Results 1 - 10 of 55092
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[en] A numerical study was carried out using a molecular dynamics program to examine the wetting characteristics of nano-sized water droplets on surfaces with various pillar surface fractions under different conditions. Square-shaped pillars had surface fractions that increased from 11.1 % to 69.4 %. The pillars had 4 different heights and 3 different surface energies. When the pillar surface fraction changed, the contact angle of a water droplet also changed due to the attraction between the droplet and the pillar surface or the inner attraction of the water molecules. The pillar height also has different effects on the water droplet depending on the magnitude of surface energy
[en] This article is about discretion dynamic model of constructions on the basis of the method of focusing deformation. On the basis of exploit algorithms were received the result of calculation of three storied chassis with solitary parameters, without taking fade into account, corresponding act with solitary power, above the third floor. (author)
[en] We study how the dynamics of a food chain depends on the biology of the top-predator. We consider two model food chains with specialist and generalist top-predators. Both types of food chains display same type of chaotic behavior, short-term recurrent chaos; but the generating mechanisms are drastically different. Food chains with specialist top-predators are dictated by exogenous stochastic factors. On the contrary, the dynamics of those with the generalist top-predator is governed by deterministic changes in system parameters. The study also suggests that robust chaos would be a rarity
[en] Results are presented from a series of simulations undertaken to determine whether dynamic processes observed in device-scale liquid crystal cells confined between aligning substrates can be simulated in a molecular system using parallel molecular dynamics of the Gay-Berne model. In a nematic cell, on removal of an aligning field, initial near-surface director relaxation can induce flow, termed 'backflow' in the liquid. This, in turn, can cause director rotation, termed 'orientational kickback', in the centre of the cell. Simulations are performed of the relaxation in nematic systems confined between substrates with a common alignment on removal of an aligning field. Results show /that relaxation timescales of medium sized systems are accessible. Following this, simulations are performed of relaxation in hybrid aligned nematic systems, where each surface induces a different alignment. Flow patterns associated with director reorientation are observed. The damped oscillatory nature of the relaxation process suggests that the behaviour of these systems is dominated by orientational elastic forces and that the observed director motion and flow do not correspond to the macroscopic processes of backflow and kickback. Chevron structures can occur in confined smectic cells which develop two domains of equal and opposite layer tilt on cooling. Layer lilting is thought to be caused by a need to reconcile a mismatch between bulk and surface smectic layer spacing. Here, simulations are performed of the formation of structures in confined smectic systems where layer tilt is induced by an imposed surface pretilt. Results show that bookshelf, chevron and tilled layer structures are observable in a confined Gay-Berne system. The formation and stability of the chevron structure are shown to be influenced by surface slip. (author)
[en] This work aimed to investigate the structural and dynamical properties of ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) confined between two parallel and flat Au sheets. Thus, molecular dynamic (MD) simulations were performed for different pore sizes including 1.2, 2.0, and 3.0 nm at 300 K. The results showed that the behavior of confined ILs are totally depart from the bulk ones. Further, it is should be noted that, these differences greatly depended on the pore size. Our results suggest that the interactions between Au pore walls and the ILs are obviously strengthened by the decrease of the pore sizes.
[en] We consider a one-dimensional chain of sites, appropriate for colonization by a biological species. The dynamics at each site is subjected to the demographic Allee effect. We consider non-zero probability p of dispersal to the nearby sites and we prove for small values of p, the existence of asymptotically stable localized solutions, such that the population of the central site almost equals the carrying capacity, while the populations at nearby sites attain small values, which drop exponentially with the distance from the central site. We study numerically a chain of 101 sites. Three different cases of behavior are observed, corresponding to the source-sink effect, the rescue effect and extinction. We study the bifurcations leading to transition from one behavior to the other. The motion of the invasion wavefront and the effect of heterogeneity of sites are also studied
[en] In this report, the beam dynamics in the magnetic field defined by the integral expression of the vector potential is considered. The influence of transverse components of the magnetic field on the shift of the beam trajectory in the helical solenoid of the LUE-200 accelerator of the IREN setup (Joint Institute for Nuclear Research, Dubna) is analyzed.
[en] We compare vibrational dynamics in two structurally distinct, simple monatomic model glasses simulated by molecular dynamics: the Lennard-Jones glass with an fcc-related structure and a glass with predominantly icosahedral short-range order. The former, characterized by a single local quasiperiodicity, supports only modes with acoustic behavior. In the latter, the presence of optic modes and two incommensurate length scales is observed. This pattern of vibrational dynamics is shown to be closely related to that of a Frank-Kasper crystal having the same local topological order
[en] Purpose of this job is demonstration of universal methods of dynamical systems theory possibility use to multiple production processes. The Poincare's method of reflecting functions (RF) is used in capacity of analysis way. Serviceability of this way for particle generation analysis is proved. It is interlined, that key concept is the station point and it has real physical substance. It is related with important characteristics of the process - with average plurality of particles produced under interaction. Character of station point reflects a nature and general state of generation mechanism. With the RF help in e+e- -annihilation, diffraction dissociation and multiple production have being revealed differences of its dynamic regimes. 14 refs., 5 figs
[en] The coupling effects between the primary and secondary systems can be significant in many practical cases. To evaluate these effects and to obtain a more realistic response of the subsystems, the Dynamic Force Method can be applied in a reliable way, with the possibility of considering local stiffness or damping effects. The DFM is presented and applied to some representative cases. (orig.)