Read by QxMD icon Read

European Physical Journal. E, Soft Matter

Shahrazad M A Malek, Richard K Bowles, Ivan Saika-Voivod, Francesco Sciortino, Peter H Poole
It is common practice in molecular dynamics and Monte Carlo computer simulations to run multiple, separately-initialized simulations in order to improve the sampling of independent microstates. Here we examine the utility of an extreme case of this strategy, in which we run a large ensemble of M independent simulations (a "swarm"), each of which is relaxed to equilibrium. We show that if M is of order [Formula: see text], we can monitor the swarm's relaxation to equilibrium, and confirm its attainment, within [Formula: see text], where [Formula: see text] is the equilibrium relaxation time...
November 10, 2017: European Physical Journal. E, Soft Matter
Fabio Giavazzi, Paolo Edera, Peter J Lu, Roberto Cerbino
Differential Dynamic Microscopy (DDM) analyzes traditional real-space microscope images to extract information on sample dynamics in a way akin to light scattering, by decomposing each image in a sequence into Fourier modes, and evaluating their time correlation properties. DDM has been applied in a number of soft-matter and colloidal systems. However, objects observed to move out of the microscope's captured field of view, intersecting the edges of the acquired images, can introduce spurious but significant errors in the subsequent analysis...
November 9, 2017: European Physical Journal. E, Soft Matter
Manoj Kumar, Varsha Banerjee, Sanjay Puri
In this paper, we study the random field Ising model (RFIM) in an external magnetic field h . A computationally efficient graph-cut method is used to study ground state (GS) morphologies in this system for three different disorder types: Gaussian, uniform and bimodal. We obtain the critical properties of this system and find that they are independent of the disorder type. We also study GS morphologies via pinned-cluster distributions, which are scale-free at criticality. The spin-spin correlation functions (and structure factors) are characterized by a roughness exponent [Formula: see text]...
November 8, 2017: European Physical Journal. E, Soft Matter
Prasenjit Das, Tanusri Saha-Dasgupta, Sanjay Puri
We study phase ordering kinetics in symmetric and asymmetric binary mixtures, undergoing an order-disorder transition below the critical temperature. Microscopically, we model the kinetics via the antiferromagnetic Ising model with Kawasaki spin-exchange kinetics. This conserves the composition while the order parameter (staggered magnetization) is not conserved. The order-parameter correlation function and structure factor show dynamical scaling, and the scaling functions are independent of the mixture composition...
November 8, 2017: European Physical Journal. E, Soft Matter
Norihiro Oyama, John Jairo Molina, Ryoichi Yamamoto
We have investigated the onset of collective motion in systems of model microswimmers, by performing a comprehensive analysis of the binary collision dynamics using three-dimensional direct numerical simulations (DNS) with hydrodynamic interactions. From this data, we have constructed a simplified binary collision model (BCM) which accurately reproduces the collective behavior obtained from the DNS for most cases. Thus, we show that global alignment can mostly arise solely from binary collisions. Although the agreement between both models (DNS and BCM) is not perfect, the parameter range in which notable differences appear is also that for which strong density fluctuations are present in the system (where pseudo-sound mound can be observed (N...
November 8, 2017: European Physical Journal. E, Soft Matter
Han-Fei Chen, Jiang-Tao Li, Fang Gu, Hai-Jun Wang
The Kirkwood-Buff (KB) theory of solution is employed to investigate several macroscopic properties of the one-component hard-core Yukawa (HCY) fluid, where the key physical quantities are the KB integrals (KBIs). For both repulsive and attractive HCY fluids, the radial distribution functions are calculated by using the classical density functional theory, and then the corresponding KBIs are carried out. Since the local structure and global properties of a fluid can be related by KBI, we presented the isothermal compressibility and the derivative of the chemical potential with respect to bulk density for both repulsive and attractive HCY fluids...
