2,168 research outputs found

    Processing of Waste from Enrichment with the Production of Cement Clinker and the Extraction of Zinc

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    This paper presents studies on the processing of enrichment tailings as a component of a raw mixture in order to obtain cement clinker, with simultaneous distillation of zinc. Thermodynamic studies were carried out in the temperature range of 600–1600 °C using the software application “HSC Chemistry 6” developed by the metallurgical company Outokumpu (Finland). As a result of the conducted studies, we found that zinc contributes to the intensification of mineral formation of cement clinker. In particular, it was found that the formation of belite is possible in the temperature range from 990.7 to 1500 °C with Gibbs energy values of −0.01 and −323.8 kJ (which is better than the standard process by −11.4 kJ), respectively; the formation of alite is possible in the temperature range from 982.9 to 1500 °C with Gibbs energy values of −0.05 and −402.1 kJ (better than the standard process by −11.4 kJ), respectively; the formation of tricalcium aluminate is thermodynamically possible in the temperature range from 600 °C at ΔGTo = −893.8 kJ to 1500 °C at ΔGTo = −1899.3 kJ (better than the standard process by −1570.1 kJ), respectively; and the formation of four calcium aluminoferrite is possible in the temperature range from 600 °C at ΔGTo = −898.9 kJ to 1500 °C at ΔGTo = −1959.3 kJ (better than the standard process by −1570.2 kJ), respectively, with simultaneous distillation of zinc into a gaseous state for its further capture

    Problems of Professional Self-Development Among Undergraduates in the Digital Space, Identified During the COVID-19 Pandemic

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    The article examines the problems of professional self- development among undergraduates in the digital space, identified during the COVID-19 pandemic. The results of the study showed that students have characteristics that are necessary for further personal growth. They want to know themselves and ready to change and learn new things, improve themselves. Conducted during a pandemic and distance learning in self- isolation showed that 50% of students expressed satisfaction with this form of education, explaining their opinion with a high level of independent search for the necessary information, opportunities for self-development, self-realization, and self-improvement. Among the difficulties of distance learning, all surveyed identified: search and critical analysis of digital information; communicative dissatisfaction, the need for approval. The surveyed students in their self-development need a micro- and macro- environment that would create a secure creative educational space. It is necessary to search for new solutions to overcome psychological barriers associated with the need for self-development as future highly qualified specialists in the context of modern trends in the development of digital education

    International experience and Russian peculiarities of ensuring the quality of higher education

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    The development of trends in modern society (with its rapid development of cloud, communication technologies, technological innovations in education, scientific and technological progress) requires education to increase the dynamism and efficiency in training highly qualified specialists. The issue of providing quality educational services in order to meet the requirements and needs of the constantly changing demand for specialists, the labor market becomes urgent. The article identifies the factors influencing the quality of educational services at the modern university, describes the importance and functions of institutions of different levels in ensuring the quality of higher education, the purpose of higher education by students and audience, the level of their satisfaction with educational quality and educational process in higher education institution was found out. The analysis of assessment of educational services received by students and university audience is presented. Particular attention is paid to European institutions of assessment and quality assurance in higher education

    Self-tuning speed controller with load parameters observer for servo drives

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    Servo drives are widely employed in a large range of industrial applications where the load inertia and torque are varying. This paper proposes a control approach utilizing the load parameters adaptive observers to provide a stable servo drive operation under mechanical parameters variation. In contrast to other solutions, the observers are processing real speed and acceleration values instead of their command. It was shown that the observers are capable of estimating the load torque and total inertia of the drive system under different types of commands. The simulation of the proposed control approach demonstrated that the proportional gain of the speed controller tunes automatically according to the estimated inertia ensuring the required quality of the transient regardless variation of the mechanical subsystem parameters

    Triplet production by linearly polarized photons

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    Abstract The process of electron-positron pair production by linearly polarized photons is used as a polarimeter to perform mobile measurement of linear photon polarization. In the limit of high photon energies, ω, the distributions of the recoil-electron momentum and azimuthal angle do not depend on the photon energy in the laboratory frame. We calculate the power corrections of order m/ω to the above distributions and estimate the deviation from the asymptotic result for various values of ω

    Methodology for cadastral valuation of agricultural lands occupied by water bodies

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    The article considers features of cadastral valuation of agricultural lands occupied by water bodies. The research is based on natural water bodies of the Samara region water fund. A methodology for determining the cadastral value of agricultural lands occupied by artificial water bodies is proposed. The methodology links the land value with the size of the land plot, profit and such objects as dams and other hydraulic structures located within the land plot. The paper confirmed the suggestion that the owner of the land that shall be used for the construction of a pond has the right to the added value of land in the amount of return rate of contributed capital (26.28%). The cadastral value of 1 square meter of agricultural land is 3.11 rubles

    A model of a transition neutral pion form factor measured in annihilation and scattering channels at high momentum transfer, Phys.Part.Nucl.Lett

