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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Mineral content of vegetables grown with organic and mineral fertilizers

Spruill-Pollock, Mary Ann January 1973 (has links)
The mineral content of vegetables grown with organic and mineral fertilizers was investigated in order to determine the nutritional superiority or non-superiority of organically raised foods. Duplicate samples of split peas, pinto beans, kidney beans, blackeye peas and tomatoes of each treatment were wet washed with concentrated nitric and perchloric acid. Concentrations of Cu, Fe, Mn, Zn, Na, K, Ca and Mg were determined using the Perkin-Elmer Atomic Absorption Spectrophotometer. Unequal variation between treatments rendered the F test meaningless for many minerals. Where differences were found, they were in favor of chemically fertilized vegetables as often as in favor of those fertilized organically. It was concluded that methods of fertilization will not differently affect nutrient content of a crop and that organically grown foods are not worth the extra cost to the consumer in terms of nutritional quality. / Master of Science
42

Amateurs and professionals at the 1972 Republican National Convention: seeking correlates of participatory political style

Sieg, David Harry January 1973 (has links)
The twofold purpose of this thesis included the operationalization of a measure of participatory style and a quest for correlates of said style in several selected areas. Using survey data based upon the responses of 827 delegates to the 1972 Republican National Convention, this study developed a stylistic index which was finally structured into four categories of Amateur-Professional orientation. The fourfold index was first cross-tabulated with several selected socio-economic variables and then compared to several variables directly related to party service longevity. The findings with respect to socio-economic variables largely confirmed the results of previous research which has failed to substantiate the existence of relationships between political style and such possible correlates. With respect to service longevity, findings indicated that the Amateur style is more prevalent among relative newcomers to political party activism. The Amateur-Professional index was compared to three indices computed for each delegate and designed to tap preferences for material, solidary, and purposive incentives for maintenance of political activism. It was found that while the majority of all delegates manifested a strong preference for purposive incentives, such a preference was greatest among individuals of the Amateur orientation. Alternatively, such persons indicated the strongest distaste for material incentives. The hypothesis, which was formulated in accordance with the findings of previous research, was confirmed. A comparison of the stylistic index with the intensity of views regarding current issues failed to confirm the hypothesis that while the content or direction of views or attitudes has not provided a basis of style differentiation, issue saliency well might. / Master of Arts
43

Growth and metabolism of Aquaspirillum gracile

Laughon, Barbara Ellene January 1973 (has links)
Several aspects of the growth and metabolism of Aquaspirillum gracile ATCC 19624 were investigated including its relationship to oxygen, ability to grow on defined media, and carbohydrate catabolism. Although previously reported to be microaerophilic, A. gracile was demonstrated to be aerobic by comparing growth responses in varying concentrations of oxygen. A defined medium for the growth of A. gracile ATCC 19624 was developed which contained mineral salts, succinate, glutamine, leucine, phenylalanine, aspartate, and biotin. Biotin appeared to be an essential growth requirement. A. gracile is one of the few spirilla that yield acid reactions from sugars, but its sugar catabolism has not been previously investigated. Only D-glucose, D-galactose, and L-arabinose are attacked. The soluble portion of extracts of glucose-grown cells was found by spectrophotometric methods to contain enzyme activities characteristic of the Entner-Doudoroff and the Embden-Meyerhof-Parnas pathways. Much lower specific activities occurred in succinate-grown cells. No activity for 6-P-gluconate dehydrogenase was detected. Inducible dehydrogenase activities for arabinose and galactose occurred in cells cultured on either sugar. Glucose-grown cells contained not only glucokinase and glucose-6- p dehydrogenase activities but also glucose dehydrogenase activity. Gluconate dehydrogenase activity was not detected but gluconate kinase activity was present, Paper chromatographic analysis of the spent culture supernatants from glucose-grmm cells indicated an accumulation of gluconic acid and this hypothesis was confirmed by a more specific enzymatic assay for gluconate. Preliminary evidence is presented for the accumulation of galactonic and L-arabonic acids in galactose and L-arabinose cultures, respectively. / Master of Science
44

Analysis of the structure of the immature insect segment of a stream riffle community

