265 research outputs found

    Vorratsschutz im Ökologischen Landbau: Entscheidungshilfe durch das Computerprogramm VOEL 1.0

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    VOEL 1.0 is a decision-support software for the protection of organic stored-products that was developed for store-keepers, farmers and pest control specialists in Ger-many. Most of the information given applies to all Central European countries, except for some legislative aspects concerning registration, which are specific for Germany. The program contains a decision-support module for monitoring and control of stored product pest, an encyclopedia on pests and beneficial organisms, a key for the deter-mination of these organisms, information on registered products for stored product protection in Germany, a data bank where literature concerning associations of pests and beneficials can be retrieved, a list of references on stored product protection in general and several original papers on stored-product protection

    Truly unentangled photon pairs without spectral filtering

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    We demonstrate that an integrated silicon microring resonator is capable of efficiently producing photon pairs that are completely unentangled; such pairs are a key component of heralded single photon sources. A dual-channel interferometric coupling scheme can be used to independently tune the quality factors associated with the pump and signal and idler modes, yielding a biphoton wavefunction with Schmidt number arbitrarily close to unity. This will permit the generation of heralded single photon states with unit purity.Comment: 5 pages, 3 figure

    Analysis of vapor barrier experiments to evaluate their effectiveness as a means to mitigate HF concentrations: final report

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    CER88-89RNM-DEN-SHS-TS-TZT-GW-1.Prepared for Exxon Research and Engineering Company.On behalf of An Industry Cooperative HF Mitigation Program, Vapor Barrier Subcommittee.Includes bibliographical references (pages 153-159).July 1988 (Revised February, 1989).Accidental releases of Hydrogen Fluoride (HF) can result in initially dense, highly reactive and corrosive gas clouds. These clouds will typically contain a mixture of gases, aerosols and droplets which can be transported significant distances before lower hazard levels of HF concentration are reached. Containment fences or vapor barriers have been proposed as a means to hold-up or delay cloud expansion, elevate the plume downwind of the barriers, and enhance cloud dilution. Previous related field and laboratory experiments have been analyzed to estimate the effectiveness of barrier devices. The experiments were examined to determine their relevance to Hydrogen Fluoride spill scenarios. Wind tunnel and field data were compared where possible to validate the laboratory experiments. Barrier influence on peak concentrations, cloud arrival time, peak concentration arrival time, and cloud departure time were determined. These data were used to develop entrainment models to incorporate into integral and depth averaged numerical models. The models were then run to examine barrier performance for a typical Hydrogen Fluoride spill for a wide range of vapor barrier heights, spill sizes, meteorological conditions and release configurations. Finally the results of the data analysis and numerical sensitivity study were interpreted and expressed in a form useful to evaluate the efficacy of vapor barrier mitigation devices

    Mitigating the effects of future climate on maize productivity.

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    Current climate changes affect agricultural production. Crop management strategies can be used to mitigate these effects. This study was carried out to evaluate the use of crop and soil management strategies to mitigate the effects of future climate on maize yield in mesoregions of the state of Minas Gerais, Brazil. The CSM-CERESMaize model was used to simulate the effect of maize root system depth and of the amount of plant residue left on the soil surface by the previous crop in maize yield for different scenarios of change in precipitation and solar radiation. The decrease in rainfall volume reduced the average maize yield in some regions by more than 50%. The increase in solar radiation maize yield rise, while its reduction caused more than 20% yield drop in most regions. The management strategies evaluated have the potential to mitigate such effects

    Nonlinear Photon Pair Generation in a Highly Dispersive Medium

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    Photon pair generation in silicon photonic integrated circuits relies on four wave mixing via the third order nonlinearity. Due to phase matching requirements and group velocity dispersion, this method has typically required TE polarized light. Here, we demonstrate TM polarized photon pair production in linearly uncoupled silicon resonators with more than an order of magnitude more dispersion than previous work. We achieve measured rates above 2.8 kHz and a heralded second order correlation of . This method enables phase matching in dispersive media and paves the way for novel entanglement generation in silicon photonic device
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