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Tecnologia de geração de energia limpa a serviço da promoção da saúde / Technology of clean energy to health promotionLuiz Felipe de Camargo Kastrup 24 February 2006 (has links)
A falta de acesso à energia elétrica e a todos os benefícios que ela pode trazer levou à elaboração desta pesquisa, tendo como foco principal o atendimento às necessidades básicas de saúde. Para a presente pesquisa estudou-se: o acesso à saúde no Brasil; a seleção de um município como piloto, em um estado brasileiro com baixo IDH (índice de Desenvolvimento Humano), precário atendimento básico à saúde e sem eletrificação rural; oss sistemas de geração de energia elétrica no Brasil, com destaque para os sistemas de geração distribuída; as tecnologias disponíveis no Brasil, para geração de energia elétrica distribuída e limpa; a definição de uma UBS (Unidade Básica de Saúde), quanto a compartimentos, equipamentos, consumo energético, baixa manutenção e facilidade na construção. Foi dimensionada uma Unidade Básica de Saúde, que atendesse a este município, resultando em um projeto de UBS e de um sistema de geração de energia para atender às suas demandas. Desenvolveu-se então um sistema de geração de energia elétrica distribuída e limpa, para a UBS, através da integração de painéis fotovoltaicos com célula a combustível que utiliza hidrogênio, e para a produção do hidrogênio, um eletrolisador para a eletrólise da água. O sistema proposto permite o funcionamento continuo desta UBS, com baixa manutenção, de forma sustentável, em qualquer região isolada, necessitando apenas da incidência da luz solar e de água, permitindo promover a saúde das populações carentes, residentes nos locais mais longínquos, fixando-as em seus locais de origem, sem causar impactos ambientais. / The lack of access to electric energy and all the benefits that it can bring led to the elaboration of this research, having as main focus the attendance to the basic necessities of health. For the present research it was studied: the access to health in Brazil; the election of a city as pilot, in a Brazilian state with low IDH (index of Human Development), precarious basic health attendance and without agricultural electrification; the electric energy generation systems in Brazil, with prominence for the distributed systems generation; the available technologies in Brazil, for distributed electric and clean energy generation; the definition of a BHU (Basic Health Unit), about compartments, equipment, energy consumption, low maintenance and easy construction. The BHU's size was calculated, for this city, resulting in a project of BHU and a generation energy system for its demands. A distributed electric and clean energy generation system was developed, for the BHU, through the integration of photovoltaic panels with fuel cells that use hydrogen, and for the hydrogen production, an electrolyser for electrolysis of water. The considered system allows the continuous functioning of this BHU, with low maintenance, in sustainable form, in any isolated region, needing only the solar light incidence and water, allowing to promote the health of the poor populations living 9in places most distant, fixing them in their places of origin, without environmental impacts.
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Tecnologia de geração de energia limpa a serviço da promoção da saúde / Technology of clean energy to health promotionKastrup, Luiz Felipe de Camargo 24 February 2006 (has links)
A falta de acesso à energia elétrica e a todos os benefícios que ela pode trazer levou à elaboração desta pesquisa, tendo como foco principal o atendimento às necessidades básicas de saúde. Para a presente pesquisa estudou-se: o acesso à saúde no Brasil; a seleção de um município como piloto, em um estado brasileiro com baixo IDH (índice de Desenvolvimento Humano), precário atendimento básico à saúde e sem eletrificação rural; oss sistemas de geração de energia elétrica no Brasil, com destaque para os sistemas de geração distribuída; as tecnologias disponíveis no Brasil, para geração de energia elétrica distribuída e limpa; a definição de uma UBS (Unidade Básica de Saúde), quanto a compartimentos, equipamentos, consumo energético, baixa manutenção e facilidade na construção. Foi dimensionada uma Unidade Básica de Saúde, que atendesse a este município, resultando em um projeto de UBS e de um sistema de geração de energia para atender às suas demandas. Desenvolveu-se então um sistema de geração de energia elétrica distribuída e limpa, para a UBS, através da integração de painéis fotovoltaicos com célula a combustível que utiliza hidrogênio, e para a produção do hidrogênio, um eletrolisador para a eletrólise da água. O sistema proposto permite o funcionamento continuo desta UBS, com baixa manutenção, de forma sustentável, em qualquer região isolada, necessitando apenas da incidência da luz solar e de água, permitindo promover a saúde das populações carentes, residentes nos locais mais longínquos, fixando-as em seus locais de origem, sem causar impactos ambientais. / The lack of access to electric energy and all the benefits that it can bring led to the elaboration of this research, having as main focus the attendance to the basic necessities of health. For the present research it was studied: the access to health in Brazil; the election of a city as pilot, in a Brazilian state with low IDH (index of Human Development), precarious basic health attendance and without agricultural electrification; the electric energy generation systems in Brazil, with prominence for the distributed systems generation; the available technologies in Brazil, for distributed electric and clean energy generation; the definition of a BHU (Basic Health Unit), about compartments, equipment, energy consumption, low maintenance and easy construction. The BHU's size was calculated, for this city, resulting in a project of BHU and a generation energy system for its demands. A distributed electric and clean energy generation system was developed, for the BHU, through the integration of photovoltaic panels with fuel cells that use hydrogen, and for the hydrogen production, an electrolyser for electrolysis of water. The considered system allows the continuous functioning of this BHU, with low maintenance, in sustainable form, in any isolated region, needing only the solar light incidence and water, allowing to promote the health of the poor populations living 9in places most distant, fixing them in their places of origin, without environmental impacts.
