An analytical method for preliminary assessment of the compactability of charges made from fine materials of the mining and smelting industry is developed. The method allows establishing the ...functional dependence of the density of a briquette on the applied pressure without experiments on the compression of a charge in special pressure equipment. The method involves the use of a new compaction model and the relationship between the compact density at a given pressure and the physical and mechanical properties of a charge (loose bulk density, tapped bulk density, true density of particles) for dry charges and charges mixed with water or liquid binder. The method can be used in briquette production when choosing processing modes and creating pressure equipment.
The authors analyze the two-stage Popov method with Bregman divergence and a new adaptive rule for choosing the step size, which does not require the Lipschitz constants to be known and operator ...values at additional points to be calculated. For variational inequalities with pseudo-monotone and Lipschitz continuous operators acting in a finite-dimensional normed linear space, the convergence theorem for the method is proved.
In this work we present the test run results for the electron cooling system at the Booster synchrotron, which were conducted at the Nuclotron-based Ion Collider facility (NICA) injection complex in ...2020–2023. We have demonstrated a successful cooling of the
56
Fe
14+
and
124
Xe
28+
ion beams at the injection energy 3.2 MeV/u. In this work, we provide parameters of the ion and electron beams, as well as a detailed description of the tuning procedures used for the e-cooling system during the experiments.
Activation of the emergency protection entails the injection of a boric acid solution into the reactor core to the standstill value, after which the control rods are raised, and then it is possible ...to obtain permission to start the reactor. The first stage of reaching the minimum controlled power level (MCL) is associated with feeding the pure condensate to the start-up interval at a high injection rate; the second stage is the mixing of the first circuit and then the injection of the pure condensate, but at a low rate. At the same time, the technical guidelines for safe operation indicate that the flow rate of pure condensate in the start-up interval should not exceed the flow rate of pure condensate to compensate for xenon poisoning by more than 10 t/h, and the rate of introducing the positive reactivity should not exceed 0.02 β
eff
/min. At the same time, it is not entirely clear how to estimate the flow rate of pure condensate in the start-up interval, since there is no equipment on the power unit for measuring the magnitude of xenon poisoning and the rate of reactivity input. This study answer the question of what is the permissible flow rate of pure condensate the operator can use in the start-up interval in the presence of xenon processes.
A numerical method is used to study the structure and energy of the Néel domain wall in an ultrathin magnetic film of the permalloy type. It is shown that the structure of the Néel domain wall is ...determined by a pattern of changes in the magnetostatic energy, which is divided, so as to decrease its value, into the following three regions: the core region and two regions of lateral turnarounds.
A new extragradient-type method is proposed for approximate solution of variational inequalities with pseudo-monotone and Lipschitz-continuous operators acting in a finite-dimensional linear normed ...space. The method uses Bregman divergence (distance) instead of Euclidean distance and a new adjustment of step size, which does not require knowledge of the Lipschitz constant of the operator. In contrast to the previously used rules for choosing the step size, the method proposed in the paper does not perform additional calculations for the operator values and prox-map. A theorem on the convergence of the method is proved.
Effectiveness of a new stage equation for identifying and analyzing individual stages of compaction was assessed. Results revealed that the newly developed equation describes correctly and accurately ...the experimental compaction curves, which considers the periodic nature of the process and enables the determination of characteristic transition points between stages, whereas. the determination coefficient is close to unity. On the basis of the use of the basic and stage compaction equations, methods were developed to determine the stabilizing pressure, briquettability, and stiffness of the charge. Anew attribute was proposed for the energy classification of briquetted materials.
In current work, we conducted comparative studies of electrolyte-supported and anode-supported solid oxide fuel cells by means of electrochemical techniques (studies of I-V curves and impedance ...spectroscopy) as well as using Raman spectroscopy from the inner interface of the anode electrode and solid electrolyte. Electrolyte-supported (ESC) SOFCs were based on thick single-crystalline 8YSZ anion conductor membrane and had multilayered composite electrodes. Anode-supported cells (ASC) were based on thick two-layered commercially available anode supports, the thin-film electrolyte was deposited using a magnetron sputtering technique. Comparative studies showed a significant dependence of 460 cm−1 Raman peak both on fuel mixture composition and current load applied to the cell. Linear dependences of OCV on normalized peak area gave an opportunity to estimate local anodic overpotential on the current load applied for both SOFC structures. Application of ASC model cells gave an opportunity to significantly extend a range of current loads applied. Analysis of impedance spectra gave the opportunity to study the structure of complex resistance as well as the structure of local anodic overpotential obtained.
•Comparative studies ESC/ASC SOFCs via electrochemical techniques and Raman spectroscopy.•Significant dependence of 460 cm−1 peak (GDC sublayer) on fuel composition and current load was shown.•Local anodic overpotential was estimated using dependences of OCV on Raman peak area.•Application of model ASC gave an opportunity to significantly extend a range of current loads.•Impedance spectra showed Raman estimated anode overpotential to be contribution of the fuel oxidation anode reaction.
Abstract
Information about properties of liquid-crystalline dispersions of DNA molecules formed as a result of their phase exclusion is systematized. The influence of temperature and osmotic pressure ...on the structure of these dispersions has been elucidated in the framework of the concept of ‘quasinematic’ layers of orientationally ordered DNA molecules in dispersion particles. A new hexagonal → ‘re-entrant’ cholesteric packing phase transition of DNA molecules discovered by the authors is described, taking into account the generalized Lindemann criterion. The multiplicity of the ‘re-entrant’ phases and their structure are shown to depend on the characteristics of DNA and water-polymer solutions.
The results of the first direct experiments on the passage of pulses of ultra-wideband radiation of subnanosecond duration in the Earth’s atmosphere at a distance of more than 10 km are presented. In ...contrast to the work calculated, the preservation of the amplitude–time shape of the pulses in the process of increasing the distance is shown. The establishment of this fact is of decisive importance in the practical application of ultra-wideband pulses in new technological developments.
