932 research outputs found

    Latitude variation of recurrent fluxes in the outer solar system

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    Recurrent low energy (greater than or = to 0.5 MeV) proton flux enhancements, reliable indicators of corotating plasma interaction regions, were observed on the Voyager 1 and 2 and Pioneer 11 spacecraft in the heliographic latitude range 2 deg S to 23 N and the heliocentric radial range 11 to 20 AU. After a period of rather high correlation between fluxes at different latitudes in early 1983, distinct differences developed in the fluxes during an overall flux decrease. The flux intensities returned to higher levels in early 1984 and differences in both the recurrence frequency and flux intensity persisted into 1985, as Voyager 1 traveled to 23 AU and 25 N latitude. Intercomparison of data from the three spacecraft indicates that the flux differences are most likely due to latitudinal rather than radial or temporal variations

    Pengaturan Hukum Mengenai Pemalsuan Uang Rupiah Menurut Pasal 244 Sampai Dengan Pasal 252 Kuhp

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    Tujuan dilakukannya penelitian ini adalah untuk mengetahui bagaimana pengaturan hukum mengenai tindak pidana pemalsuan uang rupiah menurut Pasal 244 sampai dengan Pasal 252 KUHP dan bagaimana tindak pidana pemalsuan uang rupiah menurut Undang-Undang Republik Indonesia Nomor 7 Tahun 2011 tentang Mata Uang. Dengan menggunakan metode penelitian yuridis normatif, disimpulkan: 1. Ketentuan tindak pidana pemalsuan uang yang diatur dalam Kitab Undang-Undang Hukum Pidana belum mengatur secara komprehensif jenis perbuatan tersebut dan sanksi yang diancamkan. Oleh karena itu ketentuan-ketentuan hukum mengenai tindak pidana pemalsuan uang disempurnakan dalam Undang-Undang Republik Indonesia Nomor 7 Tahun 2011 tentang Mata Uang. 2.Tindak pidana pemalsuan uang rupiah menurut Undang-Undang Republik Indonesia Nomor 7 Tahun 2011 tentang Mata Uang telah diatur secara lebih lengkap dan terinci sebagaimana diatur dalam Pasal 33 sampai dengan Pasal 41 pengaturan mengenai ketentuan pidana terkait masalah penggunaan, peniruan, Perusakan, dan pemalsuan Rupiah

    Large-eddy simulations of turbulent flow for grid-to-rod fretting in nuclear reactors

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    The grid-to-rod fretting (GTRF) problem in pressurized water reactors is a flow-induced vibration problem that results in wear and failure of the fuel rods in nuclear assemblies. In order to understand the fluid dynamics of GTRF and to build an archival database of turbulence statistics for various configurations, implicit large-eddy simulations of time-dependent single-phase turbulent flow have been performed in 3x3 and 5x5 rod bundles with a single grid spacer. To assess the computational mesh and resolution requirements, a method for quantitative assessment of unstructured meshes with no-slip walls is described. The calculations have been carried out using Hydra-TH, a thermal-hydraulics code developed at Los Alamos for the Consortium for Advanced Simulation of Light water reactors, a United States Department of Energy Innovation Hub. Hydra-TH uses a second-order implicit incremental projection method to solve the single-phase incompressible Navier-Stokes equations. The simulations explicitly resolve the large scale motions of the turbulent flow field using first principles and rely on a monotonicity-preserving numerical technique to represent the unresolved scales. Each series of simulations for the 3x3 and 5x5 rod-bundle geometries is an analysis of the flow field statistics combined with a mesh-refinement study and validation with available experimental data. Our primary focus is the time history and statistics of the forces loading the fuel rods. These hydrodynamic forces are believed to be the key player resulting in rod vibration and GTRF wear, one of the leading causes for leaking nuclear fuel which costs power utilities millions of dollars in preventive measures. We demonstrate that implicit large-eddy simulation of rod-bundle flows is a viable way to calculate the excitation forces for the GTRF problem.Comment: Accepted for publication in Nuclear Engineering and Design on June 12, 201

    Solar modulation and interplanetary gradients of the galactic electrons flux, 1977 - 1984

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    The flux of electrons with energy from approx. 10 to 180 MeV measured with the electron telescope on the Voyager 1 and 2 spacecraft in the heliocentric radial range 1 - 22 AU between 1977 and 1984 is reported. Jovian electrons were clearly observable between 1978 and 1983 (radial range 2 - 12 AU) at energies below approx. 50 MeV. Above approx. 50 MeV the electron intensity exhibited temporal variations generally related to the 11 year modulation of protons 75 MeV. The overall magnitude of the electron intensity changes between the maximum intensity observed in 1977 and the minimum intensity in 1981 was a factor approx. 2, also comparable to that observed for 75 MeV protons. By early 1985 the electron intensity had apparently recovered to the level observed in 1977 whereas the proton intensity was still about 20% lower. A detailed interpretation of these electron variations in all energy channels depends on an accurate subtraction of background induced by energetic protons of a few 100 MeV. This subtraction is facilitated by calibration results at several energies

