An r-f ion source has been constructed for the V.P.I. electrostatic generator. The ion source has been in operation for approximately one thousand hours with an average beam current of one micro-ampere. This beam has been sufficient to test and calibrate the accelerator. Experiments which require beam currents in the order of 100 micro-ampere can now be conducted with the ion source operating at its designed capacity. / Master of Science

The sensible heat losses in the flue gases was exceeding the best economical operating ranges of the Boiler No. 6. This was done to study the adverse effect on the flue dust carryover in the furnace. / Master of Science

Amino acids were determined in two types of chinchilla fur (chewed and normal), using three methods for analyses The methods included microbiological assays of Barton-Wright(5) and two column chromatography techniques of Moore and Stein (7, 8). The data obtained from this investigation indicate that of the 16 amino acids analyzed, only one (lysine) was forum to be significantly lower in the chewed fur, as indicated by the "t" test. This difference between the normal and chewed fur was significant at the 2.5% 1evel. Also, arginine was lower and histidine was higher in the chewed fur than in the normal fur, but these difference: were not as conspicuous. In general, the microbioligical analyses were more time consuming end less reproducible than the chromatographic analysis. With the exception of proline, glycine, and leucine, higher values were obtained fer the mine acids using the microbiological methods than with the column fractions. The greatest difficulty was encountered in analyzing the basic amino acids. / Master of Science

Newborn rats and young guinea pigs have been exposed to high oxygen concentrations with subsequent analyses of ascorbic acid in liver and brain tissue. Newborn vats show a depletion of liver ascorbic acid only after exposure to 100% oxygen. Extending the exposure period in 70% oxygen did not result in any depletion. Brain ascorbic acid levels in newborn rats were depleted by exposure to both 100% and 70% oxygen until the 14th day of life. After that age, exposure failed to cause depletion. Guinea pigs identically exposed showed ascorbic acid depletion in both brain and liver tissue with the more marked depletion occurring in liver tissue. Abnormalities in the eyes of the experimental guinea pigs were demonstrated. Results of the tissue Vitamin A analyses are incomplete and inconclusive at this time. / Master of Science

There is a significant difference between the effects of different curing temperatures on the strength of shell molds, A curing temperature of 500°F is more desirable than one of 600°F. / Master of Science

The following general conclusions were drawn from the results of this study which included (1) measurement of speed; control; and a combination of both speed and control; and (2) preferences of the students regarding the two lengths of writings. The five-minute tests were the primary measurements in this study. The last writing in each rotation period and the averages of the daily timed writings served as secondary measurements. / Master of Science

Coal is one of the world's largest remaining mineral resources. The supply of this rich source of fuel and chemicals is sufficient to serve the world for several thousand years. Coal is used directly and is also heat treated at high and low temperatures to produce fuel and by-products. Of the several methods of treatment that can be used, low-temperature carbonization is one of the most promising. Nearly all of the coke and coal chemicals produced today come from the production of high temperature coke. However, there are many lower rank coals not suited for metallurgical purposes that will produce an excellent char and high yields of by-products. One of the disadvantages of many lower rank coals is their tendency to swell and become plastic when heated to carbonization temperatures, and this property has to a great extent made the operation of the retorts difficult. In an effort to reduce or circumvent this undesirable property, several methods of pretreating the raw coal have been tried including preoxidation, dilution with non-coking coal, preheating, and weathering. The type and severity of the pretreatments vary in their effects on the coking properties of different coals. The purpose of this investigation was to study the effect of preoxidation on the coking properties and the quantities and composition of the byproducts and char obtained from the low-temperature carbonization of Penn-Lee coal. / Master of Science

Liquid extraction is a means of separating two or more components of a solution. The process involves mixing the solution with an immiscible solvent, separating the two phases, and recovery of the desired materials and of solvent from the solvent phase, usually by distillation. Separation is accomplished if certain of the solution components are more soluble in the extracting solvent employed than in the feed solution. Liquid extraction is used to concentrate aqueous solutions of acetic acid produced in the esterification of cellulose and in other manufacturing processes because acetic acid and water are not easily separated by direct rectification. Liquid extraction of acetic acid must always be followed by solvent-recovery systems. Then the selection of solvents suitable for extraction of acetic acid must be based not only on the relative affinity of the solvents for acetic acid but also on consideration of heat and other energy requirements of the extraction and solvent recovery systems. The purpose of this investigation was to develop a method of evaluating solvent extraction systems for the recovery of acetic acid from aqueous liquors, by comparisons of selected solvent systems on the basis of: (a) theoretical transfer units required for extraction, (b) in the case of solvents boiling below 100 °C, theoretical plates required for distillation of extracts, and (c) heat required for recovery of pure acetic acid and of solvent. / Master of Science

