72 research outputs found

    Classical Integrable 2-dim Models Inspired by SUSY Quantum Mechanics

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    A class of integrable 2-dim classical systems with integrals of motion of fourth order in momenta is obtained from the quantum analogues with the help of deformed SUSY algebra. With similar technique a new class of potentials connected with Lax method is found which provides the integrability of corresponding 2-dim hamiltonian systems. In addition, some integrable 2-dim systems with potentials expressed in elliptic functions are explored.Comment: 19 pages, LaTeX, final version to be published in J.Phys.

    The adjoint problem in the presence of a deformed surface: the example of the Rosensweig instability on magnetic fluids

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    The Rosensweig instability is the phenomenon that above a certain threshold of a vertical magnetic field peaks appear on the free surface of a horizontal layer of magnetic fluid. In contrast to almost all classical hydrodynamical systems, the nonlinearities of the Rosensweig instability are entirely triggered by the properties of a deformed and a priori unknown surface. The resulting problems in defining an adjoint operator for such nonlinearities are illustrated. The implications concerning amplitude equations for pattern forming systems with a deformed surface are discussed.Comment: 11 pages, 1 figur

    Symplectic Structures for the Cubic Schrodinger equation in the periodic and scattering case

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    We develop a unified approach for construction of symplectic forms for 1D integrable equations with the periodic and rapidly decaying initial data. As an example we consider the cubic nonlinear Schr\"{o}dinger equation.Comment: This is expanded and corrected versio

    Spectroscopy with random and displaced random ensembles

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    Due to the time reversal invariance of the angular momentum operator J^2, the average energies and variances at fixed J for random two-body Hamiltonians exhibit odd-even-J staggering, that may be especially strong for J=0. It is shown that upon ensemble averaging over random runs, this behaviour is reflected in the yrast states. Displaced (attractive) random ensembles lead to rotational spectra with strongly enhanced BE2 transitions for a certain class of model spaces. It is explained how to generalize these results to other forms of collectivity.Comment: 4 pages, 4 figure

    The Lake Baikal neutrino experiment: selected results

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    We review the present status of the lake Baikal Neutrino Experiment and present selected physical results gained with the consequetive stages of the stepwise increasing detector: from NT-36 to NT-96. Results cover atmospheric muons, neutrino events, very high energy neutrinos, search for neutrino events from WIMP annihilation, search for magnetic monopoles and environmental studies. We also describe an air Cherenkov array developed for the study of angular resolution of NT-200.Comment: 25 pages, 12 figures. To appear in the Procrrdings of International Conference on Non-Accelerator New Physics, June 28 - July 3, 1999, Dubna, Russi

    Клиническая оценка эффективности кашля у больных неспецифическими заболеваниями легких на основе туссографии и времени экспекторации

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    The article deals with the investigation of cough and mico-cilliary clearence in patients with nonspecific iung diseases (lobular pneumonia, lung abscess, intrinsic asthma). The aim of this study is to define quantitative criteria of cough efficacy which in terms give the integral characteristic of tracheobronchial clearence components. It is achieved by monitoring the time of inuline expectoration and registering of cough jolts with the help of tussograph IKT-1. In case of prolongation of inuline expectoration time using drug suppression of cough, the latter is regarded effective.

    Simultaneous measurements of water optical properties by AC9 transmissometer and ASP-15 Inherent Optical Properties meter in Lake Baikal

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    Measurements of optical properties in media enclosing Cherenkov neutrino telescopes are important not only at the moment of the selection of an adequate site, but also for the continuous characterization of the medium as a function of time. Over the two last decades, the Baikal collaboration has been measuring the optical properties of the deep water in Lake Baikal (Siberia) where, since April 1998, the neutrino telescope NT-200 is in operation. Measurements have been made with custom devices. The NEMO Collaboration, aiming at the construction of a km3 Cherenkov neutrino detector in the Mediterranean Sea, has developed an experimental setup for the measurement of oceanographic and optical properties of deep sea water. This setup is based on a commercial transmissometer. During a joint campaign of the two collaborations in March and April 2001, light absorption, scattering and attenuation in water have been measured. The results are compatible with previous ones reported by the Baikal Collaboration and show convincing agreement between the two experimental techniques.Comment: 16 pages, submitted to NIM-

    Results from the BAIKAL Neutrino Telescope

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    Abstract We review the present status of the Baikal Neutrino Project, present updated results on the search for high energy extraterrestrial neutrinos, fast magnetic monopoles and neutrinos induced by WIMP annihilation in the center of the Earth and compare the recorded atmospheric neutrino flux to predictions
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