980 resultados para Altitude


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Alguns exemplos de formação de minério supérgeno e sua interação com a morfogênese (paleosuperfícies) e resistência mineralógica são discutidas aqui. Registros geomorfológicos e mineralógicos na caracterização paleosuperfícies associam o intemperismo de minerais primários e sua relação com as concentrações de cobre e minério de ferro no sudeste do estado de São Paulo, Brasil. Distinguiram-se duas paleosuperfícies geradas por várias fases de intemperismo e controladas pela estrutura geológica. A primeira, mais antiga, é a paleosuperfície superior (900 - 1000 m de altitude), situado em Ribeirão Branco (Alto do Brancal), foram desenvolvidas em rochas silico-calcários. É formada por lateritas de ferro enriquecido por produtos secundários de cobre. O segundo nível de paleosuperfície é mais novo está localizado na região de Itapeva (Santa Blandina e Bairro do Sambra). Esta paleosuperfície é formada por percolação de cobre através da rocha alterada (saprolito). Outras características podem ser observadas como produtos neoformados em lateritas. Eles são classificados em dois tipos: a argila como produtos silico-cuprífero (com quantidades significativas de ferro) e de cobre minerais (crisocola, fixas nas vertentes). Essas feições reconheceram a presença de minérios de cobre e seu controle morfogénetico ajudando na exploração e prospecção de minérios supérgenos.

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Este trabalho teve por objetivo estudar os efeitos da cobertura do solo sobre o manejo da irrigação do feijoeiro (Phaseolus vulgaris L.). Os tratamentos constaram de diferentes níveis de cobertura morta com palhada de capim braquiária (Brachiaria decumbens), obedecendo delineamento experimental de blocos ao acaso com quatro repetições para os seguintes tratamentos: 0% (0 t/ha), 25% (2,25 t/ha), 50% (4,50 t/ha), 75% (6,75 t/ha) e 100% (9,0 t/ha). O experimento foi conduzido na Embrapa Arroz e Feijão, no município de Santo Antonio de Goiás, GO, a 16° 28’ 00” de latitude sul, 49° 17’00” de longitude oeste e 823 m de altitude, num Latossolo Vermelho escuro argiloso, durante o período de junho a setembro de 1997. O manejo da irrigação por microaspersão foi realizado utilizando tensiômetro e a curva característica de água no solo, irrigando toda vez que tensão matricial da água do solo atingia 30 kPa. A análise dos resultados mostrou diminuição do número de irrigações e aumento do turno de rega nos tratamentos onde a cobertura atingiu mais de 50% da superfície do solo. Os valores médios da tensão da água do solo nos tratamentos com 0,25 e 50% apresentaram maior variação (turno de rega menor). A cobertura do solo propiciou maior eficiência do uso da água. A produção de grãos foi avaliada não havendo diferença de produtividade entre os tratamentos de cobertura morta.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The present work describes an alternative methodology for identification of aeroelastic stability in a range of varying parameters. Analysis is performed in time domain based on Lyapunov stability and solved by convex optimization algorithms. The theory is outlined and simulations are carried out on a benchmark system to illustrate the method. The classical methodology with the analysis of the system's eigenvalues is presented for comparing the results and validating the approach. The aeroelastic model is represented in state space format and the unsteady aerodynamic forces are written in time domain using rational function approximation. The problem is formulated as a polytopic differential inclusion system and the conceptual idea can be used in two different applications. In the first application the method verifies the aeroelastic stability in a range of air density (or its equivalent altitude range). In the second one, the stability is verified for a rage of velocities. These analyses are in contrast to the classical discrete analysis performed at fixed air density/velocity values. It is shown that this method is efficient to identify stability regions in the flight envelope and it offers promise for robust flutter identification.

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The Brazilian campos rupestres (high-altitude grasslands) are very important on the world conservation scenario because of high species richness and endemism. These grasslands are regarded as threatened ecosystems due to intense, on-going disruption by man's activities. The aim of this study was to describe the reproductive and vegetative phenological patterns of six shrub species endemic to these grasslands in the Espinhaço Range, sympatric in Serra do Cipó, MG. We tested the relationship between species phenophases and local climate seasonality. We expect that the species phenophases are strongly correlated with variations of the dry and wet seasons. Observations were conducted monthly on reproductive (flowering, fruit production and dispersal) and vegetative (leaf fall and budding) phenophases. Given the combination of reproductive phenology, vegetative phenology, and seasonality, we observed four phenological strategies for the six species. Therefore this study revealed great diversity in phenological patterns, even when considering the small number of species sampled. Moreover, all species showed a significant seasonal pattern for the reproductive phenophases, with high concentrations of species reproducing during a given season, suggesting a key role of climate in defining phenological patterns in the campo rupestre grasslands.

