The goal of this research project was to characterize the physical and electrochemical properties of a commercially available fuel cell-based breath alcohol sensor. Characteristics of the existing sensor were compared with state of the art power generating fuel cells with the goal of understanding the factors that limit performance, lifetime and cost effectiveness of the sensors. This will guide the development of the next generation of breath alcohol sensors. The average lifetime of the current sensor falls short of the industry standards. In particular, sensors operating in dry conditions experience more rapid loss of sensitivity and failure. Two primary causes of degradation were investigated in this study. Loss of proton conductivity as a result of membrane dehydration was shown to be reversible by rehydrating the membrane in humid conditions. Loss of electrochemically active surface area of Pt is irreversible and seems to be caused by a change in sensor morphology after long-term exposure to dry conditions. / UOIT

In the Third World, the Oil Crisis has emphasized the vulnerability of certain large oil-importing countries, engaged in an extensive process of industrialization. The author asks whether Brazil's response to this new challenge will emerge from a tradition of direct State involvement in Energy (exemplified by PETROBRAS), or an original strategy based on the private sector. Both the personal commitment of General Geisel to enhance the national bourgeoisie, and the general context of the mid-Seventies, favour the latter. As the locally-owned sugar-producing oligopoly promotes an alcohol program to replace gasoline, the State is seeking a loose formula--an Alliance of the agro-energetic sector with the multinational automobile industry and PETROBRAS. Its success would be based on the performance of each actor. / Given a tradition of susceptibility of the Brazilian State to internal lobbying, and the choice in favour of indirect involvement in the program, it is not surprising that controls remained largely ineffective. Further structural limitations--an archaic agriculture resulting in low productivity of land, a lack of private funding, and technological deficiencies (caused by inadequate R & D activities)--induced the failure of the program in its original conception. However, the national bourgeoisie's fear of foreign control lead the military to veto the possible alternative of further internationalization of the alcohol sector. It remains to be seen, in the light of the weakening position of Brazil in the world economy, if such a stance can be maintained in the long term.

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 74-78).