Maughan, James T. January 1973 (has links)
Samples were collected monthly from July, 1972 through June 1973 using 1m² bottom sampler from a rifle in Sinking Creek in Giles County, Virginia to analyze the structure of the immature insect segment of the community. The following characteristics of the insect segment of the community were examined: life histories of the major species; total numbers; total biomass; species diversity; and energy distribution. Four types of insect life histories were observed which differed in the length of time required for development of individuals. The life histories of closely related species were found to be synchronized so that hatching times were staggered. Seasonal fluctuations in the insect segment of the community were illustrated by changes in the total number of individuals and total biomass. The fluctuation were attributed primarily to the life histories of the component species. Species diversity was calculated with numbers showed little difference than diversity calculated with biomass. Diversity calculated both ways reflected seasonal changes and indicated a rich insect fauna. There was not significant seasonal variation in energy distribution examine but this could possibly be due to calorimetry methods. Investigation of the above parameters enable one to assess the insect segment of the community as dynamic yet containing structures and functions, such as relationships between populations, which can be described. / Master of Science
45

An experimental study of the wall characteristics of a local fluid constriction plasma generator

Smith, Wayne Lee January 1973 (has links)
A local energy conversion efficiency for a confined-discharge plasma generator is defined as the fraction of local power input which is transferred to the gas. The local efficiency is a maximum near the gas inlet and diminishes with axial distance. The thermal development length is the axial extent of that region in the plasma generator duct where the local efficiency is nonzero. This length varies with mass flow rate, current, and duct diameter. Nondimensionalization of the energy equation results in a dimensionless S parameter which determines the thermal development length. The S parameter is the product of mass flow rate, electrical conductivity, enthalpy, and duct diameter divided by the arc current squared. The thermal development length is the product of two times the S parameter and the duct diameter. Below-atmospheric static pressures occur when a calorimeter is installed at the generator plasma exit. These pressures result from deceleration of the plasma in the calorimeter. Empirical expressions for enthalpy and electrical conductivity as functions of current and mass flow rate are substituted into the S parameter, allowing the parameter to be evaluated directly from the mass flow rate and current. The S parameter is effective in evaluating redevelopment thermal lengths downstream of local radial fluid injection into the plasma. Also, the S parameter is found to be effective in evaluating thermal development lengths of independent data from a previous investigator. / Master of Science
46

Seasonal population levels, breeding and hunting of waterfowl on the New River, Virginia

Grubb, Michael M. January 1973 (has links)
A 15 mile portion of the New River was censused by canoe 33 times over a 1 year period. Species and number of waterfowl were recorded for each operation. A total of 16 species were observed, including 8 species of diving ducks, 7 species of dabbling ducks and 1 species of goose. Species diversity was highest in February and March and lowest in the summer months. Mallards were sighted more frequently than any other species, followed by the wood duck and the black duck. The most abundant diving ducks were scaup, bufflehead and common goldeneye. Peak numbers of waterfowl were sighted during December; the lowest numbers during the summer. Diving ducks reached their peak in terms of number of species and number of individuals during the winter period; buffleheads were the third most abundant species. Number of ducks and species diversity dropped during the spring period. Mallards and wood ducks were the only species present during the summer. Brood sightings consisted entirely of wood ducks with an observed production index of 2.9 young per river mile. The author believes 16.6 to be a more accurate estimate of this production index. Hunters responding to questionnaires bagged an average of 9.10 ducks per man during the season, considerably higher than the state average. Mallards comprised 38 percent of the total kill. The author concluded that western Virginia waterways are important to waterfowl as wintering habitat. Furthermore, wood duck breeding in Virginia makes a substantial contribution to the flyway population. / Master of Science
47

