Improving the Reliability of Aluminum-Alloy Pistons in Internal-Combustion Engines by Microarc Oxidation

The wear resistance of pistons in internal-combustion engines may be improved if a hardened layer is created on the surface of the piston skirt by microarc oxidation.     

The effect of a magnetic field on the kinetics of melting of ionic crystals

The kinetics of melting of an ionic crystal treated in a pulsed magnetic field (H ∼ 10⁶ A/m) was studied by a computer-aided DTA technique. Significant changes in the nonequilibrium thermodynamic parameters of transient processes during melting and in the enthalpy of melting were observed for KCl crystals, which is evidence that the magnetic field induces a special nonequilibrium state in these nonmagnetic crystals.     

Fuzzy Logic Algorithm of Ecological Forest Zoning in the Vicinity of Chemical Plants Based on a Hierarchical System of Fuzzy Composite Indices

Theoretical Foundations of Chemical Engineering - A hierarchical system of fuzzy composite indices calculated for natural forest levels is put forward. For each of the levels, its own composite...     

Wavelet morphometric neural network algorithm for analyzing nanomaterial porous texture

A wavelet morphometric neural network algorithm for analyzing the porous texture of a nanomaterial that differs from the use of the procedure for identifying the binary clusters for the morphometric analysis obtained as a result of the analysis of the neural network cluster of a micro photo image of a nanomaterial instead of the procedure for identifying binary objects on binary cross sections of the original micro photo image have been proposed. Using this algorithm, we calculated the quantitative morphometric estimations of the geometric parameters of the nanocluster texture of solid and porous components, which have been applied to predict the density distribution of pores inside of a nanomaterial.     

Computer-aided tools for molecular systems engineering and wavelet-morphometric analysis of the texture of nanomaterials

An analysis of present-day computer-aided tools for molecular systems engineering and the possibility of their use for developing the texture of new nanomaterials is performed. A wavelet-morphometric algorithm for a computer-aided analysis of the texture of nanomaterials using the original photomicrographs is proposed that includes the following main stages: the decomposition of the original photomicrographs into low-frequency and high-frequency components using a discrete wavelet transform, the calculation of energymechanical characteristics for the identified images of the texture elements of the high-frequency component, and further binary decomposition and calculation of morphometric parameters for the created images of energy-mechanical characteristics (parameters of texture elements). A system of energy-mechanical and morphometric parameters of the elements of the texture of nanocomposites is proposed that is based on the use of binary decomposition filtration of textural photomicrographs and the morphometric parameters of the identified images of clusters in the binarization sections.     

Determining the Threshold of Detection of a Minimal Specific Weight of Particles in the Study of Shock-Wave Dusting of Surfaces of Materials

Particles are discharged from surfaces of materials under a shock-wave load. Experimental results on determining the minimal values of a specific weight of particles with which their velocity can be detected using a heterodyne interferometer [photon Doppler velocimetry (PDV) method] are presented. An effect of multiple frequency shift of a Doppler signal in the case of laser radiation being reflected from surfaces of materials and a semitransparent layer of dust particles is described.     

Computer molecular-dynamics simulation of the structure of crystal nanomaterials

The molecular-dynamics simulation of crystal system of silicon carbide at various temperatures has been performed using methods and programs of computer molecular design. Graphs of radial-distribution functions have been obtained for Si-C pairs of atoms, as well as the configurations of atoms in crystal systems at various temperatures. The dependence of the melting point of the SiC crystal system vs. the characteristics of the initial crystal structure to the approximation of the given Tersoff potential and molecular assembly has been studied at the constant number of particles, pressure, and temperature.     

Computer-aided method of analysis of nanocomposite structure on the basis of calculations of isolines of fractal dimensionality

A computer-aided method of analysis of nanocomposite textures on the basis of calculation of the fractal dimensions of nanostructures using microphotographs of the nanocomposites is proposed. The computer-aided method of assessment of the fractal dimensions is notable for the use of an algorithm of calculation of the self-similarity indices of the power spectra of two-dimensional luminance fields of the nanostructure imaging on microphotographs and the use of the box-counting algorithm for measurement of the fractal dimensions. This method makes it possible to assess the rates and directions of cluster growth in the nanocomposite texture. On the basis of numerous computer experiments using the method proposed, we have ascertained that dark zones of two types are present on microphotographs of the texture of the nanocomposites obtained by sedimentation of tin oxides and formation of fine-particle silicon carbide: homogeneous zones, where there is no manifestation of the fine structure of the nanocomposites, and indistinctly contoured structured zones that hypothetically can correspond to the formation of new clusters or ensembles of nanoparticles.     

Texture and fractal analysis of silica-alumina glass ceramics

Using electron-microscopy micrographs, texture and fractal characteristics of the microstructure of silica-alumina glass ceramics are calculated at different temperatures. The relationship between the numerical characteristics of the intensity of liquation and crystallization processes of aluminosilicate glass ceramic samples and their thermal coefficients of linear expansion with the values of the fractal dimension and its derivatives is established for photomicrographs of the studied heat-treated samples.     

Recording the particle velocity spectrum at the time the shock wave reaches the surface of liquids of different viscosities

This paper presents the results of experimental studies of the cavitation breakdown of liquids in a wide range of shock-wave loading. The free surface velocity of liquids and the velocity spectrum of the cloud of particles and jets were measured using a laser heterodyne interferometer (photon Doppler velocimetry), and their size was determined. The spall strength of distilled water was determined.