Spinodal Decomposition of the Interface in a Nonlinear Growth Model with Noise

1991 ◽  
Vol 237 ◽  
Author(s):  
Leonardo GoluBovic ◽  
R. P. U. Karunasiri
Keyword(s):  
Phase Transition ◽  
Surface Tension ◽  
Surface Diffusion ◽  
Spinodal Decomposition ◽  
Growth Model ◽  
Interface Model ◽  
Nonlinear Growth ◽  
Diffusion Relaxation ◽  
Non Linear ◽  
Linear Version

ABSTRACTWe consider a non-linear version of Edwards-Wilkinson interface model for the growth in the presence of a collimated partjcie flux. We include both surface tension and surface diffusion relaxation. In a range of positive small values of the surface tension, the interface develops a state which fulfills standard criteria for spinodal decomposition. This suggests the existence of a phase transition from the ordinary state with the interface perpendicular to the incoming flux to a novel, noue.induced state with the interface apontaneously tilted with respect to the direction of the flux.

GLOBAL EXISTENCE FOR PHASE TRANSITION PROBLEMS VIA A VARIATIONAL SCHEME

2004 ◽  
Vol 01 (04) ◽  
pp. 747-768
Author(s):  
CHRISTIAN ROHDE ◽  
MAI DUC THANH
Keyword(s):  
Phase Transition ◽  
Surface Tension ◽  
Initial Data ◽  
Time Discretization ◽  
Approximate Solutions ◽  
Implicit Time ◽  
Time Step ◽  
Dynamical Phase Transition ◽  
Transition Dynamics ◽  
Variational Scheme

We construct approximate solutions of the initial value problem for dynamical phase transition problems via a variational scheme in one space dimension. First, we deal with a local model of phase transition dynamics which contains second and third order spatial derivatives modeling the effects of viscosity and surface tension. Assuming that the initial data are periodic, we prove the convergence of approximate solutions to a weak solution which satisfies the natural dissipation inequality. We note that this result still holds for non-periodic initial data. Second, we consider a model of phase transition dynamics with only Lipschitz continuous stress–strain function which contains a non-local convolution term to take account of surface tension. We also establish the existence of weak solutions. In both cases the proof relies on implicit time discretization and the analysis of a minimization problem at each time step.

TEMPERATURE DEPENDENCE OF SURFACE TENSION OF LIQUID CRYSTALS AT THE PHASE TRANSITION

1995 ◽  
Vol 09 (03n04) ◽  
pp. 237-242 ◽  
Author(s):  
R. MOLDOVAN ◽  
M. TINTARU ◽  
T. BEICA ◽  
S. FRUNZA ◽  
D. N. STOENESCU
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Surface Tension ◽  
Free Energy ◽  
Surface Layer ◽  
Order Parameter ◽  
Unit Area ◽  
Negative Slope ◽  
First Order ◽  
First Order Transition

The surface tension is calculated as the excess of the free energy per unit area, due to the presence of a surface layer, using Landau–de Gennes expansions, in the hypothesis of a first order transition in the bulk and taking into account the dependence of the surface free energy from the surface tilt angle. The surface order parameter is calculated and surface-ordered phase above the phase transition temperature has been found. A variety of calculated surface tension versus temperature curves with a jump at the phase transition, with positive or negative slope, well describing the experimental data from literature, have been attained.

scholarly journals SOLVING COCOA POD SIGMOID GROWTH MODEL WITH NEWTON RAPHSON METHOD

2012 ◽  
Vol 09 ◽  
pp. 44-51
Author(s):  
ALBERT LING SHENG CHANG ◽  
NAVIES MAISIN
Keyword(s):  
Growth Model ◽  
Morphological Characteristics ◽  
Growth Period ◽  
Growth Function ◽  
Growth Data ◽  
Non Linear ◽  
Newton Raphson ◽  
Pod Length ◽  
Raphson Method ◽  
Pod Growth

Cocoa pod growth modelling are useful in crop management, pest and disease management and yield forecasting. Recently, the Beta Growth Function has been used to determine the pod growth model due to its unique for the plant organ growth which is zero growth rate at both the start and end of a precisely defined growth period. Specific pod size (7cm to 10cm in length) is useful in cocoa pod borer (CPB) management for pod sleeving or pesticide spraying. The Beta Growth Function is well-fitted to the pods growth data of four different cocoa clones under non-linear function with time (t) as its independent variable which measured pod length and diameter weekly started at 8 weeks after fertilization occur until pods ripen. However, the same pod length among the clones did not indicate the same pod age since the morphological characteristics for cocoa pods vary among the clones. Depending on pod size for all the clones as guideline in CPB management did not give information on pod age, therefore it is important to study the pod age at specific pod sizes on different clones. Hence, Newton Raphson method is used to solve the non-linear equation of the Beta Growth Function of four different group of cocoa pod at specific pod size.

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