Brayton cycles are open gas turbine cycles extensively used in aviation and industrial applications because of their advantageous volume and weight characteristics. With the bulk of waste exhaust heat and engine emissions associated, there is need to be mindful of environmentally-friendliness of these engine cycles, not compromising good technical performance, and economic viability. This research considers assessment of power plants in helicopters, and aeroderivative industrial gas turbines combined-heat-and-power (ADIGT-CHP) in the petrochemical industry. Thus, it consists of two parts: part A focuses on performance analysis of helicopter gas turbines, while part B entails technoeconomic and environmental risk assessment of ADIGT-CHP in the petrochemical industry. The investigation encompasses comparative assessment of simple cycle (SC) and advanced gas turbine cycle options including the component behaviours and the environmental and economic analysis of the systems. The advanced cycles considered include: recuperated (RC), intercooled (IC), intercooled-recuperated (ICR), and low pressure compressor zero-staged (LPC-ZS), cycles. The helicopter engines are analysed and subsequently converted to small-scale ADIGT engines. Also, modelling combined-heat-and-power (CHP) performances of small-scale (SS), and large-scale (LS) ADIGT engines is implemented. More importantly, a large part of the research is devoted to developing a techno-economic model for assessing, predicting, and comparing viability of simple and advanced cycle ADIGT-CHP in the petrochemical industry in terms of net present value (NPV), internal rate of return (IRR), and simple payback period (SPBP). The techno-economic performances of the ADIGT-CHP cycles are measured against the conventional case of grid power plus on-site boiler. Besides, risk and sensitivity of NPV with respect to uncertain changes in grid electricity cost, gas fuel cost, emission cost, and electricity export tariff, are investigated. Two case studies underlie the development of the techno-economic model. One case study demonstrates the application of the model for large-scale (LS) ADIGT-CHP, and the other for small-scale (SS) ADIGT-CHP, all in the petrochemical industry. By so doing, techno-economic and environmental risk analysis framework (a multi-disciplinary preliminary design assessment tool comprising performance, emissions, economic, and risk modules) is adapted to ADIGT-CHP in the petrochemical industry, which is the aim of this research. The investigation and results led to the conclusions that advanced cycle helicopter and ADIGT engines exhibit higher thermal efficiencies than simple cycle, and that savings exist in operational costs of ADIGT-CHP above the conventional case. Thus, for both SS ADIGT-CHP, and LS ADIGT-CHP cases, all ADIGT-CHP cycles are profitable than the conventional case. For LS ADIGT- CHP category, the IC ADIGT-CHP is the most profitable, whereas for SS ADIGT-CHP category, the RC ADIGT-CHP is the most profitable. The contribution to knowledge of this research is the development of a technoeconomic model for assessing, predicting, and comparing viability of simple and advanced cycle ADIGT-CHP in the petrochemical industry in terms of NPV, SPBP, and IRR over the conventional case of grid power plus on-site boiler. A second contribution is the derivation of simple and advanced cycle small-scale ADIGT and ADIGT-CHP from helicopter engines. Cont/D.

Nuclear power plants across the United States are reaching the end of their current operating licenses, forcing decision makers to think about the way forward. As they consider the best alternatives for dealing with aging nuclear plants, it is becoming increasingly important to have an accurate method for calculating the long-term costs of nuclear power plants. This report begins by investigating the methodologies currently used in these calculations. They focus on the uncertainty associated with deregulated electricity markets and can be broken down into two main categories: discounted cash flow and real options analysis. Next the report discusses the limitations of the current methodologies, focusing specifically on those aspects of evaluation that are currently eclipsed by electricity market uncertainty. Finally the report offers recommendations for addressing these limitations and creating a stronger analytical framework for calculating the lifetime cost of nuclear power plants. / text

