Development of standardized circuit solutions for control and data acquisition systems of a research complex on the basis of electron-beam technological installations

The structure, contents, and operations of electrical equipment, which are parts of a test bench for investigating the characteristics of technological electron guns, are reviewed. A list is given of critical problems that were solved with the equipment under which the basic requirements for system control and data acquisition were designed. Based on the classification of the control and recorded signals, the characteristics of input–output modules of digital and analog signals are defined. Taking into account the features of the equipment, standardized circuit solutions were developed that provide acceptable accuracy for control and signaling, as well as trouble-free operation of a computerized data acquisition system. The use of modem solutions providing galvanic insulation by optical transmission channel technology for both digital and analog signals is discussed. A method of selection of specialized microchips on the parameters of control and measurement signals is shown. Recommendations on the use of measuring complex for research and design of control systems of electron-beam welding installations are provided.     

Kinetic Regimes of Developed Chain Combustion

It is shown that chain thermal explosion is an inherent property of chain branching combustion that is due to simultaneous action of a chain avalanche and self-heating, which under certain conditions also becomes a progressively accelerating process. An attempt to deny this phenomenon is in fact equivalent to denying thermal explosion. This phenomenon is also observed in the absence of convection. The chain branching reaction mechanism is involved in all regimes of gas-phase combustion of hydrogen-containing compounds with oxygen. This results in inhibition or promotion of flame propagation, indicating the necessity of taking into account competition between reaction chain branching and termination.     

THERMODYNAMICS OF GLYCEROL NITRATION（英）

An entire thermodynamic research of the reaction of glycerol nitration with nitric acid is reviewed,in which the basic equations and data are of great scientific and practical importance,especially for the nitration of the primary and secondary hydroxyl groups.     

Production of New Types of Rolled Products — Customer Focus

Metallurgist - The paper describes the main stages of the development of sectional and shaped profiles by the JSC “EVRAZ NTMK” over the past years. The plant operates three longitudinal...     

Detection of Particle Ejection from Shock-Loaded Metals by Synchrotron Radiation Methods

The mass distribution along a flow of microparticles is measured by methods of synchrotron radiation generated by the VEPP-3 collider. The use of the soft spectrum of radiation allows microparticle flows to be measured with a record-beating (minimum) specific density (1 mg/cm³). Simultaneous recording of microparticle flows by piezoelectric sensors offers a possibility of comparisons and extension of results.     

Analysis of the harmonic composition of a phase current curve for estimating the power distribution in the crucible of an electric ore smelting furnace

A model is proposed for the phase of an electric ore smelting furnace with a hidden arc, and its implementation with Simulink is presented. The possibility of estimating the powers releasing in the arc and the charge from the harmonic composition of the phase current of the furnace is shown.     

Crystal Structure and Physical Properties of Lead Titanate Ceramics Produced by Cold Pressing at 1.2–7.0 GPa

Detailed data are presented on the crystal structure of ferroelectric lead titanate ceramics produced by cold pressing at 1.2–7.0 GPa. The displacement of the Ti ions is shown to decrease with increasing compacting pressure. In addition, increasing the compacting pressure reduces the tetragonal distortion of the PbTiO₃ lattice, increases the distortion of the TiO₆ tetrahedra, and lowers the ferroelectric transition temperature of the ceramics.     

An express method of measurements of parameters of technological electron beams

An express method of direct measurements of the current density distribution of axially symmetric electron beams is proposed. It is shown that use of the technique is urgently needed to improve the reproducibility of the results of electron-beam processing. Comparative analysis of existing methods to measure the parameters of electron beams used for technological purposes is carried out. A technique to restore a radial distribution of electron beam current density as well as a device to implement the technique is developed. The results of radial distribution recovery are analyzed in the case in which the initial distribution is given in the form of a model function of normal distribution. An algorithm to determine estimated sizes of the area within which spatial distribution discretization is carried out is developed. Based on analysis of the experimental dependences, it is shown that the suggested numerical method can be applied to all types of axial-symmetric distributions. The nature of errors occurring after distribution function recovery is analyzed. A technological projection of express diagnostic systems for the processing electron beams is made taking into account parameters of the existing element base.