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This study was undertaken to determine the aptitude and interest profiles of industrial arts majors as derived from certain standardized tests administered to freshmen entering North Texas State University, Denton, Texas, from 1955 through 1959.

Energetic polyatomic cluster beams are increasingly used in materials processing and surface analysis applications. In secondary ion mass spectrometry (SIMS) such beams have previously been utilised to investigate the chemical distribution of organic molecules (polymers, biological molecules and pharmaceuticals etc). One important application is in organic electronics, where the depth-distribution of organic components is important in the device performance. Massive gas cluster ion beams (GCIBs) have produced more successful depth-profiles for organic electronic devices that smaller projectiles including SF5+ and C60+. However, further work is needed to investigate and optimise experimental parameters to deliver the necessary SIMS performance. This study focused on molecular depth profiling of organic insulator (PMMA) and semiconductor (PTAA and TIPS-pentacene) materials, in single and bi-layered combinations, utilising cluster SIMS, using C60+ and Arn+, at different temperatures and energies. In general, at room temperature, the best depth resolution was obtained, using large Ar-GCIBs of low energy per atom (E/n ~10 eV), in comparison with the smaller Ar-GCIBs or with C60+ beams at the same total impact energy. On materials which sputtering under C60+ bombardment, ion and neutral yields were greatest due to the higher E/n, compared with GCIBs. Data from PMMA show that the sputter yield under C60 and Arn projectiles conform to the published 'universal' dependence of Y/n to E/n. Depth profiling of the semiconductor compounds were unsuccessful, using C60+ projectiles. For depth profiles using large GCIB projectiles, an increase in the secondary ion yield was observed at the interface with the silicon substrate - a phenomenon which was not observed for the smaller projectiles. In general, the most successful depth profiles (i.e. more constant molecular and fragment secondary ion yields, observed at pseudo-steady-state regions) and best depth resolutions were obtained at cryogenic temperatures - conditions under which corresponding sputtering yields and secondary ion yields were suppressed.

Nowadays, the bevel gears are widely applied in the industry for the intersected-axial transmission system. But the applications of the bevel gears are mostly limited to the usage of involute bevel gears. In this thesis, the bevel gear with circular-arc tooth profiles is derived by using general theorem of conjugate surfaces, coordinate transformation, constrained meshing equation, and spherical trigonometry. According to the bevel gears with circular-arc tooth profile derived above, the analyses and discussions of the interference are proposed. The interference situation is detected by applying the phase lead-lag concept while circular-arc curve is moving on the spherical cross-section. Furthermore, the ideal conditions to avoid occurrence of interference are proposed. Design charts for the maximum values of tooth profile angle are also constructed as a reference for designers. The 3D solid models of the bevel gear with circular-arc tooth profiles are constructed by using the computer software (Pro/E). Finally, the transmission ability is verified through the computer animation using CAE software (Visual Nastran). It is believed that the mathematical models and design method developed in the thesis will provide a useful foundation for the further studies.

Curvic couplings have been widely applied to various industrial applications. Presently the Gleason No.120 special grinding machine developed by Gleason Works Co. is one of the commonly used machine tool for the curvic coupling manufacturing. On the other hand, in response to the issue of improving the domestic design and manufacturing ability, an alternative manufacturing method of curvic coupling is introduced in this study. In this study the geometrical characteristics of the novel gear profile are investigated. Firstly, applying the spatial transformation matrix theorem to the relationship between the cutting tool path and the cutting tool position, the cutting tool profile equation of curvic coupling is successfully derived. Secondly, the mathematical model of the envelope surface of the generating tool, or generally being called the gear surface, is constructed based on the trajectory equation of the generating tool motion and the tool-workpiece meshing equation. Finally, the solid model is established based on the obtained mathematical model, and the comparison works with the conventional curvic coupling are also carried out. The analysis of gear surface is graphically depicted with respect to the various machining parameters. It is believed that this thesis provides a useful tool for the following studies of curvic couplings for the different demand of application fields.

Intelligent well completions are increasingly being used in horizontal, multilateral, and multi-branching wells. Such completions are equipped with permanent sensors to measure temperature and pressure profiles, which must then be interpreted to determine the inflow profiles of the various phases produced that are needed to characterize the well??s performance. Distributed temperature measurements, using fiber optics in particular, are becoming increasingly more often applied. The value of an intelligent completion hinges on our capability to extract such inflow profiles or, at a minimum, to locate the entry locations of undesirable water or gas entries. In this research, a model of temperature behavior in multilateral wells was developed. The model predicts the temperature profiles in the build sections connecting the laterals to one another or to a main wellbore, thus accounting for the changing well angle relative to the temperature profile in the earth. In addition, energy balance equations applied at each junction predict the effects of mixing on the temperature above each junction. The multilateral wellbore temperature model was applied to a wide range of cases, in order to determine the conditions for which intelligent completions would be most useful. Parameters that were varied for this experiment included fluid thermal properties, absolute values of temperature and pressure, geothermal gradients, flow rates from each lateral, and the trajectories of each build section. From this parametric study, guidelines for an optimal application of intelligent well completion are represented.

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This thesis is an examination of language and number in two atypically developing groups, Williams Syndrome (WS) and Down's Syndrome (DS). These groups were chosen because their cognitive profiles in adulthood differ significantly. It is already known that language is a relative strength in WS but that it is poorer than non-verbal ability in DS. The precursors to both language and number ability were studied in 24-36 month old infants and performance at this stage was compared with that in the steady state, by testing older children and adults, aged 9-35 years. Similar age-appropriate tests were used with both groups so that performance in the steady state could be compared with that in infancy. Specific subdomains of language and number were assessed to investigate whether the pattern seen in the adult steady state was also present in infancy, or whether the mature phenotype is a product of the different developmental trajectories followed by each group. The overall cognitive profile of infants with WS and DS did not differ significantly, despite clear distinctions between the adult profiles. However, their performance on number and language tasks did differ in infancy. While in adulthood WS performance on number tasks was poorer than that of DS, in infancy this pattern was reversed. For language, infants with DS exhibited a large discrepancy between productive and receptive vocabulary. A more even pattern was present for the WS group. In adulthood, vocabulary was better in WS than DS but both groups had problems with syntactic structures. Taken together these results suggest that it is not possible to derive the pattern of infant performance from the steady state in adulthood. The developmental trajectories from precursors to mature phenotype need to be thoroughly charted in atypical populations because the study of development, not just the characterisation of the endstates, is crucial.