Phase Separation and Elastic Fields: Three Dimensional Simulations of a Phase Field Model

1999 ◽  
Vol 580 ◽  
Author(s):  
Daniel Orlikowski ◽  
Celeste Sagui ◽  
Andrds Somoza ◽  
Christopher Roland
Keyword(s):  
Phase Separation ◽  
Large Scale ◽  
Ostwald Ripening ◽  
Three Dimensional ◽  
Selection Criterion ◽  
Phase Field Model ◽  
Dynamic Scaling ◽  
Shear Moduli ◽  
Elastic Fields ◽  
Three Dimensional Simulations

AbstractThe effects of long-range elastic fields on the phase separation process of three- dimensional binary alloy systems was investigated with large-scale Langevin simulations. The elastic effects incorporated in the model are the result of anisotropy and dilational misfits introduced via inhomogeneities in the elastic constants of the constituents. The domain morphology obtained is readily understandable in terms of selection criterion for the shape and/or orientation of the domains, and is based on the different shear moduli that are present in the system. Coarsening mechanisms were found to be a combination of the classical Ostwald ripening mechanism and the elastically-driven coalescence of domains. Other aspects of the coarsening process such as dynamic scaling of the structure function is presented.

Three-Dimensional Simulations of Phase Separation in Model Binary Alloy Systems with Elasticity

1997 ◽  
Vol 481 ◽  
Author(s):  
D. Orlikowski ◽  
C. Sagui ◽  
A. S. Somoza ◽  
C. Roland
Keyword(s):  
Phase Separation ◽  
Binary Alloy ◽  
Large Scale ◽  
Three Dimensional ◽  
Elastic Field ◽  
Dimensional System ◽  
Elastic Fields ◽  
Slowing Down ◽  
Three Dimensional Simulations ◽  
Alloy Systems

ABSTRACTWe report on large-scale three-dimensional simulations of phase separation in model binary alloy systems in the presence of elastic fields. The elastic field has several important effects on the morphology of the system: the ordered domains are subject to shape transformations, and spatial ordering. In contrast to two-dimensional system, no significant slowing down in the growth is observed. There is also no evidence of any “reverse coarsening” of the domains.

AGN torus threaded by large scale magnetic field

2018 ◽  
Vol 27 (10) ◽  
pp. 1844006
Author(s):  
A. Dorodnitsyn ◽  
T. Kallman
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Accretion Disk ◽  
Large Scale ◽  
Three Dimensional ◽  
X Ray ◽  
Radiative Feedback ◽  
Large Scale Magnetic Field ◽  
Three Dimensional Simulations

Large scale magnetic field can be easily dragged from galactic scales toward AGN along with accreting gas. There, it can contribute to both the formation of AGN “torus” and help to remove angular momentum from the gas which fuels AGN accretion disk. However the dynamics of such gas is also strongly influenced by the radiative feedback from the inner accretion disk. Here we present results from the three-dimensional simulations of pc-scale accretion which is exposed to intense X-ray heating.

Two- and three-dimensional simulations of the phase separation of elastically coherent binary alloys subject to external stresses

2000 ◽  
Vol 62 (5) ◽  
pp. 3160-3168 ◽  
Author(s):  
Daniel Orlikowski ◽  
Celeste Sagui ◽  
Andrés M. Somoza ◽  
Christopher Roland
Keyword(s):  
Phase Separation ◽  
Binary Alloys ◽  
Three Dimensional ◽  
External Stresses ◽  
Three Dimensional Simulations

Simulation of Ideal Grain Growth Using the Multi-Phase-Field Model

2007 ◽  
Vol 558-559 ◽  
pp. 1177-1181 ◽  
Author(s):  
Philippe Schaffnit ◽  
Markus Apel ◽  
Ingo Steinbach
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Phase Field ◽  
Large Scale ◽  
Field Model ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Two Dimensions ◽  
Von Neumann ◽  
Average Grain Size

