The effect of the temperature-time mode of crystallization on the morphology and properties of nanocomposites based on polypropylene and cadmium sulfide

In this work, we describe the results of studying the effect of the temperature-time modes of crystallization on the structure and properties of nanocomposites based on polypropylene and cadmium sulfide prepared via electrical discharge treatment in an air medium above the breakdown strength of the air. The temperature-time modes of the crystallization and other treatment factors change the supramolecular structure of the polymer, the interfacial interactions between the components of the composites, and the thickness of the interfacial layer.     

Effect of the electrothermopolarization on the electret properties and the charge state of polyethylene nanocomposites with Cr and PbCrO4 additives

The results of studying the effect of electrothermopolarization on the electret properties and charge state of PE + Cr and PE + PbCrO₄ composites are described. It is shown that an increase in the polarization field intensity to E _p = 5 × 10⁶ V/m leads to an improvement in the polarization processes in the composites; at E _p > 5 × 10⁶ V/m, the space charge concentration apparently increases, which results in the deterioration of the electret properties. The observed effect can be attributed to the repeated electron capture by deeper traps owing to the internal electric field. In addition, the intensity of the TSD peaks and therefore the number of stabilized charges for the composites polarized at high intensities are higher than for the samples polarized at low intensities.     

Incompletely Coupled Equations of Hydraulic Fracturing

We study a three-dimensional coupled problem of the creeping flows of a viscous fluid in a hydraulic (and magmatic) fracture and the strain and flow in the external poroelastic medium induced by them. The process is governed by injection fluid into a well. The flow in the fracture is described by the Stokes hydrodynamic equations in the approximation of the lubricating layer. The external problem is described by the equations of poroelasticity. An ordered sequence of interdependent geomechanical processes occurring under hydraulic (and magma) fracturing is established. In other words, the solution of the coupled problem of hydraulic fracturing is reduced to the sequential solution of three incompletely coupled problems representing the motion in the fracture, as well as the elastic and flow processes in the host rock. The proposed transformation is of practical importance for petroleum geophysics; it allows conducting a more profound in-depth study of the nonisothermal and physicochemical phenomena for occurring in the above-mentioned fractures; and it provides a better insight into the physics of the associated processes.     

Formation of the granular structure in the intermetallic compound Ni3Al in high-temperature synthesis under compression

The process of high-temperature synthesis of the Ni₃Al intermetallic compound under conditions of a thermal explosion of the 3Ni-Al powder mixture under compression is considered. Quantitative estimates of dispersion of the granular structure of the synthesized intermetallide are made within the framework of the mathematical model proposed in the present paper. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 3, pp. 64–70, May–June, 2006.     

High-temperature synthesis of the Ni<Subscript>3</Subscript>Al intermetallic compound under pressure

We investigate by experimental and numerical methods the high-temperature synthesis of the Ni₃Al intermetallic compound in the thermal explosion mode under the pressure of a powder mixture of nickel and aluminum of a stoichiometric composition. The calculated and experimental thermograms of self-propagating high-temperature synthesis are analyzed depending on the temperature of preliminary heating of the powder mixture and the magnitude of external pressure.     

Level of vitamins B in yeasts of the Saccharomyces species depending on the composition of culture media]

The qualitative and quantitative composition of water-soluble vitamins B in Saccharomyces yeasts cultivated on various nutrient media was studied by high-performance liquid chromatography. New strains of Saccharomyces oviformis Y-2635 and Saccharomyces vini F-5 yeasts grown in the nutrient medium with geothermal water differed in great biological value due to high intracellular concentrations of riboflavin, thiamine, nicotinic acid, and folic acid.     

Computer Simulations of Deep Eutectic Solvents: Challenges,Solutions, and Perspectives

Deep eutectic solvents (DESs) are one of the most rapidly evolving types of solvents, appearing in a broad range of applications, such as nanotechnology, electrochemistry, biomass transformation, pharmaceuticals, membrane technology, biocomposite development, modern 3D-printing, and many others. The range of their applicability continues to expand, which demands the development of new DESs with improved properties. To do so requires an understanding of the fundamental relationship between the structure and properties of DESs. Computer simulation and machine learning techniques provide a fruitful approach as they can predict and reveal physical mechanisms and readily be linked to experiments. This review is devoted to the computational research of DESs and describes technical features of DES simulations and the corresponding perspectives on various DES applications. The aim is to demonstrate the current frontiers of computational research of DESs and discuss future perspectives.     

Study of complex heat exchange with account for phase transitions in secondary contour of the geothermal power plant

The numerical solution of complex heat exchange with account of phase transitions in secondary contour is obtained. Temperature, pressure and evaporation distributions along height of a heat exchanger and parametrical dependences of phase transitions boundaries on initial conditions are found.