Thesis (M. Sc. (Microbiology)) -- University of Limpopo, 2016 / Smart hydrogels could facilitate immobilisation of cellulases to allow recovery and decrease enzyme cost in the biofuel industry, as they have a soluble-gel transition. The aim of the study was to design and evaluate the use of smart hydrogels for immobilisation of cellulase system that can be recovered after hydrolysis of cellulosic biomass. Cellulases from Aspergillus niger FGSC A733 produced under solid state fermentation and commercial cellulases were used in immobilisation. Various support matrices prepared were poly-N-isopropylacrylamide (p-NIPAAm), poly-N isopropylacrylamide-co-Methacrylic acid (p-NIPAAm-co-MAA) and supermacroporous poly-crosslinked-Acrylamide-co-N,N’-Methylenebisacrylamide (p-crosslinked-AA-co MBA). Cellulases were coupled onto the support matrices by covalent attachment method through reactive groups of N-acryloxysuccinimide (NAS) or Methacrylic acid N-hydroxysuccinimide (NMS). The low critical solution temperature (LCST) of formed p-NIPAAm-co-MAA copolymer was determined by the inflection point method. The shrinking and swelling kinetics and pH sensitivity of p-NIPAAm-co-MAA copolymer and conjugates were characterised using a cloud point method. Hydrolysis of CMC using cellulase-microbeads-p-NIPAAm and cellulase-crosslinked-p-NIPAAm with different percentage gel showed activity trend of 0.05>1>10>5>0.1% and 5>2>10% respectively. HPLC analysis showed that supplementation of β-glucosidase in cellulase-crosslinked-p-NIPAAm conjugates increased glucose by 12 and 14-fold at 30 and 50 °C respectively in the avicel hydrolysate in comparison with no β glucosidase supplementation. In the hydrolysis of avicel using cellulase-crosslinked p-NIPAAm-co-MAA conjugate a total of 13.6 g/L of reducing sugar was liberated after three cycles. In comparison a total of 21.4 g/L of reducing sugars were released from avicel hydrolysis using cellulase-crosslinked-p-AA-co-MBA conjugate after 3 cycles. In contrast, reducing sugars released in thatch grass hydrolysis using free enzyme were 8 times greater than in cellulase-crosslinked-p-AA-co-MBA conjugate. Cellulase crosslinked-p-NIPAAm-co-MAA conjugates were more stable than free enzyme at 50 and 60 °C after 24 hour and 120 minutes of incubation respectively, but lost activities at 65 °C after 120 minute. Therefore the activity loss in the immobilised enzymes was more due to thermal inactivation during precipitation and recovery than incomplete recovery during precipitation cycles. The results show that cellulases immobilised on smart polymers with sol-gel transition could be used in hydrolysis of cellulose due to ease of recovery. Hydrolysis kinetics was efficient for both immobilised enzyme system (cellulase-crosslinked-p-AA-co-MBA and cellulase-crosslinked-p-NIPAAm-co MAA conjugate) since were re-used in hydrolysis of avicel. Therefore the use of these smart polymers for cellulase immobilisation can contribute in cost reduction of the enzymatic hydrolysis process in the biofuel industry. / National Research Foundation (NRF) , University of Limpopo financial aid office and Flemish Interuniversity Council (VLIR-UOS) fo

Aproveitar oportunidades de negócios em ambientes turbulentos e instáveis, os quais envolvem aspectos econômicos e ambientais, tem sido a razão de existência das empresas, as quais mudam e reconfiguram espaços no mundo. Dentro desse contexto, é importante mencionar o avanço recente na expansão da cultura da cana de açúcar, que vem ocorrendo nesta última década. Estes eventos originados pelo aumento da demanda interna do etanol devido às inovações tecnológicas relacionadas à entrada no mercado nacional do carro flexfuel em 2003 e, ainda na crescente demanda externa do etanol, por alterações na legislação em termos de mandatórios em países como Japão, Canada, Estados Unidos. Nesse ambiente, o estudo deste setor revela-se de grande importância, pois, além do etanol ser um combustível alternativo, sua produção envolve um setor com características únicas (trata-se de uma atividade produtiva integrada), capaz de produzir novas contribuições a Teoria da Localização. Dessa maneira, o objetivo desta tese foi de identificar os fatores importantes capazes de definir um local como ideal e, os fatores que podem levar ao descarte de locais na localização de Usinas e Destilarias do setor Sucroalcooleiro Brasileiro. O estudo foca inicialmente as teorias Clássica e Neoclássica da localização, e a seguir explora os estudos a respeito do setor. Nesse sentido, estes componentes teóricos formam a base de sustentação dos objetivos propostos e da questão de pesquisa. Na metodologia o uso de diferentes ferramentas de análise, como a metodologia Delphi e os Estudos de Casos Múltiplos, propiciaram responder a questão de pesquisa. As entrevistas, com especialistas e com gestores das empresas