The possibility of Pd (II), Pt (IV), and Rh (III) separation from chloride solutions by solvent extraction in rotating coiled columns (RCC) is demonstrated. The reagents most frequently used in extraction of platinum metals were selected as extractants: trioctylamine (TOA), methyltrialkylammonium chloride (MTAA), tributylphosphate (TBP), N, N, N',N'-tetra-re-octyldiglyTOlamide (TODGA). The completeness of extraction of the platinum group metals from individual and mixed hydrochloric acidic and chloride solutions was studied depending on the nature and concentration of the extractant, acidity of the test solutions and other factors. Optimal conditions for the quantitative extraction of metals from model hydrochloric acidic and chloride solutions and subsequent selective separation at the stripping stage are specified. A scheme of multistaged extraction separation of Pd (II), Pt (IV), and Rh (III) from chloride solutions using a 0.05 M solution of MTAA in toluene as a stationary phase in RCC is proposed. The scheme includes extraction of Pd (II) and Pt (IV) ions from a chloride solution (0, 1 M HCl + 30 g/liter NT) into the organic phase with simultaneous separation of Rh(III) remaining in the aqueous phase, and sequential stripping of Pd (II) and Pt (IV) from the organic phase with a 0.01 M solution of thiourea in 0.1 M HCl and a 1 M solution of thiourea in 0.5 M HCl, respectively. The scheme was tested in separation of the platinum group metals from the technological solution of a given composition. The degree of metal extraction with a 0.05 M MTAA solution in toluene and sequential stripping with thiourea solutions is 99.5% for Rh (III), 99.9% for Pd (II), and 97.4% for Pt (IV). The separated water fractions of rhodium and platinum after leaving the column did not contain impurities of other platinum metals whereas the water fraction of palladium contained 0.5% Pt.

The reference polymers and polymers with molecular imprints of carboxylic acids (MIPs-CA) — propionic (MlP-Propionic) and butyric (MIP-Butyric) acids — were synthesized on the surface of piezoelectric sensors using aromatic compounds by the non-covalent imprinting method. Molecularly imprinted polymer (MIP) is a polymer produced through molecular imprinting, which leaves cavities in the polymer matrix with affinity to a chosen "template" target molecule. The values of the imprinting factor and selectivity coefficients were calculated to assess the ability of MIPs-CA to recognize the target molecules. It is shown that the sensors modified by the molecularly imprinted polymers exhibit high selectivity for the acid that was a template during their synthesis. The detection limits for propionic and buty ric acids are 7.40 x 10~6 and 8.81 x 10-6 g/dm3, respectively. Correctness of the carboxylic acid determination in model solutions was verified in the spike/recovery tests. The relative standard deviation is less than 10%. The modified piezoelectric sensors were tested in analysis of the intermediate products of edible ethanol production (distillate of fermentation mixture, epyurat, bottom liquids of columns). The correctness of the determination of carboxylic acids in liquids was evaluated using an Agilent Technological 7890B GC Systems. The difference in the results of acid determination between both methods (piezoelectric sensor and chromatography-mass spectrometry) does not exceed 6%. The modified piezosensors expand the potential of rapid determination of carboxylic acids in the intermediate products of ethyl alcohol production.

Conditions for interaction of the iodate ions with iodide and methylene blue as a chromogenic reagent were studied. The interaction of iodate with an excess of iodide depends on the medium acidity. In dilute acids, the reaction of IO3 with Г is accompanied with a release of iodine which oxidizes the dye. The observed weakening of the color which is proportional to the concentration of iodate ions in the solution, results from the oxidative destruction of methylene blue. Spectra of methylene blue, conditions of the redox interaction, as well as the effect of the solution acidity and reagent concentration on the completeness of the reaction were studied. The light absorption of the solutions was measured at a wavelength of 664 nm. The reaction of the free iodine formation is rapid and quantitative at pH 4 - 5 . The desired acidity of the medium was attained using 1 M solution of acetic acid. The optimal concentration of methylene blue was determined. The results of the study formed a base for developing a technique of iodate ion determination in iodides of alkaline metals. The analyzed solutions were prepared with addition of sodium acetate to prevent iodide oxidation by atmospheric oxygen. To eliminate the interfering effect of Fe (III), sodium pyrophosphate (which should be introduced after acidification of the solution and isolation of iodine) was used. The accuracy of the technique was proved in spike tests on the model solutions and real samples by the method of sample weight variation. The developed technique was tested in determination of the iodate ions in cesium and sodium iodides. The relative standard deviation does not exceed 15%. The sensitivity of the developed technique is 10 times higher compared to the technique based on the formation of an iodine-starch complex.

