scholarly journals SUBSOLIDUS STRUCTURE OF THE MgO – FeO – Al2O3 SYSTEM

2021 ◽  
pp. 59-64
Author(s):  
Oksana Borysenko ◽  
Sergey Logvinkov ◽  
Galina Shabanova ◽  
Alla Korohodska ◽  
Marina Ivashura ◽  
...  
Keyword(s):  
Minimum Degree ◽  
Technological Parameters ◽  
Concentration Region ◽  
Thermal Expansion Coefficients ◽  
Homogenization Time ◽  
Physicochemical Basis ◽  
Temperature Ranges ◽  
Topological Characteristics ◽  
Spinel Mgal2o4 ◽  
High Degree

Three-component systems constitute the physicochemical basis of most refractory materials and the analysis of their subsolidus structure makes it possible to accurately predict the areas of compositions with optimal properties, as well as give recommendations on the technological parameters of production, sintering, and operation of the materials obtained. As a result of the carried out thermodynamic analysis of the MgO – FeO – Al2O3 system, it was found that the partition of the system into elementary triangles undergoes changes in two temperature ranges: I – up to a temperature of 1141 K and II – above a temperature of 1141 K. By calculation methods, the geometrical-topological characteristics of the subsolidus structure of the system are determined MgO – FeO – Al2O3: areas of elementary triangles, degree of their asymmetry, area of regions in which phases exist, probability of phase existence in the system. It has been established that, over the entire temperature range, there is a fairly extended concentration region of spinel phases: hercynite (FeAl2O4) – noble spinel (MgAl2O4). Moreover, periclase (MgO) coexists simultaneously with both spinels only in the low-temperature region. This indicates that when obtaining periclase-spinel refractories with increased heat resistance, an important technological parameter is a cooling rate below 1141 K. To obtain periclase-spinel refractories with branched microcracking of the structure due to differences in the thermal expansion coefficients of periclase, hercynite and noble spinel, the most rational concentration region of the system under study is which is common for two elementary triangles (MgO – FeAl2O4 – MgAl2O4 and MgO – FeO – MgAl2O4) existing in different temperature ranges. At high firing temperatures, the elementary triangle MgO – FeO – MgAl2O4 has a maximum area and a minimum degree of asymmetry, and upon cooling, MgO – FeAl2O4 – MgAl2O4 is formed, which is quite large in area, but has a high degree of asymmetry. Therefore, the composition of the charge for periclase-spinel refractories should be predicted with a high dosage accuracy and with a significant homogenization time of the components during mixing, since the concentration region common for both of the above elementary triangles is significantly reduced. Thus, the division of the MgO – FeO – Al2O3 system into elementary triangles and the analysis of the geometrical-topological characteristics of the phases of the system made it possible to select in the system under study the range of compositions with optimal properties for obtaining spinel-containing materials.

A possibility of using nickel concentrate, obtained as a result of hydrometallurgical enrichment of manganese-containing raw materials, at steel alloying

2020 ◽  
Vol 76 (7) ◽  
pp. 709-715
Author(s):  
O. Yu. Kichigina
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Selective Extraction ◽  
Technological Parameters ◽  
Nickel Iron ◽  
Nickel Recovery ◽  
Nickel Concentrate ◽  
Steel Alloying ◽  
High Degree ◽  
Comprehensive Processing

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.

scholarly journals The influence of geological and technological factors on the probability of determining zones of residual oil reserves

2019 ◽  
pp. 46-56
Author(s):  
E. S. Azarov
Keyword(s):  
Correlation Coefficient ◽  
Residual Oil ◽  
Technological Parameters ◽  
2D Modeling ◽  
Technological Factors ◽  
Oil Reserves ◽  
Probability Map ◽  
Probability Maps ◽  
Final Probability ◽  
High Degree

This article is devoted to the probability maps have been constructed for predicting the zones of residual oil reserves using the example of deposits in Shaim region. The refinement of the previously presented algorithm [4] has been made, which helps with a fairly high degree of probability to quickly localize the residual oil reserves based on 2D modeling. In the process of work, the influence of many geological and technological parameters on the final probability map was established, the influence of the observation zone on the value of the correlation coefficient of the map of residual mobile oil reserves with the map of current mobile oil reserves based on geological and hydrodynamic modeling was established.

