A characterization of the linear groups L 2(p)

Let G be a finite group and π _e (G) be the set of element orders of G. Let k ∈ π _e (G) and m _k be the number of elements of order k in G. Set nse(G):= {m _k : k ∈ π _e (G)}. In fact nse(G) is the set of sizes of elements with the same order in G. In this paper, by nse(G) and order, we give a new characterization of finite projective special linear groups L ₂(p) over a field with p elements, where p is prime. We prove the following theorem: If G is a group such that |G| = |L ₂(p)| and nse(G) consists of 1, p ² ? 1, p(p + ?)/2 and some numbers divisible by 2p, where p is a prime greater than 3 with p ≡ 1 modulo 4, then G ? L ₂(p).     

Astrophysical S-factor of the d(p,γ)~3 He process by effective field theory

We summarize the recent effective field theory (EFT) studies of low-energy electroweak reactions of astrophysical interest, relevant to big-bang nucleosynthesis. The zero energy astrophysical S(0) factor for the thermal proton radiative capture by deuteron is calculated with pionless EFT. The astrophysical S(0) factor is accurately determined to be S(0)=0.243 eV·b up to the leading order (LO). At zero energies, magnetic transition M1 gives the dominant contribution. The M1 amplitude is calculated up to the LO. A good, quantitative agreement between theoretical and experimental results is found for all observables. The demonstrations of cutoff independent calculation have also been presented.     

A new application for diethyl azodicarboxylate: efficient and regioselective thiocyanation of aromatics amines

Highly regioselective thiocyanations of indoles, anilines and pyrrole are achieved via an efficient and simple protocol using NH₄SCN and diethyl azodicarboxylate (DEAD) as a mild oxidant.     

Characterization of projective linear groups by the order of the normalizer of a Sylow subgroup

Let $r$ be a prime and $G$ be a finite group, and let $R, \,S$ be Sylow $r$ -subgroups of $G$ and $\text{ PGL }(2, r)$ respectively. We prove the following results: (1) If $|G|=|\text{ PGL }(2, r)|$ and $|N_{G}(R)|=|N_{\mathrm{PGL}(2, r)} (S)|$ and $r$ is not a Mersenne prime, then $G$ is isomorphic to $\text{ PSL } (2, r) \times C_{2}, \,\text{ SL }(2, r)$ or $\text{ PGL }(2, r)$ . (2) If $|G|=|\text{ PGL }(2, r)|, \,|N_{G}(R)|=|N_{\mathrm{PGL}(2, r)}(S)|$ where $r>3$ is a Mersenne prime and $r$ is an isolated vertex of the prime graph of $G$ , then $G\cong \text{ PGL }(2, r)$ .     

Selective mono- and di-N-alkylation of aromatic amines with alcohols and acylation of aromatic amines using Ph3P/DDQ

Selective N-monoalkylation of aromatic amines with 1° and 2° alcohols and conversion of aromatic amines to amides are performed immediately and in excellent yields using triphenylphosphine (PPh₃) and 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in dichloromethane at room temperature. Symmetrical and unsymmetrical N,N-dialkylation of aromatic amines are also carried out in modest yield at room temperature by this reagent system.     

Ultrasound-promoted an efficient method for one-pot synthesis of 2-amino-4,6-diphenylnicotinonitriles in water: a rapid procedure without catalyst

A green and convenient approach to the synthesis of 2-amino-4,6-diphenylnicotinonitriles via four-component reaction of malononitrile, aromatic aldehydes, acetophenone derivatives and ammonium acetate in water under ultrasound irradiation is described. The combinatorial synthesis was achieved for this methodology with applying ultrasound irradiation while making use of water as green solvent. In comparison to conventional methods, experimental simplicity, good functional group tolerance, excellent yields, short routine, and selectivity without the need for a transition metal or base catalyst are prominent features of this sonocatalyzed procedure.     

