This study examines the effects of cryogenic temperatures on the mechanical properties of carbon, aramid, and poly(p-phenylene-2, 6-benzobisoxazole) (PBO) fibers. Although the mechanical properties are documented for these fibers at ambient and elevated temperatures, there is an absence of data in the open literature for how these fibers behave at very low temperatures. To evaluate the mechanical properties, the ASTM standard method for testing at ambient temperature was used as a baseline. The low temperature tests were conducted inside a double walled cryogenic chamber to evaluate the fiber performance at 100K. Fiber properties at low temperatures displayed differences from room temperature properties in the form of increased ultimate tensile strength (UTS), decreased in elongation to failure, and increased Young’s Modulus. The change in properties due to the effect of temperature was more pronounced in fibers with a higher degree of crystallinity.

M.Com. (Industrial Psychology) / Please refer to full text to view abstract

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 154-170). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 154-170). Also available on the Internet.

D.Litt. et Phil. (Psychology) / The generalizability of scores obtained on the General Scholastic Aptitude Test (GSAT) was investigated for a number of subpopulations. It was shown that acceptable procedures for limiting bias against certain subpopulations had been implemented in the course of test development. In order to facilitate an empirical investigation of the GSAT, random samples of Afrikaans-speaking whites, English-speaking whites, Afrikaans-speaking coloureds, English-speaking coloureds and English Speaking Indians were tested. The nature and intensity of cognitive stimulation as well as the direction of intellectual development differed from group to group and had definite implications for achievement in a test such as the GSAT. All the groups contained persons who could be regarded as fully integrated into an advanced technological society, but their average level of development, measured against this criterion, differed considerably. The test displayed a one-factor structure with respect to all the groups. On the basis of the content of the subtests this factor can be equated with Spearman's g factor. The ecological validity of test scores was studied on the basis of Berry's model for the generalization of behaviour aeross various environmental contexts. The nature of the differences between the groups with respect to both the internal and external structure of the test scores was investigated by means of conceptual as well as statistical analyses. The extent to which test scores could be generalized was indicated for different combinations of groups. On the basis of regression models it was shown that could to a large extent be used as a substitute for group membership as regards the explanation of GSAT scores. Differences in functioning found between the groups could often be attributed to differences in levels of achievement. Within Berry's experimental context the test was found to be almost equally valid for all the groups and it measured developed general scholastic ability equally well. With respect to most of the pupils in the white groups, the Indian group and the English-speaking coloured group, the test results could be generalized similarly in the behaviour context. The test measured general reasoning ability with scholastic symbol material almost equally well for these four groups, so that cross-cultural comparisons witp respect to this type of reasoning ability could be made reasonably reliably. However, most of the Afrikaans-speaking coloured subjects were probably handicapped by a lack of relevant experience. There are substantial differences between the groups as regards the generalizability of scores to intellectual achievements in the ecological context. In respect of the majority of white pupils such generalization is probably acceptable, as they could be regarded as fully integrated into an advanced technological society.

This study looked at the relationship between the 27 indices on the California Verbal Learning Test - Children's Version (CVLT-C) and the 19 scores on the Wechsler Intelligence Test for Children - Third Edition (WISC-III). The sample consisted of 58 children, ages 6-16 from a clinical population. The subgroups with Attention Deficit Hyperactivity Disorder (ADHD), Learning Disabilities (LD), and High Ability (HA) were compared to children with no clinical diagnosis (ND) on WISC-III Full Scale IQ, Verbal IQ, and Performance IQ; on CVLT-C Total Recall Trials 1-5; and on CVLC factors of Attention Span, Learning Efficiency, Free Delayed Recall, Cued Delayed Recall, and Inaccurate Recall. Twelve significant correlations were found between the CVLT-C and WISC-III including Full Scale IQ with Total Recall Trials 1-5, Discriminability, and False Positives; Verbal IQ with False Positives; Vocabulary with Total Recall Trials 1-5; Information with Serial Cluster Ratio; Digit Span with Total Recall Trials 1-5 and Discriminability; Processing Speed with Discriminability and False Positives; and Symbol Search with False Positives, all within the moderate range. In comparing clinical subgroups, children with ADHD did not differ significantly from those without a clinical diagnosis (ND) on any selected measures. Children diagnosed with learning disabilities were significantly lower on Total Recall Trials 1-5, Attention Span, and Cued Delayed Recall. Children with high abilities (HA) were significantly higher on WISC-III Full Scale IQ, Verbal IQ, Performance IQ, CVLT-C Total Recall Trials 1-5, Learning Efficiency, and Free Delayed Recall. This study empirically supported a positive relationship between memory processes and cognitive abilities while also confirming that each are a part of a larger cognitive process. / Department of Educational Psychology

