We perform a systematic comparison of the statistical model parametrization of hadron abundances observed in high-energy
pp
,
AA
and
e
+
e
−
collisions. The basic aim of the study is to test if the ...quality of the description depends on the nature of the collision process. In particular, we want to see if nuclear collisions, with multiple initial interactions, lead to “more thermal” average multiplicities than elementary
pp
collisions or
e
+
e
−
annihilation. Such a comparison is meaningful only if it is based on data for the same or similar hadronic species and if the analyzed data has quantitatively similar errors. When these requirements are maintained, the quality of the statistical model description is found to be the same for the different initial collision configurations.
For the first time, charge characteristics of an organometallic complex with a radiative LMCT (ligand-to-metal charge transfer) state have been systematically evaluated using 124 methods at different ...levels of theory (for Ti(η
5
:η
1
-CpCMe
2
CB
10
H
10
C)
2
taken as an example). Reliability of the results of calculation in the Mulliken approximation was considered.
The article is devoted to a review of approaches used to simulate thermal processes occurring during electron beam welding of thin-walled products. The analysis of more than fifty sources is carried ...out on the basis of which ideas about the current state of the problem considered in the article are formed. To implement the simulation, it is possible to use modern software systems such as: ANSYS, Comsol Multiphysics, Abaqus and NX Nastran, each of which has its own set of advantages and disadvantages. By using the method of expert evaluation on the basis of the formulated criteria, the most effective software was selected. The results of the study of mathematical models implemented in the selected software system will allow not only to get an idea of the thermal process occurring during electron beam welding of thin-walled products, as such, but also to form a mathematical justification for making technological and control decisions.
The control of the induction soldering technological process is significantly complicated by the presence in the heating zone of physical phenomena that make it difficult, and sometimes completely ...impossible, to measure the temperature in the heating zone using non-contact temperature sensors. At the same time, the use of contact sensors is also difficult in the production of spacecraft's elements due to the high requirements for the quality of the product surface, as well as the high time required for the installation of contact sensors and the human factor. This paper presents the concept of a cyber-physical system for controlling the technological process of induction soldering of spacecraft waveguide paths in the framework of Industry 4.0, which is actively developed at the enterprises of the rocket-space complex. As a part of this concept implementation, it is proposed to develop mathematical models for each element of the waveguide assembly separately, and for the entire assembly of the waveguide path. The use of mathematical models developed within the framework of this concept will make it possible to improve the quality of the induction heating process control using adaptive and intelligent methods.
The article presents an approach to solve the problem of non-standard errors correction in the process of creating permanent joints using high-temperature methods such as induction soldering, ...electron beam welding, diffusion welding. The use of such high-tech methods for creating integral joints causes the use of intelligent methods for correcting non-normative errors. Within the framework of this work, it is proposed to use artificial neural networks for correction of non-normative errors in the technological process of creating integral connections. The work includes the process of development, training and experimental verification of the non-normative errors correction method of based on artificial neural networks.
The processes that occur during the electron beam welding are very complex. The main problem of electron beam welding is obtaining a reproducible cross section of the weld. This place is subjected to ...rigorous quality control during the welding of thin-walled joints. In particular, it is required to solve the problem of the welded joint optimal formation on the electron beam input/output section. The development of the mathematical models for the electron beam input and output modes, their joint use as a justification for the choice of the latter modes will allow a reasonable approach to the seam optimal formation in the area under consideration. In the framework of this study, the concept of an electron beam input-output control system for a weld optimizing in the electron beam welding process is presented. Within the framework of this concept, it mathematical and algorithmic software have to be developed for electron beam welding of thin-walled aerospace structures in terms of the electron beam input/output. Such approach will improve the quality of formed integral joints, as well as reduce the complexity of setting up the technological process of electron beam welding. It has to be developed and verified the mathematical models of temperature distribution under various modes of an electron beam input and output, models for optimizing input and output modes of an electron beam, and a software system prototype using the obtained models.
A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure
CF
4
. It has a 50
cm ...long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.
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