http://dspace.rri.res.in:8080/jspui The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Search the Channel search http://dspace.rri.res.in:8080/jspui/simple-search http://hdl.handle.net/2289/4179 Title: X-ray and neutron scattering studies of lip-sterol model membranes<br/><br/>Authors: Sarangi, Bibhu Ranjan; Karmakar, Sanat; Raghunathan, V.A.<br/><br/>Abstract: Sterols are major components of many biomembranes and are known to play animportant role in several biological processes. In order to understand thecomplex lipid–sterol interactions and their influence on membrane structureand properties, model membranes containing cholesterol and other sterolshave been widely studied using a variety of experimental techniques. Thischapter gives a brief review of X-ray and neutron scattering studies of thesesystems, highlighting the detailed structural information they provide.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4178 Title: Improved optical limiting in dispersible carbon nanotubes and their metal oxide hybrids<br/><br/>Authors: Anand, Benoy; Susana, Addo Ntim; Muthukumar, V Sai; Sai, S Siva Sankara; Philip, Reji; Mitra, Somenath<br/><br/>Abstract: The mechanism and performance of optical limiting in carbon nanotubes (CNTs) and their metal oxide hybrids are presented. The mechanism of nonlinear absorption (NLA) in dispersed CNTs was an "effective" three-photon absorption arising due to sequential transitions between the real excited states. The effect of nonlinear scattering was minimal, and it was found that the metal oxide immobilization on the CNT surface does not alter either the mechanism of NLA, or the optical limiting threshold. With limiting thresholds in the range of 0.37-0.46 J/cm(2), these highly dispersible MWCNTs and their hybrids are excellent optical liming nanocarbons. (C) 2011 Elsevier Ltd. All rights reserved.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4177 Title: Electro-optical investigations and effect of asymmetry in bent-core liquid crystals<br/><br/>Authors: Balamurugan, S.; Kannana, P.; Yadupati, K.; Roy, Arun<br/><br/>Abstract: We report the synthesis and mesomorphic properties of a homologous series (10a–10g) of bent-core moleculesconstructed through covalent linkage of structurally non-symmetrical rod-like mesogens connected with a 1,3-phenylene unit. The study of homologous series underlines the importance of length and nature of terminalchains. The homologues of shorter chains show a typical non-switchable rectangular columnar B1 phase, while theswitchable lamellar (B2) phase is induced on moving to higher homologues. X-ray diffraction patterns indicate thepresence of B1 and B2 mesophases. Polarised optical microscopy investigations under electric field in the B2 phasesrevealed the existence of anticlinic antiferroelectric texture. The measured spontaneous polarisation value in oneof the compounds is 936 nC cm−2, a high polarisation value in bent-core liquid crystals.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4176 Title: A simple electro-optic technique for studying the electroclinic effect in the smectic A∗ phase<br/><br/>Authors: Datta, Soma; Roy, Arun<br/><br/>Abstract: The critical behaviour of the electroclinic response in the chiral smectic A∗ phase in the vicinity of the second-ordersmectic A∗ to smectic C∗ phase-transition temperature has been investigated using a new electro-optic technique.The temperature variation of the electroclinic coefficient, the relaxation frequency and the coefficient of the quarticterm in the tilt angle in the Landau free energy expansion have been studied. The electroclinic coefficient divergeswith decreasing temperature as the smectic A∗ to smectic C∗ phase-transition temperature is approached with acritical exponent, as predicted in the mean field Landau theory. The measured quartic coefficient varies stronglywith temperature, contrary to the usual assumptions of the mean field Landau theory.<br/><br/>Description: Restricted Access.