The process of nanoparticle generation during nanosecond and picosecond laser ablation of various metals (Ni, Al, W, and stainless steel) in ambient air and argon gas was investigated. The number concentration of nanoparticles generated by laser ablation in argon gas was up to 100 times higher compared to that in ambient air. Three stable separate size peaks of nucleation, Aitken, and accumulation modes of nanoparticles were observed in case of argon gas, while in ambient air particles of a wide size spectrum (8-200 nm) were generated. The natural precursors in ambient air can have an effect on the size spectrum of particles composed of various chemical compounds with target material during the ablation process. The influence of laser process parameters and properties of investigated metals on the number concentration and size distribution of nanoparticles generated during ns-and ps-laser ablation was observed.

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The motion of water due to surface waves is the most dynamic factor observed in the marine environment. In this review various aspects of the wave modelling of non-linear, steep surface waves and their role in the atmosphere-ocean interaction are discussed. Significant improvements in wave forecasting have been made in the last ten years. This is to a large extent related to substantial progress in the description of wind forcing and other processes, as well as to the more efficient use of satellite observations and assimilation methods. One striking observation is the increasing variety and complexity of models in which more physical processes are implemented, greater precision and resolution achieved and extended ranges of applicability demonstrated. However, in order to evaluate the applicability of particular models, comparison with high quality experimental data, collected in nature or under laboratory conditions, is necessary. Notation lista -wave amplitude, constant a 1 -functionThe complete text of the paper is available at http://www.iopan.gda.pl/oceanologia/