The implicit method of flood routing has been modified so as to make it applicable to open-channel shocks. The output of the computer program with θ = 0.6 compared favorably with the experimental result. A comparison was also made with other explicit schemes and a two step implicit scheme proposed by other investigators. The implicit method with θ = 0.6 gave results as good as the explicit scheme and much better than the two step implicit scheme. In this method the equations of continuity and momentum for gradually varied flow have been written in finite difference form for a point in the (x,t) plane specified by the co-ordinates (x+dx/2, t+θdt). The variable e was made to take on values from 0 to 1.0. A computer program was written to obtain the output hydrograph at the downstream end of a rectangular channel for any type of inflow hydrograph at the upstream end of the channel. Three types of inflow hydrographs were chosen and the outflow hydrographs were obtained for different values of θ. For that type of inflow hydrograph that caused a surge to occur in the channel, it was found that θ = 0.6 gave the most satisfactory results. Experimental results of a surge in a channel were obtained from published literature. / Master of Science

An economical process for the removal of nutrients to receiving waters has become a difficult problem of major proportions. It was the purpose of this study to clarify the importance of the food-to-microorganism ratio (F/M) and to evaluate the nature of phosphate uptake in the activated sludge environment. The investigation consisted of two batch studies which allowed the F/M to vary as follows: 0.20, 0.75, 1.25 and 2.00. The phosphate concentration (PO₄) was allowed to vary in the first batch study and was kept constant in the second batch study. Measurements of pH, soluble COD and soluble PO₄ were made on all samples taken. Certain samples were measured for sludge total phosphorus content. Results obtained showed that both the biological and chemical processes have roles in phosphate uptake, but it was concluded that phosphate removal is predominately biochemical in nature. It was also found that physical adsorption was not the primary mechanism of phosphate uptake in an activated sludge environment, and the best overall soluble phosphate removal occurred when the food-to-microorganism ratio ranged between 0.75 and 1.25. / Master of Science

The objective of this study was to develop an airport simulator and present statistical techniques with which the output may be meaningfully interpreted. The system modeled includes the runway and its associated approach and departure path airspace, including a holding stack. As an example of how the simulator may be used: and its results interpreted, a regression analysis was performed on the simulator output in order to arrive at equations with which to predict runway capacity from a knowledge of the independent variables under study. Before any analysis could take place it was necessary to know how much data should be collected through simulation to insure-statistically sound results. The combinations of levels of the independent variables were selected at random and the number of replications of the simulation at each combination.of levels was defined in accordance with prescribed α and β values. A complete statistical analysis was also performed after data collection to ensure that the desired power of the regression equations was present. / Master of Science

Increased confinement housing of turkeys has created a need for data on the moisture production of turkeys. Sufficient data do not exist in the literature. Some research has been conducted at the Virginia Polytechnic Institute and State University Turkey Research Center, but the past facilities dealt only with full grown turkeys. Some modifications of these facilities were necessary in order to adapt them to growing turkey poults. These modifications were made and the moisture production of one group of medium white female turkey poults was determined during the grow-out period. The environmental temperature was kept constant at 70°F ± 1°F; relative humidity ranged from 42.8 percent to 64.8 percent. A brief summary of the results obtained from the moisture production study are as follows: 1. The rate of fecal moisture production per pound of bird declined with age during the grow-out period. A logarithmic function was found to best describe this relationship. 2. The rate of fecal moisture production per bird increased with weight during the grow-out period; an equation was found which satisfactorily described this. 3. The rate of respired moisture production per pound of bird decreased linearly with age. 4. The rate of respired moisture production per bird increased with weight during the grow-out period. A second degree polynomial best described this relationship. 5. A moisture input and output balance was used to help check accuracy. Input measurements were consistently greater than the output; this range was from 3.3 percent to 21.4 percent. / Master of Science

A method is presented for augmenting the control of an EBF-STOL aircraft using a real model-following technique. The method is based on the solution of the discrete matrix Riccati equation to generate the required feedback and feedforward gains. The feedback gains provide a means of closing the control loop around each of the plant states while the feedforward gains multiply the states of the inputs to some desirable reference model, thus making it a prefilter to the plant. The model chosen for this research is that of a B-26 aircraft. The longitudinal equations of motion of the STOL aircraft are linearized about a preselected point of the flight regime and written as linear state equations. A new system state vector is then constructed which includes the difference between plant and model states. The problem is formulated as a discrete linear regulator with the inputs to the model simulated as state variables. In solving the matrix Riccati equation, a quadratic cost function which includes the system state vector is minimized, thus making the plant states follow those of the model. The type of STOL aircraft used in this study has three possible fixed flap positions. Results are obtained for the half-flap configuration with step inputs to the elevator and thrust coefficient. Results are also presented for a filtered gaussian input to each of these control variables. / Master of Science

Age correction factors were developed from 336,253 individual classification results and were applied to final score, final classification, general appearance, dairy character, body capacity, and mammary system. Using a within-herd model, 30,715 daughter dam pairs were 2 analyzed to determine estimates of heritability (h²) and genetic and phenotypic correlations. Heritability estimates were: final classification, 0.31; final score, 0.25; general appearance, 0.26; dairy character, 0.15; body capacity, 0.23; mammary system, 0.20; stature, 0.38; head, 0.11; front end, 0.11; back, 0.14; rump, 0.21; hind legs, 0.07; feet, 0.08; fore udder, 0.16; rear udder, 0.17; udder support, 0.13; udder quality, 0.04; and teats, 0.17. When traits were expressed as 1 for desirable and 0 for undesirable, h² estimates were lower. Genetic correlations were generally positive, ranging from 1.01 ± 0,08 between final score and final classification to -0.17 ± 0.22 between dairy character and udder quality expressed as a binomial. Regression of the son progeny test on that of his sire indicated that head, front end, hind legs, feet, rear udder, and udder quality were poor indicators of son's performance when the sire's progeny test result was used for selection decisions. Considerable emphasis was placed on type in selecting sires of sons, especially for final score, hind legs, fore udder, udder support, and teats, since bulls whose daughters scored high in these traits sired more future sires than other bulls. / Master of Science

