Lutsk National Technical University

The article discusses the importance of digital transformation in achieving increased efficiency and sustainability of cities in the modern world. The main objective of the work is to explore the potential of digital transformation, assess the institutional prerequisites for its development, the concept of smart cities, trends, challenges, and vectors of digital transformation development, and its impact on enhancing the efficiency and sustainability of cities. The relevance of addressing the stated problem lies in the fact that urban population growth, changes in the economy, technological progress, and environmental issues pose complex challenges for cities, and digital technologies can provide solutions for managing transportation, energy supply, waste management, and improving access to information and services for residents. This publication highlights key aspects of transformative changes and digital integration processes, the role of information and communication technologies in public life. An attempt has been made to provide a systematic exposition of the main advantages of using information and communication technologies as a tool for shaping a smart society, implementing the concept of a smart city, and democratic state development. It is found that the main challenges on the path of digital transformation include the lack of a unified approach at the state and local levels, unsatisfactory development of digital infrastructure, inadequate level of automation and digitization of government services, lack of digital literacy among the population and local government officials, and the presence of digital «Inequality» among the population. The research concludes that the use of advanced digital technologies can be a key tool in achieving the strategic development goals of cities, particularly in the context of Sustainable Development Goals.

The economy of Ukraine during the period of war experienced significant losses not only economic but also social, environmental, and informational. As a result, difficulties arise, and an imbalance is formed in the development of its structural elements. Due to the sharp increase in the outflow of human resources from Ukraine, it is on the brink of demographic collapse, which may lead to the disruption of development processes. Before the war, there was a significant population decline in Ukraine, and migration exacerbated the demographic crisis by more than 9 million people. Considering the fact that only 10% of refugees return to the country, such a situation has a destructive impact on achieving sustainable development goals. One of the tools that would contribute to achieving sustainable development goals through establishing constructive dialogue between business, government, education, and society is the construction of innovative mechanisms for regulating the social welfare of refugees. They are capable of ensuring the recovery of Ukraine’s economy, preventing demographic collapse, and ensuring the sustainable development of society. The purpose of the research is to develop mechanisms for regulating the social welfare of refugees on innovative principles. The research tasks include assessing the demographic situation in Ukraine, analyzing the level of migration before and after the war, studying the level of social welfare, determining the components of innovative mechanisms for regulating business social welfare, and the stages of their implementation. Based on this, conclusions are drawn that Ukraine has exhausted the potential for demographic growth, with a low share of the working-age population, high mortality among adults, significant migration flows, uneven population distribution across the country, and a worsening environmental situation. With the deepening of these processes, the Ukrainian economy faces demographic collapse rather than achieving sustainable development goals. One of the ways to prevent demographic collapse is to develop measures that would increase the level of social welfare. It is proposed that innovative mechanisms be used to regulate the social welfare of refugees. They rely on innovations in business, regulatory, administrative, social, and informational mechanisms for regulating social welfare. Seven stages of implementing innovative mechanisms have been identified, based on choosing the optimal strategy for improving the welfare of refugees in terms of labor, non-material, material, natural, and informational resources.

The article clarifies the essential features of innovation, classification, integral qualities of innovation; factors of innovative learning technologies, and modern innovative learning models. New innovative learning technologies in the modernization of training of specialists in the educational process are defined as distance, blended, and mobile learning. The study's ascertaining stage showed that students' readiness to implement innovative technologies is insufficient, which confirmed the study's relevance in the modernization of professional training of specialists and the role of innovative learning technologies. Based on the generalization of the results of the formative stage of experimental training, it was confirmed that the proposed special course of the specified training is statistically justified and effective, the level of readiness of EG students is higher than that of CG students. Methodological recommendations have been developed for the use of innovative technologies in the modernization of the professional training of specialists and their further application in the professional activities of specialists.

