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Mechanical activation (MA) of industrial carbon black (CB) by steel milling bodies with a diameter of 2 and 8 mm in air is performed. It was found that in the process of MA, the size of the CB aggregates decreases by an order of magnitude. The oxygen content on the carbon surface increases from 1.8 to 8.0 wt.%. Rubbers were prepared and vulcanized from methyl styrene-butadiene rubber (MSBR) industrial and mechanically activated CB; their dynamic mechanical analysis was carried out and strength indicators were determined. The temperature dependences of storage modulus E′ and mechanical loss factor tan δ were obtained. It was found that the glass transition temperature Tg of rubbers with the introduction of MA CB decreases to − 56 °C, compared with industrial CB: − 52 °C. This is due to the smaller size of the CB aggregates and the high oxygen content on the carbon surface. Strength tests have shown that for rubbers with mechanically activated CB, the maximum values of strength and elongation increase by more than 20% compared with the rubbers that contain industrial CB.

Intestinal microflora in terms of the integral body of knowledge about its importance for the human body is now considered as an additional “virtual” organ, producing many biologically active compounds that affect the various properties and functions of the macroorganism: fermentation of non-digestible food polysaccharides, maintenance of the optimal values of the intra-lumen pH and “intestinal barrier”, the activity of the immune system, vitamin status, energy homeostasis, angiogenesis. Saccharomyces boulardii is not a representative of the natural microflora of the human intestine, but, used as a probiotic, interacts with it, restoring the balance of short-chain fatty acids, reducing the levels of bacterial toxins, acting as a surrogate normal microflora until it is restored and replaced by natural representatives. S. boulardii has immunostimulating and anti-inflammatory activity. The results of clinical studies have demonstrated the effectiveness of S. boulardii in correcting pathological conditions associated with Helicobacter pylori, Clostridium difficile, Candida albicans, Salmonella typhimurum, Yersinia enterocolitium, protozoa Entamoeba and in treating irritable bowel syndrome and antibiotic-associated diarrhea. The efficacy of a drug containing S. boulardii has been demonstrated in the article by clinical studies and a clinical example. This drug has proven to be a highly effective and safe probiotic agent for the prevention and treatment of a number of diseases of the gastrointestinal tract with physiologically optimized pharmacodynamic effect that simulates the protective properties of normal human intestinal microflora. When using a drug containing S. boulardii, both adults and children do not have serious side effects, which increases the possibility of its safe use in clinical practice.

Pulsed-laser irradiation of a globular turbostratic carbon material under diverse conditions was carried. A TEM examination revealed formation of nanostructured particles (nanocapsules) under exposure to 1064 nm pulsed radiation at the power density of 108 W/cm2, whose increase to 1011 W/cm2 led to formation of structures with a higher degree of ordering. Pulsed irradiation of the initial globules at 532 nm wavelength allowed reducing the interplanar spacings of the graphene layers in the resultant nanocapsules from 0.410 to 0.346 nm. The dependence of the maximum heating temperature of the nanoparticles on the power density in the laser spot was analyzed. The influence of the heating temperature of the carbon nanomaterial on its structure and morphology was assessed.

Results of studying the structural defects in MgAl and NiAl layered double hydroxides and in the products of their thermal decomposition to 1000°C, obtained over the last 10 years at the Laboratory of Analytical and Physicochemical Methods of Research, Institute of Hydrocarbons Processing, Siberian Branch, Russian Academy of Sciences, were reviewed. These studies were performed using the method of simulation of X-ray diffraction patterns for one-dimensionally (1D) disordered crystals. Changes in the type of the structural defects depending on the calcination temperature were revealed, in particular, via in situ X-ray diffraction. A structural mechanism of the formation of the dehydrated phase at T = 200°C was proposed. New models of the MgAl and NiAl oxide structures were presented. The structures of the phases contained in the products of hydration of the oxides were established. The difference in the behavior of the oxides during hydration was explained.

