This thesis is concerned with the physical principles, methodology and applications of neutron diffraction in the measurement of residual stress. Work on three main areas is presented. 1) Carbon steels 2) Data and Peak Broadening analysis and 3) Single lap glue shear joints. The Carbon steels section shows the drastic effect of the content of carbon on the measured stress. This is an aspect which has been somewhat neglected in the past. The carbon is in the form of cementite, which is a hard compound and causes the carbon steel to act like a composite material, the ferrite acting as a soft matrix and the cementite as a reinforcement. The consequence of this is that the two components develop high microstresses with plastic deformation. This is clearly illustrated in the work of [Bon 97] where values of approx. 460 MPa in the residual stress in the ferrite are balanced by negative residual stresses of 2300 MPa in cementite yielding an overall macro residual stress of zero. In this work it has been shown that even knowledge of the cementite and ferrite residual stresses and fractions may not be sufficient to accurately calculate the macro stress since the ferrite unloading curve is non linear. The use of a single valued constant modulus to convert from strain to stress is hence not valid. Peak shape analysis enables dislocation density and cell size estimates to be made. The thesis examines several methods of data weighting and deconvolution in order to asses the best means of extracting this information from standard residual stress data. Care should be taken for the peaks with very low backgrounds when finding the Gaussian and Lorentzian components. A weighting that avoids the strong bias of zero and I counts in the detector channels should be used e.g. W = I / ( 10 + Y). Lorentzian and Gaussian components can be successfully extracted from asymmetrical peaks (of peaks that broaden symmetrically), using deconvolution method 1, although the data should be of good quality. Reproducibility has been shown in the Gaussian, Lorentzian and FWHM for different instruments at different institutes. This is extremely important for the use of these values for peak broadening analysis and for estimation of the plastic deformation within a sample. The neutron diffraction technique has been used to investigate the longitudinal stresses in the adherend produced as a result of cure and due to the application of a tensile load in a single lap shear joint. The results throw doubt on widely used finite element predictions.

Les contraintes mécaniques liées à la pratique physique jouent un rôle prépondérant dans l’optimisation de la masse, la géométrie et le métabolisme osseux. Pour ce travail, nous avons suivi pendant deux années une cohorte de 170 personnes âgées de 16-28 ans, pratiquant ou non un sport de haut niveau (>6heures/semaine). Nous avons décrit que lorsque la pratique sportive était débutée à l’adolescence et maintenue à l’âge adulte, le statut osseux était significativement meilleur par rapport à des individus non sportifs. D’autre part, plus les impacts mécaniques et l’intensité de pratique étaient élevés plus les valeurs osseuses biologiques de formation et densitométriques étaient importantes. Nous avons confirmé l’implication de la leptine et de l’insuline dans le métabolisme énergétique. Nous avons également validé une méthode novatrice d’analyse du tibia par la DXA et avons démontré que ce site osseux répondait fortement aux contraintes mécaniques. Afin d’étudier un modèle de masse corporelle extrême, nous avons spécifiquement étudié les rugbymen. Ils présentaient une hypoleptinémie significative avec une masse grasse similaire à celle des témoins, d’où probablement un effet direct de l’exercice physique sur le métabolisme de la leptine. Enfin, nous avons démontré que les paramètres osseux biologiques et densitométriques ne semblent plus évoluer significativement sur la période d’étude de deux ans. Les Pics de Masse et de Géométrie Osseuse semblent donc atteints, indépendamment du sexe et du statut sportif pour ce type de population d’adultes jeunes. / Mechanical strains induced by physical activity play an important role in bone mass, geometry and metabolism optimization. For this work, we have followed during 2 years, a cohort of 170 persons aged 16-30 years, who practiced or not a high level weight bearing sport (>6hours/week). We have described that when the practice was initiated during adolescence and maintained during adulthood, bone status was significantly greater compared to sedentary controls. Moreover, the more the mechanical impacts and practice intensity were, the higher bone formation rates and densitometry parameters were. We have confirmed the leptin and insulin implication in energy metabolism. We have also validated a new method to assess tibia bone parameters with DXA and we have demonstrated that this bone site strongly responded to mechanical strains. On the other hand, we have specifically studied rugby players as a model of “extreme” body composition. We have observed a significant hypoleptinaemia compared to controls whereas they had a similar fat mass: “extreme” practice would have a depressive action on leptin metabolism. Finally, we have showed that biology and densitometry bone parameters did not significantly evaluate whatever the bone site: Peak Bone Mass and Geometry appeared to be reached, independently of sex and sport status.

