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Development of nanostructured bioanodes containing dendrimers and dehydrogenases enzymes for application in ethanol biofuel cells

AQUINO NETO, S.; FORTI, J. C.; ZUCOLOTTO, V.; CIANCAGLINI, P.; ANDRADE, A. R. de
Fonte: ELSEVIER ADVANCED TECHNOLOGY Publicador: ELSEVIER ADVANCED TECHNOLOGY
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.93%
This paper describes the use of the electrostatic layer-by-layer (LbL) technique for the preparation of bioanodes with potential application in ethanol/O(2) biofuel cells. More specifically, the LbL technique was employed for immobilization of dehydrogenase enzymes and polyamidoamine (PAMAM) dendrimers onto carbon paper support. Both mono (anchoring only the enzyme alcohol dehydrogenase, ADH) and bienzymatic (anchoring both ADH and aldehyde dehydrogenase, AldDH) systems were tested. The amount of ADH deposited onto the Toray (R) paper was 95 ng cm(-2) per bilayer. Kinetic studies revealed that the LbL technique enables better control of enzyme disposition on the bioanode, as compared with the results obtained with the bioanodes prepared by the passive adsorption technique. The power density values achieved for the mono-enzymatic system as a function of the enzyme load ranged from 0.02 to 0.063 mW cm(-2) for the bioanode containing 36 ADH bilayers. The bioanodes containing a gas diffusion layer (GDL) displayed enhanced performance, but their mechanical stability must be improved. The bienzymatic system generated a power density of 0.12 mW cm(-2). In conclusion, the LbL technique is a very attractive approach for enzyme immobilization onto carbon platform...

Development of novel bioanodes for ethanol biofuel cell using PAMAM dendrimers as matrix for enzyme immobilization

FORTI, J. C.; AQUINO NETO, S.; ZUCOLOTTO, V.; CIANCAGLINI, P.; ANDRADE, A. R. de
Fonte: ELSEVIER ADVANCED TECHNOLOGY Publicador: ELSEVIER ADVANCED TECHNOLOGY
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.93%
This paper describes the preparation and application of a novel bioanode for use in ethanol/O(2) biofuel cells based upon immobilization of alcohol dehydrogenase (ADH) and polyamidoamine (PAMAM) dendrimers onto carbon cloth platforms. The power density measurements indicated a direct relationship between the amount of anchored ADH and the anode power values, which increased upon enzyme loading. The power density values ranged from 0.04 to 0.28 mW cm(-2), and the highest power density was achieved with the bioanode prepared with 28 U of ADH, which provided a power density of 0.28 mW cm(-2) at 0.3 V. The latter power output values were the maximum observed, even for higher enzyme concentrations. Stability of the bioanodes was quite satisfactory, since there was no appreciable reduction of enzymatic activity during the measurements. The method of bioanode preparation described here has proven to be very effective. The PAMAM dendrimer represents a friendly environment for the immobilization of enzymes, and it is stable and capable of generating high power density compared to other immobilization methods. (C) 2010 Elsevier B.V. All rights reserved.; FAPESP; CNPq; DS-CAPES; CAPES

Triphenylmethane dyes, an alternative for mediated electronic transfer systems in glucose oxidase biofuel cells

H, Camilo E. La Rotta; CINICIATO, Gustavo P. M. K.; GONZALEZ, Ernesto R.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.08%
The bioelectrochemical behavior of three triphenylmethane (TPM) dyes commonly used as pH indicators, and their application in mediated electron transfer systems for glucose oxidase bioanodes in biofuel cells was investigated. Bromophenol Blue, Bromothymol Blue, Bromocresol Green were compared bio-electrochemically against two widely used mediators, benzoquinone and ferrocene carboxy aldehyde. Biochemical studies were performed in terms of enzymatic oxidation, enzyme affinity, catalytic efficiency and co-factor regeneration. The different features of the TPM dyes as mediators are determined by the characteristics in the oxidation/reduction processes studied electrochemically. The reversibility of the oxidation/reduction processes was also established through the dependence of the voltammetric peaks with the sweep rates. All three dyes showed good performances compared to the FA and BQ when evaluated in a half enzymatic fuel cell. Potentiodynamic and power response experiments showed maxima power densities of 32.8 mu W cm(-2) for ferrocene carboxy aldehyde followed by similar values obtained for TPM dyes around 30 mu W cm(-2) using glucose and mediator concentrations of 10 mmol L(-1) and 1.0 mmol L(-1), respectively. Since no mediator consumption was observed during the bioelectrochemical process...

