Engineering Commons^™

Calibrated Short Tr Recovery Mri For Rapid Measurement Of Brain-Blood Partition Coefficient And Correction Of Quantitative Cerebral Blood Flow, Scott William Thalman

Theses and Dissertations--Biomedical Engineering

The high prevalence and mortality of cerebrovascular disease has led to the development of several methods to measure cerebral blood flow (CBF) in vivo. One of these, arterial spin labeling (ASL), is a quantitative magnetic resonance imaging (MRI) technique with the advantage that it is completely non-invasive. The quantification of CBF using ASL requires correction for a tissue specific parameter called the brain-blood partition coefficient (BBPC). Despite regional and inter-subject variability in BBPC, the current recommended implementation of ASL uses a constant assumed value of 0.9 mL/g for all regions of the brain, all subjects, and even all species.

The …

Biomechanical Effects Of A Hip Orthosis On Lumbo-Pelvic Coordination, Matthew Ballard

Theses and Dissertations--Biomedical Engineering

Abnormal lumbar movement has been observed in individuals who have a history of low back pain (LBP). Affected individuals display a reduction in lumbar spine rotation during trunk movement tasks, while pelvic rotation increases to compensate. Reduced lumbar contribution to forward bending is associated with increased compressive forces and increased shearing demand of the task on the lower back. This abnormal lumbo-pelvic coordination (LPC) can persist beyond LBP symptom alleviation and may contribute to further occurrences or more severe cases of LBP. This study serves as a first step in investigating if abnormal LPC can be corrected with a hip …

Noninvasive Multimodal Diffuse Optical Imaging Of Vulnerable Tissue Hemodynamics, Mingjun Zhao

Theses and Dissertations--Biomedical Engineering

Measurement of tissue hemodynamics provides vital information for the assessment of tissue viability. This thesis reports three noninvasive near-infrared diffuse optical systems for spectroscopic measurements and tomographic imaging of tissue hemodynamics in vulnerable tissues with the goal of disease diagnosis and treatment monitoring. A hybrid near-infrared spectroscopy/diffuse correlation spectroscopy (NIRS/DCS) instrument with a contact fiber-optic probe was developed and utilized for simultaneous and continuous monitoring of blood flow (BF), blood oxygenation, and oxidative metabolism in exercising gastrocnemius. Results measured by the hybrid NIRS/DCS instrument in 37 subjects (mean age: 67 ± 6) indicated that vitamin D supplement plus aerobic training …

Redefining Construction “As-Built” Plans To Meet Current Kentucky Transportation Cabinet Needs, Victoria Lynn Lasley

Theses and Dissertations--Civil Engineering

As-built drawings are the traditional method used by the construction industry to record changes made during construction. As-builts provide valuable information for new design projects as well as rehabilitation and remediation projects. The completeness and accuracy of these plans are essential for transportation industries and their success. While the importance of as-builts is widely recognized, the process of creating them has proven to be difficult. It is a time consuming process and entities often lack the resources necessary to complete accurate and detailed as-builts. After an investigation of current as-built operations within State Transportation Agencies, recommendations have been made to …

Improving Safety Performance Of Highway Maintenance Crews Through Pre-Task Safety Toolbox Talks, Zamaan Al-Shabbani

Theses and Dissertations--Civil Engineering

The dangerous work environment in the construction industry and the inherent high risks associated with construction work make it the focus of safety training and regulations. Highway construction and maintenance has unique hazards but seemingly less directly applicable safety standards, regulations, and programs. Department of Transportation (DOT) employees working in highway maintenance are exposed to a variety of unique hazards specifically associated with their work and not relating to the adjacent traffic. Yet, highway construction and maintenance work has not received sufficient attention in terms of safety research and programs. The lack of safety training and education in highway construction …

An Assessment Of Historical Traffic Forecast Accuracy And Sources Of Forecast Error, Jawad Mahmud Hoque

Theses and Dissertations--Civil Engineering

Transportation infrastructure improvement projects are typically huge and have significant economic and environmental effects. Forecasts of demand of the facility in the form of traffic level help size the project as well as choose between several alternatives. Inaccuracy in these forecasts can thus have a great impact on the efficiency of the operational design and the benefits accrued from the project against the cost. Despite this understanding, evaluation of traffic forecast inaccuracy has been too few, especially for un-tolled roads in the United States. This study, part of a National Cooperative Highway Research Program (NCHRP) funded project, bridges this gap …

