Digital Commons Network^™

Modeling And Quantitative Analysis Of White Matter Fiber Tracts In Diffusion Tensor Imaging, Xuwei Liang

University of Kentucky Doctoral Dissertations

Diffusion tensor imaging (DTI) is a structural magnetic resonance imaging (MRI) technique to record incoherent motion of water molecules and has been used to detect micro structural white matter alterations in clinical studies to explore certain brain disorders. A variety of DTI based techniques for detecting brain disorders and facilitating clinical group analysis have been developed in the past few years. However, there are two crucial issues that have great impacts on the performance of those algorithms. One is that brain neural pathways appear in complicated 3D structures which are inappropriate and inaccurate to be approximated by simple 2D structures, …

Advanced Studies On Series Impedance In Waveguides With An Emphasis On Source And Transfer Impedance, Jinghao Liu

University of Kentucky Doctoral Dissertations

Series impedances, including source and transfer impedances, are commonly used to model a variety of noise sources and noise treatment elements in duct systems. Particle velocity is assumed to be constant on the plane where the series impedances are defined. The research reported herein details investigations into measuring source and transfer impedance. Especially, the measurement and prediction of the transfer impedance of micro-perforated panel (MPP) absorbers is considered.

A wave decomposition method for measuring source impedance and source strength was developed that was purely based on acoustic concepts instead of the equivalent circuit analysis. The method developed is a two-load …

Estimation Of Pedestrian Safety At Intersections Using Simulation And Surrogate Safety Measures, Nithin K. Agarwal

University of Kentucky Doctoral Dissertations

With the number of vehicles increasing in the system every day, many statewide policies across the United States aim to increase the use of non- motorized transportation modes. This could have safety implications because the interaction between motorists and non-motorists could increase and potentially increasing pedestrian-vehicle crashes. Few models that predict the number of pedestrian crashes are not sensitive to site-specific conditions or intersection designs that may influence pedestrian crashes. Moreover, traditional statistical modeling techniques rely extensively on the sparsely available pedestrian crash database.

This study focused on overcoming these limitations by developing models that quantify potential interactions between pedestrians …

Continuous Monitoring Of Bioactive Glass Conversion Using Optical Biosensors, Prajakta Bhagwat

Masters Theses

"The engineered regeneration of bone is a significant challenge being undertaken to treat conditions such as traumatic casualties, bone cancer, osteoporosis, etc. Advances in hard tissue regrowth may potentially lead to significantly improved lives for millions of people. Bioactive glasses as potential materials in the fabrication of scaffolds for hard tissue regeneration have been studied recently. Bone regrowth requires maintenance of optimal levels of oxygen, glucose, phosphate, calcium, and pH. Current work at Missouri S & T's Center for Bone and Tissue Repair and Restoration focuses on developing optical biosensors to monitor: conversion of bioactive glass to hydroxyapatite, ease of …

Selective Laser Sintering Of 13-93 Bioactive Glass, Krishna C. R. Kolan

Masters Theses

"Bioactive glasses are promising materials for bone scaffolds due to their ability to assist in tissue regeneration. When implanted in vivo, bioactive glasses can convert to hydroxyapatite, the main mineral constituent of human bone and form a strong bond with the surrounding tissues, thus providing an advantage over polymer scaffold materials. Bone scaffold fabrication using additive manufacturing techniques like selective laser sintering (SLS) provide control over pore interconnectivity during the fabrication of scaffold, which helps in mimicking human trabecular bone. 13-93 glass, a third-generation bioactive material designed to accelerate the body's natural ability to heal itself, was used in …

Economic Evaluation Of Sustainable Strategies For The Transportation Sector, Yaqin Lin

Masters Theses

"Sustainable strategies are drawing growing attention as global environmental challenges increase concerns over energy consumption. As one of the most intensive consumers of energy, the transportation sector has a particular need to go green. Implementing alternative energy sources and applying advanced energy efficient technologies are two major approaches to achieve sustainability. Much work thus far used cost-effectiveness as an important criterion for assessing the practicability of sustainable strategies. However, few studies have evaluated such strategies systematically. This thesis has developed a framework of cost-effectiveness analysis to assess sustainability strategies. The framework summarizes the various effects of five representative alternative energy …

