Engineering Commons^™

Direct Measurement Of Crosstie-Ballast Interface Pressures Using Granular Material Pressure Cells, Travis James Watts

Theses and Dissertations--Civil Engineering

The magnitudes and relative pressure distributions transmitted to the crosstie-ballast interface of railroad track significantly influences the subsequent behavior and performance of the overall track structure. If the track structure is not properly designed to distribute the heavy-axle loads of freight cars and locomotives, deficiencies and inherent failures of the crossties, ballast, or underlying support layers can occur, requiring substantial and frequent maintenance activities to achieve requisite track geometrical standards. Incorporating an understanding of the pressure distribution at the crosstie-ballast interface, appropriate designs can be applied to adequately provide a high performing and long-lasting railroad track. Although this can be …

Understanding Inhibition Of A Biodesulfurization Enzyme To Improve Sulfur Removal From Petroleum, Yue Yu

Theses and Dissertations--Chemical and Materials Engineering

The biodesulfurization 4S-pathway is a promising complementary enzymatic approach to remove sulfur from recalcitrant thiophenic derivatives in petroleum products that remain from conventional hydrodesulfurization method without diminishing the calorific value of oil. The final step of this pathway involves the carbon-sulfur bond cleavage from HBPS, and the production of the final products 2-hydroxybiphenyl (HBP) and sulfite, has been recognized as the rate-limiting step, partially as a result of product inhibition. However, the mechanisms and factors responsible for product inhibition in the last step have not been fully understood. In this work, we proposed a computational investigation using molecular dynamic simulations …

Automated Tree-Level Forest Quantification Using Airborne Lidar, Hamid Hamraz

Theses and Dissertations--Computer Science

Traditional forest management relies on a small field sample and interpretation of aerial photography that not only are costly to execute but also yield inaccurate estimates of the entire forest in question. Airborne light detection and ranging (LiDAR) is a remote sensing technology that records point clouds representing the 3D structure of a forest canopy and the terrain underneath. We present a method for segmenting individual trees from the LiDAR point clouds without making prior assumptions about tree crown shapes and sizes. We then present a method that vertically stratifies the point cloud to an overstory and multiple understory tree …

Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford

Theses and Dissertations--Earth and Environmental Sciences

Landslide characterization and hazard assessments require multidisciplinary approaches that connect geologic processes with geotechnical parameters. Field monitoring of hydrologic variables such as water content and water potential, coupled with geoelectrical measurements that can establish relationships used for geotechnical and landslide hazard investigations is deficient.

This study brings together different techniques to develop a methodology that connects geoelectrical measurements and shear strength. A field-based framework was established that includes (1) analysis of long-term soil moisture fluctuations within different landslides (2) establishment of constitutive and new equations that test the use of electrical conductivity to predict soil-water relationships and shear strength (3) …

Fractionation Of Lignin Derived Compounds From Thermochemically Processed Lignin Towards Antimicrobial Properties, Luke A. Dodge

Theses and Dissertations--Biosystems and Agricultural Engineering

The overuse of antibiotics in agriculture is an emerging concern, due to their potential detrimental impact to the environment. This study focuses on exploring antimicrobial properties of lignin derived compounds. Lignin is of interest as a feedstock to replacing some petroleum-based chemicals and products because it is the most abundant source of renewable aromatic compounds on the planet. Two lignin rich streams, residues from the enzymatic hydrolysis of dilute acid and alkaline pretreated corn stover, were decomposed via pyrolysis and hydrogenolysis, respectively. The resulting liquid oils were subjected to sequential extractions using a series of solvents with different polarities. Chemical …

Pre-Wilting Burley Tobacco To Enhance Manual And Mechanical Harvesting And Housing, Ben C. Herbener

Theses and Dissertations--Biosystems and Agricultural Engineering

Traditionally, burley tobacco has been harvested by hand because the green plant weight, volume, and leaf fragility make mechanical harvesting very challenging. This study examined possible ways to wilt a plant still standing in the field (termed ‘pre-wilting’) to reduce weight, volume, and leaf fragility. Several methods of pre-wilting burley tobacco plants in the field were explored including: root pruning, stalk girdling, freezing with liquid nitrogen, and burning. Experiments were conducted in three locations over three consecutive years during the tobacco harvest season. Leaf breaking angle, leaf moisture content and time-lapse photography were investigated as methods to quantify treatment effects …

