3,091 research outputs found

    Prediction of physical-chemical and fire hazard characteristics by carbon chain rules. 2. Carboxylic acids

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    Investigation of the dependence of physico-chemical and fire hazard properties from the chemical structure of carboxylic acids is carried out. Forecasting of the boiling temperature, the flash point, the temperature and the concentration flammability limits, the heats of combustion and vaporization is performed by the carbon chain rules (CCR). The following empirical equations for the calculation of physico-chemical and fire hazard indices from the conventional carbon chain and from the number of carbon atoms are proposed for the convenience of practical application of the CCR. A comparative analysis of the proposed methods for the flash point calculating and the already known methods of GOST 12.1.044-89, Mendeleev and ACD/Lab 2014 is carried out. It is shown, basically, that the new methods give more accurate calculation results than the comparison design procedures. © Siberian Federal University. All rights reserve

    Continuous and jump betas: Implications for portfolio diversification

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    © 2016 by the authors; licensee MDPI, Basel, Switzerland. Using high-frequency data, we decompose the time-varying beta for stocks into beta for continuous systematic risk and beta for discontinuous systematic risk. Estimated discontinuous betas for S&P500 constituents between 2003 and 2011 generally exceed the corresponding continuous betas. We demonstrate how continuous and discontinuous betas decrease with portfolio diversification. Using an equiweighted broad market index, we assess the speed of convergence of continuous and discontinuous betas in portfolios of stocks as the number of holdings increase. We show that discontinuous risk dissipates faster with fewer stocks in a portfolio compared to its continuous counterpart

    Rate of steady-state reconnection in an incompressible plasma

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    The reconnection rate is obtained for the simplest case of 2D symmetric reconnection in an incompressible plasma. In the short note (Erkaev et al., Phys. Rev. Lett.,84, 1455 (2000)), the reconnection rate is found by matching the outer Petschek solution and the inner diffusion region solution. Here the details of the numerical simulation of the diffusion region are presented and the asymptotic procedure which is used for deriving the reconnection rate is described. The reconnection rate is obtained as a decreasing function of the diffusion region length. For a sufficiently large diffusion region scale, the reconnection rate becomes close to that obtained in the Sweet-Parker solution with the inverse square root dependence on the magnetic Reynolds number, determined for the global size of the current sheet. On the other hand, for a small diffusion region length scale, the reconnection rate turns out to be very similar to that obtained in the Petschek model with a logarithmic dependence on the magnetic Reynolds number. This means that the Petschek regime seems to be possible only in the case of a strongly localized conductivity corresponding to a small scale of the diffusion region.Comment: 11 pages, 3 figure

    Понимание логического следования стоиками и перипатетиками: сравнительный анализ

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    In the paper discussion about the notion of logical consequence that held place in philosophic schools of Hellenistic age, such as Peripatetics, Stoics, is presented. Similarities and differences of the views on the matter held by various representatives of given schools are presented.В статье представлена дискуссия о природе логического следования, которая была важной частью разработки логического инструментария в философских школах эпохи эллинизма, в первую очередь в школах перипатетиков и стоиков. Показаны сходства и различия в понимании понятий следования и валидности различными представителями данных школ

    Measurement of the neutron electric dipole moment by crystal diffraction

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    An experiment using a prototype setup to search for the neutron electric dipole moment by measuring spin-rotation in a non-centrosymmetric crystal (quartz) was carried out to investigate statistical sensitivity and systematic effects of the method. It has been demonstrated that the concept of the method works. The preliminary result of the experiment is dn=(2.5±6.5)1024d_{\rm n}=(2.5\pm 6.5)\cdot 10^{-24} e\cdot cm. The experiment showed that an accuracy of 2.51026\sim 2.5\cdot 10^{-26} e\cdot cm can be obtained in 100 days data taking, using available quartz crystals and neutron beams.Comment: 13 pages, 4 figure
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