This paper investigates the influence of design parameters on fluid leakage in axial piston pumps. Particular emphasis is placed on the analysis of operating clearances, sealing surfaces, and geometric relationships that affect volumetric efficiency and system reliability. Through a systematic review of 32 relevant sources, key components contributing to both internal and external leakage are identified, along with approaches for their optimization through material selection, microgeometry, tolerances, and thermodynamic conditions. Modern methods for diagnostics and leakage prediction are also considered, including the application of artificial intelligence and numerical simulations. The findings of this review may serve as a basis for improving the design and maintenance of axial pumps, with the aim of increasing efficiency and reducing losses.

Historical buildings represent an essential part of cultural identity and architectural heritage, particularly in countries with rich historical and urban traditions such as Serbia. However, these structures are increasingly exposed to environmental, structural, and seismic risks while simultaneously facing demands for improved energy performance and sustainable use. This paper presents an overview of the current state of research related to risk management, energy efficiency, and seismic vulnerability of historical buildings in Serbia, based on recent literature and case studies. The paper analyzes traditional construction systems, seismic assessment methodologies, energy retrofitting strategies, and sustainable regeneration approaches applied to protected historical buildings. Historical buildings in Serbia possesses significant cultural and environmental value, but there are often problems with poor thermal performance, old and aging materials and structural vulnerabilities. Through literature review is shown that integrated and context-sensitive interventions can significantly improve both the seismic resilience and energy efficiency of historical buildings while preserving their architectural authenticity and cultural significance.

The subject of this paper is the consideration of HRM determinants in relation to the quality of Product Carbon Footprint (PCF) data and the success of the integration of CBAM requirements. The framework is based on the Carbon Border Adjustment Mechanism (CBAM), which is implemented as an instrument of the European Union (EU) for equalizing the carbon price in imported products. Calculations, change significantly depending on methodological choices. The transparency of the calculation is often limited, making it difficult to use data in regulatory compliance confirmation processes. Green HRM points out that training, organizational culture and systemic HRM practices contribute to sustainability and performance, emphasizing the role of employee training and intermediary mechanisms through supply chains. The empirical part of the paper is designed as a quantitative-qualitative analysis of the data collected through the survey. The results indicate that organizational readiness and support from top management are key predictors of successful integration of CBAM requirements, while PCF data quality is a critical operational factor, and the impact of HRM practices is significant, but indirect. In conclusion, the integration of CBAM requires a multidimensional approach that goes beyond individual functions and requires the coordinated action of organizational, technological and management capacities.

This paper analyzes the potential of solar energy, the existing legal framework, and the state of installed capacities in the Republic of Serbia, in order to determine, through comparison with the European Union (EU) average, the degree of development and to identify opportunities for improving legislation. Solar energy is one of the fastest-growing renewable energy sources (RES) and a key element in achieving the European Union's climate neutrality goals. The study reviews the evolution of EU legislation, from RED I to RED III, together with the REPowerEU plan and the EU Solar Energy Strategy (2022). Serbia's solar potential exceeds the European average by approximately 30%, yet its utilization remains limited. The Law on the Use of Renewable Energy Sources (LURES) has largely transposed the RED II Directive, introducing measures such as the buyer-producer model, guarantees of origin, and market-based incentives. However, delays in adopting by-laws and incomplete harmonization with EU legislation hinder full implementation. The findings support the hypothesis that, despite favorable natural conditions and the existence of a partially harmonized legal framework, the share of solar energy in Serbia's total renewable energy capacity significantly lags behind the EU average, indicating the need for more intensive development of this sector and further alignment with EU legislation.

In mechanical engineering part design with usage of CAD/CAE software has become a necessity as one of the first steps in product production. In that stage, parts can be optimized or redesigned in order to achieve the requested design elements, like functionality, size, mechanical characteristics, etc. Through development of IT technologies, different software have almost the same possibilities for part optimization with application of various optimization algorithms. With that said, it is expected to obtain different optimization results with application of different optimization software. In this paper, we will compare the capabilities of Autodesk Inventor and SolidWorks to optimize part design for the purpose of mass reduction by using the topology optimization tools (Shape Generator in Autodesk Inventor and Topology optimization in SolidWorks) on example of mounting bracket.