possibilitaram obter as evidências objetivas das localizações ocorridas no setor. Isso determinou a convergência do estudo para a etapa de análise de resultados, oportunizando a identificação das especificidades do setor.Nos aspectos, relacionados à localização das unidades produtivas foi possível identificar as características, dos fatores que determinam sua localização. Classificaram-se os fatores em três tipos: Fatores essenciais, sem os quais a unidade não se localizará, e estão relacionados:à disponibilidade de terras mecanizáveis; a água em volume suficiente para irrigar a lavoura e a manutenção da planta; a vi variedade da cana adaptada à região de plantio e, por fim a estrutura de solo determinada por suas propriedades físico-químicas. Verificou-se ainda, que os fatores de Descarte de locais, estão relacionados: a terras sem possibilidade de mecanização; água insuficiente para abastecer a unidade produtivae ao fator delimitador da localização que está relacionado à competição por terras com outras unidades do setor. Foram identificados ainda dentro dos fatores essenciais, fatores considerados sensiveis, os quais apresentam um elevado grau de possibilidade de fracasso das operações da unidade ao longo do tempo. Tais fatores estão relacionados: dimensionamento errôneo do fornecimento de água para a unidade, mão-deobra sem qualificação, legislação ambiental com possíveis alterações e, terras sem estrutura de solo. Ficou claro ainda, a contribuição de outros fatores na localização como: transporte, canais de distribuição, mão de obra, incentivos de governo, legislação ambiental. Tais fatores foram citados como importantes, mas não determinam a localização da unidade produtiva. / Taking advantage of business opportunities in turbulent and unstable environments, which involve economic and environmental aspects, has been the reason of existence of the companies, which change and reconfigure spaces in the world. In this context, it is important to mention the recent advance in expanding sugar cultivation, which has occurred in the last decade. These events intensified by the new domestic demand for ethanol, due to technological innovations, related to the flefuel carentry into the domestic market, 2003, and the increasing foreign demand for ethanol. In addition, changes occurred in the legislation in countries like, Japan, Canada and United States. In such setting, the study of this sector proves to be of great importance because ethanol is an alternative fuel, its production involves a sector with unique features (this is an integrated production activity), and, is able to bring new contributions to the theory of location. Thus, the aim of this PhD Dissertation was to identify important factors that could set aan ideallocation as, and the factors that may lead to the elimination of locals for the location of Plants and Distilleries in the Brazilian Sugarcane Industry. The study initially focuses on the Classical and Neoclassical theories of location, and then explores the studies of the industry. In this sense, these components form the theoretical basis regarding the proposed objectives and research question. Methodology with different analysis tools, such as Delphi and Multiple Case Studies, propitiated answers to the research question. Interviews with experts and managers of companies allowed to gather objective evidence of locations occurring in the sector. Interviews with experts and managers of companies allowed to show objective evidence of localization occurring in the sector. In relating to the location of production units aspects was possible to identify the characteristics, the factors that determine its location. Factors were classified into three types: essential factors, without which the unit would not be located, such as: the availability of arable land; sufficient water to irrigate the crop and plant maintenance; the variety of sugar cane planting adapted to the region; and finally ground structure determined by its physicochemical properties. We also discovered that the factors for the sites disposal are related: a land without possibility of mechanization, i.e., over 12 º slope; insufficient water to supply the production unit, and the location of the bounding factor that is related to competition for land with other sector units (\"unaglomerative factor\"). We also identified factors considered, which have a high degree of casing failure in the unit operations over time. Such factors as wrong sizing of water supply labor lack of skill, possible changes in environmental legislation and land viii without soil structure. We identified the contribution of other factors in the location, such as transportation, distribution channels, labor, government incentives, and environmental legislation. These factors were mentioned as important, but not delimit the location of the unit.

