Ultrasonic Assessment of Permanent Joints of Powder Metallurgy Parts Obtained by Pulsed Electromagnetic Field

Radial pressing by a pulsed electromagnetic field (PEMF) is a fast and effective way of rigid connection of thin-walled powder parts. The quality of joining depends on well-chosen intensity and uniformity of the applied PEMF. The difficulty of non-destructive tests of joints by standard ultrasonic flaw detectors is often caused by a curved shape and a small radius of parts. The coarse-grained structure and porosity of powder parts cause a strong attenuation of ultrasound at frequencies above 3 MHz. Two ultrasonic methods were compared for sensitivity to weak and tight connections of “bush-on-bush” and “bush-on-rod” joints – pulse-echo and time-of-flight (TOF). Bushes were made of powder bronze graphite. The pulse-echo method was implemented using a commercial flaw detector with a 3MHz dual-element probe. A custom setup with quasi-point transducers at 2MHz was used in the TOF method. Weak joining between parts resulted in increased reflection of ultrasound from the bonded zones between the parts and the corresponding changes in the ultrasonic patterns. Both methods are potentially applicable to quality assurance in PEMF joining, where TOF is preferable for testing small curved parts

THE ASSESSMENT OF HEAVY METALS POLLUTION OF WATER BODIES AND SOIL IN THE ZONE OF ECOLOGICAL DISASTER (CITY KARABASH)

The report gives intermediate results of research carried out as the start of the INTAS Project “Strategy development for long term pollution control in regions of extreme environmental risk (ENVRISK)” The work on the project is a logical continuation of the research by project INCO-Copernicus TOXICAL (Contract No ICA2- CT2001-0016) [Ref. to preceding Conference] [14]. The major goal of the work is to elaborate a strategy and methods of pollution assessment and monitoring of Argazinskoye water storage basin, which is a reserve of drinking water supply for he city of Chelyabinsk in order to take steps for mitigating the health risk of the population of the region. The Russian project participants of the United Institute of Physics of the Earth, Russian Academy of Sciences, were presented with the following tasks. ? Grading and summing up the available data on the geological and tectonic structure and heavy metal pollution of the region; ? To substantiate field observation stations network and points of sampling of soil, biomass and surface water for laboratory analysis of heavy metal content; ? Rating stations of monitoring surface water pollution by neutron logging in relation to ecological conditions of the region; ? To obtain data on areal distribution of heavy metals pollution of soils, underground water and biomass; ? To elaborate a model of major pollutants spreading with surface runoff and hydrology system of the region on the basis of GIS technologies; ? To work out recommendations for local authorities to minimize health risk of the population. Currently a map of sampling has been made, sampling techniques have been elaborated in compliance with effective norms (GOST), samples processing and partial chemical analysis have been carried out. Some results of the research are given below

Detachment of Conductive Coatings by Pulsed Electromagnetic Field

The paper presents results of studies on the detachment of conductive coatings from the metal substrate by pulsed electromagnetic field (PEMF). It is known that at the boundary of a metal substrate and an electrically conductive coating having different electrical conductivities sharp changes of PEMF strength arise. This effect has been used to remove a copper layer from a steel substrate. Experimental studies were carried out in the Riga Technical University (Latvia), West Saxony University of Applied Science Zwickau, (Germany) and the Samara Aerospace University (Russia). Generators of pulsed current with power capacity from 1 to 60 kJ with discharge rates from 10 to 100 kHz were used. Treatment of coatings was performed using both flat and cylindrical inductors. The influence of a number of factors on the efficiency of the separation of conductive coating (Cu, Al), such as the thickness and material properties of the coating and substrate, the strength of adhesion of the coating to the substrate, the electrical parameters of the equipment and the inductor system, are shown. Examples demonstrating the main application potential of the method include: deleting of a thin conductive coating induced on metallic and non-metallic products by spraying; separation of layers of metal sheets after their joint rolling or punching; removal of conductive membranes used in the magnetic pulse compression of powders

Topology of energy surfaces and existence of transversal Poincar\'e sections

Two questions on the topology of compact energy surfaces of natural two degrees of freedom Hamiltonian systems in a magnetic field are discussed. We show that the topology of this 3-manifold (if it is not a unit tangent bundle) is uniquely determined by the Euler characteristic of the accessible region in configuration space. In this class of 3-manifolds for most cases there does not exist a transverse and complete Poincar\'e section. We show that there are topological obstacles for its existence such that only in the cases of $S^1\times S^2$ and $T^3$ such a Poincar\'e section can exist.Comment: 10 pages, LaTe

