This study investigates the influence of cracks, of semi-elliptical shape according to ASME III rules, which is assumed be located near the pipe region where tensile stress is expected. The investigation refers to pipe whip conditions. Pipe whips are a high-energy phenomenon resulting from sudden rupture in pressurized piping systems and poses a significant threat to structural integrity and safety. This research focuses on how the presence of semi-elliptical cracks alters stress distribution, deformation and failure modes during such dynamic accidental events. With the applications of numerical simulations and principles of fracture mechanics, the manuscript presents the interaction between crack geometry, pipe curvature, and dynamic loading conditions. Key findings include the amplification of stress intensity factors in the cracked regions which exacerbate local plastic deformation due to their curvature under whipping forces. Additionally, this study highlights the critical role of crack dimensions and orientation in determining failure and provides insights into the energy dissipation caused by such defect. The results will contribute to the advancement of understanding of pipe behaviour during the postulated accident scenario. Moreover, insight could allow to enhance predictive models for pipe failure assessment and adopt design strategies for mitigating risks associated with pipe whip. This study significantly enhances pipeline safety by rigorously integrating fracture mechanics into dynamic response modelling, providing a comprehensive basis for strengthening the structural robustness of piping systems operating under high-energy dynamic loads.

Among the advanced reactor designs of the fourth generation of nuclear reactors, the Lead-cooled Fast Reactor (LFR) stands out as one of six distinct types.The corrosion damage of the steels, it is caused by liquid metal acting on the structural material, which is considered a significant obstacle in the development of the fast reactors concept.The corrosion resistance and chemical compatibility with environment of 9Cr-1Mo, ferritic alloy steel (T91), in condition of the static liquid lead with 1.10 -6 wt.% oxygen at 520 C are analysed in this study.The specimens were exposed for 3500 hours.The specimens tested were the reference T91 and T91 with the coating on base Al and Ti was applied to the second specimen.The coating applied by physical vapor deposition were used for corrosion resistance improvement.The formed oxide scale of reference T91 consists of an outer layer with a Fe-Cr spinel structure and an inner internal oxidation zone (IOZ).Corrosion damage was characterized using electron microscopy techniques, which identified networks of solution-based attack (SBA) intrusion beneath liquid lead wetted surfaces.The damage to the coating depends on their chemical composition and structure of the coating.However, in general, the application of the coating increased the resistance of the surface to corrosion damage.

Metallurgy is one of the industrial sectors that very well express the basic principles of the circular economy.This study presents the production of two main metals -zinc and lead -through the lens of the circular economy.The object of analysis is KCM -AD, Plovdiv, Bulgaria -a major producer of these metals for Southeast Europe.The plant uniquely combines two modern technologies for the production of zinc and lead and the mutual recycling of waste and secondary raw materials.Exergy and environmental assessment have been made, using the exergy method of thermodynamic analysis.The resources -primary and secondary raw materials, products and emissions -gas emissions, waste water and solid waste, and the methods used to minimize technogenic emissions have been assessed.

This study presents the experimental investigation of Heat Transfer Coefficient (HTC) distributions conducted within the framework of the European RFCS SmartCool project.The SmartCool project focuses on the development and implementation of a smart-controlled actuator system designed to homogenize the temperature distribution across the width of the transfer bar in hot strip mills.The primary objective is to enhance product flatness and mechanical properties by minimizing temperature gradients, particularly in advanced high-strength steel (AHSS) production.A series of laboratory-scale measurements were performed using a custom-designed test bench equipped with a moving stainless-steel test plate and embedded thermocouples.The plate was subjected to intensive cooling by a segmented header equipped with solid jet nozzles, divided into seven zones.The cooling process occurred in a narrow gap, allowing for close-range, high-intensity water application.Measurements focused on quantifying the differential cooling capabilities and assessing the impact of water flow rate distribution across the nozzle sections.The results confirmed that the cooling intensity is naturally determined by whether the corresponding cooling zone is active.However, it was also observed that the influence of neighboring active zones is extremely strong-significantly altering the cooling intensity in the measured area.The presence or absence of cooling in adjacent zones considerably impacted the achieved HTC values, with isolated zones showing reduced cooling efficiency.The findings provide useful insights for optimizing the setup and control of selective cooling systems, contributing to a better understanding of how cooling strategies affect thermal profiles in industrial processes.

The subject of this thesis is to perform mechanical tests of rigid ballistic protection made of composite materials.The topic builds on already developed composite ballistic materials and complements the study of mechanical properties by assessing the changes in these properties after exposure to ultraviolet (UV) electromagnetic radiation.The work uses existing research on the Twaron material and previously determined strength reduction values after 1-month exposure.Experimental samples of composite plates made of this material will be produced using selected manufacturing technologies based on previous analysis.Mechanical properties of the samples will be measured after 4-month exposure in a defined environment and the results will be compared.Practical tests will be performed to determine the influence of manufacturing technology and the environment on the measured mechanical properties.

