Lately, car manufacturers have been put to a big challenge to reduce the CO2 emission of their entire fleets. Norms of pollutant emissions limit the ways to achieve the desired CO2 emission goals, as some of the solutions that would lead to lower CO2 emission also lead to higher pollutant emission. Waste Heat Recovery (WHR) could be a good solution to lower the CO2 emission of the Internal Combustion Engine (ICE) without increasing the pollutant emission. In the present thesis different WHR strategies are analysed and the results suggested it would be interesting to further study the Brayton cycle machine. Air Brayton Cycle (ABC) represents a way to recover a part of the heat energy of the ICE exhaust gases and transform it into mechanical energy. Recovered mechanical energy would then be returned to the crankshaft of the ICE, thereby reducing the amount of energy that has to be liberated by combustion of fuel which lowers the fuel consumption and CO2 emission. The study of ABC started with an analysis of the ideal cycle in order to obtain the theoretical maximum of the system. The study continued with an analysis of the semi ideal cycle where all losses are taken into account only by two efficiency coefficients. This analysis showed that for the diesel engine efficiency of the ABC is very low because of the low exhaust gas temperature. For the gasoline engine the cycle could be viable when the ICE is working under steady condition and higher load. These conditions could be fulfilled when the vehicle is driven on the highway. Detailed analysis was aimed at determining the cycle main losses. They were determined to be: pumping losses, losses caused by heat transfer and mechanical losses. Taking into account these main losses along with other direct and indirect losses it was concluded that the cycle is not viable for the types of the WHR machines that were considered in this study. In order for the cycle to be viable some other either existing or new machine type should be tested, that would lower the main losses and offer good isentropic and mechanical efficiency for desired conditions. / Últimamente los fabricantes de automóviles se han puesto el gran reto de reducir la emisión de CO2 en la totalidad de sus flotas. Las nuevas normativas para la reducción de las emisiones contaminantes limitan los medios para lograr los objetivos deseados en la emisión de CO2 porque algunas de las soluciones que llevan a la reducción en la emisión de CO2 también dan lugar a un incremento en la emisión de otros contaminantes. La recuperación de calor residual (WHR) podría ser una buena solución para reducir las emisiones de CO2 del motor de combustión interna (ICE) sin poner en peligro la emisión de contaminantes. En la presente Tesis se analizaron diferentes estrategias de WHR y se concluyó que sería interesante estudiar más a fondo la máquina de ciclo Brayton. El Ciclo Brayton de Aire (ABC) permite recuperar una parte del calor de los gases de escape del ICE y transformar este calor en energía mecánica. La energía mecánica recuperada se devuelve al cigüeñal del ICE, reduciendo de ese modo la cantidad de energía que tiene que ser liberada por la combustión del combustible, lo cual permite reducir el consumo de combustible y las emisiones de CO2. En esta Tesis se estudia el ABC mediante un análisis del ciclo ideal con el fin de obtener el máximo teórico del sistema. El modelo se mejora con un análisis del ciclo semi-ideal donde se tienen en cuenta todas las pérdidas mediante el uso de dos coeficientes generales. Este análisis muestra que para el motor diesel la eficiencia del ciclo ABC es muy baja debido a la baja temperatura del gas de escape. Para el motor de gasolina el ciclo podría ser viable cuando el ICE está trabajando bajo condiciones estacionarias y una carga mayor. Estas condiciones se podrían cumplir cuando el vehículo está circulando en autopista. El análisis detallado de este ciclo tiene como objetivo determinar las pérdidas principales de ciclo. Las pérdidas principales se identificaron como: las pérdidas de bombeo, las pérdidas causadas por la transferencia de calor y las pérdidas mecánicas. Teniendo en cuenta estas pérdidas principales junto con otras pérdidas directas e indirectas, se concluyó que el ciclo no es viable para los tipos de máquinas WHR que fueron considerados en este estudio. Para que el ciclo sea viable se tiene que buscar alguna otra máquina existente o un nuevo tipo de máquina que reduzca las principales pérdidas y ofrezca un buen rendimiento isentrópico y mecánico para las condiciones