Charge Distribution and Conformations of Weak Polyelectrolyte Chains in Poor Solvents

2008 ◽  
Vol 73 (4) ◽  
pp. 439-458 ◽  
Author(s):  
Peter Košovan ◽  
Zuzana Limpouchová ◽  
Karel Procházka

In this work we study the effect of mobility of charges in annealed polyelectrolytes on their conformational behavior in poor solvents. A combination of molecular dynamics and Monte Carlo simulation techniques was used to take the dissociation into account. We investigated the relation between the conformation of the polyelectrolyte and the distribution of charges along the chain. The results suggest that in sufficiently poor solvents the local degree of charging differs significantly from the average. When a pearl-necklace conformation is formed, the degree of charging of the pearls is significantly lower than that of the strings. The redistribution of charges stabilizes the pearl-necklace conformation and enables the formation of asymmetric conformations with a single pearl at one chain end and a string at the other end.

2008 ◽  
Vol 23 (26) ◽  
pp. 4337-4343 ◽  
Author(s):  
FENG-GE TIAN ◽  
GANG CHEN ◽  
HUI-LING WEI

The hardness properties of quark- and gluon-jets produced by different flavor quarks are compared in 3-jet events of e+e- collision generated with Monte Carlo Simulation Jetset 7.4 generator at [Formula: see text]. The 3-jet events are obtained using the Durham algorithm and the quark- and gluon-jets are identified by angular-method. The average values of transverse momentum 〈pt〉, multiplicity 〈N〉 and rapidity 〈y〉 versus hardness for quark- and gluon-jets of different flavors are compared. It turns out that the distributions of 〈pt〉, 〈N〉 and 〈y〉 versus hardness of quark-jets are different to their flavors, while those of the gluon-jets are insensitive to the flavors. On the other hand, the 〈pt〉 and 〈N〉 of quark- and gluon-jets are strong positive correlated with hardness, but the 〈y〉 of those are negatively correlated with hardness.


2020 ◽  
Vol 10 (2) ◽  
pp. 472 ◽  
Author(s):  
Amir Mahdiyar ◽  
Danial Jahed Armaghani ◽  
Mohammadreza Koopialipoor ◽  
Ahmadreza Hedayat ◽  
Arham Abdullah ◽  
...  

Peak particle velocity (PPV) is a critical parameter for the evaluation of the impact of blasting operations on nearby structures and buildings. Accurate estimation of the amount of PPV resulting from a blasting operation and its comparison with the allowable ranges is an integral part of blasting design. In this study, four quarry sites in Malaysia were considered, and the PPV was simulated using gene expression programming (GEP) and Monte Carlo simulation techniques. Data from 149 blasting operations were gathered, and as a result of this study, a PPV predictive model was developed using GEP to be used in the simulation. In order to ensure that all of the combinations of input variables were considered, 10,000 iterations were performed, considering the correlations among the input variables. The simulation results demonstrate that the minimum and maximum PPV amounts were 1.13 mm/s and 34.58 mm/s, respectively. Two types of sensitivity analyses were performed to determine the sensitivity of the PPV results based on the effective variables. In addition, this study proposes a method specific to the four case studies, and presents an approach which could be readily applied to similar applications with different conditions.


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