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 …

A Hybrid Problem-Based And Just-In-Time Inductive Teaching Method For Failure Analysis Instruction, Ryan Michael Arlitt

Masters Theses

"When engineers retire, they take their expert knowledge with them. Preservation of this expert knowledge in a usable form is beneficial for the advancement of any engineering field. Risk in Early Design (RED) is one method for preserving expert risk analysis knowledge. The first purpose of this paper is to examine the usability of RED when incorporated with a hybrid problem-based and just-in-time inductive teaching method for failure analysis instruction. The second purpose of this paper is to propose and perform steps toward verification and validation of the RED methodology and implementation. Evaluation metrics were developed, and several of these …

Communication Seminar, Steelman Library, Chad Neuman

Syllabus Repository

No abstract provided.

Microalgal Bioremediation Of Nutrients In Wastewater And Carbon Dioxide In Flue Gas, Anand Murali Narasimhan

Masters Theses

"Microalgae are potential biofuel feedstocks that can provide solutions to the twin challenges of energy security and environmental pollution. They have great potential for the removal of excess nitrogen and phosphorus from wastewater including the farm runoff. They can capture carbon dioxide in the flue gas from coal fired power plants thereby reducing greenhouse gas and also producing algal biomass, which can be converted into biofuel. In this study, the nutrient consumption of Scenedesmus algae was investigated in a batch culture and the biomass yield was determined. Algae were able to utilize carbon in the form of soluble carbonates which …

Application Of Life Cycle Assessment To Estimate Environmental Impacts Of Surface Coal Mining, Ofentse Ditsele

Masters Theses

"Coal plays an important role in meeting the energy needs of the World. Given its abundance and low cost, its use is bound to increase with the growing energy demand. Despite its importance, there are concerns over coal's environmental burdens. In order to extract and use coal in a sustainable manner, sustainability assessment has to be comprehensive. Life Cycle Assessment (LCA) provides systematic and quantifiable measures for assessing environmental burdens of products and processes. Extensive LCA work has been done on coal use, particularly in electricity generation, but, the coal mining stage has been neglected, for the most part. This …

Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes, Naveen Kumar Lingam

Masters Theses

"This work involves the photosensitization of photorefractive polymeric composites through the inclusion of multiwalled and singlewalled carbon nanotubes grafted to poly(N-vinyl carbazole). The photorefractive nature of the holograms gratings was established using two-beam-coupling, yielding two-beam-coupling gain coefficients approaching 80 cm⁻¹. Degenerate-four-wave-mixing experiments exhibited diffraction efficiencies as high as 60% as well as over-modulation voltages as low as ~ 40 V/µm. These notable figures of merit indicate that the grafting of the various carbon nanotubes to the poly(N-vinyl carbazole) polymer resulted in enhanced photorefractive performance. The mechanism responsible for this enhancement in photorefractive performance is investigated using a variety of experimental …

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 …

Dynamic Networking For Programmable Logic Controller Communication, Richard Andrew Hardison

Masters Theses

"This thesis confronts the issue of set path communication in Programmable Logic Controllers (PLCs). In order to increase reliability in a networked automated process, it is necessary to develop a dynamic method of communication between PLCs. Three methods for dynamic messaging in PLCs are explored in this work. These methods are based on the real-time reconfiguration of message paths when communication fails on the originally configured path. The simplest method involves replacing the original message block with an Add-On Instruction (AOI) which can accept multiple communication paths and has the ability to switch between these paths to maintain communication. A …

Introduction To Television Production, Steelman Library, Roxane Griner

Syllabus Repository

No abstract provided.

Event Detection From Click-Through Data Via Query Clustering, Prabhu Kumar Angajala

Masters Theses

"The web is an index of real-world events and lot of knowledge can be mined from the web resources and their derivatives. Event detection is one recent research topic triggered from the domain of web data mining with the increasing popularity of search engines. In the visitor-centric approach, the click-through data generated by the web search engines is the start up resource with the intuition: often such data is event-driven. In this thesis, a retrospective algorithm is proposed to detect such real-world events from the click-through data. This approach differs from the existing work as it: (i) considers the click-through …

The Placement Of Remediation Amendments Into Contaminated Sediments Via Waterjet Technologies, Gavin Hunter Ray Risley

