4,852 research outputs found

    Technological quality of organic wheat in Europe

    Get PDF
    The demand for high quality organic bread wheat is increasing. The quality level of organic wheat harvested in EU is mainly dependant on variety, environmental conditions and agronomic practices. In some countries, protein content and composition, influencing technological value, are equivalent to those produced under conventional practices. Beside agronomical techniques, technological processes can help to maintain a good quality. Pre-treatments before milling such as debranning were found to be efficient in reducing DON contamination. The project highlighted the necessity to redefine the methods to assess the quality of organic wheat

    Techniques to improve technological and sanitary quality

    Get PDF
    Agronomical ways for better quality and safety Choice of cultivar is an efficient way to obtain higher grain quality. Intercropping legumes (grain or forage) improves weed competition and N availability for wheat crop or succeeding crop. Green manure can be an effective alternative to farmyard manure. Fertilization with readily available nitrogen improves yield and quality when water is available. Reduced tillage affects soil fertility and wheat yield but has little effects on grain quality. Technological ways for better quality and safety Milling process strongly influences flour characteristics. Stone milling improves nutritive value; characteristics remain very stable independent of the milling yield. Flour characteristics from roller milling appear very susceptible to the milling yield. Increasing the milling yield in the aim of enriching nutritional quality has a detrimental effect either on safety (DON) or on bread-making quality (bread volume)

    Out-of-plane instability and electron-phonon contribution to s- and d-wave pairing in high-temperature superconductors; LDA linear-response calculation for doped CaCuO2 and a generic tight-binding model

    Full text link
    The equilibrium structure, energy bands, phonon dispersions, and s- and d-channel electron-phonon interactions (EPIs) are calculated for the infinite-layer superconductor CaCuO2 doped with 0.24 holes per CuO2. The LDA and the linear-response full-potential LMTO method were used. In the equilibrium structure, oxygen is found to buckle slightly out of the plane and, as a result, the characters of the energy bands near EF are found to be similar to those of other optimally doped HTSCs. For the EPI we find lambda(s)=0.4, in accord with previous LDA calculations for YBa2Cu3O7. This supports the common belief that the EPI mechanism alone is insufficient to explain HTSC. Lambda(x^2-y^2) is found to be positive and nearly as large as lambda(s). This is surprising and indicates that the EPI could enhance some other d-wave pairing mechanism. Like in YBa2Cu3O7, the buckling modes contribute significantly to the EPI, although these contributions are proportional to the static buckling and would vanish for flat planes. These numerical results can be understood from a generic tight-binding model originally derived from the LDA bands of YBa2Cu3O7. In the future, the role of anharmonicity of the buckling-modes and the influence of the spin-fluctuations should be investigated.Comment: 19 pages, 9 Postscript figures, Late

    Experimental investigations of synchrotron radiation at the onset of the quantum regime

    Get PDF
    The classical description of synchrotron radiation fails at large Lorentz factors, Îł\gamma, for relativistic electrons crossing strong transverse magnetic fields BB. In the rest frame of the electron this field is comparable to the so-called critical field B0=4.414⋅109B_0 = 4.414\cdot10^9 T. For χ=ÎłB/B0≃1\chi = \gamma B/B_0 \simeq 1 quantum corrections are essential for the description of synchrotron radiation to conserve energy. With electrons of energies 10-150 GeV penetrating a germanium single crystal along the axis, we have experimentally investigated the transition from the regime where classical synchrotron radiation is an adequate description, to the regime where the emission drastically changes character; not only in magnitude, but also in spectral shape. The spectrum can only be described by quantum synchrotron radiation formulas. Apart from being a test of strong-field quantum electrodynamics, the experimental results are also relevant for the design of future linear colliders where beamstrahlung - a closely related process - may limit the achievable luminosity.Comment: 11 pages, 18 figures, submitted to PR

    VÊrdien af sygdomsresistens i Þkologisk dyrket vÄrbyg

    Get PDF
    Bladsygdomme kan vÊre et vÊsentligt problem bÄde i konventionel og Þkologisk dyrkning af vÄrbyg. Der er gode muligheder for at forebygge bladsygdomme ved korrekt sortsvalg, sÄfremt man lÊgger vÊgt pÄ sortens (eller sortsblandingens) resistensegenskaber. Det er sÄledes afgÞrende at kende sortens resistens mod specielt de sygdomme, som har stÞrst sandsynlighed for, baseret pÄ den enkeltes erfaringer, at kunne blive et problem. Udover sortsegenskaber vil sygdomsniveauet for den enkelte sygdom i den enkelte mark afhÊnge af det lokale smittetryk i begyndelsen af vÊkstsÊsonen, jordens nÊringsstofbalance- og frigivelse, mikrobiel aktivitet samt vind og vejr

    Fast and Uniform Optically-Switched Data Centre Networks Enabled by Amplitude Caching

    Get PDF
    We propose amplitude caching to optically equalise burst mode traffic without delay stages. Through a fast, optically-switched system prototype, we demonstrate burst-mode penalties can be mitigated to within 0.4 dB at the KR4 HD-FEC level

    VLT identification of the optical afterglow of the gamma-ray burst GRB 000131 at z=4.50

    Get PDF
    We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent precursor signal 62 s prior to trigger. The afterglow was detected in ESO VLT, NTT, and DK1.54m follow-up observations. Broad-band and spectroscopic observations of the spectral energy distribution reveals a sharp break at optical wavelengths which is interpreted as a Ly-alpha absorption edge at 6700 A. This places GRB 000131 at a redshift of 4.500 +/- 0.015. The inferred isotropic energy release in gamma rays alone was approximately 10^54 erg (depending on the assumed cosmology). The rapid power-law decay of the afterglow (index alpha=2.25, similar to bursts with a prior break in the lightcurve), however, indicates collimated outflow, which relaxes the energy requirements by a factor of < 200. The afterglow of GRB 000131 is the first to be identified with an 8-m class telescope.Comment: 8 pages, 7 figures, accepted to A&A Letter
    • 

    corecore