Rad ukazuje na to koliko je bitno da se studenti, na fakultetima iz oblasti inženjerstva, osposobljavaju za rad u nekom od CAD (Computer-Aided Design) programa. Cilj je upoznavanje sa načinima pripreme studenata za njihovu dalju karijeru u oblasti inženjerskih grafičkih komunikacija primenom CAD tehnologija. To se može videti kroz teorijsko istraživanje metoda učenja i njihov uticaj na studente, kroz ispitivanje zaposlenih inženjera o CAD programima, kao i kroz testiranje studenata na osnovu usvojenog znanja i zainteresovanosti o CAD programima nakon završenog kursa.

Additive manufacturing, or 3D printing, is production technology for manufacturing parts, especially parts with complex geometry or complex structures. It opens different possibilities in part mass optimization, rapid prototyping as well as sustainable production and waste minimization. It is applicable in different fields such as mechanical engineering, civil engineering, medicine, food industry and so on. Manufactured parts from additive manufacturing can be very diversive depending on used technology and applied material. On qualitative features of 3D printed part can be influenced through various segments of additive manufacturing production from 3D modeling (optimizing model for 3D printing), 3D models slicing and production parameters adjustments (from the applied slicing software), 3D printer settings and used printing technology (applied material and used printing technology such as FDM or SLA, etc.) to 3D part post process treatment. This paper describes current 3D printing technologies, materials and methods for achieving functional 3D printed parts.

The growing negative impact of human activities increases the effect of climate change. People must adapt and change their behaviour and attitudes towards solving current environmental problems and preventing new ones. Non-formal education, such as educational workshops on environmental topics, could give results in the short term. In this research, workshops on energy efficiency and climate change were used to increase environmental knowledge and to track changes in environmental attitudes regarding generational affiliation. Workshops for pupils were held in selected primary schools in Vojvodina region in Republic of Serbia. The achievement of workshops on energy efficiency and climate change attitudes at pupils and transfer of the knowledge gained at workshops to their parents were considered through the following three attributes: perception of personal knowledge and awareness, intensity of intergenerational communication, and knowledge. Assessment of the workshops’ achievements was accomplished by preliminary and final survey, and results were compared using descriptive and inferential statistical methods. Key findings in this research revealed that there is a significant potential for changes in the attitudes by raising awareness through knowledge in pupils, but also at parents, through intergeneration communication and knowledge transfer.

In current production and industry development usage of modern technologies has become an imperative for efficient production process. Additive manufacturing contributes in production through its versatility for usage (production of complex shapes and different usage of materials and manufacturing technologies), and the usage of virtual or augmented reality improves the visualization of the machine design process. Both technologies, in combination with CAD/CAM/CAE software provide the economic and time advantage in production. Design for maintainability (DfMa) is an integral segment of Design for Excellence (DfX) that represents the systematic and proactive approach to design so that the final product would cost less while maintaining reliability, quality, durability, as well as customer expectations. In this paper it will be discussed about the usage of additive manufacturing and virtual and augmented reality from the design for maintainability point of view and the benefits that they are bringing in the overall design and production process.

The study explores the state of energy efficiency in residential buildings in the city of Zrenjanin through an analysis of a survey conducted among 662 respondents. The results indicate a prevalent issue of the inability for collective investment in the energy efficiency of communal residential buildings compared to single-family homes. By using the Chi-square test of independence, a statistically significant relationship between the type of residential property and the presence of external thermal insulation was discovered. Additionally, a moderate dependence between the age of the heating system and the need for additional heating was identified. The research’s conclusion suggests the need for subsidies to improve the energy efficiency of residential buildings, especially multi-family complexes, to achieve sustainability and reduce energy consumption in the urban environment of Zrenjanin.

The importance of the usage of renewable energy sources in powering wireless sensor nodes in IoT and sensor networks grows together with the increasing number of utilized sensor nodes. Considering the other types of renewable energy sources, solar power differs as the most suitable one and emerges as the major source for powering sensor nodes. Thus, the consideration of using sensor nodes and collected sensor data for estimating solar panel performances and therefore solar power potential can improve the efforts in this direction. This paper presents the methodology for implementing edge intelligence on wireless sensor nodes for solar panel output voltage estimation and forecasting. The methodology covers the usage of the Python Scikit-learn package and micromlgen library for the implementation of edge intelligence on Arduino clone-based sensor nodes, particularly the development boards based on the ESP8266 chips. Scikit-learn is used for analyzing the efficiency of various regressors on collected solar data. The micromlgen library is then used for implementing those regressors on Arduino and clone nodes. The prediction of solar panel voltage generation is based on a single-sensor reading—UV or BH1750 light sensor. The Random Forest and Decision Tree regressors are implemented on the ESP8266-based development board—Wemos D1 R2. The estimation accuracy of the RF model is an MSE of approximately 0.10, MAE of 0.07 for UV and 0.04 for BH1750, and an R2 of approximately 0.93 for both UV and BH1750 light sensors. The Decision Tree model has a lower accuracy with an MSE between 0.13 and 0.14, MAE of 0.07 for UV and 0.04 for BH1750, and R2 of 0.90 and 0.89 for the UV and BH1750 sensors, respectively. The methodology and its efficiency are presented and discussed in this paper.

