1,881 research outputs found
Two Cases of Primary Ectopic Ovarian Pregnancy
Primary ovarian pregnancy is one of the rarest varieties of ectopic pregnancies. Patients frequently present with abdominal pain and menstrual irregularities. Intrauterine devices have evolved as probable risk factors. Preoperative diagnosis is challenging but transvaginal sonography has often been helpful. A diagnostic delay may lead to rupture, secondary implantation or operative difficulties. Therefore, awareness of this rare condition is important in reducing the associated risks. Here, we report two cases of primary ovarian pregnancies presenting with acute abdominal pain. Transabdominal ultrasonography failed to hint at ovarian pregnancy in one, while transvaginal sonography aided in the correct diagnosis of the other. Both cases were confirmed by histopathological examinations and were successfully managed by surgery
Effect of Salt Concentration on the Electrophoretic Speed of a Polyelectrolyte through a Nanopore
In a previous paper [S. Ghosal, Phys. Rev. E 74, 041901 (2006)] a
hydrodynamic model for determining the electrophoretic speed of a
polyelectrolyte through an axially symmetric slowly varying nanopore was
presented in the limit of a vanishingly small Debye length. Here the case of a
finite Debye layer thickness is considered while restricting the pore geometry
to that of a cylinder of length much larger than the diameter. Further, the
possibility of a uniform surface charge on the walls of the nanopore is taken
into account. It is thereby shown that the calculated transit times are
consistent with recent measurements in silicon nanopores.Comment: 4 pages, 2 figure
Local Identification of Subsets of Quantum states: A Stronger Quantum Nonlocality
Nonolocality makes quantum theory nontrivially sacred and useful in the
paradigm of information theoretic tasks. Apart from Bell nonlocality, which
deals with measurement outcome statistics of spatially separated agents, there
is also another kind of quantum nonlocality, that is associated with perfect
distinguishability of quantum states by local operations and classical
communication (LOCC). We propose a distributed task: perfect identification of
subsets of a known set of multipartite orthogonal states by LOCC, namely, local
subset identification. Failure in accomplishing this task guarantees a new
notion of quantum nonlocality, viz., local subset unidentifiability. Here, we
show that both local distinguishability and local markability of quantum states
implies local subset identifiability, but the converse is not necessarily true.
This makes local subset unidentifiability a stronger quantum nonlocal
phenomenon than its predecessors -- local indistinguishability and local
unmarkability. Moreover, we also present an even stronger version of local
subset unidentifiablity involving more than two spatially separated parties
namely, genuine local subset unidentifiability, where a given subset becomes
identifiable if and only if all the parties come together in a common lab.Comment: Initial draft, New results added, Comments are welcom
Robustness of d-Density Wave Order to Nonmagnetic Impurities
Effect of finite density of nonmagnetic impurities on a coexisting phase of
d-density wave (DDW) order and d-wave superconducting (DSC) order is studied
using Bogoliubov-de Gennes (BdG) method. The spatial variation of the
inhomogeneous DDW order due to impurities has a strong correlation with that of
density, which is very different from that of DSC order. The length scale
associated with DDW is found to be of the order of a lattice spacing. The
nontrivial inhomogeneities are shown to make DDW order much more robust to the
impurities, while DSC order becomes very sensitive to them. The effect of
disorder on the density of states is also discussed.Comment: 4 pages, 3 PostScript figure
Rotation periods and colours of 10-m scale near-Earth asteroids from CFHT target of opportunity streak photometry
The rotational properties of 10~m-scale asteroids are poorly understood
with only a few measurements. Additionally, collisions or thermal recoil can
spin their rotations to periods less than a few seconds obfuscating their study
due to the observational cadence imposed by the long read-out times of
charge-coupled device imagers. We present a method to measure the rotation
periods of 10~m-scale asteroids using the target of opportunity capability of
the Canada France Hawaii Telescope and its MegaCam imager by intentionally
streaking their detections in single exposures when they are at their
brightest. Periodic changes in brightness as small as 0.05 mag along the
