An LSI-11 micro-processor and a Spectra-Physics model 3500B gradient elution liquid chromatography were interfaced for the purpose of automating the chromatograph, incorporating it into the laboratory data network system and collecting data for Michael Starlings' project. The automation involved the construction of hardware for the control of the chromatograph and for data acquisition and display and the writing of software to operate the interface. The LSI-11 collects data by clock interrupts while displaying the current data buffer on the oscilloscope. It stores all data files on a floppy disk storage device, accessed through the main host computer. An analysis of the data is performed by a peak processing routine, calculating peak area and retention time. The network is the DEC Rr-11/REMOTE system. It operates on a PDP-11-03 with a floppy disk system for mass storage. The laboratory system has three satellites operating under it. They can utilize all of the facilities of the main computer while maintaining a minimal operational configuration. The project also had the purpose of being assimilated into Michael Starlings' data correlation system. The LSI-11 will collect data and send it to the NOVA computer system where it will be stored. The system was tested with several mixtures and the results were found to be accurate and easily obtainable, / Master of Science

The objective of this study was to investigate what effect the concentration of microorganisms would have on substrate removal, microbial substrate storage, and oxygen utilization at a constant food-to-microorganism ratio. Batch experiments were conducted, under aerated and completely mixed conditions, using a domestic wastewater, a paper mill wastewater, and a food processing wastewater. A series of three batch experiments were run for each of these wastes. The food-to-microorganism ratio for each series was kept constant while the mixed liquor suspended solids concentration was varied for each of the experiments within the series. The following analyses were conducted on samples that were withdrawn at specified time intervals: filtered and settled COD, oxygen uptake, mixed liquor volatile suspended solids (MLVSS), pH, protein concentration and carbohydrate concentration. No significant uptake and subsequent release of organic substrate was observed for any of the wastewaters studied. For the same F/M ratio, the rate of removal of organic substrate and the degree to which it was removed in the activated sludge system was found to be a direct function of the MLVSS concentration. The change in the cellular carbohydrate to cellular protein ratio in the activated sludge during substrate metabolism was a function of the MLVSS concentration. As the MLVSS concentration increased, the carbohydrate to protein ratio, which is an indicator of substrate storage, also increased, even though the F/M ratio was held constant. / Master of Science

Some alarming trends in commercial forest acreage and pine growing stocks have been developing over the course of four Forest Surveys in eastern Virginia; Forest Survey Unit 1. The importance of the timber resource to the region's economy has brought about a need for research into the long-run timber prospects. Long-run timber output potentials in eastern Virginia are primarily dependent upon two factors: Prospective changes in commercial forest acreage and the intensity with which the forest acreage is managed. An analysis of past trends and a study of the opinions of knowledgeable persons in eastern Virginia lead to the estimate that commercial forest acreage will dec~ease approximately 9 percent by 2020. As for timber management intensity, the study commences with data on cubic-foot yields for the five major forest types, as related to stand age and stocking. From these data, potential yield, per acre and total, is estimated for each class of forest owner. The study finds that in eastern Virginia, nonindustrial private owners are managing their timber much more intensively than generally supposed. In fact, their timber output per acre is on a par with that of public and forest industry owners. If pine timber output is to be increased in the long run, apparently conversion of hardwood stands to pine, not more intensive management of existing stands, will be the means. / Master of Science

Because of a prevalent concern that feeder heifer prices are often bid below their true value, particularly in Virginia, a study was made of factors affecting price differentials between steers and heifers, and of variations in these differentials across regions and over time. The fall market sex price differential for feeder calves in Virginia (1964 through 1976) was compared to the differential in five other regions: the Corn Belt, the Southeast, the Plains, the Mountain States, and California. A cross-section time-series model was designed in which sex price differentials across years and regions were regressed against hay prices, short-term feeder cattle price expectations, the corn price, the fed cattle sex price differential, and the heifer-steer proportion on feed. In addition to these economic variables, five regional zero-one intercept shifters were included; all explanatory variables accounted for 84.8 percent of the variation in the feeder sex price differential, while the economic variables alone accounted for 71.6 percent of the variation across regions and over time. Based upon this research, the steer-heifer feeder price differential in Virginia may be expected in most years to exceed the sex price spread in other markets; however, the estimated effect of the economic variables was not sufficient to entirely account for the higher Virginia sex price differential. One possible reason is that some relevant economic variable(s) were excluded; or pricing distortions may exist due to a lack of price information or due to imperfections in the grading system. / Master of Science

