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We present a study of structural features of diamond coatings prepared by chemical vapor deposition from a hydrogen/methane mixture activated by a microwave discharge using a high-speed jet to transport the mixture to molybdenum substrates heated up to 525 °C, 690 °C, and 1000 °C. The influence of the substrate temperature on morphology, composition, and structure of diamond coatings are studied by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and near edge X-ray absorption fine structure. The diamond crystals enlarge in size, their density on the substrate increases, while the quality and the crystal surface purity are enhanced as a result of temperature increase.

The gas-jet method of the deposition of diamond-like structures using super-high-frequency (SHF) discharge for activating gases is considered. Direct statistical simulation is applied to analyze the gasdynamic processes occurring in the conditions of the gas-jet deposition of diamond structures. An activated gas flow in a nozzle is investigated and a considerable influence of the processes in the compressed layer formed near the substrate on the rate of synthesis of diamond structures is established. The regimes of flow of mixture components activated in the discharge chamber toward the substrate are determined and a considerable deceleration of heavy components in the compressed layer is found to exist. It is shown that with increase in the pressure in the deposition chamber from 10 to 80 Torr the crystal growth rate increases fourfold at the expense of an increase in the specific flux of the activated components toward the substrate.

A method of gas-phase deposition of diamond structures with the use of high-velocity jets for transporting gases activated in a microwave plasma to the substrate is developed. The diamond structures are synthesized from a hydrogen–methane mixture with the methane concentration of 1%. The influence of the gas mixture flow rate on the synthesis of the diamond structures with an unchanged composition of the mixture, pressure in the deposition chamber, and substrate temperature is studied. It is found that an increase in the flow rate leads to an increase in the polycrystalline film density and in the size of the diamond crystals forming the film. The composition of the mixture at the discharge chamber exit is numerically analyzed for different flow rates of the gas mixture. A correlation of the mixture composition with the growth rate and quality of the diamond structures is demonstrated.

A new method of gas-phase diamond deposition with a high-velocity jet used to transport gases activated in microwave plasma to a substrate is developed. Diamond was synthesized from a mixture of hydrogen with the addition of 1% methane. The deposition rate (78 μm/h) was more than an order of magnitude higher than that achieved earlier in experiments with activation of similar initial mixtures in microwave plasma.

The paper describes synthesis of diamonds by the method of gas-jet deposition with microwave activation of precursor gases. This method involves the use of a supersonic jet for delivering the components activated in the discharge chamber to the substrate located in the deposition chamber. A series of experiments was carried out with different amounts of methane supplied at a hydrogen flow rate of 8000 sccm. The obtained samples of diamond coatings were studied by scanning electron microscopy and Raman spectroscopy. The temperature of the mixture and the intensities of H, CH, and C2 lines in the plasma of the discharge chamber were measured by optical emission spectroscopy. The values of pressure and temperature in the discharge chamber were used to estimate the composition of the mixture. Thus, the numerical dependences of the molar concentrations of CH3, CH, C2 and C2H2 on the initial concentration of methane have been obtained. These dependences are in qualitative agreement with the dependences of the intensities of H, CH, and С2 lines. The numerical-experimental study performed allows us to conclude that the optimal value of methane concentration in the supplied mixture for the gas-jet deposition method in the considered range of parameters is about 1%.

The formation of a fluoropolymer coating by chemical deposition has been studied experimentally. It has been found that increasing the flow rate of the precursor gas leads to a decrease in the growth rate of the coating. Deposition conditions were analyzed, and the gas-dynamic parameters of the process were estimated. The estimates are consistent with experimental data.

The paper presents the results of the Hot-Wire Chemical Vapor Deposition of fluoropolymer films from C3F6O precursor gas, activated by NiCr wire catalyst mesh, at varying deposition process parameters. The temperature of activator wire is varied within the range of 580–900 °C, precursor gas pressure is changed within the range of 4–1333 Pa, and the temperature of the substrate is changed from 20 to 400 °C. The different surface structures of fluoropolymer coatings are obtained by changing the deposition parameters. The morphology and composition of the films and the growth rate were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy methods. We have measured contact angle, contact angle hysteresis, and surface free energy of the resulting fluoropolymer coatings. The surface structure of the coatings is shown to have a significant effect on the coating wettability. One of the main results is that the increasing of the activating mesh wire temperature leads to increasing of the contact angle and allows us to obtain superhydrophobic coatings. We have shown that the wettability properties can be regulated by deposition parameters. Experimentally determined optimal values of deposition parameters ensure uniform deposition of the film with superhydrophobic properties.

