324 research outputs found

    Physicochemical investigation of NiAl with small molybdenum additions

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    Specimens of four cast NiAl alloys, three of them containing 0.5, 1.0 and 1.5 at. % Mo., were homogenized for 10, 10, and 140 hr at 1373, 1523 and 1273 K, respectively, then kept at 1073, 1173 and 1323 K for 60, 120 and 3 hr, respectively, and quenched in icy water. The precipitation of a metastable Ni3Mo phase was observed at temperatures between 1073 and 1523 K. Molybdenum substituted for nickel was found to inhibit the lattice disordering in NiAl at 1073 and 1523 K

    ОПРЕДЕЛЕНИЕ МАТРИЧНОГО СОСТАВА ХАЛЬКОГЕНИДНЫХ СТЕКОЛ СИСТЕМЫ GE-SE-TE МЕТОДОМ АЭС-ИСП

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    One of the most important stages of the high-purity chalcogenide glasses’ analytical control is the determination of matrix elements’ content with the uncertainty at the levels of 0.1–0.2 mol.%.  The content of the macro-components may differ from the composition of the initial charge; therefore, an important task is the macro-composition determination of the final materials. This article describes the development of the technique for determining the matrix elements of high-purity Ge-Se-Te glasses in the range of germanium content from 10 to 35 mol. %, selenium and tellurium content from 20 to 50 mol. % with the expanded uncertainty within 0.01–0.2 mol. % (P = 0.95) using the inductively coupled plasma atomic emission spectrometry (ICP-AES). A simple technique for the preparation of primary calibration solutions from pure elementary Ge, Se and Te is proposed. The correctness of the analysis results is confirmed by comparing the calculated matrix composition of model glass samples, prepared by direct synthesis from high-purity simple substances in the sealed quartz glass ampoule, with the analysis results.  The main advantage of the proposed analysis technique is the absence of the need for the reference samples identical to the analyzed material, which is especially important for determination of new materials’ matrix composition. The minimum sample mass for the determination of matrix elements is about 1 mg, which makes it possible to analyze not only bulk glass samples, but also fibers and expensive materials.Key words: Ge-Se-Te chalcogenide glasses, determination of matrix elements, high accuracy, inductively coupled plasma atomic emission spectrometry.DOI: http://dx.doi.org/10.15826/analitika.2020.24.4.002 D.A. Fadeeva, I.I. Evdokimov, V.G. PimenovG.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, Box-75, 49 Tropinin Str., Nizhny Novgorod, 603951, Russian FederationОдин из важнейших этапов аналитического контроля высокочистых халькогенидных стекол, используемых для изготовления оптоволоконных устройств, является установление содержания матричных элементов с неопределенностью на уровне 0.1–0.2 % мол. Необходимость данного этапа аналитического контроля возникает из-за сложности получения высокочистых халькогенидных стекол с необходимой точностью задания матричного состава, что связано, отчасти, с возможными потерями матричных элементов на многочисленных стадиях синтеза и очистки. Методик определения матричных элементов стекол системы Ge-Se-Te с необходимыми метрологическими характеристиками найти не удалось. В статье описана разработка методики определения матричных элементов высокочистых стекол вышеуказанной системы в диапазоне содержания германия от 10 до 35 % мол., селена и теллура – от 20 до 50 % мол. с расширенной неопределенностью результатов анализа на уровне 0.01–0.2 % мол. (P = 0.95) с использованием атомно-эмиссионной спектрометрии с индуктивно связанной плазмой. Предложен способ приготовления первичных градуировочных растворов, необходимых для достижения заявленного уровня неопределенности, с использованием германия, селена и теллура в форме чистых простых веществ. Корректность оценки точности результатов анализа подтверждена сопоставлением расчетного матричного состава модельных образцов стекол, изготовленных прямым синтезом из высокочистых простых веществ в запаянной ампуле из кварцевого стекла, с результатами анализа. Главное достоинство предложенной методики анализа – отсутствие потребности в образцах сравнения, идентичных анализируемому материалу, что особенно важно при установлении матричного состава новых материалов (т.е. когда образцы сравнения, и даже способы их изготовления отсутствуют в принципе). Минимальная для определения матричных элементов масса пробы составляет около 1 мг, что позволяет проводить анализ не только массивных образцов стекол, но и изготавливаемых из них волокон, а также дорогостоящих материалов.Ключевые слова: халькогенидные стекла Ge-Se-Te, определение матричных элементов, высокая точность, атомно-эмиссионная спектрометрия с индуктивно связанной плазмой.DOI: http://dx.doi.org/10.15826/analitika.2020.24.4.00

    Минералогические и биологические свидетели Редикарского захоронения X–XI вв.

