337 research outputs found
Time-fractional kinetic equation for the non-Markovian kinetic processes
In this study, we analytically formulated the path integral representation of
the conditional probabilities for non-Markovian kinetic processes in terms of
the free energy of the thermodynamic system. We carry out analytically the
time-fractional kinetic equations for these processes. Thus, in a simple way,
we generalize path integral solutions of the Markovian to the non-Markovian
cases. We conclude that these pedagogical results can be applied to some
physical problems such as the deformed ion channels, internet networks and
non-equilibrium phase transition problems.Comment: No figur
Chaotic interactions between dark matter and dark energy
In this study, we consider dark matter and dark energy as grand-canonical
systems which are open, non-equilibrium coupled, and interacting systems. It is
the first time, we propose a new more realistic interaction schema to explain
dynamics between coupled interacting thermodynamic systems. Based on this new
interaction schema, we propose new theorems to define the interactions. We
proved the theorems based on the energy conservation law of thermodynamics.
Furthermore, we obtain new coupled equations using the theorems. We numerically
solve the interaction equations and obtained phase space diagrams and Lyapunov
exponents. We show that the interaction between dark matter and dark energy is
chaotic. We conclude that these theorems and results can be generalized to all
coupled interacting non-equilibrium systems. Finally, we give a new definition
of chaos.Comment: 7 figures, 8 page
Memory effects and KWW relaxation of the interacting magnetic nano-particles
The nano-particle systems under theoretically and experimentally
investigation because of the potential applications in the nano-technology such
as drug delivery, ferrofluids mechanics, magnetic data storage, sensors,
magnetic resonance imaging, and cancer therapy. Recently, it is reported that
interacting nano-particles behave as spin-glasses and experimentally show that
the relaxation of these systems obeys stretched exponential i.e., KWW
relaxation. Therefore, in this study, considering the interacting nano-particle
systems we model the relaxation and investigate frequency and temperature
behaviour depends on slow relaxation by using a simple operator formalism. We
show that relaxation deviates from Debye and obeys to KWW in the presence of
the memory effects in the system. Furthermore, we obtain the frequency and
temperature behaviour depend on KWW relaxation. We conclude that the obtained
results are consistent with experimental results and the simple model,
presented here, is very useful and pedagogical to discuss the slow relaxation
of the interacting nano-particles.Comment: Accepted in Physica
Rotational Brownian motion on the sphere surface and rotational relaxation
The spatial components of the autocorrelation function of noninteracting
dipoles are analytically obtained in terms of rotational Brownian motion on the
surface of a unit sphere using multi-level jumping formalism based on Debye's
rotational relaxation model, and the rotational relaxation functions are
evaluated.Comment: RevTex, 4 pages, submitted to Chin. Phys. Let
Decoherence in Two-Dimensional Quantum Random Walks with Traps
Quantum random walk in a two-dimensional lattice with randomly distributed
traps is investigated. Distributions of quantum walkers are evaluated
dynamically for the cases of Hadamard, Fourier, and Grover coins, and quantum
to classical transition is examined as a function of the density of the traps.
It is shown that traps act as a serious and additional source of quantum
decoherence. Furthermore, non-trivial temporal dependence of the standard
deviation of the probability distribution of the walker is found when the
trapping imperfections are introduced.Comment: 7 pages, 9 figure
The value of laparoscopic classifications in decision on definitive surgery in patients with nonpalpable testes: our experience and review of the literature
Background/purpose The aim of the study was to present our clinical experience with the laparoscopic approach in patients with nonpalpable testes (NPTs) and review the literature on laparoscopic classifications.Materials and methods Between May 2010 and August 2012, 30 boys with NPT (mean age 3.9 years) underwent laparoscopy as a part of diagnosis and treatment in our clinic. The laparoscopic findings were classified into four types according to Castilho. The patients were managed according to the presence or position of the testes and testicular vessels.Results Six patients were excluded from the study. Twenty-six testicular units (19 left, three right, and four bilateral units) in 24 patients were managed laparoscopically. Laparoscopy was terminated in eight patients in whom blind-ending cord structures were detected intra-abdominally. An inguinal canal exploration was performed in 10 cases in whom cord structures were seen entering the internal inguinal ring. No viable testis was found, and testicular remnants were excised for histopathologic examination. Four canalicular testes (peeping) were treated with open orchiopexy. Laparoscopy-assisted orchiopexy without vascular ligation was performed in two testes. Fowler-Stephens orchiopexy in single stage was performed in one testicular unit and in two stages in another unit. All patients were discharged on the same day. The testes were normal in size and found in the scrotum after a mean follow-up period of 14 months.Conclusion The laparoscopic findings in NPT had an important influence on treatment decisions. To be able to interpret the definitive surgery relative to the laparoscopic classification, collaborative studies are required. Keywords: laparoscopy, nonpalpable testis, nubbin, orchiopexy, vas deferen
Cooperation and defection in ghetto
We consider ghetto as a community of people ruled against their will by an
external power. Members of the community feel that their laws are broken.
However, attempts to leave ghetto makes their situation worse. We discuss the
relation of the ghetto inhabitants to the ruling power in context of their
needs, organized according to the Maslow hierarchy. Decisions how to satisfy
successive needs are undertaken in cooperation with or defection the ruling
power. This issue allows to construct the tree of decisions and to adopt the
pruning technique from the game theory. Dynamics of decisions can be described
within the formalism of fundamental equations. The result is that the strategy
of defection is stabilized by the estimated payoff.Comment: 12 pages, 2 figure
Lattice distortions in a sawtooth chain with Heisenberg and Ising bonds
An exactly solvable model of the sawtooth chain with Ising and Heisenberg
bonds and with coupling to lattice distortion for Heisenberg bonds is
considered in the magnetic field. Using the direct transfer-matrix formalism an
exact description of the thermodynamic functions is obtained. The ground state
phase diagrams for all regions of parameters values containing phases
corresponding to the magnetization plateaus at and 1/2 have been
obtained. Exact formulas for bond distortions for various ground states are
presented. A novel mechanism of magnetization plateau stabilization
corresponding to state is reported.Comment: 16 pages, 12 figure
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