Digital Commons Network^™

Evaluation Of Alternative Methods For Surface Preparation And Deposition Of Cerium-Based Conversion Coatings On Aluminum Alloys, William J. Gammill

Masters Theses

"This thesis investigates alternative surface preparation and deposition methods for cerium-based conversion coatings (CeCC) on high strength aluminum alloys. Cerium-based conversion coatings are being investigated as a more environmentally friendly replacement for chromium-based conversion coatings. Currently, the alloys are immersed in strong alkaline and acidic solutions to prepare the aluminum surfaces for conversion coating, in which immersion may not be suitable for all situations. Alternatives to this method were investigated, including wipe application of solution, ultrasonic processing in deionized water, and abrasive blasting with alumina. AI 7075-T6 test panels were prepared using each of these methods and compared to a …

Sintering And Microstructural Effects On Mechanical Properties Of Zirconium Carbide-Tungsten Cermets, Melissa M. Giles Craft

Masters Theses

"Zirconium carbide-tungsten cermets were prepared by in situ reaction sintering a mixture of zirconia and tungsten carbide. Tungsten is a refractory metal with a melting point of 3422⁰C; however, its mechanical strength decreases significantly with increasing temperature. One approach to improve the elevated temperature strength is to add ceramic particulates to the matrix. Zirconia and tungsten carbide were compacted and then reacted and sintered in a single step by heating to 2050⁰C. The resulting stoichiometric zirconium carbide-tungsten cermet had a relative density greater than 96%. Cermets with two different grain sizes were produced by altering the final sintering temperature. Sintering …

"In Situ" Printed Circuit Board Material Extraction Procedure With Conductor Surface Roughness Study, Amendra Koul

Masters Theses

"Analysis of printed circuit board (PCB) behavior in a wide frequency range from tens MHz to at least 40 GHz is very important for modern high-speed digital design and assuring for signal integrity (SI). this analysis includes preliminary evaluation of per-unit-length parameters of the PCB transmission line and transmission line characteristics, such as propagation and attenuation constants, and also extraction of these parameters from measurements on real test vehicles. This thesis describes an impedance calculator tool, which can substantially speed up PCB design, and the second topic considered in this work is characterization of dielectric parameters of substrates of printed …

Selective Solubilisation Of Single Walled Carbon Nanotubes Using Polycyclic Aromatic Hydrocarbons, Sourabhi Debnath

Doctoral

Single-walled carbon nanotubes (SWCNTS) are proposed to be one of the most promising nanomaterials, with unique electronic and mechanical properties which lend themselves to a variety of applications. In all cases the quality of the SWCNT material is important, and for some applications it is paramount. Despite sustained efforts, all currently known SWCNT synthetic techniques generate significant quantities of impurities. They also grow in bundles or ropes and are largely insoluble in common organic solvents. SWCNTS can have a range of structures and their electronic properties (metallic or semiconducting) depend on their structure and as well on their diameters. Currently …

Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite

Doctoral

Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their successful synthesis. The dependence of grating performances in these nanocomposites on recording intensity, spatial frequency and zeolite concentration were studied. It was found that the incorporation of silicalite-1 nanoparticles or a small amount of zeolite A nanoparticles (up to …

Visible And Hyperspectral Imaging Systems For The Detection And Discrimination Of Mechanical And Microbiological Damage Of Mushrooms, Edurne Gaston

Doctoral

Horticultural products such as mushrooms are exposed to environmental conditions during their postharvest life, which may affect product quality. Loss of whiteness during storage is particularly important in the mushroom industry. Rough handling and distribution, fruiting body senescence and bacterial infections are among the main causes of mushroom discolouration. The aim of this work was to study the use of visible and hyperspectral imaging (HSI) systems for the detection and discrimination of mechanical and microbiological damage of mushrooms. This piece of research involved a) monitoring the browning of mushroom with visible computer imaging systems, b) investigating the effect of mechanical …

Efficacy Of Ozone And Ultrasound For Microbial Reduction In Fruit Juice, Sonal Patil

Doctoral

Concerns have arisen regarding the microbiological safety of fruit juices due to a number of outbreaks associated with pathogens. Non-thermal technologies for the inactivation of microorganisms are of increasing interest to the food industry for the control of spoilage as well as safety concerns. The objective of this thesis was to investigate the efficacy of ultrasound and ozone treatments for control of microbial issues associated with fruit juices. Inactivation of Escherichia coli (ATCC 25922, NCTC 12900) using power ultrasound was found to be influenced by strain, prior acid adaptation and suspension liquid, but the effect was negated at the higher …

Assessing The Application Of 3d Collaborative Interfaces Within An Immersive Virtual University, Gavin Mcardle, Bianca Schoen-Phelan, Michela Bortolotto

Articles

The need to stimulate and engage students is of paramount importance within any learning scenario. Despite this, recent developments in online learning have failed to take this requirement into account. As a result e-learning courses which utilise traditional online learning management systems have a higher dropout rate than their classroom based counterparts. The attrition rate is attributed to boredom with the interfaces used to deliver learning material and also to the lack of opportunities to interact socially with others. Furthermore, being in a virtual environment imposes a whole new set of challenges onto users due to the distinct lack of …

Dietary Energy Density As Marker Of Dietary Quality In Swedish Children And Adolescents: The European Youth Heart Study, Emma Patterson, J. Wärnberg, E. Poortvliet, John Kearney, M. Sjöström

Articles

To investigate if dietary energy density is associated with measures of dietary quality (food group, micronutrient and macronutrient intakes) in children and adolescents.