Masters Theses

"The use of amendments to perform in situ remediation of contaminated sediments is a technique that is relatively mature. The need exists to develop a method of amendment delivery that will efficiently place the amendments into the contaminated zone at depth with minimal impacts to the benthic communities and contaminant resuspension. Waterjets have been used for hundreds of years as an excavation, cutting, and cleaning tool, but they can also be used to inject remediation amendments into contaminated sediments if setup properly. In order to test this concept, a waterjet amendment injection system and nozzle have been developed and tested. …

Understanding Corrosion Of Ni₃(Si,Nb) Alloys In Hot Sulfuric Acid, Jen-Hsien Hsu

Doctoral Dissertations

"The Sulfur-Iodine thermochemical cycle has been proposed as a method for producing large quantities of hydrogen gas from water. However, the extreme operating environments involved limit the possible materials for construction.

Through proper heat treatment and composition control, the modified patented Ni₃(Si,Nb) alloy keeps high temperature strength to greater than 750⁰C and can be deformed by cold rolling more than 50% using multiple passes and intermediate anneals. The corrosion resistance is reproducible and maintains less than 5 mpy for a broad range of boiling sulfuric acid concentrations, including 70 wt%.

In the boiling 70 wt% sulfuric acid corrosion tests, kinetic …

Computational Intelligence Methods In Wireless Sensor Networks, Raghavendra V. Kulkarni

Doctoral Dissertations

"Wireless sensor networks (WSNs) are networks of autonomous nodes that sense, compute and communicate in order to monitor an environment collectively. Ad hoc deployment, dynamic environment and resource constraints in nodes need to be considered while addressing WSN challenges such as deployment, localization, routing and scheduling. Adaptive mechanisms that exhibit intelligent behavior in complex and dynamic environments are desirable to address these challenges. The potential of computational intelligence ( CI) based approaches for addressing WSN challenges is investigated in this study. Contributions of this dissertation are in the following three areas: critical literature analysis, new architectures and approaches, and new …

Synthesis And Characterization Of Metal Decorated Bamboo Structured Carbon Nanotubes For Hydrogen Storage, Sean Charles Mickey

Doctoral Dissertations

"Although hydrogen has been considered as a viable alternative fuel, the storage systems used to contain the hydrogen must be improved for large scale use. A variety of conceivable storage options exist ranging from compressed gas, cryogenic liquid, chemical solid state storage, and adsorptive surfaces. Carbon nanotubes (CNTs) provide a potentially viable option for hydrogen storage applications as a high surface area, lightweight media for adsorptive storage, but do not efficiently store hydrogen at ambient temperatures. Metal hydrides, on the other hand, are able to store large weight percents of hydrogen in a chemical solid state, but generally have unfavorable …

Nmr Investigations Of Biomass-To-Fuel Conversions By Hydrothermal Processes, Wenjia Zhang

Doctoral Dissertations

"Biofuels have gained significant attention as the most promising alternative energy and fuel supply for the near future because of two dominant reasons: first, biofuels are environmentally friendly; and second, they afford a sustainable technology. Biofuels can be synthesized from biomass by several different processes, among which, hydrothermal conversion is considered to be more energy efficient. However, scientific efforts to improve hydrothermal biomass-to-fuel (HT-BTF) conversion efficiencies are severely limited because little is known about the salient reaction mechanisms and intermediates. This study is aimed at a better understanding of the hydrothermal biomass degradation kinetics by advanced NMR spectroscopy and, accordingly, …

Haart Drugs Induce Oxidative Stress And Mitochondrial Dysfunction In Blood-Brain Barrier, Kalyan Reddy Manda

Doctoral Dissertations

"The era of highly active antiretroviral therapy (HAART) has controlled AIDS and its related disorders considerably; however, the prevalence of HIV-1-associated neurocognitive disorders (HAND) has been on the rise in the post-HAART era. In view of these developments, we investigated whether a HAART drug combination of 3'-Azido-2', 3'-deoxythymidine (AZT) and Indinavir (IDV) can alter the functionality of the blood-brain barrier (BBB) endothelial cells, thereby exacerbating the condition. Viability of hCMEC/D3 cells (in vitro model of BBB) that were exposed to the drugs was significantly reduced after a 72 hr treatment, in a dose-dependent manner. Reactive oxygen species (ROS) were highly …

Robust Frequency-Domain Turbo Equalization For Multiple-Input Multiple-Output (Mimo) Wireless Communications, Jian Zhang

