Заводская лаборатория. Диагностика материалов最新文献

{"title":"Evaluation of embrittlement of construction steels by microindentation","authors":"A. E. Zorin, A. S. Romantsov","doi":"10.26896/1028-6861-2023-89-9-64-72","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-9-64-72","url":null,"abstract":"The mechanical characteristics of a metal are determined by a combination of three groups of factors: the chemical composition, structural features and the deformation ability of the structure, i.e., the ability of elements to relax internal stresses during deformation through dislocation sliding which does not lead to the crack formation and destruction. The possibility of using microindentation to assess the deformation ability of the structure of structural steels with a relatively high ductility is the goal of the study. The theoretical analysis revealed that an increase in the stiffness and a decrease in the plasticity of a metal leads to a change in the deformation model during indentation and, in particular, to the occurrence of deformation effects of various morphologies on the surface near the imprint, which can be indicative of the metal plasticity. Experimental studies performed on pipe steels of various strength and types of the structure confirmed that as the deformation ability of the metal decreases (primarily as a result of deformation hardening), a system of localized shears is formed near the imprint along the lines of action of maximum tangential stresses. A scale for ranking data of localized shears is proposed and the optimal load value and shape of the indenter are determined which provide gaining maximum information by microindentation. A methodology for assessing the embrittlement of plastic construction steels based on the results of microindentation has been developed, which can form a basis for creating an effective technology of nondestructive evaluation of the metal state.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135924150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of inverted multivariate calibrations to determination of the total content of phenols","authors":"V. I. Vershinin, L. S. Bazhenova","doi":"10.26896/1028-6861-2023-89-9-5-12","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-9-5-12","url":null,"abstract":"The total content ( c Σ ) of toxic phenols in water is usually determined using the procedures which include the introduction of a group reagent, measurement of the generalized signal ( A Σ ) at a selected wavelength, and assessment of c Σ in terms of C 6 H 5 OH. The use of diazotized sulfanilic acid (DSA) as a group reagent leads to the errors of c Σ determination which do not exceed 30% thus ensuring more adequate estimates of c Σ than measuring phenolic index. We suppose that further reduction of errors in group analysis would be possible with multiwavelength measurements and multivariate calibrations but these promising techniques have not been used yet for the determination of total phenol. To check up this assumption, model multicomponent colored solutions of the known composition were prepared and analyzed. These model mixtures contained simultaneously up to 5 different phenols with a total concentration ranged from 15 to 70 μmol/L. After converting all phenols to corresponding azo-dyes their generalized signals were measured at m wavelengths in the UV region of the spectrum 10 minutes after mixing the solutions. The results of group analysis were calculated with the multivariate calibrations; the recalculation of A Σ values to standard substance concentration we used only for comparison. The inverted multivariate calibrations were calculated with A Σ values of n model mixtures which formed a training set. For optimized conditions ( m = 7, n = 10) the systematic error of c Σ prediction is less than 13 % rel., that is half of errors for total index calculation. Therefore, inverted multivariate calibrations can be rather useful to control the total content of phenolics in natural and waste waters (instead of the total indices). However, systematic errors raised sharply when the analyzed sample contained some individual phenols which were absent in samples of the training set; in such cases the errors can increase up to 80 % rel. To maximize the correctness of corresponding techniques, it is desirable to elucidate beforehand the qualitative composition of phenol mixtures in water samples under study and take it into account when the multivariate calibration is used.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135924497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modern methods for identification of atoms, molecules, and aerosols in various objects","authors":"A. T. Khalmanov, N. Toshkuvatova","doi":"10.26896/1028-6861-2023-89-6-23-34","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-6-23-34","url":null,"abstract":"The study is aimed at developing highly sensitive methods of laser analytical spectroscopy. The physical mechanisms of forming useful signals (selective ionization signal and cavity ring-down signal) were identified that provided registration of parameters of atomic and aerosol systems in the intensive pulsed laser field. High-sensitive laser methods of laser resonance ionization spectroscopy in vacuum, laser-enhanced ionization spectrometry in flame, and cavity ringdown laser absorption spectroscopy (CRLAS) are used for the determination of ultra-small concentrations of atoms in different phase states of the substance. Samples of aqueous standard solutions and solid metals of s (Li, K, Na, Ca, Cs), p (Al, In), d (Cr, Mn, Fe, Co, Ni, Cu, Ag, Au, Pt, Zn, Hg), f (Yb) elements, aluminum alloys, especially pure solvents, crystals (NH4F, NaF), semi-conductor materials (GaAs, Si) and various aerosols of salts (NaCl, CsCl, NaI, NaF, KCl AgNO 3 ), chemicals, organic dyes, alloys, soils and rocks were studied. The new mechanisms of getting free particles are revealed and new methods increasing the efficiency of atomization, selective ionization and excitation of atoms in systems «flame», «rod – flame», in atomizer «graphite – furnace» are proposed. The particle size distribution of aerosols formed under the impact of high-power laser radiation on the surface of a solid sample has been studied. The dependence of the absolute concentration of aerosol particles on their size has been determined. Aerosol extinction coefficients and extinction efficiency have been measured using intracavity laser spectroscopy. For the first time new parameters of aerosols are revealed by physical and chemical properties of aerosol plumes from solid surfaces and aerosols of salt of metals and organic aerosols. Methods of additives and calibration curve were used to examine the effects of the matrix on the analytical signal of the studied atoms.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136356028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of the GC-MS method in combination with preliminary solid phase extraction on a magnetic molecular imprinted polymer for the determination of bisphenol A in soils of various types","authors":"A. S. Gubin, A. A. Kushnir, P. T. Sukhanov","doi":"10.26896/1028-6861-2023-89-6-13-22","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-6-13-22","url":null,"abstract":"A method of gas chromatography-mass spectrometry (GC-MS) in combination with pre-concentration on a sorbent with BPA molecular imprints (dosage of sorbent — 50 mg, sorption time — 10 min, pH — 3, desorption with methanol) is used to determine bisphenol A (BPA). The sorbent extracts about 96% of BPA from aqueous solutions with a single sorption and is characterized by a high imprinting factor reaching 7.1. The samples of soils of urbanized territories, as well as typical chernozems and residual carbonate chernozems outside the large cities of the Voronezh region were studied. The limit of BPA detection was 0.07 μg/kg (in terms of dry soil), the range of the linearity of the calibration graph was 0.3 – 35 μg/kg. Determination of bisphenol is hindered by soil contamination with petroleum products, which can be eliminated by washing with heptane. It has been revealed that pH of soils has a significant effect on the BPA migration of along the soil profile. The concentration curves of the BPA distribution over the soil profile up to a depth of 1 m were plotted. The maximum BPA concentrations in the soils of urbanized territories depend on the contamination of the territory with polymer waste. The maximum BPA concentrations (29.84 μg/kg) were determined at a depth of 20 cm in samples taken near the landfill of municipal solid waste. At other points within the city limits, the maximum concentrations range within 5.38 – 8.77 μg/kg. Outside the city of Voronezh, the mobility of BPA increases in more alkaline typical and residual-calcareous chernozems and significant concentrations of the pollutant were found at a depth of 50 – 80 cm. The developed scheme can be applied to targeted screening and monitoring of the BPA content. The method can be used for BPA determination in soil horizons for various soil types, meteorological conditions (precipitation, annual temperature regime), and contamination of the territory (the presence of unauthorized landfills, MSW landfills, sewage treatment facilities near the sampling point).","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136356020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}