Carrying capacity of thick-walled glass-reinforced plastic rings operating under pressure

Experimental data are presented on the carrying capacity and deformability of thick-walled rings made of unidirectional and two-way glass-reinforced plastic subjected to external and internal pressure. A limitation on the carrying capacity of the rings with increase in relative thickness is noted; an explanation of this effect is offered.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 6, pp. 1130–1132, November–December, 1971.     

Structure of the R1 and R2 Bands of Isotopes of Cr3+ Ion in a Single Crystal of Ruby at Room Temperature

Optics and Spectroscopy - Room-temperature absorption and luminescence spectra of the R1 and R2 bands in a single crystal of Ruby Al2O3:Cr3+ (0.05%) are analyzed. The luminescence in these bands...     

Photoluminescence of erbium in polycrystalline ceramics and in crystalline film of erbium oxide

Structural, optical, and electric properties of Er₂O₃ films obtained from Er₂O₃ ceramic target by the method of vacuum electron-beam deposition on sapphire substrates have been investigated. Optical characteristics of the films are studied in the range from UV up to IR using techniques of absorption, reflection, and emission spectroscopy; specific resistance of the obtained films was also measured. After excitation with the radiation of semiconductor diode laser at 980 nm, IR glow has been obtained at room temperature at the wavelength of approximately 1550 nm from Er³⁺ ions in polycrystalline ceramic target and in crystalline films. In addition, fluorescence was observed, in the visible range of spectrum, from ceramic target; this fluorescence corresponds to two-step mechanism of excitation with frequency up-conversion.     

Stresses in an anisotropic ring with moduli of elasticity varying along the radius subjected to internal and external pressure

The effect of nonuniformity of the elastic properties on the state of stress of an orthotropic ring subjected to pressure has been theoretically investigated. The results of the numerical calculations show that the effect of the variability of the circumferential modulus is more important.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 6, pp. 1128–1130, November–December, 1971.