Kinetic and thermodynamic studies of the dissolution of thoria-urania solid solutions

RADIOC

XAFS study of local structure with picometer accuracy: Th1−x_{1-x}Ux_xO2_2 and Th1−x_{1-x}Pux_xO2_2 solid solutions

Radioc

Ab initio calculations of the Ni K-edge XANES in Ni c Mg 1-c O solid solutions

An interpretation of the Ni K-edge X-ray absorption near edge structure (XANES) in pure NiO and Ni c Mg 1-c O solid solutions is given based on three types of ab initio theoretical calculations: the fullmultiple-scattering (FMS) approach, the finite difference method (FDM) and the full potential linear muffin-tin orbital (FP-LMTO) method within the LSDA+U approach. The first two methods differ in the cluster potential approximation: the spherically symmetric muffin-tin potential is used in the FMS approach, whereas a non-muffin-tin numerical potential makes the core of the FDM. We found that the FMS and FDM techniques allow rather accurate description of the experimental XANES signal especially above the absorption edge and produce close results, the FP-LMTO is more accurate close to the absorption edge. X-ray absorption spectroscopy (XAS) became in the last ten years a routine structural tool, especially suitable to study the local environment around impurities or in multicomponent systems In this work, we compare three theoretical methods, the FMS approach Pure nickel oxide NiO is a type-II antiferromagnetic charge-transfer insulato

Electronic structure of cubic ScF₃ from first-principles calculations

The ground state properties of cubic scandium trifluoride (ScF₃) perovskite were studied using first-principles calculations. The electronic structure of ScF₃ was determined by linear combination of atomic orbital (LCAO) and plane wave projector augmented-wave (PAW) methods using modified hybrid exchange-correlation functionals within the density functional theory (DFT). The comprehensive comparison of the results obtained by two methods is presented. Both methods allowed us to reproduce the lattice constant found experimentally in ScF₃ at low temperatures and to predict its electronic structure in good agreement with known experimental valence-band photoelectron and F 1 s x-ray absorption spectra

Developing innovative system antiriskovyh activities (for example " Stereoart Ltd".

Магістерська робота за спеціальністю 8.03060102 – Менеджмент інноваційної діяльності. – Тернопільський Національний Технічний Університет імені Івана Пулюя. – Тернопіль, 2013. Метою роботи є проведення дослідження діяльності підприємства з точки зору менеджменту ризику для розробки інноваційних заходів покращення роботи підприємства. У теоретичній частині дані визначення таких економічних категорій як підприємницький ризик, фактори, джерела та наслідки ризику. Досліджені співвідношення ризику і прибутку. Обґрунтована класифікація підприємницьких ризиків. Аналітико-дослідницька частина присвячена аналізу діяльності ТОВ «Стереоарт». Виявлено, що на підприємстві відсутня єдина служба маркетингу, а витрати на рекламу і стимулювання збуту носять разовий і безсистемний характер. У проектно-рекомендаційній частині запропоновані заходи для покращення діяльності досліджуваного підприємства, а саме: формування єдиної служби маркетингу із застосуванням інноваційних технологій; виготовлення безкоштовних зразків рекламно-інформаційного характеру; реклама у спеціалізованих виданнях. Після реалізації запропонованих заходів чистий прибуток фірми зросте на 23,4 тис.грн.Master's degree work after speciality 8.03060102 is Management of innovative activity. it is Ternopil Ivan Pul’uj National Technical University, 2013. The aim is the study of the company in terms of risk management to develop innovative measures to improve the enterprise. In the theoretical part of the data definition of such economic categories as business risk factors, sources and consequences of risk. Studied the ratio of risk and profit. Reasonable classification of business risks. Analytical and research devoted to the analysis of the activity of "Stereoart" Ltd. We found that the enterprise's no single service marketing and advertising costs and sales promotion are of one-off and ad hoc in nature. In the design and recommendation of proposed measures to improve the activity of the investigated companies, namely: creation of a single marketing services with the use of innovative technologies; production of free samples of advertising-information character; advertising in specialized publications. After the implementation of the proposed activities of the company's net profit to grow by 23.4 thousand uah.Магистерская работа за специальностью 8.03060102 – Менеджмент инновационной деятельности. – Тернопольский Национальный Технический Университет имени Ивана Пулюя. – Тернополь, 2013. Целью предприятия работы с является точки зрения проведение исследования менеджмента риска для деятельности разработки инновационных мероприятий по улучшению работы предприятия. В теоретической части даны определения таких экономических категорий как предпринимательский риск, факторы риска, источники и последствия риска. Исследованы соотношения риска и прибыли. Обоснована классификация предпринимательских рисков. Аналитико-исследовательская часть посвящена анализу деятельности ООО «Стереоарт». Выявлено, что на предприятии отсутствует единая служба маркетинга, а затраты на рекламу и стимулирование сбыта носят разовый и бессистемный характер. В проектно-рекомендательной части предложены меры по улучшению деятельности исследуемого предприятия, а именно: формирование единой службы маркетинга с применением инновационных технологий; изготовление бесплатных образцов рекламно-информационного характера; реклама в специализированных изданиях. После реализации предложенных мероприятий чистая прибыль фирмы вырастет на 23,4 тыс.грн

