The tunable conduction of coumarin-based composites has attracted considerable attention in a wide range of applications due to their unique chemical structures and fascinating properties. The incorporation of graphene oxide (GO) further enhances coumarin properties, including strong fluorescence, reversible photodimerization, and good thermal stability, expanding their potential use in advanced technological applications. This review describes the developmental evolution from GO, GO-polymer, and coumarin-based polymer to the coumarin-GO composite, concerning their synthesis, characterization, unique properties, and wide applications. We especially highlight the outstanding progress in the synthesis and structural characteristics along with their physical and chemical properties. Therefore, understanding their structure-property relations is very important to acquire scientific and technological information for developing the advanced materials with interesting performance in optoelectronic and energy applications as well as in the biomedical field. Given the expertise of influenced factors (e.g., dispersion quality, functionalization, and loading level) on the overall extent of enhancement, future research directions include optimizing coumarin-GO composites by varying the nanofiller types and coumarin compositions, which could significantly promote the development of next-generation polymer composites for specific applications.

Industrial plastics have seen considerable progress recently, particularly in manufacturing non-lethal projectile holders for shock absorption. In this work, a variety of percentages of alumina (Al2O3) and carbon black (CB) were incorporated into high-density polyethylene (HDPE) to investigate the additive material effect on the consistency of HDPE projectile holders. The final product with the desired properties was controlled via physical, thermal, and mechanical analysis. Our research focuses on nanocomposites with a semicrystalline HDPE matrix strengthened among various nanocomposites. In the presence of compatibility, mixtures of variable compositions from 0 to 3% by weight were prepared. The reinforcement used was verified by X-ray diffraction (XRD) characterization, and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used for thermal property investigation. Alumina particles increased the composites’ thermal system and glass transition temperature. Mechanical experiments indicate that incorporating alumina into the matrix diminishes impact resistance while augmenting static rupture stress. Scanning electron microscopy (SEM) revealed a consistent load distribution. Ultimately, we will conduct a statistical analysis to compare the experimental outcomes and translate them into mathematical answers that elucidate the impact of filler materials on the HDPE matrix.

The rapid growth of portable electronics and electric vehicles has intensified the global demand for high-performance energy storage devices with superior power density, energy density, and long cycle life. Among transition metal oxide-based electrode materials with potential for energy storage, we report the development of MnO2–V2O5 nanocomposite electrodes for supercapacitor applications. Pure MnO2 and V2O5 were successfully fabricated via a simple and economical sol–gel method, while (MnO2)x–(V2O5)1−x (x = 1, 0.75, 0.50, and 0) nanocomposites were fabricated through an ex situ method. Analytical techniques, including X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and UV-visible spectroscopy, were employed to investigate the structural, morphological, and optical properties of the electrodes. Furthermore, the electrochemical properties were systematically analysed using cyclic voltammetry, galvanostatic charge–discharge measurements, and electrochemical impedance spectroscopy. The (MnO2)0.75–(V2O5)0.25 nanocomposite demonstrated a remarkable specific capacitance of 666 F/g at a current density of 0.5 A/g in 1 M KOH electrolyte. Additionally, the electrode material exhibited an energy density of 23 Wh/kg and a power density of 450 W/kg, while maintaining a capacitance retention of 95% after 1,500 cycles. The incorporation of V2O5 boosted the conductivity and significantly optimised the number of lattice defects. This work substantially reinforces the importance of metal oxide-based nanocomposites for future energy storage devices.

The increased awareness of the environmental effects of petroleum based plastics has stimulated the coffee price emergence of biodegradable polymers such as polylactic acid (PLA). In a bid to increase the sustainability of PLA agricultural residues of animal feeds (corn stover, rice straw, and soybean hulls) have been explored and examined as reinforcing fillers to PLA composites. The consideration of such applications is suitable to the goals of the circular economy as it recycles low-value agricultural products. The current review critically evaluates lately carried out life cycle assessment (LCA) studies on PLA composites that have implemented such waste fillers with the full focus being on their environmental performance as well as methodological consistency. The review shows that these fillers have a potential of reducing the amount of greenhouse emission, energy usage, and other environmental effects, compared to pure PLA. However, unevenness in LCA methodology, especially in functional units, the system boundaries, and impacts categories obstructs direct LCA comparisons. The 1997 State of the Market report also has limited options of feedstocks and the lack of appraisals in the socio-economic front, so the overall sustainability analysis is restricted. Some of the remaining limitations that can be critical are to have generalized LCA frameworks, extended exploration of waste-based fillers, as well as combination of techno-economic analysis and social impact. Future inquiries ought to devise design considerations that would optimize both the functional characteristics and the performance of the environment and improve the reliability of sustainability measures. This review is evidence to the potential of agricultural waste reinforced PLA composites in the progress towards environmentally friendly materials and the need of integrative evaluation in the sustainable maturation of bioplastics.

The relationship between transport infrastructure and accessibility has long stood as a central research area in regional and transport economics. Often invoked by governments to justify large public spending on infrastructure, the study of this relationship has led to conflicting arguments on the role that transport plays in productivity. This paper expands the existing body of knowledge by adopting a spatial analysis (with spillover effects) that considers the physical effects of investment in terms of accessibility (using distinct metrics). The authors have used the Portuguese experience at regional level over the last 30 years as a case study. The main conclusions are as follows: i) the choice of transport variables matters when explaining productivity, and more complex accessibility indicators are more correlated with; ii) it is important to account for spill-over effects; and iii) the evidence of granger causality is not widespread but depends on the regions.