Digital Commons Network^™

Quantum Chemical Calculations Of The Polymorphic Phase Transition Temperatures Of Zns, Znse, And Znte Crystals, Raşi̇t Ahiska, Dmytro Freik, Taras Parashchuk, Igor Gorichok

Turkish Journal of Physics

Molecular models of polymorphs modifications of zinc chalcogenides have been designed. Based on the results of ab initio quantum chemical calculations of the crystal structure of clusters the temperature dependences of the Gibbs energy of sphalerite and of wurtzite have been found. Phase transformations \"sphalerite-wurtzite\" temperatures have been evaluated.

An Investigation On Silar Deposited Cu_Xs Thin Films, Aykut Astam, Yunus Akaltun, Muhammet Yildirim

Turkish Journal of Physics

A copper sulfide thin film was deposited on glass substrate by successive ionic layer adsorption and reaction method at room temperature, using cupric sulfate and sodium sulfide aqueous solutions as precursors. The structural, surface morphological, optical, and electrical properties of the as-deposited film were investigated via X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, optical absorption, and d.c. 2-point probe methods. The film was found to be amorphous, dense, and uniform. Average atomic percentage of Cu:S in the as-deposited film was calculated as 63:37. The band gap energy of copper sulfide thin film was found to be 2.14 eV …

The Interactions Between Jak/Stat Signaling Ligands In Drosophila Melanogaster, Qian Chen

Theses and Dissertations--Biology

The development of multi-cellular organisms requires extensive cell-cell communication to coordinate cell functions. However, only a handful of signaling pathways have emerged to mediate all the intercellular communications; therefore, each of them is under an array of regulations to achieve signaling specificity and diversity. One such signaling pathway is the Janus Kinase/ Signal Transducer and Activator of Transcription (JAK/STAT) pathway, which is the primary signaling cascade responding to a variety of cytokines and growth factors in mammals and involved in many developmental processes. This signaling pathway is highly conserved between mammals and Drosophila, …

Hybrid Power System Options For Off-Grid Rural Electrification In Northern Kenya, June M. Lukuyu, Judith Cardell

Engineering: Faculty Publications

For domestic consumers in the rural areas of northern Kenya, as in other developing countries, the typical source of electrical supply is diesel generators. However, diesel generators are associated with both CO2 emissions, which adversely affect the environment and increase diesel fuel prices, which inflate the prices of consumer goods. The Kenya government has taken steps towards addressing this issue by proposing The Hybrid Mini-Grid Project, which involves the installation of 3 MW of wind and solar energy systems in facilities with existing diesel generators. However, this project has not yet been implemented. As a contribution to this effort, this …

Integrated Consensus Based Frameworks For Unmanned Vehicle Routing And Targeting Assignment, Waleed T. Barnawi

Dissertations

Unmanned aerial vehicles (UAVs) are increasingly deployed in complex and dynamic environments to perform multiple tasks cooperatively with other UAVs that contribute to overarching mission effectiveness. Studies by the Department of Defense (DoD) indicate future operations may include anti-access/area-denial (A2AD) environments which limit human teleoperator decision-making and control. This research addresses the problem of decentralized vehicle re-routing and task reassignments through consensus-based UAV decision-making. An Integrated Consensus-Based Framework (ICF) is formulated as a solution to the combined single task assignment problem and vehicle routing problem. The multiple assignment and vehicle routing problem is solved with the Integrated Consensus-Based Bundle Framework …

Status Quo Bias And Ambiguity Aversion In Engineers, Christopher L. Brown

Dissertations

Systems engineers routinely engage in exercises, such as a trade studies or Multiple Criteria Decision Analysis processes, to select the best among multiple options. Managers ideally assume that these processes are conducted in a manner that is strictly rational and repeatable. A cognitive bias leading to selection of a sub-optimal choice could then have significant consequences. Research has demonstrated a number of biases in the general population, but these have not been specifically studied in systems engineers. Two such biases are ambiguity aversion and status quo bias. A survey instrument was developed to test for ambiguity aversion and status quo …

Computational Optimization Models For Investigating Digital Crime And Intrusion Detection Alarms, Ezhil Selvam Kalaimannan

