New equipment for enhancement of oil recovery and cementing of wells

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 7, pp. 9–10, July, 1992.     

Detection of and allowance for loss of petroleum products due to leaks and evaporation in tanks

Algorithms are proposed for detection of and allowance for loss of petroleum products, making it possible to make a substantiated decision about the state of a tank under the conditions of actual use.Translated from Izmeritel'naya Tekhnika, No. 2, pp. 27–28, February, 1994.     

Recurrence of peptic ulcer

In the paper, the causes, clinic and treatment in 15 patients with recurrent peptic ulcer after repeated operative procedures for duodenal ulcer are described. The main causes of the recurrence were as follows: the remaining of the mucous membrane of the antral gastric portion in Finsterer gastric resection for ulcer exclusion (5) and Zollinger-Ellison syndrome (10). The surgical therapy consisted in resection of the antral portion and repeated gastric resection (the first group) or in subtotal gastrectomy associated with trunk vagotomy (the second group).     

Implicit Lagrangian-Eulerian Tvd Method For Solving Two-Dimensional Hydrodynamic Equations On Unstructured Meshes

An ALE method for solving hydrodynamic equations on unstructured meshes is presented. It is based on an implicit finite-volume scheme derived in Godunov’s approach. The basic quantities (the density, temperature, and velocity) are defined at cell centers. For relations between pressure and velocities at the centers and their analogs at the nodes, we use the relations proposed by P.H. Maire et al. A piecewise-linear TVD reconstruction of the pressure and velocity in the cell is used to achieve the second-order approximation of smooth solutions, preserving their monotonicity. Mesh rezonings are implemented during the calculation. To recalculate the values, the old mesh is covered onto the new one so that a bounded piecewise-linear representation is used for the values in the cells of the old mesh, while the interface in the mixed cells is reconstructed by the VOF method. The mass, momentum, and total energy are conserved under the recalculation.     

Phase transformations and properties of Ag1 ? yNbO3 ? y/2 (0 ≤ y ≤ 0.20) ceramics

We have studied the phase transformations, microstructure, and dielectric, piezoelectric, and thermophysical properties of Ag_{1 − y} NbO_{3 − y/2} (0 ≤ y ≤ 0.20) ceramics. Within its homogeneity range (y ≤ 0.10), silver niobate undergoes a complex sequence of phase transformations, accompanied by anomalies in its physical properties. The observed dispersion effects are interpreted in terms of electrical conductivity above the Curie temperature and in terms of the motion of domain walls and interfaces below the Curie temperature.     

Phosphorescence Kinetics of Singlet Oxygen in HeLa Cells Suspension

Technical Physics Letters - The kinetics of singlet oxygen phosphorescence in HeLa cells suspended in phosphate buffered saline (PBS) being generated under photosensitized excitation with...     

An Apparatus for Measuring the High-Temperature Thermal Conductivity of Semiconductors and Their Melts

An installation for investigating the thermal conductivity of semiconductors and their melts over a wide temperature range (300–1100 K) is described. In contrast to the devices used earlier for this purpose, the thermal conductivity was measured in a hermetically sealed autoclave filled after evacuation with spectroscopically pure argon to prevent the oxidation, evaporation, and decomposition of the substance under study. The error of thermal-conductivity measurements did not exceed 8% at 1000 K.     

Checking multivariate model fit from the generalized Wishart-statistic variance

A confidence range has been constructed for the generalized variance of the Wishart statistic and used in an algorithm for checking model fit for multivariate dynamic systems.Translated from Izmeritel'naya Tekhnika, No. 12, pp. 9–11, December, 1993.     

Digitizing floating marine platform coordinate measurements for a knowna priori probability of occurrence in a permissible drilling region

An algorithm is described for digitizing the coordinate measurements on floating marine platforms subject to a known a prioriprobability of the platform being in a permissible drilling region, which enables one to determine the digitization interval from the rate of displacement and the statistical characteristics of the measured coordinates.Translated from Izmeritel'naya Tekhnika, No. 7, pp. 14–16, July, 1994.     

Harmonic mode-locking in quantum dot lasers with tunnel-coupled waveguides

Passive mode-locking has been studied in the lasers with tunnel-coupled waveguides with the active region based on InAs/InGaAs quantum dots emitting in the range of 1.3–1.31 μm. Specific optical mode formation in this composite waveguide reduces the output beam divergence and raises the temperature stability of the lasing wavelength. The reduced optical confinement factor facilitates obtaining passive modelocking regimes. High response rate of the saturable absorber associated with the carrier escape time shorter than 20 ps allows generating a third harmonic with the frequency as high as 46.1 GHz.