The article proves that effective crisis communications, allow not only to inform staff about the current situation promptly but also to maintain stability and cohesion in the team, quickly adapt employees to new conditions, and maintain their productivity and psycho-emotional state. The study is based on the use of a wide range of methods for assessing social and psychological threats in the context of crisis communication, namely: the results of questionnaire surveys and sociological research by consulting agencies and international organisations to study and systematise social and psychological risks in the organisation; statistical analysis to identify the direction and dynamics of the development of the main manifestations of mental health; correlation and regression analysis to assess the impact of mental health on employees’. The development of crisis communication models in wartime is based on adapting classical crisis communication models and elements of strategic matrix modelling. The study was based on the results of surveys of employees of Ukrainian organisations for the period 2018-2023, which allowed us to determine the impact on their mental state of the biggest challenges of recent years, namely the Covid-19 pandemic and the war launched by the Russian Federation against Ukraine in February 2022.

The article presents the results of experimental studies of the effect of material anisotropy and the presence of tunnel inhomogeneity of 3D-printed elements relative to the direction of compression on the mechanical and strength characteristics of the obtained samples. Test samples made by 3D printing using PETG plastic were used for the research. Research was performed for solid samples and samples with a system of free and reinforced cavities. The results of experimental studies allow us to study the influence of the presence of geometric and structural heterogeneity of bodies on their mechanical and strength characteristics during their 3D printing. Thepeformed studies allow to optimally choose the modes of 3D printing of elements taking into account the anisotropy of the material in order to ensure their maximum strength characteristics. The results of experimental studies confirm the results of numerical calculations [1] obtained on the basis of the finite element method.

The paper examines the influence of loading modes on polyurethane foam elements on the change in mechanical properties of the material under load, resulting in plastic deformation of the material. Studies were carried out on polyurethane foam samples with different ratios of polyol and isocyanate in the foam-forming mixture. From the materials obtained, groups of samples were formed for which a comparison was made of their mechanical behaviour when compressed under the action of a load that causes plastic deformation of the material. To evaluate the change in characteristics, multiple cyclic loading was carried out in the zone of plastic deformation and the change in Young's modulus under the action of such loading was studied.

The work notes the negative consequences of Russia's military aggression for the population, economy, infrastructure and natural ecosystems of Ukraine. In addition, a large-scale problem of waste management resulting from hostilities, related to the amount of this waste and its various effects on people and the environment, is highlighted. Further analysis of informational and literary sources demonstrated the necessity of mandatory inclusion of construction waste generated as a result of hostilities in the system of secondary processing and further reconstruction of our state. The growing role of digitization in modern society and the necessity of using technologies based on artificial intelligence, the Internet of Things, blockchain and big data analytics, virtual and augmented reality in the field of waste management as necessary elements for ensuring a digital circular economy are noted. The available separate digital tools for regulation of this sphere in Ukraine need further development. Further, in the work, an algorithm for the functioning of the construction waste collection system, which was formed as a result of hostilities, was developed. the architecture of the information system for the collection of these wastes is proposed, and its implementation is verified on individual examples. The proposed architecture is based on the use of well-known messengers in mobile devices, which ensures massiveness and convenience of informing. It is envisaged to create a digital information space in which the destruction waste collection system includes users, a means of communication, a communication path, an interactive array of data, an automated router providing information, and the indirect participation of the owner of this system. Features of the interaction of the elements of this space are outlined. Individual examples of implementation of the proposed architecture include the development of a chatbot, an author's information channel, and an online training course. It was noted that these components are aimed at the introduction of a closed-cycle economy in the country and will contribute to its achievement of the goals of sustainable development.

Geopolymer materials are increasingly being considered as an alternative to environmentally damaging concrete based on Portland cement. The presented work analyzed waste from mines and waste incineration plants as potential precursors for producing geopolymer materials that could be used to make lightweight foamed geopolymers for insulation applications. The chemical and phase composition, radioactivity properties, and leachability of selected precursors were analyzed. Then, geopolymer materials were produced, and their strength properties were examined through compression and flexural tests. The results of the strength tests guided the material selection for foamed geopolymer materials. Next, geopolymer foams were foamed with hydrogen peroxide and aluminum powder. The produced foamed materials were subjected to strength and thermal conductivity tests. The results demonstrated the great potential of mine waste in the synthesis of geopolymers and the production of lightweight geopolymer foams with good insulating properties.

