Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 91 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 77-80).

Thesis (M. Sc.)--University of Hong Kong, 2005.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains x, 87 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-82).

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xv, 194 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 180-188).

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 169-176). Available also in a digital version from Dissertation Abstracts.

Recently, attentional focus studies involving force production have demonstrated that when participants focused externally motor units were recruited more efficiently and muscular communication was enhanced. When participants focused internally, however, increased "noise" was incorporated into the neuromuscular system resulting in energy waste. The present study explored the effects of an external or internal focus of attention in the isometric wall sit endurance test. Since motor unit recruitment is more efficient under an external focus, it was hypothesized that participants (n = 23) would have a higher endurance time when they focused externally (ex. I want you to focus on pretending like you are sitting in a chair through the duration of the trial) rather than internally (ex. I want you to focus on keeping your knee at 90 degrees through the duration of the trial). Results revealed when participants focused externally they had a significantly higher endurance time (68.41 ± 34.12 sec) than when they focused internally (60.22 ± 34.54 sec). Participants also adopted the correct attentional focus in a majority of the endurance trials (70% and 69% for the external and internal conditions, respectively). This was the first study to demonstrate the benefits of an external focus over an internal focus in an isometric wall sit endurance test. Future studies should use biomechanical analyses such as EMG and kinematic measures and perceived force measures such as RPE to explore the reasons why an external focus provided performance benefits.

A potência em um motor de combustão interna depende, dentre outros parâmetros, da proporção da reação da mistura oxidante/combustível. Esses reagentes são oriundos de hidrocarbonetos e do oxigênio disponível no ar atmosférico. Para cada tipo de combustível utilizado, a mistura apresenta diferentes curvas de desempenho do motor, cuja máxima potência disponibilizada está diretamente relacionada ao valor e à posição da pressão desenvolvida no cilindro em cada ciclo. A posição da máxima pressão deve ser ajustada na melhor condição de aproveitamento do mecanismo biela/manivela a partir da variação do ponto de ignição. O valor da pressão varia, fundamentalmente, com a eficiência de conversão de combustível, com a variação do número de mols proveniente da combustão, com a entalpia de vaporização, com a temperatura de funcionamento do motor, e com a relação entre o carbono, o hidrogênio e o oxigênio existente na molécula. Com a finalidade de verificar o ponto de máxima potência desenvolvida no motor em relação à mistura ar/combustível, foram levantadas curvas de potência para cinco combustíveis, quais sejam: gasolina montadora e condensado, etanol (álcool hidratado 98%), tolueno e mtbe. O fator que estabelece a proporção da mistura ar/combustível real na combustão com a mistura quimicamente balanceada (estequiométrica) é designado por λ. Utilizou-se valores de λ >1, caracterizando a mistura pobre, até os valores de λ <1, os quais permitem o funcionamento do motor em condição de mistura rica. Os experimentos foram realizados em um motor ciclo Otto quatro cilindros, montado em um dinamômetro elétrico e monitorado por uma injeção eletrônica programável. O objetivo deste trabalho foi o de estudar, a partir de dados experimentais, a influência de λ na potência efetiva do motor. Os valores de λ de maior potência obtidos ficaram entre 0,85 e 0,90 podendo servir de parâmetro para o mapeamento da injeção de combustível na condição de aceleração do veículo quando se fizer necessário imprimir a máxima potência. A aquisição de tais valores pode auxiliar ainda no desenvolvimento de novas misturas de combustíveis, em que se procura maior desempenho do motor para competições automobilísticas. / The power developed in an internal combustion engine depends, amongst other parameters, on the ratio oxidizer/combustible. These reagents are deriving of hydrocarbons and atmospheric air. For each type of used fuel, the mixture presents different types of performance curves for the same engine, whose maximum available power is directly related to the value and the crank position of the maximum pressure developed in the cylinder, in each cycle. The crank position of the maximum pressure must be rightly placed, with ignition timing changes, in order to get the best exploitation of the rod/crankshaft mechanism. The value of the pressure varies, basically, with the fuel conversion efficiency, with the mole number variation due to combustion, with the enthalpy of formation, the engine’s operating temperature and with the relation between carbon, hydrogen and the existing oxygen in the fuel’s molecule. With the purpose of verifying the point of highest engine power with relation to the air/fuel ratio, curves of power for five different fuels had been raised. These fuels are: condensed gasoline, OEM gasoline, ethanol, toluen and mtbe. The factor that establishes the air/fuel ratio with the stoichiometric mixture is assigned by λ . Values of λ > 1 characterize lean mixture until the values of λ <1 characterize a rich mixture condition. The experiments had been carried with a four cylinders Otto cycle engine, with programmable electronic fuel injection and ignition control, assembled in an eddy current dynamometer. The objective of this work was to verify, from experimental data, the influence of λ in the engine’s output. The λ values for highest power lie between 0.85 and 0.91, being able to act as an input for tuning the fuel injection system for getting better throttle response and maximum power. The acquisition of such values can still assist in new fuel mixtures development, where increase in power and torque are expected.

