A possibility of arsenic and selenium determination at the MPC level in drinking water using atomic emission spectrometry with a microwave plasma (MP-AES) and hydride generation is demonstrated even for samples with a high degree of mineralization (up to 12 g/liter). To ensure the desired sensitivity of the determination for both elements we optimized the operation modes of the atomizing chamber for hydride generation. Conditions for their determination in mineral and medicinal table waters are specified.

An ICP-AES technique (atomic emission spectrometry with inductively coupled plasma) providing simultaneous determination of arsenic, antimony and bismuth in a wide range of tungsten- and copper-containing materials (ferrotungsten, copper and tungsten concentrates, copper based alloys) in a single extraction procedure using coprecipitation on iron hydroxide (III) is presented. Optimal conditions of coprecipitation (i.e., 0.02 mole Fe (III) and 30-min coagulation of the precipitant at pH = 10) are specified. The results of analysis of the reference samples of ferrotungsten, copper and tungsten ores and concentrates, copper-Nickel alloys, bronzes containing arsenic, antimony and bismuth in the range of 0.001 - 0.4 wt.%, satisfactory match the certified content that proving the effectiveness of the proposed method.

The method of gas chromatography-mass spectrometry is first used to study the impurity composition of SF₆ enriched with³⁴S isotope. Adsorption capillary columns with a modified silica gel and polytrimethylsilylpropyne (PTMSP) are used to separate the impurities. We managed to identify 23 substances: permanent gases, saturated, unsaturated and aromatic hydrocarbons C₁ - C₈, diethyl ether, diethylsulfide and 2-methyl-furan. Compared to natural isotopic composition of SF₆, 18 substances are detected for the first time. The detection limits of the impurities range within 1 X 10⁵ - 5 X 10⁸ % mol. The correctness of analysis is confirmed by the method of varying the sample size.

Voltmammetry is used to study electrochemical behavior of Carmoisine (synthetic red food dye from azo dye group) on a glassy carbon electrode. Different factors affect the cathode signal of the dye: pH, potential and accumulation time, and the sweep rate of the potential. We specified working conditions for Carmoisine determination in model solutions: pH = 1.65, E_acc = -0.1V, t_acc =10 sec, W =100mV/sec. Linear dependence of Carmoisine electroreduction current on the dye concentration at a potential value of 0.15 V is observed in the range of 0.05 - 0.5 mg/liter. Carmoisine detection limit is 0.02 mg/liter. Results of comparative determination of carmoisine in soft drinks using voltammetric and spectrophotometric techniques are presented.

We propose a relatively simple procedure which provides improving the accuracy of the thermal diffusivity determination and temperature dependence using numerical and analytical method at small Fourier numbers (Fo < 0,3). The calculation is performed for each time interval thermal of symmetric temperature field of infinite plate (thickness 2R). The temperature values of the experimentally obtained temperature field x = 0, x = z, x = R (0 < z < R, in the particular case z = R/2) are used in calculations. We assessed the complexity and accuracy of the determination of the thermal diffusivity and convective heat transfer coefficient using test temperature fields calculated by the method of finite differences for the plates made of steel and red brick under varying boundary conditions. The method is rather accurate, descriptive and easy to use; data processing can be carried out using Microsoft Excel. Lines of further developing of the method are considered.

The effect of the procedure of polyhydroxybutyrate and polyamide (PP) mixing (in the solvent or in the melt using heated rolls with a friction clutch) on their dispersion is considered. A method of nondestructive control of the composition of thin films of PP mixture using Infrared Fourier Transform Spectroscopy is developed. A possibility of using small samples and high sensitivity are considered the advantages of the developed procedure. Mixing of the polymers in the melt leads to uneven dispersion of polyhydroxybutyrate and polyamide, whereas mixing in a solution results in more homogeneous dispersion. The proposed approach can be extended to other polymer compositions.

Problems regarding grain-size analysis of molding sand and corresponding data processing are considered. Usually, to determine distribution of the particles in size a sand sample is sifted through a stack of sieves thus dividing a set of sand grains into broad and irregular intervals. Hence, the calculated statistical characteristics of the sand can substantially deviate from the true values. A very important indicator of the sand quality is a form of grains which is currently determined indirectly. Therefore, the analysis of those samples requires a modern method of analysis, e.g., an optical method which is capable of providing reliable quantitative information on the particle size and shape of the molding sand.

A method of constructing 3D color maps that can be used to represent the results of metallographic study of the structure and properties of the samples subjected to shock-wave loading is considered. The method is used to measure damage, hardness and micro-hardness of metallographic specimens of two spherical shells made of uranium alloys subjected to symmetrical explosive compression. Structural changes and damage of the shell material attributed to shock-wave processes are localized in the bulk alternating zones. Analysis of the damage consists in assessing the size and shape of the microcracks in cross section and determation of their location. Distributed measurements of the hardness and microhardness are carried out over the entire cross section in study. The data array (up to 50 GB) of the measured values is too large for “traditional” methods of analysis, whereas the method of color mapping demonstrated the capability of processing data on hundreds of thousands cracks and several thousands of tests for hardness- and micro-hardness still being rather efficient.

Evolution of the parameters of fracture mechanics at different stages of low cycle damage is analyzed. The developed approach is based on processing the results of optical interferometric measurements of the deformation response to a small increment of the crack length. Three consecutive symmetrical notches are used to simulate the process of fatigue crack propagation through the zone of accumulated damage induced by low cycle fatigue. The magnitude of tangential component of the displacement measured at several points on the edge of the notch using speckle-inter-ferometry is an input experimental data. The first four coefficients of the Williams series solution are used to determine the stress intensity factor (SIF) and T-stress values. The values of crack opening, SIF and T-stress for cracks of different lengths are obtained at a fixed number of preliminary loading cycles N_c = 0, 100, 1000, 1800, 2500, and 3300. The dependences of the parameters of fracture mechanics for the cracks of fixed length on N_c number which illustrate a process of fatigue damage accumulation are constructed.

We discuss the methodology of plotting curve of the probability of defect detection in the case of testing bulk defects in the base metal of aluminum parts. Method of control, interfering factors, finite element model for pulse-echo simulation, method of interfering factor simulation, mathematical apparatus for plotting the curve of the probability of defect detection are described. The results of simulation of 350 different defects are analyzed and curve of the probability of their detection is plotted.

The history of creation and development of the Analytical center CJSC “ROSA” is described. Main activity of AC “ROSA” is the analysis of the different types of water, soil, sewage sludge, water treatment reagents. More than 400 chemical and biological indicators are determined at AC “ROSA” using modem analytical equipment of leading world companies. The center has internal sampling service. Experts of AC “ROSA” developed more than 90 methods for analysis of various objects. AC “ROSA” is a provider of proficiency testing of laboratories through inter-laboratory comparative tests. AC “ROSA” was awarded prizes in the field of quality, including “Silver mole” prize constituted by the national “Analytics” Association.

A generalizing notion of “return metal-containing raw material” (RMRM) is introduced to consider the sources of RMRM containing non-ferrous, rare and noble metals. Generalized information about the content of valuable components in various types of return metal-containing raw material, as well as RMRM classification according to various criteria is presented.