Naukovi notatky
type: channel
description: “Naukovi Notatki” is a peer-reviewed, open-access journal (Category B) that publishes review articles and the results of original fundamental and applied research in the field of “Mechanical Engineering and Machine Building.” Scientific papers are published in the following specialties: G8 Materials Science; G9 Applied Mechanics; G11 Mechanical Engineering (by specialization)
publisher: Луцький національний технічний університет
language: en
publication name: Naukovi notatky
issn: 2415-3966
items: EIGENFUNCTIONS OF THE LAPLACE/HELMHOLTZ EQUATION FOR WEDGE-SHAPED DOMAIN
items: DEVELOPMENT AND STRUCTURAL-PHASE EVOLUTION OF THE BIODEGRADABLE HIGH-ENTROPY Fe-Zn-Mn-Cu ALLOY
items: FORWARD-ACCELERATED SIMP FOR TOPOLOGY OPTIMIZATION OF LOAD-BEARING MACHINE PARTS
items: DETERMINATION OF THE STRENGTH CHARACTERISTICS OF TRAPEZOIDAL MULTIFRACTALS
items: RESEARCH ON INDIVIDUAL REHABILITATION VEHICLES: MAINTENANCE AND REPAIR
items: DEVELOPEMENT OF BIOMPOSITE MATERIALS BASED ON GLUTIN AND FLAX FIBER
items: INTELLIGENT SYSTEM FOR MONITORING THE TECHNICAL CONDITION OF AN ABOVEGROUND PIPELINE
items: PROSPECTS OF USING COMPOSITES BASED ON THE ZrB₂–HEASYSTEM FOR THE AEROSPACE INDUSTRY
items: STRAINED n-SI CRYSTAL LATTICE IN THE PRESENCE OF PHOSPHORUS IMPURITY
items: OPERATING CONDITIONS FOR MULTI-DEGREE-OF-FREEDOM ACTUATORS IN MULTIMODAL COMBAT SUPPORT ROBOTS
items: COLD STAMPING WITH SELF-REGULATING COUNTERPRESSURE USING LIQUID AISI 52100 STEEL PUNCHES FOR COIN MINTING
items: AUXETIC LATTICE STRUCTURES FABRICATED BY 3D PRINTING USING FUSED DEPOSITION MODELING AND LCD-SLA PHOTOPOLYMERIZATION
items: UTILIZATION OF ULTRASONIC SENSORS ON DRONES AND ANALYSIS OF THEIR ACCURACY
items: CURRENT STATE AND PROSPECTIVE DIRECTIONS OF RESEARCH ON THE TECHNOLOGICAL ACCURACY OF WOODWORKING MACHINES
items: APPLICATION OF THE MODULAR DESIGN PRINCIPLE FOR CNC MACHINE TOOLS
items: STUDY OF THE FORCE CHARACTERISTICS OF SOIL-WORKING IMPLEMENTS
items: INNOVATIVE TRANSPORT AND LOGISTICS TECHNOLOGIES AND MATERIALS SCIENCE SOLUTIONS IN THE POST-WAR RECOVERY OF THE KHERSON REGION
items: EFFICIENCY ASSESSMENT OF A ROBOTIC WELDING SYSTEM CONSIDERING STABILIZATION OF THERMOPHYSICAL PARAMETERS OF THE TECHNOLOGICAL PROCESS
items: METHODOLOGY FOR COMPUTATIONAL EVALUATION OF THE ACCURACY AND STIFFNESS OF ROBOTIC TECHNOLOGICAL COMPLEXES
items: INFLUENCE OF THE BILLET GEOMETRIC SHAPE ON THE PROCESS OF HOT BACKWARD EXTRUSION OF HOLLOW PRODUCTS FROM HIGH-CARBON STEEL
items: FRACTOGRAPHIC FEATURES OF FRACTURE OF A STEAM TURBINE CONTROL VALVE STEM
items: JUSTIFICATION OF THE NUMBER OF HARVESTING AND TRANSPORT UNITS FOR FLOW FRUIT HARVESTING
items: METODS OF CALCULATION OF OPTIMAL PARAMETERS OF ROLLING
items: EXPERIMENTAL STUDY OF THE LIGHT CHARACTERISTICS OF A PHOTOVOLTAIC MODULE
items: TO DETERMINATION OF DEFORMATION CHARACTERISTICS OF GLUE-LAIMED PINE AND SPRUCE WOOD AT DIFFERENT HUMIDITIES IN THE PRECRITICAL AND POSTCRITICAL STAGES OF WORK: EXPERIMENTAL STAGE
items: INVESTIGATION OF HYDRODYNAMIC AND GAS DYNAMIC PROCESSES IN A CLOSED BYPASS CHANNEL WITH A RECTANGULAR CROSS-SECTION OF VARYING ASPECT RATIOS
items: ULTRASONIC NON-DESTRUCTIVE STUDY OF REACTION-SINTERED SILICON CARBIDE MODIFIED WITH TUNGSTEN CARBIDE
items: PREREQUISITES FOR TAKING INTO ACCOUNT MODIFICATIONS OF CONIFERS OF WOOD SPECIES IN CALCULATIONS OF TIMBER ELEMENTS AND STRUCTURES
items: CURRENT ISSUES OF STRUCTURAL TRANSFORMATIONS IN POLYMER COMPOSITE MATERIALS UNDER THE INFLUENCE OF PHYSICAL FIELDS: A REVIEW
items: SPECTROPHOTOMETRIC METHODS FOR QUALITY ASSESSMENT OF BIOFUEL MATERIALS DERIVED FROM OIL FLAX STEMS: IMPLICATIONS FOR SUSTAINABLE DEVELOPMENT

EIGENFUNCTIONS OF THE LAPLACE/HELMHOLTZ EQUATION FOR WEDGE-SHAPED DOMAIN
type: item
description: The Laplace/Helmholtz equation for wedge-shaped regions (wedge-shaped sector of finite width, wedge-shaped sector of finite length) in a cylindrical coordinate system is solved. The solutions are obtained in the form of series in an orthonormal system of modified Bessel and McDonald functions. Formulas for estimating the required number of first terms of the corresponding series to ensure the given accuracy of calculations are derived.
subject: Статті
  topic: section
subject: Laplace/Helmholtz equation
  topic: keywords
subject: wedge-shaped region
  topic: keywords
subject: Bessel functions
  topic: keywords
subject: remainder of the series
  topic: keywords
creator: B.K. Hanulich
creator: O.V. Huda
creator: T.A. Kradinova
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 195
ending page: 202
doi: 10.36910/775.24153966.2026.86.26

