The response of boundary layer velocity and temperature distributions to small amplitude oscillations imposed by the free-stream is investigated. A straightforward combination of perturbation and numerical methods is applied. The analysis of the effect of the frequency of oscillations shows that in many respects the response of the boundary layer to the oscillations in time is periodic in ξ (ξ = frequency parameter), with the period Δξ ≈ 4.0 and the first harmonic manifesting itself strongly at ξ ≈ 1.15. The available experimental data seem to confirm this finding. Second-order effects of oscillations on velocity and temperature fields are studied for laminar flows. In general the steady-streaming contributions are small, but it appears from the present results that for large Eckert numbers the wall heat transfer may be altered up to 40% by the streaming phenomena. Unfortunately there is no experimental data on this subject. Several models of the oscillatory Reynolds stress (eddy viscosity type) are tested for oscillating turbulent boundary layer flow on a flat plate. Satisfactory results are obtained by decoupling the mean and oscillatory Reynolds stresses. It appears that theoretical profiles of oscillating velocity in low or high frequency regions are relatively insensitive to the details of the models used. This is not the case for intermediate frequencies for which in fact the performance of the present models is not very good. It is concluded that the interaction between the random turbulent motion and oscillations is probably too strong to be neglected and therefore more complex models, capable of incorporating the interaction process, are required to successfully predict the behavior of oscillatory turbulent boundary layers. / Ph. D.

An in-depth study on the time-temperature behavior of epoxy based continuous and elastic fiber reinforced composite materials and the feasibility of using the time-temperature analogy as an accelerated characterization method to predict the long-term behavior are presented. This is a two-pronged investigation as the material investigated (graphite/epoxy) is essentially quasi-elastic at room temperature and viscoelastic at elevated temperatures. Correlations between analysis and experiments are presented whenever possible. At elevated temperatures, master curves of matrix dominated unidirectional laminates are obtained using the time-temperature superposition principle. Using the principal properties (E₁₁, E₂₂(t), G₁₂(t) and v₁₂), master curves of other off-axis laminates reduced at any arbitrary ambient temperature are predicted. The results obtained from the short-term (16-minute) tests, medium term (25-hour) tests and predictions are shown to correlate reasonably well. In addition, the delayed failure prediction and experimental results are shown to correlate reasonably well. Both the experimental and predicted delayed failure results indicate that the creep strength master curves are dependent on the in-plane stress states and that failure modes vary from ductile to aquasi-brittle depending on the duration of the tests. At room temperature, a summary of the unnotched and notched behavior is presented. In the unnotched case, total stress-strain responses of general symmetric laminates are predicted with a non-linear analysis and compared with experimental results. The analysis is used to validate intralamina shear test methods. In the notched case, test results for specimens containing variations in notch geometries and anisotropy are given. These results are correlated to three two-parameter and one one-parameter analytical fracture models. / Ph. D.

The purpose of this study was to develop a conceptual framework for improved financial reporting in public higher education in the District of Columbia. Implementation of major concepts was accomplished through development of an accounting manual for public higher education in the District of Columbia which was consistent with the accounting and reporting principles enunciated by the American Institute of Certified Public Accountants (AICPA), in Audits of Colleges and Universities, and by the National Association of College and University Business Officers in College and University Business Administration. The District of Columbia is unique because the local government performs the functions of state, county, and municipal governments, in addition to functioning as a quasi-federal agency. The District of Columbia government has been severely criticized for the overall quality and integrity of its financial accounting and reporting system. In response to a congressional mandate, the city is undertaking a complete revision of its financial accounting and reporting system. The existing financial accounting and reporting system for public higher education in the District of Columbia has been following federal agency guidelines in contrast to recommended practices by AICPA, NACUBO, and NCHEMS. In development and evaluation of an Accounting Manual to be used by the University of the District of Columbia, the author modified a questionnaire, the manual requirements, and. supporting reference information to four jury groups. The primary jury group consisted of professionals in higher education financial management in the District of Columbia; the remaining jury groups represented various constituencies that would use the proposed manual or be responsible for its adoption. Based on the recommendations of these jury groups and an analysis of the various legal and operational requirements imposed by statue, a manual was developed that was determined satisfactory for operational implementation. The author recommends the use of a similar procedure for developing accounting manuals for use by other institutions and cites the benefit of multiple jury groups broadly representative of experts and users. / Ed. D.

