Digital Commons Network^™

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 …

Projectile Impact Effects On A 50 Psi Plug Type Coal Mine Seal, Bruce Albert Von Niederhäusern

Masters Theses

"The current lack of projectile damage criteria for mine seals is assessed to determine if criteria should be developed. Impact experiments were performed on a full-scale 50 psi mine seal to determine failure modes, dynamic stress state, and assess risk to existing operational mine seals. Test projectiles were selected from common underground coal mine items propelled by means of a black powder projectile generator. Projectile velocities attained in testing ranged from approximately 100 to 650 ft/s (30 to 200 m/s). Dynamic strain was measured on the non-impact face to derive the state of stress and estimate failure criteria. Penetration models …

Review And Data Analysis Of Low Salinity Water Effect Through Induced Fine Migration, Dawei Xu

Masters Theses

"Low salinity water flooding (LSWF) is well proved to be an effective EOR technology both in laboratory and field tests, however, the conditions for LSWF to work and EOR mechanism is still debatable. Up till now, many mechanisms have been proposed to explain the incremental oil recovery in sandstone by LSWF, for instance, fine migration, ionic exchange, wettability alteration and pH increase.

In this study, we only focus on low salinity water flooding effect through induced fine migration mechanism. The objective of this study is to conduct a comprehensive analysis using statistical analysis methods and explaining the mechanism of fine …

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 …

Estimating Electromagnetic Emissions From A Site Installation With Multiple Racks Of Server Equipment, Ze Sun

Masters Theses

“There are hundreds, sometimes even thousands, of servers working simultaneously inside a data center. Their radiation can be a problem and cause EMI issues. However, it is not feasible to perform full-wave simulation of these racks because of the large electric size of the model. In this thesis, an algorithm is proposed to predict the emission form rack array. The equivalent dipole source is extracted from EMI measurement data of a single rack and used as the radiation source in the multiple rack model. The coupling between racks cannot be ignored, but through the simulation, it is also found that …

Exploration For Alteration Halos Around The Ag-W Deposits In Southeastern Missouri, Usa, Daniel Joseph Warbritton

Masters Theses

"The St. Francois Mountains in SE Missouri are an extensive terrane of granitic ring complexes and associated rhyolites. They were an important source of Ag, W, and Sn and mined intermittently from the 1800s until the 1950s. The Ag-W ores occur in the Silvermine Granite and rhyolite roof rocks. The deposits are classified as a xenothermal ore system with mineralization occurring in quartz veins and surrounding greisen (up to 2.5 m). Exploration for hydrothermal ore deposits often focuses on the identification of alteration halos in the surrounding host rocks. In the vast majority of xenothermal ore deposits, such as in …

Effects Of Uncertainty Refinement On Satellite Collision Probability, Bruce Thomas Morrison

Masters Theses

"Due to the drastic increase in orbital debris about the Earth, the likelihood for new and current mission satellites to collide with other objects grows. When a mission satellite is placed in a highly populated orbit in the vicinity of other satellites or debris, it is necessary to consider the probability of collision to assess any possible conjunctions. The computation of the collision probability is heavily dependent on the relative position and velocity of the objects during conjunction, as well as the combined covariance. There are two main types of analytic collision probability computations; the first assumes that the objects …

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 …

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) …

Development Of Castrip Dual Phase Steel, Brenton Allen Hrebec

Masters Theses

“Thermomechanical processing necessary to produce DP 980 steel using CASTRIP hot band was investigated. The resultant steel has an ultimate tensile strength of 1038 MPa, yield strength of 744 MPa, and total elongation of 8.6%. These mechanical properties were achieved by batch annealing the hot band at 649°C for 48 hours and cold rolling to a 20% reduction. The steel was continuously annealed to simulate a galvanization cycle with an intercritical temperature of 810°C. The possibility of improving the texture of the steel by warm rolling under dynamic strain aging conditions was investigated. Dynamic strain aging in the CASTRIP hot …