DEVELOPMENT AND STRUCTURAL-PHASE EVOLUTION OF THE BIODEGRADABLE HIGH-ENTROPY Fe-Zn-Mn-Cu ALLOY
type: item
description: The synthesis and investigation of the structural and phase evolution patterns of an equiatomic high-entropy Fe-Zn-Mn-Cu alloy were carried out. The alloy was obtained by powder metallurgy methods: high-energy mechanical alloying (20 hours in "Kalosha" petroleum ether) followed by liquid-phase sintering at a temperature of 900 ℃ in a pure nitrogen atmosphere. It is shown that this technological approach overcomes the thermodynamic immiscibility of the elements (specifically the Fe–Cu pair) and forms a supersaturated solid solution without a critical accumulation of oxide phases. It was established that after sintering, the alloy forms a specific microporous structure (scaffold), which reduces the elastic modulus of the material and promotes the free circulation of physiological fluids. The prospects of the developed system for creating new-generation biodegradable orthopedic implants with a controlled corrosion rate and potential antibacterial properties are proven.
subject: Статті
  topic: section
subject: biodegradable alloys
  topic: keywords
subject: high-entropy alloys
  topic: keywords
subject: powder metallurgy
  topic: keywords
subject: mechanical alloying
  topic: keywords
subject: liquid-phase sintering
  topic: keywords
subject: microporous structure
  topic: keywords
subject: osteointegration
  topic: keywords
creator: M. Kovalenko
creator: T. Soloviova
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 187
ending page: 194
doi: 10.36910/775.24153966.2026.86.25

FORWARD-ACCELERATED SIMP FOR TOPOLOGY OPTIMIZATION OF LOAD-BEARING MACHINE PARTS
type: item
description: A modification of the SIMP method for topology optimization of load-bearing elements of mechanical engineering structures is proposed – the FA-SIMP (Forward-Accelerated SIMP) algorithm, which combines an adaptive lookahead step governed by a FISTA-type momentum coefficient with a double box/volume projection of the lookahead point. The sensitivity is evaluated at a physically admissible lookahead point shifted along the previous descent direction, and an adaptive momentum restart reduces the risk of divergence in the non-convex problem. This approach makes it possible to assess not only the final stiffness of the optimized structure but also the stability of the iterative process under changes in geometry and discretization. The method is studied on compliance minimization of a cantilever beam for three configurations differing in physical size and finite-element mesh density. At the same volume fraction and iteration budget, FA-SIMP consistently reduces compliance (up to 3.95 %), grayness index (up to 10.90 %) and maximum displacement while preserving the prescribed mass and keeping the computation time practically unchanged, providing a mesh-stable acceleration of SIMP.
subject: Статті
  topic: section
subject: topology optimization
  topic: keywords
subject: SIMP
  topic: keywords
subject: FA-SIMP
  topic: keywords
subject: accelerated gradient descent
  topic: keywords
subject: lookahead step
  topic: keywords
subject: cantilever beam
  topic: keywords
subject: finite element analysis
  topic: keywords
subject: grayness index
  topic: keywords
subject: mesh stability
  topic: keywords
creator: R. R. Pyshka
creator: B. Ya. Bakay
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 176
ending page: 186
doi: 10.36910/775.24153966.2026.86.24

DETERMINATION OF THE STRENGTH CHARACTERISTICS OF TRAPEZOIDAL MULTIFRACTALS
type: item
description: The article presents the results of an experimental study of the strength of trapezoidal multifractals manufactured from PETG by FDM (Fused Deposition Modeling) 3D printing. The investigated specimens were regular discrete structures with a trapezoidal outer contour and a multifractal system of internal triangular cells, whose geometry was defined by the anisotropy parameter ε. The specimens were subjected to uniaxial compression tests with continuous recording of the load–displacement curves and determination of the maximum failure load. The relationship between the ultimate load-bearing capacity of the multifractals and the anisotropy parameter ε was established, and their fracture behavior was investigated. It was found that an increase in the anisotropy parameter leads to a higher maximum failure load, while the deformation process is accompanied by the formation of inclined shear planes and the localization of residual deformation mainly in the edge regions of the specimens. The obtained results can be used in the design of lightweight structures with controlled mechanical properties for applications in mechanical engineering, transportation engineering, civil engineering, and additive manufacturing.
subject: Статті
  topic: section
subject: trapezoidal multifractals
  topic: keywords
subject: multifractal lattices
  topic: keywords
subject: mechanical properties
  topic: keywords
subject: trength
  topic: keywords
subject: FDM printing
  topic: keywords
subject: PETG
  topic: keywords
subject: compression
  topic: keywords
creator: O.V. Ksiukovskyi
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 170
ending page: 175
doi: 10.36910/775.24153966.2026.86.22

RESEARCH ON INDIVIDUAL REHABILITATION VEHICLES: MAINTENANCE AND REPAIR
type: item
description: Providing mobility for people with disabilities is a critically important challenge for modern engineering. Individual rehabilitation vehicles (IRVs), including manually and electrically powered wheelchairs, operate under demanding and often unpredictable conditions. As a result, they are subject to accelerated wear, as well as mechanical and electronic failures, which reduce operational safety and increase maintenance and repair costs. Therefore, investigating the operational performance of IRVs, analyzing the mechanisms of their failures, and developing scientifically grounded strategies for preventive maintenance and repair constitute important scientific and practical tasks in the field of rehabilitation engineering.
subject: Статті
  topic: section
subject: vehicle
  topic: keywords
subject: typical failures
  topic: keywords
subject: reliability
  topic: keywords
subject: durability
  topic: keywords
subject: maintenance
  topic: keywords
subject: routine repairs
  topic: keywords
creator: D.A. Dubovik
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 166
ending page: 169
doi: 10.36910/775.24153966.2026.86.21

DEVELOPEMENT OF BIOMPOSITE MATERIALS BASED ON GLUTIN AND FLAX FIBER
type: item
description: The article presents a study on the compressive strength of biocomposite materials based on an aqueous solution of glutin and chopped technical flax fibers with a length of 5 mm. Biocomposite materials were developed with various component ratios: 50% glutin solution and 50% flax fibers; 46% glutin solution and 54% flax fibers; 43% glutin solution and 57% flax fibers; 40% glutin solution and 60% flax fibers Under compressive load, the destruction of biocomposite materials with various component ratios at lower pre-drying degrees (5–15%) is accompanied by plastic deformation and shear cracking. The maximum compressive strength value of 71.7 MPa was obtained for biocomposite materials containing 43% glutin solution and 57% chopped flax fibers at a composition pre-drying degree of 20%. A further increase in the filler content or excessive pre-drying of the composition impairs the wettability of the fibers by the binder, leading to brittle fracture and splitting of the material.
subject: Статті
  topic: section
subject: biocomposite
  topic: keywords
subject: glutin solution
  topic: keywords
subject: chopped flax fiber
  topic: keywords
subject: degree drying
  topic: keywords
subject: compressive strength
  topic: keywords
creator: О. Sadova
creator: Ye. Chernota
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 158
ending page: 165
doi: 10.36910/775.24153966.2026.86.20

