Influence of radiation and viscous dissipation on MHD heat transfer Casson nanofluid flow along a nonlinear stretching surface with chemical reaction

The present article investigates the influence of Joule heating and chemical reaction on magneto Casson nanofluid phenomena in the occurrence of thermal radiation through a porous inclined stretching sheet. Consideration is extended to heat absorption/generation and viscous dissipation. The governing partial differential equations were transformed into nonlinear ordinary differential equations and numerically solved using the Implicit Finite Difference technique. The article analyses the effect of various physical flow parameters on velocity, heat, and mass transfer distributions. For the various involved parameters, the graphical and numerical outcomes are established. The analysis reveals that the enhancement of the radiation parameter increases the temperature and the chemical reaction parameter decreases the concentration profile. The empirical data presented were compared with previously published findings.     

Dietary and bioactive properties of the berries and leaves from the underutilized Hippophae salicifolia D. Don grown in Northeast India

Food Science and Biotechnology - The physico-chemical, polyphenols, antioxidant and antibacterial properties of berries and mixture of male and female leaves of Hippophae salicifolia were...     

On performance studies during micromachining of quartz glass using electrochemical discharge machining

The electrochemical discharge machining is a highly stochastic process involving a number of complex parameters. Controlling of these process parameters simultaneously to fetch the best possible performance is a difficult task. Determining an optimal parametric combination has become complex owing to interdependency of the parameters. In this work, the authors have made an attempt to establish the optimal combination of control parameters for machining of micro-channels on quartz glass. Taguchi’s standard orthogonal array (L ₉) with Grey relational analysis (GRA) approach was used to establish the optimal parametric conditions for reducing the Width overcut (WOC) of micro-channels and increasing the Material removal rate (MRR). In order to optimize MRR and WOC together, the optimal combination of the selected control variables was obtained using the GRA. The experimental results showed the effectiveness of the adapted method to indicate the performance of the electrochemical discharge machining process.

     

Utilization of green seed canola oil for in situ epoxidation

Green seed canola oil is underutilized for edible purposes due to its high chlorophyll content, which makes it more susceptible to photo‐oxidation and ultimately reduces the oxidation stability. The present work is an attempt to compare the kinetics of epoxidation of crude green seed canola oil (CGSCO) and treated green seed canola oil (TGSCO) with peroxyacids generated in situ in presence of an Amberlite IR‐120 acidic ion exchange resin (AIER) as catalyst. Among the two oxygen carrier studied, acetic acid was found to be a better carrier than the formic acid, as it gives 8% more conversion of double bond than the formic acid. A detailed process developmental study was then performed with the acetic acid/AIER combination. For the oils under investigation parameters optimized were temperature (55°C), hydrogen peroxide to double bond molar ratio (2.0), acetic acid to double bond molar ratio (0.5), and AIER loading (15%). An iodine conversion of 90.33, 90.20%, and a relative epoxide yield of 90, 88.8% were obtained at the optimum reaction conditions for CGSCO and TGSCO, respectively. The formation of the epoxide product of CGSCO and TGSCO was confirmed by Fourier Transform IR Spectroscopy (FTIR) and NMR (1H NMR) spectral analysis.     

Effect of fibre content and alkali treatment on mechanical properties of Roystonea regia-reinforced epoxy partially biodegradable composites

The present paper investigates the effect of fibre content and alkali treatment on tensile, flexural and impact properties of unidirectional Roystonea regia natural-fibre-reinforced epoxy composites which are partially biodegradable. The reinforcement Roystonea regia (royal palm) fibre was collected from the foliage of locally available royal palm tree through the process of water retting and mechanical extraction. The poor adhesion between fibre and matrix is commonly encountered problem in natural-fibre-reinforced composites. To overcome this problem, specific physical and chemical treatments were suggested for surface modification of fibres by investigators. Alkali treatment is one of the simple and effective surface modification techniques which is widely used in natural fibre composites. In the present study both untreated and alkali-treated fibres were used as reinforcement in Roystonea regia epoxy composites and the tensile, flexural and impact properties were determined at different fibre contents. The alkali treatment found to be effective in improving the tensile and flexural properties while the impact strength decreased.     