Performance Of One-Part And Two-Part Class C Fly Ash-Based Alkali Activated Mortars, Cedric Chani Kashosi

Masters Theses

“Seeking an eco-friendly concrete, researchers have conducted studies to fully replace ordinary Portland cement (OPC) with fly ash (FA) producing alkali-activated concrete (AAC). Results showed better performance of AAC in terms of high early compressive strength, and durability compared to conventional concrete. However, much is still unknown about the behavior of AAC. From the type of materials used, the curing procedure, and long-term strength development of these binders; a thorough investigation is needed in order to fill the existing gap from previous studies and thus make a step forward to the safely use of AAC in the construction industry. The …

Laser Machining Countersinks In Carbon Fiber Reinforced Polymer, Leon James Neely Hill

Masters Theses

“Laser machining countersinks with a frequency doubled Q-switched diode pumped Nd:YAG laser is demonstrated. Tests were conducted in 0.100" thick IM7 prepreg CFRP with [0,90]3S orientation. The HAZ is minimized to avoid stress concentrations in the epoxy matrix. A chamber and filtration system was designed and built to contain the byproducts produced in the machining process. The variables investigated are the number of repetitions in the offset path, the plunge rate, and the line energy. The research was performed over one baseline study, one parameter space exercise, two full factorial experiments, and one repeatability study. Assessment was done under an …

Removal Of Antimony And Bismuth From Copper Electrorefining Electrolyte By Two Proprietary Solvent Extraction Extractants, Andrew Artzer

Masters Theses

"Antimony and bismuth are two of the most problematic impurities in copper electrorefining (ER). Because of this, much research has been done investigating the ways to remove them. Processes that are currently being used industrially include anode additions, liberators, ion exchange (IX), and solvent extraction (SX). Of these, liberators and anode additions are the most common while SX is the least, mostly being used for arsenic removal. There are other methods that have been evaluated, but are not in commercial use. These include the use of various electrolyte additives, and adsorbents such as bentonite clay and heavy metal sulfates.

Two …

Asphaltene Stability In Crude Oil During Carbon Dioxide Injection And Its Impact On Oil Recovery: A Review, Data Analysis, And Experimental Study, Sherif M. Fakher

Masters Theses

"Crude oils are usually associated with many compounds, some of which are favorable and others, which are not. One of the most unfavorable components of crude oil that pose severe operational problems and decreases oil production significantly are asphaltenes. These compounds are solids that are homogenized in the crude oil at room temperature but tend to separate from solution when agitated. They can deposit in the reservoir pores, wellbore, and transportation pipelines thus causing severe operational problems and oil recovery reduction.

Even though researchers have been studying asphaltenes for more than 100 years, there is still an ambiguity concerning asphaltene …

Propagation Of Uncertainty Through Coning, Sculling, And Scrolling Corrections For Inertial Navigation, James Daniel Alan Brouk

Masters Theses

"This thesis investigates the propagation of estimation errors through generalized coning, sculling, and scrolling algorithms used in modern day inertial navigation systems, in order to accurately quantify the uncertainty in the estimation of position, velocity, and attitude. The corrections for coning, sculling, and scrolling algorithms have an often unaccounted for effect on documented and empirically derived error statistics for measurements used to predict the uncertainty in a vehicle's position, velocity, and attitude estimates. Through the development of an error analysis for these generalized algorithms, mappings of the measurement and estimation errors through the correction termare generated. Using the developed mappings, …

Performance Investigation Of Surface Modified Ceramic Microfiltration Membranes And The Effects Of Ionic Strength, Choji Bitrus Daches

Masters Theses

"The performance of ceramic membranes surface coated with cysteic acid to improve efficiency and reduce fouling rate was studied under two transmembrane pressure (TMP) and constant crossflow velocity (CFV). The filtration process was done in crossflow mode to allow for extended operation of the membranes. the performance of the membranes were determined in terms of the measured fluxes and on content rejection. Cleaning-in-place (CIP) was done on the membranes to ensure flux recovery after each run. The results showed significant improvement on the performance of the membranes with respect to high permeate fluxes and high oil content rejection (> 99.5%). …

Practical Methods For Source Separation In Emc Measurements, Yuanzhuo Liu

Masters Theses

"Electromagnetic emission is critical in the electronic industry with the rapid growth of the development of the electronic device. To identify the emission from the multipule sources, two methods are proposed in the near field scan and total radiated power measurement respectively.

