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Doctoral Dissertations

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Articles 781 - 810 of 1882

Full-Text Articles in Physical Sciences and Mathematics

Detection And Removal Of Emerging Environmental Contaminants, Ruipu Mu Jan 2015

Detection And Removal Of Emerging Environmental Contaminants, Ruipu Mu

Doctoral Dissertations

"Water is a very crucial natural resource for human. The increasing number of contaminants detected in water bodies has drawn considerable increasing attention over the last decade. There are numerous emerging environmental contaminants which may cause serious health issues. The recent occurrence studies of these contaminants show both industrial and household activity introduction of chemicals into water resources. These various sources result in a large variety of chemicals such as explosives, pharmaceutical and personal care products (PPCPs) and disinfection byproducts detected in water worldwide. Due to the relatively low contaminant concentrations, development of new and improved detection methods along with …


Occurrence, Monitoring And Removal Of Drinking Water Contaminants By Advanced Technologies, Danielle Marie West Jan 2015

Occurrence, Monitoring And Removal Of Drinking Water Contaminants By Advanced Technologies, Danielle Marie West

Doctoral Dissertations

"In order to maintain drinking water primary standards compliance under the USEPA Stage 2 Disinfectant Disinfection Byproducts Rule, drinking water treatment plants (DWTPs) are switching from free chlorine (FC) to chloramines (MCA). Concerns are raised as MCA disinfection has been linked N-nitrosamine formation. N-nitrosamines are a group of nitrogenous DBPs (N-DBPs) which are highly carcinogenic in comparison to regulated DBPs (THMs and HAAs, generated by FC disinfection). Also in the forefront of drinking water concerns are other emerging drinking water contaminants such as perchlorate. Perchlorate is a contaminant which can enter drinking water from natural deposits or through introduction by …


Privacy-Preserving Power Usage Control In Smart Grids, Huchun Jan 2015

Privacy-Preserving Power Usage Control In Smart Grids, Huchun

Doctoral Dissertations

"The smart grid (SG) has been emerging as the next-generation intelligent power grid system because of its ability to efficiently monitor, predicate, and control energy generation, transmission, and consumption by analyzing users' real-time electricity information. Consider a situation in which the utility company would like to smartly protect against a power outage. To do so, the company can determine a threshold for a neighborhood. Whenever the total power usage from the neighborhood exceeds the threshold, some or all of the households need to reduce their energy consumption to avoid the possibility of a power outage. This problem is referred to …


Small Sample Umpu Equivalence Testing Based On Saddlepoint Approximations, Renren Zhao Jan 2015

Small Sample Umpu Equivalence Testing Based On Saddlepoint Approximations, Renren Zhao

Doctoral Dissertations

"In the first section, we consider small sample equivalence tests for exponentiality. Statistical inference in this setting is particularly challenging since equivalence testing procedures typically require a much larger sample size, in comparison to classical "difference tests", to perform well. We make use of Butler's marginal likelihood for the shape parameter of a gamma distribution in our development of equivalence tests for exponentiality. We consider two procedures using the principle of confidence interval inclusion, four Bayesian methods, and the uniformly most powerful unbiased (UMPU) test where a saddlepoint approximation to the intractable distribution of a canonical sufficient statistic is used. …


Vrcc-3d+: Qualitative Spatial And Temporal Reasoning In 3 Dimensions, Nathan Eloe Jan 2015

Vrcc-3d+: Qualitative Spatial And Temporal Reasoning In 3 Dimensions, Nathan Eloe

Doctoral Dissertations

"Qualitative Spatial Reasoning (QSR) has varying applications in Geographic Information Systems (GIS), visual programming language semantics, and digital image analysis. Systems for spatial reasoning over a set of objects have evolved in both expressive power and complexity, but implementations or usages of these systems are not common. This is partially due to the computational complexity of the operations required by the reasoner to make informed decisions about its surroundings. These theoretical systems are designed to focus on certain criteria, including efficiency of computation, ease of human comprehension, and expressive power. Sadly, the implementation of these systems is frequently left as …


