Voronezh State Technical University (Russian: Воронежский государственный технический университет) is a public university located in Voronezh, Russia..
This study presents a comprehensive investigation of the CoFe2O4–Pb2ScNbO6 (0.5CFO–0.5PSN) composite, synthesized via a solid-state reaction method. The composite, comprising a ferrite spinel and a relaxor ferroelectric, was characterized using a suite of techniques including dielectric spectroscopy, optical analysis, X-ray diffractometry, magnetometry, magnetodielectric measurements and electrocatalytic testing. At room temperature, the real part of the complex permittivity (ε′) attains a value of 105. Within the temperature range of 100–250 °C, ε′ increases significantly to approximately 1.4 × 106. The temperature dependence of permittivity, ε′(T), exhibits a relaxor behaviour, which is attributed to the diffuse phase transition inherent to the PSN component and contributions from Maxwell–Wagner interfacial polarization. A distinct anomaly in the ε′(T) curve is observed near 450 °C, manifested as a kink followed by a sharp increase. This feature is associated with the transition of the CFO component from a ferrimagnetic to a paramagnetic state. The analysis of the magnetoresistance coefficient, MR(H), reveals that the composite exhibits colossal magnetoresistance (CMR) on the order of 530
The effects of reinforcement type (steel cable and mesh, glass roving and mesh) and aggregate type (sand and limestone powder) on the shrinkage of 3D printed concrete were determined. To simulate different drying conditions of the material in thin layers of 3D printed structures, 3D printed plate samples were used and kept in environments with relative humidity of 30
The dielectric response dispersion in the solid solution 0.9Pb0.95Sr0.05(Zr0.52Ti0.48)O3–0.05Pb(Zn1/3Nb2/3)O3–0.05Pb(Mn1/3Sb2/3)O3 + 0.1 mol
The paper discusses a relevant issue arising from the ban on the extraction of common minerals on land in the Rostov Region and the growing demand for high-quality crushed stone for reinforced concrete products and road surfacing. Consequently, there is a need for a rapid transition to alternative raw material sources for modern construction; in particular, sandstone crushed stone from the Tula Region could be used as an alternative. The study provides a comprehensive assessment of the performance properties of sandstone crushed stone from various deposits and offers recommendations for its most effective use.
Постановка задачи. Провести комплексный анализ дефектов сварных соединений прямошовных труб большого диаметра и установить причины их возникновения. Результаты. Проведены исследования методами макроструктурного и микроструктурного анализа изготовленных шлифов, определен химический состав и проведены замеры твердости и микротвердости сварного соединения. Выводы. Установлены причины возникновения дефектов сварных соединений в виде макро- и микротрещин в сварном соединении прямошовной трубы большого диаметра.