Assessing The Spatial Accuracy And Precision Of Lidar For Remote Sensing In Agriculture, Surya Saket Dasika

Theses and Dissertations--Biosystems and Agricultural Engineering

The objective of this whole study was to evaluate a LiDAR sensor for high-resolution remote sensing in agriculture. A linear motion system was developed to precisely control the dynamics of LiDAR sensor in effort to remove uncertainty in the LiDAR position/velocity while under motion. A user control interface was developed to operate the system under different velocity profiles and log LiDAR data synchronous to the motion of the system. The LiDAR was then validated using multiple test targets with five different velocity profiles to determine the effect of sensor velocity and height above a target on measurement error. The results …

Classifying Soil Moisture Content Using Reflectance-Based Remote Sensing, Ali Hamidisepehr

Theses and Dissertations--Biosystems and Agricultural Engineering

The ability to quantify soil moisture spatial variability and its temporal dynamics over entire fields through direct soil observations using remote sensing will improve early detection of water stress before crop physiological or economic damage has occurred, and it will contribute to the identification of zones within a field in which soil water is depleted faster than in other zones of a field.

The overarching objective of this research is to develop tools and methods for remotely estimating soil moisture variability in agricultural crop production. Index-based and machine learning methods were deployed for processing hyperspectral data collected from moisture-controlled samples. …

Development Of A Decision Support System For Capacity Planning From Grain Harvest To Storage, Aaron P. Turner

Theses and Dissertations--Biosystems and Agricultural Engineering

This dissertation investigated issues surrounding grain harvest and transportation logistics. A discrete event simulation model of grain transportation from the field to an on-farm storage facility was developed to evaluate how truck and driver resource constraints impact material flow efficiency, resource utilization, and system throughput. Harvest rate and in-field transportation were represented as a stochastic entity generation process, and service times associated with various material handling steps were represented by a combination of deterministic times and statistical distributions. The model was applied to data collected for three distinct harvest scenarios (18 total days). The observed number of deliveries was within …

High Resolution Sensing Of Nitrate Dynamics In A Mixed-Use Appalachian Watershed: Quantifying Nitrate Fate And Transport As Influenced By A Backwater Riparian Wetland, Alexandria Kosoma Jensen

Theses and Dissertations--Biosystems and Agricultural Engineering

As harmful algal blooms begin to appear in unexpected places such as rivers in predominantly forested systems, a better understanding of the nutrient processes within these contributing watersheds is necessary. However, these systems remain understudied. Utilization of high-resolution water quality data applied to deterministic numerical modeling has shown that a 0.42% watershed area backwater riparian wetland along the Ohio River floodplain can attenuate 18.1% of nitrate discharged from local mixed-use watersheds and improves in performance during high loading times due to coinciding increased hydrological connectivity and residence times of water in these wetlands. Loading from the Fourpole Creek watershed was …

Valorization Of Proso Millet And Spent Grain For Extruded Snack Development, Joseph Woomer

Theses and Dissertations--Biosystems and Agricultural Engineering

Fast-paced lifestyles result in consumers replacing traditional meals with on-the-go snack foods. In general, snacks are higher in saturated fats and simple sugars, and pose health concerns for consumers, which prompts the need for healthy nutritious alternatives to common snacks. Proso millet is a nutritious, and fast growing gluten free cereal. Spent grain (SG), the main by-product of brewing and distilling, contains high amount of protein and insoluble fibers. This study utilized proso millet and spent grain in the production of an extruded expanded snack, demonstrating their appropriateness as an ingredient in food production.

