This experimental study investigated whether affective states influence physical strength. A sample of 32 university students participated in two interventions and one control condition. The interventions were a time-constrained puzzle and a guided, anger focused visualisation. After each intervention and during the control, participants tested their grip strength with a hand dynamometer and estimated eight different affective states through continuum-scales. Participants were the strongest during the control, being statistically weaker during the puzzle intervention compared to control. Both interventions induced multiple affective states, including anger. A simple linear regression gave a statistically significant model where 13% of the variation in grip strength difference, between the puzzle intervention and control, could be explained by the difference in anger between the same trials. Participants’ difference in grip strength between the trials could be predicted as -5.08 + 0.09. For each value that the puzzle intervention rated higher in anger, grip strength was increased by 0.09 kg compared to the control. The model showed a positive moderate correlation. Higher anger during the puzzle intervention increased strength output relative to the control, despite showing a lower mean grip strength. Anger, under the proper circumstances, appear to increase strength output, but more research is needed.

No description available.

No description available.

<p>This thesis presents the design stages in creating a robotic driving system for performing in-lab driving schedule playback using a chassis dynamometer. This equipment is intended to assist research in improving the power train system in Hybrid Electric Vehicles (HEV). The design stage layout contributes to showing how to effectively breakdown a mechatronics related project into manageable steps. The process includes background research, system requirements, system design and validation. Design stages are further broken up into three subsystems, mechanical, electrical and software.</p> <p>Two actuators control the gas and brake pedals of the test vehicle. An active control system allows the vehicle to follow a speed vs. time driving schedule. The control feedback loop uses two cascading Proportional-Integral (PI) controllers (vehicle speed and pedal position). Feedback signals come from the onboard diagnostics (OBD-II) port. The control software is implemented on a dSPACE MicroAutoBox capable of multiple inputs and outputs including a built in CAN Bus controller to receive messages from the OBD-II port. The control software is implemented in Simulink and provides a modular, maintainable architecture for future development.</p> <p>The system design steps lead to a practical system obtained through a systematic approach. Design documentation will allow for further development of this test system to meet future requirements.</p> / Master of Applied Science (MASc)

Yes / There is no single, universally accepted method of measuring isometric neck strength to inform exercise prescription and injury risk prediction. This study aimed to establish the inter- and intra-rater reliability of a commercially available fixed frame dynamometer in measuring peak isometric neck strength. A convenience sample of male (n = 16) and female (n = 20) university students performed maximal isometric contractions for flexion (Flex), extension (Ext), left- (LSF) and right-side flexion (RSF) in a quadruped position over three sessions. The intra-rater reliability results were good-to-excellent for both males (ICC = 0.83–0.90) and females (ICC = 0.86–0.94) and acceptable (CV < 15%) across all directions for both males and females. The inter-rater reliability results were excellent (ICC = 0.96–0.97) and acceptable (CV < 11.1%) across all directions. Findings demonstrated a significant effect for sex (p ≤ 0.05): males were stronger in all four directions, and a significant effect for direction (p ≤ 0.05): Ext tested stronger (193 N) than Flex (176 N), LSF (130 N) and RSF (125 N). The findings show that the VALD fixed frame dynamometer can reliably assess isometric neck strength and can provides reference values for healthy males and females.

This study investigated the determination of an optimal resistive force for use during a short-term, high-intensity cycling power test. Twenty-four college females [age (yrs) x̄=22.0 ± 0.50; weight (kg) x̄=60.3 ± 1.46] gave consent and participated in a 1 repetition maximum (RM) test of the leg extensors and 5 maximal 15 s cycling tests using a modified Monark cycle ergometer. The 1 RM test was performed using a Nautilus leg extensor machine. Even increments between six to ten % 1RM test were utilized to determine the resistive force applied to the flywheel. The 5 tests were divided into a 2 testing sessions occurring at least 48 h apart. Each subject warmed-up at 50 - 60 rpms for 2 - 5 minutes without resistance prior to testing. Each test consisted of a maximal cycling bout of 15 s with 20 minutes rest between tests. The variables measured included peak power (PP), time to peak power (TTPP), power fatigue rate (PFR), power fatigue index (PFI), and average power (AP). These values were collected by a microcomputer interfaced with the cycle ergometer. In general, PP decreased at a resistance greater than 9 % 1RM. The average reported PP values were 363±15, 413±19, 465±19, 520±21, and 460±41 for loads 6 to 10 % 1RM respectively. Similar results were reported for AP. The differences in PP for loads between 8 and 10 % 1RM were statistically different. Results show that PP varies based on loads of % 1RM and the optimal range is between 8 and 10% 1RM. / Master of Science