Vacancy Defects in Ga2O3: First-Principles Calculations of Electronic Structure

First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga2 O3 crystals. Hybrid exchange– correlation functional B3LYP within the density functional theory and supercell approach were successfully used to simulate isolated point defects in β-Ga2 O3. Based on the results of our calcu-lations, we predict that an oxygen vacancy in β-Ga2 O3 is a deep donor defect which cannot be an effective source of electrons and, thus, is not responsible for n-type conductivity in β-Ga2 O3. On the other hand, all types of charge states of gallium vacancies are sufficiently deep acceptors with transition levels more than 1.5 eV above the valence band of the crystal. Due to high formation energy of above 10 eV, they cannot be considered as a source of p-type conductivity in β-Ga2 O3. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP08856540) as well as by the Latvian research council via the Latvian National Research Program under the topic “High-Energy Physics and Accelerator Technologies”, Agreement No: VPP-IZM-CERN-2020/1-0002 for A.I. Popov. In addition, J. Purans is grateful to the ERAF project 1.1.1.1/20/A/057 while A. Platonenko was supported by Latvian Research Council No. LZP-2018/1-0214

ODS ferritic steels obtained from gas atomized powders through the STARS processing route: Reactive synthesis as an alternative to mechanical alloying

Oxide Dispersion Strengthened Ferritic Stainless Steels (ODS FS) are candidate materials for structural components in fusion reactors. Their ultrafine microstructure and the presence of a very stable dispersion of Y-Ti-O nanoclusters provide reasonable fracture toughness, high mechanical and creep strength, and resistance to radiation damage at the operation temperature, up to about 750 °C. An innovative route to produce ODS FS with composition Fe-14Cr-2W-0.3Ti-0.3Y2O3 (wt.%), named STARS (Surface Treatment of gas Atomized powder followed by Reactive Synthesis), is presented. This route avoids the mechanical alloying (MA) of the elemental or prealloyed powders with yttria to dissolve the yttrium in the ferritic matrix. In this study, starting powders containing Ti and Y are obtained by gas atomization at laboratory and industrial scale. Then, a metastable Cr- and Fe- rich oxide layer is formed on the surface of the powder particles. During consolidation by HIP the metastable oxide layer at Prior Particle Boundaries (PPBs) dissociates, the oxygen diffuses towards saturated solutions or metallic Ti- and Y-rich particles, and Y-Ti-O nano-oxides (mainly Y2TiO5) precipitate in the ferritic matrix. Detailed Microstructural characterization by X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of powders and consolidated materials is presented and correlated with mechanical behaviour