Article
Physics, Fluids & Plasmas
Sandipan Dutta
Summary: Fluctuations are important in stochastic system dynamics, especially in small systems where the most probable thermodynamic quantities differ from their averages. This study analyzes the most probable paths for nonequilibrium systems, particularly active Ornstein-Uhlenbeck particles, using the Onsager Machlup variational formalism, and investigates the difference between entropy production along these paths and the average entropy production. It explores how much information about their nonequilibrium nature can be obtained from extremum paths and how these paths are influenced by persistence time and swim velocities. Additionally, it examines how active noise affects entropy production along the most probable paths and how it differs from average entropy production. This research is valuable for designing artificial active systems with specific target trajectories.
Article
Chemistry, Physical
Myeonggon Park, Kisung Lee, Steve Granick
Summary: We experimentally investigated the influence of enclosed active matter on the shape fluctuations of vesicles using the Takatori-Sahu model. Our results showed that collective motion patterns, such as vortex flow, dipolar flow, and chaotic motion, have an impact on the shape of vesicles. The Takatori-Sahu model generalized well in this situation when the size of the collectively-moving flock was considered.
Article
Physics, Fluids & Plasmas
Pavel Sasorov, Arkady Vilenkin, Naftali R. Smith
Summary: The Brownian bees model describes a collection of N independent branching Brownian particles. The density of the particles is governed by a reaction-diffusion equation. The particle density approaches a symmetric steady-state solution at long times, but fluctuates at finite N values.
Article
Multidisciplinary Sciences
Timofey Kozhukhov, Tyler N. Shendruk
Summary: Coarse-grained, mesoscale simulations are essential for studying soft condensed matter. We introduce an algorithm to simulate active nematics, which can model complex systems in an active medium. The method exhibits the key characteristics of active nematic turbulence and active particle models.
Article
Chemistry, Physical
Yann-Edwin Keta, Rituparno Mandal, Peter Sollich, Robert L. Jack, Ludovic Berthier
Summary: In this study, we simulate the dynamics of dense assemblies of self-propelled particles with extremely large but finite persistence times. The system undergoes intermittent evolution between mechanical equilibria and active force balance, leading to elastic and plastic relaxation events. These events are scale-free and dependent on system size, and the correlations between plastic events result in emergent dynamic facilitation and heterogeneous relaxation dynamics.
Article
Chemistry, Physical
Lasse Bonn, Aleksandra Ardaseva, Amin Doostmohammadi
Summary: Mechanical stress is associated with biological functionalities, and topological defects are points of localized mechanical stress. Simulation results show that increasing material elasticity changes the stress pattern around topological defects. Elastic anisotropy alters the extent and intensity of stresses, leading to dominance of tension or compression around defects.
Article
Chemistry, Physical
Timo Krueger, Ivan Maryshev, Erwin Frey
Summary: Topological defects play a central role in the formation and organization of various biological systems. In this paper, agent-based simulations are used to study phase-separated active nematics and the formation of -1/2 defects. The authors investigate the morphology and characteristics of these defects, as well as observe and characterize lateral arc-like structures separating from nematic bands. The study also introduces a hydrodynamic theory that explains the emergence of defects and arcs.
Article
Chemistry, Physical
S. Zhou
Summary: By combining classical density functional theory with modified interfacial statistical associating fluid theory, this study investigates the novel properties of surface electrostatic force (SEF) induced by dimer counter-ions. The results show that the SEF exhibits different attractive and repulsive features under varying conditions.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Physics, Fluids & Plasmas
Wei Zhou, Jaquelin Dezha Peralta, Zhuonan Hao, Nick Gravish
Summary: Studied the effect of contact interactions on the planar configurations of undulatory swimmers. Found that varying the phase relationship drives neighboring swimmers into stable equilibrium configurations. Proposed a compatibility model to describe this behavior.
