The Cole-Cole Law for Critical Dynamics in Glass-Forming Liquids

Within the mode-coupling theory (MCT) for glassy dynamics, the asymptotic low-frequency expansions for the dynamical susceptibilities at critical points are compared to the expansions for the dynamic moduli; this shows that the convergence properties of the two expansions can be quite different. In some parameter regions, the leading-order expansion formula for the modulus describes the solutions of the MCT equations of motion outside the transient regime successfully; at the same time, the leading- and next-to-leading order expansion formulas for the susceptibility fail. In these cases, one can derive a Cole-Cole law for the susceptibilities; and this law accounts for the dynamics for frequencies below the band of microscopic excitations and above the high-frequency part of the alpha-peak. It is shown that this scenario explains the optical-Kerr-effect data measured for salol and benzophenone (BZP). For BZP it is inferred that the depolarized light-scattering spectra exhibit a wing for the alpha-peak within the Gigahertz band. This wing results from the crossover of the von Schweidler-law part of the alpha-peak to the high-frequency part of the Cole-Cole peak; and this crossover can be described quantitatively by the leading-order formulas of MCT for the modulus.Comment: 15 pages, 9 figure

Orden och världen. Lexikografens dubbla perspektiv

In this paper I try to establish both differences and interrelations between mono- andbilingual lexicography (for which I coin the term glossography) from the making ofspecialized dictionaries and encyclopedias (for which I coin the term cosmography).Glossography aims at establishing a semantic equivalent between the entryword and its explanation. Cosmography aims at the opposite: with the entry word asa point of departure, a cosmographic article will provide the user with new informationthat is not inherent in the entry word itself. On another level, the cosmographerstrives to organize the world systematically and to find the most suitable entry wordfor the fragment of the world he wants to describe. The glossographer takes theword as the point of departure, and relations between words (hyponomy, synonymyetc.) is secondary. But in practice the two approaches are interrelated. A typicalglossography will contain lots of more or less specialized technical terms from differentfields which cannot be explained without reference to the world. Also, glossographicarticles often include cosmographic information that places the meaningof a word in an extralinguistic context. And glossographic features are often includedin cosmographic articles: pronunciation, etymology

Test of electromagnetic, non-destructive method for determining material properties in steel

This study, in the area of non-destructive testing and measuring technology, shows that it is possible toinspect and determine the mechanical properties and micro structure of a material using electro-magnetictechnique. The goal has been to on-line determine material properties like residual stress distributions,variations in tensile strength and fatigue strength in a material. In the project the latest in materials inspectionusing electro-magnetic methods combined with statistic modelling is used. The project has shown that thesenew methods can non-destructively determine the mechanical properties of a material or a machine detail. Itis believed that this measuring technique has a clear place in industry

Derivation of the nonlinear fluctuating hydrodynamic equation from underdamped Langevin equation

We derive the fluctuating hydrodynamic equation for the number and momentum densities exactly from the underdamped Langevin equation. This derivation is an extension of the Kawasaki-Dean formula in underdamped case. The steady state probability distribution of the number and momentum densities field can be expressed by the kinetic and potential energies. In the massless limit, the obtained fluctuating hydrodynamic equation reduces to the Kawasaki-Dean equation. Moreover, the derived equation corresponds to the field equation derived from the canonical equation when the friction coefficient is zero.Comment: 16 page

Pressure induced structural and dynamical changes in liquid Si. An ab-initio study

The static and dynamic properties of liquid Si at high-pressure have been studied using the orbital free ab-initio molecular dynamics method. Four thermodynamic states at pressures 4, 8, 14 and 23 GPa are considered. The calculated static structure shows qualitative agreement with the available experimental data. We analize the remarkable structural changes occurring between 8 and 14 GPa along with its effect on several dynamic properties.Comment: 10 pages, 11 figures. Accepted for publication in Journal of Physics: Condensed Matte

Density fluctuations and single-particle dynamics in liquid lithium

The single-particle and collective dynamical properties of liquid lithium have been evaluated at several thermodynamic states near the triple point. This is performed within the framework of mode-coupling theory, using a self-consistent scheme which, starting from the known static structure of the liquid, allows the theoretical calculation of several dynamical properties. Special attention is devoted to several aspects of the single-particle dynamics, which are discussed as a function of the thermodynamic state. The results are compared with those of Molecular Dynamics simulations and other theoretical approaches.Comment: 31 pages (in preprint format), 14 figures. Submitted to Phys. Rev.