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

Dans cette thèse, nous abordons la conception des composants d'électronique de puissance, intégrés sur semi-conducteur. Dans cette large problématique, nous nous intéressons plus particulièrement aux méthodes et outils logiciels et numériques pour le dimensionnement technologique et géométrique. Ainsi, nous abordons le dimensionnement en faisant des compromis d'intégration entre la technologie du composant de puissance et les fonctions électriques de ses composants annexes, en prenant en compte la fiabilité de la réalisation technologique en salle blanche et les impacts de l'environnement électronique. Pour cela, nous avons proposé des démarches, méthodes et outils pour repousser les limites existantes de la conception, visant à offrir le support correspondant en terme de « design kit ». Finalement, nous appliquons les méthodes et les démarches choisies et développées, au dimensionnement d'un MOSFET de puissance (VDMOS), pour différents cahiers des charges. / The thesis deals with the design of integrated power electronics components. In this large problematic, the thesis focuses on the methods and numerical and software tools for the geometrical and technological sizing. So, the thesis deals with the sizing carrying out compromises between the technology of a power component and the electrical characteristics of its auxiliary components, taking into account the reliability of the technological making and the impacts of the electronic environment. In this way, approaches, methods and tools are proposed to push away the existing design limits, to offer the corresponding elements for the design kit. Finally, the developed and chosen methods and approaches are applied to the sizing of a power MOSFET (VDMOS) according to several cases of specifications

Orientador: Ruth Künzli / Banca: Rosângela Custódio Cortez Thomaz / Banca: João Osvaldo Rodrigues Nunes / Resumo: O objetivo deste trabalho é mostrar a contribuição que uma pesquisa arqueológica pode oferecer à compreensão da formação do espaço geográfico e suas transformações. Tanto para a Geografia quanto para a Arqueologia é fundamental o estudo das técnicas, pois é através delas que o homem pode medir seu nível cultural. Tentar entender e compreender que essas técnicas são a peça chave para saber quais eram os hábitos e costumes dos povos pré-históricos, pois através dessas técnicas é que podemos saber quais eram seu modo de vida e sua relação com o espaço ocupado. Com isso podemos ver que numa análise mais abrangente através do conhecimento de técnicas, podemos estar descrevendo os costumes dos povos que habitaram determinada região. Neste aspecto, o projeto tem por objetivo analisar o material arqueológico encontrado durante as escavações, procurando identificar, através de um sítio definido, que servirá como parâmetro, quais as técnicas utilizadas pelos povos pré-históricos que habitaram a região, bem como compreender e identificar qual a origem desses povos, e a que grupos pertenciam, bem como a forma pela qual eles se relacionavam com o meio natural para a construção do espaço geográfico no qual habitaram no passado. Identificando esses povos não apenas estaremos descobrindo uma parte de nossa própria história regional, bem como avançando na compreensão da evolução do homem enquanto agente transformador do espaço em que habitava e interagia. / Abstract: This work is a contribution to archaeological research that can provide the understanding about the formation of geographical space and their transformations. Both for the Geography and the Archeology the study of techniques is fundamental, for it is through them that man can measure their cultural level. Trying to understand and realize that these techniques are the key to what the habits and customs of prehistoric people were, because through these techniques is that we can know what were their way of life and their relation to space. With this we can see that in a more comprehensive analysis of their techniques we can describe the customs of peoples who inhabited a region. Here, the project aims to analyze the material found during the archaeological excavations, seeking to identify, through a established site to serve as a parameter to which techniques were used by prehistoric peoples who inhabited the region, and understand and identify which origin of these peoples and groups that belonged, and the way in which they interact to the natural environment for the construction of the geographical area in which they inhabited in the past. By identifying these people, we will not only discover a part of our regional history, as well as advancing the understanding of the evolution of man as an agent of transformation of the space in which they lived and interacted. / Mestre

