5,041 research outputs found

    Study of non-equilibrium effects and thermal properties of heavy ion collisions using a covariant approach

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    Non-equilibrium effects are studied using a full Lorentz-invariant formalism. Our analysis shows that in reactions considered here, no global or local equilibrium is reached. The heavier masses are found to be equilibrated more than the lighter systems. The local temperature is extracted using hot Thomas Fermi formalism generalized for the case of two interpenetrating pieces of nuclear matter. The temperature is found to vary linearly with bombarding energy and impact parameter whereas it is nearly independent of the mass of the colliding nuclei. This indicates that the study of temperature with medium size nuclei is also reliable. The maximum temperatures obtained in our approach are in a nice agreement with earlier calculations of other approaches. A simple parametrization of maximal temperature as a function of the bombarding energy is also given.Comment: LaTex-file, 17 pages, 8 figures (available upon request), Journal of Physics G20 (1994) 181

    Domain Growth in Random Magnets

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    We study the kinetics of domain growth in ferromagnets with random exchange interactions. We present detailed Monte Carlo results for the nonconserved random-bond Ising model, which are consistent with power-law growth with a variable exponent. These results are interpreted in the context of disorder barriers with a logarithmic dependence on the domain size. Further, we clarify the implications of logarithmic barriers for both nonconserved and conserved domain growth.Comment: 7 pages, 4 figure

    COMMUNALIZATION OF PEKULEN LAND AND DISTRIBUTION OF ITS UTILIZATION AS A MECHANISM FOR REALIZING AGRARIAN JUSTICE

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    Purpose: The purpose of this study is to describe the tradition of communalization of pekulen land and the distribution of its use. Methodology: This research conducted with empirical legal research those locations in Pituruh Subdistrict, Purworejo Regency, Central Java with the socio-legal approach. Results: This research found that the communal mechanism for pekulen land was first developed by the Dutch colonial government by utilizing local customary law to guarantee the availability of labor and agricultural land for land taxes and cultuurstelsel. This model now transformed and has many benefits such distribute the right of land use,  protecting the rights of landholders, guaranteeing the protection of land functions, maintaining the integrity of village communities, and so on. The implementation of communalization of pekulen land and distribution of its use is a mechanism of local wisdom that grows and develops by transforming the values of customary law in land regulation. Implications: This paper provides a new way of understanding the practice of communalization of land that initiated by the citizens. Pekulen land is a form of land rights originating from customary law which is owned by the village community who are given the right of use to members of the village community to be used for their personal interests. Thus, Land communalization is an alternative policy model that is applied to regulate land ownership in a more organized manner with a strong collectivity bond in a community

    Amplification of Fluctuations in Unstable Systems with Disorder

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    We study the early-stage kinetics of thermodynamically unstable systems with quenched disorder. We show analytically that the growth of initial fluctuations is amplified by the presence of disorder. This is confirmed by numerical simulations of morphological phase separation (MPS) in thin liquid films and spinodal decomposition (SD) in binary mixtures. We also discuss the experimental implications of our results.Comment: 15 pages, 4 figure

    Cerebral spectroscopic and oxidative stress studies in patients with schizophrenia who have dangerously violently offended

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to bring together all the results of <it>in vivo </it>studies of ethane excretion and cerebral spectroscopy in patients with schizophrenia who have dangerously seriously violently offended in order to determine the extent to which they shed light on the degree to which the membrane phospholipid hypothesis and the actions of free radicals and other reactive species are associated with cerebral pathophysiological mechanisms in this group of patients.</p> <p>Methods</p> <p>The patients investigated were inpatients from a medium secure unit with a DSM-IV-TR diagnosis of schizophrenia. There was no history of alcohol dependency or any other comorbid psychoactive substance misuse disorder. Expert psychiatric opinion, accepted in court, was that all these patients had violently offended directly as a result of schizophrenia prior to admission. These offences consisted of homicide, attempted murder or wounding with intent to cause grievous bodily harm. Excreted ethane was analyzed and quantified by gas chromatography and mass spectrometry (<it>m</it>/<it>z </it>= 30). 31-phosphorus magnetic resonance spectroscopy data were obtained at a magnetic field strength of 1.5 T using an image-selected <it>in vivo </it>spectroscopy sequence (TR = 10 s; 64 signal averages localized on a 70 × 70 × 70 mm<sup>3 </sup>voxel).</p> <p>Results</p> <p>Compared with age- and sex-matched controls, in the patient group the mean alveolar ethane level was higher (<it>p </it>< 0.0005), the mean cerebral beta-nucleotide triphosphate was lower (<it>p </it>< 0.04) and the mean gamma-nucleotide triphosphate was higher (<it>p </it>< 0.04). There was no significant difference between the two groups in respect of phosphomonoesters, phosphodiesters or broad resonances.</p> <p>Conclusion</p> <p>Our results are not necessarily inconsistent with the membrane phospholipid hypothesis, given that the patients studied suffered predominantly from positive symptoms of schizophrenia. The results suggest that there is increased cerebral mitochondrial oxidative phosphorylation in patients with schizophrenia who have dangerously and seriously violently offended, with an associated increase in oxygen flux and subsequent electron 'leakage' from the electron transport chain leading to the formation of superoxide radicals and other reactive oxygen species. In turn, these reactive species might cause increased lipid peroxidation in neuroglial membranes, thereby accounting for the observation of increased ethane excretion.</p