deseadas. / Últimament els fabricants d'automòbils s'han posat el gran repte de reduir l'emissió de CO2 de la totalitat de les seues flotes. Les noves normatives de reducció de les emissions contaminants limiten els mitjans per assolir els objectius desitjats d'emissió de CO2 perquè algunes de les solucions que porten a la reducció en l'emissió de CO2 també donen lloc a un increment a l'emissió de altres contaminants. La recuperació de calor residual (WHR) podria ser una bona solució per reduir les emissions de CO2 del motor de combustió interna (ICE) sense posar en perill l'emissió de contaminants. En la present Tesi s'han analitzat diferents estratègies WHR i es va concloure que seria interessant estudiar més a fons el cicle Brayton. El Cicle Brayton d'Aire (ABC) representa una manera de recuperar una part de la calor dels gasos d'escapament de l'ICE i transformar calor a l'energia mecànica. L'energia mecànica recuperada es retorna al cigonyal de l'ICE reduint d'aquesta manera la quantitat d'energia que ha de ser alliberada per la combustió del combustible permitint la reducció del consum de combustible i les emissions de CO2. En aquesta Tesi s'ha començat estudiant un ABC amb una anàlisi del cicle ideal per tal d'obtenir el màxim teòric del sistema. Este model es millora amb una anàlisi del cicle semiideal on es tenen en compte totes les pèrdues amb tan sols dos coeficients d'eficiència. Aquesta anàlisi va mostrar que per al motor dièsel l'eficiència del cicle ABC és molt baixa a causa de la baixa temperatura del gas d'escapament. Per al motor de gasolina el cicle podria ser viable quan l'ICE està treballant sota condicions estacionàries i una càrrega més gran. Aquestes condicions es podrien complir quan el vehicle està circulant en autopista. L'anàlisi detallada del cicle va tenir com a objectiu determinar les pèrdues principals de cicle. Les pèrdues principals es van identificar com: les pèrdues de bombament, les pèrdues causades per la transferència de calor i les pèrdues mecàniques. Tenint en compte aquestes pèrdues principals juntament amb altres pèrdues directes i indirectes, es va concloure que el cicle no és viable per als tipus de màquines WHR que van ser considerats en aquest estudi. Perquè el cicle puga ser viable s'ha de buscar alguna altra màquina existent o un nou tipus de màquina que puga reduir les principals pèrdues i puga oferir un bon rendiment isentròpic i mecànic per a les condicions desitjades. / Kleut, P. (2016). Recuperation of the exhaust gases energy using a Brayton cycle machine [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/76807

Made available in DSpace on 2014-12-17T15:16:06Z (GMT). No. of bitstreams: 1 SheylaTSL.pdf: 1123530 bytes, checksum: 9d193a5e8ae6cbd93482dabd85a41d69 (MD5) Previous issue date: 2009-07-30 / Introduction: The ability to walk is impaired in obese by anthropometric factors (BMI and height), musculoskeletal pain and level of inactivity. Little is known about the influence of body adiposity and the acute response of the cardiovascular system during whole the 6-minute walk test (6mWT). Objective: To evaluate the effect of anthropometric measures (BMI and WHR waist-to-hip ratio), the effort heart and inactivity in ability to walk the morbidly obese. Materials and Methods: a total 36 morbidly obese (36.23 + 11.82 years old, BMI 49.16 kg/m2) were recruited from outpatient department of treatment of obesity and bariatric surgery in University Hospital Onofre Lopes and anthropometric measurements of obesity (BMI and WHR), pulmonary function, pattern habitual physical activity (Baecke Questionnaire) and walking capacity (6mWT). The patient was checking to measure: heart rate (HR), breathing frequency (BF), peripheral oxygen saturation, level of perceived exertion, systemic arterial pressure and duplo-produto (DP), moreover the average speed development and total distance walking. The data were analysed between gender and pattern of body adiposity, measuring the behavior minute by minute of walking. The Pearson and Spearmam correlation coefficients were calculated, and stepwise multiple Regression examined the predictors of walking capacity. All analyses were performed en software Statistic 6.0. Results: 20 obese patients had abdominal adiposity (WHR = 1.01), waist circumference was 135.8 cm in women (25) and 139.8 cm in men (10). Walked to the end of 6mWT 412.43 m, with no differences between gender and adiposity. The total distance walked by obesity alone was explained by BMI (45%), HR in the sixth minute (43%), the Baecke (24%) and fatigue (-23%). 