A bioreactor using a tapered fluidized bed was built, characterized and tested. The test consisted of biologically removing phenol from an artificial wastewater in the absence of activated carbon. The data collected during this fermentation were logged on a PDP 11/40 minicomputer. Variables such as oxygen and carbon dioxide percent by volume evolved, the dissolved oxygen concentration, temperature, pH and volumetric air flow rate were monitored. The rate of phenol disappearance was also determined. This system was then used to study the biological regeneration of activated carbon. The bioregeneration study showed that up to 67% of the activated carbon adsorptive capacity could be recovered. It also proved that the rate of phenol biodegradation was higher in the presence of activated carbon than in its absence. / Master of Science

A microcomputer based system is described that controls the operation of a dual chamber, diaphragm-type pneumatic blood pump in both open-loop and closed-loop modes. The open-loop mode of operation allows selection of pumping rate and systolic time parameters. The closed-loop mode of operation allows selection of pumping rate and pump output parameters, with the systolic time parameter adjusted automatically to maintain a selected pump output in spite of load changes. Digital display of all pump operating parameters is provided. A description of the device and the control techniques employed, the interface circuitry and software algorithm developed, a calibration and tuning procedure, and closed-loop response curves are included. / Master of Science

The possible relationship between body fatness and taste sensitivity was studied. Twenty-five preschool children aged 42 to 61 months served as subjects. Heights, weights, arm circumferences, and triceps skinfolds were measured. Taste sensitivity to quinine sulfate and sucrose was assessed with paired-comparison tests. Eating habits and food preferences were examined via questionnaires and two-day food records. Analysis of data was by simple correlations, means, and analysis of variance. There appeared to be a relationship between taste sensitivity and body fatness. Weight-for-height percentiles were positively correlated with sensitivity to quinine sulfate (p < .05 ). There was a negative correlation between quinine sulfate and the Ponderal Index (p < . 05 ). Sensitivity to sucrose was negatively correlated with the Ponderal Index (p < .01). Subjects were distributed into two groups, those sensitive to quinine sulfate (taste threshold ceiling 2.03 X 10⁻⁵ M) and those insensitive to quinine sulfate (taste threshold ceiling non-existant ). There were significant differences between the two groups in terms of body fatness and percent of foods liked. More sensitive tasters liked fewer foods and had less body fat. Diet during infancy was not correlated with either taste sensitivity or body fatness. There was no relationship between the degree of body fatness and the percent of foods liked. These results support the idea of a relationship between taste sensitivity and body fatness. Subjects more sensitive to taste appeared to have less body fat and to be more discriminating in their food choices than those subjects more insensitive to taste. / Master of Science

The purposes of this study were to determine the consistency of subjective ratings among four professional judges and between those judges and wearers of four fabric series nightgowns. The fabrics included: (1) 100% polyester brushed knit; (2) 100% nylon knit; (3) 80/20% acetate-polyester brushed knit and (4} 80/20% acetate-nylon brushed knit. Data were collected from 55 women who each wore and cared for two garments of differing fiber contents and evaluated them on eight performance characteristics. The consumers rated the fabrics on the following characteristics: soil removal, colorfastness, shape retention, appearance, hand, durability and static. An overall rating was obtained by combining data for the above seven factors. The gowns were also evaluated by four professional raters on the above factors. An overall rating was also determined for these judges. Weighted kappa and z scores were used to measure agreement between judge pairs and between each judge and the wearers for the eight factors. The researcher accepted the hypothesis that rater agreement exceed that expected by chance for all judge pairs on all factors except shape retention. However, for one judge-pair the hypothesis of agreement was not accepted for shape retention. The hypothesis of rater agreement was rejected for each of the judges and the wearers on all factors except overall rating. The hypothesis of agreement was accepted for Judge III and the wearers for the overall rating. The consumers were generally more lenient than the professionals in their evaluations of all fabric characteristics except static electricity. The judges were less critical than the wearers in assessing that factor. / Master of Science

An airport environmental impact information system was created for the Commonwealth of Virginia. This computer-assisted system provides readily accessible, timely, pertinent, concise, and easily comprehensible information for those who make airport development decisions significantly affecting the quality of the human environment in Virginia. The Airport Environmental Information System {A*E*I*S) contains relevant airport environmental impact assessment information for airport E.I.S considerations regarding noise, water quality, air quality, wetlands, cultural impacts, socioeconomic impacts, threatened and endangered species, ecological impacts, and other areas. Three computer software systems -- the Conversational Monitoring System (CMS), NOISEMAP, and SURFACE II were utilized to store, process, and report the information contained in the A*E*I*S system. Users may request information by individual chapter (e.g. noise), and in aggregate book form. A*E*I*S contains provisions for the continued use and update of the system. / Master of Science

Master of Science

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