Control of weeds is an agricultural problem of great importance. For centuries, only salts, ashes, or mechanical means of eradication such as hoeing, cutting, or burning were used in weed control. A large number of chemicals have been used for this purpose also. With the advent of modern railroads, highways, and power lines, the demand has grown for newer and more effective control of weeds and brush. The initial application of chemical herbicides produced erratic results in many instances. Some herbicides retarded the growth rate of certain forms of vegetation but left other forms unaffected. Likewise, some herbicides killed the entire plant, while others killed only the portion sprayed. Since 19ul, however, the discovery of synthetic growth regulating substances or plant hormones as effective weedkillers has brought about a revolutionary change in the chemical control of weeds. The synthetic hormone substances are greatly superior to ordinary chemicals in that they are highly selective as between plant species and have many other additional advantages. They are now being used in many places throughout the world, but too often with little accurate knowledge of their nature or of the special circumstances under which they should and should not be used. Such information is important because these substances can be very destructive to vegetation when improperly applied. Maleic acid hydrazide is a relatively new herbicide, possessing the hormone—like property of retarding plant growth for long periods of time by preventing the division of cell nuclei. Field applications of the hydrazide have shown good growth retarding ability on many types of weed and shrubs In view of the wide variation in environmental conditions and farming practices in different parts of the world, as well as the great variety of crop and weed plants involved, the control of weeds is essentially a local problem, and instructions for specific regions and for specific purposes cannot be given until results of local tests become available. It is therefore necessary to rely on experimental work conducted locally for information on how to use these substances. / Master of Science

Crude culture filtrates of Myrothecium verrucaria. were investigated in an attempt to gain information on the following: (A) the multiplicity of the cellulolytic system, (B) the formation of glucose in the course of cellulose hydrolysis, (C) the significance of intermediate dextrins in the course of cellulose hydrolysis, (D) the properties of a β-aryl-glucosidase present in filtrates of this organism, and (E) a transglucosidase which synthesized higher saccharides from cellobiose. In paper electrophoresis at pH 8.55 in veronal buffer of ionic strength 0.05 and a potential gradient of 10 volts/cm, concentrated culture filtrates exhibited multiple components with cellulase activity. The electrophoretic pattern for each filtrate could be reproduced; however, different filtrates gave different proportions of the components. The presence of electrophoretically distinct components with cellulase activity indicated the multiplicity of the cellulolytic system. At pH 7.0 and lower there was no separation of the cellulase in the filtrates into the components shown at 8.55. The β-aryl-glucosidase also exhibited several peaks on paper electrophoresis, indicating that it, too, was dependent on several proteins for its activity. With the exception of a peak of activity that remained at the origin, the mobile peaks of cellulase and β-aryl-glucosidase did not coincide, indicating that the two separate activities are not dependent on the same proteins for their respective activities. The activities remaining at the origin were also dependent on different proteins because the β-aryl-glucosidase was destroyed by heat whereas the cellulase was not. The concentrated culture filtrates were subjected to column chromatography on alkali-swollen cellulose. The enzymes were eluted with phosphate-citrate buffers of increasing pH and ion strength. Effluent fractions were collected and assayed for their ability to hydrolyze carboxymethyl cellulose of two degrees of polymerization, insoluble cellulose dextrins, soluble cellulose dextrins, cellobiose, 6-bromo-2-naphthol-β-D-glucopyranoside, and 4-0-β-D-glucopyranosyl-D-sorbitol. The results not o~ indicated a multienzymatic nature of cellulase but also that the components of the cellulase system were specific for a particular range of chain lengths of cellulose. Some of the fractions hydrolyzed carboxymethyl cellulose (DP 200) but did not hydrolyze the insoluble dextrins, the soluble dextrins or cellobiose; some hydrolyzed both the carboxymethyl cellulose and the insoluble dextrins but did not hydrolyze the soluble dextrins or cellobiose; and some hydrolyzed the carboxymethyl cellulose, the insoluble and soluble dextrins but not cellobiose. There were a few fractions which hydrolyzed the carboxymethyl cellulose, soluble and insoluble dextrins and cellobiose. Cellobiase was confined to a relatively few fractions and all the fractions with cellobiase activity also exhibited transglucosidase activity. Cellulase fractions which were void of cellobiase and transglucosidase activity accumulated glucose, cellobiose, and higher saccharides when hydrolyzing insoluble cellulose dextrins. The formation of glucose in the absence of cellobiase indicated that the cellulase is capable of removing single glucose units from the end of the chain and cellobiose is not an obligatory glucose precursor. The formation of higher saccharides in the absence of transglucosidase indicated that these sugars were true intermediate dextrins, arising as the result of random cleavage of the cellulose molecule, and were not the synthetic products of a transglucosidase. A β-aryl-glucosidase, which was not a cellobiase, chromatographed off the cellulose column. Some of the properties of this enzyme were studied. It was found to hydrolyze several β-aryl-glucosidases with varying ease. In the presence of various alcohols it transferred the glucose moiety of the glucoside to the alcohol. With methanol the product was methyl glucoside, but it was not possible to establish the configuration of the linkage that was formed. The transglucosidase synthesized, from cellobiose, several higher saccharides which appeared to be the homologous series of cellulose dextrins through the hexasaccharide. / Ph. D.