Determining bumpiness and inclination of surfaces is very important in many different areas, such as airports and at constructions sites. In this study, a surveying trolley and a remote controlled (RC) car were used to determine the bumpiness of two different surfaces. The aim with this study was to test the accuracy of a surveying trolley and an RC car to see how the accuracy can be increased with different observation methods. Total station, GPS and laser scanner surveying equipments were used, and all observations obtained by them were analysed. The laser scanner data was found to have the best precision. For that reason, it was accepted as the “true” data and it was used for comparing and evaluating other methods. It was found that the trolley and the RC car provided good height information with total stations and they were corresponding to the laser scanner data. When they were used with GPS, the accuracy was much lower. It was concluded that using two total stations is not increasing the accuracy, the RC car and the trolley are good measuring methods but not capable to inspect 1,2 mm tolerance for the floors, and finally, 2-3 cm positioning accuracy is obtainable when using GPS.

Dans cette thèse, on s'intéressera aux points de petite hauteur dans le groupe multiplicatif et sur une courbe elliptique.Dans le cas du groupe multiplicatif, on étudiera tout d'abord les corps dont les points de petites hauteurs sont les racines de l'unité.Ensuite, on localisera les points de petite hauteur dans un corps généré par certains groupes de rang fini.Pour cela, on aura besoin d'étudier les groupes de ramification de certaines extensions radicales.Ces résultats vont dans la direction d'une conjecture de Rémond.Il existe aussi un analogue de cette conjecture dans le cas des variétés abéliennes et il semblerait qu'on puisse même l'étendre au cas des variétés semi-abéliennes isotriviales.Cette nouvelle conjecture permet de relier entre eux certains théorèmes déjà présent dans la littérature.Cependant, ces résultats ne concerne que le cas où les points de petite hauteur sont des points de torsion.Pour conclure cette thèse, on donnera un premier exemple de cette conjecture dans le cas où les points de petite hauteur ne sont pas nécessairement des points de torsion. / In this thesis, we will focus on points of small height in both multiplicative group and on an elliptic curve.Firstly, in the multiplicative group case, we will study fields whose points of small height are eNSUITE? roots of the unity.In a second time, we will localise the points of small height on a field generated by some groups of finite rank, according to a conjecture of Rémond. To this end, we will study ramification groups concerning radiciel extensions.There also exists an analogue of this conjecture of Rémond on the abelian varieties case and it would seem that we can expand it by including split semi-abelian varieties. This new conjecture allows us to connect some theorems already present in the literature.However, these results only concern the case where the points of small height are torsion points.To conclude this thesis, we will give a first example of this conjecture in the case where points of small height are not necessarily torsion points.

One purpose of this study was to determine of the actual physical dimensions of an individual are related to the dimensions of his human figure drawings. The specific physical dimension used in this study is that of stature of height. Another purpose of this study was to determine if college males majoring in Physical Education might be superior to college males majoring in Industrial Arts in terms of their clarity of body image.

Research has demonstrated a clear relationship between dynamic strength and vertical jump (VJ) performance; however, the relationship of isometric strength and VJ performance has been studied less extensively. The aim of this study was to determine the relationship between isometric strength and performance during the squat jump (SJ) and countermovement jump (CMJ). Twenty-two male collegiate athletes (mean ± SD; age 21.3 ± 2.9 years; height 175.63 ± 8.23 cm; body mass 78.06 ± 10.77 kg) performed isometric midthigh pulls (IMTPs) to assess isometric peak force (IPF), maximum rate of force development, and impulse (IMP) (I100, I200, and I300). Force-time data, collected during the VJs, were used to calculate peak velocity, peak force (PF), peak power (PP), and jump height. Absolute IMTP measures of IMP showed the strongest correlations with VJ PF (r 0.43-0.64; p ≤ 0.05) and VJ PP (r 0.38-0.60; p ≤ 0.05). No statistical difference was observed in CMJ height (0.33 ± 0.05 m vs. 0.36 ± 0.05 m; p 0.19; ES-0.29) and SJ height performance (0.29 ± 0.06 m vs. 0.33 ± 0.05 m; p 0.14; ES-0.34) when comparing stronger to weaker athletes. The results of this study illustrate that absolute IPF and IMP are related to VJ PF and PP but not VJ height. Because stronger athletes did not jump higher than weaker athletes, dynamic strength tests may be more practical methods of assessing the relationships between relative strength levels and dynamic performance in collegiate athletes.

