Metal rupture under the effect of concentrated heat fluxes

The temperature distribution during metal heating by a concentrated surface heat source is found numerically. The shapes of the melted puddles are analyzed, and dependences are constructed connecting the quantitative characteristic of metal rupture to the heat source parameters.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 22, No. 1, pp. 142–146, January, 1972.     

Heat exchange in the heat-supply zone of two-phase thermosiphons for small degrees of filling

The intensify of the heat exchange in evaporation and boiling in the heat-transmitting element is investigated as a function of the geometrical, physical, and operating parameters.Fiftieth Year of the Great October Socialist Revolution Kiev Polytechnic Institute.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 35, No. 4, pp. 690–605, October, 1978.     

Corrosion of Heating Surfaces of Power Station Boiler Equipment Made of Steel 12X18H10T

The long-term operation of thermal power equipment made of 12X18H10T steel at a temperature of 550°C and higher changes its performance due to the changed composition of inside surfaces and bodies of tubes. To avoid deterioration of service characteristics during the operation, the thermal equipment is recommended to make of low-carbon chrome-nickel stainless steels or niobium-stabilized steels. Preservation of the equipment by octadecylamine should be carried out only at a working temperature below its thermodestruction temperature.     

Investigations of Ultrasound Propagation in Porous Impurity-Helium Solids

The velocity and attenuation of ultrasound passing through porous impurity-helium solids immersed in liquid ⁴He have been measured in the temperature range 1.1–2.3 K. These solids were formed by injecting a mixture of impurity (e.g. D₂, Ne, N₂ or Kr) and helium gases into superfluid ⁴He. The sound signal seemed to propagate mainly in the helium contained in the pores, rather than through the solid sample itself. We found that the speed of sound at low temperatures is close to and decreases more rapidly with temperature than first sound in bulk helium, similar to behavior observed in aerogel. The attenuation of sound in helium in the compressed impurity-helium solids is bigger than in bulk helium and increases rapidly with temperature up to 1.65 K, after which a crossover to a much weaker temperature dependence was observed.     

Correction of ozone influence on TOA radiance

An accurate atmospheric correction (AC) of Earth remote-sensing data in the spectral region 450–800 nm has to account for the ozone gas absorption influence. Usual operational AC codes employ a fixed ozone concentration corresponding to a climatologic average for a certain region and season, e.g. the mid-latitude summer atmosphere of the Moderate Resolution Atmospheric Transmission (MODTRAN) code. The reasons for a fixed ozone column are that ozone does not vary rapidly on a spatial and temporal scale, and additionally, the look-up table (LUT) size for AC is already big. This means that another degree of freedom for the ozone parameter would dramatically increase the size of the LUT database and the time required for LUT interpolation. In order to account for this effect, we use already existing LUTs that were calculated for a certain ozone reference level, e.g. an ozone column of g = 330 Dobson Units (DU) for MODTRAN’s mid-latitude summer atmosphere. Then the deviation of the top-of-atmosphere (TOA) radiance ΔL(g) from the reference level L(g = 330) is calculated as a function of solar and view geometries. The calculation is performed for a set of 36 wavelengths in the ozone-sensitive spectrum (450–800 nm) and five ozone columns. The last step computes the linear regression coefficients for each wavelength and geometry. The results are stored in a small table (11 kB). It is shown that the ozone influence is accurately accounted for by multiplying the modelled radiance L(g = 330) with a factor depending on g and wavelength yielding TOA radiance relative errors smaller than 0.5% for a wide range of ozone concentrations between 180 and 500 DU. Selected examples of a sensitivity study of the ozone effect on the retrieval of water constituents demonstrate the need to account for ozone in the AC step.     

Coal mixtures for coke production: Patent errors revisited

A recent patent regarding the preparation and composition of coal batch is analyzed.     

Programmed input of energy into the discharge chamber of a light-gas electric-discharge accelerator of bodies

The effect is investigated of the duration of electrical energy input into working gas and of discharge power profile on the launching velocity and efficiency of acceleration of bodies using a light-gas electric-discharge accelerator with a caliber of 30 mm. It is found that, for the same energy input to the arc or for the same pulsed pressure of working gas in the discharge chamber of the accelerator, the projectile velocity in the mode being programmed is 7–10% higher, and the efficiency of conversion of internal energy of working gas to kinetic energy of projectile is 2 or 3% higher, than those in the synchronous mode.