Repeatabilities (t) and heritabilities (h²) for racing time were estimated from data on 7206 2- and 3-year-old standardbred racehorses competing in charted races at six tracks between 1975 and 1976. There were a total of 38,487 records from 2367 sire progeny groups. The data were divided according to gait into two subsets. Trotters only were used to test alternative models proposed to characterize horse’s racing time. Initially, class of race was recognized as a subjective categorization reflective of non-random assignment of horses to races. After extensive investigation, it was concluded that adjustment of horse’s time should include regression on pace (time of the winner). Data were analyzed within track-age-gait subclasses. Intra-horse regression coefficients of time on pace (sec/sec) ranged from .61 ± .08 to .79 ± .05. When records were adjusted for pace, repeatability and heritability estimates ranged from .32 ± .08 to .55 ± .04 and from -.25 ± .22 to .66 ± .15, respectively. Pooled estimates of t and h² were .44 ± .01 and .29 ± .03, respectively. When records were not adjusted for pace, sire, horse and error variance components were inflated by environmental bias (t_pooled = .62: h² pooled = .36). When records were pre-adjusted for pace, the permanent environmental variance appeared smaller compared with the total phenotypic variance than if there was no preadjustrnent for pace. Since genetic progress is based on selection of genetically superior sires and dams, time adjusted for pace should be used for estimation of breeding values and for objective evaluation of an individual horse's real ability to compete against horses having similar abilities. Thus, resulting breeding values should be more accurate dnd biased to a lesser degree than if unadjusted racing times were utilized. / Ph. D.

Lignin degradation, is quite common in nature and is an important link in the natural carbon cycle. A large variety of microorganisms are know to degrade lignin in nature as well as in contrived fermentation systems. White-rot and soft-rot fungi, as well as Actinomycetes, are apparently the most active lignin degraders in nature. The large, cross-linked, polymeric structure of the lignin macromolecule makes its direct uptake, during the initial stages of its degradation, by microbial cells improbable. Moreover, the fact that the lignin macromolecule is composed of different monomeric units linked by a large variety of non-hydrolyzable intermonomeric bonds precludes hydrolytic cleavage of the biopolymer. Despite the fact that many extracellular and membrane-bound enzymes have been suspected in the initial breakdown of lignin, such activities have not yet been found. A close review of the literature indicates that the initial breakdown of the lignin macromolecule may be nonenzymatic. In addition, the degradation of the lignin polymer appears to follow an exo-degradation mechanism. That is, many lignin degrading microorganisms are apparently incapable of splitting the lignin molecule into intermediate molecular weight polyphenolic moieties which are further degraded; instead, they attack the periphery of the macromolecule. The possible involvement of reduced oxygen species produced by white-rot fungi in the initial breakdown of the lignin macromolecule, during its biodegradation, was investigated. Using Coriolus versicolor as a representative of white-rot fungi, I demonstrated that C. versicolor exports superoxide radical and hydrogen peroxide during lignin degradation, into the lignolytic medium. Results presented in this study indicate that a correlation between the concentration of extracellular superoxide radical in the medium and the extent of lignin degradation may exist. Moreover, I have shown that superoxide radical is produced in the cell membrane, and not the organism's mitochondria. This precludes the possibility that such reduced oxygen species are produced as a result of normal respiration by the organism. An investigation of the effects of aeration and agitation indicated that agitation has a detrimental effect on the extent of lignin degradation. On the other hand, increased oxygen tension in lignolytic cultures appeared to enhance the extent of lignin degradation. Another interesting finding was the fact that conditions leading to the formation of reproductive fruits in the lignolytic microorganism favored the degradation of the lignin fraction in lignocellulosic materials. A comparative study of two different fennentation schemes, designed to degrade lignin in 1ignocellu1osic materials on a large scale, indicated that solid state fermentation of such materials led to greater lignin degradation. Fluidized bed fermentations, on the other hand, appeared to favor the degradation of the carbohydrates rather than the lignin fraction of lignocellulosic materials. Studies of the biodegradation of monomeric lignin model compounds do not shed light on the initial step(s) involved in the breakdown of the lignin polymer. Such studies assume that microbial breakdown of lignin model compounds is similar to microbial breakdown of lignin an assumption that may not be correct. It is true that degradation of monomeric lignin model compounds can conceivably elucidate the mode of degradation of low molecular weight moieties resulting from initial breakdown of the lignin macromolecule. However, the chemical identities of these low molecular weight intermediates are not yet known. The efficacy of studies using aromatic, monomeric lignin model compounds in attempts to identify intracellular pathways for metabolism of lignin depends on the assumption that lignin breakdown products are indeed mononuclear phenolic materials. Careful analysis of soluble and insoluble residual lignin resulting from lignin fermentations is a critical step in assessing the lignolytic ability of microorganisms. Furthermore, such analyses are essential in understanding the steps involved in lignin metabolism by microorganisms. To date the methods for residual lignin analyses are complex, time consuming and error prone. There is an urgent need to develop a quick and simple method for residual lignin analysis that will yield accurate and reproducible results capable of elucidating structural changes in residual, biodegraded lignin. The development of such an analysis technique will undoubtedly lead to a better understanding of the complex problem of lignin biodegration. / Ph. D.