November 3, 2017: European Physical Journal. E, Soft Matter
Len M Pismen, Francesc Sagués
We consider active flow and dynamics of topological defects in an active nematic interfacial layer confined between immissible viscous fluid layers. The velocity of defects is determined by asymptotic matching of solutions in the defect core and the far field. Self-propulsion of positive defects along the direction of their "comet tails" is identified as the principal deterministic component of defect dynamics, while topological and hydrodynamic interactions among mobile defects is responsible for quasi-random jitter...
October 26, 2017: European Physical Journal. E, Soft Matter
Stanard Mebwe Pachong, Kristian K Müller-Nedebock
We investigate a system of sufficiently dense polar actin filaments considered rigid and cross-linked by dimer myosin II protein within the contractile ring. The Langevin dynamics of this system is cast in a functional integral formalism and then transformed into density variables. Using the dynamical Random Phase Approximation (RPA) along with the a one-dimensional Langevin dynamics simulation (LDS), we investigate the structural integrity of the actin bundle network. The active force and the networking force reveal a non-trivial diffusive behaviour of the filaments within the ring...
October 23, 2017: European Physical Journal. E, Soft Matter
Alexander B Mikishev, Alexey Y Rednikov, Pierre Colinet
It is known that the addition of an insoluble surfactant to a Bénard-Marangoni (BM) layer heated from below or cooled from above can give rise to a supplementary, oscillatory mode of instability. Here the objective is to see how exactly this plays out in the framework of a recently studied and experimentally tested case of a non-long-wavelength BM instability driven by diffusion-limited evaporation into air in isothermal surroundings. Linear stability analysis is accomplished within a now standard reduction to a one-sided model...
October 18, 2017: European Physical Journal. E, Soft Matter
Ramin Rabani, Hatim Machrafi, Pierre Dauby
In this paper, we study the influence of the upper gas layer on the drying and gelation of a polymer solution. The gel is formed due to the evaporation of the binary solution into (inert) air. A one-dimensional model is proposed, where the evaporation flux is more realistically described than in previous studies. The approach is based on general thermodynamic principles. A composition-dependent diffusion coefficient is used in the liquid phase and the local equilibrium hypothesis is introduced at the interface to describe the evaporation process...
October 17, 2017: European Physical Journal. E, Soft Matter
So Kitsunezaki, Arina Sasaki, Akihiro Nishimoto, Tsuyoshi Mizuguchi, Yousuke Matsuo, Akio Nakahara
It is known that pastes of fine powder, for example those of clay, retain memory of shaking applied early in a drying process. This memory results in the appearance of anisotropic patterns of desiccation cracks after drying. In this work, we find a similar behavior in pastes consisting of large granular particles, specifically cornstarch and Lycopodium spores. Because of the large particle size, we were able to observe particle arrangements in Lycopodium paste with micro-focus X-ray computerized tomography ( μ CT)...
October 12, 2017: European Physical Journal. E, Soft Matter
Horst-Holger Boltz, Stefan Klumpp
We study the buckling of an idealized, semiflexible filament along whose contour magnetic moments are placed. We give analytic expressions for the critical stiffness of the filament below which it buckles due to the magnetic compression. For this, we consider various scenarios of the attachment of the magnetic particles to the filament. One possible application for this model are the magnetosome chains of magnetotactic bacteria. An estimate of the critical bending stiffness indicates that buckling may occur within the range of biologically relevant parameters and suggests a role for the bending stiffness of the filament to stabilize the filament against buckling, which would compromise the functional relevance of the bending stiffness of the used filament...
October 2017: European Physical Journal. E, Soft Matter
D Rosenberg, R Marino, C Herbert, A Pouquet
After publication of the paper, an error in computing the ratio γ of kinetic to potential energy transfer times has been detected, which has led the authors to amend two figures, as explained in the main text.
October 2017: European Physical Journal. E, Soft Matter
P Mahmoudi, M W Matsen
Chain ends are known to have an entropic preference for the surface of a polymer melt, which in turn is expected to cause the short chains of a polydisperse melt to segregate to the surface. Here, we examine this entropic segregation for a bidisperse melt of short and long polymers, using self-consistent field theory (SCFT). The individual polymers are modeled by discrete monomers connected by freely-jointed bonds of statistical length a , and the field is adjusted so as to produce a specified surface profile of width [Formula: see text]...
