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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Community- and species-level consequences of competition in an unproductive environment: an experimental approach using boreal forest understory vegetation

Treberg, Michael Anthony 05 1900 (has links)
In this thesis, I describe three experimental studies that investigate the hotly debated role of competition in structuring communities in unproductive habitats. The studies were done in a boreal forest understory plant community in the southwestern Yukon. The first study was a traditional neighbour removal experiment. Ten of the most common species were transplanted as seedlings into transects with and without neighbours in a factorial design with two levels of water addition and two levels of fertilizer addition. The presence of neighbours increased survival and biomass of 6 species indicating a facilitative effect of neighbouring plants. The second study used the Community Density Series (CDS) methodology. The first of these was a 10-speciesexperimental community established from seed and grown in sandboxes at 6 densities with 2 watering levels and 2 fertilizer levels in a factorial design. At the community level, density dependence was observed at all life stages, but was not consistently competitive or facilitative - both emergence and final per plant shoot mass were density dependent, while survival to the end of the season was inversely density dependent. The effect of water was positive at seed emergence whereas fertilizer negatively affected survival. Species specific responses were also dependent on life stage. The final study was a 4-year CDS in the field using 9 common understory species at 6 densities and 3 fertilizer levels. Density negatively affected the community every year except for the first with competition being important at all densities above x1/8th the average community density. Constant final yield was reached in plots above the naturalx1 density for the last two years of the study. Responses to density were species-specific and 7 species declined with increasing density. No facilitative effects were observed. These studies demonstrate that density dependence is important in structuring this unproductive boreal understory habitat. The CDS approach allows us to quantify both the intensity and importance of plant competition at the community and species levels and to determine whether the importance of these biotic interactions depend on abiotic factors. The results clearly show that species-specific responses to biotic interactions are not necessarily the same as community level responses and if we are to understand community structure, it is necessary to use appropriate methodologies.
2

Community- and species-level consequences of competition in an unproductive environment: an experimental approach using boreal forest understory vegetation

Treberg, Michael Anthony 05 1900 (has links)
In this thesis, I describe three experimental studies that investigate the hotly debated role of competition in structuring communities in unproductive habitats. The studies were done in a boreal forest understory plant community in the southwestern Yukon. The first study was a traditional neighbour removal experiment. Ten of the most common species were transplanted as seedlings into transects with and without neighbours in a factorial design with two levels of water addition and two levels of fertilizer addition. The presence of neighbours increased survival and biomass of 6 species indicating a facilitative effect of neighbouring plants. The second study used the Community Density Series (CDS) methodology. The first of these was a 10-speciesexperimental community established from seed and grown in sandboxes at 6 densities with 2 watering levels and 2 fertilizer levels in a factorial design. At the community level, density dependence was observed at all life stages, but was not consistently competitive or facilitative - both emergence and final per plant shoot mass were density dependent, while survival to the end of the season was inversely density dependent. The effect of water was positive at seed emergence whereas fertilizer negatively affected survival. Species specific responses were also dependent on life stage. The final study was a 4-year CDS in the field using 9 common understory species at 6 densities and 3 fertilizer levels. Density negatively affected the community every year except for the first with competition being important at all densities above x1/8th the average community density. Constant final yield was reached in plots above the naturalx1 density for the last two years of the study. Responses to density were species-specific and 7 species declined with increasing density. No facilitative effects were observed. These studies demonstrate that density dependence is important in structuring this unproductive boreal understory habitat. The CDS approach allows us to quantify both the intensity and importance of plant competition at the community and species levels and to determine whether the importance of these biotic interactions depend on abiotic factors. The results clearly show that species-specific responses to biotic interactions are not necessarily the same as community level responses and if we are to understand community structure, it is necessary to use appropriate methodologies.
3

Community- and species-level consequences of competition in an unproductive environment: an experimental approach using boreal forest understory vegetation

