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131.
M. T. Kamel P. N. Kaloni 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1977,28(4):551-576
Summary A theoretical analysis is made of the flow of a Cosserat fluid in a curved pipe under a pressure gradient. It is assumed that the curvature of the pipe is small, that is the radius of the circle in which the central line of the pipe is coiled is large in comparison with the radius of the cross-section. Following Dean [2] a solution is developed by the method of successive approximation. The paths of the particles in the central plane and the projection of the streamlines on the cross-section of the pipe are compared with those of a Newtonian fluid. It is observed that in the theory of Cosserat fluids the curvature of the streamlines in the central plane increases and the motion is slower in the cross-section of the pipe. It is also shown that the rate of flow of a Cosserat fluid through a curved pipe is decreased due to the curvature of the pipe.
Résumé On fait une analyse théorique de l'écoulement d'un fluide de Cosserat dans un tube sous un gradient de pression. On suppose que la courbature du tube est faible, c'est-à-dire que le radius du cercle qui fait la ligne du centre du tube est fort par rapport au radius de la coupe transversale.D'après Dean [2], on développe une résolution par approximations successives. On fait la comparaison des trajectoires des particules dans le plan central et la projection des lignes d'écoulement sur la coupe transversale du tube avec celles d'un fluide de Newton.On note que dans la théorie des fluides de Cosserat, la courbature des lignes d'écoulement dans le plan central augmente, et que la motion est ralentie dans la coupe transversale du tube. On démontre ensuite que le taux d'écoulement d'un fluide de Cosserat dans un tube courbe se diminue à raison de la courbature.相似文献
132.
Statistical analysis of HDPE fatigue lifetime 总被引:1,自引:0,他引:1
Fatigue lifetime of HDPE structures such as pipes is recognized to show a large scatter. This study aims to compare different
statistical methods and distributions, in order to give convenient modeling of tensile and fatigue test results of commercially
available polyethylene compression molded sheets. The median rank, the maximum likelihood and the Kolmogorov-Smirnov fitting
are compared for the estimation of Weibull parameters. The choice of the best distribution to fit fatigue lifetime is discussed
on the basis of the goodness-of-fit results. It is found that whether the three-parameter distributions of Weibull and lognormal
types are suitable for lifetime prediction, the two-parameter Weibull is more conservative for probabilistic fatigue design. 相似文献
133.
Taibi A. Ishak-Boushaki G. Medkour Idiri Z. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):687-696
Journal of Radioanalytical and Nuclear Chemistry - True coincidence summing (TCS) correction factors were determined for 152Eu volume sources used for γ-ray efficiency calibration as the ratio... 相似文献
134.
135.
Ismail M. Nassar Aladin H. Kamel Diaa Khalil Omar A. Omar 《Optical and Quantum Electronics》2012,44(14):623-633
A planar lens structure based on an array of nanoscale slits in a metallic film is modeled using a waveguide modal technique. The structure is modeled as a one dimensional lens followed by free space propagation. The obtained results are compared to published experimental results as well as numerical simulations using either the finite difference frequency domain or the transmission line method. A good agreement has been obtained with significant simulation time reduction. 相似文献
136.
In this paper, we present an explicit realization of q-deformed Calogero-Vasiliev algebra whose generators are first-order q-difference operators related to the generalized discrete q-Hermite I polynomials recently introduced in [14]. Furthermore, we construct the wave functions and we determine the q-coherent states. 相似文献
137.
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139.
Thin films of SnS were cathodically deposited onto stainless steel substrates from bath containing 0.025 M SnSO4, 0.25 M KSCN and 0.25 M Na2SO4. The mechanism of electrochemical co-deposition of tin and sulphur was investigated by cyclic voltammetry. Analysis of the
chronoamperometric current–time transients suggested that, in the potential range −560 to −590 mV vs saturated calomel electrode,
the electrodeposition of SnS involved progressive nucleation model. However, at a potential −600 mV, the electrodeposition
involved instantaneous nucleation model. The deposits have been characterized by scanning electron microscopy, X-ray diffraction
and optical measurements. SnS films were found to be polycrystalline with an optical energy gap of 1.38 eV. 相似文献
140.