897 resultados para Numerical Analysis and Scientific Computing
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WVIS 2014 - 5th Workshop on Visual Analytics, Information Visualization and Scientific Visualization
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The financial crisis and Great Recession have been followed by a jobs shortage crisis that most forecasts predict will persist for years given current policies. This paper argues for a wage-led recovery and growth program which is the only way to remedy the deep causes of the crisis and escape the jobs crisis. Such a program is the polar opposite of the current policy orthodoxy, showing how much is at stake. Winning the argument for wage-led recovery will require winning the war of ideas about economics that has its roots going back to Keynes’ challenge of classical macroeconomics in the 1920s and 1930s. That will involve showing how the financial crisis and Great Recession were the ultimate result of three decades of neoliberal policy, which produced wage stagnation by severing the wage productivity growth link and made asset price inflation and debt the engine of demand growth in place of wages; showing how wage-led policy resolves the current problem of global demand shortage without pricing out labor; and developing a detailed set of policy proposals that flow from these understandings. The essence of a wage-led policy approach is to rebuild the link between wages and productivity growth, combined with expansionary macroeconomic policy that fills the current demand shortfall so as to push the economy on to a recovery path. Both sets of measures are necessary. Expansionary macro policy (i.e. fiscal stimulus and easy monetary policy) without rebuilding the wage mechanism will not produce sustainable recovery and may end in fiscal crisis. Rebuilding the wage mechanism without expansionary macro policy is likely to leave the economy stuck in the orbit of stagnation.
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Schistosomiasis is still an endemic disease in many regions, with 250 million people infected with Schistosoma and about 500,000 deaths per year. Praziquantel (PZQ) is the drug of choice for schistosomiasis treatment, however it is classified as Class II in the Biopharmaceutics Classification System, as its low solubility hinders its performance in biological systems. The use of cyclodextrins is a useful tool to increase the solubility and bioavailability of drugs. The aim of this work was to prepare an inclusion compound of PZQ and methyl-beta-cyclodextrin (MeCD), perform its physico-chemical characterization, and explore its in vitro cytotoxicity. SEM showed a change of the morphological characteristics of PZQ:MeCD crystals, and IR data supported this finding, with changes after interaction with MeCD including effects on the C-H of the aromatic ring, observed at 758 cm(-1). Differential scanning calorimetry measurements revealed that complexation occurred in a 1:1 molar ratio, as evidenced by the lack of a PZQ transition temperature after inclusion into the MeCD cavity. In solution, the PZQ UV spectrum profile in the presence of MeCD was comparable to the PZQ spectrum in a hydrophobic solvent. Phase solubility diagrams showed that there was a 5.5-fold increase in PZQ solubility, and were indicative of a type A(L) isotherm, that was used to determine an association constant (K(a)) of 140.8 M(-1). No cytotoxicity of the PZQ:MeCD inclusion compound was observed in tests using 3T3 cells. The results suggest that the association of PZQ with MeCD could be a good alternative for the treatment of schistosomiasis.
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Haemoglobins constitute a set of proteins with interesting structural and functional properties, especially when the two large animal groups reptiles and fishes are focused on. Here, the crystallization and preliminary X-ray analysis of haemoglobin-II from the South American fish matrinxa (Brycon cephalus) is reported. X-ray diffraction data have been collected to 3.0 Angstrom resolution using synchrotron radiation (LNLS). Crystals were determined to belong to space group P2(1) and preliminary structural analysis revealed the presence of two tetramers in the asymmetric unit. The structure was determined using the standard molecular-replacement technique.
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The objective of this study was to evaluate the quality of bovine frozen-thawed sperm cells after Percoll gradient centrifugation. Frozen semen doses were obtained from six bulls of different breeds, including three taurine and three Zebu animals. Four ejaculates per bull were evaluated before and after discontinuous Percoll gradient centrifugation. Sperm motility was assessed by computer-assisted semen analysis and the integrity of the plasma and acrosomal membranes, as well as mitochondrial function, were evaluated using a combination of fluorescent probes propidium iodide, fluorescein isothiocyanate-conjugated Pisum sativum agglutinin and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide. The procedure of Percoll gradient centrifugation increased the percentage of total and progressive sperm motility, beat frequency, rectilinear motility, linearity and rapidly moving cells. In addition, the percentage of cells with intact plasma membrane and mitochondrial membrane potential was increased in post-centrifugation samples. However, the percentage of sperm cells with intact acrosomal membrane was markedly reduced. The method used selected the motile cells with intact plasma membrane and higher mitochondrial functionality in frozen-thawed bull semen, but processing, centrifugation and/or the Percoll medium caused damage to the acrosomal membrane.
