The article discusses the modeling of the curvilinear motion of a mobile robotic complex (MRC) with a caterpillar-modular mover on sandy deformable soil. Dependencies describing the main ...characteristics of the support base (modulus of elasticity, angle of internal friction, specific cohesion of soil, soil density) are given. The simulation was conducted in the Adams Tracked Vehicle environment. Shown are 3D views of the developed model of MRC. Typical sections of MRC curvilinear motion simulation on a sandy support base are considered. Graphs of changes in resistance to movement MRC are given for curved and straight sections. The calculations of the total resistance in a rectilinear motion and during rotation showed that the average values of the resistance to movement in a rectilinear motion are 1.6 kN with a curvilinear of 1.94 kN. The experimental values of the resistance force in a rectilinear motion were 1.45-1.7 kN. Thus, the maximum deviation between theoretical and experimental data was no more than 10%.
The article deals with the issues relating to the qualitative assessment of the operational properties of nautical polymer ropes on the basis of computer forecasting and system analysis of their ...viscoelastic-plastic properties. Computer forecasting methods for the systematic analysis of the viscoelastic-plastic properties of polymer ropes are based on mathematical modeling of involved processes.
The paper is dedicated to studying the structural and mechanical properties of ceramic coatings obtained by micro-arc oxidation (MAO) using a cathodic-anodic mode in alkali-silicate, borate, and ...alkali-silicate-phosphate electrolytes from an experimental sample of compositions. Coatings formed using borate electrolyte have the best mechanical properties, resulting in the improvement of wear resistance of an unprotected aluminum surface by 2.1 to 3.1 times, depending on the content of borate ions in the utilized electrolyte. Ceramic MAO coatings offer a potential for use at the Russian repair and maintenance enterprises, which are engaged in the repair and restoration of worn aluminum and steel materials used in critical components of agricultural machinery.
Methods of modeling and computer-aided prediction of relaxation of medical-purpose textile elastomers are described. Mathematical modeling and subsequent computer-aided prediction of these processes ...enables qualitative evaluation of functional and performance potentials of the studied textile elastomers, which is particularly important at the stage of their designing and production organization.
The problem of the measurement of the parameters of picosecond electric pulses with bandwidth greater than 110 GHz was examined. In order to measure the parameters of the specified electric pulses, ...it was proposed to use an electro-optic sampling measurement system. Several variants for implementation of a coplanar waveguide, a central node of the electro-optic sampling measurement system, are described. The parameters of a coplanar waveguide with a gallium arsenide substrate were calculated. An energy calculation was conducted for an electro-optic sampling measurement system in which the parameters of past probing laser radiation were determined. An optical circuit of an electro-optic sampling measurement system is presented, and its optical devices are preliminarily calculated. Ways toward enhancement of the sensitivity of the system are described, as well as a method of focusing the laser radiation to a spot with diameter of several tens of μm.
The characteristics of composite materials in the system Al
2
O
3
– carbon nanotubes – eutectic additives are investigated. The effect of the content of the reinforcing component as well as ...high-temperature heat treatment in vacuum on the strength of the material is examined. The obtained samples with 0.4 wt.% carbon tubes had the following characteristics: average tensile strength in three-point bending 380 MPa, open porosity 0.9%, average density 3.71 g/cm
3
.
Problems of modeling and prediction of deformation and relaxation processes of polymer yarn products are studied. Mathematical models of these processes that allow prediction of these processes with ...an adequate degree of accuracy for polymer yarn products, which makes possible qualitative assessment of its functional-performance properties, are given.
A technology was developed for obtaining glass silica based on fractionated cullet of colored container glass and the waste from enrichment of ferruginous quartzites of the Kursk of Magnetic Anomaly ...(KMA) at the Lebedinskii Mining and Processing Combine Lebedinskii GOK. By using the waste from enrichment of ferruginous quartzites of the KMA the sintering temperature could be lowered and the quality of the glass raised. The obtained glass silica exhibits high performance and aesthetic properties.
Hydrogen Bonds in a Water–Pyrrolidone System Makarov, D. M.; Dyshin, A. A.; Krestyaninov, M. A. ...
Russian Journal of Physical Chemistry A,
04/2022, Volume:
96, Issue:
4
Journal Article
Peer reviewed
Structural properties of a mixture of water–2-pyrrolidone are studied using a set of physicochemical means. Spectral and numerical means are used to determine the parameters of hydrogen-bonded ...structures, and to calculate the structural and energy characteristics that describe the topology of hydrogen bonds under conditions of a change in the composition of the mixture. The most probable structure of the resulting hydrogen-bonded complexes has been determined.
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