Scab formation in hot rolling is investigated. A prototype apparatus for scab removal by metal brushes is developed; the corresponding operating conditions are determined. A system is manufactured ...for the removal of small scabs from rolled strip in a continuous etching line. Conditions are selected for brushing the strip after etching. The optimal strip velocity and speed of brush rotation are determined.
—The results of an experiment on the face milling of a VT6 titanium alloy and an ultrafine-grained (UFG) VT6 titanium alloy fabricated by equal-channel angular pressing are analyzed. The technology ...of producing an UFG alloy and its physicomechanical properties are considered. The results of experiments on determining the dependence of the cutting force on the cutting conditions for face milling on a universal FHV-50PD (PROMA) milling machine are presented. During a three-factor experiment, the cutting conditions were varied: cutting depth (
t
= 0.4, 0.6, 0.8 mm), feed (
s
= 65, 100, 185 mm/min), and milling cutter rotation speed (
n
= 580, 720, 875 rpm). No coolant is used during processing. The cutting force was determined indirectly by measuring the displacement of the milling cutter mandrel using a vibration sensor. The vibrations of the tool subsystem are recorded at a sampling frequency of up to 5 kHz using a noncontact vibration sensor. Regression dependences of the cutting force on the milling conditions are determined for both alloys with confirmation of their statistical significance. Based on the data obtained on cutting forces and an analysis of chip formation features (burr parameters and the type of chips formed), a comparative analysis of the data is carried out and conclusions are drawn about the features of cutting a new alloy. The problems of practical application of the experimental results are considered.
—The problems of ensuring the uniformity of axial deformation distribution during the tension of cylindrical workpieces using a new technique for estimating deformation localization are considered. ...This estimation is necessary on designing and carrying out thermal-force treatment at the preparation stage of the technological process of manufacturing low-rigid long blanks. It consists in simultaneous heating and deformation, which ensures the formation of linear workpieces with leveling and reducing the level of residual technological stresses. For long workpieces, the strain distribution in the axial direction along individual regions along the shaft length is characterized by instability, which is associated with the initial heterogeneity of the material properties and nonuniform heating. A method for estimating deformation localization, which provides a comprehensive estimation of the uniformity of tension along the length, is considered. The influence of the autowave character of plastic flow on deformation localization during high-temperature tension of 12Kh18N10T alloy workpieces is proved.
Dysprosium hafnate is proposed as a promising absorbing material for control rods of thermal nuclear reactors. The properties of dysprosium hafnate pellets with different Dy and Hf contents are ...presented in this article. The fluorite phase is characterized by the density range 6.8–7.8g/cm3 and; the thermal diffusivity achieves 0.58–0.83mm2/s at 20°C, thermal conductivity of 1.5–2.0W/(Km) and TLEC of (8.4–8.6)×10−6K−1 at 20°C. The temperature dependence of the thermophysical properties of dysprosium hafnate are presented. The neutron absorption efficiency of dysprosium hafnate was estimated in comparison with boron carbide. The radiation resistance of pellets after irradiation in the BOR-60 reactor is presented as well.
The defect of “local thickness variation” during rolling on wide-strip hot rolling mills was investigated. A mathematical algorithm and a program “polinom” have been developed. The program “polinom” ...allows a qualitative assessment of the current deviation of the rolling strip from the specified quality parameters. An accompanying document has been developed showing the presence of deviations and its numerical characteristic, and the binding of the deviation to the current coordinate along the strip length.
The article dwells on the results of the search for the archeological site – Ashlama-Saray – the country palace of the Crimean Khans. The palace was built in the second half of the 17th century. At ...the end of the 18th century, the main buildings of the palace were reconstructed. Currently, the ruins of the palace are not identified on the surface. The location of this monument was determined by a general plan of Bakhchisaray city. During the series of archaeological and natural-scientific works carried out in 2015–2016, this palace was precisely localized in the valley of Ashlama-Dere.
El artículo se centra en los resultados de la búsqueda del sitio arqueológico - Ashlama-Saray - palacio de los Khans de Crimea. El palacio fue construido en la segunda mitad del siglo XVII. A finales del siglo XVIII, los principales edificios del palacio fueron reconstruidos. Actualmente, las ruinas del palacio no están identificadas en la superficie. La ubicación de este monumento fue determinada por el plan general de la ciudad de Bakhchisaray. Durante la serie de trabajos arqueológicos y científicos naturales llevados a cabo en 2015-2016, este palacio fue localizado precisamente en el valle de Ashlama-Dere.
16α,17- and 15α,16-Epoxy derivatives of diterpenoid steviol having ent-kaurane structure were found for the first time to undergo Wagner-Meerwein rearrangement in alkaline medium or by the action of ...boron trifluoride-diethyl ether complex to give products with ent-beyerane structure. The geometric parameters of steviol 16α,17- and 15α,16-epoxides were determined by X-ray analysis.
In this paper we experimentally demonstrated a broadband scheme of the multiresonator quantum memory-interface. The microwave photonic scheme consists of the system of mini-resonators strongly ...interacting with a common broadband resonator coupled with the external waveguide. We have implemented the impedance matched quantum storage in this scheme via controllable tuning of the mini-resonator frequencies and coupling of the common resonator with the external waveguide. Proof-of-principal experiment has been demonstrated for broadband microwave pulses when the quantum efficiency of 16.3% was achieved at room temperature. By using the obtained experimental spectroscopic data, the dynamics of the signal retrieval has been simulated and promising results were found for high-Q mini-resonators in microwave and optical frequency ranges. The results pave the way for the experimental implementation of broadband quantum memory-interface with quite high efficiency η > 0.99 on the basis of modern technologies, including optical quantum memory at room temperature.
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