8,965 research outputs found
Sulfur studies on lithium sulfur dioxide batteries
Studies investigating the chemistry of the lithium SO2 batteries are described
Behaviour of the EAS Age Parameter in the Knee Energy Region
Analyzing simulated EAS events generated with the CORSIKA code, the
characteristics of lateral distribution of electrons in EAS around the knee
energy region of the primary energy spectrum have been studied and compared
with experimental observations. The differences between the EGS4 and the NKG
output of CORSIKA in respect to electron radial density distribution have been
investigated. The relation between lateral and longitudinal age parameters has
been studied after introducing the notion of the local age parameter that
reflects the profile of the lateral distribution of electrons in EAS. The
present analysis motivates the inclusion of the lateral shower age in a
multiparameter study of EAS to extract information on hadronic interactions and
primary composition.Comment: Talk presented at XVI International Symposium on Very High Energy
Cosmic Ray Interactions (ISVHECRI 2010), Batavia, IL, USA (28 June - 2 July
2010). 4 pages, 5 figure
Spectroscopic Confirmation of a Protocluster at z=3.786
We present new observations of the field containing the z=3.786 protocluster,
PC217.96+32.3. We confirm that it is one of the largest and most overdense
high-redshift structures known. Such structures are rare even in the largest
cosmological simulations. We used the Mayall/MOSAIC1.1 imaging camera to image
a 1.2x0.6 deg area (~150x75 comoving Mpc) surrounding the protocluster's core
and discovered 165 candidate Lyman Alpha emitting galaxies (LAEs) and 788
candidate Lyman Break galaxies (LBGs). There are at least 2 overdense regions
traced by the LAEs, the largest of which shows an areal overdensity in its core
(i.e., within a radius of 2.5 comoving Mpc) of 14+/-7 relative to the average
LAE spatial density in the imaged field. Further, the average LAE spatial
density in the imaged field is twice that derived by other field LAE surveys.
Spectroscopy with Keck/DEIMOS yielded redshifts for 164 galaxies (79 LAEs and
85 LBGs); 65 lie at a redshift of 3.785+/-0.010. The velocity dispersion of
galaxies near the core is 350+/-40 km/s, a value robust to selection effects.
The overdensities are likely to collapse into systems with present-day masses
of >10^{15} solar masses and >6x10^{14} solar masses. The low velocity
dispersion may suggest a dynamically young protocluster. We find a weak trend
between narrow-band (Lyman Alpha) luminosity and environmental density: the
Lyman Alpha luminosity is enhanced on average by 1.35X within the protocluster
core. There is no evidence that the Lyman Alpha equivalent width depends on
environment. These suggest that star-formation and/or AGN activity is enhanced
in the higher density regions of the structure. PC217.96+32.3 is a Coma cluster
analog, witnessed in the process of formation.Comment: Accepted for publication in the Astrophysical Journal (March 27,
2016
Spin Hall effect in a Kagome lattice driven by Rashba spin-orbit interaction
Using four-terminal Landauer-B\"{u}ttiker formalism and Green's function
technique, in this present paper, we calculate numerically spin Hall
conductance (SHC) and longitudinal conductance of a finite size kagome lattice
with Rashba spin-orbit (SO) interaction both in presence and absence of
external magnetic flux in clean limit. In the absence of magnetic flux, we
observe that depending on the Fermi surface topology of the system SHC changes
its sign at different values of Fermi energy, along with the band center.