Introdução - A análise da força de preensão manual durante a força realizada ao longo do tempo fornece dados referentes ao funcionamento biomecânico dos grupos musculares, com destaque à influência da musculatura flexora profunda e superficial dos dedos, bem como traz informações pertinentes ao desempenho funcional para atividades cotidianas. Objetivos - Analisar as curvas força-tempo da preensão palmar sob os aspectos de seus parâmetros discretos e de sua característica temporal. Identificar a influência da musculatura flexora profunda de dedos na preensão palmar. Método - Os voluntários realizaram o teste de esforço isométrico máximo utilizando o dinamômetro Jamar® e o transdutor de força computadorizado com duas empunhaduras, uma que permitia a ação do músculo flexor superficial de dedos e outra que a bloqueava. Foram analisadas as curvas força-tempo geradas de 9 indivíduos tanto em seus parâmetros discretos como em suas características temporais. Resultados - A força máxima média obtida com o Jamar® na Posição 1, sem distinção entre os sexos, (30,76 Kgf) aproximou-se dos valores da média nacional para mulheres (30,4 Kgf). Tanto no teste com o Jamar® como com o transdutor de força, os valores discretos foram maiores na Posição 1 (Fmáx Jamar®: 30,76/25,14 kgf; Fmáx transdutor: 22,16/17,37 kgf; Tmáx: 1,41/1,54 seg; Finf: 7,06/5,80 kgf). A fase de manutenção da força, equivalente a força de resistência, teve menor decréscimo nos testes realizados na Posição 2 (-1,02/-0,61). Além disso, os valores obtidos entre os dinamômetros mostram que o Jamar® superestima os valores de força máxima. Conclusões - Os dados apontam que há diferença na capacidade de manutenção da força, para a qual a ação do músculo flexor profundo dos dedos mostrou-se mais eficaz do que quando em conjunto com o flexor superficial dos dedos, tendo assim, grande importância funcional para a execução das atividades de vida diária. Evidencia-se que a análise da força por meio de suas características temporais fornece maior elucidação do desempenho muscular durante a força de preensão do que testes dinamométricos pontuais. / Introduction - The analysis of the manual grip force along time presents the biomechanical movement of muscle groups data, with emphasis on the deep and superficial flexor musculature of the fingers, as well as provides relevant information for the functional performance of daily activities. Objectives - To analyze the force-time curves of the palmar grip under the aspects of its discrete parameters and its temporal characteristic. Either, to identify the the influence of the flexor muscles of fingers in the palmar grip. Method - The volunteers performed the maximum isometric effort test using the Jamar® dynamometer and the computerized force transducer with two grips, one that allowed the action of the flexor superficial finger muscle, and another that blocks it. The force-time curves generated from 9 individuals were analyzed in both their discrete parameters and their temporal characteristics. Results - The medium of maximum strength obtained with Jamar® at Position 1, without distinction between gender, (30.76 Kgf) approached the national average for women (30.4 Kgf). In both the Jamar® and the force transducer tests, the discrete values were higher in Position 1 (Fmax Jamar®: 30.76 / 25.14 kgf; Fmax transducer: 22.16 / 17.37 kgf; Tmax: 1.41 / 1.54 sec; Finf: 7.06 / 5.80 kgf). The strength maintenance phase, equivalent to the resistive force, had a smaller decrease in the tests performed in Position 2 (-1.02 / -0.61). In addition, the values obtained between the dynamometers show that the Jamar® overestimates the maximum force values. Conclusions - The data points that there is a difference between the action of the flexor profound muscle group of the fingers and the flexor superficial one in the capacity of maintaining the force, showing that the profound group is more effective than combined with the superficial flexor, thus, the first one has great functional importance for performing activities of daily life. It evidences that the analysis of force on its temporary characteristics is more elucidative of the muscular performance during the grip force than the punctual dynamometric tests.

Dentro da seqüência natural de testes para validar o uso do biodiesel (éster etílico) misturado ao óleo diesel em maiores proporções no Brasil, este trabalho teve o objetivo de estudar os efeitos do uso de uma mistura combustível B10 (com concentração de 10% em volume de biodiesel diluído em óleo diesel) na degradação do óleo lubrificante de um motor de ignição por compressão, aspirado, de 1,9 L e de injeção indireta. Acoplado a um dinamômetro, o motor foi submetido à condição de velocidade constante de 2.500 rpm, sob carga variável, e abastecido com três combustíveis diferentes: óleo diesel puro, B10 de biodiesel de soja e B10 de biodiesel de soja e nabo forrageiro. Cada combustível alimentou o motor durante 30 horas. Para determinar a degradação resultante, selecionaram-se as propriedades do óleo lubrificante usado em cada etapa para serem analisadas (viscosidade, contaminação por água e presença de elementos). Os resultados revelaram que o uso de 10% volume dos dois tipos de biodiesel na mistura combustível não causou variação significante na concentração de elementos e nas propriedades físico-químicas do óleo lubrificante. / Adding to an ongoing sequence of tests aimed at validating the use of biodiesel (ethyl ester) mixed with diesel in higher proportions in Brazil, this study was conducted to investigate the effects of utilizing a B10 fuel mixture (10% volume biodiesel diluted in diesel) on the degradation of lubricating oil in an aspirated, indirect-injection, 1.9 L compression-ignition engine. Coupled to a dynamometer, the engine was operated at a constant speed of 2,500 rpm under variable load and run with three types of fuel: pure diesel, B10 soy biodiesel, and B10 soy and fodder turnip biodiesel. Each type of fuel fed the engine for 30 hours. To determine the resulting degradation, selected properties of the lubricating oil used in each run were analyzed (viscosity, contamination by water and presence of elements). The results revealed that the use of a 10% volume of either type of biodiesel in the fuel mixture did not lead to significant variation in the concentration of elements or in the physico-chemical properties of the lubricating oil.

