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The Rosaceae family plays a leading role in the dendroflora of Armenia. The Pyrus, Sorbus, Crataegus, Cotoneaster, Rubus and Rosa genera representing the family are of great importance in Armenia in the formation of various plant coexistences. With its species composition and taxonomic diversity, Crataegus is one of the largest genera in the Rosaceae family. Growing in Armenia in low, medium and high mountain zones, Crataegus has a great role in the formation of dendroflora: they are an important element of a number of forest coexistences, form a sub-forest with other representatives of dendroflora, grow in arid sparse forests, scrub, shoreline areas of mountain rivers. Crataegus is a valuable plant resource. Some species produce tasty and nutritious fruits that are rich in sugars, organic acids, mineral salts and vitamins. Since ancient times, the people of Armenia have used it in food and folk medicine, for example there is a decoction of hawthorn root and bark dyed threads. Currently, Crataegus has great economic importance. Drought-resistant and frost-resistant species are used as grafts for obtaining high-value varieties of apple, pear, and quince, decorative species are suitable for greening cities and settlements, creating living fences. Furniture and carpentry tools are made from its hard and strong natural wood. Due to their hardiness, some species of Crataegus are promising for the creation of arid arboretums in the lower and middle mountain zones of Armenia. In Armenia the genus Crataegus is represented by 23 species belonging to three sections: Crataegus, Pentagynae C. K. Schneid. and Azaroli Loud. Species C. ulotricha Pojark. ex Gladkova, C. razdanica Pojark. ex Sargsyan, C. gabrielianae Pojark. ex Sargsyan, C. susanykleinae Gabrieljan et Sargsyan and C. gregorianii Gabrielian et Sargsyan are endemic to Armenia. An updated key is provided to identify species based on new data. Altitudinal and geographical distribution of species, habitat, flowering and fruiting time are given.

Objective: To search and select the most suitable dispersion media for adsorption immobilization, effective as a complex carrier, with the possibility of their further application in the food industry

The development and implementation of new technologies for enriching the finished product with trace elements is important and relevant. Deviations in the elemental state of the body are found in the vast majority of the adult population of Russia, significantly differing in nature and degree of severity in representatives of different regions and persons divided by profession and occupation. At the same time, it is recognized that in Russia, on average, about two-thirds of adults and three-quarters of children are classified as at risk for hypomicroelementosis, on the other hand, about one-third of the population is more or less susceptible to hypermicroelementosis. The most common deficiency of trace elements such as iron, zincum, copper, chromium, iodine, selenium, cobalt, silicium. The main problem of detecting microelementosis is that the deficiency of essential elements does not have a pronounced clinical picture. To correct the finished formulations of products, it is necessary to take into account the indicators of the level of absorption and the rate of release of these elements, as well as ways of their disposal in the body. One of the most effective ways to introduce essential and conditionally essential elements into formulations is the immobilization of colloidal solutions with a high content of these elements on a polymeric materialor protein carrier, followed by introduction into the composition of the prepared product. The efficiency of using elements such as silver, gold, zinc, cobalt and selenium as a colloidal phase is described. Antagonistic and synergistic interactions of essential elements, their effect on the body, taking into account the indicators of absorption and the rate of their excretion, are described.