Treberg, Michael Anthony 05 1900 (has links)
In this thesis, I describe three experimental studies that investigate the hotly debated role of competition in structuring communities in unproductive habitats. The studies were done in a boreal forest understory plant community in the southwestern Yukon. The first study was a traditional neighbour removal experiment. Ten of the most common species were transplanted as seedlings into transects with and without neighbours in a factorial design with two levels of water addition and two levels of fertilizer addition. The presence of neighbours increased survival and biomass of 6 species indicating a facilitative effect of neighbouring plants. The second study used the Community Density Series (CDS) methodology. The first of these was a 10-speciesexperimental community established from seed and grown in sandboxes at 6 densities with 2 watering levels and 2 fertilizer levels in a factorial design. At the community level, density dependence was observed at all life stages, but was not consistently competitive or facilitative - both emergence and final per plant shoot mass were density dependent, while survival to the end of the season was inversely density dependent. The effect of water was positive at seed emergence whereas fertilizer negatively affected survival. Species specific responses were also dependent on life stage. The final study was a 4-year CDS in the field using 9 common understory species at 6 densities and 3 fertilizer levels. Density negatively affected the community every year except for the first with competition being important at all densities above x1/8th the average community density. Constant final yield was reached in plots above the naturalx1 density for the last two years of the study. Responses to density were species-specific and 7 species declined with increasing density. No facilitative effects were observed. These studies demonstrate that density dependence is important in structuring this unproductive boreal understory habitat. The CDS approach allows us to quantify both the intensity and importance of plant competition at the community and species levels and to determine whether the importance of these biotic interactions depend on abiotic factors. The results clearly show that species-specific responses to biotic interactions are not necessarily the same as community level responses and if we are to understand community structure, it is necessary to use appropriate methodologies. / Science, Faculty of / Botany, Department of / Graduate
4

Trabalho produtivo em Karl Marx: novas e velhas questões / Productive labour in Karl Marx: new and old issues

Cotrim, Vera Aguiar 17 September 2009 (has links)
Esta pesquisa examina a conceituação de Marx acerca do trabalho produtivo, tanto em suas determinações gerais, quanto como categoria econômica particular do modo de produção capitalista. Tem por objetivo, em primeiro lugar, explicitar o critério distintivo do trabalho produtivo com relação ao trabalho improdutivo na forma de sociabilidade capitalista, analisando a relação que ambas as categorias estabelecem com o capital social, bem como entre si. Com isso, pretende-se explicitar os fundamentos da unidade da classe trabalhadora e a base de sua oposição ao capital. Em segundo lugar, temos como finalidade expor as transformações concretas que o trabalho experimenta após a subsunção ao capital, em sua relação com a categoria de trabalho produtivo. Assim, abordamos o trabalho complexo e o trabalho imaterial como formas do trabalho produtivo para o capital, em sua conexão com o desenvolvimento da produtividade do trabalho social. / This research examines Marx conception of productive labour concerning both its general determination and its existence as a particular economic category of capitalist mode of production. Firstly, it is aimed at eliciting the distinctive criteria of productive labour with regard to unproductive labour in capitalist form of sociability and analyzing the relationship that both categories establish with social capital, as well as to one another. On that basis, it is intended to show the chief principles of working class unity and its opposition to capital. Secondly, it is aimed at presenting concrete labour transformations after its subsumption to capital in respect to the category of productive labour. Thus, complex and immaterial labours as forms of labour productive to capital are approached in their connection to the development of productivity of social labour.
5

Trabalho produtivo em Karl Marx: novas e velhas questões / Productive labour in Karl Marx: new and old issues

Vera Aguiar Cotrim 17 September 2009 (has links)
Esta pesquisa examina a conceituação de Marx acerca do trabalho produtivo, tanto em suas determinações gerais, quanto como categoria econômica particular do modo de produção capitalista. Tem por objetivo, em primeiro lugar, explicitar o critério distintivo do trabalho produtivo com relação ao trabalho improdutivo na forma de sociabilidade capitalista, analisando a relação que ambas as categorias estabelecem com o capital social, bem como entre si. Com isso, pretende-se explicitar os fundamentos da unidade da classe trabalhadora e a base de sua oposição ao capital. Em segundo lugar, temos como finalidade expor as transformações concretas que o trabalho experimenta após a subsunção ao capital, em sua relação com a categoria de trabalho produtivo. Assim, abordamos o trabalho complexo e o trabalho imaterial como formas do trabalho produtivo para o capital, em sua conexão com o desenvolvimento da produtividade do trabalho social. / This research examines Marx conception of productive labour concerning both its general determination and its existence as a particular economic category of capitalist mode of production. Firstly, it is aimed at eliciting the distinctive criteria of productive labour with regard to unproductive labour in capitalist form of sociability and analyzing the relationship that both categories establish with social capital, as well as to one another. On that basis, it is intended to show the chief principles of working class unity and its opposition to capital. Secondly, it is aimed at presenting concrete labour transformations after its subsumption to capital in respect to the category of productive labour. Thus, complex and immaterial labours as forms of labour productive to capital are approached in their connection to the development of productivity of social labour.
6