Biomass-based reducing agents have a potential to substitute fossil reducing agents in the steel industry. However, the industrial use of biomass-based reducing agents is currently in an early stage of development and has not yet been considered as a means to reduce fossil CO2 emissions, even though the use of fossil-based reducing agents for the iron and steel making cause the highest share of CO2 emissions. This master thesis presents a techno-economic analysis of a 10 MW biochar production plant integrated with sponge iron production in Höganäs. In this study, a steady-state process model was developed, where state-of-the-art research and development in biochar production for increased biochar yield was applied and adapted, using the principle of bio-oil recycle. The developed process model was used to evaluate the biochar production plant, in terms of conversion efficiency, production costs and CO2 emissions, for different process configurations. The results show that bio-oil recycle with 20 wt.% bio-oil increases the energy yield of biochar with 14%. However, it was found that bio-oil recycle increases the required heat input of pyrolysis which led to reduced plant efficiency with 4%-units and increased biochar production costs of 500-1000 SEK/ton biochar. It was found that system integration with Höganäs can reduce the production cost of biochar from over 5000 SEK/ton to under 2000 SEK/ton, where the most significant integration aspect was flue gas integration. The sensitivity analysis showed that the cost of biomass feedstock and total capital investment were the most sensitive input parameters. It was found that system integration with Höganäs was essential to achieve production costs of biochar below the price of fossil reducing agents. It was also found that co-produced bio-oil becomes a main product, essential for the economic performance of the biochar plant, even though the intended main product was the biochar.

A comparison between a traditional fixed high voltage direct current energy transmission system and a mobile transmission system utilizing vanadium redox flow batteries has been conducted in this degree work.  The purpose of this comparison was to evaluate if a mobile energy transmission system could be competitive in terms of energy efficiency and cost-effectiveness for use in offshore wind power applications. A literary study was made to fully grasp the various technologies and to create empirical ground of which cost estimation methods and energy calculations could be derived. A specific scenario was designed to compare the two transmission systems with the same conditions. To perform the comparison, a model was designed and simulated in MATLAB. The results from the model showed that the flow battery system fell behind in energy efficiency with a total energy loss of 33.3 % compared to the 11.7 % of the traditional system, future efficiency estimations landed it at a more competitive 17.5 %. The techno-economic results proved that a mobile flow battery system would be up to nine times more expensive in comparison to a traditional transmission system, with the best-case scenario resulting in it being roughly two times more expensive. The main cause of this was found out to be the expensive energy subsystem, specifically the electrolyte, used in the flow battery system. Several environmental risks arise when using a flow battery system with this electrolyte as well which could harm marine life severely. In conclusion; with further development and cost reductions, a case could be made for the advantages of a truly mobile energy transmission system. Specifically, in terms of the pure flexibility and mobility of the system, allowing it to circumvent certain complications. The mobility of the system gives the possibility of selling energy where the spot prices are at their highest, providing a higher revenue potential compared to a traditional fixed system. As for now though, it is simply too expensive to be a viable solution.

Technological Education had a significant increase in its quantitative courses and offered vacancies in recent years, especially after the establishment of REUNI, the reconstituting of the former Federal Centers of Technological Education (CEFET's) and the implementation of the Federal Institutes of Education, Science and Technology (IFET's). However, many issues related to the educational process of future technologists need to be reexamined. This paper, based on the case study of the Technology Course in Environmental Management (CSTGA) from UFSM, intends to: determine whether, in CSTGA, there is a dialogue between scientific-technical training and the humanistic training; examine according to the theoretical framework of this study - Freire / STS - the elements involved in the articulation or non-articulation between the techno-scientific and humanistic training, as well as to discuss possible implications to the training process, based on the verification of this study. As a methodological approach we use the Text Analysis Discourse, the corpus of analysis were the Pedagogical Project of the Course, the questionnaire answered by the students and the semi-structured interview with the teachers of the course. From this corpus of analysis meaning units emerge which bring forward categories, from which it is discussed the specific situation of the studied course. The results of this analysis point in the direction of non-articulation between techno-scientific and humanistic formation, with possible causes related to the teacher training, the curriculum inflexibility and the presumption on the part of the academic community that these courses are guided, almost exclusively, by the demands the labor market. / A Educação Tecnológica, nos últimos anos, principalmente após a instituição do REUNI, da reestruturação dos antigos Centros Federais de Educação Tecnológica (CEFET‟s) e da implantação dos Institutos Federais de Educação, Ciência e Tecnologia (IFET‟s), teve um significativo aumento em seu quantitativo de cursos e de vagas ofertadas. No entanto, muitas questões que permeiam o processo formativo dos futuros tecnólogos necessitam ser problematizadas. Assim, este trabalho, a partir do estudo de caso do Curso Superior de Tecnologia em Gestão Ambiental (CSTGA) da UFSM, tem como objetivos: verificar se, no cotidiano do CSTGA, ocorre o diálogo entre a formação tecnocientífica e a humanística; analisar, à luz do referencial teórico balizador deste estudo Freire/CTS - os fatores envolvidos na articulação ou não articulação entre a formação tecnocientífica e a humanística, bem como discutir possíveis implicações ao processo formativo, a partir das constatações feitas durante este estudo. Como recurso metodológico utiliza-se a Análise Textual Discursiva, constituindo-se como corpus de análise o Projeto Pedagógico do Curso, o questionário aplicado aos discentes e a entrevista semiestruturada realizada com os docentes do curso. Deste corpus de análise emergem unidades de sentido que permitem chegar a categorias, a partir das quais problematiza-se a situação concreta do curso objeto deste estudo. Os resultados desta análise apontam na direção da não articulação entre a formação tecnocientífica e a humanística, com possíveis causas vinculadas à formação docente, ao engessamento do currículo e à presunção por parte da comunidade acadêmica de serem estes cursos pautados, quase que exclusivamente, pelas exigências do mercado de trabalho.