88.6% of obese (31) performed the test above 60% of maximal HR, while the peak HR achieved at 5-minute of 6mWT. Systemic arterial pressure and DP rised after walking, but with no differences between gender and adiposity. Conclusion: The walk of obese didn?t suffers influence of gender or the pattern of body adiposity. The final distance walked is attributed to excess body weight, stress heart, the feeling of effort required by physical activity and level of sedentary to obese. With a minute of walking, the obeses achieved a range of intensity cardiovascular trainning / Introdu??o: A capacidade de caminhar dos obesos ? prejudicada pelo ?ndice de Massa Corporal (IMC), dores osteomioarticulares e n?vel de sedentarismo. Pouco se sabe sobre a influ?ncia do perfil da adiposidade corporal, do g?nero e da resposta aguda do sistema cardiovascular sobre a capacidade de caminhada do obeso. Objetivo: Avaliar o efeito de medidas antropom?tricas (IMC e WHR, waist-to-hip ratio), esfor?o card?aco e sedentarismo sobre a capacidade de caminhada de portadores de obesidade m?rbida. Materiais e M?todos: Entre setembro de 2007 e setembro de 2008, 36 obesos m?rbidos (idade 36,23 + 11,82; IMC 49,16 kg/m2) foram recrutados no ambulat?rio de tratamento da obesidade e cirurgia bari?trica do Hospital Universit?rio Onofre Lopes e avaliados quanto marcadores antropom?tricos de obesidade, fun??o pulmonar, n?vel de atividade f?sica habitual (Question?rio de Baecke) e capacidade de caminhar (TC6M). O paciente era monitorado para verificar: freq??ncia card?aca (FC) e respirat?ria (FR), satura??o perif?rica de oxig?nio, n?vel de esfor?o percebido, press?o arterial sist?mica (PA) e duplo-produto (DP). Durante a caminhada, ainda mensurava-se a velocidade m?dia desenvolvida e dist?ncia total percorrida pelos portadores de obesidade m?rbida. Os dados foram analisados entre os g?neros e o tipo de distribui??o de gordura corporal, avaliando o comportamento das vari?veis a cada minuto caminhado. As correla??es de Pearson e Spearmam foram analisadas. A Regress?o M?ltipla buscou preditores da capacidade de caminhada. Foi utilizado o software Statistic 6.0 para an?lise estat?stica. Resultados: 20 obesos tinham adiposidade abdominal (WHR = 1,01), circunfer?ncia da cintura de 135,8 cm nas mulheres (25) e de 139,8 cm nos homens (10). Durante TC6M, foi caminhada uma dist?ncia de 412,43 m, sem diferen?as entre g?nero ou adiposidade. Essa dist?ncia total percorrida foi explicada isoladamente pelo IMC (45%), FC no sexto minuto (43%), Baecke (24%) e fadiga (-23%). 88,6% dos obesos (31) realizaram o teste acima de 60% da FCM?xima, sendo o pico de FC atingido aos 5 minutos de caminhada. PA e DP aumentaram significativamente com a caminhada, mas sem diferen?as entre g?nero ou adiposidade. Conclus?o: A acaminhada dos obesos m?rbidos n?o sofre influ?ncia do g?nero ou do perfil de adiposidade corporal. A dist?ncia final percorrida ? atribu?da ao excesso de peso corporal, estress card?aco, sensa??o de esfor?o imposta pela caminhada e ao n?vel de sedentarismo pr?vio do obeso. Dentro de 1 minuto de caminhada, os obesos atingem uma zona de treinamento cardiovascular

Title: Movement intervention like a tool of subject's life style influence in age from 20 to 53 years Student: Bc. Vít Živný Supervisor: prof. Ing. Václav Bunc, CSc. Purpose: To provide the informations about lifestyle of subject in age 20 - 53 years . To show risks factors of health problems derived from their current status - body weight, BMI, waist circumference, and more. Using anthropometric methods used to assess current physical condition. With physical activities intervention affect and decrease these risk factors. Methods: Aplication of physical intervention in the range of 11 to 17 weeks for the subject. Regular anthropometric measurements and filling data into tables. Comparing with common standards. Determination of the actual level of health risks. Progressive evaluation of improving the condition and reducing risks. Results: Applied movement interventions significantly reduce health risks associated with current physical condition detected by anthropometric methods. The application also affect the overall view of the lifestyle chosen people. Regular physical activity of right intensity significantly reduces the risk of health problems and other diseases. Key words: lifestyle, physical activity, hypokinesis, nutrition, obesity, BMI, WHR, reducing program, health risks

