Directional transport of active particles in the two-dimensional asymmetric ratchet potential field

2020 ◽  
Vol 34 (12) ◽  
pp. 2050125 ◽  
Author(s):  
Yu-Qing Wang ◽  
Cheng Huang ◽  
Chao-Fan Zhou ◽  
Chang Xu ◽  
Sheng-Jie Qiang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Potential Field ◽  
Statistical Physics ◽  
The Self ◽  
Critical Parameters ◽  
Two Dimensional ◽  
Active Particles ◽  
Brownian Particles ◽  
Directional Transport ◽  
Ratchet Potential

Relationship between matter and energy transport has always been one of the key issues that researchers have been searching for in statistical physics and complexity science. In many transport phenomena, the active transport with zero or even no external force in life activities has attracted extensive attention of scholars. As a special kind of active particles, active Brownian particles have received the attention of physicists and biophysicists. These active particles are natural or artificially designed particles, whose scale is in the order of micrometer or nanometer. Different from the traditional passive Brownian particles driven by the equilibrium heat wave generated by the random collision of the surrounding fluid molecules, active Brownian particles can extract energy from their own environment to drive their own motion. Here, directional transport process of active particles in the two-dimensional asymmetric ratchet potential field is analyzed. Both the overdamped medium and the critically damped one are emphasized. Langevin equations with inertia term are introduced to describe the impacts of the self-driven force, friction coefficient, etc. on the directional motion. Then, the average particle speed is found. Thereafter, the relationships between the speed and critical parameters like self-driven force, friction coefficient, etc. are obtained. Two different dynamical domination mechanisms are found, which are expressed as the random collision domination and the self-driven force domination, respectively. Furthermore, the random collision domination is found to correspond to the much higher peak of the two-dimensional asymmetric Brownian rachet potential field, while the self-driven force domination is found to correspond to the much lower peak of the introduced potential. The study will be helpful for discovering the stochastic thermodynamics mechanisms in nonlinear dynamics and nonlinear properties of such multibody interaction system in statistical physics and complex system science.

CALCULATION OF THE DEPENDENCE OF THE DISTANCE TO THE LOCATED OBJECT FROM THE CORNER POSITION OF THE VEHICLE LINE

2018 ◽  
pp. 14-18
Author(s):  
V. V. Artyushenko ◽  
A. V. Nikulin
Keyword(s):  
Real Time ◽  
Statistical Physics ◽  
Angular Position ◽  
Three Dimensional ◽  
Line Of Sight ◽  
Two Dimensional ◽  
Radar Station ◽  
Flight Mode ◽  
Vector Algebra ◽  
Analytical Expressions

To simulate echoes from the earth’s surface in the low flight mode, it is necessary to reproduce reliably the delayed reflected sounding signal of the radar in real time. For this, it is necessary to be able to calculate accurately and quickly the dependence of the distance to the object being measured from the angular position of the line of sight of the radar station. Obviously, the simplest expressions for calculating the range can be obtained for a segment or a plane. In the text of the article, analytical expressions for the calculation of range for two-dimensional and three-dimensional cases are obtained. Methods of statistical physics, vector algebra, and the theory of the radar of extended objects were used. Since the calculation of the dependence of the range of the object to the target from the angular position of the line of sight is carried out on the analytical expressions found in the paper, the result obtained is accurate, and due to the relative simplicity of the expressions obtained, the calculation does not require much time.

scholarly journals Circular quiver gauge theories, isomonodromic deformations and $$W_N$$ fermions on the torus

2021 ◽  
Vol 111 (3) ◽  
Author(s):  
Giulio Bonelli ◽  
Fabrizio Del Monte ◽  
Pavlo Gavrylenko ◽  
Alessandro Tanzini
Keyword(s):  
Integrable System ◽  
Gauge Theories ◽  
The Self ◽  
Free Fermion ◽  
Two Dimensional ◽  
Isomonodromic Deformation ◽  
Specific Time ◽  
Dimensional Torus ◽  
Isomonodromic Deformations ◽  
Deformation Problem

AbstractWe study the relation between class $$\mathcal {S}$$ S theories on punctured tori and isomonodromic deformations of flat SL(N) connections on the two-dimensional torus with punctures. Turning on the self-dual $$\Omega $$ Ω -background corresponds to a deautonomization of the Seiberg–Witten integrable system which implies a specific time dependence in its Hamiltonians. We show that the corresponding $$\tau $$ τ -function is proportional to the dual gauge theory partition function, the proportionality factor being a nontrivial function of the solution of the deautonomized Seiberg–Witten integrable system. This is obtained by mapping the isomonodromic deformation problem to $$W_N$$ W N free fermion correlators on the torus.

scholarly journals Universality class of the motility-induced critical point in large scale off-lattice simulations of active particles.

