Mathematical Notes - Let $$\mathcal{A}$$ be a prime $$\ast$$ -algebra. In this paper, assuming that $$\Phi:\mathcal{A}\to\mathcal{A}$$ satisfies $$\Phi(A\diamond B \diamond C)=\Phi(A)\diamond B... 相似文献
Modification of shear stress due to air bubbles injection in a rotary device was investigated experimentally. Air bubbles inject to the water flow crosses the neighbor of the hub which can rotate just by water flow shear stresses, in this device. Increasing air void fraction leads to decrease of shear stresses exerted on the hub surface until in high void fractions, the hub motion stopped as observed. Amount of skin friction decrease has been estimated by counting central hub rotations. Wall shear stress was decreased by bubble injection in all range of tested Reynolds number, changing from 50,378 to 71,238, and also by increasing air void fraction from zero to 3.06%. Skin friction reduction more than 85% was achieved in this study as maximum measured volume of air fraction injected to fluid flow while bubbles are distinct and they do not make a gas layer. Significant skin friction reduction obtained in this special case indicate that using small amount of bubble injection causes large amount of skin friction reduction in some rotary parts in the liquid phases like as water. 相似文献
AnL1-existence theorem is proved for the nonlinear stationary Boltzmann equation with hard forces and no small velocity truncation—only
the Grad angular cut-off-in a setting between two coaxial rotating cylinders when the indata are given on the cylinders. 相似文献
We propose, in this Note, a new procedure for data completion based on the minimization of an energy like error functional. The efficiency of the proposed method is illustrated by a thermostatic application. To cite this article: S. Andrieux et al., C. R. Mecanique 333 (2005).相似文献
H(2)-broadening coefficients have been measured for 66 rovibrational lines of NH(3) at room temperature in the (P)P and (R)P branches of the nu(4) band in the range 1470-1600 cm(-1), using a high-resolution Fourier transform spectrometer. The collisional widths are obtained by fitting Voigt profiles to the measured shapes of the lines. The broadening coefficients are found to decrease on the whole as J increases and they increase with K for a given J value. The results are compared with those calculated from a semiclassical model in which the inversion vibration of NH(3) and collision-induced transitions with DeltaK = 0 and DeltaK = +/- 3 are taken into account. The intermolecular potential used includes electrostatic, induction, and dispersion energy contributions. The calculations performed by considering only DeltaK = 0 transitions provide significantly lower broadenings but with a satisfactory J and K dependence. The same trends are obtained for the broadening coefficients in inversion-rotation transitions and in the Q branch of the nu(1) parallel band of NH(3). Copyright 2001 Academic Press. 相似文献
The slurry homopolymerization of ethylene catalyzed by a Cp2ZrCl2/MAO catalytic system was studied. A simple kinetic model including initiation, propagation, transfer to monomer and cocatalyst, spontaneous transfer and spontaneous deactivation was developed to predict dynamic yield of polymerization and molecular weight of final products. Kinetic constants were estimated by numerical solution of polymerization kinetic model, combined with Nelder‐Mead simplex method. The model predicts that the propagation reaction has the lower activation energy in relation to chain transfer reactions which leads to decrease of molecular weight at elevated temperatures. The initiation reaction has however, the highest activation energy that results in raising the peak of reaction rate at higher temperatures.
The jet from an axiymmetric convergent nozzle has been investigated at pressure ratios of 1.9 and 3.6 corresponding to exit Mach numbers of unity and 1.49. Velocity characteristics were measured with a laser-Doppler velocimeter and complemented by shadography which showed the structure of the expansion-compression waves. The sinuous longitudinal variations of the axial velocity are shown to be large at the higher pressure ratio with amplitudes which decreased with increasing distance from the jet exit and from the axis. The use of the jet for the quantification of droplet breakup is considered and it is evident that the higher pressure ratio requires careful consideration of the location at which a droplet is allowed to fall into the jet.Financial support from the Ministry of Defence under agreement 2037/001/CBDE is gratefully acknowledged. 相似文献
We prove the existence for short times of analytic solutions to a Vlasov type equation. The corresponding model is one-dimensional but uses a quite singular force term which involves a full derivative in x of the macroscopic density, making the existence of solutions a difficult question. 相似文献
Simple and accurate integral equation formulation using a three dimensional finite element (3DFEM) to determine the propagation of microwave passive structures is presented. This technique is applied to solve the scattering problems due to various forms of irises in lossless rectangular waveguide.The analysis of these components is highly dependent of the numbers of modes considered in the neighbourhood of the discontinuity. The theoretical model is compared with measurements and Mode Matching Method (MMM). Results are found to be good agreement. 相似文献