http://repository.enu.kz/handle/enu/1408 Sat, 04 Apr 2026 09:09:53 GMT 2026-04-04T09:09:53Z http://repository.enu.kz/handle/enu/1422 Research of heating the lining of high-temperature units in order to increase their residual resource Nikiforov, A.S.; Karmanov, A.E.; Prikhod’ko, E.V.; Kinzhibekova, A.K.; Zhumagulov, M.G. The article contains an analysis of the initial stage of the heating process of hightemperature units. The heating modes used at the enterprises lead to various difficulties: a delay in the heating process or heating at a high speed at which mechanical stresses arise and exceed the permissible values. The proposed graphical dependencies for heating allow us to heat up at the highest possible speeds, taking into account the time spent on drying. In this case, the ultimate strength of refractory materials is not exceeded, which leads to a significant reduction in the time for the heating process. Fri, 01 Jan 2021 00:00:00 GMT http://repository.enu.kz/handle/enu/1422 2021-01-01T00:00:00Z http://repository.enu.kz/handle/enu/1421 Numerical analysis of pile foundations in seasonally freezing soil ground Tleulenova, G.; Zhussupbekov, A.; Shakhmov, Zh.; Omarov, A. The article presents the results of numerical analysis for pile foundation in seasonally freezing soil ground. This project uses the static tests of soil by piles at the construction site of Cargo off-loading facilities (Prorva, Atyrau region, Kazakhstan). The project area is located along the east coast of the Caspian Sea, both onshore and offshore, near the Prorva oilfield, Kazakhstan. At present, the North Caspian Sea has a limited water depth (max 8 m). According to the test results have been made design changes in the pile foundation. Static tests (SCLT) were carried out on the piles with 16m in length and precast concrete joint pile foundations with a total length of 22m to 27m. This research is important for an understanding of the interaction mechanism of precast composite joint piles with seasonally freezing soil ground of the Caspian Sea coastal area of the site. Fri, 01 Jan 2021 00:00:00 GMT http://repository.enu.kz/handle/enu/1421 2021-01-01T00:00:00Z http://repository.enu.kz/handle/enu/1420 Evaluation of frost heave in clay soils Sarsembayeva, А.; Zhusshupbekov, A.; Collins, Ph.E.F. Frost heaving in clayey soils with a low coefficient of permeability raises a lot of questions regarding the cryosuction, surface tension forces, and accompanying phase transfer of water. The freeze-thaw laboratory test results were considered in this work in terms of temperature and volumetric parameters change, dry density, and water mass transfer. The article presents a model for calculating the mass transfer of water (vapour) in the gas state under the influence of cryogenic forces. Findings include the improved understanding of the heat and mass transfer phenomenon during the unidirectional freezing of soils in an open system. Most of the tests for engineering properties registered a slight reduction in relation to strength, cohesion, and angle of internal friction. However, there was a significant increase in the coefficient of permeability after the freeze-thaw cycles with initially dense compacted soil samples, which was due to loosening and moistening of the soil samples during the heave at sub-zero temperatures. The conceptual model for frost heave in soils was developed based on the vapour mass transfer. There was presented algorithm of vapour flow calculation in unsaturated soils using fundamental thermodynamic equations. Fri, 01 Jan 2021 00:00:00 GMT http://repository.enu.kz/handle/enu/1420 2021-01-01T00:00:00Z http://repository.enu.kz/handle/enu/1419 Comparison of the results of pH measurements in a buffer solution Baikhozhayeva, B.U.; Zhumagali, A.K.; Moldakhmetova, A.E. As a result of the increasing need to study the choice of the assigned value during the inter-laboratory comparisons is becoming more and more relevant. Since the assigned value is a reference point when comparing the results of the participants of the qualification test. Frequently, qualification verification providers face a number of problems when choosing the assigned value. An incomplete analysis of the results of interlaboratory comparisons will lead to an inaccurate assessment of the competence of the laboratory, which contributes to the revocation of the certification of the accreditation of the laboratory participant. This article attempts to provide a complete statistical analysis of the results of interlaboratory comparisons from the beginning to the end of the tour with the content of all statistical analyses recommended in GOST ISO/IEC 17043-2013. The results of interlaboratory comparisons conducted in testing laboratories of Kazakhstan aimed at ensuring metrological traceability of pH measurements in a buffer solution are presented. The reference values of the buffer solution are determined in the state scientific metrological center. Fri, 01 Jan 2021 00:00:00 GMT http://repository.enu.kz/handle/enu/1419 2021-01-01T00:00:00Z