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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Schnellwachsende Baumarten

23 February 2012 (has links) (PDF)
Die Broschüre informiert über den Anbau von Pappeln und Weiden in Kurzumtriebsplantagen. Die Empfehlungen zu Anbauverfahren, Pflanzung, Düngung, Ernte und Trocknung beruhen auf langjährigen Versuchen im Plantagen- und Streifenanbau. Ergänzt wird die Broschüre um wirtschaftliche Aspekte, Fördermöglichkeiten und um die ökologischen Auswirkungen von schnellwachsenden Baumarten auf landwirtschaftlichen Flächen.
22

Optimal Management of Renewable Resources: A Dynamic Model of Surface Water Contamination From Pesticide Use in Rice Production in the Mekong Delta, Vietnam

Dang, Phuong M. 12 1900 (has links)
Both rice production and fish culture in the Mekong Delta, Vietnam have a close mutual relationship with the use of water and land resources. First, they are competitive in the use of land and water. Second, rice production discharges pesticides into water bodies causing an external cost to fish culture, which, in turn, leads to an increase in fish cost and price. A dynamic model for maximizing the social surplus is developed for optimal management of resources as well as production. Its first-order conditions provide some important quantitative as well as qualitative interpretation that explains the dynamic relationships among prices, water quality, and shadow price. The time paths and phase diagrams of the model show the variations and the changes in prices, outputs, and water quality over time, and the initial position in regions leading to divergence or convergence. As a result, effective policies are set up to maximize social welfare. Data are collected and used in estimations of demand functions of rice and fish, the function of assimilative capacity, the fish cost function, and the parameter of pesticide discharge. The total loss of fish culture (total external cost in the year 2001) due to pesticide use is about 9 billion $US. Two cases of linear and nonlinear forms are simulated with scenarios of initial values for the year 2001. The simulation shows optimistic results with prices going down and water quality going up over time, meaning the social surplus will rise. The phase diagram shows that the social manager should look for policies to raise the initial value of water quality to get an optimal solution. A comparative analysis of the model simulation shows the directions of change in parameters leading to a change in the steady state values. How to change the parameter values is analyzed and the analysis suggests different policies.
23

On strategic incentives and the management of stochastic renewable resources /

Hennlock, Magnus, January 2005 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.
24

Uso de instrumentos econômicos para incremento da eficiência na irrigação : aplicação na bacia do Rio Pardo com rizicultura

Nonnemacher, Eder January 2008 (has links)
O crescimento da população mundial tem demandado um aumento na produção de alimentos, fazendo com que avancem as áreas agrícolas e evoluam as tecnologias de produção. O aumento das áreas agrícolas gera uma maior demanda de água para irrigação, causando muitas vezes, conflito entre os diversos usuários deste bem. Dentre as culturas que mais consomem água se encontra a do arroz irrigado, responsável por grande parte dos conflitos nas Bacias Hidrográficas do Rio grande do Sul, pois seu período de plantio se dá justamente nos meses de verão. Então, alguma metodologia se faz necessária para estudar a possibilidade da maximização dos benefícios ou redução dos custos para uma área de cultivo de arroz. Por outro lado, a Economia fornece instrumentos para maximizar os benefícios produzidos através de um bem. Neste trabalho, será aplicada a Teoria Econômica dos Recursos Naturais Renováveis, através de um modelo proposto, considerando como Estoque do Recurso Natural a área cultivada com arroz irrigado em cada tempo e para cada sistema de cultivo, tendo como restrição as Vazões de Referência adotadas (Vazões Ecológicas). Desta forma, a água utilizada em excesso será considerada como a externalidade. Para conversão desta externalidade em valores de moeda, ela será multiplicada por um Custo de Oportunidade. Após, seu valor será agregado aos Custos de Produção do arroz. Através de Cenários, obtidos do cruzamento de algumas Vazões de Referência e de algumas Taxas de Juros, pode-se fazer uma análise dos Benefícios Líquidos (W) gerados por esta cultura. Os Resultados mostram que a internalização das externalidades não inviabiliza economicamente a prática desta cultura. / Agricultural areas are increasing and production technologies in developing given the global population growth and given the resulting increase of food necessities. Increase in water demands for agricultural also conflicts with other purposes of this scarce source that have its availability reduced. Rice is one of the most water consuming crops, and at the Rio Grande do Sul watersheds, it is responsible of the bigger conflicts between water users because planting takes place, precisely, in the months of summer, when water demands for urban supply are higher. Then, some methodology is needed to study the feasibility of rice cultivation for the area with the maximization of benefits or minimization of the cost. Economics provides tools to maximize benefits produced by different elements. This study applies Renewable Natural Resources economic theory through the previously presented problem by a developed model presented in this study. The Natural Resources Supply is the rice cultivated area in each time step and for each cultivation methodology, where the restrictions are based on references streamflow, as the Ecological streamflow. Thus, water used in excess will be the externality. To convert this externality in monetary values, it will be multiplied by a cost of opportunity. Then, its value will be added to the rice production cost. Several scenarios were tested based on different streamflow reference and interests rate values. Results shown the rice cultivation is economically feasible also with the internalization of externalities.
25