D.Ed (Educational Psychology) / It is a well known fact that, especially in the developed and industrialised countries the child can not but attain adulthood and independence via the school and school learning. The child's progress at school depends largely on his readiness to learn. Because it is no longer acceptable for the school to receive school beginners with a take-it or leave-it attitude and practice, the Transvaal Education Department adopted the policy that all school beginners be subjected to a school readiness programme to ensure that they will in fact profit from formal learning. Because application of the prescribed procedures which underlies all these programmes had not yet been investigated empirically, an intensive evaluation was conducted in 1977 at the RAU. The findings indicated certain deficiencies in the existing programme. It appeared, for example, that differentiation was not applied sufficiently and that more emphasis should be laid on certain aspects of cognitive development. An attempt was therefore made in this study to redesign the existing programme. Firstly it was necessary to arrive at a pedagogical view of school entrance which implied a close examination of the school beginner's development and learning, whi~h also emphasised the importance of the teacher's becoming acquainted with the child's level op development on school entry as well as with its learning in order to know how, where and how much she can, may and ought to intervene in the child's development and learning.

No description available.

The study focused on the aptitude test performances of intellectually sub-normal subjects on the Nonreading Aptitude Test Battery (R-NATB) vs. the General Aptitude Test Battery (GATB). There were two research questions investigated: (1) Are there performance differences on the RNATB vs. GATB of borderline and/or mildly retarded individuals?, and (2) Is the Wide Range Achievement Test-Revised (WRAT-R) a better predictor than the Wide Range Scale (WRS) of R-NATB and/or GATB aptitude performances in borderline and/or mildly retarded individuals? Two groups were selected for the study - 80 borderline and 80 mildly retarded subjects, ages 15-25 years. Each group contained 40 subjects with high reading skills and 40 with low reading skills as determined by the WRS. The order of aptitude test administration was also controlled. The research data collection began in November 1984 and was completed in October 1987. The following were the major findings for borderline and mildly retarded subjects. ages 15-25: (1) individuals with higher reading skills performed significantly higher on the General Intelligence (G), Verbal (V), and Numerical (N) aptitudes on the GATB and R-NATB than those with lower reading skills; (2) generally, the GATB and R-NATB did not meet the established criteria for tests known to have acceptable levels of convergent and discriminant validity; (3) subjects performed higher on the General Intelligence (G), Verbal (V), and Numerical (N) aptitudes when taking the GATB in comparison to the R-NATB; (4) subjects performed higher on the Spatial (S), Form Perception (P), and Clerical Perception (Q) when taking the R-NATB in comparison to the GATB; and (5) neither the Wide Range Scale nor the Wide Range Achievement Test-Revised proved to be effective predictors of higher GATB vs. R-NATB aptitude performances in intellectually subnormal individuals. If the GATB or R-NATB must be taken, borderline and mildly retarded individuals would optimize their aptitude test performances if they would take the B-1001 form of the GATB so they could mark their answers in the test booklet instead of on an answer sheet. Furthermore, the WRS and WRAT-R are not adequate screeners for predicting optimal aptitude performances / Ed. D.

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