Research was initiated in the spring of 1972 to evaluate the effects of the Smith Mountain Pumped Storage Project on the spawning success of centrarchid fishes in the lower impoundment, Leesville Lake. Hydroelectric power generation operations at the Smith Mountain Dam power plant create high water velocities with daily flow reversals, and water level and temperature fluctuations in Leesville Lake. Water levels in Leesville fluctuate as much as 3.5 m (11 ft) per day and 4 m (13 ft) per week during spawning periods of centrarchid fishes. In addition, daily intrusions of subsurface water from Smith Mountain Lake into Leesville Lake during periods of power generation average less than 20 C in temperature. At night and on weekends, surface waters from Leesville Lake are pumped back to Smith Mountain Lake. These project operations create three fluctuating, relatively unstable sections in Leesville Lake; a cool upper reservoir zone, a mid reservoir temperature mixing zone, and a warmer lower reservoir zone. Centrarchid fishes were collected from the three reservoir zones in Leesville Lake and gonads were examined. Generally, gonadal maturation and the presence of fish in spawning condition occurred earliest in the warmer lower zone, later in the mid reservoir, and last in the cooler upper zone of Leesville Lake during 1972 and 1974. During 1974, trained divers located and inspected 2010 centrarchid fish spawning nests in Leesville Lake. Based on a constant unit of diving effort, 40 percent of nests occurred in lower Leesville, 57 percent in mid, and about 3 percent in the upper reservoir zone. High water velocities restricted spawning activity in the mid and upper reservoir zones almost entirely to cove areas. Water velocities in lower Leesville had negligible effects on the distribution of spawning activity. A stepwise regression model indicated that water velocities during power generation at Smith Mountain Dam was the single most important factor affecting the distribution of spawning nests in the main lake. Vertical distribution of centrarchid fish spawning nests suggested that adjustment to the spawning depth had occurred in response to the fluctuation in water levels. Nearly 40 percent of all spawning nests in Leesville Lake were located 0.3 to 1.5 m below minimum pool elevation or about 4. 5 m below maximum pool level. Laboratory and field studies were conducted to evaluate hatching success of bluegill (Lepomis macrochirus) eggs under controlled water temperatures and exposures to air. Average hatching success increased as hatching temperatures increased from 16 to 28 C. Hatching success of naturally spawned bluegill eggs exposed during night and daytime hours in natural spawning nests in Leesville Lake decreased with increased exposure to air. SUCCESS, a computer-implemented mathematical model using data generated in this study, indicated that the average spawning success of bluegill would be about two times higher in the lower zone than in upper Leesville Lake. Predicted estimates of spawning success of bluegill for the entire reservoir were about 31 percent. Based on the current levels of exploitation, natural spawning success of largemouth bass and bluegill in Leesville Lake appears adequate to maintain the densities of these centrarchid fish stocks. / Ph. D.

In 1974 the state of Virginia began a legislative study of the methods utilized to fund teacher aides and developed accreditation standards for elementary and secondary schools permitting employment of teacher aides. Prior to this time, the Virginia State Department of Education had no state program for training or certification. However, it had suggested (in 1969) limited personnel policies for selection of teacher aides, which proved to be a stimulus for several local school districts in the state to develop limited personnel policies relating to the employment of teacher aides. This study was designed to present descriptive data concerning areas of existing local teacher aide personnel policy. The study also delineated, as normative data, those policy areas considered important for inclusion in future local and state guidelines. A study was made of the teacher aide policy handbooks received from an inquiry addressed to the directors of 141 local Career Opportunities Programs in the United States. Similarly, a study was made of the status of teacher aides as indicated in responses elicited from the Department of Certification and Teacher Training in each of the 50 states. With the data received from these studies, a three-part survey instrument was developed which contained 40 policy items under each of three major areas of concern, "current local policy," "opinion for future local policy," and "opinion for future state policy." An additional item was included to ascertain legal status and opinions relative to certification. The instrument was mailed to all (131) of the local district superintendents in Virginia, selected (24) administrative and instructional personnel in the Virginia State Department of Education, and all (67) of the teacher aides who were members of the Department of Teacher Aides, Virginia Education Association, in 1974. The rate of return for superintendents was 92.4 percent, for state department personnel, 87.5 percent, and for teacher aides, 61.2 percent. Statistical procedures of frequency distribution and percentage were utilized in analysis of the data. Of those items which are currently part of local policy, 15 were unanimously recommended for inclusion in both future local and state guidelines. Inclusion of 40 policy items was recommended by a majority of the superintendents for future local policy, while state department personnel recommended 38 and teacher aides, 34. For inclusion in future state policy, a majority of superintendents recommended 35 policy items, state department personnel, 22, and teacher aides, 33. The study revealed that for Virginia instructional teacher aides there should be developed a comprehensive set of local and state policy guidelines for training, certification and related personnel practices. These were seen as means of providing for shared accountability between state and local policymakers in those areas of funding and permanacy of the instructional teacher aide position. Policy guidelines for certification, training and related personnel areas have further implications for the individual instructional teacher aide. These were seen as means for providing greater job security, higher salaries, status, and availability of financial assistance for pre-service and in-service career training programs. / Ed. D.