Dissertations

The Internet is a source of information, communication and entertainment, which makes it impossible for us to imagine a world without being connected. However, there has been a tremendous growth of crimes targeting any form of digital medium. The main objective of this dissertation is to develop and empirically evaluate computational optimization models for investigating digital crime and computer/network intrusion. The first research problem considered in this dissertation relates to the Crime Scene Investigation (CSI) in digital forensics. First, a mixed integer linear programming (MILP) model is proposed to allocate optimal investigation times for evidence, thereby maximizing the overall effectiveness …

Modular Network Construction Using Eqtl Data: An Analysis Of Computational Costs And Benefits, Yen Yi Ho, Leslie M. Cope, Giovanni Parmigiani

Faculty Publications

Background: In this paper, we consider analytic methods for the integrated analysis of genomic DNA variation and mRNA expression (also named as eQTL data), to discover genetic networks that are associated with a complex trait of interest. Our focus is the systematic evaluation of the trade-off between network size and network search efficiency in the construction of these networks. Results: We developed a modular approach to network construction, building from smaller networks to larger ones, thereby reducing the search space while including more variables in the analysis. The goal is achieving a lower computational cost while maintaining high confidence in …

Modeling And Validation Of A Synchronous-Machine/Controlled-Rectifier System, Kyle A. Hord

Theses and Dissertations--Electrical and Computer Engineering

The hardware validation of a novel average-value model (AVM) for the simulation of a synchronous-generator/controlled rectifier system is presented herein. The generator is characterized using genetic algorithm techniques to fit standstill frequency response (SSFR) measurements to q and d-axis equivalent circuits representing the generator in the rotor reference frame. The generator parameters form the basis of a detailed model of the system, from which algebraic functions defining the parametric AVM are derived. The average-value model is compared to the physical system for a variety of loading and operating conditions including step load change, change in delay angle, and external closed-loop …

Model Analysis And Predictive Control Of Double Electrode Submerged Arc Welding Process For Fillet Joints With Root Opening, Yi Lu

Theses and Dissertations--Electrical and Computer Engineering

Submerged Arc Welding (SAW) for fillet joints is one of the major applications in the shipbuilding industry. Due to the requirement for the weld size, a sufficient amount of metal must be deposited. In conventional SAW process, the heat input is proportional to the amount of metal melted and is thus determined by the required weld size. To meet this requirement, an excessive amount of heat is applied causing large distortions on the welded structures whose follow-up straightening is highly costly. In order to reduce the needed heat input, Double-Electrode (DE) technology has been practiced creating the Double-Electrode SAW (DE-SAW) …

Machine-Human Cooperative Control Of Welding Process, Weijie Zhang

Theses and Dissertations--Electrical and Computer Engineering

An innovative auxiliary control system is developed to cooperate with an unskilled welder in a manual GTAW in order to obtain a consistent welding performance. In the proposed system, a novel mobile sensing system is developed to non-intrusively monitor a manual GTAW by measuring three-dimensional (3D) weld pool surface. Specifically, a miniature structured-light laser amounted on torch projects a dot matrix pattern on weld pool surface during the process; Reflected by the weld pool surface, the laser pattern is intercepted by and imaged on the helmet glass, and recorded by a compact camera on it. Deformed reflection pattern contains the …

Reference Compensation For Localized Surface-Plasmon Resonance Sensors, Neha Nehru

Theses and Dissertations--Electrical and Computer Engineering

Noble metal nanoparticles supporting localized surface plasmon resonances (LSPR) have been extensively investigated for label free detection of various biological and chemical interactions. When compared to other optical sensing techniques, LSPR sensors offer label-free detection of biomolecular interactions in localized sensing volume solutions. However, these sensors also suffer from a major disadvantage – LSPR sensors remain highly susceptible to interference because they respond to both solution refractive index change and non-specific binding as well as specific binding of the target analyte. These interactions can severely compromise the measurement of the target analyte in a complex unknown media and hence limit …

Single Ended Traveling Wave Based Fault Location Using Discrete Wavelet Transform, Jin Chang

Theses and Dissertations--Electrical and Computer Engineering

In power transmission systems, locating faults is an essential technology. When a fault occurs on a transmission line, it will affect the whole power system. To find the fault location accurately and promptly is required to ensure the power supply. In this paper, the study of traveling wave theory, fault location method, Karrenbauer transform, and Wavelet transform is presented. This thesis focuses on single ended fault location method. The signal processing technique and evaluation study are presented. The MATLAB SimPowerSystem is used to test and simulate fault scenarios for evaluation studies.