scholarly journals Selected Traits of Spring Wheat in Polish Climatic Conditions

2014 ◽  
Vol 66 (1) ◽  
pp. 29-38
Author(s):  
Magdalena Gut ◽  
Przemysław Szecówka ◽  
Andrzej Bichoński
Keyword(s):  
Yield Components ◽  
Large Degree ◽  
Climatic Conditions ◽  
Yield Component ◽  
Falling Number ◽  
Technological Parameters ◽  
Visual Evaluation ◽  
Basic Quality ◽  
Selected Traits ◽  
High Degree

Abstract The purpose of the paper was to determine phenotype and genotype variability of yield components structure (number of grains, grain mass and 1000 grain weigh) as well as of the basic technological traits (sedimentation number, falling number, protein percentage content per grain). The research also considered the issue of pre-harvest sprouting. During each vegetation season rainfall and temperature were recorded. The examined material were the strains of F6 - F7 generation. Coefficients of correlation between the values of particular traits and mean temperatures and rainfall sum during a given season showed that yield component parameters were significantly modified by temperature; whilst warm vegetation seasons proved to be beneficial. Negative correlation between the rainfall sum and the number of grains and grain mass as well as 1000 grain weight suggests that the excess of water may be more detrimental for the yield than its shortage. Coefficients of correlation between the values of basic technological parameters and mean temperature were negative and not very high or low or even – insignificant, as in the case of falling number. High h2 coefficients suggest a good heritability of yield components parameters, and yield per ear seem to be the trait that was transmitted best. Amongst the basic quality indicators, the highest heritability was observed in the case of falling number and the lowest one in the case of sedimentation number. The weakest genetic conditioning was observed in the case of resistance to sprouting, measured as the percentage of sprouting grains in the ear. It seems therefore that genetic variability was, to a large degree, masked by the environmental impact and, in spite of a high degree of genetic conditioning, the effectiveness of selection based on a visual evaluation of the forms rated for further cultivation might be limited.

scholarly journals RADIATION RESISTANT BINDING MATERIALS BASED ON SILICATE ALUMOBARIUM CEMENTS

2020 ◽  
Vol 1 (154) ◽  
pp. 67-70
Author(s):  
N. Tsapko
Keyword(s):  
Physical And Mechanical Properties ◽  
High Strength ◽  
Technological Parameters ◽  
Protective Properties ◽  
Initial Strength ◽  
Radiation Resistant ◽  
Biological Protection ◽  
Effects Of Radiation ◽  
Main Components ◽  
High Degree

The article analyzes the possibility of developing custom binders with a set of set properties. Particular attention is paid to the development of radiation-resistant barium-containing cements based on aluminates and barium silicates. In order to normalize the radiation situation in Ukraine, it is urgent to develop structural materials with specified high protective properties against the effects of radiation, a high degree of biological protection in combination with high strength and fire resistance. The main components of the technological parameters of synthesis of the presented cements are determined. Test results of physical and mechanical properties of refractory radiation resistant cements are presented and general recommendations on the scope of the developed binder materials are given. It is determined that the resulting refractory cement can be used as a bond in the manufacture of special concretes and materials that have high protective properties while exposed to high temperatures and radiation. Thermal stability of concrete based on silicate alumobarium cement with different fillers was determined (cooling of the samples was carried out in air). As a result of the tests, it was found that all concrete specimens withstood more than 20 cycles (1000 ° C - air), while maintaining more than 80 % of the initial strength. These results confirm the known pattern: the higher the material density, the greater the material's ability to absorb radiation. Thus, the obtained data allow us to conclude that concrete based on silicate alumobarium cement have high absorption rates of brake radiation, which is more than 1.5 times higher than currently used concrete based on Portland cement. Therefore, it can be concluded that the concretes obtained are radiation resistant, with a high degree of attenuation of gamma rays and can be recommended as protective materials. Keywords: cement, composition, synthesis parameters, radiation resistance, property, strength

scholarly journals Exploring the Relationships between the Topological Characteristics of Subway Networks and Service Disruption Impact

