846 research outputs found
Balance network of asymmetric simple exclusion process
We investigate a balance network of the asymmetric simple exclusion process
(ASEP). Subsystems consisting of ASEPs are connected by bidirectional links
with each other, which results in balance between every pair of subsystems. The
network includes some specific important cases discussed in earlier works such
as the ASEP with the Langmuir kinetics, multiple lanes and finite reservoirs.
Probability distributions of particles in the steady state are exactly given in
factorized forms according to their balance properties. Although the system has
nonequilibrium parts, the expressions are well described in a framework of
statistical mechanics based on equilibrium states. Moreover, the overall
argument does not depend on the network structures, and the knowledge obtained
in this work is applicable to a broad range of problems
Controversy in the Management of Cholangitis Secondary to Hydatid Daughter Cysts
A 36 year old Cypriot woman, resident in the U.K. since the age of three years, presented with pyrexia,
jaundice and upper abdominal pain. On ultrasound examination the biliary tree was dilated, contained
sludge and a cystic lesion was present in the liver. An endoscopic cholangiogram showed multiple filling
defects in the bile duct which were not felt to be removable endoscopically and a nasobiliary drain was
therefore inserted. On resolution of the cholangitis with drainage and antibiotics a laparotomy was
performed. The right lobe of the liver was largely replaced by a multiloculated cyst and the bile duct
contained multiple hydatid daughter cysts. A right hepatectomy was performed with t-tube drainage of
the evacuated bile duct. She made an uneventful recovery and has had no problems on subsequent
follow up. Histology confirmed an intrabiliary rupture of a hydatid liver cyst
Probing the Shape of Quantum Dots with Magnetic Fields
A tool for the identification of the shape of quantum dots is developed. By
preparing a two-electron quantum dot, the response of the low-lying excited
states to a homogeneous magnetic field, i.e. their spin and parity
oscillations, is studied for a large variety of dot shapes. For any geometric
configuration of the confinement we encounter characteristic spin singlet -
triplet crossovers. The magnetization is shown to be a complementary tool for
probing the shape of the dot.Comment: 11 pages, 4 figure
Full Quantum Analysis of Two-Photon Absorption Using Two-Photon Wavefunction: Comparison with One-Photon Absorption
For dissipation-free photon-photon interaction at the single photon level, we
analyze one-photon transition and two-photon transition induced by photon pairs
in three-level atoms using two-photon wavefunctions. We show that the
two-photon absorption can be substantially enhanced by adjusting the time
correlation of photon pairs. We study two typical cases: Gaussian wavefunction
and rectangular wavefunction. In the latter, we find that under special
conditions one-photon transition is completely suppressed while the high
probability of two-photon transition is maintained.Comment: 6 pages, 4 figure
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