Engineering Commons^™

Characterization Of Iron Oxides And Atmospheric Corrosion Of Steel, Sei Jin Oh

Physics Theses & Dissertations

The study of corrosion behavior was performed using three different analytical techniques, which provided information on the formation, development and layering of iron oxides on the corrosion products as a function of atmospheric conditions, exposure time and type of steel. In particular, the protective layer formed on weathering steel was investigated as a function of different amounts of alloying elements in the steel, atmospheric conditions and exposure times. Combined together, the results provided a better understanding of the atmospheric corrosion behavior of steel, and formed a part of database of the atmospheric corrosion characteristics.

Accurate characterization of the iron oxides …

Modeling Of Fading Dynamics For The Indoor Microwave Channel, Mangeet Singh

Theses : Honours

This report outlines the multipath fading phenomenon and its relationship to wireless system design. The work was conducted for the academic year of 1996. This report provides the reader with an insight into the phenomenon called fading and its relevance when designing wireless systems. Fading is an important consideration when wireless systems are to be designed. Because fading is very unpredictable and it cannot to totally eliminated in a wireless system, systems engineers have a hard time trying to design and commission efficient communication systems for a particular environment. Over the years, there has been a existing need worldwide to …

The Electrodynamic Levitation Of A Collar : Analysis, Experimentation And Simulation, Philip Nixon

Theses

This dissertation describes various methods of maintaining a collar levitated in a vertical axis, using the well-known principle of electromagnetic induction between two circuits. The advantages of closing the magnetic loop around the collar, to obtain large radial flux cutting the collar and, therefore, large lifting forces for a given induced current, are considered in depth.

The ideal magnetic circuit and the equivalent electrical circuit are used in developing a model for two topologies of core (both an open and closed-circuit core) levitating a nonmagnetic conducting collar above a coil. Various affects that degrade the performance of the levitation rig …

The Effects Of Human-Computer Communication Mode, Task Complexity, And Desire For Control On Performance And Discourse Organization In An Adaptive Task, Cristina Bubb-Lewis

Psychology Theses & Dissertations

The present study examined how different communication patterns affected task performance with an adaptive interface. A Wizard-of-Oz simulation (Gould, Conti, & Hovanyecz, 1983) was used to create the impression of a talking and listening computer that acted as a teammate to help participants interact with a computer application.

Four levels of communication mode were used which differed in the level of restriction placed on human-computer communication. In addition, participants completed two sets of tasks (simple and complex). Further, a personality trait, Desire for Control (DC), was measured and participants were split into high and low groups for analysis. Dependent measures …

Stemming Technique For Loading Angled Holes Charged With Anfo, Michael David Wilkins

Masters Theses

"Little research has been published on stemming blast holes, particularly what happens during the process. Previous work has concentrated on the performance of the inert material to find the best way to seal the hole and retain the explosive energy, at the exclusion of determining what happens during the loading and stemming process. Such studies were carried out by Konya and Worsey.

The major problem with stemming studies is that rock is an opaque material, and the actual mechanisms involved during the stemming process cannot be viewed. For this reason, tests were performed using clear tubes to simulate a blast …

Practice And Fit In The Allocation Of The Resource Of Faculty Time: A Study Of Current And Preferred Scholarly Practice Of The Faculties Of Ten Theological Schools Affiliated With The Presbyterian Church (Usa), Roger Allen Nicholson

Theses and Dissertations

Faculties, deans, and trustees of theological schools affiliated with the Presbyterian Church (USA) were surveyed to determine current faculty practice; the practice preferred by faculty, deans. and trustees; the fit between current and preferred practice; and faculty practice and faculty preference difference according to categorical variables such as gender, race, and rank.

Seven variables defined faculty practice: workweek in hours, instruction, scholarship, service, advising, governance, and other. Scholarship was subdivided into three categories adapting Ernest Boyer’s multi-dimensional definition of scholarship: orginitive, applied, and teaching. Fit was defined in two ways: statistical fit and practical fit.

The reported workweek was comparable …

A Monte Carlo Model Of Uncertainty In A Deterministic Hazardous Waste Transportation Risk Assessment, Michael A. Cowen

Masters Theses

This thesis is aimed at developing and applying advanced modeling tools in the prediction of risk to the general public from transportation of chemical waste on public highways. The modeling tools developed can then be used to compare alternative waste management scenarios. The application considered is related to the transport of hazardous waste generated by the United States Department of Energy (DOE) to current treatment, storage, and disposal facilities. DOE is currently considering four different scenarios.

