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[en] It was investigated the oxidation of zirconium metal in air with an atmospheric pressure in the range of temperatures T=373 - 973°C by the thermo gravimetric method. It is revealed that processes of oxidation in all studied ranges of temperatures with high precision are described by linear dependence on time. It was noted periodic change of rate of oxidation from time in experimental works. The oxide layer which was formed on a sample surface at long oxidation in comparison with an initial sample has become covered by network of deep cracks. Zirconium and its alloys are the main constructional materials applied in the atomic industry to production of fuel elements of atomic reactors (1-3, 7, 9). Conditions of their operation are very extremal: high temperature, existence of the oxidizing environment (superheated water vapor) and rather high pressure against the background of intensive radiation effects. But zirconium is quite active metal. It reacts with oxygen and nitrogen, and with water vapor, carbon dioxide, and also with hydrogen and hydrocarbons. Nvertheless, use of zirconium as material for reactors was promoted by its property to form the strong and chemically steady oxide films protecting him from corrosion on a surface.
[en] Full text: There are principal possibility of performing the reaction of reduction ammination of monoethanolamine in presence of Ni-Co BP4 γAl2 O3 - catalyst at atmospheric pressure in this work. It has been degtermined the next conditions of reaction in the investigated range: Temperature 563-623 K; conditional contact time 10-30 s; mole relation of monoethanolamine: NH3 :H2 = 1: 0,5 - 4,0 :2,0. The main products of conversion of the monoethanolamine are ethylendiamine, diethylentrianmine - the valuable components of low temperature hardener of the epoxy resin
[en] Atmospheric-pressure plasmas (APPs) have attracted great interest and have been widely applied in biomedical applications, as due to their non-thermal and reactive properties, they interact with living tissues, cells and bacteria. Various types of plasma sources generated at atmospheric pressure have been developed to achieve better performance in specific applications. This article presents an overview of the general characteristics of APPs and a brief summary of their biomedical applications, and reviews a wide range of these sources developed for biomedical applications. The plasma sources are classified according to their power sources and cover a wide frequency spectrum from dc to microwaves. The configurations and characteristics of plasma sources are outlined and their biomedical applications are presented. (invited review)
[en] Corona discharges in gases exist under several distinctive forms. In this paper, a survey study has been made of ac corona discharge modes generated in some different gases fed in a wire-duct reactor with a constant rate of flowing at atmospheric pressure. The properties of different corona modes are analyzed under some condition transitions from Trichel pulses to a steady glow. In the course of the presented experimental work, numerous apparent contradictions with earlier observations necessitated further study and are given to provide more information on the physical mechanisms of the ac corona discharges. Furthermore, we have gained insight into some new technologies and applications of the environmentally friendly corona and plasma discharges.
[en] Since air is a natural part of our environment, special attention is given to the study of plasmas in air at atmospheric pressure and their applications. This fact promoted the study of electrical conduction in air-like mixtures, i.e. mixtures containing an electronegative gas component. If the ionization growth is not limited its temporal evolution leads to spark formation, i.e. a thermal plasma of several thousand kelvins in a quasi-local thermodynamic equilibrium state. But before reaching such a thermal state, a plasma sets up where the electrons increase their energy characterized by an electron temperature Te much higher than that of heavy species T or T+ for the ions. Since the plasma is no longer characterized by only one temperature T, it is said to be in a non-thermal plasma (NTP) state. Practical ways are listed to prevent electron ionization from going beyond the NTP states. Much understanding of such NTP may be gathered from the study of the simple paradigmatic case of a discharge induced between a sharp positively stressed point electrode facing a grounded negative plane electrode. Some physical properties will be gathered from such configurations and links underlined between these properties and some associated applications, mostly environmental. Aerosol filtration and electrostatic precipitators, pollution control by removal of hazardous species contained in flue gas exhaust, sterilization applications for medical purposes and triggering fuel combustion in vehicle motors are among such applications nowadays.
[en] Atmospheric pressure plasma jet (APPJ) is non-thermal plasma source producing plasma at room temperature and is touchable by bare hands. In recent years APPJ has been developed as an innovative approach in life science for a wide range of applications, including its role in blood coagulation, cosmetics, dental and cancer treatment. However, the molecular mechanisms of interaction of APPJ with human cells remain unclear. In this report we present preliminary results on the interaction of APPJ with human lung cancer cell line (A549). Cells were cultured in 35 mm plates and treated with plasma for various time periods (2 min, 5 min, and 10 min). Cell viability was studied using MTT assay after 24h of plasma treatment. Our analysis showed a 50% decrease in cell viability after 24h indicating the effectiveness of APPJ in killing cancer cells. Further studies are currently underway to study the effect of APPJ on the reproductive cell death by measuring colony formation ability of these cells after 14 days. (author)
[en] Highlights: • HE for binary systems of cycloalkanones with n-nonane have been measured. • Experimental data were well represented by the Redlich–Kister equation. • The experimental results have been used to test the applicability of the Wilson, NRTL and UNIQUAC models. - Abstract: Excess molar enthalpies, HE, for the binary mixtures of cyclopentanone, cyclohexanone, or cycloheptanone with n-nonane were measured at T = 298.15 K and 0.1 MPa, by means of a Setaram Tian-Calvet MS80 microcalorimeter. All the binary systems investigated show endothermic behaviour (positive values) over the whole mole fraction range. The molar excess enthalpies decrease as the size of the cycloalkanone increases. The experimental results of HE are fitted to the Redlich–Kister equation to correlate the composition dependence. The experimental HE data are also used to test the suitability of the Wilson, NRTL, and UNIQUAC models. The correlation of excess enthalpy data in these binary systems using the UNIQUAC model provides relatively the most appropriate results
[en] Carbon nanostructures have received much attention for a wide range of applications. This paper reviews the historical role of plasmas in the gas-phase synthesis of carbon nanostructures and the present plasma technologies for industrial production purposes. It enumerates the advantages and disadvantages with respect to concurrent technologies commonly employed nowadays. Finally, some carbon nanostructures produced in our laboratory will serve as examples of the plasma processes potential. (review article)
[en] In this work, the superoxide ion was generated and analysed electrochemically using cyclic voltammetry (CV) techniques from oxygen dissolved in a room-temperature ionic liquid, 1-(3-methoxypropyl)-1-methylpiperidinium bis (trifluoromethylsulfonyl) imide, at atmospheric pressure. It was found that the generated superoxide ion was stable which indicates its possible use for further useful applications. To the best of our knowledge, this is the first time a piperidinium based IL has been used for the electrochemical generation of O2.