Volume And Surface Integral Equations For Solving Forward And Inverse Scattering Problems, Xiande Cao

Theses and Dissertations--Electrical and Computer Engineering

In this dissertation, a hybrid volume and surface integral equation is used to solve scattering problems. It is implemented with RWG basis on the surface and the edge basis in the volume. Numerical results shows the correctness of the hybrid VSIE in inhomogeneous medium. The MLFMM method is also implemented for the new VSIEs.

Further more, a synthetic apature radar imaging method is used in a 2D microwave imaging for complex objects. With the mono-static and bi-static interpolation scheme, a 2D FFT is applied for the imaging with the data simulated with VSIE method. Then we apply a background cancelling …

Multifrequency Averaging In Power Electronic Systems, Fei Pan

Theses and Dissertations--Electrical and Computer Engineering

Power electronic systems have been widely used in the electrical power processing for applications with power levels ranging from less than one watt in battery-operated portable devices to more than megawatts in the converters, inverters and rectifiers of the utility power systems. These systems typically involve the passive elements such as inductors, capacitors, and resistors, the switching electronic components such as IGBTs, MOSFETS, and diodes, and other electronic circuits. Multifrequency averaging is one of the widely used modeling and simulation techniques today for the analysis and design of power electronic systems. This technique is capable of providing the average behavior …

Coordinated Voltage And Reactive Power Control Of Power Distribution Systems With Distributed Generation, Esa A. Paaso

Theses and Dissertations--Electrical and Computer Engineering

Distribution system voltage and VAR control (VVC) is a technique that combines conservation voltage reduction and reactive power compensation to operate a distribution system at its optimal conditions. Coordinated VVC can provide major economic benefits for distribution utilities. Incorporating distributed generation (DG) to VVC can improve the system efficiency and reliability. The first part of this dissertation introduces a direct optimization formulation for VVC with DG. The control is formulated as a mixed integer non-linear programming (MINLP) problem. The formulation is based on a three-phase power flow with accurate component models. The VVC problem is solved with a state of …

Adeno-Associated Virus (Aav) Transduction Of Primary Human Cd4+T Lymphocytes, Sahar Hussein Kamel

Browse all Theses and Dissertations

Development of latent HIV-infected CD4+ T lymphocytes is the major cause of HIV treatment failure. Adeno-associated virus (AAV) is an attractive vector for anti-HIV gene therapy due to its lack of pathogenicity, low immunogenicity, and persistent transgene expression. However, a major limitation for AAV gene transfer is the cell-specific tropism of each serotype. Only AAV serotypes 2 and 5 have been investigated in hematopoietic cells, both of these serotypes have shown low transduction efficiency. Since each of the currently described AAV serotypes demonstrate distinct tissue tropism, I hypothesized that other serotypes such as AAV1, 4, 8, or 9 may demonstrate …

Expression Of The Alpha, Beta, And Gamma Subunits Of The Interleukin-2 Receptor By Human Vascular Smooth Muscle Cells, Sultan Mohammed Alhayyani

Browse all Theses and Dissertations

Interleukin 2 (IL-2) is a member of the cytokine family and contributes to the proliferation, survival, and death of lymphocytes [1]. The interleukin-2 receptor (IL-2) is a tripartite receptor commonly expressed on the surfaces of many lymphoid cells and is composed of three non-covalently associated subunits, alpha (CD25), beta (CD122), and gamma (CD132) [2]. Our laboratory has previously described IL-2 receptor Beta expression by vasculature smooth muscle cells (VSMC) in mice and humans [3]. The current work expands our previous observations by assessing the expression of the alpha and gamma subunits of the IL-2R by VSMCs. Analysis of IL-2R expression …

Full Wave Electromagnetic Simulations Of Terahertz Wire Grid Polarizers And Infrared Plasmonic Wire Gratings, John Cetnar

Browse all Theses and Dissertations

This dissertation is a study of the interaction of terahertz (THz) and long-wave infrared (LWIR) radiation with various periodic sub-wavelength metallic structures in free-space and on dielectric substrates. There are many new and useful applications for both THz and LWIR radiation. Unfortunately, heavy attenuation by the Earth's atmosphere and low output power from THz sources combine to make THz radiation weak and difficult to detect. LWIR is not as prone to atmospheric attenuation as THz radiation. Nevertheless, the detection of LWIR can be improved upon by strengthening the coupling between incoming radiation and LWIR detector systems.

