Tungstate Based Ceramics Obtained By Spark Plasma Sintering Method – Possible Material for Consolidation of Radioactive Wastes’ Components

The Spark Plasma Sintering method was used to produce high-density ceramics from tungstates SrWO4 and NaNd(WO4)2 with scheelite structure. These compounds are proposed as possible matrices for the consolidation of radwaste components. Powder samples were obtained by coprecipitation method and studied by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). After sintering, the samples retained their phase identity (scheelite structure). The total duration of sintering was ∼ 13-15 min, the relative density was reached ∼ 92, 99%. Keywords: Tungstates, RW, Spark Plasma Sintering, high density, microstructur

Investigation of the microstructure of the fine-grained YPO4_4:Gd ceramics with xenotime structure after Xe irradiation

The paper reports on the preparation of xenotime-structured ceramics by the Spark Plasma Sintering (SPS) method. Phosphates Y$_{0.95}$Gd$_{0.05}$PO$_4$ (YPO$_4$:Gd) were obtained by the sol-gel method. The synthesized nanopowders are collected in large agglomerates 10-50 mkm in size. Ceramics has a fine-grained microstructure and a high relative density (98.67%). The total time of the SPS process was approximately 18 min. High-density sintered ceramics YPO$_4$:Gd with a xenotime structure were irradiated with Xe$^{+26}$ ions (E = 167 MeV) to fluences of $1\times10^{12}$-$3\times 10^{13}$ cm$^{-2}$. Complete amorphization at maximum fluence was not achieved. As the fluence increases, an insignificant increase in the depth of the amorphous layer is observed. According to the results of grazing incidence XRD (GIXRD), with an increase in fluence from $1\times10^{12}$-$3\times 10^{13}$ cm$^{-2}$, an increase in the volume fraction of the amorphous structure from 20 to 70% is observed. The intensity of XRD peak 200 YPO$_4$:Gd after recovery annealing (700$^\circ$C, 18 h) reached a value of ~80% of the initial intensity I0.Comment: 16 pages, 10 figure

Напряженность иммунитета к кори в различных группах населения

Objective: to examine the state of the immunity to measles in different age groups.Materials and methods: In 2018, 4444 people were examined at the Diagnostic Center (virological). Among them, 3783 people were examined using the passive haemagglutination test for measles (manufactured by Pasteur Research Institute of Epidemiology and Microbiology, Russia). In the remaining 661 cases, the IgG to measles were detected using the enzyme-linked immunosorbent assay (ELISA) by VektoMeaseles IgG test (manufactured by Vector-Best, Russia). The correlation between the measles IgG level (ELISA) and the age was examined in 518 patients. Results: In this study, the immunity to measles was shown to be insufficient in all groups of observed people. Even among medical staff, nearly 10% had no protective level of measles antibodies. We have shown that the correlation between the measles IgG level and the age is statistically significant, so that the number of seronegative persons in different age groups differs significantly. Conclusion: The highest ratio of seronegative individuals was found in the age group between 18 and 25 years (52,33%), which can lead to serious measles outbreaks. Hence, this study confirms a strong need for additional immunization in all groups and especially in young population.Цель: изучить состояние иммунитета к кори в различных возрастных группах.Материалы и методы: В 2018 г. в Клинической инфекционной больнице им. С.П. Боткина в Городском консультативно-диагностическом центре (вирусологическом) было обследовано 4444 человека: у 3783 человек исследование было выполнено при помощи набора реагентов для реакции пассивной гемагглютинации к кори (производитель Научно-исследовательский институт эпидемиологии и микробиологии имени Пастера, Россия), в 661 случае был выполнен иммуноферментный анализ по определению IgG к вирусу кори с использованием тестсистемы «ВектоКорь IgG» (производитель АО «ВекторБест», Россия). Зависимость уровня антител к кори (метод иммуноферментного аналаиза) от возраста была исследована у 518 пациентов. Результаты: в данном исследовании было показано, что в настоящее время напряженность иммунитета во всех возрастных группах недостаточна. Даже среди медицинских работников был отмечен высокий процент серонегативных лиц. Показано наличие достоверной корреляции между уровнем IgG к кори и возрастом пациентов. Выявлены достоверные отличия по количеству серонегативных по кори лиц в различных возрастных группах. Заключение: значительное количество серонегативных лиц в возрастной группе до 25 лет создает серьезный риск возникновения эпидемии кори. Данное исследование показывает необходимость дополнительной иммунизации против кори всех групп населения и особенно лиц молодого возраста.

CHARACTERISTICS OF SUPERCAPACITORS ELECTRODES BASED ON TITANIA AND CARBON NANOTUBES

TiO2-NT and CNT based electrodes have been fabricated by anodizing and pyrolysis and characterized by scanning electron microscope. Electrochemical performances such as spe-cific capacitance, energy and power have been calculated in frame of the galvanostatic charge-discharge curves analysis.Исследование выполнено в рамках инициативного научного проекта FEUZ-2020-0059 Минобрнауки РФ

Development and validation of the quantitative determination procedure of iodine in the iodides form in the kelp thallus by the ionometry method

Introduction: Iodine is an important compound in the kelp thallus; it should be determined to control the quality of crude herbal drugs of Laminaria sp. The ionometry method is perspective iodine (in the iodides form) determination method in the crude herbal drugs; it is characterized by the availability and relative cheapness of iodide-selective electrodes and equipment in general. This method provides an effective combination of the determination step with the fast, simple, and safe step of sample preparation. Aim: The current study aims to develop and validate a simple, effective procedure for the quantitative determination of iodine in the form of iodide by ionometry in the kelp thallus (Laminaria sp.). Materials and methods: The determination of iodides was carried out by using the 'Ecotest-120' pH meter. 'Ekom-I' was used as an ion-selective electrode. Silver chloride electrode 'ESR 10101' was used as a reference electrode. Results and Discussion: The developed procedure has a suitable level of linearity (correlation coefficient = 0.9995%), correctness (variation coefficient = 1.58%), repeatability (variation coefficient = 6.67%), and analytical area (0.03-209.4 μg/mL analyte in the test solution). The procedure allows us to determine iodine in the form of iodides with an accuracy comparable to the accuracy of neutron activation analysis and can be recommended as an alternative to titrimetric methods existing in the world-leading pharmacopoeias. © 2020 Wolters Kluwer Medknow Publications. All rights reserved

Measles immunity in different population groups

Objective: to examine the state of the immunity to measles in different age groups.Materials and methods: In 2018, 4444 people were examined at the Diagnostic Center (virological). Among them, 3783 people were examined using the passive haemagglutination test for measles (manufactured by Pasteur Research Institute of Epidemiology and Microbiology, Russia). In the remaining 661 cases, the IgG to measles were detected using the enzyme-linked immunosorbent assay (ELISA) by VektoMeaseles IgG test (manufactured by Vector-Best, Russia). The correlation between the measles IgG level (ELISA) and the age was examined in 518 patients. Results: In this study, the immunity to measles was shown to be insufficient in all groups of observed people. Even among medical staff, nearly 10% had no protective level of measles antibodies. We have shown that the correlation between the measles IgG level and the age is statistically significant, so that the number of seronegative persons in different age groups differs significantly. Conclusion: The highest ratio of seronegative individuals was found in the age group between 18 and 25 years (52,33%), which can lead to serious measles outbreaks. Hence, this study confirms a strong need for additional immunization in all groups and especially in young population