Constitutive Activity In Orphan G Protein Coupled Receptors, Adam Lee Martin Jan 2015

Constitutive Activity In Orphan G Protein Coupled Receptors, Adam Lee Martin

Doctoral Dissertations

"The goal of this research was to use a distal signaling pathway analysis to evaluate the extent of agonist independent constitutive signaling among orphan class-A G protein coupled receptors (GPCRs). These receptors translate extracellular signals via conformational change into intracellular activation of different G proteins and subsequent second messenger synthesis. These small molecules regulate cellular biochemistry, eventually leading to nuclear signaling that results in changes in gene expression. Some GPCRs are capable of signaling in the absence of an activating ligand, a phenomenon called constitutive activity that is inhibited via an "inverse-agonist". The use of cAMP dependent Luciferase expression is …


Synthesis, Characterization And Application Of Acrylic Colloidal Unimolecular Polymer (Cup), Ameya Manohar Natu Jan 2015

Synthesis, Characterization And Application Of Acrylic Colloidal Unimolecular Polymer (Cup), Ameya Manohar Natu

Doctoral Dissertations

"Colloidal Unimolecular Polymer (CUP) particles were prepared by the process of water reduction on amphiphilic acrylic copolymers prepared via free radical polymerization technique. The formation of CUP particles was driven by the polymer-polymer interaction being greater than the polymer-solvent interaction and entropically favored by release of the water. It was demonstrated by Dynamic Light Scattering technique that CUP particles based on copolymers below 13,000 MW were unstable and the particles aggregated to a higher particle size. For the polymers with molecular weight (MW) above 13,000, a good correlation between the theoretical and experimental CUP particle size was observed. The rheology …


Computational Intelligence Based Complex Adaptive System-Of-Systems Architecture Evolution Strategy, Siddharth Agarwal Jan 2015

Computational Intelligence Based Complex Adaptive System-Of-Systems Architecture Evolution Strategy, Siddharth Agarwal

Doctoral Dissertations

The dynamic planning for a system-of-systems (SoS) is a challenging endeavor. Large scale organizations and operations constantly face challenges to incorporate new systems and upgrade existing systems over a period of time under threats, constrained budget and uncertainty. It is therefore necessary for the program managers to be able to look at the future scenarios and critically assess the impact of technology and stakeholder changes. Managers and engineers are always looking for options that signify affordable acquisition selections and lessen the cycle time for early acquisition and new technology addition. This research helps in analyzing sequential decisions in an evolving …


Volterra Difference Equations, Nasrin Sultana Jan 2015

Volterra Difference Equations, Nasrin Sultana

Doctoral Dissertations

"This dissertation consists of five papers in which discrete Volterra equations of different types and orders are studied and results regarding the behavior of their solutions are established. The first paper presents some fundamental results about subexponential sequences. It also illustrates the subexponential solutions of scalar linear Volterra sum-difference equations are asymptotically stable. The exact value of the rate of convergence of asymptotically stable solutions is found by determining the asymptotic behavior of the transient renewal equations. The study of subexponential solutions is also continued in the second and third articles. The second paper investigates the same equation using the …


Computing And The Electrical Transport Properties Of Coupled Quantum Networks, Casey Andrew Cain Jan 2015

Computing And The Electrical Transport Properties Of Coupled Quantum Networks, Casey Andrew Cain

Doctoral Dissertations

In this dissertation a number of investigations were conducted on ballistic quantum networks in the mesoscopic range. In this regime, the wave nature of electron transport under the influence of transverse magnetic fields leads to interesting applications for digital logic and computing circuits. The work specifically looks at characterizing a few main areas that would be of interest to experimentalists who are working in nanostructure devices, and is organized as a series of papers. The first paper analyzes scaling relations and normal mode charge distributions for such circuits in both isolated and open (terminals attached) form. The second paper compares …


Performance Analysis And Modelling Of Hybrid Photovoltaic-Thermal Solar Panels, Nicole C. Annis Jan 2015

Performance Analysis And Modelling Of Hybrid Photovoltaic-Thermal Solar Panels, Nicole C. Annis

