The knowledge of zeta potential is a very useful indicator of the stability of dispersed systems. This is especially important in many industrial processes, such as e.g. mineral processing, purification of water and many others. This article deals with the investigation of the electrokinetic behavior of goethite, quartz and clay minerals depending on pH and the presence of inorganic dispersants: sodiumhexamethaphosphate (SHMP), sodiumpyrophosphate (SPP) and sodium silicate (SS). All studies are conducted on natural samples, taken from Omarska iron mine (Bosnia and Herzegovina) by measuring the zeta potential. From the experimental results, it was found that the increase of the suspension pH resulted in an increase in the negative charge of all three tested samples. The clay did not show any isoelectric point (IEP). Quartz showed isoelectric points at pH about 2.6 and close to 2 in the absence and presence of sodium silicate in suspensions, respectively. Goethite showed isoelectric points at pH 6.7 and 4.95 in the absence and presence of sodium silicate in suspensions, respectively. An IEP could not be detected when the SHMP and SPP were used and the surface charge is negative from pH 2 to pH 12 in all tested samples. The addition of SHMP provided the highest negative zeta potential, i.e. the most stable dispersion, in all three tested samples.Keywords: zeta potential, isoelectric point, goethite, quartz, clay, inorganic dispersants.
This paper analyzes the quantitative and qualitative recovery of pedunculate oak (Quercus robur) logs processed in the modern sawmilling facility of “Drvoprodex” d.o.o. in Srbac, Bosnia and Herzegovina. The research was conducted through a combination of direct measurements during two operational shifts, encompassing 185 logs and company-maintained production records. Logs were classified into three quality grades, with detailed analysis of dimensions and produced assortments, including lamellae (grades A–C), rustic-grade elements (R class), and friezes. The overall recovery from debarked log volume reached approximately 30%, aligning with the lower end of typical industry expectations for oak flooring production. Friezes dominated in quantity (2,376 pcs), particularly in 70 mm width, while lamellae and R-class elements showed optimal yields at 135 mm and 215 mm widths. Regression analysis confirmed a statistically significant positive influence of log diameter on both recovery rate and daily processing volume. While advanced equipment such as a band saw head rig, CNC optimizer, and multi-blade rip saws are employed, several older machines occasionally limit throughput, underscoring the need for further modernization. Importantly, about 70% of the log volume remains as sawmill residue, including slabs, edgings, sawdust, and bark. Recommendations are made for systematic valorization of these co-products: coarse residues can be chipped for biomass energy or panel manufacturing, while sawdust and bark can serve for pellet production or biochemical extraction (e.g. tannins). Enhancing residue utilization would increase material efficiency and economic sustainability, aligning the mill with circular economy principles and near-zero-waste production goals.Keywords: oak sawmilling, log recovery, wood processing.
Laser-induced graphene (LIG) has been the subject of extensive research over the past decade and has found promising applications in physiological monitoring processes in both sports and medicine. Its excellent characteristics, such as good electrical conductivity, piezoresistivity, flexibility, and low-cost production, make it a suitable material for use in wearable electronics and sensors. Poly(dimethylsiloxane) (PDMS) has attracted attention as a substrate for wearable sensors due to its good biocompatibility, elasticity, and mechanical characteristics. However, since its structure contains no readily carbonizable atoms, PDMS must be modified with glycol additives such as diethylene glycol (PDMS/DEG) and ethylene glycol (PDMS/EG) to enable graphene induction. This paper presents the laser induction of graphene on a PDMS/DEG and PDMS/EG composite, electronic testing, and physicochemical characterization. By optimizing laser parameters, LIG with the lowest electrical resistance was obtained, with PDMS/DEG samples showing superior surface morphology compared to PDMS/EG. Raman spectroscopy revealed the characteristic D, G, and 2D bands typical for graphene. The assignment of bands in infrared spectroscopy (FTIR) and SEM micrographs confirmed the structure of graphene. Characterization revealed that the optimal glycol compound concentration in PDMS is 20 wt.%. In the future, this material has the potential to be used for measuring physiological processes and limb movements.Keywords: laser-induced graphene, PDMS, sensors, diethylene glycol, ethylene glycol.
