule and fluorinated ethylene were carried out previously and found two different …

Creg1: Its Role As A Master Regulator Of Liver Function, Iffat Jahan

Masters Theses

Mammalian development involves a complex system of regulatory signals and reactions resulting in highly differentiated cell types with specific structure and function. The liver is a major organ that has been studied extensively to understand underlying genetic processes responsible for specification, establishment and maintenance of tissue identity. Hepatoma and hepatoma variant cell lines have been used as models to understand genetic networks responsible for liver function. Whole genome microarray analysis of hepatocyte cell lines has revealed candidate genes that may serve as regulators or master regulators of liver specificity. In two previous studies in our lab, the role of candidate …

Surrender Dorothy: A Battle With Alzheimer's, Rebecca Lynn Lawson

Masters Theses

No abstract provided.

Implementing Reading Strategies With Ell Elementary Students, Nelofar Khamisani

Masters Theses

This study shows the challenges the English Language Learners face in learning reading at the Elementary level; implementing reading strategies for them; and choosing effective strategies for the students to learn reading more easily. The findings of the study show that teachers use different strategies according to the language proficiency level of the students. ELL students face challenges in communication, pronunciation, sound recognition, and vocabulary. As a strategy to overcome these challenges, the teachers emphasize learning phonics and vocabulary. Observations of three teachers in three mainstream classrooms show that teachers implement nearly similar strategies for teaching phonics and vocabulary. The …

Vhf Transmitter Development For Wildlife Tracking, Bryan Westra

Masters Theses

Wildlife biologists often use collars with VHF transmitters to gather wildlife data. The purpose of this project is to determine the best approach to designing a wildlife tracking VHF transmitter on a Printed Circuit Board (PCB). A variety of frequency generation methods were considered for the transmitter, including transistor-based crystal oscillators and chip based solutions from the chip manufacturers Analog Devices and Silicon Labs. Prototypes of the feasible options were built and evaluated for cost, power consumption, efficiency, size, frequency range, signal bandwidth, and frequency stability. It was found that the Silicon Labs Si4010 chip was the best solution based …

Inclusion Engineering In Femnal Steels, Rairu Vaz Penna

Masters Theses

"Low density high Mn and Al steels, or FeMnAl steels, show great promise for military vehicles and automotive applications in which high strength and toughness is a requirement. However, these steels are subject to processing challenges including development of oxide and nitride inclusions during melting and casting as well as a large as-cast grain size and heavy interdendritic segregation. This can lead to non-uniform heat treatment response and cracking during subsequent hot rolling. Adding up to 10%Al lowers the density of these steels by as much as 15%, unfortunately, this also results in large amounts of hard and faceted AlN …

Controlled Switching In Kalman Filtering And Iterative Learning Controls, He Li

Masters Theses

“Switching is not an uncommon phenomenon in practical systems and processes, for examples, power switches opening and closing, transmissions lifting from low gear to high gear, and air planes crossing different layers in air. Switching can be a disaster to a system since frequent switching between two asymptotically stable subsystems may result in unstable dynamics. On the contrary, switching can be a benefit to a system since controlled switching is sometimes imposed by the designers to achieve desired performance. This encourages the study of system dynamics and performance when undesired switching occurs or controlled switching is imposed. In this research, …

Investigating The Use Of Class C Flyash-Based Geopolymer Cement As A Potential Alternative To Portland Cement To Seal Co₂ Storage Wells, Priyesh Parimal Jani

Masters Theses

"Capturing emitted carbon dioxide from the source of emission and storing it underground is one effective way to reduce the amount of CO₂ in the atmosphere and is called carbon capture and storage (CCS). For the successful CCS project, it is necessary to ensure long term storage of injected CO₂ inside these selected reservoirs. Portland cement used to cast wells in these reservoirs degrade in CO₂ environment and can create migration path for leakage of CO₂. The aim of this study was to provide a comprehensive review about the problem, to propose a new geopolymer …

Routing Algorithm For The Ground Team In Transmission Line Inspection Using Unmanned Aerial Vehicle, Yu Li

