1,090 research outputs found

    Rendimento do óleo essencial de Ocimum selloi benth. submetido a diferentes adubos orgânicos em associação ou não à adubação verde.

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    Este trabalho teve por objetivo verificar o efeito de diferentes adubos orgânicos em associação ou não com adubo verde no rendimento de óleo essencial de folhas de Ocimum selloi Benth., planta nativa do Brasil. O experimento foi conduzido na área experimental da Embrapa Meio Ambiente (CNPMA), localizado no município de Jaguariúna, em duas áreas distintas, sendo uma delas submetidas anteriormente ao plantio e incorporação de adubo verde (Crotalaria juncea). Os tratamentos utilizados foram: T1 - testemunha (solo sem adubação), T2 - cama de aviário (5 kg/m2), T3 - hidrolisado de peixe (produto comercial Fishfértil - 5 mL/m2) e T4 - composto orgânico (4 kg/m2). A colheita foi realizada 180 dias após o plantio, em Janeiro de 2011, sendo colhidas as plantas úteis (quatro plantas por parcela). Os óleos essenciais das folhas foram extraídos por hidrodestilação em aparelho tipo Clevenger modificado. Avaliou-se o rendimento de óleo essencial sobre o rendimento de fitomassa seca. O elineamento experimental adotado foi o esquema fatorial 2x4, com quatro repetições (DBC). As médias obtidas foram submetidas à análise de variância seguida de teste de médias (Tukey). Não foram observadas diferenças significativas no rendimento do óleo essencial de folhas de O. selloi submetidas ou não à adubação verde, em associação aos diferentes tipos de adubo orgânico quando os mesmos foram comparados à testemunha. Com base nos resultados obtidos, pode-se concluir que, nas condições ensaiadas, as adubações verde e orgânica não influenciaram no rendimento do óleo essencial de Ocimum selloi

    Physiological characterization of common bean (Phaseolus vulgaris L.) genotypes, water-stress induced with contrasting response towards drought.

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    Among the three annual common bean seasons in Brazil, two of them are subject to drought. The objective of this study was to identify physiological traits in common bean under water restriction. The common beans genotypes, BAT 477 (tolerant to water-stress) and Perola (sensitive to water-stress), were grown under greenhouse conditions under two different watering regimes: irrigated (control treatment) and non-irrigated (stress treatment). The water deficit treatment consisted of suspension of irrigation to the plants at 10 days after emergence (DAE) (at the V2 physiological stage) for 30 days, followed by the irrigation?s re-establishment at 40 DAE (at the R6-R7 physiological stage) up to the phase of physiological maturity of the grains for assessment of grain yield and production components. Under water-stress, BAT 477 showed less reduction in grain yield (33%), more capacity for osmotic adjustment (0.30 MPa) and superiority in the root system´s development (~50%) compared to Perola that showed a 53% reduction in the grain yield and 0.06 MPa of osmotic adjustment. In this study, the robustness of the root system and osmotic adjustment are the main physiological indicators of tolerance to water deficit in common bean plants

    Non-equilibrium entangled steady state of two independent two-level systems

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    We determine and study the steady state of two independent two-level systems weakly coupled to a stationary non-equilibrium environment. Whereas this bipartite state is necessarily uncorrelated if the splitting energies of the two-level systems are different from each other, it can be entangled if they are equal. For identical two-level systems interacting with two bosonic heat baths at different temperatures, we discuss the influence of the baths temperatures and coupling parameters on their entanglement. Geometric properties, such as the baths dimensionalities and the distance between the two-level systems, are relevant. A regime is found where the steady state is a statistical mixture of the product ground state and of the entangled singlet state with respective weights 2/3 and 1/3

