1000 resultados para Conversão de unidades


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Esta nota necrológica es una adaptación para la RIS del comentario publicado por Salvador Aguilar en la página web de la Editorial Hacer con motivo del fallecimiento de Charles Tilly. Esta editorial, uno de cuyos editores es Salvador Aguilar, ha publicado o está en vías de hacerlo cinco obras mayores del sociólogo norteamericano desaparecido el 29 de abril de 2008 a los 78 años. Salvador Aguilar es Profesor Titular de Estructura y Cambio Social (Universidad de Barcelona).

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OBJETIVO: Desenvolvimento e implementação de um programa, fundamentado no algoritmo de cálculo manual, para verificação dos cálculos de unidades monitoras em radioterapia e estabelecimento de patamares de aceitação, como mecanismo de garantia da qualidade. MATERIAIS E MÉTODOS: Os dados apresentados foram obtidos a partir dos aceleradores lineares modelo Clinac 600C e 2100C, da Varian, e o sistema de planejamento de tratamento computadorizado utilizado foi o CadPlan™. RESULTADOS: Para os feixes de 6 MV os patamares de aceitação para desvios entre os cálculos de unidades monitoras, separados por região de tratamento, foram: mama (0,0% ± 1,7%), cabeça e pescoço (1,5% ± 0,5%), hipófise (-1,7% ± 0,5%), pelve (2,1% ± 2,1%) e tórax (0,2% ± 1,3%). Para os feixes de 15 MV, o patamar sugerido para pelve em todas as técnicas de tratamento foi de (3,2% ± 1,3%). CONCLUSÃO: Os dados são suficientes para justificar seu uso na prática clínica como ferramenta no programa de garantia da qualidade.

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El present treball pretén oferir al lector la venta d’unitats productives com una solució adient quer permet conjugar els diferents interessos que conflueixen en un procediment concursal. De la mateixa manera, neix amb la vocació de servir com a base i guia als professionals del sector en la realització d’aquest tipus d’operacions davant la mancança del seu estudi i normativització.

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Conformational constraint is an approach which can be used to restrict the flexibility of peptide molecules and to provide information on the topographical requirements of receptors. The incorporation of conformationally constrained units in a peptide can lead to peptide analogues that present numerous advantages such as the potentialization of the pharmacological activity and the decrease of enzymatic degradation. This review discusses the peptide analogues containing a lactam or azalactam unit in their sequences. Of particular interest has been the replacement of a dipeptide motif in a peptide that simulates a beta-turn.

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Biodiesel was produced by the transesterification of neutral soybean oil and anhydrous ethanol using NaOH as catalyst. Combinations of biodiesel and diesel in the proportions of 0, 5, 10, 20, 40, 60, 80 and 100% were tested, respectively, as fuel in an energy generator. The average consumption and mixture performance were analysed. The tests showed a reduction in Diesel oil consumption when mixed with up to 20% of biodiesel. The quality characteristics of these fuels were analyzed.

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LaNiO3 perovskite was modified by partial substitution of nickel by cobalt in order to increase the stability and resistance to carbon deposition during the methane CO2 reforming. The results showed that a suitable combination of precipitation and calcination steps resulted in oxides with the desired structure and with important properties for application in heterogeneous catalysis. The partial substitution of Ni by Co resulted in lower rates of conversion of both the reactants, but the catalyst stability was highly increased. The LaNi0.3Co0.7O3 catalyst, calcined at 800 ºC, was the most active under the reaction conditions.

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The crystallization of hydroxyapatite (HA) in aqueous solution can be described by the mechanism ACP -> OCP -> HA. In this work, it was studied the influence of K+, Mg2+, SO4(2-) and CO3(2-) ions in the formation of ACP and in its conversion to OCP, using biomimetic coatings on metallic substrates of commercially pure titanium (Ti c.p.). The results showed that Mg2+ and CO3(2-) ions favored both the formation of ACP and its conversion to OCP. Differently, K+ and SO4(2-) ions did not influence the formation of ACP and, consequently, interfered in the conversion to OCP.

