A thermodynamically consistent framework for non-isothermal modelling of local heat generation and electromotive force in SOFC single electrodes

Mathematical models for single electrode reversible heat and non-isothermal electromotive force (EMF) of a solid oxide fuel cell (SOFC) are developed. These models estimate the volumetric reversible heat generation and EMF of electrochemical reactions, within each electrode at local conditions of temperature and pressure, based on entropy change of half reactions. The resulting equations are thermodynamically consistent. They inherently obey the conservation of energy law as the electrochemical energy released added to the heat of reactions at each electrode equate the enthalpy change of the reacted species. The equations are implemented to model electrodes in a tubular micro- solid oxide fuel cell (TμSOFC). The thermodynamic consistency of the model is numerically confirmed as the enthalpy of the reactants equates the electric energy released by the cell plus the sum of electrode heats plus electrolyte Ohmic heat. The effect of thermal gradients on the cell's overall EMF is found to be negligible. The reversible and irreversible heat generation of each electrode are distinguished. Overall, the anode is found to be endothermic, and the cathode exothermic.     

A Silicon on Nothing LDMOS with Two Air Pillars in Gate Insulator for Power Applications

Silicon - This paper proposes a new silicon on nothing lateral double-diffused metal-oxide-semiconductor with two air gaps in the gate insulator (SON-APG LDMOS). Utilizing air for the buried layer...     

Correction to: Double Vision Model Using Space-Time Function Control within Silicon Microring System

Silicon - The original version of this article unfortunately contained a mistake in the “Acknowledgments” section.     

Development,In Vitro and In Vivo Evaluation of pH Responsive β-CD-Comethacrylic Acid-Crosslinked Polymeric Microparticulate System for Solubility Enhancement of Rosuvastatin Calcium

Current research work was conducted for enhancing solubility of rosuvastatin calcium. A highly stable, biocompatible, and nontoxic β-cyclodextrin-g-poly(methacrylic acid) graft polymeric network was developed. Formulations proved entrapment efficacy (%) in between 82.30?±?0.25 and 89.00?±?0.25 and gel fraction between 90.34?±?1.012 and 95.25?±?1.331. Formulation HM2 had shown optimum swelling and drug release, i.e., 85.74% at pH 6.8. The best-fit model was first-order kinetics with anomalous diffusion as release mechanism. Likewise, solubility enhancement, i.e., 9.59-folds was determined at pH 6.8. It was concluded that hydrogel microparticles are the promising tools for improving solubility and bioavailability of hydrophobic drugs.     

Nanoencapsulation of montmorillonite clay within poly(ethylene glycol) nanobeads by electrospraying

The present study describes the preparation and characterization of a novel nanocomposite, based on montmorillonite clay (MMT) encapsulation in poly(ethylene glycol) (PEG) by an electrospraying process. PEG/MMT nanocomposites with MMT contents ranging from 1 to 5 wt % were successfully prepared and characterized in relation to their morphological, spectroscopic, structural, and thermal properties. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy micrographs showed that the PEG nanobeads formed spherical shapes, and with increasing amount of MMT clay, the size of the beads decreased significantly, ranging from 120 to 3.7 nm. The Fourier transform infrared spectroscopy results suggested that there was no significant chemical interaction between PEG and MMT clay. However, the d‐spacing of MMT clay in PEG/MMT increased, a clear indication of the intercalation of PEG in the interlayer spaces of MMT clay. Furthermore, the thermal stability of PEG polymer decreased upon encapsulation of MMT clay in PEG/MMT composites. Nanoindentation results showed that the hardness and Young's modulus of the PEG/MMT composites increased with 3 wt % loading of MMT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45048.     