Article
Physics, Multidisciplinary
Liam J. Ruske, Julia M. Yeomans
Summary: This study numerically investigates the morphology and disclination line dynamics of active nematic droplets in three dimensions, revealing a wide range of complex behaviors. The interaction between active anchoring, active flows, and the dynamics of the motile disclination lines are found to explain the diversity of behavior observed. The findings suggest that some biological systems may share the same underlying mechanisms as active nematic droplets, providing insights into processes such as morphogenesis and collective cancer invasion.
Article
Physics, Fluids & Plasmas
Harsh Soni
Summary: This article investigates the dissipation function and its relationship with probability distribution. The expressions of the dissipation function for passive and active systems are derived using the Langevin equations. The fluctuation theorem of the dissipation function is numerically verified in a one-dimensional case. In both cases, if the probability distribution of the dynamical variables is symmetric under time reversal, the average rate of change of the dissipation function with trajectory duration is equal to the average entropy production rate of the system and reservoir.
Article
Energy & Fuels
Jie Chen, Zhengcai Zhang, Yongchao Hao, Daniel Porfirio Luis Jimenez, Jiafang Xu, Nengyou Wu, Fulong Ning, Bin Fang, Jun Zhang, Jianye Sun, Xiluo Hao, Qingguo Meng, YanLong Li, Yizhao Wan, Chanjuan Liu, Gaowei Hu
Summary: The formation and dissociation of gas hydrate can be influenced by electrostatic fields, making it a potential technology with great application value in hydrate exploitation, prevention, and related technologies. The molecular dynamics simulation revealed that the migration and destruction of ions in the hydrate are influenced by the strength of the electrostatic field. The insights gained from this study are beneficial for the application of electrostatic field in hydrate mining and safety of oil and gas pipeline transportation.
Article
Physics, Multidisciplinary
Kai Qi, Elmar Westphal, Gerhard Gompper, Roland G. Winkler
Summary: This study presents computational simulations of spheroidal model-microswimmers confined between two walls, revealing two collective dynamic states, depending on density and hydrodynamic interactions. Microswimmers exhibit an highly-dynamic collective motion with large-scale swirling patterns denoted as active turbulence. Various approaches have been applied to elucidate similarities and differences of inertial hydrodynamic and active turbulence.
COMMUNICATIONS PHYSICS
(2022)
Review
Nanoscience & Nanotechnology
Rui Zhang, Ali Mozaffari, Juan J. de Pablo
Summary: Active liquid crystals, with their inherent structural anisotropy, exhibit long-range order and topological defects. This Review discusses both natural and synthetic active liquid crystals, exploring their autonomous behavior as well as potential applications.
NATURE REVIEWS MATERIALS
(2021)
Article
Chemistry, Physical
Hossein Jalali, Erfan Lotfi, Boya Radha, Mehdi Neek-Amal
Summary: This study investigates the impact of sodium chloride dissolution on the dielectric properties of nanoconfined water between graphene layers using molecular dynamics simulations. The results show that the out-of-plane dielectric constant of water increases with higher salt concentrations, while the in-plane dielectric constant decreases non-linearly. Interestingly, an abnormal increase in the in-plane dielectric constant is observed for channels with specific heights, possibly linked to the formation of a 2D-ice-like structure.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Physics, Multidisciplinary
Sayanti Dasgupta, Pralay Kumar Karmakar
Summary: A relativistic quantum plasma model is proposed to analyze the stability of ion-acoustic waves in a gyromagnetoactive spherical electron-ion plasma. The study shows that the Coriolis rotation and magnetic field act as growth boosters for the waves, leading to a unique pattern of zero growth-bouncing point in the wavenumber space. The magnetic field and plasma concentration can play both stabilizing and destabilizing roles depending on the wavenumber windows.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Pralay Kumar Karmakar, Utpal Deka
Summary: This study reports a model formalism for small-scale radial fluctuations in the athermal solar plasma system, based on the non-extensive gravito-electrostatic sheath (GES) model. The unique aspect is the intercoupling of solar interior plasma (SIP) and solar wind plasma (SWP) via the gravito-electrostatic interfacial diffused solar surface boundary (SSB), with electrons described by kappa distribution laws and ions treated as an inhomogeneous fluid.