Thermoplastic composites have garnered significant attention in various industries due to their exceptional properties, such as recyclability and ease of molding. In particular, biocomposites, which combine biopolymers with natural fibers, represent a promising alternative to petroleum-based materials, offering biodegradability and reduced environmental impact. However, there is limited knowledge regarding the efficacy of joining PLA/PHBV-based biocomposites modified with nanocrystalline cellulose (NCC) using vibration welding, which restricts their potential applications. This study demonstrates that vibration welding enables efficient bonding of PLA/PHBV composites with NCC, resulting in strong, biodegradable, and environmentally friendly materials. The investigation revealed that the addition of nanocrystalline cellulose (NCC) at 5, 10, and 15 wt.% significantly enhanced the strength of welded joints, with the highest strength achieved at 15% NCC content. Microstructural analysis using scanning electron microscopy (SEM) and deformation studies with digital image correlation (DIC) indicated that a higher NCC content led to greater local deformation, reducing the risk of brittle fracture. Mechanical hysteresis tests confirmed the composites’ favorable resistance to variable loads, highlighting their stability and energy dissipation capabilities. Optimization of welding parameters, such as vibration amplitude, welding time, and pressure, is crucial for achieving optimal mechanical performance. These findings suggest that PLA/PHBV composites modified with NCC can be utilized as durable and eco-friendly materials in various industries, including automotive and packaging. This research presents new opportunities for the development of biodegradable high-strength materials that can serve as alternatives to traditional plastics.

Today, the unique highly productive pine-oak and hornbeam-oak stands in Volynsk Polissia have been preserved in separate areas of the Tsumanska Pushcha Kivertsi National Nature Park (NNP) and need protection, regeneration and study of their condition and productivity at various stages of development. The objects of research were pine-oak and hornbeam-oak stands growing in different types of forests of the NNP. Forest management materials of the park for 2018 and typological analysis methodology were used for the study of the stands. The distribution of stands according to age classes and predominant species and stand density was carried. It was determined that productivity of stands with oak participation and forest typological potential in different types of forest is used by 82%–91%. In the wet and fresh hornbeam-oak-pine fairly fertile forest site type and wet hornbeam fairly fertile oak forest type the average actual volume of stands reaches the greatest value in the ninth age class (382, 350 and 309 m ³ ha ⁻¹ ). From the tenth age class and older there is a decrease of the average actual stand stock. Mature and overmature pine-oak stands of a wet fairly fertile site type are characterised by low productivity. As a result of non-observance of the formation and improvement felling rules of forests, secondary stands were formed in the NNP. The share of secondary stands in the most widespread forest types is 66%–78%. Pine, red oak, birch and alder dominate in the secondary stands. Spruce, aspen, hornbeam, ash, linden, larch and acacia grow in small forest areas. Secondary stands of hornbeam fertile oak forest type are formed by middle-aged red oak and fir. In order to increase the productivity and stability of stands with the participation of English oak in the conditions of the NNP, it is necessary to transform secondary stands into primary stands. The study of the features of the formation of the primary stands based on the principles of close to nature forestry is a prospect for further research.

This study investigates the physical and mechanical properties of biodegradable composites based on PLA/PHBV blends modified with different content of nanocrystalline cellulose (NCC) of 5, 10, and 15 wt.%. Density measurements reveal that the density of the composite increases with increasing NCC content. Water absorption tests demonstrate a gradual increase in the composite water content with increasing incubation time, reaching stabilization after approximately 30 days. Mechanical testing was also carried out on both on conditioned samples after the process of hydrolytic degradation and accelerated thermal aging. The conditioned composites show an increase in the stiffness of the materials with increasing content of nanocrystalline cellulose. The ability to deform and the ability to absorb energy when the sample is dynamically loaded decrease. The repeated strength tests, after the process of incubation of samples in water and after the process of accelerated thermal aging, show the degradation of composite materials; however, it is noticed that the introduction of cellulose addition reduces the impact of the applied artificial environment in aging tests. The findings of this study indicate promising applications for these types of materials, characterized by high strength and biodegradability under appropriate conditions. Household items such as various containers or reusable packaging represent potential applications of these composites.