Intelligent Container Stacking System at Seaport Container Terminal

ABBAS, FAHEEM January 2016 (has links)
Context: The workload at seaport container terminal is increasing gradually. We need to improve the performance of terminal to fulfill the demand. The key section of the container terminal is container stacking yard which is an integral part of the seaside and the landside. So its performance has the effects on both sides. The main problem in this area is unproductive moves of containers. However, we need a well-planned stacking area in order to increase the performance of terminal and maximum utilization of existing resources. Objectives: In this work, we have analyzed the existing container stacking system at Helsingborg seaport container terminal, Sweden, investigated the already provided solutions of the problem and find the best optimization technique to get the best possible solution. After this, suggest the solution, test the proposed solution and analyzed the simulation based results with respect to the desired solution. Methods: To identify the problem, methods and proposed solutions of the given problem in the domain of container stacking yard management, a literature review has been conducted by using some e-resources/databases. A GA with best parametric values is used to get the best optimize solution. A discrete event simulation model for container stacking in the yard has been build and integrated with genetic algorithm. A proposed mathematical model to show the dependency of cost minimization on the number of containers’ moves. Results: The GA has been achieved the high fitness value versus generations for 150 containers to storage at best location in a block with 3 tier levels and to minimize the unproductive moves in the yard. A comparison between Genetic Algorithm and Tabu Search has been made to verify that the GA has performed better than other algorithm or not. A simulation model with GA has been used to get the simulation based results and to show the container handling by using resources like AGVs, yard crane and delivery trucks and container stacking and retrieval system in the yard. The container stacking cost is directly proportional to the number of moves has been shown by the mathematical model. Conclusions: We have identified the key factor (unproductive moves) that is the base of other key factors (time & cost) and has an effect on the performance of the stacking yard and overall the whole seaport terminal. We have focused on this drawback of stacking system and proposed a solution that makes this system more efficient. Through this, we can save time and cost both. A Genetic Algorithm is a best approach to solve the unproductive moves problem in container stacking system.
7

Análise dos indicadores de desempenho fabril no setor de usinagem pesada em indústria de produção sob encomenda

Guadagnim, João Luís 17 October 2008 (has links)
A indústria brasileira produtora de bens de capital para o setor sucroalcooleiro, teve no início do século XXI grandes taxas de crescimento devido ao aumento do consumo do álcool combustível. Na onda deste crescimento, aumentou também o interesse das empresas em ingressar neste mercado. Para obter êxito, qualquer empresa deve conhecer muito bem os seus recursos de fabricação e gerenciá-los da melhor forma. Uma boa maneira de se conhecer o sistema produtivo de uma empresa é utilizando os indicadores de desempenho fabril. De posse destes indicadores é possível avaliar a eficiência, o índice de ciclo e os tempos de fila do setor. Assim, o objetivo deste trabalho é avaliar os indicadores de desempenho do setor mostrando o impacto que os tempos improdutivos podem causar no resultado final do exercício, usando como objeto de pesquisa o castelo de moenda, principal peça do conjunto do terno de moenda. Para o conhecimento dos indicadores foram acompanhadas 12 peças entre os meses de fevereiro e maio de 2008 e os resultados anotados. Com base nos resultados das 12 amostras a eficiência do setor ficou em 102%, o índice de ciclo em 19,8% e o tempo médio de fila entre as operações foi de 6,4 dias. Por meio da avaliação dos dados, conclui-se que o maior problema do setor é o gargalo formado antes das operações nas mandriladoras, estes gargalos influenciam diretamente no resultado do setor. O conhecimento destes valores pode orientar a empresa na busca por melhores resultados e direcionar esforços de maneira correta. / The brazilian industry that produces capital possessions for the sugar and alcohol sector, had, in the beginning of the XXI century, a very high growth due to increasing of the fuel alcohol consumption. With this growth, there also was an increasing in the interests of the companies about entering this market. To be successful, any company should know very well its fabrication resources and manage them as well as possible. A good way to know the production system of a company is to use the indicators for the factory performance. Though these indicators is possible to evaluate the efficiency the cycle indexes and the row times of the sector. Another way to manage the production is through the analysis of the DRE (is the chart that contains the results of the exercise) that is totally connected with the performance indicators. Therefore, the purpose of this work is to evaluate the efficiency of the production, the index of the products cycles and the times of the rows at the sector showing the impact that the non productable times can cause in the final results of the exercise. For the evaluation of the indicators twelve housings were analyzed (main part of the milling tandem) between the months of February and May of 2008 and based in the results of the twelve pieces, the efficiency was 102%, value considered high for the sector, the cycle index was 19,8%, and the mean row times between the operations was 6,4 days. The study of the times and movements at the housings showed that during all the transformation process, the main obstade for the production flow was the milling machine. The evaluation of the efficiency and IC of the sector pointed out that the problem generated by the critical point of the production can damage too much the demonstrative of the results of the exercises (DRE) of the sector.
8

