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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.
91

Μοντέλο για τεχνο-οικονομική ανάλυση δικτύων οπτικών ινών

Σπυρώνης, Ιωάννης 21 December 2011 (has links)
Η ραγδαία αύξηση της κίνησης στο διαδίκτυο έχει δημιουργήσει ολοένα και μεγαλύτερη ζήτηση για ευρυζωνικά δίκτυα. Τα δίκτυα οπτικών ινών είναι μια κατηγορία ευρυζωνικών δικτύων που υπόσχονται ευέλικτες και ικανές να υποστηρίξουν πληθώρα υπηρεσιών, δικτυακές επικοινωνίες με θεωρητικά απεριόριστη χωρητικότητα. Πλέον, τα οπτικά δίκτυα δεν καλύπτουν μόνο το βασικό δίκτυο κορμού, αλλά εκτείνονται μέχρι τον τοπικό βρόχο αλλά και την κατοικία των τελικών χρηστών. Έτσι, τα οπτικά δίκτυα πρόσβασης FTTx και οι διάφορες τεχνολογίες τους όπως PON, AON και Home Run εφαρμόζονται στις δικτυακές υποδομές που αναπτύσσονται από το κεντρικό γραφείο του δικτύου της περιοχής κάλυψης μέχρι το συνδρομητή. Η παρούσα εργασία μελετά τεχνικά θέματα που αφορούν κυρίως το εξωτερικό τμήμα των FTTH δικτύων, δηλαδή των FTTx μέχρι το σπίτι, όπως η υποδομή σωληνώσεων, καλωδίων, τάφρων, φρεατίων, κ.λπ. Τα στοιχεία αυτά προκαλούν τα υψηλότερα κόστη στο δίκτυο πρόσβασης (κόστη CAPEX) και για αυτό το λόγο δίνεται ιδιαίτερη έμφαση σε αυτά. Εκτός από αυτά, υπάρχουν και τα OPEX κόστη, που δεν ασχολούμαστε εκτενώς στα πλαίσια της εργασίας. Επίσης, στην εργασία παρουσιάζεται μια μεθοδολογία για την επιχειρησιακή μελέτη σε δίκτυα FTTH, στην οποία παρουσιάζονται τα στάδια για την οικονομική μελέτη ανάπτυξης των δικτύων. Ο βασικός στόχος της εργασίας είναι η υλοποίηση ενός μοντέλου που αυτοματοποιεί τη διαδικασία σχεδιασμού των υπόγειων FTTH δικτύων πρόσβασης, που χρησιμοποιούν την τεχνολογία Home Run. Το μοντέλο χρησιμοποιεί στοιχεία από γεωγραφικό σύστημα πληροφοριών GIS για το σχεδιασμό του δικτύου, κάνει τους κατάλληλους υπολογισμούς στοιχείων υποδομών με βάση αλγορίθμους και προδιαγραφές και στο τέλος με είσοδο τους πίνακες κόστους των στοιχείων δίνει τις δαπάνες για την ανάπτυξη των υποδομών. Πριν από την ανάπτυξη του μοντέλου, περιγράφονται απλά θεωρητικά γεωμετρικά μοντέλα που μπορούν να απεικονίσουν ένα υπόγειο και εναέριο FTTH δίκτυο. Το μοντέλο εκτελείται σε τρεις περιοχές της Αττικής, που έχουν διαφορετικές πυκνότητες κτιρίων και νοικοκυριών με σκοπό τον ακριβή προσδιορισμό των τελικών κοστών ανά περιοχή. Επιπλέον, μπορούν να υπολογιστούν τα κόστη ανά νοικοκυριό, κτίριο, μονάδα μήκους των τάφρων και γενικά υπόγειων υποδομών. Η αποτύπωση του εξωτερικού δικτύου των περιοχών, των στοιχείων υποδομών, των εξοπλισμών και των τελικών δαπανών τους γίνεται με πλήρως αυτοματοποιημένο τρόπο. / The rapid growth of Internet traffic has created increasing demand for broadband networks. Fiber optic networks are a category of broadband networks that promise flexible and capable for supporting various services, network communications with limitless capacity. Plus, the optical networks do not only cover the core backbone network, but extend to the local loop and the households of end users. Thus, FTTx optical access networks and their various technologies such as PON, AON, and Home Run are implemented in the network infrastructure, which is developed from the central office of the coverage area network to the subscriber. This diploma thesis examines the technical issues related mainly to the outside plant of FTTH networks (FTTx up to the household), such as infrastructure ducts, cables, trenches, holes, etc. These elements rise to higher costs in the access network (CAPEX costs) and for this reason, special emphasis is placed on them. Apart from these, there are OPEX costs. Also, the thesis presents a methodology for the business study of FTTH networks, which shows the stages to study for the economic development of networks. The main aim of this work is to implement a model that automates the design of underground FTTH access networks, that use Home Run technology. The model uses data from Geographical Information System (GIS) for network design, makes the appropriate calculations, based on data infrastructure algorithms and specifications and in the end returns the total costs for infrastructure development based on material cost tables. Before the development of the model, there are descriptions of simple geometric models that can represent an underground and aerial FTTH network. The model runs on three areas of Attica, that have different densities of buildings and households in order to accurately determine the final cost per area. Moreover, they can calculate the cost per household, building, length unit of trenches and other underground infrastructure. The representation of the external network, elements, data infrastructure, equipment and final expenditure is fully automated.
92

