4,595 research outputs found

    Control of the apple sawfly Hoplocampa testudinea Klug in organic fruit growing

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    The best application technique and application data for the treatments with Quassia extract against the apple sawfly Hoplocampa testudinea Klug were tested. The spraying solution was distributed best on the receptacle of the blossom – the place where the sawfly larvae feed before the enter the blossom – when the treatment was effecttuated at fading blossom with a high amount of water (about 500 l/ha/mTh). The addition of T/S forte, a wetting agent, could also improve the efficacy of Quassia treatments in a lower dose. Thus, it is recommended to apply in fading blossom with addi-tion of T/S forte and high amounts of water to obtain the best effect. If the conditions for applica-tions are good and the infestation is not too high, the normally recommended dose of 6 g/ha/mTh can even be reduced

    Efficacy of Quassia extract on the apple sawfly Hoplocampa testudinea Klug

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    The efficacy of Quassia extract with a standardized content of Quassin was proved in various field trials in different regions during three years. The amount of Quassin of 6 g/ha/m tree height will be recommended to practice. It is not important to have a contact effect on the eggs. The larvae must feed on the product before they enter the fruit. There is a very good efficacy on primaray infestation. Furthermore, there is even an efficacy on secondary infestation. Thus, even if due to difficult conditions during application or not optimal termination of the treatment the efficacy on the primary infestation is not entirely sufficient, the secondary infestation will be controlled better

    Wirkung von Quassiaextrakt auf die ApfelsÀgewespe Hoplocampa testudinea Klug

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    The efficacy of Quassia extract with a standardized content of Quassin was proved in various field trials in different regions during three years. The amount of Quassin of 6 g/ha/m tree height will be recommended to practice. It is not important to have a contact effect on the eggs. The larvae must feed on the product before they enter the fruit. There is a very good efficacy on primaray infestation. Furthermore, there is even an effi-cacy on secondary infestation. Thus, even if due to difficult conditions during application or not optimal ter-mination of the treatment the efficacy on the primary infestation is not entirely sufficient, the secondary in-festation will be controlled better

    Cost benefit analysis of space communications technology: Volume 1: Executive summary

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    The questions of (1) whether or not NASA should support the further development of space communications technology, and, if so, (2) which technology's support should be given the highest priority are addressed. Insofar as the issues deal principally with resource allocation, an economics perspective is adopted. The resultant cost benefit methodology utilizes the net present value concept in three distinct analysis stages to evaluate and rank those technologies which pass a qualification test based upon probable (private sector) market failure. User-preference and technology state-of-the-art surveys were conducted (in 1975) to form a data base for the technology evaluation. The program encompassed near-future technologies in space communications earth stations and satellites, including the noncommunication subsystems of the satellite (station keeping, electrical power system, etc.). Results of the research program include confirmation of the applicability of the methodology as well as a list of space communications technologies ranked according to the estimated net present value of their support (development) by NASA

    Efficient extraction of a collimated ultra-cold neutron beam using diffusive channels

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    We present a first experimental demonstration of a new method to extract a well-collimated beam of ultra-cold neutrons (UCN) from a storage vessel. Neutrons with too large divergence are not removed from the beam by an absorbing collimation, but a diffuse or semidiffuse channel with high Fermi potential reflects them back into the vessel. This avoids unnecessary losses and keeps the storage time high, which may be beneficial when the vessel is part of a UCN source with long buildup time of a high UCN density

    Entropic and gradient flow formulations for nonlinear diffusion

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    Nonlinear diffusion ∂tρ=Δ(Ί(ρ))\partial_t \rho = \Delta(\Phi(\rho)) is considered for a class of nonlinearities Ί\Phi. It is shown that for suitable choices of Ί\Phi, an associated Lyapunov functional can be interpreted as thermodynamics entropy. This information is used to derive an associated metric, here called thermodynamic metric. The analysis is confined to nonlinear diffusion obtainable as hydrodynamic limit of a zero range process. The thermodynamic setting is linked to a large deviation principle for the underlying zero range process and the corresponding equation of fluctuating hydrodynamics. For the latter connections, the thermodynamic metric plays a central role

    Spin Glass and ferromagnetism in disordered Cerium compounds

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    The competition between spin glass, ferromagnetism and Kondo effect is analysed here in a Kondo lattice model with an inter-site random coupling JijJ_{ij} between the localized magnetic moments given by a generalization of the Mattis model which represents an interpolation between ferromagnetism and a highly disordered spin glass. Functional integral techniques with Grassmann fields have been used to obtain the partition function. The static approximation and the replica symmetric ansatz have also been used. The solution of the problem is presented as a phase diagram giving T/JT/{J} {\it versus} JK/JJ_K/J where TT is the temperature, JKJ_{K} and J{J} are the strengths of the intrasite Kondo and the intersite random couplings, respectively. If JK/JJ_K/{J} is small, when temperature is decreased, there is a second order transition from a paramagnetic to a spin glass phase. For lower T/JT/{J}, a first order transition appears between the spin glass phase and a region where there are Mattis states which are thermodynamically equivalent to the ferromagnetism. For very low T/J{T/{J}}, the Mattis states become stable. On the other hand, it is found as solution a Kondo state for large JK/JJ_{K}/{J} values. These results can improve the theoretical description of the well known experimental phase diagram of CeNi1−xCuxCeNi_{1-x}Cu_{x}.Comment: 17 pages, 5 figures, accepted Phys. Rev.
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