Soft Matter ◽  
2021 ◽  
Author(s):  
Claudio Maggi ◽  
Matteo Paoluzzi ◽  
Andrea Crisanti ◽  
Emanuela Zaccarelli ◽  
Nicoletta Gnan
Keyword(s):  
Phase Separation ◽  
Critical Point ◽  
Computer Simulations ◽  
Large Scale ◽  
Universality Class ◽  
Critical Behaviour ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Active Particles ◽  
Two Dimensional Model

We perform large-scale computer simulations of an off-lattice two-dimensional model of active particles undergoing a motility-induced phase separation (MIPS) to investigate the systems critical behaviour close to the critical point...

PSS Business Case Map: Supporting Idea Generation in PSS Design

2012 ◽  
Author(s):  
Fumiya Akasaka ◽  
Kazuki Fujita ◽  
Yoshiki Shimomura
Keyword(s):  
Idea Generation ◽  
Business Case ◽  
Literature Survey ◽  
The Self ◽  
High Dimensional ◽  
Self Organizing Map ◽  
Two Dimensional ◽  
Service Type ◽  
Business Cases ◽  
Low Dimensional

This paper proposes the PSS Business Case Map as a tool to support designers’ idea generation in PSS design. The map visualizes the similarities among PSS business cases in a two-dimensional diagram. To make the map, PSS business cases are first collected by conducting, for example, a literature survey. The collected business cases are then classified from multiple aspects that characterize each case such as its product type, service type, target customer, and so on. Based on the results of this classification, the similarities among the cases are calculated and visualized by using the Self-Organizing Map (SOM) technique. A SOM is a type of artificial neural network that is trained using unsupervised learning to produce a low-dimensional (typically two-dimensional) view from high-dimensional data. The visualization result is offered to designers in a form of a two-dimensional map, which is called the PSS Business Case Map. By using the map, designers can figure out the position of their current business and can acquire ideas for the servitization of their business.

The Influence of the Addition of Ti on the Mechanical Properties of W-S-Ti Coatings

2006 ◽  
Vol 514-516 ◽  
pp. 687-691 ◽  
Author(s):  
Manuel Evaristo ◽  
Ana Nossa ◽  
Albano Cavaleiro
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Tribological Performance ◽  
The Self ◽  
Wear Coefficient ◽  
Gradual Loss ◽  
Order Of Magnitude ◽  
Amorphous Structures ◽  
Ti Content ◽  
Ti Films

In this work, W-S-Ti films were deposited by r.f. magnetron sputtering, using simultaneously WS2 and Ti targets. The atomic percentage of Ti in the coating was varied from 0 at.% up to 28 at.%. No significant variations in the S/W ratio with the increase of Ti content were observed. The increasing Ti contents in the films led to a gradual loss of crystallinity. Coatings with contents greater than ≈ 16 at.% only presents a broad peak characteristic of amorphous structures. Alloying the films with Ti led to significant improvements in the hardness (from 0.3 to 8.9 GPa). Also, the adhesive critical load continuously grew with the increase of the Ti content in the films. The wear coefficient of the films dropped more than one order of magnitude with the increase of Ti content whereas the friction coefficient was kept fairly constant with just a small increase in relation to single W-S film. In conclusion, to have a good tribological performance, the addition of Ti to the films should be balanced in order that the increase of the mechanical properties does not lead to severe loss of the self-lubricant properties.