The purpose of the study was to evaluate the efficacy of the procedures described in the PEAK-E curriculum in teaching addition skills to children with developmental disabilities. In the present study, three participants were taught to match sample addition problems (A) to a number of pictures (B) corresponding to the sum of A (A-B), and to match sample pictures (B) to textual numbers (C) (B-C). They were then tested to see if they could match sample addition problems (A) to with the textual numbers (C) that were the solution of the addition problems A (A-C). Following mastery of the A-B and B-C relations, none of the participants were able to demonstrate the derived transitive A-C relation. An additional training phase was conducted across all participants whereby two of the five stimulus classes were provided “equivalence” C-A training (matching the textual number C to the equation A), after which all of the participants were able to demonstrate the derived transitive A-C relations across all stimulus classes without direct training of any of the stimulus classes. The results expand on previous research evaluating behavioral approaches to teaching math skills by showing how the development of equivalence class can result in the untrained emergence of novel math skills. Keywords: Stimulus Equivalence, PEAK, Addition, Autism, Developmental Disabilities

In recent times Jamaica has experienced an increase in infrastructure and mineral resource (bauxite) developments. As a result, quarrying activities have also increased to supply the needed construction material. Blasting has been the main technique for loosening insitu rock before transporting to construction site. Consequently there is a growing concern of the effects of blasting activities on the environment. These effects are normally nuisances to the neighbouring residence as they come in the form of: dust, toxic gases, noise, fly rocks and ground vibration. Of the set of nuisances the one that is of most concern is ground vibrations which can cause damage to structures. In most cases worldwide, after blasting activities there are the usual complaints about damage to residence, which is also a focus of the thesis. There have been researches on the subject of ground vibrations to help refute some of these complaints. The works of Lewis Oriard and Charles Dowding are the foundation on which standards and regulations are built as guides to assist blasters in the prevention of creating unnecessary nuisances. Most countries have developed their own regulations with respect to blasting and parameters are set according to the geological conditions. This is of importance as the rock structures determine the transmission of the peak particle velocity. However, most countries in the west adopt standards similar to ones put forward by the United States Bureau of Mines or The Office of Surface Mining. It is my opinion that a whole scale adoption should not take place, as the criteria used may not be suitable for other countries’ geological conditions. For this thesis the aim was to identify a vibration level that will not cause damage to structures close to a quarry. Based on the literature review it was revealed that there are a number of parameters that needed to be considered. These ranges: construction material, age of structures, distance from structures, geology of the location, type and quantities of explosives and the blast design. There was also the review of standards to building threshold with respect to the level of ground vibration. The case study with its main focus on vibration levels at structures in close proximity to the Bengal quarry revealed that a tolerable level can be determined which will not result in any form of damage to the structures. However, having established a PPV limit using the USBM and OSM standards that appears reasonable there is the need for criteria similar to those of the USBM and OSM using blasting and geological conditions in Jamaica. Due to the time constraints (20 wks) it is recommended that future research is carried out in this area especially in relation to assessing the performances of the structures. / <p>Validerat; 20101217 (root)</p>