The authors analyze two very important topics, which are intertwined, and relate to the legal regulation and application of solar energy in agriculture in our country. Solar energy reduces the costs of agricultural production in the long term and increases sustainability and competitiveness. Therefore, when it comes to the application of solar energy in agriculture, an important factor that directly affects market positioning is the greater competitiveness of food produced using clean energy. In addition, legal frameworks significant for the use of solar energy in agriculture at the European level and within the borders of the Republic of Serbia were considered as the subject of the paper. The Republic of Serbia has real potential for the production and application of solar energy, but these potentials are not sufficiently used, and the experiences of EU countries can be significant when adopting measures from the sphere of energy policy, especially if one takes into account the context of European integration in accordance with environmental protection.

Rechargeable batteries are historically the oldest chemical source of electricity, and are still used today as a backup source of electricity to support power plants operation. The batteries connected to the auxiliary DC voltage busbars are powered from the AC mains by means of industrial electronics devices. The paper presents a study of the choice of appropriate battery maintenance methodology in order to increase the safety of thermal power systems, reduce system failure and increase reliability. A proposal for preventive maintenance through regular inspections and periodic replacement of individual cells is presented. The search for weak cells and their elimination is accompanied by technical diagnoses and tests of correctness and capacity. Finally, the results of the tests carried out at the Zrenjanin thermal power plant (the part of the company Panonske Termo-elektrane—toplane Zrenjanin) at five-year intervals are presented. In the concluding remarks, the need for maintenance is emphasized with a view to improving the system and reliability.

Energy efficiency, sustainability, and renewable energy sources are becoming increasingly relevant topics in today’s world. Buildings are one of the largest consumers of energy in society, and as such, improving their energy efficiency by reducing unnecessary energy loss and utilizing solar power is crucial. This paper comprehensively analyzes a neighborhood with buildings characteristic of the researched area by applying empirical and theoretical methods and calculations that have been proven in numerous individual cases. The main contribution of this paper is its demonstration that implementing methods to increase the energy efficiency of buildings and utilizing the potential of solar power can result in significant savings in energy consumption, increase the energy sustainability of the analyzed buildings, and substantially reduce the negative environmental impact. The novelty of this study lies in the location and multiple software applications for data analysis. The data and conclusions obtained in this paper serve as a foundation and path towards sustainable development in the field of energy efficiency for buildings in this and similar areas. Heat loss was calculated by analyzing households in the urban neighborhood of Nova Kolonija. All analyzed houses exceeded the maximum allowed annual required energy for household heating (75 kWh/m2). After the reconstruction and implementation of the proposed measures to increase energy efficiency, all houses met the requirements and entered a higher energy class, C. Energy for heating was reduced from 9294.68 kWh/a to 4641.84 kWh/a, representing a reduction of 50.03%. Simulations were conducted regarding solar rooftop power plant installation of 5655 Wp capacity. Software that was used included: a Photovoltaic Geographical Information System (PVGIS), Photovoltaic System software (PVsyst 7.3.), and Photovoltaic Design and Simulation software (PV*SOL). The results of the analysis indicated that the average amount of electricity produced is 6186.98 kWh, which meets 98.12% of households’ annual electricity consumption of 6278.41 kWh. The paper contributes to the existing body of literature and provides significant insight for both practical implications and future studies.