Web 2.0 : uma análise evolucionária do seu impacto nas empresas a nível global

Valdez Montalván, Daniel Borja January 2010 (has links)
O objetivo principal desta dissertação é analisar as tecnologias de aplicativos da Web 2.0, desde uma perspectivas evolucionária, e dos seus impactos nas empresas em nível global. Desta forma, para poder entender o seu nascimento, essência e importância econômica para as empresas, se tomou como base teórica o conceito evolucionário de revoluções tecnológicas e paradigmas tecno-econômicos, o qual serviu como modelo para interpretar a atual revolução das tecnologias de informação e comunicação (TIC) e seu conseqüente paradigma tecnoeconômico, e na qual se constatou que este grupo de tecnologias surgiu no período de tempo atual de dito paradigma conhecido como “intervalo de reacomodação” (turning point). Por outro lado, se ressaltou que uma das principais características no processo de difusão de cada paradigma tecno-econômico é o seu impacto na organização das empresas. Desta forma, a teoria evolucionária se apresentou como a abordagem adequada para entender tanto o caráter da empresa atual, entendida esta em termos do conjunto de suas rotinas (conhecimentos e habilidades), quanto as suas principais inovações organizacionais como respostas aos desafios apresentados pela própria difusão do paradigma tecno-econômico atual das TIC, na qual o acumulo permanente de novos conhecimentos e informações, isto é, de rotinas dinâmicas se tornam variáveis chaves para o próprio processo permanente de inovação, vital para as empresas. Diante da crescente utilização das tecnologias de aplicativos da Web 2.0 entre as empresas a nível mundial como meios potenciais para atingir esses objetivos, o presente trabalho analisou o seu potencial para gerar de forma mais fluida novos conhecimentos e informações, isto é rotinas dinâmicas, tanto dentro da organização das empresas como na interação com os seus consumidores, refletindo-se, assim, no aumento de inovações permanentes de novos produtos e serviços. / The main objective of this dissertation is to analyze the technologies of Web 2.0 applications, from an evolutionary perspective, and its impacts on businesses globally. Thus, in order to understand its birth, nature and economic importance for companies, it was taken as theoretical basis the evolutionary concept of technological revolutions and technoeconomic paradigms, which served as a model to interpret the current revolution in information and communication technologies (ICT) and its consequent techno-economic paradigm, in which it was found that this group of technologies originated in the current time of said paradigm known as turning point. On the other hand, it was emphasized that a key feature in the process of diffusion of each techno-economic paradigm is its impact on business organization. Thus, evolutionary theory appeared as the appropriate approach to understand both the character of the current company, which is understood in terms of its set of routines (knowledge and skills), as its main organizational innovations as answers to the challenges presented by the own diffusion of the current ICT techno-economic paradigm, in which the continuous accumulation of new knowledge and information, that is, dynamic routines, become key variables to the self process of continuous innovation, vital for companies. With the increasing use of Web 2.0 application technologies among the companies in the world as a potential means to achieve these goals, this study examined its potential to generate more fluidly new knowledge and information, that is dynamic routines, both within the business organizations and in their interaction with their consumers, which was reflected in the increase of permanent innovations of new products and services.
93

