916 resultados para Functions of complex variables.
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A complex system is often identified by the absence of a characteristic length, e.g. as in a fractal. A very large system subject to a fragmentation and/or aggregation dynamics passes through such complex configurations. We study statistically creation and maintenance of such configurations in space dimensions d = 1 to 5 and find that they are easily created (maintained) for small (large) d. An intermediate d such as d = 3 seems to be ideal for the creation and maintenance of complex systems. This has consequences in a statistical description of the universe.
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We present predictions for the spin structure functions of the proton in the framework of a unitary isobar model for one-pion photo- and electroproduction. Our results are compared with recent experimental data from SLAC. The first moments of the calculated structure functions fullfil the Gerasimov-Drell-Hearn and Burkhardt-Cottingham sum rules within an error of typically 5-10%.
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The formation of complex coacervates between chitosan and alginate was evaluated during microparticles formation. Mass ratio between polyelectrolytes and calcium chloride concentration were determinated by conductimetric analysis and by calcium ions quantification, respectively. Inert microparticles were prepared using a complex coacervation method in W/O emulsion and morphological analyses of microparticles were carried out. This method enabled the production of spherical particles, with slightly rough surface and narrow size distribution with maximal diameter of 10 μm.
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The growing demand for steels with tighter compositional specifications led the Companhia Siderúrgica Nacional (CSN) to develop more efficient processes. To solve this problem this paper aims to identify the operational variables more impacting in the desulfurization process, specifically in torpedo car, as well as its causes and solutions. Then select and test, with laboratorial and industrial tests, desulfurizing agents based of CaC 2, CaO, CaCO3, and Mg to assess the cost per quantity of product desulfurized. The mixture with best results was not that one with highest content of CaC2. It is believed that this mixture showed better efficiency because of the increased agitation of the bath, produced by the releasing of gas from compound CaCO3 present in this mixture. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Incluye Bibliografía
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Incluye Bibliografía
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Incluye Bibliografía
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Aim: Cognitive functions can decline with age, and interventions focusing on stimulating them may have positive results. Previous studies have shown that square-stepping exercise (SSE) has a good influence on balance, but this exercise also seems to promote cognitive stimulation. Therefore, the purpose of the present study was to analyse the effect of 16 weeks of SSE on cognitive functions in non-demented community-dwelling older people. Methods: This was a longitudinal, non-randomized study. Forty-one older adults (60 years and older) were recruited, and 21 participated in the SSE group (practised only SSE sequences) and 20 were in the control group (continued with their activities of daily living). Both groups were evaluated using the Mini-Mental State Examination, the Digit Span test, the Toulouse-Pierón Attention Test and the Modified Card Sorting Test. Results: The SSE group showed a significant improvement in global cognitive status, concentrated attention and mental flexibility after 16 weeks of the SSE intervention. Conclusion: Evidence shows that SSE is a physical activity that positively influences cognitive functions in non-demented older people. © 2013 Japanese Psychogeriatric Society.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Includes bibliography
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Report submitted by the Energy Division of the United Nations Economic Commission for Europe