https://www.scientific.net/AST Latest Results for Advances in Science and Technology en-us https://www.scientific.net https://www.scientific.net/Image/JournalCover/14 https://www.scientific.net/AST.178.-7 Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br /> <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.3 10.4028/p-zUs8MI Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Daniel Popescu, Ionut Geonea <br />Electro erosion is a manufacturing process designed for machining difficult-to-process materials. This paper presents the fabrication of a miniature punching die used for perforation and cutting, made from X15 steel, using electro erosion. Due to its properties, such as high hardness, complexity, and the need for protection against surface layer damage, this material cannot be processed with conventional methods. The electro erosion process ensures high quality and dimensional precision in the finished product. A digital surface roughness meter and the functional schematic of the PGI system are also discussed. Various roughness measurement techniques are presented, along with graphical representations and the bearing area curve. The paper highlights variations in parameters at four measurement points, as well as changes in the "c" coefficient. Finally, the surface roughness parameters Ra, Rq, and Rz are analyzed. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.11 10.4028/p-Jtz4lY Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Dumitru Panduru, Emil Nicusor Patru, Marin Bica, Nicolae Craciunoiu <br />The main purpose of this paper is to analyze the values of the temperature after turning of pure titanium and its alloy, Ti6Al4V, as function of different cutting parameters (rotational speed, feed and depth of cut). Based on an infrared thermometer measurements for dry turning, with un-coated carbide insert, graphically dependencies of temperature as function of the cutting parameters are presented for the both materials. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.17 10.4028/p-7P8oTc Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Emil Nicusor Patru, Dumitru Panduru, Marin Bica, Nicolae Craciunoiu <br />In this paper a comparative study regarding the temperature in milling process for some types of aluminum alloys and an austenitic stainless steel is presented. In order to measure the temperature two methods are used, non-contact method, using an infrared thermometer and a contact method with six thermocouples installed along the workpiece. From the point of view of cutting parameters, for the both methods, different rotational speed and depth of cut were used, while feed speed was kept constant. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.25 10.4028/p-dIpv5c Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Mihăiță Costin Călin, Lucian Matei, Mihai Mușat, Marius Pandelea, Mihaiela Iliescu <br />This article focuses on minimizing the resistance of the blades to the air stream and improving the energy efficiency for the horizontal three-blade turbine NREL 5 MW. The study is structured on two levels: the design of a new geometric structure for the propeller blade and the development of an advanced control method, considering a range of 5–15 m/s wind speed. The research includes design and simulation with the Ashes software, using Computational Fluid Dynamics (CFD) and Blade Element Momentum (BEM) theories. The study shows that the new geometric blade profile improves aerodynamic effectiveness over that range. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.35 10.4028/p-LsL0Ec Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Maria Loredana Proistosescu Necsoi, Eduard Laurențiu Nițu, Cornelia Ana Gavriluță <br />Robotic arms significantly help automate production processes, which is why they are important for Industry 4.0. Depending on production requirements, each operation is matched to a type of robotic arm, as they have specific and unique characteristics. A well-defined classification of robotic arms is fundamental to ensure proper selection, use, and maintenance according to the particular operations performed. This paper presents a classification of the main robotic arms used in logistics and production processes. It also summarizes the main research on the use of robotic arms in logistics and manufacturing. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.47 10.4028/p-ui4BfY Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Ovidiu Antonescu, Viorica Veliscu, Ionut Daniel Geonea, Paun Antonescu <br />The paper presents a general view on the evolution of the endoscopic instrumentation as manipulators of the urinary tract. Afterwards in the years 1990s the flexible endoscopes have found their way into the bladder, ureter and kidney, revolutionizing endoscopy in urology. The urologists continue to adapt the rigid and flexible cystoscopes to modify old procedures and innovate new ones so that little or no postoperative hospitalization is required. Standard rigid cystoscopy is generally performed with the patient in the lithotomy position. A large variety of flexible and semi-rigid graspers and biopsy forceps are also available for use through the standard working post of the modern-day cystoscope. Additionally, the laser fibers can be used through a standard cystoscope. Alternatively, the instruments such as the rigid biopsy forceps and graspers are structurally incorporated into the bridge. The development of extracorporeal shock wave lithotripsy (ESWL) and the ureteroscopy revolutionized the treatment of ureteral calculi. