Digital Commons Network^™

Updated Eor Screening Criteria And Modeling The Impacts Of Water Salinity Changes On Oil Recovery, Ahmad Aladasani

Doctoral Dissertations

"Developing technologies for enhanced oil recovery (EOR) from existing oil fields would supply the world's energy needs for several decades. The application of EOR in many major oil-producing countries remains in its conceptual stage. Thermal and gas EOR methods achieve high incremental rates; however, their application range has not broadened significantly as they have matured, while the rate at which new, promising EOR methods such as Low-salinity water flooding (LSWF) are being implemented is alarming. Despite, the potential of LSWF its development and application has been hindered by the lack of consensus concerning its recovery mechanism(s). Every oil reservoir has …

Electrodeposition And Electrochemical Reduction Of Epitaxial Metal Oxide Thin Films And Superlattices, Zhen He

Doctoral Dissertations

"The focus of this dissertation is the electrodeposition and electrochemical reduction of epitaxial metal oxide thin films and superlattices. The electrochemical reduction of metal oxides to metals has been studied for decades as an alternative to pyrometallurgical processes for the metallurgy industry. However, the previous work was conducted on bulk polycrystalline metal oxides. Paper I in this dissertation shows that epitaxial face-centered cubic magnetite (Fe₃O₄) thin films can be electrochemically reduced to epitaxial body-centered cubic iron (Fe) thin films in aqueous solution on single-crystalline Au substrates at room temperature. This technique opens new possibilities to produce special epitaxial metal/metal oxide …

Data Fusion By Using Machine Learning And Computational Intelligence Techniques For Medical Image Analysis And Classification, Beibei Cheng

Doctoral Dissertations

"Data fusion is the process of integrating information from multiple sources to produce specific, comprehensive, unified data about an entity. Data fusion is categorized as low level, feature level and decision level. This research is focused on both investigating and developing feature- and decision-level data fusion for automated image analysis and classification. The common procedure for solving these problems can be described as: 1) process image for region of interest' detection, 2) extract features from the region of interest and 3) create learning model based on the feature data. Image processing techniques were performed using edge detection, a histogram threshold …

A Monte Carlo Study Of The Scaling Of Nucleation Rates In A Lennard-Jones System, Mark Allan Thomason

Doctoral Dissertations

Temperature scaling of the homogenous vapor-to-liquid nucleation rate, J, is examined in a model Lennard-Jones (LJ) system. The model uses the Bennett Metropolis Monte Carlo technique to determine small cluster growth/decay rate constant ratios ß_n-1|α_n at four temperatures (T = 40, 50, 60, and 83.6K) below the argon Lennard-Jones critical temperature, T_c. The ß_n-1|α_n for clusters ranging in size from n = 2 to n = 192 LJ particles are applied to a kinetic steady-state nucleation rate formalism and nucleation rates are determined at the same four temperatures. When these rates are …

Characterization Of Soil Variability For Reliability-Based Design, Sitenikechukwu Onyejekwe

Doctoral Dissertations

"A very carefully planned Missouri-wide field exploration and laboratory investigation program, with a focus on fine-grained soils, was executed with the aim of characterizing the variability of geotechnical parameters statistically with a view to increasing the use of reliability-based design (RBD) among geotechnical engineers. Geotechnical parameters were characterized in terms of both their first and second statistical moments and their coefficient of variation (COV). Their probability distributions and their scale of fluctuation, θ, were also determined. Correlations between difficult-to-obtain parameters and more easily-obtained parameters were developed and the degree of fit of study data to published empirical correlations was investigated. …

Wavelet Based Contrast Limited Histogram Equalization For Contrast Enhancement Of Digital Mammography, Ashish Vighnahar Avachat

Masters Theses

"Mammography has been the most efficient tool for screening of microcalcification and cancer tissues; however, the raw images produced by mammography systems are usually of poor contrast. In order to use these raw images for early diagnosis; their contrast, sharpness and noise need to be enhanced. Among these important enhancement parameters contrast enhancement is critical. A novel algorithm is introduced which blends wavelet transforms with Contrast Limited Adaptive Histogram Equalization (CLAHE) for contrast enhancement. In this algorithm, the input image is decomposed to its low frequency and high frequency components in wavelet domain. Decomposed coefficients from different bands are then …

Spiking Neural Networks Encoding And Decoding Algorithms For Time Series Estimation And System Identification, Sinchan Roychowdhury

Masters Theses

"Artificial Neural networks (ANNs) have increasingly been applied to different system identification, pattern recognition and function approximation problems. The predominantly used neural network architectures are the feedforward and feedback networks. Multilayer perceptrons and radial basis function networks are among the most commonly used feed-forward architecture neural networks and the Elman and Jordan networks are the most widely used recurrent neural networks. These networks are also called as second generation ANNs.