Efeito da lignina de bagaços de cana-de-açúcar pré-tratados na hidrólise enzimática da celulose / Effect of the lignin from pretreated sugarcane bagasses in the enzymatic hydrolysis of the cellulose

Siqueira, Germano Andrade 10 April 2015 (has links)
No presente trabalho, avaliou-se o efeito limitante da lignina residual de bagaço de cana submetido a diferentes pré-tratamentos na hidrólise da celulose. O bagaço foi submetido a cinco pré-tratamentos: NaOH (5%), Na2SO3/NaOH (10%/5%), H2SO4 (0,75%), NaHSO3/H2SO4 (5%/0,75%) e explosão a vapor catalisada por SO2 (3%). Os pré-tratamentos resultaram em bagaços com diferentes composições químicas, sendo que os tratamentos alcalinos favoreceram a solubilização de lignina e os tratamentos ácidos favoreceram a solubilização de hemicelulose. Os bagaços tratados com Na2SO3/NaOH e por explosão a vapor resultaram em rendimentos de hidrólise de celulose superiores a 80% ao utilizar altas cargas de enzima (Celluclast), indicando a maior acessibilidade da celulose desses materiais. Isso foi confirmado pela técnica de coloração de Simons, que mostrou que a área superficial acessível da celulose desses dois bagaços foi maior que a dos demais. Boas correlações (R2>0,8) entre o rendimento de hidrólise da celulose em 72 h e a celulose superficial acessível só foram obtidos com altas cargas de enzima, evidenciando que fatores além da acessibilidade limitaram a hidrólise da celulose com quantidade menor de enzimas. As ligninas dos bagaços pré-tratados foram isoladas e a capacidade adsortiva de proteínas foi determinada. A lignina de bagaço tratado por explosão a vapor apresentou maior capacidade adsortiva, seguida da lignina de bagaço tratado com NaOH. Os pré-tratamentos com íons sulfito (Na2SO3/NaOH e NaHSO3/H2SO4) resultaram em ligninas com capacidades adsortivas inferiores quando comparado aos seus análogos sem sulfito (NaOH e H2SO4), possivelmente pela sulfonação da lignina residual, confirmada pela presença de grupos ácidos fortes nesses bagaços. A adição de BSA prévia à adição de celulases confirmou o forte efeito da adsorção improdutiva causada pela lignina nos bagaços tratados com NaOH e por explosão a vapor, materiais cujas ligninas apresentaram maiores capacidades adsortivas. A adsorção improdutiva foi menor ao utilizar o extrato enzimático Cellic CTec3, evidenciando que as enzimas desse coquetel são menos sensíveis à presença da lignina. Do extrato Celluclast, a enzima que mais adsorveu nas ligninas de bagaço tratado com NaOH e por explosão a vapor foi a ?-glicosidase, seguida da endoglucanase. As enzimas purificadas CBHI e EGII de T. longibrachiatum adsorveram menos à lignina de bagaço tratado por explosão a vapor que as mesmas enzimas de T. reesei. A ?-glicosidade de A. niger não adsorveu a essa lignina. Independentemente do pré-tratamento, a presença de fenóis solubilizados a partir da lignina, em baixas concentrações, resultou em aumento no rendimento de conversão de celulose ao utilizar baixas cargas de enzima, possivelmente pelo efeito positivo causado por esses na atividade de enzimas oxidativas, ou pela presença de lignossulfonatos. Em concentrações mais elevadas, independente da carga enzimática, os fenóis liberados foram inibitórios em todos os pré-tratamentos. A atividade de CBHI foi mais sensível à presença dos compostos fenólicos que a atividade de ?