Parte 1 - Estudos para a síntese do petrosinol O petrosinol é um produto natural obtido a partir de esponjas do gênero Petrosia sp. Trata-se de um poliacetileno que possui atividade anti-HIV. A síntese deste composto, ainda não descrita na literatura, mostrou-se difícil. No presente trabalho são descritas as rotas sintéticas testadas para a obtenção do petrosinol. Foram feitas abordagens, totalizando sete, que consistiram na síntese de sistemas dicarbonílicos α,β-insaturados, os quais se mostraram pouco reativos, que não permitiram a continuidade das rotas com esta abordagem, ou tentativas de construção de álcoois propargílicos, que neste caso, os intermediários de síntese se mostraram muito instáveis. A síntese do petrosinol necessita de mais estudos visando novas tentativas para se obter o sistema diol insaturado central presente na molécula, chave para a síntese total da mesma. Parte 2 - Estudos para a síntese da amamistatina B A amamistatina B faz parte do grupo de moléculas que são sideróforos, utilizadas por bactérias para o transporte de íons ferro. O estudo de sideróforos tem crescido muito nos últimos anos devido o interesse de se obter prófármacos que utilizem tais sideróforos como transportadores. No presente trabalho foram feitos estudos para obtenção de fragmentos úteis na síntese convergente da amamistatina B. Foram realizados estudos de obtenção de β-hidróxiácidos α,α-dissubstituidos usando-se como direcionadores quirais as oxazolidinonas. O uso de agentes oxidantes foi necessário na obtenção de nitronas, intermediários sintéticos úteis na obtenção de formamidas substuidas, e que podem ser usados na síntese da amamistatina B. / Part 1 - Studies on the synthesis of petrosinol - Petrosinol is a natural product isolated from the marine genus from sponge Petrosia sp. It is a poliacetylene which has citotoxic and anti-HIV activity. The synthesis of this compound is not described on literature yet and it is very difficult. This work describes synthetic routes which were tested to obtain petrosinol. There were made seven approaches to construct α,β-unsaturated dicarbonyl systems which showed little reactivity. It was not possible to continue the routes to use this approach to construct propargyllic alcohols because these are very unstable. The synthesis of the petrosinol needs some more studies aiming new attempts to obtain the central unsaturated diol system in the molecule, the key to the total synthesis of it. Part 2 - Studies on the synthesis of amamistatin B - Amamistatin B is part of the group of molecules called siderophores, used by bacteria for the transportation of iron. Studies on siderophores has grown a lot in the last years because of the interest on the obtention of prodrugs that use such sidrophores as transport. In the present work the main goal was the obtention of useful fragments for the convergent synthesis of amamistatin B. Studies for the obtention of α,α-disubstituted β-hidroxyacids were achieved using chiral directors such as oxazolidinones. The use of oxydizing agents for the obtention of nitrones, synthetic internmediates useful for the obtention of substituted formamides.

