The demand for potable water may be culminating in a compromise on what constitutes a "safe" drinking water due to the rapidly approaching need to utilize recycled waters. The elimination of viruses pathogenic to humans from recycled waters will depend on the removal efficiencies of treatment processes and the sensitivity of detection methodologies. Enteric viruses can survive current wastewater treatment practices, and some even persist for long periods of time in natural waters. The objectives of this investigation were threefold: first, to construct a virus concentrator suitable for sampling secondary sewage treatment plant effluents; second, to sample the effluent of trickling filter sewage treatment plants prior to chlorination to determine the remaining amount of enteric viruses; third, to determine the virus removal efficiencies of a final settling and chlorination operation by using bench-scale simulations of the two units. Viruses were not detected in any of the secondary effluents of three trickling filter plants samples. However, these results may have been obtained because the level of viruses was below the minimum detection limits of the virus concentrator that was constructed. Also, if viruses were present, the high pH elution process may have been deleterious, or the BGM host cell was incompatible. Detention times in the model system studies of a final sedimentation basin and chlorine contact chamber were based on Rhodamine WT dye studies of plant-scale units. These studies suggested that 98.5 to 100 percent of the enteric viruses contained in the actual plant effluent would be removed or inactivated by the combination of final settling and chlorination. / Master of Science

The ability of a mixed oak forest in the Ridge and Valley Province of Virginia to provide the seasonal digestible protein and energy requirements of a white-tailed doe following a commercial thinning operation was evaluated. The element of time elapsed since thinning was emphasized and was represented by three contiguous forested parcels thinned over 3 consecutive years and an unthinned parcel. Digestible protein and energy requirements of a doe, whitetailed deer in four different physiological conditions associated with four seasons were obtained directly from the literature or calculated from data in the literature. Availability of dietary digestible energy and protein coincident with the requirement periods were determined by clipping, weighing and analyzing for digestible protein and energy content food items commonly used by white-tailed deer. Calculation of carrying capacity was based on the ability of a white-tailed doe to obtain sufficient energy and protein from the daily diet. When the ratio, energy or protein density of the daily diet: daily energy or protein requirements of the doe was less than 1, the doe was unable to meet her requirements. Thus, carrying capacity was determined to be 0 ha/deer. When this ratio equalled or exceeded 1, carrying capacity was calculated by dividing the daily standing crop of protein or energy by the daily protein or energy requirements of the doe. Summer, winter and mast-supplemented fall diets were deficient in energy. Thus, potential carrying capacity, based on immediately available dietary digestible energy, was estimated as 0 ha/deer during these periods. Spring and mast-supplemental fall diets provided adequate digestible energy for maintenance of the doe. Diets from all parcels and seasons provided sufficient protein for maintenance. For those periods when dietary protein and energy were sufficient, carrying capacity exceeded 0 ha/deer and was greater with increased standing crop of the seasonal diets. Standing crop of seasonal diets tended to be larger with increased time since thinning, although this pattern was confounded by the drier nature of one parcel. The role of seasonal energy and protein excesses and deficiencies in the annual nutrition of white-tailed deer are discussed. The necessity of considering dietary quality as well as quantity and the year-round nutritional plans of deer are emphasized for forage-based evaluations of deer habitat. calculations suggest that dietary energy is a more important limiting factor than protein on the abundance of white-tailed deer in this forest stand. / Master of Science

Materials for and implementation of a course in government nutrition education programs taught by personalized system of instruction (PSI) is described. Twenty-four students learned by progressing through nine units of written objectives, reading assignments and tests at their own pace. Ninety percent mastery was required to pass unit tests and tests were retaken without penalty until the criterion was met. Three course assistants, called proctors, provided immediate individualized scoring of unit tests. Twenty-two students received an A for the course; one student, a B; one student completed only one unit and received an F. Course evaluations reflected positive student and proctor attitudes toward course material and the PSI method. Four factors correlated with final exam performance: quality cumulative average (QCA), the number of unit test retakes, total unit test errors and working rate. High ability students out-performed low ability students on the final exam. Students with fewer test retakes and errors generally did better on the final exam than students who took more tests to achieve the 90 percent mastery criterion or who made more test errors. Those who began taking tests early in the term had higher final exam grades than those who began later in the term. / Master of Science

