Utilization of the activated sludge process is widespread although many of the mechanisms involved are still relatively misunderstood. Incorporation of nitrate respiration (denitrification) into the activated sludge process can have many advantages, but little is known about microbial growth and substrate removal when nitrate respiration is employed. The primary objective of this study was to evaluate and compare microbial growth and biokinetic coefficients in an aerobic and an anoxic (anaerobic with nitrate as the terminal electron acceptor) activated sludge process. Two bench-scale continuous flow reactors were operated over a range of mean cell residence times with organic carbon as the limiting nutrient. Alkalinity changes were monitored and compared with theory. Engineering applications of the results were discussed. The maximum microbial yield and endogenous decay coefficient were lower, and the maximum substrate utilization rate was higher for nitrate versus oxygen respiration. Alkalinity production during denitrification was very near the theoretical stoichiometric value of 3.57 mg as CaCO₃ per mg NO₃⁻-N denitrified. It was concluded that single-sludge systems incorporating organics removal, nitrification, and denitrification can potentially achieve a high degree of nitrogen and organic carbon removal at lower cost than a similar size system incorporating organics removal and nitrification only. Aeration energy savings and reduced sludge production obtained by the utilization of nitrate respiration in single-sludge systems should result in significant cost savings. / M.S.

The purpose of this thesis is to establish the fact that a single protagonist exists in James Joyce's Dubliners, that Joyce masks the enduring Dubliner-consciousness under the guises of various protagonists, and that this consciousness develops and matures within the many lives Joyce traces in his book. Indeed, many critics have examined Dubliners and have presented a great deal of evidence that points to structural unities in the book by exploring Joyce's use of allegory, allusion, foreshadowing, imagery, and symbol. But none has stated, nor does any appear ready to find, a single protagonist in Dubliners. Consequently, the ultimate conclusion of a successful study in this area would be that Joyce's first major work tends to be a novel rather than a short-story collection. My major point of departure is the Joyce letters, to establish unequivocally Joyce's intent and purpose in writing Dubliners. I furnish additional external evidence pertinent to the publication history of the book, as well as biographical elements that directly influenced the writing and publication of Dubliners, from Ellmann's biography of Joyce. But an important examination of this nature cannot ignore the internal evidence the book itself affords, Consequently, I deal with Joyce's arrangement of each Dubliners segment, categorize groups of these segments under the four phases of Dublin-life Joyce structured his work around, identify and trace the developing protagonist through the life-to-death pattern Joyce set for him, and delineate units of Dubliners as transitions between the stages of a Dubliner's life. This process demonstrates that Joyce set the Dubliner on a circular road of life and that the Dubliner follows such a circular path because of his circular and moribund mental process. This book, then, concerns structural unities in Dubliners. It offers at once a critical reading of Joyce's work and an attempt to uncover those traits of specific characters, as they comprise what can be termed a Dubliner-consciousness. Chapter I is an introduction and deals with the overall design and publication history of Dubliners; Chapter II offers a discussion of Childhood as the first major unit of the book; Chapter III, a consideration of Joyce's notions of Adolescence; Chapter IV, a study of Maturity; and Chapter V, a reading of the Dubliner's Public Life. Chapter VI is a consideration of ''The Dead" in particular as an epilogue to Joyce's volume and a reconsideration of Dubliners in general as, as it were, "A Book of the Dead." / Master of Arts

A 21-day metabolic balance study was designed to test the hypothesis that dietary zinc level affects protein utilization in growing children. Subjects' mean age was 8 years 5 months, mean weight was 29.5 kg, and mean height was 132.1 cm. The subjects were divided on the basis of weight into four treatment groups following a 2x2 factorial experimental design. After an eight day adjustment period in which all subjects consumed a mixed diet known to contain 28.8 g protein, 5.5 mg zinc, and 2,000 Kcal, the four treatments were administered for 12 days. One group was supplemented with the essential amino acids found by analysis to be most limiting with respect to whole egg protein. Threonine, valine, methionine, isoleucine, and lysine were added in amounts to reach a chemical score of 80 based on whole egg protein. The sources and amounts of nitrogen were: food, 4.18 and supplements, 0.14 g/day. One group received these same amino acids plus a zinc supplement of 5.0 mg/day. One group received an isonitrogenous amount of ammonium citrate matching the nitrogen contained in the amino acids supplement. The last group received the isonitrogenous amount of ammonium citrate plus 5.0 mg zinc. All supplements were given daily and were incorporated into meals. All urinary and fecal excretions were collected and analyzed for nitrogen and zinc. Nitrogen analysis was accomplished using a modified Kjeldahl-Gunning-Arnold method and zinc was determined spectrophotometrically on wet-ashed samples. Nitrogen retentions for the four groups were: amino acids plus zinc, 1.00; amino acids, 1.01; ammonium citrate, 0.90; and ammonium citrate plus zinc, 0.81 g/day. Analysis of variance on the balance data from the four groups showed no effect of zinc, added essential amino acids or the interaction of the two on the nitrogen balance of the subjects, although the trends of retention favored amino acids. There was a significant effect (p<.01) of added zinc on zinc balance, however. It was concluded that zinc did not affect nitrogen utilization in the growing child, but that zinc balance is affected by zinc quantity in the diet. The present Recommended Dietary Allowance of 10 mg zinc/day for this age group is the minimum necessary to maintain positive zinc balance. / Ph. D.