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Analysis and design of MEMS scan mirrors using periodically stiffened silicon nitride: Author: Lutzenberger, Bert Jeffrey; Date: 2006-05-15; Program: Engineering; Abstract: This research presents a novel fabrication method combining surface and bulk micromachining techniques to deposit mechanically stiffened silicon nitride films for use in MEMS fabrication. The stiffened silicon nitride film consists of a thin (~1.5 um) top sheet with stiffening fins molded to the back of the film. In the final configuration, the fins extend between 15 um and 40 um vertically from the back of the film. The molded fins are arranged into periodic square and hexagonal cell configurations ranging in size from 10 um to 250 um. The periodic cells significantly increase the bending sti...; Download File | View full details

Control of acid rock drainage from mine tailings through the addition of dissolved organic carbon: Author: Sturman, Paul John; Date: 2004-12-15; Program: Engineering; Abstract: Acid mine drainage detrimentally affects thousands of surface watercourses throughout the world and costs tens of millions of dollars annually in site remediation expenditures. This process is accelerated by the activity of iron- and sulfur-oxidizing bacteria which grow chemolithotrophically in mine tailings. Low cost, environmentally acceptable, and low maintenance treatment technologies are needed to both treat acid mine drainage and prevent its occurrence. The addition of dissolved organic carbon to mine tailings has the potential to stimulate beneficial heterotrophic populations of bacteri...; Download File | View full details

Design of model reactor systems for evaluating disinfectants against biofilm bacteria: Author: Goeres, Darla Marie; Date: 2006-05-15; Program: Engineering; Abstract: Laboratory reactors are devices which grow biofilms under controlled and/or field relevant conditions for the purpose of developing biofilm control strategies. In disinfectant efficacy testing, as well as in research, choosing the best reactor to use is important because different laboratory reactors impart unique characteristics in the biofilm that influence everything form biofilm architecture and protein regulation to the response of biofilm bacteria to disinfection. In this dissertation, three laboratory reactors and associated standard operating protocols were developed to provide a relia...; Download File | View full details

Intergranular water and permeability of the Lake Vostok accretion ice, Eastern Antarctica: Author: Jepsen, Steven Michael; Date: 2005-12-15; Program: Engineering; Abstract: The relative importance of nonhydrostatic stress and lattice-rejected impurities on the phase equilibrium of intergranular liquid water in the Vostok accretion ice, Eastern Antarctica, was examined in this study. In addition, experiments were conducted to examine the influence of intergranular water in ice on the permeability of a Light Non-Aqueous Phase Liquid (LNAPL) hydrocarbon. Sub-grain scale stresses in the Vostok accretion ice were simulated with anisotropic elastic and elastocreep finite element (FE) models and compared to X-ray dislocation topographs. The phase equilibrium conditions ...; Download File | View full details

Mems 3-D scan mirror for an endoscopic confocal microscope: Author: Shao, Yuhe; Date: 2005-12-15; Program: Engineering; Abstract: Optical MEMS is at a very exciting stage and has become an enabling technology for a variety of applications in telecommunications and high-resolution display and imaging. Among many novel MEMS devices, MEMS scanners and deformable membrane mirrors are especially useful for scanned-beam imaging systems. MEMS scanners are usually used for laser beam scanning. Deformable mirrors provide an approach to modify the optical wavefront adaptively. In optical microsystems, packaging is often a critical part of the system design. Combining functionalities at a single device can reduce complexity of the ...; Download File | View full details

Theoretical investigation of biofilm detachment and protection from killing using a bacterium level automata model: Author: Hunt, Stephen Michael; Date: 2004-08-15; Program: Engineering; Abstract: This dissertation presents a three-dimensional dynamic, stochastic computer model of biofilm development, BacLAB, created to theoretically explore conjectures associated with biofilms. BacLAB simulates the life cycle of a biofilm by mimicking the physical and biological behavior of a system with a simple set of experimentally determined "rules" applied to the smallest possible biofilm unit (the cell). These rules, however, lead to patterns on a larger scale. Much as bacterial cells organize themselves in a biofilm as a response to individual spatial conditions, the resulting model st...; Download File | View full details

