This volume is based on some representative contributions presented in the wo- shop: "Trends in nanophysics: theory, experiment, technology", which took place in Sibiu, Romania, 23-29 August 2009, being organized by ICTP-Trieste, IAEA, IFIN-HH - Bucharest and ULB - Sibiu. The aim of this workshop was to faci- tate experts and active researchers to exchange ideas and information on the most recent results in nanophysics and nanotechnology. It was also an opportunity for young researchers and for researchers from developing countries to enlarge their knowledge and to approach new themes in this area. In fact, the articles contained in this book represent written and enriched versions of the workshop oral presentations. The topics covered by them are the following: 1. Ordered atomic-scale structures 2. Nanowires: growth and properties 3. Transport phenomena in nanostructures 4. Optical properties of nanostructures 5. Magnetic nanophases; magnetic and non-magnetic nanocomposites 6. Nano uids and ows at nanoscale 1 Ordered Atomic-Scale Structures The quest of a reliable method for fabricating ordered atomic-scale structures is a prerequisite for future atomic-scale technology - the ultimate goal of nanosciences.