Parte 1 - Estudos para a síntese do petrosinol O petrosinol é um produto natural obtido a partir de esponjas do gênero Petrosia sp. Trata-se de um poliacetileno que possui atividade anti-HIV. A síntese deste composto, ainda não descrita na literatura, mostrou-se difícil. No presente trabalho são descritas as rotas sintéticas testadas para a obtenção do petrosinol. Foram feitas abordagens, totalizando sete, que consistiram na síntese de sistemas dicarbonílicos α,β-insaturados, os quais se mostraram pouco reativos, que não permitiram a continuidade das rotas com esta abordagem, ou tentativas de construção de álcoois propargílicos, que neste caso, os intermediários de síntese se mostraram muito instáveis. A síntese do petrosinol necessita de mais estudos visando novas tentativas para se obter o sistema diol insaturado central presente na molécula, chave para a síntese total da mesma. Parte 2 - Estudos para a síntese da amamistatina B A amamistatina B faz parte do grupo de moléculas que são sideróforos, utilizadas por bactérias para o transporte de íons ferro. O estudo de sideróforos tem crescido muito nos últimos anos devido o interesse de se obter prófármacos que utilizem tais sideróforos como transportadores. No presente trabalho foram feitos estudos para obtenção de fragmentos úteis na síntese convergente da amamistatina B. Foram realizados estudos de obtenção de β-hidróxiácidos α,α-dissubstituidos usando-se como direcionadores quirais as oxazolidinonas. O uso de agentes oxidantes foi necessário na obtenção de nitronas, intermediários sintéticos úteis na obtenção de formamidas substuidas, e que podem ser usados na síntese da amamistatina B. / Part 1 - Studies on the synthesis of petrosinol - Petrosinol is a natural product isolated from the marine genus from sponge Petrosia sp. It is a poliacetylene which has citotoxic and anti-HIV activity. The synthesis of this compound is not described on literature yet and it is very difficult. This work describes synthetic routes which were tested to obtain petrosinol. There were made seven approaches to construct α,β-unsaturated dicarbonyl systems which showed little reactivity. It was not possible to continue the routes to use this approach to construct propargyllic alcohols because these are very unstable. The synthesis of the petrosinol needs some more studies aiming new attempts to obtain the central unsaturated diol system in the molecule, the key to the total synthesis of it. Part 2 - Studies on the synthesis of amamistatin B - Amamistatin B is part of the group of molecules called siderophores, used by bacteria for the transportation of iron. Studies on siderophores has grown a lot in the last years because of the interest on the obtention of prodrugs that use such sidrophores as transport. In the present work the main goal was the obtention of useful fragments for the convergent synthesis of amamistatin B. Studies for the obtention of α,α-disubstituted β-hidroxyacids were achieved using chiral directors such as oxazolidinones. The use of oxydizing agents for the obtention of nitrones, synthetic internmediates useful for the obtention of substituted formamides.

A expressão agronegócio (agribusiness) originou-se na Universidade de Harvard na School of Business Administration, em 1957, com a publicação do livro A Concept of Agribusiness, de John Davis e Ray Goldberg. A ideia do agronegócio resulta em uma cadeia produtiva, com vários elos bastante interdependentes, das fases de produção até a comercialização do produto final O Brasil é visto por especialistas como um potencial fornecedor de alimentos global. E assim, a manutenção e o crescimento da participação produtiva do setor agrícola e pecuário nacional dependem de questões relacionadas à tecnologia. A problemática do trabalho envolve questões da diferenciação entre agropecuária e agronegócio. As fontes de referências de dados trazem informações, mas não englobam atividades da pré-produção, por isso, procurou-se responder: Não seria mais apropriado acrescentar a esta balança comercial os setores para trás, já que se trata como agronegócio? O objetivo é analisar por outra perspectiva os dados da balança comercial do agronegócio, propondo a adição de insumos intrínsecos aos produtos agropecuários, sob a ótica das intensidades tecnológicas, analisando seu comportamento no período de 1997 a 2017, permitindo assim, discorrer sobre o desempenho dos principais grupos de produtos da pauta de exportação e importação desse setor que serve de alicerce para a economia brasileira. Os resultados apontaram para fez diferença em termos de contribuição para a balança comercial do agronegócio a inclusão dos grupos de produtos peixes e crustáceos; produtos farmacêuticos; adubos (fertilizantes); e tratores na nova proposta a contribuição para a balança comercial total é menor. Ademais, os dados mostraram que o país tem dependência externa das vacinas e dos adubos e que esses produtos são de alta e média-alta intensidade tecnológica. / The term agribusiness originated at Harvard University at the School of Business Administration in 1957 with the publication of A Concept of Agribusiness by John Davis and Ray Goldberg. The idea of agribusiness results in a productive chain, with several interdependent links, from the production phases to the commercialization of the final product. Brazil is seen by experts as a potential global food supplier. The maintenance and growth of the productive participation of the national agricultural and livestock sector depends on issues related to technology. The problem of this papers involves issues of differentiation between agriculture and agribusiness. The sources of data references provide information, but do not include pre-production activities, so we tried to answer: Would it not be more appropriate to add the input sector to this trade balance, since it is called as agribusiness? The objective is to analyze from another perspective the agribusiness trade balance data, proposing the addition of intrinsic inputs to agricultural products, from the perspective of technological intensities, analyzing their behavior in the period from 1997 to 2017, thus allowing a discussion on the performance of the agribusinesses. main product groups of the export and import tariff of this sector that serves as a foundation for the Brazilian economy. The results pointed to the difference in terms of the contribution to the agribusiness trade balance to include the fish and crustaceans product groups; pharmaceutical products; fertilizers; and tractors in the new proposal the contribution to the total trade balance is lower. In addition, the data showed that the country has external dependence on vaccines and fertilizers and that these products are high and medium-high technological intensity.

