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Previous research studies which have used Health Belief Model (I-IBM) dimensions in order to understand health outcomes have many problems which prevent clear and reliable conclusions about their results. Studies about diabetes-related health beliefs have proved to be no exception to this rule. The research presented here is an attempt to address some of these problems which include the lack of satisfactory scales to measure diabetes-related health beliefs, the use of heterogeneous samples of patients with different disease and regimen types, and the lack of prospective studies in which health beliefs are used to predict outcomes in the future. Another major problem which applies to all HBM research is that the relationships between the various dimensions of the model have not been determined. As such, the HBM is not a model at all but a catalogue of variables. The present research aimed to specify the relationships between the components of the HBM and attempted to integrate self-efficacy and locus of control beliefs in order to extend the model and improve the amount of outcome variance explained. Scales to measure diabetes-specific health beliefs were developed from the responses of 187 tablet-treated outpatients with Type II diabetes. Health beliefs were examined, on the one hand, in relation to other psychological and behavioural variables, and on the other, for their sensitivity to change after educational and treatment interventions. Both cross-sectional and longitudinal study designs were employed. The relationships between the HBM components themselves were explored in a linear and non-linear fashion.

Ferrocement is often believed to be a form of reinforced concrete. However, in spite of the similarities between the two materials there are still major differences, indicating that ferrocement requires a separate study to establish its structural performances. On the other hand, although a large amount of research has been carried out on ferrocement, its flexural behaviour is still not fully understood. The aim of this investigation is to study the structural behaviour of ferrocement plates under flexural loading and the influence of the different variables on the strength and deformation characteristics. The variables studied were the mesh number, strength, opening and distribution, presence of steel bars, and the thickness of the section and the mortar cover. The experimental programme included 49 plates, 1000x300 mm in dimensions, reinforced with woven type steel wire mesh and tested under two lines load. Deformation measurements were taken from first application of the load up till failure and about10000 crack measurements (crack width and spacing) were recorded. The crack width data were dealt with statistically. The effect of the variables on the crack width was studied, quantitatively, by comparing the rate of growth of crack width of the plates. It was found that ferrocement cracking behaviour is characterized by almost a full development of the cracks at relatively early stages of the load (about 30-50% of the ultimate load) and the crack width is smaller and more uniformly distributed than in reinforced concrete. The mesh number and yield strength influenced significantly the crack width and spacing. There was a limit for the mesh number after which the enhancement in the cracking performance of the plates slowed down noticeably. Crack width prediction equations were derived from these tests showed good correlation, whereas the published crack width formulae largely overestimated or underestimated the measured crack width. The strength and deformation were influenced mainly by the yield strength and fraction volume of reinforcement in the loading direction. The deflection is most likely to exceed the serviceability criteria before the crack width. For a span-deflection ratio of 180, the mean crack width was mostly below 20 microns, and the load was about 15-30% of the ultimate load. A procedure is proposed to analyse ferrocement sections under flexural loading. While application of reinforced concrete theory to predict the ultimate moment largely underestimated the experimental results, the proposed procedure predicted closely the experimental moment and deflection at first cracking, yielding and failure of the tested plates.

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In Experiment 1, groups of 10 goldfish and of 10 grey mullet were trained to press a lever for food under a fixed, daily, light cycle. The periods during which responses were reinforced were restricted to two, 1-hr periods in every 24 hrs. These periods occurred at the same time each day. Responses were coordinated with the temporal contingencies of the schedule, and this pattern persisted for a number of days when no responses were reinforced. Experiment 2 demonstrated that a fixed light cycle was not essential for the maintenance of temporal discrimination. Experiment 3 followed a similar procedure to that of Experiment 1, except with individual goldfish and with only one, 1-hr feeding period in every 24. Experiment 4 produced evidence that temporal discrimination could develop under continuous illumination in individual goldfish. In Experiment 5, individual goldfish under continuous illumination were exposed to schedules that reinforced lever presses with food during a 1-hr period each day. Training with simultaneous temporal and visual contingencies, where food was available only in the presence of a stimulus light and at the same time each day, did not attenuate control over responding by either contingency. Further, pretraining on the temporal contingency did not prevent the subsequent acquisition of control by a stimulus light that was presented during the feeding hour. Similarly, pretraining on a visual contingency in which food was available at a different time each day did not prevent the subsequent acquisition of control by the temporal contingency (established by fixing the time of food availability). In Experiment 6, pretraining on the visual contingency did attenuate the subsequent acquisition of control by a different visual stimulus, showing that the lack of interference in control observed in Experiment 5 was not simply due to the intertrial interval used. These findings suggest that concurrent temporal and visual contingencies may control behaviour in parallel rather than in a competitive manner.

This thesis is concerned with the use of rheological equations of state to describe the behaviour of vulcanised elastomers and, in particular, vulcanised elastomers loaded with carbon black. The properties of these materials are dependent upon the specific combination of elastomer and carbon black, and the effect of carbon black loading is studied by means of experiments on a butadiene-acrylonitrile base polymer KRYNAC 806, unfilled and loaded with 50phr SRF N774 carbon black. The first part of this work concerns small ampIitude oscillatory shear experiments carried out on a Weissenberg rheogoniometer over a range of amplitudes, frequencies, and temperatures. Both materials are found to remain within the linear viscoelastic region for temperatures greater than about -10°c, to obey the time-temperature superposition principle, and to have identical shift factors. Dynamic moduli over a reduced frequency range of about ten decades of log frequency are characterised by the Huet model. The second part concerns finite deformation experiments consisting of prestraining samples in simple tension and applying small axial oscillations when stress relaxation is almost complete. Dependencies of the incremental dynamic moduli measured in this way are investigated with regard to frequency and extension ratio. Moduli measurements indicate that the time dependence of the materials is unaffected by deformation, although relaxation spectrum functions for the filled sample are strain dependent. A criterion is established for testing whether results can be modelled by a certain class of non-linear viscoelastic constitutive equations. A constitutive equation is proposed which represents the strain dependence of moduli for both the filled and unfilled materials. Other published data are shown not to conform to the above criterion. It is also shown that despite this fact, in some cases at least, the proposed constitutive equation provides a better represent at ion of published data than other constitutive equations which have hitherto been applied.

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No description available.