The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ralf Metzler - One of the best experts on this subject based on the ideXlab platform.
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aging effects and population splitting in single Particle Trajectory averages
Physical Review Letters, 2013Co-Authors: Johannes H P Schulz, Eli Barkai, Ralf MetzlerAbstract:We study time averages of single Particle trajectories in scale-free anomalous diffusion processes, in which the measurement starts at some time ta > 0 after initiation of the process at t ¼ 0. Using aging renewal theory, we show that for such nonstationary processes a large class of observables are affected by a unique aging function, which is independent of boundary conditions or the external forces. Moreover, we discuss the implications of aging induced population splitting: with growing age ta of the process, an increasing fraction of Particles remains motionless in a measurement of fixed duration. Consequences for single biomolecule tracking in live cells are discussed.
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ageing effects in single Particle Trajectory averages
arXiv: Statistical Mechanics, 2012Co-Authors: Johannes H P Schulz, Eli Barkai, Ralf MetzlerAbstract:We study time averages of single Particle trajectories in scale free anomalous diffusion processes, in which the measurement starts at some time t_a>0 after initiation of the process at the time origin, t=0. Using ageing renewal theory we show that for such non-stationary processes a large class of observables are affected by a unique ageing function, which is independent of boundary conditions or the external forces. We quantify the weakly non-ergodic nature of this process in terms of the distribution of time averages and the ergodicity breaking parameter which both explicitly depend on the ageing time t_a. Consequences for the interpretation of single Particle tracking data are discussed.
Tomohide Niimi - One of the best experts on this subject based on the ideXlab platform.
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estimation of diffusive states from single Particle Trajectory in heterogeneous medium using machine learning methods
Physical Chemistry Chemical Physics, 2018Co-Authors: Yu Matsuda, Itsuo Hanasaki, Ryo Iwao, Hiroki Yamaguchi, Tomohide NiimiAbstract:We propose a novel approach to analyze random walks in heterogeneous medium using a hybrid machine-learning method based on a gamma mixture and a hidden Markov model. A gamma mixture and a hidden Markov model respectively provide the number and the most probable sequence of diffusive states from the time series position data of Particles/molecules obtained by single-Particle/molecule tracking (SPT/SMT) method. We evaluate the performance of our proposed method for numerically generated trajectories. It is shown that our proposed method can correctly extract the number of diffusive states when each Trajectory is long enough to be frame averaged. We also indicate that our method can provide an indicator whether the assumption of a medium consisting of discrete diffusive states is appropriate or not based on the available amount of Trajectory data. Then, we demonstrate an application of our method to the analysis of experimentally obtained SPT data.
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faster convergence of diffusion anisotropy detection by three step relation of single Particle Trajectory
Analytical Chemistry, 2016Co-Authors: Yu Matsuda, Itsuo Hanasaki, Ryo Iwao, Hiroki Yamaguchi, Tomohide NiimiAbstract:We focus on the issue of limited number of samples in the single Particle tracking (SPT) when trying to extract the diffusion anisotropy that originates from the Particle asymmetry. We propose a novel evaluation technique of SPT making use of the relation of the consecutive three steps. More specifically, the trend of the angle comprised of the three positions and the displacements are plotted on a scatter diagram. The Particle anisotropy dependence of the shape of the scatter diagram is examined through the data from the standard numerical model of anisotropic two-dimensional Brownian motion. Comparison with the existing method reveals the faster convergence in the evaluation. In particular, our proposed method realizes the detection of diffusion anisotropy under the conditions of not only less number of data but also larger time steps. This is of practical importance not only when the abundant data is hard to achieve but also when the rotational diffusion is fast compared to the frame rate of the camera...
Hiroshi Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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a new charge conservation method in electromagnetic Particle in cell simulations
Computer Physics Communications, 2003Co-Authors: Takayuki Umeda, Yoshiharu Omura, T Tominaga, Hiroshi MatsumotoAbstract:Abstract We developed a fast algorithm for solving the current density satisfying the continuity equation of charge in electromagnetic Particle-in-cell (PIC) simulations. In PIC simulations of the charge conservation, a Particle Trajectory over one time step is conventionally assumed to be a straight line. In the present new scheme we assume that a Particle Trajectory is a zigzag line. Compared with the Villasenor–Buneman method and Esirkepov's method, the present scheme has an advantage in computation speed without any substantial distortion of physics.
Zhenming Xu - One of the best experts on this subject based on the ideXlab platform.
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eddy current separation technology for recycling printed circuit boards from crushed cell phones
Journal of Cleaner Production, 2017Co-Authors: Jia Li, Yiqun Jiang, Zhenming XuAbstract:Abstract Eddy Current Separation (ECS) is a classic method to separate light metal (aluminum) from plastic in the recycling industry. The aim of this paper is to present an innovative method that using the ECS to separate the printed circuit board (PCB) from the plastic generated from the crushed cell phone. A theoretical model of Particle Trajectory was established. On the basis of the computer simulation, it is found that ECS can be used to separate PCB from plastic with specific parameters. With the help of Design-Expert, the optimum separation conditions and selected operating parameters are analyzed with different velocities of feeding belt ( v ), rotating speeds of magnetic roller (ω), and radius of the Particle ( R p ). The separation gets its optimal condition ( v = 1.18 m/s, ω = 3000 rpm, R p = 8.44 mm) by model calculation. A practical experiment showed that the separation efficiency reached 95.54%.
Sunil Kumar Tripathy - One of the best experts on this subject based on the ideXlab platform.
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Particle flow modeling of dry induced roll magnetic separator
Powder Technology, 2013Co-Authors: Sunil Kumar TripathyAbstract:Abstract Magnetic separators have unrestricted industrial application and are widely used in mineral beneficiation, food, textiles, plastic and ceramic processing industry. Separation efficiency of magnetic separator depends on material characteristics and the design features of equipment along with the optimization of process variables. This study is based on a novel application of image processing technique to capture the Particle Trajectory on induced roll in an electromagnetic separator while treating magnetic Particles. Three different minerals of different magnetic susceptibility were selected to investigate this approach. Trajectories of 3 mm diameter balls of mineral fines were captured using an image analyzer at different operating conditions. The Particle Trajectory captured was compared with the Trajectory predicted by Cakir mathematical model. The separation angle between roll and Particles was considered as a separation performance measure. It was found that Cakir mathematical model produce reliable result and a new model was proposed to increase the reliability of separation angle prediction by including the Particle shape factor. The proposed model can be utilized to optimize the magnetic separation process while treating paramagnetic minerals.