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Propagation of a vapor explosion through a linear array of tin droplets in waterCiccarelli, Gaby January 1988 (has links)
No description available.
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Coefficients of heat transfer between condensing organic vapors and a vertical copper tubeHenderson, Harvey Ellett January 1940 (has links)
Master of Science
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Analysis of evaporative coolers and condensersDreyer, Andre Alexis January 1988 (has links)
Thesis (MEng.) -- Stellenbosch University, 1988. / ENGLISH ABSTRACT: In this report various mathematical models for the thermal evaluation of
evaporative coolers and condensers are presented. These models range from
the exact model based on the work by Poppe [84P01] to the simplified
logarithmic models based on the work of McAdams [54Mcl] and Mizushina
et al. [67MI1], [68MI1].
Various computer programs were written to perform rating and selection
calculations on cross-flow and counterflow evaporative coolers and
condensers.
Experimental tests were conducted on a cross-flow evaporative cooler to
determine the governing heat and mass transfer coefficients. The
experimentally determined coefficients were cqrrelated and these
correlations are compared to the existing correlations. The two-phase
pressure drop across the tube bundle was also measured and a correlation
for two-phase pressure drop across a tube bundle is presented.
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Radiative heat transmission from non-luminous gases. Computational study of the emissivities of water vapor and carbon dioxide.Farag, Ihab Hanna January 1976 (has links)
Thesis. 1976. Sc.D.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / Microfiche copy available in Archives and Science. / Bibliography: leaves 225-237. / Sc.D.
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Photochemistry of aromatic hydrocarbons: implications for ozone and secondary organic aerosol formationSuh, Inseon 16 August 2006 (has links)
Aromatic hydrocarbons constitute an important fraction (~20%) of total volatile
organic compounds (VOCs) in the urban atmosphere. A better understanding of the
aromatic oxidation and its association in urban and regional ozone and organic aerosol
formation is essential to assess the urban air pollution.
This dissertation consists of two parts: (1) theoretical investigation of the
toluene oxidation initiated by OH radical using quantum chemical and kinetic
calculations to understand the mechanism of O3 and SOA precursors and (2)
experimental investigation of atmospheric new particle formation from aromatic acids.
Density functional theory (DFT) and ab initio multiconfigurational calculations have
been performed to investigate the OH-toluene reaction. The branching ratios of OH
addition to ortho, para, meta, and ipso positions are predicted to be 0.52, 0.34, 0.11,
and 0.03, respectively, significantly different from a recent theoretical study of the
same reaction system. Aromatic peroxy radicals arising from initial OH and
subsequent O2 additions to the toluene ring are shown to cyclize to form bicyclic
radicals rather than undergoing reaction with NO under atmospheric conditions.Isomerization of bicyclic radicals to more stable epoxide radicals possesses
significantly higher barriers and hence has slower rates than O2 addition to form
bicyclic peroxy radicals. At each OH attachment site, only one isomeric pathway via
the bicyclic peroxy radical is accessible to lead to ring cleavage. Decomposition of the
bicyclic alkoxy radicals leads primarily to formation of glyoxal and methyl glyoxal
along with other dicarbonyl compounds.
Atmospheric aerosols often contain a considerable fraction of organic matter,
but the role of organic compounds in new nanometer-sized particle formation is highly
uncertain. Laboratory experiments show that nucleation of sulfuric acid is considerably
enhanced in the presence of aromatic acids. Theoretical calculations identify the
formation of an unusually stable aromatic acid-sulfuric acid complex, which likely
leads to a reduced nucleation barrier. The results imply that the interaction between
organic and sulfuric acids promotes efficient formation of organic and sulfate aerosols
in the polluted atmosphere because of emissions from burning of fossil fuels, which
strongly impact human health and global climate.
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Improved thermal energy utilization through coupled and cascaded cooling cyclesBrown, Ashlie M. 18 November 2009 (has links)
Limited worldwide energy supplies demand the
improved utilization of thermal energy, which is the dominant form of all primary energy sources used today. Large quantities of waste heat are routinely exhausted wherever thermo-mechanical energy conversion occurs, providing an opportunity to improve utilization. Two waste-heat-driven cycles are analyzed: an absorption/compression cascade cooling cycle and a coupled Rankine/compression cycle. The absorption/compression cascade provides an environmentally-sound option for a common approach to thermal energy recovery: the use of absorption cycles for cooling applications. To achieve cooling at temperatures below 0ºC, ammonia-water is the overwhelming choice for the working fluid. However, concerns about the toxicity and flammability of ammonia sometimes limit its application in sensitive arenas. In this study, a lithium bromide-water absorption cycle is coupled with a carbon dioxide vapor compression cycle to realize the benefits of high-lift cooling without the concerns associated with ammonia. This cycle utilizes a waste heat stream at temperatures as low as 150°C to provide cooling at -40°C. The topping absorption cycle achieves a coefficient of performance (COP) of about 0.77, while the bottoming cycle achieves a
COP of about 2.2. The coupled Rankine/compression cycle provides a mechanical expansion and compression approach to achieve thermally activated cooling, again driven by waste heat. The power produced in the turbine of the Rankine cycle is directly coupled to the compressor of a vapor-compression cooling cycle to generate cooling to be utilized for space-conditioning. The refrigerant R245fa is used throughout the cycle. Even with low grade waste heat sources, a Rankine cycle efficiency of about 11-12 percent can be achieved. When coupled to the bottoming compression cycle with a COP of about 2.7, this yields an overall waste heat to cooling conversion efficiency of about 32 percent
at nominal conditions.
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Spontaneous spin polarization and hysteresis in cesium vapor pumped by linearly polarized light : an experimental, theoretical, and computational study /Andalkar, Amar, January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 224-236).
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Surface studies of model catalysts using metal atoms and particles on ZnO(0001)-Zn and -O and TiO₂(110) /Grant, Ann W. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 173-183).
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The removal of an airborne low-volatility heavy metal from exhaust gases through condensation onto sorbent particlesRodriguez, Alexander 04 April 2011 (has links)
Not available / text
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Physically based closed-form solutions for film condensation of pure vapors in vertical tubesLe, Quang 13 April 2012 (has links)
This work analytically solves the governing equations of the laminar film condensation from pure vapors in vertical tubes to find the condensate film thickness. The solution is then extended to turbulent flow conditions for steam. All other relevant quantities are derived from the film thickness solution. For laminar film condensation of quiescent vapors, an exact explicit solution and an approximate closed-form solution were found by using a new definition of the dimensionless film thickness, the Lambert W-function, and a logarithmic function approximation. For laminar mixed-convection film condensation with interfacial shear stress, an approximate closed-form solution was found by using a new definition of the pressure gradient. For turbulent film condensation of steam, correlations of the turbulent vapor and liquid viscosities were formed by asymptotically comparing this approximate laminar closed-form solution to a turbulent flow numerical solution. The present solutions compared very well to published numerical and experimental data.
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