The results of a survey on the relative abundance of sulfur isotopes are presented, together with a review of previous work on the same subject. The possible causes of the variations found, and the biological and geological significance of these varia­tions is discussed. In addition, the equilibrium constant for the isotopic exchange between hydrogen sulfide and hydro­sulfide solution is determined experimentally and the results related to theoretical cal­culations based on partition functions. / Thesis / Master of Science (MS)

The practice of acidifying the tomato (Lycopersicum esculentum) by additives in canning was investigated from the standpoint of adjusting and maintaining a pH desirable to prevent microbial growth without adversely effecting quality. Approximately one-third or more of tomato acids were in their salt form and, consequently, the most effective acid groups are neutral. In 75°F storage for 52 weeks the pH of non-acidified tomatoes packed in #303x406 cans rose 0.1 units. This rise was believed to be due to corrosion points through pinholes in the enamel films of all the cans by the reaction: H⁺ + Sn⁰ → H⁰ + Sn⁺. Ten tomato varieties from four geographical regions were canned and evaluated for effects of additives on pH and composition. No distinguishing characteristics were noted in packs from the different regions. Salts with citric and malic acids added at less than 1.0 meq/100 g tomato equally depressed the pH by about 0.2 units. Fumaric and phosphoric acids were more effective. None of the acids used as acidulants showed any significant effects on drained weight, refractive index, can vacuum, can corrosion, or chemical composition. The effects of neutral salts for adjusting canned tomato pH were evaluated. Calcium and magnesium chloride depressed the pH by 0.06 units for each meq added up to two meq/100 g tomato. These salts were approximately seven times more effective than sodium chloride for depressing pH. Calcium chloride was more effective than magnesium, sodium, or potassium chlorides in preventing drained weight loss when up to 2.0 meq of each of these salts were added per 100 g tomato (2 meq CaCl₂ = 0.11% CaCl₂). Evidence shown by alcohol soluble acidity indicates that sodium ions were removed from added sodium chloride into the alcohol insoluble fraction. Processing times of 15 and 45 minutes at 210℉ were compared as to their effect on tomato compositional changes. Heat penetration curves 0 showed that internal fruit temperature reached 150℉ in the 15 minute 0 heat process, while over 190℉ was reached inside tomatoes processed 45 minutes. Five tomato varieties showed no significant pH change related to length of heat process. Titratable acidity was slightly higher by 0.1 meq/100 g in tomato samples processed 45 minutes. Other variables for the sample sets of the two processing times were compared by Duncan's multiple range tests and by partial correlations among them. Variables also included alcohol soluble and insoluble acidities, water insoluble solids, reducing sugars, amino nitrogen, phosphoric acid, refractive index, and lactic, oxalic, fumaric, succinic, malic, citric and pyrrolidone carboxylic (PCA) acid determined by gas chromatography. Although differences between the two processes were small, correlations among variables were higher in the sample set processed for 45 minutes. These relationships imply that thermal, non-enzymatic effects were slightly more pronounced in the set processed for 45 minutes. The rate of formation of PCA appears to be higher during the early stages of heat processing. Small within-can variations were found to exist. Centrifuged tomato solids were 0.028 pH lower than that of the serum. / Ph. D.

Regional and local geologic structures in the San Francisco Mountains vicinity, southwestern Utah, are investigated using magnetic-field intensity and gravimetric data. Aeromagnetic data are interpreted to indicate a buried Tertiary pluton whose northern boundary runs from east to west across the 980 square mile study area, and which extends beyond the coverage of the aeromagnetic map to the east, south, and west. Local cupolas, some of which outcrop at the surface, extend upwards from the main igneous body. A three-dimensional model which generates a magnetic field similar to that which is observed is developed, using a digital computer, for the distribution of the magnetic intrusive rocks in the area. These model studies indicate that the pluton is distinctively tabular, and about five miles thick, and has a near-vertical and linear northern edge which may have resulted from the structural control exerted by an east-west trending fault zone. The Bouguer gravity anomalies in the San Francisco Mountains district reflect horst and graben structures typical of the Basin and Range Province, and indicate that an approximate density contrast with the surrounding consolidated sedimentary rocks of +.10 grams per co. is associated with the local intrusive cupolas. Three interpretive east-west geologic cross-sections reproduce the observed residual gravity anomalies. The cross-sections are obtained using a computer program for the evaluation of the two-dimensional gravity anomalies on the ground surface. The regional gravity data are interpreted to show the effect of at least three regional structures which are distinct from the local near-surface structures: 1) An underlying intrusive body. 2) An east-west fault zone bounding the intrusive body on the north. 3) A continuation od Basin and Range structure at depths exceeding two miles. Vertical-field ground magnetic data were obtained during three and one-half months of fieldwork in selected areas of the Star Range, located in the southeast quadrant of the thesis area. The igneous structure compromising the local Milford Flat intrusive body is found to terminate abruptly to the northwest, presumably as a result of post-intrusive faulting, while to the east the depth of burial increases gradually. The intrusive rock near the Wild Bill mine plunges steeply to the east and more gently to the south. An anomaly in the south-central portion of the Wild Bill magnetic grid is interpreted as representing an upward protrusion of the local quartz monzonite body. The contact zone along the southern edge of the Shauntis intrusive body, southeast of the old townsite of Shamite, is mapped on the basis of magnetic evidence, and four zones of magnetite mineralization between 8 and 25 feet thick are defined. / Ph. D.

There is an increasing need for a methodology which will provide quick and inexpensive forecasts of inputs from a variety of alternative transportation plans. QUADATT II (<u>Qu</u>ick <u>A</u>nd <u>D</u>irty <u>A</u>nalysis <u>T</u>echniques for <u>T</u>ransportation — Version II) is a set of simplified models which has been compiled in order to fulfill this need. The QUADATT II procedure was applied for this analysis to thirty transportation zones in the metropolitan area of Roanoke, Virginia. Five transit configurations were designed as input to QUADATT II, and the resultant impacts were evaluated. Based on the results of this application it was determined that QUADATT II provides reasonable trends in activity distributions and transportation characteristics related to a given set of alternative transportation plans, and does so at a much reduced level of cost and time over that of the typical large scale studies. / Master of Science

An apparatus to experimentally verify the accuracy of filmwise condensation heat transfer theories for small diameter horizontal tubes was developed. The apparatus was designed so that the condensation pattern was visible at all locations, all of the parameters necessary to calculate the average heat transfer coefficient were accurately determinable, and the removal of noncondensible gases was effected before the start of the condensation process. A method was devised to insulate the test specimen and cooling water from the rest of the apparatus to obtain an accurate measure of the heat transfer rate. The surface temperature of the tubes was directly measured by copper-nickel thermocouples which were electroplated onto the tube. Initial testing of the apparatus was performed using steam as the condensing vapor. Difficulty in obtaining and maintaining filmwise condensation was caused by small amounts of impurities which were introduced during the assembly of the apparatus. The surface thermocoup]es produced output of approximately l mv per 75 F and were responsive to transient temperature fluctuations. / Master of Science

No description available.

Ph. D.