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Microparticulate Drug Reformulation Using Electrostatic Layer -By -Layer Assembly And Co-Entrapment With Anionic Phospholipids In Calcium Carbonate Matrix, Krishna Gopal

Doctoral Dissertations

Non-invasive drug delivery systems for therapeutic drugs are gaining prominence. One such system, the nasal delivery system, shows good prospect for effective delivery of some drugs, however, it is yet to be well established for others. The preparation of a reformulated drug and studying its in vitro characteristics is a crucial step in the process of adapting the new drug for nasal delivery systems. The purpose of this research is to study the effect of electrostatic layer by layer assembly of polyelectrolytes on PROMAXX®insulin microparticles and to study the chemical, physical and corresponding release properties of the resulting formulations. PROMAXX® …

Membrane Systems With Limited Parallelism, Bianca Daniela Popa

Doctoral Dissertations

Membrane computing is an emerging research field that belongs to the more general area of molecular computing, which deals with computational models inspired from bio-molecular processes. Membrane computing aims at defining models, called membrane systems or P systems, which abstract the functioning and structure of the cell. A membrane system consists of a hierarchical arrangement of membranes delimiting regions, which represent various compartments of a cell, and with each region containing bio-chemical elements of various types and having associated evolution rules, which represent bio-chemical processes taking place inside the cell.

This work is a continuation of the investigations aiming to …

Investigation Of Ethanol Dehydration In A Microscale Pervaporation Process, Sudhir Ramprasad

Doctoral Dissertations

Challenges due to surface tension effects for vaporization in microchannels have restricted the implementation of conventional separation processes that involve liquid boiling in a micro-chemical system. However, membrane separations offer a feasible alternative for exploring the advantages of liquid phase separation in micro-chemical systems. The main objective of this research was to evaluate the process intensification effects in a microscale pervaporation process with experiments involving the separation of ethanol/water using a commercially available polymer dehydration membrane.

The microchannels in the microseparator were fabricated by the dry etch process at Louisiana Tech University. Microchannel depths of 20 to 120 μm, with …

Fluorescent Enzymatic Smart Tattoos Comprising Hybrid Silicate Microparticles, Metalloporphyrin Complexes, And Mass Transport-Limiting Nanofilms, Erich Wayne Stein

Doctoral Dissertations

Diabetics are often required to self-monitor blood glucose levels to effectively deliver prescribed therapies. However, the pain and bother associated with traditional finger-prick measurements often result in decreased patient compliance and therefore poor disease management, which could result in the early-onset of complications. Enzymatic "smart tattoos"—implantable luminescent particles that may be transdermally interrogated with light—are being pursued as minimally-invasive diabetic monitoring devices, with hopes of increasing diabetic compliance by reducing excessive pain and bother associated with finger-prick measurements. These devices typically comprise an oxygen-quenched luminescent dye and glucose oxidase (GOx), an enzyme that catalyzes the oxidation of β-D-glucose. Under glucose-limited …

Design And Development Of Triangular, Spiral, And Fractal Antennas For Radio Frequency Identification Tags, Jeevan K. Vemagiri

Doctoral Dissertations

This dissertation reports on the design and development of three compact, non-meandered microstrip patch antennas for ultra high frequency (UHF) radio frequency identification (RFID) applications. The monopole antennas considered in this work are an inset-fed triangular antenna, one arm Archimedes spiral antenna and a Half-Sierpinski fractal antenna. These antennas with small length to width ratios (< 2/1), can be the preferred choice, in the tagging of small size consumer end products, over the ubiquitous meandered dipole antenna (length/width > 5/1), which is often the antenna of choice, due to its high gain for UHF RFID applications. The lengths and widths of all three antennas are less than 5.5 cm. Earlier reports of planar antennas for RFID applications in the UHF range have lengths …

Delay Line Based Passive Radio Frequency Identification Tags, Aravind Chamarti

Doctoral Dissertations

This work describes the concept, design, fabrication, and characterization of delay-based radio frequency identification (RFID) tags and RFID-based sensor tags, representing a novel RFID technology. The presented delay-based RFID concept is based on the LC-delay-line and transmission-delay-line based approaches. The proposed concept allows the realization of RFIDs and RFID-based sensor tags at any allowed radio frequency, with the limitation of realizing delay elements capable of producing required delays. The RFID configurations presented in this work are for operation at 915 MHz. Simulations are used to design and optimize components and devices that constitute the tags, and to integrate them to …

The Prediction Of Career Decision-Making Self-Efficacy From Black And White Racial Identity Attitudes, Jennifer K. Montgomery

