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Systematic approach for chemical reactivity evaluationAldeeb, Abdulrehman Ahmed 30 September 2004 (has links)
Under certain conditions, reactive chemicals may proceed into uncontrolled chemical reaction pathways with rapid and significant increases in temperature, pressure, and/or gas evolution. Reactive chemicals have been involved in many industrial incidents, and have harmed people, property, and the environment. Evaluation of reactive chemical hazards is critical to design and operate safer chemical plant processes. Much effort is needed for experimental techniques, mainly calorimetric analysis, to measure thermal reactivity of chemical systems. Studying all the various reaction pathways experimentally however is very expensive and time consuming. Therefore, it is essential to employ simplified screening tools and other methods to reduce the number of experiments and to identify the most energetic pathways. A systematic approach is presented for the evaluation of reactive chemical hazards. This approach is based on a combination of computational methods, correlations, and experimental thermal analysis techniques. The presented approach will help to focus the experimental work to the most hazardous reaction scenarios with a better understanding of the reactive system chemistry. Computational methods are used to predict reaction stoichiometries, thermodynamics, and kinetics, which then are used to exclude thermodynamically infeasible and non-hazardous reaction pathways. Computational methods included: (1) molecular group contribution methods, (2) computational quantum chemistry methods, and (3) correlations based on thermodynamic-energy relationships. The experimental techniques are used to evaluate the most energetic systems for more accurate thermodynamic and kinetics parameters, or to replace inadequate numerical methods. The Reactive System Screening Tool (RSST) and the Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) were employed to evaluate the reactive systems experimentally. The RSST detected exothermic behavior and measured the overall liberated energy. The APTAC simulated near-adiabatic runaway scenarios for more accurate thermodynamic and kinetic parameters. The validity of this approach was investigated through the evaluation of potentially hazardous reactive systems, including decomposition of di-tert-butyl peroxide, copolymerization of styrene-acrylonitrile, and polymerization of 1,3-butadiene.
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The influence of orientation on the stabilization and carbonization of acrylic precursors and the influence of phosphorous-containing comonomers on the electrical conductance of acrylic-based carbon fibersMorgan, James Randall January 1989 (has links)
No description available.
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Synthesis and characterization of poly(acrylonitrile-CO-vinyl phosphonate) carbon fiber precursorsSparks, William Robert 12 1900 (has links)
No description available.
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Determination of fabric ignition time through use of a convective heat source apparatusChampion, Edward Ray 08 1900 (has links)
No description available.
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SIC BASED SOLID STATE POWER CONTROLLERFeng, Xiaohu 01 January 2007 (has links)
The latest generation of fighter aircraft utilizes a 270Vdc power system [1]. Such high voltage DC power systems are difficult to protect with conventional circuit breakers because the current does not automatically go to zero twice per cycle during a fault like it does in an AC power system and thus arcing of the contacts is a problem. Solid state power controllers (SSPCs) are the solid state equivalent of a circuit breaker that do not arc and which can respond more rapidly to a fault than a mechanical breaker [2]. Present SSPCs are limited to lower voltages and currents by the available power semiconductors [8,9]. This dissertation presents design and experimental results for a SSPC that utilizes SiC power JFETs for the SSPC power switch to extend SSPC capability to higher voltages and currents in a space that is smaller than what is practically achievable with a Si power switch. The research started with the thermal analysis of the SSPCs power switch, which will guide the development of a SiC JFET multi-chip power module to be fabricated by Solid State Devices Inc. (SSDI) using JFETs from SiCED and/or Semisouth LLC. Multiple multi-chip power modules will be paralleled to make the SSPC switch. Fabricated devices were evaluated thermally both statically and dynamically and electrically both statically and dynamically. In addition to the SiC module research a detailed design of the high voltage SSPC control circuit capable of operating at 200andamp;ordm;C was completed including detailed analysis, modeling and simulations, detailed schematic diagrams and detailed drawings. Finally breadboards of selected control circuits were fabricated and tested to verify simulation results. Methods for testing SiC JFET devices under transient thermal conditions unique to the SSPC application was also developed.
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Fire propagation and heat transfer modelling within the BR710 nacelle for certification purposesDonaghy, Kevin Robert January 2000 (has links)
No description available.
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Materials and methods for nanolithography using scanning thermal cantilever probesHua, Yueming. January 2008 (has links)
Thesis (Ph. D.)--Chemical and Biomolecular Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Henderson, Clifford; Committee Member: Hess, Dennis; Committee Member: King, William; Committee Member: Lu, Hang; Committee Member: Tolbert, Laren.
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Differential thermal analyses of some quaternary clays of FennoscandiaSoveri, U. January 1950 (has links)
Originally presented as the author's Thesis (Helsinki). / Includes bibliographical references (p. [97]-103).
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Preparation and characterization of semi - flexible Thermotropic poly(ester-imide)s /Facinelli, John V. January 1989 (has links)
Thesis (M.S.)--Rochester Institute of Technology 1989. / Includes bibliographical references (leaves 59-60).
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Differential thermal analyses of some quaternary clays of FennoscandiaSoveri, U. January 1950 (has links)
Originally presented as the author's Thesis (Helsinki). / Includes bibliographical references (p. [97]-103).
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