Made available in DSpace on 2014-06-11T19:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-04Bitstream added on 2014-06-13T20:21:41Z : No. of bitstreams: 1 andrade_mg_dr_jabo.pdf: 575183 bytes, checksum: c078d7148dcec00acf084e11bfb365c2 (MD5) / O uso do lodo de esgoto (LE) com finalidade agronômica e/ou condicionador é uma das alternativas ambientalmente e economicamente atraente, quando comparadas a outros destinos (incineração, aterro sanitário, etc.). As substâncias inorgânicas potencialmente tóxicas contidas no LE são uma das maiores preocupações ao meio ambiente e à cadeia trófica. O objetivo deste trabalho foi avaliar os teores e o efeito cumulativo dos elementos As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se e Zn, em dois latossolos vermelhos (um eutroférrico – LVef, e um distrófico – LVd) e plantas de milho (Zea mays L.) cultivadas nos mesmos após a aplicação de LE por treze anos ininterruptos. Em condições de campo e delineamento experimental de blocos ao acaso, cada solo recebeu quatro tratamentos (0; 5; 10 e 20 t de LE ha1) com cinco repetições. Amostras dos insumos agrícolas aplicados na cultura do milho, LE, solos, materiais vegetais e materiais de referência certificados foram digeridas em forno de micro-ondas (método 3051A), e os analitos foram quantificados por ICP-OES. Após 13 aplicações anuais sucessivas de LE no LVef e LVd, os maiores teores dos ETs foram encontrados no LVef e ainda não atingiram o valor de investigação (VI) agrícola (mais restritivo) da resolução 420 do CONAMA. Persistindo a atual taxa de aplicação de LE e teores médios de ET incorporados aos solos, é de se esperar que o Ba, Cd, Cr, Cu, Ni e Zn serão os primeiros elementos a atingir o VI no LVef. Para o LVd, o primeiro elemento a atingir o VI é o Cr somente. Os teores de ET encontrados nos insumos agrícolas não devem causar impacto ambiental imediato. Os ETs não proporcionaram fitotoxidade ou contaminação nas partes aéreas, folhas para diagnose e grãos das plantas de milho / The use of sewage sludge (SS) as agronomic and/or soil conditioner purposes presents a correct environmental and economically attractive alternative when compared to other disposal methods as incineration and landfills. The potentially toxic inorganic substances contained in SS is a major concern for the environment and food chain. This work aimed evaluate the content and the cumulative effect of the Trace Elements (TE) As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn in two different soils: an Eutroferric Clayed Red Latosol (Typic Eutrorthox – “E”) and a Dystrophic Red Latosol (Typic Haplorthox – “H”) and with maize plants (Zea mays L.) growth after fertilize the soil with SS for thirteen years continuously. Under field conditions and under a randomized blocks experimental design each soil received four treatments (0, 5, 10, and 20 t of SS ha-1) with five replications. Fertilizers, SS, soils, vegetal materials, and the reference material were digested in microwave oven (method 3051A) and the analytes were quantified by ICP-OES. After thirteen years fertilizing the soil with SS in the soils “E” and “H”, the higher amounts were found in the “E” and these amounts did not reach the agricultural investigation value (more restrictive) yet. Persisting the actual fertilization rate of SS and an average amount of TE incorporated in the soil, Ba, Cd, Cr, Cu, Ni, and Zn will be probably the firsts elements to reach the agricultural investigation value in the “E”. To “H”, the first element to reach this value will be probably Cr. The TE found in the fertilizers should not cause immediate environmental impact. The TE did not provide neither phytotoxicity nor contamination in the maize aerial part, diagnose leaf, and grains