Risk Assessment For Conceptual Design Of Hydrokinetic Turbines, Praveen Kailkere Srinivas

Masters Theses

"Hydrokinetic energy is a relatively new concept in the field of renewable energy. The rotor of the turbine, immersed in water, uses the velocity from the flowing water to generate power. Thus the hydrokinetic turbines are also known as zero head turbines. These turbines can be installed in rivers, oceans and sea beds. The design of these systems depends on the site conditions, installation and maintenance costs. Since this technology has not been assessed for its potential power producing capabilities, not much research has been done in order to harness this form of renewable energy and to study the impact …

Hilbert Transform Applications In Signal Analysis And Non-Parametric Identification Of Linear And Nonlinear Systems, Zuocai Wang

Doctoral Dissertations

"Hilbert Huang Transform faces several challenges in dealing with closely-spaced frequency components, short-time and weak disturbances, and interrelationships between two time-varying modes of nonlinear vibration due to its mixed mode problem associated with empirical mode decomposition (EMD). To address these challenges, analytical mode decomposition (AMD) based on Hilbert Transform is proposed and developed for an adaptive data analysis of both stationary and non-stationary responses. With a suite of predetermined bisecting frequencies, AMD can analytically extract the individual components of a structural response between any two bisecting frequencies and function like an adaptive bandpass filter that can deal with frequency-modulated responses …

Ozone And Terpene Reactions On Indoor Surfaces: Reaction Rates And Implications For Indoor Air Quality, Shi Shu

Doctoral Dissertations

No abstract provided.

Diesel Particulate Matter Dispersion Analysis In Underground Metal/Nonmetal Mines Using Computational Fluid Dynamics, Yi Zheng

Doctoral Dissertations

"Diesel Particulate Matter (DPM) is a natural by-product from operating diesel engines. Since diesel power is a major source of energy for mining operations today, the adverse health effects of DPM are of a great concern. To thoroughly resolve DPM problems, it is critical that DPM propagation characteristics be understood to arrive at a sensible and practical method for addressing DPM-related issues. To achieve this, a computational fluid dynamics (CFD) method is used to simulate DPM dispersion and to predict its concentration distribution. Industrial field studies were reconstructed to evaluate the possibility of different CFD models. Experiments were also carried …

Dynamic Ergonomic Analysis And Simulation Of Fastening Operation, Akul Joshi

Doctoral Dissertations

"Operator performing fastening operation with powered hand-tools at awkward postures is subjected to external forces that may pose a risk of developing ergonomic injuries. For design of safe workplaces and selection of tools it is necessary to identify the probable causes of discomfort by simulating the work conditions and quantifying the risk factors. An ergonomic simulator is developed to simulate the fastening operation and quantify the effects of posture and force in fastening operation. The effect of dynamic forces is analyzed using two approaches. The first approach analyzes the effect of tool vibration while the second analyzes the hand-arm system …

Leaching Characteristics Of Inorganic Contaminants From Coal Fly Ash, Tingzhi Su

Doctoral Dissertations

"Leaching of trace elements raises environmental concerns in coal fly ash disposal and reuse. US EPA is in the process of creating the first national rule on coal ash management. However, due to the complexity of coal fly ash composition, the leaching characteristics of trace elements are not well understood. Meanwhile, driven by the tightening emission regulations, new types of coal fly ashes are continuously generated as a result of the technological evolution at coal energy industry. The changing landscape highlights the needs for a comprehensive database to assess the leaching characteristics of different types of coal fly ashes, evaluation …

Solution Phase And Membrane Immobilized Iron-Based Free Radical Reactions: Fundamentals And Applications For Water Treatment, Scott Romak Lewis