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    The study of products of copper alloys of the Lomatov culture of the X-XI centuries from the collection of the Cherdyn Museum revealed two types of patina. The first pseudomorphic might be composed of intergrowths of chlorides formed upon interaction with the sweat of the hands, or a zonal rim of cuprite-malachite-azurite composition, due to interaction with groundwater. The second type, which distorts the shape of the original product, is associated with the leaching of copper and other metals and the crystallization of oxides and salts on the surface in the form of worm-like, kidney-shaped and drusoid aggregates. Fragments of mineralized biological objects (wings, eggs and larvae of flies, mole hair) found on the surface of the patina testify to the rapid oxidation of bronze, which is associated with flooding of the soil of the burial ground immediately after burial.Археоминералогическое изучение изделий из медных сплавов ломоватовской культуры X–XI вв. из коллекции Чердынского краеведческого музея позволило выявить два типа патины. Первая – псевдоморфная – может быть сложена вростками хлоридов, формирующихся при взаимодействии с потом рук, или зональной оторочкой куприт-малахит-азуритового состава, обусловленной взаимодействием с грунтовыми водами. Второй тип, искажающий форму исходного изделия, связывается с выщелачиванием меди и других металлов и кристаллизацией оксидов и солей на поверхности в виде червеобразных, почковидных и друзовидных агрегатов. Выявленные на поверхности патины фрагменты минерализованных биологических объектов (крылья, яйца и личинки мух, волосы крота) свидетельствуют о быстрой скорости окисления бронзы, что связывается с обводнением грунта могильника сразу после захоронени

    ICP-AES analysis of high-purity arsenic

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    В настоящее время практически отсутствуют экспрессные многоэлементные методики анализа мышьяка, позволяющие определять широкий круг примесей на уровне 10⁻⁷-10⁻⁵ % мас. (в соответствии с современными требованиями), включая близкие по летучести к матрице элементы: P, S, Sb, Se и Te. Это связано с тем, что искровая масс-спектрометрия и нейтронно-активационный анализ сейчас труднодоступны, а атомно-эмиссионная спектрометрия с дуговым разрядом в сочетании с предварительным концентрированием примесей, позволяющая определять примеси до уровня 10⁻⁸-10⁻⁴ % мас., сокращает число определяемых примесей (например, P, S, Sb, Se, Te теряются при концентрировании отгонкой матрицы), отличается повышенной трудоёмкостью и длительностью анализа. В данной работе оценены возможности анализа высокочистого мышьяка доступным и широко распространённым методом атомно-эмиссионной спектрометрии с индуктивно связанной плазмой. Исследованы матричные помехи при распылении в индуктивно связанную плазму растворов с концентрацией мышьяка до 150 мг/мл. Установлено, что для достижения низких пределов определения примесей целесообразно анализировать растворы проб с концентрацией мышьяка ~100 мг/мл, что не вызывает технических трудностей. Проведение пробоподготовки в химически стойкой посуде из PFA (PerFluoroAlkoxy polymer) и использование доочищенных реактивов (вода, азотная кислота) позволило снизить влияние загрязнений на пределы определения большинства примесей. Разработана методика определения 39 элементов-примесей в высокочистом мышьяке, включая наиболее распространённые металлы (Al, Ca, Cu, Mg, Fe) и Si, и обычно теряемые при концентрировании отгонкой матрицы элементы (B, P, S, Sb, Se, Te). Пределы определения примесей в мышьяке составили ~10⁻⁷-10⁻⁵ % мас. При необходимости круг определяемых примесей может быть расширен, исходя из возможностей определения конкретных элементов методом атомно-эмиссионной спектрометрии с индуктивно связанной плазмой с учётом предложенной методики пробоподготовки и наличия соответствующих стандартных растворов солей определяемых элементов.The arc discharge atomic emission spectrometry method with pre-concentration of impurities is mainly used for multi-element analysis of high-purity arsenic. Spark ionization mass-spectrometry and neutron activation analysis are applied less often. The use of spark ionization mass-spectrometry and neutron activation analysis is quite problematic at the present time. Arc discharge atomic emission spectrometry in combination with pre-concentration of impurities makes it possible to determine the impurities at the level of 10⁻⁸-10⁻⁴ % mass. At the same time the number of the determined impurities is reduced (e.g., P, S, Sb, Se, Te are getting lost during concentration by matrix sublimation) with the increase in the duration of the analysis. Thus, at the present time the express multi-element techniques of analysis of arsenic which can provide the determination of wide range of impurities at the level of 10⁻⁷-10⁻⁵ % mass. (according to the modern requirements), including the elements P, S, Sb, Se and Te (with volatility close to that of the matrix) are actually absent. In the present paper the capabilities of available and widely used method of inductively-coupled plasma atomic emission spectrometry are estimated for analysis of high-purity arsenic. The matrix interference was investigated in the process of spraying the solutions with arsenic concentration up to 150 mg/mL into inductively-coupled plasma. It was found that in order to attain low limits of quantification of impurities it is expedient to analyze sample solutions with arsenic concentration ~100 mg/mL. It does not present a problem technically. Preparation of samples in chemically resistant vials of PFA (PerFluoroAlkoxy polymer) and the use of additionally purified reagents (water, nitric acid) made it possible to decrease the effect of contaminations on the limits of quantification of most impurities. A technique for determination of 39 elements in high-purity arsenic has been developed. The diapason of determined impurities includes the most abundant metals (Al, Ca, Cu, Mg, Fe) and Si, as well as the elements usually getting lost during concentration by matrix sublimation (B, P, S, Sb, Se, Te). The limits of quantification (as well as the limits of detection) of impurities in arsenic are equal ~10⁻⁷-10⁻⁵ % mass. If necessary, the range of impurities can be widened in view of the possibilities of inductively-coupled plasma atomic emission spectrometry, the possibilities of the suggested sample preparation technique and the availability of the corresponding standard solutions of the determined elements

