Ural Federal University: URFU Journal Systems / Журнальный портал УРФУ
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The economic potential of “green” hydrogen production and consumption in Russian regions
No full textRelevance. The global energy agenda is focused on the transition to a carbon-neutral economy and ensuring the energy independence of governments. This has created the prerequisites for the “green” hydrogen energy, which presents the production of the most environmentally friendly energy sources. On the one hand, “green” hydrogen can be used as a storage system for subsequent energy supply to domestic needs. On the other hand, its export can become an effective direction, which will allow state not only to diversify the energy resources sold, but also to use new revenue sources for the budget.Research Objective is to economically substantiate the priority areas of production and consumption of “green” hydrogen in Russian regions.Data and Methods. The cases on the production of “green” hydrogen based on electricity from solar, wind and hydroelectric power plants in 14 Russian regions are considered. Scenarios for domestic consumption, as well as for the export of hydrogen to Asian and European countries through sea and pipeline transportation are proposed. The method to discounted assessment of the levelized cost of “green” hydrogen is proposed. It accounts the full costs of all stages of the project life cycle — from scientific research to equipment disposal. The decision on the project feasibility is based on a comparative assessment with the alternative prices of hydrogen.Results. The calculation of the levelized cost of hydrogen and electricity has shown that the domestic consumption of “green” hydrogen is not economically feasible in the territories with the centralized energy supply. In turn, the export of hydrogen abroad is becoming a promising direction.Conclusions. In the near future, economically feasible projects may be the export of Russian “green” hydrogen to Asian and European countries using both pipeline and sea transportation. However, not all Russian regions are able to ensure the optimal price level for national hydrogen. The proximity of regions to the hydrogen sale markets, as well as the maximum volume of hydrogen production become decisive factors in the formation of an effective levelized cost
Формирование временной диаграммы работы РСА при использовании частотно-манипулированных сигналов
Full text linkThe use of frequency-shift waveform signals (FSWS) allows achieving the required high resolution in synthetic aperture radar (SAR), but most often the maximum possible mapping range is reduced. This problem can be solved by changing the time diagram of SAR operation using the emission and reception intervals of the group of frequencies. The description of the principle of forming such a time diagram and the results of assessing the maximum achievable range of SAR are given. The example of choosing the optimal number of frequency groups is considered, which ensures the observation of the given area while minimizing the interference level of range ambiguity.Применение частотно-манипулированных сигналов (ЧМнС) позволяет достичь в радиолокаторах с синтезированием апертуры антенны (РСА) требуемой высокой разрешающей способности, но при этом чаще всего уменьшается максимально возможная дальность картографирования. Решить эту проблему можно изменением временной диаграммы работы РСА с использованием интервалов излучения и приема для группы частот. Приведены описание принципа формирования такой временной диаграммы и результаты оценки максимально достижимой дальности действия РСА. Рассмотрен пример выбора оптимального количества частотных групп, при котором обеспечивается съемка заданного района
Параметры и характеристики транзисторного автодинного приемопередатчика в режиме асинхронного приема запросных сигналов системы радиозондирования атмосферы
Full text linkBased on the developed mathematical model of a transistor autodyne transceiver (APP) designed for a promising atmospheric radar sensing system, calculations and analysis of the APP’s parameters and characteristics have been performed in asynchronous mode of receiving radar request radio pulses when the frequency of the received signal is outside the APP’s synchronization band. Noise and energy parameters and characteristics are investigated when approximating the impedance characteristic of the active element by the biquadrate parabola. Calculations of the range of the system have also been performed both via the «requester — responder» channel and the «responder–requester» return channel. Practical conclusions necessary for the development of this system are drawn.На основе разработанной математической модели транзисторного автодинного приемопередатчика (АПП), предназначенного для перспективной системы радиолокационного зондирования атмосферы, выполнены расчеты и анализ параметров и характеристик АПП в асинхронном режиме приема запросных радиоимпульсов РЛС, когда частота принимаемого сигнала находится за пределами полосы синхронизации АПП. Исследованы шумовые и энергетические параметры и характеристики при аппроксимации импедансной характеристики активного элемента биквадратной параболой. Выполнены также расчеты дальности действия системы как по каналу «запросчик — ответчик», так и по обратному каналу «ответчик — запросчик». Сделаны выводы практического характера, необходимые при разработке данной системы