    Propagating transverse waves in soft X-ray coronal jets

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    Aims. The theoretical model for magnetohydrodynamic (MHD) modes guided by a field-aligned plasma cylinder with a steady flow is adapted to interpret transverse waves observed in solar coronal hot jets, discovered with Hinode/XRT in terms of fast magnetoacoustic kink modes. Methods. Dispersion relations for linear magnetoacoustic perturbations of a plasma jet of constant cross-section surrounded by static magnetised plasma are used to determine the phase and group speeds of guided transverse waves and their relationship with the physical parameters of the jet and the background plasma. The structure of the perturbations in the macroscopic parameters of the plasma inside and outside the jet, and the phase relations between them are also established. Results. We obtained a convenient expansion for the long wave-length limit of the phase and group speeds and have shown that transverse waves observed in soft-X-ray solar coronal jets are adequately described in terms of fast magnetoacoustic kink modes by a magnetic cylinder model, which includes the effect of a steady flow. In the observationally determined range of parameters, the waves are not found to be subject to either the Kelvin-Helmholtz instability or the negative energy wave instability, and hence they are likely to be excited at the source of the jet

    Optimal transfers from Moon to L2L_2 halo orbit of the Earth-Moon system

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    In this paper, we seek optimal solutions for a transfer from a parking orbit around the Moon to a halo orbit around L2L_2 of the Earth-Moon system, by applying a single maneuver and exploiting the stable invariant manifold of the hyperbolic parking solution at arrival. For that, we propose an optimization problem considering as variables both the orbital characteristics of a parking solution around the Moon, (namely, its Keplerian elements) and the characteristics of a transfer trajectory guided by the stable manifold of the arrival Halo orbit. The problem is solved by a nonlinear programming method (NLP), aiming to minimize the cost of ΔV\Delta V to perform a single maneuver transfer, within the framework of the Earth-Moon system of the circular restricted three-body problem. Results with low ΔV\Delta V and suitable time of flight show the feasibility of this kind of transfer for a Cubesat

    Numerical investigations of the orbital dynamics around a synchronous binary system of asteroids

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    In this article, equilibrium points and families of periodic orbits in the vicinity of the collinear equilibrium points of a binary asteroid system are investigated with respect to the angular velocity of the secondary body, the mass ratio of the system and the size of the secondary. We assume that the gravitational fields of the bodies are modeled assuming the primary as a mass point and the secondary as a rotating mass dipole. This model allows to compute families of planar and halo periodic orbits that emanate from the equilibrium points L1 L_1 and L2L_2. The stability and bifurcations of these families are analyzed and the results are compared with the results obtained with the Restricted Three-Body Problem (RTBP). The results provide an overview of the dynamical behavior in the vicinity of a binary asteroid system

    Caracterização socioambiental da Unidade de Planejamento e Gerenciamento Apa, Mato Grosso do Sul.

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    Resumo: O Mato Grosso do Sul foi dividido em 15 Unidades de Planejamento e Gerenciamento (UPGs), sendo nove situadas na bacia hidrográfica do rio Paraná e seis na Bacia do Alto rio Paraguai (BAP), onde está inserida a UPG Apa (sub-bacia do rio Apa), área de estudo deste trabalho. A UPG Apa apresenta atividades econômicas e possui grande importância em biodiversidade com paisagens únicas e deslumbrantes que merecem ações para a conservação. Portanto, o objetivo deste trabalho foi à caracterização socioambiental da UPG Apa. O mapeamento de uso e ocupação da terra e cobertura vegetal foi elaborado na escala de 1:100.000 através de imagens de satélite CBERS 2 do ano de 2007. Todas as imagens passaram pelos mesmos processos, foram georreferenciadas, realçadas, segmentadas, mosaicadas, interpretadas e classificadas no SIG Spring. Praticamente metade desta UPG é coberta por área natural, sendo que na área antrópica predomina a pastagem plantada. Contudo, a UPG Apa encontra-se em uma área de extrema importância a biodiversidade em que 67,53% de seu território estão inseridos em áreas prioritárias para a conservação da biodiversidade segundo o MMA e 16,12% do território está protegido por Unidades de Conservação. Concluiu-se que o levantamento de dados socioeconômicos concomitantemente com a espacialização deles e os de uso da terra e cobertura vegetal permitem subsidiar planejamento ambiental de uma área a fim de se obter um desenvolvimento sustentável. Pois a integração dos dados permite entender as fragilidades e os pontos fortes de cada área.Geopantanal 2012
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