Principal Difference Research Articles

Линия методологических и прикладных разработок российской культурно-исторической клинической психологии, ориентированной на работу с индивидуальным случаем

In the Russian cultural-historical psychology (in the clinical psychology, first of all), there was a bunch of studies based on the exploration of individual (singular) case. The article focuses on analysis of those studies and demonstrates principal difference of the approach used in them from other methodologies and approaches to the analysis of individual case. Russian perspective was originally based on the fundamental ideas of Lev S. Vygotsky; nevertheless, they were not sufficiently reflected in the Russian psychology. Examining Vygotsky’s texts, the authors discuss more profound reflection and further development of Vygotsky’s ideas as applied to the analysis of the individual case in the cultural-historical psychology. The article shows the possibilities to elaborate this approach on the basis of concepts by Lev Vygotsky and Mikhail Bakhtin and gives own studies of the authors as an example of such an elaboration. Furthermore, the article argues that the integration of objective cultural-historical psychology and phenomenology, hermeneutics, dialogical psychology would be of significance if developed in the direction of cultural-historical psychology of Vygotsky — Bakhtin. Such an approach allows to address general psychological issues and opens up new opportunities in certain applied studies in the field of cultural-historical psychology.

Juri Lotman, Gilles Deleuze and their approaches to cinema: Points of intersection

Engaging with the methods of studying contemporary digital audiovisual art is a dominant topic in contemporary theories of art. Against this background, the article offers a view onto some aspects of Juri Lotman’s and Gilles Deleuze’s studies on the cinema.
 As a rule, contemporary studies of digital audiovisual art take place in the context of interdisciplinary studies. One of the methodological principles of such studies consists in adopting a structural and semiotic approach. As of today, this methodological approach to studying audio-visual art is most developed in semiotics of the cinema, which is why in this article visual semiotics in general is viewed through semiotics of the cinema (proceeding from the approach of Juri Lotman). Also, the philosophical understanding of the nature of the cinema offered by Gilles Deleuze has proven fundamental for the study of contemporary audio-visual art.
 The two authors were contemporaries, but represented different scholarly paradigms: while Juri Lotman was an adherent of structuralism, Gilles Deleuze was a poststructuralist who criticized the structuralist approach. Yet despite this principal difference, both scholars still arrived at similar conclusions as concerns several questions regarding the understanding of the cinema and its very nature. In the present paper I focus on the features of these authors’ approach to spatial and temporal relations in the cinema, audiovisual relations in film as a heterogeneous form of the work of art, virtuality and mythologism in the viewer’s perception of cinema.
 The differences and similarities in academic approaches to cinema, developed by Lotman and Deleuze, indicate a common direction in the development of the cinema and visual arts theory, which seems relevant for the study of contemporary audio-visual arts.

Substantiation of the Erdenetiyn-Ovoo copper-molybdenum ore flotation technology with the use of tertiary acetylene alcohol

