379 research outputs found
The effect of detachment and attachment to a kink motion in the asymmetric simple exclusion process
We study the dynamics of a kink in a one-lane asymmetric simple exclusion
process with detachment and attachment of the particle at arbitrary sites. For
a system with one site of detachment and attachment we find that the kink is
trapped by the site, and the probability distribution of the kink position is
described by the overdumped Fokker-Planck equation with a V-shaped potential.
Our results can be applied to the motion of a kink in arbitrary number of sites
where detachment and attachment take place. When detachment and attachment take
place at every site, we confirm that the kink motion obeys the diffusion in a
harmonic potential. We compare our results with the Monte Carlo simulation, and
check the quantitative validity of our theoretical prediction of the diffusion
constant and the potential form.Comment: 10 pages, 5 figure
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
Fabrication of Unglazed Ceramic Tile Using Dense Structured Sago Waste and Clay Composite
In Indonesia, the sago processing industry generates every year huge amount of sago waste, and converting this waste into a useful material is possible. In the present study, physical properties of dense structured sago waste and clay composite were investigated in order to study the feasibility of reuse this sample as raw material in the producing of ceramics. Firstly, the chemical composition of ash (obtained from the sago waste) and clay was characterized. The prepared sample was sintered at the temperature range from 800 to 1,200 °C using electric furnace. The density, linear shrinkage and water absorption of the sintered sample were determined by using the Archimedes' method. The experimental result indicated that the density of the sintered sample increased with increasing sintering temperature up to 1100 °C and then slightly decreased afterward. The water absorption of the products decreased with an increase in sintering temperature. In the sintered sample at 1,100 °C, the water absorption decreased rapidly and water adsorption of less than 1%was achieved. This water absorption was less than 5% which was needed for unglazed floor tile. The result of water adsorption suggest that it is possible to use this sample as a raw material for producing the ceramic floor tile
Development of Gyrotrons as Radiation Sources for Diagnostics of LHD Plasma and Their Application to Scattering Measurements
The first experiment of a THz gyrotron with a pulse magnet
A THz gyrotron with a pulse magnet has been designed, constructed and operated in FIR FU. It is developed as one of high frequency gyrotrons included in Gyrotron FU Series. The gyrotron has already achieved the first experimental result for high frequency operations whose radiation frequency exceeds 1 THz. In this paper, the design detail and the operation test results for sub-terahertz to terahertz range are described. The second harmonic operation is confirmed experimentally at the expected frequency of 1.005 THz due to TE_6,_11 cavity mode at the magnetic field intensity of 19.0 T
Traffic jams induced by rare switching events in two-lane transport
We investigate a model for driven exclusion processes where internal states are assigned to the particles. The latter account for diverse situations, ranging from spin states in spintronics to parallel lanes in intracellular or vehicular traffic. Introducing a coupling between the internal states by allowing particles to switch from one to another induces an intriguing polarization phenomenon. In a mesoscopic scaling, a rich stationary regime for the density profiles is discovered, with localized domain walls in the density profile of one of the internal states being feasible. We derive the shape of the density profiles as well as resulting phase diagrams analytically by a mean-field approximation and a continuum limit. Continuous as well as discontinuous lines of phase transition emerge, their intersections induce multi-critical behaviour
Power-law behavior in the power spectrum induced by Brownian motion of a domain wall
We show that Brownian motion of a one-dimensional domain wall in a large but
finite system yields a power spectrum. This is successfully
applied to the totally asymmetric simple exclusion process (TASEP) with open
boundaries. An excellent agreement between our theory and numerical results is
obtained in a frequency range where the domain wall motion dominates and
discreteness of the system is not effective.Comment: 4 pages, 4 figure
Parallel Coupling of Symmetric and Asymmetric Exclusion Processes
A system consisting of two parallel coupled channels where particles in one
of them follow the rules of totally asymmetric exclusion processes (TASEP) and
in another one move as in symmetric simple exclusion processes (SSEP) is
investigated theoretically. Particles interact with each other via hard-core
exclusion potential, and in the asymmetric channel they can only hop in one
direction, while on the symmetric lattice particles jump in both directions
with equal probabilities. Inter-channel transitions are also allowed at every
site of both lattices. Stationary state properties of the system are solved
exactly in the limit of strong couplings between the channels. It is shown that
strong symmetric couplings between totally asymmetric and symmetric channels
lead to an effective partially asymmetric simple exclusion process (PASEP) and
properties of both channels become almost identical. However, strong asymmetric
couplings between symmetric and asymmetric channels yield an effective TASEP
with nonzero particle flux in the asymmetric channel and zero flux on the
symmetric lattice. For intermediate strength of couplings between the lattices
a vertical cluster mean-field method is developed. This approximate approach
treats exactly particle dynamics during the vertical transitions between the
channels and it neglects the correlations along the channels. Our calculations
show that in all cases there are three stationary phases defined by particle
dynamics at entrances, at exits or in the bulk of the system, while phase
boundaries depend on the strength and symmetry of couplings between the
channels. Extensive Monte Carlo computer simulations strongly support our
theoretical predictions.Comment: 16 page
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