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Study of gravitational radiation from inspiralling binary sources and data analysis
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Laser induced breakdown spectroscopy (libs) and time resolved studies of copper plasma excited by nanosecond and femtosecond laser pulses
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The tattooed Fakir
No full textTable of ContentsA young woman – Roshanara – is kidnapped by the village zamindar. The British sahib, owner of the indigo plantation, intervenes, but then takes her as his own mistress. She is not, however, any local woman – she is a fakir’s daughter.
It is the end of the eighteenth century in northern Bengal. Roshanara’s father, Cherag Ali and her husband, Asif go to Majnu Shah’s band of fakirs to plead for help in getting her back. The fakirs are known for their heroic battles with the British, for their arms and horses.
Asif feels nothing is left for him in the village and joins the fakirs, training in the use of weapons and ammunition, skirmishing with them up and down the country, but pining, always, for his Roshanara. Years later, in an oddly fated rescue mission he ends up, not with her, but with her son – Roshan – who evolves into a ferocious fakir soldier, tattooed and insecure about his identity.
A spare, elegant rendition of political clashes driven by personal agendas of rage and revenge, The Tattooed Fakir underlines a lesser known section of history with deep emotions
Near-resonant two-photon absorption in luminescent CdTe quantum dots
No full textOpen Access.We report the nonlinear optical absorption studies in two differently sized water-soluble cadmium telluride quantum dot (QD) samples, exhibiting first excitonic absorption peaks at 493 nm and 551 nm, respectively. An optical limiting behavior is observed for near-resonant excitation at 532 nm using nanosecond laser pulses, originating from the effective two-photon absorption (TPA) mechanism. The effective TPA coefficient (beta(eff)) is measured to be in the range of 10(-12) m/W. This is one order of magnitude higher than the TPA coefficient (beta) reported for off-resonant excitation. At this excitation wavelength, the smaller QD shows a relatively weaker photoluminescence and stronger nonlinear absorptio
Heat and work fluctuations for a harmonic oscillator
No full textOpen Access.The formalism of Kundu [J. Stat. Mech.1742-546810.1088/1742-5468/2011/03/P03007 P03007 (2011)], 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-λQ>≈g(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
Classical orbital magnetic moment in a dissipative stochastic system
No full textOpen AccessWe present an analytical treatment of the dissipative-stochastic dynamics of a charged classical particle confined biharmonically in a plane with a uniform static magnetic field directed perpendicular to the plane. The stochastic dynamics gives a steady state in the long-time limit. We have examined the orbital magnetic effect of introducing a parametrized deviation (η-1) from the second fluctuation-dissipation relation that connects the driving noise and the frictional memory kernel in the standard Langevin dynamics. The main result obtained here is that the moving charged particle generates a finite orbital magnetic moment in the steady state, and that the moment shows a crossover from para- to diamagnetic sign as the parameter η is varied. It is zero for η=1 that makes the steady state correspond to equilibrium, as it should. The magnitude of the orbital magnetic moment turns out to be a nonmonotonic function of the applied magnetic field, tending to zero in the limit of an infinitely large as well as an infinitesimally small magnetic field. These results are discussed in the context of the classic Bohr-van Leeuwen theorem on the absence of classical orbital diamagnetism. Possible realization is also briefly discussed
H-index as research performance Indicator : A study at Raman Research Institute
No full textRestricted Access, Book chapter, Proceedings of the National workshop on using different metrics for assessing research productivity, at ISI, New Delhi, from 16-17, 2012. Edited by S.M. Dhawan, N.K Khatri, A.Ratnakar. Book Published by ISI, Delhi.h-Index is a single number proposed by J.E. Hirsch in 2005 that has since gained popularity in
measuring research performance of individuals, institutions and universities etc. This paper attempts
to introduce this relatively new indicator and bring out the concepts underlying this indicator The
study applies h-index to studying research performance of scientists at Raman Research Institute
and compares the results of this stuy with the findings from Hirsch's investigations on h-index of
physicist
Corrigendum: The third post-Newtonian gravitational wave polarizations and associated spherical harmonic modes for inspiralling compact binaries in quasi-circular orbits
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Electrochemical impedance analysis of adsorption and enzyme kinetics of calf intestine alkaline phosphatase on sam-modified gold electrode
No full textRestricted Access.In this work, we have explored the potential of electrochemical impedance technique to follow the kinetics of nonspecific adsorption of enzymes on to a self-assembled monolayer (SAM) of 3-mercapto benzoic acid (3-MBZ) formed on gold electrodes. We have also studied kinetics of enzyme-substrate reactions on the immobilized surface using this technique. During the adsorption process, the surface coverage is measured using the imaginary component of the impedance at a given frequency, which was found to follow Langmuir adsorption kinetics. The adsorbed enzyme was then allowed to interact with different concentrations of its substrate and the resulting reaction was followed in real time. Changes in the imaginary component of the impedance at various substrate concentrations have been found to follow Michelis-Menten kinetics. The results show that electrochemical impedance spectroscopy (EIS) is a powerful technique that can be used to follow enzymatic reactions on surfaces in real time. Our results also suggest that this technique has the potential to emerge as an effective immunosensor tool that can be utilized for a large range of enzyme systems