INTELLIGENT SYSTEM FOR MONITORING THE TECHNICAL CONDITION OF AN ABOVEGROUND PIPELINE
type: item
description: The paper considers modern approaches to monitoring the technical condition of main aboveground pipelines using intelligent diagnostic systems. An analysis of the main types of pipeline defects was carried out, including corrosion damage, cracks, mechanical deformations, weld defects, and damage to the insulation layer. It was established that the development of such defects leads to pipeline leakage and emergency situations with significant environmental and operational consequences. Modern methods of non-destructive pipeline testing are considered, including electromagnetic, ultrasonic, radiographic, acoustic, and surface diagnostic methods. Special attention is paid to the Smart Maintenance concept, which involves the integration of unmanned aerial vehicles (UAVs), IoT technologies, sensor systems, and machine learning algorithms for continuous monitoring of the technical condition of pipeline infrastructure. The prospects of applying computer vision methods, convolutional neural networks, and semantic segmentation systems for automated defect detection and classification are demonstrated. The main advantages of intelligent monitoring systems are identified, including improved diagnostic accuracy, reduced human factor influence, and optimization of pipeline maintenance processes.
subject: Статті
  topic: section
subject: defects
  topic: keywords
subject: machine learning
  topic: keywords
subject: neural networks
  topic: keywords
subject: non-destructive testing
  topic: keywords
subject: pipeline
  topic: keywords
subject: unmanned aerial vehicles
  topic: keywords
creator: R.T. Bishchak
creator: O.O. Sapronov
creator: A.V. Buketov
creator: V.V. Sotsenko
creator: M.V. Brailo
creator: V.L. Demchenko
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 150
ending page: 157
doi: 10.36910/775.24153966.2026.86.19

PROSPECTS OF USING COMPOSITES BASED ON THE ZrB₂–HEASYSTEM FOR THE AEROSPACE INDUSTRY
type: item
description: This paper summarizes the current state of research on ZrB₂-based ceramics and their modification using high-entropy systems. The influence of composition and fabrication technologies on densification processes, microstructure formation, and mechanical properties of the materials is analyzed. The main problems of ZrB₂ are assessed, in particular its low fracture toughness and sintering difficulties, and the effectiveness of using high-entropy alloy (HEA) additives to address these issues is demonstrated. Promising directions for further development are proposed, focusing on composition optimization, phase state control, and the improvement of manufacturing technologies for high-density composite materials designed for use in extreme conditions.
subject: Статті
  topic: section
subject: high-temperature ceramics
  topic: keywords
subject: composites
  topic: keywords
subject: ZrB2
  topic: keywords
subject: high-entropy alloys
  topic: keywords
creator: D.S. Sudakov
creator: M.Y. Vterkovsky
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 145
ending page: 149
doi: 10.36910/75.24153966.2026.86.18

STRAINED n-SI CRYSTAL LATTICE IN THE PRESENCE OF PHOSPHORUS IMPURITY
type: item
description: The successful application of heterojunctions in various devices is due to the ability of epitaxy technology to grow semiconductor materials with a well-matched lattice structure on top of each other practically without traps at the interface. Therefore, it is relevant to study (investigate) the characteristics (parameters, behavior) of semiconductor materials caused by deformations of the crystal lattice and deformation changes in their properties in the presence of impurities. This can provide important information in modeling heterostructures and successful application of heterojunctions (strained heteroepitaxy) in creating various devices with predicted properties. In the development of electronic devices, the main attention is paid to the three most-important semiconductors: silicon (Si), germanium (Ge) and gallium arsenide (GaAs). Silicon has been studied extensively and widely used in commercial electronics products. The paper presents the results of research for undeformed and uniaxially deformed (Х ≤ 1.2 GPa) along [100] Si n-type crystals with a concentration of NP donor phosphorus (Р) impurity of 2.4 · 1013 cm-3 and 2.3 · 1015 cm-3. We studied the longitudinal (Х || j [100]) and transverse (Х ⊥ j [100]) piezoresistance in the temperature range 78 ÷ 300 K. When the crystal lattice of n-Ge and n-Si crystals is deformed, the mobility anisotropy parameter K is an important characteristic. For sufficiently pure n-Ge crystals, the set of curves ρX/ρ0 = f(Х) for different temperatures in the case of Х || j || [111] is characterized in the temperature range T > 120 K by essentially a single plateau ρ∞/ρ0 value, which determines the value of the mobility anisotropy parameter. For the correct determination of the parameter K in n-Si in such cases, the experimental data on the longitudinal piezoresistance must be supplemented with the results of measurements of the transverse piezoresistance. The work aims to comprehensively investigate the features of changes in el…
subject: Статті
  topic: section
subject: Si crystal
  topic: keywords
subject: n-type
  topic: keywords
subject: impurity
  topic: keywords
subject: mechanical stress
  topic: keywords
subject: strain
  topic: keywords
subject: uniaxial pressure
  topic: keywords
subject: deformation
  topic: keywords
subject: resistivity
  topic: keywords
subject: anisotropy
  topic: keywords
creator: S. Fedosov
creator: L. Yashchynskyy
creator: Yu. Koval
creator: D. Zakharchuk
creator: L. Panasyuk
creator: N. Koval
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 139
ending page: 144
doi: 10.36910/775.24153966.2026.86.17

OPERATING CONDITIONS FOR MULTI-DEGREE-OF-FREEDOM ACTUATORS IN MULTIMODAL COMBAT SUPPORT ROBOTS
type: item
description: The paper investigates the operating conditions of a multi-degree-of-freedom drive intended for multimodal robotic platforms used in military support operations. The growing demand for robotic systems capable of performing reconnaissance, logistics, engineering, and rescue missions in hazardous environments requires the development of adaptive locomotion mechanisms. A review of existing multimodal robots demonstrates the advantages of combining different locomotion modes, including wheeled, legged, aerial, and amphibious movement. A concept of a reconfigurable robotic platform with a variable-geometry chassis is proposed. The platform is based on wheel modules capable of changing their spatial orientation through a drive system incorporating spherical joints and harmonic gear transmissions. The developed architecture enables multiple operational modes, including high-speed wheeled motion, enhanced obstacle-crossing capability, vertical observation, and potential aerial mobility. The study identifies the kinematic, geometric, stability, and power requirements necessary for reliable operation of the drive system. Particular attention is paid to the integration of harmonic drives within spherical joints, providing compact dimensions, high positioning accuracy, and increased torque transmission. The obtained results confirm the feasibility of using multi-degree-of-freedom drives for the development of adaptive multimodal robots capable of effective operation under the challenging conditions of the modern battlefield.
subject: Статті
  topic: section
subject: multi-degree-of-freedom drive
  topic: keywords
subject: robotic platform
  topic: keywords
subject: spherical joint
  topic: keywords
subject: harmonic drive
  topic: keywords
subject: reconfigurable chassis
  topic: keywords
subject: military operations
  topic: keywords
subject: robotics
  topic: keywords
creator: M.L. Riabchykov
creator: V.S. Puts
creator: R.V. Andrushchak
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 131
ending page: 138
doi: 10.36910/775.24153966.2026.86.16