Zonal modeling of radiative heat transfer in industrial furnaces using simplified model for exchange area calculation

The zonal analysis of industrial furnaces is considered with three-dimensional radiative heat transfer, incorporated with the mathematical zone method. In this method exchange areas are determined by simplified numerical integration in three dimensions for surface-surface, surface-gas and gas–gas zones for absorbing and emitting media. By focusing on new strategies to overcome the drawbacks of evaluating direct exchange areas, it is shown that the zone method is an effective numerical method for modeling three-dimensional thermal performance of gas-filled enclosures. Also the developed method for evaluating of exchange area is presented and compared with other methods in both sides of CPU time and accuracy. The method can decrease about 70% in error of calculation of some exchange areas as compared with the other numerical methods.     

Salvadora Persica branches biomass adsorbent for removal of uranium(VI) and thorium(IV) from aqueous solution: kinetics and thermodynamics study

Adsorption isotherms of U(VI) and Th(IV) in water were obtained and removal kinetics was studied. The main functional groups on the surface of Salvadora Persica branches adsorbent were identified using a Fourier-transform infrared and the surface morphology of adsorbent was characterized by a Scanning Electron Microscope. Effects of the U(VI) and Th(IV) initial concentrations, contact time, the mass of adsorbent loading, pH of the solution were investigated at 25?±?0.3 °C. The efficiencies with which this adsorbent removes U(VI) and Th(IV) from their solutions in water are reported. The adsorption isotherm fitted the Freundlich model. The adsorption of U(VI) and Th(IV) follows the pseudo-second order kinetic with squared correlation coefficients (R²) close to 1.0. The thermodynamic parameters (i.e. the free energy (\(\Delta G_{\text{ads}}^{o}\)), the enthalpy (\(\Delta H_{\text{ads}}^{o}\)) and the entropy of adsorption (\(\Delta S_{\text{ads}}^{o}\)) for the adsorption of U(VI) and Th(IV) on the Salvadora Persica branches adsorbent were reported.

     

ZnO-based ternary nanocomposite for decolorization of methylene blue by photocatalytic dynamic membrane

In this article, novel Ag–ZnO/g-C₃N₄/GO ternary nanocomposites were prepared via co-precipitation method by 1%w Ag, 50% w g-C₃N₄, 10% w GO concentration and applied in dynamic membranes. The characteristics of Ag–ZnO/g-C₃N₄/GO nanocomposite were evaluated by various techniques such as X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray map, transmission electron microscopy, X-ray photoelectron spectroscopy, photocatalyst. The photocatalytic degradation of methylene blue was investigated under visible light. The photocatalytic efficiency of 93.43% for methylene blue degradation was obtained for Ag–ZnO/g-C₃N₄/GO nanocomposite after 50 min of irradiation, which was remarkably higher than that of pure ZnO, bare g-C₃N₄, Ag–ZnO, and Ag–ZnO/g-C₃N₄ at the same irradiation time. Likewise, in self-forming and pre-coated membranes, ternary nanocomposites can play a vital role in the membrane surface properties, as well as their decolorization performance. The rejection of methylene blue was 30% in pure polyethersulfone membrane, while the photocatalytic degradation of methylene blue in Ag–ZnO/g-C₃N₄/GO nanocomposites was 88.46% and 98.86% after 10 and 15 min of irradiation in both self-forming and pre-coated dynamic membranes, respectively. Experimental results show that the dynamic membrane possesses a higher ability for degradation of MB in a shorter period of time than the static system.     

A new way to evaluate the Probability and Fresnel integrals

In this article, we show how Laplace Transform may be used to evaluate variety of nontrivial improper integrals, including Probability and Fresnel integrals. The algorithm we have developed here to evaluate Probability, Fresnel and other similar integrals seems to be new. This method transforms the evaluation of certain improper integrals into evaluation of improper integrals of the corresponding Laplace transform, which in many cases are much easier.