6,618 research outputs found
Role of cross-links in bundle formation, phase separation and gelation of long filaments
We predict the thermodynamic and structural behavior of solutions of long
cross-linked filaments. We find that at the mean field level, the entropy of
self-assembled junctions induces an effective attraction between the filaments
that can result in a phase separation into a connected network, in equilibrium
with a dilute phase. A connected network can also be formed in a
non-thermodynamic transition upon increase of the chain, or cross link density,
or with decreasing temperature. For rigid rods, at low temperatures, we predict
a transition from an isotropic network, to anisotropic bundles of rods tightly
bound by cross links, that is triggered by the interplay between the
configurational entropy of the cross-link distribution among the rods, and the
rotational and translational entropy of the rods.Comment: typos and graphics corrected; 6 pages 1 figur
Inclusions induced phase separation in mixed lipid film
The effect of rigid inclusions on the phase behavior of a film containing a
mixture of lipid molecules is investigated. In the proposed model, the
inclusion-induced deformation of the film, and the resulting energy cost are
strongly dependent upon the spontaneous curvature of the mixed film. The
spontaneous curvature is in turn strongly influenced by the composition of
film. This coupling between the film composition and the energy per inclusion
leads to a lateral modulation of the composition, which follows the local
curvature of the membrane. In particular, it is shown that the inclusion may
induce a global phase separation in a film which would otherwise be
homogeneously mixed. The mixed film is then composed of patches of different
average composition, separated by the inclusions. This process may be of
relevance to explain some aspects of lipid-protein association in biological
membranes.Comment: 19 pages, 5 figure
Phase behavior and material properties of hollow nanoparticles
Effective pair potentials for hollow nanoparticles like the ones made from
carbon (fullerenes) or metal dichalcogenides (inorganic fullerenes) consist of
a hard core repulsion and a deep, but short-ranged, van der Waals attraction.
We investigate them for single- and multi-walled nanoparticles and show that in
both cases, in the limit of large radii the interaction range scales inversely
with the radius, , while the well depth scales linearly with . We predict
the values of the radius and the wall thickness at which the gas-liquid
coexistence disappears from the phase diagram. We also discuss unusual material
properties of the solid, which include a large heat of sublimation and a small
surface energy.Comment: Revtex, 13 pages with 8 Postscript files included, submitted to Phys.
Rev.
Molecular dynamics study of nanoparticle stability at liquid interfaces : effect of nanoparticle-solvent interaction and capillary waves
While the interaction of colloidal particles (sizes in excess of 100 nm) with liquid interfaces may be understood in terms of continuum models, which are grounded in macroscopic properties such as surface and line tensions, the behaviour of nanoparticles at liquid interfaces may be more complex. Recent simulations [D. L. Cheung and S. A. F. Bon, Phys. Rev. Lett. 102, 066103 (2009)] of nanoparticles at an idealised liquid-liquid interface showed that the nanoparticle-interface interaction range was larger than expected due, in part, to the action of thermal capillary waves. In this paper, molecular dynamics simulations of a Lennard-Jones nanoparticle in a binary Lennard-Jones mixture are used to confirm that these previous results hold for more realistic models. Furthermore by including attractive interactions between the nanoparticle and the solvent, it is found that the detachment energy decreases as the nanoparticle-solvent attraction increases. Comparison between the simulation results and recent theoretical predictions [H. Lehle and M. Oettel, J. Phys. Condens. Matter 20, 404224 (2008)] shows that for small particles the incorporation of capillary waves into the predicted effective nanoparticle-interface interaction improves agreement between simulation and theory
Elastic Interactions of Cells
Biological cells in soft materials can be modeled as anisotropic force
contraction dipoles. The corresponding elastic interaction potentials are
long-ranged ( with distance ) and depend sensitively on elastic
constants, geometry and cellular orientations. On elastic substrates, the
elastic interaction is similar to that of electric quadrupoles in two
dimensions and for dense systems leads to aggregation with herringbone order on
a cellular scale. Free and clamped surfaces of samples of finite size introduce
attractive and repulsive corrections, respectively, which vary on the
macroscopic scale. Our theory predicts cell reorientation on stretched elastic
substrates.Comment: Revtex, 6 pages, 2 Postscript files included, to appear in Phys. Rev.
Let
Sumber Daya Manusia Pendidikan Dalam Menghadapi Era Industri 4.0.
Indonesia is a developing country that is facing the Industrial Revolution 4.0 Era. Many things must be changed in a country if the country wants to become a developed country. This also applies to Indonesia, especially when the level of competition is getting tougher in various sectors of our lives. From the various changes that must be made, improvement of Human Resources (HR) is one of the priorities that must be considered, especially HR in the field of Education.
The worldwide Industrial Revolution 4.0 has changed the mindset and the application of educational innovation in all fields of educational programs. Therefore, all stakeholders, implementers of education in Indonesia must be able to take advantage of Information Technology advancement in developing appropriate and religious education models to produce educational human resources that are in accordance with the Industrial 4.0 Erain order to realize Indonesian people who understand Science and Technology, have Faith and Taqwa and ready to face the times.
In terms of the availability of Human Resources in the field of Education to face the Industry 4.0 Era, the role of Higher Education should not be ignored, because all
activities, professions, and our social life are directly related to the quality of existing Higher Education graduates. Thus, this paper is focused on how to realize Human Resources in the field of Educationin Facing the Industry 4.0 Era
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