Technical Faculty in Bor
Welcome to the digital repository of the University of Belgrade – Technical Faculty in Bor.
The software platform meets the current requirements that apply to the dissemination of scholarly publications and it is compatible with relevant international infrastructures.
Recent Submissions
Electrochemical behavior and determination of cefradine at a pencil graphite electrode
(Institute of General and Physical Chemistry, Belgrade, Serbia, 2026) Bogdanović, Anđelija; Tasić, Žaklina; Petrović Mihajlović, Marija; Simonović, Ana; Radovanović, Milan; Antonijević, Milan
Cephalosporins are a group of β-lactam antibiotics derived from 7-aminocephalosporanic acid (7-ACA). They have a broad spectrum of antibacterial activity and are widely used to treat various bacterial infections in both human and veterinary medicine (1). Cephradine, a first-generation cephalosporin, acts by inhibiting bacterial cell wall synthesis. Cephalosporins are susceptible to hydrolysis in surface water systems, especially under alkaline conditions. They tend to form complexes with cations and accumulate in wastewater sediments. They enter aquatic systems primarily from industrial and manufacturing facilities, which are their main source. Other sources are more difficult to identify because antibiotics undergo structural and compositional changes over time after entering the environment. Intensive use of β-lactam antibiotics in livestock and aquaculture often leads to low concentrations of antibiotic residues in food products and by-products. First-generation cephalosporins, such as cephradine and cefadroxil, can reach high concentrations in urine after ingestion of contaminated food. Antibiotic residues pose a potential risk to human health and contribute to environmental imbalance when released into ecosystems. Such contamination may negatively affect aquatic organisms and promote the spread of resistant bacterial strains. Given these challenges, accurate and sensitive detection of β-lactam antibiotics in complex environmental and food samples is essential. Such detection is necessary to ensure food safety, monitor environmental pollution, and implement regulatory standards. Traditional analytical and optical methods, such as high-performance liquid chromatography (HPLC), liquid chromatography–mass spectrometry (LC-MS), and UV-Vis spectrophotometry, offer high accuracy in antibiotic determination. However, these methods are expensive, require laboratory conditions, and involve complex, time-consuming sample preparation procedures, limiting their use for rapid on-site analysis. They also often require organic solvents that may harm the environment. Due to these limitations, electrochemical techniques and sensors are increasingly used. Electrochemical methods are faster, more efficient, more sensitive, simpler, and more cost-effective. They allow the detection of low concentrations of antibiotics in small sample volumes. These techniques measure electrical parameters such as current or potential and correlate them with the presence of specific chemical species in the sample. The main electrochemical methods for antibiotic detection include amperometry/potentiometry, voltammetry, and electrochemical impedance spectroscopy. Various electrochemical sensors have been used to detect cephalosporins, employing different electrolytes and buffer solutions depending on the analyte and method. The choice of electrode significantly affects the sensitivity and selectivity of the method. Commonly used electrodes include mercury electrodes, glassy carbon electrodes, and electrodes modified with nanomaterials, while Britton-Robinson and phosphate buffers are frequently used as supporting media. These methods have been successfully applied to the analysis of real samples, including serum and other clinical specimens. The choice of medium influences the shape, intensity, and position of the voltammetric peak. The electrochemical behavior of cephalosporins is often studied in buffers of different pH values, as acidity or alkalinity can affect the reaction mechanism and electrochemical activity of the analyte. Britton-Robinson buffer is used over a wide pH range, while phosphate buffer (PBS) is suitable for certain cephalosporins, such as cefotaxime. In some cases, acidic or alkaline media are used to induce degradation of cephalosporins and form electroactive products, enabling indirect detection of compounds that do not exhibit a significant electrochemical signal (3). In this study, the electrochemical detection of ephradine was investigated using differential pulse voltammetry (DPV). The effects of concentration and electrolyte pH were examined. A Pencil graphite electrode served as the working electrode, a saturated calomel electrode (SCE) as the reference electrode, and a platinum electrode as the counter electrode. The pH 7.5 solution was prepared by mixing BR buffer with 0.1 M NaOH. The effect of concentration was studied in Britton-Robinson (BR) buffer at pH 2, using concentrations of 2 × 10⁻⁵, 5 × 10⁻⁵, and 6 × 10⁻⁵ mol/L (Figure 1.). The results showed that increasing concentration led to higher peak currents, with the highest peak observed at 6 × 10⁻⁵ mol/L. All voltammograms displayed a well-defined peak at approximately E ≈ 1.0–1.1 V. As the concentration decreased, the peak current also decreased, while the peak potential remained nearly unchanged. These results indicate a concentration-dependent oxidation process without changes in the reaction mechanism.