Low-temperature plasma is used in metallurgy for steel alloying by nitrogen, deoxidization of magnetic alloys, obtaining of steels with particularly low carbon content, metal cleaning of nonmetallic inclusions, desulfurization and other refining processes. The wide application of those technologies is restrained by absence of reliable generators of low-temperature plasma (GLP) with sufficient resource of continuous operation. As a result of studies, a universal generator of high-enthalpy plasma jet of various working gases was created. The generator has expanding channel of the output electrode with an efficiency of ~60 % for argon working gas and ~80% for nitrogen and air. It was shown that the developed generator of low-temperature plasma ensures formation of a weakly diverging (2α = 12°) plasma jet with a diameter D = 5–12 mm, an enthalpy of 5–50 kJ/g and a mass average temperature of 5–10 kK, at a full electric power of the arc discharge of 5–50 kW and a plasma-forming gas flow rate of 1–3 g/s. Results of the study of propane additions to the plasma-forming gas effect on the state of cathodes with inserts made of pure tungsten, lanthanum tungsten, and hafnium presented. It was shown that a small propane addition (1%) to the plasma-forming gas, results in reducing effect of the insert material. Study of the GLP operation at arc current 100A with addition to the working gas nitrogen maximum possible volume of propane, which don’t disturb stability of arc showed that for the developed plasma generator at the nitrogen flow rate ~0,45 g/s, the propane flow rate was ~0,33 g/s (not more than ~73 % of the plasma-forming gas). The created high-resource GLP with changeable electrodes enables to obtain at the exit a high-enthalpy plasma flow of various gases (argon, nitrogen, air) and can be a prototype of more powerful plasmotrons of various technological application, in particular for plasma metallurgy.

The general approach to study the properties of the mechanical deformations of solid nematics, which are the macroscopic homogeneous elastic media having the rotational symmetry of the nematic liqu...

We have experimentally investigated lasing peculiarities in a cholesteric liquid crystal – dye-doped polymer layer – cholesteric liquid crystal three-layer wedge-cell system with different laser dy...

We study the possibility of application of direct laser writing technique for the fabrication of large-size uniform phase structures in the bulk of the borosilicate glass N-BK7. The morphology and the type of modifications induced by the sub-picosecond (500 fs) pulses are studied depending on the energy dose of irradiation. We show that with moderate focusing and at pulse energies below the threshold of self-focusing effects, it is possible to choose writing regimes (the scanning speed, the repetition rate of pulses) which allow the fabrication of extended structures with flat modification of the glass refractive index in the layer-by-layer scanning mode. At higher peak intensities of the laser, the Kerr nonlinearities affect the pulse propagation and the dynamics of the relaxation processes, and the resulting structures are essentially inhomogeneous with the alternating sign of refractive index change. To validate the approach, a buried phase structure with large dimensions was fabricated showing a rather uniform refractive index change over the entire processed range.

Introduction. The pharmacological market, which is rapidly developing, as well as the appearance of combined forms of drugs, determine the trend in the conservative treatment of patients with symptoms of the lower urinary tract due to benign prostatic hyperplasia (BPH). However, simultaneous administration of drugs from several drug groups, by the patients, who are burdened with concomitant diseases (cardiovascular disease, diabetes) in certain cases, makes surgical treatment of BPH preferable and sometimes the only possible option. In this instance, the doctor’s task is to choose the optimal method of surgery that minimizes the risks of complications and provides a long-term clinical effect. The actively developing technique of endoscopic enucleation of prostate corresponds to the current needs. Various types of energies, which have appeared lately in urological practice for enucleation of the prostate, have become an attractive alternative to transurethral resection of the prostate (TURP). The introduction of a bipolar technology into clinical practice has allowed to significantly expand the use of operations among elderly patients with comorbidities. Laser endourology has gone further in reducing the risks of possible complications. Currently we are witnessing a lack of research, which compares the use of modern methods with bipolar TURP (B-TURP) in elderly patients, i.e. groups with a high risk of intraoperative & postoperative complications.Purpose of the study. To compare the results of various types of BPH endoscopic surgical treatment in elderly patients (> 60 years old).Materials and methods. The study included patients who underwent three different operations treating BPH (B-TURP, B-TUEP, HoLEP) from October 2017 to September 2018. The criteria for inclusion in the study were as follows: the presence of moderate or severe obstructive symptoms of the lower urinary tract, prostate volume > 40 cm3, maximum urine flow Results. 190 patients operated during the year were examined in the current study. Duration of operation, extent of resection, time of postoperative catheterization and duration of hospital stay rates were significantly lower in the HoLEP group. There have been no cases of complications above the 3 level by the Clavien‒Dindo scale.Conclusions. HoLEP is the preferred method of surgical treatment of prostatic hyperplasia over 40 cm3 in terms of surgical safety, efficacy, and the duration of the patient’s recovery period. This method can serve as an alternative to electrosurgical techniques in elderly patients.

