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.

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.

Science is built upon the continuous re-evaluation of evidence and empirical research driven by the desire for success and the fear of failure, while religion is based on the unconditional acceptance of original dogmatic traditions and fundamental principles of belief in God and eternal reward, coupled with the fear of divine punishment. Metaphysics, as the foundation of philosophical scientific thought, examines the nature of reality and existence, asking questions about what exists, why, in which time, space, and causality. Disaster risk management is an exact scientific discipline established on metaphysical examinations of causes and phenomena, along with mathematical models of prediction and consequence analysis. This paper explores the intriguing correlation between the logical relationships of metaphysical principles and disaster risk management. By delving into the philosophical realm of metaphysics, we analyze concepts such as uncertainty, causality, and the nature of reality. Drawing correlative connections, we examine the development of a logical matrix of cause and effect to better understand metaphysical principles that can timely alert decision-makers and improve their risk management strategies. Researching the interconnections of fundamental principles in the domains of risk, impact, and response capacity to crises offers a fresh perspective on addressing uncertainty and making informed decisions in complex situations. Conclusions will be defined using analytical-deductive and synthetic methods, comparing the relationship between metaphysics and applied science within the framework of the multimillennial challenges faced by humanity, from the time of Noah's flood to contemporary crises and approaches to resolving them. The paper will scientifically determine risks, impacts, and capacities for more effective responses to climatic and socio-political crises, challenging the professionalscientific community to proactively offer answers to the question: Can the acceptance and understanding of the 3D logical model of integrated application of metaphysics and risk management contribute to reducing the vulnerability of humankind?

Pediatric arrhythmology deals with studying of frequency and regularity of heart rhythm disorders in childhood. Rhythm disturbances (dysrhythmias, arrhythmias) occur as a result of disturbances in the creation or conduction of stimuli in the specific or working musculature of the heart. Simplifying the knowledge of everyday work on pediatric arrhythmias, they can originate from the atria of the heart when we speak about supraventricular arrhythmias or from the heart chambers when we talk about ventricular arrhythmias. There are currently three major problems that burden pediatric cardiologists and pediatric arrhythmologists, and which are the focus of interest in pediatrics as a whole. These are primarily sudden cardiac death in children (SCD), fetal arrhythmias (FA) and postoperative-incisional arrhythmias (IA). The development of pediatric arrhythmology is imperative in the development of pediatrics and pediatric cardiology.

Given the undeniable clinical and prognostic value, the function of the left atrium (LA) plays a leading role in the contemporary evaluation of cardiac diseases and is considered an essential morphological substrate for the development of cardiovascular diseases. It is sensitive to nervous, endocrine, and immunological stimuli. New evidence from the literature highlights the importance of fibrotic, electrical, and autonomic remodeling of the LA, introducing the concept of atrial cardiomyopathy, which is closely associated with atrial fibrillation and stroke. In the past, the diameter of the LA was the most important parameter for assessing its characteristics, but new information about the various roles of the LA has created the need for parameters that more precisely or thoroughly evaluate LA function. The function of the LA is complex, consisting of three phases: the reservoir phase (ventricular systole), the conduit phase (early diastole), and the pump phase (late diastole). The introduction of myocardial deformation analysis, or strain of the LA via speckle tracking, has achieved significant progress in detecting even subtle functional abnormalities before an increase in LA size. This method improves the diagnostic capabilities of standard echocardiographic examinations, and its diagnostic and prognostic value is sometimes comparable to more advanced and less accessible techniques such as cardiac magnetic resonance imaging and computed tomography.

Introduction/purpose: The paper presents the multi-criteria Fuzzy DIBR-Fuzzy DIBR II-EWAA-BM-DEXi-Fuzzy LMAW model for choosing a location for crossing water obstacles by fording in a defense operation. After the identification of the criteria by experts in this field, the mentioned model was applied and the optimal point was determined. In order to test the consistency of the results and the validity of the model, experts were consulted again, and the sensitivity analysis and the comparative analysis were performed. Methods: The Fuzzy DIBR and Fuzzy DIBR II methods were used to determine the weighting coefficients of the identified criteria, while the aggregation of the expert opinions and the obtained values was performed using the EWAA and BM operators. To select the optimal location, the Fuzzy LMAW method was applied, while the linguistic descriptors were determined using the DEXi decision support system. Results: The proposed methodology made it possible to identify all the criteria that determine the choice of a location and the choice of the optimal point for crossing a water obstacle in a defense operation. The testing of the model by experts, the analysis of the sensitivity of the output results to changes in the weights of the criteria and the comparison of the obtained results with the results of other methods indicated the fact that the model is valid and that it gives consistent results. Conclusion: It was concluded that the multi-criteria model provides the necessary help to decision makers in conditions of imprecise and unspecified information and that it is applicable in real situations. Also, the proposed model takes into consideration all the aspects that must be considered when making such a complex decision and helps less experienced officers in the decision-making process, reducing the possibility of errors, which can result in human casualties. Finally, directions for further research in the field of overcoming water obstacles and multicriteria decision making are suggested.

Distributed generation (DG) especially energy acquired from renewable energy sources (RES) plays a significant role in modern power sector due to high carbon emissions around the globe. Its emerging potential is feasible by implementing microgrids as they are beneficial for networks in terms of increasing flexibility and stability, providing frequency and voltage support, power factor compensation etc. This makes the investment into microgrid incorporating RESs attractive, while at the same time reducing overall investment in the grid. Higher cost and stochastic nature of intermittent RES are complications for the implementation and operation of such solutions. This paper will analyse economic feasibility of hybrid power system (HPS) implementation consisting of a wind generator (WG), a photovoltaic system (PVS), gas combined heat and power plant (CHP) and storage batteries. Each of the elements is optimized according to power demand and RES’s potential. Technical analysis of the grid integration, parallel operation of the system and the grid is analysed with an example of a real medium-voltage distribution network operating in Bosnia and Herzegovina by using quasi-dynamic load flow simulation of one-week time-period. Finally, different operating mechanisms and strategies will be proposed, following the minimal power form the grid premise to satisfy maximum usability of RES’s potential. It is shown that implementing such HPS would be beneficial in terms of both economy and, ecology, as well as in reducing energy losses. Besides, it will reduce power supplying costs and energy losses, as well as and secure better exploitation and utilization of natural renewable energy sources. These technologies positively affect power network by decreasing the risk of network-components overloading, better exploiting the power-generation facilities based on renewable resources and positively impacting voltage profiles. Similar places, situated on remote locations, may use this analysis as an example to follow, to reduce their costs of electricity, acquire more reliable and sustainable power supply, and embrace green future.