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.

Three groups of business educators assigned priorities to 41 competency statements and five competency clusters that had been identified in previous research as being important for vocational and technical education teachers. One hundred fifty survey instruments were distributed among 55 business teacher educators, 80 cooperating teachers, and 15 local supervisors of business education. Responses were received from 120, or 80 percent, of them. The responses were analyzed and the results used to answer the following research questions: 1. How do the groups rank selected clusters of teacher competencies? 2. How do the groups rank selected competencies within clusters? 3. To what extent do the groups agree with regard to priority ranking of clusters of teacher competencies? The findings of the study indicate that business educators assign priorities to clusters of teacher competencies in the following order: (1) Student-Centered Teaching, (2) Lesson Preparation, (3) Performance Oriented Teaching, (4) Nondirective Teaching, and (5) Student Discipline and Control. Significant agreement was found in every case except two. Local supervisors did not agree on the order of priorities for competency statements within clusters related to"Individualized Evaluation and Instruction"--one of the competency patterns in Cluster 1--and"Lesson Preparation." The conclusions of the study were as follows: 1. In developing teacher competencies for prospective business teachers, business educators probably place the greatest amount of emphasis on those competencies needed in working directly with students in a classroom setting. 2. In developing teacher competencies for prospective business teachers, business educators probably place high emphasis on competencies needed in lesson preparation. 3. In developing teacher competencies for prospective business teachers, business educators probably place high emphasis, but to a lesser degree than lesson preparation, on those competencies related to results of teaching. 4. In developing teacher competencies for prospective business teachers, business educators probably place moderate emphasis on those competencies related to process of teaching. 5. In developing teacher competencies for prospective business teachers, business educators probably place the least amount of emphasis on those competencies related to" student discipline. Based upon the findings and conclusions of the study, the following recommendations were made: 1. In revising their curriculums, course content, program experiences, and teaching methodology, business teacher educators should consider the priorities revealed in this study. Revisions based on these priorities should reflect greatest emphasis on competencies needed by prospective business teachers related to student-centered teaching. 2. Since the priorities revealed in this study represent responses from three groups of business educators, State Department of Education personnel should consider using them in revising curriculum guides and other materials related to business teacher education programs. 3. In order to provide a basis for comparison of the assignment of priorities to teacher competencies across vocational programs, research studies similar to this one should be undertaken in other vocational areas. 4. Since priorities change with changing conditions, business · educators should reexamine priority strategies on a continual basis. / Doctor of Education

The effect of participation in an environmental education program on the cognitive and affective growth of teachers and students was investigated. Fourth, fifth, sixth and eighth grade teachers from selected schools in Prince William County Virginia, were enrolled in an environmental education project funded by the National Science Foundation. These teachers, teachers who taught in the same school but not enrolled in the project, and teachers from schools (control) not involved in the project composed the three teacher groups for the study. The students of these three groups of teachers were the student groups of interest in the study. The three groups of teachers were administered environmental attitude and environmental knowledge measures. Analysis of the data indicated that hypothesized differences between the groups were inconclusive. The students, while not treated directly, were administered an Environmental Semantic Differential, as an attitude measure and a knowledge test. Analysis of covariance indicated that there was a significant group by grade by sex interaction, with fifth and fourth grade treatment females scoring significantly higher on the attitude measure than the other groups. The results of the analysis of these student attitude data provide evidence of both the effectiveness of the environmental education program and the use of the semantic differential as a measurement of students' attitudes toward the environment. / Doctor of Education

The use of response latencies to determine item weights in the construction of multiple-choice test scores was investigated. Three times were measured on each test item by the computer system which administered two tests. The times recorded were: the reading time which the student used to read the stem of the question; the decision time which the student used to read the alternatives, to eliminate the incorrect choices he could identify, and to indicate the correct choice; the third time recorded was the choice reaction time which the student required to identify the number of the correct alternative. Each of the three response times was analyzed as a function of two independent variables: the number of alternatives eliminated, and the correctness of the answer selected. Reading time was not significantly related to either of the independent variables. Decision time was shorter when correct answers were selected than when incorrect answers were selected. Furthermore, decision time was shorter when zero or three alternatives were eliminated than when one or tvo alternatives vere eliminated. Reaction time was also shorter when correct answers were selected than when incorrect answers were selected. In contrast to the decision time results of two independent main effects, the reaction time analysis indicated an interaction between correctness of the student's choice and the number of alternatives eliminated: when the decision was correct, reaction time became shorter as the number of eliminations increased; when the decision was incorrect, reaction time became longer as the number of eliminations increased. Both decision time and reaction time results were consistent with those of laboratory studies. Item weights were constructed as the differences between item response latencies for each student so that between-student differences in absolute response time were eliminated. Given a confidence construct popular in decision time and reaction time research, the latency item weights were formulated to maximize weight of items answered with relative certainty and to minimize weight of items answered with relative uncertainty. Test scores used in evaluating the latency weighted scores included raw scores (the number correct) and the Coombs mode scores (the number of alternatives correctly eliminated minus three times the number of alternatives incorrectly identified, since all items had four choices), and several personality trait scores. The reaction time scores had higher validity estimates than either the Coombs mode or raw scores from the same test, but did not correlate with corresponding raw scores as well as the Coombs mode scores. In contrast, the decision time scores had validity estimates higher than raw scores and comparable to the Coombs mode scores, but were very highly correlated with the corresponding raw scores. In addition, decision time scores correlated with the exam raw scores more so than any other measure. Finally, the effect of personality traits on each of the test scores was investigated. Both reaction time and decision time scores were less correlated with a measure of test-taking anxiety than either the Coombs mode or raw scores. / Ph. D.

