26,831 research outputs found

    A method of selecting grid size to account for Hertz deformation in finite element analysis of spur gears

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    A method of selecting grid size for the finite element analysis of gear tooth deflection is presented. The method is based on a finite element study of two cylinders in line contact, where the criterion for establishing element size was that there be agreement with the classical Hertzian solution for deflection. The results are applied to calculate deflection for the gear specimen used in the NASA spur gear test rig. Comparisons are made between the present results and the results of two other methods of calculation. The results have application in design of gear tooth profile modifications to reduce noise and dynamic loads

    Subtropical middle atmosphere dynamics observed by the Chung Li radar

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    The Chung Li Radar (24.91 N; 121.24 E) has been operating since 1986. A five beam observational configuration was used on a regular basis to study the various dynamics processes in the atmosphere-lower stratosphere height region. Due to its geographical location, the annual Typhoon and Mei-Yu seasons provide good opportunities to study the various interesting dynamic processes such as instabilities, generation of gravity waves, wave mean field interaction, etc. Three dimensional air motions due to these fronts are presented. Special cases of gravity wave generation, propagation and their effects on the turbulent layers are discussed

    Bosonic Super Liouville System: Lax Pair and Solution

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    We study the bosonic super Liouville system which is a statistical transmutation of super Liouville system. Lax pair for the bosonic super Liouville system is constructed using prolongation method, ensuring the Lax integrability, and the solution to the equations of motion is also considered via Leznov-Saveliev analysis.Comment: LaTeX, no figures, 11 page

    On the use of colour reflectivity plots to monitor the structure of the troposphere and stratosphere

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    The radar reflectivity, defined as the range squared corrected power of VHF radar echoes, can be used to monitor and study the temporal development of inversion layer, frontal boundaries and convective turbulence. From typical featurs of upward or downward motion of reflectivity structures, the advection/convection of cold and warm air can be predicted. High resolution color plots appear to be useful to trace and to study the life history of these structures, particularly their persistency, descent and ascent. These displays allow an immediate determination of the tropopause height as well as the determination of the tropopause structure. The life history of warm fronts, cold fronts, and occlusions can be traced, and these reflectivity plots allow detection of even very weak events which cannot be seen in the traditional meteorological data sets. The life history of convective turbulence, particular evolving from the planetary boundary layer, can be tracked quite easily. Its development into strong convection reaching the middle troposphere can be followed and predicted

    On C*-algebras related to constrained representations of a free group

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    We consider representations of the free group F2F_2 on two generators such that the norm of the sum of the generators and their inverses is bounded by μ[0,4]\mu\in[0,4]. These μ\mu-constrained representations determine a C*-algebra AμA_{\mu} for each μ[0,4]\mu\in[0,4]. We prove that these C*-algebras form a continuous bundle of C*-algebras over [0,4][0,4] and calculate their K-groups.Comment: 9 page

    Study of pesudoscalar transition form factors within light front quark model

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    We study the transition form factors of the pesudoscalar mesons (π,η\pi,\eta and η\eta^{\prime}) as functions of the momentum transfer Q2Q^2 within the light-front quark model. We compare our results with the recent experimental data by CELLO, CLEO, BaBar and Belle. By considering the possible uncertainties from the quark masses, we illustrate that our predicted form factors can fit with all the data, including those at the large Q2Q^2 regions.Comment: 10 pages, 4 figures, accepted for publication in Phys. Rev.

    Fourier mode dynamics for the nonlinear Schroedinger equation in one-dimensional bounded domains

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    We analyze the 1D focusing nonlinear Schr\"{o}dinger equation in a finite interval with homogeneous Dirichlet or Neumann boundary conditions. There are two main dynamics, the collapse which is very fast and a slow cascade of Fourier modes. For the cubic nonlinearity the calculations show no long term energy exchange between Fourier modes as opposed to higher nonlinearities. This slow dynamics is explained by fairly simple amplitude equations for the resonant Fourier modes. Their solutions are well behaved so filtering high frequencies prevents collapse. Finally these equations elucidate the unique role of the zero mode for the Neumann boundary conditions
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