Article
Astronomy & Astrophysics
Pankaj Sarma, Pralay Kumar Karmakar
Summary: This article introduces the gravitoelectrostatic sheath (GES) model for exploring the surface emission mechanism of the solar wind plasma. It considers previously unaddressed key factors and explores different GES-microphysical features influenced by plasma characteristics. The study reveals the sensitivity and insensitivity of various parameters in the solar interior plasma and solar wind plasma, and analyzes the inhomogeneity-induced GES properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Multidisciplinary
A. Atteya, S. K. EL-Labany, P. K. Karmakar, M. S. Afify
Summary: This study investigates the generation mechanism and characteristics of oblique electron acoustic waves, revealing their dependency on plasma parameters and their potential impact on magnetic reconnection and anomalous resistivity.
Article
Multidisciplinary Sciences
W. F. El-Taibany, P. K. Karmakar, A. A. Beshara, M. A. El-Borie, S. A. Gwaily, A. Atteya
Summary: This study focuses on the solitary waves that emerge from the nonlinear properties of plasmas. A nonlinear homogeneous quantum Zakharov-Kuznetsov equation is derived for a three-component collisionless quantum plasma consisting of electrons, positrons, and ions in the presence of an external static magnetic field. The dependence of the solitary wave structures on various parameters, such as the Bohm potential, magnetic field, obliqueness, species Fermi temperatures, and densities, is investigated. The study also examines the soliton's electric field, energy, and instability growth rate. Comparison of system parameters to the behavior of energy and instability growth rate is performed. The findings contribute to the understanding of dynamics in magnetic white dwarfs, pulsar magnetospheres, semiconductor plasma, and high-intensity laser-solid matter interaction experiments involving e-p-i plasma.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Pralay Kumar Karmakar, Dhrubajit Kalita, Ahmed Atteya
Summary: A semi-analytic admixed model is proposed to study the stability effects of the inner crust regions in non-rotating neutron stars. It is found that a hybrid gravito-nucleo-acoustic (GNA) instability mode is excited, and various factors have different effects on its stability.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Multidisciplinary
Sayanti Dasgupta, Ahmed Atteya, Pralay Kumar Karmakar
Summary: We analyze the NAW modes in the CD core and ND ambience of ONe and CO white dwarfs using a quantum hydrodynamic plasma model. The model considers non-thermal quantum electrons, classical thermal light nuclear species, and classical thermal heavy nuclear species. The electronic energy distribution is controlled by the Fermi-Dirac temperature and chemical potential. The dispersion relation shows the multiparametric dependence of the NAW features, and a numerical platform demonstrates the NAW propagation and dispersion behaviors in a biscale form.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Astronomy & Astrophysics
Souvik Das, Ahmed Atteya, Pralay Kumar Karmakar
Summary: A recently developed gravito-electrostatic sheath model is used to study the helioseismic oscillation features in the bi-fluidic solar plasma system. The model reveals the evolution of both dispersive and non-dispersive features of the modified gravito-electrostatic sheath mode fluctuations. Different spectral profiles show important features of the perturbations. The stability of the system depends on various parameters and the dispersive features are more pronounced in the self-gravitational domains.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Sayanti Dasgupta, Ahmed Atteya, Pralay Kumar Karmakar
