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Search Results: 1 - 10 of 11579 matches for " Cláudio;Rezende "
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Genetic variability in three species of Gymnotus Linnaeus, 1758 (Gymnotiformes: Gymnotidae) from Caracu stream of the upper Paraná River basin, Brazil
Rezende, Judy Ruiz;Renesto, Erasmo;Zawadzki, Cláudio Henrique;
Neotropical Ichthyology , 2009, DOI: 10.1590/S1679-62252009000400010
Abstract: the genetic variability of three gymnotus species from the caracu stream, a small tributary of the left margin of paraná river (brazilian upper paraná river floodplain), was estimated with data of 17 putative allozyme loci, which were obtained by using corn starch gel electrophoresis of 10 enzymatic systems: aspartate aminotransferase (e. c. 2.6.1.1), alcohol dehydrogenase (e. c. 1.1.1.1), esterase (e. c. 3.1.1.1), glucose dehydrogenase (e. c. 1.1.1.118), glycerol-3-phosphate dehydrogenase (e. c. 1.1.1.8), isocitrate dehydrogenase (e. c. 1.1.1.42), l-lactate dehydrogenase (e. c. 1.1.1.27), malate dehydrogenase (e. c. 1.1.1.37), superoxide dismutase (e. c. 1.15.1.1) and sorbitol dehydrogenase (e. c. 1.1.1.14). the genetic diversity was estimated as he = 0.3458 for g. pantanal, he = 0.2481 for g. inaequilabiatus, and he = 0.3152 for g. sylvius. the most divergent species were g. sylvius and g. pantanal (d = 0.117), and the most similar were g. inaequilabiatus and g. pantanal (d = 0.051). the data indicates that the observed genetic variability was very low and the expected variability estimated for these three species is very high, and the genetic differences among them are small. the data suggest that the process of speciation which produced these three species is recent.
Critical values of nitrogen indices in tomato plants grown in soil and nutrient solution determined by different statistical procedures
Fontes, Paulo Cezar Rezende;Ronchi, Cláudio Pagotto;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002001000010
Abstract: the objective of this study was to establish critical values of the n indices, namely soil-plant analysis development (spad), petiole sap n-no3 and organic n in the tomato leaf adjacent to the first cluster (lac), under soil and nutrient solution conditions, determined by different statistical approaches. two experiments were conducted in randomized complete block design with four repli-cations. tomato plants were grown in soil, in 3 l pot, with five n rates (0, 100, 200, 400 and 800 mg kg-1) and in solution at n rates of 0, 4, 8, 12 and 16 mmol l-1. experiments in nutrient solution and soil were finished at thirty seven and forty two days after transplanting, respectively. at those times, spad index and petiole sap n-no3 were evaluated in the lac. then, plants were harvested, separated in leaves and stem, dried at 70oc, ground and weighted. the organic n was determined in lac dry matter. three statistical procedures were used to calculate critical n values. there were accentuated discrepancies for critical values of n indices obtained with plants grown in soil and nutrient solution as well as for different statistical procedures. critical values of nitrogen indices at all situations are presented.
Critical values of nitrogen indices in tomato plants grown in soil and nutrient solution determined by different statistical procedures
Fontes Paulo Cezar Rezende,Ronchi Cláudio Pagotto
Pesquisa Agropecuária Brasileira , 2002,
Abstract: The objective of this study was to establish critical values of the N indices, namely soil-plant analysis development (SPAD), petiole sap N-NO3 and organic N in the tomato leaf adjacent to the first cluster (LAC), under soil and nutrient solution conditions, determined by different statistical approaches. Two experiments were conducted in randomized complete block design with four repli-cations. Tomato plants were grown in soil, in 3 L pot, with five N rates (0, 100, 200, 400 and 800 mg kg-1) and in solution at N rates of 0, 4, 8, 12 and 16 mmol L-1. Experiments in nutrient solution and soil were finished at thirty seven and forty two days after transplanting, respectively. At those times, SPAD index and petiole sap N-NO3 were evaluated in the LAC. Then, plants were harvested, separated in leaves and stem, dried at 70oC, ground and weighted. The organic N was determined in LAC dry matter. Three statistical procedures were used to calculate critical N values. There were accentuated discrepancies for critical values of N indices obtained with plants grown in soil and nutrient solution as well as for different statistical procedures. Critical values of nitrogen indices at all situations are presented.