Preparação e caracterização de bioanodos para biocélula a combustível etanol/O2; Preparation and characterization of bioanodes for ethanol/O2 biofuel cell

Aquino Neto, Sidney de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/09/2012 PT
Relevância na Pesquisa
37.08%
Este trabalho descreve a preparação e caracterização de bioanodos para biocélula a combustível etanol/O2 utilizando enzimas desidrogenases, tanto com transferência eletrônica mediada como com transferência eletrônica direta. Na primeira etapa do trabalho, os resultados de cinética enzimática com as enzimas comerciais álcool desidrogenase e aldeído desidrogenase em solução e imobilizada mostraram claramente que os vários parâmetros cinéticos analisados devem ser considerados, a fim de se obter atividade máxima com os biocatalisadores; além disso, os resultados obtidos com as diferentes metodologias de imobilização empregadas (adsorção passiva e automontagem) confirmaram que tal etapa é crucial para a obtenção de um sistema viável. Os testes de semi-célula e estabilidade com transferência eletrônica mediada mostraram que o dendrímero PAMAM se mostra bastante atrativo na preparação de bioanodos para biocélula a combustível enzimática com ambas as metodologias testadas. Na segunda parte do trabalho, os resultados obtidos com os bioanodos preparados com as enzimas desidrogenases contendo o grupamento pirroquinolina quinona extraídas da bactéria Gluconobacter sp. 33 e purificadas em laboratório mostraram que ambos os protocolos de imobilização empregados nesta etapa (dendrímero PAMAM e Nafion-modificado) foram capazes de proporcionar um ambiente no qual as enzimas são capazes de realizar transferência eletrônica diretamente com superfícies de ouro e carbono. Com base nos resultados de caracterização eletroquímica...

Desenvolvimento de biocélulas a combustível de glicose/oxigênio em microfluídica; Development of microfluidic glucose/oxygen biofuel cells

Ciniciato, Gustavo Pio Marchesi Krall
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/02/2013 PT
Relevância na Pesquisa
37.25%
O objetivo principal desta tese foi o de se desenvolver uma biocélula a combustível enzimática em microfluídica, utilizando a glicose como combustível e o oxigênio como oxidante. Foram utilizadas as enzimas Glicose Oxidase ou Glicose Desidrogenase em um bioânodo, de forma a promover reações bioeletrocatalíticas de oxidação da glicose e as enzimas Lacase ou Bilirrubina Oxidase, de forma a promover reações bioeletrocatalíticas de redução do oxigênio molecular. O trabalho se procedeu por tentativas de imobilizar estas enzimas, de forma a promover o mecanismo de transferência eletrônica direta com um eletrodo. Nas situações as quais isso não foi possível, foram utilizados mediadores eletrônicos, de forma a promover o mecanismo de transferência eletrônica mediada. O melhor par de sistemas de bioeletrodos e mediadores foi escolhido para serem aplicados em uma biocélula a combustível. O trabalho se procedeu em adaptar este par de bioeletrodos desenvolvidos para um sistema de microfluídica em papel, sendo ambos biocátodo e bioânodo em papel. Como as condições de concentração de combustível e de cofatores foram otimizadas para o bioânodo, foi necessário trabalhar com os biocátodos, de forma a apresentar as características de um biocátodo respirador...