The remarkable applications of flexible and wearable sensors in human motion detection and health monitoring have attracted considerable attention from both academic and industrial communities. Wearable strain sensors for finger-motion monitoring demand materials that combine high conductivity, flexibility, long-term durability, fast response, and stable interfaces. Here we report a MXene–polyurethane (PU) platform built on an MDI/HBP/PDMS network with 50 wt% soft segments (PU-50) that serves as a biocompatible, elastic substrate for a Ti₃C₂Tₓ conductive layer. MXene-PU composites were characterized by scanning electron microscopy (SEM), tensile testing and electrical measurements. SEM confirms the intended morphologies: layered, lamellar MXene stacks that form percolating pathways and a PU microphase-separated morphology between soft and hard segments. Three device variants were evaluated under finger flexion with increasing frequency: MXene on neat PU, PU with 1 wt% pure MXene in the bulk (PUMX), and PU with 1 wt% functionalized MXene (PEG-MXene) in the bulk (PUMP). Time-resolved resistance measurements acquired every 20 ms yielded clear, low-hysteresis ΔR/R₀ waveforms across all frequencies, with a consistent performance hierarchy in which PUMP exhibited the lowest baseline drift and the most stable cycle-to-cycle response, while the neat PU device displayed the largest resistance modulation amplitude. On-surface drawing tests on the neat-PU-MXene sensor further demonstrated pattern-robust sensitivity, producing distinct, repeatable temporal signatures for triangle, circle, and square trajectories with rapid baseline recovery and minor residual offsets. The obtained results validate MXene–PU as a fast, stable, and comfortable candidate for wearable finger motion sensors. They also identify mild interface optimization—via functionalized MXene in the substrate—as an effective way to enhance signal stability and suppress baseline drift while preserving signal fidelity across frequencies. This motivates future work on long-term stability, environmental compensation, and integration with compact wireless readout for multi-gesture recognition.Keywords: MXene, polyurethanes, tensile testing, wearable sensors, finger-motion sensing.
Fenton processes, in which hydrogen peroxide in the presence of divalent iron ions generates hydroxyl radicals (•OH), are widely used for the degradation of organic pollutants (phenols, antibiotics, dyes). In this review, red mud is analysed as a cheap source of iron ions in Fenton processes. Raw red mud can be used without additional modifications, but to increase the catalytic efficiency, its modification is required, which includes chemical reduction, carbothermal treatment or doping with metals. Particular attention is given to photo-Fenton and electro-Fenton processes, where red mud doped Cо, Sn or Cе, or in combination with reduced graphene oxide and biochar, allow the generation of not only hydroxyl radicals (•OH) but also singlet oxygen (1O2) and superoxide radicals (•O2–), achieving ≥99% pollutant removal. At the same time, the synthesised catalysts showed high stability and reusability. Based on a comparative analysis of more than 30 studies, it is concluded that red mud represents a cheap source of iron ions for heterogeneous Fenton processes, with significant potential for industrial application.Keywords: Fenton process, hydroxyl radicals, organic pollutants, red mud.
The versatile chemistry of polyurethanes (PUs) makes them suitable for a wide range of applications. In particular, surface topography and thermal behavior can be effectively tailored by adjusting the soft segment content (SSC) within the PU structure. However, as an intrinsically nonconductive class of polymers, PUs are not suitable for electronic applications. With the increasing interest in polymer/graphene heterostructures, the formation of graphene conductive pathways on polymer surfaces has emerged as a promising approach to overcome this limitation. In this study, we systematically examined the effects of varying SSC (expressed in wt.%) in synthesized cross-linked PUs, as well as the influence of laser-induced graphene (LIG) transferred onto the PU surface on several key properties: surface roughness via atomic force microscopy (AFM), surface wettability using water contact angle (WCA) measurements, and thermal properties through differential scanning calorimetry (DSC). An increase in SSC led to a reduction in surface roughness and a concomitant increase in WCA, indicating enhanced hydrophobicity. The presence of LIG further augmented the hydrophobic character of the surface. The PU structure exhibited a pronounced effect on both glass transition (Tg) and melting temperatures (Tm), while LIG had a minimal impact on thermal properties. This research provides a framework for engineering the surface and thermal properties of PU-based materials for applications in flexible electronics and smart coatings.Keywords: polymers, composites, structure-property relationship, AFM, WCA, DSC.
