16 research outputs found
Dynamic processes happening during the evaporation of films of fusible materials
Optical waveguides on glass substrates are a promising area in their application in simple and cheap optoelectronic devices. As shown in [1], the highest refractive index is achieved during the formation of waveguides by oxidized film diffusion. However, realization of a number of electro-optical effects is restrained by probabilistic repeatability of wave guiding layers which holds down the development of optoelectronics [1-3]. This happens due to the fact that film formation in gas exchange mode isn't explored enough. One of the reasons of probabilistic repeatability of local thickness and film composition is dynamic processes which happen during the material evaporation. The regularities of evaporation, which were earlier found by Knudsen, Langmuir and other scientists for point sources, fail when it comes to the line where one material escape into another state. Most materials, which have three states - solid, liquid, gaseous - at ambient pressure heating, in vacuum, lose their liquid state partly or completely. Moreover, the film distribution over the substrate is quite unclear because of the poor study of molecular vapor flow and substrate interaction
Effect of Small Methane and Monosilane Additives on Clustering in Pulsed Supersonic Argon Jets
Investigation of the Flow Structure on a Miniature Gas-Dynamic Setup: Identification of the Secondary Flow in a Clustered Supersonic Jet Escaping Into a Rarefied Space
Condensation in pulsed free jets of silane-argon mixture: Time characteristics of the pulses
Formation of mixed clusters in a pulsed supersonic helium-oxygen-isoprene jet
An experimental study of the formation of mixed van der
Waals oxygen-isoprene complexes, generated in an expanding supersonic
helium-oxygen-isoprene jet at various stagnation pressures and at diverse
oxygen and isoprene concentrations, has been performed. To measure the
composition and distribution of the partial densities of the individual
components, molecular beam mass spectrometry was adapted to pulsed modes of
gas source operation. The particularities of applying mass spectrometry to
studying clustered isoprene streams in a pulsed mode have been discussed.
The composition of small clusters generated in a free supersonic jet has
been checked for dependencies upon the initial mixture composition and
stagnation pressure. The mechanism of nucleation has been identified for
different partial concentrations of impurities in the helium stream. It has
been shown that, even at a 0.3% concentration of isoprene in the mixture,
nucleation starts with the formation of hydrocarbon complexes. The specific
features of the dissociative ionization of van der Waals complexes,
consisting of pure isoprene and mixed complexes, have been discussed. The
conditions needed for the formation of binary oxygen-isoprene van der Waals
complexes have been identified