The paper presents the results of an experimental study of heating molybdenum and silicon substrates under the conditions of gas-jet deposition of diamond structures using the precursor gases of a microwave discharge to activate. A cooled substrate holder using a metal melt to improve heat removal by reducing the thermal resistance between the substrate and the substrate holder has been developed. The use of the melt allowed lowering the temperature of the silicon substrate under the conditions of gas-jet deposition to a level that ensures the preservation of its structure. The developed substrate holders were used to carry out gas-jet synthesis of diamond structures on molybdenum and silicon substrates.

We present the results of studying the structure of gold nanoparticles synthesized on the silicon surface by two techniques: pulsed laser ablation and magnetron sputtering. The surface morphology is examined by scanning electron microscopy. The structure of the obtained gold nanoparticles is analyzed by transmission electron microscopy and electron diffraction. It is shown that nanoparticle sizes and crystal structures can be controlled by their thermal annealing. Mechanisms occurring during annealing of thin gold films and also their effect on the formation of nanoparticles with different structures are investigated.

Diamond coatings on a molybdenum substrate were obtained by gas-phase deposition from a high-speed jet of activated gases. In the most common case, diamond film is formed as a result of the appearance of discrete nuclei on the substrate, their growing and competing. We observed the formation of coatings consisting of separate isometric aggregates with different types of packaging (111) or (100) plates depending on the process parameters (gas flow, the H2/CH4 ratio, the substrate temperature). The study of coating morphology using optical and electron scanning microscopy suggests that the particles were in the gas phase for a long time and increased to the size of tens of microns, and then deposited on the substrate. This process can be explained by the charged state of the particles, according to the charged cluster model of Hwang (1996). The study of the structure and phase composition by XRD and Raman spectroscopy revealed amorphous carbon, disordered and crystalline graphite, molybdenum carbide with the dominant contribution of diamond). The broadband luminescence of the coating under UV excitation is related to amorphous carbon, whereas 532 nm excitation causes the glow of vacancy centers such as (NV−) and (SiV−).

Degradation-resistant two-dimensional metal–fluoropolymer composites consisting of gold nanoparticles coated with a thin fluoropolymer film were deposited on a substrate by hot wire chemical vapour deposition (HWCVD) and ion sputtering. The morphology and optical properties of the obtained coatings were determined. The thickness of the thin fluoropolymer film was found to influence the position of the surface plasmon resonance peak. Numerical calculations of the optical properties of the deposited materials were performed using Mie theory and the finite-difference time-domain (FDTD) method. The calculation results are consistent with the experimental data. The study shows that the position of the resonance peak can be controlled by changing the surface concentration of particles and the thickness of the fluoropolymer coating. The protective coating was found to prevent the plasmonic properties of the nanoparticles from changing for several months.

This paper describes the method of obtaining composite coatings consisting of silver nanoparticles covered by a fluoropolymer film. The morphology and optical properties of resulting coatings are given within. The presence of a surface plasmon resonance (SPR) minimum of silver nanoparticles deposited on glass and fused silica surfaces has been revealed. The paper describes a shift towards the infrared (IR) region when the average size of deposited silver nanoparticles is changed. However, coating the nanoparticles in a fluoropolymer film does not significantly shift their resonance.

The present work is devoted to a numerical and experimental investigation of the effect of conditions of methane decomposition on the growth of diamond structures during gasjet deposition. The results of experiments on the diamond gas-jet synthesis from methane and hydrogen mixture flows are presented. The direct simulation Monte Carlo method in cylindrical geometry for numerical analysis of these experiments is applied. A one-dimensional approach based on the solution of equilibrium chemical kinetics equations is used to analyze gas-phase methane decomposition. The conducted research has shown that at a decrease in methane decomposition time in the absence of high temperatures of the fed mixture it is possible to receive higher rates of growth of diamond structures. The obtained results can be useful for optimization of gas-dynamic sources of activated gas diamond synthesis.

The main purpose of the epidemiological surveillance system for malaria in the Russian Federation is now to prevent the possible consequences of malaria-imported by Russians and foreigners from endemic areas. A quarter of the approximately 100 cases notified each year in the country are detected in Moscow. During an epidemic season, a package of measures to identify infection sources (malaria patients and parasite carriers) and to decline the number of malaria vectors is implemented and the sanitary state, of open water bodies and the efficiency of larvicidal measures are supervised.

Thin films of amorphous silicon with inclusions of a nanocrystalline silicon phase have been obtained by the method of gas-phase chemical deposition with hot-wire activation of the precursor. The influence of the gas pressure and of the hydrogen–monosilane ratio on the rate of growth and the degree of crystallinity of the deposited silicon has been investigated. Characteristic values of the synthesis parameters for obtaining silicon films of various degrees of crystallinity have been established.

