The main purpose of this study was to measure the differences in ground reaction forces (GRFs) produced from an anteroposterior versus a mediolateral style hockey skating arm swing. Twenty four elite level female hockey players performed each technique while standing on a ground mounted force platform, all trials were filmed using two video cameras. Force data was assessed for peak scaled GRFs in the frontal and sagittal planes, and resultant GRF magnitude and direction. Upper limb kinematics were assessed from the video using Dartfish video analysis software, confirming that the subjects successfully performed two significantly distinct arm swing techniques. The mediolateral arm swing used a mean of 18.38° of glenohumeral flexion/extension and 183.68° of glenohumeral abduction/adduction while the anteroposterior technique used 214.17° and 28.97° respectively. The mediolateral arm swing produced 37% greater frontal plane and 33% lesser sagittal plane GRFs than the anteroposterior arm swing. The magnitudes of the resultant GRFs were not significantly different between the two techniques however the mediolateral technique produced a resultant GRF with a significantly larger angle from the direction of travel (44.44°) as compared to the anteroposterior technique (31.60°). The results of this study suggest that the direction of GRFs produced by the mediolateral arm swing more consistent with the direction of lower limb propulsion, perhaps resulting in a greater contribution to high velocity skating. Based on the findings from the present study ice hockey skaters should perform the mediolateral arm swing to maximize the effective GRFs produced with each stride.

The main purpose of this study was to measure the differences in ground reaction forces (GRFs) produced from an anteroposterior versus a mediolateral style hockey skating arm swing. Twenty four elite level female hockey players performed each technique while standing on a ground mounted force platform, all trials were filmed using two video cameras. Force data was assessed for peak scaled GRFs in the frontal and sagittal planes, and resultant GRF magnitude and direction. Upper limb kinematics were assessed from the video using Dartfish video analysis software, confirming that the subjects successfully performed two significantly distinct arm swing techniques. The mediolateral arm swing used a mean of 18.38° of glenohumeral flexion/extension and 183.68° of glenohumeral abduction/adduction while the anteroposterior technique used 214.17° and 28.97° respectively. The mediolateral arm swing produced 37% greater frontal plane and 33% lesser sagittal plane GRFs than the anteroposterior arm swing. The magnitudes of the resultant GRFs were not significantly different between the two techniques however the mediolateral technique produced a resultant GRF with a significantly larger angle from the direction of travel (44.44°) as compared to the anteroposterior technique (31.60°). The results of this study suggest that the direction of GRFs produced by the mediolateral arm swing more consistent with the direction of lower limb propulsion, perhaps resulting in a greater contribution to high velocity skating. Based on the findings from the present study ice hockey skaters should perform the mediolateral arm swing to maximize the effective GRFs produced with each stride.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Aug. 24, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Mechanical Engineering, University of Alberta." Includes bibliographical references.

Thesis (M.S.)--Springfield College, 2003. / Includes bibliographical references (leaves 107-111).

No description available.

It is important to investigate how the golf swing changes with extended play because fatigue affects the performance of athletes playing sports similar to golf. Golf is a physically demanding sport when playing 18 holes while walking and carrying a bag. The effect of playing 18 holes of golf on the mechanics and swing outcome of the golfer are currently unknown. The knowledge of how extended play affects the golf swing will aid golfers, golf coaches, and researchers in understanding proper golf training and play affected swing mechanics. This study investigates the effect of playing 18 holes of simulated golf on the mechanics and performance of the golfer. A total of seven male and female recreational golfers scoring between 80 and 95 on 18 holes of walked golf were recruited for 3-D motion analysis of 140 tee shots. Mechanical variables and outcome variables at three phases of the golf swing were tested over time to evaluate the relationship between time (playing golf), mechanical variables, and the outcome of the golf shot tested statistically using path analysis. Weight transfer to the lead leg at ball contact was significantly related to club head velocity (CHV). Over time, golfers were less able to achieve a weight transfer to the lead leg, which was directly related to the golfers' club head velocity. The lead knee and lead ankle angles were also affected by time, which had an influence on club head velocity. These results suggest that golfers do change their swing throughout the course of 18 holes of walked golf and there are key swing mechanics which significantly influence golf performance. / School of Physical Education, Sport, and Exercise Science

