Four power flow algorithms were developed, and qualitative and quantitative comparisons were given in terms of solution time required, computer storage necessary, convergence characteristics, and ease of programming and program modification. Sparsity techniques were outlined, and a suggestion of the effects of these techniques on the four algorithms was included. An outline was given of criterion that must be considered before selecting a power flow algorithm. / Master of Science

The study was conducted to determine congruence in the role of principals of vocational-technical centers in Virginia as perceived by principals, superintendents, and teachers. Twenty-three out of the 24 vocational-technical centers in the state were included in the study. There were 23 superintendents, 23 principals, and 65 teachers from a 20 percent sample who provided useable returns. Design and method of research. A list of 78 items believed to be the functions of principals of vocational-technical centers was developed from the literature and subjected to a jury of experts. Forty-eight items were included in the final instrument which utilized a Likert-type scale to measure perceptions of the respondents. The mail questionnaire technique was used. Analysis of data. Means and standard deviations were obtained on each item for each of the three subgroups. Factor analysis of the items resulted in the identification of six factors underlying the 48 functions. A z-test was used to determine the differences between the sample of teachers, and the principals and superintendents on each factor. / M.S.

The study consisted of two parts: following the fade rates of killed field-grown Virginia pine (<u>Pinus virginiana</u> Mill.); and to study the effects of different stresses on seedlings. Foliage fade rates of killed field-grown Virginia pine varied with the time of the year the tree was killed. Little variation in fade rates was found between years. Foliage of seedlings grown under stress due to: girdling; sevpring; defoliating; and drought, were studied by paper chromntographv, cross sectioning, and photography. The four pigments found appeared to decline proportionately as the foliage went from green to red. An error in technique resulted in uninterpretable needle cross sections. Photography using black and white, black and white infrared, color, and color infrared films gave no previsual detection of stress. / Master of Science

Ph. D.

Ph. D.

An attempt was made to study the effects of a tranquilizer (metoserpate hydrochloride), specifically designed for poultry, on the neonatal approach response of domestic chicks. Acquisition of this response was accomplished in a straight alley on birds ranging in age from 24 to 120 hours old. Testing of this response was done when all birds were 144 hours old under a no-drug condition. At 168 hours of age all subjects were subjected to extinction procedures. The strength of the response was measured in terms of latency to start as well as time spent traversing the alley. Resistance to extinction was measured in terms of the latencies mentioned above as well as number of trials to extinction. The results of the present study show a peak in imprinting susceptibility between 72 and 96 hours after hatching. The tranquilizer had a traditional interference effect except for those birds exposed on Day 3 while the injection control procedure had an enhancement effect on birds treated on Days 4 and 5. In addition, there were no differences observed during extinction between groups. / Master of Science

Earlier investigations indicated that the genes involved in the biosynthesis of tryptophan from anthranilic acid were located in at least two separate regions on the chromosome of Streptomyces coelicolor A3(2). Tryptophan-requiring mutants capable of utilizing indole mapped counterclockwise of hisC9 between hisC9 and proAl. Trp mutants unable to use indole in place of tryptophan mapped clockwise of hisC9 between hisC9 and ammA5. Other genetic markers, located between proAl and hisC9, include leuAl, rif'B37 and thiC2. Twenty indole-utilizing Trp mutants were mapped relative to leuAl, rifB37 and thiC2. All but two recently isolated mutants, Trp-e8 and e22, mapped between rifB37 and thiC2. Genetic and enzymatic analyses of Trp-e8 and e22 indicate that these mutants map between hisC9 and ammA5, fail to complement each other in vivo and lack indoleglycerol phosphate synthase. Two mutants, Trp-e14 and 8, mapping between hisC9 and ammA5 were assayed for their tryptophan enzymes. Trp-el4 lacks tryptophan synthase B activity. Tryptophan synthase A activity was missing and tryptophan synthase B activity was relatively weak in crude extracts of Trp-8. Anthranilate-PRPP phosphoribosyltransferase activity was not detected in crude extracts of two mutants, Trp-e6 and e10, mapping between rifB37 and thiC2. / Master of Science

