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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

The energy delivery paradigm

Bukowski, Stephen A. 12 March 2015 (has links)
<p> A sustainable world is one in which human needs are met equitably without harm to the environment, and without sacrificing the ability of future generations to meet their needs. Electrical energy is one such need, but neither the production nor the utilization are equitable or harmless. Growth of electricity availability and how we use electricity in industrialized nations has established a dichotomy between usage and sustainability. This dichotomy is best illuminated by the current "just-in-time" approach where excessive electricity generation capacity is installed to be able to instantaneously meet load from consumers at all times. Today in the United States, electricity generation capacity is approximately 3.73 kW per person versus 3.15 kW per person in 2002. [1] [2] At this magnitude of installed capacity the entire world would need approximately 25.5 TW of generation or approximately 12,250 Hoover Dams today and must add 766 MW of capacity every day. [3] This unsustainable effect is further exacerbated by the fact that consumers do not have a strong vested incentive to keep electricity generation sustainable because the producers shoulder the burden of instantaneously meeting demand. </p><p> What is needed are paradigms to make these resources economically sustainable. The opportunity provided by the smart-grid is lost if we just automate existing paradigms, hence it is new paradigms that should be enabled by the smart-grid. This dissertation examines a new paradigm which shifts the problem towards `energy delivery' rather than `power delivery' for economic sustainability. The shift from a just in time power model to an energy delivery represents a fundamental change in approach to the research happening today.</p><p> The energy delivery paradigm introduces the concept of a producer providing electrical energy to a system at a negotiated cost and within power limits, leaving the issue of balancing instantaneous power to the consumer, which has overall control on its demand and power requirements. This paradigm has potential to alter the current technical, market, and regulatory problem in electrical energy production and move the economic landscape toward electrical energy production for a more sustainable, reliable, and efficient electrical energy system. This dissertation examines concepts along the path of energy delivery which crosses many fields including power systems, data communications, controls, electric markets, and public utility regulation ultimately proposing a mathematical formulation and solution. The dissertation then shifts to examining potential physical interpretations of the formulation and solution and impacts to different fields within the energy paradigm.</p>
302

Evaluating System Readiness Level Reversal Characteristics Using Incidence Matrices

London, Mark Alan 11 February 2015 (has links)
<p> Contemporary system maturity assessment approaches have failed to provide robust quantitative system evaluations resulting in increased program costs and developmental risks. Standard assessment metrics, such as Technology Readiness Levels (TRL), do not sufficiently evaluate increasingly complex systems. The System Readiness Level (SRL) is a newly developed system development metric that is a mathematical function of TRL and Integration Readiness Level (IRL) values for the components and connections of a particular system. SRL acceptance has been hindered because of concerns over SRL mathematical operations that may lead to inaccurate system readiness assessments. These inaccurate system readiness assessments are called readiness reversals. A new SRL calculation method using incidence matrices, the Incidence Matrix System Readiness Level (IMSRL), was proposed to alleviate these mathematical concerns. The presence of SRL readiness reversal was modeled for four SRL calculation methods across several system configurations. Logistic regression analysis demonstrated that the IMSRL has a decreased presence of readiness reversal than other approaches suggested in the literature. The IMSRL was also analytically evaluated for conformance to five standard SRL mathematical characteristics and a sixth newly proposed SRL property. The improved SRL mathematical characteristics discussed in this research will directly support quantitative analysis of system technological readiness measurements.</p>
303

Encapsulation of organic light emitting diodes

Visweswaran, Bhadri 30 December 2014 (has links)
<p> Organic Light Emitting Diodes (OLEDs) are extremely attractive candidates for flexible display and lighting panels due to their high contrast ratio, light weight and flexible nature. However, the materials in an OLED get oxidized by extremely small quantities of atmospheric moisture and oxygen. To obtain a flexible OLED device, a flexible thin-film barrier encapsulation with low permeability for water is necessary. </p><p> Water permeates through a thin-film barrier by 4 modes: microcracks, contaminant particles, along interfaces, and through the bulk of the material. We have developed a flexible barrier film made by Plasma Enhanced Chemical Vapor Deposition (PECVD) that is devoid of any microcracks. In this work we have systematically reduced the permeation from the other three modes to come up with a barrier film design for an operating lifetime of over 10 years. </p><p> To provide quantitative feedback during barrier material development, techniques for measuring low diffusion coefficient and solubility of water in a barrier material have been developed. The mechanism of water diffusion in the barrier has been identified. From the measurements, we have created a model for predicting the operating lifetime from accelerated tests when the lifetime is limited by bulk diffusion. </p><p> To prevent the particle induced water permeation, we have encapsulated artificial particles and have studied their cross section. A three layer thin-film that can coat a particle at thicknesses smaller than the particle diameter is identified. It is demonstrated to protect a bottom emission OLED device that was contaminated with standard sized glass beads. </p><p> The photoresist and the organic layers below the barrier film causes sideways permeation that can reduce the lifetime set by permeation through the bulk of the barrier. To prevent the sideways permeation, an impermeable inorganic grid made of the same barrier material is designed. The reduction in sideways permeation due to the impermeable inorganic grid is demonstrated in an encapsulated OLED. </p><p> In this work, we have dealt with three permeation mechanisms and shown solution to each of them. These steps give us reliable flexible encapsulation that has a lifetime of greater than 10 years.</p>
304

Molecular beam epitaxy of gallium arsenide antimonide-based ultra-high-speed double heterojunction bipolar transistors and light emitting transistors /

Wu, Bing-Ruey. January 2006 (has links)
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 68-02, Section: B, page: 1204. Adviser: Keh-Yung Cheng. Includes bibliographical references (leaves 83-90) Available on microfilm from Pro Quest Information and Learning.
305

Perfect reconstruction of digital transmission through channels with bounded additive noise /

Touri, Rouzbeh, January 2007 (has links)
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7566. Adviser: Christoforos N. Hadjicostis. Includes bibliographical references (leaves 109-112) Available on microfilm from Pro Quest Information and Learning.
306

Ohmic metallizations to AlGaN/GaN high electron mobility transistors : electrical and microstructural studies /

Wang, Liang, January 2008 (has links)
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. / Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 3196. Adviser: Ilesanmi Adesida. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.
307

Integration of single-walled carbon nanotubes with gallium arsenide(110) and indium arsenide(110) surfaces : a scanning tunneling microscopy study /

Ruppalt, Laura B., January 2007 (has links)
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-07, Section: B, page: 4723. Adviser: Joseph W. Lyding. Includes bibliographical references (leaves 140-149) Available on microfilm from Pro Quest Information and Learning.
308

Collocation based meshless methods for microelectromechanical systems /

Jin, Xiaozhong. January 2007 (has links)
Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7620. Adviser: N.R. Aluru. Includes bibliographical references (leaves 156-166). Available on microfilm from Pro Quest Information and Learning.
309

Design, modeling, fabrication, and characterization of a MEMS device for measuring the mechanical compliance of a biological cell.

Zhang, Wenyue (Lydia). January 2008 (has links)
Thesis (Ph.D.)--Lehigh University, 2008. / Adviser: Svetlana Tatic-Lucic.
310

Implementation d'un algorithme de localisation, suivi et separation de sources sonores sur DSP pour un robot mobile.

Briere, Simon. Unknown Date (has links)
Thèse (M.Sc.A.)--Université de Sherbrooke (Canada), 2007. / Titre de l'écran-titre (visionné le 1 février 2007). In ProQuest dissertations and theses. Publié aussi en version papier.

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