Hazard Recognition And Risk Perception Among Union Electricians, Elyas Jazayeri

Theses and Dissertations--Civil Engineering

Hazard recognition and risk perception are two important factors that are a focus of most safety training programs. According to previous research, unrecognized hazards could lead to underestimation of risks, which ultimately could lead to injuries and fatalities. The primary objective of this research was to assess hazard recognition and safety risk perception skills in the electrician trade among electricians in unions. Another goal of this study was to find possible correlation between level of engagement in safety training and hazard recognition and risk perception skills. The research objectives were accomplished by gathering data from sixty-seven apprentices and journeymen across …

Use Of Functionalized Bimetallic Membranes For Treatment Of Contaminated Groundwater At A Hazardous Waste Site In Kentucky, Lucy C. Pacholik

Theses and Dissertations--Civil Engineering

Providing access to clean drinking water will continue to be a challenge for civil engineers for generations to come. Since many communities around the world rely on groundwater as a source of drinking water, remediation technologies must be implemented at sites where groundwater contamination exists due to years of mismanagement of hazardous waste. Using nanosized zero-valent metals such as iron and zinc embedded within and on the surface of functionalized (PAA) membrane filters has shown to be an effective dechlorination technique for contaminated groundwater. Introducing a noble metal such as Pd or Ni increases reaction rates by acting a catalyst …

Connected And Autonomous Vehicles Effects On Emergency Response Times, Austin William Obenauf

Theses and Dissertations--Civil Engineering

Emergency response times have been shown to be directly correlated with mortality rates of out-of-hospital patients. Studies have been conducted to show the relationship between time and mortality rates until patients receive the proper treatment. With more cardiac arrests and other life threatening illnesses occurring in the United States, more emergency calls will be required as well. As of today, technological advancements have been made to reduce response times, but human factors still require certain procedures, causing delays in the run time and increasing the rate of mortality. Here we show the results of emergency response times with the market …

Adapting Crash Modification Factors For The Connected And Autonomous Vehicle Environment, Federico Valentin Lause Iii

Theses and Dissertations--Civil Engineering

The Crash Modification Factor (CMF) clearinghouse can be used to estimate benefits for specific highway safety countermeasures. It assists safety professionals in the allocation of investments. The clearinghouse contains over 7000 entries of which only 446 are categorized as intelligent transportation systems or advanced technology, but none directly address connected or autonomous vehicles (CAVs). Further, the effectiveness of highway safety countermeasures is assumed to remain constant over time, an assumption that is particularly problematic as new technologies are introduced. For example, for the existing fleet of human-driven vehicles, installation of rumble strip can potentially reduce “run-off-road” crashes by 40%. If …

Pathway Connectivity In An Epigenetic Fluviokarst System: Insight From A Numerical Modelling Study In Kentucky Usa, Ethan Adams

Theses and Dissertations--Civil Engineering

Fluviokarst landscapes are dominated by both fluvial and karst features. Interpreting hydrologic pathways of fluviokarst can be confounded by the unknown connectivity of the various flow regimes. A combined discrete-continuum (CDC) hybrid numeric model for simulating the surface and subsurface hydrology and hydraulics in fluviokarst basins was formulated to investigate fluviokarst pathways. This model was applied to the Cane Run Royal Springs basin in Kentucky USA. A priori constraints on parameterization were avoided via multi-stage optimization utilizing Sobol sequencing and high performance computing. Modelling results provide evidence of hydrologic pathways dominated by fracture flow, epikarst transfer and runoff. Fractures in …

Decomposing A Watershed’S Nitrate Signal Using Spatial Sampling And Continuous Sensor Data, Evan Clare

Theses and Dissertations--Civil Engineering

Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region.