Augmented feedback is typically defined as performance- or outcome-related information presented to a motor skill learner in a practice environment (Schmidt & Lee, 2001). This information, which supplements naturally-occurring, task-intrinsic information, has been found to facilitate motor skill learning (Salmoni, et al., 1984). These benefits to motor learning, however, are mediated by several factors including the sensory channel (modality) in which feedback is presented. While augmented feedback presented visually does not typically produce lasting benefits to skilled performance (Sigrist et al, 2013), research in related areas suggests that augmented feedback presented in an audiovisual fashion may benefit motor learning in ways that overcome the limitations of unimodal visual research. Building off this research, the current series of experiments examined how augmented feedback presented audiovisually influenced motor learning of a simple motor task relative to augmented feedback presented either visually or aurally. The first experiment, subjects performed a novel steering task with their non-dominant hand and were tasked with staying within a pre-established boundary. During the practice phase, participants received concurrent feedback regarding their performance. Participants were then tested 24-hours post-practice to examine how feedback presented during practice would affect performance on no-feedback retention and transfer tests. Results from this study indicated that both audiovisual and aural feedback presented during practice facilitate motor learning, whereas feedback presented visually does not. In the second experiment, participants completed the steering task used in experiment one but with an additional timing component added. During practice participants were given two simultaneous streams of concurrent feedback presented either multimodally (e.g. timing information presented aurally, spatial information presented visually) or unimodally (e.g. both timing and spatial information presented aurally). Results from the second study indicated that modally-appropriate multimodal feedback facilitated motor learning to a greater degree than unimodal feedback even when multiple streams of information are presented within the augmented feedback. Theoretical and practical implications are further discussed.

Previous research has demonstrated a retrieval-induced forgetting effect for verbal material (Anderson & Spellman, 1995), colours and shapes (Ciranni & Shimamura,1999), eyewitness testimony (MacLeod, 2002), and images of novel actions (Koutstaal et al., 1999). However, little research has been conducted into retrieval-induced forgetting and self-performed actions. A recent study by Sharman (2011) demonstrated retrieval-induced forgetting for familiar and bizarre self-performed actions. The current thesis aims to examine retrieval-induced forgetting and actions including self-performed and observed actions, and combinations of self-performed and observed actions. The first experiment demonstrated retrieval-induced forgetting for novel motor sequences. In addition, retrieval-induced forgetting was also found for less novel actions (Experiments 3 and 4) for both typical and non-typical self-performed actions (Experiment 3) and memorable self-performed actions (Experiment 4). Experiment 2 demonstrated a retrieval-induced forgetting effect for objects associated with actions suggesting that retrieval-induced forgetting effects occur both for the action and the object. However the findings of experiment 5 suggest that retrieval-induced forgetting may not occur for goal-orientated actions. These experiments may suggest that retrieval-induced forgetting occurs for non goal-orientated actions, but may not occur for goal-orientated actions. These findings are discussed in terms of the inhibitory account.