Towards a creative psychological practice: Preparing for the attention to diversity Hacia un quehacer psicológico creativo: la preparación para la atención a la diversidad
Christina Cupertino,Cláudio de Rezende Barbosa,Gustavo Nisencwajg Faleck
Revista de Psicología , 2008,
Abstract: An atypical psychological intervention, the Creativity Workshops, understood as the possibility of transformation of people, environments and/or relationships, which took place in a social Project for youths in the outskirts of Sao Paulo, is presented. Resources common to artistic expression, located in the interface between Art, Psychology, and Education were used, as well as activities of Organic Music (or corporal percussion), offered for the youngsters of the pop-rock band classes of the institution. It is discussed how the abandonment of the expectations and the opening to significant exchanges allowed the establishment, finally, in an unexpected place, of the space in where psychological care could take place, flowing and transitory as the movement of life, creating new ways of professional insertion. Se presenta una intervención psicológica atípica realizada en un proyecto social para jóvenes, los Talleres de Creatividad, en la periferia de S o Paulo, Brasil, donde la atención psicológica institucional es comprendida como la posibilidad de transformación de las personas, de los ambientes y de las relaciones. Se utilizan recursos expresivos comunes al quehacer artístico, ubicando los talleres en la interfaz entre arte, psicología y educación, así como actividades de Música Orgánica (o percusión corporal), administradas por los jóvenes de las clases de banda pop-rock de la institución. Se analiza y discute cómo la ruptura de las expectativas y la apertura a los intercambios significativos permiten el establecimiento de un espacio de cuidado psicológico fluido y transitorio, enfocado en el movimiento de la vida, creando nuevos caminos de inserción profesional.
Efeito da concentra??o do catalisador acetilacetonato férrico na cura de poliuretano à base de polibutadieno líquido hidroxilado (PBLH) e diisocianato de isoforona (IPDI)
Paterlini, Willian César;Botelho, Edson Cocchieri;Rezende, Luís Cláudio;Louren?o, Vera Lucia;Rezende, Mirabel Cerqueira;
Química Nova , 2002, DOI: 10.1590/S0100-40422002000200009
Abstract: the reaction between hydroxy-terminated polybutadiene and isophorone diisocyanate constitutes the base of the curing process of the most composite solid propellant used in the propulsion of solid rocket propellant. in this work, differential scanning calorimetry and viscosity measurements were used to evaluate the effect of the ferric acetylacetonate catalyst concentration on the reaction between htbr and ipdi. these analyses show one exotherm, which shifts to lower temperatures as the catalyst concentration increases. the viscosity analyses show that the increase of temperature causes, at first, a reduction in the mixture viscosity, reaching a minimum range called gelification region (increasing the crosslinking density).
A review on the development and properties of continuous fiber/epoxy/aluminum hybrid composites for aircraft structures
Botelho, Edson Cocchieri;Silva, Rogério Almeida;Pardini, Luiz Cláudio;Rezende, Mirabel Cerqueira;
Materials Research , 2006, DOI: 10.1590/S1516-14392006000300002
Abstract: weight reduction and improved damage tolerance characteristics were the prime drivers to develop new family of materials for the aerospace/aeronautical industry. aiming this objective, a new lightweight fiber/metal laminate (fml) has been developed. the combination of metal and polymer composite laminates can create a synergistic effect on many properties. the mechanical properties of fml shows improvements over the properties of both aluminum alloys and composite materials individually. due to their excellent properties, fml are being used as fuselage skin structures of the next generation commercial aircrafts. one of the advantages of fml when compared with conventional carbon fiber/epoxy composites is the low moisture absorption. the moisture absorption in fml composites is slower when compared with polymer composites, even under the relatively harsh conditions, due to the barrier of the aluminum outer layers. due to this favorable atmosphere, recently big companies such as embraer, aerospatiale, boing, airbus, and so one, starting to work with this kind of materials as an alternative to save money and to guarantee the security of their aircrafts.