Light passing through periodic …

Phylogenetics, Population Genetics, And Evolution Of The Mallard Complex, Philip Lavretsky

Browse all Theses and Dissertations

Speciation is primarily regarded as an ancestral split that results in two distinct taxonomic units, and proceeds in stages along a continuum from initiation (i.e., population divergence) to completion (i.e., reproductively isolated species). Establishing how and why populations diverge, including the primary mechanisms influencing these events is a major objective for evolutionary scientists. Focusing on incipient forms, researchers attempt to disentangle the antagonistic nature of selection, genetic drift, and gene flow in the speciation process.

In chapter 1, I investigate the phylogenetic relationships of 14 closely related taxa within the mallard complex (Anas spp.) that underwent a radiation within the …

Rings Of Frobenius Operators, Mordechai Katzman, Karl Schwede, Anurag K. Singh, Wenliang Zhang

Department of Mathematics: Faculty Publications

Let R be a local ring of prime characteristic. We study the ring of Frobenius operators F(E), where E is the injective hull of the residue field of R. In particular, we examine the finite generation of F(E) over its degree zero component F⁰(E), and show that F(E) need not be finitely generated when R is a determinantal ring; nonetheless, we obtain concrete descriptions of F(E) in good generality that we use, for example, to prove the discreteness of F-jumping numbers for arbitrary ideals in determinantal rings.

Bootsie – Estimation Of Coefficient Of Variation Of Aflp Data By Bootstrap Analysis, Justin Payne, Erica Lindroth, K. M. Kneeland, Steven R. Skoda, Fatima Mustafa, Muhammad Irfan Ullah, John E. Foster

Department of Entomology: Faculty Publications

Bootsie is an English-native replacement for ASG Coelho's “DBOOT” utility for estimating coefficient of variation of a population of AFLP marker data using bootstrapping. Bootsie improves on DBOOT by supporting batch processing, time-to-completion estimation, builtin graphs, and a suite of export tools for creating data files for other population genetics software.

The Emerging Field Of Geogenomics: Constraining Geological Problems With Genetic Data, Paul A. Baker, Sherilyn C. Fritz, Christopher W. Dick, Andrew J. Eckert, Brian K. Horton, Stefano Manzoni, Camila C. Ribas, Carmala N. Garzione, David S. Battisti

Department of Earth and Atmospheric Sciences: Faculty Publications

The development of a genomics-derived discipline within geology is timely, as a result of major advances in acquiring and processing geologically relevant genetic data. This paper articulates the emerging field of “geogenomics,” which involves the use of large-scale genetic data to constrain geological hypotheses. The paper introduces geogenomics and discusses how hypotheses can be ad-dressed through collaboration between geologists and evolutionary biologists. As an example, geogenomic methods are applied to evaluate competing hypotheses regarding the timing of the Andean uplift, the closure of the Isthmus of Panama, the onset of trans-Amazon drainage, and Quaternary climate variation in the Neotropics.

Daily Area Of Snow Melt Onset On Arctic Sea Ice From Passive Microwave Satellite Observations 1979–2012, Angela C. Bliss, Mark R. Anderson

Department of Earth and Atmospheric Sciences: Faculty Publications

Variability in snow melt onset (MO) on Arctic sea ice since 1979 is examined by determining the area of sea ice experiencing the onset of melting during the melt season on a daily basis. The daily MO area of the snow and ice surface is determined from passive microwave satellite-derived MO dates for the Arctic Ocean and sub-regions. Annual accumulations of MO area are determined by summing the time series of daily MO area through the melt season. Daily areas and annual accumulations of MO area highlight inter-annual and regional variability in the timing of MO area, which is sensitive …

