Identities, quantities, and costs associated with producing a set of selected enrichments and blending them to provide fuel for existing reactors are investicated using on optimization model constructed with appropriate constraints. Selected enrichments are required for either nuclear reactor fuel standardization of potintial uranium enrichment alternatives such as the gas centrifuge. Using a mixed-integer linear program, the model minimizes present worth costs for a 39-product-enrichment reference case. For four ingredients, the marginal blending cost is only 0.18 percent of the total direct production cost. Natural uranium is not an optimal blending ingredient. Optimal values reappear in most sets of ingredient enrichments. / Master of Science

The purpose of this study was to investigate whether relationships existed between attitude toward involvement in dormitory vandalism and selected demographic and environmental variables including sex, military status, dormitory size, involvement in university life, perceived social isolation, perceived general maintenance of the dormitory, aesthetic quality of the dormitory interior, and finally, perceived personal space in the dormitory. A questionnaire was developed including three scales previously used and proven valid and reliable as well as items added by the researcher to measure variables for which no scales were available. The sample of 539 was selected from a dormitory population of 8506 students in 25 dormitories at Virginia Polytechnic Institute and State University. A number of factors were given attention in the sampling procedure: differences in males and females, civilians and Cadets, and residents in small and large dormitories. Eight dormitories were chosen to meet the aforementioned criteria. Questionnaires were distributed by the researcher throughout the dormitories. Because a representative sample was desired from each of the residence halls the instrument was randomly distributed within each floor. As a result of this sampling procedure, 95.5% or 518 of the questionnaires were returned. Point-biserial correlation coefficients, Pearson product-moment correlation coefficients, t-tests, z-tests, and multi-regression were the statistical treatments employed. The .05 probability level was accepted as significant and the .01 level was accepted as highly significant. The results of this study suggest highly significant inverse relationships between attitude toward involvement in dormitory vandalism and degree of involvement in university life, perceived general maintenance of the dormitory, perceived aesthetic quality of the dormitory interior, and perceived personal space in the dormitory. There was a positive but insignificant relationship between social isolation and attitude toward involvement in dormitory vandalism. A highly significant difference was found in examining attitude toward involvement in vandalism between males and females. Dormitory size and attitude toward involvement in vandalism were found to be uncorrelated and there was no relationship between military status and attitude toward involvement in dormitory vandalism. / Master of Science

The relative importance of contact with family and friends for an.elderly person's life satisfaction was investigated. A random sample of 167 noninstitutionalized elderly residents (65 and over) of Philadelphia completed an extensive in-depth interview packet. Each subject was then rated by a trained interviewer on their life satisfaction. The results indicated that increased activity with friends was directly related to the elderly person's life satisfaction, while increased family contact had a negligible effect. With the use of regression analysis, perceived health status was found to be the most salient predictor for life satisfaction, followed by friend contact intensity and objective health. In addition, the use of various specification variables, previously posited to relate with life satisfaction, did not change the initial findings of the sample. The implications of these findings for the Activity Theory of Aging were discussed. / Master of Science

This research attempted to study the possible relationship between achievement motivation as displayed by the child and the parental situation in the home in which the child finds himself a parts. Fifty-four children in grades nine to 12 were administered the Adjective Check List (ACL) to determine the amount of achievement motivation felt by the child. The chldren were selected through single-parent organizations and schools. Of the children in the study, 16 lived with both parents, 21 lived with the mother, and 17 lived with the father. The subjects were compared according to the number of parents in the home; the sex of the parent in the single-parent home; the number of years spent in the single-parent home; the reason for that particular parent receiving custody; and the relationship of the sex of the parent in the single-parent home to the sex of the child. No significant relationship was found between any of these factors and the achievement motivation displayed by the subject. / Master of Science

Modified contemporary sire evaluation procedures, using first lactation records only, were used to compute Predicted Differences for all Holstein bulls having 10 or more daughters calving in any calendar year between January 1964 and June 1973. Significant heterogeneity of within sire daughter milk yield variance was found although only 18% of the differences in sire variances could be accounted for by factors examined. Repeatability of sire daughter variances suggested that 23 to 32% of the differences in sire variances could be attributed to sire differences. Heritability estimates of sire daughter variance were low to moderate and ranged from -.14 to .29. The standard deviations of mean milk yield, adjusted for number of contemporaries, of paternal half-sibs in the same herd-year-season ranged from 999 to 522 kg for groups of 2 to 16 daughters. Repeatabilities of contemporary comparison sire summaries were examined to determine their impact on the accuracy of sire selection. A set of 455 bulls have final Repeatabilities exceeding 90% was used to examine the effects of initial Predicted Difference and Repeatability on final Predicted Difference. The effect of initial Predicted Difference on final proof was highly significant (P .01) and was the most important predictor of final proof. However, the linear effect of Repeatability on final proof was also significant (P< .05), indicating an increase of 1.53 kg in final proof per 1% increase in initial Repeatability. Relationships between semen cost and Repeatability indicated that low Repeatability bulls frequently represented most economical semen purchases. / Master of Science