To study the thermophysical, electrophysical and optical properties of argon, as well as the implementation of various plasma-chemical reactions, a direct-current generator of a high-enthalpy argon plasma jet with a self-adjusting arc length and an expanding channel of the output electrode has been developed. A comparative analysis of the electrophysical characteristics (current–voltage characteristics—CVC, efficiency) in the expanding and cylindrical channels of constant cross section was carried out. Electrical, calorimetric and spectral studies have shown that the created generator of low-temperature plasma provides the formation of a slightly divergent plasma jet of argon with a diameter of 5–8 × 10–3 m and enthalpy of 5–10 MJ/kg and a mass-average temperature at the outlet of the gas-discharge channel of 5–12 × 103 K with an electron concentration in the axial plasma of 1017 cm–3, the total electric power of the arc discharge 2–10 kW and the plasma-forming gas consumption rate of 1.5–3 × 10–3 kg/s. Depending on the initial conditions at a distance of 0–3 × 10–2 m from the nozzle section of the low-temperature plasma generator, the plasma flow velocity varies from 990 to 300 m/s.

A new peculiar species Crataegus gregorianii is described from the Dalar (Arzakan) River gorge, from Aparan floristic district of Armenia. The species clearly differs from the other hawthorns by complete absence of thorns as well as by 3-lobed, shiny dark green leaves, broadly falcate-denticulate stipules, as well as barrel-shaped fruits with narrow, pear-like base.

The spatio-temporal structure and plasma parameters of a new type of glow discharge—atmospheric-pressure interelectrode microwave discharge in gas flow—were studied experimentally and numerically. A multi-electrode coaxial-type cold plasma torch developed for large-area surface treatment was used as a gas discharge device. The torch was supplied with microwave power (2.45 GHz, ∼100 W) via a coaxial cable by a typical wave-guide plasmatron. Self-sustained glow discharges were excited between the round ends of the rod-like electrodes and inner wall of the cylindrical discharge chamber near the outlet. The filamentation of the discharge channel in the near-electrode regions was detected by high-speed video filming. The dendritic self-similar (fractal) character of the filaments’ structure was revealed and analyzed. The branching factor and fractal dimension of this structure were estimated as 3 and 1.1–1.3, respectively. Using discharge gas temperature T g = 1200 ± 100 K, as determined from the emission spectroscopy measurements, the following discharge plasma parameters were obtained from numerical calculations: electron temperature T e = 1.14 eV and concentration n e ∼ 10 21 – 10 22 m−3, conductivity σ ∼ 400 Ω − 1 m − 1 , current density j ∼ 10 6 A m−2, and electric field strength E ∼ 10 4 V m−1.

Goal: To study the peculiarities of the course of acute glomerulonephritis in youngmen. Material and research methods: Current study presents the results of clinical examination of 150 youngmen, aged 18-22, who were hospitalized with acute glomerulonephritis. The control group consisted of 50 practically healthy youngmen. Results: The study results showed, that subclinical liver injury was observed in 66 out of 150 examined patients with acute glomerulonephritis, the cause of which can be hepatotoxic effects of antipyretic drugs, taken in the early stages of the disease. In general, liver injuries occurred in acute glomerulonephritis caused by streptococcal infection. Moreover, manifestation of liver injury did not depend on the dose of medicine. Due to toxic and immunological liver injury, levels of transaminases increase and albumin levels decrease.