Objetivo. Ao mesmo tempo em que a obesidade aumenta no mundo todo e se torna cada vez mais um problema de Saúde Pública, o stress aumenta no cotidiano das pessoas e na busca pela sobrevivência. Verificar a possível associação entre prevalências de obesidade centralizada e indicadores de stress é o objetivo desse trabalho. Métodos. Utilizam-se dados de um estudo transversal, com informações de 298 mulheres de 20 a 59 anos, moradoras de um município da Grande São Paulo, as quais responderam questionários especialmente elaborados para avaliar o stress psicológico. O diagnóstico de obesidade centralizada foi feito através da medida da circunferência da cintura (CC) e da razão cinturaquadril (RCQ). O stress psicológico foi medido em escores atribuídos às respostas dos questionários e classificado em 3 categorias: isento, resistência e exaustão. A análise estatística foi realizada mediante dois modelos de regressão linear generalizada múltipla entre a variável resposta obesidade centralizada em duas categorias (sim, não) e o stress psicológico em três fases (isento, resistência e exaustão), controlando-se as variáveis demográficas: idade e escolaridade. Resultados. As prevalências de obesidade centralizada foram semelhantes nos dois modelos, respectivamente 40,6 % e 42% para CC e RCQ. As prevalências de stress psicológico foram 61,7% e 8,4% para as fases resistência e exaustão. As associações entre a categoria sim foram positivas e significantes, respectivamente para CC e RCQ (RP 1,51, P 0,028 e RP 1,52, P 0,022) com o stress na fase de exaustão, com o aumento da idade (RP 1,02, P 0,001 e RP 1,01, P 0,002) e com baixa escolaridade (RP 0,67, P 0,030 e RP 0,59, P 0,005). O teste de tendência foi positivo (P 0,029) para a categoria sim do RCQ e aumento das categorias de stress. Conclusões. A fase de exaustão do stress mostrou associação positiva e significante com a obesidade centralizada nos dois modelos estudados, CC e RCQ. O teste significante de tendência com a RCQ sugere efeito gradativo das fases do stress sobre a obesidade centralizada. São necessários, no entanto, outros estudos que comprovem a associação da obesidade centralizada com o stress subdividido em categorias. / Objective. When observing modern life nowadays we find out that, at the same time that obesity increases all around the world and becomes a real concern to public health authorities, we also see stress proliferating in peoples everyday life, specially in the fight for survival. The purpose of this work is to verify the association between prevalence of abdominal obesity and stress indicators. Methods. This work uses given data of a transversal study, containing information of 298 women aged between 20 and 59, inhabitants of the Great São Paulo, who had been submitted to questionnaires especially formulated to evaluate psychological stress. The diagnosis of abdominal obesity was made using two models: measuring Waist Circumference (WC) and Waist - Hip ratio (WHR). Psychological stress was measured in scores attributed to answers of the questionnaires and classified in 3 categories: Exempt, Resistance and Exhaustion. The statistics analysis were carried through two models of multiple generalized linear regression between the variable which is the answer- abdominal obesity focused in two categories (Yes, No) and psychological stress focused in three categories (Exempt, Resistance, Exhaustion) maintaining under control the demographic variables such as age and scholarship. Results. The results referring to the prevalence of abdominal obesity were similar in the two models showing respectively 40.6% and 42% for WC and WHR. The results on the prevalence of psychological stress were 61.7% and 8.4% respectively for the phase of Resistance and the phase of Exhaustion. The associations in the Yes category were classified as being positive and significant, for WC and WHR respectively, Prevalence Ratio PR 1,51, significancy P 0,028 and PR 1,52, P 0,022 for the stress in the phase of Exhaustion, when considered also an increase in age (PR 1,02, P 0,001 and PR 1,01, P 0,002) and a decrease in the level of education (PR 0,67, P 0,030 and PR 0,59, P 0,005) The trend analysis was positive (P 0,029) for the increase of the WHR and the categories of stress. Conclusions. The phase of Exhaustion of Stress showed positive and significant association with the Abdominal Obesity in the two models, WC and WHR. The positive results in the trend tests with the WHR suggest that abdominal obesity may be gradually affected by the phases of stress. Nevertheless, there is the need of further investigation to confirm the association between abdominal obesity and the various categories of stress.