The present study pursued the effect of Rational Emotive Education on irrational beliefs, assertiveness, and/or locus of control in fifth grade students. A random sample of two hundred students were pre- and post-tested in accordance with the Solomon Four Group Design. The Children's Survey of Rational Concepts From C, Revised Rathus Assertiveness Schedule, and the Intellectual Achievement Questionnaire were selected as instruments to measure irrational beliefs, assertiveness, and locus of control respectively. A ten week guidance program was presented to the Experimental Groups by twelve elementary school counselors using lessons from Rational Emotive Education: A Manual for Elementary Teachers. Pre-test and post-test scores were subjected to statistical analyses using ANCOVA and ANOVA. The results of both the ANCOVA and ANOVA revealed that a significant difference at the .05 level was evident only on the Children’s Survey of Rational Concepts which tested the rational beliefs of the students. One week after post-testing, fifteen students and five teachers were randomly selected from the Experimental Groups to be interviewed using questions that focused on the three variables: irrational beliefs, assertiveness, and Iocus of control. Their anecdotal remarks were collected to provide additional information on subtle changes in students that may not have been evidenced by quantitative data. The following is a summary of the results concluded from the study: 1. There was a statistically significant difference between experimental and control groups in irrational beliefs after Rational Emotive Education as measured by the Children's Survey of Rational Concepts. Anecdotal remarks lent support to the statistical evidence. 2. There was no statistically significant difference between experimental and control groups in assertiveness as measured on the Revised Rathus Assertiveness Schedule after Rational Emotive Education. However, assertive behavioral changes were evidenced in anecdotal data as reported by teachers and students. 3. There was no statistically significant difference between experimental and control groups in locus of control as measured on the Intellectual Achievement Responsibility Questionnaire after Rational Emotive Education. However, students did demonstrate very subtle change in locus of control as evidenced in anecdotal data, with teachers more explicit in reporting internality changes in locus of control than students. There are implications from these findings in the area of elementary counselor education and elementary guidance program selections. Also, alternative measures of assessing assertiveness in young students might be attempted which are more qualitative than quantitative. Future studies may attempt to modify rational emotive education to include lessons and activities designed to increase knowledge of internality and externality which may influence locus of control in upper elementary school age students. / Ed. D.

This research was concerned with the effects of a six week short term career education program on self appraisal, knowledge about occupation information, goal selections, career planning, and career decision making as measured by the Career Maturity Inventory (CMI). Only the Competence Scale of the CMI was utilized in conducting this study. This study was not a true experimental research design, instead it was a developmental study designed to establish baseline data for longitudinal studies. Although a true experimental design was not utilized in conducting the study, a treatment group of 53 students and a control group of 53 students were used. The short term career education program was developed specifically for rural Black youth taking into account economic, social, and geographical factors of the population. Non-commercial activities such as music adapted from the culture, multi-ethnic scrapbook, developed by the participants in the short term career education program, and career education activities related to the Black dialect spoken in the community were among some of the innovative and creative activities that attributed to the uniqueness of the short term career education program. The results indicated no significant difference in the treatment group and control group on pretest~pretest comparison on the total competence scale of the CMI. A dependent t-test was performed on each of the five CMI subtests on the competence scale. There was a statistically significant difference in the group mean scores on the five CMI subtests for the treatment group after exposure to the short term career education program. The treatment group mean score indicated an improved gain score on each of the five CMI subtests of the competence scale. The following research questions were developed for each of the five subtests on the Competence Scale of the CMI. 1. Does a short term career education program improve the self appraisal of rural senior high Blacks as measured by Career Maturity Inventory (CMI)? 2. Does a short term career education program improve knowledge of career information of rural senior high Blacks as measured by the CMI? 3. Does a short term career education program improve goal selection skills of senior high Blacks as measured by the CMI? 4. Does a short term career education program improve career planning of rural senior high Blacks as measured by the CMI? 5. Does a short term career education program improve the career decision making skills of senior high Blacks as measured by the CMI? For each of the five research questions the data revealed significant mean score difference gains for the treatment group at the .05 level. The control group experienced a decrease in posttest group mean score after the six week period. Two instruments, the Career Maturity Inventory (Crites, 1973) and a Career Education Program Survey designed by.the researcher were utilized to analyze the data. The findings in this study suggested that the short term career education program was successful with the predominately rural Black population in Port Gibson, Claiborne County, Mississippi. / Ed. D.