COLD STAMPING WITH SELF-REGULATING COUNTERPRESSURE USING LIQUID AISI 52100 STEEL PUNCHES FOR COIN MINTING
type: item
description: In the context of mass production of products using cold deep-drawing processes, the challenge is to improve the durability of punches and ejectors, which can be addressed by replacing machining with cold extrusion in the manufacture of such tools.This work employs FEM modeling using an elastic-plastic metal model to determine the parameters for cold extrusion with self-regulating counterpressure of AISI 52100 steel punches for coin minting, and experiments were conducted to produce the punches. For two geometric shapes of punches, the simulation established maximum fluid counterpressure values of 200 and 300 MPa, which ensured the extrusion of punches with deformation rates of 40.8% and 50.6%, respectively. The relationship between the extrusion force and the displacement of the forming tool, the force required to eject the formed blanks from the containers, and the distribution of specific forces on the surfaces of the blank in contact with the tool have been determined. The shape and dimensions of the punches after extrusion, as well as the distributions of temperature and the components of stresses and strains in the deformed metal, were identified. The work hardening of the metal structure due to cold plastic deformation was analyzed based on the distribution of strain intensity. The greatest work hardening occurs at the transition from the cylindrical deforming surface of the punches to the conical support surface, which is necessary to increase the stability of the punches during stamping. Experimental studies were conducted and confirmed the results of the calculations. The results of the modeling and experiments on extrusion with counterpressure for AISI 52100 steel are novel. Extrusion with self-regulating counterpressure can be used in the manufacture of forming tools from low-ductility die and tool steels for metal forming processes.
subject: Статті
  topic: section
subject: Cold extrusion
  topic: keywords
subject: self-regulating counterpressure
  topic: keywords
subject: stamping punches
  topic: keywords
subject: finite element method
  topic: keywords
subject: force
  topic: keywords
subject: specific force
  topic: keywords
subject: stress
  topic: keywords
subject: strain
  topic: keywords
subject: plasticity limit
  topic: keywords
creator: V. Kaliuzhnyi
creator: V. Gornostai
creator: O. Markov
creator: P. Abkhari
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 116
ending page: 130
doi: 10.36910/775.24153966.2026.86.14

AUXETIC LATTICE STRUCTURES FABRICATED BY 3D PRINTING USING FUSED DEPOSITION MODELING AND LCD-SLA PHOTOPOLYMERIZATION
type: item
description: The paper presents a study of auxetic lattice structures fabricated by additive manufacturing using fused deposition modeling (FDM) and liquid crystal display stereolithography (LCD-SLA). The investigated samples were produced from TPU filament and ABS-like photopolymer resin. Particular attention was paid to the influence of printing technology on the accuracy of reproducing thin ribs, nodes, and repeating auxetic cells. It was shown that LCD-SLA provides higher geometric accuracy, better surface quality, and more precise reproduction of small structural elements, which is especially important for research and demonstration samples. At the same time, FDM printing with flexible thermoplastics, particularly TPU, may be more suitable for functional auxetic structures subjected to repeated deformation or impact loading. The main technological difficulties of both methods are discussed, including shrinkage and increased stiffness of photopolymer samples, as well as first-layer adhesion problems, layer shifting, and stringing during FDM printing. The results confirm that the choice of 3D printing technology and material is critical for obtaining auxetic lattice structures with the required geometry and deformation behavior.
subject: Статті
  topic: section
subject: auxetic structures
  topic: keywords
subject: lattice structures
  topic: keywords
subject: 3D printing
  topic: keywords
subject: FDM
  topic: keywords
subject: LCD-SLA
  topic: keywords
subject: TPU
  topic: keywords
subject: photopolymer resin
  topic: keywords
subject: additive manufacturing
  topic: keywords
creator: V.I. Panchenko
creator: Y.Y. Brek
creator: O.B. Zgalat-Lozynskyi
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 111
ending page: 115
doi: 10.36910/775.24153966.2026.86.13

UTILIZATION OF ULTRASONIC SENSORS ON DRONES AND ANALYSIS OF THEIR ACCURACY
type: item
description: Unmanned aerial vehicles (UAVs), commonly referred to as drones, have become an increasingly important part of modern technological systems. Over the last decade, their development has accelerated significantly, mainly due to advances in electronics, embedded systems, sensor technologies, and autonomous control algorithms. Today, drones are no longer limited to recreational use; they are widely applied in industrial inspection, agriculture, environmental monitoring, rescue operations, terrain mapping, logistics, and security applications. One of the key aspects influencing drone performance is the implementation of sensor systems. Sensors provide essential information about the surrounding environment and the current state of the aircraft. Without reliable sensor data, autonomous flight, stabilization, and obstacle detection would not be possible. Modern UAV platforms typically integrate multiple sensing technologies such as gyroscopes, accelerometers, GPS modules, optical cameras, LiDAR systems, infrared sensors, and ultrasonic sensors. Among these technologies, ultrasonic sensors represent one of the simplest and most affordable solutions for short-range distance measurement. Their low weight, compact dimensions, and relatively low power consumption make them suitable for integration into lightweight drone platforms. Ultrasonic sensors are most commonly used for altitude stabilization, automatic landing, obstacle avoidance, and indoor navigation, where GPS signals may not be sufficiently accurate or available. The operating principle of ultrasonic sensors is based on the transmission and reception of high-frequency sound waves. After the emitted acoustic signal reflects from an obstacle, the sensor evaluates the return time of the reflected wave and calculates the distance between the sensor and the object. Although the principle itself is relatively simple, measurement accuracy may be influenced by several environmental factors, including temperature, air humidit…
subject: Статті
  topic: section
subject: sensor
  topic: keywords
subject: ultrasound
  topic: keywords
subject: guidance
  topic: keywords
subject: means
  topic: keywords
subject: distance
  topic: keywords
creator: P. Mikuš
creator: A. Breznická
creator: M. Kohutiar
creator: M. Eckert M. Eckert
creator: M. Krbaťa
creator: I. Grytsuk
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 104
ending page: 110
doi: 10.36910/775.24153966.2026.86.12