To determine the phase relationships in the system (1 - 2x)BiSc0₃ • xPbTi0₃ • xPbMg_1/3Nb_2/30₃ near the morphotropic boundary, the ceramic samples for x = 0.34 and x = 0.46 were studied by the XRD method. The profiles of nine regions of the XRD patterns were analyzed using WinFit software. In both cases, a much better agreement with the experimental data was observed with the introduction of additional phases with cubic symmetry. The simulation of the full x-ray diffraction patterns of the samples using the Le Bail method was also carried out. The studied samples contain two phases: the main with a cubic (o = 4.0432 A) (x = 0.34) and tetragonal (o = 3,9963 А, с = 4.0580 A) (x = 0.46) unit cells and additional one. The additional phases with broad diffraction peaks can be considered cubic (with the unit cell parameters a - 4.045 A and a - 4.017 A, respectively).

Experimental time dependences of the electric voltage U(t), taken from the induction magnetic head when scanning it with a magnetic carrier with magnetic field records of artificial defects of the integrity (slits) with a width of (1.0 - 10.0) x 10^-5  m in aluminum plates from 1.5 x 10^-6 to 2.0 x 10^-3 m are presented. On the magnetic carrier the magnetic fields of the defects that occur when aluminum plates are exposed to a pulse of magnetic field of plane inductor (action time of about 1.0 x 10^-4 sec). Dependences of U(t) for different depths of bedding of the defects and thickness of the layer of the material above them in the specified ranges of influences are obtained. In this case, distributions of instantaneous magnetic fields are recorded on the surface area of objects of the order of 1.0 x 10^-3 m² with a resolution in the measurement plane of 1.0 x 10^-8 m². The novelty of the method consists in determination of the amplitude of the main pulse of the field and build up time, the shape of the leading and trailing edges, as well as the amplitude, build up time, the number and polarity of the outliers of magnetic field, direction of the applied field, operations of smoothing, calculation, separation of the useful signal and operations of recognition of the defect information recorded on the magnetic medium with analysis of the dependences U(t). The developed method for controlling objects from electrically conductive materials makes it possible to increase several times the accuracy and speed of the control of the integrity defects in diamagnetic and paramagnetic metals.

The results of studying the efficiency of the laser-acoustic method of ultrasonic testing in determination of the degree of polymerization of the matrix of polymer composite material (PCM) are presented. We have studied the PCM samples used for manufacturing integrated structures. It is shown that excessive degree of polymerization of the preformed blanks leads to a decrease in the strength of connection of the structural elements and precludes obtaining the desired shape and geometric dimensions of the product. We developed fundamentally new diagnostic parameters, which are characterized by high reliability and accuracy of determination. To forecast sample curing regimes with given values of the degree of transformation, the reaction kinetics was analyzed using differential scanning calorimetry Experimental results used for calculation of the kinetic parameters were obtained on a thermoanalytical complex DSC 1 (Switzerland). The kinetic parameters of polymerization and degree of binder curing in plastics were determined by the thermal effect of the reaction. It is shown that when determining the degree of polymerization of a PCM matrix by an ultrasonic method (laser-acoustic method of exciting ultrasonic vibrations), the product of attenuation of the bottom signal of longitudinal ultrasonic vibrations by the signal round-trip time and energy of the structural noise (thus taking into account the porosity of the material), can be used as reliable parameters of diagnostics. The proposed method provides higher accuracy compared to other methods used for control of the degree of polymerization.

The problems regarding arrangement and implementation of the intralaboratory quality control (ILC) of test results in testing laboratories (TL) are reviewed and summarized. The main goals of ILC directly aimed at minimization of the risks of getting unsatisfactory test results are considered along with the choice of the methods and types of control. The process and system approaches to organization and performance of the ILC are proposed with allowance for the risk assessment at the stages of planning, implementation, and monitoring of the ILC, which provide a control of all measurement techniques (MT) used in the laboratory, thus making the control procedure transparent to all the parties concerned. An effective way to describe the ILC starting with the stage of planning is recommended. The proposed "ILC Program" ensures the efficiency and effectiveness of the process to match the goals set for ILC: ensuring of the required accuracy (uncertainty) of current test results for the entire nomenclature of measurement techniques, maintaining the testing processes in a statistically controlled state, and, consequently, ensuring of the confidence of internal and external customers and supervisory organizations to the results of testing and activities of the TL as a whole thus proving the technical competence of the laboratory. We present the results of analysis of all ILC stages using the Shewhart-Deming — PDCA principle with a list of possible risks of obtaining unreliable results. Recommendations on the effective implementation of each stage of the process are given. Listed typical mistakes of ILC implementation can help the readers not only to avoid them, but also consider them as possible risks.