Development of a full range multi-scale model to obtain elastic properties of CNT/polymer composites

The main goal of this study was to develop a full range multi-scale modeling technique to extract Young??s modulus and Poisson??s ratio of carbon nanotube reinforced polymer (CNTRP) composites covering all nano, micro, meso and macro scales. The developed model consists of two different phases as top-down scanning and bottom-up modeling. At the first stage, the material region will be scanned from the macro level downward to the nano-scale. Effective parameters associated with each scale will be identified through this scanning procedure. Taking into account identified effective parameters of each specific scale, the suitable representative volume elements (RVE) will be defined for all nano, micro, meso and macro scales, separately. In the second stage of the modeling procedure, a hierarchical multi-scale modeling approach is developed. This modeling strategy would analyze the material at each scale and obtained results that were fed to the upper scale as input information. Due to involved random parameters, the developed modeling technique is implemented stochastically. It has been shown that the developed modeling procedure provides a clear insight to the properties of CNTRP and it is a very efficient tool for simulation of mechanical behavior of CNTRP composites. A sensitivity analysis was conducted to quantify the influence of the identified random parameters on the overall behavior of CNTRP.     

Rheological and thermal stability of novel weak gels based on sulfonated polyacrylamide/scleroglucan/chromium triacetate

The present study deals with weak gels based on sulfonated polyacrylamide (SPA)/scleroglucan (SC)/Cr³⁺ with an exceptional thermal stability in electrolyte media. The rheological results showed that on increasing the SC concentration the shear viscosity and storage modulus of the SPA/SC/Cr³⁺ system were increased and the dependence of the storage modulus on frequency became weaker. The yield stress of the SPA/SC/Cr³⁺ system was higher than that of the corresponding SPA/SC system. The thermochemical stability increased with increasing relaxation time. The SPA/SC/Cr³⁺ semi‐interpenetrating network exhibited the lowest viscosity loss in electrolyte media; therefore this system may be a potential candidate for enhanced oil recovery applications. © 2016 Society of Chemical Industry     

Synthesis and Characterization of Anti-fungus,Anti-corrosion and Self-cleaning Hybrid Nanocomposite Coatings Based on Sol–Gel Process

Anti-corrosion, anti-fungus, and self-cleaning properties of coatings containing ZnO–TiO₂, SiO₂–TiO₂ and SiO₂/TiO₂/ZnO nanoparticles synthesized based on sol–gel precursors using tetra methoxysilane, 3-glycidoxypropyl trimethoxysilane, tetra (n-butyl orthotitanate) and zinc acetate dihydrate were investigated by FESEM, EDAX and TEM analyses. Results indicated uniform dispersion of inorganic nanoparticles in the range of 20–40 nm in size. Anti-corrosion property of the hybrid coating was characterized by EIS measurements and parametrically analyzed in an equivalent circuit when the coating was exposed to salt solution. Results showed that, ZnO and TiO₂ nanoparticles enhance anti-corrosion property of the hybrid coatings. Anti-fungus and anti-bacterial properties of the coatings were determined by diameter of inhibition zone and inhabitation of bacterial growth, respectively. The coating containing ZnO and TiO₂ nanoparticles showed anti-fungus and anti-bacterial properties which were related to their photocatalytic properties. Degradation of methylene blue in aqueous solution was determined by UV–Visible tests which indicated self-cleaning property of the coatings containing ZnO and TiO₂ nanoparticles.     

Reinforcement of electroactive characteristics in polyvinylidene fluoride electrospun nanofibers by intercalation of multi-walled carbon nanotubes

This research work reports on development and characterization of multi-walled carbon nanotube (MWCNT)-doped polyvinylidene difluoride (PVDF) nanofibers by the electrospinning method. PVDF is an extensively studied polymer both theoretically and experimentally due to its appealing ferroelectric, piezoelectric, and pyroelectric properties which strongly favors its promising applications in the development of micro/nanostructure devices. The foremost reason for its ferroelectric and piezoelectric behaviors has been attributed to its crystalline structure, specifically the presence of β-phase; however, the existence of the small percentage of β-phase in pristine PVDF limits its applications. To enhance the electroactive features in the PVDF, MWCNTs have been doped in it to prepare electrospun nanofibers, as electrospinning is a single-step approach. These nonwoven nanofibers were prepared at a DC voltage of 20 kV which were subsequently calcined at 100 °C for 12 h. The estimation of crystal structure and phase identification in these nanofibers have been determined by attenuated FT-IR and XRD, while the morphology, microstructure, mean diameter, and length have been examined by FE-SEM. The observed electrical conductivity, capacitance, permittivity (ε), conductivity (δ), and impedance (Z) in these samples have been tailored by doping a range of MWCNT contents and optimizing the experimental conditions.