Doctoral Dissertations

Racial identity has been related to a variety of interpersonal, psychological, behavioral, environmental, and cognitive factors. Although Black racial identity is often researched in relation to career development, there are few studies examining the relationship between career development and White racial identity. Additionally, review of the career development studies that focused on Black racial identity reveals that they have failed to consider the role of social cognitive factors, instead using traditional career models that were created from the standpoint of middleclass non-minorities. The focus of this study was to examine the distinct relationship between Black and White racial identity and …

Stochastic Propagation Modeling And Early Detection Of Malicious Mobile Code, Xin Xu

Doctoral Dissertations

Epidemic models are commonly used to model the propagation of malicious mobile code like a computer virus or a worm. In this dissertation, we introduce stochastic techniques to describe the propagation behavior of malicious mobile code. We propose a stochastic infection-immunization (INIM) model based on the standard Susceptible-Infected-Removed (SIR) epidemic model, and we get an explicit solution of this model using probability generating function (pgf.). Our experiments simulate the propagation of malicious mobile code with immunization. The simulation results match the theoretical results of the model, which indicates that it is reliable to use INIM model to predict the propagation …

Sleep Quality Of College Students And Its Relationship To Coping Styles And Well-Being, Cathy Alison Word

Doctoral Dissertations

College students suffer from more sleep disturbances than the general population. Sleep difficulties in college students can lead to lower levels of performance, memory, and cognitive ability, as well as increased levels of anxiety and decreased levels of well-being. Sleep quality is known to impact individuals' physical and psychological health, which are indicators of well-being. Sleep also appears to influence individuals' choices of coping strategies. Sleep quality is also highly correlated with college students' emotional response to stress. The relationships between and among sleep quality, well-being, and coping style have not been fully examined. The purpose of this study was …

Molecular Modeling Of Proteins And Peptides Related To Cell Attachment In Vivo And In Vitro, Wanhua Zhao

Doctoral Dissertations

Polypeptides constitute half of the dry mass of the cell, they form the bulk of the extracellular matrix (ECM), and they are a common element of extra- and intracellular signaling pathways. There is increasing interest in the development of computational methods in polypeptide and protein engineering on all length scales. This research concerns the development of computational methods for study of polypeptide interactions related to cell attachment in vivo and in vitro.

Polypeptides are inherently biocompatible, and an astronomical range of unique sequences can be designed and realized in massive quantities by modern methods of synthesis and purification. These …

The Determinants Of Executive Compensation In The Commercial Banking Industry, David A. Romer

Doctoral Dissertations

The primary purpose of this study is to examine the viability of two basic theories of compensation to explain executive compensation in the banking industry. The two executive compensation motivation theories are sales/sales growth maximization and profit/shareholder wealth maximization. Overall, strong support is found for both theories. This research also seeks to significantly expand, compared to previous research, the number of banks investigated. This study succeeds, with over a four-fold increase in the number of banks analyzed, including over 330 banks not previously used in the literature. This investigation is further motivated by the paucity of banking studies on compensation …

Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal

Doctoral Dissertations

The extracellular matrix (ECM) plays an important role in regulating a number of cellular properties and functions like cell differentiation, cell synthesis and degradation, cell viability and proliferation, cell function, and cell aging. Surface modification of planar substrates with self-assembled monolayers (SAMs) is a promising technique to achieve stable ECMs.

In this work, substrates such as silicon (Si), gallium arsenide (GaAs) and indium tin oxide (ITO) substrates were modified with SAMS containing amino (-NH2), methyl (-CH3), thiol (-SH) and carboxylic (-COOH) end groups and characterized using contact angle measurements, surface infrared (IR) spectroscopy and atomic force microscopy (AFM). Different cell …

Development Of A High Spatial Selectivity Tri-Polar Concentric Ring Electrode For Laplacian Electroencephalography (Leeg) System, Kanthaiah Koka

Doctoral Dissertations

Brain activity generates electrical potentials that are spatio-temporal in nature. Electroencephalography (EEG) is the least costly and most widely used non-invasive technique for diagnosing many brain problems. It has high temporal resolution but lacks high spatial resolution.

The surface Laplacian will enhance the spatial resolution of EEG as it performs the second spatial derivative of the surface potentials. In an attempt to increase the spatial selectivity, researchers introduced a bipolar electrode configuration using a five point finite difference method (FPM) and others applied a quasi-bipolar (tri-polar with two elements shorted) concentric electrode configuration. To further increase the spatial resolution, the …

Measuring Inequality: Statistical Inference Theory With Applications, Mihaela Paun

Doctoral Dissertations

In this dissertation we develop statistical inference for the Atkinson index, one of the measures of inequality used in studying economic inequality.