Epoxidation of Canola Oil with Hydrogen Peroxide Catalyzed by Acidic Ion Exchange Resin

Canola oil with an iodine value of 112/100 g, and containing 60% oleic acid and 20% linoleic acid, was epoxidised using a peroxyacid generated in situ from hydrogen peroxide and a carboxylic acid (acetic or formic acid) in the presence of an acidic ion exchange resin (AIER), Amberlite IR 120H. Acetic acid was found to be a better oxygen carrier than formic acid, as it produced about 10% more conversion of ethylenic unsaturation to oxirane than that produced by formic acid under otherwise identical conditions. A detailed process developmental study was then performed with the acetic acid/AIER combination. The parameters optimised were temperature (65 °C), acetic acid to ethylenic unsaturation molar ratio (0.5), hydrogen peroxide to ethylenic unsaturation molar ratio (1.5), and AIER loading (22%). An iodine conversion of 88.4% and a relative conversion to oxirane of 90% were obtained at the optimum reaction conditions. The heterogeneous catalyst, AIER, was found to be reusable and exhibited a negligible loss in activity.     

Prediction of Mass Transfer Coefficients in a Packed Bed using Tamarind Nut Shell Activated Carbon to Remove Phenol

Phenol is a refractive pollutant that is generated from almost all the types of industries. Removal of phenol can be achieved economically by using a cost effective technique like adsorption on to activated carbon. The present paper reports on the preparation and characterization of activated carbon from tamarind nutshell, an agricultural waste byproduct, and its use in a packed bed for the removal of phenol. The breakthrough curves for column sorption of phenol from aqueous solutions to TNSAC have been measured at various flow rates and different particle sizes at 28 °C. The results obtained showed that the sorption of phenol is dependent on both the flow rate and the particle size of the adsorbent, and that the breakpoint time and phenol removal yield decrease with increasing flow rate and particle size. The overall mass transfer coefficient is calculated from the experimental data and compared with the values obtained from the correlation. Experimental values are in excellent agreement with the predicted values from the correlation.     

Jitter reduction in self-sustaining monostable clock recovery circuit

A simple circuit modification is presented for reducing the output jitter of the self-sustaining monostable multivibrator clock recovery circuit. Jitter is reduced by preventing the monostable multivibrator from being triggered by pulses that arrive early. Experimental results in a fibre-optic system employing the Petrovic code show that, with this modification, the jitter variance can easily be reduced by a factor of 6.     

Noninvasive measurement of the pH of the endoplasmic reticulum at rest and during calcium release

The pH within individual organelles of the secretory pathway is believed to be an important determinant of their biosynthetic activity. However, little is known about the determinants and regulation of the pH in the secretory organelles, which cannot be readily accessed by [H+]-sensitive probes. We devised a procedure for the dynamic, noninvasive measurement of pH in the lumen of the endoplasmic reticulum in intact mammalian cells. A recombinant form of the B subunit of Shiga toxin, previously modified to include a carboxyl-terminal KDEL sequence and a pH-sensitive fluorophore, was used for a two-stage delivery strategy. Retrograde traffic of endogenous lipids was harnessed to target this protein to the Golgi complex, followed by retrieval to the endoplasmic reticulum (ER) by KDEL receptors. Immunofluorescence and immunoelectron microscopy were used to verify the subcellular localization of the modified B fragment. Fluorescence ratio imaging and two independent calibration procedures were applied to determine the pH of the ER in situ. We found that the pH of the endoplasmic reticulum is near neutral and is unaffected during agonist-induced release of calcium. The ER was found to be highly permeable to H+ (equivalents), so that the prevailing [H+] is susceptible to alterations in the cytosolic pH. Plasmalemmal acid-base transporters were shown to indirectly regulate the endoplasmic reticulum pH.     

New CMOS compatible junction-isolated lateral base resistancecontrolled thyristor

A new 550 V lateral base resistance controlled thyristor structure is proposed and its operation is rigorously characterised by two-dimensional numerical simulation in the off-state, on-state, and turn-off transient mode. Simulations indicate a 40% lower forward voltage drop over a comparable LIGBT, and a superior switching property over other competing lateral thyristor structures