CURRENT STATE AND PROSPECTIVE DIRECTIONS OF RESEARCH ON THE TECHNOLOGICAL ACCURACY OF WOODWORKING MACHINES
type: item
description: This article presents an analytical review of the current state and prospective directions of research on the technological accuracy of woodworking machines. Four main research directions have been identified: structural provision of machining accuracy, experimental investigation of actual accuracy and dynamics of its changes, mathematical modelling, and automatic in-process control of part dimensions. It is established that the moving workpiece-feeding system of conventional four-side plano-milling machines contributes up to 60% of the total machining error, while at critical cutting tool wear the actual errors exceed permissible tolerances by up to 3.7 times. The distribution of machining errors is most accurately described by the Weibull law with shape parameter b = 1.89–3.11. The most promising direction is the integration of in-process workpiece measurement and machine learning algorithms (Random Forest, CNN, LSTM) for predictive maintenance with prediction accuracy above 99%. Prospective directions for further research are outlined.
subject: Статті
  topic: section
subject: plano-milling machine
  topic: keywords
subject: machining accuracy
  topic: keywords
subject: machining error
  topic: keywords
subject: modelling
  topic: keywords
subject: active control
  topic: keywords
creator: Y.I. Tyrpych
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 95
ending page: 103
doi: 10.36910/775.24153966.2026.86.11

APPLICATION OF THE MODULAR DESIGN PRINCIPLE FOR CNC MACHINE TOOLS
type: item
description: The development of the machine tool industry, driven by the implementation of cutting-edge technologies, equipment, and production management methods, is a crucial factor for industrial growth. Continuous and stringent requirements for higher productivity and quality in the manufacturing of machine parts and structures necessitate the improvement of methods for developing new machine tool models. The objective is to minimize design and manufacturing time while optimizing resource consumption. The application of the aggregate-modular principle enables the rapid creation of manufacturing equipment from a relatively limited set of unified units within the framework of modern automated production. This study analyzes the conditions, limitations, and specific features of applying the modular principle to the creation of new CNC machine tools. The structural units of machines designed using the modular approach are systematized, alongside the conditions for implementing unified modules. Furthermore, the general principles of modular configuration for metal-cutting CNC machine tools are examined, and a refined algorithm for the design synthesis of new machine tools is proposed.
subject: Статті
  topic: section
subject: CNC machine tool
  topic: keywords
subject: module
  topic: keywords
subject: configuration
  topic: keywords
subject: algorithm
  topic: keywords
creator: Y.A. Stepchyn
creator: S.I. Radkevych
creator: V.V. Otamanskyi
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 89
ending page: 94
doi: 10.36910/775.24153966.2026.86.10

STUDY OF THE FORCE CHARACTERISTICS OF SOIL-WORKING IMPLEMENTS
type: item
description: This paper presents a methodology and apparatus for testing, as well as the results of statistical analysis of the dynamic performance of a plow body, using the PLN 3-35 as an example. The authors conducted a comparative assessment of the energy and force parameters of the interaction between the working surface of the plow body and the soil, which makes it possible to identify the three components of the resultant resistance force during soil cultivation and allows for their more accurate consideration when designing new surfaces for soil-working implements.
subject: Статті
  topic: section
subject: plow body beam
  topic: keywords
subject: power characteristics
  topic: keywords
subject: traction resistance
  topic: keywords
subject: soil cultivation
  topic: keywords
subject: strain gauge measurement
  topic: keywords
subject: energy consumption
  topic: keywords
creator: V. Kurka
creator: H. Herasymchuk
creator: О. Karlash
creator: B. Onishchenko
creator: O. Lavrinenko
creator: N. Garkusha
creator: Y. Rosamaha
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 81
ending page: 88
doi: 10.36910/775.24153966.2026.86.9

INNOVATIVE TRANSPORT AND LOGISTICS TECHNOLOGIES AND MATERIALS SCIENCE SOLUTIONS IN THE POST-WAR RECOVERY OF THE KHERSON REGION
type: item
description: The article explores the challenges and prospects for restoring the transport infrastructure of the Kherson region following large-scale destruction. The research analyzes the damage to industrial and engineering facilities and identifies critical challenges for the region’s logistics and economic activity. Drawing on international experience (Europe, Asia), the study substantiates the necessity of combining financial support with innovative technological solutions. The system-forming role of logistical systems is demonstrated, and alternative short-term solutions are proposed, specifically the development of inland water transport. Particular attention is paid to the implementation of materials science innovations – polymer and composite coatings – to enhance the durability of infrastructure. Strategic directions for post-war recovery are proposed based on the principles of "Industry 4.0."
subject: Статті
  topic: section
subject: post-war recovery
  topic: keywords
subject: economic development
  topic: keywords
subject: structural transformation
  topic: keywords
subject: transport technologies
  topic: keywords
subject: advanced materials
  topic: keywords
subject: inland water transport
  topic: keywords
creator: A.V. Sapronova
creator: P.P. Fostyk
creator: V.L. Aleksenko
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 73
ending page: 80
doi: 10.36910/775.24153966.2026.86.8

EFFICIENCY ASSESSMENT OF A ROBOTIC WELDING SYSTEM CONSIDERING STABILIZATION OF THERMOPHYSICAL PARAMETERS OF THE TECHNOLOGICAL PROCESS
type: item
description: The article examines the evaluation of the efficiency of a robotic welding system with consideration of the stabilization of the thermophysical parameters of the technological process. It is substantiated that the efficiency of welding robotization should be determined not only by productivity, labor intensity, and payback period, but also by the stability of current, voltage, torch travel speed, arc energy, and linear heat input. A calculation framework is proposed that relates the stabilization of the tool trajectory to the conditions of weld pool formation, weld geometry, defect rate, and production performance.For a standard welding operation, it is shown that reducing the primary welding time from 5 to 3 minutes while maintaining constant values of current at 150 A and voltage at 18 V increases the torch travel speed from 3.33 to 5.56 mm/s. Under these conditions, the arc energy per unit length decreases from 0.810 to 0.486 kJ/mm, i.e., by 40.0%. This confirms the necessity of coordinated control of current, voltage, and speed in order to stabilize heat input in the robotic process.It was established that robotization reduces the average deviation of weld geometry from 2.5 to 0.8 mm, the standard deviation from 1.2 to 0.3 mm, and the probability of defects from 0.10 to 0.03. For a standard operation duration of 10 minutes, the productivity of manual welding amounts to 48 units per 8-hour shift, whereas a robotic operation with a duration of 6 minutes ensures 80 units per shift. Taking into account the reduction in defects, the output of acceptable products increases from 43.2 to 77.6 units per shift, i.e., by 79.6%.The obtained results demonstrate that the production and economic effect of robotization is achieved through the combination of reduced operation time, stabilization of the thermophysical conditions of the process, and improved repeatability of welded joint quality.
subject: Статті
  topic: section
subject: robotic welding
  topic: keywords
subject: welding system
  topic: keywords
subject: heat input
  topic: keywords
subject: arc energy
  topic: keywords
subject: thermophysical parameters
  topic: keywords
subject: weld quality
  topic: keywords
subject: productivity
  topic: keywords
subject: defect rate
  topic: keywords
creator: L. Samchuk
creator: S. Karpus
creator: N. Huliieva
creator: V. Sychuk V. Sychuk
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 63
ending page: 72
doi: 10.36910/775.24153966.2026.86.7