Doctoral Dissertations

A photovoltaic-thermal (PVT) panel was constructed, tested, and modelled using both MATLAB and TRNSYS. During the experimental testing, which took place on the Missouri University of Science and Technology campus in Rolla, Missouri; two identical PVT panels were tested alongside two PV panels to gather an electrical baseline for comparison. Approximately 69 days’ worth of data were of data were collected during the summer of 2014. The PV electrical, PVT electrical, PVT thermal and PVT combined (electrical and thermal) efficiencies were 3.5-5.6%, 3.4-5.4%, 20.9-11.6%, and 24.3-17.0%, respectively.

A MATLAB program was developed using existing equations for one-dimensional, quasi-steady model of …


Accuracy Of Theory For Calculating Electron Impact Ionization Of Molecules, Hari Chaluvadi Jan 2015

Accuracy Of Theory For Calculating Electron Impact Ionization Of Molecules, Hari Chaluvadi

Doctoral Dissertations

The study of electron impact single ionization of atoms and molecules has provided valuable information about fundamental collisions. The most detailed information is obtained from triple differential cross sections (TDCS) in which the energy and momentum of all three final state particles are determined. These cross sections are much more difficult for theory since the detailed kinematics of the experiment become important. There are many theoretical approximations for ionization of molecules. One of the successful methods is the molecular 3-body distorted wave (M3DW) approximation. One of the strengths of the DW approximation is that it can be applied for any …


Privacy-Preserving Query Processing Over Encrypted Data In Cloud, Yousef M. Elmehdwi Jan 2015

Privacy-Preserving Query Processing Over Encrypted Data In Cloud, Yousef M. Elmehdwi

Doctoral Dissertations

"The query processing of relational data has been studied extensively throughout the past decade. A number of theoretical and practical solutions to query processing have been proposed under various scenarios. With the recent popularity of cloud computing, data owners now have the opportunity to outsource not only their data but also data processing functionalities to the cloud. Because of data security and personal privacy concerns, sensitive data (e.g., medical records) should be encrypted before being outsourced to a cloud, and the cloud should perform query processing tasks on the encrypted data only. These tasks are termed as Privacy-Preserving Query Processing …


Quantification Of Information Flow In Cyber Physical Systems, Li Feng Jan 2015

Quantification Of Information Flow In Cyber Physical Systems, Li Feng

Doctoral Dissertations

"In Cyber Physical Systems (CPSs), traditional security mechanisms such as cryptography and access control are not enough to ensure the security of the system since complex interactions between the cyber portion and physical portion happen frequently. In particular, the physical infrastructure is inherently observable; aggregated physical observations can lead to unintended cyber information leakage. Information flow analysis, which aims to control the way information flows among different entities, is better suited for CPSs than the access control security mechanism. However, quantifying information leakage in CPSs can be challenging due to the flow of implicit information between the cyber portion, the …


Methods And Algorithms For Service Selection And Recommendation (Preference And Aggregation Based), Kenneth Kofi Fletcher Jan 2015

Methods And Algorithms For Service Selection And Recommendation (Preference And Aggregation Based), Kenneth Kofi Fletcher

Doctoral Dissertations

"In order for service users to get the best service that meets their requirements, they prefer to personalize their non-functional attributes, such as reliability and price. However, the personalization makes it challenging because service providers have to deal with conflicting non-functional attributes when selecting services for users. In addition, users may sometimes want to explicitly specify their trade-offs among non-functional attributes to make their preferences known to service providers. Typically, users' service search requests with conflicting non-functional attributes may result in a ranked list of services that partially meet their needs. When this happens, it is natural for users to …


Mechanical Characteristics Of Organically Modified Fly Ash-Kaolinite Mixtures, Xin Kang Jan 2015

Mechanical Characteristics Of Organically Modified Fly Ash-Kaolinite Mixtures, Xin Kang