Program "Zelená úsporám" a jeho efektivnost ve městě Milevsko / Program " Green savings" and his efficiency in the city Milevsko

STUDENOVSKÁ, Monika January 2012 (has links)
Program "Green savings" was initiated in April 2009. It was developed by the Czech Republic's Ministry of Environmental Affairs. The main governing body is the state fund for environmental affairs. The main objective of the program was the reduction of CO2 emmissions, encouragement of the use of renewable energy sources and the increase in energy efficiency. The program also supports the use of renewable energy sources for the purpose of heating and hot water production, as well as providing subsidies for partial or complete insulation of apartments or family homes. The program is divided into three parts which encompass Part A energy saving for the purpose of heating, Part B development in the passive energy standard and Part C the use of renewable energy sources for heating and hot water production. Subsidies are provided only to citizens of Czech Republic. By October 31st 2010, the program "Green savings" had documented 78 643 applications worth 22,53 billion Krowns. To this day, 64 136 applications have been approved, which represent 16.6 billion Krowns. Within different phases of completion were a further 14 507 applications representing 5,9 billion Krowns. The program has become very popular, and has had to be prematurely closed because the number of approved applications exceeded the program's designated financial budget. In the town of Milevsko, the program "Green savings" was most effective in Part A, primarily within the area of applications for family homes. The second most successful area was Part C. For Part B, there were no applications from the town of Milevsko. The level of financial support paid for all types of applications from Milevsko reached 38 134 708 Krowns , which is 8,27% of the total amount paid out in Czech Republic. Just as this example shows the effectiveness of the program ?Green savings? in Milevsko, this project can also help improve the overall consciousness with regard to energy saving, the use of renewable energy sources and the overall consciousness regarding the protection of the environment. If we want to improve our environment, it is important that not only do citizens change their way of thinking and their actions, but also that the State supports this new mentality with a positive momentum, for instance, such as supporting programs like "Green savings".
26

Uso de instrumentos econômicos para incremento da eficiência na irrigação : aplicação na bacia do Rio Pardo com rizicultura

