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This issue of the RECENT journal was edited with the support of: ContentsKinematic Structures for Surface Processing with Straight-Line Directrix and Circle Generatrix
RECENT J. (2022), 66:004-012 https://doi.org/10.31926/RECENT.2022.66.004 Abstract The technical surfaces are characterized by directrix (D) and generatrix (G). They can be materialized, obtained by copying, obtained as the trajectory of a point, obtained as a wrapper of a family of curves, obtained by rolling or programmed. It turns out that 36 ways to generate an area by combining the ways of obtaining the directrix and the generatrix are possible. This paper exemplifies the six ways to obtain an area characterized by a straight directrix obtained by copying. Keywords directrix, generatrix, surface, links Digital Platform for the Optimization of Occupational Health and Safety Systems Specific to the Industrial Area - Part II
RECENT J. (2022), 66:013-020 https://doi.org/10.31926/RECENT.2022.66.013 Abstract Digital platforms are now increasingly used by the European economy, with a significant increase in their economic and social importance. The benefits of digitalization, mainly for the occupational health and safety system (OHS) are multiple. This paper continues the research carried out using our online application SSM.RO with the goal to analyse this application in terms of efficiency and accessibility. The most important tool was a questionnaire that was answered by 246 respondents. Fisher's exact test also helped us to conclude that the area in which the employees operate is related to the fact that the online training sessions with SSM.RO have a higher degree of efficiency than other instruction forms. One of the most important components of the application SSM.RO is the possibility to generate and send by phone message or by e-mail any type of training related to the legislation on occupational health and security systems or informative materials related to the rules of conduct and protection measures (the transmitted documents can have a pdf, audio, video or pps format). Keywords occupational health and safety, digital platform, optimization The Mirroring of a Transient Regime of a Lathe Headstock Gearbox in the Evolution of Supplying Voltage of the AC Driving Motor
RECENT J. (2022), 66:021-030 https://doi.org/10.31926/RECENT.2022.66.021 Abstract This paper aims to prove in experimental terms that a transient regime of a lathe headstock gearbox described by the evolution of the active electrical power absorbed by an AC driving motor supplied with a three-phase electrical system is also quite well mirrored in the evolution of the root mean square of the electrical voltage measured at the motor input. A simple computer assisted setup and some relatively simple techniques of active electrical power and electrical voltage monitoring are used for experimental purposes and signal numerical processing in a study of a transient regime characterized by a strong positive and negative absorbed active electrical power. This active electrical power is converted in active mechanical power requested by a transient regime of the gearbox, characterised by the increasing of speed (acceleration) and deceleration with electrically breaking (when the motor works as generator). It is proved that the evolution of the root mean square of the input voltage (on each of three phases) is related by the evolution of active electrical power with a simple equation. In this way it is possible to define a simple experimental technique to measure indirectly the active electrical power or the active mechanical power delivered by the rotor of an AC motor as well. Keywords lathe headstock gearbox, transient regime, AC motor, supplying voltage, monitoring From COVID-19 Pandemic to Next Generation EU
RECENT J. (2022), 66:031-036 https://doi.org/10.31926/RECENT.2022.66.031 Abstract The post COVID-19 pandemic European Union (EU) funds will be an opportunity for the European Union to create a more solid economy, to create a bigger cohesion between countries and to open the door for the creation of the future United States of Europe, which will give more EU competitiveness throughout the world. Is for the first time when the EU economy will be financed by common European loans made by the European Commission at smaller rates than most of the countries can borrow. It will be an advantage for everybody, consolidating the irreversible development of the EU, despite the initial opposition of the more developed countries from northern Europe. In the history of humanity always the bigger crises and wars were the turning point which boosted future enhanced development, practically when the countries were somehow forced to risk not to get destroyed. The innovative Next Generation EU fund will go in parallel with the Multiannual Financial Framework and will consolidate the classical development programs by financing new updated programs which are helping to the optimisation of the necessary infrastructure for future ecological economic growth. Environmental protection should be a must for the future existence of this planet, in the last years a lot of steps were made just to destroy it. Increased environmental requirements and quality standards must be implemented in national legislations, with the obligation for all the companies, public institutions and individuals to bring them to fruition. Social cohesion policies must reduce the gap between rich and poor, one idea currently being proposed is to create a minimum wage in all the EU countries represented by 60% of the average wage of the country concerned. History has shown that the poor will get poorer and the rich will get richer. We need scientific governmental strategies to be implemented so that everyone can be in a win-win position in the future. Keywords pandemic, Next Generation EU, green, digital and resilient A Study on the Influence of the Pressure upon the Pneumatic Muscle Forces
RECENT J. (2022), 66:037-044 https://doi.org/10.31926/RECENT.2022.66.037 Abstract The paper presents an experimental study regarding the evolution of the forces developed by a pneumatic muscle under the action of pressure. Pneumatic muscles are consisted by an elastic membrane covered with a braided structure and they act as a spring, shortening its length and increasing its diameter, under the action of compressed air. The aim of the paper is to identify the regression that corresponds to the evolution of the force developed by the pneumatic muscle in relation to the compressed air pressure. The analysis of the obtained results also highlighted the correlation between pressure and force. The measured force was then compared with the force provided by the manufacturer and some conclusions were drawn, which highlight the real possibilities of the pneumatic muscle. Keywords pneumatic muscle, the least squares method, correlations, force, pressure
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