Doctoral Dissertations

"Fly ash is a hazardous waste material to the environment. Beneficial reuse of fly ash, however, brings economic and environmental benefits, i.e., decreases the cost of disposal, reduces greenhouse gas emission, and improves mechanical properties of construction materials. Due to the lack of pozzolanic properties, the reuse rate of Class F fly ash in geotechnical engineering is relatively low (ACAA 2013). In order to promote the effectiveness and sustainability of high volume reuse of class F fly ash in geotechnical engineering, biopolymers (Chitosan, and Xanthan gum) and synthetic polymers (Polyethylene Oxide, PEO) were used instead of the traditional stabilizers to …


The Synthesis And Characterization Of Water-Reducible Nanoscale Colloidal Unimolecular Polymer (Cup) Particles, Cynthia J. Riddles Jan 2015

The Synthesis And Characterization Of Water-Reducible Nanoscale Colloidal Unimolecular Polymer (Cup) Particles, Cynthia J. Riddles

Doctoral Dissertations

"The coatings industry has adapted to more stringent guidelines in paint formulations. Current VOC (volatile organic compound) limits placed by the federal government have pushed the industry toward the development of paint formulations which have very little to no VOC's. The development of Colloidal Unimolecular Polymer (CUP) particles is a step in the direction of providing a resin system which exists in zero VOC aqueous dispersion.

The CUP particles are a part of the polymer field of Single Chain Nano Particles (SCNP) and ranged in diameters of 3-9 nm. The research presented in this dissertation describes the synthesis and design …


Essays On Unit Root Testing In Time Series, Xiao Zhong Jan 2015

Essays On Unit Root Testing In Time Series, Xiao Zhong

Doctoral Dissertations

"Unit root tests are frequently employed by applied time series analysts to determine if the underlying model that generates an empirical process has a component that can be well-described by a random walk. More specifically, when the time series can be modeled using an autoregressive moving average (ARMA) process, such tests aim to determine if the autoregressive (AR) polynomial has one or more unit roots. The effect of economic shocks do not diminish with time when there is one or more unit roots in the AR polynomial, whereas the contribution of shocks decay geometrically when all the roots are outside …


Distributed State Verification In The Smart Grid Using Physical Attestation, Thomas Patrick Roth Jan 2015

Distributed State Verification In The Smart Grid Using Physical Attestation, Thomas Patrick Roth

Doctoral Dissertations

"A cyber process in a distributed system can fabricate its internal state in its communications with its peers. These state fabrications can cause other processes in the distributed system to make incorrect control decisions. Cyber-physical systems have a unique advantage in the detection of falsified states because processes typically have observable effects on a shared physical infrastructure. This physical infrastructure acts as a high-integrity message channel that broadcasts changes in individual process states. The objective of this research is to demonstrate that there are cases where physical feedback from the shared infrastructure can be used to detect state fabrications. To …


Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan Jan 2015

Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan

Doctoral Dissertations

"Holocene sedimentary deposits in Al Qahmah coast, southern Red Sea, in Saudi Arabia have been accumulated on an arid siliciclastic coast in a rift tectonic setting. This study provides a detail interpretation and analysis of sedimentary facies, stratigraphy, depositional environment, and major geological processes. Two studies have been undertaken. First, petrological study of composition and texture of modern sediments and facies mapping delineate facies distribution and mechanisms of sediment transport and deposition. A unique suite of complex riverine, wave, tidal, wind, and chemical and biological processes affect the composition, texture, and distribution of the facies. Second, the depositional environments of …


Small Sample Saddlepoint Confidence Intervals In Epidemiology, Pasan Manuranga Edirisinghe Jan 2015

Small Sample Saddlepoint Confidence Intervals In Epidemiology, Pasan Manuranga Edirisinghe

Doctoral Dissertations

"In section 1, we develop a novel method of confidence interval construction for directly standardized rates. These intervals involve saddlepoint approximations to the intractable distribution of a weighted sum of Poisson random variables and the determination of hypothetical Poisson mean values for each of the age groups. Simulation studies show that, in terms of coverage probability and length, the saddlepoint confidence interval (SP) outperforms four competing confidence intervals obtained from the moment matching (M8), gamma-based (G1,G4) and ABC bootstrap (ABC) methods.

