Physical Sciences and Mathematics Commons^™

The Qse-Reduced Nuclear Reaction Network For Silicon Burning, Suzanne T. Parete-Koon

Doctoral Dissertations

Iron and neighboring nuclei are formed by silicon burning in massive stars before core collapse and during supernova outbursts. Complete and incomplete silicon burning is responsible for the production of a wide range of nuclei with atomic mass numbers from 28 to 70. Because of the large number of nuclei involved, accurate modeling of these nucleosynthetic stages is computationally expensive. For this reason, hydrodynamic models of supernovae often employ a limited set of nuclei to track the nuclear energy generation until nuclear statistical equilibrium is reached. These limited approximations do not include many of the reaction channels important for the …

Poly(Ethylenedioxythiophene) Based Electronic Devices For Sensor Applications, Jie Liu

Doctoral Dissertations

Organic electronic devices, based on Poly (3,4-ethylenedioxythiophene)-Poly (styrene sulfonic acid) (PEDOT-PSS) as the active layer for sensor applications, have been studied. Two sets of sensors have been developed. In one case, sensors consisting of PEDOT-PSS resistors have been realized and demonstrated for soil moisture monitoring. The resistor model for the soil moisture sensor enables the sensor device to be fabricated at low cost and easily tested with a simple structure. Unlike the large dimension device used in Time Domain Reflectometry (TDR), the sensors are small and are capable of capturing microscale behavior of moisture in soil which is useful for …

A Finite Difference Method For Studying Thermal Deformation In Three-Dimensional Thin Films Exposed To Ultrashort Pulsed Lasers, Suyang Zhang

Doctoral Dissertations

Thermal analysis related to ultrashort-pulsed lasers has been intensely studied in science and engineering communities in recent years, because the pulse duration of ultrashort-pulsed lasers is only the order of sub-picoseconds to femtoseconds, and the lasers have exclusive capabilities in limiting the undesirable spread of the thermal process zone in the heated sample. Studying the thermal deformation induced by ultrashort-pulsed lasers is essential for preventing thermal damage. For the ultrashort-pulsed laser, the thermal damage is different from that caused by the long pulsed lasers and cracks occur after heating.

This dissertation presents a new finite difference method for studying thermal …

Novel Approaches To Prepare And Utilize Sers Substrates: Multiplex Microfluidics And Nanotransfer Printing, Nahla A. Abu-Hatab

Doctoral Dissertations

Over the past few decades, surface enhanced Raman spectroscopy (SERS) has garnered respect as an analytical technique with significant chemical and biological applications. SERS is important for the life sciences because it can provide trace level detection and a high level of molecular structure information. The development of quantitative, highly sensitive substrates requires control over size, shape, and position of metal nanoparticles which function as the SERS active medium. Thus, creating and successfully implementing a sensitive, reproducible, and robust SERS active substrate continues to be a challenging ask. Its future development depends critically on techniques for lithography and nanofabrication. Herein, …

Approaches To Generating Selectivity In Microcantilever Sensors, Peter J. Chapman

Doctoral Dissertations

Microcantilever (MC) sensors have emerged as sensing transducers that offer greater sensitivity than comparable sensors due in large part to their very small dimensions. MCs have been utilized in many chemical sensing applications. Not only do MCs demonstrate greater sensitivity, but they also are relatively low in cost, they can be used in an array format, and they can be integrated into on-chip electronic circuitry.

While MC sensors demonstrate great sensitivity, an area of weakness that MC sensors must overcome is that of selectivity. The response of a MC sensor to analyte is mechanical; these mechanical responses lack the information …

Materials Chemistry Of Nanocubes And Mesoporous Silicas: Characterization And Adsorption Studies, Sami Ziad Chanaa

Doctoral Dissertations

Metal oxides (MO) and their surfaces play a vital role in numerous phenomena, including metal surface passivation, catalysis, integrated optoelectronic technology, and pollution monitoring via solid-state gas sensing. This experimental study seeks to aid in the development of accurate and predictive theoretical models of the potential energy surfaces described in the interaction of these small molecules with the magnesium oxide (MgO) substrate. MgO, with its structural simplicity and capacity to be fabricated with a predominantly (100) exposed face, is an ideal representative of the MO family popular for both experimental and theoretical studies. Using high-resolution volumetric adsorption isotherms, a thermodynamic …