2020 ◽  
Vol 12 (10) ◽  
pp. 3960 ◽  
Author(s):  
Zhiru Wang ◽  
Wubin Ma ◽  
Albert Chan
Keyword(s):  
Significant Relationship ◽  
Rank Correlation ◽  
Data Set ◽  
Service Interruption ◽  
Delay Duration ◽  
Topological Characteristics ◽  
Service Disruption ◽  
High Degree ◽  
The Impact ◽  
The Relationship

Although numerous studies have considered the topological characteristics and the impact of disruptions in subway systems, their results have not been verified by empirical data. To address this limitation, we used a data set containing 392 detailed records of disruptions to subway services in Beijing from 2011 to 2017. The Spearman rank correlation coefficient analysis results indicate that the delay duration exhibits no significant relationship with the topological characteristics, whereas the reverse is true for the relationship between the number of affected trains and the topological characteristics. The results also demonstrate that subway network expansion will not result in a paradox between convenience and vulnerability from an actual data perspective. Moreover, contrary to previous research results, no significant relationship was found to exist between service interruption impact and the transit and key bridge stations. However, a high degree of clustering, characterized by redundant tracks between neighbours, tends to provide protection against service disruption for stations. In terms of the spatial variation, the influence of the disruption is greater when the station is further from the centre of the line. These results can support sustainable design in subway network planning.

Optimization and Design for Parameter in Injection Molding Technology of Cell Shell of Polypropylene

2011 ◽  
Vol 189-193 ◽  
pp. 537-540
Author(s):  
Jia Min Zhang ◽  
Ming Yi Zhu ◽  
Zhao Xun Lian ◽  
Rong Zhu
Keyword(s):  
Injection Molding ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Technological Parameters ◽  
Molding Process ◽  
Melt Temperature ◽  
Injection Speed ◽  
Technical Parameters ◽  
High Degree

The use of L27 (35) orthogonal to the battery shell injection molding process is optimized. The main factors of technical parameters were determined mould temperature, melt temperature, the speed of injection, injection pressure, cooling time.On the basis of actual production, to determine the factors values of different process parameters.Combination of scrapped products in key (reduction and a high degree of tolerance deflated) tests were selected in the process parameters within the scope of the assessment. Various factors impact on the product of the total height followed by cooling time, mold temperature, melt temperature, injection pressure, injection speed from strong to weak .The best products technological parameters were determined.Good results were obtained for production.

scholarly journals Nitrate removal from wastewater generated in wet Flue Gas Desulphurisation Systems (FGD) in coal-fired power generation using the heterotrophic denitrification method

2020 ◽  
Vol 31 (3) ◽  
pp. 27-34
Author(s):  
Krzysztof Iskra ◽  
Łukasz Krawczyk ◽  
Jan M. Miodoński ◽  
Dominika Wierzbicka-Kopertowska
Keyword(s):  
Flue Gas ◽  
Nitrate Nitrogen ◽  
Nitrate Removal ◽  
Oxygen Demand ◽  
Active Surface ◽  
Adaptation Period ◽  
Technological Parameters ◽  
Rate Test ◽  
High Degree ◽  
Heterotrophic Denitrification

Abstract The article presents an assessment of the possibilities of using the heterotrophic denitrification process to remove nitrates from wastewater produced in wet flue gas desulphurisation (FGD) installations and also its optimization in the scope of basic technological parameters. This kind of wastewater is characterized by high salinity (even up to 40,000 g/m3), high temperature (up to 50°C) and low biodegradability, which is expressed by the biochemical oxygen demand (BOD5). The experimental rig consisted of a storage tank and a bioreactor in the form of a bed with an apparatus for measuring basic parameters (temperature, pH, nitrate nitrogen). After an initial adaptation period, a high degree of nitrate nitrogen removal from wastewater (exceeding 95% reduction) was obtained with a reaction time of 180 minutes during the denitrification rate test (NUR). It was also determined that the optimal loading range of the active surface of the bed of 300 m2/m3 should be between 1.5–2.5 gN-NO3/m2·d. The results of the study show that when the required conditions for the development of microorganisms are provided, it is possible to fully adapt the denitrification biomass to the adverse composition of wastewater from wet FGD unit.

