New measurements and reanalysis of 14N elastic scattering on 10B target

The angular distributions of elastic scattering of ¹⁴N ions on ¹⁰B targets have been measured at incident beam energies of 21.0 and 24.5 MeV. Angular distributions at higher energies 38–94.0 MeV (previously measured) were also included in the analysis. All data were analyzed within the framework of the optical model and the distorted waves Born approximation method. The observed rise in cross sections at large angles was interpreted as a possible contribution of the α-cluster exchange mechanism. Spectroscopic amplitudes SA₂ and SA₄ for the configuration ¹⁴N→ ¹⁰B +α were extracted. Their average values are 0.58±0.10 and 0.81±0.12 for SA₂ and SA₄, respectively, suggesting that the exchange mechanism is a major component of the elastic scattering for this system. The energy dependence of the depths for the real and imaginary potentials was found.     

Performing thermodynamic analysis by simulating the general characteristics of the two-spool turbojet engine suitable for drone and UAV propulsion

Journal of Thermal Analysis and Calorimetry - This study presents determining performance parameters as well as thermodynamic analysis through certain design parameters of a two-spool turbojet...     

Continuous production of (S)-1-phenylethanol by immobilized cells of Rhodotorula glutinis with a specially designed process

A specially designed process for the continuous production of a chiral alcohol by immobilized Rhodotorula glutinis was prepared and is reported. The performance of the process with immobilized cells was also investigated. The run time of the immobilized cells, the flow rates of the substrate, and tris buffer containing 4% glucose in the process were optimized. The immobilized R. glutinis biocatalyst could be used for 15 days with maximum reaction activity. Under the optimized conditions, the continuous production process was operated for 30 days and resulted in 10.8 mL (S)-1-phenylethanol [(S)-1-PE]. The process has been demonstrated on a multigram scale in 75% overall yield with a purity of >99%.     

Numerical approximation of the generalized regularized long wave equation using Petrov–Galerkin finite element method

The generalized regularized long wave (GRLW) equation has been developed to model a variety of physical phenomena such as ion‐acoustic and magnetohydrodynamic waves in plasma, nonlinear transverse waves in shallow water and phonon packets in nonlinear crystals. This paper aims to develop and analyze a powerful numerical scheme for the nonlinear GRLW equation by Petrov–Galerkin method in which the element shape functions are cubic and weight functions are quadratic B‐splines. The proposed method is implemented to three reference problems involving propagation of the single solitary wave, interaction of two solitary waves and evolution of solitons with the Maxwellian initial condition. The variational formulation and semi‐discrete Galerkin scheme of the equation are firstly constituted. We estimate rate of convergence of such an approximation. Using Fourier stability analysis of the linearized scheme we show that the scheme is unconditionally stable. To verify practicality and robustness of the new scheme error norms L₂, L_∞ and three invariants I₁, I₂, and I₃ are calculated. The computed numerical results are compared with other published results and confirmed to be precise and effective.     

A novel approach for highly proton conductive electrolyte membranes with improved methanol barrier properties: Layer-by-Layer assembly of salt containing polyelectrolytes

A series of highly proton conductive electrolyte membranes with improved methanol barrier properties are prepared from polyallylamine hydrochloride (PAH) and polystyrene sulfonic acid (PSS) including salt by Layer-by-Layer (LbL) method. The effects of added salt type (NaCl, MgCl₂) and salt concentration (1.0 M, 0.1 M) on proton conductivity (σ) and methanol barrier properties of the LbL self-assembled composite membranes are discussed in terms of controlled layer thickness and charge density. Furthermore, the influences of ion type in the multilayered composite membranes are studied in conjunction with physicochemical and thermal properties.The deposition of the self-assembly of PAH/PSS film on Nafion is followed by UV–Vis spectroscopy and it is observed that the polyelectrolyte layers growth on both sides of Nafion membrane regularly. (PAH/PSS)₅–Na⁺ and (PAH/PSS)₅–H⁺ with 1.0 M NaCl exhibits 49.6 and 27.8% reduction in lower methanol permittivity in comparison with the pristine Nafion^®117, respectively, while the proton conductivities are 12.97 and 74.69 mS cm⁻¹. Promisingly, it is found that the membrane selectivity values (Φ) of all multilayered membranes in H⁺ form are much higher than that of salt form (Na⁺ and Mg²⁺) and perfluorosulfonated ionomers reported in the literature. Also, we find out that the use of polyelectrolytes with high charge density causes a further improvement in proton conductivity and methanol barrier properties simultaneously. These encouraging results indicate that upon a suitable choice of LbL deposition conditions, composite membranes exhibiting both high proton conductivity and improved methanol barrier properties can be tailored for fuel cells.     

