Deformation of rock in the explosion of a cylindrical charge in a coaxial cavity filled with liquid

A study is made of the effect of a water sheath around a cylindrical explosive charge on the parameters of shock waves in rocks. A coupled problem for the detonation-product-water-rock system is examined within the framework of continuum mechanics. A binomial isentropic equation is used for the detonation products, water is modeled by a Tate-type equation, and the rock is modeled by an elastoplastic medium which undergoes dilatation. A numerical solution is obtained by a finite-difference scheme. The dependence of the wave processes in the rock and the dimensions of the crushing zone on the radius of the water sheath is studied with the use of sandstone and siltstone as examples. Institute of Hydromechanics, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Prikladnaya Mekhanika, Vol. 35, No. 3, pp. 83–88, March, 1999.     

Estimating speech spectra for copy synthesis by linear prediction and by hand

Linear prediction is a widely available technique for analyzing acoustic properties of speech, although this method is known to be error-prone. New tests assessed the adequacy of linear prediction estimates by using this method to derive synthesis parameters and testing the intelligibility of the synthetic speech that results. Matched sets of sine-wave sentences were created, one set using uncorrected linear prediction estimates of natural sentences, the other using estimates made by hand. Phoneme restrictions imposed on linguistic properties allowed comparisons between continuous and intermittent voicing, oral or nasal and fricative manner, and unrestricted phonemic variation. Intelligibility tests revealed uniformly good performance with sentences created by hand-estimation and a minimal decrease in intelligibility with estimation by linear prediction due to manner variation with continuous voicing. Poorer performance was observed when linear prediction estimates were used to produce synthetic versions of phonemically unrestricted sentences, but no similar decline was observed with synthetic sentences produced by hand estimation. The results show a substantial intelligibility cost of reliance on uncorrected linear prediction estimates when phonemic variation approaches natural incidence.     

Viscoelastoplastic Deformation of Reinforced Shells of Revolution Under Nonstationary Loading

The elastoviscoplastic behavior of a discretely reinforced shell under axisymmetric nonstationary loading is considered within the framework of the geometrically and physically nonlinear Timoshenko-type theory of shells. The stress–strain state of the structure is studied in terms of the incremental plasticity with kinematic hardening and dynamic yielding condition, which allows for the dynamic viscosity of the structure. The nonstationary behavior of a rigidly fastened reinforced shell under axisymmetric pulse loading normal to the shell surface is considered as an example. The deflection–time and deflection–space relationships are found     

The Sorben-Tec system for rapid dosimetric evaluation of <Superscript>137</Superscript>Cs in drinking water

The Sorben-Tec system was developed for rapid evaluation of ¹³⁷Cs in drinking water using a domestic personal dosimeter or beta-radiometer. Linear calibration curves were obtained for dosimetric and beta-radiometric measurement of caesium. In case of 20 L drinking water sample, detection limits of ¹³⁷Cs were found to be 12.3 and 2.0 Bq L^?1 for dosimetric and beta-radiometric measurement respectively. This system is recommended for using by non-professionals who are living at radioactively contaminated areas or near nuclear power plants.     

A study of YBa2(Cu1?xMex)3O6 + δ (Me = Al, Co, Fe) electrophysical and electrochemical properties

The structure, thermal expansion coefficient, and electroconductivity of YBa₂(Cu_1−x Al _x )₃O_6+δ (x = 0.0–0.9) were studied at 20 to 900°C in air. The most conducting compositions of YBa₂(Cu_1−x Me _x )₃O_6+δ (Me = Al, Co, Fe) were determined. The electrochemical activity of electrodes with the most conducting compositions of YBa₂(Cu_1−x Me _x )₃O_6+δ (Me = Al, Co, Fe) was studied in a wide polarization range in the contact with 0.9ZrO₂ + 0.1Y₂O₃ solid electrolyte in air at the temperatures of 700 to 900°C. Original Russian Text ? V.K. Gil’derman, I.D. Remez, 2009, published in Elektrokhimiya, 2009, Vol. 45, No. 5, pp. 612–615. Published by report at IX Conference “Fundamental Problems of Solid State Ionics”, Chernogolovka, 2008.     

Potentials of Silver and Gold Electrodes of ZrO2-Based Cells in N2+ O2+ CO2+ CO Gas Mixtures

Steady-state electrode potentials in cells with a ZrO₂+ 10 mol % Y₂O₃electrolyte are measured at 400 to 500°C in nonequilibrium N₂+ O₂+ CO₂+ CO gas mixtures containing 0–3 and 0–10 vol % of CO and O₂, respectively. In CO-free mixtures, the potentials obey the Nernst equation. The CO-caused deviation of the potential from its equilibrium value depends on the O₂content and temperature and is due mainly to the CO adsorption at electrodes.     

Propagation of cylindrical blast waves in a multicomponent,viscoplastic medium having variable viscosity

Institute of Fluid Mechanics, Academy of Sciences of the Ukraine, Kiev. Translated from Prikladnaya Mekhanika, Vol. 28, No. 10, pp. 29–35, October, 1992.