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.

Cold pressing of flaxseed produces high-quality oil along with a nutritionally rich by-product—flaxseed cake. While the cold-pressing process is valued for its minimal processing and preservation of oil quality, it is also characterized by low resource utilization efficiency and significant by-product generation. Specifically, the production of 1 kg of flaxseed oil results in approximately 2 kg of residual cake. Given its high protein content (approximately 35–40%), flaxseed cake holds considerable potential as a source of bioactive peptides and other value-added compounds

In this study, flaxseed cake obtained from cold pressing was milled and sieved to a particle size below 0.6 mm. Its chemical composition (protein, oil, fiber) was analyzed. Controlled enzymatic hydrolysis was performed with Trypsin for 2 h. An E/S ratio was 5 %, and the temperature used for hydrolysis was 37 °C. The antioxidant capacity of the non-hydrolyzed sample and hydrolysate was determined.

Protein content was 37 %, oil was about 21 %, and fiber was approximately 28 %. The results showed a degree of hydrolysis of about 5 % and a significant increase in antioxidant activity. By determining the concentration of flaxseed powder required to inhibit 50 % of the DPPH free radicals, it was observed that this concentration was significantly (p < 0.05) higher in the non-hydrolyzed sample (11.0 mg/mL) compared to the hydrolysate (9.1 mg/mL).

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. 

The beginnings of artificial intelligence are linked to 1956 and the Dartmouth conference organized by Stanford University. From those beginnings until the end of the 20th century, its development was relatively slow due to hardware and software limitations. However, the 21st century brings a turning point in every sense. ln the 21st century, there was also a division into specialized artificial intelligence, which was primarily developed in the 20th century, and general artificial intelligence, on which the focus of development has been placed in recent decades. The positive economic effects of the adoption of artificial intelligence, according to the conducted research, are unequivocal. The effects on individuals and humanity are significantly more open to discussion. Almost half of the respondents in the conducted research are not in favor of accepting artificial intelligence for private purposes, and the other half is almost equally divided between those who do not have an opinion on this issue and those who are not against its acceptance. About 70% of respondents believe that artificial intelligence can become a threat to humanity and the mental health of individuals. At the same time, the majority of respondents do not see challenges in their employment. As a solution, the respondents see a clear and strict regulation of the development and possibilities of artificial intelligence itself. Institutions of the society we live in and companies that develop artificial intelligence are seen as responsible for this regulation. A real step in this direction was taken by the European Union with the adoption of the Act on Artificial Intelligence in March 2024. What is expected is that this example of the EU will be followed by other countries, which would ensure the correct development and use of artificial intelligence for the general benefit of humanity, which it should serve. 

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.