Creation Of An Ice Hockey Tradition In The South, Daryl Paul Wenner

Doctoral Dissertations

This dissertation examines the links between culture and tradition. It argues that traditions are influenced by the underlying cultural foundations from which they develop. It also argues that as traits diffuse between cultures, they do not do so “as is” but are interpreted by the recipient culture group and altered by their cultural beliefs. Because of the alterations that occur, the diffusion event is not a one-directional incident. The alteration of the trait causes the original exporter to evaluate the changes made, thereby altering the source culture’s opinion of the recipient group.

The dissertation uses a three-stage model to examine …

Investigating The Petrogenesis Of The Basaltic Crust Of Asteroid 4 Vesta: A Combined Petrologic-Spectral Study Of The Unbrecciated Eucrites, Rhiannon Gwenllian Mayne

Doctoral Dissertations

The Dawn mission, which launched in September 2007, will orbit and analyze two of the largest asteroids, 4 Vesta and 1 Ceres. These small, proto-planetary bodies retain a record of the conditions and processes that occurred in the early history of the Solar System, and, as such, provide us with a tool to understand its formation and evolution. Additional information can also be gleaned from the meteorite samples derived from such objects. This dissertation aims to increase understanding of the formation of the basaltic crust of the asteroid Vesta, and the lithologic variety that exists within it, by studying the …

Treeline Responses To Climate Change In High-Elevation Landscapes Of Western Montana, U.S.A., David F. Mann

Doctoral Dissertations

The purpose of this research was to use whitebark pine trees at three major sites in western Montana to: (1) determine tree species response to climate, (2) reconstruct past climate conditions, (3) determine the effects of climate shifts on treeline, and (4) reconstruct fire history from fire-scar data. I collected samples from whitebark pine and subalpine fir and from remnant whitebark pine in the western Beaverhead-Deerlodge and Lolo National Forests.

In the climate response analysis, the Palmer Drought Severity Index (PDSI) had the highest correlations with whitebark pine growth. The strongest relationship occurred in the previous year’s June and July. …

Development Of A Simulation System For Testing Hardwood Plantation Silviculture, Christopher Michael Oswalt

Doctoral Dissertations

Hardwood plantations are becoming increasingly important in the United States. To date, many foresters have relied on a conifer plantation model as the basis of establishing and managing hardwood plantations. The monospecific approach suggested by the conifer plantation model does not appear to provide for the development of quality hardwood logs similar to those found in natural hardwood stands. Thus, there is interest in creating mixed species plantations to simulate natural hardwood stand development.

A simulation system, CherrybarkSQ, was developed to provide a platform for investigating the impacts of mixed species management of hardwood plantations on the stem quality of …

Determination Of Mineral Abundances In Ordinary Chondrites Using Powder X-Ray Diffraction: Applications To Parent Body Processes And Asteroid Spectroscopy, Tasha L. Dunn

Doctoral Dissertations

The ordinary chondrites, the most abundant group of meteorites, are divided into three chemical groups (H, L, and LL), which are distinguished based on variations in bulk composition and iron content. Although ordinary chondrites are relatively abundant, our understanding of their formation has been hampered by an inability to accurately measure the abundances of minerals that they contain. Here I use power x-ray diffraction (XRD) to quantify the modal abundances of 48 unbrecciated ordinary chondrite falls, which represent the complete petrologic range of equilibrated ordinary chondrites (types 4-6).

Although the degree of metamorphism varies within each ordinary chondrite group, many …

Synthesis, Characterization, And Applications Of Responsive Polymer Brush-Grafted Particles, Dejin Li

Doctoral Dissertations

In this dissertation, I present the synthesis, characterization, and applications of responsive polymer brush-grafted silica/crosslinked polymeric particles. The polymer brush-grafted particles were synthesized by surface-initiated "living"/controlled radical polymerizations from initiator-functionalized particles in the presence of free initiators. Two types of core particles were used in my research. One was silica particles, which were synthesized by Stöber method. The other one was crosslinked PtBA particles, which were prepared by seeded emulsion polymerization. The responsive properties of the grafted polymer brushes were characterized with ¹H NMR and Dynamic Light Scattering.

