•Revealed oxidation features of OM and asphaltenes from rocks of the Permian deposits.•The efficiency of metal complex in processes of transformation of rock‘s OM is shown.•By DSC method is shown a ...decrease in initial temperature of asphaltenes oxidation in catalytic experiment.•Revealed a decrease in activation energy of asphaltenes in catalytic hydrothermal experiments.•Thus oil-bearing potential of Permian deposits can be realized using by catalytic thermal methods.
In this work, on the example of rock samples from Permian deposits of the heavy oil field from the depth interval 117.5–188.6 m, a comprehensive study of the composition of oil-saturated rocks, as well as thermogravimetric parameters and kinetics of oxidation of organic matter (OM) and extracted asphaltenes before and after catalytic hydrothermal treatment was carried out of the rocks. It was shown that rocks with different mineral composition, OM content, and group composition of oil extracts also have different quantitative characteristics of the thermal effect in the processes of OM oxidation. According to the DSC data in the range of 20–600 °C in air atmosphere, several exothermic effects of chemical reactions of OM at stages low-temperature (LTO) and high temperature oxidation (HTO) oxidation were fixed indicating various destructive processes. By the TG/DTG method was shown that asphaltenes, regardless of the chemical nature of OM, have a similar and almost identical set of mass loss peaks. Catalytic hydrothermal treatment of the rock samples at 300 °C in CO2 media in the presence of a catalytic composition based on transition metal carboxylates (Fe, Co and Cu) led to a significant increase in the content of saturated and aromatic hydrocarbons in produced oil extracts due to the intense destruction of resins and asphaltenes. The presence of the catalyst composition in the reaction system leads to a decrease in the initial temperature of asphaltenes oxidation by almost 10 °C, as well as to a decrease in the activation energy by more than 1.5 times as compared to asphaltenes from the original rock. The research results show that the use of thermal and catalytic methods is promising for the successful implementation of the residual oil-bearing potential of productive strata of the Permian deposits of Tatarstan.
The current state of the rheology of various polymeric and other materials containing a high concentration of spherical solid filler is considered. The physics of the critical points on the ...concentration scale are discussed in detail. These points determine the features of the rheological behavior of the highly filled materials corresponding to transitions from a liquid to a yielding medium, elastic-plastic state, and finally to an elastic solid-like state of suspensions. Theoretical and experimental data are summarized, showing the limits of the most dense packing of solid particles, which is of key importance for applications and obtaining high-quality products. The results of model and fine structural studies of physical phenomena that occur when approaching the point of filling the volume, including the occurrence of instabilities, are considered. The occurrence of heterogeneity in the form of individual clusters is also described. These heterogeneous objects begin to move as a whole that leads to the appearance of discontinuities in the suspension volume or wall slip. Understanding these phenomena is a key for particle technology and multiphase processing.
This study assesses the possibility of grassland monitoring based on various spectral vegetation indices (NDVI, ClGreen, NDRE, and NDMI) calculated according to Sentinel-2 satellite data during the ...2018 growing season. Geobotanical studies and the collection of ground-based spectrophotometry data were carried out simultaneously, at the same time of day, and were used as an additional stage of monitoring haymaking. It was possible to identify grasslands and determine the date of mowing based on ground and satellite spectrometric data. A drop in the indices (NDVI, clGreen, NDRE, and NDMI) was observed on the date of mowing (July 25, 2018). The possibility of grassland interpretation based on the NDVI index was proven reliable. It was shown that the dates of mowing, determined according to satellite data, were in good agreement with the ground dates of mowing (July 25 and August 27). The spatial distribution maps of the NDVI index of grasslands according to Sentinel-2 satellite data for certain dates (June 18, July 10, and August 27) were drawn. The resulting maps make it possible to identify grasslands and mowing dates in large areas.
Paper provides a comparative analysis of three nuclear power plants: Novovoronezh NPP in Russia, Kudankulam NPP in India, and Bruce NPP in Canada. The basic parameters (site plan, biosphere ...diversity, types and capacity of reactors, amount of electricity generated and its cost) are compared. Types of waste generated at all three nuclear power plants and methods of their treatment are analyzed. Brief overview of some of the security systems used at these power plants is conducted. On the basis of comparative analysis, proposals for improving the environmental situation in the Novovoronezh NPP region (e.g. improvement of the wastes management) are made, with the proposal of nuclear fuel cycle scheme enhancement.
