The differential approximation for radiative transfer in an emitting,absorbing and anisotropically scattering medium

The validity of the well-established differential approximation in radiative transfer is extended to include linear-anisotropic scattering. Sample results demonstrate the accuracy of the method.     

A general Struble's technique for solving an nth order weakly non-linear differential system with damping

A general formula (based on the method of variation of parameters) has been presented for determining an approximate solution of an nth order n=2,3,… weakly non-linear differential system with several damping effects. The general solution covers the under-damped, undamped and over-damped cases. The formulation as well as determination of the solution is simple. The method is illustrated by several examples.     

Direct observation of a transition of a surface plasmon resonance from a photonic crystal effect

Transition of surface-plasmon resonance from out-of-plane photonic crystal effect is observed in a semiconductor array of subwavelength holes by optical pump-terahertz probe measurements. The dielectric properties of the photoexcited array are essentially altered by the intense optical excitation due to photogenerated free carriers. As a result, the array becomes metallic and favors the coupling and propagation of surface plasmons. The photoinduced resonant extremes agree well with the Fano model.     

Products of the gas‐phase photooxidation reactions of 1‐propanol with OH radicals

An experimental investigation of the hydroxyl radical initiated gas‐phase photooxidation of 1‐propanol in the presence of NO was carried out in a reaction chamber using gas chromatography mass spectrometry. The products identified in the OH radical reactions of 1‐propanol were propionaldehyde and acetaldehyde, with corresponding formation yields of 0.719 ± 0.058 and 0.184 ± 0.030, respectively. Errors represent ±2σ. The experimental product yields were compared to predictions made using chemical mechanisms. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 810–818, 1999     

On the effective stress in unsaturated porous continua with double porosity

Using mixture theory we formulate the balance laws for unsaturated porous media composed of a double-porosity solid matrix infiltrated by liquid and gas. In this context, the term ‘double porosity’ pertains to the microstructural characteristic that allows the pore spaces in a continuum to be classified into two pore subspaces. We use the first law of thermodynamics to identify energy-conjugate variables and derive an expression for the ‘effective’, or constitutive, stress that is energy-conjugate to the rate of deformation of the solid matrix. The effective stress has the form , where σ is the total Cauchy stress tensor, B is the Biot coefficient, and is the mean fluid pressure weighted according to the local degrees of saturation and pore fractions. We identify other emerging energy-conjugate pairs relevant for constitutive modeling of double-porosity unsaturated continua, including the local suction versus degree of saturation pair and the pore volume fraction versus weighted pore pressure difference pair. Finally, we use the second law of thermodynamics to determine conditions for maximum plastic dissipation in the regime of inelastic deformation for the unsaturated two-porosity mixture.     

Synthesis and analysis of ZnO-CoMoO4 incorporated organic compounds for efficient degradation of azo dye pollutants under dark ambient conditions

In recent years, the degradation of organic dyes under dark conditions, at room temperature and atmosphere pressure, without additional lights or chemical stimulants, has been widely investigated. Here, a nanocomposite of ZnO-CoMoO₄ was synthesized using an organic template and investigated as a catalyst to degrade methyl orange in aqueous environment under dark, ambient conditions. The organic compounds of Abies Pindrow Royle were reacted with a precursor solution following sol–gel synthesis methodology to modify the chemistry and morphology of ZnO-CoMoO_4, so formed. The structure of the nanocomposite was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray spectroscopy while nanostructures were examined by field emission scanning electron microscopy. Organic functional groups were determined by Fourier transform infrared spectroscopy and Gas chromatography–mass spectrometry. The organic compound incorporated nanocomposite was revealed to be an excellent catalyst with 95% degradation of methyl orange in aqueous environment under dark ambient conditions within 10 min. The catalyst also revealed 99% degradation of azo dye in the presence of solar light. Furthermore, the catalysts illustrated good stability with pseudo first order kinetics (R² < 1) in the light as well as in the dark conditions with outstanding reusability till four cycles of experiments. Therefore, nanostructure and organic species of Abies Pindrow Royle were found to enhance the catalytic behavior of ZnO-CoMoO₄ towards methyl orange degradation even in dark conditions.     

The second regularized trace of differential operator equation with the semi‐periodic boundary conditions

In this paper, we have obtained the second regularized trace formula for the differential operator equation with the semi‐periodic boundary conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

Ultra‐small and highly dispersed Pd nanoparticles inside the pores of ZIF‐8: Sustainable approach to waste‐minimized Mizoroki–Heck cross‐coupling reaction based on reusable heterogeneous catalyst

The rapid development of nanomaterials, particularly advanced hybrid nanoparticles, has made new opportunities for the design and fabrication of high‐performance metal‐based catalysts. However, generating metal nanoparticles of desired size without aggregation is an important challenge for enhancing the catalytic activity of metal nanoparticles supported in the host matrix. In this work, a hybrid nanoporous material, namely Pd nanoparticles@N‐heterocyclic carbene@ZIF‐8, with a high internal surface area was successfully prepared using a dispersed anionic sulfonated N‐heterocyclic carbene–Pd(II) precursor inside the cavities of zeolitic imidazolate framework (ZIF‐8) using an impregnation approach followed by reduction with NaBH₄. The anionic sulfonated N‐heterocyclic carbene was found to be a superb ligand for the stabilization of Pd nanoparticles in the pores of ZIF‐8. The resulting system was applied to the Mizoroki–Heck cross‐coupling reaction, in which the catalyst showed high catalytic activity under mild reaction conditions.     

Synthesis,spectral studies,thermal behavior,and antibacterial activity of Ni(Ⅱ),Cu(Ⅱ),and Zn(Ⅱ) complexes with an ONO tridentate Schiff base

Three new transition metal complexes have been synthesized with a Schiff base,3-(2-hydroxy-5-chlorophenylimino)-l,3- diphenylpropen-1-one.In all complexes Schiff base is completely deprotonated and coordinated to metal as tridentate ligand via phenolic and enolic oxygens and imine nitrogen.Thermal decomposition of the complexes has been studied by thermogravimetry. The in vitro antibacterial activity of Schiff bases and their complexes has been evaluated and compared with the standard drugs.