2,119 research outputs found
Electron-phonon interaction in the solid form of the smallest fullerene C
The electron-phonon coupling of a theoretically devised carbon phase made by
assembling the smallest fullerenes C is calculated from first
principles. The structure consists of C cages in an {\it fcc} lattice
interlinked by two bridging carbon atoms in the interstitial tetrahedral sites
({\it fcc}-C). The crystal is insulating but can be made metallic by
doping with interstitial alkali atoms. In the compound NaC the
calculated coupling constant is 0.28 eV, a value much larger
than in C, as expected from the larger curvature of C. On the
basis of the McMillan's formula, the calculated =1.12 and a
assumed in the range 0.3-0.1 a superconducting T in the range 15-55 K is
predicted.Comment: 7 page
Suppression of inelastic bound state resonance effects by the dimensionality of atom-surface scattering event
We develop a multidimensional coupled channel method suitable for studying
the interplay of bound state resonance and phonon assisted scattering of inert
gas atoms from solid surfaces in one, two and three dimensions. This enables us
to get insight into the features that depend on the dimensionality of inelastic
resonant processes typically encountered in low energy He atom scattering from
surfaces, in general, and to elaborate on the observability of recently
conjectured near threshold resonances in scattering from Einstein phonons, in
particular.Comment: 2 figure
Responsible Management in the Framework of Market Economy
Background
. It is more and more evident that long-term sustainable management cannot be
carried out based only on financial data. Corporations operating in a market economy
environment do not only aim at profit maximization as they have already realized that the
ir
performance depends on the sustainability of the environment and society. Financial
motivations are the engine of corporate management, however, corporations c
an still serve
common wealth. Capitalism offers ever so many possibilities, opportunities f
or corporations
to be socially responsible.
Research aim
. This study was carried out to examine the CSR attitudes and commitments
of the management of a corporation operating in the capitalist environment
as well as to
study their exact CSR practices.
Method
. The research is based on the questionnaire carried out among domestically and
internationally owned SMEs in Hungary. The so-called snowball sample method was u
sed.
Key findings.
The study attempts to find and reveal the reasons for the gap between the
manager attitude and CSR practice based on the VoC
Estimation of the Poisson’s Rate of the Intact Rock in the Function of the Rigidity
Although Poisson’s ratio is one of the basic rock mechanical parameters, it is less investigated than the other parameters. It can be assumed, that this material constant depends on the rigidity of the rock, among the others. The goal of this research is to find a theoretical relationship between the rigidity of the intact rock and Poisson’s ratio. It was assumed that there is a connection between the internal friction angle (or cohesion) and rigidity of the isotropic, linear elastic material, using the Mohr-Coulomb theory. Based on these equations from different published limit equilibrium, six different equations were compared. It is published that the rigidity value is equal (within the experimental error) to the Hoek-Brown material constant (mi) which value is well-known for many different rock types. Plotting the published Poisson’s ratio in the function of the rigidity of the intact rock the optimal connection was chosen
Theoretical Relationship between the Confining Pressure and Poisson’s Ratio of Intact Rock
The Poisson’s ratio of the intact rock material is one of the basic material constants for rock engineering calculations in and on rock environments. Recently, several relationships were developed to calculate of the Poisson’s ratio of the intact rock from different mechanical parameters (e.g., rigidity index, cohesion, internal friction angle). This value can be measured under standardized laboratory conditions using traditional uniaxial compressive test at zero confining pressure. Analyzing the laboratory tests carried out at different confining pressure, it was found that this material constant should be increasing as a function of confining pressure. This paper aims to present a theoretical relationship between Poisson’s ratio of intact rock and the confining pressure, using the Hoek-Brown failure criteria. It was assumed that the Poisson’s ratio is increasing linearly, and at the brittle-ductile transaction point, it is 0.5. The proposed relationship can be extended to rock mass, using the Geological Strength Index (GSI)
New insight into cataract formation -- enhanced stability through mutual attraction
Small-angle neutron scattering experiments and molecular dynamics simulations
combined with an application of concepts from soft matter physics to complex
protein mixtures provide new insight into the stability of eye lens protein
mixtures. Exploring this colloid-protein analogy we demonstrate that weak
attractions between unlike proteins help to maintain lens transparency in an
extremely sensitive and non-monotonic manner. These results not only represent
an important step towards a better understanding of protein condensation
diseases such as cataract formation, but provide general guidelines for tuning
the stability of colloid mixtures, a topic relevant for soft matter physics and
industrial applications.Comment: 4 pages, 4 figures. Accepted for publication on Phys. Rev. Let
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