In the relatively young sub-discipline of Public Choice, there are a number of theoretical models predicting the type of equilibrium that would be expected in the production of goods and services in the public sector. These models arrive at a number of different conclusions; but one major class of models predicts that public sector output will cater to the demands of the median voter, while another class of models predicts that the amount of public sector output will exceed that level most preferred by the median voter. More information can be generated about the nature of equilibrium in the production of public education than for most other goods and services produced in the public sector, because of the existence of millage issue elections that are held in many states. Two aspects of millage issue ·elections are emphasized in this analysis. First, millage issue elections . act as a constraint on the behavior of school boards, since the school board cannot enact a millage rate without first receiving the approval of the voters. Second, millage issue elections act as a revealed preference experiment, since voters are being asked to state their preferences on the millage issue presented in the referendum. These two aspects of millage issue elections generate information about the nature of equilibrium in the production of public education, and provide the basis for using millage issue elections as a vehicle for studying the nature of equilibrium in the production of public education. A model for interpreting the results of millage issue elections is developed, followed by a survey of institutional differences in public school finance from state to state. Some empirical propositions are forwarded, based on the hypothesis that there is a general tendency for school expenditures to exceed the level most preferred by the median voter. Two empirical analyses fail to support the propositions, but are in agreement with the results that would be expected if public education were being produced at close to the level most preferred by the median voter. / Ph. D.

A study was made to ascertain the mechanism by which ortho-positronium reacts with nitroaromatics in solution. These reactions are two to three orders of magnitude faster than expected by simple pickoff. Conjugation of the nitro group with the aromatic ring was found to be a necessary condition for this behavior. The rate constant for each of these reactions was measured in suitable solvents over a wide temperature range, 200-500°K. Distinct departure from the Arrhenius law was found. In general, the rate constant increased linearly with increasing temperature up to a point, and then decreased linearly as the temperature was raised further. The following mechanism is postulated: Ps + M [stacked right and left arrows with k₁ above and k₋₁ below] PsM [right arrow with k₂ above] M + 2γ. Ortho-Positronium reacts with the nitroaromatic, M, to form a complex in a reversible step. The complex may either decompose into a positronium atom and nitroaromatic molecule or it may go on to annihilate the positron. A steady-state concentration ot the complex is assumed and the observed rate constant for the process is K_obs = k₁k₂ /(k₋₁+ k₂) The two limiting cases are: (1) k₂ >> k₋₁ causing k_obs = k₁ . Typical Arrhenius behavior is expected and observed in this region, and (2) k₋₁ >> k₂ causing k_obs = K_EQk₂ . In this region H_EQ + E_a(2) <O and the observed rate constant decreases with increasing temperature. This corresponds to a stable but temperature sensitive PsM complex. An approximate molecular orbital study has been made to study the possible existence of positron and positronium complexes with a select number of organic molecules. The CND0/2 approximation is used for all electronic integrals and for electron positron Coulomb integrals. The core Hamiltonian matrix elements for the positron were estimated by combining the Wolfsberg-Helmholtz and Cusachs-Cusachs approximations. This approach shows that the positron should become bound to the molecules. Using the same criteria, the formation of stable positronium complexes is more improbable. The calculated binding energies are strongly dependent on the value of the Wolfsberg-Helmholtz proportionality constant for positrons. / Doctor of Philosophy

