Mémoire (M.Sc.T.)--Unviversité du Québec à Chicoutimi, 2001. / Document électronique également accessible en format PDF. CaQCU

Thèse (D.R.Min.) -- Université du Québec à Chicoutimi, 1994. / Bibliogr.: p. 167-184. Document électronique également accessible en format PDF. CaQCU

Thesis (Ph.D.)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Haddad, Wassim; Committee Member: Feron, Eric; Committee Member: JVR, Prasad; Committee Member: Taylor, David; Committee Member: Tsiotras, Panagiotis

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 1990. / Thesis Advisor(s): Atchley, Anthony A. ; Hofler, Thomas J. "December 1990." Description based on title screen as viewed on March 31, 2010. DTIC Descriptor(s): Heat Transfer, Coupling (Interaction), Peak Values, Ratios, Temperature, Thermodynamics, Edges, Isolation, Sensitivity, Regions, Short Range (Time), Profiles, Plates, Internal, Acoustic Arrays, Pressure, Drives, Leading Edges, Mean, Amplitude, Sound Pressure, Stacking, Thermopiles. DTIC Identifier(s): Heat Pumps, Energy Conversion, Energy Storage, Heat Transfer, Thermoacoustic Couples, Theses Author(s) subject terms: Acoustics, Thermoacoustics, Thermoacoustic Heat Transport. Includes bibliographical references (p. 34). Also available in print.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (p. 113-122).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M.S.)--Ohio University, March, 2007. / Title from PDF t.p. Includes bibliographical references.

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<p>Tremendous research efforts have been conducted studying the capturing and conversion of solar energy. Solar thermal power systems offer a compelling opportunity for renewable energy utilization with high efficiencies and excellent cost-effectiveness. The goal of this work was to design a non-concentrating collector capable of reaching temperatures above 250 °C, use this collector to power methanol steam reforming, and operate a proton exchange membrane (PEM) fuel cell using the generated hydrogen. The study presents the construction and characterization of a non-concentrating, intermediate-temperature, fin-in-tube evacuated solar collector, made of copper and capable of reaching stagnation temperatures of 268.5 °C at 1000 W/m2 irradiance. The collector was used to power methanol steam reforming, including the initial heating and vaporization of liquid reactants and the final heating of the gaseous reactants. A preferential oxidation (PROX) catalyst was used to remove CO from simulated reformate gas, and this product gas was used to operate a PEM fuel cell. The results show 1) that the outlet temperature is not limited by heat transfer from the absorber coating to the heat transfer fluid, but by the amount of solar energy absorbed. This implicates a constant heat flux description of the heat transfer process and allows for the usage of materials with lower thermal conductivity than copper. 2) It is possible to operate a PEM fuel cell from reformate gas if a PROX catalyst is used to remove CO from the gas. 3) The performance of the fuel cell is only slightly decreased (~4%) by CO2 dilution present in the reformate and PROX gas. These results provide a foundation for the first renewable electricity generation via solar-powered methanol reforming through a hybrid PEM fuel cell system based on novel non-concentrating, intermediate-temperature solar collectors.</p> / Dissertation

In their attempts to understand the unwritten past of human technology and progression, archaeologists have borrowed aspects of the natural sciences to answer big questions. In one such pursuit, fundamental aspects of the sciences have been employed towards the chemical compositional analysis of copper-based artifacts, often to simply classify which is bronze, brass, or pure copper, and to explain why they are significant in limited space and time. This thesis takes the variety of identified metal types and compositions from these analyses and builds the beginnings of an ambitious thermodynamic model based on the accepted premise of consistent and widespread recycling of ancient metals over time. Following the laws of thermodynamics, in systems at equilibrium, the model predicts the outcome of metal losses over the course of ancient pyrometallurgical processes from molten systems through both volatilization and oxidation using rigorous and established mathematics and theory. Elemental loss likelihoods are modeled for all binary copper-based metals, using activity coefficients, and ternary copper and zinc-based systems, with the excess Gibbs free energy, respectively. The calculations are performed using custom-written software designed to account for hundreds of thousands of compositional permutations after the method described by Redlich and Kister (1948). The results of these calculations are given as activity (binary) and isoactivity (ternary) contour lines. Quantified tables for the oxidation and volatilization of elements from a copper melt at 1200 ºC and 1 atm are also given as rough indicators of element loss in ancient pyrometallurgical systems. A proof of concept of the models viability is also provided for binary Cu-M and ternary Cu-M-Zn (M = Ag, As, Au, Bi, Co, Fe, Ni, Pb, Sb, Sn, Zn), Cu-Sn-Pb, and Cu-Sb-As systems from the Late Bronze Age to post-medieval periods in Britain, which is based on several substantial artifact chemical datasets. For each ternary system, the interaction parameters used for higher-order calculations from the fitted behavior of each contributing binary systems are provided. Comparison of the calculated models to available experimental system assessments, and to published archaeological chemical datasets, show that in both respects the proposed modeling of ancient copper-based metal losses works. And given the near ubiquity of ancient metal use around the world, the consistency in metal production and recycling technology, and the chemical analyses available, this preliminary model can be applied virtually anywhere the technology for smelting and recycling existed. In addition to loss modeling, this thesis has the additional offshoots of predicting ancient furnace conditions based on the calculated behavior of interacting metals, and of the controlling thermodynamic factors in the ancient calamine process.