This paper presents the results of a study assessing the degree of weed infestation of wheat crops. They are obtained using optical ground-based and satellite spectral data with a 3-m spatial ...resolution from PlanetScope Dove satellites for 2019. The vegetation indices, including the normalized difference vegetation index (NDVI), the relative chlorophyll index (Chlorophyll Index Green—ClGreen or GCI), the modified soil-adjusted vegetation index (MSAVI2), and the visible atmospherically resistant index (VARI) are used in the interpretation of ground-based spectrometric and space images. This paper indicates the possibility of assessing the degree of weed infestation of agricultural fields. The higher the weed infestation, the lower the index values. The dynamics of VARI is found to be different from the dynamics of NDVI, ClGreen, and MSAVI2 during the growing season. The strong correlation between NDVI, ClGreen, and MSAVI2 and the weak correlation between VARI and other indices are observed. The possibility of identifying weedy sites in the agricultural fields is shown using the spatial distribution map of ClGreen dated August 2, 2019.
This article presents the surface morphology effect of silicon carbide (SiC) particles on the polyurethane binder’s structure formation in a dispersed-filled composite. The difference in the ...morphology and surface relief of filler particles was ensured by the implementation of plasma chemical modification. As a result of this modification, the filler consisted of core-shell particles characterized by a SiC core and a carbon shell (SiC@C), as well as a carbon shell decorated with silicon nanoparticles (SiC@C/SiNP) or nanos (SiC@C/SiNW). The study of the relaxation properties of polyurethane composites has shown that the strongest limiting effect on the molecular mobility of boundary layer’s chain segments is exerted by a highly developed surface with a complex relief of SiC@C/SiNP and SiC@C/SiNW particles. An empirical method was proposed to find the polymer fractions spent on the formation of the boundary, transition and bulk layers of the polymer matrix in the composite. It was shown that the morphology of the filler particles’ surface does not affect the dependence of the boundary layer thickness on the filler’s volume fraction. However, with an increase in the degree of surface development, the boundary layer thickness decreases.
A technology is proposed for producing electrochemically and electromagnetically activated water and, from the standpoint of resource saving, high-quality cement composite materials. The results of ...the physicochemical analysis and morphology of the sediment of naturally non-mineralized water activated by different regimes are presented. A quantitative and qualitative X-ray phase analysis, as well as the results of the study of the microstructure of cement stone samples based on mixing water activated in different modes, are given. The strength indicators of cement stone, mortar and concrete samples were established, and the results of a study of the water resistance of cement composites made with the use of activated mixing water were presented. It has been established that electrochemical and electromagnetic activation of mixing water contributes to a change in its physicochemical properties, influences the structure-forming factors of the cement stone and contributes to the improvement of the strength and performance indicators of cement composite materials.
Carbonate-Quartz Cement Composites Erofeeva, V; Emelyanov, D V; Bushes, M A S ...
IOP conference series. Materials Science and Engineering,
11/2020, Letnik:
972, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The technology of obtaining multicomponent high-quality concrete using limestone powders as fillers is considered. In order to select fillers for powder-activated concrete, a study was made of the ...water absorption of limestone gravel of various kinds. According to the water absorption index, eight categories of limestone species have been identified. It was revealed that organogenic limestone is one of the materials that is preferred as a filler for high-quality concrete. The experimental results were obtained and graphical dependences of changes in the tensile strength under bending and compression, the dynamic modulus of elasticity and water demand of organogenic cement composites filled with limestone from granulometric composition and filler content were constructed. It has been established that the best strength properties are manifested in materials with optimal indicators of the content and size of limestone and silica powder.
The paper presents the results of tests of cement composites under the conditions of cyclic exposure to negative and positive temperatures for 45 days. The stability factor (durability) compares the ...compositions with various fillers and additives. Resistance (long-term preservation of the structure and properties) of composites was estimated from the change in the relative hardness of the material, characterized by the area of the polygon, obtained as a result of a piecewise linear approximation of the exposure points of the test materials.
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