Drilling operations require an in-depth understanding of rock destruction mechanics to improve efficiency, reduce operational costs, and extend equipment lifespan. The fragmentation of rock is governed by interactions between the drilling bit, rock properties, and external forces such as weight on bit (WOB), rotational speed, and fluid pressure. Conventional methods for predicting rock fragmentation rely on empirical relationships, but these approaches often fail to adapt to real-time changes in drilling conditions.

Rock fragmentation during drilling operations is a complex process influenced by various parameters, including rock properties, drill bit geometry, and operational conditions. Understanding the dynamics of rock destruction is critical for optimizing drilling efficiency and minimizing energy consumption. This study investigates the influence of rock destruction parameters on process dynamics using high-speed imaging and develops a mathematical model to describe the fragmentation process. The model integrates key variables such as rock strength, impact energy, and fracture propagation velocity. High-speed imaging is used to validate the model, providing insights into the real-time behavior of rock fragmentation. The results demonstrate the potential for improving drilling performance through optimized parameter selection.

Drilling mud, also known as drilling fluid, is a crucial component in oil and gas drilling operations. It serves multiple essential functions, including lubricating the drill bit, carrying rock cuttings to the surface, controlling pressure in the wellbore, and preventing formation damage. The composition of drilling mud varies but typically includes water or oil-based fluids, additives, and solids like clay or barite.

Blockchain technology has been proposed as a tool for modernizing elections, but before its adoption, significant security and privacy risks must be addressed. While blockchain offers decentralization and cryptographic protections, deeper analysis reveals vulnerabilities that could undermine election integrity.

The image of public servants plays a key role in ensuring public trust in public administration. In times of war, this aspect is especially important, as the effectiveness of the government largely depends on the perception of its representatives by citizens and the international community.

The ongoing conflict on Ukrainian territory has presented numerous challenges to society, with particular emphasis on the most vulnerable demographic - children. Thousands of families have been forced to flee their homes, leaving many children without proper care. Under these circumstances, the number of children in need of assistance has sharply increased. Consequently, foster care has emerged as one of the primary mechanisms for safeguarding the rights and welfare of children impacted by the war. This study aims to examine the organization of foster care in Ukraine under martial law, the challenges confronting the system, and potential strategies to ensure a safe and dignified life for children during this crisis. In accordance with Article 252 of the Family Code of Ukraine, foster care is defined as a form of temporary guardianship over children, designed to create a secure environment conducive to their development and upbringing. In Ukraine, foster parents assume responsibility for children who, for various reasons, cannot remain with their biological families. These reasons may include violence, poverty, or threats to the child's life and health. Numerous institutions that traditionally cared for children have either been damaged by the conflict or evacuated. Under these exceptional circumstances, foster care has become a critical tool for assisting children who have been deprived of parental care.

Aluminum is one of the most widespread elements in the Earth’s crust, being a component of over two hundred minerals; however, only a few of them have industrial significance. The main sources of aluminum raw materials are bauxites, nepheline ores, kaolins, and alunite rocks. Ukraine possesses significant reserves of these resources, which makes the study of their geological structure, distribution, and occurrence conditions an important aspect. The largest aluminum reserves are found in residual and re-deposited weathering crusts of acidic, alkaline, and basic rocks. In Ukraine, the main forms in which aluminum occurs are bauxites, nephelines, alunites, and kaolinites. Bauxites are represented by relatively small explored reserves, concentrated in the Smila, Vysokopillia, and Nikopol deposits, located within the weathering crusts of Precambrian formations. Bauxites are also found in the Pryazovia region and the Carpathians.

Coal is recognized as a valuable source for the recovery of Rare Earth Elements and Yttrium (REY) – a group comprising the 15 lanthanides (La–Lu) as well as scandium (Sc) and yttrium (Y), which share similar chemical properties. These metals are in high demand across various industrial sectors, including the production of batteries, lightweight alloys, magnets, medical equipment, and electronics. Of particular interest are the so-called critical REY (Nd, Eu, Tb, Dy, Y, Er), which relative abundance may vary depending on the origin and characteristics of a given coal. Traditionally, REY are produced via mining of primary deposits (e.g., monazite, xenotime, bastnaesite). However, such methods often carry high costs and significant environmental risks, leading to increased interest in alternative (secondary) sources, among which coal ash has emerged as particularly important.

The necessity to provide stability of slopes, structures, and bearing capacity of rock masses disturbed by blast loading depends upon the temporal and spatial changes in soil parameters. Hence, we have analyzed the regularities characterizing a range of changes in loess soil resulting from dynamic (namely, blasting) loads taking into consideration their technogenesis under various conditions. The research territory is within the terraced right-bank share of Dnipro city in its southern part. The territory is represented by a sedimentation mass of the Anthropogene and Upper Pliocene deposits occurring on crystalline rocks and their weathering crust (i.e. kaolin and granitic subsoil). They contain Poltava series sand; mottled and red-brown clay; and loess-soil series. In this place, loess clay loam was sampled after blast loading on the formation happened.

The effectiveness of extraction operations and the comprehensive quantitative and qualitative recovery of ore reserves are critical issues in the development of high-grade iron ore through sublevel caving systems in Kryvbas mines. A primary technological process in this system is ore release through horizontal bottom drifts of the receiving levels. Ore transportation is a crucial component of the extraction process, determining the efficiency of ore release and overall mining productivity. The selection of transportation equipment significantly impacts the organization of work and the productivity of the entire block. In modern underground ore deposit extraction systems, ore release and transportation are among the most labor-intensive and inefficient processes. The release of fragmented ore from the extraction area is typically carried out from under caved surrounding rock or through a network of specialized drifts uniformly distributed beneath the extraction face. The ore moves through the extraction area and release drifts under the influence of gravity.