The first method can be applied in the measurement of the field generated by multiple non-correlated sources. The contribution of each source is determined using a blind source separation (BSS) technique. The measurements are performed using one scanning probe and stationary reference probes, avoiding the need to measure the spatial correlations of the random field. The resolving result …

Changes In Fresh Properties Of Flowable Concrete Induced By Pumping And Composition Of The Lubrication Layer, Alexis Salinas

Masters Theses

"Pumping is an easy method to move concrete while keeping stability. It is worldwide accepted as one of the principal methods for concrete placement, as it accelerates construction. Typically, concrete acceptance in terms of fresh quantitative empirical properties (i.e. slump/slump flow and air content) are performed prior to the pumping process. However, empirical measurements have the drawback that they only measure 1 point. Rheology is better tool to evaluate the behavior of concrete. Pumping is a process that induces considerable shearing in the concrete that can impact its rheological properties. Therefore, the magnitude of these changes in fresh properties depends …

Performance Evaluation Of Bmi Resin System For Thin-Ply Composites, Manoj Kumar Reddy Rangapuram

Masters Theses

"Composites materials are increasingly being used in aerospace applications over the past few years. The unique properties like high strength to weight ratio, thermal stability, fatigue and corrosion resistance set them apart from the conventional materials. Composite materials are well suited for the applications where weight is the primary concern in the design. Composites structures are vulnerable to mechanical as well as thermal loadings. Transverse micro-cracking and delamination are the most common type of failures in composite materials. The thickness of the ply being used play a key role dictating the properties of the resultant composite structure. As the ply …

Exploring High School Students' Attitudes Towards Reading, Heather G. Crivilare

Masters Theses

This study explored high school students’ attitudes towards reading as both a recreational activity and academic endeavor; while there are numerous studies regarding the reading habits of younger children, there is a deficit of research into the reading habits of students beyond the middle school years. This study surveyed and interviewed freshmen-through-senior students in a medium-sized, rural Illinois high school about their habits as readers in order to explore the relationship between different environmental factors and reading, as well as between reading habits and college readiness. This study found a gender gap in reading enjoyment favoring female students; a decline …

College Students Experiences Participating In International Alternative Break Trips, Dayton L. Ehrlich

Masters Theses

This study sought to explore undergraduate students’ experiences participating in international alternative break trips. A qualitative approach was used to understand the motivating factors as well as the impact the trip had on them. Participants included three female undergraduate students who had participated in an international alternative break trip in Mexico were interviewed one-on-one. The results demonstrated there were multiple different motivating factors and impacts the students experienced. The motivating factors consisted of student involvement, they were all personally invited on the trip, practicing a new language, opportunity to leave the country, and service was not a motivator. The impacts …

A Pipeline For Exogenous Gene Expression And Biomass Analysis In Plants, Bijay Bisunke

Masters Theses

Biological pretreatment of biomass is typically required for the production of liquid biofuels, which are viable alternatives to traditional fossil fuels. While traditional thermomechanical pretreatments are effective at helping to deconstruct lignocellulose, they are often expensive and tend to generate environmentally dangerous waste materials. An alternative to traditional pretreatment strategies is biological pretreatment, which has focused on lignocellulose-degrading organisms, such as white-rot fungi. While direct pretreatment of biomass with white-rot fungi has shown great promise, directly expressing functional white-rot fungi genes in plants (i.e. in planta expression) has the potential to be even more efficient because the biomass itself …

Cavalier Reading: Examining The Problematic Nature Of Signifiers, Monique Nichelle Branscumb

Masters Theses

No abstract provided.

