All Articles

Summary: As it is known, the recycled steel smelting industry is considered as one of the economically and ecologically very important fields. In this industry, the repro-cessing of obsolete steel waste, which is dangerous for the environment, is of great economic importance as well as environmentally beneficial. the processes of ore extraction and its subsequent stages of processing save on the use of natural resources. steel smelting is important. During the research carried out by us, it was determined that a large amount of water is also used in the recycling processes of out-of-service steel technological equipment in the recycled steel smelting industry. The object of the study was the Baku Steel Smelting Enter-prise. For the first time, in-depth environmental analyzes of the composition of the industrial streams-wastewater received during the technological process of that production were carried out by us. It was determined by us the emissions of ecotoxicant substances - H2S, SO2, NH3, SO3, NO2 Cl2, HCl, HCN, PH3 which are contained in the industrial streams formed in the main production areas of that enterprise and evaporate in a short period of time.

Summary: This study investigates the thermochemical luminescence (TCL) behavior of heavy residues derived from Karabakh, Absheron, and Naftalan crude oils to examine their chemical transformations and implications for quality. Crude oil is a complex mixture of hydrocarbons, dissolved gases, water, salts, and impurities, with its composition varying significantly. Advanced spectroscopic techniques, including UV, NMR, IR, and luminescence analysis, were utilized to explore the structural-group composition and physicochemical properties of these oils. TCL analysis revealed consistent characteristics among the heavy oil residues, marked by hybrid molecular structures and weakly bonded C–H linkages. The residues, after undergoing de-resinification and deasphalting, exhibited a notable uniformity, making them promising candidates for use as biologically active substances. Photoirradiation experiments demonstrated that the TCL maxima for heavy residues appear in lower-temperature spectral regions compared to many distillate fractions. The visible light emission was attributed to the decomposition of endoperoxides during the recombination of peroxide radicals. This observation opens the possibility of utilizing hydrocarbons as alternative light sources, including applications involving solar energy. These results have implications for improving refining processes, optimizing the transportation and storage of crude oil, and broadening the industrial applications of petroleum and its by-products.

Summary: In this study, we delve into the spectral properties of a pencil of nonself-adjoint second-order differential operators characterized by almost periodic potentials and impulse conditions. Such operators arise in various physical models, particularly in quantum mechanics, where they describe systems with discontinuities in their potentials or boundary conditions. Understanding the spectrum of these operators is crucial for comprehending the stability and dynamics of the associated physical systems. By investigating the spectral gaps and accumulation points we aim to contribute to the broader understanding of non-self-adjoint operator theory and its applications in mathematical physics.

Summary: In this paper, a model of single server queueing-inventory system (QIS) with Markovian Arrival Process (MAP) and phase-type distribution (PH-distribution) of the service time of consumer customers (????-customers) is considered. After completing the service of ????-customer, he (she) can make one of the following decisions: (1) eventually leave the system with probability (w.p.) ????ℓ; (2) after a random “thinking” time returns the purchased item w.p. ????????; (3) after a random “thinking” he (she) feedback to buy a new item w.p. ???????? . It is assumed that ????ℓ+????????+???????? = 1. If upon arrival of the ????-customer the system main warehouse (SMW) is empty, then the incoming customer, according to the Bernoulli scheme, is either joins the infinite queue or leaves the system. A virtual finite orbit can be considered as a waiting room for feedback customers (????-customers). Returned items are considered new and are sent directly to SMW if there is at least one free space; otherwise, this item is sent to a special warehouse for returned items (WRI). After completing the service of each customer, one item is instantly sent from the WRI (if any) to the SMW. In SMW, the (????, ????) replenishment policy is used and it is assumed that the lead time follows exponential distribution with finite parameter. When the stock level reaches its maximum value due to items returns, the system immediately cancels the regular order. Along with classical performance measures of QIS new specific measures are defined and numerical method for their calculation as well as maximization of the revenue function are developed. Results of numerical examples to illustrate the effect of different parameters on the system’s performance measures are provided and analyzed. We also provide a detailed analysis of an important special case of the Poisson process/exponential service time model.

