This scientific paper presents the results of the study of the synthesis of carbon nanoparticles in radio-frequency ( RF ) discharge plasma at low pressures in a vacuum apparatus. The growth of carbon nanoparticles was studied under different plasma parameters, such as variation of self-displacement voltage, temperature, and discharge power. The experiment was performed in the pressure range of 0.5-1.1 mbarr and powers of 6-20 W. The results showed that the synthesis time of carbon nanoparticles, including their formation and growth, depends on the plasma parameters. Small changes in temperature, pressure, and plasma power can significantly change the growth and formation of nanoparticles. An important conclusion of this work is that increasing the temperature of the plasma-forming gas leads to an increase in the formation time of carbon nanoparticles. The dependences of nanoparticle growth on the discharge power, selfdisplacement voltage on the discharge pressure, and temperature on the discharge power were also obtained. The results obtained provide valuable information for understanding and controlling the synthesis process of carbon nanoparticles in the plasma environment. This is important for various technological applications, including nanoelectronics and catalysis.

This scientific article is devoted to the study and modeling of composite manhole covers made of polyester fiberglass, which are an alternative to traditional metal covers. These substitutes were introduced due to the problems associated with corrosion and theft of steel and cast iron manhole covers, as well as their insufficient resistance to chemicals. Manhole covers made from fiber reinforced plastic have a number of advantages over traditional metal covers. They provide a high strength-to-weight ratio, making them easy and comfortable to install. This material also has a high resistance to corrosion, which greatly extends its service life. Despite the advantages of composite manhole covers, studies related to their mechanical testing and simulations remain insufficient. This article presents the results of a study in which a manhole cover was made from two layers of polyester sheet press material using an additional stiffener. Then, bending tests were carried out, and the results were analyzed using finite element method (FEM) simulation. The purpose of this study was to confirm the validity of the model built for composite manhole covers, as well as to compare the results with experimental data on deformations. The results obtained are of great practical importance for the further development and optimization of the design of composite manhole covers, as well as for improving their reliability and durability.

In this work, monocrystalline films of silicon carbide were synthesized on the surface of a Si(100) silicon wafer using the method of coordinated substitution of atoms. The films were synthesized at temperatures of 1200 °C and 1300 °C for 20 minutes in a CO gas flow at a pressure of 0.8 Pa. The effect of 1200–1300 °C temperatures on the formation of single- and polycrystalline layers, as well as nanostructured SiC phases in the near-surface region of silicon by the method of atom substitution, is analyzed. The formation of a high-quality crystalline silicon carbide film and the influence of synthesis conditions on the total volume of SiC structural phases, microstructure and nanostructure of the surface are shown. It was found that an increase in temperature from 1200 °C to 1300 °C led to a more intensive formation of silicon carbide and an increase in the number of Si–C bonds by 1.9 times due to an increase in the thickness of the synthesized silicon carbide layer. There is an increase in the proportion of the crystalline phase due to a more intense transformation of the nuclei of nanocrystals into micro- and nanocrystals. Intense processes of penetration of carbon atoms deep into silicon at a temperature of 1300 °C with amorphization of its structure and the formation of Si-C, which can transform into crystalline phases at temperatures above 1300 °C, are assumed. The proportion of the SiC crystalline phase increases to 50.2% of the film volume due to the intensive transformation of nanocrystal nuclei into micro- and nanocrystals. It has been experimentally shown that the formation of various SiC structures on Si (100) occurs in full accordance with the main principles of the method of coordinated substitution of atoms.

The work of Bazhenov N.A., Zubkov M.V., Kalmurzayev B.S. started investigation of questions of the existence of joins and meets of positive linear preorders with respect to computable reducibility of binary relations. In the last section of this work, these questions were considered in the structure of computable linear orders isomorphic to the standard order of natural numbers. Then, the work of Askarbekkyzy A., Bazhenov N.A., Kalmurzayev B.S. continued investigation of this structure. In the last article, the notion of a self-full linear order played important role. A preorder R is called self-full, if for every computable function g(x), which reduces R to R, the image of this function intersects all supp(R)-classes. In this article, we measure exact algorithmic complexities of index sets of all self-full recursive linear orders isomorphic to the standard order of natural numbers and to the standard order of integers. Researching the index sets allows us to measure exact algorithmic complexities of different notions in constructive structures, that we are investigating. We prove that the index set of all self-full computable linear orders isomorphic to the standard order of that we are investigating. We prove that the index set of all self-full computable linear orders isomorphic to the standard order of integers is П3 0-complete.