A method for synthesis of carbide containing composites by mechanical activation has been developed. A mixture of molybdenum oxide, carbon black and Al or Zn metal reductant have been treated for 15 min in air followed by a subsequent calcination in argon atmosphere at 800 °C. The elemental and phase composition, structure, texture and particle morphology of these composites were studied. Mechanically activated and calcined samples were found to contain 6.5 and 5.9% of the molybdenum carbide phase, respectively.

Commercial carbon black (CB) was mechanically activated in air for 5–60 min and 100 g acceleration of milling bodies, which were represented by steel balls with the diameter of 2, 5 and 8 mm. Changes in the composition and structure of the tested objects, including their surface layers, were considered. IR spectroscopy and acid-base titration showed that mechanical activation (MA) of CB results in the formation of oxygen-containing surface functional groups in the amount of 0.21–0.34 mEq/g. The analysis of the pore texture of mechanically activated CB samples revealed that an increase in MA intensity increases the specific surface area and decreases the total pore volume. The high intensity of MA leads to the formation of the pore system in CB that differs from the initial system and consists of 10–100 nm pores and thin pores with the size of 3–5 nm. A TEM study on the morphology of mechanically activated CB samples demonstrated that activation at the high intensity results in the partial destruction of globules and the appearance of small particles with the size of 2–5 nm. A structural study showed that mechanical activation at the high intensity may lead to rearrangement of graphene layers in globules.

This paper presents the results of an electron paramagnetic resonance (EPR) and thermal analysis (TGA, DTA) study of a series of bifunctional NiMo/WO3–Al2O3 catalysts containing 0 to 30 wt % WO3 modifier before and after testing them in the process of hydrodeoxygenation of vegetable oil. The dependence of the content of carbonaceous deposits in the spent samples (according to EPR and TGA) on the concentration of acid sites as determined by EPR of perylene probe molecules in the initial catalysts is determined. Deactivation is explained by the participation of medium- and weak-strength Bronsted acid sites in the condensation of the initial unsaturated hydrocarbon molecules and their intermediates leading to the formation of various forms of coke precursors.

Abandoning the assumption of nested magnetic surfaces in tokamak plasma expands the field of research and opens up new approaches for both theoretical and experimental plasma physics. The computer code KINX for calculations of the ideal MHD stability was developed for studies of doublet plasmas with two magnetic axes and using block-structured grids in each subdomain with nested magnetic surfaces. Then, the MHD_NX code on unstructured grids was developed to calculate the stability of two-dimensional equilibria with an arbitrary topology of magnetic surfaces. The study of equilibrium and stability of equilibrium configurations with toroidal current density reversal and axisymmetric n = 0 islands, which are associated with internal transport barrier and low current density at the magnetic axis, as well as with the operation of tokamaks in the alternating current regime, leads to more general issues of MHD stability of two-dimensional solutions of the Grad−Shafranov equations with islands under other types of symmetry—chain of islands in helical symmetry and cylindrically symmetric m = 0 islands in configurations with the longitudinal field reversal. New ideal MHD unstable modes have been discovered for various types of two-dimensional island configurations. The energy principle with MHD-compatible boundary conditions at open magnetic field lines is necessary for the self-consistent stability analysis of divertor configurations in tokamaks with a finite current density at the separatrix, taking into account the plasma outside the separatrix. Several codes have been developed for calculations of plasma equilibrium and stability, taking into account the influence of currents outside the separatrix, which are ready for integration with other codes for edge plasma modeling.

The paper presents the results of an experimental study of the processes of obtaining a permanent connection of porous stainless steel using laser welding and some technological methods (intermediate inserts of monolithic metal, nanomodifying additives). It was established that in order to obtain a durable defect-free joint, it is necessary to use an intermediate insert made of compact metal of the same composition as the welded parts, placed between the ends of the butt-welded parts. The use of modifying additives based on refractory joints increases the dispersion and uniformity of the weld structure, which positively affects the mechanical characteristics of the welded joint.

A series of propylene metathesis MoO3/Al2O3 catalysts (2–10 wt. % of MoO3) activated in Ar and under ex situ reaction conditions was studied by EPR spectroscopy. Similar EPR signals from surface molybdate clusters (Mo5+) were observed for each sample. The concentration of pentavalent molybdenum in paramagnetic form determined by EPR increases with an increase in the MoO3 content from 2 to 5 wt. %, then changes slightly. It was also found that the activity of the catalysts in the propylene metathesis reaction is proportional to the increment in the concentration of Mo5+ paramagnetic species determined after contact with propylene. This indicates that higher oxidation states of molybdenum form active paramagnetic complexes during the reaction with propylene.

