Photocatalytic degradation of methyl orange dye by NiFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanoparticles under visible irradiation: effect of varying the synthesis temperature

Nanoparticles of nickel ferrites (NiFe₂O₄) were synthesized at different temperature of synthesis (25, 50 and 80 °C) through the chemical co-precipitation method. The synthesized powders were characterized using X-ray diffraction for crystallite size and lattice parameter calculation. It reveals the presence of cubic spinel structure of ferrites with crystallite size between 29 and 41 nm. Transmission electron microscopy and scanning electron microscopy showed uniform distribution of ferrite particles with some agglomeration. The Fourier-transform infrared spectroscopy showed absorption bonds, which were assigned to the vibration of tetrahedral and octahedral complexes. Raman spectroscopy is used to verify that we have synthesized ferrite spinels and determines their phonon modes. The thermal decomposition of the NiFe₂O₄ was investigated by TGA/DTA. The optical study UV–visible is used to calculate the band gap energy. Magnetic measurements of the samples were carried out by means of vibrating sample magnetometer and these studies reveal that the formed nickel ferrite exhibits ferromagnetic behavior. Photoluminescence showed three bands of luminescence located at 420, 440 and 535 nm. The photocatalytic properties of nickel ferrite (NiFe₂O₄) nanoparticles were evaluated by studying the photodecomposition of methyl orange as organic pollutant models and showed a good photocatalytic activity.     

Synthesis and evaluation of the thermal properties of biosourced poly(ether)ureas and copoly(ether)ureas from 1,4:3,6‐dianhydrohexitols

A new series of poly(ether)ureas were prepared by solution polyaddition of three diamines based on 1,4:3,6‐dianhydrohexitols with three types of diisocyanate. The corresponding poly(ether)ureas were obtained with high yields. They were characterized by various analytical techniques (NMR, TGA and differential thermal analysis, DSC). NMR spectroscopy allowed us to confirm structure type and to optimize reaction conditions and DSC proved the high thermal properties of the products obtained (T_g and T_m in the range 126 ? 158 °C and 235 ? 330 °C respectively). Then, copoly(ether)ureas partially based on commercial diamines were synthesized in order to reduce polymer cost and tune their thermal behaviour. The reactivity of both diamines was evaluated by their incorporation in the polymer by means of NMR spectra. Then their thermal properties were compared with fully commercial diamine based polyureas by DSC studies. © 2014 Society of Chemical Industry     

Wear Behavior of Biodegradable Mg–5Zn–1Y–(0–1)Ca Magnesium Alloy in Simulated Body Fluid

Metals and Materials International - In this study, wear behavior of biodegradable Mg–5Zn–1Y–(0–1)Ca alloys is investigated in simulated body fluid. Wear test is performed...     

Vibration control of laminated truncated conical shell via magnetostrictive layers

Abstract

In this study feedback control is applied to control the free vibration response of an isotropic truncated conical shell embedded with magnetostrictive layers. Classical shell theory is applied to derive the shell vibration equations. The results are derived based on the Galerkin method and the results are compared with published results and the results of finite element software in order to determine the accuracy of using method. The influence of several parameters such as the thickness of magnetostrictive layers, control gain, length and radius of the large edge of the shell on the vibration suppression of fundamental frequency is determined.     

Hybrid intelligent framework for one-day ahead wind speed forecasting

Neural Computing and Applications - Nowadays wind power is considered as one of the fastest growing alternative energies, that is expected to continue to grow rapidly in the upcoming...     

Experimental investigation on the effect of surface characterization of electrodes on the gas bubble dynamics in electrolyte flow and performance of FLA batteries by using PIV

In the flooded lead_acid batteries (FLAB), gas bubbles are initially formed on the surface of the electrodes, which are produced by electrochemical reactions, and then released into the electrolyte. In the present investigation, the effect of surface characterization of electrodes of FLAB on the gas bubble dynamic parameters in the electrolyte flow at different charging/discharging rates (C-rates) are studied utilizing particle image velocimetry (PIV) method. The results show that the capacity of FLAB have a linear behav-ior due to changes in each of the two parameters of the surface characterization of electrodes and the C-rate. At all State of charges (SOCs) of FLAB cells in different tests, increasing average roughness (Ra) and average wavelength of the roughness (ka) in the electrode surfaces, results in an increase in average bub-ble diameter and bubble rising velocity. Nevertheless, a sharp decrease in the void fraction of bubbles within the electrolyte was observed due to the increment in ka and Ra. Also, the effect of the rising move-ment of gas bubbles within the electrolyte on the average electrolyte velocity pattern in the gap between the electrodes by changing the surface characterization of electrodes are investigated in detail.