Masters Theses

"With the rapid development of robotics technology, robots are increasingly used to conduct various tasks by utility companies. An unmanned aerial vehicle (UAV) is an efficient robot that can be used to inspect high-voltage transmission lines. UAVs need to stay within a data transmission range from the ground station and periodically land to replace the battery in order to ensure that the power system can support its operation. A routing algorithm must be used in order to guide the motion and deployment of the ground station while using UAV in transmission line inspection. Most existing routing algorithms are dedicated to …

High-Speed Pcb Trace Design Using A Behavioral Surface Roughness Model And High-Speed Test Coupon Design With Non-Functional Pads, Han Gao

Masters Theses

"In high-speed digital systems as data rates increase to tens of gigabits per second, the loss from the conductor surface roughness cannot be ignored. Djordjeic and Huray roughness model is widely used to count for the conductor roughness loss. However the practical application of the existed models are not straight forward since the frequency-dependent dielectric loss is usually unknown, leading to high discrepancies at high frequencies (above 10 GHz). To solve this problem, a behavioral model was developed by adding a dispersive term to the dielectric. The dispersive term in the model captures dispersion behavior observed in the measurement accurately. …

Student Perceptions And Attitudes Towards A Technical Writing Service Course At Missouri S&T, Hannah Claire Coffman

Masters Theses

"In order to learn how STEM students perceive Missouri S&T's English 3560 Technical Writing class, I designed a research study to investigate how a sample population of 90 students viewed the class. Due to the nature of qualitative research, the results of this study cannot be generalized to a larger population. However, the results can and do provide insight into the situation of these Missouri S&T students in English 3560 classes and contribute to our collective understanding of the technical writing service course at Missouri S&T and other US universities. The study investigated whether the sample population of students who …

Radiation Immunity In Cable Harnesses And Differential P/N Skew In Pcb, David Nozadze

Masters Theses

"We develop an efficient method to model RF immunity of multiwire cable harnesses and study differential P/N skew effects on channels, channel performance and specifically on the eye diagrams at the SerDes receiver.

External radiation can induce unwanted signals in transmission lines. For example, external radiation from an antenna induces common-mode currents on the outer surface of cable shields. This common-mode signal makes its way through the shied due to its imperfections, inducing the inner common mode. When twisted pairs inside the cable are not balanced, inner common mode is in turn converted to the differential mode, which might compromise …

Program Management For Concurrent University Satellite Programs, Including Propellant Feed System Design Elements, Shannah Withrow-Maser

Masters Theses

"Propulsion options for CubeSats are limited but are necessary for the CubeSat industry to continue future growth. Challenges to CubeSat propulsion include volume/mass constraints, availability of sufficiently small and certified hardware, secondary payload status, and power requirements. A multi-mode (chemical and electric) thruster was developed by at the Missouri University of Science and Technology to enable CubeSat propulsion missions. Two satellite buses, a 3U and 6U, are under development to demonstrate the multi-mode thruster's capabilities. Two key challenges related to these missions are the development of the feed system to support the thruster and management of the two bus programs' …

Gel Composition And Brine Concentration Effect On Hydrogel Dehydration Subjected To Uniaxial Compression, Xinrui Zhao

Masters Theses

"Gel treatment is a process that injects the gel into a reservoir to control the conformance and improve the sweep efficiency of injection fluids. At a certain pressure gradient, the gel dehydrates in a reservoir due to mechanical forces. This work evaluates the effects of the gel composition and brine concentration on gel dehydration under uniaxial compression. A sodium acrylate-co-acrylamide based gel cross-linked with N, N'-Methylenebisacrylamide (MBAA) was used for the study. The compression test is performed with a rheometer with a plate-plate geometry. The gel dehydration under pressure was measured to see how gel dehydration would be impacted by …

Diffusion Kinetics In Promising Adsorbents For Gas Capture Processes, Teresa Gelles

Masters Theses

"This reports the results of experimental studies aimed at characterizing the transport properties of promising adsorbents for various gas capture processes by the "zero length column" (ZLC) technique. ZLC was used to measure the intracrystalline diffusivities of single and binary components of ethane and ethylene in powder and pellet samples of paraffin-selective adsorbents Ni(bdc)(ted)_0.5 (Ni-BT) and ZIF-7 for the purpose of olefin/paraffin separation. Results show that binary gaseous systems result in intracrystalline diffusion time constants slightly lower than those in single component gaseous streams due to coadsorption effects. It was also found that ethylene diffusion was affected by surface …