The purpose of this study was to compare the sources of revenues received by Historically Black Colleges to the sources of revenues received by predominantly white colleges during the 1970’s. More specifically, seventy-six HBC were paired with seventy-six predominantly white colleges, and the basis of control (public or private), Carnegie classification, size, and geographic location, were arranged into two groups. Public comprehensive colleges, both black and white, were identified as group 1. Private liberal arts colleges, both black and white, were identified as Group 2. The sources of revenues for these two groups were analyzed to determine how sources of revenues compared between black and white colleges, within groups, fiscal years 1971 through 1979. The sources of revenues were (a) tuition and fees, (b) federal government revenues, (c) state and local government revenues, (d) private gifts, grants and contacts, (e) endowment, (f) other sources of revenues, and (g) total revenues. Fourteen null hypotheses were formulated to determine if statistically significant differences existed between black and white colleges, within each group, for each of the seven sources of revenues. Data were obtained from the Higher Education General Information Surveys of the National Center for Education Statistics. The MANOVA procedures were used to analyze the data and the .05 level of significance was required to reject the hypotheses. Analysis of the data for black and white public comprehensive colleges showed: 1. There was not a statistically significant difference between black and white public comprehensive colleges for revenues received through the sources of tuition and fees; private gifts, grants and contracts; endowment; and other sources of revenues. 2. There was a statistically significant difference between black and white public comprehensive colleges for revenues received through the sources of federal government revenues, state and local government revenues, and total revenues. Analysis of the data for black and white private liberal arts colleges showed: 1. There was not a statistically significant difference between black and white private liberal arts colleges for revenues received through the sources of endowment and other sources of revenues. 2. There was a statistically significant difference between black and white private liberal arts colleges for revenues received through the sources of tuition and fees; federal government revenues; state and local revenues; private gifts, grants and contracts; and total revenues. The MANOVA procedures were also used to analyze the sources of revenues for public comprehensive colleges with black land grant institutions removed. Chapter five listed some of the past operational practices of historically black colleges which may have contributed to the higher cost of operation where revenues are calculated on a per student basis. / Ed. D.

A nonlinear programming technique using the penalty function method,which. is especially suitable for power. converter design optimization, is utilized for the comparison of the conventional BuckBoost and Cuk converters. Detailed comparisons are made with respect to the loss and weight breakdowns. of the optimum design of the two converters for a given set of performance specifications. The comparison shows that the Cuk converter outperforms the conventional Buck-Boost converter in both operating efficiency and weight considerations for both the step up or step down modes of operation. Also, a detailed comparison of the coupled inductor version of the Cuk converter under both the balanced and unbalanced current ripple reduction modes of operation is made. From this comparison, it is shown that the unbalanced current ripple reduction is more advantageous. The effects of using different input voltages and different core materials with different saturation flux densities on the global power converter optimization were also studied. The new Cuk converter was disclosed for the first time in 1977. Since then, there are several controversies about the claims made by Cuk of the advantages. of his. converter with respect to the conventional Buck-Boost converter. The comparisons made by Cuk of the two converters did Iiot satisfy the same performance specifications. Consequently, his conclusions of the superiority of his converter cannot be fully justified. In this work the comparisons are made of these two converters based upon the optimum designs. £or a given set of performance specifications. With the detailed comparisons of the loss/weight breakdowns of these two converters, the controversies surrounding the Cuk converter are solved. / Ph. D.