Most discussions of telephone rate of return regulation center upon the regulatory effects of the Federal Communication Commission. Little attention is given to the regulatory activities of the state utility commissions. Even when attention is directed toward state commissions, little of it is directed toward the decision-makers (the commissioners) of these agencies. Little explanation is given as to why a 2.49 percent rate of return is approved in one case and a 6.75 percent rate of return in another. Two main theories of regulatory behavior have been offered in the past. The public interest theory offers the hypothesis that regulators are able to discern the public interest and attempt to pursue courses of action that are in the public interest. The theory does not show how the regulators are able to discriminate between the true public interest position and the aberrations sponsored by special interest groups. The "capture" theory hypothesizes that the regulating commission and its commissioners come under the influences of special interest groups. Rather than being concerned with the public interest, the regulators are concerned with distributing the gains from regulation among the special interest groups, including themselves. The model developed within this study flows out of the "capture" theory. It is hypothesized that regulators award rates of return in intrastate telephone cases based upon the appeal probabilities of the relevant parties, the company and the intervenor. The concern for the appeal probabilities arises from the likelihood that an appeal will direct legislative and voter attention to the activities of the commission. Such attention is likely to trigger legislative review with the possible loss of commission prestige, power, budget, etc., or legislative change in the commission structure or scope of responsibility. It is assumed that any adverse effects of legislative action will flow through and have similar effects upon the commissioners. Based upon the theoretical model, empirical models are structured to identify the important public choice variables influencing decisions of the commissions and commissioners, to test for differences between the rates of return awarded in formal vis-a-vis informal cases, and to test the implied allocation under the adversary process. To test these hypotheses, ordinary least-squares regressions were run, using case data from 1965-1969 and commission data from 1967. The regression results raise some interesting questions concerning intrastate telephone regulation. Neither intervenors nor the commission staff appear to have a significant effect upon the awarded rate of return, thus raising serious questions about the adversary proceedings concept. The lower rates of return awarded Bell Telephone Companies raises concern about the alleged benefits from pursuing the Department of Justice plan to disintegrate the Bell Telephone System. It appears that the major limiting force mitigating the power of the firm is the choice of the regulatory procedure used. Finally, jurisdictions using the fair value evaluation method appear more generous in awarding rates of return than those using the original cost method. / Ph. D.

The best characterized of the autonomous parvoviruses are those of rodent origin. The purpose of this study was to examine the physicochemical characteristics of the genome of an autonomous parvovirus of non-rodent origin, bovine parvovirus (BPV). BPV was isolated from infected cells by centrifugation through a sucrose-CsCl step-gradient. The virion DNA was released from the capsids by alkali treatment. Upon chromatography on hydroxyapatite, two peaks of radioactivity were consistently observed. Peak I eluted at a sodium phosphate concentration of 0.17 M, intermediate between single- and double-stranded DNA markers. Peak II eluted in the same position as double-stranded DNA. The DNA eluting in peak I represented the viral genome. About 7% of the genome length was found to exist as a duplex. The BPV DNA was found to have sedimentation coefficients of 16.5 Sand 27 S in alkaline and neutral sucrose, respectively. These S values corresponded to a molecular weight of approximately 1.7 x 10⁶ daltons. The BPV DNA was rich in thymine (31.3%) and had a GC content of 45.1%. The buoyant density of the single-stranded BPV genome was determined to be 1.721 g/cm³. The DNA eluting in peak II was shown by hybridization to be of BPV origin. Furthermore, the peak II DNA was shown to be of the same size as the single-stranded BPV genome, by sedimentation in alkaline sucrose. Electron microscopy revealed that the peak II DNA was linear and double-stranded. It is concluded that BPV packages the plus strand into separate virions in significant amounts, resulting in the reannealing of complimentary plus and minus strands upon release from the virions during isolation of the DNA / M.S.