The paper considers various causes of explosions on the cathodes surface in the region of arc attachment in a direct current arc discharge. Estimates of the characteristic times of the development of instabilities during the passage of current through the liquid tip of the cathode are made. As a result, an assumption was put forward that, starting from the moment of formation of the stretched tip and up to the explosion, at different stages of the stretches development, various instabilities alternately play the main roles.

A one-step procedure has been developed for the synthesis of previously unknown ethyl 5-(arylcarbamoyl)-6-methyl-2-oxo-1,2-dihydropyridine-3-carboxylates by reaction of ethyl 2-cyano-3-ethoxyprop-2-enoate with acetoacetanilides in the presence of a catalytic amount of piperidine in ethanol at room temperature.

The reaction of (ethoxymethylidene)cyanoacetic ester with arylamides of acetoacetic acid proceeds under heating in the presence of triethylamine or at room temperature in the presence of sodium ethoxide. According to the NMR and IR data, the intermediate adduct undergoes no other transformations but azacyclization which predominantly involves the cyano group and forms ethyl 5-acetyl-1-aryl-6-hydroxy-2-imino-1,2-dihydropyridine-3-carboxylates in yields of 30–78%. In some cases, 5-acetyl-1-aryl-2-hydroxy-6-oxo-1,6-dihydropyridine-3-carbonitriles resulting from cyclization involving the ethoxycarbonyl group were isolated as minor products (3–12%).

The results of experimental investigations of the noise temperatures of the RT-13 radio telescope receiver system of a two-element radio interferometer with a very long baseline in the 2.2–2.6, 7.0–9.5, and 28–34 GHz frequency range are presented. The measurements were taken by wide-aperture low-temperature noise generators developed and certified on the standard baseline of VNIIFTRI. The error of measuring the noise temperatures of the radio telescope receiver system was determined. The confidence limits of the measurement error (for fiducial probability P = 0.95) were not more than 3.7 K.

A complex of wide-aperture, low-temperature noise generators developed and certified at the All-Russia Research Institute of Physicotechnical and Radio Measurements (VNIIFTRI) and intended for metrological assurance of the RT-13 radio telescopes of a two-element radio interferometer with very long baseline is described. The results of studies and calibration of standard and working wide-aperture, low-temperature noise generators needed for metrological assurance of instruments used in the measurement of radio brightness and noise temperatures in the microwave region of the spectrum from 2 to 40 GHz are presented.

An experimental set-up with a unified system of synchronized control signals was constructed to study the interaction of high-enthalpy plasma jet with the surface of heat-resistant materials. The analysis of air–plasma stream interaction with technical (isotropic) graphite is performed. The air–plasma jet has a temperature of 7000–8000 K in the interaction zone, this interaction is accompanied by destruction of the graphite material and lasts for 100–200 s. Using methods like two-positioning visualization, micropyrometry and spectroscopy the following data are obtained: temperature fields on the graphite sample’s surface and their temporal and spatial changes, dynamics of the sample’s mass loss rate, changes in the parameters (temperature and concentration of electrons, heavy particles temperature) of the incoming plasma stream.

The article is devoted to the goals and issues of formal description of Armenian word formation. Although recently formal description of the language has become more practical, it should be noted that the full formal description of the Armenian language has not been done yet. The author of the article states that the formal description of the Armenian vocabulary will enable to reveal as the regular structures, as well as the variative forms, deflections, and irregularities with frequency data with their automatic analysis and the possibility of derivation. It has an informative value, it can clarify and explain many problems in Armenian linguistics, and also can give much material for the further researches of Armenian grammar.