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The Hazard Analysis and Critical Control Point (HACCP) is a preventive system that intends to guarantee the safety and harmlessness of food. It improves the quality of products as it eliminates possible defects during the process, and saves costs by practically eliminating final product inspection. This work describes the typical hazards encountered on the mushroom processing line for fresh consumption. Throughout the process, only the reception stage of mushrooms has been considered a critical control point (CCP). The main hazards at this stage were: the presence of unauthorised phytosanitary products; larger doses of such products than those permitted; the presence of pathogenic bacteria or thermo-stable enterotoxins. Putting into practice such knowledge would provide any industry that processes mushrooms for fresh consumption with a self-control HACCP-based system for its own productions.
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O presente estudo teve como objetivo avaliar a composição nutricional dos cogumelos produzidos em substratos alternativos à base de resíduos agrícolas e agroindustriais da Amazônia. Determinou-se C, N, pH, umidade, sólidos solúveis, proteína, lipídios, fibra total, cinzas, carboidratos e energia. Os substratos foram formulados a partir de serragem de Simarouba amara Aubl. (marupá), Ochroma piramidale Cav. ex. Lam. (pau de balsa) e do estipe de Bactris gasipaes Kunth (pupunheira) e de Saccharum officinarum (cana-de-açúcar). Os resultados demonstraram que: a composição nutricional do P. ostreatus variou com o substrato de cultivo e; O P. ostreatus pode ser considerado um importante alimento devido suas características nutricionais: altos teores de proteínas, carboidratos metabolizáveis e fibras; baixos teores de lipídios e de calorias.
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A set of NIH Image macro programs was developed to make qualitative and quantitative analyses from digital stereo pictures produced by scanning electron microscopes. These tools were designed for image alignment, anaglyph representation, animation, reconstruction of true elevation surfaces, reconstruction of elevation profiles, true-scale elevation mapping and, for the quantitative approach, surface area and roughness calculations. Limitations on time processing, scanning techniques and programming concepts are also discussed.
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Bi4-xLaxTi3O12 (BLT) thin films and powders with x ranging from 0 to 0.75 were prepared by the polymeric precursor solution. The effect of lanthanum on the structure of BIT powders was investigated by Rietveld Method. The increase of lanthanum content does not lead to any secondary phases. Orthorhombicity of the bismuth titanate (BIT) crystal lattice decreased with the increase of lanthanum content due the reduction of a/b ratio. The BLT films show piezoelectric coefficients of 45, 19, 16 and 10 pm/V for x = 0, 0.25, 0.50 and 0.75, respectively. The piezoelectric response is strongly reduced by the amount of lanthanum added to the system. (c) 2006 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In most cases, the cost of a control system increases based on its complexity. Proportional (P) controller is the simplest and most intuitive structure for the implementation of linear control systems. The difficulty to find the stability range of feedback systems with P controllers, using the Routh-Hurwitz criterion, increases with the order of the plant. For high order plants, the stability range cannot be easily obtained from the investigation of the coefficient signs in the first column of the Routh's array. A direct method for the determination of the stability range is presented. The method is easy to understand, to compute, and to offer the students a better comprehension on this subject. A program in MATLAB language, based on the proposed method, design examples, and class assessments, is provided in order to help the pedagogical issues. The method and the program enable the user to specify a decay rate and also extend to proportional-integral (PI), proportional-derivative (PD), and proportional-integral-derivative (PID) controllers.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Purpose - The purpose of this paper is to provide information on lubricant contamination by biodiesel using vibration and neural network.Design/methodology/approach - The possible contamination of lubricants is verified by analyzing the vibration and neural network of a bench test under determinated conditions.Findings - Results have shown that classical signal analysis methods could not reveal any correlation between the signal and the presence of contamination, or contamination grade. on other hand, the use of probabilistic neural network (PNN) was very successful in the identification and classification of contamination and its grade.Research limitations/implications - This study was done for some specific kinds of biodiesel. Other types of biodiesel could be analyzed.Practical implications Contamination information is presented in the vibration signal, even if it is not evident by classical vibration analysis. In addition, the use of PNN gives a relatively simple and easy-to-use detection tool with good confidence. The training process is fast, and allows implementation of an adaptive training algorithm.Originality/value - This research could be extended to an internal combustion engine in order to verify a possible contamination by biodiesel.