979 resultados para Glycine soja Sieb.
Resumo:
Nas ltimas dcadas, o agronegcio brasileiro tem ganhado cada vez mais relevncia para a economia nacional, apresentando significativos ganhos de produtividade. Estes ganhos ocorreram devido a maior absoro de tecnologia pelos produtores agrcolas, incluindo o uso de insumos, dentre os quais se destacam os fertilizantes. As vendas de fertilizantes no Brasil cresceram 5,9% entre 1991 e 2012, atingindo 29,5 milhes de toneladas em 2012. Apesar disso, no Brasil, poucos trabalhos tratam dos fatores que afetam as suas vendas. Justifica-se, assim o presente estudo que tem como objetivo analisar os principais fatores que afetam as vendas brasileiras de fertilizantes para a soja. A metodologia utilizada a de sries temporais e o perodo da anlise o de 1988 a 2012. Para atingir o objetivo uma funo de vendas foi estimada considerando as propriedades de integrao e cointegrao das sries temporais. O modelo proposto para explicar as vendas de fertilizantes para a soja incluam as seguintes variveis exgenas: rea plantada de soja; preo dos fertilizantes para a soja; produtividade da soja e preo da soja. A varivel preo da soja apresentou uma alta multicolinearidade com a rea plantada de soja, e por isto no foi includa no modelo final. Os resultados encontrados no estudo mostram que a rea plantada o fator que exerce maior influncia sobre as vendas de fertilizantes para a soja, sendo que um choque positivo de 1% sobre o crescimento da rea plantada tem efeito positivo de 1,8% sobre as vendas de fertilizantes para a soja. O preo dos fertilizantes para a soja resultou em um coeficiente negativo conforme era esperado. A produtividade da soja foi utilizada como uma proxy para a capitalizao do produtor agrcola, e, assim como a rea plantada, ela apresentou sinal positivo, embora de menor magnitude e no estatisticamente significativo.
Resumo:
A avaliao de imveis uma prtica normatizada pela ABNT que vem desde a dcada de 60, quando surge a necessidade de se fazer grandes desapropriaes. A normatizao para imveis rurais ganha corpo na dcada de 70 e desde ento a ABNT NBR 14653-3 organiza e padroniza os conceitos da engenharia de avaliaes. O mtodo utilizado para se avaliar imveis rurais se baseia em preos de mercado e este apresenta algumas fragilidades. Neste contexto, o objetivo deste trabalho de propor o uso de uma metodologia, baseada no valor presente da renda do imvel rural, que complemente a metodologia de preos de mercado, incorporando assim geradores de valor que so importantes para a gesto na alocao de capital em propriedades agrcolas. Discorre-se tambm ao longo deste trabalho a exemplificao da metodologia proposta por meio de um estudo de caso, abordando a caracterizao do imvel, premissas utilizadas para anlise e a valorao do hectare da propriedade, comparando-a com a avaliao pelo mtodo de preos de mercado. Acredita-se que esta abordagem baseada em fundamentos econmico-financeiros, aliada ao levantamento de preos de mercado traro mais robustez para a avaliao de imveis agrcolas com propsito gerencial, trazendo para discusso outras variveis de relevncia para a gesto agro imobiliria.
Resumo:
O presente trabalho buscar apresentar as principais barreiras ao comrcio e polticas de subsdios impostas ao milho, arroz, trigo e soja, a fim de permitir uma adequao desses setores e das polticas pblicas a eles destinadas, para que a insero da produo brasileira no comrcio internacional seja possvel. O primeiro captulo apresentar as barreiras tarifrias impostas ao milho, arroz, trigo e soja pelos principais consumidores e importadores mundiais, verificando-se, tambm, a existncia de tarifas preferenciais concedidas a outros importantes exportadores, o que poderia prejudicar a competitividade do Brasil. O segundo captulo abordar as barreiras no tarifrias aplicadas aos setores, com a discusso dos principais temas que vm sendo discutidos e questionados nos comits relevantes da OMC, bem como a anlise e desenvolvimentos das regras que regem a aplicao de barreiras tcnicas, sanitrias e fitossanitrias. O terceiro captulo tratar das regras da OMC referentes aos subsdios agrcolas e apresentar alguns dos programas de subsdios voltados ao milho, arroz, trigo e soja notificados e/ou questionados na OMC, incluindo as questes levantadas acerca da conformidade dos programas de subsdios brasileiros s regras de comrcio internacional. Finalmente, o quarto captulo discorrer sobre as negociaes da Rodada Doha, que caso concludas com base nos textos atuais, podero trazer alteraes significativas s regras e barreiras aplicveis ao setor agrcola, trazendo impactos diretos s exportaes brasileiras
Resumo:
Imagem componente do jogo DigesTower (http://www.loa.sead.ufscar.br/digestower.php) desenvolvido pela equipe do Laboratrio de Objetos de Aprendizagem da Universidade Federal de So Carlos (LOA/UFSCar).