Geração de energia elétrica a partir de eletrodos imersos em sistema do tipo célula a biocombustível composta por reator anaeróbio e reator aeróbio operados em série alimentado com esgoto sanitário; Generation of electric energy from electrodes immersed in system named of biofuel cell consisted of an anaerobic and an aerobic reactor operated in series fed with wastewater

Gonzalez, Beatriz Cruz
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/08/2013 PT
Relevância na Pesquisa
37.41%
A presente pesquisa teve como objetivo primordial a verificação da viabilidade técnica de empregar sistema do tipo célula a biocombustível para tratamento de esgoto sanitário com geração de energia elétrica. A célula a biocombustível, em escala de bancada, adotada foi constituída por reator anaeróbio seguido de reator aeróbio, visando à remoção de matéria orgânica carbonácea e à nitrificação Cada reator apresentou área de 0,6275 m2 e volume útil de 24,0 L. A célula a biocombustível foi alimentada com esgoto sanitário com tempo de detenção hidráulica médio de 8 horas (nos dois módulos). Em cada reator instalou-se um eletrodo imerso, de modo que os dois eletrodos foram unidos por fio condutor externo. Foi verificada a potencialidade do sistema em gerar energia elétrica a partir das reações químicas e bioquímicas que se deram junto aos eletrodos e nos biofilmes aderidos aos mesmos. A operação da célula a biocombustível foi dividida em cinco Fases, denominadas de I, II, III, IV e V, sendo que o fator principal que distinguiu essas Fases consistiu no material eletródico. Manta de fibra de carbono e placa de grafite foram adotadas como ânodo da célula (reator anaeróbio). Chapa de aço inoxidável (AISI 316) e malhas de aço inoxidável (AISI 316) foram usadas como cátodo do sistema (reator aeróbio). Para monitoramento do sistema foram realizadas análises físico-químicas do afluente...

Biocélulas a combustível metanol e etanol/O2: preparação e caracterização de biocátodos; Methanol and ethanol/O2 biofuel cell: preparation and caracterization of biocathodes

Cardoso, Franciane Pinheiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/07/2014 PT
Relevância na Pesquisa
37.08%
Este trabalho descreve a preparação e caracterização de biocátodos para biocélula a combustível Etanol e Metanol//O2 utilizando a enzima lacase (trametes versicolor) num sistema de transferência eletrônica mediada (TEM). Na primeira etapa do trabalho, os resultados de cinética enzimática com a enzima lacase em solução e imobilizada sobre tecido de carbono mostraram que os vários parâmetros experimentais (pH, temperatura, estabilidade) analisados devem ser considerados, a fim de se obter atividade máxima com os biocatalisadores. Além disso, em relação aos testes cinéticos e de estabilidade, pode-se inferir que o dendrímero PAMAM pode ser empregado como um bom agente imobilizante na preparação de bicátodos para biocélula a combustível enzimática. Na segunda etapa do trabalho, uma semibiocélula Etanol//O2 foi testada e os eletrocatalisadores testados foram o verde de metileno (VM) e o azul de meldola (AM). Os testes de potência mostraram a importância da presença do mediador ABTS e do eletrocatalisador (VM) para melhorar o desempenho do dispositivo. Na terceira etapa do trabalho, eletrodos com diferentes mediadores (ABTS, ferro porfirina, ferroceno, complexo de ósmio e complexo de rutênio) e com polipirrol eletropolimerizado na superfície do eletrodo foram testados numa semibiocélula Metanol//O2. Os testes de semibiocélula Etanol e Metanol//O2 com transferência eletrônica mediada mostraram que os biocátodos preparados com o dendrímero PAMAM e com os diferentes eletrocatalisadores e mediadores...

New energy sources: the enzymatic biofuel cell

Aquino Neto,Sidney; De Andrade,Adalgisa R.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
37.18%
The continuous search for alternative energy sources, imposed by economic and environmental concerns, has motivated investigations into clean and efficient alternatives for energy production. Studies have shown that fuel cells are a potentially efficient strategy for energy conversion. Biofuel cells constitute a subclass of fuel cells with promising application in low-power devices (generally in the order of micro to milli watts). Instead of metallic catalysts, biological power sources employ biological molecules such as enzymes, organelles, or microorganisms to convert chemical energy into electricity. Biofuel cells offer several advantages over traditional batteries, including the use of renewable and non-toxic components, reaction selectivity, fuel flexibility, and ability to operate at lower temperatures and near neutral pH. Indeed, recent papers have demonstrated the promising characteristics of these devices; however, some challenges remains to be faced despite the several advances in this area. This review aims to provide the readers of the Journal of the Brazilian Chemical Society with an overview of enzymatic biofuel cells, their development since its first description in 1964, and the most recent outcomes. The latest papers in this field (including implantable technology) and an outlook for future research in this area are also presented.