Magistro darbe atlikta G. Žilėno ūkio veiklos analizė ir struktūrinės paramos priemonių poveikis ūkio restruktūrizavimui. Studijuojant Lietuvos ir užsienio autorių mokslinius veikalus, periodinę mokslinę literatūrą apie žemės ūkio gamybos įmones, Lietuvos Respublikos įstatymus, darbe nagrinėjama ūkio veiklos rezultatai bei ES paramos įtaka ūkininkavimo plėtotei bei ekonominės veiklos rodikliams. Apskaičiavus ūkio ekonominį dydį ir ūkininkavimo tipą, buvo palyginti augalininkystės ir gyvulininkystės sektorių veiklos rodikliai su žemės ūkio respondentinių įmonių veiklos rodikliais, siekiant nustatyti esminius dydžių ir sklaidos skirtumus. Naudojantis respondentinių įmonių finansinėmis bei veiklos ataskaitomis palyginti ir išsamiai išanalizuoti G. Žilėno ūkio finansiniai rodikliai. Siekiant įvertinti ES struktūrinių fondų ir valstybės paramos įtaką G. Žilėno ūkio konkurencingumui, esant skirtingoms valstybės paramos sąlygoms, apskaičiuotas daugiafunkcinis konkurencingumo indeksas. Apibendrinus gautus rezultatus, numatytos ūkio veiklos perspektyvos. / Analysis of G. Žilėnas‘farming activity and impact of structural support measures to the farm restructurization were performed in this master thesis. When studying scientific works by Lithuanian and foreign authors, periodic scientific literature about agricultural production companies, laws of the Republic of Lithuania, farming activity results and the EU impact on farming development and economic activity indicators were analysed in the thesis. Having estimated economic size of the farm and farming type, activity indicators of plant-cultivation and stock-raising were compared with activity indicators of agricultural respondent companies in order to establish the substantial differences in sizes and dispersion. Using financial and activity reports of respondent companies, financial indicators of G. Žilėnas‘farm were compared and thoroughly analysed. Upon different state support conditions, multifunctional competitiveness index was calculated in order to assess the impact of the EU structural funds and state support to the competitiveness of G. Žilėnas‘farm. Having summarized the obtained results, farming activity perspectives were anticipated.

In the central United States, undefined earthquake sources, long earthquake recurrence intervals and uncertain ground motion attenuation models have contributed to an overstatement of regional seismic hazard for the New Madrid Seismic Zone on the National Seismic Hazard Maps. This study examined concerns regarding scientific uncertainties, overly stringent seismic mitigation policies and depressed local economy in western Kentucky through a series of informal interviews with local businessmen, public officials, and other professionals in occupations associated with seismic mitigation. Scientific and relative economic analyses were then performed using scenario earthquake models developed with FEMA’s Hazus-MH software. Effects of the 2008 Wenchuan earthquake in central China and seismic mitigation policies in use there were considered for potential parallels and learning opportunities. Finally, suggestions for continued scientific research, additional educational opportunities for laymen and engineering professionals, and changes in the application of current earthquake science to public policy in the central United States were outlined with the goal of easing western Kentucky economic issues while maintaining acceptable public safety conditions.

An investigation was undertaken to determine the feasibility of increasing the hydrogen production rate by coupling the water gas shift (WGS) process to the hybrid sulphur process (HyS). This investigation also involved the technical and economical analysis of the water gas shift and the H2 separation by means of Pressure swing adsorption (PSA) process. A technical analysis of the water gas shift reaction was determined under the operating conditions selected on the basis of some information available in the literature. The high temperature system (HTS) and low temperature system (LTS) reactors were assumed to be operated at temperatures of 350ºC and 200ºC, respectively. The operating pressure for both reactors was assumed to be 30 atmospheres. The H2 production rate of the partial oxidation (POX) and the WGS processes was 242T/D, which is approximately two times the amount produced by the HyS process alone. The PSA was used for the purification process leading to a hydrogen product with a purity of 99.99%. From the total H2 produced by the POX and the WGS processes only 90 percent of H2 is recovered in the PSA. The unrecovered H2 leaves the PSA as a purge gas together with CO2 and traces of CH4, CO, and saturated H2O. The estimated capital cost of the WGS plant with PSA is about US$50 million. The production cost is highly dependent on the cost of all of the required raw materials and utilities involved. The production cost obtained was US $1.41/kg H2 based on the input cost of synthesis gas as produced by the POX process. In this case the production cost of synthesis gas based on US $6/GJ for natural gas and US $0/Ton for oxygen was estimated to be US $0.154/kg. By increasing the oxygen and natural gas cost, the corresponding increase in synthesis gas has resulted in an increase in H2 production cost of US $1.84/kg. / Thesis (M.Sc. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2006.

