Granular Al - Cr catalysts of paraffin dehydrogenation in a fixed bed with a chromium mass fraction about 14% are studied using stoichiographic method of differential dissolution (DD). The experiment on obtaining qualitative and quantitative results of phase analysis for those objects is described. Differences in the phase composition of two catalysts of the same composition with different catalytic activity are observed: both catalysts have the same set of phases, but differ in their amount. The obtained results are compared with the known qualitative results of physical methods. Conclusions are made about the coincidence of qualitative results of chemical and physical methods of phase analysis.

Study of the flame radiation properties on a portable multichannel spectrometer “Kolibri-2” developed at the Institute for Automation and Electrometry Siberian Branch of the Russian Aademy of Sciences is presented. The device is created according to Czerny-Turner’s optical circuit using plane diffraction grating as dispersive element and linear array of photo diodes as the radiation receiver. The structure of spectrometer is optimized to observe spectrum in any of the areas from the spectral interval 190 - 1100 nm. It is found that the bands of radicals are present within an internal gas fuel reaction zone, whereas radiation of water and soot prevail in the external zone. Radiation of the solid fuel flame is similar in spectral structure to radiation of external diffusion zone of a gas torch. It is shown that a possibility of flame blowout can be determined in analysis of the radiation spectra of the torches with swirlers through reduction of the intensity of radical luminescence in a zone of normal front position, whereas blowback - through occurrence of sodium and potassium spectrum lines. The obtined data can be used in developing sensors for remote optical control of the flame stability of hydrocarbons and determination of the torch informative zones.

The electrochemical activity of betulin (the ability to electrochemical oxidation) is determined by the method of voltammetry on carbon containing (glassy-carbon) electrodes in aqueous solutions. The suggested method of identification is based on measuring the values of currents corresponding to the oxidation peaks of active functional groups of betulin, their heights being linearly dependent on the betulin concentration within a range of 1 x 10⁶ - 8 x 10⁵ mole/liter. The developed voltammetric procedure provides betulin determination in plant extracts. Voltametric curves are obtained for dry extracts of betulin prepared using different purification procedures to demonstrate a possibility of betulin determination. The results are proved in spiking tests.

A technique for qualitative and quantitative control of all stages ofN-octadecyl-1,3-diaminopropane production by reversed-phase high-performance liquid chromatography is developed. A mixture of isopropanol with an aqueous solution of triethylamine and trifluoroacetic acid (eluent) and refractometric detector are used. Calibration curves are plotted for the mixtures “initial reagent-final product.” It is shown that concentrations of the components calculated from the chromatograms match the actual concentration of the components in the mixture.

A new method of sampling tritiated vapors (TV) from gas phase is developed on the basis of the phase isotopic exchange (PhIE) of water. Theoretical foundations of the PhIE process are described. Experimental results of gas sampling (100- and 40% relative humidity) demonstrate high accuracy of the method. Thus, the difference between tritium concentrations in the model mixture and experimentally measured value is 2 - 3%, regardless of the initial parameters of the test gas. The proposed method is more informative compared to bubbling through the liquid, and provides tracing changes in TV concentration in the tested gas. High capture performance eliminates the leakage of tritium, whereas a small degree of flow dilution can improve the accuracy of measuring low tritium concentrations.

The defective areas of tanks constructions with abnormal dispersion of magnetic parameters (strength of self-magnetic dispersion field and local change of the field gradient) are analyzed using the magnetic memory method. More than 80 horizontal and vertical tanks made of steel ST3 and 09G2S were examined without their retirement from service and some of them were partially subjected to full inspection in different geographical regions (Northern Europe, Yamalo-Nenets Autonomous Okrug, Eastern Siberia and Far East). It was determined that the character of distribution of the strength and gradient of self-magnetic dispersion field atop damages provides visualization and recording of corrosive fracture and cracks using compact magnitometric devices similar to SCM (stress concentration meter). It is shown that stress concentration zones can be identified by a magnetic signal without any optional visual control and the values of strength and gradient of the self magnetic field provide determination of the damage parameters. In most cases (90 %) the results of traditional methods of non-destructive testing (eddy current flaw detection, fluorescent magnetic testing, ultrasound detection and optical visual control) match the location of magnetic anomalies and corrosive crack-like damages of tanks.