This thesis focuses on the third generation ANNs which are biologically inspired and operate on the same principles as the living neurons. These are also known as biologically inspired artificial …

Mantle Flow And Lithosphere-Asthenosphere Coupling Beneath The Southwestern Edge Of The North American Craton: Constraints From Shear-Wave Splitting Measurements, Hesham A. Refayee

Doctoral Dissertations

"High-quality broadband seismic data recorded by the USArray and other stations in the southwestern United States provide a unique opportunity to test different models of anisotropy-forming mechanisms in the vicinity of a cratonic edge. Systematic spatial variations of anisotropic characteristics are revealed by 3027 pairs of splitting parameters measured at 547 broadband seismic stations. The western and southern edges of the North American craton show edge-parallel fast directions with larger-than-normal splitting times, and the continental interior is characterized by smaller splitting times spatially consistent fast directions that are mostly parallel to the absolute plate motion direction of North America. Except …

Nitrification Performance Of Activated Sludge Under Low Dissolved Oxygen Conditions, Guoqiang Liu

Doctoral Dissertations

"The combined effects of solids retention time (SRT) and dissolved oxygen (DO) concentration on nitrification, nitrifying bacterial communities, and aeration needs in the activated sludge process were studied. Nitrification was almost completed in the 10, 20, and 40-day SRT reactors with a minimum DO of 0.37, 0.25, and 0.16 mg/L, respectively. Under long-term low DO conditions, the endogenous decay of nitrifiers was slowed down and then nitirfier biomass concentration increased, thereby reducing the adverse effect of low DO on nitrification. Under long-term low DO conditions, the oxygen affinity of nitrite-oxidizing bacteria (NOB) increased significantly and as a result, NOB became …

Plate Kinematics Of The Afro-Arabian Rift System With An Emphasis On The Afar Depression, Helen Carrie Bottenberg

Doctoral Dissertations

This work utilizes the Four-Dimensional Plates (4DPlates) software, and Differential Interferometric Synthetic Aperture Radar (DInSAR) to examine plate-scale, regional-scale and local-scale kinematics of the Afro-Arabian Rift System with emphasis on the Afar Depression in Ethiopia. First, the 4DPlates is used to restore the Red Sea, the Gulf of Aden, the Afar Depression and the Main Ethiopian Rift to development of a new model that adopts two poles of rotation for Arabia. Second, the 4DPlates is used to model regional-scale and local-scale kinematics within the Afar Depression. Most plate reconstruction models of the Afro-Arabian Rift System relies on considering the Afar …

Quantitative Analysis Of Co-Enzyme A In A Plant Tissues And Cancer Biomarkers In Urine Samples By Using Capillary Electrophoresis And Liquid Chromatography-Mass Spectrometry, Yongqing Jiang

Doctoral Dissertations

"Despite continuous effort and progress in cancer detection and therapy, cancer remains one of our greatest health concerns because of its low survival rate and rapid incidence increase. One reason for this is the late detection and therefore pre-cancer diagnosis is crucial. In pre-cancer studies, cancer biomarkers become significant because of the useful information it contains such as possible cancer type and stage. Separation and detection technique plays an important role in cancer biomarker identification.

