22 research outputs found
Characterization of optical properties and surface roughness profiles: The Casimir force between real materials
The Lifshitz theory provides a method to calculate the Casimir force between
two flat plates if the frequency dependent dielectric function of the plates is
known. In reality any plate is rough and its optical properties are known only
to some degree. For high precision experiments the plates must be carefully
characterized otherwise the experimental result cannot be compared with the
theory or with other experiments. In this chapter we explain why optical
properties of interacting materials are important for the Casimir force, how
they can be measured, and how one can calculate the force using these
properties. The surface roughness can be characterized, for example, with the
atomic force microscope images. We introduce the main characteristics of a
rough surface that can be extracted from these images, and explain how one can
use them to calculate the roughness correction to the force. At small
separations this correction becomes large as our experiments show. Finally we
discuss the distance upon contact separating two rough surfaces, and explain
the importance of this parameter for determination of the absolute separation
between bodies.}Comment: 33 pages, 14 figures, to appear in Springer Lecture Notes in Physics,
Volume on Casimir Physics, edited by Diego Dalvit, Peter Milonni, David
Roberts, and Felipe da Ros
Application of Topological Analysis of the Electron Localization Function to the Complexes of Molybdenum Carbide Nanoparticles with Unsaturated Hydrocarbons
The catalytic transformation of the heavy aromatics in bitumen into lighter components is the key to the upgrading and refining of the oil sands. To understand the chemical bonding in molybdenum carbide nanoparticle (MCNP) catalysts and the chemisorption bonds between the MCNPs and unsaturated hydrocarbons, the topological analysis of the electron localization function was applied to various MCNPs and the complexes of them with unsaturated hydrocarbons. For some of the smaller complexes comparisons are made with the Atoms-in-Molecules approach, including the calculation of delocalization indices. The results are interpreted in the Lewis bonding scheme. It was found that the Mo-C bonding can be highly ionic in cases like MoThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author