A new method for measuring the amount of heat on the diathermic combustion calorimeter is presented. The method is based on filling the calorimeter vessel at room temperature and placing of the vessel in the measuring cell of the calorimeter (calorimeter is preliminary brought to a constant temperature) without preheating of the vessel in an isolated thermostat. Placing of a "cold" vessel into the cell and subsequent release of the reactive heat virtually balance each other, thus reducing the load on the temperature controller of the calorimeter. Note that not only pulse, but also the heat release of unrestricted continuance is recorded. Elimination of the preheating thermostat obviously simplifies the device design. The method has been patented.

Significance of assessing the characteristics of crack resistance of centrifugal-cast (CFC) tubes made of steel 15KhlMlF is substantiated. The characteristic features of the metal under study are considered along with the methodology of crack resistance tests. Three modifications of the metal of the CFC pipes in the initial state, that differ in the degree of developed segregational heterogeneity, and two modifications of the metal with almost the same degree of structural heterogeneity, which differ in the running time as a part of the operating equipment are studied. It is shown that a decrease in the intensity of the segregational damage of the metal structure has almost no effect on the level of the strength characteristics, but is accompanied by an increase in the plastic properties and toughness of the metal. We present the results of studying crack resistance of centrifugal-cast pipes (steel 15KhlMlF) under static, cyclic and prolonged static loading in conditions of high-temperature creep. It is shown that an increase in the degree of structural heterogeneity of the CFC steel adversely affects the characteristics of static crack resistance and cyclic crack resistance as well, but to a far lesser extent and has little if any effect on the crack resistance of the CFC steel at creep. Cyclic crack resistance slightly decreases with increase of the operating time of the metal in functioning pipelines, whereas the characteristics of the prolonged static crack resistance get worse significantly. It is shown that welded joints of the CFC pipelines have a substantially lower crack resistance under creep conditions compared to the base metal. Statistical processing of the experimental data is used to get kinetic diagrams of cyclic and prolonged static crack resistance of 15X1M1F CFC-steel in creep conditions. The results of practical applications of the obtained crack resistance characteristics of the metal of the CFC pipes are demonstrated with a focus on the problems of ensuring the reliable operation of the steam pipelines of thermal power plants at the end of their service lifetime.

The study is aimed at the development of the new failure criteria for quasi-brittle materials in conditions of stress concentration. The possibility of using non-local failure criteria for description of the brittle, quasi-brittle and ductile fracture of the materials with notches is analyzed. The general feature of these criteria consists in the introduction of the internal dimension characterizing the structure of the material, which provides the possibility of describing a large-scale effect in conditions of the stress concentration and thereby expand the area of their application compared to traditional criteria though it is limited to the cases of brittle or quasi-brittle fracture with a small pre-ffacture zone. To broaden the scope of their application to quasi-brittle fracture with a developed pre-fracture zone we propose to abandon the hypothesis about the size of the pre-fracture zone as a constant related only to the structure of the material. A number of the new nonlocal criteria, which are the development of the criteria of the mean stress and fictitious crack, are developed, substantiated from the physical standpoint, and proved experimentally. These criteria contain a complex parameter characterizing the size of the pre-fracture zone and taking into account not only the structure, but also the ductile properties of the material, specimen geometry and loading conditions. The expressions for the critical pressure in the problem of tensile crack formation upon compression of the samples of geomaterials with a circular hole are derived. The results of calculations match rather well the experimental data on the destruction of drilled gypsum slabs.

When determining the mechanical properties of materials in kinetic indentation tests using indentation diagrams, careful consideration of the elastic compliance of the device, i.e., the hardness tester, is required. The determined values of the Young's modulus of the tested material substantially depend on the reliability of the method of evaluation and accounting for the elastic compliance. Therefore, verification of the test techniques based on kinetic indentation should be carried out using the materials with the known, but rather different values of the Young's modulus. Successful experience has been gained to date in the evaluating and accounting for the elastic compliance of the device upon kinetic indentation of the materials by a diamond pyramid which is reflected in the relevant standards. However, there is no way of transferring this experience to the kinetic indentation by a steel or carbide ball without additional research and experimental verification. We proposes a technique for estimating the elastic compliance of a hardness tester using a kinetic ball indentation diagram based on the G. Hertz equation for the case of elastic contact of a ball with a plane. A linear correlation has been determined between the additional elastic deformations of the device and indentation load, which is characteristic of each device and independent on the ball diameter. The obtained dependence allows for correct consideration of the elastic compliance of the device using software applications in recording and processing the ball indentation diagrams. Experiments have been carried out to determine the hardness and the Young's modulus through ball instrumented indentation of different materials (steel, aluminum alloy, magnesium alloy, and titanium alloy) using the existing and developed methods of taking into account the elastic compliance of the device. The coincidence or proximity of the values of the Young's modulus of the same material determined from the ball indentation diagrams and sample tensile tests is considered the main criterion proving the accuracy of the technique. The advantages and shortcomings of the known and proposed procedures are discussed along with practical recommendations for their applications.