By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The …

Improving Bicycle Infrastructure With The Use Of Bicycle Share Travel Data, Jennifer Mintao Weast

Theses and Dissertations--Civil Engineering

Bicycling as a mode of transportation has been increasing in recent years due to its environmental and health benefits. The availability of bicycles through bicycle share programs has made bicycling a more viable option. With this increase, there is a need for complementary improvements of bicycle infrastructure. Many local and regional transportation agencies are recognizing this need and developing a master plan or safety action plan to improve the city’s bicycle and walking facilities. This study examines bicycle travel demands and travel patterns in Lexington, Kentucky as generated by SPIN bicycle share users. It is hypothesized that the SPIN users …

Biological Selenium Control: Selenium Reduction By Shigella Fergusonii Strain Tb42616 And Pantoea Vagans Strain Ewb32213-2 In Bioreactor Systems, Yuxia Ji

Theses and Dissertations--Civil Engineering

Se(VI) and Se(IV), as the two major species of selenium in water, are toxic to aquatic lives and may cause adverse health effects to humans at high levels. Biological reduction of Se(VI) is a two-stage process first from Se(VI) to Se(IV) and then from Se(IV) to Se(0) with potential accumulation of the more toxic Se(IV) due to the slower rate of the second stage.

Selenium reduction was first evaluated with batch cultures of Shigella fergusonii strain TB42616 (TB) and Pantoea vagans strain EWB32213-2 (EWB) isolated in our laboratory from sludge and coal slurry sediment samples, respectively. In order to facilitate …

Characterization Of Nanostructure, Materials, And Electron Emission Performance Of Next-Generation Thermionic Scandate Cathodes, Xiaotao Liu

Theses and Dissertations--Chemical and Materials Engineering

Scandate cathodes, where scandia is added to the tungsten cathode pellets, have recently received substantial and renewed research interest owing to significantly improved electron emission capabilities at lower temperatures, as compared with conventional dispenser cathodes. However, there are several persistent issues including non-uniform electron emission, lack of understanding regarding scandium’s role in the emission mechanism, and unreliable reproducibility in terms of scandate cathode fabrication. As a result, scandate cathodes have not yet been widely implemented in actual vacuum electron devices (VEDs).

The surface structure and chemical composition of multiple scandate cathodes – prepared with the powder using the liquid-solid (L-S) …

Investigation Of Transition-Metal Ions In The Nickel-Rich Layered Positive Electrode Materials For Lithium-Ion Batteries, Shuang Gao

Theses and Dissertations--Chemical and Materials Engineering

Layered lithium transition-metal oxides (LMOs) are used as the positive electrode material in rechargeable lithium-ion batteries. Because transition metals undergo redox reactions when lithium ions intercalate in and disintercalate from the lattice, the selection and composition of transition metals largely influence the electrochemical performance of LMOs. Recently, a Ni-rich compound, LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811), has drawn much attention. It is expected to replace its state-of-the-art cousins, LiCoO₂ (LCO) and LiNi_1/3Co_1/3Mn_1/3O₂ (NCM111), because of its higher capacity, lower cost, and reduced toxicity. However, the excess Ni, as a …

Synthesis, Design, And Evaluation Of The Fluorescent Detection Of Polychlorinated Biphenyls(Pcbs) In Aqueous System, Irfan Ahmad

Theses and Dissertations--Chemical and Materials Engineering

The exposure to halogenated persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), has been linked to numerous inflammatory diseases, including diabetes, cancer and lowered immune response. PCBs have low solubility in water, and they interact with other contaminants, making their detection quite challenging. While, there have been several attempts at improving the ease of detection and sensing of PCBs, gas chromatography-mass spectrometry (GC-MS) remains the gold standard. However, despite its ubiquitous use, GC-MS is a challenging technique that requires high skill and careful sample preparation, which are time-consuming and costly. As such, there is still a need to develop …

Understanding The Structure-Property-Performance Relationship Of Silicon Negative Electrodes, Jiazhi Hu

Theses and Dissertations--Chemical and Materials Engineering

Rechargeable lithium ion batteries (LIBs) have long been used to power not only portable devices, e.g., mobile phones and laptops, but also large scale systems, e.g., electrical grid and electric vehicles. To meet the ever increasing demand for renewable energy storage, tremendous efforts have been devoted to improving the energy/power density of LIBs. Known for its high theoretical capacity (4200 mAh/g), silicon has been considered as one of the most promising negative electrode materials for high-energy-density LIBs. However, diffusion-induced stresses can cause fracture and, consequently, rapid degradation in the electrochemical performance of Si-based negative electrodes. To mitigate the detrimental effects …