-glicosidase. A partir dos resultados, conclui-se o aumento da acessibilidade, seja pela remoção ou pela relocalização da lignina, é o fator que mais influencia a hidrólise eficiente da celulose do bagaço. A adsorção improdutiva foi dependente do pré-tratamento, e resultou em diminuição significativa dos rendimentos de hidrólise da celulose com baixas cargas de enzima. / The present work evaluated the limiting effect of the residual lignin of sugarcane bagasse submitted to different pretreatments: NaOH (5%), Na2SO3/NaOH (10%/5%), H2SO4 (0.75%), NaHSO3/H2SO4 (5%/0.75%) and SO2-catalyzed steam explosion (3%). The pretreatment resulted in bagasses with different chemical compositions, wherein the alkaline treatments resulted in a more efficient solubilization of lignin, and the acidic treatments solubilized the hemicellulose. The bagasses treated with Na2SO3/NaOH and by steam explosion resulted in cellulose hydrolysis yields above 80% using higher enzyme loadings (Celluclast), indicating the increased accessibility of the cellulose in these materials. This was confirmed by Simons\' Stain, which showed that the accessible surface area of the cellulose in these bagasses was higher than in the others. Good correlations (R2>0.80) between the 72 h hydrolysis yields and the accessible surface area of cellulose were only observed at higher enzyme loadings, indicating that other factors than accessibility, limit the hydrolysis at lower enzyme loadings. The lignins were isolated from the pretreated bagasses and the protein binding capacity was determined. The lignin from steam exploded bagasse showed the highest binding capacity, followed by the lignin extracted from NaOH-treated bagasse. The sulfite pretreatments (Na2SO3/NaOH e NaHSO3/H2SO4) resulted in lignins with lower binding capacities, when compared to their analogues without sulfite (NaOH e H2SO4), possibly because of the sulfonation of the residual lignin, confirmed by the presence of strong acid groups in these bagasses. BSA addition prior to the cellulases confirmed the strong effect of unproductive binding caused by the lignin in the NaOH-treated and steam exploded bagasses, materials with the highest binding capacity lignins. Less unproductive binding was observed using the enzyme extract Cellic CTec3, showing that the enzymes in this cocktail are less sensitive to the presence of lignin. From the extract Celluclast, the enzyme that most adsorbed to the lignins isolated from NaOH-treated and steam exploded bagasses was ?-glucosidase, followed by the endoglucases. The purified CBHI and EGII from T. longibrachiatum were less adsorbed to steam exploded bagasse lignin that the same enzymes from T. reesei. ?-glucosidase from A. niger did not bind to this lignin. Despite of the pretreatment, the presence of phenols solubilized from lignin, at lower concentrations, increased the cellulose hydrolysis yields with lower enzyme loading, possibly because of the positive effect of these compounds in the activity of oxidative enzymes, or because of the presence of lignosulfonates. At higher concentrations, despite of the enzyme loading, the phenols were inhibitory in all the pretreatments. The CBHI activity was more sensitive to the presence of phenolic compounds than the ?-glucosidase activity. From these results, it is possible to conclude that the increase in the accessibility, due to the lignin removal or relocation, influences the most the efficient hydrolysis of bagasse cellulose. The unproductive binding was pretreatment dependent and resulted in a significant decrease in the hydrolysis yields of the cellulose at lower enzyme loadings.
9