In this paper we investigated the deposition process of the fluoropolymer coatings by the method of Hot Wire Chemical Vapor Deposition. The dependence of precursor gas pressure on deposition rate, structure and properties of the formed film was investigated. The study has shown that the increasing of precursor gas pressure leads to change of the film structure from porous to continuous with globules and further to solid that have different wettability. Depending on the mode of deposition was obtained the fluoropolymer coating with different structure: the wetting angle changed from 60 to 170°. A mechanism of the formation of fluoropolymer coating was discussed.

The gas jet deposition of metal-polymer composites is studied. A detailed description of the method is followed by results of studying the properties of the coatings. In particular, optical and antibacterial properties of the obtained samples are presented.

The scheme of gas temperature measurements in flows of rarefied precursor gases by HW CVD was elaborated. The gas flow temperature of air, argon and hexafluoropropylene oxide was measured at different mass flow rates. The presence of a large well-heated area in gas flows forward the activator was discovered. Asymmetric heating of the gas flow in areas above and under an activator was observed. Cooling of gas flows by increase in the precursor gas mass flow rate was confirmed. The parameters, optimal for the formation of the area with uniform temperature flows above the surface of substrate holder, were determined.

The gas-jet diamond deposition with the activation of H2 + CH4 mixture by microwave discharge has been implemented. The maximum crystal size was observed at the substrate temperature of 850°C. The dependence of a film structure on the substrate temperature has been established. Diamond coating was received at a low substrate temperature (524°C).

Gold thin films were deposited on the substrate of silicon and fused silica by method of Vacuum Gas Jet Deposition. Obtained films were coated with a fluoropolymer and annealed in a rarefied inert gas atmosphere at the temperature of 400 °C. The film morphology and composite were studied by the scanning electron microscopy. Optical properties of obtained coatings and composites were investigated. The influence of the fluoropolymer coating on formation of gold nanoparticles in the result of annealing of its thin films is established. The critical gold film thickness coated with fluoropolymer is determined, below which the presence of fluoropolymer lends to the formation of spherical nanoparticles during annealing of the composite in a studied range of parameters.

In this work, we studied influence of fluoropolymer thin film deposition on wettability of the silicon oxide nanowires array. Deposition of fluoropolymer coating on the silicon oxide nanowires array changes the surface properties from hydrophilic to hydrophobic, and micro and nano scale surface roughness does not change significantly. In addition, it was shown that the deposition of fluoropolymer coating on nanowires protects the nanostructures from bundling together as a result of the attractive capillary forces that arise during evaporative drying.

The gas-jet deposition of carbon and diamond-like films on a substrate with precursor gas activation by a hot wire mesh has been studied experimentally. Several designs of the wire activator for depositing films from a gaseous mixture of CH4, H2, and Ar have been tested. The carbon structure of obtained films was determined by Raman spectroscopy.

In this paper the results of a study of the deposition of silver nanoparticles with characteristic particle sizes from several nanometers to tens of nanometers obtained by gas-jet deposition from a specially developed thermal source are presented. The characteristics of the thermal source are given as dependences of nanoparticle size values on the source temperature and pressure. Flow regions responsible for the formation of metal clusters have been detected.

A new method of gas-jet deposition of metal-polymer composites with simultaneous deposition of polymer matrices and silver clusters from two gas-dynamic sources is presented. Specific features of cluster deposition and the properties of composite films are described. Results on the antibacterial effect of silver-polymer composites on stock cultures of various bacteria are reported.

Solid zinc (Zn)S and liquid zinc (Zn)L are oxidized by water with the formation of zinc oxide (ZnO) nanostructures and the evolution of hydrogen. The maximum rate of this process, called chemical supercondensation by water (CSW), is realized on approaching the melting temperature of zinc from the left and right with increasing density of supercritical water. The CSW process begins with the formation of (ZnO) n clusters via the reaction (Zn)S,L + nH2O = [(Zn)S,L · (ZnO) n ] + nH2, followed by their subsequent growth at n > 7 in the exothermal process of epitaxy on (Zn)S and coagulation of (ZnO) n in (Zn)L. The CSW of (Zn)S leads predominantly to the formation of nanowires and nanorods, while the CSW of (Zn)L practically always proceeds with the formation of nanoparticles. The rate of (Zn)S oxidation increases with the thickness of a layer converted into ZnO. This is related to the self-heating and local melting of (Zn)S in the course of CSW. The complete CSR of (Zn)S plates and cylinders results in the formation of highly porous nanostructural ceramics.

