2,850 research outputs found

    Upaya Kasasi Terhadap Putusan Bebas Dalam Perkara Pidana

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    This Research was to identiy the ratiodecidendi behind the sentence of verdict in appeal against a non-guilty verdict and the implication of a legal appeal against a non-guilty verdict in a criminal case. It was a judicial normative research adopting juridical, historical, conceptual approach and cases. The legal resource were primary ones and secondary ones through bibliographical data collection. The collected data were analyzed descriptively and concluded deductively. Reffering to the results of analysis and discussions, it was concluded that : (1) the ratiodecidendi of an appeal by a general prosecutor was based on philosophy (fairness), juridical (certainty) and sociology (benefit). Among the aforementioned 3 basis, the juridical one was the most prominent, and (2) an appeal by a general prosecutor was not acceptable against all non-guilty verdicts, saved to impure acquittals

    Anisotropy effects on the magnetic excitations of a ferromagnetic monolayer below and above the Curie temperature

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    The field-driven reorientation transition of an anisotropic ferromagnetic monolayer is studied within the context of a finite-temperature Green's function theory. The equilibrium state and the field dependence of the magnon energy gap E0E_0 are calculated for static magnetic field HH applied in plane along an easy or a hard axis. In the latter case, the in-plane reorientation of the magnetization is shown to be continuous at T=0, in agreement with free spin wave theory, and discontinuous at finite temperature T>0T>0, in contrast with the prediction of mean field theory. The discontinuity in the orientation angle creates a jump in the magnon energy gap, and it is the reason why, for T>0T>0, the energy does not go to zero at the reorientation field. Above the Curie temperature TCT_C, the magnon energy gap E0(H)E_0(H) vanishes for H=0 both in the easy and in the hard case. As HH is increased, the gap is found to increase almost linearly with HH, but with different slopes depending on the field orientation. In particular, the slope is smaller when HH is along the hard axis. Such a magnetic anisotropy of the spin-wave energies is shown to persist well above TCT_C (T1.2TCT \approx 1.2 T_C).Comment: Final version accepted for publication in Physical Review B (with three figures

    A model colloidal fluid with competing interactions: bulk and interfacial properties

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    Using a simple mean-field density functional theory theory (DFT), we investigate the structure and phase behaviour of a model colloidal fluid composed of particles interacting via a pair potential which has a hard core of diameter σ\sigma, is attractive Yukawa at intermediate separations and repulsive Yukawa at large separations. We analyse the form of the asymptotic decay of the bulk fluid correlation functions, comparing results from our DFT with those from the self consistent Ornstein-Zernike approximation (SCOZA). In both theories we find rich crossover behaviour, whereby the ultimate decay of correlation functions changes from monotonic to long-wavelength damped oscillatory decay on crossing certain lines in the phase diagram, or sometimes from oscillatory to oscillatory with a longer wavelength. For some choices of potential parameters we find, within the DFT, a λ\lambda-line at which the fluid becomes unstable with respect to periodic density fluctuations. SCOZA fails to yield solutions for state points near such a λ\lambda-line. The propensity to clustering of particles, which is reflected by the presence of a long wavelength σ\gg \sigma, slowly decaying oscillatory pair correlation function, and a structure factor that exhibits a very sharp maximum at small but non zero wavenumbers, is enhanced in states near the λ\lambda-line. We present density profiles for the planar liquid-gas interface and for fluids adsorbed at a planar hard wall. The presence of a nearby λ\lambda-transition gives rise to pronounced long-wavelength oscillations in the one-body densities at both types of interface.Comment: 14 pages, 11 figure

    Recent developments of the Hierarchical Reference Theory of Fluids and its relation to the Renormalization Group

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    The Hierarchical Reference Theory (HRT) of fluids is a general framework for the description of phase transitions in microscopic models of classical and quantum statistical physics. The foundations of HRT are briefly reviewed in a self-consistent formulation which includes both the original sharp cut-off procedure and the smooth cut-off implementation, which has been recently investigated. The critical properties of HRT are summarized, together with the behavior of the theory at first order phase transitions. However, the emphasis of this presentation is on the close relationship between HRT and non perturbative renormalization group methods, as well as on recent generalizations of HRT to microscopic models of interest in soft matter and quantum many body physics.Comment: 17 pages, 5 figures. Review paper to appear in Molecular Physic

    Effect of antiferromagnetic exchange interactions on the Glauber dynamics of one-dimensional Ising models