To improve the technology and extend the assortment of bakery products of preventive and functional orientation by introducing extracts of succulent plants, in particular aloe and kalanchoe, the authors have analyzed the process of extraction of vegetable materials and selected optimal conditions: process temperature - 100 °C, duration - 24 hours, the nature of the extractant - water, both for the aloe and kalanchoe extract. The study revealed that by adding the extracts to the semi-finished buns the quality of the products in organoleptic and physico-chemical parameters is not inferior to the control (without adding the plant extracts), and in some cases it becomes better, the optimum dosage is 8% of plant extracts of the amount of water in the dough. Based on the microstructure of the buns’ crumb it was found that the crumb with the addition of 8 % of plant extract in place of the amount of water in the recipe has a uniform structure, which was expressed in an increase in the pore diameter compared to other samples and a stable structure of micro-bridges between them. Such a micro pattern characterises the finished product, which has excellent quality parameters.

The effect of propane-butane addition to the plasma-forming gas on the state of cathodes with inserts made from lanthanated tungsten and hafnium is investigated. With a small propane addition (1%), the restorative effect of the insert material is noted, and the propane consumption has an upper limit when it is introduced together with the plasma-forming gas (no more than ∼ 73% of the plasma-forming gas consumption), below which the arc stability is not disturbed.

On the basis of studies of the electrophysical characteristics of a low-temperature nitrogen plasma flow, a procedure for verifying the thermophysical properties and establishing regularities in the formation of the structure, phase composition, and properties of a metal when steels surface is exposed to plasma, plasma exposure modes were determined for modifying the surface of metals and alloys used in various applications, such as nuclear power plants.

Plasma-arc heating of periclase-carbonaceous refractory was experimentally tested. A high heating rate of 600°C/h was achieved. The experimental results were used to correct the thermal characteristics of raw refractory and to determine the energy characteristics of the arc discharge. Raw periclase-carbonaceous refractory has high heat conductivity (25 W/(m·K)) and low emissivity (0.3). The radiated power (130 kW) of the discharge is calculated from spectral measurements of an argon plasma arc with a current of 1000 A and an arc voltage of 150 V. The obtained data are used to specify the parameters of the CFD-model of plasma-arc heating of periclase-carbonaceous refractory.

The food industry has a very wide range of methods and means of influencing raw materials to give them the required technological properties. One of the prospective and effective physical methods of processing raw materials and food products, according to a number of studies, is ultrasound, which helps to increase productivity, reduce energy costs, improve the quality of finished products, extend shelf life, and most importantly, ensure safe and minimally processed products. To prevent microbiological deterioration, the products are subjected to various treatments, the main of which is the effect of low temperatures (cooling, freezing) or high temperatures (pasteurization, sterilization). However, these methods either slow down microbiological processes or reduce the nutritional and biological value. In this regard, the study of innovative methods that guarantee the consumer safe and minimally processed products, one of which is the method of ultrasound processing becomes particularly relevant. The impact of ultrasonic waves on physical and chemical processes occurring during the cooling process can improve the quality of the finished product, increase storage time, reduce energy consumption and create products with new consumer properties.

In this work, the behavior of cathodes made from pure tungsten and pure hafnium in the direct current electric arc at 200 A and in atmospheric pressured argon medium was investigated. The research was focused on the processes happening with the cathodes during the arc initiation phase (first 100 ms after the power input). The processes of rapid cathode destruction were registered, and can be characterized as the destruction of the cathode in liquid phase due to electro-magnetic forces. Characteristic times of the whole process were recorded, as well as the changes in temperature fields on the cathodes surfaces and the rate of mass loss for both types of cathodes. It has been shown that the initial destruction of the cathode plays a major role in the cathodes resource life.

A low-temperature plasma generator of a mixture of nitrogen and propane has been developed, with the possibility of supplying propane to the cathode region, to the arc burning zone, and also to the plasma stream below the arc binding zone. The maximum propane flow rate for a given plasmatron design and plasma-forming nitrogen flow rate, at which the arc is stable, was determined. When propane is supplied into the arc binding zone, the decay products are deposited mainly on the electrodes, and when it’s supplied to the anode after the arc binding, the decomposition products are deposited mainly at the anode exit. The study of the microstructure and analysis of the phase composition of the decomposition products of propane were performed.

