Institute of Economic Sciences

In response to the escalating challenges posed by climate change and environmental degradation, there is a growing imperative to reduce the carbon footprint associated with monitoring technologies. The use of low-carbon materials in environmental monitoring is crucial, as it minimizes the environmental impact of these technologies and aligns with global sustainability goals. This chapter reviews various carbon-based, low-carbon materials that exhibit remarkable potential for applications in environmental sensors, detectors, and monitoring devices. It explores the synthesis and fabrication methods of these materials, outlining their unique properties that contribute to enhanced sensor performance. A significant portion of the chapter is dedicated to the diverse applications of low-carbon materials in environmental monitoring. The advantages of employing these materials, such as improved sensitivity, selectivity, and durability, are discussed in detail. Furthermore, the chapter addresses the challenges and future prospects associated with the integration of low-carbon materials into environmental monitoring systems. It explores potential hurdles in large-scale production, standardization, and technological scalability while also envisioning the role of emerging technologies and interdisciplinary collaborations in advancing the field. By highlighting the innovative solutions and encouraging a shift toward eco-conscious practices, this chapter aims to contribute to the ongoing efforts to build a more sustainable and resilient future.

This study focuses on alumina–silica oxide mixtures synthesised via sol–gel processing using rice husk and aluminium chloride hydroxide as precursors followed by calcination, yielding submicron particles suitable for reinforcing poly(methyl methacrylate) (PMMA). These hybrid oxide particles exhibit a well-dispersed phase composition of alumina and silica, enhancing mechanical properties when homogeneously distributed within the brittle PMMA matrix. X-ray diffraction (XRD) confirmed the crystallinity and phase structure of the particles. The PMMA composites were formulated with 1 wt.%, 3 wt.%, and 5 wt.% Al 2 O 3 /SiO 2 , then analysed using scanning electron microscopy (SEM), optical microscopy, and indentation testing. Vickers microhardness and tensile tests showed significant improvements in the hardness, strength, and creep resistance of the hybrid nanocomposites. The hardness increased by approximately 25.94% and creep resistance by 4.4% when 3 wt.% of Al 2 O 3 /SiO 2 particles was added to PMMA, while the tensile strength increased to approximately twice that of the pure PMMA matrix. Wettability was evaluated via sessile drop measurements using water and glycerine, representing polar liquids with differing viscosities. The surface free energy and work of adhesion were calculated using the Owens–Wendt–Rabel–Kaelble (OWRK) model. The results show that even low concentrations of hydrophilic particles markedly influence the wetting behaviour, with modular surface properties emerging as a function of filler loading. Among tested compositions, the 3 wt.% oxide-reinforced composite achieved the most favourable balance of mechanical reinforcement and wettability control, identifying it as the optimal formulation for enhanced PMMA-based dental applications.

Abstract The unfavorable global economic conditions caused primarily by the COVID-19 pandemic, as well as the ongoing geopolitical tensions and related disruptions, have adversely affected nearly all financial markets through the process of globalization. Considering these factors, this study analyzes, tests, quantifies, identifies, and compares the nature of correlation and the intensity of the impact of relevant macroeconomic variables on daily investment return rates in selected financial markets of developed countries (the United States and Germany) and emerging markets (Serbia and Croatia). The macroeconomic variables observed include inflation rate, reference interest rate, exchange rate, oil price, and gold price. Investment returns are analyzed through daily changes in the leading stock indices of the selected financial markets. The research covers the period from 2012 to 2022, examining results separately for three subperiods: the entire period (2012–2022), the pre-crisis period (2012–2019), and the crisis and post-crisis period (2020–2022). The results reveal that during the crisis period (2020–2022), stock market volatility in emerging markets (Serbia and Croatia) was primarily driven by exchange rate movements and commodity prices, while in developed markets (USA and Germany), it was more strongly influenced by interest rates and inflation. Furthermore, the estimated models indicate that the magnitude and direction of macroeconomic impacts vary substantially across markets and time periods. These findings provide valuable insight for investors and policymakers seeking to manage risk and respond to economic shocks in both mature and developing financial systems.

