GH4169 nickel-based superalloy exhibits excellent mechanical properties and has aroused wide interests in applications of aerospace engine components and transmission systems. Currently, Conventional grinding (CG)of GH4169 generates excessive heat, resulting in high grinding temperatures that can easily cause grinding burns. Ultrasonic vibration assisted grinding (UVAG)an advanced hybrid processing technology, enhances heat dissipation through the periodic variation in abrasive grain motion. It is considered an ideal method for reducing grinding temperature. However, the complex and intermittent contact between the UVAG workpiece and abrasive grains presents an essential challenge for accurate theoretical temperature prediction. To address this issue, the grinding temperature prediction model for UVAG was developed according to the Welch-Type (WT) heat source. On this basis, we performed grinding experiments for comparing temperature prediction accuracy of WT heat source with that of the conventional rectangular heat source model. According to our findings, WT heat source exhibits the maximum prediction error of 23.2
This article is devoted to the impact of the urbanized area of Naryn city on the water quality of the Naryn River. The studied river, which is 807 km long, serves as the main tributary of the Syr-Darya River and responds a key water artery of Central Asia. To assess the influence of anthropogenic activities, data on the chemical composition of surface water were collected from three monitoring stations over a five-year period (2019–2023). The results reveal significant variations in the concentration of cations, anions and heavy metals along the river’s course throw the city. The cation concentration indicates the predominant role of calcium ions (Ca2+), which is primarily due to their influx into aquatic systems as a result of the weathering of calcium-bearing rocks. Elevated concentrations of Ca2+ and Mg2+ observed at the second and third monitoring stations may indicate a potential influence of urban runoff and domestic wastewater on water quality. These finding highlight the need for improved wastewater management and сcontinuous water quality monitoring to preserve this critical freshwater resource. Furthermore, the study emphasizes the importance of implementing environmental protection measures to mitigate pollution risks and ensure sustainable water use in the region.
The study examines the relationship between the digital media environment, sociopolitical contexts, and information resilience in Muslim communities. The study is a systematic literature review and theoretical synthesis using comparative-historical, discursive, and systems approaches. The findings show that digitalization has transformed online space into a key sphere for religious practice and religious socialization, contributing to the emergence of “digital Islam.” Among young people, religious socialization and the choice of preachers increasingly occur online within “information cocoons.” In Central Asia, the influence of the internet and social networks has nearly equaled television: 56% of the population receive news from television and 50% from social networks, mainly via smartphones. Television remains dominant among people aged 55+, while younger audiences rely primarily on online sources. Young people, elderly people, and linguistic minorities are especially vulnerable to disinformation and manipulation and often become targets of Islamophobic and radical narratives. In Tatarstan, Islam is understood mainly as heritage or ethnic Islam, associated with Tatar identity and cultural heritage rather than strict ritual observance. States and organizations combine control measures with media-literacy programs, although excessive securitization can push users into closed online spaces and increase radicalization risks. The study concludes that digital technologies do not generate radicalism but accelerate its spread and transform its forms within the intersection of religion and security policy.
Amid increasing climate instability and growing concerns over food security, the development of hydraulic infrastructure (HI) has become a key factor for the sustainable functioning of agriculture in the Talas region. This article presents a comprehensive analysis of the role of the existing irrigation system—including canals, pumping stations, and reservoirs—in ensuring water supply for more than 70
Thermal calculations of heat exchangers designed to ensure comfortable indoor conditions must account for both convective and radiative components of the total heat flux. This approach enables the rational selection of geometric parameters of apparatuses to maximize the total heat output. Accurate calculation of the radiative heat flux emitted by a heat exchanger requires knowledge of the directional emissivity of the material coating its convective surfaces. Unfortunately, the scientific literature contains no works devoted to either experimental or theoretical determination of the directional emissivity of paint coatings applied to convective surfaces of heat exchanger apparatuses. Since the shape, size, and spacing of the fins on the heat exchange surface of the apparatus, in combination with its directional emissivity, can affect the magnitude of the radiant convective heat flux emanating from it, it is important to know, at what parameters of the heat exchange surface the heat flux reaches an extreme value; what proportion each heat transfer component contributes to this flux. Thus, research devoted to the development of an experimental setup and a method to determine the directional emissivity of paint coatings is relevant both from the perspective of acquiring new knowledge and from the standpoint of improving the calculation method, the implementation of which leads to the development of heat exchange equipment with high energy efficiency. The study of the directional emissivity of paint coating has been carried out experimentally on a specially designed experimental setup. An experimental setup has been developed, along with a method to evaluate the magnitude of directional emissivity of paint coatings used on convective surfaces of heat exchanger apparatuses. Experimental results of directional emissivity of paint coatings show that the influence of coating color on directional emissivity is negligible. Specifically, paint coatings of different colors but identical chemical composition exhibit closely similar directional emissivity values.
