Samples of briquettes based on dust from electric arc furnace production with various organic and mineral binders have been obtained. The study of the dependence of the ultimate strength during ...briquettes compression on the type of binders and their amount in the samples, testing of samples for dropping and abrasion, as well as the study of the chemical composition of samples of reduced briquettes have been carried out. The phase, chemical and granulometric compositions of the electric arc furnace dust have been preliminary investigated, the values of the optimum moisture content required to create briquettes with the highest mechanical characteristics have been determined.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The phase, elemental, and particle-size distributions and the morphology of a dust sample from electric steel-smelting production were studied. The heat-treatment temperature of the sample in a ...reducing atmosphere at which the greatest weight loss occurred was determined by thermogravimetric analysis. The elemental and phase compositions of the reduced sample were determined. The effect of the processing temperature regime on the degree of zinc removal from the sample was shown.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A study of the productivity of pine and spruce stands in various forest types growing on the territory of the Leningrad Region was carried out. Forest inventory materials were used to conduct a ...comparative analysis by forest type and stand composition. The analysis ANOVA was used to establish significant differences between spruce and pine stands.. The largest growing stock in stands with a predominance of pine was recorded when a share of pine in the stand composition ranged from 70 to 100%. The largest growing stock of pine trees was recorded in the Oxalis acetosella - Vaccinium myrtillus and Vaccinium myrtillus - Polytrichoso-Sphagnosa forest types. In the stands with a predominance of spruce, the largest growing stock of this species was recorded in the stands with 70 – 90% of spruce. The largest growing stock of spruce was formed in Oxalis acetosella - Vaccinium myrtillus forest types. Our studies have shown that pine-dominated forest stands were more productive in a wider range of forest types than spruce stands. In general, this is due to the fact that the sample under consideration was within the optimum growing conditions for each species, and the stands formed within these boundaries were stable and productive.
The article addressed the question of the development of stands with different proportions of pine in the stand composition on the territory of Boksitogorsk forestry unit of the Leningrad region. We ...used forest inventory data to carry out a comparative analysis of stands by forest type and stand composition. Analysis of variance was used to determine statistically significant differences in the growing stock depending on the stand composition and growing conditions. Based on the results of the study, we made a conclusion that on the territory of the forest fund in the part of the Boksitogorsk region considered, mixed stands with a share of pine of 50-80% and almost pure pine stands in blueberry types of forest growing conditions were the most promising. The stand composition did not make a significant effect on the productivity of stands with different proportions of pine. Apparently, this is due to the replacement of pine by other species and formation of growing stock similar to that of a pine forest. In the wetter forest types, stands with a lower productivity formed.
This article presents the development of a method for producing a finely dispersed fraction of ground blast-furnace granulated slag. The resulting material with an alkaline additive can serve as an ...alternative to analogous finely dispersed mineral binders such as microcement. A comprehensive study was conducted on granulated slags from two metallurgical plants. The physical and chemical characteristics of the materials were determined. Finally, we demonstrated the possibility of producing a fraction of ground granular slag with a particle size of no more than 16 microns using vortex electromagnetic homogenization and subsequent air classification.
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The present research provides data on the density (ρ), viscosity (η) and ability to absorb carbon dioxide of systems containing amine, molecular solvent (MS) and choline chloride (ChCl), with the ...investigation of the physical properties of both neat amine/MS/ChCl mixtures and their samples after complete CO2 saturation. The effect of the mixture composition was studied by varying amine from primary (monoethanolamine, MEA) to secondary (diethanolamine, DEA) and tertiary (triethanolamine, TEA) amine, and the degree of its substitution from a mono- (MEA, DEA and TEA) to a doubly-substituted (ethylenediamine, EDA) compound. The role of an MS was investigated via the exchange of ethylene glycol (EG) with water and dimethylsulfoxide (DMSO). In addition, the influence of the CO2 absorption promoters present in the ternary MEA/EG/ChCl mixture at an amount of 5 wt. % was also investigated. We show that an increase in ρ and η in the amine/EG/ChCl mixture affects the properties of neat amines. This suggests that in the studied ternary mixtures, the nature of the interspecies interactions is very similar to those in the previously studied MEA/EG/ChCl system. When EG was exchanged for H2O or DMSO, a decrease in ρ and an increase in η were observed. A comparison of the data with the corresponding properties of the systems composed of each pair of the mixture components indicates that the intensity and/or number of interspecies interactions in the present ternary mixtures were stronger than those in pure H2O, DMSO and MEA. While in the presence of promoters no significant changes in the studied properties were found, for the corresponding CO2-saturated samples, the ρ and η increased proportionally to the amount of absorbed gas. This was also the case for all the systems studied in the present research. The overall CO2 absorption of the EG-based mixtures decreased when going from primary to secondary and tertiary amines; it was 21% higher for the MEA/H2O/ChCl system compared to the mixtures containing EG and DMSO, which, in turn, showed similar absorption capacities. When the promoters were added to the MEA/EG/ChCl mixture, the highest capacity was found for the piperazine-containing system.
Ground-truth experiments are needed to calibrate and validate satellite microwave data and to improve the quality and utilization efficiency of satellite data in solving problems of ...hydrometeorological support. This paper considers the arrangement of specialized test observatories in the satellite data validation subsystem exemplified by the geophysical observatory in Lehtusi (a town in Leningrad oblast), describes the state and prospects of its equipping with modern tools of contact and remote measurements of meteorological parameters, and indicates directions of scientific research.
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Amethod of synthesis of corundum and mullite-corundum permeable refractories (with the addition of aluminum-magnesium spinel) with a total porosity of up to 76 % and average pore size of 12 – 20 μm ...based on the technology of chemical foaming of ceramic slip is proposed. To implement this method, a complex organic foaming agent and stabilizer of the foamed ceramic slurry is proposed, which burns out during the firing process and does not pollute the refractory material.
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—The possibility of improving the resistance of austenitic chromium-nickel steel of 09Kh18N9 and 08Kh16N11М3 grades to pitting and intercrystalline corrosion under the conditions of standby mode of a ...fast neutron reactor facility has been investigated. Corrosion tests lasting up to 15 000 h have demonstrated that the corrosion rate decreases significantly upon the decrease in the carbon content and the increase in the nitrogen content.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Samples of mineral hydraulic binder and artificial stone based on such binder were obtained from granulated blast furnace slag and Portland cement M500 using vortex electromagnetic homogenization. ...The following physico-chemical characteristics of mineral powders have been investigated: phase and chemical composition, specific surface area, particle size distribution, mechanical properties of artificial stone based on the slag-cement system binders. It is shown that the introduction of 10 to 50 wt.% of Portland cement into the composition of the developed materials results in the variation of ultimate compressive strength of the samples from 50 to 90 MPa, and density variation from 2.1 to 2.5 g/cm
3
. These materials have low cost due to the use of blast-furnace slag as a raw material along with an energy-efficient grinding technique.
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