This paper tries to highlight the importance of identifying dimensions of service quality and their impact on the satisfaction and loyalty of users of services provided by insurance companies in the Republic of Serbia. The focus of the study is on analyzing the key parameters of service quality and user satisfaction. The aim of the paper is to investigate the differences between expected and perceived characteristics of insurance services based on the Servqual model. The total sample in this research is 112 respondents. The specific objectives are the analysis of the differences in the ratings of the dimensions of the expected and observed attributes of the Servqual scale in relation to socio-demographic variables, such as gender, age and level of education. Based on the results of empirical research, it was concluded that all service quality parameters play a key role in user satisfaction. The results show that the five basic dimensions of Servqual – tangibility, reliability, accountability, security and empathy – have a significant and positive association with overall perceived service quality

This study provides a new perspective on trust in artificial intelligence (AI), examining people's attitudes toward trust in the use of AI systems in particular. The aim of this study is to examine attitudes and to know what are the advantages and disadvantages of artificial intelligence (AI). Also, in addition to the empirical part, this paper also deals with theoretical knowledge about artificial intelligence, which is the basis of the existing literature. For the purposes of this research, the authors created a survey based on secondary sources. The survey was conducted on the entire territory of Serbia. The subject of this work is the examination of the attitudes and knowledge of the inhabitants of Serbia about artificial intelligence as well as its technologies, which focuses on a deeper understanding of the perceptions and attitudes of the public in Serbia about artificial intelligence.

Ensuring the proper operation of a ship’s propulsion system necessitates the use of high-quality fuels. Several factors contribute to fuel quality, including the source of origin crude oil, refining methods, blending processes, and the quality of storage and distribution. Marine fuels must adhere to international standards such as ISO standards to be suitable for consumption on ships.

This article presents an analysis of over 6000 fuel samples obtained from two sample points within a purification system, conducted by independent laboratories. While all samples must meet the ISO 8217:2017 Standard for marine residual fuel before bunkering, this analysis focuses on elements with potentially harmful effects on marine engine systems. A comprehensive examination will be conducted, employing an inductive method to draw general conclusions about the current levels of abrasive impurities and other detrimental elements in fuels post-purification.

Specific attention will be given to elements like aluminium, silicon, vanadium, calcium, magnesium, lead, nickel, potassium, sodium, zinc, and phosphorus present in residual fuel oils. These elements, in certain forms or concentrations, pose challenges to marine engines. Testing conducted according to the IP 501 standard, utilizing inductively coupled plasma emission spectrometry, is essential to ensuring smooth engine operation and mitigating damages and associated costs caused by abrasive fines in the fuel oil.

Aluminium and silicon particles in fuel known as “cat fines” are catalytic residues from the refinery process. They can cause mechanical damage to fuel pumps, injectors, piston rings and cylinder liners. They are very hard and highly abrasive, thus causing abrasive wear to main engine components. These impurities in marine fuel must be minimised to recommended levels. One of the main tasks of the fuel treatment plant on a ship is to separate solids and water from the fuel. Modern vessels are equipped with fuel separators which rotate at a high speed (more than 6,000 rev/min) producing centrifugal force and providing good separating effect even for small solid particles (Al+Si). Proper settling and regular drainage from the tanks, even when adequate filtration is applied, are not sufficient for proper fuel preparation. The quality of purifier operation varies over years because it is affected by a large number of factors. For the purpose of this paper, over twelve thousand fuel samples were analysed to determine the current efficiency of the purifiers and whether they can meet the stringent requirements of marine engine manufacturers. The data will be taken from a tanker ship, considering different operational scenarios. These scenarios are linked to the maximum possible fuel consumption on the ship during exploitation. Using the Simulink program for the system simulation, optimisation can be achieved in the operation of fuel separator. This optimization refers to the required amount of fuel and quality of separation, particularly concerning the removal of abrasive impurities.

The existence of an efficient system of public health care in the social community is a characteristic for a quality social entity and a measuring element of the life quality in a population. Like any other sub-system in the state, it is necessary to finance the sustainable development of the public health system. The paper contains an analysis of several payments models from the funds of the obligatory health insurance to the health system and health service providers, with a presentation of the existing systems and models of covering costs. For this purpose, research was conducted by comparing historical data on health care costs and analyzing their trends. The aim of the paper is to research and select adequate financing models for provided health services, which is the job of managers in health care, in order to choose between several models developed for this purpose. The manner in which health care costs are settled in the Republic of Srpska, as well as the amounts in the observed period, is also shown. Conclusions on trends confirmed, that the costs of medical treatments, for which the state allocates money for the health care system, are increasing. At the same time, it was observed that the number of insured persons is decreasing, and that despite the relatively high average allocation for treatment per capita, considerable amounts of direct personal payment for services and medicines are still high, which are either not available from obligatory health insurance, or are difficult to access through regular procedures. Keywords: health care, health insurance, medical costs, financing models.