Nanomagnets: Magnetic Properties And Inelastic Neutron Scattering Studies, Jason T. Haraldsen

Doctoral Dissertations

In this thesis, small quantum spin systems, known as nano-magnets or molecular magnets, have been investigated. This is an area of great interest in the development of nanotechnology and quantum computers. Previous research on molecular magnets has concentrated on large, complex materials, which have many magnetic ions competing for superexchange pathways. Due to the large number of magnetic ions, the Hamiltonians resulted in very large Hilbert spaces, which makes it difficult for the magnetic interactions to be characterized and analyzed. Through the analysis of smaller and simpler magnetic clusters, insight can be gained from the interactions of the magnetic ions …

Imaging By Detection Of Infrared Photons Using Arrays Of Uncooled Micromechanical Detectors, Dragoslav Grbovic

Doctoral Dissertations

The objective of this dissertation was to investigate the possibility of uncooled infrared imaging using arrays of optically-probed micromechanical detectors. This approach offered simplified design, improved reliability and lower cost, while attaining the performance approaching that contemporary uncooled imagers. Micromechanical infrared detectors undergo deformation due to the bimetallic effect when they absorb infrared photons. The performance improvements were sought through changes in structural design such as modification and simplification of detector geometry as well as changes in the choice of materials. Detector arrays were designed, fabricated and subsequently integrated into the imaging system and relevant parameters, describing the sensitivity and …

A Finite State Machine Approach To Cluster Identification Using The Hoshen-Kopelman Algorithm, Matthew L. Aldridge

Doctoral Dissertations

The purpose of this study was to develop an efficient finite state machine implementation of the eponymous Hoshen-Kopelman cluster identification algorithm using the nearest-eight neighborhood rule suitable to applications such as computer modeling for landscape ecology. The implementation presented in this study was tested using both actual land cover maps, as well as randomly generated data similar to those in the original presentation of the Hoshen-Kopelman algorithm for percolation analysis. The finite state machine implementation clearly outperformed a straightforward adaptation of the original Hoshen-Kopelman algorithm on either data type. Research was also conducted to explore the finite state machine's performance …

Establishment Of A Structure-Activity Relationship In Heterogeneous Titanosilicate Catalysts For Olefin Epoxidation Via A Building Block Method, Geoffrey T. Eldridge

Doctoral Dissertations

The non-aqueous building block (NABB) method is a synthetic method that has the goal of producing atomically dispersed, well-defined, single-site heterogeneous catalysts. The active sites of these catalysts are able to be structured on the nanometer scale using the process of sequential additions. The method is designed in such a manner that it should be able to produce a series of catalysts each with a unique, well-defined, single active site. This series of catalysts can then be used to elucidate the structure-activity relationship for the active site in a particular chemical reaction.

In this dissertation a new building block, …

Parallel Simulation Of Individual-Based, Physiologically-Structured Population And Predator-Prey Ecology Models, Jeffrey A. Nichols

Doctoral Dissertations

Utilizing as testbeds physiologically-structured, individual-based models for fish and Daphnia populations, techniques for the parallelization of the simulation are developed and analyzed. The techniques developed are generally applicable to individual-based models. For rapidly reproducing populations like Daphnia which are load balanced, then global birth combining is required. Super-scalar speedup was observed in simulations on multi-core desktop computers.

The two populations are combined via a size-structured predation module into a predator-prey system with sharing of resource weighted by relative mass. The individual-based structure requires multiple stages to complete predation.

Two different styles of parallelization are presented. The first distributes both populations. …

Zero-Divisor Graphs, Commutative Rings Of Quotients, And Boolean Algebras, John D. Lagrange

Doctoral Dissertations

The zero-divisor graph of a commutative ring is the graph whose vertices are the nonzero zero-divisors of the ring such that distinct vertices are adjacent if and only if their product is zero. We use this construction to study the interplay between ring-theoretic and graph-theoretic properties. Of particular interest are Boolean rings and commutative rings of quotients.