An investigation was undertaken to determine the feasibility of increasing the hydrogen production rate by coupling the water gas shift (WGS) process to the hybrid sulphur process (HyS). This investigation also involved the technical and economical analysis of the water gas shift and the H2 separation by means of Pressure swing adsorption (PSA) process. A technical analysis of the water gas shift reaction was determined under the operating conditions selected on the basis of some information available in the literature. The high temperature system (HTS) and low temperature system (LTS) reactors were assumed to be operated at temperatures of 350°C and 200°C, respectively. The operating pressure for both reactors was assumed to be 30 atmospheres. The H2 production rate of the partial oxidation (POX) and the WGS processes was 242T/D, which is approximately two times the amount produced by the HyS process alone. The PSA was used for the purification process leading to a hydrogen product with a purity of 99.99%. From the total H2 produced by the POX and the WGS processes only 90 percent of H2 is recovered in the PSA. The unrecovered H2 leaves the PSA as a purge gas together with C02 and traces of CH4, CO, and saturated H20. The estimated capital cost of the WGS plant with PSA is about US$50 million. The production cost is highly dependent on the cost of all of the required raw materials and utilities involved. The production cost obtained was US $1.41/kg H2 based on the input cost of synthesis gas as produced by the POX process. In this case the production cost of synthesis gas based on US $6/GJ for natural gas and US $0/Ton for oxygen was estimated to be US $0.154/kg. By increasing the oxygen and natural gas cost, the corresponding increase in synthesis gas has resulted in an increase in H2 production cost of US $1.84/kg. / Thesis (M.Sc. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.

An investigation was undertaken to determine the feasibility of increasing the hydrogen production rate by coupling the water gas shift (WGS) process to the hybrid sulphur process (HyS). This investigation also involved the technical and economical analysis of the water gas shift and the H2 separation by means of Pressure swing adsorption (PSA) process. A technical analysis of the water gas shift reaction was determined under the operating conditions selected on the basis of some information available in the literature. The high temperature system (HTS) and low temperature system (LTS) reactors were assumed to be operated at temperatures of 350°C and 200°C, respectively. The operating pressure for both reactors was assumed to be 30 atmospheres. The H2 production rate of the partial oxidation (POX) and the WGS processes was 242T/D, which is approximately two times the amount produced by the HyS process alone. The PSA was used for the purification process leading to a hydrogen product with a purity of 99.99%. From the total H2 produced by the POX and the WGS processes only 90 percent of H2 is recovered in the PSA. The unrecovered H2 leaves the PSA as a purge gas together with C02 and traces of CH4, CO, and saturated H20. The estimated capital cost of the WGS plant with PSA is about US$50 million. The production cost is highly dependent on the cost of all of the required raw materials and utilities involved. The production cost obtained was US $1.41/kg H2 based on the input cost of synthesis gas as produced by the POX process. In this case the production cost of synthesis gas based on US $6/GJ for natural gas and US $0/Ton for oxygen was estimated to be US $0.154/kg. By increasing the oxygen and natural gas cost, the corresponding increase in synthesis gas has resulted in an increase in H2 production cost of US $1.84/kg. / Thesis (M.Sc. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 4 uppsatser.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The experiment was conducted at the Laboratory of Sheep, Federal University of Santa Maria and aimed to evaluate the effect of using different high grain diets on nutrient intake, performance, carcass characteristics, tissue composition of the palette, the feeding behavior and conduct an economic analysis of the supply of lambs finished in feedlot. Thirty-two male castrated Texel breed, born of simple birth and weaned at an average of 50 days old lambs were used. The treatments consisted of different types of grains, not processed, as follows: corn grain, oat grain, oat grain or grain of paddy. The animals were slaughtered when they reached a body weight of pre - established 32kg slaughter, which corresponds to 60 % of mature weight of their mothers. Lambs fed diets with high corn grain have higher intakes of dry matter, organic matter, crude protein, total carbohydrates and total digestible nutrients, and lower intake of neutral detergent fiber. Also present body condition score, weight gain and higher feed conversion, which leads to reduction in the number of days in confinement to reach slaughter weight. Also provide best economic outcome when compared with lambs finished in feedlot diets with the use of top-grain base of oat, oat or rice in the husk. Lambs fed diets with high corn grain have higher weights and yields of hot and cold carcass, better carcass conformation and greater loin eye area when compared to lambs from the other treatments. Also, have a higher state of greasing and back fat thickness at slaughter, which leads to reduction in the rate of break after cooling carcass. The weights of the regional courts were higher in lambs of treatment based on corn grain, although a smaller proportion of leg, most side cut and fat in the palette, a factor that may be undesirable for the consumer market. As for the feeding behavior of feedlot lambs, one can observe that the changes were caused mainly by the voluntary feed intake and the proportion of dietary NDF, but ensuring necessary to maintain rumen health conditions. Thus the use of diets high grain corn, oat, oat or rice in the husk for finishing lambs in feedlot is a viable alternative productive point of view. However, the use of corn grain provides better performance and economic results. / O experimento foi conduzido no Laboratório de Ovinocultura da Universidade Federal de Santa Maria e teve como objetivo avaliar o efeito do uso de diferentes dietas de alto grão sobre o consumo de nutrientes, o desempenho, as características da carcaça, a composição tecidual da paleta, o comportamento ingestivo e realizar uma análise econômica da alimentação de cordeiros terminados em confinamento. Foram utilizados 32 cordeiros machos, castrados, da raça Texel, nascidos de parto simples e desmamados com média de 50 dias de idade. Os tratamentos foram constituídos por diferentes tipos de grãos, não processados, sendo: grão de milho, grão de aveia branca, grão de aveia preta ou grão de arroz com casca. Os animais foram abatidos quando atingiram o peso vivo de abate pré-estabelecido de 32 kg, que corresponde a 60% do peso adulto de suas mães. Cordeiros alimentados com dietas de alto grão de milho apresentam maiores consumos de matéria seca, matéria orgânica, proteína bruta, carboidratos totais e nutrientes digestíveis totais, e menor consumo de fibra em detergente neutro. Além disso, apresentam escore de condição corporal, ganho de peso e conversão alimentar superiores, o que leva a redução do número de dias em confinamento para atingir o peso de abate. Também proporcionam melhor resultado econômico quando comparados com cordeiros terminados em confinamento com o uso de dietas de alto grão a base de aveia branca, aveia preta ou arroz com casca. Cordeiros alimentados com dietas de alto grão de milho apresentam maiores pesos e rendimentos de carcaça quente e fria, melhor conformação da carcaça e maior área de olho de lombo quando comparados aos cordeiros dos demais tratamentos. Além disso, apresentam maior estado de engorduramento e de espessura de gordura subcutânea no momento do abate, o que leva a redução do índice de quebra ao resfriamento das carcaças. Os pesos dos cortes regionais foram superiores nos cordeiros do tratamento a base de grão de milho, embora tenham menor proporção de perna, maior de costilhar e de gordura na paleta, fator este que pode ser indesejado pelo mercado consumidor. Quanto ao comportamento ingestivo dos cordeiros em confinamento, pode-se observar que as alterações foram provocadas principalmente pelo consumo voluntário de alimento e pela proporção de FDN na dieta, mas garantindo condições necessárias para manutenção da saúde ruminal. Deste modo o uso de dietas de alto grão de milho, aveia branca, aveia preta ou arroz com casca para terminação de cordeiros em sistema de confinamento é uma alternativa viável do ponto de vista produtivo. Porém, o uso de grão de milho proporciona melhores resultados produtivos e econômicos.