РЕНТГЕНОФЛУОРЕСЦЕНТНОЕ ОПРЕДЕЛЕНИЕ ОСНОВНЫХ ПОРОДООБРАЗУЮЩИХ ЭЛЕМЕНТОВ ИЗ ОБРАЗЦОВ МАССОЙ 50 и 110 мг

X-ray fluorescence (XRF) techniques have been developed for the determination of major rock forming elements in small mass 50 and 110 mg of rock samples. In order to remove the influence of particle size and mineralogical composition on the results of the analysis, the samples fusion with lithium tetraborate and lithium metaborate was used. The metrological parameters of the different procedures of the sample preparation with different fluxes and dilution rates were comparable with the parameters of the routine procedure of sample preparation using 500 mg sample mass. The repeatability of the XRF analysis for the certified reference samples of ultramafic, mafic, intermediate and felsic rocks doesn’t exceed the allowable standard deviation for the wide range of contents for all preparation procedures. Certified reference materials of rocks (SDU-1, ST-2, SGD-1, SA-1, GBPg-1, SNS-2, SSn-1, SSV-1, SG-1, SG-2, SG-3, MGL-OShBO and SI-2) were used to obtain the calibration curves. Relative standard deviation for the obtained calibration curves doesn’t exceed the allowed values. The accuracy of the technique was estimated by the comparison of XRF determination results of 10 major rock forming elements with the certified values in CRM MGL-GAS, SGD-2, SKD-1 and SG-4. The relative standard deviation of XRF analysis was 0.4-8.9 % on average, depending on the element, the level of content and the procedure of the sample preparation. It was shown that the developed technique allows us to use the obtained glass beads for further determination of rare earth elements by inductively coupled plasma mass spectrometry analysis.Keywords: X-ray fluorescence analysis, rocks, major rock forming elements(Russian)   DOI: http://dx.doi.org/10.15826/analitika.2015.19.2.009A.A. Amosova1, S.V. Panteeva2, V.V. Tatarinov3, V.M. Chubarov1,A.L. Finkelshtein1 1Vinogradov Institute of Geochemistry SB RAS, Irkutsk, Russian Federation2Institute of the Earth’s crust SB RAS, Irkutsk, Russian Federation3Irkutsk National Research Technical University, Irkutsk, Russian FederationРазработана методика рентгенофлуоресцентного определения основных породообразующих элементов в горных породах из навесок 110 и 50 мг. Рассмотрены способы подготовки образцов горных пород сплавлением с метаборатом, тетраборатом лития и их смесью c добавлением раствора LiBr, обеспечивающие формирование стеклянных дисков размером 10-12 мм, пригодных для измерения на рентгенофлуоресцентном спектрометре S8 Tiger с маской - коллиматором потока флуоресцентного излучения пробы 8 мм. Метрологические характеристики пробоподготовки образцов с различными флюсами и степенями разбавления сопоставимы с характеристиками способа пробоподготовки, оперирующего навеской 500 мг. Оценка воспроизводимости подготовки проб для стандартных образцов горных пород ультраосновного, основного, среднего и кислого состава показала, что предлагаемые способы обеспечивают необходимую точность определения основных породообразующих элементов. Правильность методики подтверждена сравнением результатов рентгенофлуоресцентного определения 10 основных породообразующих элементов в стандартных образцах MGL-GAS, СГД-2, СКД-1 и СГ-4 с аттестованными значениями. Средние квадратические отклонения результатов определений элементов в горных породах для рассмотренных способов подготовки проб не превышают допустимые. Показано, что разработанная методика позволяет использовать полученные излучатели для дальнейшего определения микроэлементов методом масс-спектрометрии с индуктивно связанной плазмой.Ключевые слова: рентгенофлуоресцентный анализ, горные породы, основные породообразующие элементы.   DOI: http://dx.doi.org/10.15826/analitika.2015.19.2.009

X-ray fluorescence determination of major rock forming elements in small samples 50 and 110 mg