Maintaining pulp vitality is essential for the long-term health of teeth. Direct pulp capping aims to stimulate reparative dentin formation and prevent pulp necrosis. This study aimed to evaluate the effects of novel calcium silicate–based materials on the pulpal inflammatory response and dentin bridge formation using a Wistar rat model.A total of 18 Wistar rats (72 maxillary molars: 36 first and 36 second) were included and divided into two groups (A and B; n = 9). In Group A, Theracal LC was applied to the exposed pulp of the right maxillary molars, while MTA was applied to the left molars. In Group B, Calxyl was applied to the right molars, and Biodentine and MTA were applied to the first and second left molars, respectively. The Wilcoxon signed-rank test was used for statistical analysis.After 30 days, the lowest pulpal inflammatory response was observed with Theracal LC, followed by Biodentine, which showed a comparable level of inflammation but with slightly more polymorphonuclear leukocytes. The highest inflammatory response was recorded with Calxyl. A statistically significant difference in inflammation levels was found between Theracal/Calxyl (p = 0.041), Theracal/MTA (p = 0.034), Biodentine/Calxyl (p = 0.044), and Biodentine/MTA (p = 0.039). All tested materials demonstrated a strong capacity to induce dentin bridge formation.In conclusion, the new calcium silicate–based materials exhibited favorable biological properties, with Theracal LC and Biodentine showing the lowest inflammatory response. All materials promoted reparative dentinogenesis, confirming their potential for use in direct pulp capping procedures.Keywords: pulp capping, Theracal LC, Biodentine.
The reaction of a warm methanolic solution of iron(II)-bromide and an acetone solution of 2,6-diacetylpyridine-bis(phenylhydrazone) (L) gave dark red prismatic single crystals of the complex [FeL2]Br2. The composition and purity were elucidated via elemental analysis, and the coordination mode was determined based on FTIR spectra. The latter was confirmed by X-ray structural analysis. This complex is isostructural with previously synthesized complexes [CuL2]Br2 and [CoL2]I2 – all three complexes crystallize in the C2/c space group and have very similar unit cell parameters. [FeL2]2+ lies on a two-fold rotation axis; thus, the asymmetric unit consists of one ligand molecule, a half of the Fe(II) ion, and one bromide ion. Fe(II) is situated in a very distorted octahedral environment formed by six nitrogen atoms of two ligand molecules, with trans-angles having the values of 146.81° and 173.43°. Due to steric factors, the phenyl rings of the ligand are twisted, which can be seen from the torsion angles of 141.42° for one and 155.27° for the other phenylhydrazone moiety. Besides, the complex is characterized by coupled TG-MS measurements.Keywords: metal complexes, hydrazones, synthesis, characterization.
Drinking water is a vital resource for public health and sustainable development, yet its quality is increasingly threatened by pollution, climate change, and emerging contaminants. Directive (EU) 2020/2184 on the quality of water intended for human consumption introduces stricter requirements for monitoring, risk management, and public transparency. This paper analyzes the content and significance of the Directive, with a focus on the challenges of its implementation in Bosnia and Herzegovina.Special attention is given to harmful substances such as bisphenol A, PFAS compounds, and cyanotoxins, which pose serious risks to human health. The Directive introduces new water quality parameters, promotes access to water as a human right, and encourages the use of tap water to reduce plastic waste.In conclusion, aligning national legislation with this Directive is essential for improving water quality, protecting public health, and achieving sustainable development goals.Keywords: drinking water, EU Directive 2020/2184, pollutants.