The analysis of the current state of the technological process and equipment for plasma coating of various powder materials has been carried out. To increase the processing efficiency during the deposition of ceramic materials and refractory alloys a novel technological scheme of plasma spraying with a powder feed axially to the cathode was proposed and preliminarily tested. Basing the plasma torch with an expanding channel of the output electrode its plasma-spraying version has been developed in which the sprayed powder was supplied both to the cathode or anode arc striking zone and to the current-free plasma jet. The electrophysical parameters of the argon plasma torch and the speed, size and temperature of particles of sprayed powder were investigated. It was shown that the particle velocity of Al2O3 powder depending on the gas flow and arc current reaches up to 100 m/s. The temperature of the powder particles in the vicinity of substrate at a current of 300 A approximately equals to 2400–2500 K.

With the aim of studying nitrogen plasma flow impacting graphite surfaces, we investigated the evolution of a plasma jet moving from the nozzle of the plasma torch to the target. The motion is accompanied by a decrease in temperature from 10 to 7 kK with a loss of ≈ 60% of the deposited energy and an increase in the density of carbon-containing impurities with partial preservation of the local thermodynamic equilibrium. The main reactions are thermal processes of the formation and decomposition of molecules, dissociative recombination and recharging of nitrogen ions. In the presence of carbon impurities, this set is supplemented with the substitution reaction C + N2 ↔ CN + N, electron-collision processes of stepwise ionization and recombination, and a whole ion-molecular cascades of reloads and substitutions. It has been established that a small admixture of carbon (∼ 0.1%) manifests itself only in ion-molecular kinetics, increasing the electron concentration, determining the ionic composition of the plasma, and thereby violating the equilibrium between its neutral and charged components. This leads, in particular, to the recombination nonequilibrium distribution of carbon atoms over electronic states. Other carbon-containing impurities (CN and C2) are not significant.

The measurements and analysis of the emission spectra both of atmospheric-pressure electrode microwave discharge in argon flow and cold plasma jet induced by the discharge are conducted. We used experimental setup based on the previously developed multipurpose 2.45-Hz-plasmatron with the external portable discharge chamber (plasma torch) with the outlet of 2.5 cm in diameter and power of about several hundred watts. Discharge chamber has 6 rod-like electrodes which form a regular hexagon in a cross section of the torch. Discharge channels are formed between the ends of the electrodes and the inner wall of the chamber. Molecular bands of NO, OH, N2, NH and atomic lines of Ar were found in the spectrum of the discharge channels. Based on the analysis of the spectra, it was shown that the gas temperature in the discharge channel was about 1200 K. In the cold plasma jet spectrum, due to its weak luminescence, only the molecular lines OH and N2 were reliably observed.

In the present work, the structure of the discharge channels glow of a discharge with a liquid cathode at different pH values of the solution at a given concentration of alkali metal (Na) ions in the solution is investigated by the methods of emission spectroscopy and high-speed photography. The dependence of the atomic sodium line intensity in the emission spectrum of the discharge plasma from the pH value of the solution is investigated. The dependence of the discharge channels filaments shape on the presence of sodium impurities in them is found. The spatial and temporal inhomogeneity of sodium luminescence in the emission spectrum of the discharge channel of a discharge with a liquid cathode at different pH values of the solution is studied. Its connection to the mechanism of sodium transfer into the gas phase is discussed.

We present results of spectroscopic measurement of electron temperature in submerged nitrogen and argon mixture plasma jet for cases of free flow and introduction of thin graphite rod into the jet. The observed cooling of plasma caused by rod introduction agrees with the calculated enthalpy decrease from graphite rod heating and ablation. In this experiment, a marker was used to create artificial optical inhomogeneities in the flow, which allowed us to determine flow velocity from the analysis of their movement. In this case, we aim to determine the degree of influence of rod introduction into the plasma on its parameters. Upon introduction into the plasma, the rod was heated and partially destroyed by the plasma flow, reducing its temperature by 8-20% depending on the flow rate of the plasma-forming gas. The observed plasma cooling was compared with the calculated decrease in enthalpy caused by the cost of heating and ablation of the rod material.