This structured keyword-based meta-analysis reviews the estimation of climate risk factors and their economic impact in the recent literature between 2009 and 2023. Via examining existing research we are able to extract core statements, critical success and risk factors, considered data sets, implemented quantitative methods, and the core empirical results. This allows us to identify current state-of-the-art topics and methodologies. Furthermore, we identify three major interrelated pillars, namely, policy-level considerations, macroeconomic effect chains paired with market-level dynamics, and quantitative modelling methodologies. According to the analysed research articles, a comprehensive understanding of at least two of these pillars is essential for effectively identifying, controlling, and modelling climate risk. This, in turn, helps to develop political strategies for mitigating climate change, which is displayed as a comprehensive triad model that can serve as a didactical basis for policy-decision making.

This work presents an experimentally viable synthetic approach for developing visible light-active water-splitting photocatalysts based on organic semiconductors with tunable bandgaps. Chromophore–catalyst dyad assemblies were synthesized by covalently linking catalytic units to donor–acceptor conjugated organic semiconductors. These ensembles demonstrate photocatalytic activity, with hydrogen evolution rates of 1.12 mmol g–1 h–1 and oxygen evolution rates of 420 μmol g–1 h–1 during 12-h studies. Computational analyses indicate that the improved performance results from advantageous energy level alignment between the chromophore and catalytic unit, promoting efficient charge transfer. This research illustrates the feasibility of organic semiconductor photocatalysts for sustainable hydrogen generation and offers mechanistic insights to inform future advancements in clean energy technology.

Women's financial inclusion represents a key element in enhancing women's entrepreneurship. The aim of this study is to investigate the impact of age, education, employment, income quintile, and region on the level of financial inclusion (FI). The data for the four Gulf countries (Gulf Cooperation Council) and five Western Balkan countries were gathered from the Global Findex Database 2017. The total sample includes 3,973 women. Multiple linear regression is used to investigate the impact of socio-demographic factors on FI. Additionally, the paper provides an overview of the latest available data on several indicators related to FI at the macro level. The results show that education, employment, and income quintile have a statistically significant positive impact on FI. The relationship between age and FI is statistically significant, exhibiting an inverted U-shape. This means that FI increases up to 55 years, and after that transition point, it starts to decline. Moreover, the region plays a significant role, considering that the level of FI of the respondents from Western Balkan countries is lower than that of those from the Gulf region.

Polymer pollution transcends national boundaries and threatens both human health and the environment. Despite efforts for efficient reuse of polymer waste, the majority of it accumulates in landfills and dumps or is mismanaged and is being dispersed in the environment. The application of ionizing radiation techniques could serve to reprocess and recycle polymer waste. Using a radiation source (gamma, electron beam or X-ray) to irradiate post-consumer plastics enhances their recyclability and facilitates their transformation into new products. Application of radiation technology is promising because it is not a novel one. Irradiated polymers could be found all around, from vehicle tires to hot water pipes and food packaging. Idea is to use irradiation applying different dose rates to gain reform and restructure polymer structure, with the aim to improve its recyclability and reduce the amount of polymer waste. The use of electron beam irradiation to form bridges between polymer strands refers to the process of cross-linking. Polymers degradation occurs after radiation is applied in the opposite way through chain scission, in that process polymers are cut up or ‘degraded’. Radiation can also induce an electric charge on the surface of plastics, making it easier to sort plastic waste more accurately. This improves both the volume and the number of times the waste can be recycled, such as with thermoplastics, which can be melted and reshaped repeatedly. Radiation technology can drive the economic potential of plastic upcycling by enabling the production of upscaled secondary products, like wood-plastic composites (WPC), from plastic waste, rather than downscaled alternatives.

