Digital Commons Network^™

Thermal Analysis For The Purpose Of Fault Diagnosis Of Commercial Proton Exchange Membrane Fuel Cells (Pemfc), Reem Izzeldin Elsadig Salim

Theses

The world's awareness towards the amount of destruction that our extensive and ignorant lifestyles in the past few decades have imposed on the environment is growing day after day. This resulted in an increased governmental and research interest towards the development and use of green technology. Fuel Cells are one of the green technologies that received a major share of research interest in the past decade.

However, despite their promising features, Fuel Cell systems still lack a solid fault diagnosis and predictive maintenance study. There are numerous faults that have to be detected and diagnosed on a fuel cell power …

Some Algebraic Aspect And Applications Of A Family Of Functions Over Finite Fields, Shaima Ahmed Thabet

Theses

We study two families of functions over finite fields; the Multivalued Threshold

Functions and the Multivariate Polynomials. Recent advances made in our Conception and our understanding of Boolean Threshold Functions and Multivariate Threshold Functions have considerably increased the importance of the role that they Play in our days in areas like cryptography, circuit complexity, learning theory, social choice, quantum complexity, and in many other areas. Theoretical aspects of Bovid and Gauche who gave an algebraic first studied threshold functions Approach of Boolean Threshold Functions using group ring theory. We will present some algebraic properties of Boolean threshold functions. For the …

Study Of The Seasonal And Interannual Variability Of Phytoplankton Bloom In Arabian Gulf Using Modisdata, Malik Mutasim Malik Gasim

Theses

The Arabian Gulf is a semi enclosed large water body that experiences seasonal

variations and reversal of it water currents flow circulation. The Gulf waters are characterized by having high primary productivity and strong phytoplankton blooms at particular seasons within the year. Phytoplankton is a base of the food chain for marine species, providing an essential food resource for aquatic life. Marine phytoplankton affects the diversity of any marine ecosystem and drives its functioning and is strongly correlated with fishery yields. The primary

objectives of this research study are to answer key research questions related to phytoplankton blooms in the …

Biometrics-Based Dynamic Authentication For Secure Services, Saif Mohammed Saeed Abdulla Al Aryani

Theses

This thesis proposes a secure authentication protocol against physical session hijacking attacks. In client/server technology, users establish sessions to access the services offered by the servers. However, using physical session hijacking attacks, malicious users may physically take control of ongoing sessions. Malicious users also can establish sessions with servers using stolen passwords. In both cases, the server will be communicating with the wrong user who pretends to be the real user. The goal of this authentication protocol is to continuously and dynamically ensure that during an ongoing session the current session’s user is himself the real person that is known …

Evaluating The Gasday Security Policy Through Penetration Testing And Application Of The Nist Cybersecurity Framework, Andrew Nicholas Kirkham

Master's Theses (2009 -)

This thesis explores cybersecurity from the perspective of the Marquette University GasDay lab. We analyze three different areas of cybersecurity in three independent chapters. Our goal is to improve the cybersecurity capabilities of GasDay, Marquette University, and the natural gas industry. We present network penetration testing as a process of attempting to gain access to resources of GasDay without prior knowledge of any valid credentials. We discuss our method of identifying potential targets using industry standard reconnaissance methods. We outline the process of attempting to gain access to these targets using automated tools and manual exploit creation. We propose several …

Developing A Framework For Creating Mhealth Surveys, Veli Melih Bilen

Master's Theses (2009 -)

Various issues in the design of surveys for mobile health (mHealth) research projects yet exist. As mHealth solutions become more popular, new issues are brought into consideration. Researchers need to collect some critical information from participants in these mHealth studies. These mHealth studies require a specialized framework to create surveys, track progress and analyze user data. In these procedures, mHealth’s needs differ from other studies. Therefore, there has to be a new framework that satisfies needs of mHealth research studies. Although there are studies for creating efficient, robust and user-friendly surveys, there is no solution or study, which is specialized …

Application Of A Multi-Zone Model For The Prediction Of Species Concentrations In Rapid Compression Machine Experiments, David Wilson

Master's Theses (2009 -)

