Resgate de germoplasma de Stylosanthes em áreas do semi-árido baiano.

O bioma caatinga apresenta uma paisagem bastante diversificada, na qual se destaca principalmente a família guminosae.Algumas espécies de leguminosas têm potencial para serem empregadas na alimentação animal, permitindo o pastoreio direto ou, sendo conservada, na forma de feno ou silagem. Entre as diversas leguminosas existentes em ambientes tropicais e subtropicais, destaca-se o gênero Stylosanthes. Neste, a maioria das espécies constituintes são perenes, dotadas de um potente sistema radicular, resistente à seca e apresentando boa adaptação a solos de baixa fertilidade. Para enriquecimento do banco de germoplasma de espécies forrageiras da Universidade Estadual de Feira de Santana, no estado da Bahia, foram realizadas expedições para coleta de acessos de Stylosanthes, com os dados de passaporte registrados em caderneta de coleta, com as principais informações tais como latitude e longitude, tipo de solo, de vegetação, dentre outros. Foram feitas exsicatas e os acessos coletados, após a triagem dos frutos e manejo de sementes, foram armazenados em um banco de sementes e acondicionados em potes herméticos com sílica gel; as exsicatas foram depositadas no herbário da Universidade Estadual de Feira de Santana ? HUEFS, onde estão sendo identificados por especialistas. Dentre os 57 acessos coletados, foram identificados cinco espécies, havendo diferenças de cor de sementes e tipo de planta prostrada ou ereta

Prewetting transitions of Ar and Ne on alkali metal surfaces

We have studied by means of Density-Functional calculations the wetting properties of Ar and Ne adsorbed on a plane whose adsorption properties simulate the Li and Na surfaces. We use reliable ab-initio potentials to model the gas-substrate interactions. Evidence for prewetting transitions is found for all the systems investigated and their wetting phase diagrams are calculated.Comment: 6 pages, 8 figures, submitted for publication in Phys. Rev.

Drop motion induced by vertical vibrations

We have studied the motion of liquid drops on an inclined plate subject to vertical vibrations. The liquids comprised distilled water and different aqueous solutions of glycerol, ethanol and isopropanol spanning the range 1–39 mm2 s−1 in kinematic viscosities and 40–72 mN m−1 in surface tension. At sufficiently low oscillating amplitudes, the drops are always pinned to the surface. Vibrating the plate above a certain amplitude yields sliding of the drop. Further increasing the oscillating amplitude drives the drop upward against gravity. In the case of the most hydrophilic aqueous solutions, this motion is not observed and the drop only slides downward. Images taken with a fast camera show that the drop profile evolves in a different way during sliding and climbing. In particular, the climbing drop experiences a much bigger variation in its profile during an oscillating period. Complementary numerical simulations of 2D drops based on a diffuse interface approach confirm the experimental findings. The overall qualitative behavior is reproduced suggesting that the contact line pinning due to contact angle hysteresis is not necessary to explain the drop climbing

Simple Model of Capillary Condensation in porous media

We employ a simple model to describe the phase behavior of 4He and Ar in a hypothetical porous material consisting of a regular array of infinitely long, solid, parallel cylinders. We find that high porosity geometries exhibit two transitions: from vapor to film and from film to capillary condensed liquid. At low porosity, the film is replaced by a ``necking'' configuration, and for a range of intermediate porosity there are three transitions: from vapor to film, from film to necking and from necking to a capillary condensed phase.Comment: 14 pages, 7 figure

Assessment of Indoor Levels of Carbon Monoxide Emission from Smoldering Mosquito Coils Used in Nigeria

Mosquito coils are commonly burnt in indoor environments to drive away mosquitoes which are vectors for malaria parasites. The levels of carbon monoxide (CO) emitted and human health implications during smoldering of 5 different brands of mosquito coils commonly used in Nigeria were investigated in 4 microenvironments of different sizes. The experiments were done by taking a scenario of a sleeping arrangement and the farthest distance between the coil burning and an arbitrary bed position in 4 different bedrooms of different sizes in poor ventilation condition of closed doors and windows. With monitoring device, ALTAIR 5X portable gas analyzer, at the position of the bed, measurements were taking at 2 minutes interval from start to the end of burning of each coil. The emission profile was determined by making concentration-time plots of CO emission to determine its levels from the burning of each brand of the mosquito coils in each microenvironment. From the emission profile, coils A, C, and D showed that CO levels exceeded Nigeria’s Federal Ministry of Environment (FMEnv) and the World Health Organization (WHO) statutory limit of 9.0 ppm for indoor environments in each of the microenvironments between 3 and 7 hours after the burning commenced. It was concluded that the CO concentrations from smoldering mosquito coils is a function of the size of the microenvironment in which it is used. It was recommended that the size of a microenvironment be determined for consumption of a mosquito coil before it is released into the marke

Threshold criterion for wetting at the triple point

Grand canonical simulations are used to calculate adsorption isotherms of various classical gases on alkali metal and Mg surfaces. Ab initio adsorption potentials and Lennard-Jones gas-gas interactions are used. Depending on the system, the resulting behavior can be nonwetting for all temperatures studied, complete wetting, or (in the intermediate case) exhibit a wetting transition. An unusual variety of wetting transitions at the triple point is found in the case of a specific adsorption potential of intermediate strength. The general threshold for wetting near the triple point is found to be close to that predicted with a heuristic model of Cheng et al. This same conclusion was drawn in a recent experimental and simulation study of Ar on CO_2 by Mistura et al. These results imply that a dimensionless wetting parameter w is useful for predicting whether wetting behavior is present at and above the triple temperature. The nonwetting/wetting crossover value found here is w circa 3.3.Comment: 15 pages, 8 figure

Carotenoides totais em acessos de Cucurbita maxima do banco ativo de germoplasma de cucurbitáceas da embrapa clima temperado.

Os agricultores do Sul do Brasil cultivam uma grande diversidade de variedades crioulas de abóboras (Cucurbita moschata, C. maxima, C. pepo, C. ficifolia e C. argyrosperma).Os frutos de Cucurbita maxima são uma rica fonte de nutrientes importantes para a saúde humana, dentre os quais se destacam os carotenoides. O objetivo deste trabalho foi avaliar o teor de carotenoides totais em acessos de Cucurbita maxima do Banco Ativo de Germoplasma (BAG) de Cucurbitáceas da Embrapa Clima Temperado. Foram analisados nove acessos de variedades crioulas procedentes do Sul do Brasil. Para a determinação do teor de carotenoides totais foi utilizado o método de Talcott e Howard com modificações. Os resultados foram calculados através de uma curva padrão de ?-caroteno e expressos em ?g de ?-caroteno por gramas de amostra fresca. As médias obtidas para cada uma das determinações foram comparadas entre si pelo teste de Duncan a 5% de probabilidade. O acesso com maior valor médio de carotenoides totais apresentou 221,92 ?g/g, enquanto que o menor valor de carotenoides totais encontrado foi de 22,64 ?g/g. O BAG da Embrapa Clima Temperado conserva acessos de C. maxima com variabilidade genética para teores de carotenoides totais na polpa de frutos maduros

Valor nutritivo da cunhã submetida a adubação orgânica com esterco de ovinos.

Objetivou-se avaliar a influência da adubação orgânica (esterco ovino) nas características bromatológicas da cunhã, nas diferentes frações da planta