Dispersion Curves and Frequency Distribution of Polymers: Single Chain Model

1968 ◽  
Vol 48 (8) ◽  
pp. 3561-3572 ◽  
Author(s):  
Luigi Piseri ◽  
Giuseppe Zerbi
Keyword(s):  
Frequency Distribution ◽  
Dispersion Curves ◽  
Chain Model ◽  
Single Chain

Confined single-chain model of microphase-separated multiblock copolymers. 1. (AB)n copolymers

1992 ◽  
Vol 25 (2) ◽  
pp. 653-662 ◽  
Author(s):  
John M. Zielinski ◽  
Richard J. Spontak
Keyword(s):  
Chain Model ◽  
Multiblock Copolymers ◽  
Single Chain

scholarly journals Multi-chain Fudan-CCDC model for COVID-19 – a revisit to Singapore’s case

2020 ◽  
Author(s):  
Hanshuang Pan ◽  
Nian Shao ◽  
Yue Yan ◽  
Xinyue Luo ◽  
Shufen Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Penalty Function ◽  
Prevention And Control ◽  
World Wide ◽  
Data Fitting ◽  
Chain Model ◽  
Single Chain ◽  
Simulation Results ◽  
Different Characteristics ◽  
And Control

AbstractBackgroundCOVID-19 has been impacting on the whole world critically and constantly since late December 2019. Rapidly increasing infections has raised intense world-wide attention. How to model the evolution of COVID-19 effectively and efficiently is of great significance for prevention and control.MethodsWe propose the multi-chain Fudan-CCDC model based on the original single-chain model in [8] to describe the evolution of COVID-19 in Singapore. Multi-chains can be considered as the superposition of several single chains with different characteristics. We identify parameters of models by minimizing the penalty function.ResultsThe numerical simulation results exhibit the multichain model performs well on data fitting. Though unsteady the increments are, they could still fall within the range of ±25% fluctuation from simulation results. It is predicted by multi-chain models that Singapore are experiencing a nonnegligible risk of explosive outbreak, thus stronger measures are urgently needed to contain the epidemic.ConclusionThe multi-chain Fudan-CCDC model provides an effective way to early detect the appearance of imported infectors and super spreaders and forecast a second outbreak. It can also explain the data in those countries where the single-chain model shows deviation from the data.

scholarly journals Multi-chain Fudan-CCDC model for COVID-19 in Iran

2020 ◽  
Author(s):  
Hanshuang Pan ◽  
Nian Shao ◽  
Yue Yan ◽  
Xinyue Luo ◽  
Ali Ahmadi ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Prevention And Control ◽  
Data Fitting ◽  
Chain Model ◽  
Single Chain ◽  
Epidemic Curve ◽  
The World ◽  
Simulation Results ◽  
Fitting In ◽  
And Control

AbstractBackgroundCOVID-19 has been deeply affecting people’s lives all over the world. It is significant for prevention and control to model the evolution effectively and efficiently.MethodsWe first propose the multi-chain Fudan-CCDC model which is based on the original Fudan-CCDC model to describe the revival of COVID-19 in some countries. Multi-chains are considered as the superposition of distinctive single chains. Parameter identification is carried out by minimizing the penalty function.ResultsFrom results of numerical simulations, the multi-chain model performs well on data fitting and reasonably interprets the revival phenomena. The band of ±25% fluctuation of simulation results could contain most seemly unsteady increments.ConclusionThe multi-chain model has better performance on data fitting in revival situations compared with the single-chain model. It is predicted by the three-chain model with data by Apr 21 that the epidemic curve of Iran would level off on round May 10, and the final cumulative confirmed cases would be around 88820. The upper bound of the 95% confidence interval would be around 96000.

Computational Characterization of Mechanical Behavior of Polymer Electrolyte Membrane Based on Nonaffine Molecular Chain Model

2010 ◽  
Author(s):  
Isamu Riku ◽  
Kyosuke Morizane ◽  
Koji Mimura
Keyword(s):  
Mechanical Behavior ◽  
Water Content ◽  
Polymer Electrolyte ◽  
Loading Condition ◽  
Polymer Electrolyte Membrane ◽  
Molecular Chain ◽  
Chain Model ◽  
Single Chain ◽  
Electrolyte Membrane ◽  
Proposed Model

In this paper, a computational model is constituted based on the microstructural features of polymer electrolyte membrane (PEM). Assuming that the interaction between the water molecular and PEM molecular is quite weak, the cluster inside PEM is considered as void and the homogenization method is applied to constitute a unit cell model in which several voids are contained to represent the periodic microstructure of PEM. On the other hand, to account for the nonaffine movement of the molecular chains of PEM, the number of segment in a single chain is proposed as a function of the local stretch of the molecular chain and the constitutive equation of the matrix of PEM is constituted based on the nonaffine molecular chain model. It is found that this proposed model can reproduce the strain softening deformation behavior of PEM very well. Furthermore, a series simulations based on this proposed model are performed to discuss the effect of the water content and that of the triaxiality of macroscopic loading condition on the mechanical behavior of PEM. The results show that a relative quick development of the number of segments in a single chain is observed in the case of high water content and high triaxiality loading condition.

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