A Análise de Ciclo de Vida (ACV) tem se mostrado uma importante ferramenta de avaliação ambiental, devido à seu enfoque “sobre função", que permite considerar o desempenho ambiental de produtos, procedimento cada vez mais requerido por diversos atores sociais. Para que a ACV possa ser utilizada de modo amplo e confiável, faz-se necessário que se desenvolvam bases de dados regionalizadas, contendo Inventários de Ciclo de Vida (ICV) dos principais insumos usados pela sociedade- energia, matérias- primas,etc. O presente trabalho faz parte de uma projeto conduzido pelo GP2- Grupo de Prevenção da Poluição, da Escola Politécnica/ USP, de disponibilização de bases brasileiras para ACV, sendo dedicado especificamente à geração de eletricidade. Para permitir sua realização no âmbito de uma dissertação de mestrado, adotou-se como simplificação a geração de eletricidade na usina hidrelétrica de Itaipu, responsável em 2000 por 22,4% da eletricidade consumida no país. Para construir o ICV realizou-se uma revisão bibliográfica sobre o uso da ACV em hidrelétricas, estabelecendo recomendações gerais. A seguir, estudou-se Itaipu quanto à sua obra civil e consumo de insumos na construção e operação por 100 anos, obtendo ao final um ICV com os aspectos ambientais mais significativos em termos da energia gerada (MWh). Neste contexto as fronteiras estabelecidas incluem: escavações e obras de terra; instalação e operação do canteiro de obras; transporte dos operários e de cimento, cinzas, aço estrutural e diesel para a obra; ciclo de vida do aço, cobre, cimento, diesel, óleos lubrificante e de transformador usados na barragem e equipamentos permanentes (considerando inclusive manutenção e substituição); e enchimento do reservatório. Com a discussão dos resultados pode-se demonstrar, além da importância do uso de dados homogêneos, que o ICV é extremamente sensível ao horizonte de análise (na verdade à energia gerada), o que confirma que a construção é a principal origem dos aspectos ambientais significativos. Outra conclusão é que cada hidrelétrica constitui um caso particular, não sendo possível atribuir valores típicos. No entanto, há indícios de que Itaipu, por seu alto fator de capacidade e potência instalada, possua um desempenho ambiental acima da média das hidrelétricas, principalmente no que se refere ao tempo de retorno da energia investida. As estimativas indicam que os processos que mais contribuem aos aspectos ambientais de hidrelétricas sejam: enchimento do reservatório; ciclo de vida do cimento e aço, e operação das máquinas de construção. As etapas de transporte parecem não ser de relevância, ao contrário do consumo de aço nos equipamentos permanentes. Em comparação com a geração termelétrica, as emissões atmosféricas e consumo de água do ciclo de vida de Itaipu se mostraram significativamente menores. No entanto há que se considerar que esta comparação se restringiu a estes aspectos. Ao final, conclui-se que resultados mais precisos sobre aspectos e processos de maior prioridade dependem da condução da etapa de Avaliação de Impactos da ACV, e portanto não se deve utilizar os resultados desta análise de inventário como único critério para tomada de decisões em planejamento energético. / The Life Cycle Assessment (LCA) has been proven to be an important environmental assessment tool, mainly due to its “focus on function", which allows the consideration of the environmental performance of products, itself a proceeding that has been more and more requested by different social actors. However, for LCA to be widely and trustfully used, the development of local data bases containing Life Cycle Inventories (LCI) of the most used inputs (energy, raw materials, etc.) is necessary. The present thesis is part of a project conducted by GP2- Group of Pollution Prevention - Escola Politécnica/ USP, which aims to develop and make available a Brazilian LCA data base. Specifically, it focuses electricity generation. In order to allow this project to be concluded in a masters degree context, it was adopted as a simplification the electricity generation in Itaipu Hydropower Plant, responsible for 22,4% of Brazilian consumption in 2000. As a first step towards the elaboration of the LCI, a review on LCA use on hydropower plants was conducted, establishing general recommendations. On the following, Itaipu project was studied concerning its initial civil works and the materials consumption on construction and operation within a 100 year period, obtaining as a result a LCI with the most significant environmental burdens in terms of generated energy (MWh). The system boundaries on this context includes: excavations and other earthen works; building site installation and operation; transportation of: workers, cement, ashes, structural steel and diesel; life cycle of