Vinyloxiranes 6a-b and vinylaziridines 7a-b were prepared efficiently from halocyclohexadiene-cis-diols 1. Reactions of 6 and 7 with a variety of organometallic reagents were investigated in order to determine the stereo- and regiochemistry of ring opening with carbon nucleophiles. The results indicate that 6 and 7 could serve as useful new synthons for C-disaccharides and Amaryllidaceae alkaloid syntheses. The utility of synthon 7b has been demonstrated by a concise enantiocontrolled synthesis of (+)-pancratistatin (9). The key step involved the S_N2 opening of 7b with the aryl cyanocuprate derived from amide 217 to generate the pivotal cyclization precursor. / Ph. D.

The purpose of this study was to explore the effect of text-to-speech in a multimedia learning environment on science achievement for students with learning disabilities in reading. The researcher examined how student achievement on unit tests was related to their participation with the experimental treatment. A secondary purpose of the study was to determine whether students prefer the combination of digitized audio and text, or text alone. The researcher used a quasi-experimental, counter-balanced, post-test only design for the study. Qualitative information was collected using post experiment individual and small group interviewing techniques. The sample used in this study was selected from students enrolled at The Forman School, a private school specializing in the education of students with learning disabilities. Specifically, the sample consisted of students with dyslexic reading problems. This independent school is located in Connecticut and currently uses multimedia in daily instruction. The sample consisted of 22 students enrolled in life science classes. The students' ages ranged from 13-19 years and the grade levels ranged from 9-12. Intact, pre-grouped students were randomly assigned to the experimental groups. The main thrust of the study was to examine the effect on achievement of the type of instruction (with and without text-to-speech synthesis) applied. The experimental group consisted of students who received modified multimedia instruction (treatment), including the text-to-speech synthesis. The control group consisted of students who received standard multimedia instruction; a series of texts and graphics without text-to-speech synthesis. Both lessons were identical in content and appearance, with the exception of the text-to-speech synthesis modification. / Ph. D.

Results for two unrelated studies are included in this dissertation. The primary investigation focused on evaluation of the crystallization conditions utilized in commercial consolidation of ICI's semicrystalline "ITX" polymer. Manipulating the initial polymer melting temperature and time was seen to influence the crystallization behavior and final morphology of the material. Variations in the crystallization kinetics, nucleation density, and crystalline texture of ITX were observed as a function of melt history. Experimental evidence suggests that ITX, like several other rigid-chain high-performance semicrystalline materials, is melt sensitive in that its nucleation density greatly decreases as a function of time and temperature in the melt. Melt degradation does not appear to strongly influence the crystallization behavior of ITX under normal processing conditions; however, spherulitic growth rates were seen to decrease after melting under the most severe conditions indicating that some degradation may be present. Unlike polyetheretherketone, ITX which was previously melted at the processing window high temperature limit can regenerate crystalline nuclei within the material via thermal treatments. Cooling and reheating the material to a lesser temperature increases the level of crystallinity generated such that it is equivalent to that found in material treated to less harsh conditions. Wide angle x-ray diffraction and the method of Hermans and Weidinger were utilized to calculate a theoretical heat of fusion of 180 J/g for ITX, and show that absolute crystallinity decreases by ~5% within the ICI recommended processing range. The second dissertation topic discusses the effect of adhesive deformation during bond preparation on the mechanical performance of two commercial hot-melt adhesives, Dow DAF® 821 and Du Pont Surlyn® 1601. Lap shear bonds were sheared (// or ⟂ to load) during preparation to induce molecular orientation within the adhesive, before the mechanical properties were evaluated. The measured DAF 821 tensile strengths were similar, however, the Surlyn bond strengths varied in that sheared bonds were weaker than control bonds. Linear dichroism was used to quantify the level of orientation present within similarly prepared adhesive films. The technique indicated that there was no measurable preferential orientation in either adhesive. / Ph. D.

