[show abstract][hide abstract] ABSTRACT: Evolution of deep convective clouds under different size distributions of cloud con- densational nuclei (CCN) is simulated using the Hebrew University Cloud model (HUCM) with spectral microphysics. The model microphysics is based on solving an equation system for cloud hydrometeors of seven types (water drops, plate-, columnar- and branch-like ice crystals, aggregates, graupel and hail/frozen drops). Each type is described by a size distribution function containing 33 mass bins. The model is spe- cially designed to describe cloud aerosol interaction and effects of aerosol on warm and ice precipitation formation. Size distribution function of aerosol particles playing the role of cloud condensational nuclei (CCN) are described using 33 mass bins as well. New tables of height-dependent collision kernels allowing turbulence effects on the drop-drop and drop-ice collisions are used to simulate the warm and ice precipi- tating particles formation. The model accounts for deposition, condensation-freezing, and immersion ice nuclei mechanisms, as well as for secondary ice production via rime splintering. The model performance is illustrated by simulation of a deep Texas summertime cumulus cloud, containing, according to the observations of Rosenfeld and Woodley (2000), about 1.8 gm-3 supercooled cloud water at the 9.5 km level (37.5oC). The reasons allowing numerical reproduction of a narrow droplet spectrum up to the level of homogeneous freezing are discussed. Experiments reveal the cru- cial effect of atmospheric aerosols on both warm and melted precipitation amounts. Numerical experiments indicate a significant (several times) decrease in accumulated precipitation in smoky air. The fraction of warm rain in the total precipitation amount increases with a decrease in the CCN concentration. The fraction is low in smoky continental air and becomes dominating in clear maritime air. Physical mechanisms through which CCN influence cloud microphysics are discussed. It is shown in partic- ular, that the turbulent/inertia mechanism is potentially of high importance affecting the precipitation amount from deep cumulus clouds, especially from those developed in smoky air.
[show abstract][hide abstract] ABSTRACT: The relation between thermodynamic, transport and structural properties of electrolyte solutions is explored for volumes and
radii of ions in solution, water structure making and breaking by ions, ion pairing, and electromotive force of cells with
transport, and preferential solvation of ions in mixed solvents.
Key wordsthermodynamic quantities–transport quantities–structural quantities–single ions–ion pairs–solvent mixtures
Russian Journal of Electrochemistry 04/2012; 44(1):16-27.
[show abstract][hide abstract] ABSTRACT: A method is proposed for eliminating prepulses associated with high‐power ultrashort laser pulses. In this method the high‐power portion of the pulse is refractively guided due to relativistic effects associated with the plasma electrons. The low‐power prepulse, however, is unaffected and diffracts away. Optical guiding is achieved by appropriately choosing the plasma density, laser power, and wavelength. In addition, a wavebreaking stabilization mechanism for the Raman backscattering instability for intense laser pulses is proposed, which indicates that the pulse should not be significantly backscattered by the plasma.