Thesis (MA)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Research literature is increasingly referring to the therapeutic effect of experiences in nature on people. However, no research that evaluates the suitability of nature as an aid in an existential approach to psychotherapy could be found. This paper shows by means of a literature review that nature as an aid can make a significant contribution to this approach. The potential benefits of utilizing nature are integrated with the therapeutic goals of existential psychotherapy. The conclusion reached is that nature can be an important aid for leading a client to self-confrontation, increased selfawareness, acceptance of personal freedom and responsibility, and to find personal meaning in life. Proposals for future research are recommended. / AFRIKAANSE OPSOMMING: Navorsingsliteratuur bevat in 'n toenemende mate verwysings na die terapeutiese effek wat belewenisse in die natuur op mense het. Geen navorsing kon egter gevind word wat die geskiktheid van die natuur as 'n hulpmiddel in 'n eksistensiële benadering tot psigoterapie ondersoek nie. Hierdie studie toon deur middel van 'n literatuuroorsig aan dat die natuur wel as 'n hulpmiddel betekenisvolle bydraes kan lewer tot hierdie benadering, deur die potensiële bydrae van die natuur in verband te bring met die doelwitte van eksistensiële psigoterapie. Die gevolgtrekking word gemaak dat die natuur 'n belangrike hulpmiddel kan wees om die kliënt te lei na selfkonfrontasie, verhoogde selfbewussyn, aanvaarding van persoonlike vryheid en verantwoordelikheid, en die vind van persoonlike betekenis in die lewe. Aanbevelings vir verdere navorsing word ook gemaak.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Architecture, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: p. 227-237. / by Hong-Bin Kang. / Ph.D.

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In this study adaptations of bryophytes and lichens to desiccation stress were examined. The aim was to test whether desiccation tolerance in the selected species is constitutive or if desiccation tolerance could be induced by various hardening treatments. In addition, some putative tolerance mechanisms were investigated, including the accumulation of sugars, increase in ROS scavenging systems and other mechanisms e.g. energy dissipating processes. To determine if hardening treatments prior to desiccation stress increased desiccation tolerance, mosses and lichens were partially desiccated or treated with ABA. The effect of hardening treatments on the physiology of the moss Atrichum androgynum and lichens Peltigera polydactyla, Ramalina celastri and Telochistes capensis during a desiccation-rehydration cycle was investigated. Photosynthesis, respiration and chlorophyll fluorescence measurements were used as rapid tools to determine the metabolic activities in these lichens and moss species. In A. androgynum partial desiccation following slow drying at 52% RH increased the rate of recovery of net photosynthesis. Net photosynthesis recovered almost completely following slow drying in the material that was partially dehydrated and/or treated with ABA. This suggests that partial dehydration hardens the moss, and that ABA can fully substitute for partial dehydration. In R celastri and P. polydactyla both partial dehydration and ABA treatments displayed some improvement in desiccation tolerance depending on the duration and severity of stress. The reduction in the re-saturation respiration burst in P. polydactyla, although not quite significant, strongly suggests that hardening increases mycobiont tolerance. However, it is more difficult to establish whether the hardening treatments improve photobiont performance. In the moss A. androgynum ABA treatment increased the rate of recovery of photosynthesis and PSII activity, and also doubled non-photochemical quenching (NPQ). Increased NPQ activity will reduce ROS formation, and may explain in part how ABA hardens the moss to desiccation. In ABA treated, but not untreated mosses, desiccation significantly increased the concentration of soluble sugars in A. androgynum. Sugar accumulation may promote vitrification of the cytoplasm and protect membranes during desiccation. Starch concentrations in freshly collected A. androgynum and R. celastri were only c. 40 and 80 mg g ¯¹ dry mass respectively, and slightly rose during desiccation, but were only slightly affected by ABA pretreatment. ABA did not reduce chlorophyll breakdown during desiccation. In P. polydactyla ABA pretreatment had little effect on any of these parameters. Changes in the activities of the free radical scavenging enzymes ascorbate peroxidase, catalase and superoxide dismutase were measured during wetting and drying cycles in the moss A. androgynum and in the lichens P. polydactyla, R. celastri and T capensis. These species normally grow in the understorey of the Afromontane forest, moist, xeric, and extremely xeric miicrohabitats respectively. In