Home – Home – Jornals – Thermophysics and Aeromechanics 2016 number 6

This study describes the laser generation of a 6G rhodamine in artificial opals representing single-crystal and heterostructure films. The spectral and angular properties of radiation and the threshold characteristics of generation are investigated. In the case where the 6G rhodamine was in a bulk opal, the so-called random laser generation was observed. In contrast to this, the laser generation caused by a distributed feedback inside the structure of the photonic bandgap was observed in photonic-crystal opal films.

The properties of polarization holographic gratings formed in liquid crystal polymer composites doped with nonmesogenic nanoparticles (SiO₂, ZnO, Al₂O₃, and Y₂O₃) are considered. The effect of these additives on the phase transition temperature of liquid crystals of polarization gratings, diffraction efficiency, and driving voltage is demonstrated.

The development of additive technologies and their application in industry is associated with the possibility of predicting the final properties of crystallized added material. The paper describes the problem characterized by a dynamic and spatially nonuniform complexity, which, in the case of uniform decomposition of a computational domain, leads to unbalanced loading on computing cores. The strategy of partitioning of the computational domain is used, which minimizes the CPU time losses in the serial computations of the additive technological process. The chosen strategy is optimal from the standpoint of a priori unknown dynamic computational loading distribution. The scaling of the computational problem on the cluster of the Institute of Laser and Information Technologies (RAS) that uses the InfiniBand interconnect is determined. As a result of using the parallel code with optimal decomposition, it was possible to significantly reduce the computational time (down to several hours), which is important in the context of development of the software package for support of engineering activity in the field of additive technology.

This paper describes the production of analog-digital integral reading circuits for photosignals of hybrid multielement infrared photoreceivers (silicon multiplexers). This work contains the estimation of noise equivalent temperatures of infrared photoreceivers based on multiplexers with frame-by-frame and row-by-row acquisition of signals of photosensitive elements of the spectral ranges 8 to 14 and 3 to 5 m. This paper also presents the development of silicon multiplexers for infrared photoreceivers designed with the use of photodiodes based on the cadmium-mercury-tellurium compound and photodetectors on multilayer structures with quantum wells. The designed multiplexers ensure the use of matrix and ruled photoreceiving crystals, include those with increased dark currents, in order to produce infrared photoreceivers whose temperature resolution corresponds to worldwide standards.

A setup with free oscillations containing a transverse sting for holding the test model and possible test regimes are described. The method of testing and data processing is presented. Aerodynamic characteristics of the pitching moment of the model in a wide range of Mach numbers are obtained. Comparisons of quasi-steady data with numerical predictions and of damping derivatives with those obtained previously in tests of the model mounted on the base sting and with calculated results are performed. The model is found to be statically and dynamically stable except for regimes with М = 1.75 and 2.25, where nondecaying oscillations are excited.

The flow past an axisymmetric body with laminar boundary-layer separation in a low-velocity air stream has been studied. The hot-wire technique was employed to identify the variation of velocity field induced by a local stationary perturbation of separation region at the stern of the experimental model. A large-scale influence upon the near-wall flow due to a cylinder roughness element provided on the model surface was observed. The obtained data substantiate the possibility of controlling the laminar boundary-layer separation on an axisymmetric body using a local external forcing.

Direct numerical simulations of linear and nonlinear stages of the evolution of unstable disturbances of various modes and initial stages of the laminar-turbulent transition in the boundary layer on a flat plate at the freestream Mach number M = 6 are performed on the basis of full unsteady Navier–Stokes equations for a compressible gas. A considerable effect of three-dimensional unstable disturbances on initiation of the laminar-turbulent transition is demonstrated.

The work studies the flow characteristics in a channel with periodic hills on the basis of three algorithms for calculating the flow velocity fields through the images: Particle Image Velocimetry, Particle Tracking Velocimetry, and Pyramid Correlation. Descriptions of algorithms, detailed information about the experiment and parameters of the received data processing, as well as the results of calculations of instantaneous velocity fields at selected time points obtained by corresponding methods are provided. In addition, the presented techniques are compared on the basis of experimental data.

It is experimentally found that shut-in pressure conforms with the fracture initiation pressure if fracture surfaces are uniformly loaded by fluid. The article shows that equaling minimal stress and shut-in pressure in local fractures results in overestimates. The error depends on the length of a hydrofracturing facility and is high under low compression in rocks (5-10 MPa). The authors put forward decisions aimed at improvement of accuracy and enhancement of information content of hydraulic fracturing in the in situ stress measurement.

The authors discuss capabilities of taking information on mechanical processes in geomaterials under post-limiting elastic deformation based on variation in IR radiation intensity. Experimental results on recording of heat emission from specimens of rock salt exposed to cyclic loading by uniaxial compression are reported. It is concluded that thermomechanical effects are useful in recording of onset of failure activation in geomaterials under cyclic loading.