The effect of topical ethanol extract of Cotinus coggygria Scop. on cutaneous wound healing in rats

The aim of this study is to determine the cutaneous wound healing effects of the ethanol extract of Cotinus coggygria leaves in rats by excision wound model to provide scientific evidence for the traditional use of C. coggygria Scop. The levels of malondialdehyde, catalase, superoxide dismutase, glutathione and hydroxyproline were investigated in wound tissues. Histopathological examination was also performed. The hydroxyproline content of the granulation tissue and the glutathione levels were both significantly higher in the treatment group than in the control group (p < 0.05 for both); while the malondialdehyde levels were significantly lower in the treatment group (p < 0.05). These results were supported with histological results. The ethanol extract of C. coggygria Scop could be considered as an effective agent in wound healing in accordance with its traditional use.     

Oscillatory and Periodic Solutions of Impulsive Differential Equations with Piecewise Constant Argument

We study the existence of oscillatory and periodic solutions of a class of first order scalar impulsive delay differential equations with piecewise constant argument.     

A C0 finite element method for the biharmonic problem without extrinsic penalization

A symmetric C ⁰ finite element method for the biharmonic problem is constructed and analyzed. In our approach, we introduce one‐sided discrete second‐order derivatives and Hessian matrices to formulate our scheme. We show that the method is stable and converge with optimal order in a variety of norms. A distinctive feature of the method is that the results hold without extrinsic penalization of the gradient across interelement boundaries. Numerical experiments are given that support the theoretical results, and the extension to Kirchhoff plates is also discussed. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1254–1278, 2014     

Synthesis of pyrene end‐capped A6 dendrimer and star polymer with phosphazene core via “click chemistry”

Novel hexa‐armed and pyrene (Pyr) end‐capped phosphazene dendrimer [N₃P₃‐(Pyr)₆] and star polymer with poly(ε‐caprolactone) (PCL) arms [N₃P₃‐(PCL‐Pyr)₆] were prepared via two series of reactions. In these series, core‐first approach was used starting from a hexa‐hydroxy functional phosphazene derivative (N₃P₃‐(OH)₆). It was used as an initiator in the ring‐opening polymerization of ε‐caprolactone to prepare a hexa‐armed PCL star polymer (N₃P₃‐(PCL‐OH)₆). Hydroxyl functionalities of N₃P₃‐(OH)₆ and N₃P₃‐(PCL‐OH)₆ were then successfully converted into bromide and azide, in turn. Further end‐group modifications of azide functional dendrimer precursor (N₃P₃‐(N₃)₆) and star polymer (N₃P₃‐(PCL‐N₃)₆) were achieved quantitatively via the Cu(I) catalyzed click reaction between azide functional groups and 1‐ethynyl pyrene in the final step. Moreover, the pyrene end‐capped phosphazene dendrimer and star polymer were used in noncovalent functionalization of multiwalled carbon nanotubes. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

A novel amperometric glucose biosensor based on poly(glycidyl methacrylate-co-(3-thienylmethylmethacrylate))

Two novel glucose oxidase (GOx) enzyme electrodes based on the copolymer of glycidyl methacrylate with 3-thienylmethyl methacrylate (poly(GMA-co-MTM)) with and without polypyrrole (PPyr) coating were prepared and employed in the amperometric determination of glucose levels. The effect of PPyr coating on the electrode properties was investigated in detail. Cyclic voltammetry studies showed that electrical conductivity of electrode B with PPyr coating (poly(GMA-co-MTM)/GOx/PPyr) was substantially higher than that of electrode A (poly(GMA-co-MTM)/GOx). On the other hand, electrode A showed better results in terms of sensitivity (10 nA/mM), limit of detection (50.2 μM), and response time (5 s). Electrodes A and B gave linear responses to the glucose concentrations in the range of 2–20 and 2–14 mM, respectively. The ranges of linearity for both enzyme electrodes are sufficient for the determination of physiological glucose concentrations in human blood. Moreover, PPyr coating of electrode B did not result in further stabilization of the enzyme electrode.