University of Kentucky Doctoral Dissertations

Membrane-based separation processes have been used extensively for drinking water purification, wastewater treatment, and numerous other applications. Reactive membranes synthesized through functionalization of the membrane pores offer enhanced reactivity due to increased surface area at the polymer-solution interface and low diffusion limitations. Oxidative techniques utilizing free radicals have proven effective for both the destruction of toxic organics and non-environmental applications. Most previous work focuses on reactions in the homogeneous phase; however, the immobilization of reactants in membrane pores offers several advantages. The use of polyanions immobilized in a membrane or chelates in solution prevents ferric hydroxide precipitation at near-neutral pH, …

Vibration Diagnosis Of Elastic Shafts With A Transverse Crack, Cai Zhongyi

Theses: Doctorates and Masters

Detection of the shaft crack in a rotating machine is one of the most challenging problems in equipment predictive maintenance. In the available literature, various crack detection methods have been applied to study the dynamic behaviour of a cracked shaft. This study sought to attempt a vibration-based method. Elastic shafts with three different types of transverse cracks, including experimentally-induced fatigue crack, welded shaft crack, and wire-cut crack, were fabricated, and used to analyse the bending stiffness and frequency response in the vertical direction. The results from the cracked shafts were compared with that of an intact shaft. Bending stiffness of …

Neurorehabilitation Of The Hand Using The Cybergrasp[Tm] And Mirror Image, Amy Frances Boos

Theses

In recent years, researchers have explored the use of a mirror image as a means of rehabilitation for individuals suffering from hemiparesis. Through neuroimaging and functional testing, neurological improvement has been demonstrated in those that engage in mirror therapy. Bilateral training, or simultaneous movement of both sides of the body, has also been studied as a treatment method to improve function after cerebral vascular accident. The development of robotic systems to assist movement of the human body has played a major role in the fabrication of bilateral training devices.

In this experiment, the CyberGrasp™ robotic exoskeleton was used to assist …

Robotic Testing Of Proximal Tibio-Fibular Joint Kinematics For Measuring Instability Following Total Knee Arthroplasty, Wael K. Barsoum, Ho H. Lee, Trevor G. Murray, Robb Colbrunn, Alison K. Klika, S. Butler, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Pain secondary to instability in total knee arthroplasty (TKA) has been shown to be major cause of early failure. In this study, we focused on the effect of instability in TKA on the proximal tibio-fibular joint (PTFJ). We used a robotics model to compare the biomechanics of the PTFJ in the native knee, an appropriately balanced TKA, and an unbalanced TKA. The tibia (n = 5) was mounted to a six-degree-of-freedom force/torque sensor and the femur was moved by a robotic manipulator. Motion at the PTFJ was recorded with a high-resolution digital camera system. After establishing a neutral position, …

Toward A Technology Management Core: Defining What The Technology Manager Needs To Know, Mark Doggett, Pam Mcgee, Sophia Scott

SEAS Faculty Publications

With the increasing demands on organizations to do “more with less,” and produce acceptable market results, productivity and performance standards continually raise the expectations on competitive success. To meet these expectations, organizations should create learning opportunities that combine the application of technical management skills along with the softer skills involved in people management. Technical managers with little training or past experience with nontechnical skills often perform poorly in technical management positions (Kroecker, 2007). Because this generation lives in a highly technical environment, managers need to be proficient in dealing with knowledge workers and systems; therefore, there is a growing emphasis …

Approaches To Arc Flash Hazard Mitigation In 600 Volt Power Systems, Curtis Thomas Latzo

USF Tampa Graduate Theses and Dissertations

Federal regulations have recognized that arc flash hazards are a critical source of potential injury. As a consequence, in order to work on some electrical equipment, the energy source must be completely shut-down. However, power distribution systems in mission critical facilities such as hospitals and data centers must sometimes remain energized while being maintained. In recent years the Arc Flash Hazard Analysis has emerged as a power system tool that informs the qualified technician of the incident energy at the equipment to be maintained and recommends the proper protective equipment to wear. Due to codes, standards and historically acceptable design …

