An efficient regioselective sonochemical synthesis of novel 4-aryl-3-methyl-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-ones

An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6(7H)ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum’s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times(3-4 min) and excellent yields(87-95%).     

In situ monitoring the pulse CO2 laser interaction with 316-L stainless steel using acoustical signals and plasma analysis

In most laser material processing, material removal by different mechanisms is involved. Here, application of acoustic signals with thermoelastic (below threshold) and breakdown origin (above threshold) together with plasma plume analysis as a simple monitoring system of interaction process is suggested. In this research the interaction of pulse CO₂ laser with 200 ns duration and maximum energy of 1.3 J operating at 1 Hz with austenitic stainless steel (316-L) is reported. The results showed that the non-linear point of the curve can serve as a useful indicator of melting fluence threshold (in this case ≈830 J cm⁻²) with corresponding temperature calculated using plasma plume analysis. Higher acoustic amplitudes and larger plasma plume volume indicates more intense interaction. Also, analysis showed that a phase explosion process with material removal (ejecta) in the form of non-adiabatic (i.e., d_t ? α⁻¹) is at play after laser pulse is ended. Also, SEM photographs show different surface quality medication at different laser intensities, which indicates the importance of recoil momentum pressure and possibly electrons and ions densities in heat transfer. Finally, electrochemical test indicate an improved corrosion resistance for laser treated samples compared to untreated ones.     

Soft-core Interaction for the <Superscript>4,6</Superscript>He + <Superscript>64</Superscript>Zn Fusion Reactions

In this paper, the cross section of the ⁴He + ⁶⁴Zn and ⁶He + ⁶⁴Zn reactions, at bombarding energies above and below the fusion barrier, has been investigated. Soft-core nucleon-nucleon interaction and the Monte Carlo method have been employed for studying the nuclear potential of the projectile-target system. One adjustable parameter has been chosen in this study. This parameter can change the depth of the soft-core potential. It has to be adjusted so that the calculated elastic scattering and fusion cross sections are in acceptable agreement with experimental data. Our results indicate that an increase in energy decreases the depth parameter of the soft-core nucleon-nucleon potential obtained from careful analysis the ⁴He + ⁶⁴Zn and ⁶He + ⁶⁴Zn reactions. Likewise, by comparing the results obtained from both reactions, one can observe that the calculated depth parameter for the reaction related to ⁶He is larger than that for ⁴He at the same energy, in particular at the sub-barrier energies. We try to explain this behavior.     

Analysis of current ramp for a high-temperature superconducting magnet

In this paper, an equivalent electrical circuit for response of a high-temperature superconductor (HTS) system for arbitrary time varying transport current is considered and as well as an analysis of the generated resistance losses is given. Also, for the pancake coil made with superconducting Bi-2223/AgMg tape, hysteresis behavior on the voltage-current curve is examined as a function of the current rate during ramp up and down at liquid nitrogen temperature. Behavior of voltage versus current is in good agreement with considered theory.     

A Modified Quantum Search Algorithm

We show that by adding a workspace qubit to Ahmed Younes, et al. algorithm (Younes et al. AIP Conf. Proc. 734:171, 2004, 2008), and applying newly defined partial diffusion operators on subsystems, the algorithm’s performance is improved. We consider an unstructured list of N items and M matches, 1 ≤ M ≤ N.     

Converting the UK calculation of road traffic noise (CORTN) to a model capable of calculating LAeq,1h for the Tehran’s roads

This paper describes the methodology through which the UK calculation of road traffic noise (CORTN) has been converted to the algorithms that are able to calculate hourly A-weighted equivalent sound pressure level (L_Aeq,1h) for the Tehran’s roads. The methodology adopts two different approaches to model calibration and performance test through the holdout validation method on the basis of the database including 52 samples taken from 52 sampling stations located alongside 5 roads of Tehran at distances less than 4 m from the nearside carriageway edge. As to the CORTN manual the distances less than 4 m are considered to be equal to 4 m. In the first approach the model is calibrated through carrying out nonlinear regression parameter estimation using 50% of samples to replace the basic noise level parameters with the new ones that are presumably able to satisfy the objective of the study with an acceptable fitness of the model. In the second approach the model calibration is carried out on the basis of 30 measurements taken from 2 roads. In the next step the other subsets of samples are introduced into the calibrated equations to conduct the performance test. Non parametric goodness of fit tests, i.e. two related samples Wilcoxon and two independent samples Kolmogorov-Smirnov, respectively conducted for the calibration and the performance test steps; indicate satisfactory results for both approaches.     

Numerical assessment of a shock‐detecting sensor for low dissipative high‐order simulation of shock–vortex interactions

Considering the importance of high‐order schemes implementation for the simulation of shock‐containing turbulent flows, the present work involves the assessment of a shock‐detecting sensor for filtering of high‐order compact finite‐difference schemes for simulation of this type of flows. To accomplish this, a sensor that controls the amount of numerical dissipation is applied to a sixth‐order compact scheme as well as a fourth‐order two‐register Runge–Kutta method for numerical simulation of various cases including inviscid and viscous shock–vortex and shock–mixing‐layer interactions. Detailed study is performed to investigate the performance of the sensor, that is, the effect of control parameters employed in the sensor are investigated in the long‐time integration. In addition, the effects of nonlinear weighting factors controlling the value of the second‐order and high‐order filters in fine and coarse non‐uniform grids are investigated. The results indicate the accuracy of the nonlinear filter along with the promising performance of the shock‐detecting sensor, which would pave the way for future simulations of turbulent flows containing shocks. Copyright © 2014 John Wiley & Sons, Ltd.     

Ru-catalyzed double-conjugate 1,4-addition of indoles to symmetric enones

Double-conjugate 1,4-addition of indoles to dibenzylidenacetones using Ru^III as catalyst is reported. It was found that the system involving Ru^III catalyzes formation of two C–C bonds in one pot in good to high yields.     

Overview on the recently developed thiazolyl heterocycles as useful therapeutic agents

Thiazoles are important heterocyclic compounds which have many biological activities and different applications such as useful ligands, in optical sensors, etc. A literature survey shows that there are different routes to thiazoles. One of the most frequently used synthetic approaches consists of a reaction between α-halocarbonyl compounds with a CSNH₂ moiety. In this mini-review we have classified the contents based on the reagent or material providing the sulfur atom of the thiazole ring. Also, among many articles which have been devoted to thiazole syntheses here we presented some synthetic approaches published from 2012 to 2014.