Fire and Biofuel Contributions to Annual Mean Aerosol Mass Concentrations in the United States

Park, Rokjin J.; Jacob, Daniel J.; Logan, Jennifer A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
37.31%
We estimate the contributions from biomass burning (summer wildfires, other fires, residential biofuel, and industrial biofuel) to seasonal and annual aerosol concentrations in the United States. Our approach is to use total carbonaceous (TC) and non-soil potassium (ns-K) aerosol mass concentrations for 2001–2004 from the nationwide IMPROVE network of surface sites, together with satellite fire data. We find that summer wildfires largely drive the observed interannual variability of TC aerosol concentrations in the United States. TC/ns-K mass enhancement ratios from fires range from 10 for grassland and shrub fires in the south to 130 for forest fires in the north. The resulting summer wildfire contributions to annual TC aerosol concentrations for 2001–2004 are 0.26 μg C m−3 in the west and 0.14 μg C m−3 in the east; Canadian fires are a major contributor in the east. Non-summer wildfires and prescribed burns contribute on an annual mean basis 0.27 and 0.31 μg C m−3 in the west and the east, highest in the southeast because of prescribed burning. Residential biofuel is a large contributor in the northeast with annual mean concentration of up to 2.2 μg C m−3 in Maine. Industrial biofuel (mainly paper and pulp mills) contributes up to 0.3 μg C m−3 in the southeast. Total annual mean fine aerosol concentrations from biomass burning average 1.2 and 1.6 μg m−3 in the west and east...

Assessment of the current biofuel industry in India and Canada

Mathys, Amanda
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN
Relevância na Pesquisa
37.38%
The biofuel industry is developing rapidly on a global scale, and both the Canadian and Indian government are currently increasing production of the renewable energy option. The industry has the potential to improve the rural economy, reduce greenhouse gas (GHG) emissions and meet the country’s energy security requirements. The locally produced bioenergy can reduce dependence on foreign oil and provide the requirements for agricultural, industrial and household uses in urban and rural areas of the country. At the same time however, it has contributed to reduced food availability and an increase in food prices. The report looks at the current situation in both countries by investigating the available technology for conversion and its efficiency, and the biofuel resources available. It also investigates whether biofuels are a sustainable energy option by looking at their future potential in terms of the amount of energy that needs to be produced in future years and the area of land required to grow the biofuel crops. Finally, the ii environmental and socio-economic impacts of the biofuel industry are analysed. The two countries want to blend 5% ethanol with gasoline for vehicle use by 2010. Canada wants to achieve 2% of diesel requirements by increasing biodiesel development; India is aiming for 20% by 2012. Ethanol is predominately obtained from corn in Canada and both soybean and canola oil are being used as feedstock for biodiesel. In India...

Nanoporous gold electrodes as matrices for enzyme immobilization for application in biosensors and biofuel cells

Salaj-Kośla, Urszula
Fonte: University of Limerick Publicador: University of Limerick
Tipo: info:eu-repo/semantics/doctoralThesis; all_ul_research; ul_published_reviewed; ul_theses_dissertations
ENG
Relevância na Pesquisa
37.18%
peer-reviewed; Robust nanoporous gold electrodes were fabricated by sputtering a gold-silver alloy onto a glass support and subsequent dealloying of the silver component. Alloys were prepared with either a non-uniform or uniform distribution of silver alloy which showed clear differences in morphology on characterization with scanning electron microscopy. The surface area of these electrodes was up to 28 times that of the geometric surface area. The surface area accessible to modification by redox proteins was determined using cyt c as a model system. Covalent immobilization of cyt c at SAMs modified planar and nanoporous gold electrodes resulted in ca. 9 and 11 times higher surface coverages at uniform and non-uniform nanoporous gold, respectively, than at planar gold electrodes. Well defined mediatorless bioelecytrocatalytic reduction of oxygen was obtained on nanoporous gold electrodes prepared using a vacuum method and subsequently modified with Myrthecium verrucaria bilirubin oxidase (MvBOD). Diffusion limited faradaic response, with current densities of 0.8 mA/cm2, was observed when the enzyme modified electrode was stabilized with a layer the P017-epoxy polymer. The enzyme, Trametes hirsuta laccase (ThLc) also displayes direct electron transfer at unmodified nanoporous gold electrodes. The observed current densities of ca. 0.03 mA/cm2 were 10 times higher than the current densities at the ThLc modified electrode made by drop-casting and are in contrast to the absence of a response at unmodified polycrystalline gold electrodes. Nanoporous and planar gold electrodes modified with Aspergillus niger glucose oxidase (GOx) and Corynascus thermophilus cellobiose dehydrogenase (CtCDH) together with Os redox mediators and PEGDGE as a cross-linking agent resulted in glucose and lactose detecting biosensors. The sensors had (Imax...

