The concept of optimal bar roll pass design. Report 4. Optimization of roll pass design scheme

Roll pass design of shape rolling rolls is considered from the standpoint of system analysis within “UrFU concept of optimal roll pass design” created in the Chair “Metal Forming” of the Ural Federal University. Roll pass design as a technological system can be changed in two methods: 1) changing the structure of the system which corresponds to a change in the groove shape; 2) changing the control of the system, which corresponds to changing reduction through the pass in the grooves, that is, by changing the reduction mode. Roll pass design that compose of the definite grooves and realize the definite reduction mode, which assures of optimal properties of preassigned objective function depending on the specified parameters, is considered optimal. General conception of two-stage optimization of roll pass design: consistent conduct of optimization of roll pass design scheme (first stage of optimization) and mode of reduction (second stage of optimization), was considered in previous reports. Procedures of formation of optimization space for first stage – space of virtual schemes of roll pass design generated by the special generator and set of all possible types of grooves that can be used at this particular stage of rolling, were also described. To calculate the objective function of the optimality criterion of the roll pass design scheme, the authors introduced the concept of “space of grooves efficiency”. Formation of this space is carried out using a formalized procedure for expert evaluation of the degree of influence of various permissible forms of grooves used in roll pass design on the diverse technological, economic and other characteristics of a particular rolling mill. The objective function is calculated as variance of integral performance indicators of the grooves included in the roll pass design relative to the hypothetical “ideal” groove with the best values of the selected performance indicators. The roll pass design scheme corresponding to the minimum value of the objective function is considered the best. © 2022 National University of Science and Technology MISIS. All rights reserved

Concept of Optimal Bar Roll Pass Design. Report 4. Optimization of Roll Pass Design Scheme

Abstract: This study considers roll pass design from the standpoint of system-level analysis within the UrFU concept of optimal roll pass design developed at the Department of Metal Forming of the Ural Federal University. Roll pass design as a process system is changed by two methods, that is, either by changing the structure of the system, which corresponds to changes in the groove shape, or by changing the control of the system, which corresponds to changing reductions by passes in one and the same grooves, that is, by changing reduction mode. The roll pass design that is considered optimal contains such grooves and uses such reduction mode, at which the extreme properties of preset target functions are ensured depending on the indicated parameters. In previous reports, the general concept of the two-stage optimization of roll pass design is considered. This concept implies a consistent optimization of the roll pass design scheme (optimization stage one) and reduction mode (optimization stage two). In addition, procedures of shaping the optimization space for stage one are considered. This space includes virtual roll pass design schemes and is shaped by the special generator of these schemes and the set of all possible types of grooves that can be used at this particular stage of rolling. To calculate the target function of the optimality criterion of the roll pass design scheme, the groove efficiency space concept is introduced. This space is shaped by the formalized expert assessment of the degree of influence of various permissible forms of grooves used in roll pass design on the diverse technological, economic and other characteristics of a particular rolling mill. The target function is calculated as variance of integral performance indicators of the grooves included in the roll pass design relative to the hypothetical ideal groove with the best values of selected performance indicators. The roll pass design scheme corresponding to the minimal target function is considered the best. © 2022, Allerton Press, Inc

Minimal deformations of the commutative algebra and the linear group GL(n)

We consider the relations of generalized commutativity in the algebra of formal series $M_q (x^i )$, which conserve a tensor $I_q$-grading and depend on parameters $q(i,k)$ . We choose the $I_q$-preserving version of differential calculus on $M_q$ . A new construction of the symmetrized tensor product for $M_q$-type algebras and the corresponding definition of minimally deformed linear group $QGL(n)$ and Lie algebra $qgl(n)$ are proposed. We study the connection of $QGL(n)$ and $qgl(n)$ with the special matrix algebra \mbox{Mat} (n,Q) containing matrices with noncommutative elements. A definition of the deformed determinant in the algebra \mbox{Mat} (n,Q) is given. The exponential parametrization in the algebra \mbox{Mat} (n,Q) is considered on the basis of Campbell-Hausdorf formula.Comment: 14 page

Optimization of roll calibration for flange shape rolling. Groove space

The most important component of any rolling mill is the calibration of the rolls. The ability to obtain a finished product of high quality at minimal cost depends on the right calibration. According to the previous experience and practice a large number of different calibrations for the flange profiles production are known. The universal 'concept of two-stage optimization', consisting of two successively carried out optimization stages developed in the Department of Metal Forming of the Ural Federal University in relation to optimization of the roll calibration for flange shape rolling is considered in this article. Common features of these shapes classification and their variation levels are identified and justified. This developed classification structure is the basis for the formation of spaces of groove schemes, due to which the groove space is formed. In the software implementation the groove space is represented as a 'groove database'. In the future this database will be used to form the space of calibration schemes that are fundamentally suitable for these shapes rolling. © Published under licence by IOP Publishing Ltd.The reported study was funded by RFBR according to the research project 20-38-90246

Risk of sudden cardiac death in strength training

Physical activity is a generally accepted means of primary and secondary prevention of cardiovascular diseases, but in some cases, it can be a risk factor for cardiovascular events, including sudden cardiac death (SCD). Most studies analyze the relationship of cardiovascular events with the volume and general directions of exercise. Besides, a significant part of the guidelines and studies are devoted to the effects of aerobic exercise, while the importance of anaerobic exercise remains controversial. The review analyzes works devoted to the influence of strength training, such as weightlifting, bodybuilding, powerlifting, etc., on the cardiovascular system, as well as their relationship with SCD and other cardiovascular events. The design and contingent of the analyzed papers did not allow them to be systematized correctly. Therefore, the review is largely analytical in nature