395 research outputs found
Universal features of the off-equilibrium fragmentation with the Gaussian dissipation
We investigate universal features of the off-equilibrium sequential and
conservative fragmentation processes with the dissipative effects which are
simulated by the Gaussian random inactivation process. The relation between the
fragment multiplicity scaling law and the fragment size distribution is studied
and a dependence of scaling exponents on the parameters of fragmentation and
inactivation rate functions is established.Comment: 10 pages, 2 figure
Scanning the critical fluctuations -- application to the phenomenology of the two-dimensional XY-model --
We show how applying field conjugated to the order parameter, may act as a
very precise probe to explore the probability distribution function of the
order parameter. Using this `magnetic-field scanning' on large-scale numerical
simulations of the critical 2D XY-model, we are able to discard the conjectured
double-exponential form of the large-magnetization asymptote.Comment: 4 pages, 4 figure
Universal features of the order-parameter fluctuations : reversible and irreversible aggregation
We discuss the universal scaling laws of order parameter fluctuations in any
system in which the second-order critical behaviour can be identified. These
scaling laws can be derived rigorously for equilibrium systems when combined
with the finite-size scaling analysis. The relation between order parameter,
criticality and scaling law of fluctuations has been established and the
connexion between the scaling function and the critical exponents has been
found. We give examples in out-of-equilibrium aggregation models such as the
Smoluchowski kinetic equations, or of at-equilibrium Ising and percolation
models.Comment: 19 pages, 10 figure
Pseudo-critical clusterization in nuclear multifragmentation
In this contribution we show that the biggest fragment charge distribution in
central collisions of Xe+Sn leading to multifragmentation is an admixture of
two asymptotic distributions observed for the lowest and highest bombarding
energies. The evolution of the relative weights of the two components with
bombarding energy is shown to be analogous to that observed as a function of
time for the largest cluster produced in irreversible aggregation for a finite
system. We infer that the size distribution of the largest fragment in nuclear
multifragmentation is also characteristic of the time scale of the process,
which is largely determined by the onset of radial expansion in this energy
range.Comment: 4 pages, 3 figures, Contribution to conference proceedings of the
25th International Nuclear Physics Conference (INPC 2013
Order parameter fluctuations and thermodynamic phase transitions in finite spin systems and fragmenting nuclei
We show that in small and low density systems described by a lattice gas
model with fixed number of particles the location of a thermodynamic phase
transition can be detected by means of the distribution of the fluctuations
related to an order parameter which is chosen to be the size of the largest
fragment. We show the correlation between the size of the system and the
observed order of the transition. We discuss the implications of this
correlation on the analysis of experimental fragmentation data.Comment: 9 pages including 5 figures. Final version to appear in PL
Clinical Observation: Congenital Absence of the Left Portal Vein in a Patient Undergoing Hepatic Resection
Congenital absence of the left portal vein is a rare vascular anomaly with a reported prevalence varying from one in 62 to one in 507 cases. A patient admitted for recurrent cholangitis secondary to extensive dilation of the left biliary ductal system associated with Caroli's Disease was determined by preoperative dynamic CT to have an excessively large right portal vein and no left portal vein. The surgeon must be aware of any variations in portal vascular anatomy in patients undergoing hepatic resection in order to prevent potentially fatal postoperative complications
A mathematical structure for the generalization of the conventional algebra
An abstract mathematical framework is presented in this paper as a
unification of several deformed or generalized algebra proposed recently in the
context of generalized statistical theories intended to treat certain complex
thermodynamic or statistical systems. It is shown that, from mathematical point
of view, any bijective function can be used in principle to formulate an
algebra in which the conventional algebraic rules are generalized
The phase diagram of the anisotropic Spin-1 Heisenberg Chain
We applied the Density Matrix Renormalization Group to the XXZ spin-1 quantum
chain. In studing this model we aim to clarify controversials about the point
where the massive Haldane phase appears.Comment: 2 pages (standart LaTex), 1 figure (PostScript) uuencode
Diffusion-Reorganized Aggregates: Attractors in Diffusion Processes?
A process based on particle evaporation, diffusion and redeposition is
applied iteratively to a two-dimensional object of arbitrary shape. The
evolution spontaneously transforms the object morphology, converging to
branched structures. Independently of initial geometry, the structures found
after long time present fractal geometry with a fractal dimension around 1.75.
The final morphology, which constantly evolves in time, can be considered as
the dynamic attractor of this evaporation-diffusion-redeposition operator. The
ensemble of these fractal shapes can be considered to be the {\em dynamical
equilibrium} geometry of a diffusion controlled self-transformation process.Comment: 4 pages, 5 figure
Field-Induced Transition in the S=1 Antiferromagnetic Chain with Single-Ion Anisotropy in a Transverse Magnetic Field
The field-induced transition in one-dimensional S=1 Heisenberg
antiferromagnet with single-ion anisotropy in the presence of a transverse
magnetic field is obtained on the basis of the Schwinger boson mean-field
theory. The behaviors of the specific heat and susceptibility as functions of
temperature as well as the applied transverse field are explored, which are
found to be different from the results obtained under a longitudinal field. The
anomalies of the specific heat at low temperatures, which might be an
indicative of a field-induced transition from a Luttinger liquid phase to an
ordered phase, are explicitly uncovered under the transverse field. A schematic
phase diagram is proposed. The theoretical results are compared with
experimental observations.Comment: Revtex, 7 figure
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