The ICCECIP 2021 - 3rd International Conference on Central European Critical Infrastructure Protection was held this year on 15th November. This year conference was the third after the 2019 and 2020 ones. This event as part of the Hungarian Science Festival was organized by the Bánki Donát Faculty of Mechanical and Safety Engineering of the Óbuda University, Milton Friedman University and Batthyány Lajos Foundation in a historical place of the Castle, in the Villa of Lónyai-Hatvany. The motto of this year’s conference is “Kinetic and cyber tools in the critical infrastructure protection”.

The mechanical properties of Al-Si alloys have been investigated. Abrasion wear resistance is an important analysis being used in various applications so there are many laboratory testing methods to determine it. In this article, we have looked at one of the ways to determine wear resistance using a scratch tester as a relatively easy, efficient, and fast test method. Materials used in the tests were Al Si alloy. The coefficient of friction and wear of the samples were determined both by the methods of testing the wear and by investigating them in correlation with their mechanical properties.

In the steel industry, scrap metal is an important raw material resource for the electric arc furnace. The overall steel recycling rate is estimated at around 85%. The work presents an analysis of the structure of the metal load when elaborating steels in electric arc furnaces. The metal load consists of different categories of scrap metal. The influence of the quality of these types of waste on the recycling process and on the finished product by investigating the effect of the composition of the load on the steel removal is presented.

Many alloys and aluminum composites have been produced in recent years for improved material performance. Al 6061 is now an aluminum alloy with a wide range of uses owing to its excellent microstructure. For the manufacture of aluminum matrix composites (AMC), it is a wise option for the matrix. The in-situ process produces Al 6061 aluminum alloy matrix composites, according to this research. It investigates the mechanical properties of Al 6061 composites, modern in-situ fabrication, processing conditions, and multiple reinforcements employed. Numerous researches have shown that the latest in-situ process is commonly used and ideal for designing Al-6061 Alloy composites reinforcing TiC, TiB2, Al2O3, SiC, and other inorganic, biological elements, hybrid, and nanomaterials. A variety of researchers indicated that higher reinforcement material increased the composites mechanical and tribological properties. Moreover, hybrid composites outperformed single-reinforcement composites in terms of material properties. Industrial and agricultural residues are also recorded to be used in hybrid composites. Scientific investigations should concentrate on in-situ processing and material characterization of Al 6061 nanocomposites, which have a lot of promise as exotic technologies.

The biological shield is very important in the nuclear power reactor, so it is necessary to study the effect of crack on it. This work aims to study fiber composites as a radiation shielding for various purposes associated with nuclear installations, as properly as a repairing mixture for developing cracks in the biological shields of a nuclear power reactor. In this study, the MCNP5 model of a pressurized water reactor (PWR) was used. Four different fiber composites of natural fiber (FP) (?= (1.373 g/ m3 ), fiber with lead (FPPb) (?=2.756 g /cm3 ), cement fiber (CF) (?=2.095 g/ m3 ) and cement-fiber-magnetite (CFM) (? =2.858 g /cm3 ) were used as the filler materials for cracking in the biological shield. The total mass attenuation coefficients µm for the studied composites have been calculated by the Win X-Com program of gamma-ray at an energy range from 0.15 – 20 MeV. Neutron and gamma-ray fluxes and dose rates were calculated through different distances of the reactor shields for different fiber composites. Total dose rates through biological shield without cracking and after cracking have been calculated. Radiation Protection Efficiency (RPE %) for all samples at the outer surface of the biological shield was calculated. The results showed that by using fiber composites as a filler for cracking, the values of flux and dose rate for neutrons and gamma-rays have decreased. Also, FPPb is the best material for gamma-ray because it contains lead, which has a high atomic number. While CFM has the best material shield for neutron and gamma-ray in addition to magnetite and boron carbide the properties of CFM composite were improved. Max. value of RPE % for FPPb was (43.1%), then CFM (37.2%), Fp (30.2%) and CF (20.2%). From these results, it can be concluded that plastic fiber composites were the best materials that can be used as a filler in the biological shield of nuclear power reactors.

Unexpected excavation of the Osirian statuette was inaugurated in 2021 during a conservation project at the first step in the western façade of King Djoser Pyramid which dates back to the Ptolemaic era. Varies strategies of the examination techniques, such as stereo and polarizing microscopes, and scanning electron microscopy coupled to energy dispersive X-ray spectrometry and X-ray diffraction were undertaken to characterize the chemical structure of gilt-layer, preparatory layer, and bronze alloy to evaluate their condition. This paper describes the actual condition of the statuette after excavation inside the King Djoser Pyramid, and characterization of the corrosion phases, and determines the best technique for conservation. Visual investigation revealed that the core of the bronze statuette was in good condition, but most gold with gesso was misplaced. Investigation and analyses results demonstrate that amazing technique which gilding has been accomplished as a thin layer over the white substrate from gesso. X-ray diffraction establishes that cuprite and atacamite resulting from the activation corrosion were the major minerals covering the statuette. Besides, calcite and gypsum were detected, which are to be a part of the preparatory layer. EDX results demonstrate that pure gold was likely used in the gilding layer. The gilt-bronze statuette was made of multi-layered surfaces. The solid cast was used in the crafting technique. Fixation of remaining plaster to metal was undertaken using Clucel G (4%). The figure was immediately treated via popular methods as mechanical tools and solvents. Benzotriazole inhibitor (3%) was used to cure the activation of bronze disease. The coating system was applied by using 3% paraloid B72. Finally, the statuette was preserved in the storage with the appropriate conditions.

Welding as an energy-consuming process is inevitable as-welded joint can be subject to various loads without failure. Therefore, this paper presents the welding thermal cycle of Cr-Mo steel bar (ASTM A304) of dimensions 100 by 50 and various thicknesses of 5, 10- and 15-mm. Pure tungsten with 2% thoriated TIG electrodes sizes 1.6 mm X 175 mm, 2.4 mm X 175 mm, and 3.2 mm X 175 were used without filler materials for the welding process. A double V-groove weld joint, with a moving heat source, was employed to determine the temperature fields and transformation in the single-pass butt-welded joint. A calibration process was attached at each point of interest using a datalogger type K-type thermocouple 3-channel–LU-MTM-380SD during the welding process on the Cr-Mo steel bar. The results showed that the welding temperature became higher at the welding centreline and decreased towards the edges of the bar. An indication that a weld thermal cycle is a veritable tool, a function of heat input to access likely consequence of the welding process at both welded and parent metal portions of steel bar. Design of Experiment using Taguchi L9 orthogonal array matrix L9(3^4), Factors:4 and Runs:18 in Minitab 17 Taguchi Design Method that suited the experimental method used. Taguchi’s L9 orthogonal array to restrict the number of experimental runs was used for the design of the experiment (DOE). Mechanical and Microstructure tests were carried out on the samples to investigate the effect of weld heat input. The hardness test result showed that samples C15 and D15 have the highest hardness values 165.0HV and 164.0HV respectively at Base metal (BM) 20mm away from weld centreline and it was also observed that samples C15 and D15 have the highest impact values 48.53J and 48.7J respectively. The microstructure of the C15 at the weld zone WZ, which consists majorly of pearlite and less ferrite, BM shows the appearance of alpha ferrite and pearlite and heat-affected zone HAZ consists majorly of pearlite and a very small proportion of ferrite resulted in increased hardness and impact values at the HAZ.