    The Energy Spectrum of Jovian Electrons in Interplanetary Space

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    The energy spectrum of electrons with energies approx 10 to approx 180 MeV measured with the electron telescope on the Voyager 1 and 2 spacecraft in interplanetary space from 1978 to 1983 is studied. The kinetic energy of electrons is determined by double dE/dx measurements from the first two detectors (D sub 1, D sub 2) of a stack of eight solid state detectors and by the range of particle penetration into the remaining six detectors (D sub 3 to D sub 8) which are interleaved with tungsten absorbers. From 1978 to 1983 (radial range approximately 2 to a pproximately 12 AU) electrons of Jovian origin were clearly observable for electrons stopping in D(sub 3(E approximately greater than 4 MeV)) and in D(sub 4 (E approximately greater than 8 MeV)). For electrons stopping in D(sub 5(E approximately greather than 12 MeV)), the jovian flux dominated the galactic electron flux for a period of approximately one year near the encounter with Jupiter. Jovian electrons were also observed in D(sub 6(E approximately greater than 21 MeV)) but not in D(sub 7(E approximately greater than 28 MeV)). A detailed interpretation of the electron variations in all energy channels depends on an accurate subtraction of background induced by energetic protons of a few 100 MeV. This substraction is facilitated by laboratory calibration results at several energies. Further results on the differential energy spectrum of Jovian electrons and limits on the maximum detected energies will be reported

    Revisiting the role of magnetic field fluctuations in nonadiabatic acceleration of ions during dipolarization

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    Using energetic (9–212 keV/e) ion flux data obtained by the Geotail spacecraft, Ono et al. (2009) statistically examined changes in the energy density of H+ and O+ ions in the near-Earth plasma sheet during substorm-associated dipolarization. They found that ions are nonadiabatically accelerated by the electric field induced by the magnetic field fluctuations whose frequencies are close to their gyrofrequencies. The present paper revisits this result and finds it still holds

    Generalised-Lorentzian Thermodynamics

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    We extend the recently developed non-gaussian thermodynamic formalism \cite{tre98} of a (presumably strongly turbulent) non-Markovian medium to its most general form that allows for the formulation of a consistent thermodynamic theory. All thermodynamic functions, including the definition of the temperature, are shown to be meaningful. The thermodynamic potential from which all relevant physical information in equilibrium can be extracted, is defined consistently. The most important findings are the following two: (1) The temperature is defined exactly in the same way as in classical statistical mechanics as the derivative of the energy with respect to the entropy at constant volume. (2) Observables are defined in the same way as in Boltzmannian statistics as the linear averages of the new equilibrium distribution function. This lets us conclude that the new state is a real thermodynamic equilibrium in systems capable of strong turbulence with the new distribution function replacing the Boltzmann distribution in such systems. We discuss the ideal gas, find the equation of state, and derive the specific heat and adiabatic exponent for such a gas. We also derive the new Gibbsian distribution of states. Finally we discuss the physical reasons for the development of such states and the observable properties of the new distribution function.Comment: 13 pages, 1 figur

    Evidence for a Latitudinal Gradient of the Cosmic Ray Intensity Associated with a Change in the Tilt of the Heliospheric Current Sheet

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    Since mid-1985, the average flux of >70 MeV/nucleon cosmic rays at Voyager 2 (r_2 ∼ 17 AU, Θ_2 ∼ 0°) has been ∼3-5% greater than that at Voyager 1 (r_1 ∼ 24 AU, Θ_1 ∼ 26°N). This is the first direct observation over such a large radial range in which the galactic cosmic ray flux closer to the sun is higher than the flux farther from the sun for an extended period of time. This observation is consistent with the presence of a negative latitudinal gradient G_Θ=−0.36 ± 0.05 (or −0.60 ± 0.08) %/deg, assuming a coexistent radial gradient G_r of 1 (or 2) %/AU. We suggest that the appearance of this persistent negative latitudinal gradient may be due to the abrupt, large decrease of the heliospheric current sheet tilt to ∼20° in early 1985

    Formation of Power-law Energy Spectra in Space Plasmas by Stochastic Acceleration due to Whistler-Mode Waves

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    A non-relativistic Fokker-Planck equation for the electron distribution function is formulated incorporating the effects of stochastic acceleration by whistler-mode waves and Coulomb collisions. The stationary solution ff to the equation, subject to a zero-flux boundary condition, is found to be a generalized Lorentzian (or kappa) distribution, which satisfies fv2(κ+1)f\propto v^{-2(\kappa+1)} for large velocity vv, where κ\kappa is the spectral index. The parameter κ\kappa depends strongly on the relative wave intensity RR. Taking into account the critical energy required for resonance of electrons with whistlers, we calculate a range of values of RR for each of a number of different space plasmas for which kappa distributions can be expected to be formed. This study is one of the first in the literature to provide a theoretical justification for the formation of generalized Lorentzian (or kappa) particle distribution functions in space plasmas.Comment: 14 page-Latex, 1 ps-figure, agums.st

    Differential Measurement of Cosmic-Ray Gradient with Respect to Interplanetary Current Sheet

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    Simultaneous magnetic field and charged particle measurements from the Voyager spacecraft at heliographic latitude separations from 10° to 21 a are used to determine the latitude gradient of the galactic cosmic ray flux with respect to the interplanetary current sheet. By comparing the ratio of cosmic ray flux at Voyager 1 to that at Voyager 2 during periods when both spacecraft are first north and then south of the interplanetary current sheet, we find an estimate of the latitudinal gradient with respect to the current sheet of approximately -0.15 ± 0.05 %/ deg under restricted interplanetary conditions
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