Understanding Risk Governance: Introducing Sociological Neoinstitutionalism And Foucauldian Governmentality For Further Theorizing, Wee-Kiat Lim

CCX Research

This article traces the career of risk across prominent theoretical approaches by highlighting their key assumptions and premises, specifically the technical approach found in the physical sciences, and economics, psychology, and sociology in the social sciences. In each discipline, the strengths and limitations of each theoretical approach are pointed out. The discussion focuses on sociology in particular because other approaches—in treating risks as dominantly technical, psychological, or economic phenomena—tend to downplay the broader historical and socio-political context that impinges on risk construction and production, and its differential impact across society. This exploration points out that institutions play an important role …

A Multi-Species Analysis Of Biomechanical Responses Of The Head To A Shock Wave, Richard Bolander

Wayne State University Dissertations

Shock wave induced brain injury remains a field of research that has great consequences for the rehabilitation of soldiers and civilians that are exposed to an explosion. As such, for the research to be successful in developing strategies to mitigate the effects of these injuries, appropriate research methods need to be developed. Animal models are currently employed to understand the brain's response to a shock wave exposure. Unfortunately no criteria have been established that indicates in what way the mechanical inputs that the cells in an animal's brain are subjected to are similar to a human. The purpose of this …

Supercritical Carbon Dioxide-Processed Resorbable Polymer Nanocomposites For Bone Graft Substitute Applications, Kevin Baker

Wayne State University Dissertations

Numerous clinical situations necessitate the use of bone graft materials to enhance bone formation. While autologous and allogenic materials are considered the gold standards in the setting of fracture healing and spine fusion, their disadvantages, which include donor site morbidity and finite supply have stimulated research and development of novel bone graft substitute materials. Among the most promising candidate materials are resorbable polymers, composed of lactic and/or glycolic acid. While the characteristics of these materials, such as predictable degradation kinetics and biocompatibility, make them an excellent choice for bone graft substitute applications, they lack mechanical strength when synthesized with the …

The Influence Of Thermal Expansion Of A Composite Material On Embedded Polarimetric Sensors, Manjusha Ramakrishnan, Ginu Rajan, Yuliya Semenova, Piotr Lesiak, Andrzej Domanski, Tomasz Wolinksi, Anna Boczkowska, Gerald Farrell

Articles

Abstract. Some of the most critical issues of the influence of the thermal expansion of composite materials on embedded polarimetric sensors for measurements of strain and temperature are studied in this paper. A composite material sample with polarimetric fiber sensors embedded in two distinct layers of a multi-layer composite structure is fabricated and characterized. The polarimetric fiber sensors used in this study are based on panda type fiber and polarization maintaining photonic crystal fiber (PM-PCF). The temperature sensitivities of polarimetric fiber sensors with acrylate buffer coated and buffer stripped polarization maintaining optical fibers are measured in free space and compared …

Dissemination Strategy For The Nanosafety Cluster 27.09.2011, Extra Deliverable 4.12 .Nanoimpactnet Report, Gordon Chambers, Iseult Lynch, Darren Hart, Nathalie Boschung, Byrony Ross, Sonja Grossberndt

Reports

So that the widest possible group of European nanosafety stakeholders are able to meet, interact, benefit from the work of NSC project members and work using reproducible methods using the same terms, there must be coordination. The following requirements should be clearly defined in the formulation of all new EC sponsored nanosafety-related projects and should be strongly encouraged in existing NSC projects:

Natural Convection In An Internally Finned Phase Change Material Heat Sink For The Thermal Management Of Photovoltaics, M. J. Huang, P. C. Eames, Brian Norton, N. J. Hewitt

Articles

Elevated operating temperatures reduce the solar to electrical conversion efficiency of building integrated photovoltaic devices (BIPV). Phase change materials (PCM) can be used to passively limit this temperature rise although their effectiveness is limited by their low thermal conductivities and by crystallization segregation during solidification. This paper presents an experimental evaluation of the effects of convection and crystalline segregation in a PCM as a function of efficiency of heat transfer within the finned PV/PCM system. The thermal performances of bulk PCM with crystallization segregation for different internal fin arrangements are presented. It is noted that the addition of internal fins …