Development Of Test Methods For Characterizing Extrudability Of Cement-Based Materials For Use In 3d Printing, Jonathan Thomas Kuchem

Masters Theses

"3D printing is the process of creating three-dimensional objects using an automated additive manufacturing process. The 3D printing process has been used with materials such as metals and polymers, but application with cement based materials for the construction industry has yet to be developed. In this research, two main problems were investigated for printing cement based composite materials: extrudability and tensile reinforcement. Fiber-reinforced concrete (FRC) was studied as an internal reinforcing system to increase tensile/flexural strength. First, FRC was studied to investigate mechanical properties and use of fibers from waste tires as an environmentally friendly option. A reference mixture with …

Less Is More: Beating The Market With Recurrent Reinforcement Learning, Louis Kurt Bernhard Steinmeister

Masters Theses

"Multiple recurrent reinforcement learners were implemented to make trading decisions based on real and freely available macro-economic data. The learning algorithm and different reinforcement functions (the Differential Sharpe Ratio, Differential Downside Deviation Ratio and Returns) were revised and the performances were compared while transaction costs were taken into account. (This is important for practical implementations even though many publications ignore this consideration.) It was assumed that the traders make long-short decisions in the S&P500 with complementary 3-month treasury bill investments. Leveraged positions in the S&P500 were disallowed. Notably, the Differential Sharpe Ratio and the Differential Downside Deviation Ratio are risk …

Near-Field Scanning Based Shielding Effectiveness Extraction For Board Level Shielding Cans, Harsh Shrivastav

Masters Theses

"The conventional definition of shielding effectiveness is well suited for calculating electromagnetic shielding in the far-field. However, in the near field, shielding effectiveness calculation is not so straight forward. In radio frequency interference problems, most of the field coupling occurs in near field. Having a well-defined method to calculate near-field shielding effectiveness is important for estimating the suppression of radio frequency interference using the shield cans. In this research, a method to extract the shielding effectiveness of board level shielding cans using near field scanning is developed. Shielding effectiveness is defined by modelling the shielded noise source as equivalent dipole …

Developing A Model System Of Liquid Lubricants For Space Applications: Multiple Alkylated Cyclopentane In Alumina Enclosed Surface, Vidit Singh

Masters Theses

"Lubricants are substances used for reducing friction wear tear and energy losses between two moving bodies. For space applications, normal lubricants cannot be used as they cannot survive the harsh and demanding conditions of space. Multiple Alkylated Cyclopentanes (MACs) have been utilized as space lubricants in recent times with tremendous results. NASA uses the MACs for their missions in space, in particular 1,3,4- tri-(2-octyldodecyl) cyclopentane sold by Nye Lubricants under the name of Pennzane^TM.

In this research, an effort has been made to identify appropriate potential models for simulating Pennzane molecules and to develop MD simulation codes to …

Experimental Characterization Of Common-Mode Sources For Prediction Of System Level Common-Mode Current On Cable Harnesses, Sameer Sudha Arun Walunj

Masters Theses

"Common-mode current on cable harnesses is often the primary source of radiated emissions below several hundred megahertz. It is difficult, however, to estimate common-mode currents that will occur in a system from component level tests because the common-mode impedances are different in the system. Research presents two methods for using simple component level tests to estimate equivalent common-mode source voltages and source impedances responsible for generating common-mode current. Key to these methods is assuming the harness can be represented with two transmission lines, one terminated with a short and one with an open. Equivalent sources are predicted for those circuits …

Multiphysics Prediction Model Of Microwave Curing For Thick Polymer Composites, Siva Dasari

Masters Theses

"Microwave curing technologies have many advantages over the traditional thermal curing methods for the manufacturing of fiber reinforced polymers, especially the processing speed and energy efficiency. Energy can be instantaneously transferred through applied electromagnetic fields and heat is generated based on dipolar rotational interactions. Microwave curing processes have been used for glass fiber composites but there are significant challenges associated with microwave curing of carbon fiber composites. Efficient heating may be difficult due to high dielectric loss associated with carbon fibers. Laminate quality will be highly dependent on the uniformity of the electromagnetic field in the material. In this work, …

