4,095 research outputs found
Forgetfulness of continuous Markovian quantum channels
The notion of forgetfulness, used in discrete quantum memory channels, is
slightly weakened in order to be applied to the case of continuous channels.
This is done in the context of quantum memory channels with Markovian noise. As
a case study, we apply the notion of weak-forgetfulness to a bosonic memory
channel with additive noise. A suitable encoding and decoding unitary
transformation allows us to unravel the effects of the memory, hence the
channel capacities can be computed using known results from the memoryless
setting.Comment: 6 pages, 2 figures, comments are welcome. Minor corrections and
acknoledgment adde
First principles theory of fluctuations in vortex liquids and solids
Consistent perturbation theory for thermodynamical quantities in type II
superconductors in magnetic field at low temperatures is developed. It is
complementary to the existing expansion valid at high temperatures.
Magnetization and specific heat are calculated to two loop order and compare
well to existing Monte Carlo simulations and experiments.Comment: 3 .ps fig. In press Phys. Rev.
GAMMA-CONVERGENT PROJECTION-FREE FINITE ELEMENT METHODS FOR NEMATIC LIQUID CRYSTALS: THE ERICKSEN MODEL
The Ericksen model for nematic liquid crystals couples a director field with a scalar degree of orientation variable and allows the formation of various defects with finite energy. We propose a simple but novel finite element approximation of the problem that can be implemented easily within standard finite element packages. Our scheme is projection-free and thus circumvents the use of weakly acute meshes, which are quite restrictive in three dimensions but are required by recent algorithms for convergence. We prove stability and Γ-convergence properties of the new method in the presence of defects. We also design an effective nested gradient flow algorithm for computing minimizers that controls the violation of the unit-length constraint of the director. We present several simulations in two and three dimensions that document the performance of the proposed scheme and its ability to capture quite intriguing defects
Tricalcium phosphate endosseous implants in dentistry: ultrastructural findings
β-Tricalcium phosphate magnesium substitued (β-TCMP), consisting of one part small unsintered and one part large sintered granules was placed in upper and lower jaw surgical cavities of monkeys. At light and transmission electron microscope the biopsies taken at 2, 4, 8 and 24 weeks showed that both sintered and unsintered granules were well tolerated by the host tissue and result biodegradable over time.β-TCMP may stimulate the direction of bone growth enhancing osteoblasts activity and new bone deposition in direct contact and in the micropores of the biomaterial. β-TCMP containing Mg ions reabsorbs slowly when in sintered granules form and rapidly as unsintered granules. When it is placed in bone cavities, if bone reabsorption is biologically necessary, the biomaterial can be reabsorbed with bone, while if osteogenesis is required β-TCMP provides a more durable matrix to support new bone growth.Le β-phosphate tricalcique contenant à ions Mg (β-TCMP) et constitué à parts égales de fins granules non frittés et de larges granules frittés, est introduit dans des cavités chirurgicales pratiquées dans les maxillaires supérieurs et inférieurs de singes.Des biopsies pratiquées à 2, 4, 8 et 24 semaines ont été examinées au microscope optique et électronique à transmission.Les granules frittés et non frittés sont bien tolérés par les tissus hôtes et sont biodégradés avec le temps.Les observations histologiques montrent aussi que le β-TCMP peut orienter la direction de la croissance osseuse en stimulant l’activité des ostéoblastes et le dépôt d’os nouveau aussi bien autour des biomatériaux que dans leur micropores. Le β-TCMP contenant les ions Mg est réabsorbé lentement lorsqu’il se présente sous la forme de granules frittés, et rapidement lorsqu’il est sous la forme de granules non frittés.Lorsqu’il est introduit dans les cavités osseuses, si la réabsorption osseuse est biologiquement nécessaire, le biomatériau peut être réabsorbé avec l’os, tandis que si c’est l’ostéogenèse qui est sollicitée, β-TCMP fournit une matrice durable comme support à la croissance d’os nouveau
Divergence-type 2+1 dissipative hydrodynamics applied to heavy-ion collisions
We apply divergence-type theory (DTT) dissipative hydrodynamics to study the
2+1 space-time evolution of the fireball created in Au+Au relativistic
heavy-ion collisions at 200 GeV. DTTs are exact hydrodynamic
theories that do no rely on velocity gradient expansions and therefore go
beyond second-order theories. We numerically solve the equations of motion of
the DTT for Glauber initial conditions and compare the results with those of
second-order theory based on conformal invariants (BRSS) and with data. We find
that the charged-hadron minumum-bias elliptic flow reaches its maximum value at
lower in the DTT, and that the DTT allows for a value of
slightly larger than that of the BRSS. Our results show that the differences
between viscous hydrodynamic formalisms are a significant source of uncertainty
in the precise extraction of from experiments.Comment: v4: 29 pages, 12 figures, minor changes. Final version as published
in Phys. Rev.
Signature region within the 16S rDNA sequences of Aeromonas popoffii
To identify a group of eight Aeromonas strains of our collection showing ribotyping patterns similar to those described for the species Aeromonas popoffii, 16S rRNA gene sequence analysis was performed. Results were in agreement with the DNA binding values, and allowed the identification of a ‘signature region' differentiating the A. popoffii strains from all other members of the genus Aeromona
Explaining potentially unfair clauses to the consumer with the claudette tool
This paper presents the latest developments of the use of memory network models in detecting and explaining unfair terms in online consumer contracts. We extend the CLAUDETTE tool for the detection of potentially unfair clauses in online Terms of Service, by providing to the users the explanations of unfairness (legal rationales) for five different categories: Arbitration, unilateral change, content removal, unilateral termination, and limitation of liability
Plastic energies in layered superconductors
We estimate the energy cost associated with two pancake vortices colliding in
a layered superconductor. It is argued that this energy sets the plastics
energy scale and is the analogue of the crossing energy for vortices in the
continuum case. The starting point of the calculation is the Lawrence-Doniach
version of the Ginzburg-Landau free energy for type-II superconductors. The
magnetic fields considered are along the c-direction and assumed to be
sufficiently high that the lowest Landau level approximation is valid. For
Bi-2212, where it is know that layering is very important, the results are
radically different from what would have been obtained using a
three-dimensional anisotropic continuum model. We then use the plastic energy
for Bi-2212 to successfully explain recent results from Hellerqvist {\em et
al.}\ on its longitudinal resistance.Comment: 5 Pages Revtex, 4 uuencoded postscript figure
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