Realization of the strength of Armos fibres with different acidity in epoxy plastics

The acidity of Armos fibres significantly affects the strength of the fibre in a microplastic as a function of the moisture content of the starting fibre. There is an optimum moisture content at which maximum realization of the fibre strength in the microplastic is attained for each fibre pH. The highest strength of the adhesive bond of Armos fibre is attained for acid fibres, and the best realization of the strength in ringshaped samples of an organoplastic is obtained for neutral fibres.All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi. Translated from Khimicheskie Volokna, No. 1, pp. 53–54, January–February, 1996.     

The calibration of gradient heat flux sensors

Test benches for calibrating heat flux sensors at temperatures of 500–1000 K are described, and the results of such calibrations are presented.     

Numerical analysis of the influence of the physical viscosity on the vortex heat transfer in laminar and turbulent flows around a heated plate with a shallow spherical hole

The influence of the Reynolds number on the patterns of separation laminar and turbulent flows around a plane plate with a shallow hole as well as on the thermal-hydraulic characteristics of this plate was analyzed on the basis of the solution of the differential mass- and energy-conservation equations, the Navier–Stokes equations, and the Reynolds equations closed with the use of the shear-stress transfer model by the factorized finite-volume method.     

Towards understanding anelasticity of the β1′ martensitic phase of Cu–Al–Ni

The present work continues the series of experimental investigations undertaken in order to elucidate the mechanisms controlling elastic and anelastic properties of the β₁′ martensitic phase of Cu-based shape memory alloys. The paper reports an attempt to distinguish between ‘dislocation’ and ‘interface’ mechanisms of the internal friction in the β₁′ martensitic phase of Cu–Al–Ni single crystals. Two types of experiments have been performed. First, the ultrasonic strain amplitude-independent and amplitude-dependent internal friction (ADIF) of a monovariant specimen for temperatures 90–300 K is carefully re-examined. Second, in situ measurements of the ADIF and of the influence of ultrasonic oscillations on the plastic deformation (acoustoplastic effect) were carried out during quasistatic deformation of a quenched polyvariant specimen. Experimental results support a dislocation rather than an interface mechanism of anelasticity, at least at ultrasonic frequencies and moderate strain amplitudes.     

Detection of shock-wave-induced internal stresses in Cu-Al-Ni shape memory alloy by means of acoustic technique

1. The present results indicate that the stress-induced β₁→γ₁′ martensitic transformation occurs for an impact duration of 2 × 10⁻⁶ s. This time interval appears to be sufficient also for the subsequent deformation of the γ₁′ martensitic phase to occur.2. A structure memory effect has been found: Cu-Al-Ni austenitic crystals, shock-loaded at room temperature to induce γ₁′–martensite, recall during subsequent temperature-induced martensitic transformation the martensitic variant structure (elastic properties) formed under the shock loading.3. Elastic properties of quenched β₁′ and γ₁′ crystals of the Cu-Al-Ni system are extremely sensitive to the shock-wave loading. Mechanisms of these effects, as well as of the structure memory effect, include the generation of internal stresses due to the high elastic anisotropy of the martensitic phases. These internal stresses either change the distribution of martensitic variants or govern the formation of the martensitic variant structure during the temperature-induced martensitic transformation. The generation of high internal stresses by impact loading of the β₁′ martensitic phase is also detected by several anelastic phenomena.4. In contrast to elastic and anelastic properties, transformation temperatures are insensitive to the impact loading, pointing to the difference of structural elements responsible for the anelastic effects and for the interval and hysteresis of the thermoelastic martensitic transformation.     

Effect of production factors on the properties of porous filtering tubes formed from titanium powders

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 6, pp. 45–46, June, 1989.     

Effective thermal diffusivity of a vibrationally fluidized bed

Studies have been made on the effective thermal diffusivity in an extended vibrationally fluidized bed with or without a set of vertical tubes.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 58, No. 4, pp. 610–618, April 1990.     

Behavior of Cs, Np(V), Pu(IV), and U(VI) in pore water of bentonite

Sorption of Cs, Pu(IV), Np(V), and U(VI) with bentonite from solutions was studied. Physicochemical species of radionuclides in the liquid phase were determined, the sorption mechanisms were established, and the influence of bentonite colloids on the behavior of radionuclides was studied. It was shown that Cs is sorbed by the ion-exchange mechanism, whereas the sorption of actinides at pH > 5 is governed by the reaction with surface hydroxy groups of betonite, and at pH < 5 the competing processes are ion exchange and complex formation. Reduction of Np(V) and U(VI) to Np(IV) and U(IV) in the solution with Fe(II) compounds present in the system was proved by the extraction method. Various methods of separating the solid phase were used in studying the dependence of the distribution coefficients of Np and Pu on the ratio of pore water and bentonite; it was shown that Np and Pu are sorbed on bentonite colloids.