The article describes physical simulation and mathematical modeling of influence exerted by injection of thermogel on configuration of water flow in water flood recovery. Recovery of oil, especially viscous oil, with such method features unstable displacement front and formation of water fingers that eventually turn into a net of water channels directed toward the lowest flow coefficient between wells. Most of oil remains immobile and is in dynamic equilibrium with the displacement water flow. The authors show that injection of thermogel in a reservoir between wells expands displacement front at the late stage of mining, which allows enhancement of oil recovery factor.

The authors describe operation of a laser deformograph within the integrated geodynamic monitoring system in Streltsov Ore Field. Capabilities and design features of the deformograph are discussed. The article demonstrates feasibility of highly accurate measurements of deformation field parameters in an operating mine. Specificity of natural oscillations of the Earth is defined, and deformation of rock mass depending on energy of a destruction source is evaluated.

Considering features of wave pre-destruction (microfailure) of rocks under blasting, the authors put forward a new investigation approach with the use of relations of dynamic elastic stress distribution in rocks and theory of cracks. The obtained relation to estimate pre-destruction zone size in relatively solid rocks under confined explosion involves pressure of gases in explosion chamber, rock pressure, crack resistance of rocks, characteristic dimension of natural jointing (presence of defects) and deformation characteristics of rocks. It is shown that dimension of pre-destruction zone in rocks depends both on natural and production factors and can differ by a few times.

A model of a continuum with a structure described by infinite order equations of motion is proposed. In case that a wave is very long as compared with the size of the structure, equations are reduced to the fourth-order equations. A closed equation of motion, including nonlinear, dispersed and wave members, is derived. It is shown that solutions in the form of soliton waves exist only in media where wave velocity grows with pressure. In the media, where soliton waves do not exist, quasi-stationary solutions with multiple frequencies prevail. It is found that the nonlinear effect of multiple frequencies is unexpectedly high even for small deformation as dispersion violently intensifies nonlinear events. Moreover, in the domain of small deformation, there exist solutions for longitudinal and transversal waves with the same length and different frequencies. The solutions for the same length waves with different frequencies most often occur in seismology and seismic explorations.

The factors that have significant influence on efficiency of rotary-percussion rock drilling with downhole machines are discussed. The results obtained in physical simulation of dynamic driving of rock-breaking indenters in rocks are reported. The results are analyzed from the standpoint of the phenomenon of alternating response of rocks to dynamic impacts.

The article presents a procedure to calculate hydraulic pressure losses in hole drilling with units equipped with replaceable core receivers and using non-Newtonian mud fluids. It is found that main hydraulic loss takes place when mud fluid flows in clearing between a drill string and drill hole walls. Numerical modeling has shown that it is possible to reduce hydraulic pressure loss by 76.5-89.0% by increasing drill string diameter by 2 mm. Based on the analytical research results, diamond drill bits and underreamers with the outer diameters of 78.0 and 78.4 mm, respectively, are manufactured for drilling operations in Talnakh ore field.

Authors review key approaches to designing small-size air drill hammers. The approach to increasing impact capacity of air drill hammers by means of buildup of blow frequency is substantiated. The experimentally obtained and compared characteristics of air drill hammers equipped with the heads made of steel and titanium prove feasibility of increasing impact capacity by means of using low density materials. The technology of thermal treatment of a titanium-alloy hammer head is described, and its laboratory testing results are reported.

This paper presents the methods and test results of the dynamic resistance of chock and rockbolt support used in Poland. By the dynamic resistance of the support is meant the ability to absorb and suppress the fast changing with time load with the value frequently exceeding the working support capacity of the supports. This feature is required when using the support in excavations endangered by rock mass tremors, especially such tremors, which can result in rockbursts. Based on the carried out studies and analyses, numerical values of loads are given that cause the slide of a friction prop, bending the support sections, loss of stability of dog heading support and load-carrying ability of bolts.

The analysis of methods to account for stripping time difference at the stage of determination of limits in deep open pit mining reveals advantages and shortcomings of the methods and provides a principled approach to determination of a discount ultimate stripping ratio for the most representative geological and geotechnical conditions of diamond-bearing ore bodies in the form of single pipes. Discounting of ultimate stripping ratios is based on adding the common formula with an average mean discount coefficient represented by a correlation of mining rate decrease, stripping zone height and highwall slope angle. It is shown that target variation of the factors included in the discount ultimate stripping ratio allows considerable influence on depth and efficiency of open pit mining.

The author characterizes ore production loss depending on time, properties and production technology. Typification of technologies aimed at improvement of ore-drawing quality using canopies is performed. Operating principle of canopies is theoretically generalized, and recommendations on using canopies are made. It is proved that separation of abandoned ore from overlying rocks under canopies during ore-drawing improves mineral production quality.