Análise dos indicadores de desempenho fabril no setor de usinagem pesada em indústria de produção sob encomenda

João Luís Guadagnim 17 October 2008 (has links)
A indústria brasileira produtora de bens de capital para o setor sucroalcooleiro, teve no início do século XXI grandes taxas de crescimento devido ao aumento do consumo do álcool combustível. Na onda deste crescimento, aumentou também o interesse das empresas em ingressar neste mercado. Para obter êxito, qualquer empresa deve conhecer muito bem os seus recursos de fabricação e gerenciá-los da melhor forma. Uma boa maneira de se conhecer o sistema produtivo de uma empresa é utilizando os indicadores de desempenho fabril. De posse destes indicadores é possível avaliar a eficiência, o índice de ciclo e os tempos de fila do setor. Assim, o objetivo deste trabalho é avaliar os indicadores de desempenho do setor mostrando o impacto que os tempos improdutivos podem causar no resultado final do exercício, usando como objeto de pesquisa o castelo de moenda, principal peça do conjunto do terno de moenda. Para o conhecimento dos indicadores foram acompanhadas 12 peças entre os meses de fevereiro e maio de 2008 e os resultados anotados. Com base nos resultados das 12 amostras a eficiência do setor ficou em 102%, o índice de ciclo em 19,8% e o tempo médio de fila entre as operações foi de 6,4 dias. Por meio da avaliação dos dados, conclui-se que o maior problema do setor é o gargalo formado antes das operações nas mandriladoras, estes gargalos influenciam diretamente no resultado do setor. O conhecimento destes valores pode orientar a empresa na busca por melhores resultados e direcionar esforços de maneira correta. / The brazilian industry that produces capital possessions for the sugar and alcohol sector, had, in the beginning of the XXI century, a very high growth due to increasing of the fuel alcohol consumption. With this growth, there also was an increasing in the interests of the companies about entering this market. To be successful, any company should know very well its fabrication resources and manage them as well as possible. A good way to know the production system of a company is to use the indicators for the factory performance. Though these indicators is possible to evaluate the efficiency the cycle indexes and the row times of the sector. Another way to manage the production is through the analysis of the DRE (is the chart that contains the results of the exercise) that is totally connected with the performance indicators. Therefore, the purpose of this work is to evaluate the efficiency of the production, the index of the products cycles and the times of the rows at the sector showing the impact that the non productable times can cause in the final results of the exercise. For the evaluation of the indicators twelve housings were analyzed (main part of the milling tandem) between the months of February and May of 2008 and based in the results of the twelve pieces, the efficiency was 102%, value considered high for the sector, the cycle index was 19,8%, and the mean row times between the operations was 6,4 days. The study of the times and movements at the housings showed that during all the transformation process, the main obstade for the production flow was the milling machine. The evaluation of the efficiency and IC of the sector pointed out that the problem generated by the critical point of the production can damage too much the demonstrative of the results of the exercises (DRE) of the sector.
10

Efeito da lignina de bagaços de cana-de-açúcar pré-tratados na hidrólise enzimática da celulose / Effect of the lignin from pretreated sugarcane bagasses in the enzymatic hydrolysis of the cellulose

