178 research outputs found

    Mechanisms of Dendrites Occurrence during Crystallization: Features of the Ice Crystals Formation

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    Dendrites formation in the course of crystallization presents very general phenomenon, which is analyzed in details via the example of ice crystals growth in deionized water. Neutral molecules of water on the surface are combined into the double electric layer (DEL) of oriented dipoles; its field reorients approaching dipoles with observable radio-emission in the range of 150 kHz. The predominant attraction of oriented dipoles to points of gradients of this field induces dendrites growth from them, e.g. formation of characteristic form of snowflakes at free movement of clusters through saturated vapor in atmosphere. The constant electric field strengthens DELs' field and the growth of dendrites. Described phenomena should appear at crystallization of various substances with dipole molecules, features of radio-emission can allow the monitoring of certain processes in atmosphere and in technological processes. Crystallization of particles without constant moments can be stimulated by DELs of another nature with attraction of virtual moments of particles to gradients of fields and corresponding dendrites formation.Comment: 6 page

    Near field in quantum electrodynamics: Green functions, Lorentz condition, "nonlocality in the small", frustrated total reflection

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    Investigation of near field of QED requires the refuse from an averaging of the Lorentz condition that smooths out some field peculiarities. Instead of it Schwinger decomposition of the 4-potential with the Bogoliubov method of interaction switching in time and in space regions is considered. At such approach near field is describable by the part of covariant Green function of QED, the fast-damping Schwinger function formed by longitudinal and scalar components of Aμ none restricted by light cone. This description reveals possibility of superluminal phenomena within the near field zone as a "nonlocality in the small". Some specification of Bogoliubov method allows, as examples, descriptions of near fields of point-like charge and at FTIR phenomena. Precisely such possibilities of nonlocal interactions are revealed in the common QED expressions for the Van-der-Waals and Casimir interactions and in the F\"{o}rster law. Key words: Lorentz condition, near field, propagators, superluminal, FTIR. PACS: 03.30.+p, 12.20.-m, 13.40.-f, 68.37.Uv.Comment: 21 page

    Phase Transitions of the First Kind as Radiation Processes

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    Crystallization and vapor condensation are considered as processes of sequential entering of single atoms/molecules into condensate. The latent heat can be carry away by radiation of characteristic frequencies generated in the course of transition. The estimated dependences of latent (radiated) energy of boiling on temperature confirm and prove the well-known empirical Trouton's rule applicable to many simple substances. It leads to the estimation of interrelation of critical parameters of corresponding substances. Experimental results of the authors and other researchers concerning crystallization from the melt of different substances (alkali halides, sapphire, tellurium, ice, copper) are presented, as well as condensation of water vapor, the correspondence to the offered model is established. It allows developing of the spectroscopy of phase transitions, and can lead to control of crystallization process, to crystallization stimulated by the characteristic radiation, etc. Formation of clouds in our atmosphere should be accompanied by characteristic radiation detectable for meteorological warnings.Comment: 17 page
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