Bangalore, India

Raman Research Institute
Bangalore, India

Raman Research Institute is an institute of scientific research located in Bangalore, India. It was founded by Nobel laureate C. V. Raman. Although it began as an institute privately owned by Sir C. V. Raman, it is now funded by the government of India. Wikipedia.

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French National Center for Scientific Research and Raman Research Institute | Date: 2015-09-02

For performing navigation assistance in a scattering environment, a system is intended to detect at least one navigational light marker in scenes captured by an image capturing device, each navigational light marker generating a light beam having a predefined polarization state. The system includes an image capturing device that is adapted for: capturing a first image of a scene, said first image being polarized in accordance with the predefined polarization state of the light beam generated by said navigational light marker(s); capturing a second image of the scene, said second image being polarized according to a polarization state orthogonal to the polarization state of the first image; generating a polarimetric contrast image by combining the first and second captured images; and providing a feedback for performing navigation assistance in the scattering environment, on the basis of the generated polarimetric contrast image.

Council Of Scientific & Industrial Research and Raman Research Institute | Date: 2014-01-13

The present invention relates to an etched optical fiber as force transducer with feedback control, with a force range of 1-108 pN and a displacement range of 10-105 nm with a spatial resolution of the order of tens of nanometers are accessible with the instrument. The sample deformation (evolution) can be imaged simultaneously with rheological measurements. The device is used to perform extension rheology of polymer melts, silk, or other bio-fluids at microscales, measure mechanical responses of living cells such as neurons, muscle cells, etc. It is also used as a passive probe for microscale force measurements and to investigate properties of active suspensions such as bacterial baths.

Gupta N.,Raman Research Institute
Astroparticle Physics | Year: 2013

The IceCube experiment has detected two neutrinos with energies between 1 and 10 PeV. They might have originated from Galactic or extragalactic sources of cosmic rays. In the present work we consider hadronic interactions of the diffuse very high energy cosmic rays with the interstellar matter within our Galaxy to explain the PeV neutrino events detected in IceCube. We also expect PeV gamma ray events along with the PeV neutrino events if the observed PeV neutrinos were produced within our Galaxy in hadronic interactions. PeV gamma rays are unlikely to reach us from sources outside our Galaxy due to pair production with cosmic background radiation fields. We suggest that in future with simultaneous detections of PeV gamma rays and neutrinos it would be possible to distinguish between Galactic and extragalactic origins of very high energy neutrinos. © 2013 Elsevier Ltd. All rights reserved.

Varadarajan M.,Raman Research Institute
Classical and Quantum Gravity | Year: 2013

A generalization of the representation, underlying the discrete spatial geometry of loop quantum gravity, to accomodate states labelled by smooth spatial geometries, was discovered by Koslowski and further studied by Sahlmann. We show how to construct the diffeomorphism constraint operator in this Koslowski-Sahlmann (KS) representation from suitable connection and triad dependent operators. We show that the KS representation supports the action of hitherto unnoticed 'background exponential' operators which, in contrast to the holonomy-flux operators, change the smooth spatial geometry label of the states. These operators are shown to be quantizations of certain connection dependent functions and play a key role in the construction of the diffeomorphism constraint operator. © 2013 IOP Publishing Ltd.

Kumar S.,Raman Research Institute
NPG Asia Materials | Year: 2014

Discotic liquid crystals (DLCs) are nanomaterials with sizes ranging from 2 to 6 nm, and they are emerging as one-dimensional organic semiconducting materials. Recently, hybridization of these materials with various metallic and semiconducting nanoparticles (NPs) to alter and improve their properties has been realized. This article provides an overview of the developments in the field of newly immersed discotic nanoscience, a sub-field of liquid crystal (LC) nanoscience. As this field is also of great interest to readers without an LCs background, a brief introduction of the LC field is given first, with special emphasis on DLCs. This is followed by various DLC-NP hybrid systems. Finally, an outlook into the future of this newly emerging, fascinating and exciting field of discotic nanoscience research is provided. © 2014 Nature Publishing Group.

