1,360 research outputs found

    Stored product protection in grain storage with special regard to phosphine fumigation

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    In Germany stored product protection belongs until now to the legislation field of plant protection. All stored product protection products used for controlling insect- and other pests require a legal approval of the plant protection authority. Roughly, the pesticides for stored product protection in grain storage can be divided into three groups:contact insecticides (spraying, fogging, powdering insecticides)fumigantsrodenticidesIn the last decade, the decrease of available active ingredients and compounds for stored product protection is quite obvious. Especially in grain storage more and more problems arise due to phase out and disappearance of these products. Several issues like ineffective control of pests or insect resistance against few remaining compounds contribute to the pressure in this context especially for the grain storage industry and difficulties in controlling pests. An update of all products and active ingredients that have an approval in 2009 are presented

    Systematic errors in diffusion coefficients from long-time molecular dynamics simulations at constant pressure

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    In molecular dynamics simulations under periodic boundary conditions, particle positions are typically wrapped into a reference box. For diffusion coefficient calculations using the Einstein relation, the particle positions need to be unwrapped. Here, we show that a widely used heuristic unwrapping scheme is not suitable for long simulations at constant pressure. Improper accounting for box-volume fluctuations creates, at long times, unphysical trajectories and, in turn, grossly exaggerated diffusion coefficients. We propose an alternative unwrapping scheme that resolves this issue. At each time step, we add the minimal displacement vector according to periodic boundary conditions for the instantaneous box geometry. Here and in a companion paper [J. Chem. Phys. XXX, YYYYY (2020)], we apply the new unwrapping scheme to extensive molecular dynamics and Brownian dynamics simulation data. We provide practitioners with a formula to assess if and by how much earlier results might have been affected by the widely used heuristic unwrapping scheme.Comment: 6 pages, 5 figures. The following article has been accepted for publication at The Journal of Chemical Physic

    Transport and magnetic properties of La_(1-x)Ca_xMnO_3-films (0.1<x<0.9)

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    By laser ablation we prepared thin films of the colossal magnetoresistive compound La_(1-x)Ca_xMnO_3 with doping levels 0.1<x<0.9 on MgO substrates. X-ray diffraction revealed epitaxial growth and a systematic decrease of the lattice constants with doping. The variation of the transport and magnetic properties in this doping series was investigated by SQUID magnetization and electrical transport measurements. For the nonmetallic samples resistances up to 10^13 Ohm have been measured with an electrometer setup. While the transport data indicate polaronic transport for the metallic samples above the Curie temperature the low doped ferromagnetic insulating samples show a variable range hopping like transport at low temperature.Comment: 2 pages, 3 EPS figures, LT22 Proceedings to appear in Physica

    Results of yield trials with spring barley

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    Trials with spring barley has been conducted on a farmers certified field. The varieties were grown after local standards as the farmer would normally do. Results of yield, disease susceptibility, growth characteristics and quality can be fould on this web page. Additional links for further results and administrative data can be found as well

    Results of yield trails with spring barley

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    On three locations, two growing systems have been investigated. One system with yield trails of spring barley varieties in pure stand, seed harrowing (if appropriate), and low input of nutrients (slurry), and one system with spring barley varieties as cover crop for a grass-white clover mixture, without nutrient input beside the precropping nutrient value. Data of yield, disease susceptibility, growth characteristics and quality can be found on this web page. Additional links for further results and administrative data can be found as well

    Magnetic Domain Structure of La0.7Sr0.3MnO3 thin-films probed at variable temperature with Scanning Electron Microscopy with Polarization Analysis

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    The domain configuration of 50 nm thick La0.7SrMnO3 films has been directly investigated using scanning electron microscopy with polarization analysis (SEMPA), with magnetic contrast obtained without the requirement for prior surface preparation. The large scale domain structure reflects a primarily four-fold anisotropy, with a small uniaxial component, consistent with magneto-optic Kerr effect measurements. We also determine the domain transition profile and find it to be in agreement with previous estimates of the domain wall width in this material. The temperature dependence of the image contrast is investigated and compared to superconducting-quantum interference device magnetometry data. A faster decrease in the SEMPA contrast is revealed, which can be explained by the technique's extreme surface sensitivity, allowing us to selectively probe the surface spin polarization which due to the double exchange mechanism exhibits a distinctly different temperature dependence than the bulk magnetization

    Thermal generation of spin current in epitaxial CoFe2O4 thin films

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    The longitudinal spin Seebeck effect (LSSE) has been investigated in high-quality epitaxial CoFe2O4 (CFO) thin films. The thermally excited spin currents in the CFO films are electrically detected in adjacent Pt layers due to the inverse spin Hall effect (ISHE). The LSSE signal exhibits a linear increase with increasing temperature gradient, yielding a LSSE coefficient of ~100 nV/K at room temperature. The temperature dependence of the LSSE is investigated from room temperature down to 30 K, showing a significant reduction at low temperatures, revealing that the total amount of thermally generated magnons decreases. Furthermore, we demonstrate that the spin Seebeck effect is an effective tool to study the magnetic anisotropy induced by epitaxial strain, especially in ultrathin films with low magnetic moments.Comment: 17 pages, 4 figure
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