steel, copper, cement, diesel, lubricant oil and transformer oil used on the dam and permanent equipment; (including maintenance and substitution); and reservoir filling. The results demonstrate, besides the importance of data homogeneity, that the LCI is extremely sensitive to the considered lifetime, which confirms that the construction phase is the main source of environmental burdens. Another important conclusion is that each hydropower plant is a particular case, and it is not possible to establish typical values for the environmental burdens. However there is an indication that Itaipu has a better environmental performance than other plants, mainly on respect to the energy pay back period, due to its high capacity factor and installed power. According to the estimates, the process which most contributes to the environmental burdens of hydropower plants life cycle are: reservoir filling; steel and cement life cycle; and operation of construction machines. Transport activities are of no relevance, however the steel consumption on permanent equipment is. Compared to thermal power, hydropower life cycle air emissions and water consumption are shown to be significantly lower. This comparison indeed is restricted only to this burdens. Finally, recommendations are presented, in the spirit of refining boundaries in the following studies, and the objectives attained are commented. It should be highlighted that all hypothesis and calculations are located in the Annex volume, being just referenced on the main text.

A Análise de Ciclo de Vida (ACV) tem se mostrado uma importante ferramenta de avaliação ambiental, devido à seu enfoque “sobre função”, que permite considerar o desempenho ambiental de produtos, procedimento cada vez mais requerido por diversos atores sociais. Para que a ACV possa ser utilizada de modo amplo e confiável, faz-se necessário que se desenvolvam bases de dados regionalizadas, contendo Inventários de Ciclo de Vida (ICV) dos principais insumos usados pela sociedade- energia, matérias- primas,etc. O presente trabalho faz parte de uma projeto conduzido pelo GP2- Grupo de Prevenção da Poluição, da Escola Politécnica/ USP, de disponibilização de bases brasileiras para ACV, sendo dedicado especificamente à geração de eletricidade. Para permitir sua realização no âmbito de uma dissertação de mestrado, adotou-se como simplificação a geração de eletricidade na usina hidrelétrica de Itaipu, responsável em 2000 por 22,4% da eletricidade consumida no país. Para construir o ICV realizou-se uma revisão bibliográfica sobre o uso da ACV em hidrelétricas, estabelecendo recomendações gerais. A seguir, estudou-se Itaipu quanto à sua obra civil e consumo de insumos na construção e operação por 100 anos, obtendo ao final um ICV com os aspectos ambientais mais significativos em termos da energia gerada (MWh). Neste contexto as fronteiras estabelecidas incluem: escavações e obras de terra; instalação e operação do canteiro de obras; transporte dos operários e de cimento, cinzas, aço estrutural e diesel para a obra; ciclo de vida do aço, cobre, cimento, diesel, óleos lubrificante e de transformador usados na barragem e equipamentos permanentes (considerando inclusive manutenção e substituição); e enchimento do reservatório. Com a discussão dos resultados pode-se demonstrar, além da importância do uso de dados homogêneos, que o ICV é extremamente sensível ao horizonte de análise (na verdade à energia gerada), o que confirma que a construção é a principal origem dos aspectos ambientais significativos. Outra conclusão é que cada hidrelétrica constitui um caso particular, não sendo possível atribuir valores típicos. No entanto, há indícios de que Itaipu, por seu alto fator de capacidade e potência instalada, possua um desempenho ambiental acima da média das hidrelétricas, principalmente no que se refere ao tempo de retorno da energia investida. As estimativas indicam que os processos que mais contribuem aos aspectos ambientais de hidrelétricas sejam: enchimento do reservatório; ciclo de vida do cimento e aço, e operação das máquinas de construção. As etapas de transporte parecem não ser de relevância, ao contrário do consumo de aço nos equipamentos permanentes. Em comparação com a geração termelétrica, as emissões atmosféricas e consumo de água do ciclo de vida de Itaipu se mostraram significativamente menores. No entanto há que se considerar que esta comparação se restringiu a estes aspectos. Ao final, conclui-se que resultados mais precisos sobre aspectos e processos de maior prioridade dependem da condução da etapa de Avaliação de Impactos da ACV, e portanto não se deve utilizar os resultados desta análise de inventário como único critério para tomada de decisões em planejamento energético. / The Life Cycle Assessment (LCA) has been proven