scholarly journals 4 Competition (Law Enforcement) and Economic Growth

2020 ◽  
Author(s):  
Cheng Thomas K
Keyword(s):  
Economic Growth ◽  
Law Enforcement ◽  
Developing Country ◽  
Minimum Degree ◽  
Growth Models ◽  
Competition Law ◽  
Competition Law Enforcement ◽  
Conflicting Evidence ◽  
Overwhelming Evidence ◽  
High Degree

This chapter assesses whether competition promotes economic growth. In contemplating the design of competition policy in a developing country, the first question to be answered is whether a policy that aims to maximize competition with competition law enforcement will deliver economic growth and meet the development needs of a developing country. As indicated by all the growth models examined in the previous chapter, the key to economic growth is the ability to create more output for the economy with existing resources; it relies on productivity gains and innovation. The chapter then examines whether competition promotes productivity growth and innovation. Overall, there is overwhelming evidence that increased competition leads to higher productivity and economic growth. There is also very strong evidence that competition law enforcement promotes productivity and economic growth. However, it should be noted that at least one study concludes that competition law enforcement has negligible effect on economic growth. Meanwhile, there is some conflicting evidence as to whether a minimum degree of institutional capacity is needed to allow a country to benefit from the introduction of competition law. One other factor that has been traditionally given a high degree of importance for economic growth in developing countries is foreign direct investment.

High-temperature X-ray diffraction study of Ag2S-Cu2S system

2020 ◽  
pp. 2150018
Author(s):  
Y. G. Asadov ◽  
Y. I. Aliyev ◽  
A. O. Dashdemirov ◽  
S. H. Jabarov ◽  
T. G. Naghiyev
Keyword(s):  
Thermal Expansion ◽  
Phase Transitions ◽  
High Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Cubic Phases ◽  
Temperature Ranges ◽  
Expansion Coefficients ◽  
Xrd Method

Single crystals of AgCuS, [Formula: see text], [Formula: see text] and [Formula: see text] compounds were synthesized using the Bridgman method. The crystal structures and phase transitions were studied by X-ray diffraction (XRD) method in the high temperature ranges. The monoclinic, orthorhombic, hexagonal and cubic phases were observed in the temperature range of [Formula: see text]. Thermal expansion coefficients were calculated for different phases according to the lattice parameters. It was determined that the values of thermal expansion coefficients differ in different planes depending on the space group and symmetry.

scholarly journals Properties of Barium Cerate Thin Films Formed Using E-Beam Deposition

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1152
Author(s):  
Monica Susana Campos Covarrubias ◽  
Mantas Sriubas ◽  
Kristina Bockute ◽  
Piotr Winiarz ◽  
Tadeusz Miruszewski ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Composition ◽  
Electrical Properties ◽  
Total Conductivity ◽  
Barium Cerate ◽  
Technological Parameters ◽  
Thermal Expansion Coefficients ◽  
Mechanical And Electrical Properties ◽  
The Stability ◽  
Strained Films

This article focuses on the properties of the BaCeO3 thin films formed by electron-beam vapor deposition and investigates the formation of barium cerates on supports with different thermal expansion coefficients (Stainless Steel, Invar, Glass Sealing, and Inconel substrates) and the influence of the technological parameters on the properties of the formed thin films with an emphasis on the stability of the films. Morphology and phase composition and mechanical and electrical properties were investigated. It was found that the main factors influencing the phase composition and morphology of the films are the temperature of the support and the deposition rate. However, the mechanical properties of the films are mostly influenced by strains introduced to thin films by using different supports. Two interesting features of the electrical properties of the studied strained films were noticed: the film with the highest in-plane tensile strain showed the lowest activation energy of total conductivity, whereas the film with the lowest strain showed the highest value of total conductivity.

Sign in / Sign up

Export Citation Format

Share Document