Water Analysis For Emerging Environmental Contaminants, Xiaoliang Cheng

Masters Theses

"The presence of emerging environmental contaminants in water bodies used either as drinking water or for recreational purpose has received considerable attention in the recent years. The emerging environmental contaminants can be defined as a wide range of chemicals that have been determined in the environment which may present serious health risks for humans. The occurrence of these contaminants indicate that both household and industrial chemicals have been introduced to water resources, a wide variety of chemicals, such as disinfection byproducts, pharmaceutical and personal care products and so on, have been detected at cetiain levels in either water bodies or …

Automation Of Cad Model Based Assembly Simulations Using Motion Capture, Anup Madhav Vader

Masters Theses

"The manufacturing industry often uses text and video as a supplement for worker training procedures. Unfortunately, text is often difficult to follow and video lends itself to occlusion issues. CAD based animations of assembly operations can overcome these shortcomings while offering greater potential for operations analysis and simulation flexibility. However, creating such CAD based training simulations manually is a time intensive task and many a times fail to reveal the practical assembly issues faced in the real world. Thus, it is highly beneficial to be able to automate these simulations using motion capture from a physical environment. This thesis research …

Development Of Novel Backscatter Communication Systems Using A Multi-Hop Framework And Distributed Beamforming, Vikram Reddy Surendra

Masters Theses

"The goal of this thesis it to develop a wireless networking framework for battery-free devices based on passive, backscatter communication. In contrast to traditional, active communication systems, where the radio signal has to be generated using large amount of energy from batteries, the passive systems reflect the RF signal. The information is encoded by modulating the reflected signal, which consumes significantly less energy than active transmission. The existing passive, backscatter systems have limited communication capabilities. For example, the Radio Frequency Identification (RFID) systems support short-distance, direct communication between active reader and passive tags. The communication range is limited due to …

Magnetocaloric Effect In Thin Films And Heterostructures, Christopher Bauer

USF Tampa Graduate Theses and Dissertations

The goals of this work are the optimization of the magnetocaloric effect in Gadolinium thin film structures. We approach this issue from two directions, that of process optimization and of interface effects. Past results showed Gd₂O₃ in our Gadolinium thin films, and the presence of such oxide seemed to grow with the temperature at which the film was grown or annealed. Comparison of samples grown without chamber gettering to those that were gettered show differences in their structural and magnetic properties, and we conclude that gettering is an effective step in enhancing the quality of Gd thin …

Weder Bürger Noch Mensch: Gefangener Der Medien Und Des Rechtsstaats Gekoppelte Entmenschlichung Mit Radikalisierung Zwei Auffassungen Heinrich Bölls Die Verlorene Ehre Der Katharina Blum Oder: Wie Gewalt Entstehen Und Wohin Sie Führen Kann, Tyler Robert Russ

Dissertations and Theses

In his 1974 novella The lost Honor of Katharina Blum Heinrich Böll argues for the constitutional guarantee of presumption of innocence. He states that this principle is violated when defamatory media headlines make unwarranted accusations against a private citizen destroying their reputation as part of a targeted smear campaign. The novella characterizes such intentional campaigns as both criminalizing and dehumanizing. Böll argues that the government should influence the press to conform to the limits implied in the institution of freedom of press. He shows the helplessness of a private citizen under attack from a smear campaign …

Spousal Crossover Effects Of Job Demands On Health, Rachel Jane Daniels

Dissertations and Theses

The primary goal of this dissertation was to examine the crossover effects of an individual's job demands on the perceived health of the spouse. Using a sample of grocery store employees and their partners, crossover relationships were examined for 90 dyads using Structural Equation Modeling. Although the models had good fit, the proposed direct crossover relationships of job demands on health were not supported. Job demands of one partner did not significantly predict health outcomes in the other partner; although follow-up analyses found significant crossover of women's job satisfaction on men's mental health scores. An additional crossover relationship was supported …

Local Food And Land-Use In Washington County, Oregon, Joshua James Cousins

Dissertations and Theses

Local food networks are often defined as presenting a variety of alternative food production, consumption, and distribution practices to the conventional food system such as community-supported-agriculture, farmers markets, and community gardens. Local food initiatives are commonly proposed as a model for the future of sustainable agriculture, and in the region of Portland, Oregon the abundance of such alternative venues results from the area's natural surroundings and smart planning. The region is host to 39 farmers markets and Portland is often hailed as one of the country's most sustainable cities. This study examines the role of local food networks in preserving …

Women And Resistance In The African Diaspora, With Special Focus On The Caribbean (Trinidad And Tobago) And U.S.A., Clare Johnson Washington

Dissertations and Theses

American history has celebrated the involvement of black women in the "underground railroad," but little is said about women's everyday resistance to the institutional constraints and abuses of slavery. Many Americans have probably heard of and know about Harriet Tubman and Sojourner Truth -- two very prominent black female resistance leaders and abolitionists -- but this thesis addresses the lives of some of the less-celebrated and lesser-known (more obscure) women; part of the focus is on the common tasks, relationships, burdens, and leadership roles of these very brave enslaved women.

