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A dynamic phantom for use in investigating hyperthermia heating systems has been designed, constructed, and tested. A computer controlled the flow rate of 80% Ethanol to each of 4 preserved in vitro canine kidneys which acted as the phantom material. The flow rates were regulated with stepper motor controlled valves and measured with flow meters by the computer. This provided a flexible system for adjusting the perfusion as desired. The system was tested with step and ramp changes in perfusion under constant power ultrasound and with a temperature controlled perfusion algorithm, all of which yielded repeatable results. The dynamic phantom developed in this work shows potential for expediting investigations of hyperthermia controllers, temporal blood flow patterns, and inverse problems. Its computer based nature gives it great flexibility which would lend itself well to automated testing procedures.

The purpose of this study was to lower body core temperature prior to a simulated portion of a triathlon (swim-15min; bike-45min) and examine whether precooling could attenuate thermal strain and increase subjective exercise tolerance in the heat. Six endurance trained triathletes (mean ± SE, 28 ± 2 yr, 8.2 ± 1.7 % body fat) completed two randomly-assigned trials, one week apart. The precooling trial (PC) involved lowering body core temperature (-0.5°C) in water prior to swimming and cycling. The control trial (CON) was identical except no precooling was performed. Water temperature and environmental conditions were maintained at -25.6°C and -26.6°C/60% RH respectively, throughout all testing. Mean time to precool was 31:37 ± 8:03 and average time to reach baseline temperature during cycling was 9:35 ± 7:60. Oxygen consumption (VO2), heart rate (HR), rate of perceived exertion (RPE), thermal sensation (TS), and skin (Tsk) and core (Ta) temperatures were recorded following the swim segment and throughout cycling. No significant differences in mean body (TO or Tsk were noted between PC and CON, but a significant difference (P<0.05) in T, between treatments was noted through the early phases of cycling. No significant differences were reported in HR, V02, RPE, TS or sweat rate (SR) between treatments. Body heat storage (S) was negative following swimming in both PC (92 ± 6 W/m2) and CON (66 ± 9 W/m2). A greater increase in S occurred in PC (109 ± 6 W/m2) vs. CON (79 ±4 W/m2) during cycling (P<0.05) . Precooling attenuated the rise in T,, but this effect was transient. Based on the results from this study, precooling is not recommended prior to endurance exercise in the heat. / School of Physical Education

Purpose: The impact of temperature on the coagulative response to exercise has not been well described. The purpose of this study was to assess the response of plasma thrombin-antithrombin (TAT) to exercise during exposure to both hot and cold temperatures, and to compare those responses to exercise under normal, temperate conditions. Methods: Fifteen healthy male subjects (25.3 + 4.3 years) volunteered to participate in this study. Subjects completed maximal cycle ergometer exercise tests in three different temperatures (20°C, 5° or 8° C, and 30°C) in an environmental chamber. All tests were conducted in random order and separated by at least seven days. Blood samples were obtained before and immediately after exercise and analyzed by Elisa to determine plasma concentrations of thrombin-antithrombin complex (TAT). Results: Subjects demonstrated significantly elevated plasma levels of TAT in all three temperatures immediately after exercise (normal =1.04 ± 0.44 ng/ml, cold =1.34 ± 0.79 ng/ml, hot =1.18 + 0.95 ng/ml) when compared to baseline measures (normal = 0.45 ± 0.26 ng/ml, cold = 0.88 + 0.57 ng/ml, hot = 0.64 + g/ml). Subjects also showed significant elevations in TAT concentrations both before and after exercise in the cold temperature when compared with the normal temperature. There was no significant difference between the hot and normal temperatures. Conclusion: An individual's coagulation potential is increased following maximal physical exertion and may be further increased by exposure to colder temperature. Key Words: coagulation, physical exertion, temperature, thrombosis. / School of Physical Education, Sport, and Exercise Science

