On the possibility of measuring the anapole moment of potassium atom

We suggest measuring the nuclear-spin-dependent P-odd amplitude in the transitions between hyperfine structure sublevels in the ground state of potassium isotopes. Since the main contribution to this amplitude is due to the anapole moment of the nucleus, such measurements of the P-odd spin-dependent effects may provide new information about weak interactions. It is established that the measurement of such effects with a statistical error within 1% can be performed for approximately 1 h.     

The efficacy of electrotherapy with pulsed currents of different frequencies in combined forms of cerebrovascular and vertebrogenic pathology

Sinusoidal modulated currents, fluctuorisation and interference therapy were compared for efficacy when applied according to segment-oriented technique to cervical and thoracic spine. A total of 150 patients with combined cerebrospinal and vertebrogenic lesions were treated in sanatorium on the Black sea shore (Yalta). These techniques demonstrated both similarity and difference in their effects. Mechanisms of action of the above variants of medium-frequency electrotherapy are considered.     

Stabilization of Gold Nanospheres and Nanorods in Diblock Copolymers of Styrene and Vinylpyridine

Composites based on microphase-separated diblock copolymers of styrene with vinylpyridine and gold nanoparticles, in which the block copolymers play simultaneously both the role of a stabilizer preventing the aggregation of nanoparticles and a matrix providing their selective arrangement within domains of the predefined type, are obtained for the first time. The suggested approach implies no use of additional stabilizers and is efficient for both initially organic dispersed small (~5 nm) spheres and hydrasols of larger (9 × 30 nm) rodlike nanoparticles. Nanospheres are introduced into the composites via replacement of a labile stabilizer used in synthesis with the diblock copolymer, while nanorods synthesized in aqueous media by the two-stage method are incorporated via phase transfer mediated by the diblock copolymer. Films capable of microphase separation leading to the formation of vinylpyridine cylindrical domains with a diameter of tens nanometers are spin-coated from the obtained composites. The content of nanoparticles in the composites is up to 5 wt %; they are dispersed and arranged predominantly within vinylpyridine domains, with nanospheres being localized near domain boundaries, while nanorods being mainly oriented perpendicularly to the axis of cylinders.     

Influence of plastic predeformation on the fatigue strength of compressor blades with defects

We study the influence of plastic predeformation by bending to create deep residual compressive stresses on the fatigue strength of 13Kh11N2V2MF steel specimens and compressor blades with cut and stamped V-shaped and semicircular defects, and also the use of design-based redistribution of the stresses in the blade (offsetting toward the edges) for the retardation of cracks in the stress concentrators. It is found that plastic predeformation increases the fatigue strength by about 20%, while offsetting with the creation of a compressive mean stress _m = –300 MPa in the defect region increases the fatigue strength by 2–2.5 times. We examine schemes for calculating the fatigue strength with account for the residual and mean stresses, and also examine the defect creation technique. Recommendations are made for increasing the strength of compressor blades with defects.Translated from Problemy Prochnosti, No. 10, pp. 76–88, October, 1994.     

Silicon carbide transport during carbothermic reduction of SiO<Subscript>2</Subscript>: Thermodynamic evaluation and experimental study

Mass-transfer processes during the high-temperature carbothermic reduction of silicon dioxide have been studied using thermodynamic modeling. The chemical vapor transport of silicon carbide has been investigated using SiO₂ + xSiC mixtures—major reaction products in the SiO₂-C system—as examples. Thermodynamic modeling results indicate that the vapor transport of silicon carbide is possible at temperatures from 1300 to 1500°C, and that the major gaseous species involved are Si and CO. Vapor transport processes have been studied experimentally. It is shown that the thermal reaction between carbon monoxide and silicon leads not only to direct conversion of silicon particles to silicon carbide but also to the growth of silicon oxycarbide fibers. The synthesized material has been characterized by x-ray diffraction and high-resolution optical microscopy.