Resumo:
This research aims to investigate the Hedge Efficiency and Optimal Hedge Ratio for the future market of cattle, coffee, ethanol, corn and soybean. This paper uses the Optimal Hedge Ratio and Hedge Effectiveness through multivariate GARCH models with error correction, attempting to the possible phenomenon of Optimal Hedge Ratio differential during the crop and intercrop period. The Optimal Hedge Ratio must be bigger in the intercrop period due to the uncertainty related to a possible supply shock (LAZZARINI, 2010). Among the future contracts studied in this research, the coffee, ethanol and soybean contracts were not object of this phenomenon investigation, yet. Furthermore, the corn and ethanol contracts were not object of researches which deal with Dynamic Hedging Strategy. This paper distinguishes itself for including the GARCH model with error correction, which it was never considered when the possible Optimal Hedge Ratio differential during the crop and intercrop period were investigated. The commodities quotation were used as future price in the market future of BM&FBOVESPA and as spot market, the CEPEA index, in the period from May 2010 to June 2013 to cattle, coffee, ethanol and corn, and to August 2012 to soybean, with daily frequency. Similar results were achieved for all the commodities. There is a long term relationship among the spot market and future market, bicausality and the spot market and future market of cattle, coffee, ethanol and corn, and unicausality of the future price of soybean on spot price. The Optimal Hedge Ratio was estimated from three different strategies: linear regression by MQO, BEKK-GARCH diagonal model, and BEKK-GARCH diagonal with intercrop dummy. The MQO regression model, pointed out the Hedge inefficiency, taking into consideration that the Optimal Hedge presented was too low. The second model represents the strategy of dynamic hedge, which collected time variations in the Optimal Hedge. The last Hedge strategy did not detect Optimal Hedge Ratio differential between the crop and intercrop period, therefore, unlikely what they expected, the investor do not need increase his/her investment in the future market during the intercrop
Resumo:
Biodiesel is a fuel obtained from vegetable oils, such as soy, castorbean, among others. The monoester of fatty acid of these oils have chains with mono, di and tri double connections. The presence of these insaturations are susceptible to oxidization. Antioxidants are substances able to prevent oxidization from oils, fats, fat foods, as well as esters of Alquila( biodiesel). The objective of this work is to summarize a new antioxidant from the Cashew Nut Shell Liquid (CNSL) using the electrolysis technique. A current of 2 amperes was used in a single cell of only one group and two eletrodos of stainless steel 304 in a solution of methanol, together with the eletrolits: acetic acid, sodium chloride and sodium hydroxide, for two hours of agitation. The electrolysis products are characterized by the techniques of cromatography in a thin layer, spectroscopy of infrared and gravimetric analysis. The material was submitted to tests of oxidative stability made by the techniques of spectropy of impendancy and Rancimat (EN 14112). The analyses of characterization suggest that the polimerization of the electrolytic material ocurred. The application results of these materials as antioxidants of soy biodiesel showed that the order of the oxidative stability was obtained by both techniques used
Resumo:
Biodiesel is an alternative fuel, renewable, biodegradable and nontoxic. The transesterification of vegetable oils or animal fat with alcohol is most common form of production of this fuel. The procedure for production of biodiesel occurs most commonly through the transesterification reaction in which catalysts are used to accelerate and increase their income and may be basic, acid or enzyme. The use of homogeneous catalysis requires specific conditions and purification steps of the reaction products (alkyl ester and glycerol) and removal of the catalyst at the end of the reaction. As an alternative to improve the yield of the transesterification reaction, minimize the cost of production is that many studies are being conducted with the application of heterogeneous catalysis. The use of nano-structured materials as catalysts in the production of biodiesel is a biofuel alternative for a similar to mineral diesel. Although slower, can esterify transesterified triglycerides and free fatty acids and suffer little influence of water, which may be present in the raw material. This study aimed at the synthesis, characterization and application of nano-structured materials as catalysts in the transesterification reaction of soybean oil to produce biodiesel by ethylic route. The type material containing SBA-15 mesoporous lanthanum embedded within rightly Si / La = 50 was used catalyst. Solid samples were characterized by X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, nitrogen adsorption and desorption. For the transesterification process, we used a molar ratio of 20:1 alcohol and oil with 0.250 g of catalyst at 60C and times of 6 hours of reaction. It was determined the content of ethyl esters by H-NMR analysis and gas chromatography. It was found that the variable of conversion obtained was 80%, showing a good catalytic activity LaSBA-15 in the transesterification of vegetable oils via ethylic route