Web 2.0 : uma análise evolucionária do seu impacto nas empresas a nível global

Valdez Montalván, Daniel Borja January 2010 (has links)
O objetivo principal desta dissertação é analisar as tecnologias de aplicativos da Web 2.0, desde uma perspectivas evolucionária, e dos seus impactos nas empresas em nível global. Desta forma, para poder entender o seu nascimento, essência e importância econômica para as empresas, se tomou como base teórica o conceito evolucionário de revoluções tecnológicas e paradigmas tecno-econômicos, o qual serviu como modelo para interpretar a atual revolução das tecnologias de informação e comunicação (TIC) e seu conseqüente paradigma tecnoeconômico, e na qual se constatou que este grupo de tecnologias surgiu no período de tempo atual de dito paradigma conhecido como “intervalo de reacomodação” (turning point). Por outro lado, se ressaltou que uma das principais características no processo de difusão de cada paradigma tecno-econômico é o seu impacto na organização das empresas. Desta forma, a teoria evolucionária se apresentou como a abordagem adequada para entender tanto o caráter da empresa atual, entendida esta em termos do conjunto de suas rotinas (conhecimentos e habilidades), quanto as suas principais inovações organizacionais como respostas aos desafios apresentados pela própria difusão do paradigma tecno-econômico atual das TIC, na qual o acumulo permanente de novos conhecimentos e informações, isto é, de rotinas dinâmicas se tornam variáveis chaves para o próprio processo permanente de inovação, vital para as empresas. Diante da crescente utilização das tecnologias de aplicativos da Web 2.0 entre as empresas a nível mundial como meios potenciais para atingir esses objetivos, o presente trabalho analisou o seu potencial para gerar de forma mais fluida novos conhecimentos e informações, isto é rotinas dinâmicas, tanto dentro da organização das empresas como na interação com os seus consumidores, refletindo-se, assim, no aumento de inovações permanentes de novos produtos e serviços. / The main objective of this dissertation is to analyze the technologies of Web 2.0 applications, from an evolutionary perspective, and its impacts on businesses globally. Thus, in order to understand its birth, nature and economic importance for companies, it was taken as theoretical basis the evolutionary concept of technological revolutions and technoeconomic paradigms, which served as a model to interpret the current revolution in information and communication technologies (ICT) and its consequent techno-economic paradigm, in which it was found that this group of technologies originated in the current time of said paradigm known as turning point. On the other hand, it was emphasized that a key feature in the process of diffusion of each techno-economic paradigm is its impact on business organization. Thus, evolutionary theory appeared as the appropriate approach to understand both the character of the current company, which is understood in terms of its set of routines (knowledge and skills), as its main organizational innovations as answers to the challenges presented by the own diffusion of the current ICT techno-economic paradigm, in which the continuous accumulation of new knowledge and information, that is, dynamic routines, become key variables to the self process of continuous innovation, vital for companies. With the increasing use of Web 2.0 application technologies among the companies in the world as a potential means to achieve these goals, this study examined its potential to generate more fluidly new knowledge and information, that is dynamic routines, both within the business organizations and in their interaction with their consumers, which was reflected in the increase of permanent innovations of new products and services.
94

