Nizhny Novgorod State Technical University

We have developed the fabrication technology of transition-edge sensors made of e-beam-deposited hafnium films coated with palladium to prevent oxidation and suppress their critical temperature. The measured sensors have critical temperatures of 43 -57 mK and temperature sensitivity coefficients of up to 500. The resistive state of TES near the critical temperature is fully reversible, as shown in experiments, unlike the current-initiated switching. To clarify the state of the film during the temperature change, we use the generalized TDGL model. The transition width in terms of temperature has a finite value close to experimental, even in the absence of heating terms in the model. Fabricated sensors can be used in applications that require an energy resolution below 1 eV.

RELEVANCE. Single-phase-to-ground faults remain one of the most common types of damage in distribution networks with isolated neutral. Arc-ing, intermittent single-phase-to-ground faults pose a serious threat to the power system's electrical equipment due to the transient processes occurring in the network during such faults. The prolonged flow of single-phase-to-ground fault currents in a cable line causes heating and can lead to a phase-to-phase short circuit. The development of high-speed and selective relay protection will prevent damage and ensure a reliable power supply to consumers. PURPOSE. To improve protection speed, the Clarke transform is applied, which combines the instantaneous values of the three phase currents to obtain an informational feature of a fault. It is necessary to develop a starting unit for single-phase-to-ground fault protection using the Clarke transform and to determine the properties of the resulting starting unit. METHODS. The Matlab software suite with the Simulink extension package was used for simulation modeling of current oscillograms under various operating conditions of an electrical network with an isolated neutral. The simulation results allowed for the development of a protection starting unit that utilizes the Clarke transform and features increased speed. RESULTS. A simplified structural and functional diagram of a starting unit for protection against single-phase-to-ground faults has been developed. A comparative sensitivity assessment was conducted with relay protection currently used in networks. The sensitivity of the developed protection unit during arc-ing intermittent single-phase-to-ground faults exceeds that of existing similar technical solutions. CONCLUSIONS. The research results are promising for creating new protection against single-phase-to-ground faults in networks with an isolated neutral, utilizing the Clarke transform.

В центре внимания авторов находится проблема формирования, сохранения и раз- вития субъектности студента вуза. Рассмотрены некоторые проблемы становле- ния субъектности студентов, даны практические рекомендации по их разреше- нию. Цель работы — выявить связь субъектности студента вуза с другими категориями образовательного процесса, характер и механизм взаимодействия и, в конечном итоге, влияния на уровень подготовленности студента к будущей профессиональной деятель- ности. Материалом исследования послужили открытые публикации по заявленной теме, а также опыт работы в конкретных вузах, в том числе в Нижегородском государствен- ном техническом университете им. Р. Е. Алексеева. В качестве основного инструмента исследования авторы использовали метод критического анализа. В статье показана ак- туальность проблемы в условиях тренда на индивидуализацию образования и постоянно растущей планки его качества. Выявлены связь «субъектности» с другими категориями образовательного процесса, характер и механизм их взаимодействия, подтверждена на- чальная гипотеза авторов о влиянии субъектности на уровень подготовленности студента к будущей профессиональной деятельности. The authors focus on the problem of forming, maintaining and developing the subjectivity of a university student. Some problems of developing students’ subjectivity are considered, and practical recommendations for resolving them are given. The purpose of the work is to identify the connection between the subjectivity of a university student and other categories of the educational process, the nature and mechanism of interaction and, ultimately, the influence on the level of preparedness of the student for future professional activity. The research material was open publications on the stated topic, as well as work experience at specific universities, including the Nizhniy Novgorod State Technical University named after R. E. Alekseev. The authors used the critical analysis method as the main research tool. The article shows the relevance of the problem in the context of the trend towards individualization of education and the constantly growing level of its quality. The connection between «subjectivity» and other categories of the educational process, the nature and mechanism of their interaction are revealed, and the authors’ initial hypothesis about the influence of subjectivity on the level of student preparedness for future professional activity is confirmed.

Duplex stainless-steel (DSS) powders used for hot isostatic pressing (HIP) often contain moisture, hydrogen, and carbon–oxygen species that promote pore formation and reduce mechanical performance. A staged high-vacuum degassing method with stepwise heating to 600 °C and 60-min holds was applied to quantify gas evolution using residual gas analysis (RGA). Distinct desorption peaks were observed for H2O, H2, CO, and CO2, with cumulative releases of 120, 45, 28, and 15 nmol/g, respectively, at pressures below 5 × 10−7 Torr. Activation energies determined using the Polanyi–Wigner approach ranged from 60 to 120 kJ/mol. Degassed powder achieved 99.9 pct HIP density and showed 8–10 pct higher tensile strength and 15 pct greater elongation. The results confirm the effectiveness of controlled high-vacuum pretreatment for improving DSS powder cleanliness.