The purpose of this study was threefold: ( 1) To determine the educational orientations of post-secondary occupational-technical instructors; (2) To determine the interpersonal behaviors of post-secondary occupational-technical instructors; and (3) To examine the proposed relationship between interpersonal behaviors, demographic variables, and education. orientations of occupational-technical educators. The study sample consisted of 132 occupational-technical. educators located in the four technical institutes of Tennessee. Career divisions represented in the sample were: business science, computer science, engineering science, and health science. Instrumentation included the Educational Orientation Questionnaire ([ EOQ ], Radley, 1975) which measured andragogical-pedagogical beliefs and practices. The Fundamental Interpersonal Relations Orientation Behavior Science ([ FIRO-B ], Schutz, 1967) identified teachers’ interpersonal interaction behaviors. In addition to the primary instruments, a survey form was used to collect demographic data concerning the sex, age, average class size, years of schooling, and years of occupational in£ormation. The primary data analysis used were descriptive and multiple regression. The findings were: 1. Occupational-technical instructors in Tennessee technical institutes are more pedagogical in educational orientation than similar occupational groups studied. 2. Occupational-technical instructors in Tennessee technical institutes exhibit interpersonal scores which suggest that as a group they are selective about the persons with whom they associate; they prefer not being controlled and not exercising control over others; and they have a moderate need to be liked by others. 3. The relationship between interpersonal behaviors, demographic variables, and educational orientation is doulinated by one's age, expressed control, sex, and years of schooling. The relationship between interpersonal behavior and demographic variables and education. orientation varies from school to school. 4. While the proposed relationship between variables of interpersonal behavior, demographic variables, and education orientation was found, the study's demographic variables tended to account for more variance in educational orientation. / Ed. D.

Two on-line multidimensional HPLC systems are described; one coupling two liquid chromatographic columns (LC/LC), and one coupling liquid and gas chromatography (LC/GC). Theoretical equations relating the reproducibility, accuracy and transfer efficiency to system operating variables such as flow rate, retention time, column efficiency and transfer volume have been developed. These effects are explained and verified using experimental systems. Three major applications are shown for each of the systems. For the LC/LC systems, these include; the analysis of caffeine and theophylline in biological fluids; the analysis of hydrocarbon group types in fuels and oils and the analysis of catecholamines in urine with electrochemical detection. For the LC/GC system, the applications include; the analysis of pesticides in butter, the analysis of hydrocarbon group types in fuels and the analysis of polycyclic aromatic hydrocarbons in petroleum related samples. / Ph. D.

In this work, an analysis of the Tollmien-Schlichting instability of laminar viscous flows is presented. For two-dimensional incompressible flow past a flat plate with porous suction strips, we use linear triple-deck, closed-form solutions for the mean flow to do a linear, parallel, spatial stability analysis. We develop a simple linear optimization scheme to determine the number, spacing, and mass-flow rate through the strips and conclude, surprisingly, that suction should be concentrated near the Branch I neutral point of the stability curve. We then verify the results of our optimization scheme with experimental data. We find that the theory correctly predicts the experimental results and conclude that the optimization scheme is reliable enough to replace the experiment as a tool in designing efficient strips configurations in so far as two-dimensional, incompressible flows are concerned. For axisymmetric incompressible flow past a body with porous strips, we develop linear triple deck, closed-form for the mean-flow quantities, solutions which account for upstream influence. These solutions are linear superpositions of the flow past the body without suction plus the perturbations due to the suction strips. The flow past the suctionless body is calculated using the Transition Analysis Program System (TAPS). Using these linear triple deck, closed-form solutions we then develop a simple linear optimization scheme to determine number, spacing, and mass flow rate through the strips on an axisymmetric body. At present, we are finishing the development of and documentation for a computer code for official distribution that will interface with TAPS and suggest efficient configurations using our theory. For compressible three-dimensional flow, we use the method of multiple scales to formulate the three-dimensional stability problem and determine the partial-differential equations governing variations of the amplitude and complex wavenumbers. We then propose a method for following one specific wave along its trajectory to ascertain the characteristics of the most unstable disturbance. Numerical results using the flow over the X-21 wing as calculated from the Kaups-Cebeci code will be published when they become available. / Ph. D.