This study evaluated the effect of a macro- versus a microcooling system on the cognitive, psychomotor and physiological performance of human operators. Male subjects (n = 24) were acclimatized for four days and then subjected to three different environmental conditions: hot ambient (40°C; 40% RH), microcooling and macrocooling. Each environmental condition was repeated twice; once under a rest condition and once while simulating a physical workload of 40 W. Four performance tests (reasoning, eye-hand coordination, memory, reaction time) were conducted once every hour for four hours. Five physiological measurements, viz rectal temperature, skin temperature, heart rate, total sweat loss and sweat rate, were taken. A significant difference existed between the physiological responses under the hot ambient condition and both cooling conditions. For all five physiological parameters he human operator benefitted substantially whatever the cooling condition. The psychological performance results indicated a greater benefit under the cooling conditions, though various external factors may have influenced responses. User perception showed that macrocooling was perceived to be the optimal method of cooling. The results showed that there was no difference in the extent to which both rectal temperature and heart rate (for rest and work conditions) decreased over the 4-hour study period with micro- and macrocooling. In the baseline hot environment both increase. Sweat rate was lowest when resting or working in a microcooled environment and at its highest in the hot baseline environment. Mean skin temperature was lowest (for rest and work conditions) with microcooling and highest in the hot baseline environment. Reaction time and memory/attention were the same under all three environmental conditions. Eye-hand coordination was better with cooling than without, but did not differ between the two cooling conditions. Reasoning ability was poorest under the hot baseline condition and best in the macrocooled environment. User perception showed that the subjects found macrocooling highly acceptable. Microcooling was found to be uncomfortable, particularly because cold air (18 - 21°C) entered the jacket at one point which caused numbness of the skin at that point. Jackets did not always fit subjects well and the umbilical cord restricted free movement.

A Ergonomia busca em sua essência adaptar o trabalho ao homem, usando de diversas ferramentas para atingir este objetivo, entre elas a análise ambiental. As características do ambiente como ruído, temperatura e iluminação podem influenciar o trabalho de um funcionário, e por isso necessitam ser avaliadas para verificar o seu efeito sobre a saúde dos trabalhadores e sua capacidade de trabalho. O estresse térmico, causado por calor, é a condição onde tanto o sistema fisiológico quanto o sistema psicológico são afetados pela temperatura do ambiente em que se encontra, quando esta temperatura encontra-se em níveis extremos, e pode causar efeitos como: hipertermia, tontura, desidratação, dor de cabeça, entre outros. A proposta desta pesquisa foi avaliar o efeito quantitativo que os sintomas de estresse térmico podem causar na produtividade de operadores em uma fundição. Foram empregadas duas normalizações para analisar o estresse térmico: ISO 7243 (1989), a qual apresenta a metodologia do Índice de Bulbo Úmido Termômetro de Globo (IBUTG), e ISO 7933 (2004), a qual apresenta a Taxa Requerida de Suor. Após a coleta de dados ambientais e pessoais em seis pontos diferentes do layout da fábrica, realizou análises de correlação e regressão linear entre os índices de estresse térmico e a produtividade para verificar a relação entre as mesmas. Os resultados demonstraram que a produtividade é inversamente proporcional ao nível de estresse térmico, e que o índice que apresenta a melhor correlação com a produtividade é o IBUTG, com coeficiente de determinação 94,05%, o que significa que 94,05% da variação encontrada para o tempo de vazamento de peças, indicador de produtividade, é justificada pela variação do índice IBUTG, indicador de estresse térmico. Os demais índices apresentaram correlações de 82,16% e 78,26%, e a regressão linear proporcionou em todos os métodos determinar uma equação para prever a produtividade em função da variação do estresse térmico. / Ergonomics seeks in essence to adapt the work to the individual, using various tools to achieve this goal, including environmental analysis. The characteristics of the environment such as noise, temperature and lighting can influence the work of an employee, and therefore need to be evaluated to assess its effect on the health of workers and their working ability. The thermal stress caused by heat is the condition where both the physiological system as the psychological system are affected by the environment in which it is , when this temperature is in extreme levels, and can cause effects such as: hyperthermia, dizziness, dehydration, headache, among others. The purpose of this research was to evaluate the quantitative effect that the symptoms of heat stress can cause on the productivity of operators in a foundry. Two normalizations were used to analyze the thermal stress: ISO 7243 (1989), which presents the methodology of the Index Wet Bulb Globe Temperature (WBGT) and ISO 7933 (2004), which presents the Required Sweat Rate method. After collecting environmental and personal data in six different points of the foundry, it was conducted analyzes of correlation and linear regression between the index of thermal stress and productivity to verify the relation between them. The results showed that productivity is inversely proportional to the level of heat stress, and that the index that has the best correlation with productivity is the WBGT, with a determination coefficient 94.05% , ie 94.05% of the variation found for the time of casting parts, productivity indicator is justified by the variation of WBGT index. The other indices had correlations of 82.16 % and 78.26%, and the linear regression provided in all methods determine an equation to predict productivity as a function of the variation of heat stress.