Titanium (Ti), a metal with a hexagonal close-packed structure, exhibits outstanding mechanical and thermal properties, making it ideal for applications in extreme environments. Structural integrity at elevated temperatures has been extensively studied through experimental mechanical testing. In recent years, computational modeling has provided critical insights into its plastic deformation mechanisms across different temperatures as a complement to experimental data. In this work, we employ molecular dynamics simulations to investigate the mechanical response of single-crystalline Ti under nanoindentation using a rigid spherical diamond indenter (R = 12 nm) in the 10–900 K range. The empirical interatomic potential for simulating the mechanical response of single-element materials was chosen by considering the generalized stacking fault energy and slip dissociation pathways responsible for stacking fault formation and dislocation activity during mechanical loading. Atomic strain mapping was used to visualize the evolution of plastic deformation beneath the indenter at elevated temperatures. Nanoindentation simulations reveal the development of pile-ups and changes in the surface morphology induced by dislocation motion at different temperatures. The obtained results provide fundamental insights into temperature-driven changes in dislocation dynamics, slip mechanisms, and local hardness, enhancing understanding of Ti’s thermomechanical stability. These findings contribute to the design and optimization of Ti-based materials for high-temperature structural applications.

In this study, waste hemp fibers were transformed into cationically modified materials through a two-step process. The process began with the collection of agricultural waste fibers after hemp harvesting, followed by a delignification pretreatment, and subsequently, quaternization using the synthesized Deep Eutectic Solvent of chlorocholine chloride and urea. To form the material into membranes, modified fibers were cross-linked under pressure using citric acid as a natural cross-linker. The structural and chemical characteristics of the non-treated fibers (NtHF) and formed membranes were analyzed using SEM and FTIR techniques. The mechanical properties of the membranes were determined by measuring the breaking force and calculating the tensile strength via the Brazilian test method. Biodegradability was assessed by examining the mass loss of membranes composed of unmodified and cationized hemp fibers over 90 days, using a Soil Burial Test (AATCC Test Method 30-1993) in controlled laboratory conditions (24 °C). The results demonstrated a significant improvement in the tensile strength of the synthesized material (2.41 MPa), attributed to the synergistic effect of physical intermolecular interactions within the cationically modified hemp membranes (WCHM) and enhanced cross-linking using citric acid. The newly synthesized membrane showed great potential as a biodegradable material, with the first signs of degradation, reflected by a 25% mass loss, observed after 14 days. A slightly faster degradation rate was noted for non-treated fibers, highlighting the effectiveness of citric acid as a cross-linker.

Purpose This paper examines the impact of digitalization, innovativeness, capital formation, unemployment and sustainable development on entrepreneurship in European countries. By analyzing data from 42 European Council countries between 2000 and 2021, the study aims to uncover the relationships between these factors and entrepreneurship, with a focus on upper-middle-income and high-income countries. Design/methodology/approach The research uses panel cointegration, panel ARDL and panel Granger causality to examine the data across three panels. This methodological approach allows for a comprehensive assessment of relationships between the variables of interest. Findings In all countries and high-income countries, information and communication technology (ICT), unemployment (UNE) and the Sustainable Development Goals (SDGs) positively and significantly influence entrepreneurship, while R&D expenditure (RDE) and gross fixed capital formation (GFCF) negatively and significantly influence entrepreneurship. In upper-middle-income countries, ICT has no statistical significance, but RDE, GFCF, UNE and SDG have a significant negative impact on entrepreneurship. In terms of causality, there is bidirectional causality between all variables in all countries and high-income countries, while there are mixed causal relationships in the upper-middle-income group. Originality/value This paper contributes to the literature by focusing on the macroeconomic determinants of entrepreneurship, with particular emphasis on ICT, R&D and sustainable development. The study offers new insights into how these factors influence entrepreneurship in different income levels of European countries. By examining the interaction between entrepreneurship and all considered variables, this research provides a deeper understanding of the dynamics of entrepreneurship and possible policy implications.