Biological nitrogen and phosphorus removal are being recommended at several wastewater treatment facilities in the U.S. to control eutrophication in water bodies receiving their effluent. In several instances, nitrogen removal is being recommended on a year round basis at plants located in the temperate climates. Concerns have been raised regarding the cost of additional reactors and clarifiers required for nitrogen removal in winter using activated sludge systems. Several facilities do not have the space to construct additional units. This research was undertaken to evaluate the potential for reducing reactor and clarifier requirements, maximize use of existing facilities, and economize costs for year round nitrification and nitrogen removal. The purpose was to develop Integrated Fixed Film Activated Sludge Systems in which biofilm support media was installed in the activated sludge basins to enhance nitrogen removal. The objectives were to evaluate the COD removal, nitrification and denitrification kinetics, which would help develop design and mathematical models for the process, and optimize the layout in terms of costs and media required for nitrogen removal. A bench scale pilot study was undertaken in conjunction with two full scale studies with two types of media: (i) free floating media and (ii) media fixed in frames. Amongst biofilm support media in the first category, sponge cuboids (Captor) were selected. For the second category, rope type Ringlace media was selected. Following preliminary screening for satisfactorily simulation of full scale conditions in a bench scale system, the IFAS-Sponge system was selected for kinetic coefficient evaluation and IF AS system model development. / Ph. D.

This study examined two potentially useful personality scales, the narcissistic personality inventory (NPI) and the self-report of psychopathy scale (SRPII), in terms of their factor structures. Competing factor structures for each scale were assessed via confirmatory factor analysis (n=581). Competing models were obtained from published literature associated with each scale and also through exploratory factor analysis. From the literature, Raskin and Terry (1988) provided a seven factor NPI model, whereas Emmons (1984; 1987) suggests a four factor model. Harpur and Hare (personal communication) provided a two factor model for the experimental SRPII. Exploratory factor analysis (n=581) provided four additional NPI models and five additional SRPI models to test. Various additional factor models of interest were included in the competing models pool. The published seven factor Raskin and Terry (1988) model of the NPI, the proposed two factor Harpur and Hare SRPII model, and the seven factor oblique exploratory SRPI model fit the data best in terms of common fit measures. Theoretical implications of model fit are discussed and consideration is given to this study as a method of practical scale analysis and theoretical construct validation. / Ph. D.

This study was conducted to :1) determine the effect of seminal plasma (SP) on sperm viability parameters (estimated percent motile sperm, computer-aided percent motile sperm and percent intact acrosomes) and motion characteristics (average path velocity, VAP; curvilinear velocity, VCL; and straight line velocity, VSL) of cryopreserved ejaculated spermatozoa (Experiment 1) and cauda epididymal spermatozoa, both fresh and frozen (Experiment 2).2) determine the effect of additional SP on sperm transport in the female using cryopreserved ejaculated sperm (Experiment 3) or cryopreserved cauda epididymal sperm (Experiment 4). In Experiment I, addition of SP (1:1, v/v, post-thaw) did not affect (P> .05) viability parameters; however, all sperm motion characteristics were improved at 3 h of incubation (P < .05). In Experiment 2, addition of a normal complement of SP to cauda epididymal sperm significantly improved all motion characteristics and viability parameters except acrosomal integrity (P < .05) and semen freezing did not alter this effect. In Experiment 3 and 4, addition of SP to the inseminate did not affect the mean or median accessory sperm number (P> .05); however, in both experiments there was a trend toward increased median accessory sperm values for the SP-treated semen. In Experiment 3, mean ± SD and median accessory sperm values per embryo/ovum were 19.2± 36.9 and 2.5 for the control (n = 32); and 23.1 ± 71.6 and 6.5 for the treatment (n = 32). In Experiment 4, mean± SD and median accessory sperm values per embry%vum were 9.2± 16.7 and 1.0 for the control (n = 30); and 14.2± 21.2 and 3.5 for the treatment (n = 30). We conclude from these experiments that sperm motion characteristics but not viability parameters of ejaculated frozen-thawed semen are improved by additional SP (Experiment 1) and both motility and motion characteristics are modestly improved by a normal complement of SP added to cauda epididymal sperm (Experiment 2). This positive effect of SP on motility/motion characteristics may favor sperm transport, but not at a statistically significant level to be detected by accessory sperm number. / Ph. D.