Textural, structural, and morphological changes occurring in globular carbon black of various particle size fractions under continuous irradiation with a continuous beam of 2.5-MeV accelerated electrons were studied by the methods of adsorption and high-resolution transmission electron microscopy. The electron irradiation leads to pronounced transformation of the solid globular framework of carbon black mainly into graphite-like nanocapsules of 10–50 nm size with the spacing between the graphene layers of the order of 0.355 nm. The observed effect leads to a decrease in the porosity (by a factor of approximately 1.65) and in the specific surface area (by a factor of 3–4) of the irradiated samples. This may be due to the transformation of the turbostratic (practically amorphous) form of carbon black into the nanostructured state with denser packing of carbon particles. The physicochemical properties of such carbon should be primarily determined by the structure of the solid framework.

Al/Co alloys with different element ratios were studied by X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The surface propagation of components of the Ga/In eutectic was studied in situ by energy-dispersive spectroscopy in the microscope chamber, and their propagation rate was estimated. It decreases with increasing Co content. Interaction of the Al/Co alloy with the liquid Ga/In eutectic was compared to that of the previously studied Al/Ni and Al/Fe alloys.

The effect of thermal regimes and some technological methods (the application of intermediate compact metal inserts and nanomodifying additives) on the quality of laser-welded permanent joints of porous titanium or stainless steel plates has been experimentally studied in this work. It has been established that the formation of a high-quality defectless seam requires the use of an intermediate compact (nonporous) metal insert placed butt to butt between the edges of welded plates. In this case, the position of a focal spot should be installed at a depth equal to the thickness of a plate, i.e., on its lower surface. To form a bead joint or a joint flush to the plates to be welded together, the height of an insert must exceed the thickness of the plates. The application of nanomodifying titanium nitride based additives increases the structural dispersity and uniformity of a seam, thus producing a positive effect on the mechanical characteristics of a welded joint.

The paper presents a technique for the synthesis of molybdenum carbide using mechanical activation of carbon black, which was impregnated with a 20% aqueous solution of ammonium heptamolybdate (AHM) using the incipient wetness technique, in an inert medium at a 100 g acceleration of milling bodies for 30 min. The mechanically activated carbide-containing composites were calcined in an inert medium at 800 °C. The composites were examined by a range of physical methods. It was shown that the mechanically activated composite consists of molybdenum carbide, iron oxide and iron carbide (about 4–8% according to AES-ICP). The phase addition method was used to determine the quantitative content of Мо 2 С, which was equal to 7.2 wt% in the calcined sample. Catalytic testing of mechanically activated molybdenum carbide in the partial oxidation of methane showed that the carbide-containing catalyst provides a 48–60% conversion of methane and an 83–85% selectivity for the target product (CO).

The information on the average distance between graphene layers, the length and curvature of layers in globules of highly dispersed carbon black was obtained. The globular turbostratic carbon material was irradiated with laser pulses. Carbon nanocapsules are formed during laser irradiation with a power density 1011 W/cm2. The irradiation of the initial highly dispersed carbon black globules reduces the interplanar spacing of the graphene layers from 0.39 nm to 0.35 nm in the formed nanocapsules.

The structural changes taking place in high (P-267E) and low (T-900) dispersion carbon blacks under the high energy electron beam irradiation were investigated by EPR spectroscopy. All types of defective paramagnetic structures formed during the irradiation process of the carbon materials were identified. For both samples formation of new paramagnetic defects is occurred, which are due to the decrease of particles size, conjugation (delocalization) of electrons and the length of graphene layers in general.