Coenzyme A (CoA) facilitates more than 100 chemical reactions in cells. Because of its low abundance accumulated in cells, it is critical to develop a …

Sieve Bootstrap Based Prediction Intervals And Unit Root Tests For Time Series, Maduka Rupasinghe

Doctoral Dissertations

"The application of the sieve bootstrap procedure, which resamples residuals obtained by fitting a finite autoregressvie (AR) approximation to empirical time series, to obtaining prediction intervals for integrated, long-memory, and seasonal time series as well as constructing a test for seasonal unit roots, is considered. The advantage of this resampling method is that it does not require knowledge about the underlying process generating a given time series and has been shown to work well for ARMA processes. We extend the application of the sieve bootstrap to ARIMA and FARIMA processes. The asymptotic properties of the sieve bootstrap prediction intervals for …

Spatial-Temporal Reasoning Applications Of Computational Intelligence In The Game Of Go And Computer Networks, Tae-Hyung Kim

Doctoral Dissertations

"Spatial-temporal reasoning is the ability to reason with spatial images or information about space over time. In this dissertation, computational intelligence techniques are applied to computer Go and computer network applications. Among four experiments, the first three are related to the game of Go, and the last one concerns the routing problem in computer networks.

The first experiment represents the first training of a modified cellular simultaneous recurrent network (CSRN) trained with cellular particle swarm optimization (PSO). Another contribution is the development of a comprehensive theoretical study of a 2x2 Go research platform with a certified 5 dan Go expert. …

The Characterization Of Volatiles Associated With Young Stellar Objects, Kari Anne Wojtkowski

Doctoral Dissertations

In the first portion of this work, we searched for differences in volatiles within a single star forming region, Rho Ophiuchi. We determined the amount, temperature, and composition of two ice features, the bending modes of CO₂ and H₂O at 15 µm and 6 µm, respectively, toward 28 Young Stellar Objects (YSOs). We found that more than 50% of the YSOs studied contained a portion of crystalline CO₂ ice. We also found that some sources with Flat or borderline Class II Spectral Energy Distributions (SEDs) have a larger abundance of CO₂ ice with respect to H₂O ice. In addition to …

The Effects Of Personal Protective Respirators On Human Motor, Visual, And Cognitive Skills, Anas Ahmed Alghamri

Doctoral Dissertations

"In oxygen-deficient or toxic environments in which controlling the hazard is not feasible, workers wear personal protective respirators. Hazard controls include but are not limited to engineering controls, such as ventilation, and substituting less hazardous materials. However, respirator selection and the design of tasks that require respirators are critical issues. Understanding the effects of respirators on human abilities is critical to respirator selection and therefore to the safety and efficiency of workers. This research investigated the effect of respirators on human abilities. A review of the relevant literature was conducted, revealing that respirators can affect physiological, psychological, motor, and visual …

Numerical Simulations Of Fracture Propagation And Sealing: Implications For Wellbore Strengthening, Saeed Salehi

Doctoral Dissertations

"To mitigate the small tolerance between pore pressure and fracture gradients an engineering practice referred to as "wellbore strengthening" is conducted to increase the fracture gradient. The method relies on propping and/or sealing the fractures with specially designed materials. Different competing theories exist for physical wellbore strengthening mechanisms which can be categorized into two groups. The first group explains that strengthening happens as a result of increasing wellbore hoop stress when fractures are sealed while the second group emphasis is on fracture tip isolation with suitable materials and enhancing fracture propagation pressure. The numerical models and lab experiments …

Modeling And Synthesis Of Pvdf-Based Dielectrics For Energy Storage Applications, Xuhui Lu

Doctoral Dissertations

"The purpose of this research was to develop dielectric films for high energy density capacitor applications. Also desired was to develop a deeper understanding of dielectric breakdown and electric energy storage related phenomena through simulation, theoretical analysis, and experimental investigation.

An analytical model incorporating Weibull dielectric strength statistics was developed to establish quantitative relationships between material properties and device performance of self-healing capacitors. The model is useful for designing high voltage capacitors and developing dielectric materials where the effects of electric field-dependent permittivity need to be considered.

In the experimental work, solution-cast poly(vinylidene difluoride) (PVDF) homopolymer PVDF films with high …

Modeling Aperture Radiation For Rf Interference Applications, Liehui Ren

Doctoral Dissertations

"The first topic proposes a rigorous method of moments(MoM) solution to evaluate the shielding effectiveness of a metallic enclosure with apertures on top wall by formulating a pair of coupled mixed potential integral equations (MPIEs). Application of Ewald transform to the computation of Green's function in the cavity yields fast convergence of series summation. Good agreements with a commercial tool, EMC studio, have proved the effectiveness of the proposed approach.