The first objective of this study …

Determining Heat Production Of Black Solderi Fly Larvae, Hermetia Illucens, To Design Rearing Structures At Livestock Facilities, Travis Mceachern

Theses and Dissertations--Biosystems and Agricultural Engineering

Due to their small size and ectothermic biology, the heat production of insects and insect larvae is hard to quantify. However, knowing the amount of heat production, as well as ammonia production of insects may be beneficial for commercial production of valuable insect species. Black soldier fly larvae (BSFL) are of interest in the agricultural industry because they quickly consume organic waste and have high amounts of protein and fat in their bodies. It has been proposed that BSFL be used to manage livestock waste, while serving as a high-protein feed source for livestock animals. To efficiently rear BSFL, it …

Understanding The Thermodynamics And Oral Absorption Potential Of Pharmaceutical Amorphous Solid Dispersions, Nico Setiawan

Theses and Dissertations--Pharmacy

Supersaturating drug delivery systems, such as amorphous solid dispersions (ASDs), have been used extensively to elevate the apparent solubility and oral bioavailability of poorly water-soluble drugs. However, despite the numerous examples of success in increasing solubility and oral bioavailability using ASDs, physical stability challenges remain as formulators seek to employ high drug loading for cost reduction and improved patient compliance. Therefore, stability in both the solid and solution state must be considered for ASDs to be successful. In the solid state, the drug must remain amorphous in the solid matrix throughout the shelf life of the product. Although excipients, such …

Characterization And Engineering Of Human Proteins As Therapeutic Candidates, Kyungbo Kim

Theses and Dissertations--Pharmacy

Protein engineering has been a useful tool in the fight against human diseases. Human insulin was the first recombinant DNA-derived therapeutic protein (Humulin^®) approved by the US FDA in 1982. However, many of the early protein drugs were only recombinant versions of natural proteins with no modification of their primary amino acid sequence and most of them did not make optimal drug products mainly due to their short half-life or suboptimal affinity, leading to poor therapeutic efficacy. The difficulty in the large-scale production of some therapeutic proteins was another important issue. In the past three decades, different protein …

Evaluation And Prevention Of Spontaneous Combustion During Handling And Storage Of Coal, Amir E. Najarzadeh

Theses and Dissertations--Mining Engineering

Spontaneous combustion of coal has historically been a major problem for the coal industry, predominantly during storage and transportation. Various methods have been used in the laboratory for evaluating the propensity of different coal sources to self-heat. However, the heterogeneity of coal and the complexity of the system has resulted in inconsistencies and sometimes conflicting results as indicated by the findings reported in several publications.

The primary objective of the current study was to build a laboratory scale apparatus that simulates the condition of a coal stockpile to evaluate the events leading to spontaneous combustion and develop potential remedies. As …

Investigation Of The Effectiveness Of An Integrated Flooded-Bed Dust Scrubber On A Longwall Shearer Through Laboratory Testing And Cfd Simulation, Sampurna N. Arya

Theses and Dissertations--Mining Engineering

Dust generation at an underground coal mine working face continues to be a health and safety issue. Prolonged exposure to high concentrations of airborne respirable dust can cause a debilitating and often fatal respiratory disease called Black Lung. In addition, the deposition of float dust in mine return airways poses a serious safety hazard if not sufficiently diluted with inert rock dust. A localized methane explosion can transition into a self-propagating dust explosion. Since dust is a byproduct of various mining activities, such as cutting and loading, crushing, and transportation, the dust-related issues cannot be totally eliminated. However, the adverse …

Investigation Of Environmental Cadmium Sources In Eastern Kentucky, Elizabeth Maher

Theses and Dissertations--Mining Engineering

Utilizing data collected by the University of Kentucky Lung Cancer Research Initiative (LCRI), this study investigated potential mining-related sources for the elevated levels of cadmium in Harlan and Letcher counties. Statistical analyses for this study were conducted utilizing SAS. A number of linear regression models and logarithmic models were used to evaluate the significance of the data. The linear regression models consisted of both simple and multivariate types, with the simple models seeking to establish significance between the potential sources and urine cadmium levels and the multivariate models seeking both to identify any statistically significant linear relationships between source types …

Numerical Analysis Of Stress Distributions For Multiple Backfilled Stopes, Christopher Richard Newman

Theses and Dissertations--Mining Engineering

Over the past three decades, technological innovations with respect to cemented paste backfill (CPB) as a means of ground support has allowed for increased production within the mining industry, management mine waste costs, as well as the improvement of the overall health and safety of underground mining operations. Despite the extensive use of this relatively new ground support material, many fundamental factors affecting the design of safe and economical CPB structures are still not well understood.Recently, a significant amount of academic and industry research has been conducted to better understanding the distribution of stress with respect to primary-secondary extraction sequencing …