The article presents the results of a study of the factors affecting the efficiency of the copper-molybdenum ore flotation. The objective of this work was to substantiate and develop a reagent mode for flotation of the Erdenetiyn-Ovoo porphyry copper ores, which makes possible extracting main copper and molybdenum minerals into corresponding concentrates more fully and selectively. It is shown that the use of a DC-80 (2-methyl-3-butin-2-ol) flotation reagent in assosiation with the main base mode reagents — an AERO MX-5152 (a mixture of allyl ethers of xanthogenic acids with n-butyloxycarbonyl-O-n-butylthionocarbamate) combined nonionized collector, a BK-901B (a composition of dialkyldithiophosphate and O,N-dialkyldithiocarbamate) blending ionized collector; diesel fuel; a MIBC (methyl isobutyl carbinol) frother; sodium sulphide Na2S as a modifier and lime СаО as a pH regulator of the medium allows obtaining a noticeable, economically sound additional recovery of both copper and molybdenum. Quantum chemical calculations have permitted to establish an important feature of the mechanism of interaction between the DC-80 molecules that can form stronger complexes based on -bonds with metal cations of sulfide minerals in comparison with allyl ethers of xanthogenic acids. The energy indicators of the formation of bonds between Cu2S, the DC-80 molecules and allyl ether of xanthic acid were calculated. There were shown the models of the assumed interaction of small mineral particles with air bubbles during flotation, which are determined by physical and chemical properties of the molecules of acetylene-containing reagents. The principal difference between the properties of the foam bubbles formed by acetylene-containing molecules for at least 50% and that of the ordinary foam bubbles formed by standard frothers has been demonstrated in the view of the mechanism of their fixing on the surface of small particles of sulfide minerals and the surface of the bubbles. The optimal flotation mode, comprising a DC-80 reagent, BK-901B and AERO MX-5152 base collectors has been developed. The application of this mode will allow increasing the copper and molybdenum recovery into concentrates by 0.62% and 5.76%, respectively, reducing the flotation time by 35–40%, and improving the quality of resulting concentrates. Based on the research results, it is recommended to incorporate the DC-80 acetylene reagent into the basic flotation mode for conducting pilot tests at the Erdenet Mining Corporation enterprises (Mongolia).

Single Crystal X-ray Diffraction Studies of Two Polymorphic Modifications of the Dicarbonyl-o-Semiquinonato Rhodium Complex at Different Temperatures. Destruction Stimulated by Cooling Versus Stability.

It was found that the dicarbonyl-rhodium-o-semiquinonate complex (which thread-like crystals can bend reversibly under light/warm activation) can form two polymorphic modifications: isometric prisms (1) and sticks (2). Some thin sticks can bend as mentioned above. X-ray diffraction studies of polymorphic modifications at different temperatures were carried out. It was found that crystals 1 are destructed after cooling to 110 K as opposed to crystals 2. In turn, the reversible phase transition is detected in 2. In both polymorphic modifications, stack packaging motifs through the direct Rh–Rh bond are observed. The principal difference between packages of polymorphic modifications is that molecules 1 in the adjacent stacks are shifted relative to each other along the stack, in contrast to crystal 2. It was found that different packing of stacks leads to different anisotropic compression of crystals 1 and 2 during cooling, which is a key factor of their stability. Using the molecular invariom approach, the nature of the chemical bonds and charge distribution was investigated; the energy of the Rh–Rh bonds was estimated.

Stability Analysis and Derived Control Measures for Rock Surrounding a Roadway in a Lower Coal Seam under Concentrated Stress of a Coal Pillar

Numerical simulations have often been used in close-distance coal seam studies. However, numerical simulations can contain certain subjective and objective limitations, such as high randomness and excessively simplified models. In this study, close-distance coal seams were mechanically modeled based on the half-plane theory. An analytical solution of the floor stress distribution was derived and visualized using Mathematica software. The principal stress difference was regarded as a stability criterion for the rock surrounding the roadway. Then, the evolution laws of the floor principal stress difference under different factors that influence stability were further examined. Finally, stability control measures for the rock surrounding the roadway in the lower coal seam were proposed. The results indicated the following: (1) The principal stress difference of the floor considers the centerline of the upper coal pillar as a symmetry axis and transmits radially downward. The principal stress difference in the rock surrounding the roadway gradually decreases as the distance from the upper coal pillar increases and can be ranked in the following order: left rib > roof > right rib. (2) The minimum principal stress difference zones are located at the center of the left and right “spirals,” which are obliquely below the edge of the upper coal pillar. This is an ideal position for the lower coal seam roadway. (3) The shallowness of the roadway, a small stress concentration coefficient, high level of coal cohesion, large coal internal friction angle, and appropriate lengthening of the working face of the upper coal seam are conducive to the stability of the lower coal seam roadway. (4) Through bolt (cable) support, borehole pressure relief, and pregrouting measures, the roof-to-floor and rib-to-rib convergence of the 13313 return airway is significantly reduced, and the stability of the rock surrounding the roadway is substantially improved. This research provides a theoretical basis and field experience for stabilizing the lower coal seam roadways in close-distance coal seams.