Reactions of ethoxymethylidenemalonate with malonic acid N-arylamidoesters in the presence of triethylamine afforded diethyl 1-aryl-6-hydroxy-2-oxo-1,2-dihydropyridine-3,5-dicarboxylates via the cyclization of Michael adducts. In the presence of sodium ethoxide the formed adducts may be also involved into simultaneous retro-Michael reaction leading to the formation of ethyl 1-aryl-5-arylcarbamoyl-6-hydroxy-2-oxo-1,2-dihydropyridine-3-carboxylates. Direction of heterocyclization or retro-Michael reaction is determined by the acidity of the hydrogen atoms of adducts and basicity of catalyst.

A method is described for the plasma heating of steel in the tundish of a continuous caster. Results are presented from studies of the mechanical properties of rolled products made of steel that was cast after being heated above the liquidus temperature by different amounts. The degree of superheating of the steel was stabilized by having it undergo plasma heating in the tundish. Tests of rolled products of continuouscast steel showed the positive effect of its plasma heating.

Michael addition of ethyl N-arylmalonamates to ethyl 2-(ethoxymethylidene)-3-oxobutanoate in ethanol in the presence of triethylamine at room temperature afforded the corresponding adducts which underwent cyclization to diethyl 1-aryl-6-methyl-2-oxo-1,2-dihydropyridine-3,5-dicarboxylates in 17–65% yield. N-Alkylmalonamic acid esters failed to react with ethyl 2-(ethoxymethylidene)-3-oxobutanoate under analogous conditions.

We have developed and studied a new effective megawatt double-unit generator of low-temperature argon plasma, which belongs to the class of dc plasmatrons and comprises the cathode and anode units with divergent gas-discharge channels. The generator has an efficiency of about 80–85% and ensures a long working life at operating currents up to 4000 A.

Dynamics of the discharge with a liquid cathode was studied using the method of high-speed visualization. The video data was compared with the emission spectra of the discharge plasma. Electrical parameters of the discharge were measured. The effect of organic impurities in the solution on the discharge parameters was investigated.

The parameters of a non-pulsed dc arc discharge of atmospheric pressure in argon were experimentally studied, and the chemical composition of the cathode surface in the arc binding zone was studied. The measurements were performed for thoriated tungsten cathodes (W-2% ThO2) for currents of 200 and 300 A. During the operation of the plasma torch, the temperature and electron concentration in the positive column and the surface temperature of the cathode were measured. A computational and theoretical analysis was performed on the distribution of current density and electric field strength in the arc binding zone. As a result, three fundamentally different zones of the arc binding area were identified, and their size and chemical composition were determined.The parameters of a non-pulsed dc arc discharge of atmospheric pressure in argon were experimentally studied, and the chemical composition of the cathode surface in the arc binding zone was studied. The measurements were performed for thoriated tungsten cathodes (W-2% ThO2) for currents of 200 and 300 A. During the operation of the plasma torch, the temperature and electron concentration in the positive column and the surface temperature of the cathode were measured. A computational and theoretical analysis was performed on the distribution of current density and electric field strength in the arc binding zone. As a result, three fundamentally different zones of the arc binding area were identified, and their size and chemical composition were determined.

In this work the detailed structure of a direct current discharge with a liquid cathode was studied by high-speed imaging and emission spectroscopy. The movement of filaments into which the discharge channel is divided is studied. The processes of formation and destruction of filaments are investigated. Spectra were recorded at different distances from the liquids surface on the discharge axis. The dependences of the luminescence intensity of the main spectral lines and bands on the distance to the liquid surface at different discharge currents are found.