Context Dependency Of Invasion Impacts On The Controllers Of Invasibility In Microstegium Vimineum, Scott Vincent Janis

Masters Theses

Although plant invasions are of major conservation concern, understanding of the natural controls on invasion and their impacts is largely limited to static observational studies or artificially manipulated systems. Linking patterns of invasion with subsequent impacts in natural systems is necessary to fully assess invasion causes and consequences. Therefore, I employed a long-term approach to sequentially assess the controls on invasion and their subsequent impacts in a self-assembled system for the highly invasive annual grass Microstegium vimineum. I modeled likely factors contributing to the probability of invasion and local invasion success of a natural invasion of M. vimineum in a …

A Journey Of Cross-Cultural Adaptation: An Autoethnography Of A Vietnamese Graduate Student In The American Classroom, Tram Nguyen

Masters Theses

Cross-cultural adaptation is not a new area of study, however, there is very little research focusing on the cross-cultural adaptation of Vietnamese students studying in America. The process of cross-cultural adaptation occurs naturally and necessarily regardless of the intentions of the individuals as long as they continuously engage in communication with the host environment and are functionally dependent on it. This research examines on the difference, the challenge and the way Vietnamese students have undergone throughout the process of adaptation from the original Asian culture to American culture, especially in the classroom context. The theoretical construct to guide the study …

Students Reception Of Ethnic Diversity Topics From White And Non-White Faculty, Cobi Christiansen

Masters Theses

The purpose of the study is to investigate the phenomenon of the student population being more ethnically diverse than the teacher population as well as examining student perceptions of ethnic diversity topics based on their perceptions of faculty ethnicity. A quantitative using a survey method was designed to investigate students' reception of ethnic diversity topics from White and Non-white faculty. From three different institutions in Central Illinois, 141 undergraduate education students, which included students who are majoring in early childhood, elementary, or secondary education as well as students who are receiving teaching certificates with their majors, participated in this study. …

Gifted Education In Elementary Schools, Danielle Wilkinson

Masters Theses

Gifted students have enormous potential, yet there are few consistent opportunities for gifted students to receive challenging instruction. Drawing upon literature detailing the history of gifted education nationally and in Illinois, this study sought to find what services were currently offered to Illinois students, and if the opportunities for gifted students were related to a district’s state funding tier. Findings indicated that the elementary gifted services being offered and the ways in which eligibility is determined were inconsistent among districts. In addition, many districts who offer gifted services are using local/community funds in order to provide services regardless of their …

U-Pb Detrital Zircon Geochronology Of Paleozoic Clastics Of The Ozark Plateau: Implication For Sea-Level Fluctuations And Far-Field Tectonics, Chen Zhao

Masters Theses

"The Ozark Plateau of south-central Missouri is underlain by Ordovician to Pennsylvanian carbonate and clastic strata. Enigmatic, presumably Pennsylvanian 'filled sink' structures are common on the Ozark Plateau and remain a source of controversy. We present results for U-Pb ages of detrital zircons for 13 samples from the OP. We use U-Pb ages from other Paleozoic clastics and 'filled sinks' on the OP, to suggest: 1) FSS record a period of Middle Ordovician erosion and sedimentation and 2) document significant shifts in sediment provenance that reflect regional tectonic events affecting the North American Craton.

The KDE plots of normalized detrital …

Using The Ert Method To Differentiate Resistivity Anomalies Attributed To Natural And Man-Made Activities, Ibrahim Faisal Alshareef

Masters Theses

"Karst terrain is considered to be a very complex topography compared with most other geological environments. Many features can be observed such as sinkholes, air-filled cavities, losing streams, and solution widened joints. These karst features can cause subsidence and damage infrastructure such as buildings and roads thus causing economic hardship and disruption of life. The typical geological and hydrological studies are not enough to understand the karst processes.

For this reason, two geophysical methods were involved in investigating the subsurface in the study area. In this research, the electrical resistivity tomography (ERT) and multichannel analysis of surface wave (MASW) data …