Accurate chemical kinetic models, which predict species evolution and heat release rates in chemically reactive systems, are essential for further advancements in fuel and combustion technology. An experimental facility that is widely used for evaluating the accuracy of kinetic models is a rapid compression machine (RCM), which creates a well-defined reaction environment by compressing a reactive mixture inside a chamber. Generally, RCM experiments are conducted in order to obtain ignition delay data. However, chemical speciation data provides greater insight into reaction pathways, and is therefore a more rigorous benchmark for validating kinetic models. In order for a chemical kinetic model …

Social-Context Middleware For At-Risk Veterans, Nadiyah Frances Johnson

Master's Theses (2009 -)

Many veterans undergo challenges when reintegrating into civilian society. These challenges include readapting to their communities and families. During the reintegration process veterans have difficulties finding employment, education or resources that aid veteran health. Research suggests that these challenges often result in veterans encountering serious mental illness. Post-Traumatic Stress Disorder (PTSD) is a common mental disease that veterans often develop. This disease impacts between 15-20% of veterans. PTSD increases the likelihood of veterans engaging in high risk behaviors which may consist of impulsivity, substance abuse, and angry outbursts. These behaviors raise the veterans’ risk of becoming violent and lashing out …

Modeling And Investigation Of Refrigeration System Performance With Two-Phase Fluid Injection In A Scroll Compressor, Rui Gu

Master's Theses (2009 -)

Vapor compression cycles are widely used in heating, refrigerating and air-conditioning. A slight performance improvement in the components of a vapor compression cycle, such as the compressor, can play a significant role in saving energy use. However, the complexity and cost of these improvements can block their application in the market. Modifying the conventional cycle configuration can offer a less complex and less costly alternative approach. Economizing is a common modification for improving the performance of the refrigeration cycle, resulting in decreasing the work required to compress the gas per unit mass. Traditionally, economizing requires multi-stage compressors, the cost of …

Least-Squares Mapping From Kinematic Data To Acoustic Synthesis Parameters For Rehabilitative Acoustic Learning, Xiangyu Zhou

Master's Theses (2009 -)

Thousands of people suffer from dysarthria resulting from neurological injury of the motor component of the motor-speech system, and need to rely on alternative methods to communicate in daily life, such as body language or text-to-speech [1] . However, there are currently very few effective rehabilitative therapies for helping these patients improve their speech. Because of this, research is needed to develop better rehabilitative therapies. One such area of research is the use of involuntary acoustic learning. The Speech and Swallowing lab at Marquette University has an Electromagnetic Articulography (EMA) system to collect kinematic data and a software system called …

Versus Los Angeles, Thomas Vincent Kelly

English Theses & Dissertations

The poems included in this manuscript construct, explore, and interrogate hyper reality and how it affects the twenty-first century. Simultaneously creating and destroying representations of a world made in the image of electronic entertainment, Versus Los Angeles inhabits various pop-culture personas in order to illustrate loss of identity, fame as commodity, the erosion of language, and the politics these various icons or platforms promote.

Nonlinear Flight Control Design Using Backstepping Methodology, Thanh Trung Tran

Mechanical & Aerospace Engineering Theses & Dissertations

The subject of nonlinear flight control design using backstepping control methodology is investigated in the dissertation research presented here. Control design methods based on nonlinear models of the dynamic system provide higher utility and versatility because the design model more closely matches the physical system behavior. Obtaining requisite model fidelity is only half of the overall design process, however. Design of the nonlinear control loops can lessen the effects of nonlinearity, or even exploit nonlinearity, to achieve higher levels of closed-loop stability, performance, and robustness. The goal of the research is to improve control quality for a general class of …

Collaborative Development Of An Interdisciplinary Scientific Research Proposal: Negotiation Through Boundary Objects, Laura Emond Paganucci

English Theses & Dissertations

Funding agencies are increasingly soliciting proposals that require interdisciplinary and collaborative solutions for a scientific issue. The development of these research proposals is challenging and often problematic due to the complexity involved in integrating the differing characteristics of multiple disciplines to produce a single, cohesive document. Minimal research has been conducted to examine this collaborative process as it occurs. This study uses the concept of boundary objects as a framework to analyze an interdisciplinary and collaborative team during the development of a research proposal. Multiple methods were used to identify disciplinary differences and analyze their negotiations. This study delineated disciplinary …