Slow deformation waves in an elastoplastic medium with faults

Slow deformation waves are excited mainly by natural processes in the Earth’s crust and lithosphere and are manifested in changes in the seismic regime and geophysical fields. There are two main types of slow deformation waves: inter-fault and intra-fault. The principal difference in the nature of the propagation of these zones is that in the case of transmission of deformation excitation from fault to fault (inter-fault wave) the speed value is in the range from 20 km/year to 30 km/year or more. If the excitation of processes occurs within a single fault zone (intra-fault wave) the speed varies from 10 km/year to 4 km/year or less. Structural maps of the model medium with faults were used to study the generation and propagation of inter-fault slow deformation waves. A mathematical model proposed by P. V. Makarov was used to perform test calculations for the generation and propagation of slow deformation waves in nonlinear elastic-plastic media. The features of the propagation of deformation waves are investigated for different fault positions in the calculation region. It is shown that the propagating fronts of slow perturbations in the medium have different shapes depending on the location of the faults in the calculation regions. The zigzag nature of the wave front is revealed in a medium with faults in the center. When fault ends are located near the boundary of the calculation region, they have a quasi planar shape.

Simulation of the Intrusion Process and Extrusion of Non-Wetting Liquid From Porous Media in Quasi-Static Mode

To understand the thermodynamics, transport and physical phenomena in porous media today, the most effective way is to use various models of porous media and conduct numerical experiments on their basis. It has been shown that such models are an effective tool for research of transport processes from the local scale at the level of individual pores to the level of individual granules. The approach proposed in this paper is based on numerical calculations based on known theoretical approaches. The principal difference from the previously used approaches and novelty lies in the absence of simplifications associated with the narrowing of the distribution of pores in size and the number of nearest neighbors, which allows us to take into account in detail the possible geometric configurations, when the pore of the same radius can be surrounded by a different number of neighboring pores. In addition, the use of numerical modelling allows us to obtain a large number of different parameters, ranging from structural characteristics (the number of nearest neighbors, connectivity, etc.), cluster (percolation thresholds) and ending with volume dependencies on pressure and time and the visualization of filling processes.

Промышленная и лабораторная технологии производства жидкого сернистого ангидрида на основе серы и кислорода.

The article tells about the industrial unit for production of liquid sulfur dioxide based on sulfur and oxygen, which has been developed by Research Institute of Fertilizers and Insectofungicides(patent No. 2711642 dated 01/17/2020). The principal difference of the proposed industrial process is the use of technical oxygen instead of FDF and the use of a sulfur furnace and a sulfur vapor condenser combined in one housing. To determine the design parameters of equipment and to master the process, the article describes a lab unit for production of liquid sulfur dioxide, developed by and implemented at Research Instituteof Fertilizers and Insectofungicides. At the moment, the lab unit is run to adjust the operating mode.

DNA Transformation, Cell Epigenetic Landscape and Open Complex Dynamics in Cancer Development

Statistical thermodynamics allowed the formulation of mesoscopic approach of DNA transformation in course of the excitation of collective distortion modes (denaturation bubbles) associated with hydrogen bond breaking between the base pairs. Intermediate (non-continual limit) of DNA modeling (the Peyrard-Bishop model) is combined with the field description (generalized Ginzburg-Landau approach) to analyze the dynamics of collective open complex modes associated with mesodefects in the DNA ensemble. Collective modes dynamics describes different scenario of gene expression according to statistically predicted form of out-of-equilibrium potential (epigenetic landscape) reflecting specific type criticality of “soft matter” with mesodefects (open complexes) – the structural-scaling transition. Principal difference of thermodynamics of non-continual and continual models is thermalization conditions related to thermal fluctuations responsible for the DNA breathing (localized excitation with breather dynamics) and structural-scaling parameter responsible for spinodal decomposition of out-of-equilibrium potential metastability due to generation of open complex collective modes. Open complex collective modes have the nature of self-similar solutions (breathers, auto-solitary and blow-up modes) of open complex evolution equation accounting qualitative different types of potential metastabilities. Sub-sets of collective modes represent the phase variables of attractors associated with different scenario of expression dynamics, which allows the interpretation of multistability of the epigenetic landscape and the Huang diagram of gene expression. It was shown different epigenetic pathway in attractors phase space corresponding to normal and cancer expression scenario. These scenarios were supported by laser interference microscopy of living normal and cancer cells illustrating multi- and monofractal dynamics.