Разработана методика рентгенофлуоресцентного определения основных породообразующих элементов в горных породах из навесок 110 и 50 мг. Рассмотрены способы подготовки образцов горных пород сплавлением с метаборатом, тетраборатом лития и их смесью c добавлением раствора LiBr, обеспечивающие формирование стеклянных дисков размером 10-12 мм, пригодных для измерения на рентгенофлуоресцентном спектрометре S8 Tiger с маской - коллиматором потока флуоресцентного излучения пробы 8 мм. Метрологические характеристики пробоподготовки образцов с различными флюсами и степенями разбавления сопоставимы с характеристиками способа пробоподготовки, оперирующего навеской 500 мг. Оценка воспроизводимости подготовки проб для стандартных образцов горных пород ультраосновного, основного, среднего и кислого состава показала, что предлагаемые способы обеспечивают необходимую точность определения основных породообразующих элементов. Правильность методики подтверждена сравнением результатов рентгенофлуоресцентного определения 10 основных породообразующих элементов в стандартных образцах MGL-GAS, СГД-2, СКД-1 и СГ-4 с аттестованными значениями. Средние квадратические отклонения результатов определений элементов в горных породах для рассмотренных способов подготовки проб не превышают допустимые. Показано, что разработанная методика позволяет использовать полученные излучатели для дальнейшего определения микроэлементов методом масс-спектрометрии с индуктивно связанной плазмой.X-ray fluorescence (XRF) techniques have been developed for the determination of major rock forming elements in small mass 50 and 110 mg of rock samples. In order to remove the influence of particle size and mineralogical composition on the results of the analysis, the samples fusion with lithium tetraborate and lithium metaborate was used. The metrological parameters of the different procedures of the sample preparation with different fluxes and dilution rates were comparable with the parameters of the routine procedure of sample preparation using 500 mg sample mass. The repeatability of the XRF analysis for the certified reference samples of ultramafic, mafic, intermediate and felsic rocks doesn’t exceed the allowable standard deviation for the wide range of contents for all preparation procedures. Certified reference materials of rocks (SDU-1, ST-2, SGD-1, SA-1, GBPg-1, SNS-2, SSn-1, SSV-1, SG-1, SG-2, SG-3, MGL-OShBO and SI-2) were used to obtain the calibration curves. Relative standard deviation for the obtained calibration curves doesn’t exceed the allowed values. The accuracy of the technique was estimated by the comparison of XRF determination results of 10 major rock forming elements with the certified values in CRM MGL-GAS, SGD-2, SKD-1 and SG-4. The relative standard deviation of XRF analysis was 0.4-8.9 % on average, depending on the element, the level of content and the procedure of the sample preparation. It was shown that the developed technique allows us to use the obtained glass beads for further determination of rare earth elements by inductively coupled plasma mass spectrometry analysis

Synthesis of new 2-[2-(dialkyl(diaryl)-phosphoryl)-2-methylpropyl]quinoline-4-carboxylic acids

© 2015 Springer Science+Business Media New York. [Figure not available: see fulltext.] A Pfitzinger reaction of isatin with 2-methyl-(4-oxopent-2-yl)dialkyl(diphenyl)phosphine oxides was used to synthesize new derivatives of 4-quinolinecarboxylic acids, containing a phosphine oxide fragment, and screening for antimicrobial activity was performed

ОПРЕДЕЛЕНИЕ ПОЛЯРИЗАЦИОННО-ЭНЕРГЕТИЧЕСКИХ ИНВАРИАНТОВ СОСТАВНЫХ ОБЪЕКТОВ ПРИ ДВУХПОЗИЦИОННОМ РАССЕЯНИИ НА ОСНОВЕ ОБОБЩЕНИЯ ТЕОРЕМЫ КЕЛЛА

Analysis of compound radar objects polarization-energetical invariants determination was done in the first time for the bistatic scattering on the base of Kell theorem generalization.Доказана возможность обобщения теоремы эквивалентности Келла с целью определения поляризационно-энергетических инвариантов составных радиолокационных объектов при двухпозиционном рассеянии по данным однопозиционных измерений

Теорема эквивалентности келла в радиолокации

This article (part 1) is devoted to simplified explanation of Robert Kell equivalence theorem about the derivation of bistatic RCS based on the monostatic measurements. In contrast to R.Kell’s original study, using definition based on Statton - Chu integral, this article uses methods of physical optics. The analysis was made for a complex radar object, including a considerable number of centers of scattering, also for a complex radar object, including an extended scatterer. This article (part 2) is devoted to experimental results based on Robert Kell equivalence theorem about the derivation of bistatic RCS in accordance with monostatic measurements.Первая часть статьи посвящена построению упрощенного изложения теоремы эквивалентности Келла о нахождении двухпозиционной эффективной поверхности рассеяния (ЭПР) по результатам однопозиционных измерений. В отличие от оригинальной работы Келла, использующей строгую формулировку на основе интеграла Стрэттона-Чу, в настоящей статье использованы методы физической оптики. Анализ проведен для случая сложного радиолокационного объекта (РЛО), включающего значительное число центров вторичного рассеяния, а также для случая сложного РЛО, включающего протяженный рассеиватель. Вторая часть статьи посвящена изложению некоторых экспериментальных результатов по определению двухпозиционной ЭПР по результатам однопозиционных измерений на основе теоремы эквивалентности Келла. Эксперименты проведены с использованием сложных РЛО, включающих значительное число центров вторичного рассеяния, а также протяженные рассеиватели

Synthesis and Antimicrobial Activity of New Dialkyl(diaryl)-2-(5-chloro-2-hydroxyphenyl)-2-(phenylethenyl)pentylphosphonium Salts

© 2018, Pleiades Publishing, Ltd. New dialkyl(diaryl)-2-(5-chloro-2-hydroxyphenyl)-2-(phenylethenyl)pentylphosphonium salts bearing various substituents at the phosphorus atom were synthesized. Antimicrobial activity of the salts obtained was estimated. Derivatives with 2-methoxyphenyl substituents at the phosphorus atom are most active against grampositive bacteria. Herewith, dibenzyl-substituted phosphonium derivatives possess the best antifungal activity