1,004 research outputs found
Conformal Turbulence with Boundary
Based upon the formalism of conformal field theory with a boundary, we give a
description of the boundary effect on fully developed two dimensional
turbulence. Exact one and two point velocity correlation functions and energy
power spectrum confined in the upper half plane are obtained using the image
method. This result enables us to address the infrared problem of the theory of
conformal turbulence.Comment: 10pages, KHTP-93-01, SNUCTP-93-0
Duality in Complex sine-Gordon Theory
New aspects of the complex sine-Gordon theory are addressed through the
reformulation of the theory in terms of the gauged Wess-Zumino-Witten action. A
dual transformation between the theory for the coupling constant \b > 0 and
the theory for \b < 0 is given which agrees with the Krammers-Wannier duality
in the context of perturbed conformal field theory. The B\"{a}cklund transform
and the nonlinear superposition rule for the complex sine-Gordon theory are
presented and from which, exact solutions, solitons and breathers with U(1)
charge, are derived. We clarify topological and nontopological nature of
neutral and charged solitons respectively, and discuss about the duality
between the vector and the axial U(1) charges.Comment: 10 pages, LaTe
Deformed Minimal Models and Generalized Toda Theory
We introduce a generalization of -type Toda theory based on a
non-abelian group G, which we call the -Toda theory, and its affine
extensions in terms of gauged Wess-Zumino-Witten actions with deformation
terms. In particular, the affine -Toda theory describes the
integrable deformation of the minimal conformal theory for the critical Ising
model by the operator . We derive infinite conserved charges and
soliton solutions from the Lax pair of the affine -Toda theory.
Another type of integrable deformation which accounts for the
-deformation of the minimal model is also found in the gauged
Wess-Zumino-Witten context and its infinite conserved charges are given.Comment: 11pages, SNUCTP 94-83 (One reference has been added.
Classical Matrix sine-Gordon Theory
The matrix sine-Gordon theory, a matrix generalization of the well-known
sine-Gordon theory, is studied. In particular, the -generalization where
fields take value in describes integrable deformations of conformal
field theory corresponding to the coset . Various
classical aspects of the matrix sine-Gordon theory are addressed. We find exact
solutions, solitons and breathers which generalize those of the sine-Gordon
theory with internal degrees of freedom, by applying the Zakharov-Shabat
dressing method and explain their physical properties. Infinite current
conservation laws and the B\"{a}cklund transformation of the theory are
obtained from the zero curvature formalism of the equation of motion. From the
B\"{a}cklund transformation, we also derive exact solutions as well as a
nonlinear superposition principle by making use of the Bianchi's permutability
theorem.Comment: 25 pages, 6 Postscript figure
A Comparison of the Effects of Sevoflurane and Desflurane on Corrected QT Interval Prolongation in Patients Undergoing Living Donor Liver Transplantation: A Prospective Observational Study
AbstractBackgroundQT interval prolongation has frequently been observed in patients with advanced liver disease. We investigated the influence of inhalation anesthetics on the corrected QT (QTc) interval prolongation during surgery in patients undergoing living-donor liver transplantation.MethodsOur study included 43 patients who were assigned to 2 groups: sevoflurane (n = 22) or desflurane anesthesia (n = 21). QTc intervals were measured at perioperative determined time points and calculated using Fridericia's formula.ResultsIntraoperative QTc intervals increased during the peri-intubation period versus baseline (P = .003) and were prolonged during the peri-reperfusion period (P < .001). However, there was no significant difference in intraoperative QTc interval changes between patients given sevoflurane or desflurane (P = .59).ConclusionsIn this prospective observational study, there was no significant difference in QTc intervals between sevoflurane and desflurane. QTc intervals increased during intubation and reperfusion relative to preoperative values in patients given either sevoflurane or desflurane
Path Integral Bosonization of Massive GNO Fermions
We show the quantum equivalence between certain symmetric space sine-Gordon
models and the massive free fermions. In the massless limit, these fermions
reduce to the free fermions introduced by Goddard, Nahm and Olive (GNO) in
association with symmetric spaces . A path integral formulation is given
in terms of the Wess-Zumino-Witten action where the field variable takes
value in the orthogonal, unitary, and symplectic representations of the group
in the basis of the symmetric space. We show that, for example, such a path
integral bosonization is possible when the symmetric spaces are or . We also address the
relation between massive GNO fermions and the nonabelian solitons, and explain
the restriction imposed on the fermion mass matrix due to the integrability of
the bosonic model.Comment: 11 page
Vortex String Dynamics in an External Antisymmetric Tensor Field
We study the Lund-Regge equation that governs the motion of strings in a
constant background antisymmetric tensor field by using the duality between the
Lund-Regge equation and the complex sine-Gordon equation. Similar to the cases
of vortex filament configurations in fluid dynamics, we find various exact
solitonic string configurations which are the analogue of the Kelvin wave, the
Hasimoto soliton and the smoke ring. In particular, using the duality relation,
we obtain a completely new type of configuration which corresponds to the
breather of the complex sine-Gordon equation.Comment: 20 pages, 9 figure
qqqbar to qqqbar and qqbarqbar to qqbarqbar Elastic Scatterings and Thermalization of Quark Matter and Antiquark Matter
Thermalization of quark matter and antiquark matter is studied with
quark-quark-antiquark as well as quark-antiquark-antiquark elastic scatterings.