MSc (Med), Epidemiology and Biostatistics, Faculty of Health Sciences, University of the Witwatersrand / Background The first two years of a child’s life are crucial for cognitive development. In societies where there are high rates of poverty, children are at risk of undernutrition and subsequently stunting. Insufficient nutrition in early childhood results in growth retardation in young infants and subsequently weak school performance later in life due to poorer cognitive development. As far as we know no study has been conducted in South Africa to examine the association between height at age 2 years and school performance at the end of primary school. Purpose The primary objective of this study was to investigate the association between growth at age 2 years and education performance (school performance in Mathematics and English or first language) of adolescents at the end of primary school (grade 7). In addition, other growth variables such as weight-for-age, BMIfor- age and weight-for-height were tested for the association as a secondary objective. Prevalence of stunting, underweight, wasting and obesity at age two years was also investigated. Methods This study is a primary analysis of historical data collected from Birth to Twenty (BT20) cohort in Johannesburg, South Africa. A cohort study conceptualised to v investigate the effects of the urbanization and societal transition on health and development A longitudinal study design within the BT20 cohort was employed. A total of 252 study participants were included in the study. An ordinal logistic model was used to test for association between growth at age two years and school performance. Potential confounders such as maternal education, birth weight and socio-economic status as defined by household assets were adjusted for in the model. Results At age two years, about 29% of the study participants were stunted as defined by height-for-age, based on the WHO 2006 growth standards. The proportion of girls defined as stunted was equal to that of boys. Levels of underweight, wasting and obesity were 9%, 6% and 2% respectively. The risk of low versus combined high and average performance in Mathematics at grade 7 was about three times more likely in study participants whose heightfor- age was below -3SD and seven times more likely for those below -4SD. Participants whose weight-for-age as defined by the WHO reference was below - 2SD were more than three times more likely to achieve a low score versus a combined high and average score in English or first language. There was no evidence of correlation between low birth weight, wasting and obesity and poor education performance for both Mathematics and English results Conclusion: We conclude that there is an association between height at age 2 years and school performance at the end of primary school.

The United States has arbitrary weather criteria for a prescribed burn day to happen. This arbitrary criteria gives prescribed-burn managers a limited amount of days they can burn. To solve this, I established a 30-year climatology based on daily mixing height (m). I then calculated burn-day thresholds based on different mixing heights. I found seasonal and spatial patterns of the amount of days that are prescribed burns. Southeastern United States was my study area. A small decrease in threshold values will lead to large increases in prescribed burn days. Digital maps were created to show the spatial variability of prescribed burn days and the effects of lowering thresholds for prescribed burn days. This research will aid policy makers in lessening the criteria for burn days.