Os distribuidores de insumos têm desempenhado um papel importante na comercialização e distribuição de insumos aos consumidores finais (agricultores). Além de vender os insumos, essas empresas são fornecedores de serviços importantes e também participam no processo de desenvolvimento de novas tecnologias, conhecimento de mercado e, especialmente, de fornecimento de crédito. O planejamento é necessário para que o futuro seja levado em consideração, e o sistema de gestão é essencial na organização, tornando-se um diferencial competitivo e uma ferramenta de sucesso na implementação de estratégias. O diagnóstico das práticas de gestão nos canais de distribuição de insumos permite identificar os principais pontos de melhoria, e esses merecerão todos os esforços de tempo e investimento dos gestores. O presente trabalho busca responder à seguinte pergunta: como fomentar o processo de planejamento estratégico de um canal de distribuição de insumos agrícolas utilizando projetos previamente estruturados que podem ser aplicados dependendo do nível de gestão encontrado no canal? Para tanto, lança mão de uma pesquisa exploratória qualitativa que analisa cinco estudos de casos. Como resultado, foi proposto um modelo de classificação do nível de gestão de canais de distribuição de insumos agrícolas que subsidiou as análises dos projetos estratégicos relacionados com o nível de gestão existente no canal; e também uma gama de projetos estratégicos previamente pensados em função do nível de gestão. Percebe-se uma lacuna na proposição dos projetos estratégicos e o nível de gestão, sendo importante que no exercício do planejamento estratégico, tenha-se o conhecimento prévio desse. / Agricultural input dealers play an important role in the commercialization and distribution of the inputs to final users (growers). Besides selling inputs, these companies supply important services and participate in the development of new technologies, in sharing market knowledge and specially in funding growers\' activities. Planning is necessary to bring light to the future while the management system is essential for the organization, becoming a competitive advantage and a successful tool for the implementation of the strategy. The diagnosis of management practices in input dealers allows identifying the main improvement points which should deserve time spending and investment by the firms\' managers. This research aims to address the following question: how to promote the strategic planning process of an agricultural input dealer by using previously structured projects that could be applied based on the level of management standard? In order to do so, this qualitative and exploratory research analyzed five case studies. It resulted on a framework for classifying the level of management standard of agricultural input dealers, which was used to analyze the strategic projects related to the existing management standard of each dealer. It also resulted on a range of strategic projects previously thought according to the level of management standard. It became evident that there is a gap between the proposed strategic projects and the level of management standard, being important that managers have a previous knowledge of such level for planning the firm\'s strategies.

Thesis (MBA.) -- University of Limpopo, 2016 / The objective of this study was to determine the environmental impact of agricultural inputs, to know if the environmental impacts of agricultural inputs have environmental costs, and to know who bears the environmental costs of agricultural inputs. Using a purposive sampling method, the researcher studied six farms from Chief Albert Luthuli Municipal area, Mpumalanga. The research design for the study was a mix of qualitative and quantitative research approaches. Data collection was from primary and secondary sources. Data was collected from the six farmers in Albert Lithulu, in addition secondary data was collected from the archives of Index Mundi, the University of Pretoria, the US EPA and the World Bank. Using a mix of correlation and regression analysis, findings from the study provided an answer to the three research objectives. Findings from the analysis of correlation and regression indicated that agricultural input (fertilizer, used in this study) does affect the environment; it causes an agricultural induced emission of greenhouse gases (nitrous oxide and methane). Furthermore, findings from analysis of potential environmental costs of environmental impacts (methane and nitrous oxide) showed that agricultural inputs have social costs for South Africa. Furthermore, the final findings in this study showed that the environmental costs from agricultural inputs are born by the victims. Consequently the study recommends additional environmental regulation to enable farmers internalise some of the environmental costs of agricultural inputs that are born by victims. Further research is suggested to determine the model that may be used to internalise environmental costs of agricultural inputs back to the farms. Key Words: farms, environmental costs, agricultural inputs, externalities

