In the current context of sustainability management and energy insecurity, amplified by the military instability determined by the war between Russia and Ukraine, and the increasingly frequent occurrence of a series of plausible scenarios for disasters or energy blackouts worldwide, this work is a real and applicable model for regional states that would like to critically analyze the situation of their energy security through identifying all the plausible risk scenarios targeting the energy critical infrastructures. The study has identified and assessed two of the most plausible risk scenarios (a natural disaster and a terrorist attack) in the case of a strategic power substation of 220 kV, 400 kV, or 750 kV undergoing a blackout effect. After having assessed the risks, the safety strategy for Romania’s national power system has been elaborated together with the safety strategy for the European Power system-ENTSO-E (European Network of Transmission System Operators for Electricity). The results of the study match other specialized works from different European countries and might represent a model for other types of energy safety risk assessments and for other types of critical infrastructures that are vital for the modern European society and for sustainability management.
European legislation stipulates the obligation to carry out a risk assessment for each job, as well as the application of measures to prevent these occupational risks. Therefore, taking into account the importance of risk determination at the workplace for the prevention of work accidents and occupational diseases, this paper proposes the digitization of a risk assessment method. The application of the occupational injury and illness risk assessment method begins with a document that contains a description of the company (name, location, domain of activity, organization chart, etc.), a description of the work system detailing its components and a brief description of the assessment method. Next follows a Microsoft Excel document that performs the actual application of the method. Finally, another document presents the list of measures that lead to the implementation of the prevention and protection plan. This paper presents the code design of the Microsoft Excel document, an essential part in the application of the method of assessing the risks of occupational injury and illness. The document is structured on a variable number of worksheets, which present the different types of occupational injury and illness based on risks on the components of a work system. The digitalization of the risk assessment method reduces the time allocated to the evaluation without affecting its quality.
Ceramic materials as coatings are known to have very good corrosion resistance properties compared to metallic or organic coatings, regardless of environmental conditions. The following samples were used for the experiments: an initial steel substrate and Al2O3 + YSZ (12.5%; 25% and 37.5% wt) atmospheric plasma spray-coated samples. The open circuit potential showed similar average values for all samples coated with ceramic layers, which were slightly higher than the potential of the original uncoated sample. The corrosion current densities (icorr) of all plasma jet sputter-coated systems were very similar and significantly lower than those of the original material. Corrosion rates were much lower in the coated systems due to the chemical inertness of the ceramic coatings, particularly alumina- and zirconia-based coatings. It was observed that ceramic layers improve the corrosion resistance of the metallic material, especially at higher percentages of YSZ in the plasma spray-deposited complex layer. The porosity of the sputter-deposited layers reduced their corrosion resistance due to the contact between the electrolyte solution and the metal substrate created by the interconnection of the pores. The complex equivalent electrical circuit chosen for the analysis of the values led to results in accordance with the experimental parameters.
Biodegradable metallic materials are gaining attention for medical applications in short-term implants (15–500 days) because of their good mechanical properties, biocompatibility, and generalized corrosion. Most medical applications involve implant wear processes, particularly for bone fractures. Parallelepipedic specimens (dimensions 50 mm × 10 mm × 3 mm) were obtained by cutting the hot-rolled material processed from cast ingots of ZnMgY. To test the tribological performance of these stationary specimens, they were placed at the upper point of the machine’s tribological contact. The rotating lower disk of the AMSLER machine (AMSLER & Co., Schaffhouse, Switzerland) is manufactured from AISI 52100 bearing steel with a 62–65 HRC hardness and a diameter of 59 mm both radially and axially. Frictional torque is the parameter that is measured. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to analyze the worn areas. The material behavior in the normal and wear states upon immersion in simulated body fluid (SBF) was evaluated.
The physical and mechanical properties of the coatings produced by electric arc thermal spraying are closely related to the velocity and temperature of the particles that interact with the substrate surface. Knowing the temperature variation of the sprayed particles allows establishing their aggregation state, respectively determining the spraying distance, so that the state of aggregation of the particles at the impact moment is predominantly liquid. Obviously, when the sprayed particle passes through the spray cone, it cools continuously due to the low and variable temperature of the entrainment gas. This paper aims to determine analytically the thermal behavior of the particles entrained by the gas jet formed at the thermal spraying in an electric arc, depending on the variable temperature, existing along the spraying cone. In this sense, by modeling with finite elements, using the ANSYS program, the temperature inside the spray jet was determined, and by a mathematical model carried out based on the thermal balance equations, the thermal profile of the sprayed particles was determined. The thermal profile demonstrates that their temperature suddenly increases to the solidification temperature, then increases to the melting temperature—due to the latent heat of solidification, after which it decreases to 300 K.