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    We consider an alternative explanation of newly found growth of neutral pion transition form factor with high virtuality of one of photons. It is based on Sudakov suppression of quarkÄphoton vertex. Some applications to scattering and annihilation channels are considered including the relevant experiments with leptonÄproton scattering. ¸¸³ É·¨¢ ¥É¸Ö ²ÓÉ¥·´ ɨ¢´μ¥ μ¡ÑÖ¸´¥´¨¥´¥¤ ¢´μ μ¡´ ·Ê¦¥´´μ£μ ·μ¸É Ëμ·³Ë ±Éμ· ´¥°-É· ²Ó´μ£μ ¶¨μ´ ¸μ¤´¨³ ·¥ ²Ó´Ò³¨μ¤´¨³ ¢¨·ÉÊ ²Ó´Ò³ ËμÉμ´μ³. ‚ ¤ ´´μ°¸É ÉÓ¥ ¶μ¤Ìμ¤ μ¸´μ¢ ´ ¸Ê¤ ±μ¢¸±μ³ ¶μ¤ ¢²¥´¨¨±¢ ·±-ËμÉμ´´μ°¢¥·Ï¨´Ò. ·¥¤¸É ¢²¥´Ò ¢μ §³μ¦´Ò¥ ¶·¨²μ¦¥´¨Ö ± Ô±¸ ¶¥·¨³¥´ÉÊ ¢ ± ´ ² Ì · ¸¸¥Ö´¨Ö¨ ´´¨£¨²Öͨ¨

    Multibeam spherotron

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    Предложены два типа сферотрона-диотрона на двусферическом резонаторе (раннее в статье был предложен сферотрон-диотрон с несинхронным взаимодействием на двусферическом резонаторе, где электронный поток в этом генераторе проходит по оси z резонатора от внешней сферы до внутренней и взаимодействует с продольным (осевым) электрическим полем резонатора). Первый тип сферотрона имеет ряд электронных лучей (пучков), проходящих от внешней сферы резонатора к внутренней под углами относительно оси z резонатора: =0, /8, /4. Взаимодействие электронов с полем резонатора в нем осуществляется за счет возникновения квадратичных сил в возрастающем в направлении движения электронов поле. Во втором типе сферотрона (обращенном сферотроне) радиальные электронные пучки расположены по полудуге экваториальной плоскости резонатора, а электроны движутся от внутренней сферы к внешней. Взаимодействие в нем осуществляется из-за пространственной фазировки электронов. В обоих типах сферотронов достижим КПД 30 % при сверхбольшой мощности в импульсном режиме и суммарных токах пучков в десятки килоампер. Приведенные в статье данные свидетельствуют о перспективности многолучевого и oбращенного сферотрона по следующим показателям: чрезвычайная простота конструкции; не требуется прецизионных решеток или гребенок с шагом, значительно меньшим длины волны; не требуются фокусирующие магнитные системы; обеспечивается электронный КПД 26…45 %. Заметим, что сферотрон – прибор большой мощности (10–100 МВт в импульсе длительностью 1–10 нс), поскольку для поддержания эффективности несинхронного взаимодействия нужна высокая величина напряженности электромагнитного поля, что достигается только при большой мощности прибора. The article proposes two types of multibeam spherotron-diotron based on a two-spherical resonator (an early article suggested a spherotron-diotron with non-synchronous interaction on a bi-spherical resonator, where the electron beam in this generator passes along the resonator z axis from the outer sphere to the inner one and interacts with the longitudinal (axial) electric resonator field). The first spherotron type has electron beams going from outer to inner sphere with slope about the z-axis: =0, /8, /4. The electrons interact with the resonator field through the emergence of quadratic forces in the field increasing along the electron motion. The second type (inverted spherotron) has electron beams located in half arc of the equatorial resonator plane, and the electrons move from the inner sphere to the outside. The interaction in it is carried out due to the spatial electron phasing. Both spherotron types achieve efficiency of 30 % at ultra-high pulse power and tens of kuloampère of total beam currents. The data presented in the article indicate the prospects of broad application for the inverted spherotron by the following indicators: extreme ease of design; no precision gratings or combs are required with a step significantly shorter than the wavelength; no focusing magnetic systems are required; electronic efficiency from 26 to 45 % is ensured. Note that the spherotron is fundamentally a high- power device (10-100 MW in a 1-10ns pulse) for in order to maintain the efficiency of non-synchronous interaction, one needs a high strength of the electromagnetic field, which is achieved only with a high-power device

    Robust numerical methods for solving the poorly determined tasks of electrodynamics and nonlinear dynamics

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    Приведены алгоритмы с уточняющими и стабилизирующими коэффициентами, позволяющие получать устойчивые решения систем уравнений, относящихся к плохо обусловленным задачам электродинамики и нелинейной динамики. Продемонстрировано применение модифицированных алгоритмов в задаче распространения E0i-волн в нерегулярном волноводе и модели динамического хаоса Ресслера. В последнем случае показано, что «детерминированный» (т.е. воспроизводимый) хаос невозможен.The algorithms with specializing and stabilizing coefficients to provide sustainable solutions to systems of equations related to poorly determined tasks of electrodynamics and nonlinear dynamics are described. It demonstrates the use of the modified algorithms in the task of E0i-waves propagation in irregular waveguide and dynamic model of Ressler's chaos. In the latter case it is demonstrated that ”deterministic” (i.e. reproducible) chaos is impossible
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