Presence and abundance of filamentous soil mycelium was determined in North American coastal Arctic tundra soils near Barrow, Alaska. Soils were examined at one centimeter intervals from the surface to the depth of thaw, 0-24 cm, over a three year period during the International Biological Programme Tundra Biome study. Examined were 1217 soil samples, and 57,850 microscopic fields which clearly made this quantitative study of soil fungi the most comprehensive of its kind for tundra. Over 30 study plots were regularly sampled along a 1400 meter moisture dominated gradient. The plots were conveniently categorized into one of five principal habitats in polygonally dominated terrain. The five habitats were polygon troughs, rims, low centered basins, high centered and flattened polygon tops, and mesic tundra meadows. All plots were described vegetatively and physiographically. Presence of soil fungi was expressed in meters of mycelium per gram dry weight of soil (m/gdws) and grams per square meter to a 1 cm depth. Mycelium averaged 700 m/gdws and 1.05 g/m²/cm to 7 cm during the 1972-1974 study. Mycelium values ranged from 213 to 3504 rn/gdws and .34 to 8.11 g/m²/cm at the 1-2 cm depth, and from 76 to 445 m/gdws and .29 to 1.97 g/m²/cm at the 6-7 cm depth. Seasonal fluctuation of mycelium showed early season vernal highs followed by,an abrupt decline to mid season, a build up to a Fall peak concurrent with fungal fruiting and a general decline to season endings and freeze-up. Amplitudes of mycelium level fluctuation were greater and showed greater variation in surface soils, 1-2 cm, as contrasted to the deeper profile layers, 6-7 cm. Mycelium production rates showed that 1 m of initial mycelium gave rise to 2.7 m by season's end. Over 75 % of the fungal mycelium was concentrated in the upper 4-5 cm of the soil profile. The 2-4 cm depth was also the zone of maximum vascular plant root concentration. Low levels of resident mycelium were detected at 24 cm depths in all habitats that could be sampled to that depth. Mycelium abundance decreased significantly in highly mineralized soils, but increased at greater depths where buried peat substrates were found. Clamped hyphae were most abundant, 51 %, in soils of rim habitats and least, 1 %, in low centered basin habitat soils. Polygon rim soils also supported greater numbers of mycorrhizal forming vascular plants. Soil moisture was found to be the single most important abiotic variable to influence presence and abundance of soil fungi. Optimum soil moisture ranged from 300-450 dry wt. %. Soil moisture also decreased with depth in the soil profile as did the abundance of mycelium. Optimum values for soil bulk density (g/cc) ranged from .2-.3 g/cc. The influence of soil moisture on mycelium abundance was separable from those influences of soil bulk density of same. Mycelium was least abundant where soil bulk densities were greatest, on polygon top habitats. Little or no correlation was found to exist between soil temperature and mycelium abundance. Fungi growth was most closely associated with temperatures of 4-5 C in that 69 % of the net fungal growth could be explained.. Correlations of mycelium to soil carbon showed no correlation. However, where soil carbon % was greatest mycelial abundance was least. Mycelium abundance was correlated, r² = .85, most highly with labile phosphorus in basin habitat soils even though polygon troughs had the greatest labile phosphorus levels in soil solution. The multiplicative effect of all variables was far more significant than any single variable. Hyphal widths averaged 2.75 µm. In situ growth studies showed a mycelium growth rate of 1.5 mm/day. Percent colonization of a nylon mesh substrate was low and ranged from 2-19 %. Growth rates of mycelium were highest in soils of trough habitats and lowest in soils of polygon top habitats. Insignificant amounts of soil carbon, .96-1.30 % of total, were incorporated into the mycelium. Phosphorus composition in mycelium was .9 %, which was a 10³ phosphorus increase in fungal tissues compared to an equal weight of soil. Nitrogen levels were less significant than phosphorus. If only ammonia nitrogen (NH₃-N) was absorbed by mycelium then 1/2 to all of the available NH₃-N in the soil was absorbed. Caloric values of fungal tissues ranged from) 800-4900 cal/gdw. / Ph. D.

This study was conducted to determine the effect of using high purity oxygen as the gas of aeration on the activated sludge process. Three completely-mixed cylindrical reactors were used in the study. The working volume for two of the reactors was 10.4 liters while that for the third was 4 liters. The gas of aeration for the small reactor and one of the large reactors was high purity oxygen and that for the other large reactor was compressed air. A soluble composition of nutrient broth, glucose, yeast extract, and various mineral salts was used as the substrate. The organic loading to each reactor was the same and this loading was maintained throughout the research period. Sludge age was used as the control parameter and control was achieved by wasting a specific volume of sludge each day. This procedure provided a means of operating over a range of sludge ages. Results of the study indicated that an activated sludge system operating at low solids and high dissolved oxygen concentration is susceptible to takeover by filamentous microorganisms. A model was proposed to explain this phenomenon. Results also suggest that it is not the use of oxygen which is responsible for differences in substrate removal rates and yield observed between air and oxygen activated sludge units. Such differences are probably the result of high solids levels which most oxygenation systems operate at. This argument is supported by the model proposed to explain the stimulation of filamentous growth by high dissolved oxygen levels. Results also indicate that activated sludge systems, when operated under either air or oxygen aeration, will show no significant variation in the gross composition of microbial mass between the specific growth rate range employed in this study. / Ph. D.