The purpose of this study is to construct and test decision models that will enable utility companies to identify cost effective strategies for dealing with enrichment service contracts. Specifically, three decision models are developed to analyze the 18 month decision points of the Long-Term Fixed-Commitment Contract for ten contracting years. The first model indicates ERDA's current method for acquiring enrichment services assuming maintenance of the split-tails mode of enrichment plant operation. The second model, referred to as the static decision model, utilizes the variable tails concept at a single 18 month decision point. The third model uses the basic equations of the second model to develop a dynamic inventory system that is designed to manipulate the fuel inventories and tails enrichments at the 18 month decision points over ten years. The application of the three decision models is done by using data from a typical ten year fuel contract for a 1000 Mwe reactor. A computer code is constructed to solve the decision models for the optimum decision policy in contracting for fuel enrichment services. The results indicate that the application of the dynamic inventory model produces a significant amount of savings in utility costs and uranium feed. The dynamic inventory process is more economical than the split-tails method because the utility company is allowed to manipulate the tails enrichment and the fuel inventories in the dynamic model. The dynamic inventory model appears to be an appropriate vehicle for improving the fixed-commitment contract and more study is merited. / Master of Science

Twelve study areas on abandoned contour mines in southwest Virginia were surveyed to investigate relationships between breeding bird population parameters and structural aspects of the disturbed area vegetation. The territorial mapping method was employed to census bird populations. The number of breeding species, number of breeding pairs, bird species diversity, and number of observed species (breeding or visiting) were determined for each disturbed area, the marginal undisturbed forest, and each total study area (marginal and disturbed areas combined). Vegetation was sampled within units of similar vegetation on each disturbed area; 17 vegetation parameters were recorded for each unit. These were weighted by the size of each vegetation unit and averaged for each disturbed area. Linear and multiple regressions of each population variable were performed on 51 vegetation and site-factor variables. Bird population parameters of the disturbed and total study areas showed positive relationships with several aspects of disturbed area revegetation. However, among forested orphan mines, decreases in bird populations were observed when canopy closure apparently affected a reduction in understory vegetation. Bird populations of the marginal areas decreased with the reforestation of the disturbed areas, apparently reflecting a decrease in the edge effect. Several sets of equations for population parameters of the disturbed and total study areas are presented for use in habitat evaluation. Relationships revealed for bird population parameters of the disturbed and total study areas suggest that reclamation efforts should strive to achieve a high degree of vegetative cover, increase the amount of ground layer vegetation, and provide for the future development of higher vegetational strata. These vegetational features should be introduced in a manner which will augment existing vegetational heterogeneity. / Master of Science

Eighty male and 80 female college students participated in an experiment to study reactions to stress as a function of room size and interaction distance. Two subjects (one male and one female) sat on stools either relatively close together (1.22m) or far apart (2.74m), in a waiting room relatively large 5.94m X 3.96m or small 2.44m X 3.96m. They completed a Personality and Environment questionnaire, received task instructions and consent forms, and then waited 10-min in the large or small room for the experimental task that involved receiving either shocks or lights as performance feedback. During the waiting period three observers watched through a one-way mirror and recorded specific behaviors of each of the subjects. After the 10-min wait, the Personality and Environment questionnaire was readministered as well as a sociometric questionnaire. The design was a factorial of 2(Stress Conditions) X 2(Room Sizes) X 2(Seating Distances) X 2(Sex of Subject) X 2(Assessment Times). Ten pairs of subjects were randomly assigned to one of the eight experimental conditions. The analysis of the three semantic differential items relating to current stress state (Rattled and Jittery vs Cool and Collected, Calm vs Worried, Tense vs Relaxed) indicated a significant Stress Condition X Seating Distance X Assessment Time interaction. That is, when anticipating the Shock Condition subjects showed a greater increase in stress feelings when they interacted Close than Far. No effects of sex nor room size on these stress ratings were observed. These findings supported the notion that interaction distance, and not room size, is the more prominent spatial variable associated with crowding effects. / Master of Science

The exploration of two buildings for the use by plants and animals incorporating similar structuring and checking devices. A vertical field for the cultivation of crops and a fiberglass "Barn" for livestock confinement are discussed in terms of each other, in terms of farms and farming historically, and in terms of farms and their relationship to the development of the church cloister. Each of the discussion categories function as checking and direction devices to support the projects development. A selection of drawings, investigation papers and photographs visualizing the two projects are also included. / Master of Architecture

The objectives of this study were: (1) to determine the usage patterns of gasoline, diesel fuel, and other fossil fuels in different types of agriculture; (2) to determine the demand relationships for gasoline and diesel fuel in agricultural use and to identify and assess the major factors that affect these relationships; and (3) to determine differences in the demand relations for gasoline and diesel fuel in agricultural use. The usage patterns of gasoline, diesel fuel, and other fossil fuels in agricultural production in Virginia, the South, and the U.S. were developed from cross-sectional data provided jointly by the Economic Research Service and the Federal Energy Administration. From the static theoretical development and the dynamic and technological adjustment concepts of derived input demand, the theoretical demand relationships for gasoline and diesel fuel were formulated. Asymptotically efficient, asymptotically normal, asymptotically unbiased, and consistent parameter estimates were obtained by employing a generalized least squares (GLS) procedure on the Parks model in combining cross-sectional and time-series data. All data were from the period 1971 through 1976. The agricultural sector in Virginia appears to adjust to changes in economic factors and other variables influencing the demand for gasoline and diesel fuel. While farmers.appear to be somewhat passive to increases in the real prices of gasoline and diesel fuel in the current period, they are quite responsive to such increases when given time to adjust their usage patterns. / Master of Science