Since its emergence in the educational context, the blended learning insurgentas a modality with its own identity. According to its evolution, runs through presentiality configured contexts and virtuality. In a first stage, stood as a mixed or combined mode, and then advanced to integration, which resulted in the dilutionof its components. The progressive social changes, technological and cultural towards convergence, today brings a new north-mode, given the confluence of pedagogical and technological mediations in the training process. This position places him in a new trend that more than a possibility, actually represents a more explicable on the future of Blended Learning. / Desde su emergencia en el contexto educativo, el blended learning surge como una modalidad con identidad propia. Conforme a su evolución, discurre por contextos configurados por la presencialidad y virtualidad. En un primer estadio, se situó como una modalidad mixta o de combinación; posteriormente avanzó a una integración que supuso la dilución de sus componentes. La progresiva evolución social, tecnológica y cultural hacia la convergencia aporta, en la actualidad, un nuevo norte a la modalidad dada la confluencia de las mediaciones pedagógicas y tecnológicas en el proceso formativo. Este posicionamiento lo ubica dentro de una nueva tendencia, que más que una posibilidad, representa una realidad más explicable sobre el devenir del blended learning.

abstract: Today's energy market is facing large-scale changes that will affect all market players. Near the top of that list is the rapid deployment of residential solar photovoltaic (PV) systems. Yet that growing trend will be influenced multiple competing interests between various stakeholders, namely the utility, consumers and technology provides. This study provides a series of analyses--utility-side, consumer-side, and combined analyses--to understand and evaluate the effect of increases in residential solar PV market penetration. Three urban regions have been selected as study locations--Chicago, Phoenix, Seattle--with simulated load data and solar insolation data at each locality. Various time-of-use pricing schedules are investigated, and the effect of net metering is evaluated to determine the optimal capacity of solar PV and battery storage in a typical residential home. The net residential load profile is scaled to assess system-wide technical and economic figures of merit for the utility with an emphasis on intraday load profiles, ramp rates and electricity sales with increasing solar PV penetration. The combined analysis evaluates the least-cost solar PV system for the consumer and models the associated system-wide effects on the electric grid. Utility revenue was found to drop by 1.2% for every percent PV penetration increase, net metering on a monthly or annual basis improved the cost-effectiveness of solar PV but not battery storage, the removal of net metering policy and usage of an improved the cost-effectiveness of battery storage and increases in solar PV penetration reduced the system load factor. As expected, Phoenix had the most favorable economic scenario for residential solar PV, primarily due to high solar insolation. The study location--solar insolation and load profile--was also found to affect the time of year at which the largest net negative system load was realized. / Dissertation/Thesis / Masters Thesis Engineering 2014