The circular economy provides a sustainable approach to tackling growing environmental challenges, particularly in waste management and resource depletion.This paper explores the role of circular economy objectives by converting waste into valuable products such as fuels, chemicals, and bioplastics.These technologies are assessed in terms of their environmental advantages, scalability, and economic feasibility.The study demonstrates how integrating such innovations can reduce dependence on virgin resources, decrease landfill usage, and cut carbon emissions.Real-world industrial applications are examined to show their scalability, economic practicality, and environmental impact.Ultimately, waste-to-value innovations are crucial for achieving circular economy goals, offering sustainable pathways for improving resource efficiency.While these technologies hold significant promise, further research, policy support, and technological advancements are needed to address challenges related to economic viability, regulatory obstacles, and largescale implementation.Transforming plastic waste into valuable products offers a promising solution for both waste management and sustainable energy production.Technologies like pyrolysis provide practical options for reducing plastic pollution and decreasing reliance on fossil fuels.However, further improvements in process efficiency, economic feasibility, and environmental impact are necessary to enhance the commercial viability and scalability of these solutions.By integrating these innovations into the broader circular economy framework, we can make a meaningful contribution to a more sustainable and resource-efficient future.

In the current business environment, characterised by globalisation and technological advances, metallurgical companies are facing unprecedented challenges.In order to maintain competitiveness, these companies must demonstrate a capacity to respond to these emerging trends.In the context of intensifying competition and the pressure to reduce costs, the pursuit of innovative solutions to optimise logistics process is necessary.The implementation of advanced decision support systems supports the pivotal role of innovation and technological progress in ensuring sustained competitiveness in the metallurgical industry.The aim of paper is to present a methodology for the development of a dynamic multi-criteria decision support system for the management of distribution warehouses in the metallurgical industry in order to optimise storage, picking and loading processes.The methodology is based on a comprehensive process analysis of the warehouse management system and the identification of key factors influencing the decision-making processes.The development of a system utilizes the multi-criteria decision-making method of Analytic Hierarchy Process (AHP), with the objective of evaluating and recommending optimal storage locations based on a selection of criteria.These criteria encompass trade-offs between production, logistics and warehouse requirements, including distance from critical points and warehouse location.The proposed model was tested on selected warehouse events under defined conditions, which demonstrated its potential to significantly improve the efficiency of the distribution warehouse management system, thus increasing the competitiveness in the metallurgical industry.The proposed methodology for both process analysis and decision support system design has been generalized for wider use across the metallurgical industry.

The hydrogen storage properties of ball-milled AB-type alloys containing La (a rare earth element) and Ni, Sn were investigated in this study.The experimental alloys were prepared using a compact arc melter under a high-purity argon atmosphere (99.9999%).The influence of microstructure and phase composition on the hydrogen absorption and desorption behavior was examined.The addition of Sn to the LaNi intermetallic significantly reduced the equilibrium pressure without decreasing the maximum hydrogen absorption capacity, up to a Sn content of 10 wt%.Furthermore, increasing the Sn content enhanced the hydrogen absorption rate and slightly stabilized the hydride phase HLaNi.

The evolution of paint coatings is rapid, multidirectional, and most interesting.Progress in the field of polymer coating technology stems from the three most important functions: the decorative function, the protective function, and the informative function.Paint systems account for approximately 50% of all coating systems.About 95% of steel structures are estimated to be safeguarded against corrosion with protective coatings, including as much as 90% -with paint coatings.The service life of paint systems ranges from several months to several years.A special group of paint systems is paint coatings for military applications, mainly for camouflaging weapon systems and military equipment.Paint coatings are fundamentals of camouflage -they camouflage vehicles/objects in the optical range, both visible light (VIS) and the near-infrared (NIR) range.The main task of effective camouflage is to eliminate those features that may cause the object to be differentiated from its surroundings, i.e., those that make it possible to distinguish one's assets from the background, and these may include, for example, color, shape, size, gloss, and texture.The paper analyzes the functional operational properties of two-layer coatings for use in military technology.The properties were evaluated based on microstructure analysis and measurements of surface geometric structure, nanohardness, and adhesion.The tests were carried out for two-layer masking coating systems made in three variants: coating system (SP1), coating system modified with carbon nanotubes (SP2), coating system modified with glass microspheres (SP3).Paint coating systems were applied by pneumatic spraying to DC01 steel samples using SATA guns.Due to their operational properties, the developed coating systems can be used on weapons and military vehicles.