Fast diffusion of graphene flake on graphene layer

Diffusion of a graphene flake on a graphene layer is analyzed and a new diffusion mechanism is proposed for the system under consideration. According to this mechanism, rotational transition of the flake from commensurate to incommensurate states takes place with subsequent simultaneous rotation and translational motion until the commensurate state is reached again, and so on. The molecular dynamics simulations and analytic estimates based on ab initio and semi-empirical calculations demonstrate that the proposed diffusion mechanism is dominant at temperatures T ~ Tcom, where Tcom corresponds to the barrier for transitions of the flake between adjacent energy minima in the commensurate states. For example, for the flake consisting of ~ 40, 200 and 700 atoms the contribution of the proposed diffusion mechanism through rotation of the flake to the incommensurate states exceeds that for diffusion of the flake in the commensurate states by one-two orders of magnitude at temperatures 50 - 150 K, 200 - 600 K and 800 - 2400 K, respectively. The possibility to experimentally measure the barriers to relative motion of graphene layers based on the study of diffusion of a graphene flake is considered. The results obtained are also relevant for understanding of dynamic behavior of polycyclic aromatic molecules on graphene and should be qualitatively valid for a set of commensurate adsorbate-adsorbent systems.Comment: 33 pages, 6 figure

Simulation of Atomic Structure Near Nanovoids in BCC Iron

Generally, displacement fields near voids are determined by the equations of elasticity theory. Such a description has its disadvantages as it does not take into account the discrete atomic structure of materials. In this work, we use a new variant of Molecular Static method for investigation of the atomic structure near nanovoids. In our model an iterative procedure is employed, in which the atomic structure in the void vicinity and the parameter determining the displacement of atoms embedded into an elastic continuum are obtained in a self-consistent manner. Results show that the displacements are significantly different for varies crystallographic directions. Keywords: voids; iron; simulation; atomic structure; vacancie

Individual personality traits as predictors of intra-organizational vertical career growth of employees

The paper is devoted to the research on the influence of individual personality traits on the success of intra-organizational vertical career growth of employees, the indicator of which is the promotion of employees in their position (status) in the organization, taking into account their speed of passing the career levels. The article analyzes the types of career, criteria and factors of career growth, including personality characteristics in the context of their influence on career processes. The article presents the results of an empirical study of the managers of JSC Concern Energomera, Stavropol (Russia), which determined the relationship between the success rate of intra-organizational vertical career growth and individual personality characteristics, manifested in the level of mental tension (anxiety, suspicion, inclination to risk, spontaneity and emotional sensitivity) and expressiveness. The authors did not find statistically significant contribution of regulatory properties and indicators of general mental abilities to distinguishing groups of employees with high and low indicators of vertical career growth. The averaged personal profiles of employees with high and low indicators of vertical career growth are presented.peer-reviewe

Comparison of expenditure of using experimental models of carcinogenesis

Despite significant advances in the diagnosis and treatment of oncopathology, the main epidemic indicators have a negative trend.Based on the above, a very relevant topic is the development of experimental models of carcinogenesis. The importance of scientific work in this area is increasing because in experimental conditions it is better to test new methods, diagnostics and treatment. Thus, it becomes possible to study the peculiarities of the pathogenesis of any tumor at different stages.The purpose of the work – to study and demonstrate the strengths and weaknesses of the main experimental models of carcinogenesis for further selection of the most appropriate.Results The main directions of carcinogenesis modeling are presented in the article. Initially, the problem was justified. The next step is described in chronological order of using the models.Of course, the achievements of clinical and experimental oncology played an important role in the emergence of models. Thus, the first model was the effect of physical and chemical carcinogens on a laboratory animal. The latest achievement of experimental oncology is the use of stem cells in combination with genetic engineering.No less important is the fact of comparing experimental models. We present the strengths and weaknesses of all these models.Conclusions1. To date, there are a large number of experimental models of carcinogenesis.2. When planning a study, you need to calculate all the goals to be achieved and select the appropriate model.3. The most effective and common model for ascites ovarian tumor is the transplantation of atypical cells to laboratory animals

Determination of Priority Customers for Small and Medium-Sized Machine-Building Enterprises

The article is devoted to the selection of priority customers from among new customers for small and medium-sized machine-building enterprises. The analysis of the dynamics of sales from new and existing customers for ten enterprises allowed us to offer the coefficient of its potential as a criterion for evaluating the customer. The potential coefficient shows the increase in the cost of subsequent orders compared to the first order. The correlation and regression analysis revealed the main factors that determine the customer's potential coefficient. They are the number of years of presence in the market and the profitability of sales of the customer. The introduction of the potential coefficient in the target function of the optimization task of forming a portfolio of orders will allow you to select and retain priority customers. © 2022 American Institute of Physics Inc.. All rights reserved

Obesity in Russia: modern view in the light of a social problems

The purpose of the article is to highlight the social aspects of stress as a syndrome of adaptation to the current situation in Russian society in order to justify the consideration of society as a factor contributing to the development and spread of overweight and obesity among the Russian population. The problem of the conditions and quality of everyday life of a significant part of the population of our country is raised, which are accompanied by an increased stress level of everyday life events. A modern Russian society, possessing an immanently inherent systemic quality - a stressful property, combined with the specificity of a hypodynamic lifestyle, is a powerful and systemically active factor that provokes the development and spread of obesity and overweight. The stress factors of modern society, generated by the disorder and non-complementarity of the work of social institutions, instability in the economic and political spheres are analyzed. Food family traditions, food paradigm, leisure activity of Russians are studied. The irrationality of the use of food by mankind is discussed. The proposed measures to combat and prevent obesity