METHODOLOGY FOR COMPUTATIONAL EVALUATION OF THE ACCURACY AND STIFFNESS OF ROBOTIC TECHNOLOGICAL COMPLEXES
type: item
description: The article addresses the problem of computational and information-based evaluation of the accuracy and stiffness of robotic technological complexes performing operations involving force interaction between the tool and the workpiece or manipulated object. The relevance of the study is обусловлена by the fact that the nominal specifications of an industrial robot do not provide sufficient grounds for determining the suitability of the complex for a specific technological operation, since the actual TCP error is formed under the influence of configuration-dependent compliance, technological loading, tool parameters, dynamic effects, calibration, measurement data, and the technical condition of the system. The aim of the study is to develop an integrated evaluation methodology combining a kinematic-static model of the tool center point position, a stiffness and compliance model, a dynamic error component, and a digital information data layer. A structural representation of the robotic technological complex is proposed as a system including an industrial robot, a control system, a technological tool, an interaction object, a technological operation, a sensor subsystem, and a digital information layer. A sequential evaluation procedure has been developed, within which the position of the tool center point, wrench loading, generalized joint torques, deformation error, dynamic component, and total working-point error are determined. In addition, an information data structure is proposed for storing robot, tool, operation, loading, calibration, measurement, diagnostics, and evaluation-result parameters. Unlike approaches in which accuracy, stiffness, dynamics, and digital representation are considered separately, the proposed methodology provides a formalized transition from input data and computational models to an engineering decision regarding the suitability, conditional suitability, or unsuitability of the robotic complex for a specified operation.
subject: Статті
  topic: section
subject: robotic technological complex
  topic: keywords
subject: industrial robot
  topic: keywords
subject: accuracy
  topic: keywords
subject: stiffness
  topic: keywords
subject: control system
  topic: keywords
subject: technological loading
  topic: keywords
subject: digital information layer
  topic: keywords
subject: calibration
  topic: keywords
subject: measurement
  topic: keywords
subject: software-information model
  topic: keywords
creator: B. Prydalnyi
creator: A. Siaskyi
creator: О. Mikulich
creator: R. Hrudetskyi
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 49
ending page: 62
doi: 10.36910/775.24153966.2026.86.6

INFLUENCE OF THE BILLET GEOMETRIC SHAPE ON THE PROCESS OF HOT BACKWARD EXTRUSION OF HOLLOW PRODUCTS FROM HIGH-CARBON STEEL
type: item
description: Mathematical models were developed using the finite element method to investigate the hot reverse extrusion of high-carbon steel hollow products from round and square billets. A plastic metal model was employed. The deformation rates were determined to maintain the required thermal conditions for hot deformation throughout the forming process. For both billet shapes, the relationships between extrusion force and punch displacement were established, along with the distribution of specific forces on the contact surfaces between the deformed billets and the tooling. The distribution of temperature, stress components, and strains for the final stages of extrusion are presented. The refinement of the metal structure through plastic deformation was evaluated based on train intensity distributions. The final shapes and dimensions of the products were identified. A comparative analysis of the simulation results for the extrusion processes was performed.
subject: Статті
  topic: section
subject: hot reverse extrusion
  topic: keywords
subject: hollow product
  topic: keywords
subject: finite element method
  topic: keywords
subject: round and square billets
  topic: keywords
subject: force
  topic: keywords
subject: specific forces
  topic: keywords
subject: temperature
  topic: keywords
subject: stress
  topic: keywords
subject: strain
  topic: keywords
creator: A. Titarenko
creator: V. Hornostai
creator: S. Sabol
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 41
ending page: 48
doi: 10.36910/775.24153966.2026.86.5

FRACTOGRAPHIC FEATURES OF FRACTURE OF A STEAM TURBINE CONTROL VALVE STEM
type: item
description: Fractographic analysis of the fracture surface of a steam turbine control valve stem was performed, and its fracture mechanism was examined. Damage inside the nitrided layer and the base metal of a stem was investigated. Microanalysis revealed secondary cracks along the entire perimeter of a stem, a sign of weak adhesion between the base metal and the nitrided layer, and associated with internal oxidation. The classical failure mechanism by fatigue striation formation dominated practically the majority of a stem fracture, which is typical of high-cycle fatigue. Only at the final stage of stem failure were signs of low-cycle fatigue visualized.
subject: Статті
  topic: section
subject: Steel
  topic: keywords
subject: damage
  topic: keywords
subject: failure mechanism
  topic: keywords
subject: steam turbine control rod
  topic: keywords
creator: H. V. Krechkovska
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 37
ending page: 40
doi: 10.36910/775.24153966.2026.86.4

JUSTIFICATION OF THE NUMBER OF HARVESTING AND TRANSPORT UNITS FOR FLOW FRUIT HARVESTING
type: item
description: The study focuses on improving the flow process of “harvesting – transportation – post-harvest handling” of fruit in horticulture, which is important for food security and the export potential of the industry. The impact of on-farm logistics organization on product quality preservation and loss reduction is examined. Queue formation at the reception channel and conditions ensuring continuous technological flow are analyzed. A queuing system model is proposed, enabling an analytical description of crop arrival, optimization of the number of transport units, and coordination of processing capacities. The results contribute to reducing crop losses and increasing production efficiency.
subject: Статті
  topic: section
subject: flow technology
  topic: keywords
subject: transportation
  topic: keywords
subject: post-harvest handling
  topic: keywords
subject: queuing system
  topic: keywords
subject: logistics scheme
  topic: keywords
subject: fruit harvesting
  topic: keywords
creator: V.M. Martyshko
creator: Yu.O. Gumenyuk
creator: O.P. Derkach O.P. Derkach
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 30
ending page: 36
doi: 10.36910/775.24153966.2026.86.3

