Персона: Максименко, Владимир Викторович
Email Address
Birth Date
Результаты поиска
Particle Generation in the Corona-Discharge Zone
Abstract: Experimental data on particle generation in the corona-discharge zone are obtained. The size distribution of these particles is measured as a function of the discharge parameters. The particle-size spectra are shown to slightly depend on the polarity of the corona point and are only determined by the potential difference and current strength. Various materials such as iron, copper, silver, molybdenum, tungsten, and graphite are the objects studied. The measurements are carried out under normal conditions in various gaseous atmospheres such as air, nitrogen, and argon. A theoretical model for the interaction of corona-discharge plasma with a metal surface is developed. The extraction of atoms from lattice sites supposedly occurs as a result of collective excitations of the electron gas in the metals. This theoretical model is based on the resonant excitation of a plasmon in the surface layer of a metal upon the inelastic scattering of charged particles of a corona discharge on the electrons of a metal sample. It is shown using the electrostatic-imaging method that the Coulomb interaction of a negative-charge-density wave on the surface with a surface ion of the crystal lattice is capable of extraction the ion from the metal. The interaction cross section of this process is estimated. These results are in qualitative agreement with the experimental data, which confirms the validity of the chosen interaction model. © 2022, Pleiades Publishing, Ltd.
Destruction of real metal surface due to EM-field localization in fractal system of cracks
© 2020 Elsevier B.V.A new physical mechanism is proposed in order to elucidate how properties of a metal surface can differ from those of bulk metal. It is related with localization of an external electromagnetic field in the cracks on the surface. The localization decreases Van der Waals attraction between opposite sides of the cracks. This causes the appearance of new cracks. When the system of cracks has fractal structure, this self-sustaining process leads to the appearance of a finite volume interface between the metal sample and vacuum. This additional volume manifests itself as a swelling and destruction of the sample.
Numerical Study of Bacteria Containing Droplets Aerosolized From Hot Surfaces
© 2020, The Author(s).The process of water droplet interaction with hot surface can result in droplet shooting off the surface. When the water is contaminated with bacteria the interaction causes substantial ambient air contamination due to aerosolization of live or injured microorganisms. This study investigates the behaviour of water droplets interacting with heated surfaces in the film boiling regime. A suggested mathematical model considers droplet shooting off conditions and following airborne droplet evolution due to cooling. The critical size of the droplet capable of taking off was modelled as a function of the wall temperature and droplet size. Following the departure from the hot surface, droplet cooling time mainly depends on the initial droplet radius while the influence of the ambient temperature is marginal. The experimental part of the study was focused on (1) investigation of the size of droplets capable of departing from the hot surface, and (2) evaluation of the influence of cooling time on the survivability of two common environmental bacterial species, Gram-negative Escherichia coli and Gram-positive Bacillus subtilis. Droplets with the sizes of up to one millimetre shooting off the hot surfaces were detected, which correlates with the theoretical results. It was found that, under realistic physical conditions, the process of liquid interaction with hot surface does not ensure an efficient microbial inactivation. It was also shown that the shortest cooling time was associated with higher survival rates of both bacterial strains used in this study. However, even for the longest cooling time of 15 seconds the amount of live bacteria in the aerosolized droplet carrier can be substantially high with recovery rates of approximately 50% for B. subtilis.
Study of Aerosol Nano- and Submicron Particle Compositions in the Atmosphere of Lake Baikal During Natural Fire Events and Their Interaction with Water Surface
© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.In 1996, Lake Baikal was declared a UNESCO World Heritage Site. It contains nearly 25% of the world’s fresh surface water. In recent years, anthropogenic impacts on the ecosystem of Lake Baikal have been increasing due to the development of industry in the region, expansion of the tourist infrastructure, and recreational areas of the coastal zone of the lake. In addition, an increase in the frequency of forest fires has already led to irreversible destructive processes in some areas of the lake. This project investigates the behavior of anthropogenic and natural atmospheric aerosols during forest fires that swept large areas of Siberia and their potential transportation onto Lake Baikal surface. It was found that quite substantial nano-size and submicron aerosol fluxes could reach the water surface and alter ecosystem of the lake. Such outcome is especially important as the amount of pollutants transported through the air–water interface during bush fire events is almost one order of magnitude higher as compared to the fire free scenario.