The Impacts of Biofuel Targets on Land-Use Change and Food Supply : A Global CGE Assessment

Timilsina, Govinda R.; Beghin, John C.; van der Mensbrugghe, Dominique; Mevel, Simon
Fonte: Banco Mundial Publicador: Banco Mundial
Relevância na Pesquisa
37.38%
This study analyzes the long-term impacts of large-scale expansion of biofuels on land-use change, food supply and prices, and the overall economy in various countries or regions using a global computable general equilibrium model, augmented by a land-use module and detailed representation of biofuel sectors. The study finds that an expansion of global biofuel production to meet currently articulated or even higher national targets in various countries for biofuel use would reduce gross domestic product at the global level; however, the gross domestic product impacts are mixed across countries or regions. The expansion of biofuels would cause significant land re-allocation with notable decreases in forest and pasture lands in a few countries. The results also suggest that the expansion of biofuels would cause a reduction in food supply. Although the magnitude of the impact on food supply at the global level is not as large as perceived earlier, it would be significant in developing countries like India and those in Sub-Saharan Africa. Agricultural commodities such as sugar...

A holistic high-throughput screening framework for biofuel feedstock assessment that characterises variations in soluble sugars and cell wall composition in Sorghum bicolor

Martin, A.; Palmer, W.; Byrt, C.; Furbank, R.; Grof, C.
Fonte: BioMed Central Ltd Publicador: BioMed Central Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
37.18%
Background: A major hindrance to the development of high yielding biofuel feedstocks is the ability to rapidly assess large populations for fermentable sugar yields. Whilst recent advances have outlined methods for the rapid assessment of biomass saccharification efficiency, none take into account the total biomass, or the soluble sugar fraction of the plant. Here we present a holistic high-throughput methodology for assessing sweet Sorghum bicolor feedstocks at 10 days post-anthesis for total fermentable sugar yields including stalk biomass, soluble sugar concentrations, and cell wall saccharification efficiency. Results: A mathematical method for assessing whole S. bicolor stalks using the fourth internode from the base of the plant proved to be an effective high-throughput strategy for assessing stalk biomass, soluble sugar concentrations, and cell wall composition and allowed calculation of total stalk fermentable sugars. A high-throughput method for measuring soluble sucrose, glucose, and fructose using partial least squares (PLS) modelling of juice Fourier transform infrared (FTIR) spectra was developed. The PLS prediction was shown to be highly accurate with each sugar attaining a coefficient of determination (R2) of 0.99 with a root mean squared error of prediction (RMSEP) of 11.93...

