Thesis (Ph. D.)--University of Michigan, 1934. / Cover title. Caption title: Design of fractionating columns. III. Plate efficiency and number of plates for petroleum columns [by] Sidney Charles Singer, jr., Roy Russell Wilson, and George Granger Brown. "Reprinted from Industrial and engineering chemistry, vol. 28 ... July, 1936." Bibliography: p. 835.

The production of uniform-sized drops without small follower drops or "trailers" in liquid-liquid systems was studied using a periodic injection technique for dispersing one liquid through a sharp edged nozzle into the other. Previous investigators using a continuous flow technique found that uniform sized drops without trailers were limited to systems of higher interfacial tension. The effects of nozzle inside diameter, nozzle material, and of velocity-time profile of the dispersed fluid through a nozzle at drop formation were examined using two systems; n-butanol and water of very low interfacial tension, and methyl isobutyl ketone and water of low interfacial tension. These two systems were chosen so that the results of this study could be integrated with other work. The velocity-time profiles were obtained by using a positive displacement bellows pump, the stroke of which was controlled by a cam follower through a variable ratio linkage using three different cam profiles. The conditions under which uniform sized drops without trailers were formed, were located for both systems. The effects of surface active contaminants and the wetting of the nozzle tip by the dispersed phase were considered. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Thesis (Ph.D.)--University of Tulsa, 1974. / Bibliography: leaves 40-44.

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1956. / Typewritten. Vita. Bibliography: p. 110-114. Also available via the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 318-330). Available also in a digital version from Dissertation Abstracts.

The NAD glycohydrolase (NADase) from Bungarus fasciatus venom was purified over 1000-fold to electrophoretic homogeneity through a 3-step procedure which included affinity chromatography on Cibacron Blue agarose. The enzyme exhibited a broad pH profile with the optimum range between 7-8. Studies on the substrate specificity of B. fasciatus venom NADase demonstrated that alterations in the purine ring were less pronounced then alterations in the pyridinium moiety of NAD. Product inhibition studies indicated nicotinamide to be a noncompetitive inhibitor with a K_i = 1.4 mM and ADP-ribose to be a competitive inhibitor with a K_i =0.4 mM. The purified enzyme was inactivated by both 2,4-pentane dione and Woodward's Reagent K suggesting the involvement of a lysine and carboxyl group in the catalytic process. In contrast to other known NADases, the snake venom enzyme did not self-inactivate. The purified B. fasciatus venom NADase catalyzed a transglycosidation reaction (ADP-ribose transfer) with a number of acceptor molecules. The functioning of a variety of substituted pyridine bases as acceptor molecules was demonstrated through the formation of the corresponding NAD analogs. The enzyme also catalyzed the transfer of ADP-ribose to aliphatic alcohols (methanol to hexanol, inclusive) and a positive chainlength effect was observed in the functioning of these acceptors. Kinetic studies of transglycosidation reactions were consistent with the partitioning of an enzyme-ADP-ribose intermediate between water and nucleophilic acceptors as has been proposed in earlier studies of mammalian NADases. The partitioning of this intermediate between water and pyridine bases can be correlated with the basicity of the ring nitrogen of the pyridine derivative. The K_i of pyridine bases in the hydrolytic reaction did not equate to the K_m of these bases in the pyridine base exchange reaction suggesting two forms of the NADase with varying affinity for the pyridine bases. This implys the pyridine base exchange reaction to be more complicated than originally proposed. / Master of Science

The process of fractional distillation has been performed for many years but has only within the past half century become a true science. However, because of the many variables involved and the uncertainty of their effect upon fractionating column efficiency, the design of columns has long been a major engineering problem. Plate and column efficiencies, as given in the literature, vary widely and it was thought possible that the inconsistencies of the results reported might be due to poor equilibrium within the column, caused in part by faulty sampling. In order to determine the operating characteristics of a fifteen plate bubble-cap column (8-3/8" I.D., one 3-7/8" bubble-cap per plate, and plate spacing of 5-7/8"), the effects of the operating variables, and the distillation characteristics of two different types of binary mixtures, the column assembly was redesigned for continuous distillation and provisions made for the introduction of feed at its boiling point to any one of the bottom eight plates. The binary — mixtures distilled were isopropyl alcohol — water (distillation rates 157 - 376 gms./min., feed concentrations 3.1 - 10.8 mol per cent isopropyl alcohol, reflux ratio 3:1, and feed rate of 330 gms./min.), and toluene - ethylene dichloride (distillation rates 203 and 196 gms./min., feed concentrations 41.4 and 39.7 mol percent ethylene dichloride, reflux ratio 4:1, and feed rate of 138 gms./min.) In order to reduce the possibility of disturbances within the column by removal of large plate samples, the refractive index method of analysis was used which required maximum samples of only 4 ml. Results of the experiments made indicated that the assumption of the McCabe - Thiele operating line is probably incorrect. In the case of the isopropyl alcohol — water fractionation, a considerable divergence (largest between 10 and 40 mol per cent isopropyl alcohol) between the McCabe - Thiele and the actual operating line was noted, the actual operating line being a curve approximately the shape of the equilibrium curve. Murphree Plate Efficiencies for the mixture varied from 0 to 100 per cent, depending primarily on the relative deviations of the two operating lines from the equilibrium curve. The McCabe - Thiele operating line for the system toluene — ethylene dichloride closely approximated the actual operating line. Murphree Plate Efficiencies varied from 44.5 to 121 percent, but the individual plate efficiencies were more consistent with the average efficiency. The rate of distillation over the range of 157 to 376 gms./min. and feed concentration over the range of 3.1 to 10.8 mol percent isopropyl alc1ohol, at a reflux ratio of 3:1 had negligible effect on product purity which ranged from approximately 62 to 67 mol per cent isopropyl alcohol. / Master of Science

no abstract provided by author / Master of Science

The purpose of this investigation was to improve upon the overall design of a 15-plate fractionating assembly used in the separation of simple binary mixtures of isopropyl alcohol and water, to recalibrate all measuring devices used in the operation of the column, to develop an analytical method by which the composition of liquid samples from the column could be determined accurately and quickly, and, in general, to place the assembly in such condition that experimental runs can be made more easily with a higher degree of accuracy than has previously been possible. / Master of Science

Master of Science