891 research outputs found

    A comment on BCC crystalization in higher dimensions

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    The result that near the melting point three-dimensional crystals have an octahedronic structure is generalized to higher flat non compact dimensions

    Analisis Efisiensi Sumber dan Penggunaan Modal Kerja pada PT Tri Anugrah Pratama Pekanbaru

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    This study aims to determine the level of efficiency of PT Tri Anugrah Pratama Pekanbaru in managing the sources and uses of working capital to maintain the continuity of the companys operations and to analyze the contribution of the use of their own capital and bank capital to the development of corporate profits. This research was conducted in PT Tri Anugrah Pratama Pekanbaru is located at Jln Parit Indah Grand Sudirman Pekanbaru. In this study using secondary data in the form of: 1) The financial statements of the company for 5 years 2008-2013 and 2) Financial ratios. Analysis of the data used in this research is descriptive quantitative method. The study states that in order to measure the efficiency of the sources and uses of working capital, the working capital position of the company need to be analyzed by using the ratio of liquidity, solvency and profitability. Analysis of the reports and sources and uses, and analyzes the companys cash flow statement shows that the sources and uses of working capital has not been effective and efficient. PT Tri Anugrah Pratama are in a liquid state and insovable. More corporate capital derived from medium-term debt and long-term comparison of capital it self. This condition causes the contribution of working capital in the profit has decreased, it is because the company charges them interest on bank loans which is quite large.Keywords: Efficiency, Resource Management, Working Capita

    Isolation of cationic and neutral (allenylidene)(carbene) and bis(allenylidene)gold complexes.

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    The one-electron reduction of a cationic (allenylidene)[cyclic(alkyl) (amino)carbene]gold(i) complex leads to the corresponding neutral, paramagnetic, formally gold(0) complex. DFT calculations reveal that the spin density of this highly robust coinage metal complex is mainly located on the allenylidene fragment, with only 1.8 and 3.1% on the gold center and the CAAC ligand, respectively. In addition, the first homoleptic bis(allenylidene)gold(i) complex has been prepared and fully characterized

    Sequence Specific Motor Performance Gains after Memory Consolidation in Children and Adolescents

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    Memory consolidation for a trained sequence of finger opposition movements, in 9- and 12-year-old children, was recently found to be significantly less susceptible to interference by a subsequent training experience, compared to that of 17-year-olds. It was suggested that, in children, the experience of training on any sequence of finger movements may affect the performance of the sequence elements, component movements, rather than the sequence as a unit; the latter has been implicated in the learning of the task by adults. This hypothesis implied a possible childhood advantage in the ability to transfer the gains from a trained to the reversed, untrained, sequence of movements. Here we report the results of transfer tests undertaken to test this proposal in 9-, 12-, and 17-year-olds after training in the finger-to-thumb opposition sequence (FOS) learning task. Our results show that the performance gains in the trained sequence partially transferred from the left, trained hand, to the untrained hand at 48-hours after a single training session in the three age-groups tested. However, there was very little transfer of the gains from the trained to the untrained, reversed, sequence performed by either hand. The results indicate sequence specific post-training gains in FOS performance, as opposed to a general improvement in performance of the individual, component, movements that comprised both the trained and untrained sequences. These results do not support the proposal that the reduced susceptibility to interference, in children before adolescence, reflects a difference in movement syntax representation after training

    Accelerated convergence to steady state by gradual far-field damping

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76495/1/AIAA-11054-168.pd

    Spherically symmetric relativistic MHD simulations of pulsar wind nebulae in supernova remnants

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    Pulsars, formed during supernova explosions, are known to be sources of relativistic magnetized winds whose interaction with the expanding supernova remnants (SNRs) gives rise to a pulsar wind nebula (PWN). We present spherically symmetric relativistic magnetohydrodynamics (RMHD) simulations of the interaction of a pulsar wind with the surrounding SNR, both in particle and magnetically dominated regimes. As shown by previous simulations, the evolution can be divided in three phases: free expansion, a transient phase characterized by the compression and reverberation of the reverse shock, and a final Sedov expansion. The evolution of the contact discontinuity between the PWN and the SNR (and consequently of the SNR itself) is almost independent of the magnetization of the nebula as long as the total (magnetic plus particle) energy is the same. However, a different behaviour of the PWN internal structure is observable during the compression-reverberation phase, depending on the degree of magnetization=2E The simulations were performed using the third order conservative scheme by Del Zanna et al. (2003).Comment: 11 pages, Latex, 22 Encapsulated PostScript figures, accepted f or publication on A&

    The effects of spin-down on the structure and evolution of pulsar wind nebulae

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    We present high resolution spherically symmetric relativistic magnetohydrodynamical simulations of the evolution of a pulsar wind nebula inside the free expanding ejecta of the supernova progenitor. The evolution is followed starting from a few years after the supernova explosion and up to an age of the remnant of 1500 years. We consider different values of the pulsar wind magnetization parameter and also different braking indices for the spin-down process. We compare the numerical results with those derived through an approximate semi-analytical approach that allows us to trace the time evolution of the positions of both the pulsar wind termination shock and the contact discontinuity between the nebula and the supernova ejecta. We also discuss, whenever a comparison is possible, to what extent our numerical results agree with former self-similar models, and how these models could be adapted to take into account the temporal evolution of the system. The inferred magnetization of the pulsar wind could be an order of magnitude lower than that derived from time independent analytic models.Comment: 11 pages, 7 figures, Accepted for publication on A&

    Interlayer Registry Determines the Sliding Potential of Layered Metal Dichalcogenides: The case of 2H-MoS2

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    We provide a simple and intuitive explanation for the interlayer sliding energy landscape of metal dichalcogenides. Based on the recently introduced registry index (RI) concept, we define a purely geometrical parameter which quantifies the degree of interlayer commensurability in the layered phase of molybdenum disulphide (2HMoS2). A direct relation between the sliding energy landscape and the corresponding interlayer registry surface of 2H-MoS2 is discovered thus marking the registry index as a computationally efficient means for studying the tribology of complex nanoscale material interfaces in the wearless friction regime.Comment: 13 pages, 7 figure

    Graphene transistors are insensitive to pH changes in solution

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    We observe very small gate-voltage shifts in the transfer characteristic of as-prepared graphene field-effect transistors (GFETs) when the pH of the buffer is changed. This observation is in strong contrast to Si-based ion-sensitive FETs. The low gate-shift of a GFET can be further reduced if the graphene surface is covered with a hydrophobic fluorobenzene layer. If a thin Al-oxide layer is applied instead, the opposite happens. This suggests that clean graphene does not sense the chemical potential of protons. A GFET can therefore be used as a reference electrode in an aqueous electrolyte. Our finding sheds light on the large variety of pH-induced gate shifts that have been published for GFETs in the recent literature

    Probabilistic sophistication and reverse Bayesianism

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    This paper extends our earlier work on reverse Bayesianism by relaxing the assumption that decision makers abide by expected utility theory, assuming instead weaker axioms that merely imply that they are probabilistically sophisticated. We show that our main results, namely, (modified) representation theorems and corresponding rules for updating beliefs over expanding state spaces and null events that constitute “reverse Bayesianism,” remain valid
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