A Ergonomia busca em sua essência adaptar o trabalho ao homem, usando de diversas ferramentas para atingir este objetivo, entre elas a análise ambiental. As características do ambiente como ruído, temperatura e iluminação podem influenciar o trabalho de um funcionário, e por isso necessitam ser avaliadas para verificar o seu efeito sobre a saúde dos trabalhadores e sua capacidade de trabalho. O estresse térmico, causado por calor, é a condição onde tanto o sistema fisiológico quanto o sistema psicológico são afetados pela temperatura do ambiente em que se encontra, quando esta temperatura encontra-se em níveis extremos, e pode causar efeitos como: hipertermia, tontura, desidratação, dor de cabeça, entre outros. A proposta desta pesquisa foi avaliar o efeito quantitativo que os sintomas de estresse térmico podem causar na produtividade de operadores em uma fundição. Foram empregadas duas normalizações para analisar o estresse térmico: ISO 7243 (1989), a qual apresenta a metodologia do Índice de Bulbo Úmido Termômetro de Globo (IBUTG), e ISO 7933 (2004), a qual apresenta a Taxa Requerida de Suor. Após a coleta de dados ambientais e pessoais em seis pontos diferentes do layout da fábrica, realizou análises de correlação e regressão linear entre os índices de estresse térmico e a produtividade para verificar a relação entre as mesmas. Os resultados demonstraram que a produtividade é inversamente proporcional ao nível de estresse térmico, e que o índice que apresenta a melhor correlação com a produtividade é o IBUTG, com coeficiente de determinação 94,05%, o que significa que 94,05% da variação encontrada para o tempo de vazamento de peças, indicador de produtividade, é justificada pela variação do índice IBUTG, indicador de estresse térmico. Os demais índices apresentaram correlações de 82,16% e 78,26%, e a regressão linear proporcionou em todos os métodos determinar uma equação para prever a produtividade em função da variação do estresse térmico. / Ergonomics seeks in essence to adapt the work to the individual, using various tools to achieve this goal, including environmental analysis. The characteristics of the environment such as noise, temperature and lighting can influence the work of an employee, and therefore need to be evaluated to assess its effect on the health of workers and their working ability. The thermal stress caused by heat is the condition where both the physiological system as the psychological system are affected by the environment in which it is , when this temperature is in extreme levels, and can cause effects such as: hyperthermia, dizziness, dehydration, headache, among others. The purpose of this research was to evaluate the quantitative effect that the symptoms of heat stress can cause on the productivity of operators in a foundry. Two normalizations were used to analyze the thermal stress: ISO 7243 (1989), which presents the methodology of the Index Wet Bulb Globe Temperature (WBGT) and ISO 7933 (2004), which presents the Required Sweat Rate method. After collecting environmental and personal data in six different points of the foundry, it was conducted analyzes of correlation and linear regression between the index of thermal stress and productivity to verify the relation between them. The results showed that productivity is inversely proportional to the level of heat stress, and that the index that has the best correlation with productivity is the WBGT, with a determination coefficient 94.05% , ie 94.05% of the variation found for the time of casting parts, productivity indicator is justified by the variation of WBGT index. The other indices had correlations of 82.16 % and 78.26%, and the linear regression provided in all methods determine an equation to predict productivity as a function of the variation of heat stress.

"April 2002" Includes bibliographical references (leaves 200-249)

"April 2002" / Includes bibliographical references (leaves 200-249) / xv, 249 leaves : ill., plates (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2003

"April 2002" / Includes bibliographical references (leaves 200-249) / xv, 249 leaves : ill., plates (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2003