Resistance history in the Caribbean and Americas in its various …

The Centerpiece To Real Reform? Political, Legal, And Social Barriers To Reentry In California,, Eumi Lee

Faculty Scholarship

No abstract provided.

Exclude Evidence You Exclude Justice’? A Critical Evaluation Of Israel’S Exclusionary Rule After Issacharov, Binyamin Blum

Faculty Scholarship

No abstract provided.

Misuse Made Plain: Evaluating Concerns About Neuroscience In National Security, Emily Murphy, Kelly Loweberg, Brenda M. Simon, Amy Burns, Libby Greismann, Jennifer M. Halbleib, Govind Persad, David L.M. Preston, Harker Rhodes

Faculty Scholarship

No abstract provided.

Alienated: A Reworking Of The Racialization Thesis After September 11, Ming Hsu Chen

Faculty Scholarship

No abstract provided.

Is There Monopsony In The Labor Market? Evidence From A Natural Experiment, Douglas O. Staiger, Joanne Spetz, Ciaran S. Phibbs

Dartmouth Scholarship

Recent theoretical and empirical advances have renewed interest in monopsonistic models of the labor market. However, there is little direct empirical support for these models. We use an exogenous change in wages at Department of Veterans Affairs (VA) hospitals as a natural experiment to investigate the extent of monopsony in the nurse labor market. We estimate that labor supply to individual hospitals is quite inelastic, with short-run elasticity around 0.1. We also find that non-VA hospitals responded to the VA wage change by changing their own wages.

A World Of Possibilities: Multimodalities, Collaboration And Equity In The Composition Classroom, Anicca Cox

Cal Poly Humboldt theses and projects

In this unbound project titled, A World of Possibilities: Multimodalities, Collaboration and Equality in the Composition Classroom I have shown some of the advantages of using multimodal writing instruction. Multimodal writing instruction uses a variety of methods that move beyond written text by incorporating visual, aural, cinematic or textual features together. This project focused on presenting multimodal approaches in the context of multiliteracies in order to achieve social justice and inclusion. The project is centered on collaborative methods and examines specific multimodalities to present possible techniques for incorporating these methods in a composition classroom. The goal of the project is …

Sentencing Reform In California, Aaron J. Rappaport

Faculty Scholarship

No abstract provided.

What Would The Delegates Talk About? A Rough Agenda For A Constitutional Convention, Darien Shanske

Faculty Scholarship

No abstract provided.

Above All Else Stop Digging: Local Government Law As A (Partial) Cause Of (And Solution To) The Current Housing Crisis, Darien Shanske

Faculty Scholarship

No abstract provided.

Engquist And The Erosion Of The Equal Protection Clause: An Attempt To Stop The Creep Of Irrational Dicta, Darien Shanske

Faculty Scholarship

No abstract provided.

Incorporating Information Technology In Library And Information Science Curriculum In Nigeria: A Strategy For Survival In The 21st Century, Bappah Magaji Abubakar

Library Philosophy and Practice (e-journal)

An IT revolution is occurring in almost all spheres of human endeavor. The field of Library and Information science (LIS) has also been predominated by advances in IT which has brought about dramatic changes in all ramifications. Change is now occurring in the area of education and training/curriculum, information seeking behaviour of users, as well as in the area of service delivery to clients. This paper therefore explores how IT can be incorporated into LIS curriculum in Nigeria in order to produce competent graduates that can withstand the test of time, and also function fully in the 21st century. The …

Status Of Technological Competencies: A Case Study Of University Librarians, Syeda Hina Batool, Kanwal Ameen

Library Philosophy and Practice (e-journal)

Technological expertise is the combination of knowledge and skill needed to apply technology for efficient and effective performance. This study investigates the technological expertise of eight university librarians using interview as data collection tool. Interview questions were based on technological template (T-template) or technology evaluation list for staff. It has been used by Education, Libraries & Heritage (ELH) Department’s ICT service in UK, California and Alberta public libraries to assess the IT competencies of their staff . The Template has been adopted and customized to meet the local requirements. It was used to measure the degree of professional technological expertise …

Libraries And Education For Peace In Pakistan, Rubina Bhatti

Library Philosophy and Practice (e-journal)

This paper explores the role of all kinds of libraries (school, college, university, public and national) in promoting education for peace. This paper investigates how libraries can play their part in peace building in Pakistani society. The methodology is a review of the related literature and informal discussion with educationists, psychologists, sociologists, library professionals and other society members. Extensive discussion with international participants from various countries was also conducted during the International Conference in India in February, 2010. It concluded that libraries, by organising, seminar, conferences, book displays, fairs and exhibitions can create an environment where conflict and relationships may …