Haptic and auditory interfaces as a collision avoidance technique during roadway departures and driver perception of these modalities: Author: Stanley, Laura Michelle; Date: 2006-05-15; Program: Engineering; Abstract: Roadway departure fatalities accounted for 55 percent of all roadway fatalities in the United States in 2003. In an effort to reduce the number of roadway departures, many transportation agencies have introduced static rumble strips using physical alterations of the roadway surface in shoulder and/or centerline sections of the roadway. Recently, more advanced technology has been developed in the form of in-vehicle advanced lane departure warning systems that automatically detect the vehicle's lane position and warn of possible roadway departures. These systems are currently showing their value...; Download File | View full details

Controller design for PSS and FACTS devices to enhance damping of low-frequency power oscillations in power systems: Author: You, Ruhua; Date: 2006-05-15; Program: Engineering; Abstract: Low frequency electromechanical oscillations are inevitable characteristics of power systems and they greatly affect the transmission line transfer capability and power system stability. PSS and FACTS devices can help the damping of power system oscillations. The objective of this dissertation is to design an advanced PSS and propose a systematic approach for damping controller design for FACTS devices. Intelligent control strategy which combines the knowledge of system identification, fuzzy logic control, and the neural networks are applied to the PSS design. A fuzzy logic based PSS is develo...; Download File | View full details

Spatial Heterogeneity in Pseudomonas aeruginosa Biofilms and How it Affects Antibiotic Tolerance: Author: Richards, Lee Alexander; Date: 2006-08-15; Program: Engineering; Abstract: This dissertation presents evidence of heterogeneity within Pseudomonas aeruginosa biofilms and the effects of said heterogeneity on antibiotic tolerance. The existence of oxygen concentration gradients within the biofilm was confirmed. There were in fact regions within the biofilm that were nearly anoxic, this was confirmed by use of dissolved oxygen microelectrodes. The size of the aerobic zone within the biofilm agreed with the size of the active zone indicated by the use of an inducible green fluorescent protein. We found that anoxia could explain some of the biofilm's recalcitrance to the...; Download File | View full details

Modeling and Control of Hybrid Wind/Photovoltaic/Fuel Cell Distributed Generation Systems: Author: Wang, Caisheng; Date: 2006-08-15; Program: Engineering; Abstract: Due to ever increasing energy consumption, rising public awareness of environmental protection, and steady progress in power deregulation, alternative (i.e., renewable and fuel cell based) distributed generation (DG) systems have attracted increased interest. Wind and photovoltaic (PV) power generation are two of the most promising renewable energy technologies. Fuel cell (FC) systems also show great potential in DG applications of the future due to their fast technology development and many merits they have, such as high efficiency, zero or low emission (of pollutant gases) and flexible modul...; Download File | View full details

Extended cluster weighted modeling methods for transient recognition control: Author: Zhu, Tao; Date: 2006-08-15; Program: Engineering; Abstract: This dissertation considers cluster weighted modeling (CWM), a novel nonlinear modeling technique for the electric load transient recognition problem. The original version of CWM is extended with a new training algorithm and a real-time CWM prediction method. In the training process, a new training algorithm is derived that is a mixture of expectation maximization (EM) – least mean squares (LMS). The algorithm addresses the singular matrix inversion problem in EM. A recursive EM-LMS algorithm is developed that allows the CWM to adapt to time varying systems. In the prediction process, ...; Download File | View full details

Design rules, metaroutines, and boundary objects - a framework for improving healthcare delivery systems: Author: Ghosh, Manimay; Date: 2006-12-15; Program: Engineering; Abstract: The healthcare industry in the United States has been fraught with medical errors, rising costs, and wastes for many years. Despite widespread adoption of Total Quality Management and Six Sigma programs, healthcare's woes continue unabated. The Toyota Production System (TPS), progenitor of lean manufacturing, is widely regarded as the most effective production system ever devised. It has been successfully adopted by manufacturing firms worldwide resulting in significant gains in efficiency and quality in companies of all sizes. The goal of this research is to determine whether principles from ...; Download File | View full details