An experimental study of the effect of thermal conditions and some technological methods (intermediate inserts made of monolithic metal, nano-modifying additives) on the quality of the permanent joint of porous titanium obtained by laser welding was carried out. It has been established that to obtain a high-quality defect-free weld it is necessary to use an intermediate insert made of compact metal, butt-mounted between the ends of the plates to be welded. In this case, the position of the focal spot should be set at a depth equal to the thickness of the plate, i.e. on its bottom surface. The use of modifying additives based on titanium nitride increases the dispersion and homogeneity of structure of the weld and neighboring area, which, according to the Hall-Petch law, has a positive effect on the mechanical characteristics of the metal.

In paper, weld joints between VT1-0 titanium and AISI 321 austenitic stainless steel using laser welding were obtained. To improve the quality and strength properties of joints, two types (SS–Cu–Nb/Ta–Ti) of explosively welded four-layered composite inserts were used. Barrier layers were different from each other by refractory metal. The effect of intermediate material inserts, in particular tantalum and niobium, on microstructure, chemical composition, strength properties, and fracture behaviour of weld joints was studied. Microstructural studies have revealed two bonding types as results of welding method combination. At copper–stainless steel interface, severely deformed zone characterized by low etch ability was observed. Technological parameter’s optimization provided high joint quality and absence of defects in the weld joints. According to results of strength tests, it was found that the composite insert material affects the strength of the joints. The highest ultimate tensile strength and yield strength were detected for joints containing niobium foil.

A method for the synthesis of core-shell structures during methane decomposition in a cobalt-carbon composite with metal particles uniformly dispersed in its bulk is proposed. These composites are obtained by the low-temperature formation of carbon structures based on reactive conjugated polymers obtained by the dehydrochlorination of chlorine-containing carbon-chain polymers. Eelectron microscopy studies show the formation of structures containing 10–50 graphene layers closely packed around a metal core with an interlayer distance of 0.34–0.35 nm.

The effect of strontium-containing compounds on the crystallization of strontium-substituted carbonate- hydroxylapatite from a human synovial fluid prototype was studied. Synthesis products were investigated by FT-IR spectroscopy, X-ray diffraction, and differential thermal analysis. The amount of strontium in samples was determined by atomic emission analysis. For the synthesized phases, crystallite sizes were calculated by the Selyakov–Sherer formula, and the unit cell parameters were determined. The kinetically stable brushite phase was shown to transform into the more thermodynamically stable phase of strontium-containing carbonate-hydroxylapatite with increasing exposure time of precipitates under the mother solution. Some schemes were proposed for phase transformations under heat treatment.

The acidity of a series of borate-containing aluminum oxide samples with the concentrations of B2O3 from 0.9 to 27.5 wt % and Pt-containing catalysts obtained on their basis was studied by spin probe EPR spectroscopy. With the use of anthracene and the TEMPO nitroxide radical as probe molecules, it was established that an increase in the B2O3 content of the B2O3–Al2O3 and Pt/B2O3–Al2O3 systems leads to a symbatic increase in the number of medium-strength Bronsted acid sites (BASs). In this case, the yields of target hydroisomerization products (isoheptanes and methylcyclopentane) correlate with the number of BASs.

This paper finalizes the self-consistent study of the sideways force acting on the resistive wall due to eddy currents induced by n = 1 kink instability under variations of the external poloidal field and its impact on the force peaking factor as outlined in A. A. Martynov and S. Yu. Medvedev, Phys. Plasmas 27, 012508 (2020). A proper analytical treatment of the sideways forces for a large aspect ratio circular tokamak is limited to the case q 1 at the plasma boundary, the sideways force is generated by a sideband m/n = 1/1 harmonic, which gives lower net force as compared to the q

In current work the features of 1,3,5-trinitrobenzene (TNB) transformation into paramagnetic products on the surface of aluminum/magnesium oxides calcined at 550°C, as well as MgAl double oxides, were investigated by EPR spectroscopy. It was shown that the increase of basicity (i.e. MgO content) leads to the increase in the concentration of formed radical anions, wherein the presence of acidic sites contributes to their stabilization on the surface. The effect of n-hexane and toluene used as solvents in the transformation of adsorbed TNB radical anions was established, and a new probe EPR technique for using TNB to determine the concentration of the basic sites in MgAl double oxides was proposed. The results of the proposed technique are in good agreement with the data on the basic sites concentration obtained from the adsorption capacity CO2 of the corresponding samples.