Nonnemacher, Eder January 2008 (has links)
O crescimento da população mundial tem demandado um aumento na produção de alimentos, fazendo com que avancem as áreas agrícolas e evoluam as tecnologias de produção. O aumento das áreas agrícolas gera uma maior demanda de água para irrigação, causando muitas vezes, conflito entre os diversos usuários deste bem. Dentre as culturas que mais consomem água se encontra a do arroz irrigado, responsável por grande parte dos conflitos nas Bacias Hidrográficas do Rio grande do Sul, pois seu período de plantio se dá justamente nos meses de verão. Então, alguma metodologia se faz necessária para estudar a possibilidade da maximização dos benefícios ou redução dos custos para uma área de cultivo de arroz. Por outro lado, a Economia fornece instrumentos para maximizar os benefícios produzidos através de um bem. Neste trabalho, será aplicada a Teoria Econômica dos Recursos Naturais Renováveis, através de um modelo proposto, considerando como Estoque do Recurso Natural a área cultivada com arroz irrigado em cada tempo e para cada sistema de cultivo, tendo como restrição as Vazões de Referência adotadas (Vazões Ecológicas). Desta forma, a água utilizada em excesso será considerada como a externalidade. Para conversão desta externalidade em valores de moeda, ela será multiplicada por um Custo de Oportunidade. Após, seu valor será agregado aos Custos de Produção do arroz. Através de Cenários, obtidos do cruzamento de algumas Vazões de Referência e de algumas Taxas de Juros, pode-se fazer uma análise dos Benefícios Líquidos (W) gerados por esta cultura. Os Resultados mostram que a internalização das externalidades não inviabiliza economicamente a prática desta cultura. / Agricultural areas are increasing and production technologies in developing given the global population growth and given the resulting increase of food necessities. Increase in water demands for agricultural also conflicts with other purposes of this scarce source that have its availability reduced. Rice is one of the most water consuming crops, and at the Rio Grande do Sul watersheds, it is responsible of the bigger conflicts between water users because planting takes place, precisely, in the months of summer, when water demands for urban supply are higher. Then, some methodology is needed to study the feasibility of rice cultivation for the area with the maximization of benefits or minimization of the cost. Economics provides tools to maximize benefits produced by different elements. This study applies Renewable Natural Resources economic theory through the previously presented problem by a developed model presented in this study. The Natural Resources Supply is the rice cultivated area in each time step and for each cultivation methodology, where the restrictions are based on references streamflow, as the Ecological streamflow. Thus, water used in excess will be the externality. To convert this externality in monetary values, it will be multiplied by a cost of opportunity. Then, its value will be added to the rice production cost. Several scenarios were tested based on different streamflow reference and interests rate values. Results shown the rice cultivation is economically feasible also with the internalization of externalities.
27

Jeux dynamiques relatifs au changement climatique / Dynamic games relative to climate change

Dullieux, Rémy 07 June 2013 (has links)
La thèse est consacrée à l'étude de jeux dynamiques dans le domaine climatique. Pour lutter contre l'accumulation de gaz à effet de serre dans l'atmosphère, la mise en place d'une taxe carbone est une solution possible. Toutefois on suppose ici que cette taxe carbone a pour les pays consommateurs d'énergie fossile des motivations qui ne se limitent pas à l'internalisation du dommage environnemental : il s'agit par un comportement stratégique d'essayer de capturer une partie de la rente des producteurs. On aboutit à la possibilité d'une taxe carbone à finalité Pigouvienne mais aussi stratégique. Des jeux dynamiques non coopératifs entre pays producteurs supposés cartellisés et pays consommateurs supposés également cartellisés peuvent être alors être envisagés dans ce contexte. Une littérature de jeux différentiels non coopératifs s'est d'ailleurs développée depuis une vingtaine d'années autour de cette idée d'une taxe carbone à visée stratégique. Dans l'introduction on rappelle le cadre économique de ces jeux, leur cadre analytique (jeux différentiels) et la littérature théorique afférente. On présente trois jeux qui forment le corps de la thèse. Chacun des trois chapitres suivants est consacré à un jeu différentiel original. Le premier jeu est un jeu non coopératif entre un bloc de consommateurs et un bloc de producteurs avec un plafond de pollution comme contrainte environnementale principale. L'existence de ce plafond modifie les conclusions classiques de ce type de jeu. Dans le deuxième jeu il y a également un jeu non coopératif entre un bloc de consommateurs (pays riches) et un bloc de producteurs mais il y a en plus un second bloc de consommateurs (pays pauvres et émergents), qui ne joue pas dans le jeu mais met en place la taxe carbone résultant à chaque instant du jeu en contrepartie d'un transfert de la part du premier bloc de consommateurs. Il apparaît que sous certaines conditions le second bloc a intérêt à ce schéma « taxe carbone contre transfert ». Dans le troisième jeu il y a aussi deux zones de consommation mais elles jouent maintenant un jeu non coopératif entre elles, les producteurs étant passifs. Il y a une taxe carbone par bloc et pas mondiale et pourtant le jeu fait apparaître sous certaines conditions une situation meil1eure pour les blocs de consommation qu'une situation de passivité face aux producteurs. La conclusion d'ensemble de ces trois jeux est que sous certaines conditions les pays consommateurs peuvent avoir intérêt à un comportement stratégique et pas seulement Pigouvien en matière de taxe carbone. / The world we are in : dynamic games relative to climate change. In these games the setting up of a carbon tax has Pigouvian grounds (to take into account the damage resulting of the accumulation of Green House Gas in the atmosphere due to the consumption of fossil energy) but it has also other aims that are strategic. For fossil energy consuming countries, indeed, a carbon tax can be a way to "eat" a part of the producing countries' rent. Then the resulting carbon tax has a Pigouvian part but also a strategic part. The literature developed during the last twenty years in this field is all about non cooperative games between an area of cartelized consuming countries and an area of cartelized producing countries. In the introduction, we lay out the economic framework of this type of games, their analytical framework (differential games) and the theoretical literature. Then the three original games that make up the bulk of the present work are introduced. Each of the three following chapters is devoted to one of these three games. The first one is a non-cooperative game between an area of consuming countries and an area of producing countries but with an upper limit of atmospheric carbon concentration as the main environmental constraint. This new type of constraint changes the classical results of this type of game. The second one is also a non-cooperative game between an area of consuming countries (here the old rich countries) and an area of producing countries but there is also another area of consuming countries (poor and emergent countries) that does not play the game while it sets up the tax resulting of the game. The setting up of such a tax in this area is the consequence of a transfer from the other consuming area. The conclusion is that under specific conditions this area (but also the financing area) wins some welfare in this framework versus a passive behavior in front of the producers. In the last game, there are also two consuming areas but now they play a non-cooperative game between themselves, while the producing area is passive. In consequence there is not a worldwide carbon tax but two regional carbon taxes. However, under some specific conditions, this framework is better for the two consuming areas than the passive attitude in front of the producers. The main conclusion of the three games is that in some circumstances the consuming countries can get some extra welfare from a strategic stance when setting up a carbon tax.
28

