Engineering Commons^™

Bioerodible Calcium Sulfate Bone Grafting Substitutes With Tailored Drug Delivery Capabilities, Bryan R. Orellana

Theses and Dissertations--Biomedical Engineering

Bone regeneration or augmentation is often required prior to or concomitant with implant placement. With the limitations of many existing technologies, a biologically compatible synthetic bone grafting substitute that is osteogenic, bioerodible, and provides spacing-making functionality while acting as a drug delivery vehicle for bioactive molecules could provide an alternative to ‘gold standard’ techniques.

In the first part of this work, calcium sulfate (CS) space-making synthetic bone grafts with uniformly embedded poly(β-amino ester) (PBAE) biodegradable hydrogel particles was developed to allow controlled release of bioactive agents. The embedded gel particles’ influence on the physical and chemical characteristics of CS was …

Development Of Cementitious Materials For Adhesion Type Applications Comprising Calcium Sulfoaluminate (Csa) Cement And Latex Polymer, Joshua V. Brien

Theses and Dissertations--Civil Engineering

The objective of this research was to develop high performing polymer modified calcium sulfoaluminate (CSA) cement materials for use in applications requiring superior adhesion characteristics. Little information is available describing interactions of CSA cement containing minor phase tri-calcium aluminate (C₃A) with commonly used admixtures. Given the scarcity of information, a basic approach for developing cementitious materials was followed. The basic approach consisted of four tasks: cement design, admixture design, polymer design and testing developed materials. The iterative, time consuming process is necessary for understanding the influence of specific constituent components on overall system behavior. Results from the cement …

Mucoadhesive Films For Treatment Of Local Oral Disorders: Development, Characterization And In Vivo Testing, Sandeep K. Ramineni

Theses and Dissertations--Biomedical Engineering

Mucoadhesive drug delivery systems which are being used from 1980’s to avoid first pass metabolism of drugs, commercially exist for only systemic drug delivery with fast erosion times (15-60 min), that may not be appropriate for local oral disorders. The goal of this research was to develop and characterize mucoadhesive films with flexibility of carrying different drugs and proteins and provide sustained release for local treatment of oral disorders.

Mucoadhesive films composed of polyvinylpyrrolidone (PVP) and carboxymethlycellulose (CMC) were formulated with imiquimod, an immune response modifier. Problems such as solubilization of imiquimod to increase drug loading, uniformity in films and …

Precise Control Of Carbon Nanotube Membrane Structure For Enzyme Mimetic Catalysis, Nicholas W. Linck

Theses and Dissertations--Chemical and Materials Engineering

The ability to fabricate a charge-driven water pump is a crucial step toward mimicking the catalytic ability of natural enzyme systems. The first step towards making this water pump a reality is the ability to make a carbon nanotube (CNT) membrane with uniform, 0.8 nm pore diameter. Proposed in this work is a method for synthesizing these carbon nanotubes via VPI-5 zeolite templated, transition metal catalyzed pyrolysis. Using a membrane composed of these CNTs, it is possible to get water molecules to flow single file at a high flow rate, and to orient them in such a way that would …

Clogging Of Fine Sediment Within Gravel Substrates: Macro-Analysis And Momentum-Impulse Model, Davis Huston

Theses and Dissertations--Civil Engineering

An understanding of the clogging of fine sediments within gravel substrates is advanced through the use of dimensional analysis and macro-analysis of clogging experiments in hydraulic flumes. Dimensional analysis is used to suggest that the dimensionless clogging depth can be collapsed using the original and adjusted bed-to-grain ratios, substrate porosity, roughness Reynolds number, and Peclet number. Macro-analysis followed by statistical analysis of 146 experimental test results of fine sediment deposition in gravel substrates suggests that the dimensionless clogging depth can be collapsed using the substrate porosity and roughness Reynolds number reflecting the processes of gravity settling and turbulence induced fluid …

Relationships Of Long-Term Bisphosphonate Treatment With Measures Of Bone Microarchitecture And Mechanical Competence, Jonathan Joseph Ward