Oxide-ion thermopower of acceptor-doped perovskites: The impact of inter-defect interactions
No full textThe effect of inter-defect interaction on the hopping thermopower α in acceptor-doped oxides is considered on the example of wide-gap AIIBIV1–xRIIIxO3–δ perovskites with oxide-ion charge carriers. It is shown that acceptor-bound states of defects and inter-carrier correlations essentially affect α and its dependence on dopant content and temperature even at low doping level. The method of determining the correct charge carriers concentration and heat of transport from thermopower data for such systems is discussed. The presented results can also be useful for understanding thermoelectric phenomena caused by other types of hopping charge carriers in various acceptor-doped oxides promising for electrochemical applications
Progress in infiltration technology applied to air electrodes with proton-conducting electrolyte backbones
No full textLowering the operating temperature of solid-state energy devices to 500–700 °C has driven an increased attention being paid to protonic ceramic cells (PCCs) due to several advantages they offer such as low activation energy for proton diffusion, fuel flexibility, higher power efficiency provided by the absence of fuel dilution at the anode, as well as enhanced potential for lower housing and stacking costs. However, a significant challenge for fuel/electrolysis cells based on proton-conducting electrolytes is the performance of air electrodes for efficient oxygen reduction and water splitting reactions. The infiltration of catalysts into porous backbone layers has been demonstrated to be a highly effective method for the fabrication of highly active and durable PCC electrodes. This Focus Review summarizes the achievements in the application of the infiltration technique to the formation of air electrodes with proton-conducting electrolyte/composite backbones modified with various catalysts as a promising simple and cost-effective way to eliminate electrode/electrolyte mismatch issues and provide significant performance enhancement
Electrochemical behavior of Mo(III) ions in NaCl-KCl melts
No full textIn this study, the exchange current density and the transfer coefficient of molybdenum in NaCl-KCl molten salt were accurately obtained using Tafel plot and linear polarization. The exchange current density for Mo0/Mo3+ redox couple was found to be 74 ± 0.7 mA/cm2 at 720 °C and 4.5 wt. % MoCl3. The cathodic transfer coefficient was measured to be 0.7 ± 0.02. The concentration dependence of the exchange current density was also investigated. The diffusion coefficient was determined to be 8.052 · 10–5 cm2/s and 4.012 · 10–5 cm2/s by linear and square wave voltammetry, respectively
Опыт лингвогерменевтического толкования стихотворения А. Долгаревой «Первому двадцать, второму сорок, отец и сын...»
Full text linkThe paper presents an interpretation of A. Dolgareva’s poem «The First is Twenty, the Second is Forty, Father and Son...». The subject of the work is the hermeneutic situations of the poem. The main goal is to reconstruct its implicit meanings. The novelty of the study is determined by the appeal to the linguahermeneutic interpretation of A. Dolgareva’s poem. The possibilities of the linguahermeneutic method are demonstrated, the main meanings of the poem are revealed. It is shown that A. Dolgareva can be called the successor of A. Akhmatova’s poetic mission.В статье представлено толкование стихотворения А. Долгаревой «Первому двадцать, второму сорок, отец и сын…». Предмет работы — герменевтические ситуации стихотворения. Цель — реконструкция его имплицитных смыслов. Новизна исследования определяется обращением к лингвогерменевтической интерпретации стихотворения А. Долгаревой. Продемонстрированы возможности лингвогерменевтической методики, выявлены основные смыслы стихотворения. Показано, что А. Долгарева может быть названа преемницей поэтической миссии А. Ахматовой
Thermomechanical behavior of promising mixed ion-electron conductors based on co-doped barium ferrite
No full textMixed ion-electron conductors (MIECs) represent a class of materials that have emerged as promising candidates for various applications in energy conversion and storage fields. These materials, which may demonstrate triple conducting behavior, are especially promising as symmetrical electrodes in protonic ceramic fuel cells or as oxygen-permeable membranes. Notable representatives of these materials include perovskites based on barium ferrite with an ABO3 structure, which might be doped or co-doped with various dopants. This short communication focuses on the investigation of the thermomechanical characteristics of Pr0.6Ba0.4FeO3–δ, Pr0.6Ba0.4Fe0.9Ni0.1O3–δ and (Pr0.6Ba0.4)0.9Fe0.9Ni0.1O3–δ materials. Their phase stability was investigated by high-temperature XRD analysis, while the contributions of thermal and chemical expansions as parts of the total expansion were analyzed between 25 and 1000 °C. According to the results obtained, at temperatures above 500 °C, changes in the thermal dependence patterns of the unit cell parameters for all the samples were observed. This phenomenon may be attributed to dimensional factors resulting from the variation in the ionic radii of the B-sublattice cations upon reduction of the B-cations and oxygen vacancy formation. A comprehensive analysis of the obtained results enables the formulation of conclusions regarding the rational level of co-doping for these materials, with the objective of optimizing their thermomechanical characteristics by reducing the chemical expansion contribution
