33,040 research outputs found
Very smooth points of spaces of operators
In this paper we study very smooth points of Banach spaces with special
emphasis on spaces of operators. We show that when the space of compact
operators is an -ideal in the space of bounded operators, a very smooth
operator attains its norm at a unique vector (up to a constant
multiple) and is a very smooth point of the range space. We show that if
for every equivalent norm on a Banach space, the dual unit ball has a very
smooth point then the space has the Radon--Nikod\'{y}m property. We give an
example of a smooth Banach space without any very smooth points.Comment: 12 pages, no figures, no table
Leprosy and tuberculosis concomitant infection: a poorly understood, age-old relationship
Historically, archaeological evidence, post-mortem findings and retro- spective analysis of leprosy institutions’ data demonstrates a high observed incidence of concomitant infection with leprosy and tuberculosis (TB). However, reports of concomitant infection in the modern literature remain scarce, with estimates of annual new case detection rates of concomitant infection at approximately 0·02 cases per 100,000 population. Whilst the mechanism for this apparent decline in concomitant infections remains unclear, further research on this topic has remained relatively neglected. Modelling of the interaction of the two organisms has suggested that the apparent decline in observations of concomitant infection may be due to the protective effects of cross immunity, whilst more recently others have questioned whether it is a more harmful relationship, predisposing towards increased host mortality. We review recent evidence, comparing it to previously held understanding on the epidemiological relationship and our own experience of concomitant infection. From this discussion, we highlight several under-investigated areas, which may lead to improvements in the future delivery of leprosy management and services, as well as enhance understanding in other fields of infection management. These include, a) highlighting the need for greater understanding of host immunogenetics involved in concomitant infection, b) whether prolonged courses of high dose steroids pre-dispose to TB infection? and, c) whether there is a risk of rifampicin resistance developing in leprosy patients treated in the face of undiagnosed TB and other infections? Longitudinal work is still required to characterise these temporal relationships further and add to the current paucity of literature on this subject matter
Simulation of mirror inversion of quantum states in an XY spin chain using NMR
We report an experimental quantum simulation of unitary dynamics of an XY
spin chain with pre-engineered couplings. Using this simulation, we demonstrate
the mirror inversion of quantum states, proposed by Albanese et al. [Phys. Rev.
Lett. 93, 230502 (2004)]. The experiment is performed with a 5-qubit dipolar
coupled spin system using nuclear magnetic resonance techniques. To perform
quantum simulation we make use of the recently proposed unitary operator
decomposition algorithm of Ajoy et al. [Phys. Rev. A 85, 030303 (2012)] along
with numerical pulse optimization techniques. Further, using mirror inversion,
we demonstrate that entangled states can be transferred from one end of the
chain to the other end. The simulations are implemented with high experimental
fidelity, which implies that these kind of simulations may be possible in
larger systems.Comment: 9 pages, 6 figure
Anti-correlated hard X-ray time lags in Galactic black hole sources
We investigate the accretion disk geometry in Galactic black hole sources by
measuring the time delay between soft and hard X-ray emissions. Similar to the
recent discoveries of anti-correlated hard X-ray time lags in Cyg X-3 and GRS
1915+105, we find that the hard X-rays are anti-correlated with soft X-rays
with a significant lag in another source: XTE J1550-564. We also find the
existence of pivoting in the model independent X-ray spectrum during these
observations. We investigate time-resolved X-ray spectral parameters and find
that the variation in these parameters is consistent with the idea of a
truncated accretion disk. The QPO frequency, which is a measure of the size of
truncated accretion disk, too changes indicating that the geometric size of the
hard X-ray emitting region changes along with the spectral pivoting and soft
X-ray flux. Similar kind of delay is also noticed in 4U 1630-47.Comment: 14 pages, 7 figures, accepted for publication in Ap
Some studies on a solid state sulfur probe for coal gasification systems
Measurements on the solid electrolyte cell (Ar + H(2) + H(2)S/CaS + CaF(2) + (Pt)//CaF(2)//(Pt) + CaF(2) + CaS/H(2) + H(2)+Ar) show that the emf of the cell is directly related to the difference in sulfur potentials established at the Ar + H(2) + H(2)S/electrode interfaces. The electrodes convert the sulfur potential gradient across the calcium fluoride electrolyte into an equivalent fluorine potential gradient. Response time of the probe varies from approximately 9 hr at 990 K to 2.5 hr at 1225 K. The conversion of calcium sulfide and/or calcium fluoride into calcium oxide is not a problem anticipated in commercial coal gasification systems. Suggestions are presented for improving the cell for such commercial applications
Hot Core, Outflows and Magnetic Fields in W43-MM1 (G30.79 FIR 10)
We present submillimeter spectral line and dust continuum polarization
observations of a remarkable hot core and multiple outflows in the high-mass
star-forming region W43-MM1 (G30.79 FIR 10), obtained using the Submillimeter
Array (SMA). A temperature of 400 K is estimated for the hot-core using
CHCN (J=19-18) lines, with detections of 11 K-ladder components. The high
temperature and the mass estimates for the outflows indicate high-mass
star-formation. The continuum polarization pattern shows an ordered
distribution, and its orientation over the main outflow appears aligned to the
outflow. The derived magnetic field indicates slightly super-critical
conditions. While the magnetic and outflow energies are comparable, the B-field
orientation appears to have changed from parsec scales to 0.1 pc scales
during the core/star-formation process.Comment: accepted, ApJ Letter
Corrosion of 310 stainless steel in H2-H2O-H2S gas mixtures: Studies at constant temperature and fixed oxygen potential
Corrosion of SAE 310 stainless steel in H2-H2O-H2S gas mixtures was studied at a constant temperature of 1150 K. Reactive gas mixtures were chosen to yield a constant oxygen potential of approximately 6 x 10 to the minus 13th power/cu Nm and sulfur potentials ranging from 0.19 x 10 to the minus 2nd power/cu Nm to 33 x 10 to the minus 2nd power/cu Nm. The kinetics of corrosion were determined using a thermobalance, and the scales were analyzed using metallography, scanning electron microscopy, and energy dispersive X-ray analysis. Two corrosion regimes, which were dependent on sulfur potential, were identified. At high sulfur potentials (p sub S sub 2 less than or equal to 2.7 x 10 to the minus 2nd power/cu Nm) the corrosion rates were high, the kinetics obeyed a linear rate equation, and the scales consisted mainly of sulfide phases similar to those observed from pure sulfication. At low sulfur potentials (P sub S sub 2 less than or equal to 0.19 x 10 to the minus 2nd power/cu Nm) the corrosion rates were low, the kinetics obeyed a parabolic rate equation, and scales consisted mainly of oxide phases
Stability of chromium (III) sulfate in atmospheres containing oxygen and sulfur
The stability of chromium sulfate in the temperature range from 880 K to 1040 K was determined by employing a dynamic gas-solid equilibration technique. The solid chromium sulfate was equilibrated in a gas stream of controlled SO3 potential. Thermogravimetric and differential thermal analyses were used to follow the decomposition of chromium sulfate. X-ray diffraction analysis indicated that the decomposition product was crystalline Cr2O3 and that the mutual solubility between Cr2(SO4)3 and Cr2O3 was negligible. Over the temperature range investigated, the decomposition pressure were significantly high so that chromium sulfate is not expected to form on commercial alloys containing chromium when exposed to gaseous environments containing oxygen and sulfur (such as those encountered in coal gasification)
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