Human interference with the Earth’s climate cannot be ignored any longer. Renewable energy sources need utmost attention in all energy sectors. For buildings, geothermal energy for heating, cooling, and domestic hot water is a sustainable solution. Horizontal ground heat exchangers (HGHE) demonstrate promising results with low installation costs. Research is focused on increasing their thermal performances by structural improvements and ground thermal proprieties improvements, with little research on using auxiliary heat to increase their performances. A numerical model for an HGHE was established to investigate the effects of auxiliary heat sources on the performances of the HGHE. The results demonstrate that heat transfer into the HGHE increases the overall ground temperature at the end of the heating season by 138.50% compared with no heat transfer from auxiliary heat sources. The ground freezing period decreased by approximately 24.74% by having a heated basement, approximately 40.20% by transferring heat with solar thermal panels, and approximately 62.88% by using both auxiliary heat sources. The difference between the undisturbed ground temperature and the ground temperature with no auxiliary heat sources at the end of the season was 3.45 °C. The difference between the undisturbed ground temperature and the ground temperature with all auxiliary heat sources resulted in 0.92 °C.

The paper aims to study a concrete structure, currently used in civil engineering, which has certain symmetries. This type of problem is common in engineering practice, especially in civil engineering. There are many reasons why structures with identical elements or certain symmetries are used in industry, related to economic considerations, shortening the design time, for constructive, simplicity, cost or logistical reasons. There are many reasons why the presence of symmetries has benefits for designers, builders, and beneficiaries. In the end, the result of these benefits materializes through short execution times and reduced costs. The paper studies the eigenvalue and eigenmode properties of vibration for components of the constructions’ structure, often encountered in current practice. The identification of such properties allows the simplification and easing of the effort necessary for the dynamic analysis of such a structure.

The COVID-19 pandemic, in addition to the sometimes-dramatic effects in the health sector, presented a wide range of challenges for the various sectors of the national economies. This article refers to the effects of the pandemic in the university field, especially for the period of 2021 until now. The period corresponds to the end of the pandemic overlapping with the post-pandemic return to normal. Although at the beginning of the pandemic the effects seemed terrible, being widespread and long-lasting, some effects were still useful and motivational for the “real world”. The effects in question are those of compulsory online teaching, so on a large scale, of all subjects from all disciplines. The authors modeled and implemented a database system that includes several types of tests to generate representative samples from the university population. In the content of the article, two such tests are exemplified for a single one-semester discipline: “Computer programming and programming languages II”. The experience of the authors revealed, by comparison, practical ways to teach the theory provided in the states of functions in the real world, using exclusively the online or the mixed environment. Finally, we provide a brief conclusion and ideas for future work.

The forestry industry has evolved during its history by continuously adapting to the natural environment and new technological solutions, but its progression into the future has taken some different paths depending on the level of understanding for a sustainable greener future. Countries with a long wood culture have learned from the past and brought their knowledge into a sustainable forestry and building industry. This paper presents possible solutions for reusing timber, using logs as building materials, contributing to the regeneration of traditional heritage, and exploring the possibility of recycling and reusing materials after the building’s life cycle. The study includes solutions regarding the reuse and recirculation of old weathered wooden constructions, inspired by the Nordic countries. Climate adaptation has been a challenge since ancient times, and the Nordic climate offers more than difficult conditions. The buildings are adapted to the harsh climate and local resources, and the mountainous landscape offers building materials mainly in the form of wood and stone. Reuse and recirculation have always been practiced in the traditional construction of wood culture.

Both the calculation of ground slopes at points on the map and the elevation estimation for these points bear significant importance and also have applications in various domains, such as civil engineering, road and railway design. The paper presents two methods that use level curves: one that is fast and approximate and another which is slower, but more precise. The running speed of the two proposed methods and their results are compared by performing 100 million experiments. The paper also presents how these methods can be applied to optimize embankments. An accurate method to calculate the horizontal plane of the excavation/filling when building a new house is also presented.

When the land available for a construction is in slope, with a high degree, there can be a series of problems related to geotechnical data and execution difficulties, considering the foundations and the structure itself. The grade of difficulty is considerably increased when an extension or attic is intended to be design and build. The paper is presenting some considerations to this problem, taken into account a study case – extension of an existing structure for a family house.