Motion, relaxation dynamics, and diffusion processes in two-dimensional colloidal crystals confined between walls

2012 ◽  
Vol 86 (5) ◽  
Author(s):  
Dorothea Wilms ◽  
Peter Virnau ◽  
Ian K. Snook ◽  
Kurt Binder
Soft Matter ◽  
2015 ◽  
Vol 11 (48) ◽  
pp. 9385-9392 ◽  
Author(s):  
B. van der Meer ◽  
W. Qi ◽  
J. Sprakel ◽  
L. Filion ◽  
M. Dijkstra

We investigate the microscopic origin of dynamical heterogeneities in two-dimensional colloidal crystals and hexatic phases. Our data illustrates how cooperative motions of particles are driven by the formation and diffusion of mobile defects.


Author(s):  
Chongchong Chen ◽  
Xiaoli Wu ◽  
Jie Zhang ◽  
Jingjing Chen ◽  
Xulin Cui ◽  
...  

Two-dimensional (2D) lamellar membranes are promising for efficient molecule transfer, while the underlying molecule transfer mechanism is rarely elucidated. Herein, heterostructured nanosheets are prepared by self-assembling small-sized hydrophilic cyanuric acid melamine (CMN) and hydrophobic g-C3N4 nanosheets. The resultant lamellar membranes show comparable affinity to both polar and nonpolar solvents, allowing them to dissolve on membrane surface and diffuse through membrane channels. Permeance results demonstrate that the transfer of polar solvents is controlled by dissolution and diffusion processes, while that of nonpolar solvents is governed by dissolution process. And the corresponding equations are established. Importantly, polar solvents are induced to form ordered arrangement in hydrophilic nanodomains and then maintain this state in hydrophobic nanodomains, affording low-resistance transfer thus high permeance: 1025 L m-2 h-1 bar-1 for acetonitrile. In contrast, nonpolar solvents with disordered arrangement acquire lower permeance than that of polar ones, but with comparable diffusion ability in these membranes.


Author(s):  
Petro Kostrobij ◽  
Iryna Ryzha

In the paper a study of a two-dimensional mathematical model of carbon monoxide oxidation on the Pt catalyst surface according to the Langmuir-Hinshelwood mechanism is presented. This model takes into account the nanoinhomogeneities of Pt(110) surface and diffusion processes of CO molecules and oxygen atoms adsorbed on the catalyst surface. It is shown that the structural changes of Pt(110) surface significantly affect the character of oscillatory mode of reaction, whereas the adsorbed oxygen atoms can be considered immobile.


2011 ◽  
Vol 56 ◽  
pp. 156-162
Author(s):  
Romas Baronas ◽  
Karolis Petrauskas

Biojutikliai yra analitiniai įrenginiai, skirti medžiagų koncentracijoms matuoti. Kuriant naujus biojutiklius reikia atlikti daug eksperimentų. Siekiant sumažinti atliekamų fizinių eksperimentų skaičių taikomas kompiuterinis biojutiklių veiksmo odeliavimas, kai įprastai kiekvienam struktūriškai naujam biojutikliui yra sudaromas matematinis modelis, tuomet jis keičiamas skirtuminiu, o jo lygčių sistemos sprendimas įgyvendinamas sudarant kompiuterinį modelį. Kiekvienas žingsnis reikalauja atidos ir turėtų būti automatizuotas. Straipsnyje yra pateikiamas biojutiklio metamodelis, leidžiantis formuluoti biojutiklių modelius dalykinės srities sąvokomis. Pasiūlytasis metamodelis aprašo biojutiklių modelius, formuluojamus dvimatėje erdvėje, apimančius biojutiklio struktūros, jo geometrinių savybių, biojutikliuose vykstančių reakcijų ir difuzijos procesų aprašus. Sudarius metamodelį, buvo sukurta programinė įranga, automatiškai sukonstruojanti kompiuterinį biojutiklio modelį pagal metamodeliosąvokomis išreikšto biojutiklio aprašą. Metamodelis ir programinė įranga buvo taikoma realiam biojutiklio modeliui sudaryti ir jo veiksmui modeliuoti kompiuteriniu būdu.", t. y. ištrinti žodžius "biojutiklių veiksmo.Computer-Aided Modeling of Biosensors with a Complex Geometrical StructureRomas Baronas, Karolis Petrauskas SummaryBiosensors are analytical devices used to measure the concentration of substances. When developing new biosensors, a lot of experiments are needed to be performed. Mathematical modeling of biosensors is used to decrease the number of physical experiments. Models of biosensors are usually created for each structurally unique biosensor by defining its mathematical model and the corresponding numerical approximation. Equations of the numerical model are then solved using computer programs, usually created for a particular model of the biosensor. Each of these steps requires a great attention and should be automated. The article presents a metamodel for a biosensor, enabling one to define models of biosensors in domain-specific terms. The proposed metamodel describes biosensor models, defined in the two-dimensional space and including definitions of the structure of a biosensor, its geometrical properties, reactions and diffusion processes taking place in it. Upon defining the metamodel, we compiled the computer software able to create computer models for biosensors from the models formulated according to the proposed metamodel. The metamodel was practically used to define a model for a real biosensor, and the biosensor modeling software was used to simulate its operation.


1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.


1980 ◽  
Vol 41 (C6) ◽  
pp. C6-28-C6-31 ◽  
Author(s):  
R. Messer ◽  
H. Birli ◽  
K. Differt

2020 ◽  
pp. 130-135
Author(s):  
D.N. Korotaev ◽  
K.N. Poleshchenko ◽  
E.N. Eremin ◽  
E.E. Tarasov

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.


1996 ◽  
Vol 61 (4) ◽  
pp. 536-563
Author(s):  
Vladimír Kudrna ◽  
Pavel Hasal

To the description of changes of solid particle size in population, the application was proposed of stochastic differential equations and diffusion equations adequate to them making it possible to express the development of these populations in time. Particular relations were derived for some particle size distributions in flow and batch equipments. It was shown that it is expedient to complement the population balances often used for the description of granular systems by a "diffusion" term making it possible to express the effects of random influences in the growth process and/or particle diminution.


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