Home OALib Journal OALib PrePrints Submit Ranking News My Lib FAQ About Us Follow Us+
 Title Keywords Abstract Author All
Search Results: 1 - 10 of 100 matches for " "
 Page 1 /100 Display every page 5 10 20 Item
 Physics , 2001, DOI: 10.1103/PhysRevC.65.041307 Abstract: The contribution of quantum shape fluctuations to inertial properties of rotating nuclei has been analysed within the self-consistent one-dimensional cranking oscillator model. It is shown that in even-even nuclei the dynamical moment of inertia calculated in the mean field approximation is equivalent to the Thouless-Valatin moment of inertia calculated in the random phase approximation if and only if the self-consistent conditions for the mean field are fulfilled.
 Physics , 2007, DOI: 10.1103/PhysRevLett.99.140401 Abstract: We make a model-independent measurement of the moment of inertia of a rotating, expanding strongly-interacting Fermi gas. Quenching of the moment of inertia is observed for energies both below and above the superfluid transition. This shows that a strongly interacting Fermi gas with angular momentum can support irrotational flow in both the superfluid and collisional normal fluid regimes.
 World Journal of Mechanics (WJM) , 2015, DOI: 10.4236/wjm.2015.53005 Abstract: In this study, we use a thin rotating plate to generate propulsion and lift for a paper plate. And the thin plate rotates along the spanwise axis. We numerically determine the influence on aerodynamic characteristics with a rotational velocity of the thin plate. The rotational velocity is obtained with spin parameter which is the ratio of the peripheral speed of the plate to the main flow velocity. And the numerical simulations based on the discrete vortex method show that the autorotation mode of the plate in a uniform flow appears naturally when the spin parameter is unity. Vortex formed from the backward-rotating edge is weaker than those generated from the forward-rotating edge of thin plate. The maximum lift generated at S = 0.75 if S < 1. The negative moment becomes negative for the nondimensional rotating speed S ≤ 1.75. The most negative moment appears when S = 1; at that time, autorotation occurs naturally.
 Clovis Jacinto de Matos Physics , 2007, Abstract: Non classical rotational inertia observed in rotating supersolid $He^4$ can be accounted for by a gravitomagnetic London moment similar to the one recently reported in rotating superconductive rings.
 Physics , 2015, Abstract: Vortices and vortex arrays have been used as a hallmark of superfluidity in rotated, ultracold Fermi gases. These superfluids can be described in terms of an effective field theory for a macroscopic wave function representing the field of condensed pairs, analogous to the Ginzburg-Landau theory for superconductors. Here, we have established how rotation modifies this effective field theory, by rederiving it starting from the action of Fermi gas in the rotating frame of reference. In particular, we show that the moment of inertia that can be attributed to the pairs deviates from the naive expectation that it is twice the moment of inertia of the constituent fermions, which is only realized in the deep BEC regime. Then, we use our macroscopic wave function description to study vortices and the critical rotation frequencies to form them. Phase diagrams for vortex states are derived, and they are in good agreement with available results of the Bogoliubov -- De Gennes theory and with experimental data.
 地球物理学报 , 2007, Abstract: The interaction between inertia-gravity waves (IGWs) and the balance vortex in the two-dimensional f-plan shallow water fluid is investigated. When the IGWs propagate into the vortex, the two components did interact. The vortex could be deepening, and the wind structure of the vortex could become asymmetric. However, as the IGWs leaving the vortex, it recovers its initial structure while the initially north-south symmetric IGWs take on asymmetric structure. This feature is different from the one-dimensional case. The degree of wave-vortex interaction is not same in the whole vortex region. The distribution of the maximum variety of physical variables is almost consistent with the IGWs propagation direction. There are two regions in which the physical variables vary largest as the waves entering and leaving the vortex region. Besides the wave-vortex interaction is also related to the initial structure, strength and propagating direction of the IGWs and the characters of vortex. In the linear system the interaction is weaker, but the quality is similar to that in nonlinear system.
 Physics , 2001, DOI: 10.1103/PhysRevLett.87.190401 Abstract: The properties of a rotating Bose-Einstein condensate confined in a prolate cylindrically symmetric trap are explored both analytically and numerically. As the rotation frequency increases, an ever greater number of vortices are energetically favored. Though the cloud anisotropy and moment of inertia approach those of a classical fluid at high frequencies, the observed vortex density is consistently lower than the solid-body estimate. Furthermore, the vortices are found to arrange themselves in highly regular triangular arrays, with little distortion even near the condensate surface. These results are shown to be a direct consequence of the inhomogeneous confining potential.
 Journal of Engineering and Applied Sciences , 2009, Abstract: Transient performance of any electrical machine is greatly affected by sudden changes in its supply system, operating speed, shaft load including any variations in moment of inertia due to gear arrangement applications. D, q- axis modeling which is universally acceptable to determine such analysis may be adopted using stator reference frame/rotor reference frame/synchronously rotating reference frame. In this paper, rotor reference frame is used for the simulation study of three phase induction motor. MATLAB/SIMULINK based modeling is adopted to compare the transient performance of three-phase induction motor including main flux saturation with and without the moment of inertia (MOI) of the system attached to the motor. Simulated results have been compared and verified with experimental results on a test machine set-up. A close agreement between the simulated and experimental results proves the validity of proposed modeling.
 Physics , 2011, DOI: 10.1038/srep00043 Abstract: Considerable efforts are currently devoted to the preparation of ultracold neutral atoms in the emblematic strongly correlated quantum Hall regime. The routes followed so far essentially rely on thermodynamics, i.e. imposing the proper Hamiltonian and cooling the system towards its ground state. In rapidly rotating 2D harmonic traps the role of the transverse magnetic field is played by the angular velocity. For particle numbers significantly larger than unity, the required angular momentum is very large and it can be obtained only for spinning frequencies extremely near to the deconfinement limit; consequently, the required control on experimental parameters turns out to be far too stringent. Here we propose to follow instead a dynamic path starting from the gas confined in a rotating ring. The large moment of inertia of the fluid facilitates the access to states with a large angular momentum, corresponding to a giant vortex. The initial ring-shaped trapping potential is then adiabatically transformed into a harmonic confinement, which brings the interacting atomic gas in the desired quantum Hall regime. We provide clear numerical evidence that for a relatively broad range of initial angular frequencies, the giant vortex state is adiabatically connected to the bosonic $\nu=1/2$ Laughlin state, and we discuss the scaling to many particles.
 Physics , 2005, DOI: 10.1103/PhysRevC.72.064326 Abstract: We introduce a simple model to calculate the nuclear moment of inertia at finite temperature. This moment of inertia describes the spin distribution of nuclear levels in the framework of the spin-cutoff model. Our model is based on a deformed single-particle Hamiltonian with pairing interaction and takes into account fluctuations in the pairing gap. We derive a formula for the moment of inertia at finite temperature that generalizes the Belyaev formula for zero temperature. We show that a number-parity projection explains the strong odd-even effects observed in shell model Monte Carlo studies of the nuclear moment of inertia in the iron region.
 Page 1 /100 Display every page 5 10 20 Item