Language Awareness in Italian Secondary Schools How Do Students Approach Language Awareness Tasks and What Kind of Language Awareness Emerges from Their Reflections?

The present paper aims to explore how students of Italian secondary schools approach linguistic tasks and what sort of knowledge about language emerges from their analyses. These questions arise from the observation of the results of the Invalsi tests. In order to examine how students construct their answers to a sample of language awareness questions, they were asked to explain how to answer them by making a tutorial video. The videos were discussed during a semi-structured interview. The data were transcribed and analysed by means of Qualitative Content Analysis. The results indicate that the principal difference between students relates to the stability of their “engagement with language” and their ability to switch their attention between different levels of linguistic analysis.

Ecological Population Status of the Most Common Bird Species in Northern Altai Low-Mountain Forests and the Principal Difference in Avifauna Status in Altai and Baikal Regions

In 2016 and 2017, from April to July, bird individual nesting home ranges were regularly mapped along the permanent census route (2.8 km) in the low-mountain forests dominated by pine and birch. For each bird species, the nesting densities and average sizes of the bird individual nesting home range were estimated, and raster maps of spatial allocation (MSA) at the scale of the raster grid of 50 × 50 m were obtained. The degree of spatial conservatism (DSC) for each local population was inferred from the pairwise comparisons of the specific MSAs obtained at the same area (28 ha) in different years with the use of the Gamma rank correlation method. The statistical dependence of the population habitat area on DSC was demonstrated earlier (Cherenkov, 2017). The more habitat area is found within the trial plot, the less dependent (random) the individual spatial allocation within a population is observed in different years. Significant DSC estimates (p < 0.05) were obtained for 15 species, and their habitat areas and habitat saturation were found. The population status was inferred from the degree of habitat saturation. Average estimates of the degree of habitat saturation were close in migratory and nonmigratory species (49 and 45%, respectively). The Altai migratory birds wintering in Southeast Asia did not differ statistically in the degree of habitat saturation from those wintering in Southern Europe and North Africa. A comparison of avifauna status of the Altai and Baikal regions revealed substantial differences. In Altai the number of the most common migratory nesting species is almost twice as high, their average nesting density is four times higher, and habitat saturation is twice as high as in the birds of the Baikal region. The interregional differences in the degree of habitat saturation indicate that most of populations of the migratory species of the Baikal region are subject to twice as much intensive pressure of some factors limiting the population growth compared to the Altai populations. At the same time, there were no significant differences in the ecological population status of the nonmigratory species between these regions. Close estimates of the degree of habitat saturation in nonmigratory species in the Altai and Baikal regions support a suggestion that the integrate influence of factors limiting their population numbers is similar in both regions. Close estimates of the degree of habitat saturation and nesting density in the migratory and nonmigratory Altai species show that neither of the two strategies of surviving gives a pronounced advantage. The difference between the Altai and Baikal regions in the degree of habitat saturation in the migratory species is seemingly determined by the different mortality levels in the wintering areas and on the routes of migrations.

