Comparative and competitive adsorption of Cu(II), Cd(II) and Pb(II) onto Sepia pharaonis endoskeleton biomass from aqueous solutions

In this research, the possibility of simultaneous removal of lead, cadmium and copper divalent ions from water samples through the use of Sepia pharaonis endoskeleton powder (SPEB) as bio‐material, was investigated. The bio‐sorbent was characterised by Fourier transform infrared spectrum (FT‐IR), atomic force microscopy (AFM) and X‐ray fluorescence (XRF). The different factors affecting the bio‐sorption process were studied. Langmuir and Freundlich isotherm models were applied to analyse the experimental data. The kinetic studies showed that the pseudo‐second order model kinetics were compatible with the investigated systems. It was found that under optimal conditions, this bio‐sorbent was efficient in the uptake of these heavy metal ions from both mono and multi‐metal solutions, and high removal percentages were achieved. This study verified the potential ability of SPEB as an efficient natural adsorbent for removal of Pb(II), Cd(II) and Cu(II) ions from river, tap and mineral water samples.     

Optimization of Propofol Dose Estimated During Anesthesia Through Artificial Intelligence by Genetic Algorithm: Design and Clinical Assessment

Neural Processing Letters - This paper addresses the application of an adaptive neuro-fuzzy inference system (ANFIS) to assign the optimal dose of propofol as a vital anesthetic drug considering...     

Robust fault diagnosis scheme in a class of nonlinear system based on UIO and fuzzy residual

In this study, a novel robust fault diagnosis scheme is developed for a class of nonlinear systems when both fault and disturbance are considered. The proposed scheme includes both component and sensor fault with nonlinear system that transferred to nonlinear Takagi-Sugeno (T-S) model. It considers a larger category of nonlinear system when fuzzification is used for only nonlinear distribution matrices. In fact the proposed method covers nonlinear systems could not transform to linear T-S model. This paper studies the problem of robust fault diagnosis based on two fuzzy nonlinear observers, the first one is a fuzzy nonlinear unknown input observer (FNUIO) and the other is a fuzzy nonlinear Luenberger observer (FNLO). This approach decouples the faulty subsystem from the rest of the system through a series of transformations. Then, the objective is to design FNUIO to guarantee the asymptotic stability of the error dynamic using the Lyapunov method; meanwhile, FNLO is designed for faulty subsystem to generate fuzzy residual signal based on a quadratic Lyapunov function and some matrices inequality convexification techniques. FNUIO affects only the fault free subsystem and completely removes any unknown inputs such as disturbances when residual signal is generated by FNLO is affected by component or sensor fault. This novelty and using nonlinear system in T-S model make the proposed method extremely effective from last decade literature. Sufficient conditions are established in order to guarantee the convergence of the state estimation error. Thus, a residual generator is determined on the basis of LMI conditions such that the estimation error is completely sensitive to fault vector and insensitive to the unknown inputs. Finally, an numerical example is given to show the highly effectiveness of the proposed fault diagnosis scheme.     

One-pot synthesis of ultrasmall PtAg nanoparticles decorated on graphene as a high-performance catalyst toward methanol oxidation

A one-pot synthesis method is utilized for the fabrication of ultrasmall platinum-silver nanoparticles decorated on graphene (PtAg/G) catalyst. This method has several advantages such as inexpensiveness, simplicity, low temperature, surfactant free, reductant free, being environmentally friendly and greenness. In this work, graphene and silver formate were dispersed in ultrapure water in an ultrasonic bath at 25 °C followed by through a galvanic displacement reaction; to prepare PtAg/G, PtCl₂ was added to the suspension under mild stirring condition. The morphology, crystal structure and chemical compositions of the as-fabricated PtAg/G and Pt/C catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Energy dispersive X-ray spectroscopy (EDS) techniques. Electrochemical techniques, including cyclic voltammetry (CV) and chronoamperometry (CA) measurements were used to analyze the electrochemical activity of the PtAg/G and Pt/C catalysts. The TEM images illustrate the uniform distribution of ultrasmall PtAg nanoparticles with the average size of 2–3 nm on the graphene nanosheets. The PtAg/G promoted the current density 2.46 times as much as Pt/C with a negative shift in onset oxidation potential and peak potential for oxidation reaction of methanol. Besides, the novel PtAg/G catalyst shows large electrochemically active surface area, lower apparent activation energy, and higher levels of durability in comparison to the Pt/C catalyst for the oxidation of methanol. The PtAg/G catalyst depicts extraordinary catalytic performance and stability to those of the Pt/C catalyst toward methanol oxidation in alkaline media.     