Low-swing on-chip interconnect circuits have been viewed as alternative solutions to the problem of delay and power increase of on-chip interconnects. This thesis aims to characterize and optimize several basic low-swing interconnect circuits, by developing simple delay and power estimation methodologies. Accuracies of the proposed methods are validated against SPICE-based simulations on the 90nm technology node. Based on the delay and power estimation methods developed, optimum power-delay trade-off curves are obtained and directly used for comparison among different interconnect circuit strategies. Three low-swing techniques are included, i.e. conventional level converter (CLC), pseudodifferential interconnect circuit (PDIFF), and current-mode signaling (CM). These techniques represent significantly different driver and receiver topologies, where CLC uses lower supply voltage of a normal inverter driver, PDIFF uses NMOS only drivers, while CM has a low impedance termination at the receiving end. In addition, an optimized full-swing repeater-based technique is included as a baseline for comparison. A simplified repeater performance estimation technique considering ramp input signals is also proposed. The most important step in estimating delay of different driver circuits is the accurate estimation of transistor effective resistance, which considers velocity saturation effects and voltage transition patterns. Optimization for the CM circuit for on-chip interconnects requires completely different treatment than the voltage-mode circuits, due to the different and more complex effective driver resistance and termination resistance modeling. Sizing the driver and receiver transistors should be done simultaneously as their resistive values which affect its performance are dependent on each other. Optimum transistor sizing is very dependenton the required voltage swing chosen. Results of our comparisons show that optimized CLC (reduced voltage supply) repeaters appears to give the best general performance with a slight delay overhead compared to full-swing repeaters. The fact that CLC with repeaters has shorter delay than single-segment CM and PDIFF highlights the effectiveness of repeater structures in long wires. The inclusion of inductance and closed-form solutions to derive optimum transistor sizings for various low-swing interconnect circuits may be developed as a future work using delay and power estimation models presented in this thesis, which is a challenging task to do considering the non-linear equations involved.

Canola meal was used as an adsorbent in a pressure swing adsorption (PSA) apparatus for ethanol dehydration. The experiments were conducted at different pressures, temperatures, vapor superficial velocities, vapor concentrations and particle sizes. Adsorption experiments were performed at equilibrium and breakthrough points. The results demonstrated that canola meal can break the azeotropic point 95.6 wt% and produce over 99 wt% ethanol. At elevated temperature, feed water concentration, and vapor superficial velocity, it was found that the mass transfer rate increased. In addition, the mass transfer rate decreases when either the total pressure or the size of the adsorbent particles are increased. Breakthrough curves were simulated and the overall mass transfer resistance was evaluated at all experimental runs. The internal mass transfer resistance was identified as the relevant mass transfer mechanism. For canola meal, the equilibrium water/ethanol uptake was achieved at 100, 105, and 110˚C. The Frenkel-Halsey-Hill (FHH) and Guggenheim-Andrson-de-Boer (GAB) models perfectly simulated the water adsorption isotherms. By applying Dubinin-Polanyi model to the experimental data, canola meal was identified as a large pore (non-porous) material. The heat of adsorption on canola meal with particle size of 0.43-1.18 mm was determined to be -32.11 kJ/mol. The result confirms that the adsorption process is an exothermic phenomenon and is of physical type due to the fact that the value obtained as the heat of adsorption is negative and its magnitude is within the range 20–80 kJ/mol. The equilibrium water uptake on canola meal was similar to that reported for other starchy and cellulosic adsorbents, while the ethanol uptake was higher. Water saturated canola meal was successfully regenerated by passing nitrogen at 110˚C which is lower than that for molecular sieves commonly used in industry for bioethanol dehydration. The canola meal bio-adsorbent was re-used for more than 32 cycles and no significant change in adsorption capacity was observed.

No description available.