The application considered can be more specifically defined as an analysis of the risk to the general public from transporting the 63 shipments of …

Mechanical And Tribological Properties Of Composites Of Recycled High Density Polyethylene And Recycled Rubber, Jason G. Boulanger

Masters Theses

This thesis presents a study on the mechanical and tribological properties of composite materials of recycled high density polyethylene (HDPE) and recycled rubber tire particles. The materials were compounded by extrusion and formed into test specimens by injection molding.

The first experiment studied the effect of recycled rubber percentage on mechanical properties of composites of recycled HDPE and recycled rubber. The mechanical properties included tensile strength, percent elongation, hardness, and impact resistance. Recycled rubber concentrations of 0, 5, 10, 15, 20, 25, and 30 percent were tested. The second experiment investigated the tribological properties of recycled HDPE and recycled rubber …

Damage Detection Of Bridge-Like Structures Using State Space Models, Javier Valentin Sivico

Masters Theses

"A global damage detection algorithm for bridge-like structures is proposed. This method provides the capability of determining the reduction in both stiffness and damping parameters of the structural elements. It is assumed the mass of the structural elements is not affected by the damages, which is a reasonable assumption for bridge-like structures. The proposed method uses the state space representation of the structural dynamics to make the diagnosis of the structural integrity. Given that the state space representation of any system is not unique, the damage detection procedure is developed for the physical coordinates of the state space representation. A …

Reinforcement Of Web Openings In Cold-Formed Steel Members, Erika Kirsten Nelson

Masters Theses

"To expand on previous research concerning perforated cold-formed steel web elements, an experimental investigation was conducted to examine the influence of reinforcement on the behavior and strength of single web flexural members with web openings. In current design practice, reduction factors are applied to the strength equations to account for the debilitating effect of web openings. This reduction in capacity may lead to the selection of a greater member thickness or depth than would be required of a solid web member. A more economical approach may be to reinforce the web in the proximity of the opening to increase the …

Asynchronous Distance Learning Technology: The Instructor's Perspective, Earl Alexander Evans

Masters Theses

"Advances in communications, computer technology and human-computer interfaces have enabled concurrent advances in Web-based education. A number of case studies concerning applications of Web-based education for both distance learning and on-campus programs have been published. Primarily, these studies have focused on individual assessments of the Web-based technologies. In addition, these published studies have generally highlighted the successes while little discussion about failed attempts has been presented in the literature.

In contrast, this thesis provides a broad-based assessment of applied Web technology for higher education. This research was conducted via a survey completed by twenty five university and college faculty from …

A Design In Interfacing The Mc68hc11 To The Amd Am29f010 Flash Memory Chips, David H. Hands

Theses : Honours

In many environments, motion, vibration and contamination to the Secondary Storage Devices such as hard drives can cause data to become unreadable or even lost. Elimination of these types of magnetic drives, incorporating its replacement with a Solid State Memory Storage Device would provide an invaluable solution for these type of environments. If a secondary storage system could replace these electro-mechanical disk drive systems incorporating a Solid State Secondary Storage Device such as the Flash Memory Integrated Chips, an increase in the speed of reading from milli-seconds to nano-seconds would transpire as well as providing a robust Secondary Storage Device. …

Design And Implementation Of High-Radix Arithmetic Systems Based On The Sdnr/Rns Data Representation, Paul Whyte

Theses : Honours

This project involved the design and implementation of high-radix arithmetic systems based on the hybrid SDNRIRNS data representation. Some real-time applications require a real-time arithmetic system. An SDNR/RNS arithmetic system provides parallel, real-time processing. The advantages and disadvantages of high-radix SDNR/RNS arithmetic, and the feasibility of implementing SDNR/RNS arithmetic systems in CMOS VLSI technology, were investigated in this project. A common methodological model, which included the stages of analysis, design, implementation, testing, and simulation, was followed. The combination of the SDNR and RNS transforms potential complex logic networks into simpler logic blocks. It was found that when constructing a SDNRIRNS …

As-Is Evaluation & Process Design Of The 17/18 Foot Refrigerator At General Electric In Decatur, Alabama, Yongke Thio, Nicole Hagood

Honors Capstone Projects and Theses

No abstract provided.

Immobilization Of Radioactive Materials In Iron Phosphate Glass, Melissa G. Mesko

Doctoral Dissertations

"The current study investigates the feasibility of using iron phosphate glass for the immobilization of radioactive wastes considered incompatible with borosilicate glass. Wastes may be incompatible with borosilicate glass due to high phosphorus content (Hanford tank sludges), the presence of halides (CsCl and SrF₂ capsules), or large amounts of uranium (SNF).