Analysis Of Underground Coal Mine Structures Subjected To Dynamic Events, Brooklynn Yonts

Theses and Dissertations--Mining Engineering

Underground coal mine explosions pose a significant threat to infrastructure such as mine seals and refuge alternative chambers. After a mine seal failed in the Sago mine disaster, which took the life of 12 miners, design requirements were reexamined and improved. However, most research being completed on the analysis of mine structures during an explosive event focuses solely on peak pressure values, while ignoring the impact of pressure duration. This study investigates the impact pressure duration, waveform shape, and impulse have on structural displacement, while also exploring what pressures and duration can be expected during a mine explosion. Additionally, the …

Synthesis Of Single-Hole Vibration Waveforms From A Mining Blast, Lifeng Li

Theses and Dissertations--Mining Engineering

In mining engineering, blast-induced ground vibration has become one of the major concerns when production blasts are conducted, especially when the mining areas and the blast sites are near inhabited areas or infrastructure of interest. To comply with regulations, a vibration monitoring program should be developed for each mining operation. The vibration level, which is usually indicated by the peak particle velocity (PPV) of the vibration waveform, should fall below the maximum allowable values. Ideally, when blasting is near structures of interest (power towers, dams, houses, etc.), the vibration level (PPV) should be predicted prior to the actual production blasts. …

Thermo-Mechanical Coupling For Ablation, Rui Fu

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to investigate the thermal stress and expansion as well as the associated strain effect on material properties caused by high temperature and large temperature gradient, a two-way thermo-mechanical coupling solver is developed. This solver integrates a new structural response module to the Kentucky Aerothermodynamics and Thermal response System (KATS) framework. The structural solver uses a finite volume approach to solve either hyperbolic equations for transient solid mechanics, or elliptic equations for static solid mechanics. Then, based on the same framework, a quasi-static approach is used to couple the structural response and thermal response to estimate the thermal expansion …

Pressure-Driven Stabilization Of Capacitive Deionization, Landon S. Caudill

Theses and Dissertations--Mechanical and Aerospace Engineering

The effects of system pressure on the performance stability of flow-through capacitive deionization (CDI) cells was investigated. Initial data showed that the highly porous carbon electrodes possessed air/oxygen in the micropores, and the increased system pressure boosts the gases solubility in saline solution and carries them out of the cell in the effluent. Upon applying a potential difference to the electrodes, capacitive-based ion adsorption occurs in competition with faradaic reactions that consume oxygen. Through the addition of backpressure, the rate of degradation decreases, allowing the cell to maintain its salt adsorption capacity (SAC) longer. The removal of oxygen from the …

Wing-Tip Vortex Evolution In Turbulence, Hari Charan Ghimire

Theses and Dissertations--Mechanical and Aerospace Engineering

Planar and stereo particle image velocimetry measurements were conducted of a wing-tip vortex decaying in free-stream turbulence in order to understand the evolution of a vortex and its decay mechanism. The vortex decayed faster in the presence of turbulence. The decay of the circulation was found to be almost entirely due to a decrease in circulation of the vortex core, caused by the relative decrease in peak tangential velocity without a corresponding increase in core radius. These events were found to be connected with the stripping of core fluid from the vortex core. The increased rate of decay of the …

Characterization Of The Shape Memory Behavior Of High Strength Nitihfpd Shape Memory Alloys, Guher P. Toker

Theses and Dissertations--Mechanical and Aerospace Engineering

NiTiHf alloys have emerged as potential materials for applications requiring high transformation temperatures (> 100 °C) with high strength and work output. Although they have high transformation temperatures, their low damping capacity, brittleness and poor superelastic responses (of Ti-rich NiTiHf) impedes their wider usage in many industrial applications. In this study, the quaternary alloying element of Pd has been added to NiTiHf alloys to improve and tailor their shape memory behavior,. NiTiHfPd alloys were systematically examined regarding the composition and heat treatments effects.