Failure Analysis And Reliability -Aware Resource Allocation Of Parallel Applications In High Performance Computing Systems, Narasimha Raju Gottumukkala

Doctoral Dissertations

The demand for more computational power to solve complex scientific problems has been driving the physical size of High Performance Computing (HPC) systems to hundreds and thousands of nodes. Uninterrupted execution of large scale parallel applications naturally becomes a major challenge because a single node failure interrupts the entire application, and the reliability of a job completion decreases with increasing the number of nodes. Accurate reliability knowledge of a HPC system enables runtime systems such as resource management and applications to minimize performance loss due to random failures while also providing better Quality Of Service (QOS) for computational users.

This …

Wireless Sensor Network Modeling Using Modified Recurrent Neural Network: Application To Fault Detection, Azzam Issam Moustapha

Doctoral Dissertations

Wireless Sensor Networks (WSNs) consist of a large number of sensors, which in turn have their own dynamics. They interact with each other and the base station, which controls the network. In multi-hop wireless sensor networks, information hops from one node to another and finally to the network gateway or base station. Dynamic Recurrent Neural Networks (RNNs) consist of a set of dynamic nodes that provide internal feedback to their own inputs. They can be used to simulate and model dynamic systems such as a network of sensors.

In this dissertation, a dynamic model of wireless sensor networks and its …

K-Means+Id3 And Dependence Tree Methods For Supervised Anomaly Detection, Kiran S. Balagani

Doctoral Dissertations

In this dissertation, we present two novel methods for supervised anomaly detection. The first method "K-Means+ID3" performs supervised anomaly detection by partitioning the training data instances into k clusters using Euclidean distance similarity. Then, on each cluster representing a density region of normal or anomaly instances, an ID3 decision tree is built. The ID3 decision tree on each cluster refines the decision boundaries by learning the subgroups within a cluster. To obtain a final decision on detection, the k-Means and ID3 decision trees are combined using two rules: (1) the nearest neighbor rule; and (2) the nearest consensus rule. The …

Energy Efficient Clustering And Secure Data Aggregation In Wireless Sensor Networks, Julia Albath

Doctoral Dissertations

"Communication consumes the majority of a wireless sensor network's limited energy. There are several ways to reduce the communication cost. Two approaches used in this work are clustering and in-network aggregation. The choice of a cluster head within each cluster is important because cluster heads use additional energy for their responsibilities and that burden needs to be carefully distributed. We introduce the energy constrained minimum dominating set (ECDS) to model the problem of optimally choosing cluster heads in the presence of energy constraints. We show its applicability to sensor networks and give an approximation algorithm of O(log n) for solving …

Estimating Bounds For Nonidentifiale Parameters Using Potential Outcomes, Thidaporn Supapakorn

Doctoral Dissertations

"Conclusions from studies vary regarding the association of weight loss among obese people and measures of health and/or mortality. Total weight loss for individuals in a population may be a combination of intentional weight loss (IWL) and unintentional weight loss (UWL). Among people who have no intention to lose weight, the total weight loss observed is UWL. Among people who have intention to lose weight, the total weight loss is assumed to be UWL and IWL. Note that total weight loss among subjects intending to lose weight is observable but IWL itself is not and, therefore, the latent variable that …

The Effect Of Free Chlorine And Monochloramine On Lead In Drinking Water And Epitaxial Electrodeposition Of Tin Sulfide, Sansanee Boonsalee

Doctoral Dissertations

"Electrochemical deposition is utilized in various electronic and photovoltaic applications and in the protective coating industries. This dissertation primarily addresses the environmental aspects of electrochemical deposition. In the first part of this study, Pb dissolution in drinking water was investigated in the presence of two disinfectants: free chlorine (in the form of HOCI/OCr) and monochloramine (NH₂Cl). In the second part of this study, epitaxial SnS nanodisks were electrodeposited onto a Au(100) substrate. Water utility systems use either free chlorine or monochloramine in their disinfection program. Whereas free chlorine reacts with natural organic matter in the water to produce halogenated organic …