In many sources on model theory, in addition to the proven properties about classes of algebraic systems, the characteristics of these properties are given in algebraic terms, that is, they show the nature of these properties from the perspective of universal algebra. For example, the class of quasi-varieties or varieties is defined using model-theoretic concepts, fulfillment of quasi-identities or identities, and in algebraic concepts of closedness with respect to direct products, ultraproducts, fulfillment of locality, closedness with respect to homomorphisms. H.J. Keisler gave an algebraic characterization of the criterion for the axiomatizability of a class of algebraic systems, using the closure of the class under the ultraproduct and isomorphism of algebraic systems, as well as the closure under ultrapowers to complement the class. H.J. Keisler, however, does not give any algebraic characterization of the criterion for completeness of a class of algebraic systems.In this article, an algebraic characterization of the completeness criterion for a class of algebraic systems is obtained. For comparison, it is not possible to give an algebraic description of the criterion for the model completeness of a class, in terms used in the article. This shows that the algebraic nature of complete and model complete classes is somewhat different.

In this paper, we study the notions of relative H-freedom and relative H-independence for hypergraphs of models of weakly o-minimal theories. Hypergraphs of models of a theory are derived objects that allow obtaining essential structural information both about the theories themselves and about related semantic objects. Recall that a hypergraph is any pair of sets (X, Y), where Y is some subset of the Boolean P(X) of a set X. In this case, the set X is called the support of the hypergraph (X, Y), and elements from Y are called edges of the hypergraph (X, Y). Weak o-minimality was originally deeply investigated by D. Macpherson, D. Marker, and C. Steinhorn. In the nineties of the last century, Kazakhstan scientists successfully joined the study of this concept, solving a number of problems posed by the authors. In this paper, we continue the study of model-theoretic properties of weakly o-minimal structures. A criterion for relative H-freedom of the set of realizations of non-algebraic 1-type in almost omega-categorical weakly o-minimal theories is obtained in terms of convexity rank. We also establish a criterion for relative H-independence of the sets of realizations of two non-algebraic 1-types in almost omega-categorical weakly o-minimal theories in terms of weak orthogonality of 1-types.

We define a triple Tortken product in Novikov algebras. Using computer algebra calculations, we give a list of polynomial identities up to degree 5 satisfied by Tortken triple product in every Novikov algebra. It has applications in theoretical physics, specifically in the field of quantum field theory and topological field theory. A Novikov algebra is defined as a vector space equipped with a binary operation called the Novikov bracket. The Jacobi identity ensures that the Novikov bracket behaves analogously to the commutator in Lie algebras. However, unlike Lie algebras, Novikov algebras are non-associative due to the presence of the Jacobi identity rather than the associativity condition. Novikov algebras find applications in theoretical physics, particularly in the study of topological field theories and quantum field theories on noncommutative spaces. They provide a framework for describing and analyzing certain algebraic structures that arise in these areas of physics. It's worth noting that Novikov algebras are a specific type of non-associative algebra, and there are various other types of non-associative algebras studied in mathematics and physics, each with its own defining properties and applications.

Recently, various methods similar to the “transfer principle” have been rapidly developing, where one property of a structure or pieces of this structure is satisfied in all infinite structures or in another algebraic structure. Such methods include smoothly approximable structures, holographic structures, almost sure theories, and pseudofinite structures approximable by finite structures. Pseudofinite structures are mathematical structures that resemble finite structures but are not actually finite. They are important in various areas of mathematics, including model theory and algebraic geometry. Pseudofinite structures are a fascinating area of mathematical logic that bridge the gap between finite and infinite structures. They allow studying infinite structures in ways that resemble finite structures, and they provide a connection to various other concepts in model theory. Further studying pseudofinite structures will continue to reveal new insights and applications in mathematics and beyond. Pseudofinite theory is a branch of mathematical logic that studies structures that are similar in some ways to finite structures, but can be infinitely large in other ways. It is an area of research that lies at the intersection of model theory and number theory and deals with infinite structures that share some properties with finite structures, such as having only finitely many elements up to isomorphism. A. Lachlan introduced the concept of smoothly approximable structures in order to change the direction of analysis from finite to infinite, that is, to classify large finite structures that seem to be smooth approximations to an infinite limit. The theory of pseudofinite structures is particularly relevant for studying equivalence relations. In this paper, we study the model-theoretic property of the theory of equivalence relations, in particular, the property of smooth approximability. Let L = {E}, where Е is an equivalence relation. We prove that an any ω-categorical L-structure M is smoothly approximable. We also prove that any infinite L-structure M is pseudofinite.

