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Kottayam, India

Thomas L.,Catholicate College | John J.,Catholicate College | Kumar B.R.,Catholicate College | George N.A.,Baselius College | Kurian A.,Catholicate College
Materials Today: Proceedings | Year: 2015

Dual beam Thermal lens technique is employed the thermal diffusivity of gold nanoparticle is synthesized using polyvinyl alcohol as reducing agent. The photoluminescence spectra of all the samples are carried out. The weight ratio of gold chloride increases the fluorescence peak shift towards lower wavelength and its fluorescence intensity decreases. Also the thermal diffusivity of gold nanofluid increases as the weight ratio of gold chloride increases. © 2015 Elsevier Ltd. Source

John J.,Catholicate College | Thomas L.,Catholicate College | George N.A.,Baselius College | Kurian A.,Catholicate College | George S.D.,Manipal University India
Physical Chemistry Chemical Physics | Year: 2015

Dye-nanoparticle mixtures hold great promise in biological as well as photonics applications due to their capability to tailor the emission behavior of dye by tuning the nanoparticles parameters. However, as compared to the well-defined dye-nanoparticle distance, studies lack the understanding of homogenous mixtures of dye and nanoparticles. In this work, we investigate the influence of shape and concentration of gold nanoparticles prepared via green synthesis on the optical properties of fluorescein dye in a dye-nanoparticle mixture. We have investigated the radiative path of deexcitation using steady state fluorescence and the non-radiative path is probed using a laser based dual-beam thermal lens technique. The energy transfer efficiency as well as dye-nanoparticle distance is studied using both techniques. Furthermore, we have explored the influence of nanoparticles parameters on the fluorescence quantum yield of fluorescein using the thermal lens technique. The studies indicate that spherical nanoparticles are efficient quenchers while star shaped nanoparticles can probe larger dye-NP distances. The tailoring of dye properties by tuning nanoparticle parameters can be utilized in diverse areas including bioimaging, solar cells, and sensors. © the Owner Societies 2015. Source

Krishnaraj M.V.,Baselius College | Mohanan N.,Jawaharlal Nehru Tropical Botanic Garden and Research Institute
Webbia | Year: 2014

Vigna hainiana (=Phaseolus wightianus Grah. ex Wight & Arn.) is lectotypified using Wallichian collections at CAL and an earlier typification of Vigna wightii Benth. ex Bedd. is discussed. © 2014 Dipartimento di Biologia, Università di Firenze. Source

Thomas L.,Catholicate College | John J.,Catholicate College | George N.A.,Baselius College | Kurian A.,Catholicate College
Measurement Science and Technology | Year: 2014

Nanotechnology plays a vital role in the development of biosensors by enhancing their sensitivity and performance. In this paper, we report a novel urine sugar sensing method that makes use of the unique properties of silver-nanofluids in combination with the laser induced photothermal lens technique. The thermal lens signal decreases with increase in sugar levels in urine samples, which may be attributed to the enhanced interaction of glucose and conduction electrons of silver-nanoparticles, thereby changing the surface plasmon energy. © 2014 IOP Publishing Ltd. Source

John K.J.,ICAR National Bureau of Plant Genetic Resources | Roy Y.C.,ICAR National Bureau of Plant Genetic Resources | Krishnaraj M.V.,Baselius College | Nissar V.A.M.,ICAR National Bureau of Plant Genetic Resources | And 2 more authors.
Genetic Resources and Crop Evolution | Year: 2015

Cucumis silentvalleyi (Manilal, T. Sabu et P.J. Mathew) Ghebretinsae et Thulin and Cucumis indicus Ghebretinsae et Thulin are two rare narrow endemics of Western Ghats of India. Both have morphological resemblance but distinguishable by a few key characters like shape of the leaf, ovary and fruit, and chromosome number. While both are edible and non-bitter, their distribution is mutually exclusive, but overlapping with Cucumis sativus var. hardwickii (Royle) Alef. (the wild and feral form of C.sativus L.). Interspecific crossability studies indicate that both are related to each other and to a lesser extent to Cucumis setosus Cogn. and Cucumis melo L. Being incompletely described, a comparative account of their morphology, phenology, distribution, ecology and conservation are provided. © 2015 Springer Science+Business Media Dordrecht Source

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