Optimal Energy Scheduling For A Smart Entity, Amin Fakhrazari, Hamid Vakilzadian, F. Fred Choobineh

Department of Electrical and Computer Engineering: Faculty Publications

Real-time availability of electricity prices via a smart power grid has a potential bilateral benefit to electricity users and suppliers. The users can reduce their costs by consuming energy during low-price hours and balancing their energy usage during other hours. This in turn benefits energy utility companies by reducing their peak power demand. This article describes an optimal shrinking horizon model for electricity-consuming units based on user preferences. The proposed model optimizes the end user’s electricity cost while meeting preferred comfort levels. The user can set preferences in the model using a tristate flexibility parameter for each electric-power-consuming unit. The …

Simulation Supported Estimation Of End-To-End Transmission Parameters In Non-Viral Gene Delivery, Beata Wysocki, Timothy M. Martin, Tadeusz A. Wysocki, Angela K. Pannier

Department of Electrical and Computer Engineering: Faculty Publications

Communications, in general, involve delivery of information from a source to a sink. At nano-scale, an example of a man-made communications involving interfacing with biological systems at intra-cellular level is non-viral gene delivery. From a telecommunications engineering perspective, important end-to-end parameters of such a system are: the endto- end delay, system capacity, and packet loss rate. There are neither known methods to estimate those parameters theoretically nor they are ready available from standard measurements. The paper provides estimates for those parameters based on the simulation of non-viral gene delivery system based on the queuing theory. The simulator used has bee

Terahertz-Infrared Ellipsometer System, And Method Of Use, Craig H. Herzinger, Mathias M. Schubert, Tino Hofmann, Martin M. Liphardt, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up Sh and his th. 100 THz, including: a Source Such as a backward wave oscillator, a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and a detector Such as a Golay cell; abolometer or a solid state detector: and preferably including a polarization …

Studies On Sensitivity Reduction In Solo And Mixture Treatments And Fungicide-Induced Mutagenesis In Monilinia Fructicola, Guido Schnabel, F. Chen, Sydney E. Everhart, W. C. Bridges, X. Liu

Department of Plant Pathology: Faculty Publications

Three fungicide-sensitive Monilinia fructicola isolates were exposed in weekly transfers of mycelia to a dose gradient of a DMI and a QoI fungicide (azoxystrobin) in solo or mixture treatments and fungicide sensitivity as well as genetic changes were assessed. Isolates showed a faster reduction in sensitivity (higher resistance factors) to azoxystrobin than to SYP-Z048; this process was slower in the mixture treatment. The decrease of fungicide sensitivity was not a heritable trait. Genomic mutagenesis at 8 of 15 microsatellite loci was evidenced in one of three isolates tested after exposure to azoxystrobin. These non-coding regions of the genome either showed …

Variational Formulation Of Macro-Particle Plasma Simulation Algorithms, Bradley Allan Shadwick, Alexander B. Stamm, Evstati Georgiev Evstatiev

Department of Physics and Astronomy: Faculty Publications

A variation formulation of macro-particle kinetic plasma models is discussed. In the electrostatic case, the use of symplectic integrators is investigated and found to offer advantages over typical generic methods. For the electromagnetic case, gauge invariance and momentum conservation are considered in detail. It is shown that, while the symmetries responsible for these conservation laws are broken in the presence of a spatial grid, the conservation laws hold in an average sense. The requirements for exact invariance are explored and it is shown that one viable option is to represent the potentials with a truncated Fourier basis

Approximations To The Solution Of The Frank-Kamenetskii Equation In A Spherical Geometry, Moustafa A. Soliman

Chemical Engineering

In this paper, an approximate analytical solution for Frank-Kamenetskii equation modeling a thermal explosion in a sphere, is obtained. The approximate solution is obtained by perturbation methods in terms of small and large distance parameter. The approximate solution is compared with the numerical solution obtained from an initial value problem formulation to the original boundary value problem. The approximate solution obtained is valid for all values of the distance parameter. For the original boundary value problem and for a given Frank-Kamenetskii parameter, a nonlinear algebraic equation needs to be solved to be able to apply the approximate solution.