The effect of surface roughness and sliding speed on the wear mode of low density polyethylene was studied with multipass experiments at the high sliding speeds by the use of a pin-on-disk wear machine. Surface roughness was found to be the major parameter in determining the wear mode of the polymer at two different speeds of sliding. The wear mode was shown to be abrasive on the rough surfaces and adhesive on the smooth surfaces. The high wear rates occurring on the rough surfaces was related to the production of the large amounts of loose debris. The effect of speed was found to be an increase in the temperature on the smooth surfaces. This temperature rise was used to explain the increasing wear rate and the decreasing coefficient of friction. No effect of speed was detected for sliding on the rough surfaces, where the frictional energy was dissipated by the formation of loose debris particles. / Master of Science

What it is What it does How to make a transition from the scale of downtown Blacksburg to the scale of V.P.I. academic buildings. How to connect the two parts - music and art schools. How to use walls as more than just "structural parts” How to create space rather than “divide space” How to receive light rather than "control light”"The right thing badly done is always greater than the wrong thing well done. 11 Louis I Khan / Master of Architecture

Part I: Calculation of Temperature - Oxygen Fugacity Tables for H₂ - CO₂ Gas Mixtures at One Atmosphere Total Pressure. The initial CO₂ volumes yielding selected oxygen fugacities at specified temperatures have been computed for H₂ - CO₂ gas mixtures at one atmosphere total pressure. The calculations are based on the thermochemical data of the JANAF (1971) Tables for the species CO₂-H₂-H₂O-CO-O₂-CH₄ and are carried out using the Newton-Raphson method of successive approximation. The new tables replace older ones (Dienes, Nafziger, Ulmer and Woermann, 1974) in which the effects of CH₄ on the system were treated only in an approximate manner. Part II: An Investigation of the Zoisite - Clinozoisite Transition Available data on natural coexisting zoisite - clinozoisite (Ca₂Al_3-xFe_x[Si₂O₇][SiO₄]O(OH) with x ≤ 0.33) assemblages imply that the two phases are related by a solid solution transition loop, with zoisite being the low-iron, high-temperature, high-pressure phase. Reversibility experiments at 6500 bars constrain the iron-free equilibrium clinozoisite zoisite to lie below 407°C. Electron microprobe and single crystal x-ray diffraction studies of epitactically related zoisite-clinozoisite crystals grown from seeded mixtures of anorthite, calcite, hematite and silica glass at 6500 bars and 650°C are shown to bracket the transition loop between Pistacite 3.2 (Ca₂Al_2.90Fe_0.10Si₃O₁₂(OH)) and Pistacite 12.6 (Ca₂Al_2.62Fe_0.38Si₃O₁₂(OH)). Experimental techniques used in this investigation, which focus on detalied analysis of single crystals, offer promise as a means for determining equilibrium phase relations of epidotes and other frequently zoned mineral groups. / Master of Science

This study considers the problem of estimating merchantable volume to some specified top diameter or height limit. The models were separated into two categories. Volume ratio models give the ratios of merchantable to total volume. Taper equations when integrated provide volume estimates of any segment of the bole. Data from plantations and natural stands of loblolly pine were used to compare the models for ability to predict merchantable volumes. Additional evaluations were made among the taper equations to determine the one that "best" describes stem taper. Results showed that different models should be used for different objectives. / Master of Science

Porous pavements are examined for their ability to contribute to environmentally-sound stormwater management practice. The hydrological impacts of conventional urban land development are examined. New legislative directions in stormwater management are examined and a brief sun1Inary of currently used sound stormwater management practices is presented. Porous pavements are classified and available information on design standards are presented. Realizing the lack of information on their hydrological characteristics, paver systems were tested at the Environmental Systems Laboratory of the College of Architecture and Urban Studies. Tentative coefficients of runoff were developed for these pavement systems. The coefficients for the two pavements tested were compared and a number of hydrological perf ormance characteristics were noted. A discussion of future directions of V.P.I.&S.U. research in this area is also included. / Master of Architecture