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Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective is to establish how the layers drying regime and the composition of refractory slurry when using coarse dusting quartz sand as the cushioning layer influence the strength of not pre-calcinate and calcinate liquid glass ceramic shell mold. The original methodology, standard and generally accepted research methods including a methodology to determine the relative viscosity of suspension, mass, time, temperature, relative humidity and air velocity were used in the work. The results of studies of the effect on the strength of liquid glass ceramic shell mold of various conditions of its production are shown. The greatest strength of the liquid glass ceramic shell mold acquires when duration of drying of the 2nd ... 4th layer in an air stream with a temperature of 33 ... 34 °C, speed 2.2 ... 2.5 m/s for not less than 3 hours using water glass with a specific gravity of 1.28 ... 1.29g/cm³ and a specific viscosity of liquid glass slurry of 31 ... 32 s. The data obtained allow us promptly decide on the necessary adjustment of the composition of the refractory slurry under conditions of a cast shop (Fig. 4., Table 6). [ABSTRACT FROM AUTHOR]

Objective is to determine the influence of the content of copper slag in liquid-glass slurry, temperature and specific gravity of the liquid-glass applied on the value of its relative viscosity. The relative viscosity of the refractory slurry was determined by a standard technique in the viscometer VZ-4. The results of investigation of influence of cooper slag serving as filler on the relative viscosity of glass-liquid slurry depending on its temperature, fullness and density of the of sodium liquid-glass are presented. It is found that with increasing copper slag content in refractory slurry (from 0.1 to 0.4 kg per 1dm3 of liquid-glass), the specific density of the liquid-glass applied (from 1150 to 1300 kg/m3) and temperature decrease (from 50 to 20 °C), its relative viscosity increases according to a power law. As a result of the mathematical processing of the experimental data, the empirical relationship has been obtained, the value of the relative error is less than 2.6%. The data obtained allow us to take decision rapidly on the necessary adjustment of the refractory slurry composition in the foundry shop conditions. [ABSTRACT FROM AUTHOR]

A method for the diagnosis of labyrinthine hydrops is proposed that takes advantage of specific physiological features of internal ear functioning. Namely, the basal membrane of the inner ear exposed to a low-frequency tone undergoes synchronous sinusoidal oscillations along its entire length; simultaneously, sensitivity of the organ of Corti changes periodically. Under normal conditions, perception of 1,000 Hz tonal signals at the background of a low-frequency masker varied substantially depending on the phase during which the signal came. In the maximum discharging phase that corresponded to a 270 degree deviation of the basal membrane from its initial position, it was maximally displaced towards the vestibule staircase, and perception of the test tone was most affected. Patients with hydrops of the internal ear exhibited phase-independent constant perception of high-frequency tonal signals against the background test tone. It is concluded that the method of phase audiometry can be used in large research centres for the comprehensive evaluation of cochlear-vestibular function during hydrops formation.