Dein Suchergebnis zum Thema: Jeans

We study the lifetime of the excited state of an atom or molecule near a plane surface with a given random surface roughness. In particular, we discuss the impact of the scattering of surface modes within the rough surface. Our study is completed by considering the lateral correlation length of the decay rate and the variance discussing its relation to the C0 correlation.
spontaneous emission from atoms near a rough surface Author(s): Svend-Age Biehs, Jean-Jacques

By combining stochastic electrodynamics and the Maxwell- Garnett description for effective media we study the radiative heat transfer between two nanoporous materials. We show that the heat flux can be significantly enhanced by air inclusions, which we explain by:(a) the presence of additional surface waves that give rise to supplementary channels for heat transfer throughout the gap, (b) an increase in the contribution given by the ordinary surface waves at resonance, (c) and the appearance of frustrated modes over a broad spectral range. We generalize the known expression for the nanoscale heat flux for anisotropic metamaterials.
Rosa, Philippe Ben-Abdallah, Karl Joulain, Jean-Jacques Greffet Title: Nanoscale

Wi.Recht Aktuelles Personen/Das Team Sekretariat Jean Monnet-Lehrstuhl Aktuelles

We present a formulation of the nanoscale radiative heat transfer using concepts of mesoscopic physics. We introduce the analog of the Sharvin conductance using the quantum of thermal conductance. The formalism provides a convenient framework to analyze the physics of radiative heat transfer at the nanoscale. Finally, we propose a radiative heat transfer experiment in the regime of quantized conductance.
Heat Transfer at the Nanoscale Author(s): Svend-Age Biehs, Emmanuele Rousseau, Jean-Jaqcues

The surface roughness correction to the near-field heat transfer between two rough bulk materials is discussed by using second-order perturbation theory. The results allow for estimating the impact of surface roughness to the heat transfer in recent experiments between two plates and between a microsphere and a plate (using the Derjaguin approximation). Furthermore, we show that the proximity approximation for describing rough surfaces is valid for distances much smaller than the correlation length of the surface roughness even if the heat transfer is dominated by the coupling of surface modes.
roughness on near-field heat transfer between two plates Author(s): Svend-Age Biehs, Jean-Jaqcues

17 Prozent aller Europäer haben nach Angaben der Europäischen Kommission nicht genug Mittel, um ihre grundlegendsten Bedürfnisse zu erfüllen. Wie dem Problem beikommen? Ein neues Forschungsprojekt an der Universität Oldenburg sucht nach Lösungen.
Presse & Kommunikation +49 (0) 441 798-5446 presse@uol.de  Mehr zum Thema Jean

In this work we focus on the surface roughness correction to the near-field radiative heat transfer between a nanoparticle and a material with a rough surface utilizing a direct perturbation theory up to second order in the surface profile. We discuss the different distance regimes for the local density of states above the rough material and the heat flux analytically and numerically. We show that the heat transfer rate is larger than that corresponding to a flat surface at short distances. At larger distances it can become smaller due to surface polariton scattering by the rough surface. For distances much smaller than the correlation length of the surface profile, we show that the results converge to a proximity approximation, whereas in the opposite limit the rough surface can be replaced by an equivalent surface layer.
transfer between a nanoparticle and a rough surface Author(s): Svend-Age Biehs, Jean-Jaqcues

Wi.Recht Aktuelles Personen/Das Team Sekretariat Jean Monnet-Lehrstuhl Forschung

Wi.Recht Aktuelles Personen/Das Team Sekretariat Jean Monnet-Lehrstuhl Sekretariat

Analysieren, wie die europäischen Gesellschaften zusammenwachsen – oder eben nicht: Das steht im Zentrum der Forschergruppe, die der Oldenburger Soziologe Martin Heidenreich koordiniert und die die Deutsche Forschungsgemeinschaft weiterhin fördert. Ein Interview.
presse@uol.de  Mehr zum Thema DFG-Forschergruppe „Horiziontale Europäisierung“ Jean