PRELIMINARY STUDY ON NOVEL BEAM-TO-COLUMN CONNECTION BASED ON SMA PLATE

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Michael CH Yam ◽  
Ke Ke ◽  
Ping Zhang ◽  
Qingyang Zhao
Keyword(s):  
Friction Coefficient ◽  
Energy Dissipation ◽  
Numerical Study ◽  
Numerical Models ◽  
Numerical Technique ◽  
The Self ◽  
Hysteretic Behavior ◽  
The Novel ◽  
Energy Dissipation Capacity ◽  
Preliminary Study

A novel beam-to-column connection equipped with shape memory alloy (SMA) plates has been proposed to realize resilient performance under low-to-medium seismic actions. In this conference paper, the detailed 3D numerical technique calibrated by the previous paper is adopted to examine the hysteretic behavior of the novel connection. A parametric study covering a reasonable range of parameters including the thickness of the SMA plate, friction coefficient between SMA plate and beam flange and pre-load of the bolt was carried out and the influence of the parameters was characterized. In addition, the effect of the SMA Belleville washer on the connection performance was also studied. The results of the numerical study showed that the initial connection stiffness and the energy-dissipation capacity of the novel connection can be enhanced with the increase of the thickness of the SMA plate. In addition, the initial connection stiffness and energy-dissipation behavior of the novel connection can be improved by increasing the friction coefficient or pre-load of bolts, whereas the increased friction level could compromise the self-centering behavior of the connection. The hysteretic curves of the numerical models of the connection also implied that the SMA washers may contribute to optimizing the connection behavior by increasing the connection stiffness and energy-dissipation capacity without sacrificing the self-centering behavior.

Theoretical Tire Model Considering Two-Dimensional Contact Patch for Force and Moment

2021 ◽  
Author(s):  
Y. Nakajima ◽  
S. Hidano
Keyword(s):  
Finite Element Method ◽  
Shear Force ◽  
The Self ◽  
Slip Angle ◽  
Force Distribution ◽  
Two Dimensional ◽  
Tire Model ◽  
Side Force ◽  
Contact Patch ◽  
Proposed Model

ABSTRACT The new theoretical tire model for force and moment has been developed by considering a two-dimensional contact patch of a tire with rib pattern. The force and moment are compared with the calculation by finite element method (FEM). The side force predicted by the theoretical tire model is somewhat undervalued as compared with the FEM calculation, while the self-aligning torque predicted by the theoretical tire model agrees well with the FEM calculation. The shear force distribution in a two-dimensional contact patch under slip angle predicted by the proposed model qualitatively agrees with the FEM calculation. Furthermore, the distribution of the adhesion region and sliding region in a two-dimensional contact patch predicted by the theoretical tire model qualitatively agrees with the FEM calculation.

Viscous Friction Effect During the Process of Tightening and Loosening of Bolted Joints

2021 ◽  
Author(s):  
Qingyuan Lin ◽  
Yong Zhao ◽  
Qingchao Sun ◽  
Kunyong Chen
Keyword(s):  
Friction Coefficient ◽  
Viscous Friction ◽  
Normal Pressure ◽  
Friction Model ◽  
Bolted Joints ◽  
Critical Parameters ◽  
Bolted Joint ◽  
Sliding Velocity ◽  
Friction Effect ◽  
Bearing Friction

Abstract Bolted connection is one of the most widely used mechanical connections because of its easiness of installation and disassembly. Research of bolted joints mainly focuses on two aspects: high precision tightening and improvement of anti-loosening performance. The under-head bearing friction coefficient and the thread friction coefficient are the two most important parameters that affect the tightening result of the bolted joint. They are also the most critical parameters that affect the anti-loosening performance of the bolted joint. Coulomb friction model is a commonly used model to describe under-head bearing friction and thread friction, which considers the friction coefficient as a constant independent of normal pressure and relative sliding velocity. In this paper, the viscous effect of the under-head bearing friction and thread friction is observed by measuring the friction coefficient of bolted joints. The value of the friction coefficient increases with the increase of the relative sliding velocity and the decrease of the normal pressure. It is found that the Coulomb viscous friction model can better describe the friction coefficient of bolted joints. Taking into account the dense friction effect, the loosening prediction model of bolted joints is modified. The experimental results show that the Coulomb viscous friction model can better describe the under-head bearing friction coefficient and thread friction coefficient. The model considering the dense effect can more accurately predict the loosening characteristics of bolted joints.

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