The paper presents the results obtained in determining the accommodation coefficients for the translational and rotational energy of gas molecules in a Knudsen flow past a thin wire. The method used was based on numerically solving the complete heat balance equation for a wire probe. The accommodation coef- ficients were determined for H 2 , N 2 , CH 4 , and CO 2 on a gilded tungsten surface. For hydrogen with a quenched rotational energy, a negative accommodation coefficient of rotational energy was obtained due to the conversion of the rotational energy of incident molecules into the translational energy of reflected molecules. © 2003 MAIK "Nauka/Interperiodica". PLASMA, GASES

A new experimental–computational method for determination of translational and internal energy accommodation coefficients on a thin wire in a free-molecular flow is elaborated. The method is based on numerical solution of the heat balance equation of the wire. Measurements were performed in a low-density wind tunnel with Ar, He, N2, CH4, and CO2. In addition, the proposed method provides determination of thermophysical properties of the wire.

The goal of this work is the elaboration of the new method of Hot Wire Chemical Vapor Deposition, when the activation of a precursor gas performs in a high speed jet, in which a hot-wire net is inserted. Oriented in a jet, transportation of a gas precursor adds new parameters to control a process of deposition. The first experiments were performed with the supersonic jet of C 2 F 4 , issued from the sonic nozzle after pyrolysis of the bulk Teflon in the high temperature reactor. The most interesting results are obtained by changing the net temperature. The film morphology is radically changed from separate fragments with micron characteristic sizes up to nanodisperse fractal-porous accretions.

In this paper, we report the first experiments on the deposition of silver nanoparticles by a gas dynamic spray technique, with their simultaneous stabilization in a fluoropolymer matrix, and the results of studying the properties of the produced materials, in particular, bactericide properties. Materials with silver nanoparticles in a polymer matrix exhibit a combination of properties that makes them good candidates for applications in elec� tronics, for production of optical fibers, and in med� icine [1 ⎯3]. As is known, silver has excellent antimicrobial activity against approximately 650 bacteria strains [4]. In this context, interest in silver as the antibacterial agent from the historical past has been recently renewed since many pathogenic bacterial strains

The effect of the pyrolysis conditions of hexafluoropropylene oxide on the composition of the fragments produced in a free jet was studied. The low-density gas-dynamic facility is equipped with a mass-spectrometry system. Possible reactions are determined that result in polymerization during gas jet deposition of a fluoropolymer film from a supersonic jet of pyrolysis products of hexafluoropropylene oxide.

In accordance with the normative and methodical documents [3-5, 7-9], a complex of organizational, sanitary, and antiepidemic actions is performed to protect soil from causative agents of parasitic diseases in Moscow. About 2000 soil samples are annually taken from the playgrounds of children's educational establishments and apartment houses and tested. The soil contamination averages 3.2%. It has been established that there are no sanitary-and-epidemiological opinions as to the parasitic safety of sand or lids on the sand-boxes on the playgrounds from which the soil or sand samples show causative agents of parasitic diseases (most commonly toxocariasis) and which are accessible to stray and domestic dogs. In 2005, DESINBAC super having bactericidal, fungicidal, sporocidal, and virocidal activities and ovicidal properties was approved for soil disinfection in the Russian Federation. The prevention of toxocariasis is a state problem. Executive bodies, housing-and-communal services, veterinary stations, and health care services with the participation of sanitary-and-epidemiological facilities and their control must take part in solving this problem.

The malaria situation in Moscow in 2007 versus 2006 improved--the cases of malaria reduced by 16.3%. A total of 30 new cases of malaria were notified (46 cases in 2006), of them there were 34 imported cases and 4 secondary cases to imported ones. In 2007, the proportion of tertian malaria cases reduced to 55.3% versus 60.9% in 2006. As compared with 2005, in 2007 the cases of locally transmitted malaria decreased by 5 times--from 20 to 4, only 1 case of infection occurred in Moscow (Central Administrative District) and 3 cases took place in the Moscow Region (Ramensky, Stupinsky, and Dmitrovsky districts). Cases of malaria were notified in all administrative districts, with their largest number in the South-Western Administrative District of Moscow due to the detection of ill students from the Russian University of People's Friendship who had come to study from African countries. In accordance to the performed certification of water reservoirs in 2007, a total of 722 Moscow water reservoirs of an area of 1569 ha were registered at the Administration of the Russian Agency for Consumer Surveillance. The examination frequency of all water reservoirs was about 13 per season, including 20 anopheles-containing ones. The larvae of bloodsucking mosquitoes inhabited 541 (75%) water reservoirs, including 461 (63%) water reservoirs occupied by the malaria vector. As compared with 2006, the area of treatments increased by 351 ha. In the summer, a total of 2133.3 ha ofwater reservoirs were treated, including 2009.5 ha against larvae of malaria mosquitoes. The bulk of water reservoirs were exposed to triple-quadruple treatments.