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.55 10.4028/p-B9sDZ1 Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Traian Țunescu, Iulian Ştefan, Bebe Adrian Olei, Ionel Dănuț Savu <br />The condition of a dynamic machine (equipment) can be estimated at the current level, by measuring the vibration levels. Each component of a machine produces a vibration with one or more specific frequencies. Knowing the components of the spectrum of frequencies of the global vibration, it is possible to determine which of the components of the moving assembly the problem occurred. Thus, by measuring the vibration, a multitude of defects can be detected, for a wide variety of dynamic machines. Unlike other diagnostic devices, spectrum analyzers have the widest use in the evaluation of vibrations and specific stresses on fixed structures or on rotor blades. Other experiments evaluate the natural frequencies of the rotors, the influence of the cavity of the rotor-stator interaction. Model or prototype studies establish the influence of pressure pulsations at partial load for radial axial turbines [5]. In the work, the vibrational behavior of a Kaplan hydraulic turbine with 6 rotor blades of high power (P=200MW, Dn=9.5m), was analyzed when mechanical failures (wear) appeared after several years of operation, the graphs being taken from the diagnostic system of the studied hydrogen generator. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.65 10.4028/p-dM6fjj Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Liviu Călin, Dănuț Gabriel Marinescu, Viorel Nicolae <br />The paper presents the research’s made within the Alternative Propulsion Systems Electric and Hybrid Vehicles laboratory, from Automotive Engineering Research Centre, National University of Science and Technology Politehnica Bucharest-Pitesti branch in the field of hybrid mobility. Starting with 2002, electric and hybrid vehicle projects have been developed in this laboratory with the funding of National Council for Scientific Research in Higher Education and the support of Automobile Dacia, Renault Technologie Roumanie. These are based on vehicles in production on the Dacia cars. Among the hybrid concepts studied, we mention Nova EcoMatic Hybrid, Logan Eco Hybrid, Grand Sandero Hybrid Utility Vehicle, Hamster Electricway Hybrid, Grand Hamster Electricway Plug-in Hybrid, Gaster Electricway PHEV. The electric concepts studied were Logan Electra, Duster ZERO 4X4, Sandero Electron. Other projects were related to wireless charging systems in collaboration with INDAELTRAC Craiova and with a mobile station off grid powered by an alternative source inclusive photovoltaic panel. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.79 10.4028/p-6QxTXr Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Liviu Călin, Dănuț Gabriel Marinescu, Viorel Nicolae <br />The paper presents aspects related to the development within the Alternative Propulsion Systems Electric and Hybrid Vehicles laboratory, from Automotive Engineering Research Centre, National University of Science and Technology Politehnica Bucharest-Pitesti branch of a new concept 4WD hybrid vehicle based on the Dacia Duster. The solution is a Plug-in system, parallel P4 type with two shafts, organized in a motorized solution E4WD (Electricway 4WD). The vehicle was built by implementing a hybrid propulsion system with electrified rear axle. This hybrid system is used for the first time on Dacia vehicle fitted with thermal power train with a 1.6 litre engine fuelled with Compressed Natural Gas (CNG) and a CVT (Continuously Variable Transmission), placed in the front of the vehicle and an electric powertrain located at the rear side of the vehicle. The traction battery is Lithium Fe Phosphate (LFP) type. The charging of the traction battery can be performed with the on-board charger by cable from a Wallbox or a public station. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.95 10.4028/p-Zh0fL0 Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Ilie Dumitru, Laurențiu Racilă, Gigel Paraschiv, Lucian Matei, Cătălin Drăghici <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.105 10.4028/p-3uKF7f Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Theodor George Oprica, Ilie Dumitru, Daniela Burghilă, Loreta Simniceanu, Lucian Matei <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.115 10.4028/p-iZkl5l Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Laurentiu Racila, Ilie Dumitru, Theodor Oprica, Lucian Matei <br />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). <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.123 10.4028/p-kt0MAL Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Mihai Demian, Gabriela Demian, Luminița Grecu <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.133 10.4028/p-5WxAzY Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Gabriela Demian, Luminita Grecu, Mihai Demian <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.143 10.4028/p-ac5T4k Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Veronica Iordan, Mădălina Călbureanu, Nicolae Mihai Marinache, Adriana Ionescu, Diana Călbureanu, Raluca Malciu <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.155 10.4028/p-evH78f Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Alina Mariana Codiță, Nicolae Mihai Marinache, Adriana Stăncuț, Diana Mara Călbureanu <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.161 10.4028/p-qZymp5 Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Alina Mariana Codiță, Nicolae Mihai Marinache, Adriana Stăncuț, Adriana Ionescu <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.169 10.4028/p-UKfqF0 Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Leonard Marius Ciurezu-Gherghe, Cristina Teisanu, Bogdan Hurezeanu, Madalin Mamuleanu, Gabriela Sima, Oana Gingu <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200 https://www.scientific.net/AST.178.181 10.4028/p-RfmM9m Publication date: 4 June 2026 <br />Source: Advances in Science and Technology Vol. 178 <br />Author(s): Luminița Grecu, Gabriela Demian, Mihai Demian <br />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. <br /> <br /> Thu, 4 Jun 2026 00:00:00 +0200 Fri, 12 Jun 2026 14:35:21 +0200