Experimental Investigation Of Turbulent Structures And Non-Equilibrium Effects In Axial Wake Vortices Via Particle Image Velocimetry, Jeffry William Ely

Mechanical & Aerospace Engineering Theses & Dissertations

Vortices are a common phenomenon in fluid flows that arise as kinetic energy dissipates into heat via viscous interaction. They arise naturally at large scales in the form of dust devils, tornadoes, and as a counter-rotating vortex pair in the wake of aircraft. It is important to understand the conditions leading to their formation, their duration, and their dissipation in order to forecast or prevent undesirable effects. Among these deleterious effects is a decrease in safety of aircraft operations in the wake of other aircraft, an extremely common situation at airports around the world. A large number of mathematical models …

Concurrent Spatial Mapping Of The Viscoelastic Behavior Of Heterogeneous Soft Materials Via A Polymer-Based Microfluidic Device, Wenting Gu

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents a novel experimental technique, namely concurrent spatial mapping (CSM), for measuring the viscoelastic behavior of heterogeneous soft materials via a polymer-based microfluidic device. Comprised of a compliant polymer microstructure and an array of electrolyte-enabled distributed resistive transducers, the microfluidic device detects both static and dynamic distributed loads. Distributed loads deform the polymer microstructure and are recorded as resistance changes at the locations of the transducers.

The CSM technique identifies the elastic modulus of soft materials by applying a precisely controlled indentation depth using a rigid probe to a sample placed on the device. The spatially-varying elastic modulus …

Modeling Shock Waves Using Exponential Interpolation Functions With The Least-Squares Finite Element Method, Bradford Scott Smith Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

The hypothesis of this research is that exponential interpolation functions will approximate fluid properties at shock waves with less error than polynomial interpolation functions. Exponential interpolation functions are derived for the purpose of modeling sharp gradients. General equations for conservation of mass, momentum, and energy for an inviscid flow of a perfect gas are converted to finite element equations using the least-squares method. Boundary conditions and a mesh adaptation scheme are also presented. An oblique shock reflection problem is used as a benchmark to determine whether or not exponential interpolation provides any advantages over Lagrange polynomial interpolation. Using exponential interpolation …

Secondary Electron Emission From Plasma Processed Accelerating Cavity Grade Niobium, Miloš Bašović

Mechanical & Aerospace Engineering Theses & Dissertations

Advances in the particle accelerator technology have enabled numerous fundamental discoveries in 20th century physics. Extensive interdisciplinary research has always supported further development of accelerator technology in efforts of reaching each new energy frontier.

Accelerating cavities, which are used to transfer energy to accelerated charged particles, have been one of the main focuses of research and development in the particle accelerator field. Over the last fifty years, in the race to break energy barriers, there has been constant improvement of the maximum stable accelerating field achieved in accelerating cavities. Every increase in the maximum attainable accelerating fields allowed for higher …

Scripts In A Frame: A Framework For Archiving Deferred Representations, Justin F. Brunelle

Computer Science Theses & Dissertations

Web archives provide a view of the Web as seen by Web crawlers. Because of rapid advancements and adoption of client-side technologies like JavaScript and Ajax, coupled with the inability of crawlers to execute these technologies effectively, Web resources become harder to archive as they become more interactive. At Web scale, we cannot capture client-side representations using the current state-of-the art toolsets because of the migration from Web pages to Web applications. Web applications increasingly rely on JavaScript and other client-side programming languages to load embedded resources and change client-side state. We demonstrate that Web crawlers and other automatic archival …

Cebaf Upgrade Bunch Length Measurements, Mahmoud Mohamad Ali Ahmad

Physics Theses & Dissertations

Many accelerators use short electron bunches and measuring the bunch length is important for efficient operations. CEBAF needs a suitable bunch length because bunches that are too long will result in beam interruption to the halls due to excessive energy spread and beam loss. In this work, bunch length is measured by invasive and non-invasive techniques at different beam energies. Two new measurement techniques have been commissioned; a harmonic cavity showed good results compared to expectations from simulation, and a real time interferometer is commissioned and first checkouts were performed. Three other techniques were used for measurements and comparison purposes …