This study was conducted to obtain information regarding the school business functions in school divisions in the Commonwealth of Virginia. Further objectives were to ascertain who is responsible for each job function and by whom these functions are performed, delegated, or shared. Superintendents in school divisions in Virginia with student enrollments of 5,000 pupils or less were selected to participate in the study. The population was identified from the Superintendent’s Annual Report for Virginia. This report indicated that there were 133 school divisions in Virginia and that 88 of them met the selection criteria for the study. Descriptive research methodology was used in this study. The survey procedure utilized a questionnaire to obtain information regarding the performance of school business management functions. There were 72 responses received from the 88 school divisions meeting the selection criteria. In 27 of the school divisions, the superintendents were primarily responsible for the school business management functions while 45 school divisions employed a separate individual to be responsible for these functions. The results of the study indicate that the school business management functions are delegated by both the Superintendents and non-superintendents to a series of support staff in a majority of the school divisions surveyed. The study also indicated that the school business management functions that the superintendents were most likely to identify as total responsibility items were strategic planning, salary administration, financial planning, personnel management, and financial reporting. High total responsibility items among the non-superintendents were financial reporting, payroll administration, accounting, and auditing. Topics for professional development programs on school business management that should be initiated by professional education associations were also identified by the study. / Ed. D.

Cattle feeders are in a position to incorporate the influence of current and highly specific information into price discovery processes for live cattle and feeder cattle futures. The tax treatment of speculative trades in the cattle futures markets has the potential to effective block participation of cattle feeders, however. To the extent that cattle feeders are effectively blocked from trading in futures in any capacity other than trades that meet the simplistic IRS "equal and opposite" criterion of a hedge, the correction of market imbalances may be slowed. The economic viability of investments in cattle feeding and the well-being of the consuming public can be influenced in a significant way by prolonged market imbalances. A theoretical model is developed based on a mean-variance approach. The model deals with the simultaneous determination of optimal cash and futures positions given tax parameters of marginal tax rate and percent of deductibility of any futures losses. Producers' risk aversion is considered. This research examines the impacts of changes in tax policy on the optimal cash and futures positions, equilibrium prices, pricing efficiency, welfare changes in both cash and futures markets, and on tax revenues. Comparative static analyses are performed to examine the changes in the measures of efficiency and/or welfare given a unit change in the tax parameters. A revenue-neutral tax scheme is incorporated into the model to analyze the comparative statics when tax receipts are fixed. The simulation results indicate that given a marginal tax rate, an increase in the probability of deductibility of any futures losses would increase both the optimal cash and futures positions. The adjustments of the optimal cash and futures positions reduce the spreads between expected cash prices and marginal costs for the cash market and between the expected futures prices and current futures price (including trading costs) for the futures market. This implies that pricing efficiency in both the cash and futures markets is improved by an increase in the deduction level for a given tax rate. Both producers' and consumers' welfare increases in response to the increased probability of deductibility for a given tax rate. Expected tax revenues become positive and increase as the deduction level increases. The comparative static analyses generally support the empirical findings. A revenue-neutral marginal increase in the deductibility of losses for a given tax rate would result in a transfer of risk exposure from the cattle industry to the government sector. This has an important implication for risk-sharing aspects of a revenue-neutral tax policy, and suggests that policies should examine both the potentially variable mean-level tax revenues and variance of that revenue flow under alternative scenarios. / Ph. D.