to be an important environmental assessment tool, mainly due to its “focus on function”, which allows the consideration of the environmental performance of products, itself a proceeding that has been more and more requested by different social actors. However, for LCA to be widely and trustfully used, the development of local data bases containing Life Cycle Inventories (LCI) of the most used inputs (energy, raw materials, etc.) is necessary. The present thesis is part of a project conducted by GP2- Group of Pollution Prevention - Escola Politécnica/ USP, which aims to develop and make available a Brazilian LCA data base. Specifically, it focuses electricity generation. In order to allow this project to be concluded in a masters degree context, it was adopted as a simplification the electricity generation in Itaipu Hydropower Plant, responsible for 22,4% of Brazilian consumption in 2000. As a first step towards the elaboration of the LCI, a review on LCA use on hydropower plants was conducted, establishing general recommendations. On the following, Itaipu project was studied concerning its initial civil works and the materials consumption on construction and operation within a 100 year period, obtaining as a result a LCI with the most significant environmental burdens in terms of generated energy (MWh). The system boundaries on this context includes: excavations and other earthen works; building site installation and operation; transportation of: workers, cement, ashes, structural steel and diesel; life cycle of steel, copper, cement, diesel, lubricant oil and transformer oil used on the dam and permanent equipment; (including maintenance and substitution); and reservoir filling. The results demonstrate, besides the importance of data homogeneity, that the LCI is extremely sensitive to the considered lifetime, which confirms that the construction phase is the main source of environmental burdens. Another important conclusion is that each hydropower plant is a particular case, and it is not possible to establish typical values for the environmental burdens. However there is an indication that Itaipu has a better environmental performance than other plants, mainly on respect to the energy pay back period, due to its high capacity factor and installed power. According to the estimates, the process which most contributes to the environmental burdens of hydropower plants life cycle are: reservoir filling; steel and cement life cycle; and operation of construction machines. Transport activities are of no relevance, however the steel consumption on permanent equipment is. Compared to thermal power, hydropower life cycle air emissions and water consumption are shown to be significantly lower. This comparison indeed is restricted only to this burdens. Finally, recommendations are presented, in the spirit of refining boundaries in the following studies, and the objectives attained are commented. It should be highlighted that all hypothesis and calculations are located in the Annex volume, being just referenced on the main text.

Résumé Une demande croissante sans cesse de produits alimentaires à base d’animaux influence la productivité des systèmes mondiaux de production alimentaire, et des mesures indispensables pour freiner la dégradation de l’environnement promettent des effets similaires. Si les scénarios de demande future peuvent être satisfaits de manière durable, cela dépend notamment de la possibilité de réduire de manière significative l'impact de l'aquaculture et de l'élevage sur l'environnement. Des recherches récentes suggèrent que l'utilisation d'aliments à base d'insectes (IBF) pourrait apporter une contribution significative à cet égard, et des arguments valables sont avancés pour soutenir cette hypothèse. Les larves de mouches, comme celles des mouches domestiques (Musca domestica) ou des mouches soldat noir (Hermetia illucens), sont en mesure de puiser des nutriments dans un large éventail de ressources organiques, y compris celles impropres à la consommation humaine. Cela crée la possibilité de convertir (et de réduire considérablement) les déchets organiques de faible valeur, tels que le fumier ou le sang animal, en protéines de haute qualité et en énergie alimentaire, qui se sont avérés appropriés pour nourrir différents poissons d'aquaculture et du bétail monogastrique.Bien que le concept IBF promet d’importants avantages et ait démontré sa faisabilité technique, il n’existe encore aucun système établi permettant de tester les avantages supposés en termes de durabilité. Dans cette thèse, nous avons essayé de surmonter cette lacune par la modélisation de tels systèmes. Notre objectif central était d'identifier les aspects influençant le potentiel d'application des IBF dans différents contextes géographiques et de définir des