The development of catalysts for the electrochemical reaction of hydrogen evolution is essential for the improvement of the water electrolysis process and the clean energy transition. Although catalysts from the platinum group are the most effective, their shortage and high-cost limit widespread commercial application. In this study, we developed catalysts in which ruthenium was replaced by more affordable ruthenium dioxide, and its amount was reduced by using abundant zinc oxide. The ZnO/RuO2 composite was prepared by microwave processing of precipitate and further thermally modified at 300 and 600 C, in order to examine the influence of oxygen vacancies on (photo)electrocatalytic activity in the water electrolysis reaction. Thermal stability of catalysts was determined by thermo-gravimetric/differential thermal analysis (TG/DTA) technique, while the phase composition and crystal defects were determined by X-ray powder diffraction (XRD) and photoluminescence (PL) spectroscopy, respectively. Electroand photoelectrocatalytic activity of the composite toward hydrogen evolution reaction was tested by linear voltammetry in acidic and alkaline electrolyte.

This study examined the capacitive properties of hierarchical porous carbon materials in the form of flowers, which were produced through optimized thermal treatment of synthesized particles of polyacrylonitrile (PAN) polymer. The results show that the materials retain their original morphological shape after carbonization and activation, along with a high specific surface area and a significant content of nitrogen functional groups. Thanks to these properties, the materials exhibit high specific capacitance up to 100 F g-1 in 6 M potassium hydroxide aqueous solution, and the ability for rapid ion transport through the porous structure. Interactions of nitrogen groups with ions in aqueous electrolytes further contribute to Faradaic redox processes, thereby enhancing overall capacitive performance and increasing energy density. These materials utilize environmentally friendly and safe aqueous electrolytes, improving their sustainability and practicality for applications in modern supercapacitors. The obtained results indicate the potential of these materials for use in high-performance energy storage devices.

The integration of Wireless Power Transfer (WPT) and Mobile Edge Computing (MEC) has enabled the development of Wireless Powered Mobile Edge Computing (WPMEC) networks, which are considered crucial for the sustainability of Industrial Internet of Things (IIoT) systems. The primary objective of WPMEC is to enhance the computational capabilities of mobile devices while compensating for their battery limitations. A WPMEC system consists of energy transmitters, mobile devices, and edge servers, forming a closed-loop structure. Due to network dynamics, limited battery life, and the half-duplex operation of mobile devices, the simultaneous resolution of computation offloading and resource allocation challenges in WPMEC networks is highly complex. This paper provides an overview of the fundamental characteristics of WPMEC networks. The key parameters for WPMEC architecture design are analyzed, several resource allocation models are presented, and critical challenges in their implementation are identified.

Accreditation represents one of the four fundamental elements of quality infrastructure. The bodies subject to the accreditation process include testing laboratories, calibration laboratories, medical laboratories, inspection bodies, and certification bodies for products, management systems, and persons. The main objective of this paper is to examine the correlation between socio-economic parameters and the number of accredited conformity assessment bodies in more than 30 European countries. To investigate the correlation, multivariate statistical methods were applied: Pearson correlation analysis, principal component analysis, and cluster analysis. The results indicated that the strongest correlation exists between gross domestic product and population size on the one hand, and the number of accredited testing and calibration laboratories as well as product certification bodies on the other. Principal component analysis yielded two main components, while cluster analysis grouped conformity assessment bodies into three clusters and European countries into five clusters. This study demonstrated that there are significant similarities in the accreditation system across Europe.

Deforestation is a pressing environmental issue, and assessing forest loss with precision is crucial for effective conservation strategies. This study evaluates forest area loss in the Special Nature Reserve "Gornje Podunavlje" over a seven-year period from July 2017 to July 2024. Utilizing remote sensing data from PlanetScope, Sentinel-2, and Landsat-8 satellites, the study employs the XGBoost machine learning classifier to classify forest cover. Results indicate a consistent decline in forest area across all datasets, with reductions from approximately 43 km² in July 2017 to around 33 km² by July 2024. Despite variations in reported forest area due to differences in spatial resolution-PlanetScope (3 meters), Sentinel-2 (10 meters), and Landsat-8 (30 meters)-the overall trend of forest loss is evident. Landsat-8 consistently reported higher forest area compared to PlanetScope and Sentinel-2, attributed to its coarser resolution which may include more edge effects. The high-resolution PlanetScope data allowed for more precise delineation of forest boundaries, enhancing the accuracy of forest cover assessments.