Effects Of Depositional Processes On Strength And Compressibility Of Sediments Using Elastic Shear Wave Velocity, Wisam Razzaq Muttashar

Theses and Dissertations--Earth and Environmental Sciences

Depositional processes are the most critical, complicated conditions that govern sediment properties and their variations, which in turn significantly affect the geotechnical behavior of the sediment. The complexity of depositional and post-depositional processes, which results in a variety of depositional environments, makes constructing a plausible model for the consolidation process of sediments difficult. The mutual influence between the temporal and spatial variation of depositional environments with their resultant physical and mechanical properties cause several compression issues, such as consolidation settlement and land subsidence, which mostly occur in estuarine-riverine regions throughout the world.

The first aim of this study is proposing …

Investigating The Feasibility Of Using Mesoporous Silica Particles To Deliver Glucose During Anaerobic Fermentation, Megan E. Walz

Theses and Dissertations--Biosystems and Agricultural Engineering

The study presented herein investigated a potential low-energy method to separate and concentrate glucose from a lignocellulosic hydrolysate. The motivation for this method was twofold: 1) to provide the fermentation microorganism an optimal glucose concentration and 2) to supply a fermentation media free of inhibitory compounds. Two sizes of porous silica particles (with 7 nm and 2.3 nm pores) were synthesized and their ability to adsorb glucose from solution confirmed. Next, the ability of two different microorganisms, Saccharomyces cerevisiae and Streptococcus bovis, to utilize sugars adsorbed to the porous silica particles was investigated.

Both the 7 nm and 2.3 …

Evaluation Of Air Movement In Equestrian Facilities And On Equine Athletes, Staci Elaine Mcgill

Theses and Dissertations--Biosystems and Agricultural Engineering

Ventilation and air movement are important aspects of animal agriculture and is frequently neglected in equine facilities. This paper discusses three different studies that examine different components of ventilation and air movement. One is a fan orientation study which examines how fans impact the stall environment, the second is a cooling study questioning whether forced air speed across a horse increases the rate of cool out after intense exercise, and the last is a survey examining ventilation, air quality, and health concerns in indoor arenas.

The stall fan study took place over two summers with the goal of determining how …

Evaluating The Influence Of The Forestry Reclamation Approach On The Hydrology Of Appalachian Coal Mined Lands, Morgan F. Gerlitz

Theses and Dissertations--Biosystems and Agricultural Engineering

The Appalachian Region is a rich and diverse forest ecosystem impacted by present and past mining activities. The Surface Mining Control and Reclamation Act (SMCRA) of 1977 was enacted to resolve many of the environmental problems caused by surfacing mining, such as landslides, erosion, flooding, and poor water quality. As with many solutions, this one came with its own set of environmental problems due to compaction and the introduction of aggressive non-native grasses and shrubs altering hydrologic processes and ecosystem function. The Forestry Reclamation Approach (FRA) is a method for re-establishing forested ecosystems on mined lands. This project evaluated the …

Design And Testing Of A Wind Energy Harnessing System For Forced Convective Drying Of Grain In Low Wind Speed, Warm And Humid Climates, Francis Akumabi Agbali

Theses and Dissertations--Biosystems and Agricultural Engineering

Forced convective drying using a wind turbine mechanically connected to a ventilation fan was hypothesized for low cost and rapid grain drying in developing countries. The idea was tested using an expandable wind turbine blade system with variable pitch, at low wind speeds in a wind tunnel. The design was based on empirical and theoretical models embedded in a graphical user interface (GUI) created to estimate airflow-power requirements for drying ear corn. Output airflow (0.0016 - 0.0052 m³kg^-1s^-1) increased within the study wind speed range (2.0 - 5.5 m/s). System efficiency peak (8.6%) was …

Removing Vehicle Speed From Apparent Wind Velocity, Austin M. Weiss

Theses and Dissertations--Biosystems and Agricultural Engineering

Variable-rate technologies for sprayer applications stand to increase efficacy by ensuring the right amount of chemical is applied at the right location. However, external environmental factors such as droplet drift caused by variable ambient condition, are not yet integrated into modern sprayer systems. Real-time wind velocity measurements can be used to control droplet spectra for reducing spray drift by actuating a variable-orifice nozzle. This work aimed to develop data processing methods needed to filter noise and remove vehicle speed from wind velocity measurements collected with an ultrasonic anemometer aboard a moving platform. Using a global navigation satellite system (GNSS), vehicle …

