Sreedha Sambhudevan

The VALUE @ Amrita Virtual Labs Project: Using Web Technology to Provide Virtual Laboratory Access to Students

In response to the Indian Ministry of Human Resource Development (MHRD) National Mission on Education through Information and Communication Technology (NME-ICT) Initiative, the Virtual and Accessible Laboratories Universalizing Education (VALUE @ Amrita) Virtual Labs Project was initiated to provide laboratory-learning experiences to college and university students across India who may not have access to adequate laboratory facilities or equipment. These virtual laboratories require only a broadband Internet connection and standard web browser. Amrita Vishwa Vidyapeetham University (Amrita University) is part of a consortium of twelve institutions building over two hundred virtual labs covering nine key disciplines in science and engineering. This National Mission project hopes to reach out to Indias millions of engineering and science students at both undergraduate and postgraduate levels. The Virtual Labs Project is providing virtual laboratory experiments that directly support the All India Council for Technical Education (AICTE) and the University Grants Commission (UGC) model curricula for engineering and sciences undergraduate and postgraduate programs.

Evaluation of kinetics and transport mechanism of solvents through natural rubber composites containing organically modified gadolinium oxide

The solvent transport properties of the prepared composites were analysed using solvents of varying cohesive energy density and the effect of both modified as well as unmodified filler on the sorption and diffusion behaviour of NR vulcanisates has been investigated. It is found that the equilibrium uptake decreases with increase in filler content, as anticipated owing to the restrictions offered by the filler for solvents to diffuse into the polymer matrix. The mechanism of transport in natural rubber composites was carefully tracked and it was found to exhibit an anomalous mode of solvent transport where the polymer relaxation is in par with the rate of diffusion. Theoretical modelling of the swelling parameters was done and the results were found to be in agreement with existing models. The excellent swelling resistance coupled with the simultaneous improvement in mechanical properties would definitely pave way for the utilisation of these composites as barrier membranes.

Development of X-ray Protective Garments from Rare Earth-modified Natural Rubber Composites

Commonly used shielding materials while X-ray imaging by clinical persons is based on lead but incessant contact with this toxic material can pave way to severe health problems. Polymer composites, embedded with lead-free additives, especially based on natural rubber can be chosen as a suitable alternative candidate due to its lightweight, cost-effectiveness and capability to absorb regular energy region of X-ray used in medical imaging. Rubber composites were prepared with modified rare earth oxides at different filler loadings. The characterization of the filler reveals that their size falls in the nanoregime, which, in turn, supplemented to the superior properties of the composites. Mechanical properties were found to increase with filler content. X-ray shielding studies were done at different tube voltages and thicknesses and the results prove the efficacy of materials to be considered as a promising shielding resource.

Magnetic and dielectric properties of nickel-ferrite-embedded natural rubber composites

Spinel-structured nickel ferrite has been prepared using co-precipitation method. The ferrite particles prepared were characterized using XRD, FTIR, and TEM and were confirmed to be in the nano-regime. Natural rubber composites were prepared with different loadings of nickel ferrite like 5, 15, 25, 50, and 75 (in part per hundred rubber, phr). The mechanical, swelling, and magnetic properties were analyzed using the standard methods. Dielectric measurements show that permittivity decreases with increase in frequency and increases with increase in ferrite loading. Tan delta value also was found to increase with filler loading which may be attributed to the presence of interfacial polarization.