Proposta de método para avaliação do processo de extração de sucos cítricos

Kharfan, Daniela 30 August 2011 (has links)
Made available in DSpace on 2016-06-02T19:51:53Z (GMT). No. of bitstreams: 1 4027.pdf: 1690749 bytes, checksum: 8d859783d2c99e52f4016543ef37c8dd (MD5) Previous issue date: 2011-08-30 / For almost one century, citrus chain has been one of the most important agribusiness for Brazil. Brazil is the largest world orange producer and the largest orange juice exporter, responsible for almost 90% of the worldwide orange juice exportations. Doubtless one of the most important Brazilian sectors, citrus is responsible for a huge percentage of the agribusiness exportations (around USD 1,5bilion/year) and one of the economy motors of the central regions of the State of São Paulo. Over this period, many changes occurred and are still going on into the national and international scenarios. Also, in the XXI century changes have being happened more quick and intense: great fruit and orange juice price oscillations, influence of exchange variation, the 2008 economical crisis, influence of climate conditions and incidence of new diseases, besides demand variations regarding volume and type of product (advent of NFC Not From Concentrate or single strength juice). Citrus processing industry represents a fundamental key role in the whole chain, to achieve new frontiers, putting the Brazilian product into the 5 continents, leveraging exportations to almost 1,300 k/tons of juice exported annually. To guarantee competitiveness in the business, processors have searched continuous improvement on processes, equipment, management techniques as well as quality standards of their products, in order to meet the demands of the market that, year by year, have become more discerning and demanding. There is also the need of continuous improvement and adjustment of the Research & Development techniques for equipment applied to industry, to attend the new parameters. Performance tests of citrus juice equipment are totally important to: evaluate productive process efficiency, investment definition, meet customer s standards and represent a point that impacts the strategic corporate decisions. The purpose of this master s degree dissertation is to propose a method for evaluating the technical-economic stage of citrus juice extraction. The study aims the juice extraction process introduced in the citrus juice extraction chain. For this, it was performed a review of literature and a case study in the segment of citrus juice processing. The research approach used is qualitative and quantitative, using already existent data, from empirical studies conducted in the sector. This work aims to structure and propose a method for the process of citrus juice comparative tests, and the performance evaluation of the extraction system, considering the higher number of variables and ensuring all necessary and sufficient data for decisionmaking. As academic contribution, this work aims to bring an empirical example improvement of food industry equipment, using experimental techniques and data analysis in a specific juice extraction situation, whose results are used for tracking their productive processes, monitoring and improving performance and decision-making regarding changes and investments. / A cadeia citrícola, ao longo de quase um século de existência no Brasil, tem se mostrado uma das mais importantes no agronegócio, visto que o Brasil é o maior produtor mundial de laranjas e o maior exportador de suco cítrico com quase 90% das exportações mundiais. É, sem dúvida, um dos setores mais importantes da economina brasileira, responsável por uma parcela generosa das exportações do agronegócio (cerca de US$ 1,5 bilhões / ano) e um dos motores da economia da região centro do Estado de São Paulo. Ao longo deste período, muitas mudanças ocorreram e continuam acontencendo no cenário nacional e internacional, e no século XXI as mudanças têm se tornado mais rápidas e intensas: grandes oscilações nos preços da fruta e do suco de laranja, influência da variação cambial e da crise econômica de 2008, influência das condições climáticas e incidência de novas doenças, além de variações na demanda no que se refere ao volume e tipo de produto (advento do NFC Not From Concentrate ou suco integral). Nesta cadeia, a indústria de processamento dos cítricos tem papel fundamental no avanço das fronteiras, colocando o produto brasileiro nos cinco continentes, alavancando as exportações com quase um milhão e trezentas mil toneladas de suco exportado anualmente. Para garantir a competitividade no negócio, as indústrias têm buscado melhorias contínuas nos seus processos, equipamentos, técnicas de gestão e também nos padrões de qualidade dos seus produtos, a fim de atender às exigências do mercado consumidor que tem se tornado, a cada ano, mais criterioso e exigente. A fim de atender estes novos parâmetros, há, também, uma necessidade de melhoria contínua e adequação das técnicas de Pesquisa e Desenvolvimento para os equipamentos aplicados na indústria. A realização de testes de desempenho dos equipamentos de extração de sucos cítricos é de fundamental importância na avaliação da eficiência do processo produtivo, definição de investimentos, atendimento aos padrões de qualidade dos clientes, representando um ponto que causa impacto nas decisões estratégicas das empresas. Nesse sentido, esta dissertação de mestrado tem como objetivo a proposição de um método para a avaliação técnica-econômica da etapa de extração de sucos cítricos. O objeto de estudo, inserido na cadeia de produção de sucos cítricos, é o processo de extração de sucos. Para a realização deste trabalho, foi feita uma revisão bibliográfica e um estudo de caso no segmento de processamento de sucos cítricos. A abordagem de pesquisa utilizada é a qualitativa e quantitativa, com a utilização de dados já existentes da literatura e dados de estudos práticos realizados neste setor. Espera-se com este trabalho a estruturação e proposição de um método para o processo de realização de testes comparativos de extração de suco cítrico e a avaliação do desempenho deste sistema de extração, de forma que considere o maior número de variáveis do processo e garanta a obtenção de dados necessários e suficientes para tomadas de decisão. Como uma contribuição acadêmica, espera-se que o trabalho proposto traga um exemplo prático de melhoria no segmento de equipamentos para a indústria de alimentos por meio do uso de técnicas de experimentação e análise de dados em uma situação específica de extração de suco, cujos resultados são utilizados para acompanhamento de seus processos produtivos, monitoramento e aprimoramento de desempenho e tomada de decisão de modificações e investimentos.
95