In the era of rapid technological growth, we are facing increased energy consumption. The question of using renewable energy sources is also essential for the sustainability of wireless sensor networks and the Industrial Internet of Things, especially in scenarios where there is a need to deploy an extensive number of sensor nodes and smart devices in industrial environments. Because of that, this paper targets the problem of monitoring the operations of solar-powered wireless sensor nodes applicable for a variety of Industrial IoT environments, considering their required locations in outdoor scenarios and the efficient solar power harvesting effects. This paper proposes a distributed wireless sensor network system architecture based on open-source hardware and open-source software technologies to achieve that. The proposed architecture is designed for acquiring solar radiation data and other ambient parameters (solar panel and ambient temperature, light intensity, etc.). These data are collected primarily to define estimation techniques using nonlinear regression for predicting solar panel voltage outputs that can be used to achieve energy-efficient operations of solar-powered sensor nodes in outdoor Industrial IoT systems. Additionally, data can be used to analyze and monitor the influence of multiple ambient data on the efficiency of solar panels and, thus, powering sensor nodes. The architecture proposal considers the variety of required data and the transmission and storage of harvested data for further processing. The proposed architecture is implemented in the small-scale variants for evaluation and testing. The platform is further evaluated with the prototype sensor node for collecting solar panel voltage generation data with open-source hardware and low-cost components for designing such data acquisition nodes. The sensor node is evaluated in different scenarios with solar and artificial light conditions for the feasibility of the proposed architecture and justification of its usage. As a result of this research, the platform and the method for implementing estimation techniques for sensor nodes in various sensor and IoT networks, which helps to achieve edge intelligence, is established.

We live in a time characterized by rapid technological changes in almost all spheres of life.Education must therefore be much more flexible and open to all the challenges of the 21st century.Modern educational information and communication technologies introduce innovations in the way of implementing the teaching process in order to overcome many shortcomings and in the function of modernizing education.One of the goals of modern university education is to connect formal (university education) and informal through the acquisition of applicable professional knowledge and skills through the student's work on practical problems in companies.With this combination, students who choose it, get both theoretical and required practical knowledge and skills.Applying the dual principle in the modernized system of higher professional education in Serbia will be of key importance in attracting employers and companies, as well as introducing support mechanisms that would ensure the quality of the learning process in both learning environments.At the Technical Faculty "Mihajlo Pupin" Zrenjanin, University of Novi Sad, Serbia, students' professional practice after the third and fourth year of study has been conducted for many years.This paper analyzes the role of new technologies, engineering, and other communication in the work of students of our faculty and future engineers, in solving specific problems in the industry.Also, the importance of lifelong education is highlighted as one of the elements supporting the need to introduce some modern forms of learning.

Energy efficiency has become imperative in design of vehicles. Energy efficiency can be viewed from multiple aspects like economy to environmental (from cost of transportation to carbon emissions). There are many factors that have influence on energy consumption in any type of transportation (by land, water or air) and one of them is vehicle mass. In this paper the current methods for reducing vehicle mass will be shown.

Thermoplastic materials have great usage through FDM 3D printing technology. Today, FDM 3D printer is available to the broad population, and some of the thermoplastic materials is widely used due to their small price and availability. Such thermoplastic materials are ABS (Acrylonitrile butadiene styrene) and PLA (Polylactic acid). In this paper the possibility of drone frame design optimization that can be made from ABS and PLA plastics using FDM 3D printing technology is analyzed.

Achieving sustainable development requires strategic efforts involving the entire organization. Maintenance efforts also play an important role. Company management needs to understand and develop an appropriate strategy to achieve sustainable development by applying maintenance performance measurements. The aim of this paper is to present possible ways of analyzing and ranking the impact of certain criteria with respect to achieving sustainability. The paper uses the method of Structural Equation Modeling-SEM in order to determine the most influential variable on the sustainability of maintenance of technical systems. Based on the set theoretical system model, for all its variables in the model, statements were made that describe them, on which 136 respondents gave their views (from 1 to 5, Likert scale) in the territory of the Republic of Serbia. An intuitive F-DEMATEL method was also used to prioritize variables. A team of 10 experts in the field of maintenance of technical systems was compared the criteria A-Application of technical diagnostics, B-Management of maintenance resources, C-Maintenance process planning, and the dependent variable D-Sustainability of maintenance of technical systems. According to experts, the importance of the criteria coincides with the results obtained by a survey with 136 respondents.

Serbia, as a developing country and EU accession country, faces many challenges. One of the key areas identified as the most complicated problem in the negotiation process is the issues of environmental protection and improvement, including the energy sector. Since population in Serbia is concerned because of poor living standards, high unemployment rate, and other social issues it could be questioned what is their concern and awareness about climate change since it is a realistic and visible phenomenon that is hard for someone to ignore and neglect. This paper presents some of the results of a survey conducted among adults in rural and urban parts of the Autonomous Province of Vojvodina on their perception, awareness, and knowledge about climate change issues. The research/survey also examined the specific actions that respondents would take as a personal contribution to mitigating the effects of climate problems. The results indicate that respondents have a high awareness of climate change, but the knowledge on climate change is relatively low even though the respondents graduated from faculty (about 52%).