SRM University

About: SRM University is a education organization based out in Chennai, India. It is known for research contribution in the topics: Computer science & Population. The organization has 10787 authors who have published 11704 publications receiving 103767 citations. The organization is also known as: Sri Ramaswamy Memorial University.

Modeling and optimization of supercritical fluid extraction of anthocyanin and phenolic compounds from Syzygium cumini fruit pulp.

Abstract: Supercritical carbon dioxide extraction (SC-CO2) of total anthocyanin and phenolic compounds from jamun fruits was investigated using three factors at three levels Box–Behnken response surface design. Experiments were conducted to evaluate the effects of three independent variables (pressure, temperature and co-solvent flow rate) on the maximum extraction yield of anthocyanin and phenolic compounds from jamun fruits. From the experimental data, second order polynomial mathematical models were developed with high coefficient of determination values (R2 > 0.98). From response surface plots, pressure, temperature and co-solvent flow rate exhibited independent and interactive effects on the extraction yields. Pressure of 162 bar, extraction temperature at 50 °C and co-solvent flow rate of 2.0 g/min was identified as optimal conditions. Under these optimal conditions, the experimental value agreed well with the predicted values and indicates the suitability of developed models.

Micromanipulation of Mechanically Compliant Organic Single‐Crystal Optical Microwaveguides

Abstract: Flexible organic single crystals are evolving as new materials for optical waveguides that can be used for transfer of information in organic optoelectronic microcircuits. Integration in microelectronics of such crystalline waveguides requires downsizing and precise spatial control over their shape and size at the microscale, however that currently is not possible due to difficulties with manipulation of these small, brittle objects that are prone to cracking and disintegration. Here we demonstrate that atomic force microscopy (AFM) can be used to reshape, resize and relocate single-crystal microwaveguides in order to attain spatial control over their light output. Using an AFM cantilever tip, mechanically compliant acicular microcrystals of three N-benzylideneanilines were bent to an arbitrary angle, sliced out from a bundle into individual crystals, cut into shorter crystals of arbitrary length, and moved across and above a solid surface. When excited by using laser light, such bent microcrystals act as active optical microwaveguides that transduce their fluorescence, with the total intensity of transduced light being dependent on the optical path length. This micromanipulation of the crystal waveguides using AFM is non-invasive, and after bending their emissive spectral output remains unaltered. The approach reported here effectively overcomes the difficulties that are commonly encountered with reshaping and positioning of small delicate objects (the "thick fingers" problem), and can be applied to mechanically reconfigure organic optical waveguides in order to attain spatial control over their output in two and three dimensions in optical microcircuits.

N-Doped Carbon Nanotubes Derived from Graphene Oxide with Embedment of FeCo Nanoparticles as Bifunctional Air Electrode for Rechargeable Liquid and Flexible All-Solid-State Zinc-Air Batteries.

Abstract: This work reports a novel approach for the synthesis of FeCo alloy nanoparticles (NPs) embedded in the N,P-codoped carbon coated nitrogen-doped carbon nanotubes (NPC/FeCo@NCNTs). Specifically, the synthesis of NCNT is achieved by the calcination of graphene oxide-coated polystyrene spheres with Fe3+, Co2+ and melamine adsorbed, during which graphene oxide is transformed into carbon nanotubes and simultaneously nitrogen is doped into the graphitic structure. The NPC/FeCo@NCNT is demonstrated to be an efficient and durable bifunctional catalyst for oxygen evolution (OER) and oxygen reduction reaction (ORR). It only needs an overpotential of 339.5 mV to deliver 10 mA cm-2 for OER and an onset potential of 0.92 V to drive ORR. Its bifunctional catalytic activities outperform those of the composite catalyst Pt/C + RuO2 and most bifunctional catalysts reported. The experimental results and density functional theory calculations have demonstrated that the interplay between FeCo NPs and NCNT and the presence of N,P-codoped carbon structure play important roles in increasing the catalytic activities of the NPC/FeCo@NCNT. More impressively, the NPC/FeCo@NCNT can be used as the air-electrode catalyst, improving the performance of rechargeable liquid and flexible all-solid-state zinc-air batteries.