[pt] Este trabalho visa a avaliar o comportamento dinâmico de um Giroscópio em Suspensão Cardânica com dois graus de liberdade a partir de suas equações de movimento, obtidas analiticamente, considerando possíveis imprecisões de fabricação ou variações na geometria esperada. A partir do resultado de simulações de um sistema real em voo, pretende-se compará-las com o resultado de simulações realizadas com o modelo analítico e avaliar as causas de possíveis discrepâncias. Assim, analisa-se a influência da variação de parâmetros geométricos na precisão de medição de um giroscópio cardânico de 2 eixos sob a ação do sistema em uma manobra de inclinação e sob a ação de uma elevada aceleração linear, quando houver uma excentricidade no centro de gravidade do rotor. Duas hipóteses vão ser exploradas: uma idealizando o rotor do giroscópio como livre no espaço outra imaginando a influência dos quadros da suspensão cardânica, tomados todavia como rígidos. Apresenta-se uma implementação que testa vários parâmetros geométricos e procura-se adequar a forma de representar os resultados de tal forma que seja possível uma validação do modelo matemático proposto. / [en] This paper evaluates the dynamic performance of a Two Axes Cardanic Gyroscope, based on the development of its equation of motion, considering possible manufacturing imprecisions or geometric variations on the expected geometry. Simulation results of a real guided vehicle system are used to compare with those obtained from the analytical model, in order to determine the origin of discrepancies. The simulation will allow the specification of manufacturing tolerances based on the needed precision of the dynamic behavior to keep small the overall cost. Special attention is dedicated to the influence of geometric parameters in the measurement accuracy of a two axes cardanic gyroscope, such as the eccentricity of the center of gravity of its rotor, when located inside a guided vehicle that experiences a high longitudinal acceleration and performs afterwards a specific manoeuvre. Two hypothesis for the analytical description will be explored, one considering the gyro rotor free in space and the other including the inner gimbals inertia and friction influences, while all components are considered rigid. This will show the need for a more precise model. An implementation Is presented, testing some geometric parameters, with the purpose of showing the results properly, in order to allow the mathematical model validation.

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No description available.

Obesity has reached epidemic proportions, highlighting the need to better understand contributors to under-exercise and overeating. Anxiety Sensitivity (AS) is hypothesized to amplify negative affect and avoidance motives, and has been linked to maladaptive coping behaviors such as eating pathology as well as distress during and avoidance of exercise. The current series of studies was designed to extend research that relied on self-report assessments, and investigate the role of AS in objectively-assessed eating and exercise behavior across three community samples. The first two studies examined eating in the context of experimentally-induced negative affect in a sample representing all weight categories (N = 57); and distress, perceived exertion, and affect changes during exercise in normal and obese weight groups (N = 38). The third study extended this investigation to a naturalistic setting, using actigraphy, affect, and dietary monitoring across a three-day period in normal and obese weight groups (N = 32). The hypotheses were that AS would predict more eating in the context of negative affect; greater perceived exertion and distress during exercise, as well as avoidance of exercise, with findings most pronounced in obese participants. Results were as follows. In the first study, more calories consumed following a negative affect induction was predicted by the interaction between a dimension of AS (mental concern) and the expectancy of loss of control from eating in overweight/obese participants. In the second study, there was no significant association between AS and ratings of exertion or distress during exercise; however, a trend suggested the expected affective benefits of acute exercise were not evident in obese participants with greater AS and exertion. The final study found that AS was associated with more calories consumed across the monitoring period in women but not men (who were equally represented across AS and weight groups), and was also predictive of more calories consumed in the context of negative affect. Additionally, high AS predicted less engagement in moderate-intensity exercise in obese participants and more in normal weight participants. Overall, these studies provide support for the hypothesis that AS is a predictor of both exercise avoidance and overeating behavior.