A high-energy planetary mill AGO-2 was used for mechanical activation of synthetic graphite with the particle size of 25–30 μm and specific surface area S BET = 3.0 m 2 /g in air for 1–60 min at a 100 g acceleration of milling bodies. The X-ray diffraction, Raman spectroscopy and electron microscopy studies showed that the 60 min mechanical activation of graphite decreases the number of graphene layers in graphite crystallites to 8–12 and induces their turbostratic disorder. The size of graphite particles decreases to 6.9 μm after 30 min of mechanical activation and increases to 12.1 μm when the time of mechanical activation is extended to 60 min. Similar changes are observed for the true density of graphite: after 60 min of mechanical activation it becomes equal to 2.48 ⋅ 10 3 kg/m 3 , which is by 10% higher than the true density of graphite not subjected to such treatment. The specific adsorption surface of graphite ( S BET ) reaches its maximum values, 427–460 m 2 /g, after 7–12 min of mechanical activation. A further increase in the activation time to 30–60 min decreases S BET of graphite to 230–250 m 2 /g. Due to attrition of steel milling bodies caused by mechanical activation, iron is accumulated in the samples and its content exceeds 5%. Iron is distributed uniformly in the graphite as the 30–100 and 3–5 nm particles of hematite and iron carbide. The IR spectroscopy study revealed the formation of 0.8 mEq/g of the hydroxyl, phenolic, lactone and carbonyl groups on the graphite surface in the course of mechanical activation.

Studies of the structural transformations of carbon black caused by laser and electron irradiation have been carried out using high-resolution transmission electron microscopy (HRTEM). The heterosystems of the Pt/C-type are obtained in the process of laser irradiation of carbon black suspensions in platinum-containing solutions. A high-energy electron irradiation of carbon black causes the formation of multimorphological carbon nanostructures, which possess a graphite-like arrangement of graphene layers.

The possibility of modifying hydroxyapatite by silicate ions under conditions similar to physiological ones (extracellular fluid solution prototype) has been investigated. The formation of silicon-structured hydroxyapatite with different degrees of substitution of phosphate groups by silicate ones has been established by means of the methods of chemical and X-ray diffraction analysis, IR Fourier-spectroscopy, and optical microscopy.

Nanocapsules and stacks of graphene sheets have been prepared from carbon black by irradiation relativistic electron beam. Electrons with energy of 2.5 MeV were used in these experiments to produce carbon nanoparticles with graphite-like structure of the graphene layers. High Resolution Transmission Electron Microscopy (HRTEM), Raman spectroscopy and Electron Spin Resonance (ESR) spectroscopy were used to obtain the information about morphology, crystallinity, and interlayer distance of these nanostructures.

Production of welded bimetallic structures of titanium and steel using a laser beam is a very urgent and important task in the shipbuilding, airspace and power engineering. Laser welding using an intermediate insert is one of the ways to solve this problem. In this paper, we present the results of experimental studies of formation of the structure and properties of composite insert, obtained by explosion welding, after its application at laser welding steel with titanium. A study of a four-layer composite insert obtained by explosion welding showed that it has no brittle intermetallic phases and defects in the form of cracks and pores. The boundaries between the plates to be welded in the composite insert have a characteristic wavy structure with narrow zones of mutual diffusion penetration of elements of the adjacent metals. It is established that the strength of the composite insert is comparable with the maximum strength of Grade 4 alloy, and the destruction of the product during the tensile tests in m...

The effect of thermal oxidative treatment on the structure and electroconductive properties of the particles of globular nanodispersed carbon (GNDC, carbon black) was demonstrated. The comprehensive study of the structure of GNDC particles was performed by Raman spectroscopy, X-ray diffraction (XRD) analysis, and high-resolution transmission electron microscopy (HR TEM) in comparison that of foreign and domestic commercial electroconductive brands. A correlation between structure characteristics obtained by different methods and the final properties of test GNDCs was established. The interrelation between the electroconductive properties and the length of the graphene planes of primary GNDC particles was confirmed.