    Nakajima-Zwanzig versus time-convolutionless master equation for the non-Markovian dynamics of a two-level system

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    We consider the exact reduced dynamics of a two-level system coupled to a bosonic reservoir, further obtaining the exact time-convolutionless and Nakajima-Zwanzig non-Markovian equations of motion. The considered system includes the damped and undamped Jaynes-Cummings model. The result is obtained by exploiting an expression of quantum maps in terms of matrices and a simple relation between the time evolution map and time-convolutionless generator as well as Nakajima-Zwanzig memory kernel. This non-perturbative treatment shows that each operator contribution in Lindblad form appearing in the exact time-convolutionless master equation is multiplied by a different time dependent function. Similarly, in the Nakajima-Zwanzig master equation each such contribution is convoluted with a different memory kernel. It appears that depending on the state of the environment the operator structures of the two set of equations of motion can exhibit important differences.Comment: 12 pages, no figure

    Scaling in Late Stage Spinodal Decomposition with Quenched Disorder

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    We study the late stages of spinodal decomposition in a Ginzburg-Landau mean field model with quenched disorder. Random spatial dependence in the coupling constants is introduced to model the quenched disorder. The effect of the disorder on the scaling of the structure factor and on the domain growth is investigated in both the zero temperature limit and at finite temperature. In particular, we find that at zero temperature the domain size, R(t)R(t), scales with the amplitude, AA, of the quenched disorder as R(t)=Aβf(t/Aγ)R(t) = A^{-\beta} f(t/A^{-\gamma}) with β1.0\beta \simeq 1.0 and γ3.0\gamma \simeq 3.0 in two dimensions. We show that β/γ=α\beta/\gamma = \alpha, where α\alpha is the Lifshitz-Slyosov exponent. At finite temperature, this simple scaling is not observed and we suggest that the scaling also depends on temperature and AA. We discuss these results in the context of Monte Carlo and cell dynamical models for phase separation in systems with quenched disorder, and propose that in a Monte Carlo simulation the concentration of impurities, cc, is related to AA by Ac1/dA \sim c^{1/d}.Comment: RevTex manuscript 5 pages and 5 figures (obtained upon request via email [email protected]

    Perbandingan Pengelolaan Ruang Terbuka Hijau Kota Semarang Dan Kota Surabaya Tahun 2010-2015

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    . Green Open Space is an importat element in creating qualified city in realizing ecological city in order of ecological city realization. The government policy related to the 30% proportion provision constitute the minimum size in an effort to ensure an urban development balance. Management of green open space is one of general policy and regional development programs in environment space sector by the municipality to fulfill extents of green open space. Manajement of green open space in the city of Semarang and Surabaya is done through of planning, organizing, directing, and monitoring. Research method uses descriptively qualitative approach with observation, interview, and literary review as the data collecting technique. The interviewees are Sub Field Head of Spatial Planning and Environment of Bappeda Semarang, Landscape Gardening Division Head of Hygiene and Landscaping Gardening Department of Semarang, Sub Section Head of Spatial Planning, Housing and Environment of Bappeko Surabaya, Staff of Green open Space Planning of Hygiene and Green Open Space of Surabaya In the manajement comparative of green open space in the city of semarang and Surabaya in 2010-2015, the are similarities and differences. Differences in management of Green Open Space in Semarang and Surabaya there is in quality of human resources, leadership style, budget and the involvement of private sector. The presence of this research can be used as an input in the management of Green Open Space in the city of Semarang and Surabaya Recommendation could be done to Semarang city is to improve the quality of human resources of relevan agencies and conducting CSR with private sector. Whereas the recommendation could be done to Surabaya city is to give strict punishment for the people who founded illegal building on land designated as Green Open Space

    Modelling the many-body dynamics of heavy ion collisions: Present status and future perspective

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    Basic problems of the semiclassical microscopic modelling of strongly interactingsystems are discussed within the framework of Quantum Molecular Dynamics (QMD). This model allows to study the influence of several types of nucleonic interactions on a large variety of observables and phenomena occurring in heavy ion collisions at relativistic energies.It is shown that the same predictions can be obtained with several -- numerically completely different and independently written -- programs as far as the same model parameters are employed and the same basic approximations are made. Many observables are robust against variations of the details of the model assumptions used. Some of the physical results, however, depend also on rather technical parameters like the preparation of the initial configuration in phase space. This crucial problem is connected with the description of the ground state of single nuclei,which differs among the various approaches. An outlook to an improved molecular dynamics scheme for heavy ion collisions is given.Comment: 39 pages, 12 figure
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