177 research outputs found

    СОВЕРШЕНСТВОВАНИЕ ОРГАНИЗАЦИОННО-УПРАВЛЕНЧЕСКОЙ СТРУКТУРЫ МОРСКИХ АРКТИЧЕСКИХ ПОРТОВ РОССИИ

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    Institutional and management structure of any sea port is a system of interaction between commercial enterprises engaged in cargo operations in port, a subsidiary of Rosmorport FSUE, Sea Port Authority and a number of services (immigration, customs and sanitary-veterinary). Institutional and management structure of some Russian Arctic sea ports is significantly different from the typical one resulting in management problems for these socially significant objects of the Russian Arctic. A plan is proposed to improve the organizational and administrative structure of these ports based on the use of domestic and international experience in port infrastructure management including effective cooperation between the state and the private business.Организационно-управленческая структура морского порта – это система взаимодействия коммерческих предприятий, осуществляющих грузовую деятельность в порту, филиала ФГУП «Росморпорт», администрации морского порта и ряда служб (миграционной, таможенной и санитарно-ветеринарной). Организационно-управленческая структура морских арктических портов существенно отличается от типовой, что создает проблемы управления данными социально значимыми объектами Российского Заполярья. Предлагается план мероприятий по совершенствованию организационно-управленческой структуры указанных портов, основанный на использовании отечественного и международного опыта управления портовой инфраструктурой при эффективном взаимодействии государства и частного бизнеса

    Beam-helicity asymmetries for single-hadron production in semi-inclusive deep-inelastic scattering from unpolarized hydrogen and deuterium targets

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    A measurement of beam-helicity asymmetries for single-hadron production in deep-inelastic scattering is presented. Data from the scattering of 27.6 GeV electrons and positrons off gaseous hydrogen and deuterium targets were collected by the HERMES experiment. The asymmetries are presented separately as a function of the Bjorken scaling variable, the hadron transverse momentum, and the fractional energy for charged pions and kaons as well as for protons and anti-protons. These asymmetries are also presented as a function of the three aforementioned kinematic variables simultaneously

    Transverse-target-spin asymmetry in exclusive ω\omega-meson electroproduction

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    Hard exclusive electroproduction of ω\omega mesons is studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. The amplitudes of five azimuthal modulations of the single-spin asymmetry of the cross section with respect to the transverse proton polarization are measured. They are determined in the entire kinematic region as well as for two bins in photon virtuality and momentum transfer to the nucleon. Also, a separation of asymmetry amplitudes into longitudinal and transverse components is done. These results are compared to a phenomenological model that includes the pion pole contribution. Within this model, the data favor a positive πω\pi\omega transition form factor.Comment: DESY Report 15-14

    Longitudinal double-spin asymmetries in semi-inclusive deep-inelastic scattering of electrons and positrons by protons and deuterons

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    A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering of electrons and positrons on the proton and deuteron, based on the full HERMES data set. The dependence of the asymmetries on hadron transverse momentum and azimuthal angle extends the sensitivity to the flavor structure of the nucleon beyond the distribution functions accessible in the collinear framework. No strong dependence on those variables is observed. In addition, the hadron charge-difference asymmetry is presented, which under certain model assumptions provides access to the helicity distributions of valence quarks

    Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering

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    Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.Comment: 5 pages, 3 figure

    Bose-Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

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    Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of 1^1H, 2^2H, 3^3He, 4^4He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass W of the photon-nucleon system is found when the results are compared to those of previous experiments
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