Theses and Dissertations--Biomedical Engineering

Oral bisphosphonate drug therapy is a common and effective treatment for osteoporosis. Little is known about the long-term effects of bisphosphonates on bone quality. This study examined the structural and mechanical properties of trabecular bone following 0-16 years of bisphosphonate treatment. Fifty-three iliac crest bone samples of Caucasian women diagnosed with low turnover osteoporosis were identified from the Kentucky Bone Registry. Forty-five were treated with oral bisphosphonates for 1 to 16 years while eight were treatment naive. A section of trabecular bone was chosen from a micro-computed tomography (Scanco µCT 40) scan of each sample for a uniaxial linearly elastic …

Additives To Control Mechanical Properties And Drug Delivery Of Injectable Polymeric Scaffolds, Paul Fisher

Theses and Dissertations--Biomedical Engineering

In situ forming implants (ISIs) are popular due to their ease of use and local drug delivery potential, but they suffer from high initial drug burst, and release behavior is tied closely to solvent exchange and polymer properties. Additionally, such systems are traditionally viewed purely as drug delivery devices rather than potential scaffold materials due to their poor mechanical properties and minimal porosity. The aim of this research was to develop an injectable ISI with drug release, mechanical, and microstructural properties controlled by micro- and nanoparticle additives.

First, an injectable ISI was developed with appropriate drug release kinetics for orthopedic …

Decelerating Open Channel Flow Over Gravel: Turbulence Structure & Sensor Development, Robert L. Stewart Iii

Theses and Dissertations--Civil Engineering

This dissertation describes investigations of fully turbulent decelerating hydraulically roughbed flow over gravel and the development of technology to measure turbulence and associated sediment transport in streams. Theory is developed for predicting velocity distributions in simple uniform flow using the asymptotic invariance principle and tested using laboratory and field collected data. A mixed scale is developed that accounts for bed derived turbulent structures throughout the flows depth and is used to parameterize the external boundary’s effect on the flow for the logarithmic and outer layers. The asymptotic invariance principle and similarity analysis is conducted for the equations of motion in …

Evaluating Sampling Strategies For Rainfall Simulation Studies And Surface Transport Of Antibiotics From Swine Manure Applied To Fescue Plots, Holly K. Enlow

Theses and Dissertations--Biosystems and Agricultural Engineering

Antibiotics are commonly used in animal agriculture to treat and prevent diseases and promote growth. Unfortunately, large amounts of antibiotics are not metabolized, but instead are excreted in urine and feces. Rainfall simulation studies were used to investigate the transport of the antibiotic oxytetracycline and various constituents in runoff and the ability of alum to reduce pollutant transport. Runoff samples were collected at several points during the simulated storm event from each of four treatments: control (C), manure only (M), manure and antibiotics (MA), and manure, antibiotics and alum (MAA). Flow-weighted composite samples were created and compared to the flow …

Sequential Co-Culture Of Anaerobic Bacteria On Switchgrass In A Continuous Flow-Through Reactor For Biofuel Production, Noelia M. Elia

Theses and Dissertations--Biosystems and Agricultural Engineering

Solid substrate cultivation (SSC) using lignocellulosic non-food feedstock, such as switchgrass, is an alternative for advanced biofuel production. Acetone-Butanol-Ethanol (ABE) fermentation in two stages using a sequential culture of microorganisms from the class Clostridia is an approach proposed to increase the butanol production.

The goal was to test the efficacy of a sequential culture on high solid substrate cultivation in batch and continuous cultivation, and to evaluate conditions to optimize butanol production using switchgrass as substrate.

Initial batch experiments were used to determine particle size effect, choice of solvent producer and pretreatment evaluation: The effect of particle size on gas …

Storm Hydrograph Characteristics And Curve Numbers Of Loose-Dumped Spoil In Eastern Kentucky, Mary Katherine Weatherford

Theses and Dissertations--Biosystems and Agricultural Engineering

Traditional mine reclamation often results in highly compacted lands which prohibit tree growth and survival, reduce infiltration rates, and increase runoff. In 2005, six 0.4 ha plots were constructed on the Bent Mountain surface mine in eastern KY by the University of Kentucky in accordance with Forestry Reclamation Approach’s low compaction guidelines. The plots consisted of two replications each of (1) brown weathered sandstone (BROWN), (2) gray unweathered sandstone (GRAY), (3) and a combination of both sandstones and shales (MIXED). The goal of this project was to assess the hydrologic performance on a storm event basis (monitoring years 2012-2013) of …

Low Cost Flow Sensing For Field Sprayers, Yue Zhang

Theses and Dissertations--Biosystems and Agricultural Engineering

Precisely measuring the flow rate in sprayers is a key technology to precision agriculture. With the development of advanced technologies, the demand for the ability to measure flow rate of individual nozzle has become more important and urgent.

