The purpose of this study is to develop a computer program to minimize the weight of steel frames using a penalty function technique. The program is developed and several example problems are analyzed. All structures are designed in accordance with the AISC code. One of the problems is also analyzed by the Fully Stressed Design method, and the penalty function solution has less weight, but takes more computer time. The penalty function solution is checked by hand and found to be a reasonable design. In this investigation, the penalty function method is found to be simple to use, reliable, versatile, and fairly economical for small structures. / Master of Science

Antennas with radiation patterns conforming to a specified shape have many applications. Further, precise shaping of the main beam is often required. Array antennas are especially suited for shaped beam synthesis. The purpose of this thesis is to introduce an iterative technique for the shaped-beam synthesis of unequally spaced, nonuniformly excited linear arrays. The technique requires an initial approximation to the desired radiation pattern. This approximation may be attained by any classical synthesis method. Successive iterations are then applied to the initial pattern and are of two types, element current perturbations and element position perturbations. These two iteration types are applied in a variety of sequences and with different weighting functions. Several examples are considered for some typical radiation patterns. In one particular example of a sector pattern both the maximum main beam ripple and sidelobe level are reduced to approximately -40 dB using a 20-element array. Many comparisons are made and the effectiveness of the technique is evaluated. / Master of Science

In Tanzania, both wildlife and livestock are recognized as resources of economic potential. Where they overlap, land use conflicts have arisen. This study was undertaken to determine aspects and areas of competition between cattle and wild ungulates in Maasailand, east of Tarangire Park. Subsistence pastoralism was the main form of land use and was the object of livestock development efforts. The area also was the wet season dispersal area for Tarangire ungulates and harbored a smaller number of resident wildlife. Comparison of habitats of similar potential but different management history indicated that much of the cattle area was in suboptimal condition. This was attributable partly to the restricted distribution of cattle due to tsetse infestation. Maasai movement patterns were discussed in relation to factors which contributed to habitat deterioration. It was concluded that changes in traditional attitudes towards livestock husbandry were necessary for full realization of land use objectives. Based on dry season counts at water sources it was postulated that cattle, because of greater numbers and a restricted distribution due to their owners’ directive influence, greater disease susceptibility and water constraints, outcompeted wild grazers during this time of resource scarcity. Wet season ungulate distributions were determined by counts along driven transects. It was concluded that wildebeest and zebra, in particular, competed indirectly with cattle for food through their use of the cattle belt where forage was limited in the dry season. Cattle appeared to compete directly with grazing ungulates preferring tall grass habitats (kongoni, oryx), while facilitating use of the herb layer by species preferring short grasses (wildebeest, Grant’s gazelle). / Master of Science

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