Balasubramanian Kandasubramanian

Bio: Balasubramanian Kandasubramanian is an academic researcher from Defence Institute of Advanced Technology. The author has contributed to research in topics: Materials science & Adsorption. The author has an hindex of 35, co-authored 177 publications receiving 3779 citations. Previous affiliations of Balasubramanian Kandasubramanian include Shanghai Jiao Tong University & Central Institute of Plastics Engineering and Technology.

Review of alginate-based hydrogel bioprinting for application in tissue engineering.

Abstract: The dawn of 3D printing in medicals has pinned the domain with hopes of vitality in many patients combating with multitude of diseases. Also entitled as Bio-printing, this is appertained to its sequential printing of precursor ink, embodying cells and polymer/composite, in predetermined trajectory. Precursor ink, in addition to cells, constitutes predominantly hydrogels ascribed to its biodegradability and mimic ability of body's anatomy and mechanical features, e.g. bones, etc. This review paper is devoted to explicate bio-printing (3D/4D) of alginate hydrogels, which are the extract from brown algae, through extrusion additive manufacturing. Alginates are salt derivative of alginic acid and constitute long chain of polysaccharides, which furnishes pliability and gelling adeptness to its structure. Alginate hydrogel (employed for extrusion) can be pristine or composite relying on the requisite properties (target application controlled or in-vivo environment) e.g. Alginate-natural (gelatin/agarose/collagen/hyaluronic acid/etc.) and Alginate-synthetic (polyethylene glycol (PEG)/pluronic F127/etc.). Extrusion additive manufacturing of Alginate is preponderate among others with its uncomplicated processing, material efficiency (cut down on wastage), and outspread adaptability for viscosities (0.03-6*104 Pa.s) but the procedure is limited by resolution(200 ?m) in addition to accuracy. However, 3D-fabricated bio-structures display rigidness (unvarying with conditions) that lacks smart response which is reassured by accounting time feature as noteworthy accessory to printing, interpreting as 4D Bio-printing. This review propounds specific processing itinerary for alginate (meanwhile traversing across its composites/blends with natural and synthetic consideration) in extrusion along with its pre-/during/post-processing parameters intrinsic to process. Furthermore, propensity is also presented in its (Alginate extrusion processing) application for tissue engineering, i.e. bones, cartilage (joints), brain (neural), ear, heart (cardiac), eyes (corneal), etc. due to worldwide quandary over accessibility to natural organs for diverse kinds of diseases. Additionally, the review contemplates recently invented advance printing i.e. 4D printing for biotic species with its challenges and future opportunities.

Graphene and Graphene Oxide-Based Composites for Removal of Organic Pollutants: A Review

Abstract: Graphene, graphene oxide (GO), and their composites have been prominently utilized for wastewater purification because of their adsorption, oxidation, and catalytic properties. Graphene and GO and its composites naturally have significant pore volume, high conductivity, rich surface chemistry, and an exceptionally large aspect ratio which make it favorable for adsorption and catalysis of organic pollutants from wastewater. The sheet-like, resonating, polyaromatic π-system of graphene subsidiaries play a significant role in π–π interactions, hydrogen bonding, and/or electrostatic interactions with organic pollutants that include dyes, pharmaceutical waste, and agricultural and industrial effluents whose base structure consists of notably reactive unsaturated aromatic rings and oxygen-rich functional groups. The adsorption capacities of pollutants have been widely researched and catalogued by considering the adsorption isotherm (Langmuir, Freundlich, Temkin, DR model) they fit, the kinetic models (pseudo-fi...

Effect of microplastics in water and aquatic systems.

Abstract: Surging dismissal of plastics into water resources results in the splintered debris generating microscopic particles called microplastics. The reduced size of microplastic makes it easier for intake by aquatic organisms resulting in amassing of noxious wastes, thereby disturbing their physiological functions. Microplastics are abundantly available and exhibit high propensity for interrelating with the ecosystem thereby disrupting the biogenic flora and fauna. About 71% of the earth surface is occupied by oceans, which holds 97% of the earth's water. The remaining 3% is present as water in ponds, streams, glaciers, ice caps, and as water vapor in the atmosphere. Microplastics can accumulate harmful pollutants from the surroundings thereby acting as transport vectors; and simultaneously can leach out chemicals (additives). Plastics in marine undergo splintering and shriveling to form micro/nanoparticles owing to the mechanical and photochemical processes accelerated by waves and sunlight, respectively. Microplastics differ in color and density, considering the type of polymers, and are generally classified according to their origins, i.e., primary and secondary. About 54.5% of microplastics floating in the ocean are polyethylene, and 16.5% are polypropylene, and the rest includes polyvinyl chloride, polystyrene, polyester, and polyamides. Polyethylene and polypropylene due to its lower density in comparison with marine water floats and affect the oceanic surfaces while materials having higher density sink affecting seafloor. The effects of plastic debris in the water and aquatic systems from various literature and on how COVID-19 has become a reason for microplastic pollution are reviewed in this paper.

Recent progress in fabrication and characterisation of hierarchical biomimetic superhydrophobic structures

Abstract: Here, we have reviewed brief ideas of fabrication of superhydrophobic surfaces and their important applications, which were discussed in the concluded national/international workshops and conferences organized by different industries and laboratories of ISRO (Indian Space Research Organization), DRDO (Defence Research and Development Organization) and AERB (Atomic Energy Regulatory Board) in the last four years. A comprehensive overview of wettability, development of fabrication, techniques for artificial superhydrophobic surfaces and their natures and low surface energy materials along with surface texture is presented successfully. The purpose of this review is to assist future development to make robust superhydrophobic surfaces.

Introduction to the Finite Element Method

Abstract: This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

Intrinsic ripples in graphene

Abstract: The stability of two-dimensional (2D) layers and membranes is subject of a long standing theoretical debate. According to the so called Mermin-Wagner theorem, long wavelength fluctuations destroy the long-range order for 2D crystals. Similarly, 2D membranes embedded in a 3D space have a tendency to be crumpled. These dangerous fluctuations can, however, be suppressed by anharmonic coupling between bending and stretching modes making that a two-dimensional membrane can exist but should present strong height fluctuations. The discovery of graphene, the first truly 2D crystal and the recent experimental observation of ripples in freely hanging graphene makes these issues especially important. Beside the academic interest, understanding the mechanisms of stability of graphene is crucial for understanding electronic transport in this material that is attracting so much interest for its unusual Dirac spectrum and electronic properties. Here we address the nature of these height fluctuations by means of straightforward atomistic Monte Carlo simulations based on a very accurate many-body interatomic potential for carbon. We find that ripples spontaneously appear due to thermal fluctuations with a size distribution peaked around 70 \AA which is compatible with experimental findings (50-100 \AA) but not with the current understanding of stability of flexible membranes. This unexpected result seems to be due to the multiplicity of chemical bonding in carbon.