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Research has investigated the best nitrogen rate for maize under the most diverse types of soil management. The aim of this study was to evaluate the influence of cover crops, soil management and topdressed N rates on the dry matter production, nutritional status, plant lodging, plant height and first-ear insertion of maize. Field experiments were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20º 20' S and 51º 24' W, at 340 m asl). Thirty-six treatments were established with four replications, in a randomized blocks design, to test combinations of cover crops (millet, Crotalaria juncea and millet + Crotalaria juncea), soil management (tillage with chisel plow + lightweight disking, heavy disking + lightweight disking, and no-tillage system) and N rates (0, 60, 90 e 120 kg ha-1 - urea as source). The maize hybrid DKB 350 YG® was used and topdressing N applied at stage V5 (fifth expanded leaf). Previously grown sunn hemp and millet + sunn hemp resulted in a higher shoot dry matter, P leaf content and total N, P and K uptake. In the no-tillage system, the initial and final population and shoot dry were highest, and first-ear insertion and plant height lower. The application of 120 kg ha-1 topdressed N increased the P leaf content, N and P in the entire plant, shoot dry matter, total N, P and K uptake, plant height, and the first-ear insertion of maize.

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This work evaluated the quality of the fruit in peach and nectarine cultivars with and without the application of hydrogenated cyanamide and mineral oil, for two production cycles (2009 and 2010). The experiment was carried out at the School of Agricultural Science of the São Paulo State University (UNESP), at Botucatu in the Brazilian state of São Paulo, located at latitude 22º51'55 S and longitude 48º26'22 E, at an altitude of 810 m. The predominant climate type is warm temperate (mesothermal) with rains in the summer and dry in the winter. The following were evaluated: soluble solids, titratable acidity, pH, ratio, firmness, vitamin C and pulp yield. The use of hydrogenated cyanamide and mineral oil had no effect on the quality attributes of the fruit, except for pH, where those fruits under application of the products showed higher values. The cultivars all had a pulp yield greater than 90%, with 'Tourmaline' showing the highest yield (96 %). The levels of vitamin C varied according to the cultivars, where 'Marli' (16.9 mg 100 g-1) and 'Dourado-2' (16.5 mg 100 g-1), stood out for having the highest levels.

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Agronomia - FEIS

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This study tested whether 3-4 weeks of classical Live High-Train High (LHTH) altitude training increases swim-specific VO2max through increased hemoglobin mass (Hb(mass)).Ten swimmers lived and trained for more than 3 weeks between 2,130 and 3,094 m of altitude, and a control group of ten swimmers followed the same training at sea-level (SL). Body composition was examined using dual X-ray absorptiometry. Hb(mass) was determined by carbon monoxide rebreathing. Swimming VO2peak was determined and swimming trials of 4 x 50, 200 and 3,000 m were performed before and after the intervention.Hb(mass) (n = 10) was increased (P < 0.05)after altitude training by 6.2 +/- A 3.9 % in the LHTH group, whereas no changes were apparent in the SL group (n = 10). Swimming VO2peak was similar before and after training camps in both groups (LHTH: n = 7, SL: n = 6). Performance of 4 x 50 m at race pace was improved to a similar degree in both groups (LHTH: n = 10, SL: n = 10). Maximal speed reached in an incremental swimming step test (P = 0.051), and time to complete 3,000 m tended (P = 0.09) to be more improved after LHTH (n = 10) than SL training (n = 10).In conclusion, 3-4 weeks of classical LHTH is sufficient to increase Hb(mass) but exerts no effect on swimming-specific VO2peak. LHTH may improve performance more than SL training.

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The use of coated potassium chloride can provide greater absorption of potassium resulting in the alteration of leaf contents, production components and grain yield. The objective of this study was to evaluate the effect of potassium doses using potassium chloride conventional or coated by polymer, in the corn crop under conditions of brazilian Savanna with low altitude. The experiment was conducted in Selviria, MS, Brazil, in a clayey Oxisol. The treatments consisted of four doses of K2O (0, 40, 80 and 120 kg ha(-1)), applied at sowing, and two sources: potassium chloride and potassium chloride coated by polymers. A randomized block design with eight treatments and four replications was used. The coated KCl is not efficient under the soil and climatic conditions studied, because it provided results similar to the conventional KCl for the K foliar content, crop components and grain yield of irrigated corn. The increment of K2O doses influenced positively the K and chlorophyll leaf contents, plant and spike insertion height and the number of rows and grains per spike. The maximum mean yield obtained was with 83.5 kg ha(-1) of K2O.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)