A theoretical study is performed to provide methods for evaluating balanced transportation facility arrangements. The study examines, in depth, arrangements of bus, auto, and roadway facilities for urban areas. Models for balancing intermodal and interzonal travel are developed for such transportation systems. A total community cost function incorporating auto operating costs, bus fares, travel time costs, and, in come cases, utilization costs is developed to indicate the level of service provided by specific arrangements. The best arrangement for a set of alternatives being evaluated is assumed to be the one offering the lowest total community costs. A computerized process, TRANSFARE (Transportation Facility Arrangement Evaluation), is developed to allow for easy application of the evaluation process. It is presented in package form so as to be available for further application. A sample urban network is evaluated for different levels of bus diversion under varying values of time and bus capacity conditions. Output of the example yields functions for evaluating arrangements at various diversion levels. These functions indicate the best arrange ment for each set of data as well as the sensitivity of the models incorporated within TRANSFARE. The evaluation methods which are developed here apply only to a specialized auto-bus urban transportation system. However, it is concluded, based on the results, that the study forms a basis for the examination of existing and more complex urban areas. / Master of Science

Microprobe analyses of 20 staurolites from many localities indicate that the range of composition of natural ferroan specimens is Fe_2.95-3.44 Al_17.07-17.60Mg_0.38-1.13Ti_0.09-0.14Zn_0-0.17Mn_0-0.09Cr_0-0.02V_≤.01.Co_≤.004 Si_7.64-7.91O₄₄ OH_~4. Our observations, together with chemical analyses and other experimental evidence from the literature, are sufficient to conclude that the staurolite unit cell contains ~4 H⁺ in agreement with the structural formula of Smith (1968): (7 octahedral sites, principally Al)_~18 (1 tetrahedral site, principally Fe)_≤₄ (1 tetrahedral site, principally Si)₈O₄₈H_≤₄ Assuming that Si and a small amount of Al fill the Si^IV site, we have used the method of principal component analysis to deduce that the primary substitution in the A1^VI sites is Al ⇄ (Fe+Mg+Ti) and that in the Fe^IV sites is Fe ⇄ (Zn+Al). Secondary substituents in the AI^IVsites are M and Zn, and it is likely that small amounts of and Ti are present in the Fe^IV site. The generally accepted view that Mg is the primary substituent for Fe in the Fe^IV site is not supported Lattice parameters determined by powder methods on 15 analyzed staurolites show the following ranges: a= 7.865 - 7.879Å; b = 16.600 - 16,633Å; c = 5.656 - 5.664Å; β = 90.0°. There are positive correlations of b and c with Fe content, while a is nearly independent of composition. These relationships are explained on the basis of the crystal structure and site occupancies. Natural specimens have uniformly shorter a cell edges {by ~0.015Å) than synthetic Fe-Mg staurolites. Improved curves showing the relationship of 2V and refractive indices to Fe-content have been established. / Master of Science

Four studies were conducted to determine if the copper requirement is effected by the dietary level of iron and if higher than normal levels of iron are beneficial when high dietary copper levels are fed. A factorial design utilizing 3 levels of copper and 2 levels of iron was used. Diets containing 257 ppm copper when fed to growing pigs tended to produce heavier weights when the pigs were limit-fed. The response was greater when the pigs were full-fed due to increased feed intake. Dietary copper at a level of 257 ppm significantly reduced hemoglobin values and serum iron values, in the absence of supplemental iron. Serum copper levels were significantly increased during early growth by feeding 257 ppm dietary copper. The low copper-high iron diet produced a high serum iron level which would indicate that 7 ppm dietary copper is adequate for normal iron metabolism. Copper accumulated in the liver, kidney and hair, when the pigs were fed the high copper diet. When the diet contained a high level of iron the accumulation of copper in the liver was depressed somewhat in trial IV. The iron content of the spleen, kidney and liver was significantly decreased by the high copper intake which would suggest impaired absorption of iron in the presence of high copper. / Master of Science

Sources and yields of nutrient and organic loadings in the Upper Roanoke River Basin were investigated during the summer low flow period of 1971. Parameters monitored at sampling stations in the basin included biochemical oxygen demand, chemical oxygen demand, total organic carbon, total phosphate, orthophosphate, Total Kjeldahl Nitrogen, nitrate nitrogen, sodium, potassium, calcium, and magnesium. These data were used in conjunction with flow and drainage area data to determine the relative magnitude and daily yields of nutrient and organic yields from various sources. Sources of nutrient and organic materials entering the basin included rural and urban land drainage, and domestic and industrial wastewater effluents. The yields of materials from the various sources were computed in order to determine the magnitude of each in contributing to the fertilization of Smith Mountain Lake. The domestic wastewater effluents were found to be the prime contributors of organic carbon, nitrogen, and phosphorus in the upper basin. Urban land drainage was found to be the major runoff source of· phosphorus, while rural land found to be the greatest drainage source of nitrogen. It was found that diversion of all wastewater effluents 'in the tributary watershed would not reduce the concentration.of macronutrients in the Roanoke River flow to the levels generally promulgated as being adequate to support excessive productivity in lenitic aquatic environments. / Master of Science