The formation of carbon nanoparticles with ordered structure under nanosecond-duration pulsed laser irradiation of the carbon black samples has been studied. Electron microscopic images of the original and irradiated samples have been obtained and analyzed using the Digital Micrograph software package (Gatan). The length and curvature of graphene layers in high- and low-dispersive carbon black samples have been calculated. The distance between graphene layers (d002) has been measured. It was shown that the distance d002 decreases with an increase in the irradiation energy density.

We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3 and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low $Q^2$ range from $0.0065$ to $0.35$ (GeV$/c$)$^2$. The $Q^2$ access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as $6^\circ$. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.

The paper presents the experimental investigation of the creation of complex composition corrosion-resistant coatings with low abrasive wear which are used in oil industry, by the method of laser cladding additive technology. Availability of the additive laser cladding of the complex composition corrosion-resistant coatings with a strengthening phase is shown. Optimal conditions for the cladding layers creation regarding the laser radiation parameters and radiation direction are found. The changes in micro-hardness, micro-structure and structure-phase components are established against the strengthening phase content in the upper clad layer. Different content of the strengthening phase in the upper layer from 10% to 30% does not change the micro-hardness of the upper layer and is on the average 700 HV. The laser irradiation of the powder mixture containing the strengthening phase results in the partial rupture of the WC strengthening phase. Hence the chemical interaction of the tungsten-cobalt powder mixt...

The paper concerns the possibility of obtaining a lasting permanent joint of dissimilar metals: technically pure titanium and stainless steel using laser welding and an intermediate composite insert. The insert was a four-layer composition of plates of steel, copper, niobium, and titanium welded by explosion. The material layers used in the insert prevented the molten steel and titanium from mixing, which excluded the formation of brittle intermetallic compounds, such as FeTi and Fe2Ti. The optimization of explosion welding parameters provided a high quality of the four-layer composition and the absence of defects in the area of the joint of insert plates. The results of strength tests showed that values of the ultimate strength and yield of the permanent joint with the composite insert welded by explosion are comparable to the strength characteristics of titanium.

The possibility of synthesizing bulk catalysts by means of mechanochemical activation (MCA), the basis for wasteless technologies for the production of catalysts with particle sizes less than 10 μm, is demonstrated. The precursors of Ni-Mo catalysts for hydrogenation processes are synthesized by MCA. The chemical and phase composition and specific surface area of mechanically activated composites with Ni: Mo atomic ratio = 1.0 and 1.4 are studied by DTA, XRD, TPR, and low-temperature adsorption. It is established that during the simultaneous MCA of Ni- and Mo-containing salts, solid-state reactions yield complex X-ray amorphous compounds that after calcination at 520°C form nickel molybdates composed almost entirely of highly active modified β-NiMoO4, the sulfidation of which produces MoS2 and Ni3S2 phases. Comparative testing of sulfide catalysts (i.e., bulk (Ni: Mo = 1.4) and industrial supported) in model reactions of the conversion of 1-methylnaphthalene and dibenzothiophene was performed at a temperature of 350°C, a pressure of 3.5 MPa, a feedstock hourly space velocity of 2 h−1, and a hydrogen/feedstock ratio of 600. Based on the composition of the 1-methylnaphthalene and dibenzothiophene conversion products while using industrial and bulk catalysts, it is concluded that the bulk catalyst exhibits higher hydrogenating activity.

Mechanochemical activation in high-energy planetary activators was used for the preparation of highly dispersed nickel-molybdenum compounds. Nickel hydroxocarbonate [NiCO3 · 2Ni(OH)2 · nH2O] and ammonium paramolybdate [(NH4)6Mo7O24 · 4H2O] were chosen as starting compounds. The effect of the Ni: Mo atomic ratio on the composition and structure of products formed in the process of mechanochemical activation followed by calcination was studied. It was found that, at the Ni: Mo atomic ratios of 1.0 and 1.4, the mechanically activated product after calcination at 520°C contained 70–100% β-NiMoO4, which is a stable phase at temperatures lower than 180°C.