The second topic deals with prediction of electromagnetic interference radiation from components or interconnects in a printed circuit board by using convolution of the half-space Green's functions and the equivalent …

Evaluation Of A 21st-Century After-School Program At A Southeastern Elementary School, Timothy B. Hunter

Abraham S. Fischler College of Education ETD Archive

The purpose of the research was to evaluate a 21st-century after-school program at an elementary school in the southeastern United States. The program focused on the improvement of academic skills for students in Grades 3 through 5 in the academic areas of English and math. Implementation was in response to the high rate of students scoring below average on standardized tests. The Stufflebeam model was used to guide the program evaluation. Interview data were gathered from the after-school coordinator. Survey data were gathered from the after-school teachers and regular-school teachers. Data were also gathered from archival and empirical sources.

Test …

Geomechanical Characterization Of Reservoir & Cap Rocks For Co₂ Sequestration, Sudarshan Govindarajan

Masters Theses

"Geological sequestration of CO₂ has been identified as one method to reduce global emissions of CO₂ and achieve lower levels of CO₂ concentrations in the atmosphere. Geological formations have to be assessed in terms of their capacity, sealing capabilities and economic feasibility before CO₂ sequestration can commence. Potential leakage of injected CO₂ from the reservoir formation could occur due to natural or injection induced faults or fractures in the reservoir or sealing formations. As part of a potential leakage investigation a geomechanical characterization which refers to the assessment of the in-situ stress conditions, rock strength and stiffness properties of the …

Effects Of Four Commercially Available Fxa Proteins On The Fluorogenic Anti-Fxa Assay When Monitoring Unfractionated Heparin, Vanessa Castro-Lopez, Brian Murray, Leanne F. Harris, James S. O'Donnell, Anthony J. Killard

Articles

Four commercially available Factor Xa (FXa) reagents were evaluated in a fluorogenic anti-FXa assay. The four reagents - of which three were of human origin and the fourth was bovine - were compared in terms of the resulting assay dynamic ranges, lag times, CV and R2 values, sum of squares as well as their sensitivity to unfractionated heparin (UFH) within the therapeutic range of 0-1.2 U mL-1. Based on a balance of performance characteristics, an optimum reagent was selected which had the best combination of all parameters. The best performing serine endopeptidase in the fluorogenic anti-FXa assay was found to …

Integration Of Multiple Vision Systems And Toolbox Development, Rohit Vijay Bapat

Masters Theses

"Depending on the required coverage, multiple cameras with different fields of view, positions and orientations can be employed to form a motion tracking system. Correctly and efficiently designing and setting up a multi-camera vision system presents a technical challenge. This thesis describes the development and application of a toolbox that can help the user to design a multi-camera vision system. Using the parameters of cameras, including their positions and orientations, the toolbox can calculate the volume covered by the system and generate its visualization for a given tracking area. The cameras can be repositioned and reoriented using toolbox to generate …

Cooperative Power Control Approaches Towards Fair Radio Resource Allocation For Wireless Network, Liuju Wu

Masters Theses

"Performance optimization in wireless networks is a complex problem due to variability and dynamics in network topology and density, traffic patterns, mutual interference, channel uncertainties, etc. Opportunistic or selfish approaches may result in unbalanced allocation of channel capacity where particular links are overshadowed. This degrades overall network fairness and hinders a multi-hop communication by creating bottlenecks. A desired approach should allocate channel capacity proportionally to traffic priority in a cooperative manner. This work consists of two chapters that address the fairness share problem in wireless ad hoc, peer-to-peer networks and resource allocation within Cognitive Radio network. In the first paper, …

5-Axis Tool Path Generation With Collision Detection For Finish Machining Of Freeform Surfaces, Jomy Francis

Masters Theses

"Research in the field of Tool path generation for freeform surfaces has been done intensively in the past. However, the main challenge that still exists is the computational efficiency related to the tool path generation. Tool path generation for freeform surface involves instantaneous calculation of new tool orientations which does not collide with the neighboring surfaces. Since the collision check of tool and neighboring surface is done repetitively at every instant of the tool, the calculations at every instant are to be computationally as easy as possible.