Not much is known about hawkfish worldwide including those that occur in the understudied Red Sea reef system. Hawkfishes are small reef predators that perch in ambush-ready positions and shelter within or on various substrates including live and dead coral. The aim of this study was to look at the distribution and abundance patterns of Red Sea hawkfishes across an inshore and offshore gradient and to investigate the use of benthic habitats. This study was conducted on three inshore, four midshore, and two offshore reefs with surveys at 8 meters and along the reef crest. In total, three species were documented: Paracirrhites forsteri, Cirrhitichthys oxycephalus, and Cirrhitus spilotoceps. We found clear distinctions between depth zones and between continental shelf positions. Cirrhitichthys oxycephalus only occurs at the reef slope and Cirrhitus spilotoceps is only found on reef crests. Paracirrhites forsteri was the most abundant species across all reefs and was found in four varying color morphs. Morph 1 showed the most evidence of being a generalist as it utilized the greatest number of substrates. All three species were more abundant on midshore and offshore reefs which have healthier, intact coral communities. Coral cover is a good indicator of hawkfish abundance even when the species in question does not utilize live coral directly.

A better understanding of the performance in precision of physical parameterizations in NWP models is necessary for improving forecasts of tornadic outbreaks. For this study, WRF simulations of tornadic outbreaks were run using configurations of three microphysics, three convective physics, and two PBL physics schemes. Each configuration was subjected to ten iterations of SKEBS. The means of the ten perturbation members of each parameterization configuration were bootstrapped for SB CAPE, SB CIN, and 0-3km SRH to find 95% confidence interval widths at each grid point. Maps of these spreads provided a spatial analysis of the uncertainty. Analyses on correlations and clusters were performed to determine how the configurations related spatially and in magnitude. These uncertainties were further bootstrapped to compare the mean of each configuration in boxplots. The effect on the uncertainty produced by each configuration varied according to the diagnostic variable being analyzed.

Sensitivity analysis is essential for the hydrologic models to help gain insight into model’s behavior, and assess the model structure and conceptualization. Parameter estimation in the distributed hydrologic models is difficult due to the high-dimensional parameter spaces. Sensitivity analysis identified the influential and non-influential parameters in the modeling process, thus it will benefit the calibration process. This study identified, applied and evaluated two sensitivity analysis methods for the APEX model. The screening methods, the Morris method, and LH-OAT method, were implemented in the experimental site in North Carolina for modeling runoff, sediment loss, TP and DP losses. At the beginning of the application, the run number evaluation was conducted for the Morris method. The result suggested that 2760 runs were sufficient for 45 input parameters to get reliable sensitivity result. Sensitivity result for the five management scenarios in the study site indicated that the Morris method and LH-OAT method provided similar results on the sensitivity of the input parameters, except the difference on the importance of PARM2, PARM8, PARM12, PARM15, PARM20, PARM49, PARM76, PARM81, PARM84, and PARM85. The results for the five management scenarios indicated the very influential parameters were consistent in most cases, such as PARM23, PARM34, and PARM84. The “sensitive” parameters had good overlaps between different scenarios. In addition, little variation was observed in the importance of the sensitive parameters in the different scenarios, such as PARM26. The optimization process with the most influential parameters from sensitivity analysis showed great improvement on the APEX modeling performance in all scenarios by the objective functions, PI1, NSE, and GLUE.

No description available.

An electron multiplier has been developed which has increased the sensitivity of an existing mass spectrometer toy a factor of 10^5. This increased sensitivity has permitted determination of fission yields of substances that have undergone little fission. Two such samples, for which the rare gas isotopes have been analysed, are Bohemian pitchblende and the products resulting from the neutron fission of Th232, The Bohemian ore exhibited more neutron fission than any uranium deposit previously analysed. An explanation of this effect may be obtained by considera­tion of the geological and chemical nature of the deposit. The neutron fission of thorium, which shows fine structure in both the xenon and krypton regions, is similar to the patterns of u235 U235 and pu239, / Thesis / Master of Science (MS)