The development and analysis of a multi-attribute quality control cost model

McCaslin, James Albert, 1948- January 1973 (has links)
A multi-attribute quality control cost model is presented in this thesis. The mathematical model expresses the expected total cost of the quality system per lot as a function of the decision variables, nᵢ and cᵢ, i = 1, 2, . . . , m, where nᵢ is the sample size for the ith attribute. cᵢ is the acceptance number for the ith attribute. m is the number of attributes. The expected total cost is denoted by C<sub>T</sub> and can be expressed as C<sub>T</sub> = E (cost of sampling inspection). E (cost of accepting the lot). E (cost of rejecting and scrapping the lot). E (cost of rejecting and screening the lot). An optimal sampling plan can be obtained by determining the nᵢ and cᵢ, i = 1, 2, …, m, that minimizes C<sub>T</sub>. The nᵢ and cᵢ are found by means of a search technique that has proved useful in attribute quality control systems. In addition to the model development and optimization, a sensitivity analysis is performed on the use of the gallllla distribution as an estimate of the true process distribution for single and triple attribute systems. Also, a model sensitivity analysis is performed on errors in the estimation of the Cₐᵢ, the cost of accepting a defective unit. / Master of Science
48

An RF system for millimeter wave propagation experiments

Marshall, Robert Edward January 1973 (has links)
This thesis describes a method for designing an RF system for measuring rain-induced attenuation and depolarization at millimeter wavelengths. Path length, dynamic range, and polarization isolation are discussed with respect to their importance to RF system performance. Design considerations for the VPI&SU 17.65GHz,CW, RF system are presented. The path length is 1.43km, the receiver dynamic range is 71dB, and the orthogonal polarization isolation is greater than 60dB for the receiver and transmitter. The paper concludes with sample data taken with the VPI&SU system during several rain storms in 1972. / Master of Science
49

Petrology of the Ashe Formation, Shortt's Knob area, Floyd County, Virginia

Davison, William Donald January 1973 (has links)
A small area within the Ashe Formation has been mapped at the scale 1:6000 and studied petrographically and chemically. The rocks have been metamorphosed into the lowermost amphibolite facies and folded. The gross structure is homoclinal, generally N 80° E, >50°SE. Amphibolites (39%), chlorite schists (8%), and quartzofeldspathic schists and gneisses (53%) are the major lithologies. Amphibolite assemblages are hornblende + clinozoisite and/or epidote + plagioclase + sphene ± quartz ± garnet. Amphibolites may be divided into four types on the basis of texture, sphene-content, and epidote-composition. Chlorite schists are ultrabasic rocks containing the assemblage Mg-chlorite + actinolite and/or cummingtonite + dolomite + ilmenite ± olivine. Metasediments generally contain biotite. The most distinctive metasediment is black sulfidic schist containing 15-20% amorphous carbon. The assemblage dolomite + quartz + muscovite + plagioclase + biotite occurs in the only carbonate outcrop. Anorthite content of plagioclase ranges between 18 and 40 mol % but depends on lithology. Amphibolite hornblendes have at least one A1<sup>IV</sup> per formula unit. Epidote group minerals have compositions generally <Ps₅ or >Ps₁₀ and the concept of a single miscibility gap is not supported. Upper P-T limits will be defined by the reaction dolomite + quartz + muscovite -> plagioclase + biotite + calcite + vapor and probably limit the temperature to <550°C. The reaction zoisite + CO₂ -> anorthite + calcite + H₂O limits the CO₂ content of the metamorphic fluid over most of the area to low values, probably <0.1 mol fraction. The amphibolites probably represent basaltic flows, some amygdaloidal. Chlorite schists are interpreted to have been picritic sills. / M.S.
50

A study in the sociology of criminal law: legal and non-legal factors affecting the length of prison sentence

Leggette, Thomas Alan January 1973 (has links)
This study presents an initial attempt to develop a model of a decision-making process which lawyers could employ in seeking the most lenient sentence possible for their clients. Regression equations depicting the direct effect of a number of legal and nonlegal (social) factors on the length of prison sentence were constructed on the basis of data collected from the Division of Corrections and the Bureau. of Research and Reporting of the State of Virginia. Analysis of the data revealed that the type of crime one was convicted of, acted as a specifying variable; thus, the regression equations were developed in crime specific terms. Comparing the regression equations for the seven different types of crime sampled, it was found that no two of them were the same. Moreover, the ability of the regression equations to explain the variance in the length of prison sentence was found to fluctuate drastically. Nevertheless, it was felt that the advocated model could be of some utility to lawyers. / Master of Science

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