This paper investigates the possibility of developing a low-cost flow rate measurement technique. The technique is based on analyzing the acoustic signal from a microphone placed near the nozzle tip. A comparison between acoustic signal and vibration signal was made to study the relations between them. Then several possible locations of the microphone for measuring flow rate were tested and compared, and …

Quantification Of Factors Governing Drug Release Kinetics From Nanoparticles: A Combined Experimental And Mechanistic Modeling Approach, Kyle Daniel Fugit

Theses and Dissertations--Pharmacy

Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies.

A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release …

Multiscale Modeling Of The Mine Ventilation System And Flow Through The Gob, William Chad Wedding

Theses and Dissertations--Mining Engineering

The following dissertation introduces the hazard of methane buildup in the gob zone, a caved region behind a retreating longwall face. This region serves as a reservoir for methane that can bleed into the mine workings. As this methane mixes with air delivered to the longwall panel, explosive concentrations of methane will be reached.

Computational fluid dynamics (CFD) is one of the many approaches to study the gob environment. Several studies in the past have researched this topic and a general approach has been developed that addresses much of the complexity of the problem. The topic of research herein presents …

Development Of Industry Oriented Cfd Code For Analysis / Design Of Face Ventilation Systems, Todor P. Petrov

Theses and Dissertations--Mining Engineering

Two of the main safety and health issues recognized during deep cut coal mining are methane and dust hazards. Advances in continuous miner technology have improved safety and productivity. However, these advances have created some environmental problems, notably more dust and methane being generated at the face during coal extraction.

Results of studies performed in the last three decades concerning the face ventilation for deep cut mining showed very complicated airflow behavior. The specifics of flow patterns developed by the face ventilation systems presents significant challenge for analytical description even for equipment-free entry. Fortunately, there are methods, such as numerical …

Fragmentation Analysis In The Dynamic Stress Wave Collision Regions In Bench Blasting, Catherine E. Johnson

Theses and Dissertations--Mining Engineering

The first step in many mining operations is blasting, and the purpose of blasting is to fragment the rock mass in the most efficient way for that mine site and the material end use. Over time, new developments to any industry occur, and design and implementation of traditional techniques have to change as a consequence. Possibly the greatest improvement in blasting in recent years is that of electronic detonators. The improvements related to safety and increased fragmentation have been invaluable. There has been ongoing debate within the explosives industry regarding two possible theories for this. Shorter timing delays that allow …

Evaluation Of Overpressure Wave Transition By Airblast Overpressure And Shock Wave Attenuation Analysis Using A Small Black Powder Charge, William R. Weitzel

Theses and Dissertations--Mining Engineering

Eight flush mount pressure sensors were used in a series of 3 test sequences to measure air overpressure produced by a firecracker. Overpressure was recorded at a range of 1 inch to 21 inches away from detonation, and charge weight was determined to be 0.1mg of black powder. Air overpressure prediction equations were developed from test series then compared to collected data for subsequent tests. Overpressure wave velocity was measured using wave arrival time and distance between sensors. This wave velocity was compared to calculated wave velocity using overpressure and ideal gas law. Overpressure and wave velocity are directly related …

Computational Investigation Of Injectable Treatment Strategies For Myocardial Infarction, Hua Wang

Theses and Dissertations--Mechanical and Aerospace Engineering

Heart failure is an important medical disease and impacts millions of people throughout the world. In order to treat this problem, biomaterial injectable treatment injected into the myocardium of the failing LV are currently being developed. Through this treatment, the biomaterial material injections can reduce wall stresses during the cardiac remodeling process. By using computational techniques to analyze the effects of a treatment involving the injection of biomaterial material into the LV after MI, the material parameters of the hydrogel injections can be optimized. The results shows that the hydrogel injections could reduce the global average fiber stress and the …

An Analysis Of Energy Resources Utilization For Two Metal Joining Manufacturing Processes, Jonathan Gasser