A. androgyum, enzyme activity was measured shortly after collection, after 3 d storage following hardening by partial dehydration and/or 1 h treatment with ABA or distilled water and during desiccation and rehydration. In A. androgynum enzyme activities of CAT and SOD in untreated material were always higher than in the hardened treatments, while both partial dehydration and ABA treatments tended to reduce both CAT and the induction of SOD activity, although these effects were not significant between the treatments. This suggests that ABA may not be involved in the induction of free radical scavenging enzymes and probably these enzymes are not important in desiccation tolerance of A. androgynum. In lichens, the enzyme activity was measured shortly after collection, after hydration for 48 hat 100% RH, after desiccation for 14 d and 28 d, and during the first 30 min of hydration with liquid water. Enzyme activities tended to rise or stay the same following rehydration in all the species tested. After desiccation for 14 d, enzyme activities decreased, and then decreased further to very low values after 4 weeks desiccation. In all species, including T capensis from an extremely xeric habitat, the activities of all enzymes remained at very low values during the 30 min following rehydration, and were therefore unavailable to remove any reactive oxygen species accumulating in lichen tissues as a result of desiccation. Results suggests that the enzymic antioxidants are more likely to be involved in removing reactive oxygen species produced during the normal metabolic processes of lichens than having a role in desiccation tolerance. The Afromontane understorey moss Atrichum androgynum displayed an oxidative burst of H₂O₂ during rehydration following desiccation. Maximum rates of H₂O₂ production occur during the first 15 min of rehydration. While the production of H₂O₂ increases with increasing desiccation times, the moss produced significant amounts of H₂O₂ during rehydration after desiccation for times that did not inhibit photosynthesis or cause K⁺ leakage. A. androgynum may produce more H₂O₂ during desiccation than rehydration, because desiccation artificially induced using polyethylene glycol strongly stimulates production. Experiments involving inhibitors and exogenously supplied reductants indicate that peroxidases are responsible for the synthesis of H₂O₂. Factors that influence the rate of H₂O₂ production during rehydration include light and the hormone ABA. Patterns of H₂O₂ production are discussed in terms of their possible role as a defence against pathogenic fungi and bacteria. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.

The use of fibre reinforced polymer composites and development of structural composites has expanded rapidly in the Southern African region over the past ten years. The long-term effect of placing these materials outdoors in the Southern African climate is unknown with exposure data for these materials being primarily European and North American based. This study intends to take a broad-based study to the problem of environmental degradation of advanced composite structures. This work is intended to study different degradation mechanisms. Work performed includes: a study of literature on degradation and protective measures; identification of dominant degradation mechanisms; manufacture of specimens; accelerated environmental testing; and an assessment of the effect of the exposure on the chemical properties The goal of this work is to produce information, which can be subsequently used to determine the rate of damage, methods of suitable protection and necessary maintenance intervals for polymer composite components. The approach was: to simulate outdoor exposure within a reduced period of time; to establish correlation of results with actual outdoor exposure; and to determine how the gel coats compare with other protective methods. As part of the objectives of the study (i.e. to assess the durability of polymer matrix composites materials subjected to environmental exposure), an experimental study was carried out to establish the durability of specific gel coats against ultraviolet (DV) and moisture degradation. An investigation of the effectiveness of the various protective measures has begun with a review of selected gel coats available as a protective coating. Laminates with these gel coats have been set up for both accelerated and natural exposure tests. 3000, 2500, 2000, 1600, and 800 hours of accelerated DV exposure tests were performed on polyester GRP laminates with gel coats. No measurable strength loss occurred on protected laminates; there was significant increase in yellowness on un-protected laminates; all protected specimens showed a fair retention of gloss; fibre prominence occurred on unprotected laminates; and the glass transition of samples had dropped from the normal polyester glass transition temperature range. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2004.

