63 research outputs found
Bosonic Excitations in Random Media
We consider classical normal modes and non-interacting bosonic excitations in
disordered systems. We emphasise generic aspects of such problems and parallels
with disordered, non-interacting systems of fermions, and discuss in particular
the relevance for bosonic excitations of symmetry classes known in the
fermionic context. We also stress important differences between bosonic and
fermionic problems. One of these follows from the fact that ground state
stability of a system requires all bosonic excitation energy levels to be
positive, while stability in systems of non-interacting fermions is ensured by
the exclusion principle, whatever the single-particle energies. As a
consequence, simple models of uncorrelated disorder are less useful for bosonic
systems than for fermionic ones, and it is generally important to study the
excitation spectrum in conjunction with the problem of constructing a
disorder-dependent ground state: we show how a mapping to an operator with
chiral symmetry provides a useful tool for doing this. A second difference
involves the distinction for bosonic systems between excitations which are
Goldstone modes and those which are not. In the case of Goldstone modes we
review established results illustrating the fact that disorder decouples from
excitations in the low frequency limit, above a critical dimension , which
in different circumstances takes the values and . For bosonic
excitations which are not Goldstone modes, we argue that an excitation density
varying with frequency as is a universal
feature in systems with ground states that depend on the disorder realisation.
We illustrate our conclusions with extensive analytical and some numerical
calculations for a variety of models in one dimension
Bacterial adhesion to the surfaces of elastomeric materials
This article considers connections between the characteristics of the surfaces of elastomeric materials and the adhesion of bacterial cells. The results demonstrate that the formation of colonies depends on the surface roughness and surface energy, as well as on the specific peculiarities of the studied polymer. Adhesion of bacterial cells to different solid and elastic polymeric materials is compared. © 2017, Pleiades Publishing, Ltd
Bacterial adhesion to the surfaces of elastomeric materials
This article considers connections between the characteristics of the surfaces of elastomeric materials and the adhesion of bacterial cells. The results demonstrate that the formation of colonies depends on the surface roughness and surface energy, as well as on the specific peculiarities of the studied polymer. Adhesion of bacterial cells to different solid and elastic polymeric materials is compared. © 2017, Pleiades Publishing, Ltd
Problems of the use of elastomeric medical materials in biological media
The problems of the formation of biofilms on the surface of medical products made of elastomers are considered. It is shown that a decrease in the adhesion of biofilms to elastomers may be achieved via various surface modifications, including the coating of the material surface with a fluoropolymer-containing adhesive. © 2015, Pleiades Publishing, Ltd
New Medical Materials for Urology
The influence of some polymer surface properties on bacterial attachment to the surface of the elastomeric and thermoplastic samples was shown. As promising materials in this field, butadiene-styrene thermoplastic elastomers (BSTPE) showed average characteristics of bacterial adhesion in comparison with other materials. All materials have passed cytotoxicity test. © 2016 by Apple Academic Press, Inc
Problems of the use of elastomeric medical materials in biological media
The problems of the formation of biofilms on the surface of medical products made of elastomers are considered. It is shown that a decrease in the adhesion of biofilms to elastomers may be achieved via various surface modifications, including the coating of the material surface with a fluoropolymer-containing adhesive. © 2015, Pleiades Publishing, Ltd
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