Time-optimal solutions provide us with the fastest means to regulate a system in presence of input constraints. This advantage of time-optimal control solutions is offset by the fact that their real-time implementation involves computationally intensive iterative techniques. Moreover, time-optimal controls depend on the initial state and have to be recalculated for even the slightest perturbation. Clearly time-optimal controls are not good candidates for online regulation. Consequently, the search for alternatives to time-optimal solutions is a very active area of research. The work described here is inspired by the simplicity of optimal-aim concept. The "optimal-aim strategies" provide online regulation in presence of bounded inputs with minimal computational effort. These are based purely on state-space geometry of the plant and are inherently adaptive in nature. Optimal-aim techniques involve aiming of trajectory derivative (or the state velocity vector) so as to approach the equilibrium state in the best possible manner. This thesis documents the efforts to develop an online regulation algorithm for systems with input constraints. Through a number of hypotheses focussed on trying to reproduce the exact time-optimal solution, the diffculty associated with this task is demonstrated. A modification of optimal-aim concept is employed to develop a novel regulation algorithm. In this algorithm, aim directions are chosen in a special manner to generate the time-optimal control approximately. The control scheme thus developed is shown to be globally stabilizing for systems having eigenvalues in the CLHP (closed left half-plane). It is expected that this method or its modifications can be extended to higher dimensional systems as a part of future research. An alternative control algorithm involving a simple state-space aiming concept is also developed and discussed.

Sweden, together with Norway, Finland and Denmark, have created a multi-national electricity market called NordPool. In this market, producers and retailers of electricity can buy and sell electricity, and the retailers then offers this electricity to end consumers such as households and industries. Previous studies have shown that pricing at the NordPool market is functioning quite well, but no other study has to my knowledge studied if pricing in the retail market to consumers in Sweden is well functioning. If the market is well functioning, with competition and low transaction costs when changing electricity retailer, we would expect that a homogeneous good such as electricity would be sold at the approximately same price, and that price changes would be highly correlated, in this market. Thus, the aim of this study is to test whether the price of Vattenfall, the largest energy firm in the Swedish market, is highly correlated to the price of other firms in the Swedish retail market for electricity. Descriptive statistics indicate that the price offered by Vattenfall is quite similar to the price of other firms in the market. In addition, regression analysis show that the correlation between the price of Vattenfall and other firms is as high as 0.98.

Time-optimal solutions provide us with the fastest means to regulate a system in presence of input constraints. This advantage of time-optimal control solutions is offset by the fact that their real-time implementation involves computationally intensive iterative techniques. Moreover, time-optimal controls depend on the initial state and have to be recalculated for even the slightest perturbation. Clearly time-optimal controls are not good candidates for online regulation. Consequently, the search for alternatives to time-optimal solutions is a very active area of research. The work described here is inspired by the simplicity of optimal-aim concept. The "optimal-aim strategies" provide online regulation in presence of bounded inputs with minimal computational effort. These are based purely on state-space geometry of the plant and are inherently adaptive in nature. Optimal-aim techniques involve aiming of trajectory derivative (or the state velocity vector) so as to approach the equilibrium state in the best possible manner. This thesis documents the efforts to develop an online regulation algorithm for systems with input constraints. Through a number of hypotheses focussed on trying to reproduce the exact time-optimal solution, the diffculty associated with this task is demonstrated. A modification of optimal-aim concept is employed to develop a novel regulation algorithm. In this algorithm, aim directions are chosen in a special manner to generate the time-optimal control approximately. The control scheme thus developed is shown to be globally stabilizing for systems having eigenvalues in the CLHP (closed left half-plane). It is expected that this method or its modifications can be extended to higher dimensional systems as a part of future research. An alternative control algorithm involving a simple state-space aiming concept is also developed and discussed.

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