We investigate a discrete counterpart of planar dynamical system of nonlinear differential equations induced by kinetic differential equations for a two-species chemical reaction. Chemical reactions exhibit a wide range of dynamical behavior. We show how the theoretical analysis provides insight into the potential behavior of chemical reaction systems, determining the areas of parametric space which indicate scenarios for local stability, then for one type of bifurcation co-dimension one and one type of bifurcation co-dimension two. Precisely, we prove the existence of period-doubling bifurcation and 1:2 resonance bifurcation also, by using the center manifold theorem and the technique of normal forms. All mathematical investigations are illustrated with numerical examples, bifurcation diagrams, Lyapunov exponents and phase portraits.

In this study, the selection of suppliers within an alternative food supply network for fruits and vegetables, specifically Box Schemes, was conducted using multi-criteria decision-making methods. The Entropy-MABAC method was used as the multi-criteria decision-making approach, and the research focused on five suppliers from the city of Novi Sad. Eleven socioeconomic criteria were chosen for the research to identify the most favourable supplier. The results indicate that the criterion "product character," i.e., whether the final agricultural product is organic or conventional, was rated the highest, and the first supplier was selected as the most favourable. These results provide a solid foundation for future research, which should focus on further examining the impact of supply methods on end consumers of agricultural products within the alternative food network and developing new methods to aid in selecting the most favourable supplier.

The aim of this research was to systematize the available literature on the types and frequency of locomotor injuries in combat sports. The sample consisted of martial arts athletes (judo, karate, wrestling, boxing and taekwondo) of both sexes, aged 11-49 years. Survey questionnaires and medical reports were used as measuring instruments for assessing injuries in the research. The found data, presented numerically and in percentages, were used for further analysis. The results of this research show that the characteristics of injuries of the locomotor system in martial arts usually do not depend on the sex of the respondents. There is a higher frequency of injuries in competitions and lower in training (except for under-18s). The most common locations of injuries (head and neck, extremities and joints), types of injuries (contusions, bruises and fractures), and severity of injuries (mild, moderate, or severe) depended on the characteristics of martial arts (sports techniques, tactics, physical and mental fitness, etc.). By applying additional methods, by improving physical preparation that is adequately dosed with the improvement of technical and tactical elements, injuries to athletes could be prevented.

AI-driven data analysis methods have garnered attention in enhancing the performance of wireless networks. One such application is the prediction of downlink throughput in mobile cellular networks. Accurate throughput predictions have demonstrated significant application benefits, such as improving the quality of experience in adaptive video streaming. However, the high degree of variability in cellular link behaviour, coupled with device mobility and diverse traffic demands, presents a complex problem. Numerous published studies have explored the application of machine learning to address this problem, displaying potential when trained and evaluated with traffic traces collected from operational networks. The focus of this paper is an empirical investigation of machine learning-based throughput prediction that runs in real-time on a smartphone, and its evaluation with video streaming in a range of real-world cellular network settings. We report on a number of key challenges that arise when performing prediction “in the wild”, dealing with practical issues one encounters with online data (not traces) and the limitations of real smartphones. These include data sampling, distribution shift, and data labelling. We describe our current solutions to these issues and quantify their efficacy, drawing lessons that we believe will be valuable to network practitioners planning to use such methodologies in operational cellular networks.

The casting industry uses large quantities of quartz sand, which is a cheap and accessible raw material that must be prepared for use in foundries. After the casting process, foundries generate huge amounts of waste foundry sand (WFS) as industrial waste. The regeneration and reuse of waste foundry sand is a practice and a necessity in many foundries for technological, environmental, and economic reasons. In this review paper, in addition to the characteristics of quartz sand for the casting industry and the characteristics of WFS, typical processes of regeneration in industrial practice, as well as the possibilities of using such recycled WFS in other industries, are presented.

The paper presents the results of testing the mechanical properties and evaluating the integrity of cylindrical head shells, which were obtained by the welding process and shaped by the cold process of gradual local deformation, i.e. the process of incremental deformation. Cylindrical head shells of pressure vessels are made from one part, but the standards also allow production in a welded version when the dimensions of the floors are larger than the standard dimensions of the sheets for production. Geometric shape and measurement tolerances are defined by a series of recommendations. The required mechanical properties and acceptance criteria for installation in pressure equipment are prescribed by PED 68/2014/EC and the BAS EN 13445 recommendation. The mechanical properties of the welded joint and the deformed material in the torospheric zone of the head shells, such as toughness, hardness and crack toughness, or their values are input parameters for determining the integrity of the floor structure. Using fracture mechanics criteria, detected faults can be categorized and evaluated with regard to the acceptability of the head shells for installation in pressure equipment or continued operation. The aim of the test is to determine the influence of the type of material, thickness and diameter of the head shells on the mechanical properties (ReH, Rm, A5 and KIc) and on the integrity of the cylindrical head shells.

