2,916 research outputs found
Majorization criterion for distillability of a bipartite quantum state
Bipartite quantum states are classified into three categories: separable
states, bound entangled states, and free entangled states. It is of great
importance to characterize these families of states for the development of
quantum information science. In this paper, I show that the separable states
and the bound entangled states have a common spectral property. More precisely,
I prove that for undistillable -- separable and bound entangled -- states, the
eigenvalue vector of the global system is majorized by that of the local
system. This result constitutes a new sufficient condition for distillability
of bipartite quantum states. This is achieved by proving that if a bipartite
quantum state satisfies the reduction criterion for distillability, then it
satisfies the majorization criterion for separability.Comment: 4 pages, no figures, REVTEX. A new lemma (Lemma 2) added. To appear
in Physical Review Letter
MINING PROCESS AND PRODUCT INFORMATION FROM PRESSURE FLUCTUATIONS WITHIN A FUEL PARTICLE COATER
The Next Generation Nuclear Power (NGNP) Fuel Development and Qualification Program included the design, installation, and testing of a 6-inch diameter nuclear fuel particle coater to demonstrate quality TRISO fuel production on a small industrial scale. Scale-up from the laboratory-scale coater faced challenges associated with an increase in the kernel charge mass, kernel diameter, and a redesign of the gas distributor to achieve adequate fluidization throughout the deposition of the four TRISO coating layers. TRISO coatings are applied at very high temperatures in atmospheres of dense particulate clouds, corrosive gases, and hydrogen concentrations over 45% by volume. The severe environment, stringent product and process requirements, and the fragility of partially-formed coatings limit the insertion of probes or instruments into the coater vessel during operation. Pressure instrumentation were installed on the gas inlet line and exhaust line of the 6-inch coater to monitor the bed differential pressure and internal pressure fluctuations emanating from the fuel bed as a result of bed and gas âbubbleâ movement. These instruments are external to the particle bed and provide a glimpse into the dynamics of fuel particle bed during the coating process and data that could be used to help ascertain the adequacy of fluidization and, potentially, the dominant fluidization regimes. Pressure fluctuation and differential pressure data are not presently useful as process control instruments, but data suggest a link between the pressure signal structure and some measurable product attributes that could be exploited to get an early estimate of the attribute values
HTR2008-58073 MINING PROCESS AND PRODUCT INFORMATION FROM PRESSURE FLUCTUATIONS WITHIN A FUEL PARTICLE COATER
ABSTRACT The Next Generation Nuclear Power/Advanced Gas Reactor (NGNP/AGR) Fuel Development and Qualification Program included the design, installation, and testing of a 6-inch diameter nuclear fuel particle coater to demonstrate quality TRISO fuel production on a small industrial scale. Scale-up from the laboratory-scale coater faced challenges associated with an increase in the kernel charge mass, kernel diameter, and a redesign of the gas distributor to achieve adequate fluidization throughout the deposition of the four TRISO coating layers. TRISO coatings are applied at very high temperatures in atmospheres of dense particulate clouds, corrosive gases, and hydrogen concentrations over 45% by volume. The severe environment, stringent product and process requirements, and the fragility of partially-formed coatings limit the insertion of probes or instruments into the coater vessel during operation. Pressure instrumentation were installed on the gas inlet line and exhaust line of the 6-inch coater to monitor the bed differential pressure and internal pressure fluctuations emanating from the fuel bed as a result of bed and gas "bubble" movement. These instruments are external to the particle bed and provide a glimpse into the dynamics of fuel particle bed during the coating process and data that could be used to help ascertain the adequacy of fluidization and, potentially, the dominant fluidization regimes. Pressure fluctuation and differential pressure data are not presently useful as process control instruments, but data suggest a link between the pressure signal structure and some measurable product attributes that could be exploited to get an early estimate of the attribute values
The Solar-System-Scale Disk Around AB Aurigae
The young star AB Aurigae is surrounded by a complex combination of gas-rich
and dust dominated structures. The inner disk which has not been studied