The texture characteristics of aluminum hydroxides peptized by organic acids and then calcined were studied. A decrease in the pore volume and pore diameter for aluminum hydroxide was studied as a function of the amount of a peptizer. The calcination causes basic aluminum salts obtained by peptization to decompose at different temperatures, depending on the strength of a peptizing acid. The observed regularities were explained in terms of the thermal decomposition of organic aluminum salts of varied composition.

A series of SO42−-ZrO2-Al2O3 oxide supports containing from 18.8 to 89.1 wt % alumina was prepared by mixing sulfated zirconia hydrate (weight ratio ZrO2: H2SO4 = 9 : 1) and pseudoboehmite followed by calcination at 650°C. For the subsequent use of the supports to optimize the acid and hydrogenating properties of bifunctional hydroisomerization catalysts of the Pt/SO42−-ZrO2-Al2O3 type, the formation of these catalysts in the course of thermal treatment and their texture characteristics and phase composition were studied. It was found by chemical and thermogravimetric analysis that the addition of pseudoboehmite to sulfated zirconia hydrate resulted in a decrease in sulfur losses in the course of support production from 55.0 to 2.0% with respect to its nominal amount. As the alumina content was increased from 18.8 to 89.1 wt %, the specific surface area and the pore volume of the support increased nonadditively with respect to mechanical mixtures of sulfated zirconia and γ-alumina (from 155 to 197 m2/g and from 0.24 to 0.52 cm3/g, respectively); in this case, a maximum deviation was 18–21%. The experimental results can be explained by chemical interactions between the initial components of the supports. The results of thermogravimetric and X-ray diffraction analysis suggest that the reaction products are sulfated alumina and a sulfated ZrO2-Al2O3 solid solution.

The formation of highly imperfect γ-Al2O3 oxide prepared by calcining pseuodoboehmite and plasticized by organic acids was studied. The nature of the organic acid-aluminum hydroxide plasticizer was found to substantially influence the degree of γ-Al2O3 structure imperfection estimated qualitatively as the difference between the X-ray structural density and effective density with respect to helium and aluminum oxide. A high degree of imperfection caused an increase in the intensity of the absorption band at 3775 cm−1 corresponding to OH groups localized on five-coordinate Al3+ and the concentration of Lewis acid centers. The adsorption and catalytic properties of systems based on these carriers were studied.

Theoretical and experimental studies of spectral and energy characteristics of radiation of a photoinitiated HF/DF laser working on the chain reaction in the F2:(H2+D2):O2:He=3:1:0.3:6.7 mixture are performed under atmospheric pressure as functions of the ratio of the initial concentrations of H2 and D2 and the resonator losses. Optimal conditions are determined for simultaneous lasing in HF and DF molecules in the spectral range 2.7 — 4.8 μm.

For integrated modeling of equilibrium, stability and dynamics of the divertor tokamak plasma with scrape-off layer (SOL) high resolution equilibrium calculations are needed. A new version of the CAXE equilibrium code computes the tokamak equilibrium on a numerical grid adaptive to magnetic surfaces both in the plasma region with closed flux surfaces and in the SOL region with open magnetic lines. The plasma profiles can be prescribed independently in each region with nested flux surfaces, and realistic SOL profiles with very short pressure drop off length can be accurately treated. The influence of the finite current density in SOL on the connection length is studied. From the point of view of the MHD equilibrium and stability modeling, self-consistent calculations of diverted tokamak configurations with finite current density at the separatrix require taking into account plasma outside the separatrix. Calculated high resolution equilibria provide an input to new versions of the ideal MHD stability codes treating tokamak plasma with SOL. The study of the influence of the pressure gradient profile in the pedestal plasma inside and outside the separatrix on the pedestal height limit set by external kink-ballooning mode stability is presented. Another possible application of the high resolution pedestal and SOL equilibrium code is a coupling to the SOLPS code with a purpose to increase equilibrium accuracy and support self-consistent plasma flow/equilibrium modeling.