Introduction: Treatment-resistant hypertension (TRH) is a frequent phenomenon, for which no complete solution has yet been found. More than 5% of patients treated for hypertension do not achieve blood pressure control with three first-generation antihypertensive drugs. Objective: The aim of this new cohort investigation, which is an extension of the TRYCORT study, is to re-examine the efficacy and safety of additional antihypertensive therapy in a group of adult patients with TRH. Methods: The study was designed as multi-national, multi-centre, prospective cohort study, which compared effectiveness and safety of add-on treatmentsof resistant hypertension. The patients were followed-up for 6 months, and primary outcome was treatment response. Results: In total139 patients completed the study(66women and 73 men), with average age of 63.6 years. Initial add-on therapy was changed at study visits if response to treatment was inadequate. The blood pressure below 140/90 mmHg was achieved in 75% of patients with add-on spironolactone, while effectively all patients achieved drop in systolic blood pressure ≥ 10 mmHg, and drop in diastolic blood pressure ≥ 5 mmHg. Only one treatment-related adverse effect was observed (pretibial oedema in patient taking amlodipine), while serum levels of potassium remaind within the reference limits. Quality of life increased and paralleled the treatment response. Conclusion: In conclusion, spironolactone proved to be the most effective and safe add-on therapy of resistant hypertension, but it needs several months of regular intake to achieve full effect and improve quality of life. Conclusion Spironolactone proved to be the most effective and safe add-on therapy of resistant hypertension, but it needs several months of regular intake to achieve the full effect and improve quality of life.

The UV-VIS method is an effective, non-destructive method that enables a better understanding of the electrolyte during corrosion. The aim of the study presented in this paper is to determine the existence of an organometallic complex in a 0.5 M NaCl solution with the addition of Rubus fruticosus L. leaf extract (RFLE). The experiments were conducted in a 0.5 M NaCl solution with the addition of RFLE (5 g/L and 10 g/L) with and without the immersion of a copper coupon. The results show that after the copper coupon standing in the electrolyte, there is a change in the absorbance maximum in the solution with 5 g/L RFLE, while no change is observed in the solution with 10 g/L RFLE. Such a change indicates the existence of a copper-RFLE complex in the solution with lower inhibitor concentration. In the case of RFLE, forming a copper complex with caffeic acid, isoquercetin and astragalin is possible. The absence of the complex at a concentration of 10 g/L RFLE can be attributed to a change in the mechanism and the lack of copper ions in the solution due to adequate corrosion protection.

This study investigates the kinetic models of Cu²⁺ ion adsorption onto clinoptilolite-rich zeolite. The study highlights the importance of diffusion kinetic models in understanding the adsorption process. The initial phases are significantly influenced by the ion diffusion through the film to the particle surface, particularly within the first 30 minutes, which is crucial for the heterogeneous surfaces like zeolites. Following this, the surface adsorption (intraparticle diffusion) is described by the Weber-Morris model, effective primarily during the initial stage. As the process progresses beyond 20-30 minutes, the ion removal rates decrease sharply, and diffusion within the particle core becomes the dominant factor, influencing the overall reaction rate.

This paper investigates the impact of explanatory variables that determine the financial stability of the banking sector in Bosnia and Herzegovina, and the possibility of controlling credit risk, which is a threat to the stability of the financial system for the period from 2009 to 2019 on a quarterly basis. Correlation and panel regression analysis are also applied in this paper. The selected independent (explanatory) variables are the growth rate of savings of the household sector, the growth rate of foreign direct investments, the growth rate of exports, the growth rate of total loans, the growth rate of non-per- forming loans, the growth rate of capital adequacy ratio, and unemployment growth rate. The GDP growth rate will be used as the dependent variable. The research results showed that the most significant impact on the GDP growth rate was recorded by the following variables: the growth rate of foreign direct investment, the growth rate of exports and the growth rate of total loans. On the other hand, the following variable recorded the most significant negative impact: the growth rate of the household sector. The study also shows that there is a positive causal relationship between the growth rate of non-performing loans and the growth rate of unemployment.

Rural tourism is gaining popularity due to a healthier stay in a less developed rural environment. Sarajevo Canton, Bosnia and Herzegovina’s most popular destination strives to enhance its tourism offer by developing rural tourism in its immediate surroundings. The “green ring,” a basin rim with preserved forest ecosystems and rural villages, serves as the foundation for the rural tourism product. The paper analyses the characteristics of rural tourism in the vicinity of Sarajevo and the role of stakeholders in planning rural tourism. Fieldwork, surveys, and interviews with tourism industry representatives were conducted to determine the cohesion of joint activity and the key features of rural tourism development. Domestic tourists make up the majority of rural visitors, although tourists from the Middle East and Europe are particularly interested in rural tourism. The top motives for visiting rural areas are walking and hiking, traditional gastronomy, and escaping from everyday life. The paper clarifies the challenges and barriers to rural tourism development.