1000 resultados para Espectroscopia de voltagem de transição
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The aim of this work was the development a computer code for simulation and analysis of atomic spectra from databases constructed from the literature. There were created four routines that can be useful for spectroscopic studies in the atomic processes of laser isotope separation. In the first routine, Possible Transitions, the program checks the possible electron transitions from an energy level of the atom present in the database considering the selection rules for an electric dipole transition. The second routine, Locator Transitions, checks the possible electronic transitions within a user-specified spectral region. The routine Spectra Simulator creates simulated spectra using the graphical application gnuplot through lorentzian curve and finally, the routine Electronic Temperature determines the temperature of electronic excitation of the atom, thought the Boltzmann Plot Method. To test the reliability of the program there were obtained experimental emission spectra of a hollow cathode discharge of dysprosium and argon as a buffer gas. The hollow cathode discharge has been subjected to different values of operating currents and pressure of inert gas. The spectra obtained were treated with the assistance of program routines developed (Transition Locator and Spectra Simulator) and temperatures electronic excitation of the atoms of dysprosium in the different discharge conditions were calculated (routine Electronic Temperature). The results showed that the electronic excitation temperature of the neutral dysprosium atoms in the hollow cathode discharge increases with increasing current applied to the cathode and also by increasing the gas pressure buffer. The determination coefficients, R2, obtained by the Electronic Temperature routine using the linear adjust of the Boltzmann Plot Method were greater... (Complete abstract click electronic access below)
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Matemática em Rede Nacional - IBILCE
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This paper appears in order to promote a discussion on the use and ways of working with the land. For this, we present a scenario of conflict initiated in Pontal do Parananema, São Paulo, Brazil, between the peasantry and the agrohidronegócio. The Pontal is a territory marked by agrarian and land conflicts, originated by the illegal occupation of land by the squatters, the decimation / expropriation of indigenous, and deforestation and environmental devastation. This conflict is represented today by the sugarcane agro-industrial capital companies on one side, and the other peasants. The expansion occurs agrohidronegócio strongly from 2005, due mainly to the change in the energy matrix of the country and state incentives with strong momentum in the production of flex-fuel vehicles. Rural agrarian reform settlements, made possible by the state under pressure from social movements, are spatialized in 16 municipalities with a total of 112 settlements, occupying an area of 139. 682 hectares, seating 5. 892 families. These families have seen their possibilities of social reproduction increasingly suppressed by the advance of sugarcane agrohidronegócio in the region, which suffocates the living spaces and work of these peasants. Front of it, agroecology is an alternative for these workers to ensure their reproductive possibilities. Agroecology also arises as a means of confronting agribusiness model, adding elements to the environment, such as the eradication of the use of pesticides and considering the dynamics of nature to promote agriculture, and social order, contributing food sovereignty and the production of healthy food and diversity to the population...
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The nanostructured materials over the last decade have been increasing the variety of studies and research applications in many industries. From the understanding and manipulation of nanoscale is possible to obtain high-performance materials. One method, which has been very effective in obtaining of nanostructured composites, is the electrospinning, a technique that uses electrostatic forces to produce fibers from a polymer solution. By understanding and controlling of process conditions, such as solution viscosity, working distance, the velocity of the collector, applied voltage and others conditions, it is possible to obtain fibers in many different morphologies. This work aims to obtain nanostructured composites from polysulfone (PSU) a thermoplastic polymer with high oxidation resistance and good mechanical strength at high temperatures and carbon nanotubes (CNTs) that are excellent reinforcements for polymer materials, their mechanical resistance is greater than that of all known materials; using the electrospinning process via polymer solution. Were used polysulfone solutions, n,n-ndimetil acetamide (PSU / DMAc) and this same solution added of CNTs in order to obtain the nanofibers. In both cases were analyzed the effectiveness of the process from the analysis of fiber diameters, rheological behavior and infrared spectroscopy. The results obtained confirmed the efficiency of the electrospinning process to obtain polymeric fibers
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Pós-graduação em Medicina Veterinária - FCAV
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Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV
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In this work, RVC samples were treated by plasma immersion ion implantation (PIII) for electrodes production. High-voltage pulses with amplitudes of -3.0 kV or -10.0 kV were applied to the RVC samples while the treatment time was 10, 20 and 30 minutes. Nitrogen, atmospheric air and H2:N2 mixture were employed as plasma sources. The samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The SEM images present an apparent enhancement of the surface roughness after the treatment probably due to the surface sputtering during the PIII process. This observation is in agreement with the specific electrochemical surface area (SESA) of RVC electrodes. An increase was observed of the SESA values for the PIII treated samples compared to the untreated specimen. Some oxygen and nitrogen containing groups were introduced on the RVC surface after the PIII treatment. Both plasma-induced process: the surface roughening and the introduction of the polar species on the RVC surface are beneficial for the RVC electrodes application
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Pós-graduação em Química - IQ
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Pós-graduação em Química - IQ
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This article presents the historical trajectory of agricultural technical education in the State of São Paulo, 1882-2001, with emphasis on regulatory and policy aspects of transition management agencies and disruption in the construction and consolidation of a pedagogical and curricular design of this area of teaching technical and institutional policies of these technical schools. Thus focuses on the major changes in the political-normative and pedagogical and organizational character that shaped the construction of its especificidade.Isto because it is necessary to know the history of technical education 'agricultural' (agricultural area) in order to support the analysis of its configuration current and devise new prospects for your gestão.O Paulista agricultural education was subject to constant political uncertainties as to its principles and fins.As several transfers and reallocations it has undergone through different State Secretariats, reveal political barriers regarding its management and the difficulty of situating it in an appropriate and befitting their purposes locus.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Química - IQ
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Pós-graduação em Biofísica Molecular - IBILCE
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Pós-graduação em Ciências Sociais - FFC