Theses and Dissertations--Mechanical and Aerospace Engineering

Sustainable manufacturing involves utilizing energy resources efficiently. Currently, the state of sustainability for a given manufacturing process is described by most in a qualitative sense as opposed to using quantitative metrics. This thesis offers a segment of analysis needed to understand the state of sustainability in the context of energy resource utilization. This was accomplished by measuring the order of magnitude difference between the energy consumption of a manufacturing process vs. the theoretical minimum amount of energy required to complete the same task (aluminum T-joint bond). This analysis was completed for a TIG welding process and a controlled atmosphere brazing …

Axial Compressor Flow Behavior Near The Aerodynamic Stability Limit, Bradley D. Butler

Theses and Dissertations--Mechanical and Aerospace Engineering

In this investigation, casing mounted high frequency response pressure transducers are used to characterize the flow behavior near the aerodynamic stability limit of a low speed single stage axial flow compressor. Time variant pressure measurements are acquired at discrete operating points up to the stall inception point and during the transition to rotating stall, for a length of time no shorter than 900 rotor revolutions. The experimental data is analyzed using multiple techniques in the time and frequency domains.

Experimental results have shown an increase in the breakdown of flow periodicity as the flow coefficient is reduced. Below a flow …

Theoretical Study Of Thermal Analysis Kinetics, Yunqing Han

Theses and Dissertations--Mechanical and Aerospace Engineering

In the past decades, a great variety of model fitting and model free (isoconversional) methods have been developed for extracting kinetic parameters for solid state reactions from thermally stimulated experimental data (TGA, DSC, DTA etc.). However, these methods have met with significant controversies about their methodologies. Firstly, model-fitting methods have been strongly criticized because almost any reaction mechanism can be used to fit the experimental data satisfactorily with drastic variations of the kinetic parameters, and no good criterion exists to tell which mechanism is the best choice. Secondly, previous model free methods originated from the isoconversional principle, which is often …

Investigation Of Drilling Performance In Cryogenic Drilling On Cfrp Composite Laminates, Tian Xia

Theses and Dissertations--Mechanical and Aerospace Engineering

In recent years, there has been a substantial growth in the application of carbon fiber reinforced plastic (CFRP) composite materials in automobile and aerospace industries due to their superior properties such as lightweight, high strength, excellent corrosion resistance, and minimal fatigue concerns. The present study evaluates the drilling performance of woven carbon fiber reinforced plastics under both dry and cryogenic cooling conditions using uncoated solid carbide drill with a through-hole for coolant application.

The effects of the cooling conditions and the cutting parameters on drilling performance in drilling CFRP were evaluated in terms of generated thrust force, torque, cutting edge …

Shape Memory Behavior Of Single And Polycrystalline Nickel Rich Nickel Titanium Alloys, Irfan Kaya

Theses and Dissertations--Mechanical and Aerospace Engineering

NiTi is the most commonly used shape memory alloy (SMA) and has been widely used for bio-medical, electrical and mechanical applications. Nickel rich NiTi shape memory alloys are coming into prominence due to their distinct superelasticity and shape memory properties as compared to near equi-atomic NiTi shape memory alloys. Besides, their lower density and higher work output than steels makes these alloys an excellent candidate for aerospace and automotive industry. Shape memory properties and phase transformation behavior of high Ni-rich Ni₅₄Ti₄₆ (at.%) polycrystals and Ni-rich Ni₅₁Ti₄₉ (at.%) single-crystals are determined. Their properties are sensitive …

Finite Element Modeling And Fabrication Of An Sma-Smp Shape Memory Composite Actuator, Mohammad Souri

Theses and Dissertations--Mechanical and Aerospace Engineering

Shape memory alloys and polymers have been extensively researched recently because of their unique ability to recover large deformations. Shape memory polymers (SMPs) are able to recover large deformations compared to shape memory alloys (SMAs), although SMAs have higher strength and are able to generate more stress during recovery.