voies d'optimisation pour une mise en œuvre durable. En nous basant sur des données expérimentales recueillies lors d'essais d'élevage menés en Europe (Espagne et Slovaquie) et en Afrique de l'Ouest (Ghana et Mali), nous avons formulé la conception d'un ensemble de versions de systèmes améliorés élevant M. domestica et H. illucens sur différents substrats organiques de faible valeur. Les modèles de production génériques ont servi comme base d’une analyse du cycle de vie ex ante, dans laquelle nous avons exploré les performances des systèmes à l’aide d’analyse du cycle de vie environnementale (ACV) et de l’analyse des coûts du cycle de vie (ACCV).Les ACVs et ACCVs ont montré que les performances environnementales et économiques des IBF sont largement fonction de l’efficacité de conversion des systèmes, de l’organisation du processus de production (c’est-à-dire de l’apport de main-d’œuvre et d’équipements technologiques) et du contexte géographique. La combinaison de ces facteurs a fourni des avantages pour les configurations simplistes utilisées dans la production de M. domestica en Afrique occidentale tropicale dans des conditions de ponte naturelle (c'est-à-dire d'inoculation de substrat par le biais de mouches présentes à l'état naturel). L'inoculation artificielle (c'est-à-dire l'inoculation du substrat par le biais de larves nourries provenant d'une colonie d'adultes en captivité), utilisée dans la production de H. illucens en Afrique de l'Ouest et de M. domestica dans le sud de l'Espagne, a favorisé une efficacité de conversion élevée, mais a augmenté les impacts environnementaux et les coûts, parce que le système complexe et l'organisation de processus à forte intensité de main-d'œuvre ont considérablement accru les intrants de main-d'œuvre et d'infrastructures de production.Une comparaison avec des aliments conventionnels riches en protéines a mis en évidence des inconvénients environnementaux et économiques pour les modèles de production actuels des IBF, notamment en ce qui concerne les aliments végétaux (par exemple, le tourteau de soja). Les disparités entre les alimentations IBF et conventionnelles reflètent l’utilisation des capacités sub-optimaux des systèmes (effet d’économie d’échelle insuffisant), ainsi que la perte d’énergie et de biomasse le long de la chaîne trophique (producteurs autotrophes vs consommateurs hétérotrophes). Les résultats soulèvent des doutes légitimes sur les avantages en termes de durabilité d’une mise en œuvre d'insectes dans les chaînes de valeur agricoles actuelles. Le succès commercial dépend en grande partie du niveau de salaire spécifique au contexte, des prix des substrats d'élevage et de la manière dont les marchés évaluent les multiples fonctions que les insectes sont capables de fournir. S'agissant de la performance environnementale, nos résultats nous amènent à conclure que la production d'IBF ne présente aucun avantage par rapport aux aliments conventionnels.L’évaluation de systèmes de production encore hypothétiques impliquait une bonne quantité d’hypothèses et d’approximations. Étant donné ces multiples sources d'incertitude et compte tenu du fait que seul un nombre limité de conceptions de systèmes possibles sont prises en compte, les déclarations sur le potentiel d'application d'IBF n'ont aucune validité universelle et doivent être interprétées avec prudence. Cependant, nos résultats contribuent à une meilleure compréhension des facteurs influant sur le potentiel d’application des systèmes de production d’insectes et constituent un point de référence précieux pour les discussions scientifiques et les activités de recherche et développement futures visant à mettre en place des modes de production alimentaire durables.Bien que nos recherches n’apportent aucun soutien aux avantages environnementaux ou économiques supposés de l’utilisation d’insectes dans l’alimentation animale, il est possible que leur utilisation comme aliment destiné à la consommation humaine directe (c’est-à-dire comme substitut possible aux produits à base de poisson et de viande) constitue une solution durable aux problèmes actuels et futurs. Nous recommandons donc aux recherches futures de se concentrer sur les techniques permettant d'exploiter les insectes comme nourriture. / Doctorat en Sciences / There are a few details that I could not specify in the available input fields. I would like to ask you kindly to add the following information: (1) Prof. Erik Mathijs (KUL) is my second co-supervisor; (2) Next to the Jury members listed, there are Prof. Matthias Finkbeiner (TU Berlin) and Prof. Theo Niewold (KU Leuven), which I could not enter manually. / info:eu-repo/semantics/nonPublished