Objetivo. Ao mesmo tempo em que a obesidade aumenta no mundo todo e se torna cada vez mais um problema de Saúde Pública, o stress aumenta no cotidiano das pessoas e na busca pela sobrevivência. Verificar a possível associação entre prevalências de obesidade centralizada e indicadores de stress é o objetivo desse trabalho. Métodos. Utilizam-se dados de um estudo transversal, com informações de 298 mulheres de 20 a 59 anos, moradoras de um município da Grande São Paulo, as quais responderam questionários especialmente elaborados para avaliar o stress psicológico. O diagnóstico de obesidade centralizada foi feito através da medida da circunferência da cintura (CC) e da razão cinturaquadril (RCQ). O stress psicológico foi medido em escores atribuídos às respostas dos questionários e classificado em 3 categorias: isento, resistência e exaustão. A análise estatística foi realizada mediante dois modelos de regressão linear generalizada múltipla entre a variável resposta obesidade centralizada em duas categorias (sim, não) e o stress psicológico em três fases (isento, resistência e exaustão), controlando-se as variáveis demográficas: idade e escolaridade. Resultados. As prevalências de obesidade centralizada foram semelhantes nos dois modelos, respectivamente 40,6 % e 42% para CC e RCQ. As prevalências de stress psicológico foram 61,7% e 8,4% para as fases resistência e exaustão. As associações entre a categoria sim foram positivas e significantes, respectivamente para CC e RCQ (RP 1,51, P 0,028 e RP 1,52, P 0,022) com o stress na fase de exaustão, com o aumento da idade (RP 1,02, P 0,001 e RP 1,01, P 0,002) e com baixa escolaridade (RP 0,67, P 0,030 e RP 0,59, P 0,005). O teste de tendência foi positivo (P 0,029) para a categoria sim do RCQ e aumento das categorias de stress. Conclusões. A fase de exaustão do stress mostrou associação positiva e significante com a obesidade centralizada nos dois modelos estudados, CC e RCQ. O teste significante de tendência com a RCQ sugere efeito gradativo das fases do stress sobre a obesidade centralizada. São necessários, no entanto, outros estudos que comprovem a associação da obesidade centralizada com o stress subdividido em categorias. / Objective. When observing modern life nowadays we find out that, at the same time that obesity increases all around the world and becomes a real concern to public health authorities, we also see stress proliferating in peoples everyday life, specially in the fight for survival. The purpose of this work is to verify the association between prevalence of abdominal obesity and stress indicators. Methods. This work uses given data of a transversal study, containing information of 298 women aged between 20 and 59, inhabitants of the Great São Paulo, who had been submitted to questionnaires especially formulated to evaluate psychological stress. The diagnosis of abdominal obesity was made using two models: measuring Waist Circumference (WC) and Waist - Hip ratio (WHR). Psychological stress was measured in scores attributed to answers of the questionnaires and classified in 3 categories: Exempt, Resistance and Exhaustion. The statistics analysis were carried through two models of multiple generalized linear regression between the variable which is the answer- abdominal obesity focused in two categories (Yes, No) and psychological stress focused in three categories (Exempt, Resistance, Exhaustion) maintaining under control the demographic variables such as age and scholarship. Results. The results referring to the prevalence of abdominal obesity were similar in the two models showing respectively 40.6% and 42% for WC and WHR. The results on the prevalence of psychological stress were 61.7% and 8.4% respectively for the phase of Resistance and the phase of Exhaustion. The associations in the Yes category were classified as being positive and significant, for WC and WHR respectively, Prevalence Ratio PR 1,51, significancy P 0,028 and PR 1,52, P 0,022 for the stress in the phase of Exhaustion, when considered also an increase in age (PR 1,02, P 0,001 and PR 1,01, P 0,002) and a decrease in the level of education (PR 0,67, P 0,030 and PR 0,59, P 0,005) The trend analysis was positive (P 0,029) for the increase of the WHR and the categories of stress. Conclusions. The phase of Exhaustion of Stress showed positive and significant association with the Abdominal Obesity in the two models, WC and WHR. The positive results in the trend tests with the WHR suggest that abdominal obesity may be gradually affected by the phases of stress. Nevertheless, there is the need of further investigation to confirm the association between abdominal obesity and the various categories of stress.

