Dmitry V. Bychkov

Air–Propane Mixture Ionization Processes in Gas Discharges

Investigations devoted to the analysis of effective ionization processes at early discharge stages in propane-air mixture, at propane concentration of <10% at atmospheric pressure, are the first necessary step before the analysis of air-propane discharge in real conditions. Necessary parameters of excitation and ionization in these mixtures have been determined in a wide range of electric field. Thresholds of ionization in these mixtures have been calculated.

Corona Discharge Over Liquids With Powder Addition

Corona discharge over a surface of alcohol, water, and kerosene with aluminum powder addition is applied to realize and visualize a number of electrohydrodynamic phenomena at the interaction of the discharge with a surface of the liquid. Thin aluminum powder film allows to visualize funnels and motion in them appearing under an ion wind impact.

Non-Selfmaintained Gas Discharge for Plasma Impact on Gas Flammable Mixtures

♥♥ Works on creation of non-selfmaintained discharge based on electron with the electron accelerator EOL -400 M for impact on propane-air mixture have been made. Experimental chamber, controlling devices, diagnostic complex and the reaction chamber for E-beam impact on the mixture and combustion have been created. All the equipment has been designed, manufactured and assembled. Works on modeling of electron-molecule processes in propane-air mixture in external electric field and E-beam have been made. Calculations of propane-air mixture in conditions of external electric field, electron-beam and their combination at different initial temperatures have been made.

Electron -beams for Plasma Impact on Gas Flammable Mixtures

Preliminary works on creation of electron beam based on the electron accelerator EOL -400 M have been made. Experimental chamber, controlling devices and the diagnostic complex have been created. All the equipment has been designed, manufactured and assembled. First experiments on inflammation of the flammable mixture in the chamber and injection of the beam into air and flammable mixture have been fulfilled. Works on choice of electron-molecule processes cross sections and rate constants in propane-air mixture in external electric field have been made. First calculations of propane-air mixture in hot conditions, under electric field, electron-beam and their combination have been made.

Connexin 43-targeted T1 contrast agent for MRI diagnosis of glioma

Glioblastoma multiforme is the most aggressive form of brain tumor. Early and accurate diagnosis of glioma and its borders is an important step for its successful treatment. One of the promising targets for selective visualization of glioma and its margins is connexin 43 (Cx43), which is highly expressed in reactive astrocytes and migrating glioma cells. The purpose of this study was to synthesize a Gd-based contrast agent conjugated with specific antibodies to Cx43 for efficient visualization of glioma C6 in vivo. We have prepared stable nontoxic conjugates of monoclonal antibody to Cx43 and polylysine-DTPA ligands complexed with Gd(III), which are characterized by higher T1 relaxivity (6.5 mM(-1) s(-1) at 7 T) than the commercial agent Magnevist® (3.4 mM(-1) s(-1)). Cellular uptake of Cx43-specific T1 contrast agent in glioma C6 cells was more than four times higher than the nonspecific IgG-contrast agent, as detected by flow cytometry and confocal analysis. MRI experiments showed that the obtained agents could markedly enhance visualization of glioma C6 in vivo after their intravenous administration. Significant accumulation of Cx43-targeted contrast agents in glioma and the peritumoral zone led not only to enhanced contrast but also to improved detection of the tumor periphery. Fluorescence imaging confirmed notable accumulation of Cx43-specific conjugates in the peritumoral zone compared with nonspecific IgG conjugates at 24 h after intravenous injection. All these features of Cx43-targeted contrast agents might be useful for more precise diagnosis of glioma and its borders by MRI.

Multielectrode Corona Discharge Over Liquids

Negative corona multielectrode discharge over a surface of alcohol is applied to realize a number of electrohydrodynamic phenomena at the interaction of the discharge with a surface of the liquid (alcohol). Funnels and liquid columns were realized in the case of two and four upper electrodes. Columns reveal realization of an instability of a surface of a liquid.

Electrohydrodynamic Peculiarities of Corona Discharge Interaction with a Liquid Surface

This study was devoted to experimental investigations of a corona discharge over the surface of the following liquids: tap and distilled water, alcohol, glycerin, and mixtures of alcohol with water and glycerin. One of the electrodes was placed over the liquid surface, while another one was submerged in it. Three modes of discharge over the liquid surface were obtained, namely an ordinary corona, an intermediate mode, and an arc discharge mode. In these modes, a funnel-shaped deepening, jets, and scattered jets directed toward the upper electrode were observed on the liquid surface under the action of the discharge. A qualitative mode of funnel formation on the liquid surface under the influence of an ionic wind induced by a corona discharge was presented. The formation of jets and scattered jets was related to the development of Tonks-Frenkel and Rayleigh instabilities.

Deeply undercritical microwave discharge excited by the field of a quasi-optical electromagnetic beam in a supersonic air jet

Electric discharge in a supersonic air jet is studied. It is ignited in a linearly polarized quasi-optical microwave electromagnetic beam the initial field intensity of which is much lower than the breakdown level. Electric breakdown is initiated by a tubular electromagnetic vibrator, one end of which has spikes and is covered by a quartz tube. Atmospheric air enters into a low-pressure working chamber through the inner channel of the vibrator. As a result, an immersed supersonic air jet forms in the chamber at the outlet from the quartz tube. A microwave discharge ignited in this jet is “attached” to aft spikes of the vibrator. The energy deposit into the discharge plasma and the effective area of energy interaction between the discharge and excited microwave field are estimated from the temperature and stagnation pressure distributions in the wake of the discharge.

Electrical discharge excited by the deeply undercritical field of a microwave beam in a high-speed jet of air and air-propane mixture

An electrical gas discharge initiated by a tubular linear electromagnetic vibrator is studied. The discharge is excited by the deeply undercritical linearly polarized field of a quasi-optical microwave beam. Experiments are conducted at a flow velocity of several hundreds of meters per second. The discharge region is photographed, and the stagnation temperature of the flow in the wake of the discharge is measured. It is shown that a deeply undercritical microwave discharge may arise in air even at such high flow velocities. Moreover, it is found that the discharge ignites and stabilizes the discharge region in a “lean” air-propane mixture. In such an experimental design, propane completely burns out when the flow velocity is smaller than some threshold value. When the flow velocity is high and the Mach number of the flow approaches unity, throttling effects and “thermal blocking” of the jet are observed.

Non-Selfmaintained Gas Discharge System Installation for Impact on Lean Flammable Gas Mixtures

Works on non-selfmaintained discharge system with a help electron beam installation for impact on propane-air mixture have been considered. New type of compact sealed off electron beam installation has been discussed. Works on modeling of electron-molecule processes in lean propane-air mixture in external electric field under impact of the E-beam and external electric field have been made. I. Introduction his paper is devoted to continuation of investigations [1-3] on application of the nonselfmaintained discharge with the application of the electron beam (Eb) accelerator for irradiation of the propane-air mixture. In [1-3] we have created the experimental chamber, controlling devices and the diagnostic complex for Eb experiments. First experiments on inflammation of the flammable mixture in the chamber at the application of the ignition system, of the external electric field and of the ignition system and a combination of the Eb and the electric field in air and flammable mixture have been fulfilled. In the experiments we used the industrial electron accelerator EOL -400M have. The combination of the external electric field and the electron-beam plasma create a non-selfmaintained discharge. The Plasma of the non-selfmaintained discharge has been realized in the conditions without the ignition of the propane-air flow and with it. Experiments on the inflammation of the flammable mixture [1-2] in the chamber and at the injection of the beam into air and flammable mixture have been fulfilled. Experiments have shown sharp increase in the temperature at application of