351 research outputs found

    Combined Calculated, Experimental and Determinated and Probable Justifications for Strength of Trunk Crude Oil Pipelines

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    Within the long-term Russian and foreign practice, deterministic methods of basic strength calculations have been developed and are being developed at the design stage of long-distance pipelines. Occurring operational damages, failures, accidents, and catastrophes show there are no direct substantiations for the prevention of such emergencies in the framework of existing calculations. In order to respond to these situations, the following are developed: additional precise deterministic, static, and probabilistic calculations with linear and nonlinear criteria of deformation and fracture mechanics, complex diagnostics of the state of the pipeline using in-line pigs, and laboratory, model, bench, and field tests of pipelines with technological and operational defects. The results of systematic scientific research and applied developments are presented

    Probabilistic Analysis of Transportation Systems for Oil and Natural Gas

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    In this chapter, the need of probabilistic modeling for design, construction, and operation of oil and gas pipelines is justified. Such modeling should use information and databases on deterministic and statistical dependencies related to deformation, damage accumulation, failure, fracture accidents, and catastrophes. The probabilistic design equations and their parameters for the characteristics of strength, durability, fracture toughness, risks of accidents, and manmade catastrophes are given. The economic efficiency of pipeline management based on controlling probabilistic characteristics through conducting diagnostic, repair-and-renewal operations while ensuring the acceptable levels of reliability and safety parameters is substantiated. The results of studies in the field of statistics and probabilities of emergency situations during manufacturing, construction, and operation conducted by Russian and foreign specialists are presented

    Inelastic Scattering of Tritium-Source Antineutrinos on Electrons of Germanium Atoms

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    Processes of the inelastic magnetic and weak scattering of tritium-beta-source antineutrinos on the bound electrons of a germanium atom are considered. The results obtained by calculating the spectra and cross sections are presented for the energy-transfer range between 1 eV and 18 keV.Comment: Latex, 7 pages, 8 ps figure

    Low-background applications of MICROMEGAS detector technology

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    The MICROMEGAS detector concept, generally optimized for use in accelerator experiments, displays a peculiar combination of features that can be advantageous in several astroparticle and neutrino physics applications. Their sub-keV ionization energy threshold, excellent energy and space resolution, and a simplicity of design that allows the use of radioclean materials in their construction are some of these characteristics. We envision tackling experimental challenges such as the measurement of neutral-current neutrino-nucleus coherent scattering or Weakly Interacting Massive Particle (WIMP) detectors with directional sensitivity. The large physics potential of a compact (total volume O(1)m3^{3}), multi-purpose array of low-background MICROMEGAS is made evident.Comment: 5 pg, presented at IMAGING-2000, Stockholm, June 2000. To appear in Nucl. Instr. & Meth. Final version after referees' inpu

    Decay of polarized muon at rest as a source of polarized neutrino beam

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    In this paper, we indicate the theoretical possibility of using the decay of polarized muons at rest as a source of the transversely polarized electron antineutrino beam. Such a beam can be used to probe new effects beyond standard model. We mean here new tests concerning CP violation, Lorentz structure and chirality structure of the charged current weak interactions. The main goal is to show how the energy and angular distribution of the electron antineutrinos in the muon rest frame depends on the transverse components of the antineutrino beam polarization. Our analysis is model-independent and consistent with the current upper limits on the non-standard couplings. The results are presented in a limit of infinitesimally small mass for all particles produced in the decay.Comment: elsart style, 11 pages, 2 eps figures, submitted do publicatio

    Thermal detection of single e-h pairs in a biased silicon crystal detector

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    We demonstrate that individual electron-hole pairs are resolved in a 1 cm2^2 by 4 mm thick silicon crystal (0.93 g) operated at ∼\sim35 mK. One side of the detector is patterned with two quasiparticle-trap-assisted electro-thermal-feedback transition edge sensor (QET) arrays held near ground potential. The other side contains a bias grid with 20\% coverage. Bias potentials up to ±\pm 160 V were used in the work reported here. A fiber optic provides 650~nm (1.9 eV) photons that each produce an electron-hole (e−h+e^{-} h^{+}) pair in the crystal near the grid. The energy of the drifting charges is measured with a phonon sensor noise σ\sigma ∼\sim0.09 e−h+e^{-} h^{+} pair. The observed charge quantization is nearly identical for h+h^+'s or e−e^-'s transported across the crystal.Comment: 4 journal pages, 5 figure

    Comparison of speed and accuracy of ractal methods of determined chaos applied to recognition of sleep phases

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    The article presents the results of use of various fractal methods and their author modifications applied to the automated recognition of sleep phases by computer electroencephalograms. The results of the application of the Grassberger-Procaccia method, Hurst rescaled range method, the author's modification of the method of false nearest neighbors and. the method of approximating entropy for recognition of sleep phases at polysomnography are presented in the work and. compared by relative rate and. accuracy. Brief description of peculiarities of used fractal methods is given in the article. It was showed that use of fractal methods of determinate chaos in synergic approach allows to realize differentiation of sleep stages with relatively high accuracy at significantly reduced time limits with use of only one canal of encephalogram. Reliability of obtained results was estimated. by comparison with the results obtained by certified neurophysiological specialist

    Right-handed Neutrinos in Low-Energy Neutrino-Electron Scattering

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    In this paper a scenario admitting the participation of the exotic scalar coupling of the right-handed neutrinos in addition to the standard vector and axial couplings of the left-handed neutrinos in the weak interactions is considered. The research is based on the low-energy (νμe−)(\nu_{\mu} e^{-}) and (νee−)(\nu_{e} e^{-}) scattering processes. The main goal is to show how the presence of the right-handed neutrinos in the above processes changes the laboratory differential cross section in relation to the Standard Model prediction. Both processes are studied at the level of the four-fermion point interaction. Neutrinos are assumed to be polarized Dirac fermions and to be massive. In the laboratory differential cross section, the new interference term between the standard vector coupling of the left-handed neutrinos and exotic scalar coupling of the right-handed neutrinos appears which does not vanish in the limit of massless neutrino. This additional contribution, including information about the transverse components of neutrino polarization, generates the azimuthal asymmetry in the angular distribution of the recoil electrons. This regularity would be a signature of the participation of the right-handed neutrinos in the neutrino-electron scattering. The future low-energy high-precision neutrino-electron scattering experiments using the strong and polarized artificial neutrino source would allow to search for the exotic effects coming from the R-handed neutrinos.Comment: REVTeX, 9 pages, 5 eps figures; published in Phys. Lett. B 555, 215-226 (2003
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