This thesis investigates the feasibility and benefits of integrating Thermochemical heat Storage (THS) into a CHP (Combined Heat and Power) plant. A case study is done for the CHP-plant in Sala, Sweden, with a maximum heat output of 20.9 MW and maximum electricity output of 9.6 MW. The THS type considered is calcium oxide in a hydroxide system. The fluctuations in electricity price for years 2020, 2030 and 2040 are considered and low-price electricity is used as a charging source for THS. During charging the superheated steam (endothermic reaction) is used to cover some of the district heating demand. The high temperature discharge from the THS is used as reheat in the Rankine cycle. The operations are modeled in Ebsilon and optimization is done in MATLAB using genetic algorithm with the objective to achieve maximum annual revenue. The results suggest that it is not feasible to introduce THS with electricity as a charging source in year 2020, but in 2030 and 2040 THS shows promising potential. The biggest increase in revenue comes from reduced fuel consumption, and, to a lesser extent, increased income from electricity. It is concluded that Calcium hydroxide is a promising candidate for integration into CHP during large electricity price fluctuation. The main drivers for the feasibility of this combination are high fuel price and large fluctuations of electricity price.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-10-21T19:15:34Z No. of bitstreams: 2 Dissertação - Onofre Pereira Aurélio Neto - 2014.pdf: 20265690 bytes, checksum: 3d480102b449a96bb51f1ba368cad7a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-10-21T19:15:45Z (GMT) No. of bitstreams: 2 Dissertação - Onofre Pereira Aurélio Neto - 2014.pdf: 20265690 bytes, checksum: 3d480102b449a96bb51f1ba368cad7a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-21T19:15:45Z (GMT). No. of bitstreams: 2 Dissertação - Onofre Pereira Aurélio Neto - 2014.pdf: 20265690 bytes, checksum: 3d480102b449a96bb51f1ba368cad7a1 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-03-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Goiás is example of the process of modernization in rural space occurred in the 20th century, especially between the 1960s to 1990s. The techniques innovations of the livestock and agricultural sector (mechanics, biological, physical-chemistries and in the practices of production), continue happening; now specifically to attend a market each time more global, where the meat packing industry has traced new space strategies of operation. The cattle livestock is a emblematic case of these questions, both for its productive restructuring as geographical, although of the little attention that has been received recently by the Geographers. The paper analyses the evolution of the pastoralism activity in the state of Goiás, between 1920 and 2012, in its binomial raising-slaughtering, in other words, approaches the cattle production in the rural space and the meat processing industry. In this time frame, we identified three techno-spatial phases: the traditional cattle production, the cattle industrialization, and the internationalization of the agribusiness of the cattle meat, which shows characteristics specific techniques and spatial. Other question to be discussed is that the technicisation of the countryside changed the geographical space, intensifying the use of the land and increasing the productivity, with social, economic and environmental implications, related to the techniques innovations, and the insertion of artificial objects. Due to the recent process of internationalization, the research ends the current context of projection of the agribusiness of Goiás in the international space, focusing the in the acting of the biggest multinational cattle meat industry – JBS S.A. (Friboi), in its spatial trajectory. / Goiás é exemplo do processo de modernização do campo ocorrido no século XX, sobretudo, entre as décadas de 1960 a 1990. As inovações técnicas do setor agropecuário (mecânicas, biológicas, físico-químicas e nas práticas de produção), continuam acontecendo; agora voltadas para atender um mercado cada vez mais global, em que as agroindústrias têm traçado novas estratégias espaciais de atuação. A pecuária bovina é um caso emblemático dessas questões, tanto por sua reestruturação produtiva quanto geográfica, apesar da pouca atenção recebida ultimamente por parte dos geógrafos. O trabalho analisa a evolução da atividade pastoril no estado de Goiás, entre 1920 e 2012, em seu binômio criação-abate, em outras palavras, aborda a produção bovina no espaço rural e a indústria de processamento da carne. Nesse recorte temporal, identificamos três fases tecnoespaciais: a bovinocultura tradicional, a industrialização da pecuária e a internacionalização do agronegócio da carne bovina, as quais apresentam características técnicas e espaciais específicas. Outra questão a ser discutida é que a tecnicização do campo alterou o espaço geográfico, intensificando o uso da terra e aumentando a produtividade, com implicações socioeconômicas e ambientais, relacionadas às inovações técnicas, a inserção dos objetos artificiais. Devido ao recente processo de internacionalização, a pesquisa finaliza no atual contexto de projeção do agronegócio goiano no espaço internacional, com enfoque na atuação da maior multinacional de carne bovina, JBS S. A. (Friboi), em sua trajetória espacial.