Research in sustainable energy sources has become the interest of many studies due to the increasing energy demand and the amount of wasted energy released from existing methods, along with their effect on climate change and environment sustainability. Thermo-Electric Generators (TEGs) are a potential solution that is being studied and implemented as they can convert low grade thermal energy to useful electrical energy at various operating conditions. The integration of a TEG within a heat exchanger (TEG/HX) system connected to an electrical DC micro-grid, using a Maximum Power Point Tracking (MPPT) system is the focus of this study. Using a numerical TEG/HX model from a previous study and a developed DC micro-grid model the interaction between the thermal and electrical aspects were investigated with the focus on the electrical performance of the system. The main concern of this study is to investigate the effect of the sub components of the DC micro-grid on the overall available energy. An analytic model was developed to estimate the power loss in the electrical circuit of the micro-grid, the model utilizes the equations for switching and conduction losses which have been used by several studies. Other variables such as the battery characteristics and electrical load profiles were also investigated by simulating several case studies including changing operating conditions. This study shows the effect of a TEG configuration on the power loss in an electrical system using power loss curves in comparison with the Open Circuit Voltage (OCV) of such configuration. It also covers important modes of operation for the battery, loads and MPPT for a stable and reliable operation of an isolated DC micro-grid system were TEGs are the only source of power. The result of the study presented is a system design that is able to maximize the electrical energy harvested from the TEGs to extend the operation of the dc-micro-grid first by applying a suitable TEG configuration and consequently a suitable electrical circuit. Secondly, by adapting to the changing operating conditions of the TEGs and the loads; and compensating for these changes using the battery storage system. / Thesis / Master of Applied Science (MASc)

The aim of this thesis is to evaluate ORC systems and technologies from an energy and economic perspective. ORC systems are a growing renewable electricity generation technology, but New Zealand has limited local skills and expertise for identifying ORC resource opportunities and subsequently developing suitable technologies at low cost. For this reason, this thesis researches ORC technology, resource types, and international development, with the aim to determine guidelines for how to cost-effectively develop ORC systems, and to make recommendations applicable to furthering their development within a New Zealand context. This thesis first uses two surveys, one of commercial ORC installations, and a second of economic evaluations of ORC systems in literature, to determine what resources and economic scenarios are supportive of commercial development. It is found that geothermal resources provide the largest share of ORC capacity, with biomass and waste-heat recovery (WHR) being developed more recently. The surveys also found that countries with high electricity prices or policy interventions have developed a wider range of resources using ORC systems. This thesis then undertakes an EROI evaluation of ORC electricity generation systems using a combination of top-down and process based methodologies. Various heat sources; geothermal, biomass, solar, and waste heat are evaluated in order to determine how the utilised resource can affect energy profitability. A wide range of EROIstnd values, from 3.4 – 22.7 are found, with solar resources offering the lowest EROIs, and geothermal systems the highest. Higher still EROI values are found to be obtainable with longer system lifetimes, especially for WHR systems. Specific engineering aspects of ORC design and technology such as high-side pressure, heat storage, modularity, superheating, pinch-point temperature difference, and turbine efficiency are evaluated in terms of economic performance, and a variety of general conclusions are made about each. It is found that total system thermo-economic optimisation may not lead to the highest possible EROI, depending on the objective function. Lastly, the effects of past and potential future changes to the markets and economies surrounding ORCs are explored, including the New Zealand electricity spot price, steel and aluminium prices, subsidies, and climate policy. Of the subsidy types explored, it is found that directly subsidising ORC system capital has the greatest effect on the economic performance of ORC systems, as measured by common metrics. In conclusion, this thesis finds that ORC systems have a limited applicability to New Zealand’s electricity market under current economic conditions outside of geothermal and off-grid generation, but changes to these conditions could potentially make their development more viable. The author recommends that favourable resources should be developed using systems that provide high efficiencies, beyond what might provide the best economic performance, in order to increase EROI, and reduce the future need for costly investments into increasingly less favourable resources.

