Spatio-temporal structures in sheared polymer systems
نویسندگان
چکیده
We investigate spatio-temporal structures in sheared polymer systems by solving a time-dependent Ginzburg-Landau model in two dimensions. (i) In polymer solutions above the coexistence curve, crossover from linear to nonlinear regimes occurs with increasing the shear rate. In the nonlinear regime the solution behaves chaotically with large-amplitude composition fluctuations. A characteristic heterogeneity length is calculated in the nonlinear regime. (ii) We also study dynamics of shear-band structures in wormlike micellar solutions under the condition of fixed stress. The average shear rate exhibits large temporal fluctuations with occurrence of large disturbances in the spatial structures.
منابع مشابه
استفاده از POD در استخراج ساختارهای متجانس یک میدان آشفته آماری- همگن
Capability of the Proper Orthogonal Decomposition (POD) method in extraction of the coherent structures from a spatio-temporal chaotic field is assessed in this paper. As the chaotic field, an ensemble of 40 snapshots, obtained from Direct Numerical Simulation (DNS) of the Kuramoto-Sivashinsky (KS) equation, has been used. Contrary to the usual methods, where the ergodicity of the field is need...
متن کاملAssessment of Neonate's Congenital Hypothyroidism Pattern Using Poisson Spatio-temporal Model in Disease Mapping under the Bayesian Paradigm during 2011-18 in Guilan, Iran
Background: Congenital Hypothyroidism (CH) is one of the reasons for mental retardation and defective growth in neonates. It can be treated if it is diagnosed early. The congenital hypothyroidism can be diagnosed using newborn screening in the first days after birth. Disease mapping helps to identify high-risk areas of the disease. This study aimed to evaluate the pattern of CH using the Poisso...
متن کاملContext-aware Modeling for Spatio-temporal Data Transmitted from a Wireless Body Sensor Network
Context-aware systems must be interoperable and work across different platforms at any time and in any place. Context data collected from wireless body area networks (WBAN) may be heterogeneous and imperfect, which makes their design and implementation difficult. In this research, we introduce a model which takes the dynamic nature of a context-aware system into consideration. This model is con...
متن کاملSpatio-Temporal Parameters' Changes in Gait of Male Elderly Subjects
Objectives: The purpose of this study was to compare spatio-temporal gait parameters between elderly and young male subjects. Methods & Materials: 57 able-bodied elderly (72±5.5 years) and 57 healthy young (25±8.5 years) subjects participated in this study. A four segment model consist of trunk, hip, shank, and foot with 10 reflective markers were used to define lower limbs. Kinematic data c...
متن کاملEvaluation of Tests for Separability and Symmetry of Spatio-temporal Covariance Function
In recent years, some investigations have been carried out to examine the assumptions like stationarity, symmetry and separability of spatio-temporal covariance function which would considerably simplify fitting a valid covariance model to the data by parametric and nonparametric methods. In this article, assuming a Gaussian random field, we consider the likelihood ratio separability test, a va...
متن کامل