Možnosti podpor z fondů EU pro využití biomasy na území města Třeboň. / Support from EU funds for biomass usage in the location of the town of Třeboň.

ŘEPA, Michal January 2007 (has links)
The topic of thesis "Support from EU funds for biomass usage in the location of the town of Třeboň" is a analysis of the biomass potential in selected area with a source of energy project. The first part was focused on the importance of renewabla resources of energy and their supporting by EU and Czech Republic. In the second part was presented the analysis of biomass potential, and this part was given the energy project with economic evaluation.
29

Uso de instrumentos econômicos para incremento da eficiência na irrigação : aplicação na bacia do Rio Pardo com rizicultura

Nonnemacher, Eder January 2008 (has links)
O crescimento da população mundial tem demandado um aumento na produção de alimentos, fazendo com que avancem as áreas agrícolas e evoluam as tecnologias de produção. O aumento das áreas agrícolas gera uma maior demanda de água para irrigação, causando muitas vezes, conflito entre os diversos usuários deste bem. Dentre as culturas que mais consomem água se encontra a do arroz irrigado, responsável por grande parte dos conflitos nas Bacias Hidrográficas do Rio grande do Sul, pois seu período de plantio se dá justamente nos meses de verão. Então, alguma metodologia se faz necessária para estudar a possibilidade da maximização dos benefícios ou redução dos custos para uma área de cultivo de arroz. Por outro lado, a Economia fornece instrumentos para maximizar os benefícios produzidos através de um bem. Neste trabalho, será aplicada a Teoria Econômica dos Recursos Naturais Renováveis, através de um modelo proposto, considerando como Estoque do Recurso Natural a área cultivada com arroz irrigado em cada tempo e para cada sistema de cultivo, tendo como restrição as Vazões de Referência adotadas (Vazões Ecológicas). Desta forma, a água utilizada em excesso será considerada como a externalidade. Para conversão desta externalidade em valores de moeda, ela será multiplicada por um Custo de Oportunidade. Após, seu valor será agregado aos Custos de Produção do arroz. Através de Cenários, obtidos do cruzamento de algumas Vazões de Referência e de algumas Taxas de Juros, pode-se fazer uma análise dos Benefícios Líquidos (W) gerados por esta cultura. Os Resultados mostram que a internalização das externalidades não inviabiliza economicamente a prática desta cultura. / Agricultural areas are increasing and production technologies in developing given the global population growth and given the resulting increase of food necessities. Increase in water demands for agricultural also conflicts with other purposes of this scarce source that have its availability reduced. Rice is one of the most water consuming crops, and at the Rio Grande do Sul watersheds, it is responsible of the bigger conflicts between water users because planting takes place, precisely, in the months of summer, when water demands for urban supply are higher. Then, some methodology is needed to study the feasibility of rice cultivation for the area with the maximization of benefits or minimization of the cost. Economics provides tools to maximize benefits produced by different elements. This study applies Renewable Natural Resources economic theory through the previously presented problem by a developed model presented in this study. The Natural Resources Supply is the rice cultivated area in each time step and for each cultivation methodology, where the restrictions are based on references streamflow, as the Ecological streamflow. Thus, water used in excess will be the externality. To convert this externality in monetary values, it will be multiplied by a cost of opportunity. Then, its value will be added to the rice production cost. Several scenarios were tested based on different streamflow reference and interests rate values. Results shown the rice cultivation is economically feasible also with the internalization of externalities.
30