Doctoral Dissertations

"This dissertation investigates single carrier frequency-domain equalization (SC-FDE) with multiple-input multiple-output (MIMO) channels for radio frequency (RF) and underwater acoustic (UWA) wireless communications. It consists of five papers, selected from a total of 13 publications. Each paper focuses on a specific technical challenge of the SC-FDE MIMO system. The first paper proposes an improved frequency-domain channel estimation method based on interpolation to track fast time-varying fading channels using a small amount of training symbols in a large data block. The second paper addresses the carrier frequency offset (CFO) problem using a new group-wise phase estimation and compensation algorithm to combat …

Principals' Leadership Styles And Their Impact On School Climate: Assistant Principals' Perceptions, Bruce R. Mccolumn

College of Graduate Studies: Theses & Dissertations

The primary focus of this study is to explore the perceptions of assistant principals as to how their principals' leadership styles impact school climate. A school's climate plays a vital role in student achievement and principals are the most important factor in setting a setting a school's climate. Therefore, principals' leadership behaviors warrant investigating. This qualitative study identified principal leadership styles through the perceptions of their assistant principals. Interactive interviews were conducted with selected assistant principals in the XYZ School System. Their responses were analyzed, themed and coded to draw a connection between principal leadership style and school climate. These …

Between Return And Resettlement: The Formation Of Iraqi Refugee "Communities" In Cairo And Amman, Emilie K. B. Minnick

Theses and Dissertations

The purpose of this thesis is to investigate whether or not there is community formation among Iraqi refugees living in Amman, Jordan and Cairo, Egypt. These two countries were chosen as case studies because they offer an opportunity to analyze how different host country conditions in the Global South have an impact on the process of community formation. While Egypt is a signatory to the 1951 Refugee Convention and Jordan is not, access to rights in both countries is similarly restrictive. Furthermore, whereas there has been a long history of forced migration from Iraq to Jordan and Iraqi social networks …

Xenophobia: The Consequences Of Being A Zimbabwean In South Africa, Philip Edward Culbertson

Theses and Dissertations

This paper seeks to explain and describe the xenophobia and xenophobic attacks of Zimbabwean refugees and migrants in South Africa. The political and social instability in Zimbabwe has led to mass exodus of Zimbabweans in search of stability and a means to survive. Many of these Zimbabweans have sought opportunity and refuge in South Africa only to be met with hurdles that metastasized into xenophobia. Research was done on the target population of Zimbabweans in Central Methodist Church in Johannesburg, along with interviews conducted through Medicines Sans Frontiers, and active players in the civil society in Cape Town.

Free Speech At What Cost?: Snyder V. Phelps And Speech-Based Tort Liability, Jeffrey Shulman

Georgetown Law Faculty Publications and Other Works

It is always a hard case when fundamental interests collide, but the Fourth Circuit’s decision in Snyder v. Phelps, 580 F.3d 206 (4th Cir. 2009), cert. granted, 130 S. Ct. 1737 (2010), tilts doctrine too far in the direction of free speech, upsetting the Supreme Court’s careful weighing of interests that takes into account both the need for robust political debate and the need to protect private individuals from personal abuse. Where speech is directed at a private individual, especially one unwilling to hear but unable to escape the speaker’s message, the elements of the emotional distress claim more than …

I Put You There: User-Generated Content And Anticircumvention, Rebecca Tushnet

Georgetown Law Faculty Publications and Other Works

This Article discusses recent rulemaking proceedings before the Copyright Office concerning the anticircumvention provisions of the Digital Millennium Copyright Act (DMCA). During these proceedings, non-institutionally affiliated artists organized to assert their interests in making fair use of existing works, adding new voices to the debate. A proposed exemption for noncommercial remix video is justified to address the in terrorem effect of anticircumvention law on fair use. Without an exemption, fair users are subjected to a digital literacy test combined with a digital poll tax, and this regime suppresses fair use. The experience of artists (vidders) confronting the law illustrates both …

Systemic Regulation Of Global Trade And Finance: A Tale Of Two Systems, R. Michael Gadbaw

Georgetown Law Faculty Publications and Other Works

The recent financial crisis has put enormous strains on the global systems governing international finance and trade. These two important international regulatory systems, created after World War II to promote growth and stability in the global economy, were put to the test in ways unprecedented since the 1930s. This article seeks to analyze and compare their performance as systemic regulators in the course of the crisis and concludes that the trading system performed quite well while the financial system virtually collapsed. This article seeks to account for this difference by looking at the nature of the rules and the institutions …

Experimental Study On Thermal Treatment Of Used Printed Wiring Boards (Pwbs), Xiangjun Zuo

Masters Theses

The availability of cheaper and better electronic products as a result of the rapid innovation in technology in past decades has driven the production of e-waste forward. Printed wiring board (PWB) is a component made of one or more layers of insulating material with electrical conductors. The existing processes of recycling PWBs use pyrometallurgical or hydrometallurgical methods, which generate atmospheric pollution. Green recycling has obvious benefits to decrease the amount of PWBs. Green recycling includes two features, 1) little or zero pollution of toxic gases and heavy metals, and 2) efficient (quick and economical) recycling.