This study concerns a neutronic and transient thermal study of the first wall and blanket region of a typical controlled thermonuclear reactor (CTR). Previous studies assumed a neutron wall loading of 1 ~ 5 MW/m², and usually an infinite slab for a blanket region in calculating the transient thermal behavior following a major plasma disruption (MPD). Besides, neutrons with a kinetic energy of 14 MeV were usually assumed by ignoring the energy distribution of fusion neutrons. Furthermore, the cross-sections of the interaction between the incident neutron and the first wall were neglected by assuming that all these 14 MeV neutrons were absorbed by the first wall. This study made use of a more accurate model involving a canister design and considered both the incident neutron and secondary gamma heating in calculating the volumetric heat source rate. With these modifications, the average value of the volumetric heat source rate was calculated to be 0.05 MW/m³ ~ 0.5 MW /m³. The disruption times used in this analysis were assumed to be 24 ms and 10 ms. For each case, a constant velocity model and a Gaussian velocity model were assumed for the surface heat flux impinging on the first wall after an MPD with emphasis on the constant velocity model. Neutronic studies including a Diffusion Test Model (DTM), a 23-group cross-section library, and a 37-group neutron and 21-group gamma library from ORNL used in conjunction with the ANISN Code, provided different volumetric heat source rates which were used to do a thermal analysis for the blanket at the steady state. With these volumetric heat source rates obtained, a heat conduction code HEATING5 was run for the steady state temperature distribution. Results show that the average temperature for the first wall and the blanket are ~160°C and ~200°C, respectively. This steady state temperature distribution remained almost the same no matter whether DTM, 23G or 37N-21G cross-section sets were used, since the difference in the volumetric heat source rates generated were so small they did not change the temperature distribution significantly. With the steady state temperature distribution as an initial condition, HEATING5 was run again for the transient thermal study which included the surface heat flux due to the disruption, together with a volumetric heat source rate resulting from the eddy currents induced in the wall following an MPD. Results show that there is a possibility of melting portions of the first wall if the disruption time of 10 ms is used, while no melting is possible for the 24 ms case; however, a maximum transient temperature of ~1000°C on the first wall does occur. With respect to the temperatures in the blanket region, they remained the same as they were before an MPD. The transient took place so rapidly that the effects were mostly on the first wall. For the case of 24 ms, the average number of abortions allowed for failure of the first wall was 200 thermal cycles. / Ph. D.

This study was designed to examine a return-to-industry program, an inservice approach for vocational instructors at a two-year postsecondary institution. Specifically, the study (a) examined the process of collaboration with business and industry, and (b) assessed the impact of the return-to-industry program on the vocational instructors and the participating businesses and industries. A naturalistic inquiry paradigm using the case study approach was the research design used for this study. This design was useful in identifying and describing the various patterns that emerged. with regard to the process of collaboration with business/industry and education. The design was chosen because there exists a need to document the dynamics of linkage between business/industry and education Hagerstown Junior College was purposefully selected for this study. This site was chose because it provided the researcher an opportunity to study a maximum variety of individuals from different vocational programs as well as participating businesses and industries in the Hagerstown area. The data was in the form of field notes obtained during observation, semi-structured, open-ended interviews, and an examination of the institutional records and documents associated with the return-to-industry inservice program. An inductive comparative analysis of the data resulted in patterns, categories and themes which reflected the purpose of the resea:c·ch.. A portrayal of the process of collaboration and the impact of the return-to-industry program is provided through a thematic narrative. The results of this study provide a process model for establishing a return-to-industry program for vocational instructors who wish to reinforce, update, and expand their technical skills. In addition, the results demonstrate the benefits to be derived by business, industry, and education through collaboration. Based on the findings of this study, it is recommended that a follow up of the present study be conducted at the conclusion of the funding period to determine if results other than those reported have occurred, if the process of collaboration has been altered over time, and if collaboration has continued at a level that is of benefit to all the participants. / Ed. D.

During the past fifty years many educational researchers have investigated the effectiveness of alternative methods of instruction in science. These investigations have resulted in the publication of numerous studies which frequently report contradictory findings. The purpose of this study was to synthesize the studies conducted on individualized instruction in secondary school and collegiate science courses through a meta-analysis, the statistical integration and analysis of research studies. The major goals of the meta-analysis were to determine the experimental effect of individualized instruction in science and to explain the variation in the effect sizes obtained. This dissertation included an analysis of 115 studies comparing individualized instruction with traditional lecture instruction. The methods of individualized instruction incorporated were audio-tutorial instruction, computer-assisted instruction, Keller's personalized system of instruction and programmed instruction. Instruction which was individualized but not clearly identified as one of the previously listed methods was included under a combination category. The effectiveness of individualized instruction was measured in terms of effect size, a standardized difference in means between the individualized and the lecture classes. Effect sizes were calculated using the pooled standard deviation. A number of instructional, design and miscellaneous variables were identified in the research studies. Instructional variables identified were mastery orientation, self-initiated testing, self-pacing of instruction, and choice of instructional delivery systems. Design variables identified were self-selection, historical effect, subjective rating of study, instrument development, equivalence of subjects, and instrument reliability. Miscellaneous variables identified were level of instruction, nature of instruction, source of publication, year of publication, setting of the study, and subject of instruction. Data analysis involved: (a) descriptive statistics for the entire data set, (b) descriptive statistics for each of the individualized instructional methods studied, (c) analysis of variance and t-tests to test the effect of selected variables on instructional effectiveness, and (d) regression analysis in which effect sizes were regressed onto selected independent variables. The findings of this meta-analysis suggest that individualized instruction in science is somewhat more effective than traditional instruction. All five methods of individualized instruction analyzed were not differentially effective when compared to traditional instruction. The instructional, design, and miscellaneous variables identified in this meta-analysis contributed little to the variance in effect size. / Ph. D.