Squared amplitudes of qqqbar to qqqbar and qqbarqbar to qqbarqbar at order
alpha_s^4 are derived in perturbative QCD. Solved by a new technique, solutions
of transport equations with the squared amplitudes indicate that the
scatterings qqqbar to qqqbar and qqbarqbar to qqbarqbar shorten the
thermalization time of quark matter and antiquark matter. It is emphasized that
three-parton and other multi-parton scatterings become important at the high
parton number density achieved in RHIC Au-Au collisions.Comment: 14 pages, 5 figures, Late
Broilers fed a low protein diet supplemented with synthetic amino acids maintained growth performance and retained intestinal integrity while reducing nitrogen excretion when raised under poor sanitary conditions
The present study investigated the effects of supplementing a low protein (LP) diet supplemented with key essential amino acids (AA) to broilers on growth performance, intestinal tract function, blood metabolites, and nitrogen excretion when the animals were maintained under various sanitary conditions for 35 D after hatching. Three hundred eighty-four one-day-old male broilers (Ross 308) were randomly allotted to groups that received one of 6 dietary treatments in a 2 Ă— 3 factorial arrangement (i.e., 2 environmental conditions and 3 dietary treatments) to give 8 replicates per treatment. Broilers were challenged with 2 environmental conditions (sanitary vs. poor sanitary). The dietary treatments were (1) high protein (HP) diet, (2) LP diet, and (3) LP diet with synthetic key essential AA (LPA): the LP diet was supplemented with synthetic AA up to the required levels for broilers. On day 14, birds consumed the LP diet impaired growth performance compared with those fed the HP diet, while the average daily weight gain-to-feed conversion ratio of birds fed the LPA diet improved to the level of birds fed the HP diet under poor sanitary conditions (P < 0.05). Broilers raised under poor sanitary conditions and fed the LP diet displayed higher (P < 0.05) zonula occludens (ZO-1) expression on day 14 than broilers fed either the HP or LPA diet. Under sanitary conditions, birds fed HP and LPA diets showed higher villus height and crypt depth compared with those of broilers fed the LP diet on day 35. Moreover, broilers raised in the poor sanitary environment had higher (P < 0.05) serum endotoxins than those raised in the sanitary environment. Broilers fed the LPA diet showed reduced (P < 0.05) nitrogen excretion on days 14 and 35 compared with those fed the LP and HP diets independent of the environment. In conclusion, the LPA diet did not impair growth performance under poor sanitary conditions for 14 D after hatch while resulting in lower nitrogen excretion in any environment conditions throughout the experiment
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An ultrafast x-ray detector system at an elliptically polarizingundulator beamline
An ultrafast x-ray detector system is under development atLawrence Berkeley National Laboratory (LBNL) for application primarily tostudyies of ultrafast magnetization dynamics. The system consists of a fslaser, an x-ray streak camera and an ellipitically polarization undulator(EPU) beamline. Polarized x-rays from an EPU can be used to measure x-raymagnetic circular dichroism (XMCD) of a sample. XMCD has the uniqueability to independently measure orbit and spin magnetization withsub-monolayer sensitivity and element specificity. The streak camera hassimultaneously a sub-picosecond temporal resolution and a high spatialresolution. The combination of the streak camera and EPU allows us tostudy the transfer of angular momentum from spin to orbit to the latticein the sample on an ultrafast time scale. We describe here theperformance of the ultrafast detector, the laser and the x-raysynchronization system. The observation of the demagnetization process ofdifferent samples demonstrates the ability of the apparatus
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