A procedure has been developed for solving flutter problems of simply supported laminated plates using linear small deflection theory. The plate construction may be arbitrary as long as it satisfies the assumptions of linear small deflection theory. For such plates, the bending and extensional governing equations are coupled and have cross-stiffness terms which do not appear in classical plate theory. The coupling and cross-stiffness terms occur as a result of the lamina principal directions (fibers) not coinciding with the neutral surface of the plate. The extended Galerkin method is used to obtain approximate solutions to the governing equations where the aerodynamic pressure loading used in the analysis is that given by linear piston theory with flow at arbitrary cross-flow angles. Flutter solutions were obtained for typical symmetric, angle-ply, and general laminated composite plates, and a limited parametric study was conducted. The parameters studied include the number, orientation, and orthotropy of the lamina; the plate length-width ratio; the inplane normal and shear loads; and the cross-flow angle. In addition, flutter solutions for several composite stiffened aluminum plate designs were obtained to determine the most flutter resistant design. The bending-extensional coupling and the cross-stiffness terms both have a large destabilizing effect on the flutter of unstressed laminated plates, but increasing the number of laminas, reducing the lamina orthotropy, and stacking the laminas in the"best" order reduce the destabilizing effect. For a square plate, aligning the fibers with the direction of flow (x-axis) results in the highest flutter stability, but for a plate with a length-width ratio of 2, large improvements in flutter stability may be obtained by rotating the fibers away from the x-axis. For angle-ply plates, inplane normal and shear loads and crossflow have a destabilizing effect on flutter similar to that obtained for orthotropic plates. However, for symmetric plates with the fibers not aligned with the x-axis, the cross-stiffness terms give rise to an improvement of the flutter stability with cross-flow angle. Flutter calculations for equivalent symmetric, angle-ply, and general unsymmetric plates indicate that for no cross-flow and no inplane shear loads, plates with an angle-ply construction will have the highest flutter stability. If cross-flow or inplane shear loads are present, symmetrically constructed plates may have higher flutter stability. Classical plate theory does not consider bending-extensional coupling and cross-stiffness terms, and therefore gives inaccurate and usually nonconservative flutter boundaries for laminated plates. Reduced bending stiffness theory, an approximate flutter theory which accounts for the coupling by reducing the plate bending stiffness as determined by the coupling terms and then neglects the coupling in solving the equations, gives flutter solutions that are adequate for all plates for which numerical results were obtained. / Doctor of Philosophy

This thesis reports the preparation of new pentafluorosulfanylimino (SF₅N=) derivatives, which have been synthesized from pentafluorosulfanyl isocyanate, SF₅NCO, pentafluorosulfanylamine, SF₅NH₂, and pentafluorosulfanyliminosulfur difluoride, SF₅N=SF₂. Reactions of SF₅NCO, SF₅N=SF₂, and SF₅NH₂, with appropriate substrates have produced SFN=S(CH₃)₂, SF₅N=CHC₆H₅, SF₅N=SCl₂, (SF5N=)₂C, (SF5N=)₂S and SF₅N=PCl₃, some of which are new compounds and some of which represent improved routes to compounds previously reported. When N,N'-bis(pentafluorosulfanyl)urea, (SF₅NH)₂CO, reacted with carbonyl fluoride SF₅NCO was formed. The reactivity of SF₅NCO in several basic reaction types including nucleophilic substitution, addition, exchange and coupling reactions was examined. Pentafluorosulfanyl isocyanate and dimethyl sulfoxide reacted to produce a crystalline product identified by its H-1 and F-19 nmr and in spectra as SF₅N-S(CH₃)₂. Pentafluorosulfanyl isocyanate and benzaldehyde reacted to produce a yellow solution and carbon dioxide. The solution was determined by spectroscopic mean to contain SF₅N=CHC₆H₅, a novel, electron-deficient Schiff base. Pentafluorosulfanylisocyanate and PCl5 reacted readily at 60-80° producing SF₅N=CCl₂ and POCl₃. A slow reaction between SF₅NCO and excess AgF₂ took place at room temperature. Infrared analysis of the reaction mixture at increasing temperatures gave evidence for formation and subsequent decomposition ofSF₅N=NSF₅. Pentafluorosulfanyliminosulfur difluoride (obtained from irradiation of N≡SF₃) reacted at room temperature with PCl₅ to produce SF₅N=SCl₂, a pale yellow liquid which rapidly attacked mercury, and reacted with AgF₂ (producing SF₅N=SF₂) and with SF₅NH₂(producing SF₅N=S=NSF₅). Pentafluorosulfanylamine, SF₅NH₂, and PCl₅ reacted at room temperature to give SF₅N=PCl₃ a pale yellow liquid which reacted rapidly with mercury. Thiazyl trifluoride reacted with metal carbonyls (Ni(Co)₄ , Fe(CO)₅, Mo(CO)₆, Mn(CO)₆) and ferrocene to produce thiazyl trifluoride - transition metal complexes. Chemical similarities between SF₅NCO and SF₅N=SF₂ with respect to nucleophilic substitution, exchange and coupling reaction reflect the similarity in bonding expected in these two systems. However, the failure of SF₅N=SF₂ and compounds containing the -N=SF₂ group to undergo additional reactions with polar reagents indicates some gross discrepancy from the usual behavior of these multiply bonded systems. Thus, a theoretical study of -N=SF₂ system was undertaken to clarify the role and magnitude of d-orbitals in the bonding of -N=SF₂ compounds. Theoretical calculations (CNDO) of the total energy of SF₅N=SF₂ , CF3N=SF₂ , C₂ F₅N=SF₂ , and FCON=SF₂ as a function of rotation about the N-S(IV) multiple bond showed that each total energy curve possessed a broad, flat minimum. Rotamers derived with only slight excitation would possess equal energy. Therefore, this multiple bond is nonrigid in contrast to the usual concept of the pπ-pπ double bond. The d-orbital contribution accounts for approximately 50% of the total π-bonding and is practically independent of the nature of the substituents on the nitrogen atom. Low temperature F-19 nmr studies showed that splittings occurred which can be explained on the basis of the total energy curves derived from the calculations. / Doctor of Philosophy