Between 20 and 60 wt% Hanford tank sludge was vitrified with an iron phosphate glass at ≤ 1200°C in 1 hour. The chemical durability of iron phosphate glassy wasteforms was as good as, or better than a reference borosilicate glass (10^-9 g/cm²/min) in distilled water …

Service Quality Using The Deviation-Score Approach To Fit In Contingency Theory In A U.S. Army Corps Of Engineers Setting, Donald Robert Groh

Doctoral Dissertations

"The purpose of this study is to learn how organizational work unit context, structure, and processes relate to service quality. The theoretical basis for the research is that organizational work units should be structured based on the work that they perform. If the work that a unit performs is highly variable, then the work unit should be structured in such a way as to provide flexibility, that is, few rules and procedures and highly decentralized decision making. If the work that a unit performs is not variable, then the work unit should be structured to provide a non-varying product or …

An Investigation On The Effect Of Aging And Fatigue Damage On The Mechanical Properties Of A Graphite/Bismaleimide Composite, William M. Johnston Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

This investigation utilizes the open hole tension (OHT) specimen loaded in tension-tension fatigue under isothermal, fixed frequency conditions. A range of load levels and temperature levels where chosen to assess performance. These loads and temperatures ranged from relatively benign conditions (low stress, room temperature) up through aggressive conditions (high stress, high temperature). Measurements of stiffness, damage accumulation, residual strength, weight loss, and glass transition temperature (Tg) were made. Results from this work will help explain the roles of aging, load and fatigue in the performance of elevated temperature OHT specimens as well as provide insights to the individual and synergistic …

Kramers-Kronig Anomalous Dispersion On Single-Mode Fiber-Optic Couplers And Tapers, Arnel C. Lavarias

Electrical & Computer Engineering Theses & Dissertations

The Kramers-Kronig relations couple the real and imaginary part of the dielectric constant of a medium, namely the refractive index n(ω) and the extinction coefficient κ(ω). Changes in n(ω) due to normal and anomalous dispersion (Kramers-Kronig effect) are investigated for the first time using fiber optic couplers and tapers. Kramers-Kronig effect is induced by evanescent wave absorption in these devices. Couplers and tapers have oscillatory spectral outputs that are highly sensitive to the refractive index of the surrounding medium. Theoretical modeling of the Kramers-Kronig effect on couplers and tapers shows two distinct effects. First, the spectral outputs of these devices …

Multiobjective Optimum Design Of Static And Seismic-Resistant Structures With Genetic Algorithm, Fuzzy Logic And Game Theory, Dan Li

Doctoral Dissertations

"The goal of this research is to develop a constrained multiobjective optimization method in the form of a robust, practical, problem-independent algorithm, and to investigate the effect of multiobjective optimization on structural design.

This research studies the properties and characteristics of multiobjective optimization and solutions. Design objectives, constraints and design variables as well as their effect on structural design and behaviors are investigated. Dynamic input energy for a multidegree-of-freedom structure is formulated. A multiobjective optimization algorithm based on game theory is developed. Fuzzy set theory is introduced to construct a fuzzy constrained environment. A Pareto genetic algorithm is developed based …

Perceptions Of Businesses On Environmental Regulatory Information, Kimberly K. Gunderson

Dissertations and Theses @ UNI

The purpose of this study was to determine the source and amount of information that a sample of businesses receive on environmental regulatory topics and from what sources they would prefer to receive this information. More specifically, the study demonstrated the discrepancy between the sources from which businesses currently receive their information and the sources from which they would prefer to receive it. The study also addressed how relevant this information was to the businesses and with which regulations the businesses were the most and least knowledgeable. The study was done by conducting a mail-back survey of 500 Iowa small …

Vehicle Performance Optimization Utilizing The Air Turbo-Ramjet Propulsion System; Methodology Development And Applications, Kirk Christensen

Doctoral Dissertations

"The ATR (Air TurboRocket) is an air breathing propulsion system in which the turbocompressor turbine is powered by a hot drive gas which is generated independently of the air flow through the compressor. The ATR has a lower specific impulse (Isp) and higher thrust compared to a similar size turbojet but a lower thrust and higher Isp compared to similar size solid rocket motor (SRM). This work defines the benefits of ATR propulsion for tactical vehicles.