..."there was less similarity between the response pairs comprising the PA list than there was between the response alternatives presented during the practice trial. Consequently, the anticipation of control developed from experience with the practice trial could have been reduced when the subjects chose the response words for the PA trials. It is this reduction in perceived control which is assumed to be responsible for the failure to obtain the predicted differences in PA performance between Choice and Force subjects. One method of testing the above explanation would be to introduce the experimenter's request to choose only preselected response words during the practice trial, thereby reducing the possibility of subjects experiencing a reduction in perceived control later in the experiment." / Master of Science

The Commission on State Governmental Management has nearly completed a five-year study of the executive branch of Virginia government and has developed a number of recommendations which have been implemented to varying degrees at this time. The reorganization efforts of this Commission have resulted in the initiation of a more integrated management and decision-making system--a system that promises to improve procedures for allocating resources and encourage increased accountability for performance in state government. The degree of success and also the particular failures that the Commission has experienced are explained through examination of previous reorganization efforts and the problems in state governmental management which prompted its formation--providing an outline of the historical and contemporary constraints and opportunities influencing the reform process. The Commission's approach and procedures, its specific proposals and the present status of these proposals are discussed. Special emphasis is placed on evaluating the management, planning, and budgeting systems developed as a result of Commission recommendations. This analysis is intended to provide a background for suggesting the difficulties that Commission reforms face in implementation and for preliminarily assessing the impact of the Commission's work on Virginia government. / Master of Urban Affairs

The problem considered here is one of finding the minimal Hamiltonian chain of a graph. A single chain must traverse all 𝑛 vertices of a graph with the minimal distance. The proposed procedure reduces a large problem into several smaller problems and uses a branch and bound algorithm to find the minimal Hamiltonian chain of each partitioned subproblem. The graph is decomposed and partitioned into subproblems with the use of necessary conditions for the existence of a Hamiltonian chain. This process is only applicable to graphs with relatively few incident edges per vertex. The branch and bound algorithm makes use of concepts developed by Nicos Christofides. Hamiltonian chains are derived by using minimal spanning trees. / Master of Science

Ninety 12 month old female rats were used to determine a protein requirement for tissue maintenance. Diets contained 0.84 to 4.69 percent protein and were fed for 28 days. Liver composition, carcass composition and serum protein levels were determined, and a protein requirement level was also predicted. Rats fed 0.84 and 1.86 percent protein had significantly lower serum protein values than a baseline group of rats sacrificed at the beginning of the study. Rats fed the two highest levels of dietary protein had serum protein values which were significantly higher than the baseline group and that of rats fed 2.81 percent protein was not significantly different from that of the baseline group. Rats fed 0.84, 1.86 and 2.81 percent protein had excessive liver fat, indicative of protein deficiency. No group was found to have liver nitrogen values comparable to that of the baseline group. All rats except those fed 0.84 percent protein had significantly more carcass fat than the baseline group. Total carcass nitrogen of rats fed 2.81, 3.77 and 4.69 percent protein were not significantly different from the baseline group indicating a general state of nitrogen equilibrium in these animals. Using linear regression, a protein requirement of 4.07 percent of the diet was predicted. Comparison of this value with other literature values was difficult due to differences in experimental design. It was suggested that in further research of this kind a longer study should be conducted and a concurrent baseline group should be used. / Master of Science

This article is concerned with the reapplication of procedures used by Mr. Wade D. Burns in his West End Restoration Project in other inner-city reviving and borderline neighborhoods. Besides a basic historical account, it includes an article written by Sheila Ochner about West End for publication, a descriptive outline requested by the mayor's office and a paper dealing with gentrification, a controversial evolution brought on by the revitalization process. / Master of Architecture

A project located at the VPI & SU Swine Center was used to investigate the utilization of a waste treatment lagoon as an energy source to heat swine housing. The investigation test procedure consisted of two main components: (1) the design and testing of a heating system using a solar assisted heat pump and (2) the development of a computer model to simulate lagoon response to energy gains and losses. The energy lost by the lagoon was considered to occur by conduction, convection, evaporation and radiation. Under natural weather conditions, the losses due to these factors become gains when the lagoon temperature is less than the temperature of the surrounding earth and air. Energy gain by the lagoon under most operating conditions was due to solar insolation. By using the information generated by the computer model and data collected during the testing of the system, it was concluded that there is low level energy available in the waste treatment lagoon. Also, the removal of the low level energy for heating swine housing has little effect upon the thermal stability of the lagoon. / Master of Science