Projeto e simulação numérica de uma turbina hidrocinética de eixo vertical : Project and numerical simulation of a vertical axis hydrokinetic turbine / Project and numerical simulation of a vertical axis hydrokinetic turbine

Batalha, Tiago Peres, 1986- 04 July 2014 (has links)
Orientador: Kamal Abdel Radi Ismail / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T19:59:29Z (GMT). No. of bitstreams: 1 Batalha_TiagoPeres_M.pdf: 29669933 bytes, checksum: 83773b03eb136ff18c60979de7ceaffe (MD5) Previous issue date: 2014 / Resumo: Áreas rurais ou isoladas são geralmente abastecidas com energia baseada na queima de óleo diesel. No entanto, estratégias melhores podem ser implementadas utilizando-se recursos de energia renováveis disponíveis na região como recursos hidráulicos, biomassa entre outros. A tecnologia hidrocinética está entre as mais promissoras soluções uma vez que é relativamente barata, de fácil manufatura, confiável e adequada para a maioria das áreas amazônicas devido à grande capacidade hidráulica e predominância de assentamentos de baixa densidade populacional localizados nas margens de rios. Esta dissertação desenvolve uma metodologia de simulação numérica de dinâmica dos fluidos com aplicação das equações de RANS (Reynolds Average Navier Stokes) e malhas bi e tridimensionais para caracterização e projeto de turbinas hidrocinéticas de eixo vertical. Diferentes perfis de pá foram analisados, tais como placa plana, arco circular, NACA simétrico e assimétrico. Os efeitos de número de pás, perfil da pá e velocidade do fluxo de água sobre os coeficientes de torque e potência são apresentados e discutidos. As vantagens desse tipo de turbina incluem operação independente da direção da corrente, reversibilidade, possibilidade de agrupamento, construção barata e sistemas de transmissão simples. Um sistema de apenas uma turbina de 0,5 m de raio e 1 m de altura com sete lâminas submetida à razão de velocidade da ponta de 2,5 com velocidade de fluxo de água de 2 m/s teria potência de aproximadamente 1,6 kW, o que é suficiente para alimentar aproximadamente 7 casas de padrão de consumo médio no Brasil / Abstract: Rural and isolated areas are usually served by diesel based energy supply. However, better strategies can be implemented using renewable energy sources available in the area such as hydraulic, biomass and others. The hydrokinetic technology is among the promising technologies since it is relatively cheap, easy to manufacture, reliable and suitable for most of the Amazon areas because of the large hydraulic capacity and low density population settlements near rivers borders. This dissertation uses CFD, RANS (Reynolds Average Navier Stokes) equations and two and three-dimensional meshes to characterize and develop a methodology of numerical simulation of a vertical axis hydrokinetic turbine. In the simulations, different blade profiles were used such as flat plate, circular arc, symmetric and asymmetric NACA profiles. The effects of the number of blades, blade profile and water flow velocity on the turbine torque and power coefficients were presented and discussed. The advantages of this type of turbines include operation independent of current direction, reversibility, possibility of stacking, cheap construction and simple transmission systems. A system with only one turbine with radius of 0.5 m and height of 1 m with seven blades submitted to a tip speed ratio of 2.5 with water flow velocity of 2 m/s would have power of approximately 1.6 kW, what is enough to supply energy to 7 standard homes in Brazil / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica

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