Products, throughout their life cycle from production to waste management, create emissions of greenhouse gases (GHG). This leads to environmental impacts on the climate (Swedish Environmental Protection Agency, 2016). The consumed products from households are increasing (World Wildlife Fund, 2008) and so is the waste generated from them (Avfall Sverige, n.d.). A more sustainable development generating from circular economy should be focused on to increases the reuse of products and by so reduce the amount of waste generated (Göteborgs Stad, n.d.a.) This study have examined if the use of Free Shops can help the city of Gothenburg to reach higher up the waste management hierarchy towards reuse and prevention, and if carbon dioxide equivalents (CO2e) can be avoided by using Free Shops.    Two Free Shops with the purpose to increase reuse in Gothenburg have been studied and their effect on GHG emissions, presented as CO2e, have been analysed. A Life Cycle Inventory Study (LCI) has been conducted on all, but two, different materials entering the Free Shops for four weeks, including the production, waste management, transportation and storage. The result of the study shows that a mean of 10 ton CO2e per Free Shop per year can be avoided when reusing at a Free Shop instead of buying new products. This equals leaving a low energy lamp on for approximately 590 years (World Wildlife Fund, 2009) based on a low energy lamp using 0,007 kWh (Eon, 2007). To examine if the Free Shops can reduce the amount of waste disposed of by households in Gothenburg the material entering the Free Shops was weight and analysed to estimate how it corresponded to the amount of waste disposed of. The result shows that the material entering a Free Shop only corresponds to 0.0025 percent of the household waste disposed of in the city. This indicates that Free Shops by themselves will not solve the problem with increasing amounts of waste and emissions from increasing production. However, they can help in a small scale. / <p>20180625</p>

The prospect of reducing environmental impacts is a key driver for the research and development (R&amp;D) of new forest products. Life cycle assessment (LCA) is often used for assessing the environmental impact of such products, e.g. for the purpose of guiding R&amp;D. The aim of this thesis is to improve the methods and practices of LCA work carried out in the R&amp;D of forest products. Six research questions were formulated from research needs identified in LCA work in five technical inter-organisational R&amp;D projects. These projects also provided contexts for the case studies that were used to address the research questions. The main contributions of the research are as follows: Regarding the planning of LCA work in inter-organisational R&amp;D projects, the research identified four characteristics that appear to be important to consider when selecting the roles of LCAs in such projects: (i) the project’s potential influence on environmental impacts, (ii) the degrees of freedom available for the technical direction of the project, (iii) the project’s potential to provide required input to the LCA, and (iv) access to relevant audiences for the LCA results. Regarding the modelling of future forest product systems, it was found that (i) it is important to capture uncertainties related to the technologies of end-of-life processes, the location of processes and the occurrence of land use change; and (ii) the choice of method for handling multi-functionality can strongly influence results in LCAs of forest products, particularly in consequential studies and in studies of relatively small co-product flows. Regarding the assessment of environmental impacts of particular relevance for forest products, it was found that using established climate impact assessment practices can cause LCA practitioners to miss environmental hot-spots and make erroneous conclusions about the performance of forest products vis-à-vis non-forest alternatives, particularly in studies aimed at short-term impact mitigation. Also, a new approach for inventorying water cycle alterations was developed, which made it possible to capture catchment-scale effects of forestry never captured before. To connect the LCA results to global challenges, a procedure was proposed for translating the planetary boundaries into absolute product-scale targets for impact reduction, e.g. to be used for evaluating interventions for product improvements or for managing trade-offs between impact categories.

The master thesis focuses on problems connected with the life cycle cost of property owned by the city. It analyses general issues of the life cycle cost of construction, but it mainly analyses the ways in which local authorities manage their properties and their cost. Those methods are applied in a case study, that addresses the cost and management of swimming pool sites which are owned by the city Brno.