In the European Union the legislation governing fleet CO2 emissions is already in place with a fleet average limit of 130g/km currently being imposed on all vehicle manufacturers. With the target for this legislation falling to 95g/km by 2020 and hefty fines for noncompliance automotive engineers are working a pace to develop new technologies that lower the CO2 emissions and hence fuel consumption of new to market vehicles. As average new vehicle CO2 emissions continue to decline the task of measuring these emissions with high precision becomes increasingly challenging. With the introduction of real world emissions legislation planned for 2017 there is a development driven need to precisely assess the vehicle CO2 emissions on chassis dynamometers over a wide operating range. Furthermore since all type approval and certification testing is completed on chassis dynamometers, any new technology must be proven against these test techniques. Typical technology improvements nowadays require repeatability limits which were unprecedented 5-10 years ago and the challenge now is how to deliver this level of precision. Detailed studies are conducted into the four key areas that cause significant noise to the CO2 emissions results from chassis dynamometer tests. These are the vehicle electrical system, driver behaviour, procedural factors and the chassis dynamometer itself. In each of these areas, the existing contribution of imprecision is quantified, methods are proposed then demonstrated for improving the precision and the improved case is quantified. It was found that the electrical system can be controlled by charging the vehicle battery, not using auxiliary devices and installing current measurement devices on the vehicle. Simply charging the vehicle battery prior to each test was found to cause a change to the CO2 emissions of 2.2% at 95% confidence. Whilst auxiliary devices were found to cause changes to the CO2 emissions of up to 43% for even a relatively basic vehicle. The driver behaviour can be controlled by firstly removing the tolerances from the driver’s aid which it was found improved the precision of the CO2 emissions by 43.5% and secondly by recording the throttle pedal movements to enable the validation of test results. Procedural factors, such as tyre pressures can be easily controlled by resisting the temptation to over check and by installing pressure sensing equipment. Using a modern chassis dynamometer with low parasitic losses will make the job of controlling the dynamometer easier, but all dynamometers can be controlled by following the industry standard quality assurance procedures and implementing statistical process control tools to check the key results. The implementation of statistical process control alone improved the precision of unloaded dynamometer coastdown checks by reducing the coefficient of variation from 6.6 to 4.0%. Using the dynamometer to accelerate the vehicle before coastdown checks was found to approximately halve the variability in coastdown times. It was also demonstrated that verification of the dynamometer inertia simulation and response time are both critically important, as the industry standard coastdown test is insufficient, in isolation, to validate the loading on a vehicle. Six sigma and statistical process control techniques have shown that for complex multiple input single output systems, such as chassis dynamometer fuel economy tests, it is insufficient to improve only one input to the system to achieve a change to the output. As a result, suggested improvements in each noise factor often have to be validated against an input metric rather than the output CO2 emissions. Despite this, the overall level of precision of the CO2 emissions and fuel consumption seen at the start of the research, measured by the coefficient of variation of approximately 2.6%, has been improved by over six times through the simultaneous implementation of the findings from this research with the demonstration of coefficient of variation as low as 0.4%. Through this research three major contributions have been made to the state of the art. Firstly, from the work on driver behaviour an extension is proposed to the Society of Automotive Engineers J2951 drive quality metric standard to include the a newly developed Cumulative Absolute Speed Error metric and to suggest that metrics are reviewed across the duration of a test to identify differences in driving behaviours during a test that do not cause a change to the end of test result. Secondly, the need to instrument the vehicle and test cell to record variability in the key noise factors has been demonstrated. Thirdly, a universal method has been developed and published from this research, to use response modelling techniques for the validation of test repeatability and the correction of CO2 emissions. The impact of these contributions is that the precision of chassis dynamometer emissions tests can be improved by a factor of 6.5 and this is of critical importance as the new real world driving and world light-duty harmonised emissions legislation comes into force over the next two to five years. This legislation will require an unprecedented level of precision for the effective testing of full vehicle system interactions over a larger operating range but within a controlled laboratory environment. If this level of precision is not met then opportunities to reduce vehicle fuel consumption through technology that only has a small improvement on fuel consumption, which is likely given the large advances that have be achieved over the last few decades, will be missed.

Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Wing Hong Lee. / Elec.E