The ВД-12НФП Eddy-Current Flaw Detector and Methods for Processing a Measured Signal Produced by a Flaw

The field of application, the features of operation, and the main performance characteristics of a -12 eddy-current flaw detector are considered. Methods of digital data processing for improving the recognition of flaw-produced signals against the background noise are presented.     

Measuring Geometric Parameters of Discontinuity Flaws in Ferromagnetic Plates by Minimizing Smoothing Functional. II. Estimates of Discontinuity Flaw Parameters

Estimates of geometric parameters of fabricated flaws in artificial samples are given.     

Generation on 3F4-3H6 transition in Tm3+ ion upon direct excitation of 3F4 state by nuclear pumped gas laser

The possibility of lasing in a YAP:Tm³⁺ crystal with ³F₄ level of the Tm³⁺ ion directly pumped by narrowband radiation of a gas laser operating in the middle IR range has been studied. The efficiency of the pumped energy conversion into spontaneous emission on the ³F₄-³H₆ transition in the Tm³⁺ ion was within 65–75%. The efficiency of generation with respect to the absorbed pumping energy was ～4%.     

The kinetics of copper corrosion in nitric acid

The strategy for the permanent disposal of high-level nuclear waste in Canada involves sealing it in a copper-coated steel container and burying it in a deep geologic repository. During the early emplacement period, the container could be exposed to warm humid air, which could result in the condensation of nitric acid, produced by the radiolysis of the humid air, on the copper surface. Previous studies have suggested that both nitrate and oxygen reduction will drive copper corrosion, with the nitrate reduction kinetics being dependent on the concentration of soluble copper(I) produced by the anodic dissolution of copper in the reaction with oxygen. This study focused on determining the kinetics of nitrate and oxygen reduction and elucidating the synergistic relationship between the two processes. This was investigated using corrosion potential and polarization measurements in conjunction with scanning electron microscopy and X-ray photoelectron spectroscopy. Oxygen reduction was shown to be the dominant cathodic reaction with the oxidation of copper(I) to copper(II) by nitrate, promoting the catalytic cycle involving the reaction of copper(II) with copper to reproduce copper(I).     

Measuring Geometric Parameters of Discontinuity Flaws in Ferromagnetic Plates by Minimizing Smoothing Functional. I. A Study of Parameters of Smoothing Functionals and Classifying Characteristics of Discontinuity Flaws

A smoothing functional designed for derivation of discontinuity flaw parameters from measurements of magnetic field has been optimized, and attributes used in classifying discontinuity flaws have been considered.     

Effect of the number of surface flaws in a group on their magnetic field

The effect of the number of surface flaws in a group on the value of their magnetic field in air above a ferromagnetic article is considered.Translated from Defektoskopiya, Vol. 40, No. 8, 2004, pp. 3–9. Original Russian Text Copyright © 2004 by Zagidulin, Muzhitskii, Bizyulev.     

Estimation of the Residual Magnetic Field Strength Inside a Pipeline after Testing by a Magnetic Flaw Detector

The residual magnetic field strength inside a pipeline after testing by a magnetic flaw detector is calculated. A portable device for demagnetizing local joint-pipe sections in carrying out repair-welding works is proposed.     

Dynamic model of a continuity flaw during normal magnetization of a ferromagnetic article: I. Magnetostatic field of a continuity flaw of a finite size

Analytic equations are obtained for the calculation of the magnetic-field strength and the density of magnetic charges at the faces of a finite-sized continuity flaw that is present in a ferromagnetic half-space during normal magnetization. Dependences of the components of the magnetic-field strength on the flaw’s geometric parameters and the height of the field measurement are given.     

Dynamic model of a continuity flaw during normal magnetization of a ferromagnetic article: II. Magnetostatic field of a continuity flaw during magnetization of the article with a finite-sized magnetizing instrument

A dynamic model of a finite-sized continuity flaw that is present in a ferromagnetic half-space during normal magnetization with a magnetic field produced by a bar magnetizing instrument is obtained. The model takes into account the relative position of the flaw and magnetizing system during the model’s motion along the surface of an article. During normal magnetization of the flaw with the field produced by the finite-sized bar magnet, the longitudinal component of the magnetizing field is shown to exist. The longitudinal component distorts the magnetic-field distribution of the continuity flaw and decreases its detectability.     

The impedance properties of the oxide film on the Ni–Cr–Mo Alloy-22 in neutral concentrated sodium chloride solution

The oxide film properties on Alloy-22 in the applied potential (E) range −600 mV to 600 mV (vs. saturated KCl, Ag/AgCl reference electrode) were characterized by Electrochemical Impedance Spectroscopy (EIS) in near neutral pH, 5 M NaCl solutions, at 30 °C. The impedance properties of the film were compared to the chromium content of the film determined by X-ray photoelectron spectroscopy (XPS). The oxide film properties on Alloy-22 may be divided into three applied potential (E) ranges: −600 mV ≤ E < −300 mV, −300 mV ≤ E ≤ 300 mV, and E > 300 mV. For the range −600 mV ≤ E < −300 mV the film resistance (R_film) increases with potential accompanied by an increase in Cr₂O₃ content; in the range −300 mV ≤ E ≤ 300 mV, R_film values and the Cr₂O₃ content of the oxide film achieve their maximum values; for E > 300 mV, a decrease in both R_film and Cr₂O₃ is observed accompanied by a significant increase in Cr(OH)₃. Comparison of the impedance properties for Alloy-22 to those of Ni–Cr alloys indicate that the barrier layer oxide on Alloy-22 contains a lower number of less mobile defects, most likely Cr interstitials. Destruction of the barrier layer for E > 300 mV leads to the formation of a thicker, less protective bilayer, which is high in Mo content.