The purpose of the research described herein was to establish the algorithms necessary to perform life-cycle analyses of the solar heat gain through building windows as a function of the ability of the glazing to allow the penetration and utilization within the interior built environment of available sensible radiation from the natural environment. The life-cycle cost model allows evaluations which will influence the glazing selection in response to seasonal changes in insolation and the net energy effect of orientation. The research consisted of two phases. The first included a search of the literature on energy related studies and resulted in a complication of algorithms necessary to determine heat gain through windows, equations required to determine energy cost, and equations necessary to perform life-cycle costing. The second phase of the research was a synthesis process to resolve interfacing problems between unlike calculation systems and units of measure which were encountered. This was accomplished through basic inductive processes familiar to life-cycle costing/value engineering techniques. This resulted in a schematic model to correlate the heat gain calculation with the energy cost calculation to determine the life-cycle cost for the window assembly. The research built upon existing processes to develop a more comprehensive technique for the analysis of window systems to aid in meeting economic specifications during the winter heating months. / Master of Architecture

Trapping was conducted on 12 abandoned contour surface mines in southwestern Virginia during the summer of 1976 to determine relationships between small mammal diversity and abundance and select vegetation and site factors. Eleven species of mammals were captured during four, six-night trapping periods. Peromyscus leucopus noveboracensis and P. maniculatus nubiterrae were the most abundant and widespread mammals encountered on the mines. Other mammalian species were captured infrequently. General habitat types were noted where species other than Peromyscus were most frequently captured. Reforested mine habitats were utilized most heavily by small mammals. Herbaceous areas received little use during the summer, but may be more extensively utilized during the winter when food supplies in the forest are low. Peromyscus abundance, as measured by trapping success, was positively associated with the development of forested habitats possessing a diverse vegetative profile on the mines. Areas where Peromyscus was captured had significantly greater vegetation development and significantly higher soil pH and nutrient levels than areas where these mice were not captured. Peromyscus populations on the mines may be an important source of food for larger mammals and birds. These mice may also be useful as minimum indicators of wildlife habitat quality and hence serve as a criterion in the evaluation of wildlife-oriented surface mine reclamation work. / Master of Science

New and standard pesticides applied to peanuts (Arachis hypogaea L.) in Virginia were evaluated for control of the potato leafhopper. Leafhopper populations on test plots were monitored throughout 1975 and 1976 using a 12-inch sweep net. Grade, yield, and value data were collected from all experiments. Significant reductions of leafhopper populations were achieved with a broad range of chemicals. In many instances, the pesticidal activity of the test materials was not significantly affected by reducing their rate of application. Despite heavy leafhopper populations and injury levels during the two seasons, regression analyses demonstrated a lack of association between peanut values (dollars per acre) and potato leafhopper infestations or injury. Controlling the leafhopper did not significantly affect peanut values. / Master of Science

During the refueling of a pressurized water nuclear reactor, a group of operations termed the fuel shuffle is performed. Certain fuel and control components are removed from or inserted into the reactor core. Specific assemblies are transferred to new, predetermined locations within the core. An analysis of the problem of scheduling these fuel-shuffling operations is presented. The objective is to minimize the shuffle completion time in order to ensure that the fuel shuffle does not delay reactor startup. A heuristic scheduling procedure currently employed in industry involves the decomposition of the problem into groups of related operations. A computer program is used for the identification of the groups in a given shuffle and for the application of scheduling rules for the individual groups. To provide improvements over existing techniques, attention is focused on the development of heuristic methods for scheduling these groups of operations. These groups are also combined, and an integer programming model for this integration process is presented. Three sample shuffles are considered, and an analysis of effective scheduling techniques is conducted for a representative set of fuel-handling equipment. Efforts are made to eliminate the unnecessary equipment moves and idle time present in existing schedules. Improved, near-optimal schedules are developed, and the potential benefits gained from future efforts to reduce the shuffling time are shown to be insignificant. / Master of Science

A study of two types of high efficiency gas chromatographic columns was conducted. The first type (micropacked) can be defined as columns having an internal diameter less than 1 mm and a particle/column diameter ratio between 0.1 and O.3 and a packing density comparable to conventional packed columns. The second type, slurry packed gas chromatographic columns can be defined as columns which are prepared by using high liquid pressure to rapidly pass a stable suspension of small diameter packing material into the column. This procedure packs small particles more homogeneously and more efficiently. The standard procedure for preparing micropacked columns was evaluated and modified to increase the reproducibility of the technique. Different methods of preparing the packing materials were investigated. Parameters such as particle size, column length, and sample size were studied. Slurry packing techniques which are commonly used for the preparation of high efficiency LC columns were adapted for preparation of GC columns. A study was made to determine optimum particle size for maximum efficiency in gas chromatographic columns. Columns prepared by conventional diy packing technique were compared to columns packed using the slurry packing technique to determine reproducibility of packing technique and column efficiency. Slurry packed columns were used in both LC and GC modes. A study was made to determine the effect of column diameter, column length, column temperature, and sample capacity on efficiency. Applications for slurry packed gas-solid adsorption columns were studied. This method of slurry packing GC columns increased the efficiency by as much as five-fold over values previously reported. Results of the study indicated that optimum particle diameter was 53 μm - 63 μm with an optimum column diameter of 9.9 mm. The results of column temperature studies indicate the minimum column temperature compatible with the sample being analyzed should be used for maximum efficiency. / Ph. D.