5,339 research outputs found
Shape-changing Collisions of Coupled Bright Solitons in Birefringent Optical Fibers
Wecritically review the recent progress in understanding soliton propagation
in birefringent optical fibers.By constructing the most general bright
two-soliton solution of the integrable coupled nonlinear Schroedinger equation
(Manakov model) we point out that solitons in birefringent fibers can in
general change their shape after interaction due to a change in the intensity
distribution among the modes even though the total energy is conserved.
However, the standard shape-preserving collision (elastic collision) property
of the (1+1)-dimensional solitons is recovered when restrictions are imposed on
some of the soliton parameters. As a consequence the following further
properties can be deduced using this shape-changing collision. (i) The exciting
possibility of switching of solitons between orthogonally polarized modes of
the birefringent fiber exists. (ii) When additional effects due to periodic
rotation of birefringence axes are considered, the shape changing collision can
be used as a switch to suppress or to enhance the periodic intensity exchange
between the orthogonally polarized modes. (iii) For ultra short optical soliton
pulse propagation in non-Kerr media, from the governing equation an integrable
system of coupled nonlinear Schroedinger equation with cubic-quintic terms is
identified. It admits a nonlocal Poisson bracket structure. (iv) If we take the
higher-order terms in the coupled nonlinear Schroedinger equation into account
then their effect on the shape-changing collision of solitons, during optical
pulse propagation, can be studied by using a direct perturbational approach.Comment: 14 pages, ROMP31, 4 EPS figure
EMEEDP: Enhanced Multi-hop Energy Efficient Distributed Protocol for Heterogeneous Wireless Sensor Network
In WSN (Wireless Sensor Network) every sensor node sensed the data and
transmit it to the CH (Cluster head) or BS (Base Station). Sensors are randomly
deployed in unreachable areas, where battery replacement or battery charge is
not possible. For this reason, Energy conservation is the important design goal
while developing a routing and distributed protocol to increase the lifetime of
WSN. In this paper, an enhanced energy efficient distributed protocol for
heterogeneous WSN have been reported. EMEEDP is proposed for heterogeneous WSN
to increase the lifetime of the network. An efficient algorithm is proposed in
the form of flowchart and based on various clustering equation proved that the
proposed work accomplishes longer lifetime with improved QOS parameters
parallel to MEEP. A WSN implemented and tested using Raspberry Pi devices as a
base station, temperature sensors as a node and xively.com as a cloud. Users
use data for decision purpose or business purposes from xively.com using
internet.Comment: 6 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:1409.1412 by other author
The observational evidence pertinent to possible kick mechanisms in neutron stars
We examine available observations on pulsars for evidence pertaining to
mechanisms proposed to explain the origin of their velocities. We find that
mechanisms predicting a correlation between the rotation axis and the pulsar
velocity are ruled out. Also, that there is no significant correlation between
pulsar magnetic field strengths and velocities. With respect to recent
suggestions postulating asymmetric impulses at birth being solely responsible
for both the spins and velocities of pulsars, single impulses of any duration
and multiple extended duration impulses appear ruled out.Comment: 7 pages. Accepted for publication in Astronomy & Astrophysic
A Ray-Tracing Model of the Vela Pulsar
In the relativistic plasma surrounding a pulsar, a subluminal ordinary-mode
electromagnetic wave will propagate along a magnetic field line. After some
distance, it can break free of the field line and escape the magnetosphere to
reach an observer. We describe a simple model of pulsar radio emission based on
this scenario and find that applying this model to the case of the Vela pulsar
reproduces qualitative characteristics of the observed Vela pulse profile.Comment: 23 pages, 9 figures, accepted for publication in Ap
Dynamic Impact of RuCl3 Catalyst on the Oxidation of Cyclamate with Acidified Bromamine-T: Elucidation of Mechanistic Pathways and Kinetic Modeling
Abstract: Oxidation-Kinetics of cyclamate by bromamine-T (BAT) in HClO4 medium catalyzed by RuCl3 exhibits a first-order dependence on BAT0, fractional-order on both Cyclamate0 and RuCl3, and inverse fractional-order on HClO4. RuCl3 catalyst accelerated the reaction by a splendid 48 times. Plausible mechanism and related rate law have been deduced. Graphical Abstract: The Stoichiometry of the reaction is:Figure not available: see fulltext.. © 2017, Springer Science+Business Media New York
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