The kinetics and topology of ideal grain growth were simulated using the phase-field model. Large scale phase-field simulations were carried out where ten thousands grains evolved into a few hundreds without allowing coalescence of grains. The implementation was first validated in two-dimensions by checking the conformance with square-root evolution of the average grain size and the von Neumann-Mullins law. Afterwards three-dimensional simulations were performed which also showed fair agreement with the law describing the evolution of the mean grain size against time and with the results of S. Hilgenfeld et al. in 'An Accurate von Neumann's Law for Three-Dimensional Foams', Phys. Rev. Letters, 86(12)/2685, March 2001. Finally the steady state grain size distribution was investigated and compared to the Hillert theory.

A phase-field study of domain dynamics in ferroelectric BCT-BZT system

MRS Advances ◽  
2016 ◽  
Vol 1 (40) ◽  
pp. 2783-2788 ◽  
Author(s):  
Soumya Bandyopadhyay ◽  
Tushar Jogi ◽  
Kumaraswamy Miriyala ◽  
Ranjith Ramadurai ◽  
Saswata Bhattacharyya
Keyword(s):  
Free Energy ◽  
Phase Field ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Ginzburg Landau ◽  
Equimolar Composition ◽  
Electrical Boundary Conditions ◽  
Experimental Findings ◽  
Domain Dynamics ◽  
Three Dimensional Simulations

ABSTRACTWe present a thermodynamically consistent phase-field model describing the free energy of perovskite-based BCT-BZT solid solution containing an intermediate morphotropic phase boundaries. The Landau coefficients are derived as functions of composition of zirconium. The electrostrictive and elastic constants are appropriately chosen from experimental findings. The resulting Landau free energy is constructed to describe the stable polarization states as a function of composition. The evolution of the polarization order parameters at a particular composition is described by a set of time-dependent Ginzburg-Landau (TDGL) equations. Additionally, we solve Poisson’s equation and mechanical equilibrium equation to account for the ferroelectric/ferroelastic interactions. We have performed two dimensional and three-dimensional simulations with appropriate electrical boundary conditions to study the effect of external electric field on domain dynamics in BCT-BZT system at the equimolar composition.

scholarly journals Genome Compartmentalization with Nuclear Landmarks: Random yet Precise

2021 ◽  
Author(s):  
Kartik Kamat ◽  
Yifeng Qi ◽  
Yuchuan Wang ◽  
Jian Ma ◽  
Bin Zhang
Keyword(s):  
Phase Separation ◽  
Genome Organization ◽  
Large Scale ◽  
Three Dimensional ◽  
Nuclear Lamina ◽  
Spatial Arrangement ◽  
Nuclear Bodies ◽  
Chromatin Interaction ◽  
Nuclear Speckles ◽  
Heterogeneous Distribution

The three-dimensional (3D) organization of eukaryotic genomes plays an important role in genome function. While significant progress has been made in deciphering the folding mechanisms of individual chromosomes, the principles of the dynamic large-scale spatial arrangement of all chromosomes inside the nucleus are poorly understood. We use polymer simulations to model the diploid human genome compartmentalization relative to nuclear bodies such as nuclear lamina, nucleoli, and speckles. We show that a self-organization process based on a co-phase separation between chromosomes and nuclear bodies can capture various features of genome organization, including the formation of chromosome territories, phase separation of A/B compartments, and the liquid property of nuclear bodies. The simulated 3D structures quantitatively reproduce both sequencing-based genomic mapping and imaging assays that probe chromatin interaction with nuclear bodies. Importantly, our model captures the heterogeneous distribution of chromosome positioning across cells, while simultaneously producing well-defined distances between active chromatin and nuclear speckles. Such heterogeneity and preciseness of genome organization can coexist due to the non-specificity of phase separation and the slow chromosome dynamics. Together, our work reveals that the co-phase separation provides a robust mechanism for encoding functionally important 3D contacts without requiring thermodynamic equilibration that can be difficult to achieve.

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