264 research outputs found

    Stochastic Energetics for Non-Gaussian Processes

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    By introducing a new stochastic integral, we investigate the energetics of classical stochastic systems driven by non-Gaussian white noises. In particular, we introduce a decomposition of the total-energy difference into the work and the heat for each trajectory, and derive a formula to calculate the heat from experimental data on the dynamics. We apply our formulation and results to a Langevin system driven by a Poisson noise

    Minimal Model of Stochastic Athermal Systems: Origin of Non-Gaussian Noise

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    For a wide class of stochastic athermal systems, we derive Langevin-like equations driven by non-Gaussian noise, starting from master equations and developing a new asymptotic expansion. We found an explicit condition whereby the non-Gaussian properties of the athermal noise become dominant for tracer particles associated with both thermal and athermal environments. Furthermore, we derive an inverse formula to infer microscopic properties of the athermal bath from the statistics of the tracer particle. We apply our formulation to a granular motor under viscous friction, and analytically obtain the angular velocity distribution function. Our theory demonstrates that the non-Gaussian Langevin equation is the minimal model of athermal systems.Comment: 10 pages, 5 figure

    Energetics of active fluctuations in living cells

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    The nonequilibrium activity taking place in a living cell can be monitored with a tracer embedded in the medium. While microrheology experiments based on optical manipulation of such probes have become increasingly standard, we put forward a number of experiments with alternative protocols that, we claim, will provide new insight into the energetics of active fluctuations. These are based on either performing thermodynamic--like cycles in control-parameter space, or on determining response to external perturbations of the confining trap beyond simple translation. We illustrate our proposals on an active itinerant Brownian oscillator modeling the dynamics of a probe embedded in a living medium

    Heat conduction induced by non-Gaussian athermal fluctuations

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    We study the properties of heat conduction induced by non-Gaussian noises from athermal environments. We find that new terms should be added to the conventional Fourier law and the fluctuation theorem for the heat current, where its average and fluctuation are determined not only by the noise intensities but also by the non-Gaussian nature of the noises. Our results explicitly show the absence of the zeroth law of thermodynamics in athermal systems.Comment: 15 pages, 4 figures, PRE in pres

    Waveform simulation based on 3D dose distribution for acoustic wave generated by proton beam irradiation

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    A pulsed proton beam is capable of generating an acoustic wave when it is absorbed by a medium. This phenomenon suggests that the acoustic waveform produced may well include information on the three-dimensional (3D) dose distribution of the proton beam. We simulated acoustic waveforms by using a transmission model based on the Green function and the 3D dose distribution. There was reasonable agreement between the calculated and measured results. The results obtained confirm that the acoustic waveform includes information on the dose distribution

    In-Site and Model Experiments About Ground Vibration Isolation Method by Using Scrap Tire

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    It is examined by using the structure that a steel pipe pile and a PHC stake were arranged in the central part of the scrap tire. A consideration from full-size field experiment and the model experiment was done by this paper to examine a vibration decline character as propagation route countermeasure method of the ground vibration by the isolation wall which a scrap tire was used for

    A Few Considerations about the Property of Ground Vibration Generated by Pile Driving and Its Isolation Methods

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    This paper presents the results of two field studies conducted on pile driving ground vibration at Toyota Junction on the Second Tomei High-Speed Motorway in Aich prefecture and at a thermal power plant in Chiba prefecture, both of which were under construction. Fathemore, these were compared of a number of different barriers, including open trenches, concrete walls, EPS walls and sheet-pile walls, to isolate ground vibration
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