The purpose of this study was to identify and examine selected factors related to the adoption and implementation of curriculum change by home economics teachers in Virginia's public secondary schools. The major objective was to determine the relationship between the adoption of curriculum change and: (1) participation by home economics teachers in curriculum development activities and (2) selected demographic data. The population selected for the study were the consumer and homemaking teachers employed in Virginia's public secondary schools for 1973-1974. Stratified systematic sampling procedures were employed in which the teachers were divided into two subpopulations. The first subpopulation were teachers who participated directly in curriculum development activities. The second subpopulation were teachers not directly involved in curriculum development activities. A total of 180 teachers were included in the study; 161 responded for a response rate of 89 percent. The instrument (questionnaire) contained a list of fifty-one items. The three sections of the questionnaire included demographic data and participation and implementation inventories. A likert-type scale, ranging from one (strongly disagree) to six (strongly agree) was used to determine the strength of disagreement and agreement on the selected statements pertaining to participation in curriculum development and implementation of curriculum change. The responses were analyzed statistically by factor analysis, canonical correlations, bivariate correlation coefficients, tabulation and cross tabulations, and Pearson's correlation coefficients were computed to test the null hypotheses. Factor analysis of the responses resulted in the identification of three factors rotated for both the fourteen statements and the twenty-three statements. Canonical correlations and bivariate correlation coefficients were computed to determine if there was a significant relationship between the factor scores and each of the demographic variables. Pearson's product-moment correlation coefficients were computed to test the null hypotheses for significance. The findings indicated that there was no significant relationship between participation and adoption of curriculum change. A significant relationship was found between the age of the teacher, type of school, and manner in which the teachers received the Guide and teachers' adoption of curriculum change. No significant relationship was found between the level of educational preparation, area of undergraduate preparation, number of years experience, years in present system, source of school population, size of school enrollment, presence of a local supervisor of home economics education and adoption of curriculum change. Findings indicated a significant correlation between teachers who reported teaching in high school, teaching in rural communities, receiving the Guide at the annual Vocational Home Economics Teachers Conference, less number years of home economics teaching experience and participation perceived to be useful and essential to curriculum change and adoption. In view of the findings of this study, it is recommended that careful consideration should be given to the selection of teachers for participation in curriculum development activities and the manner in which curriculum materials are presented and disseminated to teachers. It is recommended that the Guide be re-evaluated as to its appropriateness for students in the middle, junior, and/or intermediate schools. It is further recommended that factors identified in this study which have a relationship to adoption and implementation of curriculum change should be considered in future curriculum development activities. / Ed. D.

The problem of this study was twofold. The first problem was to determine whether differences existed between elementary teachers, elementary principals, secondary teachers, secondary principals, and central office administrators in tenns of their perceptions as to the effectiveness of selected personnel services in the Kanawha County School System. The second problem was to determine the relationship between selected personal characteristics of elementary teachers, elementary principals, secondary teachers, secondary principals, and central office administrators in the Kanawha County School System and their perceptions of the effectiveness of selected personnel services. A questionnaire on selected personnel services was developed from the relevant literature and national standards adopted by the American Association ot School Personnel Administration. The statistical procedures used on the responses to the questions were frequency, distribution, percentage, chi square, mean, and the Pearson Product Moment Correlation Coefficient. A series of tables was developed to present the data collected from the responses. The results of the first part of the study indicated that differences existed in the perceptions of the effectiveness of selected personnel services by the five groups surveyed. The differences were particularly noted between teachers and administrators in the area of personnel administration entitled conditions of service. The second part of the study revealed that no significant relationship existed between selected personal characteristics of the five groups surveyed and their perceptions of the effectiveness of selected personnel services. / Doctor of Education