Introduction: In the tooth bleaching process, the primary focus is often placed on selecting an adequate bleaching technique and optimal agent concentration, while the significance of daily oral hygiene during and after the bleaching treatment is frequently underestimated. The quality of oral hygiene, along with the dietary habits of patients, plays a significant role in the success and long-term stability of the achieved tooth color. This study aimed to investigate the influence of oral hygiene, smoking, and the consumption of colored beverages on the success of bleaching endodontically treated teeth.Materials and methods: The study included 30 endodontically treated teeth. In the first group, teeth were bleached using the walking bleach technique (10 teeth); in the second group, the in-office technique was used (10 teeth); and in the third group, teeth were bleached with a combined technique (10 teeth). Bleaching was performed using 30% carbamide peroxide and 35% hydrogen peroxide. All teeth were restored with the nanohybrid composite material Tetric EvoCeram (Ivoclar, Liechtenstein). Based on oral hygiene and dietary habits, patients were classified as having good/moderate/poor oral hygiene, as smokers/non-smokers, and as consumers/non-consumers of colored beverages. Before and after the bleaching treatment, the color of all teeth was determined using the Vita Classic shade guide. For statistical analysis, bleached teeth were analyzed based on the scale from the study by Ari et al.Results: Based on Fisher’s exact test results, a statistically significant difference (p
In recent years, the number of studies focused on the design and synthesis of compounds with biological and pharmacological potential has increased significantly. Special attention has been given to molecules with antitumor activity, including thiosemicarbazones and their homologues, thiocarbohydrazones. Since drug development is a complex, lengthy, and expensive process, its optimization in early stages often relies on the application of Quantitative Structure–Activity Relationship (QSAR) approach. By selecting appropriate molecular descriptors, it is possible to quantify the impact of structural modifications on compound’s biological activity prior to synthesis, thus reducing the need for extensive experimental work. Lipophilicity as key QSAR descriptor, was determined for thiocarbohydrazones by using a hybrid approach – computationally, through appropriate software tools (logP as a standard measure of lipophilicity), and experimentally, by reversed-phase thin-layer chromatography (chromatographic parameters RM0 and m). The results indicated that the nature of the substituent had a greater effect on the chromatographic behavior of thiocarbohydrazones than the applied organic modifier. The correlation between chromatographically and computationally determined lipophilicity values, as well as the acute toxicity parameters (EC50), was assessed by linear regression analysis. The obtained models showed satisfactory predictive performance.Keywords: thiocarbohydrazones, chromatography, lipophilicity, toxicity.
The flue gases from coal fired thermal power plants, contain combustion gases (SO₂, NOₓ, CO, CO₂) and fine particles of fly ash. The concentration of sulfur oxides in the flue gas depends on the sulfur content in the coal. The flue gas desulfurization (FGD) process at TPP Ugljevik utilizes a wet scrubbing method, where a limestone suspension serves as the absorbent medium for sulfur oxides, with gypsum as a byproduct. Comparative analysis of emission levels before and after the FGD system installation indicates that the applied desulfurization technology is highly effective. The efficiency of the desulfurization plant ranged from 83.91% to 100%, depending on the inlet concentration of SO₂ in the flue gas. Estimates show that the FGD plant, depending on the intensity of operation, can annually remove between 7,000 and 55,800 tons of sulfur, with by-product gypsum production ranging from 3,660 to 29,280 tons. The implementation of this flue gas purification process significantly reduces the impact on the environment and ambient air pollution caused by sulfur oxides. For economic reasons, the plant is unfortunately unable to operate continuously. Keywords: Flue gases, SO₂ emissions, desulfurization, wet scrubbing process.
This paper explores the evolution of media sentiment and thematic discourse around Renewable Energy Sources (RES) in Macedonia from 2017 to 2024. Drawing on over 9,500 news teasers retrieved from Time.mk, we apply FinBERT and BERTweet for sentiment analysis and Latent Dirichlet Allocation (LDA) for topic modeling. Our findings reveal a dominant neutral sentiment profile with notable positive sentiment peaks aligned with key regulatory developments and market shifts. Topic modeling further captures the transformation of discourse from centralized, policy-driven rhetoric toward decentralized, technologically mature themes, centered on solar expansion, public engagement, and institutional implementation. The outcome of this research contributes to understanding how public discourse on RES evolves over time, and its implications add value to the role of media in shaping societal perception and stakeholder’s response to renewable energy transition.