This study sought to verify the stages of concern theory according to Hall, Wallace, and Dossette (1973), using a school-wide educational reform. Furthermore, changes in teachers' concern profiles as a function of education levels, teaching areas, hours of reform-related training, and adoption-proneness were studied. In particular, teachers' concern profiles about implementing the High Schools That Work (HSTW) reform in Virginia were studied. One thousand two hundred and seven teachers in 19 sites implementing the HSTW reform in Virginia participated in the study. Of the purposive sample of 1207 teachers to whom study questionnaires were forwarded by mail, 674 responded and returned their questionnaires. The questionnaire consisted of three sections: the Stages of Concern section (Hall, Wallace, & Dossette, 1973), the Adoption-proneness section (Oscarson, 1977), and the demographic information section. Data were analyzed, using descriptive statistics and multivariate analysis of variance procedures (α = .05). Results revealed that teachers with no HSTW reform experience (N = 131) had highest concern at the personal stage, followed by teachers in their first year of experience (N = 207), and teachers in their second year of experience (N = 230). Teachers in their third year of experience (N = 70) revealed the least concern at the personal stage. There was significant change in teachers’ concern associated with amount of experience F(21, 1880) = 12.32, p = .00 (p < .05). Teachers with more experience had peak concerns at the consequences and collaboration stages while teachers with less experience had peak concern at the personal stage. Results agreed with the theory which states that as experience in reform use increases, concern moves from informational and personal stages to consequences and collaboration stages. Change in teachers’ concern as a function of education level was significant F(28, 2502) = 2.09, p = .001 (p < .05). Teachers with doctoral degrees, followed by those with 30 credit hours above the master's degree, revealed more collaboration concern than teachers with associate, bachelor’s, and master's degrees. Concern change due to teaching area was not significant F(7, 630) = 1.81, p = .08 (p > .05). The concern profiles of vocational and academic teachers were parallel and coincident, but not level. Teachers’ concern change as a function of hours of related training was significant F(14, 1256) = 12.12, p = .00 (p< .05). Teachers with no reform-related training had peak concern at the personal stage while those with more than 15 hours of training had peak concerns at the collaboration and consequences stages. Teachers who had 15 hours or less of training had lower personal concern than those who had no training, but higher than those who had more than 15 hours of training. Teachers’ concern as a function of adoption-proneness was significant F(7, 630) = 14.53, p = .00 (p < .05). While all the teachers revealed similar informational, personal, and management concerns, teachers who were more adoption-prone had more intense concern at the consequences and collaboration stages. / Ph. D.

Motivation is a key ingredient of successful athletic performance over time. Although the concept of maximizing motivation has long been of interest to coaches and practitioners, the vast number of motivational theories, principles, and strategies can seem overwhelming and confusing. Consequently, there is a need for providing more holistic frameworks to coaches and practitioners that not only summarize the essential findings of motivation research but also make the information more understandable and applicable in practical settings. The purpose of this study is to present and test the MUSIC Model of Motivation as a framework that can be applied in performance environments by coaches and practitioners to improve athletes' motivation, engagement, and ultimately, performance. The dissertation includes three related studies. First, I conducted a systematic content analysis to support the application of the MUSIC Model in sports. I analyzed 13 books in the realm of sport psychology and coaching. Results showed strong evidence that the underlying principles and theories of the MUSIC Model are represented in the sports literature, which supports the application of the model as a holistic framework for coaches. For the second study, Brett Jones and I developed a motivation inventory for athletes by modifying an existing motivation inventory for use with athletes. I collected data from student athletes at a large public university and conducted Exploratory Factor Analysis (EFA) with Principal Axis Factoring and Promax Rotation to examine the factor structure of the inventory scales. I used the results of the EFA to make changes to the inventory. Subsequently, I conducted a Confirmatory Factor Analysis (CFA) on a second data set to test for model fit. The fit indices for the CFA demonstrated reasonably good fit to the results, which confirmed the five-factor structure of motivation inventory. Reliability analysis based on Cronbach's alpha showed very good results with alpha ratings ranging between .84 and .94. Overall, the findings provided validity evidence for the produced scores of the MUSIC® Athletic Inventory with student-athletes. / Ph. D. / Three studies were conducted to test the feasibility of using a motivation model, designed initially for educational settings (the MUSIC® Model of Motivation), in athletic settings by coaches. The first study showed that the underlying theories and principles of the MUSIC Model of Motivation are represented in the sport psychology and coaching literature. This is important because it demonstrates that it may be possible to apply the MUSIC Model in athletic settings. The second and third study tested an athletic version of a questionnaire (the MUSIC® Model of Academic Motivation Inventory) that was originally designed to assess students’ perceptions of the MUSIC model components in educational settings. Titled the “MUSIC® Model of Athletic Motivation Inventory,” this newly developed questionnaire was adapted from the academic version so that it could be administered to student-athletes at a large public university. The results indicated that the athletic version of the inventory can produce valid scores with student-athletes in competitive sports settings. These findings indicate that coaches could consider administering the newly developed questionnaire to assess athletes’ perceptions of the athletic setting. Based on the results, they could modify their coaching strategies and/or try new coaching strategies consistent with the MUSIC® Model of Motivation.

