UNSTEADY MHD BOUNDARY LAYER FLOW WITH DIFFUSION AND FIRST-ORDER CHEMICAL REACTION OVER A PERMEABLE STRETCHING SHEET WITH SUCTION OR BLOWING

In this study, unsteady MHD boundary layer flow with diffusion of chemically reactive species undergoing first-order chemical reaction over a permeable stretching sheet with suction or blowing and also with power-law variation in wall concentration is investigated. Using similarity transformation, the governing partial differential equations are converted into nonlinear self-similar ordinary differential equations. The transformed equations are then solved by the finite difference method using the quasi-linearization technique. Due to the increase in the unsteadiness parameter, the velocity initially decreases, but after a certain point it increases. A similar effect is also observed in case of concentration distribution. The increase in magnetic parameter causes a decrease in velocity and an increase in concentration. For increasing strength of applied suction both momentum and concentration boundary layer thicknesses decrease. On the other hand, applied blowing has reverse effects. Moreover, the mass transfer from the sheet is enhanced with increasing values of Schmidt number, reaction rate parameter, and also power-law exponent (related to wall concentration distribution). For high negative values of the power-law exponent, mass absorption at the sheet occurs. Moreover, due to increase of unsteadiness, this mass absorption is prevented.     

Mass transfer kinetics during osmotic dehydration of pomegranate arils

The mass transfer kinetics during osmotic dehydration of pomegranate arils in osmotic solution of sucrose was studied to increase palatability and shelf life of arils. The freezing of the whole pomegranate at -18 °C was carried out prior to osmotic dehydration to increase the permeability of the outer cellular layer of the arils. The osmotic solution concentrations used were 40, 50, 60°Bx, osmotic solution temperatures were 35, 45, 55 °C. The fruit to solution ratio was kept 1:4 (w/w) during all the experiments and the process duration varied from 0 to 240 min. Azuara model and Peleg model were the best fitted as compared to other models for water loss and solute gain of pomegranate arils, respectively. Generalized Exponential Model had an excellent fit for water loss ratio and solute gain ratio of pomegranate arils. Effective moisture diffusivity of water as well as solute was estimated using the analytical solution of Fick's law of diffusion. For above conditions of osmotic dehydration, average effective diffusivity of water loss and solute gain varied from 2.718 × 10(-10) to 5.124 × 10(-10) m(2)/s and 1.471 × 10(-10) to 5.147 × 10(-10) m(2)/s, respectively. The final product was successfully utilized in some nutritional formulations such as ice cream and bakery products.     

Synthesis of PVA/PVP based hydrogel for biomedical applications: a review

The composition and synthesis of hydrogel were developed by using Polyvinyl alcohol (PVA) and Polyvinylpyrrolidone (PVP). Polyvinyl alcohol (PVA) and Polyvinylpyrrolidone (PVP) based hydrogels are the most popular water-soluble, biodegradable, biocompatible, non-carcinogenic, and extremely low cytotoxicity synthetic polymers due to their good biocompatibility have been used in numerous biomedical applications, such as implants, artificial organs, drug delivery devices, and wound dressings. In this review paper, details of synthetic of hydrogel formulations with PVA and PVP for biomedical applications.     

Two-dimensional mullite nanostructure: Synthesis and reinforcement effect on polypropylene/maleic anhydride graft ethylene vinyl acetate matrix

In the present work, we studied the reinforcement effect of mullite nanosheets (MNs) on the properties of polypropylene (PP)/maleic anhydride graft ethylene-vinyl acetate (EVA-g-MA) blend matrix. MNs have been prepared in the presence of polyvinylpyrrolidone (PVP) as the macromolecular surfactant through the sol–gel process followed by a thermal annealing method. The sheet-like morphology of mullite was confirmed by transmission electron microscopy analysis. The surface of the MNs was modified using 3-aminopropyltriethoxysilane. One weight percent of amine-functionalized MNs (AMNs) improved the impact strength of PP/EVA-g-MA blend matrix, which is about 52%. Melt rheology analysis resulted that the nanocomposite exhibited a viscous behavior up to 2.5 wt % of AMNs and above the content ensued a viscoelastic solid-like behavior. X-ray diffraction analysis showed a complete dispersion of AMNs in the PP/EVA-g-MA blend matrix. TEM analysis confirmed that the MNs sheets are residing mostly in EVA-g-MA phase and the interface of PP/EVA-g-MA blend. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48233.     

An automatic approach based on CNN architecture to detect Covid-19 disease from chest X-ray images

Applied Intelligence - Novel coronavirus (COVID-19) is started from Wuhan (City in China), and is rapidly spreading among people living in other countries. Today, around 215 countries are affected...     

Diffusion of chemically reactive species in Casson fluid flow over an unsteady permeable stretching surface

In this paper we investigate the two-dimensional flow of a non-Newtonian fluid over an unsteady stretching permeable surface. The Casson fluid model is used to characterize the non-Newtonian fluid behavior. First-order constructive/destructive chemical reaction is considered. With the help of a shooting method, numerical solutions for a class of nonlinear coupled differential equations subject to appropriate boundary conditions are obtained. For the steady flow, the exact solution is obtained. The flow features and the mass transfer characteristics for different values of the governing parameters are analyzed and discussed in detail.     

Investigation of tensile and in-plane shear properties of carbon fiber reinforced composites with and without piezoelectric patches for micro-crack propagation using extended finite element method

Microsystem Technologies - The smart materials are capable to integrate the remarkabale active functions into a traditional structure of the composites. There is a wide research possibility towards...     

Piezoelectric thermo electromechanical energy harvester for reconnaissance satellite structure

Microsystem Technologies - Piezoelectric materials are widely used in aerospace industry as a source of alternate energy for micro or nanoscale electronics because of voltage dependent actuation...     

Understanding Internet service switching behaviour based on the stage model

As customer switching is the major concern in the competitive Internet industry, many studies have sought to identify the determinants that cause customers to switch in order to build effective customer retention strategies. However, they were found to be insufficient for explaining the determinants and processes related to service switching. To fill this gap, this study attempts to provide a theoretical mechanism explaining customer service switching behaviours. More specifically, this study examines three hypotheses that may help ISPs develop appropriate marketing and business strategies. Survey data collected from 151 ISP customers in Australia were analysed to test the hypotheses. The results identify four stages of customers switching behaviours and suggest that motivational variables for switching behaviours differ across stages. This study provides a stepping-stone for analysing the staged model in the service-switching context and will help managers enhance their customer retention capability, and thus improve their organizational performance.