The aim of this thesis is to evaluate ORC systems and technologies from an energy and economic perspective. ORC systems are a growing renewable electricity generation technology, but New Zealand has limited local skills and expertise for identifying ORC resource opportunities and subsequently developing suitable technologies at low cost. For this reason, this thesis researches ORC technology, resource types, and international development, with the aim to determine guidelines for how to cost-effectively develop ORC systems, and to make recommendations applicable to furthering their development within a New Zealand context. This thesis first uses two surveys, one of commercial ORC installations, and a second of economic evaluations of ORC systems in literature, to determine what resources and economic scenarios are supportive of commercial development. It is found that geothermal resources provide the largest share of ORC capacity, with biomass and waste-heat recovery (WHR) being developed more recently. The surveys also found that countries with high electricity prices or policy interventions have developed a wider range of resources using ORC systems. This thesis then undertakes an EROI evaluation of ORC electricity generation systems using a combination of top-down and process based methodologies. Various heat sources; geothermal, biomass, solar, and waste heat are evaluated in order to determine how the utilised resource can affect energy profitability. A wide range of EROIstnd values, from 3.4 – 22.7 are found, with solar resources offering the lowest EROIs, and geothermal systems the highest. Higher still EROI values are found to be obtainable with longer system lifetimes, especially for WHR systems. Specific engineering aspects of ORC design and technology such as high-side pressure, heat storage, modularity, superheating, pinch-point temperature difference, and turbine efficiency are evaluated in terms of economic performance, and a variety of general conclusions are made about each. It is found that total system thermo-economic optimisation may not lead to the highest possible EROI, depending on the objective function. Lastly, the effects of past and potential future changes to the markets and economies surrounding ORCs are explored, including the New Zealand electricity spot price, steel and aluminium prices, subsidies, and climate policy. Of the subsidy types explored, it is found that directly subsidising ORC system capital has the greatest effect on the economic performance of ORC systems, as measured by common metrics. In conclusion, this thesis finds that ORC systems have a limited applicability to New Zealand’s electricity market under current economic conditions outside of geothermal and off-grid generation, but changes to these conditions could potentially make their development more viable. The author recommends that favourable resources should be developed using systems that provide high efficiencies, beyond what might provide the best economic performance, in order to increase EROI, and reduce the future need for costly investments into increasingly less favourable resources.

Organic Rankine cycles can be integrated with district heating systems and in applications of biogas digestion. Evaluating the performance of the installations by Againity AB in Ronneby and Norrköping, Sweden, is a unique opportunity which can support the establishment of ORC technology in the waste heat recovery market, unveiling its feasibilities and limitations. Operational data gathered from October 2017 until April 2018, provides this thesis with information about the ORC-systems. A method using Coolprop and Matlab has been used to detect steady-state series in the Ronneby installation using moving standard deviation and inclination criteria. By screening the data and selecting these series, analytical equations can be used to determine the performance of the installations and map the linear relationship between variables like pressure and generator power. The largest impact on the system in Ronneby is developed in the condenser. Large coolant volume flow creates large heat sink capacity and higher generator efficiency and power. However, with increasing generator power the condenser pressure decrease. Lower condenser pressure results in a decreased evaporation pressure, which could be maintained if the pump was able to run at higher frequencies. The Plant in Norrköping needs further studies and a review of its sensors. The code in Matlab is a resource to Againity and Linköpings university for future work in performance evaluation. It can be used to detect errors in energy balance, local readings, and picture the machines' performance graphically.

The thesis focuses on body image - defines the main characteristics of this area, describes cultural influences and body image history and explains basic quantitative values (Body Mass Index, Waist Hip Ratio, Bioelectrical Impedance Analysis). Furthemore the thesis deals with media influence on body ideal formation process, especially in gay subculture. The research part explores recent situation of body image in gay subculture compared with heterosexual males. This section includes the content analysis of mainstream gay movies which compares media presentation of gays and the real situation and examines media influence on gay body image formation.