October 2017: European Physical Journal. E, Soft Matter
P Oswald, L Lejček
In a recent letter (P. Oswald et al., EPL 103, 46004 (2013)), we have shown that a smectic-A phase hardens in compression normal to the layers when the liquid crystal is doped with gold nanoparticles. This is due to the formation of Cottrell clouds nearby the core of the edge dislocations and the appearance of an additional drag force that reduces their mobility. We theoretically calculate the shape of the Cottrell cloud and the associated drag force as a function of the climb velocity of the dislocations. The main result is that the drag force depends on velocity and vanishes when the temperature tends to the smectic-A-to-nematic transition temperature...
October 2017: European Physical Journal. E, Soft Matter
I V Vodolazskaya, Yu Yu Tarasevich
In this work, a model is developed for investigating the redistribution of colloidal particles in the film of an aqueous solution evaporating on a solid horizontal substrate under a mask with holes. Considering the characteristic horizontal film size as large and taking into account the symmetry in the arrangement of the holes in the mask the problem is solved for one film cell under a mask with a hole in its center. It is believed that vapour passes into the atmosphere only through the hole in the mask, the vapor flux density is calculated on the basis of the equation of steady-state diffusion of vapor in the atmosphere...
October 2017: European Physical Journal. E, Soft Matter
Jacques Rault
The properties of amorphous polymers and of organic compounds under pressure are interpreted in the framework of the modified Van der Walls Equation of State (mVW-EOS) the Vogel-Fulcher-Tamann (VFT) law and of the compensation law. We have shown recently that polymers and organic compounds in amorphous liquid and crystalline states verify the mVW-EOS which depends on three parameters, [Formula: see text] [Formula: see text] and [Formula: see text]. In this paper we compare the characteristic pressure [Formula: see text] of the mVW-EOS to the various pressures [Formula: see text] deduced from thermodynamic and kinetic properties of polymers in the liquid and solid states...
September 2017: European Physical Journal. E, Soft Matter
F Cecconi, A Puglisi, A Sarracino, A Vulpiani
We study the nonlinear response to an external force of an inertial tracer advected by a two-dimensional incompressible laminar flow and subject to thermal noise. In addition to the driving external field F, the main parameters in the system are the noise amplitude [Formula: see text] and the characteristic Stokes time [Formula: see text] of the tracer. The relation velocity vs. force shows interesting effects, such as negative differential mobility (NDM), namely a non-monotonic behavior of the tracer velocity as a function of the applied force, and absolute negative mobility (ANM), i...
September 2017: European Physical Journal. E, Soft Matter
Anupam Kumar, Biplab Kumar Mandal, Sanat Kumar, Pankaj Mishra
We have investigated the fluid-solid freezing transitions in a system of axially symmetric particles confined to a two-dimensional plane and interacting via purely repulsive octupolar interaction potential varying as the seventh power of the inverse interparticle separation. Both the one-component and two-component cases have been considered. The classical density functional theory of freezing has been employed to study the relative stability of the triangular solid phase of the system with respect to the fluid phase of the system using the structural inputs calculated by solving the Rogers-Young integral equation theory...
September 2017: European Physical Journal. E, Soft Matter
Shahin Mobarakabadi, Neda Adrang, Mehdi Habibi, Ehsan Nedaaee Oskoee
A granular mixture of identical particles of different densities can be segregated when the system is shaken. We present an efficient method of continuously segregating a flow of randomly mixed identical spherical particles of different densities by shaking them in a quasi-two-dimensional container with a sawtooth-shaped base. Using numerical simulation we study the effect of direction of shaking (horizontal/vertical), geometry of the sawtooth, and the friction coefficient between the grains and the container walls on the segregation quality...
September 2017: European Physical Journal. E, Soft Matter
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"