The phenomenon of urban heat islands is becoming increasingly pronounced and is one of the main reasons for the increase in air temperature in cities. The thermal regime of urban areas is different from peri-urban and rural areas, and is reflected in faster daytime heating and slower nighttime cooling. There are two main approaches to the study of urban heat islands - direct measurements of air temperature in the field and readings of temperatures from remote sensing products. The paper will analyze remote sensing products from the Landsat 8 satellite in order to determine differences in thermal characteristics of specific types of land use in the territory of the city of Trebinje. For the purposes of the analysis, a buffer zone was defined within a radius of 10 km from the central point of the city (geographical coordinates: 42.7112° N, 18.3436° E), which enabled the inclusion of urban, rural and natural areas. A total of 12 satellite images were collected and a time frame covering the summer months of 2024 (June 1 to August 31) was used. Given the sensitivity of thermal data to the presence of clouds, a cloud filter (CLOUD_COVER < 20%) was applied to ensure the quality of the input data. Additionally, a cloud mask and cloud shadows were implemented using the QA_PIXEL layer to remove contaminated pixels. The research results show that built-up areas have higher temperatures compared to other land use classes by more than 2°C. All analyses were conducted using open source software packages. The research results can be useful for various sectors such as public health, spatial planning, energy, water management, forestry and similar areas. In addition, the research results may contribute to future detailed studies aimed at defining local climate zones and thermal variations within them.
The widespread deployment of photovoltaic (PV) systems in urban areas poses new challenges for integration into the low-voltage grid, operation under variable meteorological conditions, and the impact of local disturbances. Research using Hardware-in-the-Loop (HIL) simulations, especially techniques with physically present controllers (Controller Hardware-in-the Loop - C-HIL), represents a powerful environment for testing and validating power electronics-based converter control strategies in real-world conditions without the risks and costs associated with field experiments. This paper presents the application of C-HIL simulation to analyze and optimize the operation of a home PV system integrated into an urban distribution grid. The conducted case studies address operational scenarios such as rapid changes in solar radiation, load fluctuations, and voltage disturbances, demonstrating the effectiveness of the C-HIL platform for assessing dynamic performance, voltage quality, and stability. The results confirm that C-HIL simulation can provide useful insights for the design of PV systems aimed at the safe and widespread deployment of distributed renewable energy sources in urban networks.
Optimal resource management and the integration of ecological materials into sustainable strategies represent the basic approach to environmental protection and the efficient use of natural and processed resources on the Globe. Ecological materials, characterized by minimal environmental footprint, recyclability, and renewability, enable implementation of circular economy principles in construction, industry, and everyday life. Their use contributes to reducing pollution, lowering energy consumption in production processes, and extending the lifecycle of products through reuse and recycling. This paper analyzes key aspects of the reuse of materials, with a focus on management strategies that ensure sustainable ecology material flows within economic systems. In particular, the role of management in designing policies that promote the transition from linear to circular models is emphasized. Sustainable strategies must include life cycle assessment (LCA) and eco-design to minimize negative impacts on ecosystems while maintaining economic competitiveness. Moreover, the selection of ecological materials affects the quality of life and health of the population, aligning environmental and social objectives with economic development goals. The results of the analysis conducted in this paper indicates that successful integration of ecological materials into resources management requires cooperation of researchers, producers, consumers, and policymakers, as well as education that raises awareness about environmental protection and responsible material use. Implementing these approaches contributes to building a resilient society based on sustainability, circular economy, and optimal resources management.
The Western Balkans region faces serious energy and environmental challenges. As the majority of electricity is still generated from lignite, this results in high pollutant emissions and makes the region one of the most polluted areas in Europe. This dependence on fossil fuels is not aligned with the legal framework of the European Union nor with the international obligations stemming from the Paris Agreement. It also may slow down the process of European integration. In addition, energy shortages and high electricity prices create political and socio-economic tensions. In this context, solar energy emerges as a key driver of sustainable development and the transformation of the energy sector. Through a systematic review of the literature and relevant reports of international organizations (IEA, IRENA, OECD), the paper explores environmental benefits (reduction of CO2 emissions and contribution to sustainable development goals), economic aspects (job creation, attraction of investments, development of new industries), and social implications (energy security, improved quality of life, education, and public awareness). Special attention is devoted to the specific challenges of the region, including outdated infrastructure, inconsistent regulatory frameworks, insufficient investment, and limited access to financing. The study demonstrates that solar energy, in addition to reducing coal dependency, has the potential to become a catalyst for broader socio-economic development by strengthening local communities, fostering the creation of green jobs, and enhancing regional cooperation. However, to fully realize this potential, a combination of increased public and private investments, reliable regulatory mechanisms, modernization of energy systems, and international support is required, alongside active involvement of the local population and the promotion of energy literacy. The aim of this review paper is to analyze the role of solar energy in the process of sustainable energy transition and its contribution to socio-economic changes in the region.