Specifically, we construct empirical estimators for the Atkinson index, both in the parametric and nonparametric case, and derive formulas for the asymptotic variances for the estimators. These statistics are used for testing hypothesis and constructing confidence intervals for the Atkinson index. We test the validity and the robustness of the asymptotic theory, by simulations (using R, a language and environment for statistical computing and graphics), in the case of one and two populations. In addition to proving asymptotic …

A Novel Computational Framework For Fast, Distributed Computing And Knowledge Integration For Microarray Gene Expression Data Analysis, Prerna Sethi

Doctoral Dissertations

The healthcare burden and suffering due to life-threatening diseases such as cancer would be significantly reduced by the design and refinement of computational interpretation of micro-molecular data collected by bioinformaticians. Rapid technological advancements in the field of microarray analysis, an important component in the design of in-silico molecular medicine methods, have generated enormous amounts of such data, a trend that has been increasing exponentially over the last few years. However, the analysis and handling of these data has become one of the major bottlenecks in the utilization of the technology. The rate of collection of these data has far surpassed …

Multicomponent Patterning Of Nanocomposite Polymer And Nanoparticle Films Using Photolithography And Layer-By-Layer Self -Assembly, Javeed Shaikh Mohammed

Doctoral Dissertations

In this dissertation, the fabrication, characterization, and application examples of 3D multicomponent nanocomposite micropatterns (MNMs) with precise spatial arrangements are described. The ability to produce such small-scale 3D structures with versatility in composition and structure is a new development based on the integration of nanoscale layer-by-layer (LbL) self-assembly and microscale photolithographic patterning, enabling construction of surfaces with microscale patterns that possess nanotopographies. The techniques used here are analogous to surface micromachining, except that the deposition materials are polymers, biological materials, and colloidal nanoparticles used to produce 3D MNMs. A key feature of the resulting 3D MNMs is that the physical …

A Numerical Method For Obtaining An Optimal Temperature Distribution In A Three-Dimensional Triple-Layered Skin Structure Embedded With Multi-Level Blood Vessels, Xingui Tang

Doctoral Dissertations

The research related to hyperthermia has stimulated a lot of interest in recent years because of its application in cancer treatment. When heating the tumor tissue, the crucial problem is keeping the temperature of the surrounding normal tissue below a certain threshold in order to avoid the damage to the normal tissue. Hence, it is important to obtain the temperature field of the entire region during the treatment. The objective of this dissertation is to develop a numerical method for obtaining an optimal temperature distribution in a 3D triple-layered skin structure embedded with multi-level blood vessels where the surface of …

Three Essays On Banking And Corporate Finance, Fang Zhao

Doctoral Dissertations

This dissertation is composed of three essays on banking and corporate finance. The first essay studies the relationship between interest-rate derivative usage and bank lending. Using recent data that cover a full business cycle, this paper documents a direct relationship between interest-rate derivative usage by U.S. banks and growth in their commercial and industrial (C&I) loan portfolios. This positive association holds for interest-rate options contracts, forward contracts, and futures contracts. This result is consistent with the implication of Diamond's model (1984) that predicts that a bank's use of derivatives permits better management of systematic risk exposure, thereby lowering the cost …

Modeling And Simulation Of Value -At -Risk In The Financial Market Area, Xiangyin Zheng

Doctoral Dissertations

Value-at-Risk (VaR) is a statistical approach to measure market risk. It is widely used by banks, securities firms, commodity and energy merchants, and other trading organizations. The main focus of this research is measuring and analyzing market risk by modeling and simulation of Value-at-Risk for portfolios in the financial market area. The objectives are (1) predicting possible future loss for a financial portfolio from VaR measurement, and (2) identifying how the distributions of the risk factors affect the distribution of the portfolio. Results from (1) and (2) provide valuable information for portfolio optimization and risk management.

The model systems chosen …

2006-2007 Louisiana Tech University Catalog, Louisiana Tech University

Louisiana Tech University Catalogs

The Louisiana Tech University Catalog includes announcements and course descriptions for courses offered at Louisiana Tech University for the academic year of 2006-2007.

Development And Applications Of Inkjet Printed Conducting Polymer Micro-Rings, Rajneek K. Khillan

Doctoral Dissertations

A drying sessile drop moves the solute particles to the periphery where they get deposited in the form of a ring. This phenomenon is prevalent even with micro drops falling at high velocity from a piezo-actuator based inkjet printer. In polymer microelectronic field, this phenomenon is a major challenge for fabricating devices using inkjet printing. We exploited this problem and applied it for various novel applications in the field of polymer microelectronics.

