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Introduction/purpose: The anticorrosion protection of steel reinforcement bars in concrete is a critical concern in civil engineering, particularly for the construction of concrete structures intended for military applications. Currently, the most important methods for achieving this protection include the application of coatings on steel rebar (such as epoxy or hot-dip galvanized zinc), the use of stainless-steel rebar, composite rebars, or high-performance concrete that incorporates corrosion inhibitors, surface sealers, silica fume, or fly ash admixtures. Methods: This study aims to determine whether an electroplated Zn-Ni coating of sufficient thickness can offer better long-term corrosion resistance to reinforcing steel in concrete compared to the traditional pure Zn coating typically used for this purpose. The Zn-Ni coatings produced were 40 µm thick and contained approximately 13 mass.% Ni. Scanning electron microscopy revealed a smooth and homogeneous surface morphology, although microcracks extending through the entire coating depth were observed. The protective effectiveness of the coatings was evaluated using electrochemical impedance spectroscopy, with samples immersed in various electrolytes that simulate the chemical environments present in different types of concrete. Results: The measurements indicated a significantly slower dissolution rate of the corrosion product formed on the Zn-Ni coating in chloride-rich environments, compared to pure Zn. Conclusion: It can be concluded that Zn-Ni alloy presents a viable alternative to pure Zn for protecting steel in concrete structures where high chloride penetration is anticipated [ABSTRACT FROM AUTHOR]

Introduction/purpose: During the 1999 NATO attack on Yugoslavia, three new weapons were used and tested for the first time. The first is the strategically invisible B-2 bomber, the second is the new JDAM (Joint Direct Attack Ammunition) and the third is the "soft bomb", or the blackout bomb, made of thin electrically conductive fibers. The aim of the paper is to present the new combat devices used during the aggression on the FRY and to quantitatively detect the elements of electrically conductive fibers. The paper also presents the lawsuit of the Federative Republic of Yugoslavia (FRY) to the International Criminal Tribunal for the former Yugoslavia (ICTY) in The Hague. The lawsuit was rejected. Methods: Physical and chemical analyzes of the fibers were performed. An electron microscope, SEM JSM Jeol 6610LV, was used to analyze the physicochemical characteristics of electrically conductive fibers. It provides the information on the morphology of the sample surface, resulting in a highresolution image.The microscope is equipped with an X-ray detector (Oxford Instrumets X-Max 20 mm2) for EDS analysis (Energy Dispersive Spectroscopy). It enables the determination of the chemical composition of the material in the analyzed sample volume, based on the interaction between the directed electron beam and the sample atom. Results: The characteristics of the B-2 stealth aircraft used to bomb the FRY are shown. The JDAM bomb is an improved ordinary MK bomb with electronic devices added to guide the bomb via satellites. A semiquantitative analysis of the fibers was performed on the SEM, confirming that the metal layer of the fiber predominantly consists of aluminum, and the non-metallic layer has the highest proportion of silicon dioxide. The fiber is carcinogenic. Conclusion: In 1999, the territory of Yugoslavia was a testing ground for new combat weapons of NATO aviation - B-2 and JDAM guided bombs. Blackout bombs were dropped on the electrical power systems of Yugoslavia leaving the whole Serbia without electricity for hours. Not only was the bombing-caused environmental pollution radiological and chemical but it was also caused by glass-aluminum electrically conductive fibers as pollutants. [ABSTRACT FROM AUTHOR]

Three commercial Al-Mg alloys containing 3 wt.% to 6 wt.% of Mg (AlMg3, AlMg4.5Mn and AlMg6Mn) were subjected to different forming processes: shear spinning and cold rolling. The effect of Mg content and reduction in thickness on the tensile properties and microstructure evolution of Al-Mg alloys were studied. Both optical (OM) and transmission electron microscopy (TEM) were used for the microstructure characterization. The results show that the addition of Mg in these alloys increases the yield strength (YS) and ultimate tensile strength (UTS) in both cold rolled and spun specimens. The strength of all Al-Mg alloys after shear spinning was lower compared to the strength after cold rolling for the same strain. This effect was attributed to the occurrence of dynamic recovery during shear spinning and confirmed by transmission electron microscopy. [Projekat Ministarstva nauke Republike Srbije, br. TR-34018]