Benjamin C.,National Institute of Science Education and Research
Applied Physics Letters | Year: 2013
Quantum pumping in graphene has been predicted in recent years. Till date there have been no experiments indicating a graphene based quantum pump. This is not uncommon as in the case of other non-Dirac behavior showing materials it has not yet been unambiguously experimentally detected. The reason is that in experiments with such materials the rectification effect overshadows the pumped current. In this work we answer the question posed in the title by taking recourse to "strain." We show that the symmetries of the rectified and pumped currents towards strain reversal can effectively distinguish between the two. © 2013 AIP Publishing LLC.
Das T.K.,Barchana Womens College |
Prusty S.,National Institute of Science Education and Research
Polymer - Plastics Technology and Engineering | Year: 2012
Conducting polymers (CPs) have drawn considerable attention because of their economical importance, good environmental stability and electrical conductivity as well as due to their useful mechanical, optical and electronic properties. Some of the widest applications of conducting polymers include: they are used in electrostatic materials, conducting adhesives, electromagnetic shielding against electromagnetic interference (EMI), artificial nerves, aircraft structures, diodes, and transistors. This review covers some of the potential applications of these nanofibers and nanotubes in sensors, nanodiodes, field effect transistors, field emission and electrochromic displays, super-capacitors and energy storage, actuators, drug delivery, neural interfaces, and protein purification and its future prospects. © 2012 Copyright Taylor and Francis Group, LLC.
Goswami C.,National Institute of Science Education and Research
Journal of Neurochemistry | Year: 2012
Existence of microtubule cytoskeleton at the membrane and submembranous regions, referred as 'membrane tubulin' has remained controversial for a long time. Since we reported physical and functional interaction of Transient Receptor Potential Vanilloid Sub Type 1 (TRPV1) with microtubules and linked the importance of TRPV1-tubulin complex in the context of chemotherapy-induced peripheral neuropathy, a few more reports have characterized this interaction in in vitro and in in vivo condition. However, the cross-talk between TRPs with microtubule cytoskeleton, and the complex feedback regulations are not well understood. Sequence analysis suggests that other than TRPV1, few TRPs can potentially interact with microtubules. The microtubule interaction with TRPs has evolutionary origin and has a functional significance. Biochemical evidence, Fluorescence Resonance Energy Transfer analysis along with correlation spectroscopy and fluorescence anisotropy measurements have confirmed that TRPV1 interacts with microtubules in live cell and this interaction has regulatory roles. Apart from the transport of TRPs and maintaining the cellular structure, microtubules regulate signaling and functionality of TRPs at the single channel level. Thus, TRPV1-tubulin interaction sets a stage where concept and parameters of 'membrane tubulin' can be tested in more details. In this review, I critically analyze the advancements made in biochemical, pharmacological, behavioral as well as cell-biological observations and summarize the limitations that need to be overcome in the future. Journal of Neurochemistry © 2012 International Society for Neurochemistry.
Kumar L.,National Institute of Science Education and Research
Nuclear Physics A | Year: 2014
The main aim of the RHIC Beam Energy Scan (BES) program is to explore the QCD phase diagram which includes search for a possible QCD critical point and the phase boundary between QGP and hadronic phase. We report the collision energy and centrality dependence of kinetic freeze-out properties from the measured mid-rapidity (|y|<0.1) light hadrons (pions, kaons, protons and their anti-particles) for Au+Au collisions at the center-of-mass energy sNN=7.7,11.5,19.6,27, and 39 GeV. The STAR detector, with a large uniform acceptance and excellent particle identification is used in the data collection and analysis. The kinetic freeze-out temperature Tkin and average collective velocity 〈β〉 parameters are extracted from blast-wave fits to the identified hadron spectra and systematically compared with the results from other collision energies including those at AGS, SPS and LHC. It is found that all results fall into an anti-correlation band in the 2-dimensional (Tkin, 〈β〉) distribution: the largest value of collective velocity and lowest temperature is reached in the most central collisions at the highest collision energy. The energy dependence of these freeze-out parameters is discussed. © 2014 Elsevier B.V.
Haque R.,National Institute of Science Education and Research
Nuclear Physics A | Year: 2014
We present the measurement of azimuthal anisotropy in the distributions of deuteron (d), anti-deuteron (d;), triton (t) and helium (3He) nuclei produced at midrapidity (|η|<1.0) in heavy-ion collisions at √sNN=200,62.4,39,27,19.6,11.5 and 7.7 GeV. We also present systematic study of the difference between particle and anti-particle elliptic flow (δv2) for identified hadrons (π±, K±, p, p;, Λ, Λ; and E±) at mid-rapidity for Au+Au collisions at RHIC Beam Energy Scan (BES) energies. Elliptic flow coefficient v2 of nuclei has been compared with those for p, p;. We observe mass ordering in nuclei v2(pT) for low transverse momenta (pT<2.0 GeV/c) and a clear centrality dependence. The triton and helium, having almost the same mass, show similar magnitude of v2 within the available event statistics. Mass number (A) scaling of nuclei v2(pT) has been observed, which indicates the possibility of coalescence mechanism to be the underlying physics behind nuclei formation in heavy ion collisions. New results on δv2 for all particles, studied in 10-40% centrality, show similar trend as was observed for minimum bias (0-80%) events. The proton and anti-proton δv2 for three different collision centralities is presented as a function of √sNN. © 2014 Elsevier B.V.