Effect of Strain Rate on Microstructure Evolution and Mechanical Behavior of Titanium-Based Materials

The goal of the present work is a systematic study on an influence of a strain rate on the mechanical response and microstructure evolution of the selected titanium-based materials, i.e., commercial pure titanium, Ti-6Al-4V alloy with lamellar and globular microstructures produced via a conventional cast and wrought technology, as well as Ti-6Al-4V fabricated using blended elemental powder metallurgy (BEPM). The quasi-static and high-strain-rate compression tests using the split Hopkinson pressure bar (SHPB) technique were performed and microstructures of the specimens were characterized before and after compression testing. The strain rate effect was analyzed from the viewpoint of its influence on the stress–strain response, including the strain energy, and a microstructure of the samples after compressive loading. It was found out that the Ti-6Al-4V with a globular microstructure is characterized by high strength and high plasticity (ensuring the highest strain energy) in comparison to alloy with a lamellar microstructure, whereas Ti6-Al-4V obtained with BEPM reveals the highest plastic flow stress with good plasticity at the same time. The microstructure observations reveal that a principal difference in high-strain-rate behavior of the tested materials could be explained by the nature of the boundaries between the structural components through which plastic deformation is transmitted: α/α boundaries prevail in the globular microstructure, while α/β boundaries prevail in the lamellar microstructure. The Ti-6Al-4V alloy obtained with BEPM due to a finer microstructure has a significantly better balance of strength and plasticity as compared with conventional Ti-6Al-4V alloy with a similar type of the lamellar microstructure.

Plant Responses to a Daily Short-term Temperature Drop: Phenomenology and Mechanisms

The review analyzes and generalizes literary data and the authors’ results demonstrating the principal difference in plant responses to low-temperature treatments of two different types: (1) long-term constant chilling and (2) short-term daily cooling (temperature drop). The literature indicating the specificity of plant responses to temperature drops as related to their parameters (intensity, duration, and timing in a diurnal cycle) is discussed. Environmental effects on plant responses to temperature drops are also considered. Peculiarity of responses to temperature drops of the plants representing the groups different in their relation to temperature and light are analyzed. Physiological and biochemical mechanisms of plant responses to temperature drops are discussed.

The Effect of Dissolved Cavern on the Fracture Propagation in Vuggy Carbonate Reservoir

Abstract The acid-fracturing is applied wildly to simulate the formation in vuggy carbonate reservoirs. But it does not figure out clearly the mechanism of fracture propagation while fracture encountering dissolved cavern, and there are few researches considering the influence of dissolved cavern on fracture propagation. In order to study fracture propagation regularity in vuggy carbonate reservoirs, numerical simulations are carried out by the seepage–stress–damage coupling equation based on the damage mechanics theory and the accuracy of the model is validated by comparison with experimental results. Some factors influencing the fracture propagation such as dissolved cavern, formation parameters, and construction parameters are considered. The simulation results show that there are four fracture propagation forms after the fracture encountering dissolved cavern, namely, block, crossing over directly, crossing over after deflection, and deflection. The entire process of injecting the pressure curve can be divided into five stages: initial initiation zone, encountering dissolved cavern pressure released zone, the dissolved cavern inside builds the pressure zone, re-ruptured zone, and fracture propagation zone. The horizontal principal stress difference of the formation controls the tendency of fracture propagation and the generation of branch fractures. It is easy to generate branch fractures under the condition of low horizontal principal stress. The increase in horizontal principal stress limits the deformation of fracture, making it more convenient for fracture to extend toward the maximum horizontal principal stress. The study results are significant for optimizing fracturing construction plans and improving the probability of connection between fracture and dissolved cavern.

True triaxial hydraulic fracturing test and numerical simulation of limestone

Hydraulic fracturing, as a key technology of deep energy exploitation, accelerates the rapid development of the modern petroleum industry. To study the mechanisms of hydraulic fracture propagation and rock failure mode of the vertical well hydraulic fracturing, the true triaxial hydraulic fracturing test and numerical simulation are carried out, and the influence of the principal stress difference, water injection displacement, perforation angle and natural fracture on fracture propagation is analyzed. The results show that the fracture propagation mode of limestone is mainly divided into two types: the single vertical fracture and the transverse-longitudinal crossed complex fracture. Under high displacement, the fracturing pressure is larger, and the secondary fracture is more likely to occur, while variable displacement loading is more likely to induce fracture network. Meanwhile, the amplitude of acoustic emission (AE) waveform of limestone during fracturing is between 0.01 and 0.02 mV, and the main frequency is maintained in the range of 230–300 kHz. When perforation angle θ=45°, it is easy to produce the T-type fracture that connects with the natural fracture, while X-type cracks are generated when 0=30°. The results can be used as a reference for further study on the mechanism of limestone hydraulic fracturing.

