7,496 research outputs found
Estudo de retenção de carotenoides totais em híbridos de mandioca cozida.
O consumo culinário das raízes de mandioca é bastante generalizado em todo o mundo, sendo que a forma de processamento mais utilizada na América Latina e África é o cozimento. As raízes de mandioca ainda podem ser integradas a pratos mais complexos. O melhoramento e a seleção de matérias primas de origem vegetal com altos conteúdos de micronutrientes vêm sendo realizada nos países em desenvolvimento com a finalidade de minimizar carências nutricionais
Zinc abundances in Galactic bulge field red giants: implications for DLA systems
Zinc in stars is an important reference element because it is a proxy to Fe
in studies of damped Lyman-alpha systems, permitting a comparison of chemical
evolution histories of bulge stellar populations and DLAs. In terms of
nucleosynthesis, it behaves as an alpha element because it is enhanced in
metal-poor stars. The aim of this work is to derive the iron-peak element Zn
abundances in 56 bulge giants from high resolution spectra. These results are
compared with data from other bulge samples, as well as from disk and halo
stars, and damped Lyman-alpha systems, in order to better understand the
chemical evolution in these environments. High-resolution spectra were obtained
using FLAMES+UVES on the Very Large Telescope. We find [Zn/Fe]=+0.24+-0.02 in
the range -1.3 < [Fe/H] < -0.5 and [Zn/Fe]=+0.06+-0.02 in the range -0.5 <
[Fe/H] -0.1, it shows a spread of -0.60 < [Zn/Fe]
< +0.15, with most of these stars having low [Zn/Fe]<0.0. These low zinc
abundances at the high metallicity end of the bulge define a decreasing trend
in [Zn/Fe] with increasing metallicities. A comparison with Zn abundances in
DLA systems is presented, where a dust-depletion correction was applied for
both Zn and Fe. Finally, we present a chemical evolution model of Zn enrichment
in massive spheroids, representing a typical classical bulge.Comment: Accepted in Astronomy & Astrophysics, in press Date of acceptance:
13/05/2015. 19 pages, 14 Figs in Astronomy & Astrophysics, 201
The effect of longitudinal distribution and seed depth on grain yield of common bean.
The aim of this study was to quantify the longitudinal distribution of plants in the row and seed depth and their effects on hypocotyl length and diameter and on yield components and grain yield of common bean, specifically the cultivar BRSMG Realce in a Latossolo soil in the Cerrado (Brazilian tropical savanna). The data on plant distances in the row were obtained in the field with the aid of a measuring tape in four rows of 2.5 m length. Seed depth was determined by measuring the length of the hypocotyl that was within the soil after pulling up the plant. Hypocotyl diameter was evaluated at ground level using a digital caliper. Descriptive (univariate) statistical analysis was applied to the data. Linear correlations were established among distribution of distance between plants in the row, the depth of sowing, the characteristics of the hypocotyls, and grain yield data of common bean. Negative linear regression was observed between grain yield with sowing depth, and positive linear regression between hypocotyl diameter and longitudinal spacing between plants in the row. In the sowing process, special attention should be given to seed distribution in the row to avoid subsequent uneven plant distribution and to seed depth to avoid yield loss
Radiolysis of ammonia-containing ices by energetic, heavy and highly charged ions inside dense astrophysical environments
Deeply inside dense molecular clouds and protostellar disks, the interstellar
ices are protected from stellar energetic UV photons. However, X-rays and
energetic cosmic rays can penetrate inside these regions triggering chemical
reactions, molecular dissociation and evaporation processes. We present
experimental studies on the interaction of heavy, highly charged and energetic
ions (46 MeV Ni^13+) with ammonia-containing ices in an attempt to simulate the
physical chemistry induced by heavy ion cosmic rays inside dense astrophysical
environments. The measurements were performed inside a high vacuum chamber
coupled to the heavy ion accelerator GANIL (Grand Accelerateur National d'Ions
Lourds) in Caen, France.\textit{In-situ} analysis is performed by a Fourier
transform infrared spectrometer (FTIR) at different fluences. The averaged
values for the dissociation cross section of water, ammonia and carbon monoxide
due to heavy cosmic ray ion analogs are ~2x10^{-13}, 1.4x10^{-13} and
1.9x10^{-13} cm, respectively. In the presence of a typical heavy cosmic
ray field, the estimated half life for the studied species is 2-3x10^6 years.
The ice compaction (micropore collapse) due to heavy cosmic rays seems to be at
least 3 orders of magnitude higher than the one promoted by (0.8 MeV) protons .
In the case of the irradiated H2O:NH3:CO ice, the infrared spectrum at room
temperature reveals five bands that were tentatively assigned to vibration
modes of the zwitterionic glycine (+NH3CH2COO-).Comment: Accepted to be published in Astronomy and Astrophysics; Number of
pages: 12; Number of Figures: 7; Number of Tables:
Conservação in vitro de germoplasma de mandioca.
A mandioca é nativa do continente americano, cultivada atualmente em muitos países, sendo o sexto produto alimentar da humanidade em volume de produção. Diante da relevância dessa cultura, a conservação in vitro constitui-se numa ferramenta importante para auxiliar na preservação de seus recursos genéticos
Resposta de milho e soja à adubação fosfatada em latossolo amarelo muito argiloso de Paragominas - Pará.
FERTBIO 2006
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