Many of the water sectors in developing countries are facing challenges and obstacles in providing potable water to their customers. These challenges resulted from many reasons such as; shortage of water, huge population, low water tariff, regulations, unplanned development, shortage of financing, absence of commercial orientation and others. Therefore, these sectors are requested to work innovatively to overcome these problems and find out proper solutions. One effective option to address these challenges is appropriate pricing of water. Setting up appropriate water price aims to recover service cost, reduce rate of subsidy and achieve financial sustainability. This research was carried out to determine how to achieve financial sustainability in the water sector in the Sultanate of Oman. The study is based on three main issues, improving the water tariff structure, the role of the customer and his expectation to increase the chance of financial sustainability. Two stages of qualitative and quantitative data collection methods were adopted in order to answer the research question. 22 semi-structured interviews were conducted with PAEW key staff and other relevant parties outside PAEW. 610 quantitative surveys were returned from a total of 1600 PAEW customers to get their views about the role of the customer and his expectations of PAEW in order to increase the chance of financial sustainability. Findings from qualitative data showed the appropriate water tariff is the cost reflective tariff which increases the chance of financial sustainability and cost recovery. The quantitative findings present the willingness of customers' participation and his expectation. Customer participation is expressed in three main roles: leakage and defect reporting, payment and conservation. In all of these, the research outcomes prove the role of the customer and the importance of these roles to increase the chance of financial sustainability. Customer expectations are expressed in customer service, billing system and water service. The outcomes reflect the customer expectations in terms of satisfaction and identify the gap that should be filled by PAEW to make the customer satisfied and loyal.

Für den wirtschaftlichen Erfolg und die Wettbewerbsfähigkeit von Industrieunternehmen ist die Gestaltung effizienter, funktionsfähiger und an die Erfordernisse des Produktionsumfeldes angepasster Fabriksysteme von entscheidender Bedeutung. Die zielgerichtete Entwicklung und Optimierung solcher Systeme im Rahmen der Fabrikplanung stellt angesichts sich kontinuierlich ändernder Rahmenbedingungen, der Vielzahl zu berücksichtigender Systemelemente und Interdependenzen sowie der Langlebigkeit des Systems eine besondere Herausforderung dar. Um in dem Kontext die Identifikation, Erarbeitung und Auswahl langfristig erfolgversprechender Fabrikkonzepte zu unterstützen, wird innerhalb der vorliegenden Arbeit ein umfassendes Instrumentarium zur Durchführung lebenszyklusorientierter Wirtschaftlichkeitsanalysen und -bewertungen entwickelt. Im Kern basierend auf dem Life Cycle Costing dient dieses vorrangig dazu, sämtliche der mit den fabrikplanerischen Festlegungen verbundenen monetären Konsequenzen systematisch zu erfassen und zu beurteilen. Die instrumentelle Ausgestaltung orientiert sich dabei an den Informationsgewinnungs- und Entscheidungsstrukturen der Fabrikplanung und umfasst Ansätze für den Umgang mit der aus der Vielzahl an Systemelementen resultierenden Komplexität ebenso wie konzeptionelle Modifikationen für eine ergänzende Bewertung nicht-monetärer Zielgrößen. Vor dem Hintergrund zunehmender Anforderungen an die Nachhaltigkeit von Fabriksystemen wird das entwickelte Instrumentarium am Beispiel der Bewertung von Energieeffizienzmaßnahmen konkretisiert und angesichts der Fülle der für lebenszyklusorientierte Analysen und Bewertungen erforderlichen Daten und Informationen um ein Rahmenkonzept zu dessen IT-gestützter Realisierung erweitert. / The development of efficient and functioning factories adapted to the requirements of the production environment is of crucial importance for the economic success and competitiveness of industrial companies. However, the targeted configuration and optimization of such systems is a particular challenge, since constantly changing conditions, a multitude of system elements and interdependencies, and the longevity of the system have to be taken into account. In order to support the identification, generation, and selection of promising planning solutions, a comprehensive instrument for life-cycle oriented profitability analyses and evaluations is developed in this thesis. Essentially basing on Life Cycle Costing it is primarily intended to systematically determine and assess all monetary consequences associated with the generated planning solutions. The instrumental design is oriented toward the structures of information retrieval and decision making in factory planning. It also comprises approaches for handling the complexity that results from the multitude of system elements as well as conceptual modifications for the complementary evaluation of non-monetary assessment criteria. Against the background of increasing demands on the sustainability of factory systems, the developed instrument is exemplarily specified for the evaluation of energy efficiency measures. Furthermore, considering the abundance of data and information required for life-cycle oriented analyses and evaluations in factory planning, the instrument is enhanced by a conceptual framework for its IT- supported implementation.

