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Abstract: The products of the combustion synthesis in titanium, silicon, and aluminum powder mixtures under a wave combustion mode are studied using X-ray diffraction analysis and optical metallography. The synthesis products contain titanium silicide Ti5Si3and titanium aluminide TiAl3, the ratio of which depends on the content of aluminum powder in the reaction mixtures. The combustion temperature of the mixtures decreases with an increase in the aluminum content owing to the substitution of titanium aluminide in the synthesis products for titanium silicide, which has a multiply less negative enthalpy of formation compared to that of the silicide. The effect of the combustion temperature on the dispersity of the structure of the synthesis products is considered using the concepts of the features of the growth of silicide and aluminide nuclei in a liquid metal solution.

Abstract: Sintering conditions for the fabrication of high strength, porous, permeable, titanium—porous titanium composites were determined. The structure and strength properties of porous permeable titanium after inward growth of bone tissue for periods of 1, 3, and 6 months were investigated. The minimum time necessary for the growth of bone tissue into an implant was determined.

We present an improved method for the precise reconstruction of cosmic-ray air showers above 1017 eV with sparse radio arrays. The method is based on the comparison of measured pulses to predictions for radio pulse shapes by CoREAS simulations. We applied our method to the data of Tunka-Rex, a 1 km² radio array in Siberia operating in the frequency band of 30-80 MHz. Tunka-Rex is triggered by the air-Cherenkov detector Tunka-133 and by scintillators (Tunka-Grande). The instrument collects air-shower data since 2012. The present paper describes an updated data analysis of Tunka-Rex and details of the new method applied. After quality cuts, when Tunka-Rex reaches its full efficiency, the energy resolution of about 10% given by the new method has reached the limit of systematic uncertainties due to the calibration uncertainty and shower-to-shower fluctuations. At the same time the shower maximum reconstruction has improved compared to the previous method based on the slope of the lateral distribution and reaches a precision of better than 35 g/cm². We also define conditions of the measurements at which the shower maximum resolution of Tunka-Rex reaches a value of 25 g/cm² and becomes competitive to optical detectors. To check and validate our reconstruction and efficiency cuts we compare individual events to the reconstruction of Tunka-133. Furthermore, we compare the mean of the shower maximum as a function of primary energy to the measurements of other experiments. [ABSTRACT FROM AUTHOR]