The dependences of the energy and spectral characteristics of the radiation of a pulsed photoinitiated chemical chain-reaction HF (DF) laser, operating at atmospheric pressure, on the optical cavity parameters were investigated. The maximum specific output energies of the HF and DF chain lasers (53 and 43 J litre-1) and their fullest spectra (47 and 83 lines, respectively) were similar when the unsaturated gain exceeded the threshold by a factor greater than 50. An analysis was made of how the energy and spectrum of the radiation of the HF (DF) laser were influenced by the spatiotemporal inhomogeneity of the initiation and of the course of the chemical chain reaction. There was a marked effect of the CO2 molecules in the active medium and in the air filling part of the volume of the complex cavity of the DF laser on its efficiency and emission spectrum.

Theoretical and experimental investigations were made of the mechanism of initiation of the H2+F2 reaction by resonant excitation of HF molecules with radiation from a pulsed H2—F2 laser, followed by transfer of the vibrational energy to H2 molecules which then participate in the energy branching of the reaction chain. It was shown theoretically that a hydrogen fluoride laser pulse of energy density 0.1–10 J cm-2 acting on an HF: H2: F2: O2: He=(0.3–1):76:228:23:578 Torr mixture can generate laser radiation after a delay of 10–100 μs. A chain H2+F2 reaction was initiated experimentally for the first time by multiline radiation from a pulsed hydrogen fluoride laser and a satisfactory correlation was observed between the calculated and measured chain-reaction development times.

An H2(D2)— F2— O2—He mixture containing disperse aluminium particles was formed and investigated experimentally. It was found that gaseous disperse active media could be prepared experimentally for pulsed chemical H2—F2 and D2—F2 lasers with mixture pressures of the order of 1 bar. The addition of aluminium particles of ~0.5 μm size in a concentration of ~105 cm-3 to a mixture of the H2 : F2 : O2 : He = 50 : 114 : 11 : 635 Torr composition did not accelerate the rate of accumulation of HF molecules and such a mixture had the necessary long-term stability. Heating and evaporation of aluminium particles in the active medium of a D2—F2 laser under the action of radiation from an H2—F2 laser was accompanied by combustion of the laser mixture in ~3 μs.

Propagation of radiation of the photo-initiated chain HF-chemical laser (in a wavelengths range 2.6 - 3.4 μ) through a real atmosphere is studied experimentally. The coefficients of absorption by molecules CO 2 and CH 4 are measured for spectral lines of the photo-initiated chain and discharge-initiated non-chain DF- lasers (3.6 - 5 μ). Experimental and numerical dependences of a passing through an atmosphere of radiation integrated on spectrum of the HF- and DF-laser are determined on a trace length up to (240-500) m and 16 km, respectively.

Numerical and experimental study of processes of absorption of pumping radiation of HF-laser, a laser oscillation and a radiation amplification in a (CO 2 +N 2 O) active medium of high pressure is carried out. Measurements and numerical estimation of an absorption coefficient for 21 spectral lines of the HF-laser radiation, which are strongly absorbed by the CO 2 and N 2 O molecules, are performed. Measurements of an integral absorption coefficient for total pumping spectrum for the laser media of various content are carried out. About 63 and 35 % of radiation of the non-chain and chain chemical HF-laser, respectively, are absorbed using a four-component laser mixture. For the mono-component active media the maximum specific energy of an output radiation in 10 microns region, efficiency of an energy conversion and a small signal gain ( 12 CO 2 - 200 J/l, 18 %, 9 m -1 ; 14 N 2 O - 100 J/l, 7 %, 6 m -1 ) are obtained. For two-component ( 12 CO 2 + 14 N 2 O)-active media these parameters are 120 J/l, 7%, 7 m -1 at maximum laser energy 12 J. According to the numerical estimation, a coefficient of conversion of energy accumulated in lasing mode to energy of a pico-second pulse in 10.6 micron region for mixture of the CO 2 and N 2 O molecules may achieve 30 %.

Results of the experimental and numerical study of system "master oscillator-power amplifier" (MOPA) of the pulsed chemical photo-initiated HF-laser on chain reaction in a mode of selection of the separate spectral lines and groups of lines are presented. The MOPA radiation energy for the separate spectral lines and their groups at operation of the MO in a mode of selection achieved 350 and 500 J, respectively, that in 2 - 4 times exceeds the radiation energy for these lines at operation of MO in a free running mode.