streak can be measured as short as a few seconds. Additionally, the streak
photometry is taken in multiple g, r, and i filter exposures enabling the
measurement of asteroid colours. The streak photometry method was tested on
CFHT observations of three 10~m-scale asteroids, 2016 GE, 2016 CG,
and 2016 EV. Our 3 targets are among the smallest known asteroids with
measured rotation periods/colours having some of the shortest known rotation
periods. We compare our rotation period and taxonomic results with independent
data from the literature and discuss applications of the method to future small
asteroid observations.Comment: Revised version, MNRAS:L, 13 pages, 10 figures, 3 table
Reactive chemical dynamics through conical intersections
Reaction dynamics of prototypical, D + H2 and Cl (2P) + H2, chemical reactions occurring through the conical intersections of the respective coupled multi-sheeted potential energy surfaces is examined here. In addition to the electronic coupling, nonadiabatic effects due to relativistic spin-orbit coupling are also considered for the latter reaction. A time-dependent wave packet propagation approach is undertaken and the quantum dynamical observables viz., energy resolved reaction probabilities, integral reaction cross-sections and thermal rate constants are reported
A GEANT-based study of atmospheric neutrino oscillation parameters at INO
We have studied the dependence of the allowed space of the atmospheric
neutrino oscillation parameters on the time of exposure for a magnetized Iron
CALorimeter (ICAL) detector at the India-based Neutrino Observatory (INO). We
have performed a Monte Carlo simulation for a 50 kTon ICAL detector generating
events by the neutrino generator NUANCE and simulating the detector response by
GEANT. A chi-square analysis for the ratio of the up-going and down-going
neutrinos as a function of is performed and the allowed regions at 90%
and 99% CL are displayed. These results are found to be better than the current
experimental results of MINOS and Super-K. The possibilities of further
improvement have also been discussed.Comment: 8 pages, 13 figures, a new figure added, version accepted in IJMP
Single-Particle Density of States of a Superconductor with a Spatially Varying Gap and Phase Fluctuations
Recent experiments have shown that the superconducting energy gap in some
cuprates is spatially inhomogeneous. Motivated by these experiments, and using
exact diagonalization of a model d-wave Hamiltonian, combined with Monte Carlo
simulations of a Ginzburg-Landau free energy functional, we have calculated the
single-particle density of states LDOS of a model high-T
superconductor as a function of temperature. Our calculations include both
quenched disorder in the pairing potential and thermal fluctuations in both
phase and amplitude of the superconducting gap. Most of our calculations assume
two types of superconducting regions: , with a small gap and large
superfluid density, and , with the opposite. If the regions are
randomly embedded in an host, the LDOS on the sites still has
a sharp coherence peak at , but the component does not, in
agreement with experiment. An ordered arrangement of regions leads to
oscillations in the LDOS as a function of energy. The model leads to a
superconducting transition temperature well below the pseudogap
temperature , and has a spatially varying gap at very low , both
consistent with experiments in underdoped Bi2212. Our calculated
LDOS shows coherence peaks for , in agreement with previous work considering phase but not amplitude
fluctuations in a homogeneous superconductor. Well above , the gap in the
LDOS disappears.Comment: 37 pages, 12 figures. Accepted by Phys. Rev. B. Scheduled Issue: 01
Nov 200
Effect of carbon nanofibre addition on the mechanical properties of different Vf carbon-epoxy composites
Carbon-epoxy (C-epoxy) laminated composites having different fibre volume fractions (40, 50, 60 and 70) were fabricated with and without the addition of aminofunctionalized carbon nanofibres (A-CNF). Flexural strength, interlaminar shear strength (ILSS) and tensile strength of the composite laminates were determined. It was observed that, the ability of A-CNF to enhance the mechanical properties of C-epoxy diminished significantly as the fibre volume fraction (Vf) of the C-epoxy increased from 40 to 60. At 70Vf, the mechanical properties of the ACNF reinforced C-epoxy were found to be lower compared to the C-epoxy composite made without the addition of A-CNF. In this paper suitable mechanisms for the observed trends are proposed on the basis of the fracture modes of the composite
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