5,907 research outputs found
Mueller matrix polarimetry of plasmon resonant silver nano-rods: biomedical prospects
Fundamental understanding of the light-matter interaction in the context of
nano-particles is immensely bene- fited by the study of geometry dependent
tunable Localized Surface Plasmon Resonance (LSPR) and has been demonstrated to
have potential applications in various areas of science. The polarization
characteristics of LSPR in addition to spectroscopic tuning can be suitably
exploited in such systems as contrast enhancement mech- anisms and control
parameters. Such polarization characteristics like diattenuation and retardance
have been studied here using a novel combination of Muller-matrix polarimetry
with the T-matrix matrix approach for silver nano-rods to show unprecedented
control and sensitivity to local refractive index variations. The study carried
out over various aspect ratios for a constant equal volume sphere radius shows
the presence of longitu- dinal (dipolar and quadrupolar) and transverse
(dipolar) resonances; arising due to differential contribution of
polarizabilities in two directions. The overlap regions of these resonances and
the resonances themselves exhibit enhanced retardance and diattenuation
respectively. The spectral and amplitude tunability of these polarimetric
parameters through the aspect ratios to span from the minimum to maximum ([0,
1] in the case of diattenuation and [0, {\pi}] in the case of retardance)
presents a novel result that could be used to tailor systems for study of
biological media. On the other hand, the high sensitivity of diattenuation dip
(caused by equal contribution of polarizabilities) could be possibly used for
medium characterization and bio-sensing or bio-imaging studies.Comment: 8 pages, 6 figures, Proceedings of the Saratov Fall Meeting, 201
Synchronization of chaotic modulated time delay networks in presence of noise
We study the constructive role of noises in a Lorenz system with functional
delay. The effect of delay can change the dynamics of the system to a chaotic
one from its steady state. Induced synchronization with white and colored (red
and green) noises are observed between two identical uncoupled systems and
enhancement of synchrony is also observed with unidirectional coupling. We
investigate both the phenomena in a globally coupled network in the presence of
white and color noises.Comment: 10 pages, 7 figure
Enhancing synchronization in chaotic oscillators by induced heterogeneity
We report enhancing of complete synchronization in identical chaotic
oscillators when their interaction is mediated by a mismatched oscillator. The
identical oscillators now interact indirectly through the intermediate relay
oscillator. The induced heterogeneity in the intermediate oscillator plays a
constructive role in reducing the critical coupling for a transition to
complete synchronization. A common lag synchronization emerges between the
mismatched relay oscillator and its neighboring identical oscillators that
leads to this enhancing effect. We present examples of one-dimensional open
array, a ring, a star network and a two-dimensional lattice of dynamical
systems to demonstrate how this enhancing effect occurs. The paradigmatic
R\"ossler oscillator is used as a dynamical unit, in our numerical experiment,
for different networks to reveal the enhancing phenomenon.Comment: 10 pages, 7 figure
Studies on Glass Reinforced Epoxy Resin Using Vulkadur- A as Crosslinking Agent both in Presence and Absence of Carbon Black and other Non black Fillers
Epoxy resin can be reinforced with glass (fabric form) in presence of Vulkadur-A, a phenol formaldehyde resin containing a hardening agent. Overall enhancement in mechanical properties has been found stocks cured with Vulkadur-A containing 2.5 parts of carbon black as filler
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