Characterization Of Soundscapes In Shallow Water Habitats Of The Florida Keys (Usa) And Their Influence On The Settlement Of Larval Fish And Invertebrates, John R. Butler

Biological Sciences Theses & Dissertations

In recent decades, changes in climate and water quality in Florida Bay and the Florida Keys (FL, USA) caused expansive cyanobacteria blooms that in turn precipitated massive sponge die-offs that drastically altered sponge-dominated hard-bottom communities in south-central Florida Bay. This area served as a model system to explore the effect of ecosystem change and habitat restoration on underwater soundscapes and larval recruitment. I had four main objectives: (1) characterize the underwater soundscapes of three near-shore, benthic habitats: mangrove islands, seagrass meadows, and hard-bottom (Chapter 2); (2) quantify larval settlement within healthy, degraded, and restored hard-bottom areas to test whether habitat …

A Hitchhiker’S Guide To Invasion Biology: Describing The Ecological Mechanisms Underlying The Range Expansions Of Two Ixodid Tick Species, Robyn M. Nadolny

Biological Sciences Theses & Dissertations

Increasing incidence of many tick-borne diseases have been linked to recent expansions of tick species distributions. Many tick species are expanding their ranges because of anthropogenic changes in the landscape, shifting climatic variables, and increasing populations of suitable host species and tick habitat. Few empirical studies have been performed, however, investigating the ecological mechanisms underlying these range expansions. Ticks are parasitic organisms that disperse across landscape by hitchhiking on hosts, but must then survive in the environment for long periods of time between bloodmeals. Two species of ixodid tick, Ixodes affinis and Amblyomma maculatum, are simultaneously expanding their ranges throughout …

Synthesis, Morphological Control, Dispersion Stabilization And In Situ Self-Assembly Of Noble Metal Nanostructures Using Multidentate Resorcinarene Surfactants, Sangbum Han

Chemistry & Biochemistry Theses & Dissertations

In this dissertation, a detailed investigation on the influence of various macrocyclic resorcinarene surfactants in determining the morphology, stabilization and self-assembly of mono- and bi- metallic nanoparticles was undertaken. Chapter 2 describes the influence of resorcinarene surfactants functionalized with amine- and thiol- headgroups in determining the morphology of monometallic Pt nanoparticles synthesized via the Brust-Schiffrin reaction. We found that while resorcinarene benzylthiol can lead to the formation of highly branched Pt nanostructures, resorcinarene amine can lead to the formation of anisotropic crystalline Pt nanoparticles. Further, we have evaluated the influence of resorcinarene ligands in determining the catalytic activity of these …

Synthesis And Mechanistic Investigations Of Transition Metal Complexes And Ligands For Chemotherapeutic Applications, Jimmie Lee Bullock Jr.

Chemistry & Biochemistry Theses & Dissertations

Transition metal complexes have played a critical role in antitumor therapy with many complexes incorporating platinum, ruthenium, and lanthanum having been investigated in preclinical and clinical trials. The best known transition metal therapeutic is cisplatin, which is utilized in nearly 50% of all cancer therapies, despite its significant toxic side effects. The toxic side effects of current FDA approved platinum-based chemotherapeutics are often overlooked due to the “special status” granted to these drugs due to their ability to fight, what is often considered an incurable disease with life expectancies often measured in months. Oncology drug development has therefore now focused …

The Effects Of Using Natural Gas In Light-Duty Vehicle Fleet Of The United States On Its Energy Dependency And Greenhouse Gas Emissions, Nurullah Ayyilmaz

Graduate Program in International Studies Theses & Dissertations

Shale boom has changed the track of discussions on the future of the U.S. energy politics. A new opportunity emerged to meet domestic demand of the U.S. by using secure sources. Transportation accounts for a quarter of energy consumption in the U.S. Increasing the share of natural gas in the transport sector bolsters the U.S. energy security because of shifting from insecure sources (imported oil) to secure sources (shale gas reserves). Using natural gas instead of oil in light-duty vehicles (LDVs) contributes to the efforts of decreasing dependence on insecure sources and also decreases anthropogenic greenhouse gas (GHG) emissions caused …