Various dispensing techniques and temperature variations for micro-drop printing were used for modifying the micro-drops in such a way that the periphery of the micro-ring holds most of …

Nanodot-Based Organic Memory Devices, Zhengchun Liu

Doctoral Dissertations

In this study, resistor-type, diode-type, and transistor-type organic memory devices were investigated, aiming at the low-cost plastic integrated circuit applications. A series of solution-processing techniques including spin-coating, inkjet printing, and self-assembly were employed to fabricate these devices.

The organic resistive memory device is based on a novel molecular complex film composed of tetracyanoquinodimethane (TCNQ) and a soluble methanofullerene derivative [6,6]-phenyl C61-butyric acid methyl ester (PCBM). It has an Al/molecules/Al sandwich structure. The molecular layer was formed by spin-coating technique instead of expensive vacuum deposition method. The current-voltage characteristics show that the device switches from the initial 'low' conduction state to …

An Investigation Of The Impact Of The Pace Of Change In Post -Ipo Corporate Governance On Firm Performance, Son A. Le

Doctoral Dissertations

In this study, I examine the impact of changes in post-IPO corporate governance on firm performance. Changes in corporate governance affect firm performance in various ways. Some theories such as agency and resource dependence theories predict that fast-paced change in post-IPO corporate governance will enhance firm performance. Other theories such as the resource-based view offer the opposite prediction that slowpaced change is more beneficial for firm performance. I, therefore, develop competing hypotheses regarding the impact of change in post-IPO corporate governance on firm performance.

IPO firms have unique characteristics. They are often small, young firms. As a matter of fact, …

The Sales Managers' Implicit Personality Theory And Leadership Variables, Gordon Gunn Mosley

Doctoral Dissertations

The purpose of this study was to explore the relationship of sales managers' implicit personality theory and various leadership variables provided to salespeople by their sales managers. Several bodies of literature were reviewed for this study from the educational psychology, management, leadership, and marketing/sales disciplines. More specifically, this study addressed the following research questions: (1) What effect does sales managers' implicit personality theory have on the nature of the feedback they provide to their salespeople? (2) What effect does sales managers' implicit personality theory have of the transformational leadership they provide to their salespeople? (3) What effect does sales managers' …

The Impact Of Sleep Quality And Duration On College Student Adjustment And Health, Robert L. Krenek Jr.

Doctoral Dissertations

College years are a time of change and transition that involves complex challenges in academic, social, personal/emotional, and institutional adjustment. Stress, anxiety, and tension are often associated with college transition and adjustment; stress and worry have been related to poor sleep quality. Studies have found that college students have more sleep problems than the general public. Research has shown that poor sleep has adverse effects on cognition, mood, and other physiological and psychological aspects of human functioning. Recent research has indicated that sleep quality may be more important than amount of sleep. Relationships have been found between sleep problems and …

An Exploratory Study Of The Influence Of Life Management Strategies On Job Satisfaction And Job Performance In A Personal Selling Context, Dheeraj Sharma

Doctoral Dissertations

Extant literature on goal oriented behaviors suggests that individual goal orientation is an important determinant of a salesperson's job satisfaction and job performance. However, the present conceptualization of goal orientation suffers from flawed paradigmatic structure. There are two major disparate paradigms of goal orientation in the extant literature. The first paradigm views goal orientation as a stable personality trait and the second paradigm views it as contextually driven phenomenon. The present study proffers a new approach of conceptualizing individual goal orientation, by introducing the meta-model of Life Management Strategies (Baltes and Baltes, 1998; Freund and Baltes, 1998) in the personal …

Factors Influencing Faculty Computer Literacy And Use In Jordan: A Multivariate Analysis, Iman Akour

Doctoral Dissertations

This study broadens the Technology Acceptance Model (TAM) proposed by Davis (1989) by incorporating multiple dimensions of cultural attributes into the model. The study also specifies and expands on the factors that may influence faculty members' computer literacy and computer usage in a developing country, namely Jordan.

To operationalize the constructs of the introduced conceptual model, eight instruments were used. They are Igbaria, Zinatelli, Cragg, and Cavaye's (1997) scales of organizational support; Hofsted's (1988) scale of cultural attributes; Igbaria and Parasuraman's (1989) scale of attitudes toward computers; Thatcher and Perrewe's (2002) scale of computer anxiety; Compeau and Higgins's (1995) scale …