Zinc polyoxometalate on activated carbon: an efficient catalyst for selective oxidation of alcohols with hydrogen peroxide

[PW₁₁ZnO₃₉]^5? was immobilized on activated carbon and characterized using Fourier transform infrared, X‐ray diffraction, Brunauer–Emmett–Teller and elemental analysis techniques. Effective oxidation of various alcohols with hydrogen peroxide was performed in the presence of this catalyst. Easy separation of the catalyst from the reaction mixture, cheapness, high activity and selectivity, stability as well as retained activity in subsequent catalytic cycles make this supported catalyst suitable for small‐scale synthesis. Copyright © 2015 John Wiley & Sons, Ltd.     

Error estimation,adaptivity and data transfer in enriched plasticity continua to analysis of shear band localization

In this paper, an adaptive FE analysis is presented based on error estimation, adaptive mesh refinement and data transfer for enriched plasticity continua in the modelling of strain localization. As the classical continuum models suffer from pathological mesh-dependence in the strain softening models, the governing equations are regularized by adding rotational degrees-of-freedom to the conventional degrees-of-freedom. Adaptive strategy using element elongation is applied to compute the distribution of required element size using the estimated error distribution. Once a new mesh is generated, state variables and history-dependent variables are mapped from the old finite element mesh to the new one. In order to transfer the history-dependent variables from the old to new mesh, the values of internal variables available at Gauss point are first projected at nodes of old mesh, then the values of the old nodes are transferred to the nodes of new mesh and finally, the values at Gauss points of new elements are determined with respect to nodal values of the new mesh. Finally, the efficiency of the proposed model and computational algorithms is demonstrated by several numerical examples.     

Convergence analysis of perturbed hemivariational inequalities

We consider the rate of convergence for a class of perturbed hemivariational inequalities in reflexive Banach Spaces. Our results can be viewed as an extension and refinement of some previous known results in this area.     

Bioaccumulation and biosorption of stable strontium and <Superscript>90</Superscript>Sr by <Emphasis Type="Italic">Oscillatoria homogenea</Emphasis> cyanobacterium

The ability of living filamentous cells of the cyanobacterium Oscillatoria homogenea to separate stable strontium and ⁹⁰Sr from aqueous solution is demonstrated in this study. On a basis of filamentous cell biovolume, the removal were 43.78 nM·ml·(mm³)⁻¹ and 3129.48 mBq·ml·(mm³)⁻¹ after 240 hour incubation. The optimum pH for strontium uptake is 9±0.3. The increasing biovolume of the blue-green alga elevates sorption. In the liquid culture containing 21.2 mm³·ml⁻¹ filamentous cells and 1000 nM·ml⁻¹ initial strontium concentration, the maximum strontium removal was 455.34 nM·ml·(mm³)⁻¹. At 1200 Lux illumination, the maximum removal value was 58.62 nM·ml·(mm³)⁻¹, and at the initial strontium concentration of 6590 nM·ml⁻¹, 235.40 nM·ml·(mm³)⁻¹ removal was observed. The experimental data fitted to Langmuir isotherm and the model parameters and correlation coefficient (R ²) were q _max = 7.143 μg·(mm³)⁻¹, b = 0.003 and 0.99, respectively.     

Design and fabrication of a Fourier transform spectrometer by means of thermally actuated tunable grating

In this article, the design and fabrication of a Fourier transform spectrometer, based on a thermally actuated tunable grating, are presented. Grooves of a binary grating are filled with nitrobenzene, the refractive index of which highly depends on temperature. Through the application of heat, the temperature of the nitrobenzene is changed, which in turn changes the efficiency of the grating. To measure the spectrum of a light beam, the light under inspection is first passed through the grating and the intensity of the zero order of diffraction is recorded as a function of temperature. Next, the Fourier transform of the measured data is calculated. The resolution of the spectrometer is also discussed. Finally, a micro-spectrometer that is based on a thermally actuated grating is proposed.     

Fabrication of a passive 3D mixer using CO2 laser ablation of PMMA and PDMS moldings

In this article a novel method for the fabrication of a passive 3D mixer is presented. It has been shown that in CO2 laser ablation of Polymethyl Methacrylate (PMMA), bending and straight cone structures can be fabricated by adjusting the laser scanning parameters. The effect of the bending cones in the flow direction of a fluid is discussed with computer simulation and a passive mixer based on such structures is designed. Bending and straight cones are fabricated on a PMMA substrate using CO2 laser ablation technique. The structure is molded with PDMS to make two half-channels with bending and straight cones extending out of the surface. Two PDMS structures are stacked on top of each other with a certain displacement to fabricate the mixer.     

On Magneto Convection in a Mushy Layer

The subject of the title is briefly discussed and clarified based on the available experimental evidence.     

Topological KKM theorems and generalized vector equilibria on G-convex spaces with applications

In the present paper, slightly modifying the topological KKM Theorem of Park and Kim (1996), we obtain a new existence theorem for generalized vector equilibrium problems related to an admissible multifunction. We work here under the general framework of G-convex space which does not have any linear structure. Also, we give applications to greatest element, fixed point and vector saddle point problems. The results presented in this paper extend and unify many results in the literature by relaxing the compactness, the closedness and the convexity conditions.