One-pot synthesis of benzochromeno-pyrazole derivatives

Abstract  

One-pot synthesis of different benzochromeno-pyrazole derivatives has been reported via reaction of aldehydes, 3-methyl-1H-pyrazol-5(4H)-one and α-naphthol/β-naphthol in the presence of sulfamic acid.     

Laser based fabrication of chitosan mediated silver nanoparticles

We report fabrication of silver nanoparticles (Ag NPs) by laser ablation technique in different concentrations of aqueous chitosan solution. The ablation process of silver plate was carried out by using a nanosecond Q-switched Nd:YAG pulsed laser and the characterization of Ag NPs was done by Transmission electron microscopy, UV-Vis spectroscopy, and X-ray diffraction. UV-visible plasmon absorption spectra revealed that the formation efficiency as well as the stability of nanoparticles was increased by addition of chitosan. On the other hand, the size decrement of nanoparticles was more remarkable in the higher chitosan concentration.     

ZnO thin film characterization by X-ray reflectivity optimization using genetic algorithm and Fourier transformation

Zinc oxide (ZnO) thin film was fabricated by sol-gel spin coating method on glass substrate. X-ray reflectivity (XRR) and its optimization have been used for characterization and extracting physical parameters of the film. Genetic algorithm (GA) has been applied for this optimization process. The model independent information was needed to establish data analyzing process for X-ray reflectivity before optimization process. Independent information was exploited from Fourier transform of Fresnel reflectivity normalized X-ray reflectivity. This Fourier transformation (Auto Correlation Function) yields thickness of each coated layer on substrate. This information is a keynote for constructing optimization process. Specular X-ray reflectivity optimization yields structural parameters such as thickness, roughness of surface and interface and electron density profile of the film. Acceptable agreement exists between results obtained from Fourier transformation and X-ray reflectivity fitting.     

Proprietor and customer costs in the incomplete hub location-routing network topology

The hub location problem finds the location of hubs and allocates the other nodes to them. It is widely supposed the network created with the hub nodes is complete in the extensive literature. Relaxation of this basic supposition forms the present work. The model minimizes the cost of the proprietor, including the fixed costs of hubs, hub links and spoke links. Costs of hub and spoke links are contemplated as fixed cost or maintenance cost. Moreover, the model considers routing costs of customers who want to travel from origins to destinations. In this study, we offer a model to the multiple allocations of the hub location problems, under the incomplete hub location-routing network design. This model is easily transformed to other hub location problems using one or more constraints. No network format is dictated on the hub network. We suggest a set of valid inequalities for the formulation. Some lower bounds are developed using a Lagrangian relaxation approach and the valid inequalities. Computational analyses evaluate the performances of the lower bounding implementations and valid inequalities. Furthermore, we explore the effects of several factors on the design and solution time of the problem formulation.     

Vibration of nanobeams of different boundary conditions with multiple cracks based on nonlocal elasticity theory

The aim of this paper is to study the free vibration of nanobeams with multiple cracks. The analysis procedure is based on nonlocal elasticity theory. This theory states that stress at a point is a function of strains at all points in the continuum. The nonlocal elasticity theory becomes significant for small length scale in micro and nanostructures. The effects of nonlocality, crack location and crack parameter are investigated on the natural frequencies of the cracked nanobeam. In this study, analytical solutions are given for cracked Euler–Bernoulli nanobeams of different boundary conditions.     

1,4,5,6-Tetrahydro - 1 - Phenylpyridazin-3(2H)-One,A Homologue of Phenidone

The title compound is synthesised in 3 steps from phenyl hydrazine, and its properties are reported.     

Vanadyl Sulfate (VOSO4.3H2O). An Efficient Catalyst for Acylation of Alcohols and Phenols under Solvent Free Condition

Alcohols and phenols were efficiently acylated with acetic anhydride in the presence of vanadyl sulfate (VOSO₄.3H₂O) at room temperature in high yields.     

Chaos-enhanced accelerated particle swarm optimization

There are more than two dozen variants of particle swarm optimization (PSO) algorithms in the literature. Recently, a new variant, called accelerated PSO (APSO), shows some extra advantages in convergence for global search. In the present study, we will introduce chaos into the APSO in order to further enhance its global search ability. Firstly, detailed studies are carried out on benchmark problems with twelve different chaotic maps to find out the most efficient one. Then the chaotic APSO (CAPSO) will be compared with some other chaotic PSO algorithms presented in the literature. The performance of the CAPSO algorithm is also validated using three engineering problems. The results show that the CAPSO with an appropriate chaotic map can clearly outperform standard APSO, with very good performance in comparison with other algorithms and in application to a complex problem.     

Combination of Dispersive Liquid‐Liquid Microextraction with Flame Atomic Absorption for Determination of Trace Ni and Co in Water Samples and Vitamin B12

A dispersive liquid‐liquid microextraction method based on the dispersion of 1,2‐dichlorobenzene as an extraction solvent into an aqueous phase in the presence of ethanol as a dispersive solvent for the preconcentration of Co²⁺ and Ni²⁺ ions is discussed. 1‐Nitroso 2‐naphtol was used as a chelating agent prior to the extraction and the preconcentrated analyte was determined by flame atomic absorption spectrometry. The effect of various experimental parameters including the extraction and dispersive solvent type and volume, pH, amount of the chelating agent, etc. on the microextraction and complex formation was investigated for finding the optimum conditions. The enhancement factors were about 61.9 and 51.8, the calibration graphs were linear in the range of 10‐150 μgL^?1 and 10‐250 μgL^?1 with detection limits of 2.42 μgL^?1 and 1.59 μgL^?1, and RSD (n = 5) of 3.08% and 2.17% for cobalt and nickel, respectively. The method was successfully applied to the determination of Co and Ni in water and vitamin B₁₂.     

Fabrication and characterization of copper nanoparticles using thermal reduction: The effect of nonionic surfactants on size and yield of nanoparticles

Thermal reduction has been applied to the preparation of copper nanoparticles (Cu-NPs) using three kinds of nonionic surfactants (Triton X-100, Tween-80, and dodecylamine). The Cu-NPs were formed by decomposition of copper(II) oxalate in presence of triphenylphosphine. The effect of the surfactants on the formation of the Cu-NPs was studied via X-ray diffraction, scanning electron microscopy, energy dispersive analysis of X-rays, transmission electron microscopy, thermogravimetric differential thermal analyses, and Fourier transform infra-red spectroscopy. It is shown that the Cu-NPs have an fcc crystal structure. Depending on the surfactant used, Cu-NPs with diameters between 8 and 20 nm can be prepared. The smallest Cu-NPs (8 nm) were formed in the presence of micelles of dodecylamine (yield 49%), while the largest particles (20 nm) were obtained with Triton X-100 (yield 99%). The use of Triton X-100 results in the highest yield and most uniform Cu-NPs.