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61.
MHD mixed free-forced heat and mass convective steady incompressible laminar boundary layer flow of a gray optically thick electrically conducting viscous fluid past a semi-infinite inclined plate for high temperature and concentration differences is studied. A uniform magnetic field is applied perpendicular to the plate. The density of the fluid is assumed to reduce exponentially with temperature and concentration. The usual Boussinesq approximation is neglected due to the high temperature and concentration differences between the plate and the ambient fluid. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The boundary layer equations governing the flow are reduced to ordinary differential equations, which are numerically solved by applying an efficient technique. The effects of the density/temperature parameter n, the density/concentration parameter m, the local magnetic parameter Mx and the radiation parameter R are examined on the velocity, temperature and concentration distributions as well as the coefficients of skin-friction, heat flux and mass flux. 相似文献
62.
Mostafa M.A. Khater Emad H.M. Zahran Maha S.M. Shehata 《Journal of the Egyptian Mathematical Society》2017,25(1):8-12
In this research, we find the exact traveling wave solutions involving parameters of the generalized Hirota–Satsuma couple KdV system according to the modified simple equation method with the aid of Maple 16. When these parameters are taken special values, the solitary wave solutions are derived from the exact traveling wave solutions. It is shown that the modified simple equation method provides an effective and a more powerful mathematical tool for solving nonlinear evolution equations in mathematical physics. Comparison between our results and the well-known results will be presented. 相似文献
63.
64.
Koczkur KM Hamed EM Houmam A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(20):12270-12274
Hexamethyldisilathiane was successfully used as a new precursor for the formation of S layers on Au and to study their interaction. Characterization of the S modified gold surface was done by X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and scanning tunneling microscopy (STM). Key findings include the direct observation by STM of (i) coexistence of different phases, (ii) multiple sulfur layers formation, (ii) formation of rectangular structures not only on the adlayer but also on the top layer, and (iv) rectangular structure mobility on different layers. These results provide clear evidence regarding the adsorbate nature of the rectangular structures, solving a highly debated question. 相似文献
65.
Dialkyl and alkylene dithiophoshoric acids react with diphenyl diselenide in a 1:2 molar ratio in refluxing benzene to yield Ph2Se2·2HS2P(OR)2 (R = Et, Pr‐n, Pr‐i, Bu‐i and Ph) and , where G = ‐CH2CMe2CH2‐, ‐CH2CEt2CH2‐ and ‐CMe2CMe2‐. The complexes are yellow solids (in the cyclic chain) and yellow sticky solids (in the open chain), are soluble in common organic solvents and are monomeric in nature. They were characterized on the basis of elemental analyses, molecular weight determinations, IR and NMR (1H, 13C and 31P). The spectral data revealed addition of dithiophosphate moieties to the diselenide. Studies were conducted to assess the growth‐inhibiting potential of some of the synthesized complexes against various bacterial strains. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
66.
A new method has been described to determine both benzodiazepines (six) and tricyclic antidepressants (four) simultaneously in saliva by HPLC with a UV detector set at 240 nm using cholchicine as the internal standard. A careful specific sequential solid‐phase elution was optimized and performed to elute benzodiazepines using a mixture of methanol‐acetonitrile (1:1 v/v) followed by the elution of tricyclic antidepressants with methanol. Separation of the compounds was performed on a Kromasil column (250 × 4 mm, 5 μm) by a gradient eluents consisting of 0.05 M CH3COONH4‐acetonitrile‐methanol (55:15:30 v/v/v). The results were linear for both benzodiazepines and tricyclic antidepressants up to 20 ng μL‐1 with the correlation coefficients greater than 0.998. The sensitivity limits, LOD and LOQ were 0.08‐0.34 ng μL‐1 and 0.28‐1.13 ng μL‐1, respectively. The method is simple, fast and reliable with good specificity and sensitivity, will be suitable for use in a clinical setting, where there is a concomitant use of 1,4‐benzodiazepines and tricyclic antidepressants. 相似文献
67.
68.
Mohammad O. Hamdan Ahmed Alawar Emad Elnajjar Waseem Siddique 《Heat and Mass Transfer》2011,47(12):1637-1642
The present study reports the effect of several operating parameters on the thermal performance of the vortex tube. The experimental
results indicate that the inlet pressure and the cold fraction are the most significant parameters influencing the vortex
tube performance. The experimental data point out that insulation has minimal effect on the vortex tube performance. The same
inlet pressure tests show that energy separation increases as number of inlet nozzle increases. 相似文献
69.
Thallada Bhaskar Kazuya Murai Toshiki Matsui Mihai Adrian Brebu Md. Azhar Uddin Akinori Muto Yusaku Sakata Katsuhide Murata 《Journal of Analytical and Applied Pyrolysis》2003,70(2):369-381
The thermal degradation of acrylonitrile-butadiene-styrene copolymer (ABS-Br; 10 g) containing brominated flame retardant (Br: 9.59 wt.%) was carried out at 450 °C using a semi batch operation using two different temperature programs. The heating rate was found to affect the quality of the degradation oil and yield of products (liquid, gas and residue). Data on the effect of the temperature program on the accumulation of liquid products was presented. It was found that the majority of the bromine was concentrated in the carbon residue and while majority of the nitrogen accumulates in the liquid products irrespective of degradation mode. The use of a one step constant heating rate process (I) produced a higher liquid yield (39%), than a two step process (29%). Differences were also noted in the Br and N contained in the liquids produced by the two processes. 相似文献
70.