Biofuels have been used as an energy source for heating and cooking since the beginning of time. However, recent changes in the demand for energy, and in particular, renewable energy, have spurred the growth of liquid biofuel industries in developed countries. Many developing countries, including South Africa have the potential to produce biofuels with benefits extending into the economic and social spheres. Despite government commitments and targets, the South African biodiesel and bio-ethanol industries have stalled in the starting blocks. This research aims to assess the reasons why. South Africa does not have the climate to compete with Brazil in bio-ethanol production and the scope for bioethanol is limited by environmental factors. However our neighbours show significantly more promise in this area. Biodiesel production is more likely to be commercially viable due to the country’s ability to grow oil crops and the need for the by-products. Despite the availability of land for cultivation of energy crops, the required technology and suitable infrastructure, progress has been slow. Uncertainty, high risk and misdirected government interventions have hampered investment in the sector and those involved in biofuel projects are very negative about the government’s ability to stimulate the industry. Consequently, they are looking towards importing feedstock material and exporting the biofuel. This will create a limited number of jobs, but will be energy and carbon negative, and will not aid rural development. Currently there is no medium or large scale virgin oil to biofuel producer operating in the country and the start-up dates for projects are beyond 2013. The WVO biodiesel industry has grown rapidly in the last five years but is limited to small scale operators with limited benefit potential. With the exception of Brazil, other world leaders in biofuels are facing heavy criticism and the mechanisms used to initially boost the industry have very limited application in South Africa. The benefits of biofuel production in South Africa are plentiful and align well with social need and development goals. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.

Biofuels have been used as an energy source for heating and cooking since the beginning of time. However, recent changes in the demand for energy, and in particular, renewable energy, have spurred the growth of liquid biofuel industries in developed countries. Many developing countries, including South Africa have the potential to produce biofuels with benefits extending into the economic and social spheres. Despite government commitments and targets, the South African biodiesel and bio-ethanol industries have stalled in the starting blocks. This research aims to assess the reasons why. South Africa does not have the climate to compete with Brazil in bio-ethanol production and the scope for bioethanol is limited by environmental factors. However our neighbours show significantly more promise in this area. Biodiesel production is more likely to be commercially viable due to the country’s ability to grow oil crops and the need for the by-products. Despite the availability of land for cultivation of energy crops, the required technology and suitable infrastructure, progress has been slow. Uncertainty, high risk and misdirected government interventions have hampered investment in the sector and those involved in biofuel projects are very negative about the government’s ability to stimulate the industry. Consequently, they are looking towards importing feedstock material and exporting the biofuel. This will create a limited number of jobs, but will be energy and carbon negative, and will not aid rural development. Currently there is no medium or large scale virgin oil to biofuel producer operating in the country and the start-up dates for projects are beyond 2013. The WVO biodiesel industry has grown rapidly in the last five years but is limited to small scale operators with limited benefit potential. With the exception of Brazil, other world leaders in biofuels are facing heavy criticism and the mechanisms used to initially boost the industry have very limited application in South Africa. The benefits of biofuel production in South Africa are plentiful and align well with social need and development goals. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.