Bisoyi H.K.,Raman Research Institute | Kumar S.,Raman Research Institute
Chemical Society Reviews | Year: 2010

The nematic phase of discotic liquid crystals, although rarely observed, has made very significant progress over the past three decades since their discovery. It has made its way from a mere scientific curiosity to application in commodities. The negative birefringence films formed by polymerized nematic discotic liquid crystals have been commercialized as compensation films to enlarge the viewing angle and enhance the contrast ratio of commonly used twisted nematic liquid-crystal displays. High strength and high performance carbon fibers for industrial applications have been obtained from the carbonaceous mesophase and a liquid-crystal display device with wide and symmetrical viewing angle has been demonstrated by using discotic nematic liquid crystals. Discotic films with patterned colours have been obtained from cholesteric lyo-mesophases of discotic liquid crystals. Various molecular architectures have been designed and synthesized to exhibit the discotic nematic phase over a wide range of temperature. This critical review focuses on the synthesis and physical properties of these fascinating materials. It deals with the structure of various nematic phases, different discotic cores exhibiting the nematic phase, novel designing and transition temperature engineering principles, alignment and physical properties, and finally the application of discotic nematic LCs as the active switching component and as optical compensation films for widening the viewing angle and contrast ratio of liquid-crystal display devices (98 references). © 2010 The Royal Society of Chemistry.

Bisoyi H.K.,Raman Research Institute | Kumar S.,Raman Research Institute
Chemical Society Reviews | Year: 2011

Liquid crystals are finding increasing applications in a wide variety of fields including liquid-crystal display technology, materials science, bioscience, etc., apart from acting as prototype self-organizable supramolecular soft materials and tunable solvents. Recently, keeping in pace with topical science, liquid crystals have entered into the fascinating domains of nanoscience and nanotechnology. This tutorial review describes the recent and significant developments in liquid-crystal nanoscience embracing contemporary nanomaterials such as nanoparticles, nanorods, nanotubes, nanoplatelets, etc. The dispersion of zero-, one- and two-dimensional nanomaterials in liquid crystals for the enhancement of properties, liquid-crystalline phase behavior of nanomaterials themselves, self-assembly and alignment of nanomaterials in liquid-crystalline media, and the synthesis of nanomaterials by using liquid crystals as 'templates' or 'precursors' have been highlighted and discussed. It is almost certain that the 'fourth state of matter' will play more prevalent roles in nanoscience and nanotechnology in the near future. Moreover, liquid-crystal nanoscience reflects itself as a beautiful demonstration of the contemporary theme "crossing the borders: science without boundaries". © 2011 The Royal Society of Chemistry.

Kumar S.,Raman Research Institute
Israel Journal of Chemistry | Year: 2012

This review article provides a bird's-eye view on discotic liquid crystals and their potential applications. Design principles, synthesis, modification of physical properties and potential applications of some common discotic liquid crystals have been briefly summarized. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sabhapandit S.,Raman Research Institute
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

The formalism of Kundu, for computing the large deviations of heat flow in harmonic systems, is applied to the case of single Brownian particle in a harmonic trap and coupled to two heat baths at different temperatures. The large-τ form of the moment generating function e -λQg(λ)exp[τμ(λ)], of the total heat flow Q from one of the baths to the particle in a given time interval τ, is studied and exact explicit expressions are obtained for both μ(λ) and g(λ). For a special case of the single particle problem that corresponds to the work done by an external stochastic force on a harmonic oscillator coupled to a thermal bath, the large-τ form of the moment generating function is analyzed to obtain the exact large deviation function as well as the complete asymptotic forms of the probability density function of the work. © 2012 American Physical Society.

Pal A.,Raman Research Institute
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2015

The steady state of a Brownian particle diffusing in an arbitrary potential under the stochastic resetting mechanism has been studied. We show that there are different classes of nonequilibrium steady states depending on the nature of the potential. In the stable potential landscape, the system attains a well-defined steady state; however, the existence of the steady state for the unstable landscape is constrained. We have also investigated the transient properties of the propagator towards the steady state under the stochastic resetting mechanism. Finally, we have done numerical simulations to verify our analytical results. © 2015 American Physical Society.

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