Lignin-Derived Carbon And Nanocomposite Materials For Energy Storage Applications, Wenqi Li

Theses and Dissertations--Biosystems and Agricultural Engineering

With a growing demand for electrical energy storage materials, lignin-derived carbon materials have received increasing attention in recent years. As a highly abundant renewable carbon source, lignin can be converted to a variety of advanced carbon materials with tailorable chemical, structural, mechanical and electrochemical properties through thermochemical conversion (e.g. pyrolysis). However, the non-uniformity in lignin structure, composition, inter-unit linkages and reactivity of diverse lignin sources greatly influence lignin fractionation from plant biomass, the pyrolysis chemistry, and property of the resulting carbon materials.

To introduce a better use of lignocellulosic biomass to biofuels and co-products, it is necessary to find novel …

Predictive Modeling Of Dc Arc Flash In 125 Volt System, Austin Cody Gaunce

Theses and Dissertations--Mining Engineering

Arc flash is one of the two primary hazards encountered by workers near electrical equipment. Most applications where arc flash may be encountered are alternating current (AC) electrical systems. However, direct current (DC) electrical systems are becoming increasingly prevalent with industries implementing more renewable energy sources and energy storage devices. Little research has been performed with respect to arc flash hazards posed by DC electrical systems, particularly energy storage devices. Furthermore, current standards for performing arc flash calculations do not provide sufficient guidance when working in DC applications. IEEE 1584-2002 does not provide recommendations for DC electrical systems. NFPA 70E …

Simplifying Techniques Applied To Computational Fluid Dynamics Modeling Of Methane Explosions, Laura Steeves

Theses and Dissertations--Mining Engineering

Traditional methods of studying underground coal mine explosions are limited to observations and data collected during experimental explosions. These experiments are expensive, time-consuming, and require major facilities, such as the Lake Lynn Experimental Mine. The development of computational fluid dynamics (CFD) modeling of explosions can help minimize the need for large-scale testing. This thesis utilized the commercial CFD software, SC/Tetra, to examine three case studies. The first case study modeled the combustion of methane in a scaled shock tube, measuring approximately 1 foot by 1 foot, by 20.5 feet long, with a methane cloud of 2.5 feet in length, at …

The Redesigned Vortecone: A Maintenance-Free Wet Scrubber Device, Allison Taylor

Theses and Dissertations--Mining Engineering

Dust creates health and safety issues in mining and there are several different ways to reduce the amount of respirable dust created. Dust particles also affect the operation and efficiency of mining equipment. One device currently used to reduce dust in a coal mine is a flooded-bed dust scrubber. These type of scrubbers are found on continuous miners and are designed to capture dust particles close to the cutting head. However, the fibrous screens on the flooded-bed dust scrubber clog easily reducing both production and the quality and quantity of air miners are exposed too. The flooded-bed dust scrubber was …

Operation And Process Control Development For A Pilot-Scale Leaching And Solvent Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources, Douglas Kweku Addo

Theses and Dissertations--Mining Engineering

The US Department of Energy in 2010 has identified several rare earth elements as critical materials to enable clean technologies. As part of ongoing research in REEs (rare earth elements) recovery from coal sources, the University of Kentucky has designed, developed and is demonstrating a ¼ ton/hour pilot-scale processing plant to produce high-grade REEs from coal sources. Due to the need to control critical variables (e.g. pH, tank level, etc.), process control is required. To ensure adequate process control, a study was conducted on leaching and solvent extraction control to evaluate the potential of achieving low-cost REE recovery in addition …

Dust Transportation And Settling Within The Mine Ventilation Network, Anand Kumar

Theses and Dissertations--Mining Engineering

Dust is ubiquitous in underground mine activities. Continuous inhalation of dust could lead to irreversible occupational diseases. Dust particles of size lower than 75.0 µm, also known as float coal dust, can trigger a coal dust explosion following a methane ignition. Ventilation air carries the float coal dust from the point of production to some distance before it’s deposited on the surfaces of underground coal mine. Sources of dust are widely studied, but study of dust transportation has been mainly based on experimental data and simplified models. An understanding of dust transportation in the mine airways is instrumental in …