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Las técnicas de análisis forense digital, de aplicación en investigación criminal, también se pueden usar en las bibliotecas para acceder a información digital almacenada en soportes o formatos obsoletos. Se analizan distintos ejemplos de departamentos de análisis forense creados por bibliotecas y se describen los elementos de hardware y software mínimos con los que se podría montar una unidad de análisis forense en cualquier biblioteca. Con este fin se presentan dos posibles configuraciones de equipamiento y se dan recomendaciones sobre organización del flujo de trabajo para la recuperación de antiguos discos duros y disquetes. Forensic analysis techniques, usually applied in criminal research, could also be used in libraries to access digital information stored in obsolete formats or storage devices. This article analyses some examples of forensic research departments created by libraries, and describes the minimal hardware and software elements required to set up a library unit specialized in forensic analysis. Two possible equipment settings are introduced and recommendations are given on how to organize a workflow to recover information stored in floppy disks, diskettes and old hard drives.

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Hydrotalcite-like compounds having Mg partially replaced by Cu or Mn were prepared and used as precursors for two mixed oxides (Cu-OM50 and Mn-OM50) that were evaluated for SOx removal in the presence of O2, NO and CO. Under SO2/O2 reaction system, SOx removal was slightly higher over Cu-OM50. The addition of CO and NO to the feed markedly hindered the SO2 oxidation over Cu-OM50 while no significant effect was observed for Mn-OM50. For the regeneration step, the use of propane instead of H2 reduces regeneration capacity, mainly for Cu-OM50. Mn-OM50 was less affected by the feed composition, suggesting that it was a promising additive for SOx removal.

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Currently, public policy has encouraged innovation in universities and also transference of technology to the industry. Another important stage to be considered would be the registration or filing of a patent and the economical viability study. Government programs, such as the innovation incentive program, among others, should facilitate popularization and promote interest by industry. In this work we described the steps, from the conception of the idea to the scale up going through its interest by the industry. The case study is about the glycerol conversion utilizing modified niobia as catalysts.

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The development of analytical procedures to evaluate transesterification process is still a challenge in biodiesel production. Then, this paper shows an electroanalytical methodology to transesterification process assessment, proposing the application of nanostructured TiO2 electrodes. The results showed, for sunflower oil - methanol reaction catalyzed by KOH, a reduction peak in - 1050 mV and the gradual appearance of a second peak at - 1160 mV. This peak was observed as originated by the transesterification process and is probably related to intermediates. By measuring the intensity of this peak a kinetic profile was determined, showing that the conversion is almost finished in 2 h.

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Developing mesoporosity in HZSM-5 zeolites is an alternative for improving their catalytic performance on chemical reactions. In this work, alkaline and thermal treatments were used to produce mesoporosity. These treatments increased mesoporous area and volume. They also influenced the acid properties of the samples. Concerning catalytic performance, treatments modified reaction product distribution. Whereas alkaline treatment favored formation of olefins and increased propene ratio in the beginning of the reaction, thermal treatment resulted in formation of only ethylene due to the low acidity of the sample.

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Cobalt or iron oxides supported or not on zeolite Hbeta were prepared and evaluated in the reduction reaction of NO by CO in presence of O2, SO2 or H2O. XRD results evidenced the Hbeta structure and the formation of Co3O4 and Fe2O3. TPR-H2 analysis showed complete reduction of cobalt oxide at lower temperatures than for iron oxide. The catalysts are quite active and the activity depends on the reaction temperature. The highest conversions rates were observed for pure iron oxide, which can be a relatively low cost catalyst for reduction of NO by CO, with high selectivity towards the N2 formation.

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Oily waste from sanitation processes was characterized for its potential use in the generation of biofuels. The waste residues studied showed high levels of oil and grease, reaching up to 87% (m/m) in a grease trap of a food company, showing that these residues can be utilized for the production of biofuels. The results revealed high levels of moisture and saponification as well as high levels of free fatty acids (FFA). Analysis of chromatographic profiles (HPLC) showed great heterogeneity of the fatty acids contained in the sample, and a predominance of palmitic, oleic, linoleic and linolenic acids.