In section 2, we first consider Brillinger's classical model for a vital rate estimate with a random denominator. We …


Dynamic Behavior Of Operational Wind Turbines Considering Aerodynamic And Seismic Load Interaction, Mohammad-Amin Asareh Jan 2015

Dynamic Behavior Of Operational Wind Turbines Considering Aerodynamic And Seismic Load Interaction, Mohammad-Amin Asareh

Doctoral Dissertations

"With the advancements in the wind energy production industry, the demand for a cost effective and safe design of wind turbine structures is growing rapidly. The wide deployment of wind turbines in locations with high seismic hazard has lead engineers to take into account a more comprehensive seismic design of such structures. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module has been developed for the publicly available National Renewable Energy Laboratory (NREL) code, FAST, at the first step of this research. This achievement allows engineers working …


Investigation Of Robust Optimization And Evidence Theory With Stochastic Expansions For Aerospace Applications Under Mixed Uncertainty, Harsheel R. Shah Jan 2015

Investigation Of Robust Optimization And Evidence Theory With Stochastic Expansions For Aerospace Applications Under Mixed Uncertainty, Harsheel R. Shah

Doctoral Dissertations

One of the primary objectives of this research is to develop a method to model and propagate mixed (aleatory and epistemic) uncertainty in aerospace simulations using DSTE. In order to avoid excessive computational cost associated with large scale applications and the evaluation of Dempster Shafer structures, stochastic expansions are implemented for efficient UQ. The mixed UQ with DSTE approach was demonstrated on an analytical example and high fidelity computational fluid dynamics (CFD) study of transonic flow over a RAE 2822 airfoil.

Another objective is to devise a DSTE based performance assessment framework through the use of quantification of margins and …


Effects Of N-Acetylcysteine Amide In Preventing/Treating Cataracts, Sri Krishna Yasaswi Maddirala Jan 2015

Effects Of N-Acetylcysteine Amide In Preventing/Treating Cataracts, Sri Krishna Yasaswi Maddirala

Doctoral Dissertations

"Cataract, the opacification of an eye lens, is a common pathological abnormality of the lens accounting for approximately 50% of all blindness. The only effective treatment currently available for a cataract is the surgical removal of the affected lens and replacement with an artificial lens for the restoration of vision. Although, cataract surgery is considered to be a very successful procedure in terms of visual outcome, the cost of surgery, need for trained personnel and surgeons, and postsurgical complications, limit the worldwide availability and accessibility of this procedure. Hence, alternative preventive and treatment procedures are worthy of investigation. The lens …


Shear Wave Splitting Analysis Beneath Tien Shan: Geodynamic Implications Of Complex Anisotropy, Solomon Gerra Cherie Jan 2015

Shear Wave Splitting Analysis Beneath Tien Shan: Geodynamic Implications Of Complex Anisotropy, Solomon Gerra Cherie

Doctoral Dissertations

"In spite of numerous studies, the mechanisms for the crustal shortening, mountain formation and associated tectonism leading to complex or simply seismic anisotropy formation beneath the Tien Shan Orogenic Belt is still debated. The most popular hypotheses suggested for the existence of seismic anisotropy are small-scale mantle convection, regional scale resistive basal shear and APM induced asthenospheric flow. Here, we used shear-wave splitting (SWS) measurements with good azimuthal coverage to provide additional constraints on the various models proposed by previous studies. One of the most effective approaches utilized to constrain convective mantle flow patterns is the splitting of P-to-S converted …


Application Of Colloidal Unimolecular Polymer (Cup) Particles In Coatings, Sagar Vijay Gade Jan 2015

Application Of Colloidal Unimolecular Polymer (Cup) Particles In Coatings, Sagar Vijay Gade