Optimisation rationnelle des performances énergétiques et environnementales d’une centrale à charbon pulvérisé fonctionnant en oxy-combustion / Rational optimization of the energetic and environmental performances of an oxy-fired pulverized-coal power plant

Hagi, Hayato 09 December 2014 (has links)
L’objectif de la thèse est de concevoir un design le plus optimisé possible d’une centrale à charbon pulvérisée fonctionnant en oxy-combustion. Une telle centrale intègre un système de production d’oxygène (ASU), une chaudière, un cycle électrogène, des équipements de dépollution ainsi qu’un système de purification et de compression du CO2 (CPU). Ainsi, dans un premier temps, la thèse portera sur la compréhension, l’analyse et la modélisation des différents procédés qui composent la chaîne d’une centrale fonctionnant en oxy-combustion. Ensuite, les performances et la configuration de la centrale seront optimisées de façon à réduire la destruction d’exergie tout s’assurant de la compétitivité économique de la solution ainsi obtenue. A l’issue de cette thèse, les origines des pertes exergétiques du système étudié et les schémas d’intégration permettant de maximiser les gains énergétique à l’échelle de la centrale seront identifiées. De plus, les stratégies de dépollution des fumées les plus adaptées seront définies et les nouveaux procédés intégrés seront évalués à la fois d’un point de vue technico-économiques et flexibilité. / The objective of the thesis is the conception of an optimized oxy-fired pulverized-coal power plant. Such a power plant is constituted of an oxygen production system (ASU), a boiler, power cycle, depollution equipments and a CO2 purification and compression system (CPU). After a first step consists in understanding, analyzing and modeling the different processes composing the oxy-combustion system; the work will focus on the optimization of the performances and the configuration of the power plant by minimizing exergy destructions while ensuring economic competitiveness of the obtained solution. At the end of the thesis, the origins of the exergetic losses in the system as well as the thermal integration scheme allowing the maximization of the energetic gains at power plant level will be identified. Additionally, the most adapted flue gas depollution strategies will be defined and the new integrated process schemes will be evaluated on both a techno-economic and flexibility basis.
96