METODS OF CALCULATION OF OPTIMAL PARAMETERS OF ROLLING
type: item
description: Enterprises in various industries are still using machines with different designs of roller working bodies, which, depending on the technological process, perform various operations. Such machines need to be improved, especially small-sized machines with controlled processes in which the main process takes place in the working area. A preliminary analysis of the operation of a certain class of machines showed insufficient productivity and quality of finished products. This problem has shown modern trends in the improvement of roller working bodies in machines of different classes where different work processes are carried out with their help. The aim of the study is to develop a method for determining and distributing the amount of compression of the dough piece in the gap between the roller working bodies, improving product quality and describing these processes using a mathematical model. The paper analyzes the complexity of the injection process, insufficient stability and reliability of operation; with uneven feeding of components into the working chamber. In addition, a number of other factors affect the quality of rolls feeding: physical and mechanical properties of raw materials, operating mode, insufficient impulse of external forces during axial movement, and an excessive number of working bodies. Determining the movement of the medium between the rolls is one of the most difficult tasks. The solution to these problems is possible on the basis of a thorough study of the essence of the process occurring during rolling. This approach will make it possible to determine the nature of the stage distribution of dough sticking together in the gap between the rolls, taking into account the contact angle. Thus, the surface design of the new roll made it possible to reduce the impact on the dough and thus improve the quality of forming with the same technological parameters. At the same time, dry matter losses and process rejects are reduced. The developed model make…
subject: Статті
  topic: section
subject: three-phase medium
  topic: keywords
subject: rollers
  topic: keywords
subject: rheology
  topic: keywords
subject: shift deformation
  topic: keywords
subject: dough
  topic: keywords
subject: gas phase
  topic: keywords
creator: V. Piddubnyi
creator: S. Holiachuk
creator: O. Pylypets
creator: V. Kaspruk
creator: V. Hydzhelitskyi
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 23
ending page: 29
doi: 10.36910/775.24153966.2026.86.2

EXPERIMENTAL STUDY OF THE LIGHT CHARACTERISTICS OF A PHOTOVOLTAIC MODULE
type: item
description: The article presents the results of an investigation of the light current–voltage characteristics of a photovoltaic module 615 W Longi Solar LR8-66HGD-615M under different levels of irradiance. The influence of solar radiation on the key electrical parameters of the module, including open-circuit voltage, short-circuit current, and output power, is analyzed. The features of changes in the photovoltaic module characteristics depending on its operating modes are studied. The obtained results can be used to improve the operating regimes of photovoltaic systems and to increase the efficiency of solar energy conversion.
subject: Статті
  topic: section
subject: photovoltaic module
  topic: keywords
subject: solar panel
  topic: keywords
subject: current–voltage characteristic
  topic: keywords
subject: I–V curve
  topic: keywords
subject: solar energy
  topic: keywords
subject: enewable energy sources
  topic: keywords
subject: irradiance
  topic: keywords
subject: short-circuit current
  topic: keywords
subject: open-circuit voltage
  topic: keywords
subject: maximum power
  topic: keywords
subject: efficiency coefficient
  topic: keywords
creator: S. Korobka
creator: M. Tolstushko
creator: I. Stukalets
creator: N. Tolstushko
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-05-31
publication date: 2026-05-31
starting page: 8
ending page: 22
doi: 10.36910/775.24153966.2026.86.1

TO DETERMINATION OF DEFORMATION CHARACTERISTICS OF GLUE-LAIMED PINE AND SPRUCE WOOD AT DIFFERENT HUMIDITIES IN THE PRECRITICAL AND POSTCRITICAL STAGES OF WORK: EXPERIMENTAL STAGE
type: item
description: Solid and glued wood is often operated in environments with different humidity levels. Current regulatory documents limit such operation to the Kmod coefficient. In some cases, it is unclear how to determine certain mechanical characteristics with increased moisture content, including deformable ones. For example, the operation of elements in bridge structures, hydraulic structures, sea piers, shore protection structures, and others. Very often, materials, elements, and structures based on wood operate in a post-critical stage of operation (seismic vibrations, dynamic loads, progressive destruction, floods, changes in water levels, and others). The purpose of our research is to conduct experimental studies of structural glued laminated wood of pine and spruce with different moisture content under a strict regime of axial compression tests along the fibers during operation in river and marine aquatic environments. As well as to establish the main deformation parameters in the pre-critical and post-critical stages of operation under such operating conditions. Experimental studies of structural glued pine and spruce wood of different humidity after immersion in river and sea water environments by axial compression along the fibers under a rigid test regime were carried out. The main mechanical characteristics of glued pine and spruce wood in the pre-critical and post-critical stages of operation were experimentally established, including the temporary ultimate strength of wood, the modulus of elasticity, relative critical, limiting and residual deformations, under such operating conditions. Formulas were proposed for determining the relative limiting deformations of structural glued wood at different humidity. The main deformation characteristics of glued pine and spruce wood, both in river and sea water environments, relative critical, limiting and residual deformations were established. At humidity levels of 21% and 30%, they increase in comparison with the character…
subject: Статті
  topic: section
subject: modified wood
  topic: keywords
subject: stress-strain state
  topic: keywords
subject: strength
  topic: keywords
subject: load-bearing capacity
  topic: keywords
subject: deformation
  topic: keywords
subject: compression
  topic: keywords
subject: bending
  topic: keywords
subject: tension
  topic: keywords
creator: O.S. Chapiuk
creator: O.M. Kratiuk
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-04-14
publication date: 2026-04-14
starting page: 257
ending page: 261
doi: 10.36910/775.24153966.2026.85.36

INVESTIGATION OF HYDRODYNAMIC AND GAS DYNAMIC PROCESSES IN A CLOSED BYPASS CHANNEL WITH A RECTANGULAR CROSS-SECTION OF VARYING ASPECT RATIOS
type: item
description: The article addresses a scientific and applied problem of determining the hydrodynamic and gas dynamic characteristics of flow in closed channels with a rectangular cross-section. It is substantiated that classical analytical relations based on the Hagen-Poiseuille law are valid exclusively for channels with a circular cross-section, whereas in real engineering systems, rectangular or more complex geometries are predominant. The study presents an analytical investigation of laminar flow of liquids and gases in a rectangular channel based on the Navier-Stokes equations. For the rectangular channel, the solution was constructed using the method of expansion in trigonometric series, which allows proper consideration of boundary conditions and the geometric characteristics of the flow domain. It was established that the flow capacity of the channel depends on the aspect ratio of its sides, with the extreme value of the corresponding coefficient being achieved for a square cross-section. The analytical results were verified through numerical simulations using MATLAB and SOLIDWORKS Flow Simulation. Functional dependencies of velocity and flow characteristics on the geometric parameters of the channel were constructed.
subject: Статті
  topic: section
subject: hydrodynamics and gas dynamics
  topic: keywords
subject: rectangular channel
  topic: keywords
subject: MATLAB system
  topic: keywords
subject: SOLIDWORKS Flow Simulation
  topic: keywords
creator: S. Baranovych
creator: I. Stukalets
creator: С.В. Коробка
creator: M. Tolstushko
creator: N. Tolstushko
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-04-14
publication date: 2026-04-14
starting page: 249
ending page: 256
doi: 10.36910/775.24153966.2026.85.38

