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61.
This paper deals with the study of the MHD flow of non-Newtonian fluid on a porous plate. Two exact solutions for non-torsionally generated unsteady hydromagnetic flow of an electrically conducting second order incompressible fluid bounded by an infinite non-conducting porous plate subjected to a uniform suction or blowing have been analyzed. The governing partial differential equation for the flow has been established. The mathematical analysis is presented for the hydromagnetic boundary layer flow neglecting the induced magnetic field. The effect of presence of the material constants of the second order fluid on the velocity field is discussed. 相似文献
62.
Nazakat Ullah 《Pramana》1993,41(2):171-174
A formulation is developed to derive exact analytic expressions for electron-electron correlation and density of electrons
in momentum space using hydrogenic wave functions. It is shown that for large atoms the expression for density of electrons
has a simple form. 相似文献
63.
Nazakat Ullah 《Pramana》1994,42(6):491-494
The distribution of quarks in light nuclei is given using the quark cluster wave function. An analytic expression for the
nucleus4He is obtained. The distribution so obtained is compared with the one obtained using a different theoretical formulation called
mapping. 相似文献
64.
Nazakat Ullah 《Pramana》1976,7(5):316-318
An exact differential equation is given to evaluate the energy average of the scattering function. The advantage of the differential
equation as compared to the earlier methods based on series expansion is that one has to evaluate only single sums over the
complex poles of the S-matrix. Using Wigner’s semicircle law for the distribution of the real parts of the poles of the scattering
matrix, the earlier expression for the energy average of the scattering function is rederived. 相似文献
65.
Nazakat Ullah 《Pramana》1983,20(2):131-135
An integral which occurs in the new matrix ensembles and the width fluctuation factor is evaluated using a transformation
which changes a Gaussian into an exponential. It is expressed in the form of a series whose terms are found using a simple
recursion relation. It is shown that the series can be summed in closed form for the two-dimensional case. 相似文献
66.
Titanium dioxide (TiO(2)) with an enhanced photocatalytic activity was developed by doping it with calcium ions through a sol-gel method. The developed photocatalysts were characterized by Fourier transform infrared (FTIR) spectroscopy, N(2) physisorption, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction. Their surface morphologies were studied using surface scanning electron microscopy (SEM). The XPS analyses confirmed the presence of Ti, O, Ca, and C in the Ca-doped TiO(2) sample. The activities of the catalysts were evaluated by photocatalytic degradation of an azo dye, acid red 1 (AR1), using UV light irradiation. The results of the investigations revealed that the samples calcined at 300 °C for 3.6h in a cyclic (2 cycles) mode had the best performance. Lower percentage dopant, 0.3-1.0 wt.%, enhanced the photocatalytic activity of TiO(2), with the best at 0.5 wt.% Ca-TiO(2). The performance of 0.5 wt.% Ca-TiO(2) in the degradation of AR1 was far superior to that of a commercial anatase TiO(2) Sigma product CAS No. 1317-70-0. The effect of pH on the degradation of AR1 was studied, and the pH of the dye solution exerted a great influence on the degradation of the dye. 相似文献
67.
68.
AH Karim AA Jalil S Triwahyono SM Sidik NH Kamarudin R Jusoh NW Jusoh BH Hameed 《Journal of colloid and interface science》2012,386(1):307-314
In this work, mesostructured silica nanoparticles (MSN(AP)) with high adsorptivity were prepared by a modification with 3-aminopropyl triethoxysilane (APTES) as a pore expander. The performance of the MSN(AP) was tested by the adsorption of MB in a batch system under varying pH (2-11), adsorbent dosage (0.1-0.5gL(-1)), and initial MB concentration (5-60mgL(-1)). The best conditions were achieved at pH 7 when using 0.1gL(-1) MSN(AP) and 60mgL(-1)MB to give a maximum monolayer adsorption capacity of 500.1mgg(-1) at 303K. The equilibrium data were evaluated using the Langmuir, Freundlich, Temkin, and Harkins-Jura isotherms and fit well to the Freundlich isotherm model. The adsorption kinetics was best described by the pseudo-second order model. The results indicate the potential for a new use of mesostructured materials as an effective adsorbent for MB. 相似文献
69.
Izaz Ullah Khan Tahir Ahmad Normah Maan 《Journal of Optimization Theory and Applications》2013,159(2):536-546
This study proposes a novel technique for solving Linear Programming Problems in a fully fuzzy environment. A modified version of the well-known simplex method is used for solving fuzzy linear programming problems. The use of a ranking function together with the Gaussian elimination process helps in solving linear programming problems in a fully uncertain environment. The proposed algorithm is flexible, easy and reasonable. 相似文献
70.
Hameed Ullah Huafei Sun Abdul Majeed Siddiqui Tahira Haroon 《Journal of Applied Analysis & Computation》2019,9(1):140-158
This paper provides the analysis of the steady, creeping flow of a special class of slightly viscoelastic, incompressible fluid through a slit having porous walls with uniform porosity. The governing two dimensional flow equations along with non-homogeneous boundary conditions are non-dimensionalized. Recursive approach is used to solve the resulting equations. Expressions for stream function, velocity components, volumetric flow rate, pressure distribution, shear and normal stresses in general and on the walls of the slit, fractional absorption and leakage flux are derived. Points of maximum velocity components are also identified. A graphical study is carried out to show the effect of porosity and non-Newtonian parameter on above mentioned resulting expressions. It is observed that axial velocity of the fluid decreases with the increase in porosity and non-Newtonian parameter. The outcome of this theoretical study has significant importance both in industry and biosciences. 相似文献