In order to achieve the objective of the work—an experimental study of the capabilities of the acoustic method for extinguishing organic compounds and for ensuring environmental monitoring—the effect of the combustion of various polymers on the acoustic parameters of the medium is considered. The negative effect of the combustion of organic substances on the medium is noted. The features of the use of fire extinguishing agents are analyzed, and it is noted that the acoustic method is a promising, inexpensive, and environmentally friendly approach for use in extinguishing fires. The ideas about the capabilities of this method using the combustion of various polymers were further developed, which is the novelty of the work. As the main results, it is proposed to use the angle of incidence, concentration of suspended particles, temperature, and wave resistance of the environment as special correction factors for acoustic sensors when monitoring in a smoky space. The possibility of using the combustion parameters of organic compounds to determine the properties of acoustic waves in a smoke-filled area is shown. The perspective of implementing the results obtained in the practice of fire prevention and liquidation was observed to increase the efficiency of fire extinguishing and increase the safety of the population and personnel of special services. The proposed approach can become part of the ecological and economic innovations of municipal communities and national strategies to achieve the goals of sustainable development.

The development of industrial hemp production necessitates the creation of new technical means and methods, and the refinement of technological approaches for cultivating and harvesting this crop. In Ukraine, where the hemp industry is experiencing a period of active growth, there is a particular need for technical solutions that can ensure a high-quality harvesting process and remain affordable for relatively small farms. The article discusses the efficiency of the machine that was developed and manufactured for spring harvesting of hemp stalks. The parameters of the hemp stalks windrow were considered, taking into account the factors affecting its quality. In addition, there were selected the parameters to asses the quality of the resulting windrow. The research was carried out using probability theory and statistical methods. Through experimental studies, the functionality of the developed and manufactured machine was confirmed. It was established that the machine facilitates the formation of a uniform windrow from hemp stalks, with the skew cutting angle not exceeding 17˚, which allows it to be collected with a baler, minimizing the risk of clogging.

Geopolymers are a modern class of construction materials that show significant potential for sustainable development, especially through the use of industrial wastes such as fly ash. This study investigated the effect of different oil additives on the properties of fly ash-based geopolymers, with particular emphasis on the use of both new and used oils. Test samples were prepared using class F fly ash and a 10-molar solution of sodium hydroxide and an aqueous solution of sodium silicate. Oil additives were added at 5%, 10% and 15% by weight. The physical and mechanical properties of the samples were assessed by measuring density, thermal conductivity, compressive and flexural strength, and by analyzing porosity and microstructure. The results showed that oil additives significantly affected the pore structure and mechanical properties of the geopolymers. Furthermore, the type and condition of the used oil determined the mechanical properties, including compressive and flexural strength. Research indicates the possibility of using oils as additives to geopolymers, which helps improve their physical properties and promotes sustainable development through recycling oil waste.

The paper proves the possibility of providing magnetic properties in the process of saturation of textile fibers with a nanomixture of divalent and trivalent iron oxides. The mechanisms of interaction of nanostructures with natural and synthetic fibers are analyzed. The peculiarities of the introduction of magnetic components into flax, cotton, polyamide, and polyester fibers are determined. The relative number of particles with nanoscale in the total was statistically proved. To evaluate the macro effects of saturation, the relative amount of the accumulated mixture of divalent and trivalent iron oxides was determined, taking into account the previous fiber weight. Two basic constants characterizing the properties of textile fibers to magnetic interaction are proposed. It is proved that flax fibers exhibit the highest magnetic efficiency. The average size of iron oxide nanoparticles is 80–90 nanometers, which is confirmed by studies using electron microscopy. The final magnetization of the obtained textile materials provides an attractive magnetization of 20–30 mPascal. The magnetic field of magnetic textile fibers acts at a height of up to 6–7 mm. The directions of the use of fibers with magnetic properties are shown as a prospect for the development of textile smart products.

The paper considers the practical possibility of self-synchronisation of two biharmonic unbalanced vibration exciters mounted on a solid body with plane oscillations. The problem is solved by the method of direct separation of motions. The equations for slow processes of establishing synchronous modes of rotation of the exciters are obtained; expressions for vibration torque; the vibration coupling coefficient and the condition for the existence of an synphase mode of motion. It is shown that the latter condition is relatively “soft”. An expression for the vibration torque is obtained for the case of “stuck” velocity of a biharmonic exciter in the resonance zone of a vibration machine. Recommendations for selecting the parameters of the vibration drive are given. The analytical conclusions are confirmed by computer modelling.