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941.
A new mathematical model is presented to study the heat and mass transfer characteristics of magnetohydrodynamic (MHD) Maxwell fluid flow over a convectively heated stretchable rotating disk. To regulate the fluid temperature at the surface, a simple isothermal model of homogeneous-heterogeneous reactions is employed. The impact of nonlinear thermal radiative heat flux on thermal transport features is studied. The transformed nonlinear system of ordinary differential equations is solved numerically with an efficient method, namely, the Runge-Kutta-Felberg fourth-order and fifth-order (RKF45) integration scheme using the MAPLE software. Achieved results are validated with previous studies in an excellent way. Major outcomes reveal that the magnetic flux reduces the velocity components in the radial, angular, and axial directions, and enhances the fluid temperature. Also, the presence of radiative heat flux is to raise the temperature of fluid. Further, the strength of homogeneous–heterogeneous reactions is useful to diminish the concentration of reaction. 相似文献
942.
The Absolute Nodal Coordinate Formulation (ANCF) has been initiated in 1996 by Shabana (Computational Continuum Mechanics,
3rd edn., Cambridge: Cambridge University Press, 2008). It introduces large displacements of planar and spatial finite elements relative to the global reference frame without
using any local frame. A sub-family of beam, plate and cable finite elements with large deformations are proposed and employed
the 3D theory of continuum mechanics. In the ANCF, the nodal coordinates consist of absolute position coordinates and gradients
that can be used to define a unique rotation and deformation fields within the element. In contrast to other large deformation
formulations, the equations of motion contain constant mass matrices as well as zero centrifugal and Coriolis inertia forces.
The only nonlinear term is a vector of elastic forces. This investigation concerns a way to generate new finite element in
the ANCF for laminated composite plates. This formulation utilizes the assumption that the bonds between the laminae are thin
and shear is non-deformable. Consequently, the Equivalent Single Layer, ESL model, is implemented. In the ESL models, the
laminate is assumed to deform as a single layer, assuming a smooth variation of the displacement field across the thickness.
In this paper, the coupled electromechanical effect of Piezoelectric Laminated Plate is imposed within the ANCF thin plate
element, in such a way as to achieve the continuity of the gradients at the nodal points, and obtain a formulation that automatically
satisfies the principle of work and energy. Convergence and accuracy of the finite-element ANCF Piezoelectric Laminated Plate
is demonstrated in geometrically nonlinear static and dynamic test problems, as well as in linear analysis of natural frequencies.
The computer implementation and several numerical examples are presented in order to demonstrate the use of the formulation
developed in this paper. A comparison with the commercial finite element package COMSOL MULTIPHYSICS () is carried out with an excellent agreement. 相似文献
943.
Magdy?A.?EzzatEmail author Ahmed?S.?El Karamany Mohsen?A.?Fayik 《Archive of Applied Mechanics (Ingenieur Archiv)》2012,82(4):557-572
In this work, the field equations of the linear theory of thermoelasticity have been constructed in the context of a new consideration
of Fourier law of heat conduction with time-fractional order and three-phase lag. A uniqueness and reciprocity theorems are
proved. One-dimensional application for a half-space of elastic material in the presence of heat sources has been solved using
Laplace transform and state space techniques Ezzat (Canad J Phys Rev 86:1241–1250, 2008). According to the numerical results and its graphs, conclusion about the new theory has been established. 相似文献
944.
On the hyperchaotic complex Lü system 总被引:1,自引:0,他引:1
The aim of this paper is to introduce the new hyperchaotic complex Lü system. This system has complex nonlinear behavior which
is studied and investigated in this work. Numerically the range of parameter values of the system at which hyperchaotic attractors
exist is calculated. This new system has a whole circle of equilibria and three isolated fixed points, while the real counterpart
has only three isolated ones. The stability analysis of the trivial fixed point is studied. Its dynamics is more rich in the
sense that our system exhibits both chaotic and hyperchaotic attractors, as well as periodic and quasi-periodic solutions
and solutions that approach fixed points. The nonlinear control method based on Lyapunov function is used to synchronize the
hyperchaotic attractors. The control of these attractors is studied. Different forms of hyperchaotic complex Lü systems are
constructed using the state feedback controller and complex periodic forcing. 相似文献
945.