Full sky imaging polarimetry for initial polarized modtran validation: Author: Pust, Nathaniel Joel; Date: 2007-05-15; Program: Engineering; Abstract: Although military studies of the last ten years have shown that visible polarimetry supplies supplemental surveillance information, the polarimetric signatures of ground-based objects greatly depend on the illuminating skylight polarization. The polarization of a pure molecular atmosphere is easily modeled, but aerosols and clouds modify clear-sky polarization substantially. The Air Force has developed a polarimetric atmospheric radiative transfer model (MODTRAN-P) to simulate atmospheric effects. To assist MODTRAN-P code validation, a full-sky visible polarimeter has been developed using liqu...; Download File | View full details

Study of solid oxide fuel cell interconnects, protective coatings and advanced physical vapor deposition techniques: Author: Gannon, Paul Edward; Date: 2007-05-15; Program: Engineering; Abstract: High energy conversion efficiency, decreased environmentally-sensitive emissions and fuel flexibility have attracted increasing attention toward solid oxide fuel cell (SOFC) systems for stationary, transportation and portable power generation. Critical durability and cost issues, however, continue to impede wide-spread deployment. Many intermediate temperature (600-800°C) planar SOFC systems employ metallic alloy interconnect components, which physically connect individual fuel cells into electric series, facilitate gas distribution to appropriate SOFC electrode chambers (fuel/anode...; Download File | View full details

A quantitative description at multiple scales of observation of accumulation and displacement patterns in single and dual-species biofilms: Author: Klayman, Benjamin Joseph; Date: 2007-08-15; Program: Engineering; Abstract: This research represents a novel approach for describing biofilm accumulation at multiple scales of observation in both single and dual-species biofilms. Pseudomonas aeruginosa PAO1 and Escherichia coli O157:H7 were grown as single and dual-species biofilms in 1 mm glass capillary flow cells and monitored over time using confocal microscopy. Colonization and biofilm development patterns were associated with the fluid flow regime as evaluated using the finite volume analysis program CFX (ANSYS Europe, Ltd). The shear stress was shown to vary along the surface from a minimum near the edges to a ...; Download File | View full details

Wireless communication for sparse and rural areas: Author: Zhang, Mingliu; Date: 2007-08-15; Program: Engineering; Abstract: Wireless technology experienced a fast development in the past few decades. However, research and investment in wireless communication so far has been focused mainly on high-density domains or fully connected networks. The technologies/solutions developed for above domains do not readily apply to rural and sparse domains. The users in rural and sparse areas are still served predominantly by either low-speed dialup access or have no data service available at all. This research work explores the largely overlooked rural and sparse domains, where distance, rough terrain and low node density are t...; Download File | View full details

Collidial suspension flow and transport behavior in small channels by magnetic resonance microscopy: Author: Brown, Jennifer Ruth; Date: 2007-12-15; Program: Engineering; Abstract: The research presented addresses colloidal transport issues in small channel systems using Magnetic Resonance Microscopy techniques. In transport phenomena, the interaction between convection or deterministic motions and diffusion or random motions is important in many Engineering and natural applications, especially relating to multiphase flows. Magnetic Resonance methods have the ability to separate coherent from incoherent motion, as well as measure spatially resolved velocity, probability distributions of displacement, and microstructure on the pore scale, even within a multiphase colloida...; Download File | View full details

An investigation of acoustic impulse response measurement and modeling for small rooms: Author: Chen, Zhixin; Date: 2007-12-15; Program: Engineering; Abstract: Room impulse response modeling has been a subject of interest to acousticians, musicians, and architects for many years. Room impulse response modeling can help to predict the acoustical characteristics of the new finished concert halls, to create a virtual studio effect for music production without building the actual studio room, and to compare the effect of different absorbing materials and treatments in architecture. The goals of this dissertation are to obtain a better match between the simulation and the measurement results of small room impulse responses, and to understand why the model...; Download File | View full details

