The influence of a probe on the optical path of atomic absorption spectrometer with a graphite tube atomizer

We have studied the influence on the atomic absorption signal of the obscuring of the transmission beam by a probe for the two-stage atomization in a graphite tube atomizer. The following parameters were varied: the thickness of the probe (0.5-1.0 mm), its displacement from the optical axis of the spectrometer (up to 2 mm), the diameter of the transmission beam (1.3-4.0 mm), the slit width of the monochromator, and the shape of the intensity distribution over the cross section of the beam emitted either by a hollow cathode lamp, or a deuterium lamp, or an electrodeless lamp. We have shown that, using a probe with a thickness that is optimal for the two-stage atomization (1 mm), it is possible to register analytical absorption signals from 28 chemical elements out of 56 (except Hg), which can be determined in graphite atomizers, with a maximal sensitivity and with no optical interference. The remaining elements can be determined with a lower sensitivity because of the necessity to lower the temperature of the secondary atomization. © 2014 Pleiades Publishing, Ltd

Dynamics of fractional condensation of a substance on a probe for spectral analysis

The fractional separation of trace metals on a cold tungsten probe from salt matrix vapor, which interferes with the spectral analysis, is studied. The spatial structure of the vapor flows of sodium chloride, potassium sulfate, and indium atoms is visualized at characteristic wavelengths as they interact with the probe. The vapor flow rate and the probe orientation were varied. It is found that the smoke of the matrix does not prevent the deposition of the metal on the probe because of spatial separation of these fractions and that the detrimental effect of thermal gas expansion and other factors is eliminated. The sensitivity of the atomic absorption analysis of indium impurities in these salts is increased by an order of magnitude. © 2008 Pleiades Publishing, Ltd

Spatial structure of absorbing vapor in a transversely heated graphite atomizer with a probe

The dynamics of the spatial structure of absorbing layers of silver atoms and molecules and condensed particles of sodium chloride and potassium sulfate in a transversely heated graphite atomizer during atomization of these substances from a platform and evaporation of their condensate from a tungsten probe is investigated by shadow spectral visualization. The fractional probe atomization significantly decreases the spatial inhomogeneities of absorbing layers, the level of nonselective absorption, and the suppression of atomic absorption. As a result, the photometric error decreases. The use of a probe made it possible to increase the maximum amounts of sodium chloride and potassium sulfate allowable for interference-free atomic absorption analysis in a silver sample from 100 to 4000 μg and from 20 to 750 μg, respectively. These values exceed by a factor of 5-8 the acceptable levels in the generally accepted procedure of atomization from a platform with the Pd-Mg modifier. © Nauka/Interperiodica 2006

Written Speech Training in RFL course: about Some Problems and their Solutions

Письменная речь на иностранном языке является продуктивным видом речевой деятельности и обеспечивает запоминание лексики, грамматики, орфографии и пунктуации, а также позволяет создавать тексты. Вместе с тем сегодня возникает много вопросов относительно методов обучения письменной речи в курсе РКИ. В настоящей статье обсуждаются некоторые актуальные проблемы в этом вопросе и предлагаются пути их решения.Written speech in a foreign language is a productive type of speech activity and provides memorization of vocabulary, grammar, spelling and punctuation, and also allows you to create texts. At the same time, today there are many questions about the methods of teaching writing in the RCT course. This article discusses some current problems in this matter and suggests ways to solve them

Phytonyms in the nomenclature of drugs

The article discusses the names of drugs, which include fragments of plant names, or phytonyms. Two main groups were identified among the studied drug names. One of them is connected with the name of plants, the other is formed not only on the basis of phytonyms, but also includes other components. Most of the names formed on the basis of phytonyms are alkaloids and glycosides. They are formed in two ways: either on the basis of generic ones, or on the basis of specific names.Another group of names are trivial names of drug, which are formed by adding up various fragments of the names of the constituent components, including phytonyms.В статье рассматриваются наименования лекарственных средств, в составе которых имеются фрагменты наименований растений, или фитонимов. Среди исследованных названий препаратов были установлены две основные группы. Одна из них полностью связана с названием растений, другая формируется не только на основе фитонимов, но и включает другие компоненты. Большая часть наименований, сформированных на основе фитонимов, – это алкалоиды и гликозиды. Они образуются двумя способами: либо основе родовых, либо на основе видовых наименований. Другая группа названий – это тривиальные наименования лекарственных средств, которые образуются способом сложения различных фрагментов названий входящих в состав составляющих, включая фитоним

Heterogeneity of population of microorganisms grown in presence of iron oxide maghemite nanoparticles

In this work γ-Fe2O3 MNPs were obtained by laser target evaporation and water based suspensions were prepared. Maximum permissive dose of iron in water (MPD) is 0.3 mg/L. It was found that 100 MPD dose of iron induces formation of non-typical colonies after 72 or 96 hours exposition: against a background of small black colonies large white colonies appeared due to a disruption in tyrosine synthesis. Multiple re-cloning of the white colonies grown with MNPs showed that they retained their properties both under standard conditions (temperature of 24 °C) and at the temperatures up to 37o C. E.nigrum grown with MNPs demonstrated very scant extension of small colonies at the cultivation temperature of 24o C, their growth was completely blocked at 37°C. Significant changes in the structure of the population were noted. First of all, large cells with pronounced aggregation were observed among the black colonies. These aggregates consisted of large cells connected to each other by matrix. In the white colonies the appearance of very long threadlike cells connecting different groups of the cells establishing an intercellular communication was evident. Fe2O3 MNPs induce an increase in the heterogeneity of the population, expressed as a change in morpho-physiological states. © 2018 The Authors, published by EDP Sciences.The work was supported by the Ministry of Education and Science of the Russian Federation (project No. 3.6121.210 )7 and R FFI №16-34-015 92 grant s. e tW hank R ndrA ade, Iu. Novoselova and I.V. Beketov for special support. Selected measurements were made at ISG KER services UPV/EHU