Atomic force microscopy is used for comparative analysis of the elastic characteristics of the structural components of multiphase materials. Changes in the dynamic characteristics of the microcantile (amplitude and phase of oscillations, resonant frequency) are recorded in the dynamic mode of the atomic force microscope operation upon interaction of the probe tip with the sample surface. The phase contrast of polymorphic materials with a nanoscale resolution is thus recorded simultaneously with the visualization of the topography of the sample surface. Using the obtained data we determined the elastic characteristics of structural components and hardened layers of ledeburite steels X210Cr12 andHSS6-5-2. To assess the elastic characteristics of the modified layers a comparative analysis of the phase contrast was performed on the prepared surface of composite samples. The samples consisted of two halves and each of them contained a modified layer. After putting together the modified layers of the both parts the samples were tightly fastened and the joint was polished. The resulting transverse microsection provided simultaneous study of thin interface of two modified layers and substrate on both sides of the layers. Evaluation of the elastic characteristics of the structural components of steels, as well as thin surface layers showed that the pattern of the phase contrast distribution formed upon scanning the sample surface reflects the properties of dissimilar materials. The developed technique can be used in determination of the modulus of elasticity of hardened layers of small thickness and structural components as well.

Mechanical properties of structural steels are studied using acoustic and magnetic methods tensile tests of flat specimens with stress concentrator. Strain dependences of acoustic and magnetic parameters assessed by several nondestructive testing techniques are obtained. Analysis of revealed regularities provides identification of the physical parameters which characterize attaining of the critical state corresponding to the yield strength and ultimate strength of the materials under studied.

The chemical composition, microstructure and mechanical properties of thin-sheet (250 - 260 pm) TRIP steel VNS9-Sh obtained by cold rolling of a hot-rolled sheet with intermediate thermal treatment are studied. It is determined that the metal microstructure consists of strain-induced martensite and metastable austenite in work hardened condition. The value of optimum indentation load equal to 1 kgf (9.81 N) for the Vickers hardness test is determined proceeding from the average grain size (35 pm) and strip thickness. The indent covers several grains on the steel surface under this load and the ratio of the steel strip thickness to the indent depth is at least 20 thus excluding the impact of the substrate (specimen stage or other equipment) on the hardness value. To determine other mechanical properties an instrumented indentation by a ball diamond indenter with a radius of 0.2 mm is used. A technique for determination of the Young’s modulus, yield stress, and ultimate stress is proposed. The discrepancy between the values of the aforementioned mechanical characteristics determined by instrumented indentation and those determined in tensile tests range within ±7%.

Three steels 25L, 08Kh14NDL, and 08Kh15N4DML are tested for cavitation wear on a magnetostrictive vibrator in fresh water at different oscillation amplitudes of the end face of the concentrator. The mass loss and profilograms of the wear surface are recorded. Dependence of the height of the irregularities on the duration of the cavitation impact is of the form of a polygonal line with two fracture points. The first fracture point corresponds to the end of the incubation period of cavitation wear. The value of the roughness height parameter corresponding to the first point of fracture does not depend on the intensity of cavitation impact for a given alloy. Proceeding from the results thus obtained a new technique for accelerated testing of steels is developed to determine the duration of the incubation period of cavitation wear.

A technique for determination of the true stress-strain curve for the material of fuel-element cladding is proposed under the assumption of isotropy of plastic hardening in the case of large plastic deformations. The material under the severe plastic deformation is described using the isotropic hardening plasticity. The method is based on the consistent application of three types of tests to determine the plastic resistance: 1) uniaxial tensile test of longitudinal specimens cut from the cladding, 2) compression with a high degree of plastic strain of the annular sample with an internal cylindrical rod, 3) compression of a segment cut from the annular specimen. The degree of strain of the ring wall in the second type of testing is determined from the results of the finite element simulation.

For an adequate probabilistic description of the objects of statistical research, it is convenient to use a generalized probability density function that provides keeping the same mathematical model when the density parameters that affect the function shape change. We present the definition of a generalized sechk-density of probability distribution and the main characteristics: distribution function, characteristic function, variance, kurtosis, differential entropy, Fisher information regarding the offset parameter. It is shown that generalized sechk-density is a convenient probabilistic model that can be used in applied statistics in the range of excess values from zero to three. Sechk-density is a smooth function minimizing Fisher’s information on the density class. The robust properties of the generalized sechk-density are studied as applied to the algorithm of estimating mixing with known and unknown density parameters. A subclass of reduced robust estimation procedures - naturally lowered estimates - is introduced into the consideration. The quantitative characteristics of the sensitivity to a large error and sensitivity to a change in the asymptotic dispersion are presented. The considered examples of possible use of sechk-density allow us to speak about the expediency of its application in theoretical and applied statistics.

We implemented algorithms developed by B. G. Litvak for calculation of Kemeny median using some approaches of V. N. Zhikharev to analyze the results of modelling random sets of expert answers using the expert system thus obtained. A possibility of adding the relative authority (credibility) of the expert ranking is considered. Computer simulation is done in Python. The conclusions regarding practical applications of the algorithms, their validity and restrictions are discussed.