It is of great importance to be able to unambiguously interpret deoxyribonucleic acid (DNA) profiles, especially with Low Template (LT) DNA and mixture DNA that may contain major and minor contributors. Reducing stochastic effects, such as heterozygote peak imbalance, dropouts, and stutter artifacts have been studied by scientists in order to improve the evaluation of low quality DNA profile. There has been much research on a compatible solute, trehalose, in its effectiveness in enhancing the polymerase chain reaction (PCR), especially with GC-rich templates of DNA, and thermal stabilizing Thermus Aquaticus (Taq) DNA polymerases. Based on previous research, the effect of trehalose on peak heights, peak height ratios, and stutter ratios (n-1) from 15 short tandem repeats (STR) loci of the AmpFℓSTR® Identifiler® Plus PCR Amplification Kit was evaluated with 0.025ng, 0.05ng, 0.1ng, and 1ng of DNA, through the addition of 0M (control), 0.2M, and 0.4M of trehalose for each quantity of DNA. Although there was an observation regarding changes in average peak heights at 1ng of DNA with the addition of 0.2M, and 0.4M of trehalose, no conclusions could be made with the average peak heights for 0.025ng, 0.05ng, 0.1ng, and 1ng of DNA. The reason is that the propagation of pipetting error during the preparation of each batch could have contributed to the difference in the amount of DNA between each conditions which can be directly reflected in peak heights. Furthermore, unexpected discrepancy between the average peak heights for 0.1ng of DNA from the first and the second experiments rendered 0.1ng of DNA incompatible for comparison. With regards to average peak height ratios for 0.025ng, 0.05ng, 0.1ng, and 1ng of DNA, and average reverse stutter ratios for 0.1ng, and 1ng of DNA, there were no evidence to suggest that 0.2M or 0.4M of trehalose had any effects. Consistent trends for 0.1ng (Exp. 1 and 2) and 1ng of DNA from a statistical analysis through one-way ANOVA of individual loci, suggested that trehalose may have varying effects on certain loci. However, this observation must be approached with caution as it is uncertain whether unique trends across each data sets for certain loci were observed by chance due to small sample sizes or due to mechanisms of stutters and trehalose that are currently unknown. Future studies regarding the effect of trehalose on peak heights should be done with more precision through minimizing pipetting error, which can be accomplished by preparing one batch from which aliquots are taken. The result of the research does not show enough evidence to prove the usefulness of trehalose since the addition of trehalose does not yield consistently higher average peak heights and peak height ratios, and lower average reverse stutter ratios across 15 STR loci. Therefore, our results do not support that 0.2M and 0.4M of trehalose are useful within the parameter of forensic DNA analysis as they do not enhance the polymerase chain reaction (PCR) and improve stochastic effects for DNA profiles.

The purpose of this dissertation was to determine the effects of several loads and multiple inter-repetition rest (IRR) intervals on peak power, peak velocity, and peak force in multiple sets of hang power cleans. Additionally, this dissertation investigates the load at which power and barbell velocity are maximized in a hang power clean, which is an area of the literature that requires greater clarity. From a practical perspective it is exceedingly difficult to make training recommendations to maximize power development or prescribe load and IRR intervals in cluster loading based on the current literature. The primary findings of this dissertation are 1) 70% 1RM maximizes power and velocity as compared to 80% 1RM in multiple sets of the hang power clean, 2) 45 seconds IRR improved peak velocity and peak power relative to a traditional set configuration, and 3) peak power output at 80% 1RM with 45 seconds IRR is equivalent to power output at 70% 1RM using a traditional set configuration. To the authors’ knowledge this is only the second study to examine the effect of IRR on multiple sets of power cleans in trained participants, and the insights from this dissertation help to build a foundation for future investigations in cluster loading with weightlifting movements. The findings from this dissertation provide further evidence for the efficacy of cluster loading as a training tool to develop power in trained individuals.

No description available.

The Applied Miniaturisation Laboratory (AML) has recently built a laser-induced fluorescent capillary electrophoresis (LIF-CE) genetic analysis instrument, called the Tricorder Tool Kit (TTK). By using a photodiode instead of photomultiplier tubes in the optical detection, the AML has lowered the cost and size compared to commercial LIF-CE products. However, maintaining an adequate signal-to-noise (SNR) and limit of detection (LOD) is a challenge. By implementing a multistage amplifier, we increased the bandwidth and voltage swing while maintaining the transimpedance gain compared to the previous design. We also developed signal processing algorithms for post-experiment processing of CE. Using wavelet transform, iterative polynomial baseline fitting, and Jansson's deconvolution, we improved the SNR, reduced baseline variations, and separated overlapping peaks in CE signals. By improving the electronics and signal processing, we lowered the LOD of the TTK, which is a step towards the realisation of inexpensive point-of-care molecular medical diagnosis instruments. / Computer, Microelectronic Devices, Circuits and Systems