The member states of European Union aim to promote the reduction of harmful emissions. Emissions from combustion processes cause effects on human health and pose environmental issues, for example by increasing greenhouse effect. There are two ways to reduce emissions; one is to promote renewable energy sources and the other to utilize more effectively the available fossil fuels until a long-term solution is available. Hence, it is necessary to strive for CO2 mitigation technologies applied to fossil fuels. Low natural gas prices together with high energy efficiency have made gas turbines popular in the energy market. But, gas turbine fired with natural gas come along with emissions of CO2, NOx and CO. However, these disadvantages can be eliminated by using gas turbine with precombustion CO2 capture, separating carbon from the fuel by using fuel reforming process and feeding pure hydrogen as a fuel. Hydrogen fired gas turbines are used in two applications such as a gas turbine with pre-combustion CO2 capture and for renewable power plants where hydrogen is stored in case as a backup plan. Although the CO2 emissions are reduced in a hydrogen fired gas turbine with a pre-combustion CO2 capture, there are still several challenges such as high flame temperatures resulting in production of thermal NOx. This project suggests a method for application of hydrogen fired gas turbine, using exhaust gas recirculation to reduce flame temperature and thus reducing thermal NOx. A NOx emission model for a hydrogen-fired gas turbine was built from literature data and used to select the best operating conditions for the plant. In addition, the economic benefits of switching from natural gas to pure hydrogen are reported. For the techno-economic analysis, investment costs and operating costs were taken from the literature, and an economic model was developed. To provide sensitivity analysis for the techno-economic calculation, three cases were studied. Literature review was carried out on several journal articles and websites to gain understanding on hydrogen and natural gas fired gas turbines. Results showed that, in the current state, pure hydrogen has high delivery cost both in the US and Europe. While it’s easy to access natural gas at low cost, therefore in the current state gas turbine fired with natural gas are more profitable than hydrogen fired gas turbine. But, if targeted hydrogen prices are reached while fuel reforming process technology are developed in the coming future the hydrogen fired gas turbine will compete seriously with natural gas.