Advances in Science and Technology Vol. 178

Abstract: This paper presents the constructive and functional optimization of a fuel tank designed for the supply system of a spark ignition engine. The study focuses on the use of high-density polyethylene (HDPE) as a lightweight and durable material, aiming to improve fuel efficiency and safety. The 3D model of the tank was developed using CATIA V5. Numerical simulations were performed in ANSYS to evaluate the structural behavior of the tank under pressure and vacuum conditions. Although not part of the formal validation process, these simulations provide valuable insights for improving the tank geometry. The results demonstrate the potential of plastic fuel tanks to meet operational requirements.

Abstract: The transition of the automotive sector towards autonomous mobility requires a sophisticated amalgamation of cutting-edge hardware, redundant software frameworks, and accurate mathematical modeling. This research examines the technologies that facilitate autonomy in passenger vehicles, highlighting the shift from distributed to centralized zonal systems. The core focus of this study is the development of a unified modeling framework that integrates Kinematic and Dynamic Bicycle Models. Kinematic models prove sufficient for operations at low speeds, while dynamic models are essential for maintaining stability at high speeds, where tire slip and lateral forces gain prominence. This research provides a comprehensive classification of existing designs and introduces a mathematical framework that facilitates transitions between modeling paradigms based on the vehicle's state. A detailed numerical calculus experiment is performed, simulating the transition from a low-speed urban turn to a high-speed interstate lane change. This illustrates the necessity for an integrated modeling approach to ensure safe autonomous navigation.

Abstract: The environmental problems, as well as the economic and health ones, are convincing enough for the design, production and deployment of clean, efficient and sustainable vehicles for transport. The idea of electrical vehicles for transportation is not recently, as a response for these environmental problems, but from the end of the XIX century. The aim of the paper is to show the evolution of this type of vehicles and the integration of electric vehicles in the actual development context. Electric vehicles (EV) are driven by an electric motor through a controller, being powered from an onboard energy source. This type of vehicle offers the possibility of having a cleaner environment and a more efficient and environmentally friendly transport system. Electric vehicles have practically no gas emissions, therefore they are able to reduce the problem of urban pollution in a very efficient way, so electric vehicles are the only zero-emission vehicles (ZEV).

Abstract: The paper presents a selection method of the most used thermal insulation materials used in the thermal rehabilitation of a building. A good thermal insulation requires that the material chosen, meets the technical and safety characteristics, is easily recyclable and is reasonable in price. After establishing the characteristics that must be analysed, the calculation is make to establish the optimal thermal insulation for a certain type of building. The calculation method takes into account the characteristics established, as the most important for the completion of the paper for thermal insulation and at the end, the material that best meets the required conditions is indicate. This method can be used for any type of building, for any type of thermal insulation, walls, roof, ceilings, etc., provided we correctly impose the desired characteristics.

Abstract: This paper presents a multi-criteria decision-making approach for selecting sound-absorbing materials used in building noise management. Several types of sound-absorbing materials were evaluated, and the selection criteria for identifying the optimal solution were established. The author presents detailed calculations for one of the multi-criteria decision-making methods, namely the Simple Additive Weighting (SAW) method. The results of the research determine the most suitable material to achieve acoustic comfort in enclosed spaces. The paper provides guidance to institutions, organizations, and the general public on how to select sound-absorbing materials using the SAW method.

Abstract: This research paper shows how the use of green roofs for a building located in Romania’s climate zones II (winter) and III (summer) can reduce the energy required for heating during the winter and cooling during the summer, supporting national nZEB performance targets. Two types of green roofs – extensive and intensive – were analyzed using Ubakus to evaluate heat and mass transfer through the roof structure. Compared to conventional insulation systems, green roofs provide improved thermal resistance, better moisture regulation and additional benefits related to biodiversity and indoor environmental quality. This study highlights the importance of selecting low-thermal-conductivity substrates and suitable plant species when designing green terraces in the Oltenia Region. Comparative energy consumption results for the extensive and intensive solutions demonstrate the advantages of implementing green roofs on a large scale within the Romanian construction sector. The purpose of this research is to describe a specific green roof configuration and to emphasize its benefits in improving heat and mass transfer through the roof terrace.

Abstract: This study presents the modelling of heat loss and mass transfer through the walls, using Ubakus program, of a block of flats built in 1978 and thermally rehabilitated after 1990. The objective of the study is to present the thermal and mass transfer parameters before and after thermal rehabilitation. Thus, the benefits obtained after the rehabilitation consist in improving the comfort and health conditions for the residents, as well as reducing the expenses for heating/cooling the house and for renovating the degradation caused by humidity in the walls.

Abstract: This study is about a church built at the end of the 19th century, made of burnt brick and lime mortar with sand, inadequately renovated. The objective of the study is to signal about the damages suffered by the old buildings due to the use of inadequate materials in repair. The present building was less than 20 years ago renovated by replacing the old lime-sand plaster with cement mortar, a fact that led to the accumulation of moisture in masonry, resulting the damage of the finishes and affecting the safe health conditions. The article presents temperature, humidity and dew point measurements, a calculation of the comfort index, and a software modelling, as well as the correct solutions.

Abstract: This study investigates the possibility of designing and creating dynamic facades of buildings located in aggressive climatic environments (temperatures, air currents, brightness etc.). The study is based on EN AW-5754 samples manufactured by U bending, representing the modules for dynamic facades. The bending process uses a 300 kN Abkant type press. ​ It is performed along two curved lines. The punch and the related mold are printed from ABS with FDM (fused deposited material) technology. Bending is facilitated by customized slots in 4 laser-cut patterns placed along the bending lines. The paper aims to analyze the influence of the slot patterns on the U-bending process, respectively the design of the mold and the punch designed and executed by 3D printing technology.

Abstract: In this paper, starting from the principles of sustainable development, and from the importance of preserving the quality of water for future generations, we propose some indices which can be used to study the evolution of surface water quality in a region. The indices are built using data offered by national institutions which are concerned with monitoring water quality, considering the classes established by the legislation in use or values of the most important factors which influence water quality, and the magnitude of the bodies of water analyzed. Using these indicators, a study of water quality evolution in the hydrological basin of the Danube in Romania (HBDR) is conducted. The results show that some of these indicators have decreasing values, which demonstrates a deterioration in the quality of the surface waters in this basin. These indices can be useful tools for studies regarding water quality evolution and they can be used by those who work in the environmental management area or sustainable development field or by policy makers who adopt or harmonize laws in this sector.