Using mosaic crystals for the generation of intense X-ray beams

The parametric X-ray (PXR) yield due to 500-MeV electrons in a 2-mm-thick diamond crystal with a mosaicity angle of ～0.2 mrad has been studied. It is shown that the mosaic crystal structure leads to a significant (about fourfold) increase in the PXR yield doe to the contribution of diffracted bremsstrahlung radiation. Advantages of using mosaic crystals for the generation of intense X-ray beams are discussed.     

Influence of temperature on the failure of brittle materials in concentrated loading

Conclusions In the area of low temperatures (Tc) the crack resistance and failure stress of high strength brittle materials decrease linearly with temperature, which is caused by the purely brittle character of the failure processes.Maximums are observed on the temperature relationships of radial and surface crack lengths. The formation of maximums may be explained by the increase with temperature of the power of the fields of residual stresses caused by the zones of plastic deformation with a simultaneous drop in crack resistance and failure stress. At increased temperatures with an increase in plasticity and relaxation capacity of the material there is a reduction in the level of residual stresses with a corresponding decrease in crack length until disappearance of them.The position of the maximums in crack length and the temperature of their disappearance depends upon the crack resistance and flow stress (hardness) and for materials with G_1C 2 _y0 the temperature of disappearance of radial cracks is close to the ductile-plastic transition temperature.Translated from Poroshkovaya Metallurgiya, No. 12(252), pp. 75–82, December, 1983.     

Adjustable synchronous electric drives of shaft fans with vector-based control oriented in the field

A special algorithm is developed that provides satisfactory control for mass high-power electric drives. Results of an experimental study and tests of drives are presented that are performed when they are being put into use.     

Properties of high-dispersion powders of tungsten carbide produced by high-temperature electrochemical synthesis

Translated from Poroshkovaya Metallurgiya, No. 8(344), pp. 1–4, August, 1991.     

Dynamometric uses of adaptive aerostatic bearings

Translated from Izmeritel'naya Tekhnika, No. 3, pp. 18–20, March, 1990.     

Interphase reaction in materials of the systems Ti-Cr and Ti(C,N)-Cr

Translated from Poroshkovaya Metallurgiya, No. 4(340), pp. 69–74, April, 1991.     

Self-propagating high-temperature synthesis of ferrovanadium nitride for use in smelting high-strength low-alloy steels

A new alloying material for smelting high-strength low-alloy steel is considered: FERVANIT fused ferrovanadium nitride. Self-propagating high-temperature synthesis in the ferrovanadium-nitrogen system permits the development of a new industrial production technology for alloys based on vanadium nitride. Self-propagating high-temperature synthesis requires no electrical energy, is environmentally benign, and results in a product with good operational properties.