Temporal production patterns for periphyton have been poorly quantified in small woodland streams. In this study periphyton production on natural substrates was measured in a second order, western Virginia trout stream and two of its tributaries. Measurements were taken about three times monthly from April 1977 through April 1978 excluding 74 days of inaccessibility due to snow. Primary production rates were estimated in situ using ¹⁴C assimilation in light and dark chambers equipped with circulating systems. Allochthonous input and physicochemical parameters were measured concurrently. Annual mean photosynthetic rates at midday were 2.27 ± 0.37 SE, 1.65 ± 0.25 SE, and 1.37 .± 0.19 SE (n = 46) for Guys Run (mainstream), Piney Branch, and Glade Brook, respectively. No relationship between the irradiance and photosynthetic rates was observed. Highest photosynthetic rates occurred in early July following the full emergence of the shading forest canopy. Tests comparing primary production rates between variously shaded and unshaded stream sites suggested periphyton light saturation to be about 20-30% of full sunlight. Mean daily irradiance for each season was calculated from light monitored at stream sites and used to estimate seasonal periphyton production in each stream. Annual autochthonous production, on a flat m² basis, was 6.54, 4.10, and 3.71 g C/y for Guys Run, Piney Branch, and Glade Brook, respectively. Compared to allochthonous input the periphyton contributed 3% of the total energy budget of the main stream and about 2% for the tributaries. Of the total autochthonous production, 90 ± 1% occurred during late spring and summer for all streams. In summer when terrestrially derived detritus was poorest in quantity and quality, periphyton was producing a majority of its annual input. Current concepts, which consider contributions by periphyton to consumer production to be extremely small in low order woodland streams, are based upon annual energy budgets. Because of the seasonal timing and high nutritional quality of periphyton, its true importance in low order streams may be greater than typically indicated in gross annual budgets. The roles of periphyton production and allochthonous input need to be reevaluated and better resolved on a seasonal basis. / Master of Science

A New method for calculating isolated resonance escape probabilities for slab lattices has been developed. It is based on the Boltzmann equation. The method avoids the use of Dancoff corrections and obviates the necessity of choosing between the wide and the narrow resonance approximations.The knowledge of the spatial dependence of the flux in the fuel region is not required. Isotropic scattering and a l/E spectrum above the resonance are assumed. The method is set up for a pure non-scattering uranium-238 absorber and a non-absorbing water moderator region. The reaction rate in the fuel region contains two contributions, the first term appears as an integral expression, which can be integrated numerically, the second term can be considered as a correction factor for oxygen scattering and is derived by using a variational approach. A computer code for calculating resonance escape probabilities in slab lattices has been developed. The results are in agreement with those obtained by Corngold. / Master of Science

M.S.

In order to assess the potential of increased mechanization of shortwood harvesting in the man-made forests of Sao Paulo, Brazil, surveys and field studies of present systems were made to provide a basis for evaluation. From this information typical domestic systems with field debarking and without field debarking were compared to mechanized systems used in other countries. The analysis of twenty-two systems were made using a deterministic mathematical model to predict total direct cost per stere, man hour per stere, and capital requirements per stere of annual production. In addition, labor and capital requirements to supply a 500 ton per day pulpmill were calculated. The analysis indicated that: (1) field debarking almost doubles direct cost, dramatically increases labor requirements, and significantly increases capital requirements when portable debarkers are used: (2) mechanical loading appears to be both cost effective and an efficient use of capital; (3) additional mechanization results in increases cost, however, this situation is due largely to the prevailing low labor rates which could change in the future; and (4) if shortages of wood labor develops, the transition from domestic systems with field debarking to mechanical systems without field debarking could be made without a major infusion of capital. This study has shown that there is a great need for the standardization of terminology and improved methods of data collection and analysis. The use of computer simulation for systems analysis should be implemented as soon as feasible to provide a sound basis for research and planning. / M.S.