This study was conducted to: (a) determine scrotal circumference (SC) and testicular consistency (tone) of performance tested, yearling beef bulls of various breeds; (b) correlate these values with performance data; (c) attempt, by means of a buyer survey, to evaluate the fertility and overall desirability of the beef bulls sold through the Virginia BCIA Bull Test Stations; (d) study the relationship between several semen characteristics, scrotal circumference, and testicular consistency measurements of yearling beef bulls. Final SC was correlated .60 (P < .01) with initial SC and -.31 (P < .01) with final weak spring tone. Final weak spring tone was correlated .87 (P < .01) with final strong spring tone. Final SC was positively correlated with final weight .44 to .64 (P < .01) and age .40 to .52 (P < .01). Final weak spring tone was negatively correlated with final weight -.35 (P < .01) and age -.30 to -.34 (P < .01). When the least-squares means were calculated for final SC, the final SC of the Angus breed was significantly different from the final SC of the Simmental and Polled Hereford breeds (both P < .01). For the bulls placed on a collection regimen, SC was positively correlated with ejaculate volume, .53 (P < .01) to .57 (P < .05), and with sperm output .55 to .71 (P < .01). No significant correlations were found between the tone measurements and the semen traits. / M.S.

Glucocorticosteroids are drugs commonly used to suppress immune or inflammatory responses. The present study was done to evaluate the influence of glucocorticoids on immunity in fibrosarcoma-bearing mice. Effects of hydrocortisone-21-sodium succinate (HCS) on mitogen-induced lymphocyte proliferation were assessed. T cells from nontumor-bearing mice showed a 2-fold suppression of phytohemagglutinin (PHA) responsiveness with the addition of 0.1 µg HCS. However, T cells from mice with 3-4 week tumors did not demonstrate as great a suppression, if any. Kinetic studies during tumor growth demonstrated a decrease in HCS suppression of mitogen-induced DNA synthesis at 8-10 days post-tumor cell inoculation. RCS-treated cells from mice with 3-4 week tumors had a 2- fold increase in blastogenesis over untreated PHA controls. The role of macrophages and their involvement in the steroid sensitivity of the PHA response is unclear. Evidence reported here indicated that macrophages may be involved as mediators of steroid sensitivity and may therefore limit the extent of their suppressive and/or enhancing activity. In vivo administration of methylprednisolone acetate (MPA) demonstrated that steroids can interfere with the growth and progression of fibrosarcomas in their syngenic BALB/c hosts. The strongest delay in tumor appearance was observed when the steroid was administered 4-7 days post-tumor cell inoculation. It is assumed that after tumor cell inoculation, precursor cells of both suppressor and cytotoxic lymphocytes were entering a proliferative stage to form mature cells. These studies indicated that steroid suppression was directed against a suppressor T cell and possibly acts by preventing its differentiation. It is thought that this suppressor cell acts by inhibiting the lytic function of effector T cells. Thus, by eliminating suppressor T cells, the immune response is capable of eliciting strong anti-tumor immunity. / M.S.

One of the most widely studied “exotic atoms" in Chemistry and Physics is positronium. Positronium (Ps) is the bound state of an electron and positron. It is formed in two ground states, para-positronium (p-Ps) and ortho-positronium (o-Ps) whose lifetimes in free space are 0.125 nsec and 140 nsec respectively. When thermalized o-Ps forms a complex with a molecule, the electron density at the position of the positron will be drastically increased thus shortening its lifetime. A study was performed to evaluate what role the solvent plays in stabilizing the complexes formed between Ps and nitroaromatics in solution and the various thermodynamic variables associated with these processes. This study also included the evaluation of the effects displayed by several different solvents on complexes formed between Ps and CuCl₂. The interpretation of the solvent effects of Ps reactions in terms of the "bubble shrinkage model" was tested using the results obtained in the reactions of Ps with various inorganic and organic molecules in different solvents. It was found that this model is definitely not applicable below a certain critical viscosity of the solvent and appears to be restricted to diffusion controlled reactions. The fact that the reactivity of Ps towards nitroaromatics is drastically reduced when the latter molecules are already complexed with other conventional molecules can be utilized to determine the molecular formation constant, K_c, for inclusion Compounds. A study was made using Ps as a probe to provide valuable information about the influence of steric factors on the ability of guest molecules to bind in the cavity of cyclohexaamylose, / Ph. D.