A Tour-De-Force In Polymer Crosslinked Aerogels, Sudhir Mulik

Doctoral Dissertations

"In the quest of building mechanically strong materials with low density and high porosity, polymer crosslinked aerogels stand as the most promising nano-engineered examples. Covalent attachment of polymers and bridging of skeletal nanoparticles of typical aerogels is demonstrated by using surface initiated polymerization (SIP) with a bidentate free-radical initiator structurally related to azobisisobutyronitrile (AIBN) and confined on mesoporous silica surfaces. Different monomers were introduced in the mesopores and upon heating at 70⁰C, all mesoporous surfaces throughout the entire skeletal framework were coated conformally with a 10-12 nm thick polymer layer indistinguishable spectroscopically from the respective commercial bulk materials. The new …

Stochastic Dynamic Equations, Suman Sanyal

Doctoral Dissertations

"We propose a new area of mathematics, namely stochastic dynamic equations, which unifies and extends the theories of stochastic differential equations and stochastic difference equations. After giving a brief introduction to the theory of dynamic equations on time scales, we construct Brownian motion on isolated time scales and prove some of its properties. Then we define stochastic integrals on isolated time scales. The main contribution of this dissertation is to give explicit solutions of linear stochastic dynamic equations on isolated time scales. We illustrate the theoretical results for dynamic stock prices and Ornstein-Uhlenbeck dynamic equations. Finally we study almost sure …

Inverse Limits Of Permutation Maps, Robbie A. Beane

Doctoral Dissertations

"In this paper we study the topological properties of continua which arise as inverse limits on [0; 1] with bonding maps chosen from the permutation family of Markov maps. For such inverse limits, we examine the occurrence of indecomposability, the number of end points in the continuum, and the types of subcontinua present in the continuum. We provide a process for determining the topological structure of the inverse limit generated by a single permutation map, or by the composition of several such maps. Additionally, we show that all such inverse limits are Kelley continua. We will apply these results to …

Synthesis And Evaluation Of Vegetable (Soybean) Oil Based Epoxy Resin For Beverage Can Coating And Enzymatic Synthesis And Characterization Of Tailored N&C End Protected Oligopeptides, Ying Gao

Doctoral Dissertations

"Research described in this dissertation covers two topics. Part-I is related to the development of a soybean oil based epoxy resin and its application in beverage can coatings. Interior surfaces of beverage can are invariably coated with polymer coating. The most commonly used coatings at present are derived from bisphenol A (BPA) based epoxy reins. However, due to perceived endocrine disrupting nature of BPA and consequential adverse effects on humans and wildlife concerns for the use of BPA based coatings and its leaching into beverages have been expressed. The research in the first part describes the synthesis and evaluation of …

Business-Oriented Software Process Improvement Based On Cmm And Cmmi Using Qfd, Yan Sun

Doctoral Dissertations

"Software Process Improvement (SPI) has become the key to the survival of many software development organizations. Many international SPI models/standards are developed for SPI. The Capability Maturity Model (CMM) and Capability Maturity Model Integrated (CMMI)) from the Software Engineering Institute are two SPI models. In this study, several existing SPI models and approaches are reviewed, their advantages are identified, and their drawbacks are discussed. A set of new SPI frameworks integrating Quality Function Deployment (QFD) with both CMM and CMMI are developed by combining the best features of previous approaches and addressing their limitations"--Abstract, page iii.

Characterization And Synthesis Of Nanoscale Materials, Jinfeng Wang

Doctoral Dissertations

"This dissertation focuses on the systematic study of techniques for characterization and synthesis of nanoscale materials. We have achieved several goals. Firstly, high number density uniform zinc oxide nanostructure growth has been achieved using thermal evaporation, through control of experimental parameters that include source material temperature, substrate temperature, substrate material, gas flow rate, and choice of catalyst. Aligned zinc oxide nanowires, randomly oriented zinc oxide nanowires, zinc oxide container-shaped structures, and zinc oxide nanobelts have been synthesized with high yield. Secondly, using a one parameter family of lattice fringe geometry curves, we show how to examine the epitaxial relationship between …