A plethora of applications in pharmacy, cosmetics, food industry and other areas are directly linked to the research fields of particle technology and contact mechanics. Here, a typical particle ensemble features particle sizes ranging from the nanometer up to the micrometer regime. In this context we introduce a nanoindentation based approach capable of probing mechanical interaction of micron-sized particles. Basically, the concept of the colloid probe technique, which is well established in the AFM community, is transferred to a nanoindenter. In particular, this setup allows addressing limitations, which are typically associated with AFM based techniques, such as particle weight and accessible load regime. Additionally, we will show the versatility of this approach by presenting simple experimental paths capable of probing sliding, rolling and torsional friction. The potential of such setting is shown by studying rolling friction of silica microspheres featuring radii of about 2.5µm, 10µm, 25 and 50µm in contact with various substrates, respectively. Substrates utilized within the framework of this study are Si surfaces featuring various roughness as well as flat gold films (300nm film thickness). Key aspects of this work include the influence of surface roughness, adhesion force, humidity and the elastic/plastic transition on the rolling contact of the corresponding particles.

We investigate the hydrodynamic interactions of spherical colloidal nano particles and nano tetrahedra near a planar wall by means of molecular dynamics (MD) simulations of rigid particles within an all-atom solvent. For both spherical and nano-tetrahedral particles, we find that the parallel and perpendicular components of the local diffusion coefficient and viscosity, show good agreement with hydrodynamic theory of Faxén and Brenner. This provides further evidence that low perturbations from sphericality of a nanoparticle’s shape has little influence on its local diffusive behaviour, and that for this particular case, the continuum theory fluid dynamics is valid even down to molecular scales.

VO-KOREL is a web service exploiting the technology of the Virtual Observatory for providing astronomers with the intuitive graphical front-end and distributed computing back-end running the most recent version of the Fourier disentangling code KOREL.

The system integrates the ideas of the e-shop basket, conserving the privacy of every user by transfer encryption and access authentication, with features of laboratory notebook, allowing the easy housekeeping of both input parameters and final results, as well as it explores a newly emerging technology of cloud computing.

While the web-based front-end allows the user to submit data and parameter files, edit parameters, manage a job list, resubmit or cancel running jobs and mainly watching the text and graphical results of a disentangling process, the main part of the back-end is a simple job queue submission system executing in parallel multiple instances of the FORTRAN code KOREL. This may be easily extended for GRID-based deployment on massively parallel computing clusters.

The short introduction into underlying technologies is given, briefly mentioning advantages as well as bottlenecks of the design used.