ATR simulation codes were developed to support analysis of hypothetical ATR powered vehicles. Both turbojet powered and SRM powered vehicles were also evaluated against …

Lithographers' Opinions About Waterless Lithography, Devang Pranlal Mehta

Dissertations and Theses @ UNI

The purposes of this study were to identify the advantages and disadvantages of waterless litho in comparison with traditional litho, to solve the controversial issues, to forecast the growth of waterless litho, and to inform graphic arts professionals about it. The problem of this research was to identify and measure perceived controversial issues for using the waterless litho process. These controversial issues were related to the return on investment and operating costs involved, productivity, quality of images, eco-friendliness, and technical problems associated with waterless litho.

Due to the fact that waterless litho was a developing technology and some controversial issues …

An Exploratory Study: Reading And Spatial Visualization Ability As Predictors Of Success For Technical Drawing, Eldon Bruce Swanson

Dissertations and Theses @ UNI

If one were to open a technical drawing book, the reader could make the observation that the book was "written" and "read" in two languages--the English language and the universal graphic language. The technical drawing is presented in the context of these two languages: written statements accompanied by their graphical translations. The two seemingly symbiotic languages are synergistically integrated in technical drawing.

The problem of this exploratory study was to determine the strength of the bivariate correlational relationships between students' assessed spatial visualization ability and their reading ability to their assessed achievement in technical drawing. Further, the problem of the …

The Use Of Solid Waste Materials As Alternative Compositions In The Development Of Wood/Cement Blocks, Haig Mamas Vahradian

Dissertations and Theses @ UNI

As the population of the planet Earth increases, the need for affordable housing becomes a paramount issue in construction. This need is further complicated by the rising cost of basic building materials due to the depletion of natural resources throughout the world. These problems have caused the construction industry to refocus its attention on the elimination of waste through a comprehensive strategy to: (a) reclaim and recycle these resources into usable materials, and (b) develop products and markets in construction for recycled materials through research and testing to prove their integrity.

The purpose of this study is to determine the …

Newspaper Recycling And Deinking, Reem Adel Fahmy Baher

Archived Theses and Dissertations

No abstract provided.

Fractal Relationships And Spatial Distribution Of Ore Body Modelling, D. J. Kentwell

Theses: Doctorates and Masters

The nature of spatial distributions of geological variables such as ore grades is of primary concern when modelling ore bodies and mineral resources. The aim of any mineral resource evaluation process is to determine the location, extent, volume and average grade of that resource by a trade off between maximum confidence in the results and minimum sampling effort. The principal aim of almost every geostatistical modelling process is to predict the spatial variation of one or more geological variables in order to estimate values of those variables at locations that have not been sampled. From the spatial analysis of these …

High-Speed Craft (Hsc) : A Study Of Their Safe Operation And Navigation, And Their Impact Upon The Malacca Strait, Lim Yew Seng

World Maritime University Dissertations

The dissertation is a study of the safe operation and navigation of High-speed Craft (HSC) and their impact upon the Malacca Strait. The definitions of HSC are compared and illustrated. The future trend, growth and development of current types of HSC and their inherent design limitations are investigated. The maneuvering systems and characteristics of HSC are analyzed. The active safety system employed by HSC is compared to the passive safety system of conventional vessels. The operation and navigation problems due to high-speed are investigated. The human resource management methods of reducing human errors are discussed. The navigational requirements of the …

A Study Of Teaching Automation For Marine Engineers, Myat Moe

World Maritime University Dissertations

This dissertation is a research into a study of teaching automation for marine engineers which is conducted at the Institute of Marine Technology (IMT)of the Union of Myanmar as related to the Fundamentals of Automation, Instrumentation and Control systems, module 9 of IMO model course 7.02. This course is now included in the mandatory part of STCW Code A of the revised STCW Convention. An examination is made of the fundamentals of ship automation and a brief overview is given of the modem developments in ship automation system. This includes modem developments in main engine automation, navigation/ bridge control, integrated …

Towards New Technology : An Overview Of The Development And Potential Use Of The Electronic Chart, King Kurwijira Ngabho Chiragi

World Maritime University Dissertations

No abstract provided.

Modeling And Simulation Of Optical Characteristics Of Microelectromechanical Mirror Arrays, Peter C. Roberts

Theses and Dissertations

MEMS (Micro-Electro-Mechanical Systems) micromirror devices can be used to control the phase of a propagating light wavefront, and in particular to correct aberrations that may be present in the wavefront, due to either atmospheric turbulence or any other type of fixed or time and space varying aberrations. In order to shorten the design cycle of MEMS micromirror devices, computer software is developed to create, from MEMS micromirror device design data, a numerical model of the MEMS device. The model is then used to compute the far field diffraction pattern of a wavefront reflected from the device, and to predict the …