25,083 research outputs found
New magic number for neutron rich Sn isotopes
The variation of E(2+_1) of (134-140)Sn calculated with empirical SMPN
interaction has striking similarity with that of experimental E(2+_1) of
even-even (18-22)O and (42-48)Ca, showing clearly that N=84-88 spectra exhibit
the effect of gradual filling up of \nu(2f_{7/2}) orbital which finally
culminates in a new shell closure at N=90. Realistic two-body interaction CWG
does not show this feature. Spin-tensor decomposition of SMPN and CWG
interactions and variation of their components with valence neutron number
reveals that the origin of the shell closure at 140Sn lies in the three body
effects. Calculations with CWG3, which is obtained by including a simple
three-body monopole term in the CWG interaction, predict decreasing E(2+_1) for
(134-138)Sn and a shell closure at 140Sn.Comment: 4 pages, 5 figure
High redshift radio galaxies and divergence from the CMB dipole
Previous studies have found our velocity in the rest frame of radio galaxies
at high redshift to be substantially larger than that inferred from the CMB
temperature dipole anisotropy. We construct a full sky catalogue NVSUMSS, by
merging the NVSS and SUMSS catalogues and removing local sources by various
means including cross-correlating with the 2MRS catalogue. We take into account
both aberration and Doppler boost to deduce our velocity from the hemispherical
number count asymmetry, as well as via a 3-dimensional linear estimator. Both
the magnitude and direction depend on cuts made to the catalogue, e.g. on the
lowest source flux, however these effects are small. With the hemispheric
number count asymmetry method we obtain a velocity of 1729 187 km/s i.e.
about 4 times larger than that obtained from the CMB dipole, but close in
direction, towards RA=149 2 degree, DEC = -17 12 degree. With the
3-dimensional estimator, the derived velocity is 1355 174 km/s towards
RA=141 11 degree, DEC=-9 10 degree. We assess the statistical
significance of these results by constructing catalogues of random
distributions and show that they are at best significant at the
(99.95% confidence) level.Comment: 13 pages, 12 figures, 10 tables; matches published versio
No-Sense: Sense with Dormant Sensors
Wireless sensor networks (WSNs) have enabled continuous monitoring of an area
of interest (body, room, region, etc.) while eliminating expensive wired
infrastructure. Typically in such applications, wireless sensor nodes report
the sensed values to a sink node, where the information is required for the
end-user. WSNs also provide the flexibility to the end-user for choosing
several parameters for the monitoring application. For example, placement of
sensors, frequency of sensing and transmission of those sensed data. Over the
years, the advancement in embedded technology has led to increased processing
power and memory capacity of these battery powered devices. However, batteries
can only supply limited energy, thus limiting the lifetime of the network. In
order to prolong the lifetime of the deployment, various efforts have been made
to improve the battery technologies and also reduce the energy consumption of
the sensor node at various layers in the networking stack. Of all the
operations in the network stack, wireless data transmission and reception have
found to consume most of the energy. Hence many proposals found in the
literature target reducing them through intelligent schemes like power control,
reducing retransmissions, etc. In this article we propose a new framework
called Virtual Sensing Framework (VSF), which aims to sufficiently satisfy
application requirements while conserving energy at the sensor nodes.Comment: Accepted for publication in IEEE Twentieth National Conference on
Communications (NCC-2014
Liquid-phase hydrogenation of bio-refined succinic acid to 1,4-butanediol using bimetallic catalysts
open access articleDevelopment of a Crotalaria juncea based biorefinery produce large quantity of waste glycerol after trans-esterification
of the juncea seeds. This glycerol, after purification, is used as a substrate for producing succinic acid on a microbial
route. Hydrogenation of this bio-refined succinic acid is carried out under high pressure in order to produce 1,4-
butanediol (BDO) using a batch slurry reactor with cobalt supported ruthenium bimetallic catalysts, synthesized inhouse.
It is demonstrated that, using small amounts of ruthenium to cobalt increases the overall hydrogenation activity
for the production of 1,4-butanediol. Hydrogenation reactions are carried out at various operating temperatures and
pressures along with changes in the mixing ratios of ruthenium chloride and cobalt chloride hexahydrate, which are
used to synthesize the catalyst. The Ru-Co bimetallic catalysts are characterized by XRD, FE-SEM and TGA.
Concentrations of the hydrogenation product are analyzed using Gas chromatography-Mass spectrometry (GC-MS).
Statistical analysis of the overall hydrogenation process is performed using a Box-Behnken Design (BBD)
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