30 research outputs found

    On the Analysis of Chemical Composition of Moon's Surface by Direct Methods

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    Proportional counter for X ray emission detection and chemical analysis of lunar surface element

    Experimental data as evidence against the hypothesis on the earth's dust cloud

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    Cosmos and Explorer satellite data used to reject hypothesis of terrestrial meteoroid and dust cloud

    Channeling Effect and Improvement of the Efficiency of Charged Particle Registration with Crystal Scintillators

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    The importance is emphasized of taking into account the channeling along the low index crystallographic axes and planes of a part of low-energy (1-10 keV) recoil ions in measurements of their parameters with crystal scintillators of the type of NaI(Tl) etc. Because the nucleus stopping power in channels is low as compared with electronic stopping power, the light yield of the scintillator must be, accordingly, higher in the given case than that for ions having higher energy (tens keV and more), which lose most part of their energy via nuclear collisions outside channels. Hence, in particular, it follows that the DAMA/NaI observations in Gran Sasso of the annual modulation of the signal frequency in a narrow range of scintillations with an amplitude of 2-6 keV electron equivalent may be due to incidence onto the Earth of exceedingly massive particles (of the type of Planckian objects) from elongated Earth-crossing heliocentric orbits at a velocity of 30-50 km/s. In NaI(Tl), these particles create the iodine recoil ions with just the energy of 2-6 keV.Comment: 10 page

    Methacrylate compositions modified by oligosilsesquioxanes with methacryl and cyclotriphosphazene substituents

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    Triethoxysilylphosphazenes have been synthesized via hydrosilylation of cyclotriphosphazenes with various contents of 4-allyl-2-methoxyphenoxy groups by triethoxysilane at an equimolar phosphazene - silane ratio. Hydrolytic copolycondensation of the latter compounds with γ-methacryloxypropyltrimethoxy - silane resulted in oligosiloxanes involving functional methacrylic and phosphazene fragment

    Absence of molecular mobility on nano-second time scales in amorphous ice phases

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    High-resolution neutron backscattering techniques are exploited to study the elastic and quasi-elastic response of the high-density amorphous (HDA), the low-density amorphous (LDA) and the crystalline ice Ic upon temperature changes. Within the temperature ranges of their structural stability (HDA at T > 80 K, LDA at T > 135 K, ice Ic at T < 200 K) the Debye-Waller factors and mean-square displacements characterise all states as harmonic solids. During the transformations HDA->LDA (T ~ 100 K), LDA->Ic (T ~ 150K) and the supposed glass transition with Tg ~ 135 K no relaxation processes can be detected on a time scale t < 4 ns. It can be concluded from coherent scattering measurements (D_2O) that LDA starts to recrystallise into ice Ic at T ~ 135 K, i.e. at the supposed Tg. In the framework of the Debye model of harmonic solids HDA reveals the highest Debye temperature among the studied ice phases, which is in full agreement with the lowest Debye level in the generalised density of states derived from time-of-flight neutron scattering experiments. The elastic results at low T indicate the presence of an excess of modes in HDA, which do not obey the Bose statistics

    Neutron Scattering Study of the Localized Mode in the beta-Pyrochlore Superconductors AOs2O6

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    Inelastic neutron scattering and neutron powder diffraction experiments were carried out to investigate a localized mode, proposed from various bulk measurements, in the beta-pyrochlore AOs2O6 (A=K, Rb, Cs). The localized mode was identified in all the three compounds as well as another beta-pyrochlore CsW2O6. The anharmonicity of the mode is weak in RbOs2O6 and CsOs2O6 but substantial in KOs2O6.Comment: 12 pages, 6 figures; typos and graph correcte

    Possible implications of the channeling effect in NaI(Tl) crystals

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    The channeling effect of low energy ions along the crystallographic axes and planes of NaI(Tl) crystals is discussed in the framework of corollary investigations on WIMP Dark Matter candidates. In fact, the modeling of this existing effect implies a more complex evaluation of the luminosity yield for low energy recoiling Na and I ions. In the present paper related phenomenological arguments are developed and possible implications are discussed at some extent.Comment: 16 pages, 10 figures, preprint ROM2F/2007/15, submitted for publicatio

    Methacrylate compositions modified by oligosilsesquioxanes with methacryl and cyclotriphosphazene substituents

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    Triethoxysilylphosphazenes have been synthesized via hydrosilylation of cyclotriphosphazenes with various contents of 4-allyl-2-methoxyphenoxy groups by triethoxysilane at an equimolar phosphazene - silane ratio. Hydrolytic copolycondensation of the latter compounds with γ-methacryloxypropyltrimethoxy - silane resulted in oligosiloxanes involving functional methacrylic and phosphazene fragment
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