The purpose of this study was to assess the social climate of different size churches and the relationship between social climate, member satisfaction, and church size. This study has investigated the extent to which (1) church member satisfaction is affected by social climate and church size and (2) the extent to which social climate is affected by church size. The social climate is the unique "personality" of a setting that gives it clarity and coherence (Moos, 1974b). The data were collected at different size churches. The sample consisted of a random sample for each church of those who completed a "church satisfaction questionnaire," which included demographic information, and the Group Environment Scale (Moos, 1986). There were 50 respondents for each church included in the sample. The sample included 114 men and 136 women. One hundred seventy eight were married and 170 reported having children. Two hundred fourteen considered themselves a member of their church.Previous research indicates satisfaction is influenced by both a setting's social climate and its size. Social climate dimensions that seem to influence member satisfaction are "cohesion," "leader support," "task orientation," "autonomy," and "innovation." Staffing theory suggests that size is also related to satisfaction. Small settings are presumed to be "understaffed" and those in understaffed settings are likely to report more feelings of satisfaction.The results of this study indicated that churches characterized by greater perceived "cohesion," "leader support," "task orientation," and "innovation" tended to have members who were more satisfied. The linear composite of these variables was statistically significant (p < .05) and identified 43.89% of the variance of the satisfaction measure. Results suggest that understanding the church social climate is helpful in understanding its members. Implications of these results relevant for church leaders are discussed.Contrary to what was anticipated, size was not a predictor of church satisfaction. The failure of size to predict church satisfaction is discussed in terms of staffing theory (Wicker, 1979a).The fact that certain social climate dimensions are. related to church member satisfaction is encouraging and justifies further research in this area. Ideas warranted for further research are developed. / Department of Counseling Psychology and Guidance Services

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High-performance polymeric composites are currently being considered as state-of-the-art material systems for future supersonic aircraft and space structures. However, the long-term durability and environmental stability of these materials continue to be under question. Continued application of these composites in aerospace structures is contingent upon the long-term durability of these material systems. Polymeric materials have been known to undergo both physical as well as chemical aging. The aging time, temperature, and environment play a significant role in affecting the physical and chemical aging behavior in the polymers. Currently, there is a dearth of information on the combined effects of physical and chemical aging in polymer-based composites. This study describes the effect of sub-T_g environmental aging on the mechanical properties of two high-performance polymeric composite systems. The effect of chemical degradation on the durability of the material systems is discussed. Further, the effect of environmental stress cracking (ESC) behavior of high-performance composite materials in the presence of organic solvents is investigated and the implications of ESC on durability are studied. Also included in this thesis is a study of the physical aging characteristics of the composites, via measurement of the viscoelastic (creep) properties. Accelerated characterization techniques were employed to predict long-term physical aging behavior. Fiberite 954-2 (a thermoplastic toughened cyanate ester resin) and its graphite-reinforced composites, and Fiberite ITX (a semicrystalline thermoplastic resin) and its graphite fiber-reinforced composites (IM8/ITX) were used in the study. These material systems were under consideration for usage in high-speed civil transport (HSCT) aircraft. This aircraft is expected to have an operating temperature of around 150°C (based on a 2.4 Mach number), an operating pressure at service altitude of 2 psi (0.136 atm), and a flight life in the excess of 60,000 hours at the above-mentioned conditions. The aging of the specimens was carried out for periods of up to 9 months at temperatures between 140°C to 200°C in three different environments; an inert nitrogen environment, an environment with a reduced air pressure of 2 psi (0.136 atm), and ambient atmospheric air. The results from stress-strain, flexure, and micro-indentation tests indicated a substantial reduction in material properties with aging in the different environments. The bending strength, strain to failure, and hardness values of the two composite systems decreased by as much as 20-50%. Tensile modulus on the other hand showed an increase of 20% after 6 months of aging in air, indicating apparent embrittlement with aging. Chemical degradation/damage was also monitored by penetrant enhanced x- radiography, scanning electron microscopy (SEM), and scanning acoustic microscopy (SAM). The chemical aging/degradation was seen to be sensitive to the oxygen partial pressure in the aging environment. The greater the amount of oxygen in the aging environment, the more the loss in the material properties. The glass transition temperatures (T​​_g) of the two material systems were sensitive to both the aging environment and aging time. The T_g of both systems increased over long aging times as seen from dynamic mechanical analysis (DMA) measurements. However, increased oxygen concentrations appear to reduce the T_g. Changes in the T_g of both material systems were a complex behavior attributable to the varying oxygen concentrations in the aging environments, and the combined occurrence of physical aging, degradation, etc. in the materials. The chemical degradation in the composites appears to be via an oxidation mechanism and the micro-indentation results further indicate diffusion-controlled oxidation. Weight changes of samples (neat resin and composites) were also monitored over the entire period of the study and these showed a sensitivity to the oxygen concentration in the aging environment. The greater the oxygen in the environment, the greater the weight loss in the specimens, indicating an oxidation phenomenon. DMA and tensile creep were performed to study the interaction of creep and physical aging in these material systems. Long-term creep predictions of the composites were made using Time-Temperature Superposition (TTSP) and Effective Time Theory (ETT) techniques. The IM8/954-2 composites behaved in an anomalous fashion at times. This may be attributable to the blended nature of the 954-2 resin system, possible post-curing and phase separation of the resin, and thermal decomposition at elevated temperatures. The solvent testing of composites based on thermoplastic polymers revealed susceptibility to ESC. Bending strength losses up to 30% were seen from flexure tests on unidirectional composites. It was also seen that residual stresses in cross-ply laminates were sufficient to trigger ESC after exposure to common organic solvents for an hour. The damage/failure modes were captured by SEM micrographs. / Master of Science