This paper provides an overview of current and future global energy challenges, focusing on the dynamics of energy demand, environmental impacts, and technological transformations that are shaping the transition toward more sustainable energy systems. Although fossil fuels continue to dominate the world’s energy mix, rapid developments in technology, efficiency, and policy are driving significant shifts in how energy is produced, delivered, and consumed. The study examines the factors influencing rising global energy demand, the role of energy security and geopolitical considerations, and the environmental consequences of continued dependence on fossil resources. Special attention is given to emerging renewable technologies, decentralization, digitalization, and the increasing importance of consumers within the evolving energy ecosystem. The analysis highlights that, despite progress in renewable energy and innovation, fossil fuels will likely remain central through mid-century, creating a pressing need for feasible carbon mitigation strategies. The paper concludes that future energy systems will depend on large-scale technological innovation, new digital infrastructures, and coordinated global policy efforts to ensure sustainability, reliability, and equity in the decades ahead.
In a time marked by climate change and the depletion of natural resources, solar energy is increasingly recognized as a key driver of sustainable development. This paper analyzes the role of solar energy in the energy transition, focusing on its technical capabilities, economic benefits, and potential for job creation. Furthermore, it explores how the synergy between technological advancement and market mechanisms can accelerate the replacement of fossil fuels and contribute to the reduction of greenhouse gas emissions. The technical section outlines recent progress in photovoltaic technologies, improvements in solar panel efficiency, cost reductions in production, and the role of smart grids in integrating renewable sources into the energy system. Through an analysis of market trends, the importance of investments in renewable energy, subsidy mechanisms, tax incentives, and public-private partnerships in expanding solar capacity is emphasized. From an economic perspective, the paper explores the potential of the solar industry to create jobs–ranging from manufacturing and installation to maintenance and research. Utilizing available statistical data and models, the study demonstrates that investments in the solar sector yield multiple benefits: energy sovereignty, reduced dependence on fossil fuel imports, and the creation of new economic opportunities in both rural and urban areas. Case studies from countries that have successfully implemented solar strategies (e.g., Germany, Spain, and India) highlight key success factors and foreseeable obstacles that can be addressed proactively. Special attention is given to the role of public policy and regulatory frameworks that support the faster integration of solar energy, as well as the need for education and workforce retraining in accordance with the demands of the new energy paradigm. The paper concludes that synchronized efforts between technological development and market instruments are essential for accelerating the green transition. Solar energy, as a clean, renewable, and increasingly accessible resource, has the potential not only to replace fossil fuels but also to become a foundation for economic resilience and social equity in a post-carbon society.
The European Green Deal represents a transformative strategy for economic growth, aiming to create a fair, prosperous, and resource-efficient Europe with a competitive economy and net-zero greenhouse gas emissions by 2050. The energy sector, as the largest emitter of greenhouse gases, is central to achieving these objectives, and renewable energy sources (RES) play a pivotal role in decarbonization. The Republic of Croatia, despite its favorable geographic potential for solar energy, remains underutilized in terms of solar electricity, heating, and cooling generation. This paper examines the potential of solar energy and other renewables to contribute to sustainable economic growth in Croatia, emphasizing energy efficiency, distributed generation, and the creation of green jobs. Demonstration projects indicate that expanding photovoltaic and solar thermal systems could generate up to 20,000 jobs while reducing carbon dioxide emissions and enhancing energy independence. The study also highlights the need for interdisciplinary approaches, integrating technical, social, economic, and environmental perspectives, to ensure a coordinated and sustainable energy transition aligned with EU and global climate goals.