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    We study the effect of antiferromagnetic interactions on the single spin-flip Glauber dynamics of two different one-dimensional (1D) Ising models with spin ±1\pm 1. The first model is an Ising chain with antiferromagnetic exchange interaction limited to nearest neighbors and subject to an oscillating magnetic field. The system of master equations describing the time evolution of sublattice magnetizations can easily be solved within a linear field approximation and a long time limit. Resonant behavior of the magnetization as a function of temperature (stochastic resonance) is found, at low frequency, only when spins on opposite sublattices are uncompensated owing to different gyromagnetic factors (i.e., in the presence of a ferrimagnetic short range order). The second model is the axial next-nearest neighbor Ising (ANNNI) chain, where an antiferromagnetic exchange between next-nearest neighbors (nnn) is assumed to compete with a nearest-neighbor (nn) exchange interaction of either sign. The long time response of the model to a weak, oscillating magnetic field is investigated in the framework of a decoupling approximation for three-spin correlation functions, which is required to close the system of master equations. The calculation, within such an approximate theoretical scheme, of the dynamic critical exponent z, defined as 1/τ(1/ξ)z{1/\tau} \approx ({1/ {\xi}})^z (where \tau is the longest relaxation time and \xi is the correlation length of the chain), suggests that the T=0 single spin-flip Glauber dynamics of the ANNNI chain is in a different universality class than that of the unfrustrated Ising chain.Comment: 5 figures. Phys. Rev. B (accepted July 12, 2007

    Phase transitions in simple and not so simple binary fluids

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    Compared to pure fluids, binary mixtures display a very diverse phase behavior, which depends sensitively on the parameters of the microscopic potential. Here we investigate the phase diagrams of simple model mixtures by use of a microscopic implementation of the renormalization group technique. First, we consider a symmetric mixture with attractive interactions, possibly relevant for describing fluids of molecules with internal degrees of freedom. Despite the simplicity of the model, slightly tuning the strength of the interactions between unlike species drastically changes the topology of the phase boundary, forcing or inhibiting demixing, and brings about several interesting features such as double critical points, tricritical points, and coexistence domains enclosing `islands' of homogeneous, mixed fluid. Homogeneous phase separation in mixtures can be driven also by purely repulsive interactions. As an example, we consider a model of soft particles which has been adopted to describe binary polymer solutions. This is shown to display demixing (fluid-fluid) transition at sufficiently high density. The nature and the physical properties of the corresponding phase transition are investigated.Comment: 6 pages + 3 figures, presented at the 5th EPS Liquid Matter Conference, Konstanz, 14-18 September 200

    Smooth cutoff formulation of hierarchical reference theory for a scalar phi4 field theory

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    The phi4 scalar field theory in three dimensions, prototype for the study of phase transitions, is investigated by means of the hierarchical reference theory (HRT) in its smooth cutoff formulation. The critical behavior is described by scaling laws and critical exponents which compare favorably with the known values of the Ising universality class. The inverse susceptibility vanishes identically inside the coexistence curve, providing a first principle implementation of the Maxwell construction, and shows the expected discontinuity across the phase boundary, at variance with the usual sharp cutoff implementation of HRT. The correct description of first and second order phase transitions within a microscopic, nonperturbative approach is thus achieved in the smooth cutoff HRT.Comment: 8 pages, 4 figure

    Solar urticaria in the visible spectrum successfully treated with astemizole

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    Three cases of solar urticaria in the visible spectrum successfully treated with astemizole, a H1 antihistamine, are reported. The administration of 10 mg a day of the drug increased the minimal urticarial dose from 2 to 12 times

    Finite-sized Heisenberg chains and magnetism of one-dimensional metal systems

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    We present a combined experimental and theoretical study of the magnetization of one-dimensional atomic cobalt chains deposited on a platinum surface. We discuss the intrinsic magnetization parameters derived by X-ray magnetic circular dichroism measurements and the observation of ferromagnetic order in one dimension in connection with the presence of strong, dimensionality-dependent anisotropy energy barriers of magnetocrystalline origin. An explicit transfer matrix formalism is developed to treat atomic chains of finite length within the anisotropic Heisenberg model. This model allows us to fit the experimental magnetization curves of cobalt monatomic chains, measured parallel to the easy and hard axes, and provides values of the exchange coupling parameter and the magnetic anisotropy energy consistent with those reported in the literature. The analysis of the spin-spin correlation as a function of temperature provides further insight into the tendency to magnetic order in finite-sized one-dimensional system
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