Machines. Technologies. Materials.
Vol. 19 (2025), Issue 12

Table of Contents

  • MACHINES

    • Design of a Robotic-Based Multi-Packaging Machine

      pg(s) 452-455

      This study presents the comprehensive design and architectural modeling of a robotic-based multi-packaging machine developed for high-speed and high-precision packaging processes. The system integrates a Delta robot-based pick-and-place unit, advanced servocontrolled horizontal packaging modules, and a modular conveyor design engineered for multi-product stream transfer. This work investigates the core operational challenges, including product flow management, optimized grouping strategies, dynamic conveyor synchronization, coordination of multi-axis servo movements, and the system’s overall operational efficiency. The results indicate that the developed system operates with high stability, achieves superior precision, and significantly enhances production throughput by providing automatic parameter optimization based on product variety, thereby aligning with modern Industry 4.0 requirements.

    • Thermodynamic Modeling and Matlab-based Simulation of a Stirling Engine for Micro- Scale Power Generation

      pg(s) 456-459

      The Stirling engine represents one of the most promising technologies for the efficient conversion of thermal energy into mechanical work, due to its ability to operate with almost any heat source and to achieve theoretical efficiencies approaching the Carnot cycle. This article aims to provide a detailed study of the Stirling cycle, the development of a mathematical model, numerical simulation using MATLAB and the analysis of the engine performance as a function of the main thermodynamic parameters, with special emphasis on applications in micro-power generation. A distinctive aspect of this study lies in the comprehensive treatment of the polynomial dependence of specific heat in all thermodynamic processes, enabling a more accurate representation of real gas behavior compared to idealized classical models. The mathematical model is formulated using the fundamental laws of thermodynamics and the ideal gas equation, as well as the well-known Schmidt model for the analytical description of pressure and volume throughout the cycle. A numerical simulation is then performed in MATLAB, where the work per cycle is calculated, p–V and T–s diagrams are generated, and the theoretical efficiency is evaluated for different operating temperatures and pressures. The simulation results show that increasing the temperature difference and average gas pressure significantly increases the mechanical output of the engine and the power output, while an efficient regenerator significantly improves the overall performance and brings the engine closer to Carnot efficiency. The study shows that the Stirling engine has significant potential for sustainable power generation systems, while the developed modeling and simulation framework provides a solid foundation for further experimental development and design optimization.

    • Research on deformations of a flexible screw sectional working body

      pg(s) 460-462

      The article presents the construction of a flexible sectional screw working body, the use of which allows to improve the performance of flexible screw conveyors with low material consumption of the working body, which reduces energy costs for the transportation process. Based on the results of static experimental studies, the nature of the change in the dependence of torque on the angle of twist of individual sections has been established.

    • Investigation of the parameters of a curved channel of the confuser type

      pg(s) 463-465

      Parametric optimization of a curved channel was made with changing the geometric shape under pre-set conditions when liquid or gas flows through it. Mathematical modelling of hydrodynamic processes was performed in curved channels of the confuser type. As a result of numerical modelling of the hydrodynamic processes, using the ANSYS Fluent CAD software product, the distributions of velocities and pressures in the confuser channel were obtained. The optimal curved channel profile was selected. based on the conditions of minimal pressure losses in the channel. The obtained results may be used in the design of the heat exchange and aerodynamic equipment.

  • TECHNOLOGIES

    • Tribological Analysis of Plasma Spray Thermal Deposition on the Active Area of Harrow Discs

      pg(s) 466-469

      The results of tribological tests of the active area of harrow disks with coatings obtained by the plasma spay thermal method are presented. This study is based on scanning electron microscopy of coated harrow disc samples undergoing standard tribological tests that focuses on the mechanical properties of coatings using tribological methodology. Tribological studies were conducted to determine the following main parameters of the harrow disc material such as: adhesion to the substrate, coefficient of friction, Young’s modulus, stiffness and hardness of coated samples and the base material. As the result, improving the mechanical and chemical properties of materials used to manufacture the working bodies of coated harrow discs allows for increased resistance to abrasive wear in modern agricultural machinery.