The article describes the applied research findings on selecting a resource-saving technology to ensure drastic reduction in loss of high-grade Kyshtym quartz. The economical-mathematical modeling yields relationships between mine efficiency, ground conditions, mine design and technology factors, and the optimal variant of a combination mining technology is determined using the maximum profit criterion. Full-scale physical simulation of closed-spaced charge blasting effect on reduction in overgrinding of quartz is discussed. Drilling and blasting pattern for experimental breaking of quartz by explosions is determined.

Using Hammett indicators, X-ray fluorescence spectroscopy and atomic force microscopy, the authors analyze influence of high-voltage nanosecond impulses on structure and chemistry of surface and on process properties of calcium-bearing minerals. As a result of impulse energy inputs for t ≤ 30 s, the change in the structure and functions of mineral surface includes: enhancement of electron-donor capacity and formation of structural defects on the surface of fluorite, and enhancement of acceptor capacity of the surface of calcite and scheelite. Pre-treatment of mono-mineral samples by electrical impulses increases flotation ability of calcium-bearing minerals: increment in froth recovery makes 10–12% for scheelite, 5–6% for fluorite and 7–8% for calcite.

New information is obtained on composition and properties of a bio-reagent-oxidizer generated by mesophilic aerobic chemo-tropholytic bacteria Acidithiobaccilus ferrooxidans under oxidation of iron ions (II) in sulfuric acid solution. The composition and properties of the bio-reagent are compared with iron sulfate (III) used to intensify agitation and heap leaching of metals from sulfide ores and concentrates. The research with IR spectroscopy, mass spectrometry, Moessbauer spectrometry and potentiometry has revealed distinctive features of the bio-reagent and explained the experimentally observed increase in its oxidative activity when interacting with mine.

The article presents data of experimental studies into magnetic properties of iron-bearing sulfide and nonsulfide minerals under radiation and heating. It is found that bulk magnetic susceptibility has increased more than 100 times in pyrite and by 6 times in bauxite ore. Usefulness of radiation-and-heating magnetization in modification and processing of bauxite and tin-bearing minerals is demonstrated.

The article presents data on separation of minerals of eudialyte ore with low magnetic susceptibility using a high-intensity wet magnetic separator and pulp pulsation. The optimal separator variables of the magnetic field inductance, pulp pulsation and matrix filler diameter to ensure maximum efficiency of processing are determined.

The discussed challenge and its prospects in mining geoinformation science are connected with Big Data concept-flows of large sets of various data on mining. The authors describe Big Data technology and its general implementation on mini-clusters using Hadoop and MapReduce with case studies presented.

The presented system is intended for multistage hydraulic fracturing in long open holes of any orientation to create transversal fractures with a radius to 5 m in soft and medium-hard rocks. The downhole system has an inbuilt transport unit. This fracking equipment uses chemically active fluids generated in the fractured interval by mixture of two components injected in individual high-pressure hoses.

The method is based on transcapillary penetration of fluorescent fluid (EpoDye colorant) in the finest cavities and flaws on the surface of polished sections. Luminophor-filed voids become visible under UV light and optical microscope. The voids are estimated with respect to their kinds, sizes and area. The estimates and the statistical property of void distribution are described.

The paper shows that engaging philosophy in solving interdisciplinary problems not only sets new tasks but also opens new opportunities for the development of philosophical knowledge. The author provides justification for using the methods and techniques of philosophical analysis in the solution of interdisciplinary problems. Philosophy in this case can play an integrating role by uniting the approaches of various disciplines and forming a common conceptual basis that would allow the representatives of different sciences to find a common language.

The phenomenon of the rhetorical turn is considered as the third link in the line of the other two theoretical turning points of the development of scientific knowledge in XX century - the linguistic and interpretative turns. The paper discusses the nature of rhetorical turn in relation to the other two, and analyzes its specific features. Among them are a focus on non-disciplinary and meta-disciplinary, more unified arguments, contextuality of methodology, giving greater weight to the principles of Human Sciences and the rejection of the principles of objectivism which are inherent in Cartesian rationality. The paper makes a conclusion about the transition, linked with the rhetorical turn, to a new, communicative type of rationality.

The article analyzes the problem of determining the truth of Godelian sentence in the context of M. Dummett’s semantic argument. N. Tennant’s strategy of avoiding the truth predicate through the deflationary conception of truth is considered in respect to the concept of semantic redundancy. The justification of the truth of Godelian sentence is associated with principles of reflection.

Different theories of de re ascriptions are being discussed in the light of how they do notion specification, if they do. It is shown, that the approach which is not notionally specifying gives such theory of de re ascriptions that it has some implausible consequences, and notionally specifying approach shifts the very understanding of de re ascription.

