Performance of conversion efficiency of a bifacial silicon solar cell with particle irradiation

This paper investigates theoretically the performance of conversion efficiency of a bifacial silicon solar cell with particle irradiation. The bifaciality coefficient and the conversion efficiency are calculated for various rear side illumination conditions and electron fluence, taking into account the diffusion length related damage coefficient. The main purpose of the work is to show that irradiation could significantly degrade both the bifaciality coefficient and then the conversion efficiency of the bifacial solar cell and to exhibit the role of the fluence and rear side illumination condition level in the performance of the bifacial silicon solar cell.     

Impacts of uniaxial elongation on the bandstructures of two-dimensional sonic crystals and associated applications

Influences of uniaxial elongation along the [11] direction of triangular and [10] direction of square sonic crystals under the constraint of conserved unit cell area are investigated by examining band structures and equi-frequency contours. Lowest-lying band gap of the triangular lattice observed at high filling fractions diminishes for negative elongation (compression), whereas another band gap develops at lower frequencies whose width reaches appreciable values for moderate elongation. The band gap of the square lattice, which appears at high filling fractions, is modified slightly with elongation. Frequency ranges of the bands, and thus the group velocities along the high-symmetry directions, vary with elongation which may be useful in applications like slow sound propagation. Elongation is observed to modify the equi-frequency contours significantly through reducing the lattice symmetry. The most prominent impact is the transformation of closed contours into open ones, whereas the rest are stretched either along or normal to the elongation axis of the 1st Brillouin Zone. This observation is utilized to implement wide-band all-angle self-collimation and superprism effect, which are demonstrated through Finite-Element computations.     

A note on defining singular integral as distribution and partial differential equations with convolution term

In this study first we consider the singular integrals as generalized functions in two dimensions and then we solve the non-homogeneous wave equation with convolutional term by using the generalized functions as boundary conditions.     

Exact solutions and conservation laws of Zakharov-Kuznetsov modified equal width equation with power law nonlinearity

This paper obtains solutions to the Zakharov-Kuznetsov modified equal width equation with power law nonlinearity. The Lie symmetry approach and the simplest equation method are used to obtain these solutions. Moreover, conservation laws are derived for the underlying equation by employing two approaches: the new conservation theorem and the multiplier method.     

Stereo-selectivity in a cyclotriphosphazene derivative bearing an exocyclic P-O moiety

Nucleophilic substitution reactions of N(3)P(3)Cl(4)[O(CH(2))(2)NCH(3)], (1) with the sodium salts of mono- and di-functional alcohols [methanol (2), phenol (3), tetraethyleneglycol (4) and 1,3-propanediol (5)] were carried out in order to investigate a possible directing effect of the spiro O-moiety on the formation of mono-substituted (2a, 3a), non-geminal di-substituted (2c, 3c) and ansa (4a, 5a) derivatives. Compounds isolated from the reactions were characterized by elemental analysis, mass spectrometry, (1)H and (31)P NMR spectroscopy and X-ray crystallographic analysis showed that the substituent OR in compounds (2a, 3a and 2c, 3c) and the ansa-ring in compounds (4a, 5a) formed cis to the P-O moiety of the exocyclic [O(CH(2))(2)NCH(3)] spiro ring. The formation of products (2a-d, 3a-d, 4a, 5a and 5b) was quantified from the (31)P NMR spectra of the reaction mixtures, which showed an overwhelming preference for derivatives (2a, 3a, 2c, 3c, 4a, 5a) with the substituent cis to the P-O moiety of the exocyclic spiro ring (2a, 3a, 2c, 3c, 4a, 5a), except for reaction with 1,3-propanediol where the six-membered ring spiro derivative (5b) was about three times more abundant than the eight-membered ring ansa-derivative (5a). Overwhelming formation of products with the substituent cis to the exocyclic P-O moiety is proof that the cation-assisted mechanism is responsible for the stereo-selectivity in the reactions with alkoxides.     

Influence of the preparation method on the physicochemical properties of econazole-β-cyclodextrin complexes

Econazole (C₁₈H₁₅Cl₃N₂O) is one of the common antifungal agents whose poor aqueous solubility restricts its use for the treatment of oropharyngeal candidiasis, which is the first symptom of HIV infection. Therefore, the aim of the current study was to investigate the effect of different preparation methods (i.e. kneading, coevaporation, sealed-heating, and supercritical carbon dioxide (SC CO₂)) for obtaining solid inclusion complexes between β-cyclodextrin and econazole. The physico-chemical properties of the different products were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (PXRD). For the complexes prepared by the SC CO₂ method, the effects of temperature and pressure have also been investigated and related to the solubility of econazole in SC CO₂. Results suggested the validity of the SC CO₂ method for preparing solid complexes between cyclodextrins and econazole, avoiding the use of organic solvents and problems of their complete removal. Moreover, temperature played a major role in promoting drug-carrier interactions, whereas pressure had limited effects.     

Synthesis and Characterization of Novel Alkyl-Substituted Aryl Diphenylphosphinate Esters

Abstract

In this work, the reactions of diphenylphosphinic chloride, (C₆H₅)₂P(O)Cl, 1, with the sodium salts of sterically hindered phenol derivatives (2a-2j) were investigated. Novel alkyl-substituted aryl diphenyl phosphinate esters (C₆H₅)₂P(O)OAr (3-12) were obtained from these reactions. Satisfactory analytical and spectroscopic results were obtained for all the new compounds.

GRAPHICAL ABSTRACT     

Solutions of Kadomtsev–Petviashvili equation with power law nonlinearity in 1+3 dimensions

This paper studies the solution of the Kadomtsev–Petviasvili equation with power law nonlinearity in 1+3 dimensions. The Lie symmetry approach as well as the extended tanh‐function and G′/G methods are used to carry out the analysis. Subsequently, the soliton solution is obtained for this equation with power law nonlinearity. Both topological as well as non‐topological solitons are obtained for this equation. Copyright © 2010 John Wiley & Sons, Ltd.