Ciclos de desenho: uma percep??o dos ciclos de economia e tecnologia

Borges, Ana L?gia do Lago 25 February 2016 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-09-27T00:02:12Z No. of bitstreams: 1 AnaLigia_Disserta??o_completa.pdf: 3275012 bytes, checksum: 3fbf17a121f3ccc63ae9e4e137889710 (MD5) / Made available in DSpace on 2016-09-27T00:02:12Z (GMT). No. of bitstreams: 1 AnaLigia_Disserta??o_completa.pdf: 3275012 bytes, checksum: 3fbf17a121f3ccc63ae9e4e137889710 (MD5) Previous issue date: 2016-02-25 / This dissertation deals an analysis of the cyclical changes of the design of industrial products, its relations with long cycles of economy and technology and its implications for local material culture. This research was conducted based on the model used by Langrish, work published in England in 1982. In his work, examine published magazines advertisements, with an emphasis on motivational spirit of society. We questioned if the Brazil, as a semi-peripheral country, has optimism cycles in design as it appears in England. The main objective is the analysis of how behaves the motivation of products design in the country, between the cyclical fluctuations of economy and technology. To achieve our goals was carried out an analysis of selected periods announcements in accordance with the variation of the national political-economic framework of the VEJA Magazine, between 1968 to 2015 years. After evaluating the results, this research reveals the perception of cyclical changes the products design in function of changes techno-economics paradigms and a heavy reliance of the design produced in the leading countries economically. In chapter one, the introduction to the survey is presented. The chapter two provides a brief historical and theoretical overview of the design, the economic cycles and technological changes. In the third chapter, we discuss the design changes opportunities and the economic situation of the peripheral countries. Analyzes and contributions is in the fourth chapter. In the fifth chapter are cited some final considerations of the research. / sta disserta??o faz uma an?lise sobre as mudan?as c?clicas do Desenho de produtos industrializados, suas rela??es com os ciclos longos de economia e tecnologia e o que isto implica como cultura material local. A pesquisa foi realizada com base no modelo utilizado por Langrish, em 1982, em seu artigo publicado na Inglaterra, que consiste em analisar imagens dos an?ncios de revistas ou peri?dicos publicados, com ?nfase no esp?rito motivacional da sociedade. Questionamos se o Brasil, como um pa?s semiperif?rico, possui Ciclos de otimismo em Desenho tal qual apresentado na Inglaterra. O objetivo principal ? a an?lise de como se comporta a motiva??o do desenho de produtos, no Pa?s, entre as oscila??es c?clicas de economia e tecnologia. Para atingir nossos objetivos foi realizada uma an?lise dos an?ncios de per?odos selecionados em conformidade com a varia??o do quadro pol?ticoecon?mico nacional, da Revista VEJA, entre os anos de 1968 a 2015. Ap?s os resultados auferidos, a pesquisa revela a percep??o das mudan?as c?clicas do desenho de produtos em fun??o das mudan?as dos paradigmas tecnoecon?micos no Pa?s e uma forte depend?ncia de desenhos produzidos em pa?ses l?deres economicamente. No cap?tulo um, encontra-se a parte introdut?ria da pesquisa. O cap?tulo dois traz um breve panorama hist?rico e te?rico sobre o Desenho, os Ciclos Econ?micos e as mudan?as tecnol?gicas. No terceiro cap?tulo, abordamos as oportunidades de mudan?as do Desenho e da situa??o econ?mica dos pa?ses perif?ricos. As an?lises e contribui??es, fruto da pesquisa, encontra-se no quarto cap?tulo. No quinto cap?tulo as considera??es finais da pesquisa.
97

Hydrogen systems : what contribution to the energy system? Findings from multiple modelling approaches / Systèmes à hydrogène : quelle contribution au système énergétique? Résultats de plusieurs approches de modélisation