Therapeutic exercise has previously been shown to alter the static height of the medial longitudinal arch (MLA). It is still unknown, however, if these effects carry over into dynamic activities. PURPOSE: To determine if an 8-week foot strengthening exercise program increases static arch height and reduces vertical deformation of the MLA during mid-stance in running.METHODS: Thirty-four recreational runners (17 males, 17 females) have completed this ongoing study (age 24.06 ± 3.61 years, body mass 68.63 ± 12.95 kg, and height 173.34 ± 9.54 cm). To date, 22 subjects have been assigned to the control group (8 weeks of normal running) and 12 to the foot strengthening group (8 weeks of foot strengthening, along with normal running). Static arch height (SAH) and dynamic arch drop (DAD) were measured at baseline and following the 8-week intervention using Vicon motion analysis. Reflective markers were placed on the proximal and distal ends of the 1st and 5th metatarsals. These 4 markers were recorded in static double leg stance to estimate SAH, and in single leg mid-stance to give a measure of DAD during treadmill running at a self-selected pace. Ten-second trials were recorded at minutes 3 and 4 during running and DAD was evaluated for right and left feet by comparing arch height in mid-stance to the SAH. Following the intervention, data for SAH and DAD were compared across time points and statistical analysis performed to identify differences in the amount of change in SAH and DAD between groups. RESULTS: There was no difference noted in DAD between the groups as a whole, but the change in DAD from baseline to the end of week 8 was statistically significant for those in the foot strengthening group with an initial DAD of ≥ 3.80 mm (p < .028). There was also a statistically significant increase in SAH in the foot strengthening group compared to the control group (p = .013). CONCLUSIONS: These preliminary data suggest that the foot strengthening intervention was effective in increasing SAH compared to the control group. The intervention was most effective at decreasing DAD in those with the largest amount of DAD at baseline. At this time it is unknown whether this decrease in arch drop is associated with performance benefits or decreased injury risk in the recreational runner, and further research is needed to determine the clinical significance of these findings.

High-voltage SiC Schottky barrier diodes have been fabricated with 1mm square contacts. The SBD?s were fabricated using both an argon implant and a field plate overlap for edge termination. The current-voltage characterization of the diodes is presented with statistical yield information on the first set of diodes produced from the Mississippi Center for Advanced Semiconductor Prototyping. After packaging, reverse bias breakdown voltages over 500V at 0.1 A/cm2 and an on-state forward voltage drop of less than 2.5V at 100 A/cm2 were demonstrated. A 0.65-0.85 eV barrier height was extracted from the SBD?s using I-V measurements. Field plate terminated devices demonstrated consistent, low standard deviation breakdown voltages and low leakage currents. The argon implanted devices demonstrated a higher breakdown voltage with higher leakage currents and a higher standard deviation. It was proven that the diodes followed the thermionic field emission model for up to one third of the breakdown voltage. Over 15,000 diodes have been tested and results analyzed in this work.

No description available.

Persistence of perennial grass crops is essential to their profitable management. Recently, orchardgrass producers in the Mid-Atlantic have reported a reduction in the persistence and regrowth vigor of their swards. The overall objective was to evaluate which factors play a major role in controlling the persistence of orchardgrass harvested for hay in the Mid-Atlantic. A survey of orchardgrass fields, growth chamber experiment, and field experiment were conducted to that end. The objectives were to: (1) assess soil fertility, management practices, disease status, and climate in relation to producer perceived stand persistence rating, orchardgrass biomass, and soil test thresholds in orchardgrass hayfields in 4 states, (2) examine the interactions of high temperature and low cutting height on the physiology and regrowth of orchardgrass in controlled environments, and (3) evaluate yield, composition, and size/density compensation-corrected productivity of orchardgrass and orchardgrass/alfalfa mixtures harvested to four cutting heights over three years. The survey of hayfields indicated that the sward age, soil organic matter, grazing, manure application, and historical average high temperature were main determinants of stand persistence score. In the growth chamber experiment, regrowth was significantly reduced by the 35°C treatment as compared to 20°C. Low cutting height significantly reduced regrowth in the cool temperature treatment, but no effect of cutting height was detected under heat stress. In the field experiment, yields were highest from plots cut to 5 cm, but orchardgrass cover in these plots thinned through the experiment. Tiller size and density measurements indicated that cutting heights of 10 cm or greater were able to achieve and maintain optimal leaf area while productivity was reduced for the 5 cm treatment. Overall, it is apparent that excessively low cutting heights are a major cause of reduced persistence in orchardgrass swards and that high temperature stress will limit regrowth. These factors likely interact with fertility and disease status, and together cause the premature loss of orchardgrass stands. Efforts should be made to communicate the importance of increased cutting height to producers. Breeding of orchardgrass resistant to fungal pathogens and heat stress may be required to sustain an orchardgrass hay industry in the Mid-Atlantic. / Ph. D.