Advanced studies of fish passage through culverts: 1-D and 3-D hydraulic modeling of velocity, fish energy expenditure, and a new barrier assessment method: Author: Blank, Matthew David; Date: 2008-05-15; Program: Engineering; Abstract: Fish passage through culverts is an important component of road and stream crossing design. Although no comprehensive inventory of the number of culverts on fishbearing streams in the United States is available, there is an estimated 1.4 million streamroad crossings. The most common physical characteristics that create barriers to fish passage include excessive water velocity, insufficient water depth and large outlet drop heights. Over the past decade, interest in the effect culvert barriers have on aquatic systems has grown; accordingly, various passage assessment techniques have been used t...; Download File | View full details

A 3D computer model investigation of biofilm detachment and protection mechanisms: Author: Chambless, Jason Daniel; Date: 2008-05-15; Program: Engineering; Abstract: A biofilm is a dense aggregation of microorganisms attached to each other and a supporting surface. Biofilms are ubiquitous in industrial environments and are also frequently recognized as the source of persistent infections. Biofilm invasions and biofilm-induced infections are often difficult or impossible to remedy. This dissertation presents the results of a 3D hybrid computer model, BacLAB, which was used to simulate detachment and protection mechanisms of biofilms in a cellular automata framework. Protection against antimicrobials afforded by each of four hypothesized protective mechanism...; Download File | View full details

Spatial and temporal patterns of antimicrobial action against Staphylococcus epidermidis biofilms: Author: Davison, William Marshall; Date: 2008-05-15; Program: Engineering; Abstract: This study investigated the spatio-temporal patterns of antimicrobial action against Staphylococcus epidermidis planktonic and biofilm bacteria. Bacteria were stained with a fluorogenic esterase substrate, Calcein-AM, which allowed for the visualization of cells that possessed intact cell membranes. Four different antimicrobial agents were tested for their effect upon cell viability as associated with membrane integrity. The four biocides were Barquat®, glutaraldehyde, chlorine, and nisin. Planktonic bacteria were analyzed with flow cytometry, observing fluorescence loss during 1 h ...; Download File | View full details

The study of errors, expectations and skills for medication delivery systems improvement: Author: Mazur, Lukasz Maciej; Date: 2008-05-15; Program: Engineering; Abstract: Medication errors occurring in hospitals are a growing national concern. The enormous gaps in knowledge related to medication errors are often seen as major reasons for increased patient safety risks and increased waste in the hospital setting. However, little research effort in industrial and management Engineering has been devoted specifically to medication delivery systems to improve or optimize their operations in terms of patient safety and systems efficiency and productivity. As a result, the current literature does not offer integrated solutions to overcome the workflow and management d...; Download File | View full details

Roust schedules and disruption management for job shops: Author: Philip, Deepu; Date: 2008-05-15; Program: Engineering; Abstract: This dissertation documents the results of research evaluating policies to schedule for unanticipated disruptions in job shops. The disruptions studied in this research are of two types - machine failure and job release-time. The study was conducted using modified classical job shop problems with the minimize maximum completion time (Cmax) objective. Best random non-delay schedules (BRS) provided job sequences for each machine. Different slack policies based on frequency, duration and location of slacks in the schedule were used to strategically insert slack in the BRS schedule. The resulting ...; Download File | View full details

Physically aware agile optical networks: Author: Lin, Wenhao; Date: 2008-08-15; Program: Engineering; Abstract: With the development of new laser sources, fiber amplifiers, and other optical components, optical communication systems have undergone enormous growth and evolution in recent decades. The current trend of optical networking is to move towards dynamic, all-optical networks. In all-optical networks, information signals are transmitted from source to destination totally in the optical domain, without the usual optical-electrical-optical conversions at intermediate nodes. New challenges and opportunities emerge in different layers of the optical network architecture in this transition process. Th...; Download File | View full details

Nitrification in premise plumbing systems: Author: Rahman, Mohammad Shahedur; Date: 2008-12-15; Program: Engineering; Abstract: Monochloramine is increasingly used instead of free chlorine as a secondary disinfectant. Ammonia is introduced into water for monochloramine formation or by decay. Nitrification can have deleterious effects on water quality that may lead to regulatory violations. In this project water quality and influence of pipe material on the onset of nitrification and consequences of nitrification in premise plumbing were investigated. Also potential control strategies for nitrification were evaluated. Initially two types of copper coupons (new and old, i.e., pre-exposed to 0.1N NaOH solution) were used ...; Download File | View full details

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