Aproveitar oportunidades de negócios em ambientes turbulentos e instáveis, os quais envolvem aspectos econômicos e ambientais, tem sido a razão de existência das empresas, as quais mudam e reconfiguram espaços no mundo. Dentro desse contexto, é importante mencionar o avanço recente na expansão da cultura da cana de açúcar, que vem ocorrendo nesta última década. Estes eventos originados pelo aumento da demanda interna do etanol devido às inovações tecnológicas relacionadas à entrada no mercado nacional do carro flexfuel em 2003 e, ainda na crescente demanda externa do etanol, por alterações na legislação em termos de mandatórios em países como Japão, Canada, Estados Unidos. Nesse ambiente, o estudo deste setor revela-se de grande importância, pois, além do etanol ser um combustível alternativo, sua produção envolve um setor com características únicas (trata-se de uma atividade produtiva integrada), capaz de produzir novas contribuições a Teoria da Localização. Dessa maneira, o objetivo desta tese foi de identificar os fatores importantes capazes de definir um local como ideal e, os fatores que podem levar ao descarte de locais na localização de Usinas e Destilarias do setor Sucroalcooleiro Brasileiro. O estudo foca inicialmente as teorias Clássica e Neoclássica da localização, e a seguir explora os estudos a respeito do setor. Nesse sentido, estes componentes teóricos formam a base de sustentação dos objetivos propostos e da questão de pesquisa. Na metodologia o uso de diferentes ferramentas de análise, como a metodologia Delphi e os Estudos de Casos Múltiplos, propiciaram responder a questão de pesquisa. As entrevistas, com especialistas e com gestores das empresas possibilitaram obter as evidências objetivas das localizações ocorridas no setor. Isso determinou a convergência do estudo para a etapa de análise de resultados, oportunizando a identificação das especificidades do setor.Nos aspectos, relacionados à localização das unidades produtivas foi possível identificar as características, dos fatores que determinam sua localização. Classificaram-se os fatores em três tipos: Fatores essenciais, sem os quais a unidade não se localizará, e estão relacionados:à disponibilidade de terras mecanizáveis; a água em volume suficiente para irrigar a lavoura e a manutenção da planta; a vi variedade da cana adaptada à região de plantio e, por fim a estrutura de solo determinada por suas propriedades físico-químicas. Verificou-se ainda, que os fatores de Descarte de locais, estão relacionados: a terras sem possibilidade de mecanização; água insuficiente para abastecer a unidade produtivae ao fator delimitador da localização que está relacionado à competição por terras com outras unidades do setor. Foram identificados ainda dentro dos fatores essenciais, fatores considerados sensiveis, os quais apresentam um elevado grau de possibilidade de fracasso das operações da unidade ao longo do tempo. Tais fatores estão relacionados: dimensionamento errôneo do fornecimento de água para a unidade, mão-deobra sem qualificação, legislação ambiental com possíveis alterações e, terras sem estrutura de solo. Ficou claro ainda, a contribuição de outros fatores na localização como: transporte, canais de distribuição, mão de obra, incentivos de governo, legislação ambiental. Tais fatores foram citados como importantes, mas não determinam a localização da unidade produtiva. / Taking advantage of business opportunities in turbulent and unstable environments, which involve economic and environmental aspects, has been the reason of existence of the companies, which change and reconfigure spaces in the world. In this context, it is important to mention the recent advance in expanding sugar cultivation, which has occurred in the last decade. These events intensified by the new domestic demand for ethanol, due to technological innovations, related to the flefuel carentry into the domestic market, 2003, and the increasing foreign demand for ethanol. In addition, changes occurred in the legislation in countries like, Japan, Canada and United States. In such setting, the study of this sector proves to be of great importance because ethanol is an alternative fuel, its production involves a sector with unique features (this is an integrated production activity), and, is able to bring new contributions to the theory of location. Thus, the aim of this PhD Dissertation was to identify important factors that could set aan ideallocation as, and the factors that may lead to the elimination of locals for the location of Plants and Distilleries in the Brazilian Sugarcane Industry. The study initially focuses on the Classical and Neoclassical theories of location, and then explores the studies of the industry. In this sense, these components form the theoretical basis regarding the proposed objectives and research question. Methodology with different analysis tools, such as Delphi and Multiple Case Studies, propitiated answers to the research question. Interviews with experts and managers of companies allowed to gather objective evidence of locations occurring in the sector. Interviews with experts and managers of companies allowed to show objective evidence of localization occurring in the sector. In relating to the location of production units aspects was possible to identify the characteristics, the factors that determine its location. Factors were classified into three types: essential factors, without which the unit would not be located, such as: the availability of arable land; sufficient water to irrigate the crop and plant maintenance; the variety of sugar cane planting adapted to the region; and finally ground structure determined by its physicochemical properties. We also discovered that the factors for the sites disposal are related: a land without possibility of mechanization, i.e., over 12 º slope; insufficient water to supply the production unit, and the location of the bounding factor that is related to competition for land with other sector units (\"unaglomerative factor\"). We also identified factors considered, which have a high degree of casing failure in the unit operations over time. Such factors as wrong sizing of water supply labor lack of skill, possible changes in environmental legislation and land viii without soil structure. We identified the contribution of other factors in the location, such as transportation, distribution channels, labor, government incentives, and environmental legislation. These factors were mentioned as important, but not delimit the location of the unit.