Summary: We used a quantum hydrodynamic model to study cylindrical acoustic waves in a gyromagnetoactive self-gravitating viscous cylinder made of electron-ion plasma. The electronic equation of state considered temperature degeneracy, which led to a generalized pressure expression including both quantum and classical pressure. Analyzing the waves using cylindrical wave analysis and the Hankel function, we obtained a sextic dispersion relation. By analyzing different parameter cases, we found that concentration is a major factor in destabilizing the system in the quantum regime, while plasma temperature plays an important role in both stabilization and destabilization in the classical regime.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Karabi Devi, Apratim Nag, Jaydeep Paul, Utpal Sarma, Pralay Kumar Karmakar
Summary: We theoretically study the nonlinear pulsational mode dynamics in strongly correlated (viscoelastic) self-gravitating complex charge-fluctuating dust molecular clouds (DMCs) on the astrophysical spatiotemporal scales. A nonlinear normal mode (local) analysis reveals a unique pair of extended Kortweg de-Vries-Burgers (KdV-B) equations on the conjugational gravito-electrostatic potential fluctuations in a mixed form. Numerical analysis of the KdV-B system within a wide-range parametric window relevant to realistic astronomical DMC circumstances demonstrates the evolution of solitary-chain patterns in fluctuation dynamics. Our results show that the amplitude of electrostatic fluctuations increases with the reference frame velocity, while gravitational fluctuations are unaffected by this velocity. Additionally, the fluctuation dynamics are found to be independent of various factors such as equilibrium dust density, equilibrium dust charge, and dust mass. The validation and reliability of our results are emphasized through comparison with existing literature. Our findings are crucial for understanding the mechanism behind bounded structure formation through non-local self-gravitational collapse dynamics.
JOURNAL OF TAIBAH UNIVERSITY FOR SCIENCE
(2023)
Proceedings Paper
Telecommunications
Pralay Kumar Karmakar, Sayanti Dasgupta
Summary: In this study, a theoretical model is presented to explore the stability dynamics of nucleus-acoustic waves in gyrogravitating degenerate quantum astroplasmas. The analysis reveals that the enhancement of Coriolis rotation suppresses the growth features of the nucleus-acoustic waves, and the system is more sensitive to rotational forces than viscoelasticity.
2022 URSI REGIONAL CONFERENCE ON RADIO SCIENCE, USRI-RCRS
(2022)
Article
Astronomy & Astrophysics
Subham Dutta, Pralay Kumar Karmakar
Summary: The study presents a theoretical model to analyze the instability of plasma fireball sheath (PFS) and applies it in both laboratory and astrophysical contexts. The research finds that there are atypical peakon-type potential-field structures on the laboratory scale, with the variations mainly concentrated in the center region.
JOURNAL OF ASTROPHYSICS AND ASTRONOMY
(2022)
Article
Astronomy & Astrophysics
Sayanti Dasgupta, Pralay Kumar Karmakar
Summary: The acoustic modal instability in a relativistic gyromagnetoactive quantum plasma model is investigated using a spherical model. Numerical simulations are used to analyze the instability behavior under parametric variations.
JOURNAL OF ASTROPHYSICS AND ASTRONOMY
(2022)
Article
Astronomy & Astrophysics
Pankaj Sarma, Pralay Kumar Karmakar
Summary: This study revisits the gravito-electrostatic sheath (GES) model, which is used to investigate the surface origin of solar wind plasma. The model considers non-thermal electrons and inertial ions as the constituents of the solar plasma system, and uses a new type of equation to describe the plasma structure. Numerical simulations are conducted to study the formation and evolution of the plasma structure, and the results are validated for their applicability in real solar plasma environments.
JOURNAL OF ASTROPHYSICS AND ASTRONOMY
(2022)
Article
Astronomy & Astrophysics
Souvik Das, Pralay Kumar Karmakar
Summary: The study applies a laboratory plasma-wall interaction-based model to investigate the dynamic stability of the solar plasma system, emphasizing the effects of magnetic field, plasma density, and temperature on the dispersion properties and stability. Computational analysis reveals the evolution of dispersive and non-dispersive features in the modified GES mode excitations.
JOURNAL OF ASTROPHYSICS AND ASTRONOMY
(2022)