    • Application of single-point incremental forming with industrial robot arm to analyze the impact of system stiffness on forming precision

      pg(s) 470-471

      Single-point incremental forming (SPIF) eliminates dedicated forming dies, enabling flexible and cost-effective production of complex thin-walled metallic components suitable for prototyping and low-batch manufacturing. This work develops and tests a robotic SPIF workstation using a Kawasaki RS030N industrial robotic arm to evaluate how system stiffness affects geometric accuracy. The research setup development includes a rigid forming table, a universal forming tool, and dedicated software for toolpath generation, robot communication, and parameter management. Experimental tests on aluminium and steel sheets of varying thicknesses assess the role of mechanical stiffness in maintaining dimensional accuracy. This foundational study completes the SPIF process chain—from toolpath generation and trajectory verification through forming trials and precision analysis—establishing a basis for future robotic additive forming systems aligned with Industry 4.0 principles.

    • Thermoeconomic Analysis of an Organic Rankine Cycle for LNG Cold Energy Utilization

      pg(s) 472-475

      Liquefied natural gas (LNG) has become a crucial source of energy supply security amid growing geopolitical tensions in recent years. During LNG regasification, a substantial amount of cold energy is released, and typically wasted into seawater. The cold-energy potential of LNG during regasification and warming from −161 °C to +15 °C at 80 bar is 750 kJ/kg, while the associated exergy potential is 400 kJ/kg. This paper investigates the potential for converting LNG cold energy into electricity through a cryogenic binary cycle. The results indicate that integrating an ORC system into the LNG regasification process can yield substantial energy and economic benefits while reducing the thermal waste at regasification terminals. The recoverable power per 1 kg/s of LNG is 90 kW/(kg/s) for a single-pressure ORC configuration using ammonia as the working fluid. The levelized cost of electricity (LCOE) is 45 €/MWh while specific installation costs (SIC) are 2225 €/kW for a brownfield retrofit project on an existing regasification unit. This research confirms that the application of innovative cryogenic cycles enables a more sustainable and efficient use of the LNG supply chain, contributing to the decarbonization of the energy sector.

  • MATERIALS

    • Optical and microstructural properties of hybrid sol–gel derived ZrO₂–Al₂O₃–Sm₂O₃ coatings on glass for photovoltaic applications

      pg(s) 476-479

      This work presents an overview of sol–gel-derived oxide materials and their relevance to optical, photonic and photovoltaic applications, followed by an experimental study of ZrO₂–Al₂O₃–Sm₂O₃ thin films deposited on glass substrates. Historical developments of the sol–gel process, beginning with early investigations on silica gels in the 19th century, are outlined together with advancements in optical glasses, anti-reflective coatings, and rare-earth-doped systems. Recent progress in functional materials—including boron-, tellurium- and rare-earth-containing glasses, luminescent oxide systems, and sol–gel-derived zirconia-based coatings—is discussed to highlight their structural, optical and radiation-shielding capabilities.
      In the present study, multilayer ZrO₂–Al₂O₃–Sm₂O₃ coatings were prepared via the sol–gel method combined with dip-coating, and subsequently thermally treated at 420 °C. Optical characterization (UV–VIS–NIR) revealed changes in transmittance and reflectance linked to film composition and thickness, while X-ray diffraction confirmed their predominantly amorphous structure at the applied heat-treatment temperature. SEM and EDS analyses provided insight into surface morphology and elemental distribution within the films. The results demonstrate that increasing Al₂O₃ content influences coating porosity and thickness, while Sm₂O₃ contributes luminescent functionality and potential reduction of optical reflection in key solar spectral regions. These findings indicate that ZrO₂–Al₂O₃–Sm₂O₃ thin films are promising candidates for protective and functional coatings in photovoltaic applications, where enhanced light harvesting and improved surface properties are essential.

    • Phenomena during liquid-phase assisted sintering in High-Entropy Ceramics with a Ni binder

      pg(s) 479-482

      This study investigates the mechanisms of liquid-phase assisted sintering in high-entropy ceramics (HECs) using a nickel binder. The research focuses on the densification process of (Ti, Zr, Hf, Nb, Ta)C-based cermets with 10 vol% Ni, and how pressure influence liquid-phase extraction. Results show that eutectic reactions between Ni and carbide phases was observed during liquid formation below 1400°C. Microstructural analysis reveals a nickel-rich matrix, solid solutions, and NbC-based carbide inclusions in the extracted drop. These findings provide insights into optimizing processing parameters for advanced HEC-based composites.