417 research outputs found

    Measurement of the half-life of 198Au in a non-metal: High-precision measurement shows no host-material dependence

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    We have measured the half-life of the beta decay of 198Au to be 2.6948(9) d, with the nuclide sited in an insulating environment. Comparing this result with the half-life we measured previously with a metallic environment, we find the half-lives in both environments to be the same within 0.04%, thus contradicting a prediction that screening from a "plasma" of quasi-free electrons in a metal increases the half-life by as much as 7%

    Half-life of the electron-capture decay of 97Ru: Precision measurement shows no temperature dependence

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    We have measured the half-life of the electron-capture (ec) decay of 97Ru in a metallic environment, both at low temperature (19K), and also at room temperature. We find the half-lives at both temperatures to be the same within 0.1%. This demonstrates that a recent claim that the ec decay half-life for 7Be changes by $0.9% +/- 0.2% under similar circumstances certainly cannot be generalized to other ec decays. Our results for the half-life of 97Ru, 2.8370(14)d at room temperature and 2.8382(14)d at 19K, are consistent with, but much more precise than, previous room-temperature measurements. In addition, we have also measured the half-lives of the beta-emitters 103Ru and 105Rh at both temperatures, and found them also to be unchanged.Comment: 6 pages, 6 figure

    Increasing the Productive Potential of Permanent Grasslands From the Forest Steppe Area of Romania

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    In Romania permanent grasslands represent 32 % of the total agricultural area, stretching over 4,872 million hectares, out of which 340,000 ha are located in the forest steppe area, on less productive soils, which explains their inadequate botanical composition and low quality and yields (Vintu, 2003). One of the main measures taken to increase the productivity of grasslands is through fertilisation (Birch, 1999). This paper presents the results obtained during 2000-2004 on the effect of organic fertiliser on degraded grasslands made up of Festuca valesiaca L

    The Influence of Harvest Period and Fertilisation on the Yield of Some Mixed Grass and Leguminous Species Under the Forest Steppe Conditions of North-East Romania

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    In the forest steppe area of North-east Romania, temporary grasslands represent an important source of high quality fodder but they have a short period of exploitation, associated with some changes in the floristic composition (Vintu, 2003). Fertiliser application and harvest period have an important role in maintaining high productivity (Hopkins, 1991). The aim of this paper is to determine the influence of harvest period and fertilization on the yield of some grass and leguminous species in the forest steppe conditions of North-east Romania
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