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Evaluating the substitution of Cd for Mn, Co, Ni, Cu, and Zn elements in the high entropy oxide structure (Mn,Co,Ni,Cu,Zn)Fe2O4, is the primary focus in this investigation. For this purpose, five different high entropy oxides (HEOs), namely (Cd,Co,Ni,Cu,Zn)Fe2O4, (Mn,Cd,Ni,Cu,Zn) Fe2O4, (Mn,Co,Cd,Cu,Zn)Fe2O4, (Mn,Co,Ni,Cd,Zn)Fe2O4, and (Mn,Co,Ni,Cu,Cd)Fe2O4 were synthesized using combustion solution synthesis (SCS) method. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), elemental mapping, and field emission scanning electron microscopy (FESEM) were used to analyze the synthesized samples. The analyses confirmed the formation of single-phase (Fd-3m) nanocrystalline powders with an increased lattice parameter. Fourier Transform Infrared Spectroscopy (FTIR) revealed the placement of Cd element in the tetrahedral sub-lattice (A-site). Vibrating sample magnetometer (VSM) was employed to assess the magnetic properties. The results indicated that, in most cases, substitution of Cd for Mn, Co, Ni, Cu, and Zn leads to an increase in both the saturation magnetization (Ms) and coercivity (Hc) of the nanocrystalline powder samples. [ABSTRACT FROM AUTHOR]

In this study, a handmade device was developed to prepare polymeric polypropylene (PP) nanofibres by forcespinning method. The characterisations of the prepared adsorbent were investigated by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). Then, the performance of the prepared nanofibres was investigated as an adsorbent for the removal of uranium (VI) ion from the aqueous solution. Experimental parameters such as contact time and pH were optimised. The maximum adsorption was obtained with the adsorbent weight of 0.03 g, contact time of 60 min, and pH of 4. This study showed that PP nanofibre is an efficient adsorbent for uranium removal from aqueous solution. Also, the uranium removal process was modelled by artificial neural network (ANN) for predicting capacity removal. In this method, feed-forward back-propagation learning with Levenberg-Marquardt (LM), adaptive learning rate back-propagation (GDX) and resilient back-propagation (RP) algorithms were used. [ABSTRACT FROM AUTHOR]

Nowadays, Tunnel Boring Machines (TBM) are widely used around the world on account of their high rate of excavation, little impact on the surrounding rock, and their high safety standards. The rock mass boreability is considered as one of the main parameters in evaluating the TBMs' performance in jointed rock masses. Boreability is a parameter reflecting the interaction between the rock mass and cutting tools. This paper aims to render an account of the effect of Joints Geometrical Parameters on the boreability by use of a database prepared to utilize the data (TBM operation and geological parameters) collected from Kerman Water Conveyance Tunnel projects in Iran. For this purpose, the joint parameters (orientation, spacing, persistence) affecting the boreability have initially been investigated. Then, the total fracturing factors (Bruland) and Persistence classification were used to investigate the effects of all three parameters on the boreability. The results showed that the boreability is also increased by increasing the joint persistency. Besides, the effect of fracturing factor (Ks-total) on boreability increases by increasing the joint persistency. In this paper, a new parameter called "Rock Joint Index"(RJI) is also presented according to the analysis performed on the database. The boreability value estimated based on the RJI shows a good agreement with the actual penetration rates. [ABSTRACT FROM AUTHOR]

A novel sorbent consisting of graphene, Fe3O4 and nylon-6 is described for removal of Pb2+ ions. Graphene has high surface area, Fe3O4 lets the nanocomposite to be controllable via magnetic field and nylon-6 increases active negative sites. Accordingly, the nanocomposite can be a good candidate to be a magnetic sorbent. Graphene oxide was prepared via modified Hummer's method and magnetized by precipitation of Fe3O4. The modification of magnetic nanocomposite was done through dispersion of the composite in solution of nylon-6. X-ray diffraction, scanning electron microscopy, electron diffraction spectroscopy and Fourier-transform infrared spectroscopy were used to characterize the nanocomposite. The optimum adsorption conditions were achieved through Taguchi method, which decreased the optimization time and usage amount of mGN6. Regarding to the data, pH of 9, sorbent amount of 10 mg and Pb2+ concentration of 6 mg L−1 were optimum conditions. The actual value from optimized level condition was 97%. In comparison with other sorbents used for Pb2+ removal and determination with FAAS, mGN6 has serious improvements including more capacity adsorption and less usage amount of sorbent. The co-existing ions effect was examined. The Freundlich model and the pseudo second-order model confirmed isotherm adsorption and kinetic adsorption behaviors, respectively. [ABSTRACT FROM AUTHOR]

