1,589 research outputs found
A discussion of the scaling effect in numerical simulation of the extrusion process
The main objective of the work of this paper is to study the possibility of using a small scale geometrical model in the numerical simulation of aluminium extrusion. The advantages and shortcomings of the application of the
geometrically similar model in FEM simulation are discussed. Thermal – mechanical and metallurgical combined
simulations are performed within two tests using geometrically similar models and assessment is made in terms of mechanical and material properties. It was found that small scale simulation could not reproduce most of the
important forming parameters of the original process, although it could help to bring about significant savings in
computation time
Cold-water corals and hydrochemistry - is there a unifying link?
Physical and chemical parameters were measured in five different regions of the Northeast Atlantic with known occurrences of cold-water coral reefs and mounds and in the Mediterranean, where these corals form living carpets over existing morphologies. In this study we analyzed 282 bottom water samples regarding delta13CDIC, delta18O, and DIC. The hydrochemical data reveal characteristic patterns and differences for cold-water coral sites with living coral communities and ongoing reef and mound growth at the Irish and Norwegian sites. While the localities in the Mediterranean, in the Gulf of Cadiz, and off Mauritania show only patchy coral growth on mound-like reliefs and various substrates.
The analysis of delta13C/delta18O reveals distinct clusters for the different regions and the respective bottom water masses bathing the delta18O, and especially between delta13CDIC and DIC shows that DIC is a parameter with high sensitivity to the mixing of bottom water masses. It varies distinctively between sites with living reefs/mounds and sites with restricted patchy growth or dead corals. Results suggest that DIC and delta13CDIC can provide additional insights into the mixing of bottom water masses.
Prolific cold-water coral growth forming giant biogenic structures plot into a narrow geochemical window
characterized by a variation of delta13CDIC between 0.45 and 0.79 per mille being associated with the water mass
having a density of sigma-theta of 27.5+-0.15 kg m-3
Tunable Intrinsic Plasmons due to Band Inversion in Topological Materials
The band inversion has led to rich physical effects in both topological
insulators and topological semimetals. It has been found that the inverted band
structure with the Mexican-hat dispersion could enhance the interband
correlation leading to a strong intrinsic plasmon excitation. Its frequency
ranges from several to tens of and can be
effectively tuned by the external fields. The electron-hole asymmetric term
splits the peak of the plasmon excitation into double peaks. The fate and
properties of this plasmon excitation can also act as a probe to characterize
the topological phases even in the lightly doped systems. We numerically
demonstrate the impact of the band inversion on plasmon excitations in
magnetically doped thin films of three-dimensional strong topological
insulators, V- or Cr-doped (Bi, Sb)Te, which support the quantum
anomalous Hall states. Our work thus sheds some new light on the potential
applications of topological materials in plasmonics.Comment: 6 pages, 5 figures, Accepted in PR
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