4,359 research outputs found

    Fundamentos para o desenvolvimento seguro da apicultura com abelhas africanizadas.

    Get PDF
    Espera-se que este trabalho possa contribuir para conscientizar apicultores e demais profissionais expostos à ação das abelhas africanizadas sobre a importância de se minimizar os riscos potenciais das abelhas africanizadas. Dessa forma, para facilitar a compreensão e a organização desse material, o mesmo foi dividido em três partes: A primeira refere-se as abelhas africanizadas enfocando seu histórico, comportamento e suas características que são fundamentais para o desenvolvimento das atividades dos profissionais que atuam na área. Na segunda, são estudados os pré-requisitos legais de segurança e medicina do trabalho de acordo com a Lei n.º 6.514/77 da Consolidação das Leis do Trabalho, a Portaria n.º 3.214/78 das Normas Regulamentadoras e a Portaria n.º 3.067/88 das Normas Regulamentadoras Rurais do Ministério do Trabalho para efeito de cumprimento da legislação pertinente ao assunto (MANUAL ..., 2003). Na terceira, são analisados os riscos presentes no ambiente de trabalho, evidenciando-se os seus prováveis efeitos e buscando-se gerenciá-los para que sejam minimizados ao máximo.bitstream/item/56920/1/DOC118-lancado.pd

    Procedimentos de segurança no desenvolvimento da apicultura com abelhas africanizadas (Apis mellifera L.).

    Get PDF
    bitstream/CPAP/56597/1/CT64.pdfFormato Eletrônico

    Principais oportunidades para a expansão da apicultura.

    Get PDF
    bitstream/CPAP-2009-09/56877/1/FOL137.pd

    Entropy and Poincar\'e recurrence from a geometrical viewpoint

    Full text link
    We study Poincar\'e recurrence from a purely geometrical viewpoint. We prove that the metric entropy is given by the exponential growth rate of return times to dynamical balls. This is the geometrical counterpart of Ornstein-Weiss theorem. Moreover, we show that minimal return times to dynamical balls grow linearly with respect to its length. Finally, some interesting relations between recurrence, dimension, entropy and Lyapunov exponents of ergodic measures are given.Comment: 11 pages, revised versio

    Efeito do recipiente utilizado na formação de mudas no crescimento e desenvolvimento de plantas de cajueiro cultivadas sob irrigação.

    Get PDF
    Utilizado ate recentemente como o principal recipiente para a propagacao de mudas de cajueiro anao precoce no Brasil, o saco plastico vem, gradativamente, sendo substituido pelo tubete. (...)bitstream/CNPAT-2010/5449/1/Pa-072.pd

    Benzyl N-(2-hy­droxy-1-{N′-[(1E)-2-hy­droxy­benzyl­idene]hydrazinecarbon­yl}eth­yl)carbamate

    Get PDF
    The mol­ecule of the title compound, C18H19N3O5, adopts a curved arrangement with the terminal benzene rings lying to the same side. The hydroxyl­benzene ring is close to coplanar with the adjacent hydrazine residue [dihedral angle = 11.14 (12)°], an observation which correlates with the presence of an intra­molecular O—H⋯N hydrogen bond. The benzyl ring forms a dihedral angle of 50.84 (13)° with the adjacent carbamate group. A twist in the mol­ecule, at the chiral C atom, is reflected in the dihedral angle of 80.21 (12)° formed between the amide residues. In the crystal, two-dimensional arrays in the ac plane are mediated by O—H⋯O and N—H⋯O hydrogen bonds

    Tolerance to in-band crosstalk of virtual carrier-assisted direct detection multi-band OFDM system

    Get PDF
    The tolerance to in-band crosstalk of virtual carrier (VC)-assisted direct detection (DD) multi-band orthogonal frequency division multiplexing (MB-OFDM) system is assessed numerically through Monte-Carlo simulation and considering a single interferer. The influence of the virtual carrier-to-band power ratio (VBPR) and the virtual carrier-to-band gap (VBG) of the interferer on the in-band tolerance is also studied. We show that, for interferers with the same VBG as the selected signal, the increase of the VBPR of the interferer leads to lower optical signal-to-noise ratio (OSNR) penalties. The increase of the VBG of the interferer with central frequency different from the selected signal also leads to lower OSNR penalties. When the central frequencies of the interferer and selected bands are the same, the variation VBG of the interferer can lead to 11 dB less tolerance to in-band crosstalk of the VC-assisted DD OFDM system.info:eu-repo/semantics/acceptedVersio

    Influence of the SSBI mitigation on the in-band crosstalk tolerance of virtual carrier-assisted DD multi-band OFDM metro networks

    Get PDF
    In this work, the tolerance to in-band crosstalk of virtual carrier (VC)-assisted direct detection (DD) multi-band orthogonal frequency division multiplexing (MB-OFDM) metro networks, with and without signal-to-signal beat interference (SSBI) mitigation, is compared numerically for 4-ary, 16-ary and 64-ary quadrature amplitude modulation (QAM) formats in the OFDM subcarriers. Our results show that the tolerance to in-band crosstalk is improved for lower modulation format orders. The tolerance to in-band crosstalk of DD OFDM receivers considering 4-QAM modulation format at the DD OFDM subcarriers is above 14 dB higher than the one obtained for the 64-QAM modulation format, regardless the receiver configuration. We have also shown that, the tolerance to in-band crosstalk for a given modulation format order depends on the difference between the virtual carrier-to-band power ratio (VBPR) of the selected and interfering signals, as interferers with same VBPR as the selected signal leads to equal tolerance to in-band crosstalk, independently from the DD OFDM receiver configuration and the subcarrier modulation format order considered.info:eu-repo/semantics/acceptedVersio

    Benzyl N-(1-{N′-[(E)-2-chloro­benzyl­idene]hydrazinecarbon­yl}-2-hy­droxy­eth­yl)carbamate

    Get PDF
    The mol­ecule of the title compound, C18H18ClN3O4, is twisted about the chiral C atom with the dihedral angle between the two amide residues being 87.8 (5)°, but, overall, it can be described as curved, with the benzene rings lying on the same side of the mol­ecule [dihedral angle = 62.8 (4)°]. The conformation about the imine bond [1.294 (7) Å] is E. In the crystal, a two-dimensional array in the ab plane is mediated by O—H⋯O and N—H⋯O hydrogen bonds as well as C—H⋯Cl inter­actions. The layers stack along the c-axis direction, being connected by C—H⋯.π contacts

    Inter-core crosstalk dependence on design parameters in coherent detection weakly-coupled multicore fiber systems

    Get PDF
    We assess, through numerical simulation, the dependence of the variance of the inter-core crosstalk (ICXT) and the maximum allowable ICXT level on the design parameters of coherent detection MCF systems. The analysed design parameters are the order of the quadrature amplitude modulation (QAM) signals, roll-off factor, time misalignment between the signal in different cores and skew between cores. The results show that, when the roll-off factor is 0, the maximum allowable ICXT level is independent of the skew and decreases for higher QAM orders. For a roll-off factor of 1, the maximum allowable ICXT level depends on the skew and time misalignment of core signals. In this case, the maximum allowable ICXT level increases by 3.6 dB relative to the case of roll-off factor of 0 with null skew, and by 2 dB, when the skew is much higher than the symbol period.info:eu-repo/semantics/acceptedVersio
    corecore