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51.
An analysis is presented to investigate the effects of thermophoresis variable viscosity on MHD mixed convective heat and
mass transfer of a viscous, incompressible and electrically conducting fluid past a porous wedge in the presence of chemical
reaction. The wall of the wedge is embedded in a uniform porous medium in order to allow for possible fluid wall suction or
injection. The governing boundary layer equations are written into a dimensionless form by local non-similarity transformations.
The transformed coupled nonlinear ordinary differential equations are solved numerically by using the R.K. Gill and shooting
methods. Favorable comparison with previously published work is performed. Numerical results for the dimensionless velocity,
temperature and concentration profiles are obtained and displayed graphically for pertinent parameters to show interesting
aspects of the solution. 相似文献
52.
An analysis is presented to investigate the effect of thermophoresis particle deposition and temperature dependent viscosity on unsteady non-Darcy mixed convective heat and mass transfer of a viscous and incompressible fluid past a porous wedge in the presence of chemical reaction. The wall of the wedge is embedded in a uniform non-Darcian porous medium in order to allow for possible fluid wall suction or injection. The governing partial differential equations of the problem, subjected to their boundary conditions, are solved numerically by applying an efficient solution scheme for local nonsimilarity boundary layer analysis. Numerical calculations are carried out for different values of dimensionless parameters arising in the problem. The results are compared with available ones in the literature and excellent agreement is obtained. An analysis of the obtained results shows that the flow field is influenced appreciably by the chemical reaction and thermophoresis particle deposition. 相似文献
53.
Ganesan Kandasamy Sitti Raehanah Muhamad Shaleh 《Applied biochemistry and biotechnology》2017,182(2):586-597
Harvesting microalgae from medium is a major challenge due to their small size and low concentrations. In an attempt to find a cost-effective and eco-friendly harvesting technique, mung bean (Vigna radiata) protein extract (MBPE) was used for flocculation of Nannochloropsis sp. The effects of parameters such as pH, flocculant dose, algae concentration, and mixing time were used to study the flocculation efficiency (FE) of MBPE. Optimum parameters of MBPE dosage of 20 mL L?1 and a mixing rate of 300 rpm for 6 min achieved a FE of >92% after 2 h of settling time. MBPE-aggregated microlga flocs were characterized by microscopy. Zeta potential values decreased with increasing flocculant dose, and the values obtained were ?6.93 ± 0.60, ?5.36 ± 0.64, and ?4.44 ± 0.22 for doses of 10, 20, and 30 mL L?1, respectively. In conclusion, MBPE flocculants used in this study are safe, nontoxic, and pollution free, so they could be used for an effective, convenient, and rapid harvesting of microalgae in an eco-friendly approach. These methods are sustainable and could be applied in industrial scale for aquaculture nutrition. 相似文献
54.
Nanofluid-based direct solar receivers, where nanoparticles in a liquid medium can scatter and absorb solar radiation, have recently received interest to efficiently distribute and store the thermal energy. The objective of the present work is to investigate theoretically the unsteady homogeneous Hiemenz flow of an incompressible viscous nanofluid past a porous wedge due to solar energy (incident radiation). The conclusion is drawn that the temperature is significantly influenced by magnetic strength, nanoparticle volume fraction, convective radiation and porosity of the wedge sheet. 相似文献
55.
Nagarajan Sathya Arumugam Manimaran Gunasekaran Raja Periyasamy Muthusamy Kandasamy Deivasigamani Chinnasamy Jayabalakrishnan 《Transition Metal Chemistry》2009,34(1):7-13
New mononuclear ruthenium(III) Schiff base complexes of the type [RuX2(EPh3)(L)] (X = Cl or Br; E = P or As; L = monobasic tridentate Schiff base derived from o-aminophenol or o-aminothiophenol with ethylacetoacetate or ethylbenzoylacetate) have been synthesized. The Schiff base ligands chelate to ruthenium
through O, N, and O/S by dissociation of the phenolic proton/thiophenolic proton forming chelate rings. These complexes have
been characterized by physico-chemical and spectroscopic methods. Cyclic voltammetric data of all the complexes showed Ru(III)/Ru(IV)
oxidation and Ru(III)/Ru(II) reduction within the range of 0–1.5 V and 0 to −1.5 V with respect to Ag/AgCl, respectively.
The complexes were tested as catalysts in the oxidation of alcohols using molecular oxygen at ambient temperature, and also
in C–C coupling reactions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
56.
The thermal radiation energy is the clean energy with a much lower environmental impact than the conventional energy. The objective of the present work is to investigate theoretically the effect of copper nanoparticles and carbon nanotubes (CNTs) in the presence of base fluid (water) with the variable stream condition due to the thermal radiation energy. Single-walled carbon nanotubes (SWCNTs) in the presence of base fluid flow over a porous wedge play a significant role compared to those of copper nanoparticles on absorbing the incident solar radiation and transiting it to the working fluid by convection. 相似文献
57.
Kandasamy Ramasamy Roland K. Robins Ganapathi R. Revankar 《Journal of heterocyclic chemistry》1988,25(3):1043-1046
4-Amino-7-(2,3,5-tri-O-benzyl-β-D-arabinofuranosyl)pyrrolo[2,3-d]pyrimidine-5-carbonitrile ( 6a ), prepared from 2-ethoxymethyleneamino-5-bromopyrrole-3,4-dicarbonitrile ( 4 ), was debenzylated with boron trichloride to give ara-toyocamycin ( 6b ). Further functional group transformation of 6b provided a route to 4-amino-7-β-D-arabinofuranosylpyrrolo[2,3-d]pyrimidine-5-thiocarboxamide (ara-thiosangivamycin, 7a ), and the corresponding 5-carboxamidoxime 8a and 5-carboxamidine 8b derivatives. Phosphorylation of unprotected 7a with phosphorus oxychloride gave ara-thiosangivamycin 5′-monophosphate ( 7b ). 2′-O-Acetyl-ara-thiosangivamycin ( 10b ) was prepared as a prodrug by acetylation of 9a , followed by deprotection of the t-butyldimethylsilyl groups under acidic conditions without acyl migration. 相似文献
58.
59.
本文定义了一个新的代数系{R×C×S}这是一个有环结构的自由R-模,并讨论了结构性质与R的性质. 相似文献
60.
Ti(II)-mediated tandem cyclization of (E)-5-(tert-butyldimethylsilyloxy)-8-trimethylsilyl-2-octen-7-ynoate (7) prepared from commercially available optically active epichlorohydrin (2) proceeded diastereoselectively to provide 7-(tert-butyldimethylsilyloxy)-2-trimethylsilylbicyclo[3.3.0]oct-1-en-3-one (1), which serves as a useful chiral building block or intermediate to prepare a variety of compounds having a bicyclo[3.3.0]octane framework. 相似文献