Human services integration attempts to improve the availability and effective delivery of services to clients who require the attentions of more than one service provider. Services integration is an issue of concern to many state governments, and has been attempted through a variety of mechanisms. Public education has typically been excluded from the human services integration movement. Although education is set apart from other human services by the comparatively large size of its state-supported budget and by its relatively autonomous administration, there are, nevertheless, significant commonalities in services provided by education agencies and other human service agencies. It is these service commonalities which warrant consideration of integration of services provided by education agencies with those of other human service agencies. The purpose of this study was two-fold: first, to develop a situational framework for analysis of the feasibility and appropriate design for human services integration; and second, to recommend a new and appropriate role for the Maryland State Department of Education, in concert with other Maryland human service agencies, directed toward the integration of State human services. Four research procedures were undertaken for accomplishing the study objectives. A review of the literature consisted chiefly of study of the experiences of other states with human services integration projects. This part of the study resulted in the development of a set of indicators to suggest the likelihood that a particular attempt to bring about services integration would or would not succeed. Information on the various mechanisms which have been used in attempts to bring about human services integration was also provided, and led to the development of a scale of possible structural and procedural mechanisms. These two classification schemes became the foundation for the situational framework which was used to analyze State human service agencies in Maryland and their social, political, and economic environment. Review of selected Maryland State documents provided the primary source of information on the organizational arrangements, missions, operational programs, and linkages of state human service agencies. A secondary source of information on the same topics was provided through the researcher's role as participant observor in Maryland State government. Validation of the material gathered and assembled from State documents and from participant observation was pr6vdded through a set of interviews with five State agency administrators and planners. The second set of interviews with these officials elicited professional judgment on desirable and feasible types of integration of the services of the Maryland State Department of Education with those of other State human service agencies. Both sets of interviews provided information for revision of the framework constructed from the review of the literature and Maryland State documents. Finally, conclusions of the study were formulated. Recommendations were provided for the development of services integration in Maryland and for the conduct of further study. / Doctor of Education

The effect of aflatoxin B₁ on RNA synthesis in phosphate-swollen rat liver mitochondria was examined. In the assay system used the incorporation of ³H-UTP into acid-insoluble product was inhibited 52% by actinomycin D (50µg/ml) and the labeled product was sensitive to pancreatic RNase. Aflatoxin B₁ inhibited in vitro mitochondrial ³H-UTP incorporation only 12% at high concentrations (0.4 mM or 130 nmol/mg protein). On the other hand, 25% inhibition was observed with mitochondria isolated 4 hr after animals had been treated with aflatoxin B₁ (5.3 mg/kg body weight by i.p. injection). This suggested that a metabolite of aflatoxin B₁ may inhibit mitochondrial RNA synthesis. The effect of aflatoxin B₁ on mitochondrial protein synthesis was examined using sterile mitochondrial preparations and two assay systems. In the first assay mitochondrial respiration served as an energy source, and in the second an ATP-generating system was used. As expected for mitochondrial protein synthesis, the incorporation of ¹⁴C-leucine into hot acid-insoluble product was inhibited 86% by chloramphenicol but was not affected by cycloheximide. Aflatoxin B₁ inhibited in vitro mitochondrial protein synthesis only at very high concentrations (13-25% inhibition at 0.4 mM or 135 nmol/mg protein). Treatment of animals with aflatoxin B₁ (5.0 mg/kg body weight), which is expected to result in relatively low concentrations of aflatoxin in the mitochondrial fraction (0.1 nmol/mg protein), produced a 23% inhibition of protein synthesis in mitochondria isolated 4 hr after injection. These data suggest that a metabolite of aflatoxin B₁ may inhibit mitochondrial protein synthesis. Using an in vitro system for the metabolism of aflatoxin B₁ by the mixed-function oxidase system in the presence of mitochondria, it was found that a metabolite(s) of aflatoxin B₁ inhibited mitochondrial protein synthesis by 40% at a concentration of 0.5 nmol/mg mitochondrial protein. This inhibition was not due to an alteration of mitochondrial respiration, as inhibition was observed in both the respiration and ATP supported assays. In addition, mitochondrial respiration, respiratory control ratios and P:O ratios were not affected. Formation of the inhibitory metabolite(s) required NADPH and 2, 3-unsaturation of the aflatoxin molecule. / Ph. D.