Система электроснабжения с трёхфазными трансформаторами для ВСМ

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT The article presents a schematic diagram of a traction substation of the 2x25 kV power supply system with three-phase transformers and a vector voltage diagram for high-speed lines. Power supply systems 2x25 kV with single-phase and three-phase transformers are compared, the power of three-phase transformers for high-speed main lines is recommended. And all this taking into account the new special technical conditions that are worked out for the design, construction and operation of Russian HSR. Keywords: railway, high-speed railway, traction substation, 2x25 kV power supply system, three-phase transformer, single-phase transformer, special technical conditions.Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).В статье предложена принципиальная схема тяговой подстанции системы электроснабжения 2x25 кВ с трёхфазными трансформаторами и векторной диаграммой напряжений для высокоскоростных магистралей. Проведено сравнение систем электроснабжения 2x25 кВ с однофазными и трёхфазными трансформаторами, рекомендована мощность трёхфазных трансформаторов для высокоскоростных магистралей. И всё это с учётом новых специальных технических условий, которые выработаны под задачи проектирования, строительства и эксплуатации российских ВСМ

Reproductive health: transformation of youth representations

A comparative analysis of the representations of students of a medical university of different age groups about reproductive health according to the results of a survey among students in a medical university from I to VI courses is presented. Information was obtained on the transformation of the reproductive representations of students, their relationship to contraceptive methods, abortion, and knowledge of the physiology of the female body.Представлен сравнительный анализ представлений студентов медицинского университета разных возрастных групп о репродуктивном здоровье по результатам анкетирования среди обучающихсяв медицинском ВУЗе с I по VI курс. Получена информация о трансформации репродуктивных представлений студентов, их отношения к методам контрацепции, прерыванию беременности, знаний о физиологии женского организма

Origin of "hot-spots" in the pseudogap regime of Nd(1.85)Ce(0.15)CuO(4): LDA+DMFT+Sigma_k study

Material specific electronic band structure of the electron-doped high-Tc cuprate Nd(1.85)Ce(0.15)CuO(4) (NCCO) is calculated within the pseudo gap regime, using the recently developed generalized LDA+DMFT+Sigma_k scheme. LDA/DFT (density functional theory within local density approximation) provides model parameters (hopping integral values, local Coulomb interaction strength) for the one-band Hubbard model, which is solved by DMFT (dynamical mean-field theory). To take into account pseudogap fluctuations LDA+DMFT is supplied with "external" k-dependent self-energy Sigma_k, which describes interaction of correlated conducting electrons with non-local Heisenberg-like antiferromagnetic (AFM) spin fluctuations responsible for pseudo gap formation. Within this LDA+DMFT+Sigma_k approach we demonstrate the formation of pronounced "hot-spots" on the Fermi surface (FS) map in NCCO, opposite to our recent calculations for Bi(2)Sr(2)CaCu(2)O(8-d) (Bi2212), which have produced rather extended region of FS "destruction". There are several physical reasons for this fact: (i) the "hot-spots" in NCCO are located closer to Brillouin zone center; (ii) correlation length of AFM fluctuations \xi is larger for NCCO; (iii) pseudogap potential \Delta is stronger, than in Bi2212. Comparison of our theoretical data with recent bulk sensitive high-energy angle-resolved photoemission (ARPES) data for NCCO provides good semiquantitative agreement. Based on that comparison alternative explanation of the van-Hove singularity at -0.3 eV is proposed. Optical conductivity both for Bi2212 and NCCO is also calculated within LDA+DMFT+Sigma_k and compared with experimental results, demonstrating satisfactory agreement.Comment: 8 pages, 10 figures, 1 tabl

BIOINFORMATION SEARCH AND ANALYSIS OF STRUCTURES OF CRISPR/CAS SYSTEMS IN PHAGE STAPHYLOCOCUS AUREUS GENOME AND ESTIMATION OF PROFILES OF PHAGE DETECTED THROUGH CRISPR-CASSETTE BACTERIA

The emergence of resistance among the most important bacterial pathogens is generally recognized as one of the major public health problems. The most important of these organisms are penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci and methicillin- and vancomycin-resistant Staphylococcus aureus. These antibiotic resistance in common pathogens have made antimicrobial therapy of many infections. Scientists need to look for new ways of treating bacterial infections in the work, using the developed algorithm from the methods of search software in the genomic structure of Staphylococcus aureus subsp. aureus ST228, the CRISPR/Cas locus and the division structures of its CRISPR cassette. The results of the bacteriophage search through the decoded spacer sequences of CRISPR-cassettes of this strain were also obtained using the developed algorithm of the software methods of bioinformatics. It was determined that the CRISPR/Cas system of strain of ST228 of S. aureus was of type IIIA. It is shown that cas-genes are in the immediate vicinity of CRISPR cassettes. The spacer structures in the detected CRISPR cassette are the Staphylococcus, Mycobacterium, Streptococcus, Bacillus, Gordonia, Arthrobacter, Streptomyces. The implementation of the algorithm of program methods for locating CRISPR/Cas-loci can be applied to many other decoded bacterial genomes to return bacteriophage therapy