C-MEMS Based Micro Enzymatic Biofuel Cells

Song, Yin
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
36.93%
Miniaturized, self-sufficient bioelectronics powered by unconventional micropower may lead to a new generation of implantable, wireless, minimally invasive medical devices, such as pacemakers, defibrillators, drug-delivering pumps, sensor transmitters, and neurostimulators. Studies have shown that micro-enzymatic biofuel cells (EBFCs) are among the most intuitive candidates for in vivo micropower. In the fisrt part of this thesis, the prototype design of an EBFC chip, having 3D intedigitated microelectrode arrays was proposed to obtain an optimum design of 3D microelectrode arrays for carbon microelectromechanical systems (C-MEMS) based EBFCs. A detailed modeling solving partial differential equations (PDEs) by finite element techniques has been developed on the effect of 1) dimensions of microelectrodes, 2) spatial arrangement of 3D microelectrode arrays, 3) geometry of microelectrode on the EBFC performance based on COMSOL Multiphysics. In the second part of this thesis, in order to investigate the performance of an EBFC, behavior of an EBFC chip performance inside an artery has been studied. COMSOL Multiphysics software has also been applied to analyze mass transport for different orientations of an EBFC chip inside a blood artery. Two orientations: horizontal position (HP) and vertical position (VP) have been analyzed. The third part of this thesis has been focused on experimental work towards high performance EBFC. This work has integrated graphene/enzyme onto three-dimensional (3D) micropillar arrays in order to obtain efficient enzyme immobilization...

Potential Gains and Losses of Biofuel Production in Argentina : A Computable General Equilibrium Analysis

Chisari, Omar O.; Romero, Carlos A.; Timilsina, Govinda
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
37.35%
Argentina is one of the world's largest biodiesel producers and the largest exporter, using soybeans as feedstock. Using a computable general equilibrium model that explicitly represents the biofuel industry, this study carries out several simulations on two sets of issues: (i) international markets for biofuel and feedstock, such as an increase in prices of soybean, soybean oil, and biodiesel, and (ii) domestic policies related to biofuels, such as an introduction of biofuel mandates. Both sets of issues can have important consequences to the Argentinean economy. The simulations indicate that increases in international prices of biofuels and feedstocks would increase Argentina's gross domestic product and social welfare. Increases in international prices of ethanol and corn also can benefit Argentina, but to a lesser extent. The domestic mandates for biofuels, however, would cause small losses in economic output and social welfare because they divert part of biodiesel and feedstock from exports to lower-return domestic consumption. An increase in the export tax on either feedstock or biodiesel also would lead to a reduction in gross domestic product and social welfare...

Advanced Biofuel Technologies : Status and Barriers

Cheng, Jay J.; Timilsina, Govinda R.
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Publications & Research :: Policy Research Working Paper
ENGLISH
Relevância na Pesquisa
37.31%
Large-scale production of crop based (first generation) biofuels may not be feasible without adversely affecting global food supply or encroaching on other important land uses. Because alternatives to liquid fossil fuels are important to develop in order to address greenhouse gas mitigation and other energy policy objectives, the potential for increased use of advanced (non-crop, second generation) biofuel production technologies has significant policy relevance. This study reviews the current status of several advanced biofuel technologies. Technically, it would be possible to produce a large portion of transportation fuels using advanced biofuel technologies, specifically those that can be grown using a small portion of the world's land area (for example, microalgae), or those grown on arable lands without affecting food supply (for example, agricultural residues). However, serious technical barriers limit the near-term commercial application of advanced biofuels technologies. Key technical barriers include low conversion efficiency from biomass to fuel...

Sharing competences in strategic alliances: a case study of the Cosan and Shell biofuel venture

Almeida,Luciana Florêncio de; Machado Filho,Cláudio Antonio Pinheiro
Fonte: Departamento de Administração da Faculdade de Economia, Administração e Contabilidade da Universidade de São Paulo Publicador: Departamento de Administração da Faculdade de Economia, Administração e Contabilidade da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 EN
Relevância na Pesquisa
37.18%
In a competitive world, the way a firm establishes its organizational arrangements may determine the enhancement of its core competences and the possibility of reaching new markets. Firms that find their skills to be applicable in just one type of market encounter constraints in expanding their markets, and through alliances may find a competitive form of value capture. Hybrid forms of organization appear primarily as an alternative to capturing value and managing joint assets when the market and hierarchy modes do not present any yields for the firm's competitiveness. As a result, this form may present other challenging issues, such as the allocation of rights and principal-agent problems. The biofuel market has presented a strong pattern of changes over the last 10 years. New intra-firm arrangements have appeared as a path to participate or survive among global competition. Given the need for capital to achieve better results, there has been a consistent movement of mergers and acquisitions in the Biofuel sector, especially since the 2008 financial crisis. In 2011 there were five major groups in Brazil with a grinding capacity of more than 15 million tons per year: Raízen (joint venture formed by Cosan and Shell), Louis Dreyfus...