    Source material for breeding winter bread wheat in the north of the Middle Volga region

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    Background. Bread wheat (Triticum aestivum L.), due to significant progress in breeding, has high potential of biological productivity, but its implementation is quite low. To change the situation for the better, it is necessary to increase the resistance of developed cultivars to unfavorable abiotic and biotic factors in the regions of its cultivation. To solve this problem, source material is required. The purpose of this research was to evaluate a set of winter wheat accessions from the VIR collection, and first of all, the newly introduced accessions, and the accessions from the working collection of Kazan Scientific Center of the Russian Academy of Sciences for variability of agronomic traits and stability under the conditions of the north of the Middle Volga region, and to identify sources promising for inclusion in the crossing programs.Materials and methods. A three-year field study of 166 winter bread wheat accessions was carried out. All accessions were assessed for their overwintering and plant and ear productivity traits using the methods developed by VIR and the State Variety Trials. The best accessions, or sources, were selected by comparing them with the reference cv. ‘Kazan 560’, taking into account the quantitative values of such indicators as “general adaptability” (ОАСi ), variance of “specific adaptability” (σ2САСi ) and “relative stability” (Sgi) for each accession according to A. V. Kilchevsky and L. V. Khotyleva.Results and conclusion. Descriptions of winter bread wheat accessions are presented in the context of their agronomic traits. Groups and subgroups of accessions with different trait variability levels were identified. Some accessions with stable levels of trait manifestation exceeded the reference in ear productivity. All of them are promising for wheat breeding programs. It is shown that the group of accessions “weakly changing” over the years of study differs from the group of “moderately/strongly changing” accessions in values of correlations between traits and the number of significant correlations

    The state of dental health in patients with malignant neoplasms

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    The incidence of malignant neoplasms remains one of the most significant problems in medicine. There is no doubt that oncological diseases have a complex interaction with the body. The General mechanisms of occurrence and progression of the tumor process are intensively studied, and to date, a huge amount of material on molecular and clinical Oncology has been accumulated, it is used in related disciplines. This article covers the study of the dental status of patients with different localizations of cancer.Заболеваемость злокачественными новообразованиями остается одной из самых значимых проблем в медицине. Не вызывает сомнений, что онкологические заболевания оказывают комплексное взаимодействие на организм. Общие механизмы возникновения и прогрессии опухолевого процесса интенсивно исследуются, и к настоящему времени накоплен огромный материал по молекулярной и клинической онкологии, который используется в смежных дисциплинах. В данной статье рассматривается изучение стоматологического статуса профиля пациентов с онкологическими заболеваниями различной локализации

    Source material for breeding winter bread wheat for grain quality in the north of the Middle Volga Region

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    Background. Development of cultivars with high stable yields and high grain quality is the main trend in wheat breeding. The aim of this study was to characterize a set of winter bread wheat accessions from the VIR collection and the working collection of Kazan Scientific Center in terms of their yield, protein content in grain (P, %), and swelling of flour in acetic acid (S, ml), and select the best accessions for the combination of these characters for use in a crossbreeding program.Materials and methods. Twenty-three winter bread wheat accessions were studied for the abovementioned characters in the north of the Middle Volga Region using conventional techniques. The study lasted three years (2016–2019).Results and conclusion. The yield of the accessions varied across the years of studies; however, none of them surpassed the reference cv. ‘Kazanskaya 560’. The values of protein content in grain were medium or high. The following accessions had high and stable levels of protein content in grain (15.1–16.1%): ‘TAW 42971/80’ (k-58363, Germany); ‘Lutescens 471 N8’ (Kazakhstan); ‘Rita’ (k-58057), ‘Scotty’ (k-59322) and ‘Nelson’ (all from the U.S.); ‘Moskovskaya 39’ (k-65160, Russia); ‘Bilotserkivchanka’ (k-64330) and ‘Barkan’ (k-64495) (both from Ukraine). Flour swelling power in acetic acid did not fall below 50 ml, attesting to the formation of high-quality grain. This was also confirmed by the protein quality index determined by the S : P ratio, which ranged from 3.6 to 4.7. Sources with high-quality protein were selected from the tested accessions for use in breeding: ‘CDC Clair’ (k-64168, Canada), ‘Lutescens 471 Н8’ (Kazakhstan), ‘Moskovskaya 39’ (Russia), ‘Barkan’ (Ukraine), and ‘Favorytka’ (k-64337, Ukraine)