The authors investigated the system for oil production using piston pumps, which represents a significant part of the global industry, relying on a mechanical exploitation method that requires optimization to reduce energy consumption and increase efficiency. The paper analyzes the application of SCADA (Supervisory Control and Data Acquisition) systems, which enable monitoring and visualization of key operational parameters, thereby creating predictive maintenance that can significantly improve oil production performance. Considering various variables, such as specific well conditions and reservoir properties, the implementation of modern technologies, including IoT, allows for real-time data integration, contributing to process optimization. Key elements of the SCADA system include sensors, programmable logic controllers (PLCs), and supervisory computers that facilitate data collection, processing, and analysis. Through the use of the AVEVA platform, the visualization of collected data enables specialists to respond to emergencies, reducing downtime and increasing productivity. This intelligent management system allows for analysis and predictive action, which is crucial for improving efficiency and reducing maintenance costs.

From the time of ancient civilizations up to the modern era in which we live, logistics has always played an important role. Everyday activities carried out by humans thousands of years ago, such as harvesting and gathering fruits, storing, preserving, processing, and transporting them to places of exchange or sale, were the precursors of modern-day logistical activities. Today, logistics is present and vital in all areas of human activity. Major geographical discoveries and expeditions, the Industrial Revolution, as well as numerous military campaigns and wars, required the existence of a complex logistical system. A completely new dimension emerged in the mid-twentieth century, when space exploration first took place. Since space is a complex and unstable environment, every mission requires strong logistics from start to its finish. Given that this is a relatively new area of logistics, this paper focuses on a comparative analysis, highlighting the similarities and differences between space logistics and logistics on Earth. The aim and contribution of this work is to initiate a scientific discussion on space logistics, with particular emphasis on the role of modern logistical systems and management in addressing the challenges of the space environment.

In accordance with the modern approach to parking management, a restrictive parking regime in the central area of Belgrade was introduced in 2003. Since then, the area where the regime is applied has been increased several times. The regime attributes, parking supply and the enforcement system have also changed. In addition, the number of registered passenger cars in Belgrade has doubled. Although the permanent monitoring of the state is a prerequisite for successful management, to the best of our knowledge, parking state in the central area has not been adequately evaluated for many years, despite all above mentioned changes. This was the motive for writing this article, which aims to examine and evaluate parking state in the inner central area of Belgrade. Analysing the data obtained by field surveys and taken from the Parking Servis site, it was assessed that the state is not good. This article further identifies the causes of the problem and proposes possible directions for state improvement.

The tradition of successful mining is long, while the mineral and raw material potential of the Republic of Serbia is very significant because, on its territory, in addition to the critical ones, there are also a large number of other deposits and occurrences of metallic, non-metallic, and energy mineral raw materials, as well as significant reserves of underground water and geothermal energy. Despite the enormous global importance of mining development, and due to growing environmental problems, today in the Republic of Serbia and around the world, the success and efficiency of the implementation of strategic mining projects are increasingly threatened, bearing in mind the different and often opposing views of interested parties. With the consistent implementation of new strategic decisions and legal regulations, which are in accordance with globally accepted standards of sustainable mining and good practice, it is possible to fulfill all prerequisites for the rehabilitation and modernization of existing ones and the realization of more new sustainable mining projects in the Republic of Serbia.

Companies in the logistics sector are often faced with the need for financial appraisal of investments with unequal economic life, which most often refers to the acquisition of fixed assets. Methods of financial valuation, such as net present value or internal rate of return, are not adequate for application in such a case. The aim of this paper is to present methods for valuation of investments with unequal economic life, which include the replacement chain method, the equivalent annual annuity approach and the method of reinvesting net cash flows. Their practical application is shown on the example of a logistics company facing the challenge of procuring a new forklift. The company needs to make a choice between four alternatives with unequal economic lives: a counterbalance, side loader, reach trucks, or automated forklift.