Microstructure, Wettability, and Thermal Properties of Sintered Sn-0.7Cu Eutectic Alloy Reinforced with Graphene Nanosheets
(Polish academy of sciences, 2025) Nedeljković, Milan; Mladenović, Srba; Ćosović, Vladan; Marković, Ivana; Petrović, Jasmina; Stamenković, Uroš
In this study, various contents of graphene nanosheets (GNS) were successfully incorporated into Sn-0.7Cu base alloy by powder metallurgy (PM) technique to form Sn-0.7Cu-xGNS composite materials. The synthesis process included mixing and mechanical alloying, compacting and sintering. The effects of GNS on the microstructure, wettability, microhardness and melting properties were investigated. Optical and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) revealed that the distribution of GNS in the solder matrix became more evident as the content of GNS increased. The reinforcement particles were homogeneously distributed at the grain boundaries, resulting in a finer β-Sn structure. The melting temperatures of the synthesized composites, determined by differential scanning calorimetry (DSC), are slightly higher than those of the Sn-0.7Cu base alloy. Incorporating GNS into the Sn-0.7Cu matrix enhanced microhardness up to 15.65% and reduced the contact angle between the composite solder and copper substrate up to 48.6%, significantly improving wettability.
Collective intelligence and project management: bibliometric analysis
(Serbian Project Management Association – IPMA Serbia, 2025) Radić, Aleksandra; Milijić, Nenad
This paper examines the role of collective intelligence and project management through a bibliometric analysis of 289 scientific publications from 2005 to 2025, using Scopus as the database for source extraction. VOSviewer was used to examine trends in publication and citation volumes, co-authorship networks, and the most influential papers in this field. By mapping the relationships between authors, countries, and key references, the study provides valuable insights into the collaborative dynamics and research gaps. In the last two decades, there has been a shift in publications, with the majority being conference papers, followed by journal articles and book chapters. At the same time, the citation trend has shown a consistent increase.The main implications highlight the necessity for more specialized journals on collective intelligence within project management. Additionally, there is a need to promote collaboration between developing and developed countries during the research.
The Role of ERP Systems in Supporting the Transition to a Circular Economy
(COSMOS S.A., 2025) Radić, Aleksandra ; Arsić, Sanela; Plotnic, Olesea; Milošević, Isidora
The introduction of Enterprise Resource Planning (ERP) systems is becoming crucial in facilitating the transition to a circular economy. These systems enable the integration and optimization of business processes, leading to more efficient resource management. The circular economy focuses on minimizing waste and extending the life cycle of products, which requires transparency, traceability, and real-time data, capabilities that ERP systems provide. This paper aims to outline the key roles that ERP systems play in supporting the transition to a circular economy, emphasizing how integrated information systems contribute to sustainability and improve operational efficiency. By analyzing the main functionalities of ERP systems, this paper explores how these systems facilitate better planning, control, and reporting in alignment with the principles of the circularity.
Examination of the Digital Economy and Society Index for Western Balkan Countries using the Entropy-based TOPSIS Method
(Complex System Research Centre, Niš, Serbia Mathematical Institute of the Serbian Academy of Sciences and Arts, 2025) Radić, Aleksandra ; Arsić, Sanela
This paper examines the Digital Economy and Society Index (DESI) of Western Balkan countries using the entropy-based TOPSIS method. The analysis reveals significant differences in digital performance, with Montenegro ranked highest and North Macedonia lowest. The findings demonstrate the applicability of the entropy-based TOPSIS method for assessing multidimensional index such as DESI, offering policymakers valuable insights into priority areas for digital development. The study provides a foundation for future research and strategies to enhance regional digital transformation.