This project focuses on procedure for fabrication and Finite Element Modeling (FEM) of a shape memory composite actuator. First, SMP was characterized to reveal its mechanical properties. Specifically, glass transition temperature, the effects of temperature and strain rate on compressive response and recovery properties of shape memory polymer were studied. Then, …

Estimating Passive Material Properties And Fiber Orientation In A Myocardial Infarction Through An Optimization Scheme Using Mri And Fe Simulation, Dimitri Mojsejenko

Theses and Dissertations--Mechanical and Aerospace Engineering

Myocardial infarctions induce a maladaptive ventricular remodeling process that independently contributes to heart failure. In order to develop effective treatments, it is necessary to understand the way and extent to which the heart undergoes remodeling over the course of healing. There have been few studies to produce any data on the in-vivo material properties of infarcts, and much less on the properties over the time course of healing. In this paper, the in-vivo passive material properties of an infarcted porcine model were estimated through a combined use of magnetic resonance imaging, catheterization, finite element modeling, and a genetic algorithm optimization …

Precipitation, Orientation And Composition Effects On The Shape Memory Properties Of High Strength Nitihfpd Alloys, Emre Acar

Theses and Dissertations--Mechanical and Aerospace Engineering

NiTiHf high temperature shape memory alloys are attractive due to their high operating temperatures (>100 ^oC) and acceptable transformation strain compared to NiTi. However, NiTiHf has limitations due to their lack of ductility and low strength, resulting in poor shape memory properties. In this study, Pd has been added to NiTiHf alloys in an attempt to improve their shape memory behavior. A combined approach of quaternary alloying and precipitation strengthening was used.

The characterization of a Ni_45.3Ti_29.7Hf₂₀Pd₅ (at. %) polycrystalline alloy was performed in compression after selected aging treatments. Transmission electron …

A Design Pathfinder With Material Correlation Points For Inflatable Systems, Jared T. Fulcher

Theses and Dissertations--Mechanical and Aerospace Engineering

The incorporation of inflatable structures into aerospace systems can produce significant advantages in stowed volume to mechanical effectiveness and overall weight. Many applications of these ultra-lightweight systems are designed to precisely control internal or external surfaces, or both, to achieve desired performance. The modeling of these structures becomes complex due to the material nonlinearities inherent to the majority of construction materials used in inflatable structures. Furthermore, accurately modeling the response and behavior of the interfacing boundaries that are common to many inflatable systems will lead to better understanding of the entire class of structures. The research presented involved using nonlinear …

Combining Sustainable Value Stream Mapping And Simulation To Assess Manufacturing Supply Chain Network Performance, Daniel T. Sparks

Theses and Dissertations--Mechanical and Aerospace Engineering

Sustainable Value Stream Mapping (Sus-VSM) builds upon traditional VSM to capture additional sustainability aspects of the product flow, such as environmental and societal aspects. This work presents research to expand the utility of Sus-VSM to supply chain networks, develop a general approach towards improving supply chain sustainability, and examine the benefits of implementing simulation and a design of experiments (DOE) style analysis. Metrics are identified to assess economic, environmental, and societal sustainability for supply chain networks and visual symbols are developed for the Supply Chain Sus-VSM (SC Sus-VSM) to allow users to easily identify locations where sustainability can be improved. …

Numerical Analysis Of Droplet Formation And Transport Of A Highly Viscous Liquid, Peiding Wang

Theses and Dissertations--Mechanical and Aerospace Engineering

Drop-on-demand (DOD) inkjet print-head has a major share of the market due to simplicity and feasibility of miniature system. The efficiency of droplet generation from DOD print-head is a result of several factors, include viscosity, surface tension, nozzle size, density, driving waveform (wave shape, frequency, and amplitude), etc. Key roles in the formation and behavior of liquid jets and drops combine three dimensionless groups: Reynolds number, Weber number and Ohnesorge number. These dimensionless groups provide some bounds to the “printability” of the liquid. Adequate understanding of these parameters is essential to improve the quality of droplets and provide guidelines for …

Sustainable Lifetime Value Creation Through Innovative Product Design: A Product Assurance Model, K. Daniel Seevers

Theses and Dissertations--Mechanical and Aerospace Engineering

In the field of product development, many organizations struggle to create a value proposition that can overcome the headwinds of technology change, regulatory requirements, and intense competition, in an effort to satisfy the long-term goals of sustainability. Today, organizations are realizing that they have lost portfolio value due to poor reliability, early product retirement, and abandoned design platforms. Beyond Lean and Green Manufacturing, shareholder value can be enhanced by taking a broader perspective, and integrating sustainability innovation elements into product designs in order to improve the delivery process and extend the life of product platforms.

This research is divided into …