Germano Andrade Siqueira 10 April 2015 (has links)
No presente trabalho, avaliou-se o efeito limitante da lignina residual de bagaço de cana submetido a diferentes pré-tratamentos na hidrólise da celulose. O bagaço foi submetido a cinco pré-tratamentos: NaOH (5%), Na2SO3/NaOH (10%/5%), H2SO4 (0,75%), NaHSO3/H2SO4 (5%/0,75%) e explosão a vapor catalisada por SO2 (3%). Os pré-tratamentos resultaram em bagaços com diferentes composições químicas, sendo que os tratamentos alcalinos favoreceram a solubilização de lignina e os tratamentos ácidos favoreceram a solubilização de hemicelulose. Os bagaços tratados com Na2SO3/NaOH e por explosão a vapor resultaram em rendimentos de hidrólise de celulose superiores a 80% ao utilizar altas cargas de enzima (Celluclast), indicando a maior acessibilidade da celulose desses materiais. Isso foi confirmado pela técnica de coloração de Simons, que mostrou que a área superficial acessível da celulose desses dois bagaços foi maior que a dos demais. Boas correlações (R2>0,8) entre o rendimento de hidrólise da celulose em 72 h e a celulose superficial acessível só foram obtidos com altas cargas de enzima, evidenciando que fatores além da acessibilidade limitaram a hidrólise da celulose com quantidade menor de enzimas. As ligninas dos bagaços pré-tratados foram isoladas e a capacidade adsortiva de proteínas foi determinada. A lignina de bagaço tratado por explosão a vapor apresentou maior capacidade adsortiva, seguida da lignina de bagaço tratado com NaOH. Os pré-tratamentos com íons sulfito (Na2SO3/NaOH e NaHSO3/H2SO4) resultaram em ligninas com capacidades adsortivas inferiores quando comparado aos seus análogos sem sulfito (NaOH e H2SO4), possivelmente pela sulfonação da lignina residual, confirmada pela presença de grupos ácidos fortes nesses bagaços. A adição de BSA prévia à adição de celulases confirmou o forte efeito da adsorção improdutiva causada pela lignina nos bagaços tratados com NaOH e por explosão a vapor, materiais cujas ligninas apresentaram maiores capacidades adsortivas. A adsorção improdutiva foi menor ao utilizar o extrato enzimático Cellic CTec3, evidenciando que as enzimas desse coquetel são menos sensíveis à presença da lignina. Do extrato Celluclast, a enzima que mais adsorveu nas ligninas de bagaço tratado com NaOH e por explosão a vapor foi a ?-glicosidase, seguida da endoglucanase. As enzimas purificadas CBHI e EGII de T. longibrachiatum adsorveram menos à lignina de bagaço tratado por explosão a vapor que as mesmas enzimas de T. reesei. A ?-glicosidade de A. niger não adsorveu a essa lignina. Independentemente do pré-tratamento, a presença de fenóis solubilizados a partir da lignina, em baixas concentrações, resultou em aumento no rendimento de conversão de celulose ao utilizar baixas cargas de enzima, possivelmente pelo efeito positivo causado por esses na atividade de enzimas oxidativas, ou pela presença de lignossulfonatos. Em concentrações mais elevadas, independente da carga enzimática, os fenóis liberados foram inibitórios em todos os pré-tratamentos. A atividade de CBHI foi mais sensível à presença dos compostos fenólicos que a atividade de ?-glicosidase. A partir dos resultados, conclui-se o aumento da acessibilidade, seja pela remoção ou pela relocalização da lignina, é o fator que mais influencia a hidrólise eficiente da celulose do bagaço. A adsorção improdutiva foi dependente do pré-tratamento, e resultou em diminuição significativa dos rendimentos de hidrólise da celulose com baixas cargas de enzima. / The present work evaluated the limiting effect of the residual lignin of sugarcane bagasse submitted to different pretreatments: NaOH (5%), Na2SO3/NaOH (10%/5%), H2SO4 (0.75%), NaHSO3/H2SO4 (5%/0.75%) and SO2-catalyzed steam explosion (3%). The pretreatment resulted in bagasses with different chemical compositions, wherein the alkaline treatments resulted in a more efficient solubilization of lignin, and the acidic treatments solubilized the hemicellulose. The bagasses treated with Na2SO3/NaOH and by steam explosion resulted in cellulose hydrolysis yields above 80% using higher enzyme loadings (Celluclast), indicating the increased accessibility of the cellulose in these materials. This was confirmed by Simons\' Stain, which showed that the accessible surface area of the cellulose in these bagasses was higher than in the others. Good correlations (R2>0.80) between the 72 h hydrolysis yields and the accessible surface area of cellulose were only observed at higher enzyme loadings, indicating that other factors than accessibility, limit the hydrolysis at lower enzyme loadings. The lignins were isolated from the pretreated bagasses and the protein binding capacity was determined. The lignin from steam exploded bagasse showed the highest binding capacity, followed by the lignin extracted from NaOH-treated bagasse. The sulfite pretreatments (Na2SO3/NaOH e NaHSO3/H2SO4) resulted in lignins with lower binding capacities, when compared to their analogues without sulfite (NaOH e H2SO4), possibly because of the sulfonation of the residual lignin, confirmed by the presence of strong acid groups in these bagasses. BSA addition prior to the cellulases confirmed the strong effect of unproductive binding caused by the lignin in the NaOH-treated and steam exploded bagasses, materials with the highest binding capacity lignins. Less unproductive binding was observed using the enzyme extract Cellic CTec3, showing that the enzymes in this cocktail are less sensitive to the presence of lignin. From the extract Celluclast, the enzyme that most adsorbed to the lignins isolated from NaOH-treated and steam exploded bagasses was ?-glucosidase, followed by the endoglucases. The purified CBHI and EGII from T. longibrachiatum were less adsorbed to steam exploded bagasse lignin that the same enzymes from T. reesei. ?-glucosidase from A. niger did not bind to this lignin. Despite of the pretreatment, the presence of phenols solubilized from lignin, at lower concentrations, increased the cellulose hydrolysis yields with lower enzyme loading, possibly because of the positive effect of these compounds in the activity of oxidative enzymes, or because of the presence of lignosulfonates. At higher concentrations, despite of the enzyme loading, the phenols were inhibitory in all the pretreatments. The CBHI activity was more sensitive to the presence of phenolic compounds than the ?-glucosidase activity. From these results, it is possible to conclude that the increase in the accessibility, due to the lignin removal or relocation, influences the most the efficient hydrolysis of bagasse cellulose. The unproductive binding was pretreatment dependent and resulted in a significant decrease in the hydrolysis yields of the cellulose at lower enzyme loadings.

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