The aim of this work …

Optimization Of Parameters And Study Of Kinetics In Lactulose Production By Lactose Isomerization Using Strong Basic Anion Exchange Resin, Arvind Nanduri

Masters Theses

"In this work, an experimental design was employed to investigate the effects of different operating conditions on the isomerization of lactose to lactulose by using strong basic anion exchange resin (AMBERLITE-IRA 402). Temperature, resin/lactose mass ratio and pH were considered to be the three factors affecting the conversion of lactose. Box-Behnken design was then used to optimize the operating conditions for maximum response and also to study the various interaction and main effects of the factors. The analysis of variance (ANOVA) of the experimental data showed a high correlation coefficient R² (0.99) and a low root mean square error (2.84) …

Synthesis And Characterization Of Microspheres For Controlled Release, Gurpartap Singh Sandhu

Masters Theses

"Synthetic hydroxyapatite (HAp, (Ca₁₀(PO₄)₆(OH)₂) has always been of interest in medical applications because of its similarities to inorganic bone matrix. It has been used in biomedical applications for bone repair and substitution due to its biocompatibility. However, there are some differences in the stoichiometry, composition, and mechanical properties of human bone as compared to pure HAP. HAp particles have been successfully used as drug delivery carriers which deliver the drug to the affected part of the body and the remaining apatite gets degraded by the physiological processes in the body. In the present work, emphasis was on developing mechanically stronger …

Nonlinear Finite Element Formulation Of The Soil Structure Interaction Through Two Parameter Foundation Model, Taraka Ravi Shankar Mullapudi

Masters Theses

"The response of shallow and raft foundations is having a significant importance due to its complex behavior because of the semi-infinite soil media. Winkler's model is the simplest model to deal with the structure and soil. The Winkler model represents the foundation reaction as proportional to the soil displacement at a particular point, which results in the elasticity of the soil being the only parameter in consideration. But in reality the soil cohesiveness is having a significant contribution in soil structure interaction, and therefore the consideration of coupling effects of Winkler springs need to be accounted. Most of the existing …

Governing Board Accountability: Competition, Regulation And Accreditation, Judith C. Areen

Georgetown Law Faculty Publications and Other Works

This article examines the three primary ways in which the governing boards of American colleges and universities are held to account: (1) competition; (2) regulation, including state nonprofit corporation laws, tax laws, and licensing laws; and (3) accreditation. It begins by tracing how lay (meaning nonfaculty) governing boards became the dominant form of governance in American higher education. It argues that governing boards provide American institutions of higher education with an exceptional degree of autonomy from state control and that, together with the shared governance approach that gives faculties primary responsibility for academic matters, they have been a vital factor …

Redressing The Unconscionable Health Gap: A Global Plan For Justice, Lawrence O. Gostin

Georgetown Law Faculty Publications and Other Works

Consider two children—one born in sub-Saharan Africa and the other in the United States. The African child is twenty-five times more likely to die in the first five years of life; if she lives to child-bearing age, she is a two hundred times more likely to die in labor; and overall, she will die thirty years earlier than the American child. The international community is deeply resistant to taking bold remedial action—more concerned with their geostrategic interests than the health of the poor. The scale of foreign aid is both insufficient and unsustainable and fails to address the key determinants …

Restoring Health To Health Reform, Lawrence O. Gostin, Peter D. Jacobson

Georgetown Law Faculty Publications and Other Works

In this article, we discuss the public health provisions of the Patient Protection and Affordable Care Act (PPACA--P.L. 111-148). We first set forth a framework to identify the key reforms that are needed for a robust public health system. These include workforce and infrastructure investments. We then assess the PPACA against these criteria. We conclude that although the act would make significant investment in public health (especially in wellness and prevention programs), it does little to improve the existing structural deficiencies that the public health system must overcome if it is to be effective in improving the population’s health.