Атомно-эмиссионные спектрометры с азотной микроволновой плазмой Гранд-СВЧ
Full text linkThe emergence of microwave plasma sources with parameters (T, ne) close to those of inductively coupled plasma, along with the possibility of using atmospheric nitrogen (approximately 80% N2 in the atmosphere) as the plasma gas, led to the development of series microwave plasma atomic emission spectrometers. To address the need for import substitution, Russian atomic emission spectrometer Grand-SVCH (No. 89108-23 in the State Register of Measuring Instruments of the Russian Federation) was developed and launched; the purpose of this work is presenting technical features and characteristics of this instrument.A microwave resonator (2.45 GHz) incorporating a dielectric element that enables the formation of toroidal plasma close in size to that of ICP in a standard three-flow vertically installed burner was developed for generating plasma. A spectrometer, based on the Paschen-Runge design, registers the plasma spectrum simultaneously in the 190-780 nm range using BLPP-4000 detectors with a resolution of 8 pm in the 190-350 nm range and 25 pm in the 350-780 nm range. The spectrometer provides axial viewing of the plasma.Grand-SVCH spectrometer matches its foreign counterparts in analytical performance: detection limits (3σ) ≤ 1 µg/L; long-term stability, characterized by the relative standard deviation of analyte signals of less than 3 %; and a linearity range exceeding six orders of magnitude when using multiple lines and measuring the spectrum with two basic exposure times. Additionally, it offers higher speed than Agilent MP-AES 4210 due to simultaneous spectrum registration across the entire spectral range and reduced matrix effects.Grand-SVCH spectrometer was successfully tested by laboratory staff at industrial enterprises in Russia and in scientific institutes of the Siberian Branch of the Russian Academy of Sciences. Keywords: atomic emission analysis, microwave plasma, detection limits, spectrometer, analytical characteristics.Появление источников микроволновой плазмы с приближающимися к индуктивно связанной плазме параметрами (T, ne), а также возможность использования азота в качестве плазмообразующего газа, вырабатываемого с помощью генераторов газа на месте проведения анализа (в атмосфере ~ 80 % N2), привело к появлению серийных атомно-эмиссионных спектрометров с микроволновой плазмой. Для решения задачи импортозамещения разработан и налажен выпуск российского атомно-эмиссионного спектрометра Гранд-СВЧ (№ 89108-23 в Госреестре средств измерений РФ), ознакомление с техническими особенностями и характеристиками которого является целью данной работы.Для получения плазмы разработан СВЧ резонатор (2.45 ГГц) с установленным в него диэлектрическим элементом, который позволяет получить тороидальную плазму близкого к ИСП размера в стандартной трех потоковой вертикально установленной горелке. Спектральный прибор по схеме Пашена-Рунге регистрирует спектр плазмы одновременно в области от 190 до 780 нм с помощью линеек детекторов БЛПП-4000 с разрешением 8 пм в области 190-350 нм и 25 пм в области 350-780 нм. Спектрометр реализует аксиальный способ наблюдения плазмы.Спектрометр Гранд-СВЧ по своим аналитическим характеристикам не уступает зарубежным аналогам: пределы обнаружения (3σ) ≤ 1 мкг/л; долговременная стабильность, характеризуемая относительным стандартным отклонением (ОСКО) сигналов аналитов, менее 3 %; диапазон линейности более шести порядков величины при использовании нескольких линий и измерении спектра с двумя временами базовой экспозиции. При этом он обладает бóльшим быстродействием по сравнению с Agilent MP-AES 4210 за счёт одновременности регистрации спектра во всём спектральном диапазоне и меньшими матричными влияниями.Спектрометр Гранд-СВЧ успешно апробирован сотрудниками лабораторий промышленных предприятий РФ и в научных институтах СО РАН. Ключевые слова: атомно-эмиссионный анализ, микроволновая плазма, пределы обнаружения, спектрометр, аналитические характеристики
Two-dimensional negative thermal expansion and ionic conductivity of a new glaserite-like ternary molybdate KZn0.5Hf0.5(MoO4)2
No full textA new glaserite-like ternary molybdate KZn0.5Hf0.5(MoO4)2 was obtained through a solid-state reaction, and its structure was refined using the Rietveld method. It was found that the compound crystallizes in the trigonal space group P m1 and melts at 656 °C with decomposition. At elevated temperatures, the compound exhibited significant ionic conductivity, reaching 0.39·10–3S/cm at 570 °C with an activation energy Еа = 1.0 eV, with oxygen ions as the probable charge carriers. The infrared spectrum simulated using DFT showed good agreement with experimental data, containing characteristic stretching modes of the MoO4 tetrahedra. The observed negative thermal expansion in the ab plane did not result in a reduction in the volume of the unit cell, with αV = 98∙10–6 °С–1 at 500 °С, indicating that KZn0.5Hf0.5(MoO4)2 can be classified as a material with high thermal expansion properties