The vocal behavior of male Rana clamitans was studied during the summers of 1974-1976 near Blacksburg, Montgomery Co., Virginia to test the hypothesis that call quality varies among callers and this variation produces different responses in recipient conspecifics. The studied call repertoire contained: a single-note call, a multiple-note call, and a growl call. The acoustical properties of the single-note calls (most frequently performed call) from 99 males were analyzed. The dominant frequency was negatively correlated (r =-.69 P < .001) with the caller's snout-vent length (SVL). Energy distribution between the call's low (200-450 Hz) and middle (500-1,000 Hz) frequency ranges shifted with the males' SVL. EIR scores (low freq. amplitude/middle freq. amplitude) were positively correlated with SVL (r = .67, P < .001). This is significant because Sachs (1964) found that green frog auditory perception of low-frequency sounds is inhibited if sufficient energy is also present in the middle-frequency range. Thus calls of small males having low EIR scores may be poorly perceived by conspecifics. Playback of a small male call (EIR score of 0.6) and a large male call (EIR score of 2.3) to males in the field showed that males definitely responded to the EIR_0.6 call, discounting the speculation that small male calls are inhibitory. However, there was still a differential response by males to the two test calls; this provides evidence that the call is more complex than a mere carrier of species-specific characteristics. When posed with the EIR_0.6 call (small male threat), the response of smaller adult males (SVL≤81 mm) was a strong increase in multiple-note and growl calls over their baseline levels, while larger males ( SVL > 81 mm) simply decreased their rate of single-note calling. To the EIR_2.3 call (large male threat), large males shifted to growl calls and approaches toward the speaker, while small males primarily responded with only a rise in multiple-note calls. My data suggest a response sequence to the male-male behavioral repertoire of green frogs (single-note calls - multiple-note calls - growl calls - approach - physical contact). Small adult males, especially when presented with a large male test call, were significantly less likely to carry the above sequence to its final stages than were the larger males. An elaborate apparatus was used to test female response against the EIR_0.6 and EIR_2.3 calls. However, female population density was not sufficient. The experiment should be retested under more ideal conditions as there remains a strong likelihood that reproductive females will be differentially attracted to large calling males rather than to smaller males. / M.S.

The efficiency of the current structure of American orporaton law was investigated. Critics of the current system point to the lack of strict government intervention. into the ongoing affairs of the business corporation as the result of state competition for corporate charters. Such competition is made feasible by the ability of each state to draft corporation laws of its own choosing, and is presumed to have created a system of law which is unfavorable to the interests of stockholders. A theory of the demand for government intervention into private contracting was developed which produced the conclusion that the welfare of contracting parties can only be maximized if they are permitted to choose from a variety of legal environments. Since such choice is only feasible under a federal.system, the efficiency of corporate federalism is established. Tests of.the various implications of the theory of the demand for government intervention were included. / Ph. D.

This dissertation is concerned with three aspects of the nucleophilic substitution reactions of some heteroaromatic halides. First, the SRN1 reaction of 2-chloroquinoline with potassioacetone was studied in several solvents. Tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and dimethoxyethane (DME) were found to be more suitable as solvents for this reaction than were diethylether and benzene. This reaction was stimulated by near UV irradiation. However, substantial reaction occurred in the more polar solvents without photostimulation. The SRN1character of these reactions was substantiated by inhibition studies. The relative rates of this reaction in the solvents generally increased with increased solvent polarity. The SRN1 reactions of 2-chloroquinoline, 2-bromopyridine, and iodobenzene with ketone enolates in THF were found to occur slower than their analogous reactions in liquid arrnnonia. Second, 4-picoline and acetonitrile anions were employed as nucleophiles for heteroaromatic SRN1 reactions. The photostimulated reaction of 2-chloroquinoline with potassioacetonitrile in liquid ammonia was complicated by 11 polymer 11 formation and by SNAR2 and SN(ANRORC) reactions with equilibrium concentrations of potassium amide. In the absence of photostimulation, 3-cyano-2-methylquinoline was the major product observed and presumably resulted from an interesting SN(ANRORC) reaction involving potassioacetonitrile. Attempts to eliminate the side reactions with amide by employing excess acetonitrile resulted in increased yields of "polymer." The reaction of 4-picoline with 2-bromopyridine was also plagued with a significant competing amination reaction. However, moderate increases in the ratio of 4-picoline to potassium amide employed reduced the yields of 2-aminopyridine. In contrast, the SRN1 reaction of 4-bromopyridine with potassio-4-picoline was accompanied by only trace amounts of 4-aminopyridine. Lastly, the SRN1 reactions of 2,4-dimethyl-3-pentanone with 2-bromopyridine and iodobenzene were accompanied by a reductive dehalogenation process. That these reactions involved the abstraction of s-hydrogens from the nucleophile was supported by the isolation of 2,4,4,5,5,7-hexamethyloctane-3,6-dione. Spectral characterizations and the independent synthesis of this ketone dimer is described. The search for a similar ketone dimer from the reaction of potassiocyclopentanone with bromobenzene was inconclusive. / Ph. D. / incomplete_metadata