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Series of blood samples were taken from Holstein calves before, and at 2, 4, and 6 hours after feeding. The blood plasma levels of tryptophane and methionine were determined by microbiological assay. It was found that the blood plasma levels of tryptophane and methionine varied considerably at different time intervals after feeding milk. One calf was fed 50 grams dl-methionine with its regular feed of milk, and series of blood samples were taken and assayed as in previous work. The methionine level increased to approximately 4 times its initial value by 2 hours after feeding, continued to rise, and at 6 hours after feeding was more than 10 times the original level. At the same time the tryptophane level showed a consistent decline. Determinations for total amino nitrogen were made, using a modification of the Folin-Wu method. The values obtained at different time intervals after feeding ranged from 6.45 to 9.33 mg./100 ml. blood. It was found that feeding methionine increased the blood level for total amino nitrogen, reaching a peak four hours after feeding. A special electrometric titration apparatus was used for making titrations. Approximately 1750 assays, consisting of standards and test samples, were titrated in this experiment. / M.S.

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In 1947, Professor H. S. Miles, Jr. of the Mechanical Engineering Department at the Virginia Polytechnic Institute, presented a thesis (1) on the design of a 65 ton steam jet refrigeration unit. Miles recommended that a small unit be constructed in the Mechanical Laboratory so that the soundness of his design be confirmed. With this in mind, Messrs. A. W. Howard and C. W. Vogelsang (2) built a 5 ton unit in the laboratory in 1948. It is the purpose of the authors of this report to determine why the steam jet refrigerating unit constructed in the Mechanical Laboratory at the Virginia Polytechnic Institute in 1948 did not reach design capacity. / M.S.

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The purpose of this investigation was to determine the effect of the operating variables of type of reactor, catalyst, ethylene feed concentration, temperature, and contact time on the products of oxidation of ethylene to ethylene oxide; and together with subsequent hydrolysis to evaluate the commercial feasibility of the manufacture of ethylene glycol. The review of the literature contained 10 references. The equipment employed was arranged as indicated in a general flow diagram for the system. A silver catalyst activated by barium peroxide was employed and prepared on No.7 and No.3 Valencia pumice as the carrier according to Wiseman. For the analysis of ethylene oxide the procedure employed was a modification of that suggested by Vaughan and Wiseman. The carbon dioxide content of the product gases was determined by absorption of the carbon dioxide by ascarite; moisture was removed by means of drierite. Data and Results: A summation was made of operating conditions, yields and conversion in the air oxidation of ethylene in a fixed bed and fluidized bed reactor as a function of type of catalyst, contact time, reactor bath temperature, ethylene feed concentration, employing a barium peroxide activated silver catalyst coated on No.3 and No.7 Valencia pumice , uncoated pumice, and mixtures of these catalysts. It was found advisable to employ a 50% mixture of catalyst-coated and uncoated carrier in the tests because of the tendency toward fusion of the catalyst particles when used alone as the reactor charge . An increase the ethylene feed concentration from 3 to 9 per cent does not seem to appreciably affect either the conversion or yield. / Ph. D.

In this investigation the stress concentration factor was evaluated for a hollow stepped shaft with variable wall thickness and two fillet sizes. Electric strain gages of the SR-4 type were employed to measure strains in the fillet section. Values of the stress concentration factor were determined with the ratio of inside to outside diameter ranging from 0.25 to 0.625. A decreasing relation was established between stress concentration and the internal diameter. A satisfactory method of positioning gages accurately on the complex fillet surface was developed. This method featured an intermediate steel template with positive referencing. / M.S.