The algorithm of calculation of the main geometrical characteristics of the section consisting of pair angles at a bend of both angles is made. The received results are applied to definition of a carrying capacity of an element of a farm.
Keywords: a rafter farm, bend, a barycentre, a moment of inertia, a radius of inertia
The structural properties of cobalt catalysts and their active component are studied. The influence of metal oxides on the specific surface area, pore volume and size, the average crystallite size and the active surface area of the catalyst Co-Al2O3/SiO2 was studied.
Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, cobalt, promoter, carrier, specific surface, porous structure, catalytic activity, degree of reduction, active surface area
The physical and chemical properties of cobalt catalysts promoted by manganese oxides for the synthesis of hydrocarbons by the Fischer-Tropsch method are studied. The influence of polymorphic modifications of the alumina carrier on the specific surface area, pore volume, degree of reduction, size of cobalt crystallites,catalytic activity, dispersion degree of catalyst reduction is considered.
Keywords: Synthesis of Fischer-Tropsch, synthetic hydrocarbons, the cobalt catalyst, promoter MnO2, the carrier of Al2O3, specific surface area, the degree of recovery of the catalytic activity, dispersion, and the crystallites of cobalt
The relevance of the correct approach to the verification of modern electronic engine control systems of the car with regard to structural complexity, as well as the possibility of timely use of various diagnostic equipment to prevent engine failure, due to the timely detection of malfunction and reduce the costs associated with the operation and maintenance of road transport. The technology of diagnostics involves the mandatory verification of data received from the diagnostic system by measuring the corresponding physical parameters. The fault may be in the wires connecting the sensor and the control unit, in the control unit itself, in the connectors. To detect a fault, it is necessary to make a certain number of measurements of voltages, currents, and resistances and to establish the fault location using special diagnostic devices. On the basis of the obtained results, malfunctions of individual systems, assemblies, and aggregates are identified, then, taking into account indirect performance indicators, their technical condition is analyzed. In the end, it is possible to reliably assess the technical condition of the car, to detect and eliminate the causes of deviations from the norm.
Keywords: electronic control unit, car, engine, check, diagnostics
The parameters of the porous structure and the active surface of cobalt catalysts for Fischer-Tropsch synthesis (SFT) prepared by the impregnation method have been studied. Characteristics of composition and porous structure were studied using elemental analysis and the Brunauer-Emmett-Taylor method (BET). The effect of the addition of oxide promoters on the specific surface area, pore volume and pore size of the Co / SiO2 catalyst has been studied.
Keywords: Fischer-Tropsch synthesis, heterogeneous catalyst, promoter, carrier, specific surface area, porous structure, selectivity, activity, dipping method
The parameters of the porous structure and the outer surface of cobalt catalysts for the synthesis of Fischer-Tropsch, promoted by magnesium, prepared by the impregnation method according to moisture capacity, were studied. The effect of polymorphic modification (γ, θ, α) of the carrier on the physicochemical properties of the catalyst Co-Mg / Al2O3 was studied.
Keywords: Fischer-Tropsch synthesis, polymorphic modifications of Al2O3, synthetic motor fuel, catalyst, carrier, elemental analysis, BET method, specific surface, porous structure
The dependence of influence of size of a bend on tensely strained state of load-bearing frames of a covering is analysed. On the basis of the received results the maximum corner of a bend of the metal corners reducing a carrying capacity of farms is defined.
Keywords: a rafter farm, bend, tensely strained state, a moment of inertia, a radius of gyration, a barycentre
Three batches of Co-MxOy / SiO2 catalysts were prepared with different methods of introducing an oxide additive. Physicochemical studies of catalysts by elemental analysis and Brunauer-Emmett-Taylor (BET) methods have been carried out. The effect of additives of oxide promoters and the method of their introduction on the specific surface, volume and pore sizes for Fischer-Tropsch synthesis catalysts were studied.
Keywords: Fischer-Tropsch synthesis, carbon-containing resources, catalyst, active component, silicate carrier, Al2O3 and ZrO2 promoters, elemental analysis, BET method, surface area, volume and pore size
Using the methods of thermo-programmed reduction (TPV) and thermo-programmed hydrogen desorption (TPD H2), physico-chemical studies of Co-MxOy / SiO2 catalysts obtained by various methods of introducing a promoter additive were carried out. The effect of the introduction method and the nature of the promoting oxide additive on the properties of the active component of the Fischer-Tropsch synthesis catalysts was studied.
Keywords: Fischer-Tropsch synthesis, catalyst, active component, silicate carrier, Al2O3 and ZrO2 promoters, TPV and TPD H2 methods, crystallite size, degree of reduction, dispersity
The physical and chemical properties of cobalt catalysts for Fischer-Tropsch synthesis have been studied. The effect of copper and iron oxides on the specific surface, pore volume and dimensions, and the degree of reduction of metallic cobalt on the surface of the Co-Al2O3 / SiO2 catalyst have been studied.
Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, cobalt, promoter, carrier, specific surface, porous structure, catalytic activity, reduction degree
The dispersion parameters of the active component of cobalt catalysts promoted by nickel for Fischer-Tropsch synthesis by the temperature-programmed hydrogen desorption method (TPD H2) were studied. The influence of the polymorph (γ, θ, α) of the support on the physicochemical properties of the Co-Ni / Al2O3 catalyst was studied.
Keywords: Fischer-Tropsch synthesis, biomass, catalyst, support, Ni promoter, polymorphic Al2O3 modifications, TPD H2 method, active surface, dispersity, cobalt crystallites
This article analyzes the stress-strain state of exploited reinforced concrete crane beams in order to identify the causes of abnormal damages. Also, the degree of influence of the revealed damages on safety and operational fitness was assessed.
Keywords: crane beam, technical condition, operational availability, defect, durability, damage, inspection, discretization, stress-strain state
This article discusses a comparative analysis of the results of calculations of a building erected on an unevenly deformable base. The authors, taking into account the peculiarities of the engineering-geological conditions of the territory of the city of Volgograd, made a verification assessment of the influence of the heterogeneity of the bedding coefficient of the soil foundation on the VAT of the structural elements of the building when calculating the final draft.
Keywords: bulk soils, foundations, bases, bed ratio, backfilling, compliance, stiffness diaphragm, stress-strain state
The parameters of the porous structure and the outer surface of cobalt catalysts for the Fischer-Tropsch synthesis prepared by the water-impregnation method were studied. The effect of the polymorphous modification of the support on the physico-chemical properties of the Co / Al2O3 catalyst was studied.
Keywords: Fischer-Tropsch synthesis, synthetic motor fuel, catalyst, carrier, promoter, polymorphic Al2O3 modifications, elemental analysis, specific surface, porous structure
The article presents the results of the use of viscous additives based on polyisobutylene to improve the performance of railway greases LZ CNII. It is established that the introduction of this type of additives into the dispersion medium of lubricants allows to increase their colloidal stability and tribological properties without deterioration of the operational parameters essential for the application of these lubricants.
Keywords: plastic lubricant, friction, thickener, polyisobutylene, wear resistance, grease film, reliability