This thesis is composed of one paper. Paper I presents a novel extension …

Should Any Workplace Be Exempt From Smoke-Free Law: The Irish Experience, M. Mccaffrey, Patrick J. Goodman, A. Gavigan, C. Kenny, C. Hogg, L. Byrne, J. Mcloughlin, Luke Clancy

Articles

Background.

In 2004, the Irish Government introduced national legislation banning smoking in workplaces; with exemptions for “a place of residence”. This paper summarises three Irish studies of exempted premises; prisons, psychiatric hospitals and nursing homes. Methods. PM2.5 and nicotine were measured in nursing homes and psychiatric hospitals, in addition to ultrafine particles in the hospitals. In the prisons, officers (n = 30) completed exhaled breath Carbon Monoxide (CO) measurements. Questionnaires determined officers’ opinion on introducing smoking prohibitions in prisons. Nursing home smoking policies were examined and questionnaires completed by staff regarding workplace secondhand smoke (SHS) exposure. Findings. Ultrafine particle concentrations …

Effect On Diagnostic Image Quality Of 3d Warping Registration Algorithms For Mr Angiography In The Lower Legs, Andrew Fagan, Daniel Foley, Jacinta Browne, Barry Sheane, Dearbhail O'Driscoll, Niall Sheehy, James Meaney

Articles

No abstract provided.

Impaired Cleanance And Enhanced Pulmonary Inflammatory/Fibrotic Response To Carbon Nanotubes In Myeloperoxidase-Deficient Mice, Anna A. Shvedova, Alexandr A. Kapralov, Wei Hong Feng, Elena R. Kisin, Ashley R. Murray, Robert R. Mercer, Claudette M. St. Croix, Megan A. Lang, Simon C. Watkins, Nagarjun V. Konduru, Brett L. Allen, Jennifer Conroy, Gregg P. Kotchey, Bashir M. Mohamed, Aidan Meade, Yuri Volkov, Alexander Star, Bengt Fadeel, Valerian E. Kagan

Articles

Advancement of biomedical applications of carbonaceous nanomaterials is hampered by their biopersistence and pro-inflammatory action in vivo. Here, we used myeloperoxidase knockout B6.129X1-MPO (MPO k/o) mice and showed that oxidation and clearance of single walled carbon nanotubes (SWCNT) from the lungs of these animals after pharyngeal aspiration was markedly less effective whereas the inflammatory response was more robust than in wild-type C57Bl/6 mice. Our results provide direct evidence for the participation of MPO – one of the key-orchestrators of inflammatory response – in the in vivo pulmonary oxidative biodegradation of SWCNT and suggest new ways to control the biopersistence …

Characterisation Of The Acoustic Output Of Three Sonoporation Drug Delivery Ultrasound Systems Using An Acoustic Radiation Force Balance, Tapihwa Mabvaro, Jacinta Browne

Articles

No abstract provided.

The Effects Of Fatty Desposits On The Accuracy Of The Fibroscan Liver Transient Elastography Ultrasound System, S. Cournane, Jacinta Browne, Andrew Fagan

Articles

A new generation of ultrasound transient elastography (TE) systems have emerged which exploit the well-known correlation between the liver’s pathological and mechanical properties through measurements of the Young’s elastic modulus; however, little work has been carried out to examine the effect that fatty deposits may have on the TE measurement accuracy. An investigation was carried out on the effects on the measurement accuracy of a transient elastography ultrasound system, the Fibroscan®, caused by overlaying fat layers of varying thickness on healthy liver-mimicking phantoms, simulating in vivo conditions for obese patients. Furthermore, a steatosis effect similar to that in non-alcoholic fatty …

Numerical Investigation Of Second-Law Characteristics Of Ramjet Throttling, Jonathan Albert Sheldon

Masters Theses

"A numerical study of a generic axisymmetric ramjet operating at conditions corresponding to flight Mach 3.0 and a standard altitude of 10 km is presented. The study includes both modeling of steady-state flowfields in the ramjet as well as transient throttling maneuvers in which the throttle is decreased or increased from maximum or minimum throttle positions. The results presented here focus on entropy generation and performance characteristics. Combustion-generated exothermic heat release is modeled using simple volumetric energy addition to the flow within a defined heat release zone. The study utilizes two levels of wall boundary modeling, corresponding respectively to inviscid …