A Model Of Giant Vacuole Dynamics In Human Schlemm’S Canal Endothelial Cells, Ryan M. Pedrigi, David Simon, Ashley Reed, W. Daniel Stamer, Darryl R. Overby

Department of Mechanical and Materials Engineering: Faculty Publications

Aqueous humour transport across the inner wall endothelium of Schlemm’s canal likely involves flow through giant vacuoles and pores, but the mechanics of how these structures form and how they influence the regulation of intraocular pressure (IOP) are not well understood. In this study, we developed an in vitro model of giant vacuole formation in human Schlemm’s canal endothelial cells (HSCECs) perfused in the basal-to-apical direction (i.e., the direction that flow crosses the inner wall in vivo) under controlled pressure drops (2 or 6 mmHg). The system was mounted on a confocal microscope for time-lapse en face imaging, and cells …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2011, 131st Anniversary Year, One Hundred-Twenty-First Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Collegiate Academy: Biology

Collegiate Academy: Chemistry and Physics

Chemistry and Physics

Biological and Medical Sciences

Junior Academy, Senior High Competition

Nebraska Wesleyan University Health and Sciences Graduate School Fair, Olin and Smith Curtiss Halls

Teaching of Science and Math

Aeronautics and Space Science, Poster Session

Applied Science and Technology

Maiben Memorial Lecture: Erin Flynn, Omaha Henry Doorly Zoo

Aeronautics

Anthropology

Earth Science

Junior Academy, Junior High Competition

Ultra-Low Power Electronics For Autonomous Micro-Sensor Applications, Rebeka Davidova

USF Tampa Graduate Theses and Dissertations

This thesis presented the research, design and fabrication associated with a unique application of rectenna technology combined with lock-in amplification. An extremely low-power harmonic transponder is conjoined with an interrogator base-station, and utilizing coherent demodulation the Remote Lock-In Amplifier (RLIA) concept is realized. Utilizing harmonic re-radiation with very low-power input, the 1^st generation transponder detects a transmitted interrogation signal and responds by retransmitting the second harmonic of the signal. The 1^st generation transponder performs this task while using no additional power besides that which accompanies the wireless signal. Demonstration of the first complete configuration provided proof of concept …

The Formation And Distribution Of Hippocampal Synapses On Patterned Neuronal Networks, Natalie Michelle Dowell-Mesfin

Legacy Theses & Dissertations (2009 - 2024)

ABSTRACT

Neuro-Fuzzy Soft-Switching Hybrid Filter For Impulsive Noisy Environments, Şaban Özer, Hasan Zorlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new soft-switching hybrid filter based on a neuro-fuzzy network for impulsive noisy environments is proposed. The hybrid filter was built by combining an adaptive finite impulse response (FIR) filter, an adaptive weighted myriad (WMy) filter, and a soft-switching mechanism based on a neuro-fuzzy (NF) network. Performance of the hybrid filter was tested in \alpha-stable noisy situations and compared with adaptive FIR, WMy, and weighted median (WMd) filter performances. According to the simulation results; the proposed hybrid filter has better performance than the adaptive FIR, WMy, and WMd filters, and has the ability of effectively suppressing the …

Ecg Denoising On Bivariate Shrinkage Function Exploiting Interscale Dependency Of Wavelet Coefficients, Sema Kayhan, Ergun Erçelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new method for electrocardiogram (ECG) denoising based on bivariate shrinkage functions exploiting the interscale dependency of wavelet coefficients. Most nonlinear thresholding methods based on wavelet transform denoising assume that the wavelet coefficients are independent. However, wavelet coefficients of ECG signals have significant dependencies. In this paper, we proposed a new method by considering the dependencies between the coefficients and their parents in detail on a bivariate shrinkage function for denoising of an ECG signal corrupted by different types of noises, such as muscle artifact noise, electrode motion, and white noise. In real-time applications, reduction of computational …