Aplicaciones de electrodos enzimáticos y multicapas enzimáticas en biosensores y bioceldas de combustible; Applications of enzymatic electrodes and enzymatic multilayers in biosensors and biofuel cells

Scodeller, Pablo David
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2011 SPA
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37.25%
El presente trabajo de tesis se basa en el estudio de multicapas enzimáticas y electrodos enzimáticos destinados a la fabricación de biosensores y biocátodos para celdas de combustible. Las multicapas, de espesores nanométricos, se fabricaron utilizando el método de autoensamblado capa por capa, empleando enzimas y el polielectrolito electroactivo PAH-Os. El primer objetivo es extender el sistema de reconocimiento molecular de glucosa integrado por una enzima redox (GOx) mediada por su cable molecular (PAH-Os) (que ha sido estudiado previamente en este laboratorio) al diseño de un nuevo biosensor que brinde posibilidades de sensado únicas y permita sensar diferentes analitos. A este respecto se construyó el primer nanobiosensor óptico autoensamblando capa por capa esos dos componentes sobre la superficie de nanopartículas de Oro para dar una transducción óptica que además aprovecha las propiedades plasmonicas de las nanopartículas de Oro. El segundo objetivo es extender ese mismo sistema (GOx/PAH-Os) a un sistema que emplee una enzima redox diferente, y que también posea interés industrial. En esta dirección, se estudió el sistema Lacasa/PAH-Os como biocátodo para celdas de combustible (la Lacasa es una enzima redox que cataliza la oxidación de bifenoles reduciendo O2 a H20). Se encontró que durante la electroreducción de oxígeno...

Competências compartilhadas em alianças estratégicas: um estudo da aliança Cosan e Shell no mercado de biocombustíveis; Competencias compartidas en alianzas estratégicas: un estudio de la asociación entre Cosan y Shell en el mercado de biocombustibles; Sharing competences in strategic alliances: a case study of the Cosan and Shell biofuel venture

Almeida, Luciana Florêncio de; Machado Filho, Cláudio Antonio Pinheiro
Fonte: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade Publicador: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 01/06/2013 ENG
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Em um mundo competitivo, a maneira como uma firma estabelece seus arranjos organizacionais pode determinar sua capacidade de ampliar suas competências essenciais, bem como a possibilidade de atingir novos mercados. Empresas que atuam em apenas um mercado encontram obstáculos para se expandir e por meio de alianças elas encontram uma forma competitiva de criar valor. Formas híbridas apresentam-se primeiramente como alternativas de capturar valor e gerenciar ativos quando o mercado e a hierarquia organizacional não apresentam ganhos para a competitividade da firma. Como resultado, essa forma apresenta desafios como a alocação de direitos e os problemas de agência. O mercado de biocombustíveis tem apresentado mudanças contínuas nos últimos dez anos. Novos arranjos intra-firmas apareceram como um caminho para participar ou sobreviver no cenário de competição global. Dada a necessidade de capital para atingir melhores resultados, tem havido um movimento consistente de fusões e aquisições no setor de biocombustíveis, principalmente desde a crise financeira de 2008. Em 2011 existiam cinco grandes grupos no Brasil com capacidade de moagem de mais de 15 milhões de toneladas por ano: Raízen (joint venture entre Cosan e Shell)...

Development of a biofuel lamp and its comparison with a kerosene lamp

Chakraborty,N; Sarkar,S C
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
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An attempt has been made to explore the suitability of crude Jatropha curcas seed oil (biofuel) as a fuel in substituting fully one of the important petroleum products like Kerosene. Expeller is used for the extraction of oil which is further filtered. This crude oil has a very high viscosity and, as result, cannot flow through capillary action in a standard lamp and, hence, requires viscosity reduction by a trans esterification process to convert it into biodiesel or by any other processes. But this is a complex chemical reaction and the cost of production becomes almost doubled unless glycerine is not recovered as a by-product. Hence, the paper describes the development of a unique lamp (lantern) fuelled by 100% biofuel (crude jatropha oil) for its illumination and its comparative performance with respect to a standard kerosene lamp.