Made available in DSpace on 2014-06-11T19:23:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-28Bitstream added on 2014-06-13T20:11:07Z : No. of bitstreams: 1 carvalho_fs_me_mar_parcial.pdf: 102655 bytes, checksum: 04d4cdc53f389adaeabd311bd7240a0e (MD5) Bitstreams deleted on 2015-06-25T13:00:50Z: carvalho_fs_me_mar_parcial.pdf,. Added 1 bitstream(s) on 2015-06-25T13:03:15Z : No. of bitstreams: 1 000696604_20160309.pdf: 102478 bytes, checksum: 789a7cb5df1bb73151547778ca2694b2 (MD5) Bitstreams deleted on 2016-03-11T14:06:56Z: 000696604_20160309.pdf,. Added 1 bitstream(s) on 2016-03-11T14:07:36Z : No. of bitstreams: 1 000696604.pdf: 4720084 bytes, checksum: 5f4455d9feedeb1c1c5152395e291d3d (MD5) / Na teoria social, uma maneira de entender a relação que envolve grupos particulares e o Estado, quando a ação pública é voltada para o interesse privado, recebe o nome de hegemonia, um conceito desenvolvido pelo italiano Antonio Gramsci. Segundo Gramsci, é possível compreender o Estado como uma arena onde muitos grupos ou classes sociais tentam obter poder e atenção aos seus interesses. Em uma situação de hegemonia, um grupo ou grupos está tão entrelaçado com o governo que os seus interesses particulares são defendidos como se fossem parte do interesse público ou geral da nação. Esta é a grande vantagem para o grupo que alcança a hegemonia. Se a hegemonia é a estratégia, uma das táticas para obtê-la é o lobby. Lobby descreve as ações capazes de influenciar as áreas públicas de uma forma legal e moral, diferente de corrupção. A hegemonia, com as ferramentas do lobby, torna o Estado um soldado para proteger os grupos de uma forma ampla, pois as ameaças podem estar na própria sociedade ou advindos da área internacional. Olhando para o exterior, as relações internacionais e seus impactos domésticos, Robert Putnam, com sua Teoria dos Jogos de Dois Níveis, mostra uma maneira de compreender como o Estado, frente às oportunidades e riscos na área internacional para seus grupos nacionais, atua em negociações internacionais, tendo que lidar com as possibilidades de ratificação ou deserção de um acordo, dependendo de seu win set doméstico. Todas estas amplas questões teóricas são necessárias para compreender um aspecto do Brasil. Durante quase 500 anos de história nacional, um grupo tem sido parte da estrutura econômica, política e social do país. As atividades relacionadas... / In social theory, one way to understand the relationship involving particular groups and the State, when the public action is directed to private interest, gets the name of hegemony, a concept developed by the Italian Antonio Gramsci. According to Gramsci it’s possible to understand the State as an arena where many groups or social classes try to get power and attention to its interests. In a situation of hegemony a group or groups are so interlaced with the government that its particular interests are defended as if they were part of public or general interest of the nation. This is a great advantage to the group that gets the hegemony. If the hegemony is the strategy, one of the tactics to get it is the lobby. Lobby describes the actions able to influence the public areas in a legal and moral way, different from corruption. The hegemony, with the tools of lobby, makes the State a soldier to protect the groups in a large way, because the threats can stay between the society and came from the international area. Looking to abroad, the international relations and the national impacts of them, Robert Putnam with his “Two Level Game Theory”, shows a way to understand how the State, facing opportunities or risks to its national groups in international area, acts in international negotiations, dealing with the possibilities of ratification or defection of an agreement, according with its national win set. All this wide theoretical questions are necessary to realize an aspect of Brazil. During almost the 500 years of Brazilian history a group has been part of the economic, politic and social feature of the country. The sugar cane activity has been with Brazil since it was officially discovered by Portuguese. The group around this... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:32:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-31Bitstream added on 2014-06-13T19:42:39Z : No. of bitstreams: 1 antonangelo_atbf_dr_botib.pdf: 1383699 bytes, checksum: 62761d8607d84c569f6220176bc59b97 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Brasil é atualmente o maior produtor mundial de álcool de cana de açúcar, sendo responsável por uma produção anual de aproximadamente 27 bilhões de litros. O álcool é produzido através da fermentação do caldo de cana-de-açúcar e/ou melaço por células de levedura da espécie Saccharomyces cerevisiae. Embora, atualmente, muitas indústrias utilizem cepas selecionadas de S. cerevisiae como iniciadoras, a condição não estéril dos substratos torna este processo sujeito a constantes contaminações por bactérias e linhagens de leveduras nativas de Saccharomyces cerevisiae e não-Saccharomyces cerevisiae. Estas leveduras nativas dominam rapidamente a população iniciadora do processo por serem cepas genética e fisiologicamente adaptadas às condições daquele ambiente. Tais leveduras podem prejudicar o processo fermentativo, porém, algumas entre elas, podem apresentar características positivas. Atualmente no Brasil várias indústrias acompanham a dinâmica populacional da fermentação por cariotipagem. No entanto este método é dispendioso, demorado e pouco acurado quando se compara a outros métodos moleculares mais sensíveis. Este trabalho se propõe a utilizar a técnica de PCR microssatélite para diferenciar linhagens de leveduras presentes no processo de fermentação em usinas de álcool, acompanhar a dinâmica populacional de uma usina durante uma safra e estudar a diversidade genética e a estrutura populacional das cepas nativas presentes no processo industrial de produção do álcool combustível. O trabalho também visa investigar a presença de single nucleotide polymorphism (SNP) ou mutações de base única nas cepas nativas de Saccharomyces cerevisiae isoladas deste processo e relacioná-los à capacidade de floculação e à tolerância ao ambiente industrial estressante. Durante o trabalho... / Brazil is the major world producer of ethanol from sugar cane, producing about 27 billion liters of ethanol a year. Alcohol is the result of sugar cane juice/ molasses fermentation by Saccharomyces cerevisiae yeast cells. Although many sugar mills in Brazil currently start the fermentation process by inoculating selected Saccharomyces cerevisiae commercial strains, it often occurs the incoming of bacteria, native Saccharomyces and non-Saccharomyces yeast strains because of its unsterile condition. In this process these indigenous strains outnumber the population inoculated and those which are genetically and physiologically better adapted tend to dominate. These strains may either show desirable fermentative qualities or not. The method currently used in Brazil to investigate sugar cane must population is electrophoresis karyotyping, however this method is expensive, time consuming and not very accurate when compared with other more sensitive molecular methods. This work aimed at using microsatellite PCR method for differentiating yeasts strains from alcohol plants fermentation process, monitoring population dynamic of a bioethanol fuel plant during a harvest season and studying the genetic diversity and population structure of native strains from bioethanol production industrial process. This work also aimed at investigating SNPs occurrence among Saccharomyces cerevisiae native strains that could be related with flocculation and stressful industrial environment tolerance. Twenty- four microsatellite loci were tested and 12 of them were polymorphic and capable of differentiating the commercial selected strains BG-1, CAT-1, PE-2 e SA-1 from each other and also capable of screening indigenous strains from the inoculated ones. Four loci were used for monitoring Usina São Manoel harvest season during 2008 where were observed... (Complete abstract click electronic access below)