previously at sufficient resolution and imaging dynamic range seems to contain
very little gas inside a radius of least 130 astronomical units (AU) from the
star. Using adaptive-optics coronagraphy and polarimetry we have imaged the
dust in an annulus between 43 and 302 AU from the star, a region never seen
before. An azimuthal gap in an annulus of dust at a radius of 102 AU, along
with a clearing at closer radii inside this annulus, suggests the formation of
at least one small body at an orbital distance of about 100 AU. This structure
seems consistent with crude models of mean motion resonances, or accumulation
of material at two of the Lagrange points relative to the putative object and
the star. We also report a low significance detection of a point source in this
outer annulus of dust. This source may be an overdensity in the disk due to
dust accreting onto an unseen companion. An alternate interpretation suggests
that the object's mass is between 5 and 37 times the mass of Jupiter. The
results have implications for circumstellar disk dynamics and planet formation.Comment: 11 pages, 5 figures, accepted for publication in Astrophysical
Journal, V. 680, June 10, 200
Measurement of the Resonant Molecular Formation Rate in Solid HD
Measurements of muon-catalyzed dt fusion () in solid
HD have been performed. The theory describing the energy dependent resonant
molecular formation rate for the reaction + HD is
compared to experimental results in a pure solid HD target. Constraints on the
rates are inferred through the use of a Monte Carlo model developed
specifically for the experiment. From the time-of- flight analysis of fusion
events in 16 and 37 targets, an average formation rate
consistent with 0.897(0.046) (0.166) times the
theoretical prediction was obtained.Comment: 4 pages, 5 figure
Use of videotape to promote parenting of infants with serious congenital heart defects
Parents of infants with serious congenital heart defects have misconceptions and negative feelings which may threaten their ability to provide optimal care for their infant. In an effort to increase knowledge and promote a more positive, less anxious attitude among these parents, a videotape entitled `Your Baby with a Congenital Heart Defect' was developed and evaluated. Forty-three parents of thirty infants who required cardiac catherization in the first 8, weeks of life were randomly assigned to experimental (N = 23) or control (N = 20) groups. In the videotape viewed by the experimental parents, three families of cardiac infants related common feelings, problems and infant care experiences. The control group viewed a videotape describing the cardiac anatomy and functional changes associated with defects. Post-videotape questionnaires demonstrated significantly greater knowledge of the infant's behavior and needs in the experimental parents compared to controls (P P P P P = 0.02). We conclude that viewing the videotape on infant care improved parental attitude and their understanding of the behavior and needs of the neonate with congenital heart disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25644/1/0000196.pd
2008 FORUM Questions
What qualities of the helping person are needed for care in the context of fear?Are the strategies of care different when fear is all around us
Atmospheric phase correction using CARMA-PACS: high angular resolution observations of the FU Orionis star PP 13S*
We present 0".15 resolution observations of the 227 GHz continuum emission from the circumstellar disk around
the FU Orionis star PP 13S*. The data were obtained with the Combined Array for Research in Millimeter-wave
Astronomy (CARMA) Paired Antenna Calibration System (C-PACS), which measures and corrects the atmospheric
delay fluctuations on the longest baselines of the array in order to improve the sensitivity and angular resolution of
the observations. A description of the C-PACS technique and the data reduction procedures are presented. C-PACS
was applied to CARMA observations of PP 13S*, which led to a factor of 1.6 increase in the observed peak flux
of the source, a 36% reduction in the noise of the image, and a 52% decrease in the measured size of the source
major axis. The calibrated complex visibilities were fitted with a theoretical disk model to constrain the disk surface
density. The total disk mass from the best-fit model corresponds to 0.06 M_â, which is larger than the median mass of a disk around a classical T Tauri star. The disk is optically thick at a wavelength of 1.3 mm for orbital radii less than 48 AU. At larger radii, the inferred surface density of the PP 13S* disk is an order of magnitude lower than that needed to develop a gravitational instability
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