5,863 research outputs found
Astrometry and Photometry with Coronagraphs
We propose a solution to the problem of astrometric and photometric
calibration of coronagraphic images with a simple optical device which, in
theory, is easy to use. Our design uses the Fraunhofer approximation of Fourier
optics. Placing a periodic grid of wires (we use a square grid) with known
width and spacing in a pupil plane in front of the occulting coronagraphic
focal plane mask produces fiducial images of the obscured star at known
locations relative to the star. We also derive the intensity of these fiducial
images in the coronagraphic image. These calibrator images can be used for
precise relative astrometry, to establish companionship of other objects in the
field of view through measurement of common proper motion or common parallax,
to determine orbits, and to observe disk structure around the star
quantitatively. The calibrator spots also have known brightness, selectable by
the coronagraph designer, permitting accurate relative photometry in the
coronagraphic image. This technique, which enables precision exoplanetary
science, is relevant to future coronagraphic instruments, and is particularly
useful for `extreme' adaptive optics and space-based coronagraphy.Comment: To appear in ApJ August 2006, 27 preprint style pages 4 figure
SERVOQUAL ANALYSIS OF TOURISM IN INDIA
Globally, the travel, tourism and hospitality industry is one of the largest service industries in terms of revenue generation and foreign exchange earnings, contributing over 9% to global GDP. It is also one of the largest employment generators in the world. An estimated 235 million people work directly or in related sectors, accounting for more than 8% of global employment. Travel, tourism and hospitality industry is an integral part of the economy. The sector accounts for around 8.0% of India's GDP. It is a significant employment generator and a substantial contributor towards foreign exchange earnings of the country. India's share in the global travel and tourism industry (in terms of international tourism receipts) is around 1.2%; it however holds immense potential, given the country's rich history, and cultural and geographical diversity. It is an attempt to develop tourism in Shivamogga and to harness full potential of the industry; GoI has taken several measures from time to time. Formulation of the tourism policy and various initiatives to promote tourism infrastructure development and marketing and promotion activities
Entropy measures for complex networks: Toward an information theory of complex topologies
The quantification of the complexity of networks is, today, a fundamental
problem in the physics of complex systems. A possible roadmap to solve the
problem is via extending key concepts of information theory to networks. In
this paper we propose how to define the Shannon entropy of a network ensemble
and how it relates to the Gibbs and von Neumann entropies of network ensembles.
The quantities we introduce here will play a crucial role for the formulation
of null models of networks through maximum-entropy arguments and will
contribute to inference problems emerging in the field of complex networks.Comment: (4 pages, 1 figure
QUALITATIVE AND QUANTITATIVE ANALYSIS OF MUSCLE POWER
Muscle power is one mechanical quantity that is not clearly understood by many coaches and teachers of human movement. This is probably due to an inadequate differentiation between the concepts of work/energy and of power. Thus we will begin this paper with a discussion of these concepts. The analysis of the vertical jump as a measure of work, energy, and power will also be discussed
Physical Properties of Metallic Antiferromagnetic CaCo{1.86}As2 Single Crystals
We report studies of CaCo{1.86}As2 single crystals. The electronic structure
is probed by angle-resolved photoemission spectroscopy (ARPES) measurements of
CaCo{1.86}As2 and by full-potential linearized augmented-plane-wave
calculations for the supercell Ca8Co15As16 (CaCo{1.88}As2). Our XRD crystal
structure refinement is consistent with the previous combined refinement of
x-ray and neutron powder diffraction data showing a collapsed-tetragonal
ThCr2Si2-type structure with 7(1)% vacancies on the Co sites corresponding to
the composition CaCo{1.86}As2 [D. G. Quirinale et al., Phys. Rev. B 88, 174420
(2013)]. The anisotropic magnetic susceptibility chi(T) data are consistent
with the magnetic neutron diffraction data of Quirianale et al. that
demonstrate the presence of A-type collinear antiferromagnetic order below the
Neel temperature TN = 52(1) K with the easy axis being the tetragonal c axis.
However, no clear evidence from the resistivity rho(T) and heat capacity Cp(T)
data for a magnetic transition at TN is observed. A metallic ground state is
demonstrated from band calculations and the rho(T), Cp(T) and ARPES data, and
spin-polarized calculations indicate a competition between the A-type AFM and
FM ground states. The Cp(T) data exhibit a large Sommerfield electronic
coefficient reflecting a large density of states at the Fermi energy D(EF),
consistent with the band structure calculations which also indicate a large
D(EF) arising from Co 3d bands. At 1.8 K the M(H) data for H|| c exhibit a
well-defined first-order spin-flop transition at an applied field of 3.5 T. The
small ordered moment of 0.3 muB/Co obtained from the M(H) data at low T, the
large exchange enhancement of chi and the lack of a self-consistent
interpretation of the chi(T) and M(H,T) data in terms of a local moment
Heisenberg model together indicate that the magnetism of CaCo{1.86}As2 is
itinerant.Comment: 18 pages, 15 figures, 4 tables, 61 references; v2: extended the fits
of experimental data by additional electronic structure calculations;
published versio
A comparative study on outcome of conservative and surgical treatment of type III supracondylar fracture of humerus in children
Background: Supracondylar fracture of humerus is most common of all the fractures around the elbow in children. They occur most commonly in children more so in male child with the peak around 5-8 years. Objective of this study was to compare the outcome of 3 different modalities of treatment for supracondylar fracture of humerus.Methods: Children with type III supracondylar fracture of humerus were categorized into group A, group B, group C based on conservative, closed reduction and percutaneous K wire fixation and open reduction and K wire fixation modalities of treatment given. All the children were followed for 6 months and the outcome of treatment was evaluated using Flynn’s criteria.Results: 40 children were treated with 3 different modalities of treatment. The rate of complications was less in children who were operated on first day of admission (p=0.02). Group B and group C had 80% and 61.11% excellent results and group A had 47.05% poor results. The outcome was better with cross K wire pinning than lateral pinning (p=0.015).Conclusions: Supracondylar fracture of humerus should be operated as early as possible to reduce the rate of complications. The outcome of surgical treatment was better than conservative treatment evaluated in terms of Flynn’s criteria. Cross wire pinning was better than lateral pinning in terms of outcome, but the rate of neuropraxias was more with cross wire pinning
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