Tlili, Olfa 07 November 2019 (has links)
L'hydrogène… Cet élément simple et très abondant pourrait être un contributeur clé à la transition énergétique, mais dans quelles conditions technico-économiques et politiques ? Cette thèse propose une contribution à l'évaluation de la faisabilité de pénétration de l'hydrogène dans le système énergétique, en mettant en oeuvre différents modèles qui permettent des éclairages complémentaires. Elle se concentre sur l’hydrogène bas carbone, obtenu par électrolyse de l’eau.Notre analyse multirégionale qui porte sur le contexte énergétique européen, américain, chinois et japonais (régions qui présentent des défis énergétiques contrastés) montre que les politiques énergétiques actuelles ne facilitent qu’une faible pénétration de l'hydrogène dans le système énergétique, lui permettant de réaliser environ 3% de l’effort à fournir par les quatre régions afin de limiter l’augmentation de la température à 2°C par rapport aux niveaux préindustriels. Nous soulignons dans cette thèse que l’injection d’hydrogène dans les réseaux de gaz naturel qui permet dans une certaine mesure d’éviter des fuites de méthane à fort pouvoir de réchauffement, pourrait jouer un rôle significatif dans la réalisation des objectifs de réduction des émissions de gaz à effet de serre.L'analyse des marchés de l'hydrogène a été menée en deux étapes. Tout d'abord, chaque marché (industriel ou énergétique) a été abordé individuellement afin d’établir des coûts d'entrée sur ce marché (pour les différents contextes énergétiques considérés). Ensuite, les différentes applications de l’hydrogène ont été resituées en interaction avec l’ensemble du système énergétique à travers le modèle TIMES-PT et un cas d’étude portant sur le Portugal, permettant ainsi d’examiner le potentiel de couplage entre les secteurs énergétiques rendu possible par l’hydrogène. Ces travaux ont permis de qualifier l'attractivité des différents marchés, celui de la mobilité apparaissant comme le plus favorable.Nous nous sommes ensuite intéressés aux coûts requis sur l'ensemble de la chaîne d'approvisionnement en hydrogène afin de pénétrer le marché de la mobilité.Pour ce faire, nous avons utilisé des modèles avec une maille géographique et temporelle fine (GLAES, EuroPower et InfraGis), en commençant par l’étape de production. Nous avons étudié le rôle potentiel de l'hydrogène pour la fourniture de flexibilité au système électrique dans un contexte de forte pénétration des énergies renouvelables intermittentes en France. Nos résultats montrent que l’hydrogène pourrait permettre non seulement d’éviter d’écrêter la production d’énergies renouvelables (entre 1,4 et 7,9 TWh en fonction du scénario de capacité d’interconnexion), mais pourrait aussi mettre à profit l’énergie nucléaire disponible (bas carbone donc), évitant par-là d’imposer de fortes rampes de puissances aux centrales. Cependant, une attention particulière doit être accordée au taux d'utilisation de l'électrolyseur afin de maintenir les coûts de production d'hydrogène suffisamment bas.Enfin, nous nous sommes concentrés sur l’approvisionnement de l’hydrogène, depuis les sites de production jusqu’à l’utilisation pour la mobilité, la question de l’infrastructure étant un problème majeur entravant les investissements dans l’hydrogène. Cinq filières d’approvisionnement (transport et distribution) ont été développées à la maille régionale et comparées sur le plan économique pour le cas français. Nos résultats montrent que, lors des toutes premières phases de pénétration du marché (scénario 1%), il est plus intéressant de privilégier la production décentralisée. / Hydrogen… This simple, very abundant element holds great promise to contribute to the transition towards a cleaner future energy system, but under which techno-economic and political conditions? This thesis is a contribution to the assessment of the hydrogen penetration feasibility into the energy system, using a multi-model approach. The focus is put on low-carbon hydrogen, obtained by electrolysis.Our multi-regional analysis on the European, American, Chinese and Japanese energy context (presenting contrasted energy challenges) show that, with the current energy policies implemented which result in a modest penetration of hydrogen into the energy system, hydrogen may achieve approximately 3% of the effort that needs to be done by the four regions, in order to limit the increase of the temperature to 2°C, compared to preindustrial levels. We highlight in this thesis that blending hydrogen with natural gas, and thereby avoiding methane leakages to a certain extent, may represent a significant contribution in achieving the carbon mitigation goals.The hydrogen market analysis has been carried out following two steps. First, each market (industrial and energy-related) was tackled aside in order to propose market entry costs considering the four energy contexts and investigate the timeframe of the market penetration potential. Then, the different hydrogen applications were examined within the overall energy system through the TIMES-PT model (for a Portugal case study), allowing to investigate the hydrogen potential for energy sector coupling. Based on this work, the markets attractiveness was evaluated: mobility (using fuel cell vehicles) appears to be the most favourable.Then, we tackled the required costs over the whole hydrogen supply chain in order to enter the mobility market.To do so, we used temporally and spatially resolved models (GLAES, EuroPower and InfraGis) starting with the production side where we studied the hydrogen potential role in providing the electricity system with flexibility and the impact of such electrolysis operation on the hydrogen generation costs in the context of high shares of renewable energies in France. Our results show that hydrogen can contribute to improve the flexibility of the electric system by allowing avoiding renewable curtailment (between 1.4 and 7.9 TWh depending on the interconnection capacity scenario) but also by taking advantage of nuclear plant available energy (thereby avoiding nuclear ramping), the latter ensuring a low carbon and low cost electricity provision. However, a special attention needs to be dedicated to the utilisation rate of the electrolyser, to keep the hydrogen production costs low enough.Last but not least, we focused on how to link the hydrogen production sites and its final use for mobility applications, the delivery infrastructure being a major issue hampering the hydrogen investments. Five transport and delivery pathways were geographically designed and economically assessed, for the French case. According to our findings, during the very first market penetration phases (1% scenario), it is more interesting to start with decentralised production that proved to be less expensive for the whole pathway at this stage.
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Pokročilé modely logistiky v oblasti odpadového hospodářství / Advanced Logistic Models for Waste Management