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Síntese e caracterização de cerâmicas do tipo BZYO e BCGO para uso em células a combustíveis / Synthesis and characterization of ceramics of BZYO and BCGO for use in full cellsBorges, Kellen Cristina Mesquita 11 April 2014 (has links)
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Previous issue date: 2014-04-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The study of the synthesis of materials which have proton conductivity
contributes to the production of solid electrolytes protonic conductors, used extensively
in the operation of fuel cells. Materials doped barium zirconate yttrium (BZYO) and
barium cerate doped with gadolinium (BCGO), were synthesized by the polymeric
precursor method, which stands as an effective technique. The synthesized powders
were characterized by thermal analysis (TG-DTA), X-ray Diffraction (XRD), Scanning
Electron Microscopy (SEM / FEG) and Zeta Potential. The sinterability of the powders
was observed by dilatometric analysis, followed by XRD, SEM / FEG and density
apparent. From the results obtained it was possible to verify the formation of BZYO
phase at a temperature of 900 °C/ 2h. A higher dopant concentration (20% Y) promoted
the formation of the phase in a temperature 800 °C/ 2h, and the formation of the phase
BCGO at 950 °C/ 2h. The crystallite size calculated by Scherrer's equation, ranged from
20,8 to 15,2 nm and 38,2 to 30,5 nm for BZYO and BCGO respectively. This results
depends on the amount of dopant and its capacity to form solid solution. The
micrographs (SEM/FEG) confirmed the nanometric nature of the material with a
spherical morphology. The zeta potential was -23,6 mV and -22,8 mV for BZYO and
BCGO, respectively, which demonstrates a good stability in the formation of colloidal
dispersions for thin film formation which are of interest for fuel cells. The pads BCGO
showed a satisfactory densification (95,1%) at 1550 °C/ 4h, a result that shows its
applicability as proton conductive solid electrolyte. For tablets BZYO the densification
was lower than BCGO with a result of bulk density of 73,8% at 1600 °C/ 4h. This result
shows the need for heat treatment at higher temperatures to obtain a higher densification
of the pellets. / O estudo da síntese de materiais que apresentam condutividade protônica
contribui para a produção de eletrólitos sólidos condutores protônicos, bastante
utilizados no funcionamento das células a combustíveis. Os materiais de zirconato de
bário dopado com ítrio (BZYO) e cerato de bário dopado com gadolínio (BCGO),
foram sintetizados pelo método precursor polimérico, que se destaca como uma técnica
eficaz. Os pós sintetizados foram caracterizados por Análise Térmica (TG-DTA),
Difração de raios-X (DRX), Microscopia Eletrônica de Varredura (MEV/FEG) e
Potencial Zeta. A sinterabilidade dos pós foi verificada por análise dilatométrica,
seguida das análises de DRX, MEV/FEG e densidade aparente. Através dos resultados
obtidos foi possível verificar a formação da fase de BZYO em uma temperatura de 900
ºC/ 2h. Uma maior concentração de dopante (20% Y) promoveu a formação da fase em
uma temperatura inferior, 800 ºC/2h, e a formação da fase de BCGO em 950 ºC/2h. O
tamanho médio de cristalito, calculado pela equação de Scherrer, variou de 20,8 a 15,2
nm e 38,2 a 30,5 nm para o BZYO e BCGO, respectivamente. Esse resultado
dependente da quantidade de dopante e da sua capacidade de formar solução sólida. As
micrografias de MEV/FEG confirmaram a natureza nanométrica do material com
morfologia do tipo esférica. O potencial zeta foi de -23,6 mV e -22,8 mV para o BZYO
e BCGO, respectivamente, o que demostra uma boa estabilidade na formação de
dispersões coloidais para formação de filmes finos, que são de interesse para células a
combustíveis. As pastilhas de BCGO apresentaram uma satisfatória densificação
(95,1%) a 1550 ºC/4 h, resultado este que apresenta sua aplicabilidade como eletrólito
sólido condutor protônico. Para as pastilhas do BZYO a densificação foi inferior ao
BCGO, com resultado de densidade aparente de 73,8% a 1600 ºC/ 4h. Este resultado
mostra a necessidade de um tratamento térmico em temperaturas superiores para
obtenção de uma maior densificação das pastilhas.
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High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling StabilityKrause, Andreas, Dörfler, Susanne, Piwko, Markus, Wisser, Florian M., Jaumann, Tony, Ahrens, Eike, Giebeler, Lars, Althues, Holger, Schädlich, Stefan, Grothe, Julia, Jeffery, Andrea, Grube, Matthias, Brückner, Jan, Martin, Jan, Eckert, Jürgen, Kaskel, Stefan, Mikolajick, Thomas, Weber, Walter M. 25 January 2017 (has links) (PDF)
We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.
