Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis. 1976. M.S. cn--Massachusetts Institute of Technology. Dept. of Nuclear Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / M.S.cn

The purpose of this thesis is to explore the nonlinear refractive index of carbon disulfide vapors as opposed to its liquid form. With CS[sub2] vapors, the vapors are less dense so they will rotate longer than liquid CS[sub2] because there are less intermolecular interactions. The electric field of the beam causes the molecules to align with the electric field and applies a torque to the molecules. After this excitation, the molecules continue rotating. The rotations change the index of refraction of the material. Continuous rotation of the molecules causes the index of refraction to be periodic which means the molecules are going through multiple revivals. I will analyze this periodic nonlinear index of refraction. However, some problems occurred while the experiment was being done as well as some issues of measuring CS[sub2] because of white light continuum generation in the cell walls. To avoid these issues we measured the air in the lab and were able to observe the periodic change of index of refraction for O[sub2] and N[sub2].

The adsorption isotherms for ethanol-cyclohexane, ethanol-benzene, and benzene-cyclohexane vapor mixtures on Cab-O-Sil and on Graphon at 20, 30, and 40°C were measured at constant total pressure. The adsorption isotherms for the pure components were also obtained. The ethanol/Graphon isotherms were intermediate between Types II and III; for the other systems, Type II isotherms were obtained. The amounts of the pure vapors adsorbed on Cab-O-Sil followed the order ethanol > benzene > cyclohexane. The adsorption isotherms for benzene and cyclohexane on Graphon were almost identical. Except at low relative pressures, the amount of ethanol adsorbed on Graphon was greater than the amounts of benzene or cyclohexane adsorbed. Isosteric heats of adsorption and BET cross-sectional areas were calculated for the pure adsorbates on Cab-O-Sil and on Graphon. The data indicated that the three adsorbates do not form close-packed monolayers on the Cab-O-Sil surface. The isosteric heat and the integral entropy of adsorption for ethanol on Graphon suggested that ethanol forms a hydrogen-bonded structure on the Graphon surface. The binary vapor adsorption isotherms were compared to the pure component isotherms. In several instances, the amounts of the components adsorbed from the mixtures were greater than from the pure states. For the Cab-O-Sil systems, selective adsorption of ethanol occurred from ethanol-cyclohexane and ethanol-benzene mixtures; benzene was selectively adsorbed from benzene-cyclohexane mixtures. The adsorbate-vapor composition diagrams for benzene-cyclohexane mixtures on Graphon all contained adsorption azeotropes. Very little selective adsorption of either component occurred. In general, benzene and cyclohexane were selectively adsorbed from benzene-ethanol and cyclohexane-ethanol mixtures on Graphon. Adsorption azeotropes occurred in the 20°C isotherms for these two systems at high ethanol mole fractions. The temperature dependence of the selectivity for the systems studied followed no consistent trend. Comparison of the binary vapor adsorption isotherms with the analogous solution adsorption isotherms indicated that selectivity is generally higher in adsorption from solution. The experimental binary vapor adsorption isotherms were compared to those calculated from the pure vapor adsorption isotherms using the ideal adsorbed solution model. It was found that the adsorbed solutions were ideal or slightly nonideal for all three mixtures on Cab-0-Sil and for benzene-cyclohexane mixtures on Graphon. The nonideal behavior observed for benzene-ethanol and cyclohexane-ethanol mixtures on Graphon was attributed to the presence of benzene or cyclohexane disrupting the hydrogen-bonded structure of ethanol on the Graphon surface. It was concluded that the ideal adsorbed solution model is a useful one for predicting binary vapor adsorption equilibria. / Ph. D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Lawrence M. Hull. / Ph.D.

Based on a Ph.D. thesis in the Dept. of Meteorology, 1967. / Bibliography: p. 99-101.

Not available

No description available.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Dr. Srinivas Garimella; Committee Member: Dr. Samuel Graham; Committee Member: Dr. Sheldon Jeter. Part of the SMARTech Electronic Thesis and Dissertation Collection.

When water vapour condenses at a sub-atmospheric pressure, the pressure drop may be a significant fraction of the absolute pressure. Furthermore the pressure drop in a condenser passage also reduces the absolute vapour temperature and therefore affects the heat transfer capacity of a condenser. For a tubular heat exchanger the pressure loss in the heat exchanger tubes can be minimized by the use of contoured or rounded inlet sections at the inlets of the tubes instead of using a sudden contracting inlet section or a protruding inlet section for the tubes. The pressure loss characteristics of different inlet sections to the tubes were obtained through a literature survey of the pressure loss coefficients. The pressure loss at the inlet sections were also investigated with computational fluid dynamics, using the Star-CD software system. The flow regimes for which the pressure loss was investigated were for the laminar incompressible and turbulent incompressible flow regimes. The inlet sections investigated were a sudden contraction and two rounded inlet sections with a rounding radius of 52% and 105% of the tube diameter respectively. The computational fluid dynamics results of the laminar flow simulations revealed that the pressure loss coefficients of the sudden contraction and rounded inlet sections were very similar. The pressure loss coefficient of the sudden contraction inlet sections only being 3 to 6% higher than the rounded inlet sections. This is due to the dominant effect of viscosity in the laminar flow regime. The viscosity reduces the extent of flow contraction occurring since transverse momentum is damped by the viscous dissipation. The dominant pressure loss mechanism in the laminar flow regime is hydrodynamic flow development. With hydrodynamic flow development the flow velocity profile changes from a uniform velocity profile before the inlet section into a pointed parabolic profile downstream in the tube. The turbulent flow simulation results revealed that the pressure loss coefficients of the rounded inlet sections investigated in this study were very similar. The pressure loss coefficient of the sudden contracting inlet section was higher than the rounded inlet sections’ pressure loss coefficient. The results indicated that rounded tubular inlet sections would be of limited value in the laminar flow regime; it would however be beneficial in the turbulent flow regime. / Prof.J.P. Meyer Prof. L. Pretorius