—
Ash and slag waste (ASW) from coal-fired thermal power plants (TPPs), the amounts of which make several tens or even hundreds of millions of tons per annum, require allocation of large land areas ...for storing them. This waste is a source of pollution emitted into the atmosphere and it poisons the aqueous medium and soil. Ash and slag waste consists primarily of powderlike material containing a large quantity of unburned carbon (5–25%), magnetic materials (5–20%), and alumino-silicate components. All these components are a valuable raw material for industry, especially silicon and aluminum oxides, which can be used in the production of construction materials. For this purpose, ash must be preliminarily subjected to beneficiation using physical and physicochemical methods. The article presents an analysis of dry and wet ash beneficiation methods with a view to increase the volumes of using ASW produced from domestic power plants. For achieving higher strength of concretes, mechanical activation is carried out, which relates to dry ASW beneficiation methods. To obtain an alumino-silicate product containing 1.5–4.5% of carbon, such dry processing method as electrostatic separation is used. By subjecting dry ash to combined magnetic and electrostatic separation methods, it is possible to obtain an ash and a conducting product with a high concentration of carbon. For Russia, wet ASW beneficiation methods are of the greatest importance, because wet ash and slag removal is used at the majority of TPPs. Hydraulic classification of waste for obtaining products containing particles of different sizes is one of the wet beneficiation process stages. By using the froth flotation method, it is possible to obtain a concentrate containing 65–70% of carbon, a material that can serve as boiler fuel. The froth flotation is regarded as a necessary method for integrated utilization of ASW. Wet magnetic and electrostatic separation are the basic methods for producing magnetic concentrate containing 62–65% of iron. The article presents methods for separating hollow microspheres from AWS, which are a valuable product for aggregates used in the civil construction industry. The article also considers integrated ash beneficiation methods for obtaining four basic products (the figures in parentheses indicate the content of the relevant element): hollow microspheres, carbon product (64.5% of carbon), magnetic product (62% of iron), and alumino-silicate product (no more than 3% of carbon).
Short-lived resonances have always played an important role in the physical programs of heavy-ion experiments. The resonances measured in the hadronic decay channels probe strangeness production, ...hadronization at intermediate and high transverse momenta, and rescattering and regeneration effects in the hadronic phase of nucleus–nucleus collisions at various energies. Properties of the resonances produced in collisions of heavy nuclei at NICA accelerator energies have never been studied in detail. Properties of the resonances and their sensitivity to various studies of collisions of Au nuclei expected at NICA energies are considered. Results of feasibility studies for reconstruction of resonances in the MPD experimental setup are presented and discussed.
—
This paper presents the results of estimating the changes in the yields and spectral properties of hadronic resonances in heavy ions collisions at NICA energies by the example of short-lived ...resonances
and
. The results of studying the feasibility of detecting hadronic resonances at the MPD detector in collisions of bismuth nuclei at an energy of 9.2 GeV are also presented.
Thermal photons are a valuable source of information about the properties of hot and dense matter produced in relativistic heavy-ion collisions. The effective temperature measured at RHIC and LHC ...energies greatly exceeds the temperature of the expected phase transition to the state with deconfined quarks and gluons known as quark–gluon plasma (QGP). Measurements of direct photons in heavy-ion collisions at the NICA accelerator will enable assessment of the effective temperature of the emerging medium at lower energies and trace the transition from partonic to hadronic degrees of freedom. The feasibility of studying thermal photons in the MPD experiment at NICA in Au–Au collisions using the photon conversion method is analyzed.
The oxidative and nonoxidative conversion of ethylene in a dielectric barrier discharge in the presence of water with the formation of predominantly unsaturated compounds (acetylene, butene, ...butadiene) has been studied. The efficiency of ethylene conversion in argon is shown in comparison with its oxidation by air into oxygenates. A simple theoretical estimate of the energy loss of discharge electrons in the feed gas mixture and simple kinetic calculations make it possible to explain both the change in the degree of ethylene conversion and the direction of the process.
The problems of data modeling for assembly process of GTE units are considered on the basis of graph approach for solving the production digitalization problem. With the help of the graph model, the ...assembly workplaces and new states of the assembled GTE units are determined.
Initial results are presented from studying the possibility of measuring different resonances on the experimental setup of the MPD spectrometer of the NICA accelerator, along with the first ...assessments of the impact the hadron phase has on the properties of resonances in heavy ion collisions at NICA energies.
The paper analyzes the problems of carbon stocks variation in the pool of cropland mineral soils at the regional scale of the Russian Federation. The carbon stock balance of cropland soils was ...evaluated by estimating carbon gains and losses, and then the components of the carbon footprint were measured as a ratio of soil organic carbon balance to crop production quantity in terms of grain equivalent (t C/t grain eq.). The estimates for the period 2011–2020 have revealed that there is generally a small net gain of carbon on cropland in Russia, mainly due to the intake of carbon from plant residues. Most of the steppe region of Russia suffers from net losses of carbon at levels from –0.15 t C/t grain eq. up to –0.69 t C/t grain eq. In other regions, such as the Central Chernozem and Black Sea Coast regions, net carbon gain is observed in the range of 0.1–0.3 t C/t grain eq. due to the intake of significant biomass of crop and root residues as a consequence of intensive crop production.
A simplified model of the process of benzene oxidation by oxygen in a dielectric barrier discharge has been developed. A kinetic scheme of oxidation is proposed that reflects the real chemistry of ...the process. The simulation results confirm the earlier assumptions about the main stages of the benzene oxidation process with oxygen.
A model is proposed for the automatic control of manufacturing processes and the necessary preparations. The model is based on step-by-step implementation of a systematic approach and a feedback ...mechanism. In automated control, the preparations, involving CAD/CAPP/CAM/PDM systems, are integrated with control of the manufacturing process. The model permits the use of paperless technology based on a 3D model of the part and three important stages in the derivation and analysis of information regarding the operation of the working centers. Subsystems permit monitoring of the equipment and the cutting tool and analysis of product quality so as to formulate corrective measures on the basis of feedback mechanisms.
