2,711 research outputs found
Experimental demonstration of coherent state estimation with minimal disturbance
We investigate the optimal tradeoff between information gained about an
unknown coherent state and the state disturbance caused by the measurement
process. We propose several optical schemes that can enable this task, and we
implement one of them, a scheme which relies on only linear optics and homodyne
detection. Experimentally we reach near optimal performance, limited only by
detection inefficiencies. In addition we show that such a scheme can be used to
enhance the transmission fidelity of a class of noisy channels
Integrable nonlinear equations on a circle
The concept of integrable boundary value problems for soliton equations on
and is extended to bounded regions enclosed by
smooth curves. Classes of integrable boundary conditions on a circle for the
Toda lattice and its reductions are found.Comment: 23 page
Schwarzschild-De Sitter black holes in 4+1 dimensional bulk
We construct a static solution for 4+1 dimensional bulk such that the 3+1
dimensional world has a linear warp factor and describes the
Schwarzschild-dS_{4} black hole. For m=0 this four dimensional universe and
Friedmann Robertson Walker universe are related with an explicit coordinate
transformation. We emphasize that for linear warp factors the effect of bulk on
the brane world shows up as the dS_{4} background which is favored by the big
bang cosmology.Comment: 6 page
Needed: a systems approach to improve flood risk mitigation through private precautionary measures
Private precautionary measures play an increasingly important role in flood risk management. The degree to which private precautionary measures mitigate flood risk depends mainly on the type of measure (and how effective it is) and how frequently and successfully it is implemented. These aspects are influenced by a complex interaction of physical and socio-economic processes, which makes the assessment and the prediction of the mitigation of flood risk via private precautionary measures a challenge. This paper provides an overview of factors and processes that influence the implementation and effectiveness of private precaution in mitigating flood risk, underpinning it with highlights from international examples. We recommend private precautionary measures for further use to improve flood risk mitigation, but stress that they need to be considered and implemented through a holistic systems approach to maximize their effectiveness
Accelerated Born-Infeld Metrics in Kerr-Schild Geometry
We consider Einstein Born-Infeld theory with a null fluid in Kerr-Schild
Geometry. We find accelerated charge solutions of this theory. Our solutions
reduce to the Plebanski solution when the acceleration vanishes and to the
Bonnor-Vaidya solution as the Born-Infeld parameter b goes to infinity. We also
give the explicit form of the energy flux formula due to the acceleration of
the charged sources.Comment: Latex file (12 pp
A Spectroscopic Survey of a Sample of Active M Dwarfs
A moderate resolution spectroscopic survey of Fleming's sample of 54 X-ray
selected M dwarfs with photometric distances less than 25 pc is presented.
Radial and rotation velocities have been measured by fits to the H-alpha
profiles. Radial velocities have been measured by cross correlation. Artificial
broadening of an observed spectrum has produced a relationship between H-alpha
FWHM and rotation speed, which we use to infer rotation speeds for the entire
sample by measurement of the H-alpha emission line. We find 3 ultra-fast
rotators (UFRs, vsini > 100km/s), and 8 stars with 30 < vsini < 100 km/s. The
UFRs have variable emission. Cross-correlation velocities measured for
ultra-fast rotators (UFRs) are shown to depend on rotation speed and the
filtering used. The radial velocity dispersion of the sample is 17 km/s. A new
double emission line spectroscopic binary with a period of 3.55 days has been
discovered, and another known one is in the sample. Three other objects are
suspected spectroscopic binaries, and at least six are visual doubles. The only
star in the sample observed to have significant lithium is a known TW Hya
Association member, TWA 8A. These results show that there are a number of young
(< 10^8 yr) and very young (< 10^7 yr) low mass stars in the immediate solar
neighbourhood. The H-alpha activity strength does not depend on rotation speed.
Our fast rotators are less luminous than similarly fast rotators in the
Pleiades. They are either younger than the Pleiades, or gained angular momentum
in a different way.Comment: 38 pages incl. 14 figures and 4 tables, plus 12 pages of table for
electronic journal only; LaTeX, aastex.cls. Accepted 07/18/02 for publication
in The Astronomical Journa
Blood Cell Morphology and Plasma Biochemistry of Captive Mauremys caspica (Gmelin, 1774) and Mauremys rivulata (Valenciennes, 1833)
Morphological characteristics of peripheral blood cells, micronucleated erythrocyte counts and plasma biochemistry profile were examined in fourteen healthy captive Mauremys caspica and in twenty-three Mauremys rivulata. The size of erythrocyte cells were 19.07 × 11.68 μm and 19.76 × 11.44 μm for M. caspica and M. rivulata, respectively. Nucleus sizes were 6.50 × 5.30 μm for M. caspica and 6.79 × 5.45 μm for M. rivulata. The micronucleated erythrocyte (MNE) values were 0.0008 and 0.0037 for the males and females of M. caspica, respectively. The MNE values were 0.0002 for male and female M. rivulata. We found sex-dependent differences only in the Ca value in the blood biochemistry profile for healthy M. caspica. Sex-dependent differences were found only in albumin and P values in the blood biochemistry profile for healthy M. rivulata. No significant differences were found between males of both species in question with respect to plasma biochemistry values. However, only plasma total protein and Ca content levels differed significantly between the females of the two species
Process development for powder injection molding of short fiber reinforced ceramic-matrix-composites
Blood Cell Morphology and Plasma Biochemistry of the Captive European Pond Turtle Emys orbicularis
The morphological characteristics of peripheral blood cells, micronucleated erythrocytes counts and plasma biochemistry profile were examined in ten healthy captive European pond turtles Emys orbicularis. Blood samples were obtained from the caudal vein. The Wright staining method was used for the classification of the blood cells. Mature erythrocytes of captive Emys orbicularis were nucleated ellipsoidal cells (21.7 ±1.27μm × 13.2 ±1.12 μm) with pink cytoplasm. The nucleus (6.9 ± 0.78 μm × 5.4 ± 0.65 μm) was centrally located and stained dark purple. Seven different types of blood cells were determined: erythrocytes, thrombocytes, monocytes, eosinophils, basophils, lymphocytes and heterophils. The micronucleated erythrocyte (MNE) values were 0.0016 and 0.003 for the males and females, respectively. The MNE results were presented as the mean frequency of micronucleated erythrocytes per 1000 cells per animal. The mean plasma concentrations in the total of specimens were as follows: total protein (25 g/L), albumin (7.2 g/L), globulin (17.8 g/L), glucose (2.91 mmol/L), calcium (2.32 mmol/L), phosphorus (1.55 mmol/L), creatinine (46.85 μmol/L), urea (10.93 mmol/L) , triglycerides (0.44 mmol/L), cholesterol (1.48 mmol/L), sodium (125.76 mmol/L), potassium (3.98 mmol/L), chloride (93.94 mmol/L), iron (13.34 μmol/L) and activities of aspartate aminotransferase (2.14 μkat/L), alanine aminotransferase (0.15 μkat/L), gamma glutamyl transpeptidase (2.15 U/L), amylase (8.09 μkat/L), lactate dehydrogenase (19.93 μkat/L). We found sex-dependent differences only in ALT [(0.21 μkat/L and 0.10 μkat/L for the males and females, respectively) (t = 3,107; df = 14; p Emys orbicularis. We suggest that the biochemical profile described in the present study may be used as a standard profile for healthy Emys orbicularis kept in captivity
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