1,126 research outputs found

    “Let the Red Terror Intensify”: Political Violence, Governance and Society in Urban Ethiopia, 1976–78

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    Paul\u27s Personality Traits- A Potent Factor in His Success as a Missionary

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    Many books have been written on the life of Paul and his Epistles, which treat the subject critically, historically, and exegetically. There are, however, only a few monographs in existence, which have as their central object a treatment of Paul\u27s life in the light of his personality or which make an analysis of his character only. Hence, it is not in accordance with the purpose of this thesis, which it is hoped will meet the wants of the general reader interested in its subject, as well as satisfy the requirements of the Biblical student, to enter upon an elaborate criticism of the Pauline Epistles

    Simulation of the Cosmic Ray Moon Shadow in the Geomagnetic field

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    An accurate MonteCarlo simulation of the deficit of primary cosmic rays in the direction of the Moon has been developed to interpret the observations reported in the TeV energy region until now. Primary particles are propagated trough the geomagnetic field in the Earth-Moon system. The algorithm is described and the contributions of the detector resolution and of the geomagnetic field are disentangled.Comment: 4 pages, 5 figures, Contribution to the 31st ICRC, Lodz, Poland, July 200

    Eyelet particle tracing - steady visualization of unsteady flow

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    It is a challenging task to visualize the behavior of time-dependent 3D vector fields. Most of the time an overview of unsteady fields is provided via animations, but, unfortunately, animations provide only transient impressions of momentary flow. In this paper we present two approaches to visualize time varying fields with fixed geometry. Path lines and streak lines represent such a steady visualization of unsteady vector fields, but because of occlusion and visual clutter it is useless to draw them all over the spatial domain. A selection is needed. We show how bundles of streak lines and path lines, running at different times through one point in space, like through an eyelet, yield an insightful visualization of flow structure ('eyelet lines'). To provide a more intuitive and appealing visualization we also explain how to construct a surface from these lines. As second approach, we use a simple measurement of local changes of a field over time to determine regions with strong changes. We visualize these regions with isosurfaces to give an overview of the activity in the dataset. Finally we use the regions as a guide for placing eyelets

    Mutually compensative pseudo solutions of primary energy spectra in the knee region

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    The problem of the uniqueness of solutions during the evaluation of primary energy spectra in the knee region using an extensive air shower (EAS) data set and the EAS inverse approach is investigated. It is shown that the unfolding of primary energy spectra in the knee region leads to mutually compensative pseudo solutions. These solutions may be the reason for the observed disagreements in the elementary energy spectra of cosmic rays in the 1-100 PeV energy range obtained from different experiments.Comment: Accepted for publication in Astroparticle Physic

    Cosmic-ray electron injection from the ionization of nuclei

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    We show that the secondary electrons ejected from the ionization of heavy ions can be injected into the acceleration process that occurs at supernova remnant shocks. This electron injection mechanism works since ions are ionized during the acceleration when they move already with relativistic speed, just like ejected electrons do. Using the abundances of heavy nuclei measured in cosmic rays at Earth, we estimate the electron/proton ratio at the source to be ~10^-4, big enough to account for the nonthermal synchrotron emission observed in young SNRs. We also show that the ionization process can limit the maximum energy that heavy ions can reach.Comment: 4 pages, 1 figure, accepted for publication in Physical Review Letter

    Magnetic domain structure and dynamics in interacting ferromagnetic stacks with perpendicular anisotropy

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    The time and field dependence of the magnetic domain structure at magnetization reversal were investigated by Kerr microscopy in interacting ferromagnetic Co/Pt multilayers with perpendicular anisotropy. Large local inhomogeneous magnetostatic fields favor mirroring domain structures and domain decoration by rings of opposite magnetization. The long range nature of these magnetostatic interactions gives rise to ultra-slow dynamics even in zero applied field, i.e. it affects the long time domain stability. Due to this additionnal interaction field, the magnetization reversal under short magnetic field pulses differs markedly from the well-known slow dynamic behavior. Namely, in high field, the magnetization of the coupled harder layer has been observed to reverse more rapidly by domain wall motion than the softer layer alone.Comment: 42 pages including 17 figures. submitted to JA

    Time-Dependent 2-D Vector Field Topology: An Approach Inspired by Lagrangian Coherent Structures

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    This paper presents an approach to a time-dependent variant of the concept of vector field topology for 2-D vector fields. Vector field topology is defined for steady vector fields and aims at discriminating the domain of a vector field into regions of qualitatively different behaviour. The presented approach represents a generalization for saddle-type critical points and their separatrices to unsteady vector fields based on generalized streak lines, with the classical vector field topology as its special case for steady vector fields. The concept is closely related to that of Lagrangian coherent structures obtained as ridges in the finite-time Lyapunov exponent field. The proposed approach is evaluated on both 2-D time-dependent synthetic and vector fields from computational fluid dynamics
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