497 research outputs found

    Composição bromatológica de silagens de híbridos de sorgo cultivados em diferentes densidades de plantas.

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    Avaliou-se a composição bromatológica das silagens de dois híbridos de sorgo, AG-2005 (duplo propósito) e VOLUMAX (forrageiro), cultivados nos espaçamentos de 0,50; 0,75 e 1,00 m, resultando nas densidades de 140.000; 186.666 e 280.000 plantas por ha, respectivamente. A silagem do híbrido AG-2005 apresentou matéria seca (MS) superior no espaçamento de 1,00 m e foi mais elevada ao da silagem de VOLUMAX em todos os espaçamentos. A proteína bruta (PB) elevou-se com a redução dos espaçamentos (6,6; 6,8 e 8%, respectivamente), com maior valor médio no AG-2005 (7,7 vs 6,5%). A fibra em detergente neutro (FDN) foi menor no AG-2005 (59,25 vs 62,3%) e no espaçamento 0,75 m. Para fibra em detergente ácido (FDA) ocorreu diferença entre os dois híbridos no espaçamento 0,5 m, sendo de 33,5 e 39,3 %, respectivamente, para o AG-2005 e VOLUMAX. O EE apresentou diferença significativa (P < 0,05) entre os dois híbridos no espaçamento 0,75 m, sendo maior no AG-2005 (2,05 vs 1,61%). Conclui-se que o híbrido AG-2005 é mais recomendado para ensilagem, pois a sua silagem apresenta características qualitativas melhores que do VOLUMAX. O espaçamento de 0,5 m é o mais indicado no plantio dos híbridos, pois melhora a composição química das silagens. Chemical composition of silage sorghum hybrids grown at different densities. AbstractT - The objective of the experiment was to evaluate the nutritive value of silages from two sorghum hybrids, AG-2005 (double purpose) and VOLUMAX (forage) cultivated with different row spacings (0.50 m; 0.75 m and 1.00 m), resulting in 140,000; 186,666 e 280,000 plants per ha, respectively. Dry matter content of AG-2005 silage was higher for 1 m row spacing, and was higher than for VOLUMAX silage in all row spacings. Crude protein increased as the row spacing was reduced (6.6; 6.8 and 8%, respectively), with higher average value for AG-2005 (7.7 vs 6.5%). Neutral detergent fiber was lower for AG-2005 (59.25 vs 62.3%) and for .75 m spacing. Acid detergent fiber differed between hybrids in .5 m row spacing, being 33.5 and 39.3%, respectively, for AG-2005 and VOLUMAX. Ether extract was significantly different between hybrids in .5 m row spacing, being higher for AG-2005 (2.05 vs 1.61%). The use of AG-2005 is recommended for silage production due to its better qualitative characteristics than the VOLUMAX. The .5 m row spacing is recommended for both hybrids, since it improves the chemical composition of the silages

    Lattice sites of ion-implanted Li in diamond

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    Published in: Appl. Phys. Lett. 66 (1995) 2733-2735 citations recorded in [Science Citation Index] Abstract: Radioactive Li ions were implanted into natural IIa diamonds at temperatures between 100 K and 900 K. Emission channelling patterns of a-particles emitted in the nuclear decay of 8Li (t1/2 = 838 ms) were measured and, from a comparison with calculated emission channelling and blocking effects from Monte Carlo simulations, the lattice sites taken up by the Li ions were quantitatively determined. A fraction of 40(5)% of the implanted Li ions were found to be located on tetrahedral interstitial lattice sites, and 17(5)% on substitutional sites. The fractions of implanted Li on the two lattice sites showed no change with temperature, indicating that Li diffusion does not take place within the time window of our measurements.

    Amorphization of ZnSe by ion implantation at low temperatures

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    Radioactive Cd and Se ions were implanted into high-resistivity ZnSe single crystals around 60 K and 300 K. Their lattice sites were determined by measuring the channelling and blocking effects of the emitted conversion electrons or positrons directly after implantation and after annealing at different temperatures up to 600 K. Implantation doses were in the range of 3×1012\times 10^{12} - 3×1013\times10^{13}/cm2^2. The experimental results of this emission channelling technique yield a high substitutional fraction of the implanted ions directly after implantation at room temperature. At 60 K the substitutional fraction of implanted ions is highly sensitive to the ion dose. Above a critical dose of around 1.4×1013\times10^{13} Cd/cm2^2 or 2.1×1013\times10^{13} Se/cm2^2 the substitutional fraction completely disappears indicating an amorphous surrounding of the probe atom. Damage recovery was observed below room temperature and at an annealing temperature around 500 K. A quantitative analysis of measured channelling yields will be given by comparison with calculated electron channelling profiles based on the dynamical theory of electron diffraction

    α\alpha-emission channeling investigations of the lattice location of Li in Ge

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    The α\alpha-emission channeling and blocking technique is a direct method for lattice site determination of radioactive atoms in single crystals. Position-sensitive detection of emitted α\alpha -particles provides an efficient means of carrying out such experiments at very low doses (1010^{10}-1011^{11} implanted probe atoms per spectrum). Comparison of the experimental data to Monte Carlo simulations of complete two-dimensional channeling patterns (e.g. ±2°C around , and axes, which also includes all relevant planar directions) allows for straight-forward identification and rather accurate quantitative determination of occupied lattice sites, while at the same time the energy spectrum of emitted a particles gives information on the probe atom depth distribution. We illustrate this for the case of ion implanted 8^8Li (t_=0.8 s) in Ge, where we identify mainly tetrahedral Li at room temperature, and bond-centered Li at slightly elevated temperature

    Características da carcaça de Tourinhos Nelore x Limousin alimentados com dietas contendo gérmen de milho integral.

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    Foram avaliadas as características quantitativas das carcaças de 24 tourinhos Nelore X Limousin submetidos a dietas contendo 0%, 15% e 45% de gérmen de milho integral (GMI), terminados em confinamento, com peso e idade média inicial de 321,25 kg e vinte meses, respectivamente
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