Analysis of the Microstructure of Thermal Spray Coatings: A Modeling Approach

Microstructure of coatings produced by thermal spray coating process depends on many parameters, including particle impact conditions, powder materials, and substrate conditions. Because of the large number of parameters affecting microstructure, developing a computational tool that can predict the microstructure of thermal spray coatings as a function of these parameters can be of great interest as it will save time and resources when developing new coatings. In this article, we examine the validity and the accuracy of such a computational tool. We present the result of a three-dimensional model of coating formation. The model is based on the Monte Carlo method with particle impact conditions, materials properties of powder, and substrate as input. The output of the model includes coating porosity, surface roughness, and coating thickness. In order to validate the model, coatings under specific conditions were deposited and the predicted results were compared to the actual deposits. The impact conditions for these cases were measured by DPV-2000 and the raw data were used as input to the computer program. The comparison between the actual deposits and the simulated ones shows good agreement. The results demonstrate the viability and usefulness of this modeling tool in developing new coatings and understanding their microstructure.     

Synthesis of Chitosan/Gelatin granule containing amine derivated octa(ammonium chloride) substituted Polyhedral Oligomeric Silsesquioxane and investigating its application as a drug carrier

In this work, we have prepared a new granule hydrogel composites of natural biocompatible polymeric chitosan and gelatin (C-G). The gelatin side groups (hydroxyl and carboxyl) can attach with amine groups of chitosan, which improve the interlink crosslinking in the final nanocomposites. The diameter of the granuls is around 3?mm to 6?mm. Furthermore, in order to reinforce the mechanical properties of granules, for the first time, octa(ammonium chloride) substituted Polyhedral Oligomeric Silsesquioxane (POSS-(NH₃⁺Cl^?)₈) has been used as a nanofiller in the structure of this nanocomposite. The effect of POSS-(NH₃⁺Cl^?)₈ on mechanical stability and swelling behavior of hydrogels has been investigated in three pH of 1.2, 7.4 and 9.5, respectively. Results demonstrate that the C-G/POSS-(NH₃⁺Cl^?)₈ granules in acidic pH has the maximum swelling percent. The encapsulation efficiency (EE) values for C-G granules in three pH of 1.2, 7.4 and 9.5 are obtained 65%, 58% and 53% and for C-G/POSS-(NH₃⁺Cl^?)₈ sample are 59%, 52% and 48%, respectively, which conform with the swelling behavior of these hydrogels. According to the obtained results from Metronidazole (MTZ) release, the as-synthesized hydrogels may have intrinsic ability in the controlled release of drugs. The as-prepared hydrogels are characterized via FT-IR, SEM, TGA and XRD analysis.     

Sulfonic Acid-Functionalized Silica-Coated Magnetic Nanoparticles as a Reusable Catalyst for the Preparation of Pyrrolidinone Derivatives Under Eco-Friendly Conditions

Silicon - The surface of silica-coated CoFe2O4 magnetic nanoparticles (CoFe2O4@SiO2), which is resistant to the oxidation due to silicone coating, was functionalized using chlorosulfonic acid and...     

Ultrasound-Assisted Emulsification-Microextraction/Ion Mobility Spectrometry Combination: Application for Analysis of Organophosphorus Pesticide Residues in Rice Samples

The present paper describes the validation of ultrasound-assisted emulsification-microextraction method followed by ion mobility spectrometry (IMS) detection for simultaneous determination of two organophosphorus pesticides, diazinon and chlorpyrifos. Ultrasound radiation was applied for accelerating the emulsification of microliter organic solvent in aqueous solutions and enhancing the microextraction efficiency. This preconcentration step combined with IMS detection provided a precise and accurate method for determination of trace amounts of diazinon and chlorpyrifos pesticides. The effect of parameters influencing the extraction efficiency such as sonication time, type of extraction solvent, extraction solvent volume, and salt concentration were investigated and discussed. The enrichment factors found, under optimum conditions, were 230 and 300 for diazinon and chlorpyrifos, respectively, with corresponding LOD of 2.1 and 3.2 μg L^?1. The presented method can be applied for the determination of diazinon and chlorpyrifos in the range 6.0–700 and 8.9–750 μg L^?1, respectively, with correlation coefficients (R ²)?>?0.99. The applicability of the proposed method was evaluated by determination of the residues of the investigated pesticides in rice paddy water gathered from four stations during 60 days after spraying (June 2014), and in storage rice samples in Mazandaran province, Iran.     

(Meth)acrylated poly(ethylene glycol)s as precursors for rheology modifiers,superplasticizers and electrolyte membranes: a review

This review summarizes current trends in (meth)acrylated poly(ethylene glycol) (PEG) systems in the last decade, with a specific focus on their most important applications, including associative rheology modifiers, superplasticizers and electrolyte membranes. Associative rheology modifiers based on (meth)acrylated PEGs have significantly contributed to improvement of the application characteristics of waterborne coatings. These materials are employed by paint formulators to provide proper viscosity profiles across an entire shear range encountered in various paint applications. In the cement and concrete industry, superplasticizers derived from (meth)acrylated PEGs have also opened the doors to advances in this area, because of their ability to produce cementitious materials with lower water content and without compromising workability. In addition, development of solid electrolyte membranes based on photo‐curable (meth)acrylated PEGs for use in polymer lithium ion batteries has recently attracted increasing attention in the energy storage industry. This review provides a comprehensive overview of the structural investigations and applications of (meth)acrylated PEGs and serves as a starting point for future studies. © 2017 Society of Chemical Industry