Orientador: Marcelo Fernandes de Oliveira / Banca: José Marangoni Camargo / Banca: Pedro Ramos / Resumo: Na teoria social, uma maneira de entender a relação que envolve grupos particulares e o Estado, quando a ação pública é voltada para o interesse privado, recebe o nome de hegemonia, um conceito desenvolvido pelo italiano Antonio Gramsci. Segundo Gramsci, é possível compreender o Estado como uma arena onde muitos grupos ou classes sociais tentam obter poder e atenção aos seus interesses. Em uma situação de hegemonia, um grupo ou grupos está tão entrelaçado com o governo que os seus interesses particulares são defendidos como se fossem parte do interesse público ou geral da nação. Esta é a grande vantagem para o grupo que alcança a hegemonia. Se a hegemonia é a estratégia, uma das táticas para obtê-la é o lobby. Lobby descreve as ações capazes de influenciar as áreas públicas de uma forma legal e moral, diferente de corrupção. A hegemonia, com as ferramentas do lobby, torna o Estado um soldado para proteger os grupos de uma forma ampla, pois as ameaças podem estar na própria sociedade ou advindos da área internacional. Olhando para o exterior, as relações internacionais e seus impactos domésticos, Robert Putnam, com sua "Teoria dos Jogos de Dois Níveis", mostra uma maneira de compreender como o Estado, frente às oportunidades e riscos na área internacional para seus grupos nacionais, atua em negociações internacionais, tendo que lidar com as possibilidades de ratificação ou deserção de um acordo, dependendo de seu win set doméstico. Todas estas amplas questões teóricas são necessárias para compreender um aspecto do Brasil. Durante quase 500 anos de história nacional, um grupo tem sido parte da estrutura econômica, política e social do país. As atividades relacionadas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In social theory, one way to understand the relationship involving particular groups and the State, when the public action is directed to private interest, gets the name of hegemony, a concept developed by the Italian Antonio Gramsci. According to Gramsci it's possible to understand the State as an arena where many groups or social classes try to get power and attention to its interests. In a situation of hegemony a group or groups are so interlaced with the government that its particular interests are defended as if they were part of public or general interest of the nation. This is a great advantage to the group that gets the hegemony. If the hegemony is the strategy, one of the tactics to get it is the lobby. Lobby describes the actions able to influence the public areas in a legal and moral way, different from corruption. The hegemony, with the tools of lobby, makes the State a soldier to protect the groups in a large way, because the threats can stay between the society and came from the international area. Looking to abroad, the international relations and the national impacts of them, Robert Putnam with his "Two Level Game Theory", shows a way to understand how the State, facing opportunities or risks to its national groups in international area, acts in international negotiations, dealing with the possibilities of ratification or defection of an agreement, according with its national win set. All this wide theoretical questions are necessary to realize an aspect of Brazil. During almost the 500 years of Brazilian history a group has been part of the economic, politic and social feature of the country. The sugar cane activity has been with Brazil since it was officially discovered by Portuguese. The group around this... (Complete abstract click electronic access below) / Mestre