Ce travail est consacré au développement d’un couplage méthodologique entre la méthode d’Analyse de Cycle de Vie (ACV) et un logiciel de génie de procédés (Aspen Plus), en vue d’améliorer la qualité des données de l’Inventaire du Cycle de Vie (LCV) de la filière classique de production d’acier. La nouvelle approche développée est destinée à la réalisation de l’inventaire pour un système défini à partir de modèles physico-chimiques simplifiés. Ainsi, à l’aide du logiciel Aspen Plus, nous avons mis en oeuvre la modélisation de chaque sous-système considéré dans les frontières de la filière classique de production d’acier : cokerie, agglomération, haut fourneau, convertisseur et laminoir à chaud. L’approche de modélisation adoptée a été basée sur des considérations physiques et chimiques et sur des observations expérimentales à l’échelle industrielle et/ou à l’échelle pilote pour chaque sous-système. Les modèles permettent le calcul de la plupart des émissions engendrées par le système : CO2, CO, NO, SO2, COV, HCl, H2S, poussières et métaux lourds ainsi que des déchets. La validation des modèles a été faite par comparaison des résultats calculés avec des mesures expérimentales disponibles pour des sites industriels. De plus, le comportement des modèles a été testé en réalisant des simulations en utilisant une base de données "de référence" définie dans le cadre du projet européen ULCOS (Ultra Low CO2 Steelmaking). Il est montré que cette approche méthodologique assure le contrôle total du bouclage des bilans de matière et d’énergie du système, difficile à réaliser à partir des données provenant exclusivement de mesures industrielles et/ou de la littérature. De plus, le fait que les émissions soient calculées sur des considérations physicochimiques, conduit à donner une forte crédibilité à l’inventaire réalisé / This work was devoted to a new methodological framework, which combines the Life Cycle Assessment (LCA) method and the process simulation software (Aspen Plus), in order to improve the quality of data used for carrying out the Life Cycle Inventory (LCI) of the classical steelmaking route. The new approach adopted in the present work, is to carry out the inventory of the defined system via simplified physical-chemical models. Using Aspen Plus software, we have developed simplified physical-chemical models for each of the subsystem defined by the boundaries of the classical steelmaking route: coking plant, sintering plant, blast furnace, basic oxygen furnace and hot rolling. The modelling strategy was based on physical and chemical considerations and on the experimental observations made on an industrial and/or a pilot scale for each subsystem.The models allow for calculation of the principal pollutants evolved by the system such as CO2, CO, NO, SO2, COV, HCl, H2S, dust, heavy metals and solid waste. The models validation was made by comparing the calculated results with experimental data given by the industrial sites. Furthermore, the maturity of the models was tested through simulations using data coming from the "benchmark" data base defined in the frame of ULCOS project (Ultra Low CO2 Steelmaking).Through the models simulation, it was proved that this methodological framework assures the total control of mass and heat balances of the system which is difficult to achieve when using only data from industry and/or literature. However, the fact that the emissions calculated within the models are based on physical-chemical considerations gives a strong credibility to the life cycle inventory

This dissertation is focused on relations between corporate life cycle and the structure of entrepreneurial risk, that is measured by cost of equity. Besides the corporate life cycle there is considered also the market life cycle. The research results prove, that there are only little differences in the structure of entrepreneurial risks depending on the corporate life cycle and the market position.