Paraffin wax is the most common phase change material (PCM) that has been broadly studied, leading to a reliable optimal for thermal energy storage in solar energy applications. The main advantages of paraffin are its high latent heat of fusion and low melting point that appropriate solar thermal energy application. In addition to its accessibility, ease of use, and ability to be stored at room temperature for extended periods of time, Nevertheless, improving its low thermal conductivity is still a big, noticeable challenge in recently published work. In this work, the effect of adding nano-Cu₂O, nano-Al₂O₃ and hybrid nano-Cu₂O-Al₂O₃ (1:1) at different mass concentrations (1, 3, and 5 wt%) on the thermal characteristics of paraffin wax is investigated. The measured results showed that the peak values of thermal conductivity and diffusivity are achieved at a wight concentration of 3% when nano-Cu₂O and nano-Al₂O₃ are added to paraffin wax with significant superiority for nano-Cu₂O. While both of those thermal properties are negatively affected by increasing the concentration beyond this value. The results also showed the excellence of the proposed hybrid nanoparticles compared to nano-Cu₂O and nano-Al₂O₃ as they achieve the highest values of thermal conductivity and diffusivity at a weight concentration of 5.0 wt%.

Relying on the D-Vine copula model, this paper delves into the hedging capabilities of Brent crude oil against the exchange rate of oil-exporting and oil-importing nations. The results affirm Brent crude oil’s role as a safeguard and a refuge against the fluctuations of major currencies. Furthermore, we reaffirm that oil retains its robust hedging and safe-haven attributes during times of crisis, with currency co-movements across all countries exhibiting greater correlation than during the entire dataset. Additionally, our empirical findings highlight an unusually positive correlation between Brent crude oil and the Russian exchange rate during the Russia-Ukraine conflict, demonstrating that oil functions as a less effective hedge and a less dependable refuge for the Russian exchange rate in such geopolitical turbulence.

The significance of remittances to the Vietnamese economy necessitates investigating how they affect the value of the Vietnamese currency and other macroeconomic factors. Macroeconomic articles struggle to discover their impact on economic development, but measured remittances by migrant workers have recently soared. There is no academic study that has examined this phenomenon in Vietnam. This study uses wavelet frameworks to analyze the lead-lag nexus between exchange rates, remittances, and economic growth in Vietnam in time-frequency domains from 1995 to 2020. Overall, we find that: (i) remittances enhance economic growth in the short and medium run; (ii) exchange rates boost remittances in the short and medium run; (iii) exchange rates promote GDP in all frequency and time domains. Moreover, the partial wavelet coherence and multiple wavelet coherence frameworks also offered evidence supporting the wavelet coherence approach. More importantly, the outcomes of wavelet-based Granger causality unveil that there is two-way causality between the selected indicators, which means that all the indicators can predict each other at different frequencies. Our empirical results provide meaningful information for market participants and policymakers.

The current era of Industry 4.0, driven by advanced technologies, holds immense potential for revolutionising various industries and fostering substantial economic growth. However, comprehending intricate processes of policy change poses difficulties, impeding necessary adaptations. Public apprehensions are growing about the inertia and efficacy of policy changes, given the influential role of policy environments in shaping development amidst resource constraints. To address these concerns, the study introduces the Kaleidoscope Model of policy change, serving as a roadmap for policymakers to enact effective changes. The study investigates the mediating impact of cultural change within the framework of the Kaleidoscope Model. The study delves into cultural influences by incorporating the Behavior Change Wheel (BCW) Theory. The methodology involves questionnaires survey, analysing using Structural Equation Modelling (SEM). The findings reveal that only the Policy Adoption and Policy Implementation components significantly affect the assessment of the effectiveness of the Construction 4.0 policy. Intriguingly, the final model demonstrates no discernible connection between the Kaleidoscope Model and the cultural influences. This study makes a noteworthy contribution to the realm of political science by furnishing a comprehensive framework and directives for the successful implementation of the Construction 4.0 policy.

The article reveals the problems of the transition to a “green” economy based on sustainable technological changes, which are caused by global ecological pollution of the ecosystem, which leads to warming and ecological changes and the insufficiency of the natural resource potential to meet the needs of the population of the planet, which does not contribute to development. The essence of the study is to determine the impact of a green economy on economic growth and development, in which natural assets continue to provide resources and environmental services. It is shown that the green economy provides a practical and flexible approach to achieving concrete, measurable progress in all its economic and environmental principles, while at the same time fully taking into account the social consequences of greening the dynamics of economic growth. Green economy strategies aim to ensure that natural assets can fully realize their economic potential in a sustainable manner. This potential includes the provision of vital life support services—clean air and water, as well as the sustainable biodiversity needed to support food production and human health. Natural assets cannot be replaced indefinitely, so the policy of the green economy should take this into account. It is characterized that the green economy provides a practical and flexible approach to achieving concrete, measurable progress in all its economic and environmental principles, while at the same time fully taking into account the social consequences of greening the dynamics of economic growth. The problems of the post-war revival of Ukraine’s economy are systematized and proposals for their solution are substantiated, which is the scientific contribution of the authors to the coverage of this problem. The global problems of the transition to a green economy, which are closely related to Ukrainian realities, are revealed. The practical content is determined by the fact that the theoretical and methodological provisions, conclusions and scientific and practical recommendations constitute the scientific basis for the development of a new holistic concept of the development of the green economy of Ukraine. The conclusions that it is the “green” economy that is able to most closely link the ecological and economic aspects of the national economy, acting as a key direction for ensuring the sustainable “green” development of the region and the state as a whole, actualize the prospects of creating a green economy in Ukraine and become necessary and quite achievable in the post-war period.