ULTRASONIC NON-DESTRUCTIVE STUDY OF REACTION-SINTERED SILICON CARBIDE MODIFIED WITH TUNGSTEN CARBIDE
type: item
description: Using the technology of reactive sintering of nanosized powders, composite materials based on silicon carbide, containing in the charge from 1 to 8% (wt.) of tungsten carbide powder particles were fabricated. The influence of the WC content in the charge on the regularities of changes in the electrical resistivity and elastic characteristics of composites, determined from the results of ultrasonic measurements of the propagation velocities of elastic waves of various types using pulse methods, was investigated.
subject: Статті
  topic: section
subject: reaction sintering
  topic: keywords
subject: carbides
  topic: keywords
subject: ultrasonic testing
  topic: keywords
subject: electrical resistivity
  topic: keywords
creator: O.V. Vdovychenko
creator: M.P. Gadzyra
creator: I.D. Hnylytsia
creator: A.M. Kolesnykov
creator: O.V. Talko
creator: N.D. Tkachuk
creator: A.M. Vysotskyy
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-04-14
publication date: 2026-04-14
starting page: 243
ending page: 248
doi: 10.36910/775.24153966.2026.85.35

PREREQUISITES FOR TAKING INTO ACCOUNT MODIFICATIONS OF CONIFERS OF WOOD SPECIES IN CALCULATIONS OF TIMBER ELEMENTS AND STRUCTURES
type: item
description: The study highlights the methodology for considering the impact of softwood modification in the design of timber structures. Although timber is a widely used building material due to its environmental friendliness, low weight, ease of processing, high longitudinal strength and cost-effectiveness, it has limitations such as moisture sensitivity, anisotropy and natural defects that limit its structural application. Modification of timber with various composite materials improves the physical and mechanical properties of timber, improves moisture resistance and increases durability. Such types of modifications change the behaviour of timber structures and their stress-strain state, which is not taken into account in current design standards, which highlights the need to update design approaches. The study focuses on structural elements, including beams, columns and cross-laminated panels, where longitudinal strength largely determines the load-bearing capacity and stiffness. Traditional design includes characteristic and design values of compressive, tensile, and flexural strengths, as well as elastic and shear moduli modified by reliability factors. This paper presents the possibility of using experimental data when taking into account the modification of coniferous wood species. In this case, experimental values are used to determine modification factors that correct the design resistance to bending, compression, tensile, and elastic moduli. Formulas are given to illustrate the application of these factors under uniaxial bending and combined loading conditions. A methodology is proposed that allows for accurate consideration of changes in mechanical behavior due to processing with composite materials, providing an accurate assessment of the strength and improved serviceability of wooden structures. The introduction of these factors into structural calculations demonstrates that modification can significantly improve the performance and service life of wooden structur…
subject: Статті
  topic: section
subject: modified wood
  topic: keywords
subject: stress-strain state
  topic: keywords
subject: strength
  topic: keywords
subject: load-bearing capacity
  topic: keywords
subject: deformation
  topic: keywords
subject: compression
  topic: keywords
subject: bending
  topic: keywords
subject: tension
  topic: keywords
creator: O.O. Homon
creator: O.M. Suvorov
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-04-14
publication date: 2026-04-14
starting page: 239
ending page: 242
doi: 10.36910/775.24153966.2026.85.34

CURRENT ISSUES OF STRUCTURAL TRANSFORMATIONS IN POLYMER COMPOSITE MATERIALS UNDER THE INFLUENCE OF PHYSICAL FIELDS: A REVIEW
type: item
description: The article analyzes the literature in the aspect of the formation of polymer composites under the influence of physical fields, which provide intensive structuring of the composition based on thermosets. The characteristics of physical fields and the features of structural transformations at the level of fine structure and supramolecular formations, which occur as a result of external energy influence, are presented. The positive influence of physical fields on the processes of structuring of polymer composite materials based on reactive polymers is proven, which is determined by the processes of ordering structural components and the formation of polymer composites with a low stress state and a high degree of structuring of the polymer matrix.
subject: Статті
  topic: section
subject: mechanical field
  topic: keywords
subject: thermal field
  topic: keywords
subject: magnetic field
  topic: keywords
subject: electromagnetic radiation
  topic: keywords
subject: ultrasonic treatment
  topic: keywords
subject: macromolecule segments
  topic: keywords
subject: supramolecular formations
  topic: keywords
subject: chemical bonds
  topic: keywords
creator: V. Kashytskyi
creator: P. Savchuk
creator: О. Sadova
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-04-14
publication date: 2026-04-14
starting page: 230
ending page: 238
doi: 10.36910/775.24153966.2026.85.33

SPECTROPHOTOMETRIC METHODS FOR QUALITY ASSESSMENT OF BIOFUEL MATERIALS DERIVED FROM OIL FLAX STEMS: IMPLICATIONS FOR SUSTAINABLE DEVELOPMENT
type: item
description: The study is devoted to the development of a spectrophotometric methodology for evaluating biofuel materials produced from non-conditioned oil flax (Linum usitatissimum L.) stems. Solid biofuel briquettes with different ratios of flax biomass and sapropel binder (L70/S30, L50/S50, L100) and a control wood sample were investigated. Aqueous extracts of combustion residues were analyzed using spectrophotometry in the wavelength range of 200–1100 nm. The obtained transmission spectra demonstrated similar overall patterns for all samples, indicating comparable structural features of combustion residues. A pronounced minimum at a wavelength of 975 nm was identified for all investigated samples. This spectral feature is attributed to the second overtone of O–H stretching vibrations and reflects the presence of hydroxyl-containing compounds and bound water in the analyzed systems. Comparative analysis showed that the differences in transmission values between flax-based biofuels and the control wood sample do not exceed 3–4%, indicating a high degree of similarity in the chemical composition of their combustion residues. The use of sapropel as a binder does not significantly affect the overall spectral characteristics, although it increases absorption intensity due to higher mineral content. The results confirm the feasibility of using oil flax stem biomass for the production of solid biofuels and demonstrate that spectrophotometric analysis can be applied as a rapid diagnostic tool for assessing their quality and environmental safety.
subject: Статті
  topic: section
subject: spectrophotometric analysis
  topic: keywords
subject: spectrophotometry
  topic: keywords
subject: combustion residues
  topic: keywords
subject: lignocellulosic biomass
  topic: keywords
subject: agricultural waste valorization
  topic: keywords
subject: sapropel binder
  topic: keywords
subject: spectral markers
  topic: keywords
subject: biofuel quality assessment
  topic: keywords
creator: S. Yaheliuk
rights: Copyright (c) 2026 Naukovi notatky
date: 2026-04-14
publication date: 2026-04-14
starting page: 223
ending page: 229
doi: 10.36910/775.24153966.2026.85.32