Interlocking order parameter fluctuations in structural transitions between adsorbed polymer phases

2016 ◽  
Vol 18 (3) ◽  
pp. 2143-2151 ◽  
Author(s):  
Paulo H. L. Martins ◽  
Michael Bachmann

By means of contact-density chain-growth simulations of a simple coarse-grained lattice model for a polymer grafted at a solid homogeneous substrate, we investigate the complementary behavior of the numbers of surface–monomer and monomer–monomer contacts under various solvent and thermal conditions.

Author(s):  
D. Jou ◽  
P. K. Galenko

In standard descriptions, the master equation can be obtained by coarse-graining with the application of the hypothesis of full local thermalization that is equivalent to the local thermodynamic equilibrium. By contrast, fast transformations proceed in the absence of local equilibrium and the master equation must be obtained with the absence of thermalization. In the present work, a non-Markovian master equation leading, in specific cases of relaxation to local thermodynamic equilibrium, to hyperbolic evolution equations for a binary alloy, is derived for a system with two order parameters. One of them is a conserved order parameter related to the atomistic composition, and the other one is a non-conserved order parameter, which is related to phase field. A microscopic basis for phenomenological phase-field models of fast phase transitions, when the transition is so fast that there is not sufficient time to achieve local thermalization between two successive elementary processes in the system, is provided. In a particular case, when the relaxation to local thermalization proceeds by the exponential law, the obtained coarse-grained equations are related to the hyperbolic phase-field model. The solution of the model equations is obtained to demonstrate non-equilibrium phenomenon of solute trapping which appears in rapid growth of dendritic crystals. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.


Author(s):  
José Weberszpil ◽  
José Abdalla Helayël-Neto

This contribution sets out to extend the concept of helicity so as to include it in a fractional scenario with a low-level of fractionality. To accomplish this goal, the authors write down the left- and the right-handed Weyl equations from first principles in this extended framework. Next, by coupling the two different fractional Weyl sectors by means of a mass parameter, they arrive at the fractional version of Dirac's equation, which, whenever coupled to an external electromagnetic field and reduced to the non-relativistic regime, yields a fractional Pauli-type equation. From the latter, they are able to present an explicit expression for the gyromagnetic ratio of charged fermions in terms of the fractionality parameter. They then focus their efforts to relate the coarse-grained property of space-time to fractionality and to the (g-2) anomalies of the different leptonic species. To do this, they build up an axiomatic local metric derivative that exhibits the Mittag-Leffler function as eigenfunction and is valid for low-level fractionality, whenever the order parameter is close to 1.


2020 ◽  
Vol 27 (2) ◽  
pp. 189-199
Author(s):  
Francesco Delfino ◽  
Yuri Porozov ◽  
Eugene Stepanov ◽  
Gaik Tamazian ◽  
Valentina Tozzini

Soft Matter ◽  
2016 ◽  
Vol 12 (29) ◽  
pp. 6253-6260 ◽  
Author(s):  
Aleks Reinhardt ◽  
Daan Frenkel

We show that many-component addressable self-assembly of DNA bricks is possible to achieve with a coarse-grained but realistic off-lattice model.


1985 ◽  
Vol 6 ◽  
pp. 150-153
Author(s):  
Xik Zichu

Snow stratigraphical studies, together with crystallographic and oxygen isotope analyses, have affirmed the existence of a complete range of ice formation zones on the Law Dome, Antarctica. Asymmetric distribution of these zones and changes in the types of ice formation with depth in snow pits dug near the boundaries of the zones show an asymmetry in accumulation and thermal conditions in different sites on Law Dome, and a climatic change in past years. Crystallographic studies of ice from two boreholes near Cape Forger (BHC i and BHC 2) show change of microtexture and fabric of the ice crystals with depth. Six different layers of ice can be identified: 1) a deposition layer with polygonal shaped crystals, an ice fabric which is dependent on the ice formation process; 2) a transition layer with porphyrblastic crystals and a girdle fabric pattern developing toward a two-pole fabric; 3) a fine grained layer with cataclastic crystals and strong, nearly vertical single pole c-axis fabric; 4) a coarse grained layer with large, interlocking, branched crystals and a diamond pattern of fabric; 5) a second fine grained layer with single maximum fabric; 6) a second coarse grained layer with multi-maxima fabric. The origin of the second fine grained layer, found in the ice of the last glaciation is discussed. The author suggests that this ice results from conditions during the last glaciation.


2005 ◽  
Vol 42 (2) ◽  
pp. 515-527 ◽  
Author(s):  
J -M Konrad ◽  
N Lemieux

The influence of fines on the frost susceptibility of base-course crushed aggregates was established by laboratory freezing tests simulating closely the thermal conditions in the field. The frost susceptibility of the fines was varied by use of different mixtures of granitic fines and commercially available kaolinite clay. A total of 13 samples with fines content of 5%, 10%, and 15% and kaolinite fractions of 10%, 50%, 75%, and 100% were subjected to four freeze–thaw cycles. The frost susceptibility of well-graded crushed aggregates increases with increasing fines content and increasing kaolinite fraction. From a quantitative point of view, for a given kaolinite fraction, the segregation potential increases linearly with fines content, until the fines create a matrix in which the coarser particles are embedded. For the material studied, this occurs when the fines content is higher than 15%. For a given fines content, it was also established that the segregation potential increases linearly with kaolinite fraction, indicating the importance of mineralogy. It was also established that appropriate thermal testing conditions need to be adopted to prevent undue pore water extraction from the unfrozen soil close to the frost front during laboratory freezing of unsaturated coarse-grained soils.Key words: coarse grained, soil, frost susceptibility, pavements, laboratory, fines.


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