The results of study of the low density gas jet deposition for different schemes are presented. The possibility to activate the precursor gas flow by a hot wire net allows to obtain different structures of deposited films. The experimental results are accompanied by data for flow structure, density, velocity, and temperature determined by the DSMC method, which are useful for the understanding of deposition process. The deposition of metal‐polymer film by interaction of two separate jets is realized.

The fluoropolymer coatings of different morphologies are deposited by the HWCVD (Hot Wire CVD) method. The effect of activator filament temperature on the structure of fluoropolymer coating is shown. The results of studying the hydrophobic fluoropolymer coatings with different structures, deposited by the HWCVD method, are presented.

Malaria was eradicated on the territory of Moscow in 1960; its imported cases mainly from the countries of Asia and Africa and sporadic cases secondary to the imported ones were recorded during the following 40 years. Mass migration of the population (businessmen, seasonal workers, etc.) from the endemic CIS countries in the late 1990s, particularly to the Moscow Region, increased cases of tertian malaria, resulting from the transmission of the infection by the mosquitoes Anopheles. A total of 793 cases of malaria, including 27 parasitic carriers, were recorded from 2000 to 2004. The proportion of Muscovites was 24.1% of the total cases of malaria in 2002 and increased up to 50% in 2004. The causative agents of tertian malaria (Plasmodium vivax) were detected in 74.8% of the total number of cases. The ongoing importation of malaria from Tadjikistan and Azerbaijan, the late establishment of final diagnosis, the shortage of antimalarial drugs make the malaria situation worse in Moscow, which requires that antiepidemic measures should be intensified in the coming 3 years.

The deposition of fluoroplastic (Teflon) films on a substrate by the method of hot wire chemical vapor deposition has been experimentally studied. It is established that the structure of obtained coatings strongly depends on nonequilibrium processes in a supersonic jet of a gaseous precursor. The dependence of the film morphology on the wire temperature is demonstrated.

The paper outlines the results of studies dealt with the detection of risk factors and groups for enterobiasis, the efficiency of the treatment of children suffering from the disease with medamine, biologicals, and Normase. It is shown that risk factors may include an abnormal course of antenatality, minor developmental malformations (diastema, dystrophy, abnormalities of the eye, hand, foot, etc.), as well as early artificial feeding of babies (before they reach 3 months of life). Enterobiasis is found to have a negative influence on the physical, nervous, and mental development and suppression of non-specific immunity in children, which is suggested by the reduction in salivary lysozyme activity, which is lower than the normal level and on blood alpha-interferon production. There is strong evidence for the considerable immunosuppressive effects of enterobiasis on the formation of a postvaccinal immunity against measles. When given in a single course dose, medamine shows a 100% efficiency in the treatment of enterobiasis. Moreover, bificol, bifidumbacterin, and Normase may be useful to enhance the treatment efficiency and children's recovery from enterobiasis.

Renal involvement in chorionepithelioma is attributed to tumor destruction and metastases to the kidneys. A rare case of secondary paraneoplastic nephropathy manifesting as nephrotic syndrome in the presence of renal metastases is described. Metastatic lesion of the lungs provoked spontaneous pneumothorax. It is not easy to detect chorionepithelioma and related paraneoplastic nephropathy. Therefore, special attention should be given to puerperants with unusual clinical presentation of nephrotic syndrome, with bloody expectorations. In the above cases chorionepithelioma must not be excluded.

A technique and method for measuring the velocity-distribution function of the atoms in rarefied gas flows are described. Some results obtained with flows of binary gas mixtures behind a sonic nozzle are presented. The temperature of the light component (helium) is determined from the half width of the distribution function. Incomplete restoration of the helium temperature occurs in the Mach disk. This effect is examined in relation to concentration. A qualitative explanation is proposed for the effect in question.

This paper evaluates the regime of air flow through a ventilation shaft and the nondimensional heat-exchange criteria. It is shown that the air temperature in the shaft is affected more by the walls than by the reinforcement structure metal and that the heat released by internal combustion engines could be an alternative source for heating the air. High bypass aircraft turbojet engines decommissioned after their maximum surface life on planes could be used for this purpose. The study of the thermal regime in the shaft in the case of a sudden change of air temperature such as occurs during ventilation reversals has established the requirements for air heating equipment.