Doctoral Dissertations

"Colloidal unimolecular polymer (CUP) particles were prepared by the process of water reduction on copolymers containing hydrophobic and hydrophilic monomers at definite ratio using free radical polymerization. The CUPs are formed by the effect of hydrophilic /hydrophobic interactions of the polymer with a change in the solvent environment around them. Once formed these colloidal particles are thermodynamically stable with collapsed hydrophobic groups forming a spheroidal core and hydrophilic charges on the surface stabilizing the particle by the charge repulsion. CUPs contain only the charged CUP particles, water and counterions with all the functionality on the surface for further chemistry. CUP …


Analytical And Numerical Studies Of Photo-Injected Charge Transport In Molecularly-Doped Polymers, Amrita Roy Chowdhury Jan 2015

Analytical And Numerical Studies Of Photo-Injected Charge Transport In Molecularly-Doped Polymers, Amrita Roy Chowdhury

Doctoral Dissertations

"The mobility of photo-injected charge carriers in molecularly-doped polymers (MDPs) exhibits a commonly observed, and nearly universal Poole-Frenkel field dependence, µ ~ exp [square root (ß0E)], that has been shown to arise from the correlated Gaussian energy distribution of transport sites encountered by charges undergoing hopping transport through the material. Analytical and numerical studies of photo-injected charge transport in these materials are presented here with an attempt to understand how specific features of the various models developed to describe these systems depend on the microscopic parameters that define them. Specifically, previously published time-of-flight mobility data for the molecularly …


Detection And Recognition Of R/F Devices Based On Their Unintended Electromagnetic Emissions Using Stochastic And Computational Intelligence Methods, Shikhar Prasad Acharya Jan 2015

Detection And Recognition Of R/F Devices Based On Their Unintended Electromagnetic Emissions Using Stochastic And Computational Intelligence Methods, Shikhar Prasad Acharya

Doctoral Dissertations

"Radio Frequency (RF) devices produce some amount of Unintended Electromagnetic Emissions (UEEs). UEEs are generally unique to a device and can be thought of as a signature of the device. This property of uniqueness of UEEs can be used to detect and identify the device producing the emission. The problem with UEEs is that they are very low in power and are often buried deep inside the noise band which makes them difficult to detect. There are two types of UEE detection methods. The first one is called stimulated detection method where the UEEs of a device are enhanced using …


Origin And Stratigraphic Architecture Of The Middle Permian Lower And Upper Quanzijie Low-Order Cycles, Bogda Mountains, Nw China, Jonathan Obrist-Farner Jan 2015

Origin And Stratigraphic Architecture Of The Middle Permian Lower And Upper Quanzijie Low-Order Cycles, Bogda Mountains, Nw China, Jonathan Obrist-Farner

Doctoral Dissertations

"This study is carried out in the Bogda Mountains, NW China, and aims to provide a detailed sedimentary, stratigraphic, environmental, and paleoclimatic reconstruction in the paleo-mid-latitude along the east coast of Pangea. The Middle Permian lower and upper Quanzijie low-order cycles (QZJ LCs) provide a nearly complete sedimentary record in an area were little is known. In the first part of this work, the previously-established QZJ LC is divided into two LCs on the basis of regional stratigraphic correlation and major changes in depositional environments and tectonic and climatic processes. The newly-established lower QZJ LC is mainly composed of meandering …


Nmr T₁ Studies Of Colloidal Unimolecular Polymer (Cup) Surface Water, Yousef Abobaker Dawib Jan 2015

Nmr T₁ Studies Of Colloidal Unimolecular Polymer (Cup) Surface Water, Yousef Abobaker Dawib

Doctoral Dissertations

"This dissertation is subdivided into three topics: Experimental study of colloidal unimolecular polymer (CUP) hydration; probing of polymer chain dynamics by 13C solid state NMR technique; and the anticorrosive effect of 5-mercapto-1, 3, 4-thiadiazole-2(3H)-thione (MTT) derivatives.

The states of water in colloidal unimolecular polymer system were investigated by low field proton NMR. Bound and free water fractions were determined using spin-lattice relaxation measurements. A model equation was used to analyze the inversion recovery data.

The proton cross polarization and the pulse sequence for total spinning sideband suppression CP-TOSS NMR method were developed to determine the chain mobility of polymers …