Unlike the infinite system (where SHC is a universal constant ), here SHC depends on the external parameters like SO coupling strength,
Fermi energy, etc. We show that in the presence of any arbitrary magnetic flux,
periodicity of the system is lost and the features of SHC tends to get reduced
because of elastic scattering. But again at some typical values of flux
($\phi=1/2, 1/4, 3/4..., etc.) the system retains its periodicity depending on
its size and the features of spin Hall effect (SHE) reappears. Our predicted
results may be useful in providing a deeper insight into the experimental
realization of SHE in such geometries.Comment: 10 pages, 10 figure
Non-diffracting Optical Beams in a Three-level Raman System
Diffractionless propagation of optical beams through atomic vapors is
investigated. The atoms in the vapor are operated in a three-level Raman
configuration. A suitably chosen control beam couples to one of the
transitions, and thereby creates a spatially varying index of refraction
modulation in the warm atomic vapor for a probe beam which couples to the other
transition in the atoms. We show that a Laguerre-Gaussian control beam allows
to propagate single Gaussian probe field modes as well as multi-Gaussian modes
and non-Gaussian modes over macroscopic distances without diffraction. This
opens perspectives for the propagation of arbitrary images through warm atomic
vapors.Comment: 8 pages, 7 figure
Born-Infeld black holes coupled to a massive scalar field
Born-Infeld black holes in the Scalar-Tensor Theories of Gravity, in the case
of massless scalar field, have been recently obtained. The aim of the current
paper is to study the effect from the inclusion of a potential for the scalar
field in the theory, through a combination of analytical techniques and
numerical methods. The black holes coupled to a massive scalar field have
richer causal structure in comparison to the massless scalar field case. In the
latter case, the black holes may have a second, inner horizon. The presence of
potential for the scalar field allows the existence of extremal black holes for
certain values of the mass of the scalar field and the magnetic (electric)
charge of the black hole. The linear stability against spherically symmetric
perturbations is studied. Arguments in favor of the general stability of the
solutions coming from the application of the "turning point" method are also
presented.Comment: 26 pages, 16 figure
Physico-chemical changes during fruit growth and developmental stages in yellow type passion fruit (Passiflora edulis f. flavicarpa Degener) accessions
Physiological and biochemical changes during fruit growth, development and maturity of six yellow type passion fruit (Passiflora edulis f. flavicarpa Degener) accessions were studied at weekly interval after fruit set from 21 days to 91 days after fruit set and after dropping from vine also. Fruit growth of passion fruit followed a single sigmoid growth curve. Fruit length (cm), diameter (cm) and weight (g) increased continuously (25.24%, 33.13% and 75.08% respectively) (from the initial stage till maturity up to 84 days), which slightly declined at ripening stage. Fruits developed acceptable physico-chemical qualities with good colour, when harvested at 84 to 91 days after fruit set (DAF). The study further revealed that the days taken from fruit set to maturity and ripening, colour change, total soluble solids and acidity may be considered as the most reliable maturity indices for taking harvest decision in pas-sion fruit
Fisheries rehabilitation in post-tsunami Aceh: Status and needs from participatory appraisals
The widespread and long-term nature of the tsunami damage in Aceh province, Indonesia has threatened the continued use of coastal and fisheries resources. This article describes the application of the Rapid Appraisal of Fisheries Management System (RAFMS) methodology and presents key findings from the participatory appraisals in 15 study sites. The focus is on changes in the number and types of fishing boats and fishing effort, consumption and marketing flow patterns and community perspectives on livelihood options. The level of aid (for new boats), mainly from international organizations, has been unevenly distributed with the number of boats in 13 of 15 villages still being well below the pre-tsunami levels. A focus on supplying small vessels may put increased fishing pressure on the near-shore zone. Consumption data and marketing flows suggest that most fishing villages are supplying outside markets and adding considerably to the wider food security of the province. Despite the tsunami, marine fisheries-related livelihoods are still preferred, although there are indications for the potential expansion of livelihoods into the culture of new species. Alternative resource-based livelihoods need to be tested and refined to fit the needs of the current conditions in Aceh to provide viable options for eliminating hunger and reducing poverty
Documentation of ethno-medicinal practices: A case study on tribal forest fringe dwellers of Terai West Bengal in India
The ethno-medicinal practices were documented which were being used by tribal population dwelling forest fringe areas of Terai zone of West Bengal, India on under exploited, non conventional, traditional and indigenous plant species for the sustainable utilization of these resources to cure day to day ailments. A total number of forty seven medicinal plant species belonging to 25 families were documented during the survey period 2012-13, which was used in curing many diseases. Among the families, Euphorbiaceae, Zingeberaceae and Leguminosae were the dominant families that represented four species each. Herb was the highest proportion of plant species 18 (38%) followed by 15 tree species (32%), 8 species of shrubs (17%) and rest were climbers and fern. It was observed that the tribal forest fringe communities of the Terai zone of the West Bengal have a good ethno-medicinal knowledge of using plant resources and developed their own traditional practices to cure day to day diseases
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