This study explores the use of natural plant extracts as a sustainable method to enhance the quality and safety of long-life sausages by incorporating them into natural edible casings. Ethanol (E) and aqueous (A) extracts of blackthorn (BT) and red cherry (RC), as well as their ethanol and water-based solutions, were prepared and analysed for their antioxidant and antimicrobial properties. The analyses included the quantification of total phenols, non-flavonoids, flavonoids, flavonols, and anthocyanins, along with antioxidant activity assessments using FRAP, DPPH, and ABTS assays. Antimicrobial efficacy was tested against Gram-positive and Gram-negative bacteria (Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella enterica) and mold Penicillium expansum via agar dilution methods to determine MIC and MBC/MFC.

Results showed that ethanol extracts had higher antioxidant activity than aqueous ones (p<0.05), with the ethanol extract of blackthorn (EBT) containing the highest levels of phenolics (54.11 mg GAE/g d.e.) and exhibiting the strongest antioxidant, antimicrobial, and antifungal activities. Casings treated with EBTE (ethanol BT extract dissolved in ethanol) demonstrated significant antibacterial properties, particularly against Gram-negative bacteria. This study confirms that plant-extract-enriched natural casings can protect against oxidation and microbial spoilage, thereby enhancing the overall quality and safety of dry-cured sausages. 

In this paper, we explore the potential of blockchain technology to enhance public  administration efficiency in Bosnia and Herzegovina. Facing challenges in communication and service delivery between the government and its citizens, our research investigates how blockchain can provide solutions. We employed questionnaires to gather citizens' opinions and conducted a comparative analysis of best practices from countries that have successfully implemented blockchain in public sectors. This approach allows us to identify specific areas where blockchain, particularly through smart contracts and hybrid networks, can improve efficiencies and outcomes. Blockchain technology, known for its decentralization, transparency, and security features, shows promise in several sectors, including finance, cryptocurrency, business support, and law, offering substantial benefits. Our analysis suggests that by adopting similar strategies, Bosnia and Herzegovina can address many current issues undermining public administration effectiveness. Our findings, based on citizens' feedback and international case studies, indicate that the existing system falls short in efficiency, underscoring the need for innovative solutions like blockchain to enhance public service delivery. We acknowledge potential challenges in implementation, such as technological infrastructure, legal frameworks, and socioeconomic considerations. Despite these hurdles, our research presents a compelling case for blockchain technology as a means to facilitate  more effective communication and services between the government and its citizens. We conclude with recommendations for adopting blockchain technology in Bosnia and Herzegovina's public administration, supported by our comparative analysis and questionnaire insights. Additionally, we suggest areas for future research to continue exploring the transformative potential of blockchain in public services

The digital technological revolution began in the second half of the last century. Its development in the first decades after the discovery of the transistor was rather slow. Acceleration and a wider awareness of the possibilities began to spread after the introduction of the Internet. And then the last two decades brought rapid development of digital technologies and general acceptance in private and business life. The benefits for individuals, companies, institutions and society as a whole are enormous and unquestionable. Nevertheless, bearing in mind the conducted studies on the degree of digitization of certain areas of society and certain countries, it is considered that the potential is huge. And significant breakthroughs supported by artificial intelligence are still expected. However, in addition to the undoubted benefits, there are also certain negatives, which are not sufficiently clarified or which are often obscured. Therefore, this paper aimed to determine the attitudes of the users themselves towards digital technologies, and in its last part, it examined the existence of negative effects on the mental health of users of digital technologies. The results are expected in the part of the examination of the benefits arising from the use of digital technologies. The existence of negative effects on the health of users is not a surprise either. The surprise is the degree of negative impact and lack of corrective action by the user. In other words, users are aware of the negatives that arise from, primarily, the excessive use of digital technologies, but they still do almost nothing to reduce these negative consequences.

Observed from the school education system, it can be said that the entire educational activity should respect the needs and possibilities of each student and develop his potential to the maximum. In parallel with the development of students' potential, the students' needs for everyday coping and solving problem situations also grow. Contemporary views on students' acquisition of knowledge and skills in mathematics teaching is learning through inquiry and problem solving. In this paper, we will answer the question whether the application of problem-based teaching makes the teaching of mathematics interesting for students. We will examine how students, parents and teachers think, to what extent the application of problem-based learning, teaching and problem solving in mathematics classes makes mathematics teaching interesting for students, from the perspective of students, parents and teachers. 

Optical detection of plant stress in real-time is crucial as it enables timely interventions to mitigate potential damage. This study presents a detailed evaluation of a system that detects changes in plant metabolism in real-time by distributing optical signals across the leaf. The methodology facilitates continuous monitoring of changes in the optical properties of plant leaves through measurements of optical transmission coefficients using a 665 nm LED light signal, thereby recording the circadian rhythm over time. Given that the photosynthetic processes within the leaves are closely linked to the plant’s overall health, this system can detect stress caused by various factors and identify metabolic changes by analysing the circadian rhythm patterns of the observed plants.
For inducing metabolic changes, the plant Vriesea carinata Wawra, a verified representative of dual metabolism, was subjected to high light intensity stress. To validate the method, the collected results were compared with data obtained through chemical methods to establish a correlation between the traditional, destructive method and the non-destructive, optical method.
The findings successfully identify circadian rhythms as parameters for recognizing changes in plant metabolism, demonstrating the significance of the proposed method in researching plant physiology through the optical identification of biological processes.