Gregor, Jiří January 2019 (has links)
The purpose of the dissertation thesis is to prepare transport techno-economic models which will be able to estimate the transportation cost for selected scenarios. The main goal is to describe the complex transport chains in waste management, using different types of transportation (road, rail) and transport different types of waste. The key element of preparing techno-economic models is the identification of input parameters which are important for estimating the cost of transport. At the same time, it is necessary to correctly identify the processing facilities that will be part of complex transport chains. The total outputs will be presented in the form of a feasibility study.
99

Technologie řezání plazmovým paprskem / Technology Plasma Beam Machining

Sedlák, Ondřej January 2011 (has links)
This diploma thesis focuses on the unconventional method of metal separation, namely on the cutting technology based on the plasma arc. The introductory part deals with studies which focus on the given issue from a theoretical point of view. The core of the work rests in the practical part which is dedicated to the production of samples using a plasma burning machine called Hypertherm HPR 260. The burned samples are monitored and assessed for the surface quality and dimensional accuracy for every created part. The final part of the work is dedicated to the techno-economic assessment of the burned parts. In the end, the evaluation of the attained results is made.
100

Analýza vlivu zateplení na cenu bytové jednotky v Opavě / Analysis of the influence of insulation on the price of housing units in Opava

Adamus, Aleš January 2013 (has links)
This dissertation analyzes the effect of insulation on the price of housing units in Opava city. In the theoretical part of the dissertation deals with the subject of appraisement, the energy intensity of buildings and technical-economic evaluation. In the practical part sets the prices of selected housing units by direct comparison, the comparative method by regulation and yield value. It assesses whether the possible range in the valuation regulations (5%) reflects the fact that the recognized building insulated in accordance to the current legislation. It detects the energy nature of a apartment building in which they are placed selected apartments. The goal is to determine a price increase of housing units due to insulation and evaluates the appropriateness and inappropriateness of buying from the investor's perspective.

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