112 research outputs found
DEBT, FINANCIAL FRAGILITY AND ECONOMIC GROWTH: A POST-KEYNESIAN MACROMODEL
It is developed a mathematical post-keynesian macromodel of capacity utilization and growth in which the supply of credit-money is endogenous and firms' debt position - and thus the financial fragility of the economy - is explicitly modeled. Both the influence of interest rate and indebtedness on capacity utilization and the rates of profit and growth, on the one hand, and the effect of the parameters of the saving and investment functions on financial fragility, on the other hand, are carefully analyzed.
A MACRODYNAMICS OF DEBT REGIMES, FINANCIAL INSTABILITY AND GROWTH
It is developed a dynamic macromodel of utilization and growth of productive capacity, in which the supply of credit-money is endogenous and firms' debt position - and thus the financial fragility of the economy Ă la Hyman Minsky - is explicitly modeled. The rate of interest is set as a markup over the base rate, which is exogenously determined by the monetary authority. Banking markup varies with changes in economic activity, which is measured by capacity utilization, while firms' debt position varies with the rates of interest, profit and capital accumulation. Regarding dynamics, it is shown the possibility of relating the stability properties of a system with the interest rate and the debt ratio as state variables to the type of minskyan regime - hedge, speculative, Ponzi - which prevails.
RIQUEZA RENTISTA, ENDIVIDAMENTO PRODUTIVO E SOLVĂNCIA BANCĂRIA: UMA ABORDAGEM PĂS-KEYNESIANA
Riqueza Rentista, Endividamento Produtivo e SolvĂȘncia BancĂĄria: Uma Abordagem PÂŽos-Keynesiana
Desenvolve-se um modelo formal na tradição pĂłs-keynesiana de economia polĂtica da acumulação de capital, crescimento econĂŽmico e distribuição funcional da renda, no qual a riqueza rentista, a dĂvida do setor produtivo e a solvĂȘncia bancĂĄria sĂŁo explicitamente modeladas. Relaciona-se as condiçÔes de solvĂȘncia bancĂĄria aos parĂąmetros dos planos de acumulação das firmas e Ă s propensĂ”es a poupar dos capitalistas e rentistas.Riqueza Rentista, Crescimento, Distribuição, SolvĂȘncia BancĂĄria
The Crystal-t Algorithm: A New Approach To Calculate The Sle Of Lipidic Mixtures Presenting Solid Solutions.
Lipidic mixtures present a particular phase change profile highly affected by their unique crystalline structure. However, classical solid-liquid equilibrium (SLE) thermodynamic modeling approaches, which assume the solid phase to be a pure component, sometimes fail in the correct description of the phase behavior. In addition, their inability increases with the complexity of the system. To overcome some of these problems, this study describes a new procedure to depict the SLE of fatty binary mixtures presenting solid solutions, namely the Crystal-T algorithm. Considering the non-ideality of both liquid and solid phases, this algorithm is aimed at the determination of the temperature in which the first and last crystal of the mixture melts. The evaluation is focused on experimental data measured and reported in this work for systems composed of triacylglycerols and fatty alcohols. The liquidus and solidus lines of the SLE phase diagrams were described by using excess Gibbs energy based equations, and the group contribution UNIFAC model for the calculation of the activity coefficients of both liquid and solid phases. Very low deviations of theoretical and experimental data evidenced the strength of the algorithm, contributing to the enlargement of the scope of the SLE modeling.1616740-5
High conversion of palm olein to ethyl esters using a strong anion exchange resin: study of the operational parameters
Biodiesel, known as a mixture of fatty acid ethyl/methyl esters, is seen as an alternative, ecofriendly, biodegradable and renewable non-fossil fuel. The use of heterogeneous catalysts for biodiesel synthesis can solve several problems associated with the homogeneous alkaline catalyzed-transesterification. Therefore, this work reports the evaluation of the commercial resin Amberlyst A26OH, a strong anion exchange resin, as a heterogeneous catalyst for the batch transesterification of refined palm olein with ethanol. It was studied the effects of the main operational parameters, considering the molar ratio of the reaction mixture (MRRM), namely the molar ratio of ethanol to olein taking into account only the ethanol added to the reaction system, and the total molar ratio (TMR), in this case considering also the amount of ethanol carried by the resin after its pretreatment. It was determined an optimal range of operational conditions by response surface methodology, guaranteeing conversion to ethyl esters higher than 96% with a catalyst amount corresponding to a range from 10.4 to 11.4% of the oil quantity, a temperature within the range of 55 to 60 ÂșC and a MRRM within the range from 3.5:1 to 6.0:131714011412CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP406963/2016-9; 406856/2013-3; 429873/2018-2; 305870/2014-9Sem informação2014/21252-0; 2016/10636-
Phase diagrams of mixtures of ethyl palmitate with fatty acid ethyl esters
Keywords: Cloud point Fatty acid ethyl ester (FAEE) Ethyl palmitate Solid-liquid equilibrium Predictive UNIQUAC a b s t r a c t The cloud point is an important property of biodiesel, controlling its low temperature behaviour, especially the fluidity of the fuel. Although biodiesel is an interesting renewable energy source, data for the melting/cloud point of biodiesel or simple binary or ternary mixtures of fatty acid ethyl esters (FAEE) are still scarce in the literature, particularly for those involving ethyl esters. The phase diagrams of six binary mixtures of ethyl palmitate with saturated and unsaturated fatty acid ethyl esters were determined by Differential Scanning Calorimetry (DSC). The determined systems were successfully described employing the UNIQUAC model. The experimental data indicates that the cloud point is controlled by the fatty acid ethyl ester in the mixture with higher melting temperature
For an ecology of scientific work: science, politics and the case of streams Pampa and Luiz Rau in Novo Hamburgo, Brazil
Environmental control on water vapour and energy exchanges over grasslands in semiarid region of Brazil
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