Simulation of fracture propagation and optimization of ball-sealer in-stage diversion under the effect of heterogeneous stress field

Ball-sealer in-stage diversion in horizontal wells is a key technique to realize the uniform stimulation of fractured sections in tight oil and gas reservoirs. So far, however, there are fewer research results on the propagation morphologies of multi-cluster fractures after the implementation of different ball-sealer in-stage diversion processes during the fracturing treatment, which results in less theoretical support for the preparation of field ball-sealer in-stage diversion process and measures and impacts its application effects in the fracturing field. To deal with this situation, this paper established a fully coupled “wellbore–perforation–fracture propagation” model of horizontal wells on the basis of the boundary element method. Then, a method for calculating the allocation of ball sealers was proposed. Finally, the number of ball sealers, diversion time and number of diversions during the intra-stage temporary plugging and diversion under the condition of initial heterogeneous stress field and their effects on the propagation of multi-cluster fractures were simulated. And the following research results were obtained. First, the flow restriction of perforation friction can counterbalance the intake difference caused by the induced stress interference so that the friction difference applied on the fluid flow in each fracture cluster is reduced. Second, when the effect of the heterogeneous distribution of the initial stress field is taken into consideration, the liquid intake of each fracture cluster changes greatly and even ineffective perforation clusters without liquid incoming appear in the high-stress region. And after the ball is injected, new fractures are initiated from the ineffective perforation clusters. Third, when the initial minimum horizontal principal stress difference (Δσh) is higher than 3 MPa, it is beneficial to reduce the non-uniform propagation of each fracture cluster by increasing the number of ball sealers appropriately in the middle stage of the construction (over half of the total perforations of each stage) or carrying out temporary plugging in the early–middle stage (including ball injection in batches in the early–middle stage). Fourth, when Δσh is lower than 2 MPa, it is necessary to reduce the number of ball sealers or inject balls in the middle–late stage, or the non-uniform propagation of each fracture cluster will be aggravated.

Study on the Stage Failure Mechanism and Stability Control of Surrounding Rock of Repeated Mining Roadway

China is one of the leading countries in the mining and utilization of coal resources, and the problems of coal-mining technology and safety have been concerned by the world, while the serious deformation and destruction of surrounding rock and the difficulty of support have brought inconvenience to the mining of coal resources due to repeated mining. This paper takes the actual engineering 22205 mining roadway in Buertai mine as the research background, through the combination of numerical simulation and field measurement. In this paper, the stress environment, plastic zone, and surrounding rock deformation in the advancing process of coal-mining face are studied, and the stress evolution law of surrounding rock in repeated mining roadway is obtained. It is clarified that the surrounding rock deformation is the failure mechanism under the combined action of principal stress difference and stress direction deflection. As a result, the surrounding rock of the roadway is asymmetrically deformed and destroyed, and the corresponding surrounding rock control scheme is put forward. The results show that the influence of repeated mining on roadway stress environment can be divided into four stages with the mining process: the stability stage of mining influence, the expansion stage of primary mining, the stable stage after primary mining, and the expansion stage of second mining. At the same time, the shape changes of the plastic zone and the displacement monitoring results of the monitoring are analyzed, and the results are obtained; the stage of stress change is suitable, and combined with the failure characteristics of surrounding rock in each stage, it is put forward that reinforcement measures should be taken in the stable stage after mining; the specific reinforcement scheme is determined according to the expansion form of plastic zone and field measurement. The on-site monitoring shows that there is no roof fall accident during the use of the roadway, which ensures the safety in production.