Summary: Public interest concerning the environmental progress of economies has been developing across societies and countries. Such awareness requires dealing with energy, environment, and economic sides altogether. By considering this reality, this research investigates that how there is an effect of environmental policy stringency (EPS), energy transition index (ETI), and income (gross domestic product, GDP) on CO2 emissions. In doing so, the research analyzes BRICS countries, which are leading developing countries causing high emissions and consuming large amounts of energy, uses data between 2000/Q1 and 2020/Q4, and uses wavelet local multiple correlation approach to analyzes the nexus across times and frequencies. The results demonstrate that (i) EPS declines CO2 emissions in Brazil at low and high frequencies; (ii) GDP curbs CO2 emissions in India at high frequencies; (iii) across remaining times and frequencies, EPS, ETI, and GDP have a mixed effect in BRICS countries; (iv) based on four-variate cases, EPS, ETI, and GDP have an increasing combined effect on CO2 emissions across all times, frequencies, and countries; (v) the most dominant factor differs according to frequencies and countries, where ETI is mainly leading in Brazil, Russia, and India, EPS is pioneering in South Africa, and China has a mixed situation. Thus, the research empirically proves the diverging effects of EPS, ETI, and GDP on CO2 emissions across times, frequencies, and countries.

Summary: Invisible watermarking has become a vital technique in digital image security, allowing hidden data to be embedded without affecting visual quality. This study addresses the challenge of maintaining watermark imperceptibility while resisting common image distortions. The goal of this research is to assess the effectiveness of a hybrid watermarking method that combines Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). In the proposed approach, the watermark is embedded in the DCT coefficients of the low-frequ-ency DWT sub-band. Experiments were conducted in both RGB and YCbCr color spaces, with varying strength factors (alpha). The method demonstrated high imperceptibility, with SSIM values above 0.998, but limited robustness against JPEG compression, Gaussian blur, and noise. These findings highlight the need for more resilient hybrid methods

Summary: The importance of forming and bringing the organization of databases of medical institution branches into a more suitable form in terms of their structure, accessibility and flexibility of applications, and the development of methods in this regard are presented in the article. Thus, having each branch's own database increases the flexibility of local queries, minimizes duplication of general data, and provides a structure for distributing certain data in a way that is specific to the functions and medical aspects of the branches. Many existing methods for distributed databases have been considered and the suitability of some of them for medical documents has been noted.

Summary: Mixed problem for the fourth order ordinary differential equation with general boundary conditions is considered in present paper. Soluion of the problem is found by the residue method. According to the scheame of this method the mixed problem is divided by two auxiliary- specrtal and Cauchy problems. After researching these two problems, solution of the considering mixed problem is found by residue series. It is shown , that solution of considering mixed problem surround not only parabolic equations in the sense of Shilov, but also wider classes of equations.

Summary: The thesis discusses interactive technologies for creating easy-to-understand programs by minimizing latency. What interactive techno-logy is and where it is used have been investigated. Which technologies can be interactive, how can we create interactive programs with basic elements, the design of interactive applications, its negative and positive aspects, and such issues are analyzed. Its primary benefit in the manage-ment field is explained, and its applications to increase efficacy in various sectors are also discussed. In this thesis, we can see the impor-tance of the interactive approach and its positive impact on other areas. At the same time, we will witness that future life will be mostly interac-tive, and people will reach their goals more easily thanks to applications. It is emphasized that the main starting point for the interaction of developed technologies is good design, and what are the necessary conditions for this design.

Summary: This paper considers the issue of assessing the security of a key exchange protocol based on matrix algebra. To protect the confidentiality of information, it is important that the keys are exchanged securely. This can be done by using methods such as encrypted key transmission, creation of dedicated secure channels, formation of a common key between parties without exchanging secret information using public key algorithms, etc. The paper analyzes the security of the protocol implemented using the approach based on non-invertible matrices against linear algebra and brute force attacks, shows that the use of non-invertible matrices increases the security of the system, and also evaluates the consumption of computing resources. The results confirm that this approach can be used as a secure and practical method of key exchange.