In the course of the search for the Grand Unification Theory, there happens a change of epistemological standards of experimentation. Which of the two factors primarily influence this change - a social organization of researchers’ teams and relations within them or the nature of the subject of inquiry? We briefly consider how the cognitive status of an experiment, described in terms of such knowledge properties as the objectivity, reliability and validity, changes. We conclude that the transformation of epistemological standards is caused primarily by properties of the subject of inquiry and its epistemological nature.

The paper considers pictures of the world represented in the fundamental physical theories - the classical mechanics, electromagnetic theory, relativity, quantum mechanics, string theory, and the theory of loop quantum gravity. The author shows the laws which scientists use to develop physical models of the world and organizes these laws in the following way: 1) the unification which means an integration of physical categories in a single physical pattern; 2) the simplicity which requires minimizing the number of physical categories; 3) the continuity which means retaining and generalization of the knowledge obtained before; 4) the commentary which is a synthesis of antinomic descriptions of the object; 5) the explanation which means that the physical picture of the world is an explanatory description integrating facts.

The article shows that the conformity principle serves as a factor of unification of physical theories playing both a negative role and a positive one. Its role depends on the purpose of unification which is either an attempt to reduce new data and new conceptions to those which are already accepted or a tendency to elaborating a theory which should include these data and conceptions as a special case. Both situations occur in the course of the development of physical knowledge, but the second one is the most effective in elaborating fundamental theories, while the first one seems to be more reasonable in solving specific scientific problems.

The question of the correctness of the choice of the statistical test, which J. B. Rhine did, is discussed in the article, in connection with the formation of test sequences and with the test procedures. Theoretical study of ways of test sequences generation, and statistical analysis of concrete test sequences that is taken from the protocol of the experiment of 1934, are made. Three ways of test sequences generation: 1) the method based on urn model, random drawings with replacement, 2) the method based on urn model, random drawings without replacement, 3) the method applied by J. B. Rhine, was considered in the article. It is found that the J. B. Rhine’s method provides the independent card extraction trials with uniform probability distribution. It is found that the probability of random guessing of Zener cards in the J. B. Rhine’s experiments depends upon test procedures type (BT 5, BT 25, DT). J. B. Rhine’s Extrasensory perception is examined and discussed with the object to statistical test use. It is found that the applicability of statistical test was chosen by J. B. Rhine, depends upon test procedures type.

The paper reviews the main ideas about geological knowledge beginning with those of the second half of the 19^th century and up to modern ones. We show that in the second half of the 19^th century the philosophical and methodological approach to the problems of geology had a prescriptive character, i.e. it required what geology should be, what it should study and how it should study its subject of inquiry in order to become an exact natural science. In the 20^th century, the philosophy and methodology of geology and geological knowledge focused primarily on understanding the nature of geological methods and proving the scientific character of geology. By analyzing a number of works of both foreign and domestic authors, we revealed two traditions in solving the problem of the scientific nature of geological knowledge; those are Soviet-Russian tradition and British-American one. British-American tradition considers geology to be a historical and interpretative science which interprets outcrops and thus studies the past history of the Earth. Soviet-Russian tradition treats geology as a group of historical and experimental Earth sciences; their methodological specific is complexity. The article deals with the problem of the identification of geological research and prospects of the joint use of historical, hermeneutical and experimental methods in it, as well as a place and a role of each of the three methodological approaches.

The concept of “cognitive unconscious”, widely used in current cognitive psychology, is considered. Main empirical approaches to its investigation are analyzed. Two views on the concept ontology (strong and weak versions of the unconscious) are stated. Finally, the article notes that theoretical consideration of the unconscious has to pay respect to the fact that unconscious and consciousness are genetically related to each other.

Basing on the analysis of physical, astronomical, mathematical and philosophical facts, the article explains why neither Kepler’s predecessors, nor his contemporaries could discover the laws of planetary motion. The generalization of a concrete historical material helps to make evident why in the Antiquity (Pythagoras, Plato, Aristotle, Democritus, Archimedes, Aristarchus, Apollonius, Hipparchus, Ptolemy, etc.), the Middle Ages and the Renaissance (Nicholas of Cusa, Leonardo da Vinci, Copernicus, Ramus, Giordano Bruno, Tycho Brahe, Galilei, etc.) scientists failed to do it. The author proves the approach to understanding and explaining Kepler’s scientific work which bases on the idea of various types of induction by Leonardo da Vinci, G. Galilei, F. Bacon, etc.) and explains why it was Kepler who developed the inductive method of calculation which made possible to discover the laws of planetary motion.

The article suggests a new scientometric indicator, viz the index of a scientist’s publication activity and the relevance of his or her publications (the PAIVPU index, or the PA-index). The author presents her formula of determining the PAIVPU index, considers parameters of its regularities, recommends how to do a non-automatic calculation of the index, and describes a field where it may be used. In the author’s view, an annual monitoring of the PAIVPU index should stimulate scientists to be more active in publishing their works.