This research was designed to quantify nine minerals in seven chicken parts composited into sixteen groups from one-hundred-twenty-eight chickens. The research will provide nutritionists with accurate data regarding this common food item. Also, the effects of baking or simmering on the mineral content of chicken meat were examined. Nine minerals, including calcium, magnesium, manganese, potassium, phosphorus, sodium, iron, zinc, and copper were analyzed in seven anatomical parts of the chicken including light and dark meats, skin, fat and drippings. A nitric and perchloric acid wet-ashing digestion eliminated all organic matter from ten gram samples leaving behind the elements which were detected spectrophotometrically. Values were expressed in mg/100g wet sample. The most abundant minerals studied were phosphorus and potassium with values ranging from 50.0 mg/100g to 200.0 mg/100g. Sodium was present in moderately high values, about 40 to 100 mg/100g. Copper, magnesium, manganese, and calcium were present in lesser quantities with values between 6.0 and 78.0 mg/100g. Iron and zinc with values of 1.0 mg/100g or less were found only in trace amounts. Analysis of variance revealed a significant interaction (p>.0001) between raw and baked chicken and between raw and simmered chicken. Thus, differences between the raw and corresponding cooked composites were not consistent differences and no general statement can be made regarding the leaching of minerals from raw chicken by baking or simmering the meat except that it does not seem to occur. / Master of Science

The first experiment was designed to determine if the antigenicity of egg yolk diluter could be eliminated by the addition of specific antibodies. Two virgin heifers were immunized with 20% yolk - 2.1% citrate - 7% glycerol with penicillin and streptomycin. Non-immune serum and immune sera having titers of 1:640 and 1:2560 were collected and frozen. Serum antibody titers were determined by the passive hemagglutination test. Utilizing equivalent proportions test it was determined that 80 volumes of anti-egg-yolk-diluent sera titered 1:2560 was necessary to neutralize 1 volume of 20% egg yolk diluent. The second experiment examined the effect of immune sera against egg yolk diluter upon the viability of bovine spermatozoa in that diluter. Using a split-ejaculate technique, 7 ejaculates from 3 bulls were diluted in egg yolk-citrate diluter or skimmilk diluter, cooled, glycerolated and stored at S°C. On the first day after semen dilution, complement-fixed immune serum titered 1:2560, 1:640 and non-immune serum were added to aliquots of diluted semen (1:9 v/v). Aliquots of each diluter without serum served as controls. Each treatment was evaluated immediately after addition of serum and again after 48 hr storage at 5°C. Percent intact acrosomes, percent motility and percent agglutination were measured from unfixed smears at 0, 3, 6 and 9 hr of incubation at 37°C. Both immune and non-immune serum treatments were characterized by head to head agglutination. Within both diluters, there were no significant differences in motility or intact acrosomes due to immune and nonimmune sera. However, all serum treatments were significantly higher (P < .01) in motility and percent intact acrosomes than the non-serum controls. The overall percent intact acrosomes across all hours, days and diluters were 77.9, 81.1, 81.2 and 81.7 for control, non-immune serum, 1:640 serum and 1:2560 serum, respectively. Differences in the percent head to head agglutination were not due to anitbody titer of the serum. / Master of Science

An insulated coaxial pipe for a 50,000 ft drilled geothermal well was designed, in order to remove heat from the earth's crust by the circulation of water through a single well. The design took into consideration means of insulating and supporting the inner pipe, thermal expansion, the large hydrostatic pressures involved, and a feasible means of installing the ten mile pipe. A thermodynamic analysis of the aboveground power generation system, including a once-through steam generator, condenser, circulating pumps, and a feed-water heater system, was made in order to obtain the maximum thermal efficiency. The drilled geothermal power generation equipment is different from that of conventional fossil or nuclear-fired equipment in that the water temperature arriving at the wellhead is continuously varying due to the removal of heat from the earth's crust. Due to the fact that the earth is a poor conductor of heat, continuous operation of the well results in the water at the wellhead falling below an acceptable power generation temperature after a relatively short time period. Therefore, intermittent operation of several wells in staggered fashion using the same aboveground power generation equipment is required. A determination of the well operating characteristics including optimum mass flow and well cut-on and cut-off temperatures was made. From this a justifiable well cost was determined in order to provide geothermal electrical power and process heat at a reasonable cost. / Master of Science