Naturalization Of Salt Marsh Restoration Sites In The Elizabeth River, Virginia, Assessed By Feeding Activity And Trophic Level Of Mummichogs (Fundulus Heteroclitus), Moriah Anne Good

Biological Sciences Theses & Dissertations

Recent efforts to mitigate environmental issues within the Southern Branch of the Elizabeth River, Virginia, designated a “Region of Concern” by the Chesapeake Bay Program, include several salt marsh restorations. By examining gut contents and stable isotopes values (δ13C and δ15N) from mummichogs (Fundulus heteroclitus), the functional equivalency of restored salt marshes compared to natural marshes was measured. In July 2013 I collected mummichogs from three restored and three reference salt marshes in the Southern Branch. Fish were collected for gut content analysis and were analyzed for stable isotopes (δ13C and δ15N).

I removed gut contents from 16 fish per …

Acoustic Detection Reveals Fine-Scale Distributions Of Myotis Lucifugus, Myotis Septentrionalis, And Perimyotis Subflavus In Eastern Nebraska, Jeremy A. White, Cliff Lemen, Patricia Freeman

School of Natural Resources: Faculty Publications

ABSTRACT.—Before white-nose syndrome arrives in Nebraska, it is important to document the preexposure distributions of cave bats in the state. We examined the distributions of Myotis lucifugus (little brown myotis), Myotis septentrionalis (northern long-eared myotis), and Perimyotis subflavus (tri-colored bat) in eastern Nebraska by setting acoustic detectors for a single night at 105 sites in wooded habitats during summers of 2012 and 2014. We compared 2 methods of determining presence at each site. Results of our analyses are fine-scale distributional maps for these bats and some range extensions from published records. Results for M. septentrionalis and P. subflavus are largely …

From Classification To Quantification In Tweet Sentiment Analysis, Wei Gao, Fabrizio Sebastiani

Research Collection School Of Computing and Information Systems

entiment classification has become a ubiquitous enabling technology in the Twittersphere, since classifying tweets according to the sentiment they convey towards a given entity (be it a product, a person, a political party, or a policy) has many applications in political science, social science, market research, and many others. In this paper, we contend that most previous studies dealing with tweet sentiment classification (TSC) use a suboptimal approach. The reason is that the final goal of most such studies is not estimating the class label (e.g., Positive, Negative, or Neutral) of individual tweets, but estimating the relative frequency (a.k.a. “prevalence”) …

How Money Helps Keep Students In College: The Relationship Between Family Finances, Merit-Based Aid, And Retention In Higher Education, Alexandre M. Olbrecht, Christopher Romano, Jeremy Teigen

Journal of Student Financial Aid

In this paper, we leverage detailed, individual-level student data to understand the relationships between family finances, merit-based aid, and first-year student retention. With three cohorts of student data that comprise family financial status, institutional merit scholarships, and many of the other known correlates of student retention, we regress sophomore retention of first-time, full-time students on the financial variables with controls. We find that an increase in a family’s ability to contribute to educational costs improves a student’s chances of retention. Additionally, our data show that institutional financial assistance also bolsters the likelihood that students return for their sophomore year.

Iowa Waste Reduction Center Newsletter, April 2016, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Contents:

--- It is with immense sadness we share that Chris Hernandez, an irreplaceable member of the IWRC team, passed away on Monday, March 28.
--- IWRC News
--- Industry News

School Readiness Of First Grade Charter School Students: An Evaluation Of An Early Childhood Program, Dr Shandowlyon L. Hendricks-Williams

Dissertations

This program evaluation studied the effectiveness of an early childhood program as it relates to school readiness. The early childhood program of a charter school located in Milwaukee, Wisconsin had been operating for over thirty without an evaluation of its effectiveness. To examine the effectiveness of the early childhood program, seventy-two students were evaluated using a teacher-developed First Grade Readiness Checklist; the Measures of Academic Progress (MAP) Test and Success for All (SFA) Assessment. School readiness, as a multifaceted construct, included five domains: academic, behavioral, emotional, social and self-help-skills.

The results of the survey indicate that the early childhood program …