Unmanned Aerial And Traversing Vehicle -- A Mobile Platform For Bridge Inspections, Clayton A. Fritsche

Masters Theses

“Unmanned aerial vehicles (UAVs), also known as drones, have been rapidly growing in popularity since their creation. This study aimed to create a robotic platform used to assist in the inspection process of the nation’s aging and deteriorating bridges. To this end, a multimodal inspection robot that utilized both flying and driving technologies, was designed, analyzed, and tested for aerial, traversing, and their transitional operability. The design, herein referred to as the “BridgeBot”, was evaluated both computationally and experimentally. A finite element model of the BridgeBot was established and analyzed under static loading scenarios to help determine stress distributions and …

Mightier Than The Sword: Benjamin Franklin’S Satirical Rebuke Of British Policy, Bethany L. Fontenot-Miller

Masters Theses

The genius of Benjamin Franklin resides not in his unique personality or worldly manner but in his distinct ability to eloquently express his ideas in written form. One of his most notable and peculiar scripted expressions emanated from his desire to assert American authority in peace negotiations with Great Britain in the final stages of the American Revolution. Franklin’s “Supplement” to the Boston Independent Chronicle, printed in 1782 at his press at Passy, satirized British political and economic procedure in an effort to illuminate British hypocrisy and defend American interests in the peace process. Though the “Supplement” has only recently …

Redemptive Penology Vs. Exclusive Retributive Justice, Samuel Chuks Japhets

Masters Theses

Grounded on long-standing penal notions of exclusive retributivism inherited from classical theorists, Ancient Near East lex talionis, and theonomist penology, the United States federal sentencing and corrections system aims to administer just desert sentences on offenders, to curtail crimes. This exclusively retributive model of criminal sanction is, presumably transformative and innately capable of dispensing holistic justice to society, victims, and criminals. However, the preponderance of high rates of recidivism raises the question of whether this exclusively retributive doctrinal framework that drives the federal penology empirically results in a redemptive administration of penal justice, especially to the offender. Given the traditional …

The Origins Of Western Music And Its Influence On Modern Popular Music: Teaching Music Through A Musical Exploration Of Seven Countries, Johanna Katelyn Hatt

Masters Theses

The topics of music history and music appreciation cover a wide range of composers and musical contributions that at times, can be overwhelming to a student who does not have any musical knowledge. Through limiting the music appreciation course to the discussion of composers’ works from various countries, students are able to learn about the important contributions those composers and countries had to music, including modern popular music. This topic will bring value to the field of music education as it offers an alternative approach to the traditional method of teaching a music history course. With this holistic approach to …

Single Parent Households And The Effect On Student Learning, Asia Watt

Masters Theses

The purpose of this research is to examine if there is a relationship between single-parent households and the effect on student learning. A total of seven parents and three elementary teachers took a survey. Students’ scores in math and reading from report cards and PARCC scores were also used as data sources. Results revealed that the involvement of single parents at school varies depending on the type of involvement, however, data from the report card review showed all the parents review their child’s report card. Approximately 70 % or more assisted their children in math and English homework. In addition, …

Solvation Properites Of Supercritical Carbon Dioxide Using Chirped-Pulse Fourier-Transform Microwave Spectra Of Carbon Dioxide / 1, 1-Difluoroethene (Dfe) Mixtures, Tulana Ariyaratne Subasinghe Arachchige

Masters Theses

Supercritical carbon dioxide (sc-C0₂) is a highly utilized industrial substance identified as an excellent solvent and a surfactant, which is cheaper and less hazardous than other typical solvents. The higher solubility of fluorinated hydrocarbons than their hydrocarbon (HC) analogs is not well understood and the theory behind the microsolvation of sc-C0₂ cannot be fully explained with the existing chemical information. Microwave spectroscopy is a good method of identifying the structural arrangement of clusters made from fluorinated HCs and C0₂. I n this project, microwave scans of the four different mixtures of 1 , 1-difluoroethene (DFE) …