A potência em um motor de combustão interna depende, dentre outros parâmetros, da proporção da reação da mistura oxidante/combustível. Esses reagentes são oriundos de hidrocarbonetos e do oxigênio disponível no ar atmosférico. Para cada tipo de combustível utilizado, a mistura apresenta diferentes curvas de desempenho do motor, cuja máxima potência disponibilizada está diretamente relacionada ao valor e à posição da pressão desenvolvida no cilindro em cada ciclo. A posição da máxima pressão deve ser ajustada na melhor condição de aproveitamento do mecanismo biela/manivela a partir da variação do ponto de ignição. O valor da pressão varia, fundamentalmente, com a eficiência de conversão de combustível, com a variação do número de mols proveniente da combustão, com a entalpia de vaporização, com a temperatura de funcionamento do motor, e com a relação entre o carbono, o hidrogênio e o oxigênio existente na molécula. Com a finalidade de verificar o ponto de máxima potência desenvolvida no motor em relação à mistura ar/combustível, foram levantadas curvas de potência para cinco combustíveis, quais sejam: gasolina montadora e condensado, etanol (álcool hidratado 98%), tolueno e mtbe. O fator que estabelece a proporção da mistura ar/combustível real na combustão com a mistura quimicamente balanceada (estequiométrica) é designado por λ. Utilizou-se valores de λ >1, caracterizando a mistura pobre, até os valores de λ <1, os quais permitem o funcionamento do motor em condição de mistura rica. Os experimentos foram realizados em um motor ciclo Otto quatro cilindros, montado em um dinamômetro elétrico e monitorado por uma injeção eletrônica programável. O objetivo deste trabalho foi o de estudar, a partir de dados experimentais, a influência de λ na potência efetiva do motor. Os valores de λ de maior potência obtidos ficaram entre 0,85 e 0,90 podendo servir de parâmetro para o mapeamento da injeção de combustível na condição de aceleração do veículo quando se fizer necessário imprimir a máxima potência. A aquisição de tais valores pode auxiliar ainda no desenvolvimento de novas misturas de combustíveis, em que se procura maior desempenho do motor para competições automobilísticas. / The power developed in an internal combustion engine depends, amongst other parameters, on the ratio oxidizer/combustible. These reagents are deriving of hydrocarbons and atmospheric air. For each type of used fuel, the mixture presents different types of performance curves for the same engine, whose maximum available power is directly related to the value and the crank position of the maximum pressure developed in the cylinder, in each cycle. The crank position of the maximum pressure must be rightly placed, with ignition timing changes, in order to get the best exploitation of the rod/crankshaft mechanism. The value of the pressure varies, basically, with the fuel conversion efficiency, with the mole number variation due to combustion, with the enthalpy of formation, the engine’s operating temperature and with the relation between carbon, hydrogen and the existing oxygen in the fuel’s molecule. With the purpose of verifying the point of highest engine power with relation to the air/fuel ratio, curves of power for five different fuels had been raised. These fuels are: condensed gasoline, OEM gasoline, ethanol, toluen and mtbe. The factor that establishes the air/fuel ratio with the stoichiometric mixture is assigned by λ . Values of λ > 1 characterize lean mixture until the values of λ <1 characterize a rich mixture condition. The experiments had been carried with a four cylinders Otto cycle engine, with programmable electronic fuel injection and ignition control, assembled in an eddy current dynamometer. The objective of this work was to verify, from experimental data, the influence of λ in the engine’s output. The λ values for highest power lie between 0.85 and 0.91, being able to act as an input for tuning the fuel injection system for getting better throttle response and maximum power. The acquisition of such values can still assist in new fuel mixtures development, where increase in power and torque are expected.