In this study, La and Mg doped, and co-doped ZnO nanoparticles were prepared using the sol-gel method. The prepared samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and N2 physisorption techniques. The XRD results indicated that the prepared nanoparticles can be well adopted by the hexagonal wurtzite structure crystal and there are no second impurity peaks. Studies of the FESEM, EDX and TEM have shown that the samples have uniform spherical-like morphology with a homogenous distribution. The incorporation of La and Mg into the ZnO lattice had no effect on the morphology of the nanoparticles, but a reduction in the size of the grains (≈ 14 nm to ≈ 7 nm) was observed due to the insertion of these ions. The results of N2 physisorption indicated that there was an increase in BET surface area and pore volume for doped and co-doped samples. The results of DRS showed an increase in band gap energy and a blue shift at the absorption edge for doped and co-doped samples. The photocatalytic activity of the prepared catalysts was evaluated in the removal of RhB under UVA irradiation. The results showed that Mg5%-La5%/ZnO had the highest photoactivity (91.18 %) among all samples. [ABSTRACT FROM AUTHOR]

In this work, the capability of bees-inspired algorithm with the aid of artificial neural networks (ANN-BA) for optimization of acid red 27 dye removal was studied using polypyrrole/SrFe12O19/graphene oxide (GO) as a novel nanocomposite. The nanocomposite fabricated through in situ polymerization and its characteristics were investigated by means of several instrumental techniques. The prepared polypyrrole/SrFe12O19/GO nanocomposite was employed to adsorb acid red 27 from aqueous solution. Based on the cost function as a nonlinear relation between some factors influencing the adsorption efficiency including adsorbent dosage, initial concentration, pH, shaking rate and contact time with percentage removal which were obtained by a multilayer perceptron artificial neural networks, bees metaheuristic algorithm was utilized to optimize of the batch sorption process. In addition, D-optimal response surface methodology (RSM) was also employed as a comparative study. In comparison with the D-optimal RSM, the ANN-BA model gave higher percentage removal (99%) about 4%. Under optimal conditions obtained by ANN-BA, equilibrium isotherms, kinetic behaviors and thermodynamics of the dye adsorption were thoroughly investigated. The pseudo-second-order model and the Langmuir adsorption model [with maximum capacity (qmax) of 294.11 mg g−1] fitted the experimental results with the determination coefficients (R2) of 0.94 and 0.99, respectively. The thermodynamic parameters have also been evaluated which showed the sorption procedure was endothermic and spontaneous. The findings obtained from the sorbent usage in wastewater treatment and its regeneration investigation revealed that the nanocomposite can be applied as an effective dye sorbent for removing acid red 27 dye in real samples with a reusable property. [ABSTRACT FROM AUTHOR]

The impact of effective parameters on the electrochemical deposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. To have co-deposition of gold-copper alloy with the cartage of 18 K (750 ppt) and appropriate deposition rates values of 6 mA/cm²,6gr/lit, 55gr/lit, 24gr/lit, 66 °C, 12.3, 100 rpm and 1ml lit, the specified parameters in this method, including current density, ions concentrations of gold, copper and cyanide, temperature, pH, agitation and additive concentration were effectively optimized by the "one factor at a time" method. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results showed that under the optimum conditions obtained at about 18K, the average current density (Iavg=0.6mA/cm²) and a duty cycle (30%) at the same time, the deposition rate was 0.841 µm/min and in this method, that was significantly higher than the commercial methods. It should be noted that in a pulsed electrodeposition, with increasing percentages in duty cycle, the deposition rate of the layers was reduced, which can be explained by the reduction of the double layer thickness due to shortening of the pulse off-time. [ABSTRACT FROM AUTHOR]

For the first time, sodium 30-tungstopentaphosphate, a green and efficient solid acid, was used for the isolation of cellulose from rice husk, resulting in the generation of Preyssler heteropolyacid-cellulose acetate hybrid nanofibers. These modified fibres were characterised by Fourier transform infrared spectroscopy spectrum, scanning electron microscopic images and energy-dispersive spectrometry. It was also showed that Preyssler heteropolyacid was evenly dispersed on or into the nanofibers and the distribution became denser as the concentration of Preyssler HPA increased. The electrospuned nanofibers were employed successfully for the photodegradation of methyl orange, a common azo dye pollutant in the environment. [ABSTRACT FROM AUTHOR]