The in situ stress field and microscale controlling factors in the Ordos Basin, central China

To ensure the effectiveness of fracturing treatment and improve the production reserves of individual wells, it is important to accurately predict the in situ stress distribution to prevent the collapse of horizontal wells. From the perspective of reservoir development, under similar structural environments, microscopic factors, such as reservoir and petrophysical characteristics, are often the key factors that affect reservoir fracturing differences and drilling design in different well areas. Therefore, we need to understand the microscopic factors that affect the distribution of in situ stress. Here, we have determined the three-dimensional distribution of in situ stress in the Ordos Basin of China through the finite element numerical simulation method and revealed the influencing factors. By establishing a reservoir heterogeneity model and a geomechanical heterogeneity model and with the finite element method, the 3D distribution of reservoir physical parameters and in situ stress can be predicted, and the effects of the reservoir physical properties, fluid properties, rock acoustic velocity and mechanical properties on the in situ stress can be determined. The clay content is found to be negatively correlated with the horizontal stress difference (Δσ) and horizontal principal stress difference coefficient (Kh). Rock density, porosity, and permeability have little effect on Δσ and Kh. Fluid properties affect the in situ stress magnitude. If the water saturation is greater than 60%, this parameter has a negative correlation with Δσ and Kh. Poisson's ratio has a weak effect on Δσ but a significant negative correlation with Kh.

Artistic Reality in the Space of Digital Technologies: Towards the Problem of Art Criticism

The article is devoted to the comparison of two realities – the digital and the artistic. We demonstrate the principal difference in the mechanisms of their creation. Contemporary artistic practice and theory are undergoing changes to reflect cultural and technological transformations. Today, digital technologies are ubiquitous and widely used in documenting artworks, making them popular and widely available. Also, digital technologies that work with more subtle tools and materials become especially popular and open new horizons for art. However, the structure of digital technologies does not, and possibly never will, enable a living energy impulse of the artwork to become a part of the virtual world. The nature of digital reality is rooted not in the rhythmic but in algorithmic elements, thus putting limitations to what can be achieved through such methods. We discuss the role of a work of art as a biogeochemical factor and the role of digital technologies in deeper connection between viewers and artworks.&#x0D; Keywords: artistic reality, digital reality, ”living matter”, computer graphics, theory of art.

New algorithm to simulate fracture network propagation using stationary and moving coordinates in naturally fractured reservoirs

AbstractInfluenced by natural fractures, fracture networks may be created when hydraulic fractures propagate in naturally fractured reservoirs. Simulating fracture network propagation is crucial to fracture design. In this paper, a two‐dimensional mathematical model for the direct simulation of fracture network propagation that considers fluid filtration and reservoir fluid flow is developed, and a simulation method is proposed based on the coupled flow idea of natural fractures and matrices in dual‐porosity media. The model uses dynamic coordinates to represent the extended hydraulic fracture network and static coordinates to describe natural fractures that have not been activated. The activation of natural fractures by a hydraulic fracture is determined according to the hydraulic fracture propagation scenario after an intersection with natural fractures. The geometric shape and size of the network fracture are obtained by changing the size of the simulated area and solving the mass balance, fracture width, and reservoir fluid flow equations numerically in a coupled manner. After validating the new model, a parameter sensitivity analysis is conducted to study the effects of injected fluid volume, fracture height, fracture spacing, elastic modulus, horizontal principal stress difference, pumping rate, and fracturing fluid viscosity on the fracture network shape, fracture network size, average fracture width, and fracture‐reservoir contact area. The numerical results indicate that the model can be directly used to simulate the propagation of fracture networks. The volume of injected fluid is the most critical factor affecting the fracture network size. Increasing the fluid viscosity and injection rate can increase the width of the fracture network and the average width of a secondary fracture. However, the total contact area of the reservoir and fracture will decrease, and the reservoir‐fracture contact area and fracture network size will increase with a decrease in the horizontal stress difference and increase in elastic modulus. Decreasing a fracture's height can significantly increase the size of the fracture network and reservoir‐fracture contact area.