A microreactor has been developed to study the sensitivity of Methanol-To-Olefin (MTO) reaction to axial gas dispersion. It comprises a rectangular horizontal duct, 12.7 mm in height, 25.4 mm in width, variable in length, charged with a 1-mm-deep layer of HZSM-5 catalyst. The microreactor is constructed of aluminum alloy and heated with cartridge heaters. A glass reference duct with the same catalyst loading is mounted directly above the microreactor to provide visual check of the coherent-expanded vibration state achieved by vibrating the setup at 24 hertz and 4.3-mm vertical displacement. In this. state, catalyst powder expands to full duct height during a portion of each vibration cycle, with intense vertical mixing of powder and little horizontal. Axial gas dispersion coefficient varies linearly with superficial gas velocity, and axial Peclet Number (Pe_ax) can be studied over a wide range of values simply by varying duct length while holding weight hourly space velocity constant. Conducting the MTO reaction in microreactors of 7.62-, 15.24-, and 22.86-cm length (Pe_ax = ca. 2, 9, and 19 respectively) revealed the reaction to be sensitive to axial gas mixing. Trend in light olefin yield versus Pe_ax agrees with earlier turbulent fluid-bed data. Loss in olefins with increase in axial gas dispersion (decrease in Pe_ax) suggests that a circulating fluid bed may be the preferred reactor for this reaction. Researchers can use the microreactor to determine, quickly and inexpensively, how reaction outcomes vary with axial gas dispersion. The microreactor could help R&D managers to avoid expense of a fluid bed R&D effort where an economically significant outcome of a reaction is acutely sensitive to axial gas dispersion, and where a fixed bed is an acceptable alternative. / Ph. D.

A field evaluation of a modified version of the northern bobwhite (Colinus virginianus) Habitat Suitability Index (HSI) model was conducted using habitat and relative abundance data from 121 sites distributed throughout Halifax County, Virginia, 1986-1991. Model output and the index of relative abundance were only poorly correlated (r_s = 0.09, P = 0.31, n = 121). The model identified winter food as the limiting factor at 115 of the 121 sites. However, the Composition Suitability Index for the equivalent percent of the station providing winter food in optimum condition and the performance measure were not correlated (r_s = 0.09, P = 0.33, n = 121). Population performance at 49 of the 115 sites exceeded levels indicated by the model. Attempts to improve the fit of the model focused initially on the winter food component of the model. Attempts to improve the fit of the model by considering alternative food sources, the role of habitat interspersion, the individual variable Suitability Index curves, and a reassessment of the contribution of crop fields to the estimate of available winter food were unsuccessful. Quail appeared to be nest/brood habitat rather food limited. The index of quail abundance and the estimate of available nest/brood habitat were correlated positively (r_s = 0.55, P< 0.001, n = 121). Winter habitat use within the covey home range was evaluated January through April of 1990 and 1991 by comparing micro-habitat conditions at used and unused sites within the home range. Two different statistical treatments (regression and signed-rank) were used to determine if preferential habitat use was occurring. Whereas the signed rank test yielded significant (P = 0.04) results for only 1 of 7 micro-habitat parameters, results from the regression analyses were all significant (P < 0.05), indicating disproportional use of habitat characteristics. The potential effect of the Conservation Reserve Program (CRP) on northern bobwhite populations was evaluated by comparing nest/brood habitat conditions in crop and 4 CRP field types including CP1, CP3 < 8 yr, CP3 > 8 yr, and CP3 fields receiving some level of commercial thinning. Short-term effects are likely to be positive. Both CP1 and CP3 field types should provide more suitable nest/brood habitat conditions than crop fields. Long-term effects of the CRP on northern bobwhite are likely to be negative. Conservation Reserve fields with pines (CP3) > 8 yrs old provided virtually no nest/brood habitat. Commercial thinning did not appear to have a positive impact on habitat conditions. / Ph. D.