540 research outputs found

    Forward electron emission in collisions of He

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    INVESTIGATION OF SOME FUNCTIONAL AND NUTRITIVE PROPERTIES OF CEREAL GERM PROTEINS

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    Proteins, protein concentrates and isolates were prepared frolll wheat, rye, barley, rice and maize germs. after defatting with hexane or supercritical carbon dioxide, by alkaline extraction (NaOH, pH=10) and acid precipitation (0.1 mol/l HCI). The chemical composition, amino acid composition and functional properties (emulsifying properties, foam activity and stability, water , and oil absorption, solubility) were determined. The digestibility and biological value of protein preparations were also calculated. Protein isolates had a high protein content (75.8 - 94.3%). The oil content was low, except in maize germ protein isolates, obtained after defatting with supercritical carbon dioxide. High digestibility (83 - 90%) and moderate biological value (63 - 7,5 FAO/WHO index) was characteristic of all isolates. Methionine and cysteine were the limiting amino acids. Ivlaize germ protein isolates showed the best functional properties, being comparable with those of soy protein isolates. Other germ protein isolates also had acceptable properties. No significant. differences were observed bet ween the functional properties of isolates prepared after defatting with hexane or supercritical carbon dioxide, except the foaming properties. The latter were adversely affected by supercritical fluid extraction

    Semiclassical model for calculating fully differential ionization cross sections of the H2_2 molecule

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    Fully differential cross sections are calculated for the ionization of H2_2 by fast charged projectiles using a semiclassical model developed previously for the ionization of atoms. The method is tested in case of 4 keV electron and 6 MeV proton projectiles. The obtained results show good agreement with the available experimental data. Interference effects due to the two-center character of the target are also observed and analyzed.Comment: 11 pages, 4 figure

    Resonant scattering of positronium as a quasifree electron

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    In order to clarify the physics underlying the observations of the electronlike behavior of positronium (Ps) and its resonant scattering from CO2, we have measured the Ps+N2 total cross section and found it also to exhibit significant structure. Analysis of the resonances reveals that Ps is distorted in the collisions and classical trajectory Monte Carlo calculations indicate that the electron is on average closer to the target than the positron, which may in turn bind resonantly to the ensuing temporary negative ion. This description of the nature of Ps resonances agrees with long-standing theoretical predictions

    The Polarized H and D Atomic Beam Source for ANKE at COSY-J\"ulich

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    A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-J\"ulich. The intensities of the beams injected into the storage cell, measured with a compression tube, are 7.510167.5\cdot 10^{16} hydrogen atoms/s (two hyperfine states) and 3.910163.9\cdot 10^{16} deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are pz±0.92p_{\rm z}\approx\pm0.92. For the deuterium beam, the obtained combinations of vector and tensor (pzzp_{\rm zz}) polarizations are pz±0.90p_{\rm z}\approx\pm 0.90 (with a constant pzz+0.86p_{\rm zz}\approx +0.86), and pzz=+0.90p_{\rm zz}=+0.90 or pzz=1.71p_{\rm zz}=-1.71 (both with vanishing pzp_{\rm z}). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development.Comment: 18 pages, 26 figures, 4 table

    Linear Estimation of Location and Scale Parameters Using Partial Maxima

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    Consider an i.i.d. sample X^*_1,X^*_2,...,X^*_n from a location-scale family, and assume that the only available observations consist of the partial maxima (or minima)sequence, X^*_{1:1},X^*_{2:2},...,X^*_{n:n}, where X^*_{j:j}=max{X^*_1,...,X^*_j}. This kind of truncation appears in several circumstances, including best performances in athletics events. In the case of partial maxima, the form of the BLUEs (best linear unbiased estimators) is quite similar to the form of the well-known Lloyd's (1952, Least-squares estimation of location and scale parameters using order statistics, Biometrika, vol. 39, pp. 88-95) BLUEs, based on (the sufficient sample of) order statistics, but, in contrast to the classical case, their consistency is no longer obvious. The present paper is mainly concerned with the scale parameter, showing that the variance of the partial maxima BLUE is at most of order O(1/log n), for a wide class of distributions.Comment: This article is devoted to the memory of my six-years-old, little daughter, Dionyssia, who leaved us on August 25, 2010, at Cephalonia isl. (26 pages, to appear in Metrika

    Loss of wave-packet coherence in ion-atom collisions

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