Orientador: Débora Colombi / Coorientador: Paulo Eduardo Martins Ribolla / Banca: Maria da Graça Stupiello Andrieta / Banca: Sandra Regina Ceccato Antonini / Banca: Celso Marino / Banca: Eduardo Bagagli / Resumo: O Brasil é atualmente o maior produtor mundial de álcool de cana de açúcar, sendo responsável por uma produção anual de aproximadamente 27 bilhões de litros. O álcool é produzido através da fermentação do caldo de cana-de-açúcar e/ou melaço por células de levedura da espécie Saccharomyces cerevisiae. Embora, atualmente, muitas indústrias utilizem cepas selecionadas de S. cerevisiae como iniciadoras, a condição não estéril dos substratos torna este processo sujeito a constantes contaminações por bactérias e linhagens de leveduras nativas de Saccharomyces cerevisiae e não-Saccharomyces cerevisiae. Estas leveduras nativas dominam rapidamente a população iniciadora do processo por serem cepas genética e fisiologicamente adaptadas às condições daquele ambiente. Tais leveduras podem prejudicar o processo fermentativo, porém, algumas entre elas, podem apresentar características positivas. Atualmente no Brasil várias indústrias acompanham a dinâmica populacional da fermentação por cariotipagem. No entanto este método é dispendioso, demorado e pouco acurado quando se compara a outros métodos moleculares mais sensíveis. Este trabalho se propõe a utilizar a técnica de PCR microssatélite para diferenciar linhagens de leveduras presentes no processo de fermentação em usinas de álcool, acompanhar a dinâmica populacional de uma usina durante uma safra e estudar a diversidade genética e a estrutura populacional das cepas nativas presentes no processo industrial de produção do álcool combustível. O trabalho também visa investigar a presença de single nucleotide polymorphism (SNP) ou mutações de base única nas cepas nativas de Saccharomyces cerevisiae isoladas deste processo e relacioná-los à capacidade de floculação e à tolerância ao ambiente industrial estressante. Durante o trabalho... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is the major world producer of ethanol from sugar cane, producing about 27 billion liters of ethanol a year. Alcohol is the result of sugar cane juice/ molasses fermentation by Saccharomyces cerevisiae yeast cells. Although many sugar mills in Brazil currently start the fermentation process by inoculating selected Saccharomyces cerevisiae commercial strains, it often occurs the incoming of bacteria, native Saccharomyces and non-Saccharomyces yeast strains because of its unsterile condition. In this process these indigenous strains outnumber the population inoculated and those which are genetically and physiologically better adapted tend to dominate. These strains may either show desirable fermentative qualities or not. The method currently used in Brazil to investigate sugar cane must population is electrophoresis karyotyping, however this method is expensive, time consuming and not very accurate when compared with other more sensitive molecular methods. This work aimed at using microsatellite PCR method for differentiating yeasts strains from alcohol plants fermentation process, monitoring population dynamic of a bioethanol fuel plant during a harvest season and studying the genetic diversity and population structure of native strains from bioethanol production industrial process. This work also aimed at investigating SNPs occurrence among Saccharomyces cerevisiae native strains that could be related with flocculation and stressful industrial environment tolerance. Twenty- four microsatellite loci were tested and 12 of them were polymorphic and capable of differentiating the commercial selected strains BG-1, CAT-1, PE-2 e SA-1 from each other and also capable of screening indigenous strains from the inoculated ones. Four loci were used for monitoring Usina São Manoel harvest season during 2008 where were observed... (Complete abstract click electronic access below) / Doutor

>Magister Scientiae - MSc / Palladium can be used as an anodic catalyst for the alkaline direct alcohol fuel cells (ADAFCs). Palladium has displayed high tolerance towards carbon monoxide (CO) poisoning and high catalytic activity for alcohol oxidation reaction in alkaline medium. Palladium-based catalysts have arisen as an alternative to performing alcohol oxidation reaction, especially when combined with other transition metals and multi walled carbon nanotubes (MWCNT) as a support, which induces changes in the palladium electronic structure, and thus, increasing its activity. This research is focused on the development of palladium catalysts incorporated with nickel and tin (transitional metals) on multi walled carbon nanotubes for alkaline direct glycerol fuel cells.

No description available.

Polymer electrolyte membrane fuel cells (PEMFCs) have recently acquired much attention as alternatives to combustion engines for power conversion. The primary interest in fuel cell technology is the possibility of 60% power conversion efficiency as compared to the 30% maximum theoretical efficiency limited to combustion engines and turbines. Although originally conceived to work with hydrogen as a fuel, difficulties relating to hydrogen storage have prompted much effort in using other fuels. Small organic molecules such as alcohols and formic acid have shown promise as alternatives to hydrogen in PEMFCs due to their higher stability at ambient conditions. The drawbacks for using these fuels in PEMFCs are related to their incomplete oxidation mechanisms, which lead to the production of carbon monoxide (CO). When carbon monoxide is released in fuel cells it binds strongly to the platinum anode thus limiting the adsorption and subsequent oxidation of more fuel. In order to promote the complete oxidation of fuels and limit poisoning due to CO, various metal and metal oxide catalysts have been used. Motivated by promising results seen in fuel cell catalysis, this research project is focused on the design and fabrication of novel platinum-composite catalysts for the electrooxidation of methanol, ethanol and formic acid. Various Pt-composites were fabricated including Pt-Au, PtRu, Pt-Pd and Pt-CeO2 catalysts. Electrochemical techniques were used to determine the catalytic ability of each novel composite toward the electrooxidation of methanol, ethanol and formic acid. This study indicates that the novel composites all have higher catalytic ability than bare Pt electrodes. The increase in catalytic ability is mostly attributed to the increase in CO poison tolerance and promotion of the complete oxidation mechanism of methanol, ethanol and iv formic acid. Formulations including bi- and tri-composite catalysts were fabricated and in many cases show the highest catalytic oxidation, suggesting tertiary catalytic effects. The combination of bi-metallic composites with ceria also showed highly increased catalytic oxidation ability. The following dissertation expounds on the relationship between composite material and the electrooxidation of methanol, ethanol and formic acid. The full electrochemical and material characterization of each composite electrode is provided.