In this article, the authors present the results of research undertaken in relation to the situation regarding renewable and non-renewable energy reserves in the European Union, as well as the way in which this energy is consumed. The general view presented regarding energy resources around the world is that oil, natural gas and coal are being exhausted at an alarming rate and if we continue to exploit these oil resources at our current pace, we will see a massive depletion in energy resources over the next 41 years. The authors also focus on representing the intensity of greenhouse gas emissions from energy consumption, demonstrating that it has shown a slight decrease in the European Union. The resources and consumption of renewable and non-renewable energy were analyzed in close interdependence with these indicators under study, such as final energy consumption, renewable energy and total energy production, in order to give a correct interpretation of how these resources are used. At the same time, starting from the fact that the world economy is currently facing a cluster of crises (pandemic, financial-economic, energy, general resources), it was deemed important to highlight the fact that the total production of energy demonstrated an oscillating trend during this period.

As civilization and technology have developed, there have been multiple energy transitions that have pushed various resources like coal, wood, oil, and gas to the forefront of the energy mix. Due to a variety of geopolitical initiatives, there have been progressively more restrictions on the energy sector in recent years. One of the main concerns of researchers is the widespread use of renewable energy and the replacement of fossil resources. The utilization of non-renewable energy sources results in a detrimental increase in greenhouse gas emissions. One of the most crucial strategies for lowering energy consumption and enhancing the energy system’s sustainability is to increase energy efficiency. Numerous studies note that energy transition has become necessary in the modern day. Using the analysis of the main components as an extraction method, hierarchical cluster analysis, this study focuses on the situation of the states of the European Union in their race for energy transition, taking into account the main challenges generated by geopolitical tensions and the energy poverty spectrum for the population. The conclusions of the study call for a reconfiguration of the energy mix based on renewable energy. Increasing the share of renewable energy is a goal pursued by EU countries, but energy policies must be considered in a broader context that includes the social aspects of the energy transition. So, just transition is a new concept that reshapes the actions of public authorities on the path to a low-carbon economy. Just transition is a necessity that puts the consumer at the center of attention so that the negative externalities generated by the move away from fossil fuels are minimized in terms of social impact.

The COVID-19 pandemic crisis, which was triggered in 2019 with oscillating evolution in 2020 and 2021, was a factor that has had dramatic effects on the economic growth of countries worldwide. In the context of the pandemic crisis, population health has deteriorated; education and economic activity in all the countries around the world have been affected. The main purpose of this paper is to highlight the special situations that humanity is experiencing as a result of the unprecedented effects that the COVID-19 crisis is having on the socioeconomic evolution. Specific statistical econometric methods (such as analysis of linear correlations, multiple linear regression, analysis based on dynamics indicators, and spectral analysis, comparability based on indices) were applied to highlight the evolution and future prospects of the COVID-19 virus worldwide. The COVID-19 crisis has generated another major issue for mankind, along with global warming and the energy transition, namely, population health. For this reason, in this study, we focused on the impact of the COVID-19 crisis on population health in a broader context; the sustained growth of populations in developing countries and aging populations in developed economies.

Additive manufacturing technology, also known as 3D printing, has emerged as a viable alternative in modern manufacturing processes. Unlike traditional manufacturing methods, which often involve complex mechanical operations that can lead to errors and inconsistencies in the final product, additive technology offers a new approach that enables precise layer-by-layer production with improved geometric accuracy, reduced material consumption and increased design flexibility. Geometrical accuracy is a critical issue in industries such as aerospace, automotive, medicine and consumer goods, hence the importance of the following question: can the dimensional optimisation of 3D FDM-manufactured parts be a solution for correct design? This paper presents a complex study of model parts printed from four common polymers used in fused deposition modelling (FDM) additive technology, namely ABS (acrylonitrile–butadiene–styrene), PLA (polylactic acid), HIPS (high-impact polystyrene) and PETG (polyethylene terephthalate glycol). The results of the methodology used highlight the dimensional changes that need to be made at the design stage, depending on the direction of printing and the type of geometric elements in the final part.

The global efforts to combat climate change, decarbonize the economies, and move towards a more sustainable future are focused on improving energy efficiency and reconfiguring the energy mix. Considering the impact on the environment and economic activity of energy production and consumption, this paper focuses on identifying the driving factors of final energy consumption in the European Union countries, which are undisputed leaders in the transition to a low-carbon economy. The goals of the paper are (1) to establish a model pattern that shows the relationships between the variation in final energy consumption and its driving forces and (2) to perform a comparative analysis to better understand the differences between the European Union (EU) economies in terms of energy efficiency improvement and decarbonization opportunities. Taking into consideration the objective of the research, comparative and correlation analyses were performed, and a decomposition technique (factorial analysis) was used in order to analyze the dynamic relationships between energy-related indicators for the EU as a whole and the 27 EU countries in 2023 compared to 2015. The research question is as follows: what are the main factors that generate final energy consumption in the EU? The hypothesis of this paper (H1) is that the variation in final energy consumption is determined by economic activity, lifestyle and consumer behavior, climate effect, and energy savings. This study’s main conclusions are that the variation in final energy consumption between 2015 and 2023 in EU countries was mostly due to key factors linked to economic activity, lifestyle and consumer behavior, climate effect, and energy savings. Thus, transport contributed the most to the variation in energy consumption, followed by services and manufacturing. The results indicate a shift to less energy-intensive sectors that positively impacted final energy consumption reduction, leading to energy savings. Concerning lifestyle and consumer behavior, household energy consumption had the highest contribution to the variation in energy consumption, followed by the number of passenger cars and the average annual net earnings. The climate effect was mostly due to the change in the cooling degree days that explained over 34.4% of the variation in the final energy consumption in households per capita. As for the energy savings effect, the results show that an increase in investments in the energy sector targeting efficiency improvements contributed to a reduction in energy consumption, leading to energy savings.

The article is the result of the question mentioned in its title, namely, whether heat treatments without phase transformation and pressing of parts can improve the physicomechanical properties of metallic materials and alloys. Starting from this hypothesis, the article analyzes the influence of non-phase change thermal treatment TT and plastic deformation (compression) on a steel used for the realization of components in the engineering industry, as presented in the specific standards SR EN-10025 and SR EN-10027. The results of the tensile tests and of the Vickers hardness tests on the specimens made of this material are presented. The results in terms of material ultimate stress σ_u, yield strength S_y, elongation δ, reduction in cross section ψ, as well as those obtained in the Vickers test are summarized in tabular or graphical form. From the research conducted by the authors of this work, it can be seen that the 0.5 × T_m−s (T_m−s—melting-solidifying temperature, K) heat treatment gives the best mix of properties: mechanical strength similar to that of the non-treated material, improved elasticity and ductility, but with a small, negligible reduction in hardness. The results are useful to support the activities of optimal selection of heat treatments and plastic forming for various engineering applications. Heat treatment without phase transformation is essential for improving the mechanical properties of materials used in engineering. This study investigates the impact of heat treatments and plastic deformation on S355J2+N steel, highlighting the increase in yield strength and improvement in ductility. The results show an increase of up to 15% in yield strength and an improvement in relative elongation by 2% for treatments at 0.5 × T_m−s, while hardness remains almost unchanged.