Thermal aging of HTPB/IPDI-based polyurethane as a function of NCO/OH ratio
Villar, Luciene Dias;Cicaglioni, Thiago;Diniz, Milton Faria;Takahashi, Marta Ferreira Koyama;Rezende, Luis Cláudio;
Materials Research , 2011, DOI: 10.1590/S1516-14392011005000063
Abstract: thermal aging of hydroxy-terminated polybutadiene/isophorone diisocyanate (htpb/ipdi)-based polyurethane was studied as a function of nco/oh ratio (1.0 and 0.85). samples were aged in air ovens at 50, 60, 65, and 70 oc for periods of time from 1 to 34 weeks. changes in chemical (swelling testing and ft-ir spectroscopy) and mechanical (tension testing and hardness) properties were evaluated throughout the aging assays. correlation between equilibrium swelling ratio and elastic modulus, coupled with changes in ft-ir spectra, indicated oxidative cross-linking as the dominant mechanism for both molar ratios investigated. however, determination of arrhenius activation energy resulted in values of (82 ± 10) kj.mol-1 and (156 ± 30) kj.mol-1 for 1.0 and 0.85 nco/oh ratios, respectively, thus revealing faster oxidative degradation kinetics for higher urethane linkage networks.
Efeito da concentra o do catalisador acetilacetonato férrico na cura de poliuretano à base de polibutadieno líquido hidroxilado (PBLH) e diisocianato de isoforona (IPDI)
Paterlini Willian César,Botelho Edson Cocchieri,Rezende Luís Cláudio,Louren?o Vera Lucia
Química Nova , 2002,
Abstract: The reaction between hydroxy-terminated polybutadiene and isophorone diisocyanate constitutes the base of the curing process of the most composite solid propellant used in the propulsion of solid rocket propellant. In this work, differential scanning calorimetry and viscosity measurements were used to evaluate the effect of the ferric acetylacetonate catalyst concentration on the reaction between HTBR and IPDI. These analyses show one exotherm, which shifts to lower temperatures as the catalyst concentration increases. The viscosity analyses show that the increase of temperature causes, at first, a reduction in the mixture viscosity, reaching a minimum range called gelification region (increasing the crosslinking density).
Development and evaluation of a hypermedia system that integrates basic concepts of mechanics, biomechanics and human anatomy
Flavia Rezende,Marco Antonio Cavalcanti Garcia,Cláudio dos Santos Dias Cola
Investiga??es em Ensino de Ciências , 2006,
Abstract: This work describes the modeling of a hypermedia learning system (called “Biomec”) that integrates physical, biomechanical and anatomical concepts involved in the human motion and a study carried out with undergraduate students who interacted with the system. The instructional design of the “Biomec” hypermedia system was developed on the basis of a theoretical framework which articulates the Cognitive Flexibility Theory and the interdisciplinary approach to knowledge. The system was evaluated based on its use by students of Biomechanics I and Kinesiology in a Pre Service Teachers Training Course of Physical Education aiming to discuss the following questions: (i) what is its impact on the students’ attitude related to Physics? (ii) in what extent does the hypertextual approach to the content favor the interdisciplinary conception of human motion? (iii) in what extent do the students’ navigation profiles adapt to conceptual needs of the different disciplines of the course? The students answered instruments that assessed affective and cognitive aspects before and after the interaction with the system, and had their navigation registered and analyzed. The set of data obtained allowed to conclude that the “Biomec” system is a relevant instructional material, capable of positively influence the students’ attitude related to Physics, to favor the interdisciplinary approach of human motion and to attend the students enrolled in Biomechanics I better than the students enrolled in Kinesiology.
Performance evaluation of commercial copper chromites as burning rate catalyst for solid propellants
Eunice Aparecida Campos,Rita de Cássia L. Dutra,Luis Cláudio Rezende,Milton Faria Diniz
Journal of Aerospace Technology and Management , 2010,
Abstract: Copper chromites are well known as burning rate catalysts for the combustion of composite solid propellants, used as a source of energy for rocket propulsion. The propellant burning rate depends upon the catalyst characteristics such as chemical composition and specific surface area. In this work, copper chromite samples from different suppliers were characterized by chemical analysis, FT-IR spectroscopy and by surface area measurement (BET). The samples were then evaluated as burning rate catalyst in a typical composite propellant formulation based on HTPB binder, ammonium perchlorate and aluminum. The obtained surface area values are very close to those informed by the catalyst suppliers. The propellant processing as well as its mechanical properties were not substantially affected by the type of catalyst. Some copper chromite catalysts caused an increase in the propellant burning rate in comparison to the iron oxide catalyst. The results show that in addition to the surface area, other parameters like chemical composition, crystalline structure and the presence of impurities might be affecting the catalyst performance. All evaluated copper chromite samples may be used as burning rate catalyst in composite solid propellant formulations, with slight advantages for the SX14, Cu-0202P and Cu-1800P samples, which led to the highest burning rate propellants.
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