An unknown virus, which was detected in Wuhan city in 2019, had changed fate of the world immediately causing an economic loss, decrease in total population and etc. A penetration of coronavirus contaminated particles to a human cell is able to cause an overproduction of cytokines and antibodies. This process gives a rise to fatal cases. Hence, because of SARS-CoV-2’s pathogenicity, severity and unexpectedness, effective safety measures should be implemented. Along with safe social distancing and wearing a mask, a presence of air conditioning, ventilation system and open windows can reduce the coronavirus propagation in enclosed spaces. The present article focuses on the modeling of coronavirus particles’ propagation during human respiratory reflexes within a constructed three-dimensional confined space with inlet and outlet boundary conditions. Momentum and continuity equations, k-ε turbulence model and Lagrangian dispersion model were utilized to solve the problem. SIMPLE is a main method to solve all governing equations. The primary objectives of this work are to demonstrate the efficiency of air conditioning and open windows in preventing the spread of viruses and to examine particle behavior in the computational domain.

In recent years, tensor decomposition has gained increasing interest in the field of link prediction, which aims to estimate the likelihood of new connections forming between nodes in a network. This study highlights the potential of the Canonical Polyadic tensor decomposition in enhancing link prediction in complex networks. It suggests effective tensor decomposition algorithms that not only take into account the structural characteristics of the network but also its temporal evolution. During the process of tensor decomposition, the initial tensor is decomposed into two-way tensors, also known as factor matrices, representing different modes of the data. These factor matrices capture the underlying patterns or relationships within the network, providing insights into the structure and dynamics of the network. For evaluation, we examine a dataset derived from the WSDM. After preprocessing, the data is represented as a multi-way tensor, with each mode representing different aspects such as users, items, and time. Our primary objective is to make precise predictions about the links between users and items within specific time periods. The experimental results demonstrate that our approach significantly improves prediction accuracy for evolving networks, as measured by the AUC.

This study provides a detailed analysis and prediction of power generation at wind farms in Germany using Lasso, LightGBM, and CatBoost machine learning models. Feature Engineering was used on the data, which allowed the extraction of more detailed data, which was used to improve the quality of the models. Through Extensive Data Analysis (EDA), the authors identify and develop lagged and moving features from the energy production time series, under the assumption that accurate predictions can significantly improve the stability of energy systems, especially in the context of increasing dependence on renewable energy sources. The performance of each model is evaluated based on the Mean Absolute Error(MAE), Mean Squared Error(MSE), and Root Mean Squared Error(RMSE) metrics, with CatBoost exhibiting the highest accuracy. In conclude, pointing to opportunities for further research aimed at optimizing these models and adapting them to other regions, emphasizing the comprehensive and long-term potential of this study in the context of energy field.

Identification systems play a very important role in today's society. Complex security requirements have prompted experts to explore ways in which biometrics can be used to identify customers. In this article, the concept of biometrics, biometric data and its variants are considered. The purpose of the article is to study the process of identification, to produce its improved version and introduce innovation. Thus, the following points served as a research method:
- Initialization.
- Fitness functions.
- Unclear clusterleu method.
The results showed that the advancement of biometric systems and biometric sensors can improve the identity and prevent others from using the identity, the system has great potential to improve the security and accuracy of the biometric technology system. Biometric systems increase the security of users, as well as ensure accuracy in the identification of personal identity. Thus, the accuracy of the proposed method is compared with four modern methods. The comparison shows that the proposed approach provided a high accuracy of about 99.89% and a low error rate of 0.18%. It turns out that there is real potential for the integration of fingerprints and iris biometrics in many subjects with the appropriate assessment.

The sphere of information security in Kazakhstan affects an increasing number of industries every year, and penetration testing is also gaining popularity, as it is one of the key methods for assessing the security and risks of a company. This article is devoted to the research and development of a web application to provide full control over the penetration testing process: monitoring the implementation of tasks and projects, reporting on all processes, dividing tasks between employees. The management system automatically selects recommendations for eliminating vulnerabilities and generates reports on penetration testing. As a classification algorithm, a decision tree is used. Differentiation of users by access levels, structured data storage, automatic recording of test results, generation of reports and selection of recommendations for eliminating vulnerabilities make the web application more perfect and convenient compared to similar systems. The importance of this study lies in the simplification of the implementation of penetration testing and the development of this service in Kazakhstan, which will improve the level of information security in enterprises of all industries.