Mazhar-ul-Haque Hasan A. Tayim Jamil Ahmed William Horne 《Journal of chemical crystallography》1985,15(6):561-571
Triphenylarsine crystallizes in the triclinic space groupP¯1 (No. 2),a=11.200(2),b=15.263(7),c=17.871(6) Å,=84.63(5),=80.21(5), =86.41(6)°,Z=8, with four molecules in the asymmetric unit. The structure was solved by direct methods and refined in the initial stages by full-matrix least squares and finally by block-diagonal least-squares methods toR=0.055 for 3537 reflections. The dimensions and the conformations of the four independent molecules are almost identical. The molecules do not exhibitC
3v
symmetry. 相似文献
946.
Mazhar-ul-Haque Patrick Pollet Jamil Ahmed William Horne 《Journal of chemical crystallography》1984,14(5):495-503
The title compound crystallizes in the monoclinic space groupP21/n (No. 14),a=14.923(2),b=4.165(2),c=18.097(2) Å,=106.40(1)°,Z=4. The structure was solved by direct methods, and refined by full-matrix least squares toR=0.048 for 1313 observed reflections. Inter- and intramolecular hydrogen bonding is observed, the latter resulting in the formation of dimers. 相似文献
947.
We herein report a serendipitously observed acid mediated rearrangement of monoethylene ketal of 2-methyl-2-(3-methylbut-2-en-1-yl)cyclohex-4-ene-1,3-diones to Dihydrobenzopyran and demonstrated the application of this methodology in the construction of core carbon scaffolds of dimethoxyajacareubin, cariphenone-A and crotamadine. 相似文献
948.
Xue Li Kang Zhao Caiyin You Wensheng Linghu Feng Ye Mei Yu Ahmed Alsaedi Tasawar Hayat Hui Pan Jie Luo Xuemei Ren 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(3):509-522
The characterization of the nanocomposites (PANI@GO) by SEM, TEM, Raman and FT-IR indicated that the GO has been functionalized via PANI successfully. PANI@GO as a novel platform for the removal of Cd(II), Eu(III), Th(IV) and U(VI) from aqueous solutions, the uptake process was a spontaneous endothermic process, and is strongly dependent of pH but independent of ionic strength. The adsorption kinetic and isotherm were fitted well the Pseudo-second-order equation and Langmuir model. PANI@GO were recycled and re-used without significant loss of adsorption capacity, and real samples were also treated which showed that had little interference with the performance of it. 相似文献
949.
Ahmed I. Hashem Marwa El-Hussieny Mansoura A. Abd-El-Maksoud Soher S. Maigali Shaimaa T. Mansour 《Phosphorus, sulfur, and silicon and the related elements》2018,193(1):1-9
Reactions of nucleophilic active phosphacumulenes with iso(thio)cyanate compounds were performed. The reaction products depend on the nature of the reagent, substrate and the condition of the reaction used. New heterocyclic 4-membered or 6-membered sulfur and nitrogen compounds such as phosphoranylidene thietane, azetidine and thiazinane were obtained. On the other hand, the stable phosphonium ylides with the iso(thio)cyanate afforded phosphoranylidene thiocarbamoyl derivatives. Possible reaction mechanisms are considered and the structural assignments are based on compatible analytical and spectroscopic data. 相似文献
950.
Yhiya Amen Qinchang Zhu Hai-Bang Tran Mohamed S. Afifi Ahmed F. Halim Ahmed Ashour 《Natural product research》2018,32(16):1955-1959
Rho-kinase enzymes are one of the most important targets recently identified in our bodies. Several lines of evidence indicate that these enzymes are involved in many diseases and cellular disorders. ROCK inhibitors may have clinical applications for cancer, hypertension, glaucoma, etc. Our study aims to identify the possible involvement of Rho-kinase inhibition to the multiple biological activities of adlay seeds and provide a rationale for their folkloric medicines. Hence, we evaluated Rho-kinase I and II inhibitory activity of the ethanol extract and 28 compounds derived from the seeds. A molecular docking assay was designed to estimate the binding affinity of the tested compounds with the target enzymes. The results of our study suggest a possible involvement of Rho-kinase inhibition to the multiple biological activities of the seeds. Furthermore, the results obtained with the tested compounds revealed some interesting skeletons as a scaffold for design and development of natural Rho-kinase inhibitors. 相似文献