Rolling element bearings are critical components in many industrial applications, and their failure can lead to significant downtime and maintenance costs. Therefore, predicting the remaining useful life of bearings is essential for effective maintenance scheduling and avoiding unplanned downtime. In this study, vibration fluctuation analysis and failure modes investigation were employed to determine the failure threshold of rolling element bearings. Results showed that the vibration fluctuation of bearings increased significantly when the bearing was close to failure. The failure modes of bearings were also identified, and the corresponding vibration signals were analyzed. Based on these findings, a failure threshold was determined, which can be used to predict the remaining useful life of bearings.

Natural science education in primary general school is built on the basis of the principles of humanism, individualization, systematic and consistent, integrity, variability, information support of the pedagogical process. The main source of formation of the content of natural science education is directly natural science and the current level of its development.

This article reveals the main didactic provisions on continuity, the connection of natural science education with biology, physics, geography, astronomy, ecology, on the formation of individual research skills in younger students during the study of the integrative course "Natural Sciences".

Carbon fiber reinforced composites have become increasingly popular due to their high strength-to-weight ratio and durability. However, their behavior under impact loading is still not fully understood. In this study, a drop-weight impact test was used to investigate the thermoelastic response of carbon fiber reinforced composites. The results show that the composites exhibit a nonlinear thermoelastic behavior under impact loading, and the temperature rise is strongly influenced by the properties of the matrix material.

Spoiled fruits can harbor a variety of fungal species, causing significant economic losses and posing potential health risks to consumers. This study aimed to isolate and characterize fungal species from spoilt fruits collected from Utako Market in Abuja, Nigeria. A total of 100 spoilt fruit samples were collected and subjected to fungal isolation using standard microbiological techniques. Fungal colonies were identified based on their morphological characteristics and further confirmed using molecular techniques such as DNA sequencing. The identified fungal species were then characterized for their growth patterns, spore morphology, and enzymatic activities. The results revealed a diverse range of fungal species associated with spoilt fruits, including Aspergillus, Penicillium, Fusarium, Rhizopus, and Alternaria. Some of the isolated fungi exhibited the ability to produce mycotoxins, indicating a potential health risk. This study provides valuable insights into the fungal diversity present in spoilt fruits at Utako Market, highlighting the need for proper handling, storage, and quality control measures to minimize fungal contamination and ensure food safety.

Grouting cement is a type of Portland cement designed to insulate pipes of oil and gas wells and protect them from groundwater pressure, shifts of ground layers, and the negative effects of aggressive media. When solidified, the cement mortar forms a monolithic jacket, impermeable to liquids and gases. The material adheres firmly to the metal pipe and to the walls of the trunk drilled in the rock. The use of grouting cement creates conditions for safe operation of wells and prolongs their working period. In traditional construction, this type of Portland cement is not used. The exception is the foundation of drilling piles in difficult geological conditions. That's whay, the article presents the investigation of grouting cement with the basis of substandard raw materials.

Teaching independent work is one of the aspects of the scientific organization of labor, both students and teachers. Independent work should be carried out by students as a cognitive activity, become a means of educating such personal qualities as independence, activity, and form a creative attitude to perceived information. The search for new means and methods of teaching leads to the fact that in the first place in the learning process the tasks are put forward not so much as the maximum assimilation of scientific information, but rather the formation of the skills to think creatively and independently acquire new knowledge.

In the article, the authors provide an analysis of various approaches to the classification of types and forms of independent work of students, suggesting the correspondence of the type of independent work to the levels of assimilation.

Silica aerogels have potential applications in various fields such as catalysis, insulation, and drug delivery. In this study, we report a facile method for the preparation of transparent and biocompatible silica aerogels using choline dihydrogen phosphate ionic liquid as the solvent and catalyst. The aerogels were prepared via sol-gel reaction of tetraethyl orthosilicate in the ionic liquid followed by supercritical drying. The resulting aerogels showed excellent transparency, high porosity, and low density. The biocompatibility of the aerogels was evaluated using in vitro cytotoxicity tests, and the results showed no significant cytotoxic effects. The prepared aerogels are expected to have potential applications in biomedicine and other fields where transparent and biocompatible materials are required.

This paper discusses a method to reduce the self-discharge process of acid car batteries. The dependence of the self-discharge of storage batteries on the ambient temperature has been studied. At the same time, it was found that an increase in the storage temperature of storage batteries from + 15°C to + 45°C accelerates the self-discharge process up to 62% within 12 months. Replacing the alloy composition of the electrode, taking into account the electronegativity of the components, reduces the self-discharge process to 2% monthly. Batteries with electrodes, where antimony is replaced by calcium in the alloy, the self-discharge process is relatively low and the consumption of the working fluid is also relatively low. These parameters allow them to be manufactured as maintenance-free power sources.

This article provides information on a study on the identification of risks in analytical testing laboratories. The process of “acceptance of applications for testing, examination of samples and formalization of test results” in the quality analytical laboratory of the research object was obtained.