    Tactics of managing a patient with fatty liver disease coursing in the background of a polyorgan digestive tract: clinical observation

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    Preparations of glycyrrhizic acid (GA) and ursodeoxycholic acid (UDCA) are effective in the treatment of various forms of non-alcoholic fatty liver disease (NAFLD) and gastroesophageal reflux disease (GERD) occurring against the background of duodeno-gastroesophageal reflux. However, their effectiveness in the treatment of hologenic diarrhea and reflux gastritis has not been sufficiently studied. Currently, there are no clinical guidelines for the diagnosis and treatment of patients with hologenic diarrhea and reflux gastritis, including those with obesity and NAFLD. It is assumed that the combined administration of GA and UDCA can be accompanied by a mutual potentiation of the effect of the drugs. The article presents a clinical case of a patient with NAFLD, obesity, dyslipidemia, GERD, refractory to treatment with proton pump inhibitors, associated with duodenogastroesophageal reflux, reflux gastritis and hologenic diarrhea. It was shown that GERD, reflux gastritis, and hologenic diarrhea developed in the long-term period after cholecystectomy. At the same time, the appointment of a complex preparation containing GA (35 mg) and UDCA (250 mg) made it possible to stop the manifestations of a typical reflux syndrome in patients with a form of GERD refractory to proton pump inhibitors, reflux gastritis, and diarrheal syndrome associated with an excess of bile acids, improve lipid profile parameters. It has been shown that the administration of GA (35 mg) and UDCA (250 mg) can improve the parameters of the intestinal microbiome and lipid metabolism, which can be used in the treatment of patients with atherogenic dyslipidemia. At the same time, patients with comorbid pathology, including NAFLD, GERD, reflux esophagitis, hologenic diarrhea, and dyslipidemia require long-term maintenance therapy with GA (35 mg) and UDCA (250 mg)

    Tricalcium Phosphate Ceramics Doped with Silver, Copper, Zinc, and Iron (III) Ions in Concentrations of Less Than 0.5 wt.% for Bone Tissue Regeneration

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    © 2016, Springer Science+Business Media New York.Novel materials with a variety of properties, such as biocompatibility, antibacterial activity, interconnected porosity, and functionalities combined in one, are required for regenerative medicine. Porous β-tricalcium phosphate (β-TCP) ceramics doped with Cu2+, Zn2+, Ag+, and Fe3+ ions in the concentrations of less than 0.5 wt.% were synthesized and investigated. The obtained samples were analyzed by the diversity of analytical tools. The structure, solubility, and antimicrobial properties of the porous ceramics are shown to be very sensitive to the presence and the type of the cationic substituent. It opens the way to manage structure and properties of the materials for bone tissue regeneration by co-doping of the initial matrix simultaneously with different types of substituent ions

    MANAJEMEN STRATEGI PELAKSANAAN KURIKULUM DALAM MEWUJUDKAN MADRASAH UNGGUL (Studi atas MA Muhammadiyah Kota Metro)

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    The public demand for quality or quality education is increasing. This phenomenon is at least influenced by two main factors namely; factors of globalization challenges and parents' awareness of the need for quality or quality education for their children. Another phenomenon that is not less interesting, today many schools are qualified and give more religious content became the first choice for parents, this condition is a challenge as well as opportunities for Senior High School  (MA) Muhammadiyah Metro City to rise from the shackles of dualism that is artificial and dualism management at once showcasing the various advantages that can be an attraction at the same time can invite public interest to make this institution as an option for the continuation of their children's education. This study aims to analyze management and strategy Implementation of the curriculum in realizing Senior High School (MA) Muhammadiyah Metro City Becomes a Superior School. This type of research is descriptive qualitative in which the data collection in this study was conducted by the method of observation, interview, and documentation study. Data that have been collected is then analyzed descriptively qualitative to then drawn conclusions. The results of this study will show that the management and implementation strategy of the curriculum in realizing Senior High School Muhammadiyah Metro City becomes a superior school. The results of this study recommend to management tiem in the implementation of the curriculum in realizing Senior High School Muhammadiyah Metro City Becomes a Superior School
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