Effects of substituting Hf with Ti on the shape memory behavior of NiTHfPd alloys were investigated. There …

Regression Analysis Of Factors Impacting Problem Solving Engagement Within Lean Systems Implementation, David M. Parsley Ii

Theses and Dissertations--Mechanical and Aerospace Engineering

Organizations around the world have attempted to implement the concepts of the Toyota Production System (TPS), commonly referred to as Lean, with limited sustainable success. The central principles of TPS, continuous improvement and respect for people, are grounded in the Japanese values of Monozukuri and Hitozukuri. Monozukuri deals with creating or making a product, while Hitozukuri conveys the idea of developing people through learning. In order for organizations to adopt these values they must have a system that engages employees at all levels in applying problem solving to improve their work. This research uses organizational assessments obtained from a variety …

Characterization Of Rotary Bell Atomizers Through Image Analysis Techniques, Jacob E. Wilson

Theses and Dissertations--Mechanical and Aerospace Engineering

Three methods were developed to better understand and characterize the near-field dynamic processes of rotary bell atomization. The methods were developed with the goal of possible integration into industry to identify equipment changes through changes in the primary atomization of the bell. The first technique utilized high-speed imaging to capture qualitative ligament breakup and, in combination with a developed image processing technique and PIV software, was able to gain statistical size and velocity information about both ligaments and droplets in the image data. A second technique, using an Nd:YAG laser with an optical filter, was used to capture size statistics …

Intermittency Effects On The Universality Of Local Dissipation Scales In Turbulent Boundary Layer Flows With And Without Free-Stream Turbulence, Sabah Falih Habeeb Alhamdi

Theses and Dissertations--Mechanical and Aerospace Engineering

Measurements of the small-scale dissipation statistics of turbulent boundary layer flows with and without free-stream turbulence are reported for Re_τ ≈ 1000 (Re_θ ≈ 2000). The scaling of the dissipation scale distribution is examined in these two boundary conditions of external wall-bounded flow.

Results demonstrated that the local large-scale Reynolds number based on the measured longitudinal integral length-scale fails to properly normalize the dissipation scale distribution near the wall in these two free-stream conditions, due to the imperfect characterization of the upper bound of the inertial cascade by the integral length-scale. When a length-scale based on Townsend's …

Laminar And Turbulent Study Of Combustion In Stratified Environments Using Laser Based Measurements, Stephen William Grib

Theses and Dissertations--Mechanical and Aerospace Engineering

Practical gas turbine engine combustors create extremely non-uniform flowfields, which are highly stratified making it imperative that similar environments are well understood. Laser diagnostics were utilized in a variety of stratified environments, which led to temperature or chemical composition gradients, to better understand autoignition, extinction, and flame stability behavior. This work ranged from laminar and steady flames to turbulent flame studies in which time resolved measurements were used.

Edge flames, formed in the presence of species stratification, were studied by first developing a simple measurement technique which is capable of estimating an important quantity for edge flames, the advective heat …

Scale Models Of Acoustic Scattering Problems Including Barriers And Sound Absorption, Nan Zhang

Theses and Dissertations--Mechanical and Aerospace Engineering

Scale modeling has been commonly used for architectural acoustics but use in other noise control areas is nominal. Acoustic scale modeling theory is first reviewed and then feasibility for small-scale applications, such as is common in the electronics industry, is investigated. Three application cases are used to examine the viability. In the first example, a scale model is used to determine the insertion loss of a rectangular barrier. In the second example, the transmission loss through parallel tubes drilled through a cylinder is measured and results are compared to a 2.85 times scale model with good agreement. The third example …

NoX Formation In Light-Hydrocarbon, Premixed Flames, Robert T. Hughes

Theses and Dissertations--Mechanical and Aerospace Engineering

This study explores the reactions and related species of NO_x pollutants in methane flames in order to understand their production and consumption during the combustion process. To do this, several analytical simulations were run to explore the behavior of nitrogen species in the pre-flame, post- flame, and reaction layer regions. The results were then analyzed in order to identify all "steady-state" species in the flame as well as the determine all the unnecessary reactions and species that are not required to meet a defined accuracy. The reductions were then applied and proven to be viable.