http://elar.nung.edu.ua/handle/123456789/2101 The scientific journal Sun, 05 Apr 2026 15:34:25 GMT 2026-04-05T15:34:25Z http://elar.nung.edu.ua:80/retrieve/11378/2015, Vol. 2, № 2.jpg http://elar.nung.edu.ua/handle/123456789/2101 http://elar.nung.edu.ua/handle/123456789/2109 Title: To the issue of melting zone height control in the technology of electron-emitting crucible-less zone melting of silicon Authors: Porev, V. A.; Porev, G. V. Abstract: The new approach to the evaluation of the height of the melting zone during the crucible-less zoned melting process of silicon is substantiated. This new approach takes into account the experimentally established specifics of the brightness field formation Thu, 01 Jan 2015 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/2109 2015-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/2105 Title: Recommendations on determination of interfacial tension at the interface between two fluids by the spinning drop method Authors: Kisil, I. S.; Barna, O. B.; Kuchirka, Yu. M. Abstract: There are studied popular methods of B. Vonnegut, H. Princen, J. Slattery, S. Torza for measuring the interfacial tension at the interface between two immiscible fluids by the spinning drop method. There is provided the method for calculating the geometric parameters of the spinning drop, and its results to the emergence of a spinning drop at the centre of the severely cylindrical area that correspond to the range of the ratio of the cube of the drop`s length to its volume of 24–120, and the range of the ratio of the spinning drop`s length to its diameter 4.00–0.35. Based on the obtained calculation results there is offered the method for determining the interfacial tension by using approximation dependence of the interfacial tension from the given drop volume, its length, difference in fluid densities and the angular velocity of the drop rotation. There are assessed methodological errors of the offered and the known methods for determining interfacial tension according to the rotating drop method. A flow chart and the overall appearance of the device that implements the proposed method for measuring the interfacial tension is presented. Thu, 01 Jan 2015 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/2105 2015-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/2104 Title: Optimization of eguipment availability of a gas-pumping unit Authors: Kopey, B.; Khalimi, D. Abstract: The control of mechanical equipment availability is based on the knowledge of its behaviour and thus optimizes the timing of corrective intervention. The equipment can operate both in good conditions and even in the state of degradation, causing the unscheduled high-cost intervention at any moment. During our study we have optimized turbocharger availability by probabilistic modelling based on the turbocharger`s state parameters that define its degradation. Thu, 01 Jan 2015 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/2104 2015-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/2103 Title: To the issue of strength assessment of the pipeline-composite bandage system Authors: Shlapak, L. S.; Maksymuk, O. V.; Shyrokol, V. V. Abstract: In case of the long-term operation of pipelines under the influence of alternating loads and degradation of service characteristics of material there originate residual stresses and strains that can lead to the loss of its bearing capacity in pipes. One of the ways to increase the structural strength of pipelines is to strengthen the pipe by banding, which results in the need to develop methods for calculating the structural parameters of the pipeline – bandage system. This paper presents a mathematical model to estimate the strength of the pipeline-composite bandage system, based on the improved theory of thin shells with regard to shear and compression pliability of material. The solution allows us to simulate the stress state of a finite-length pipeline based on the given original characteristics of the pipes` material, composite, operational loads and effects. Thu, 01 Jan 2015 00:00:00 GMT http://elar.nung.edu.ua/handle/123456789/2103 2015-01-01T00:00:00Z