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Contribution à la valorisation electrique des piles à combustible microbiennes / Contribution to electrical valorization of microbial fuel cellsKhaled, Firas 21 January 2016 (has links)
Les Piles à Combustible Microbiennes (PCMs) produisent de l’électricité à partir de la dégradation de matières organiques par des bactéries. Les PCMs sont considérées comme des micro- génératrices à faible tension et faible puissance. Dans le but de récupérer l’énergie électrique produite afin de pouvoir alimenter des capteurs autonomes, des architectures mettant en œuvre plusieurs piles seront préférées. L'association d'un grand nombre de PCMs individuelles offre des perspectives très intéressantes notamment au niveau de la production d'énergie électrique. Cela permet d’atteindre des niveaux de tension acceptables en sortie et permet de mutualiser les puissances électriques de chaque cellule. L’association série d’un grand nombre de PCMs est un défi en soi à cause des couplages hydrauliques (lorsque les PCMs partagent le même substrat) et à cause des non-uniformités entre générateurs qui mènent à une association non-efficace. Les circuits d'équilibrage de tension peuvent être une solution pour compenser ces inhomogénéités. Ils peuvent améliorer l’efficacité de l’association et prévenir le phénomène d'inversion de tension. L’association hydraulique des biopiles permet d’éviter la chute de puissance liée au manque de carburant. Une fuite de charge entre les PCMs va diminuer le rendement global de l’association. Le débit du flux doit être contrôlé pour éliminer ce problème. Un flux de la cathode vers l’anode provoque des pertes supplémentaires dues à la fuite d’oxygène. La récupération d’énergie à partir de PCMs nécessite une unité de gestion d’énergie qui adapte la tension et contrôle le fonctionnement de la PCM. Un convertisseur flyback à faible tension d’entrée, autonome et auto-démarrant a été conçu et optimisé pour la récupération d’énergie à partir des PCMs. La récupération d’énergie à partir des PCMs peut être présentée comme une source alternative pour éliminer les batteries dans les applications de faible puissance (capteur autonome). / Microbial Fuel Cells (MFCs) are bioreactors that convert chemical energy in organic compounds to electrical energy through the metabolism of microorganisms. Organic matters are widely available in the environment that contains a huge amount of energy. This energy could be harvested, converted, by the technology of MFCs, to be used in certain applications. Energy production of a MFC is limited in low voltage value and low-power values what limits the potential applications. To step-up the voltage of MFCs to be suitable for real applications, an efficient power management unit (PMU) is required with a specific design to deal with their characteristics. A flyback converter under discontinuous conduction mode (DCM) is the most adapted to such low-power source like MFCs, offers a simple implementation, and low losses conversion system. The flyback converter has a good efficiency that can reach 75% with one MFC and about 80% when it is supplied by a serial stack of MFCs. Associations of MFCs are very interesting to increase the output power and expand the domain of application. Parallel association is a method to increase the output current but it imposes limitations in conversion efficiency due to the low output voltage of the stack. Contrarily, the serial association steps-up the voltage what leads to better performance of the converter. However the non-uniformities between cells in a serial stack affect negatively the performance of the stack. Voltage balancing circuits are considered as the solution to compensate this phenomenon. In the switched-capacitor method, an external capacitor is used to transfer the energy from the strongest MFC(s) to the weakest one(s). The losses in the switched-capacitor circuit are less than the losses of the switched-MFCs. The switched-capacitor offers an efficient, simple, low consumption method to optimize the performance and prevent the voltage reversal of the weak cells. Integration of this circuit can optimize the efficiency. Continuous operation mode by hydraulically connection between MFCs can continuously refresh the substrate to give an autonomous energy harvesting system. On the other hand, in some applications, e.g. a wastewater treatment plant, MFCs could not be hydraulically isolated. In this configuration, a leakage charge between the associated MFCs will decrease the global efficiency. The flow rate has to be controlled to eliminate this problem. A flow from cathodes to anodes causes additional losses due to the oxygen leakage. A temperature sensor is continuously supplied by alternatively connecting two MFCs. Each MFC supplies the sensor for two days. The flyback converter is able to continuously supply the sensor from the energy harvested from one continuously-fed MFC. This could be a good example, in a wastewater treatment plant (WWTP), to supply monitoring systems or also to supply low power applications of a building from a local WWTP.
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High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling StabilityKrause, Andreas, Dörfler, Susanne, Piwko, Markus, Wisser, Florian M., Jaumann, Tony, Ahrens, Eike, Giebeler, Lars, Althues, Holger, Schädlich, Stefan, Grothe, Julia, Jeffery, Andrea, Grube, Matthias, Brückner, Jan, Martin, Jan, Eckert, Jürgen, Kaskel, Stefan, Mikolajick, Thomas, Weber, Walter M. 25 January 2017 (has links)
We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.
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