Noncontact excitation of sound in metals by a video pulse of electric field

An acoustic signal that is excited without acoustic contact by an excitation electrode in a metal sample has been studied. A constant electric voltage close to the breakdown value was applied between the electrode and the sample. A video pulse of electric field with a duration of 0.4 μs was used to excite sound in the sample. The ratio k of signals that were registered with noncontact and contact excitation proved surprisingly large (k = 0.14) when compared to the value expected from the literature data. A strong dependence of the noncontact acoustic signal on the filling frequency f of the excitation pulse has been observed. For f > 10 MHZ, the signal dropped to the level of noises. An explanation for this frequency dependence is proposed. It is based on the assumption of quasi-atomic thickness of the charged metal layer that is created by the electric field.     

Physics of magnetic materials: A scientific school of E. A. Turov

This article is dedicated to Evgenii Akimovich Turov, a well-known scientist in the field of physics of magnetic phenomena and Corresponding Member of the Russian Academy of Sciences. The article includes an analysis of the key problems of the physics of magnetism in the early 21st century, as well as E.A. Turov’s and his school’s contributions to the science of magnetism. In 2014, we commemorate the 90th anniversary of the birthday of Evgenii Akimovich, and this article is timed to this memorable date. The article also contains a list of the basic works of the scientist.     

Electron Paramagnetic Resonance of Tb3+ Ions in YBa2Cu3O6

The first observation of electron paramagnetic resonance (EPR) of Tb³⁺ doped into YBa₂Cu₃O₆ is reported. EPR is used to determine the local symmetry of the rare-earth ion and to study the effect of suppression of high-T _c superconductivity by doping. The distance between the lowest singlets of Tb³⁺ ion 7.1 GHz 0.24 cm^–1 and g-factor g 17.9 have been estimated from measurements. Both these parameters are in a good agreement with the corresponding calculated values. No evidence of Tb⁴⁺ ions was found.     

Guaranteed Estimation Algorithms for Prediction and Interpolation of Random Processes

Prediction and interpolation of a process is investigated for known covariance functions of measurement error and perturbations belonging to a set of nonnegative-definite functions. Guaranteed estimation is studied, assuming that the guaranteed estimate is the best estimate of the parameters of the useful signal in the sense of the minimum of the mean-square error under the worst behavior of measurement errors and perturbations with covariance functions belonging to the set . Depending on the type of constraints, i.e., characteristics of the set , different approaches and methods are applied to guaranteed estimation. Papers concerned with this topic are reviewed. Prediction and interpolation are analytically investigated for the case in which covariance functions are bounded by the constraints imposed on their variance matrices. For the continuous case, the weight function and its equations are derived. Prediction and interpolation accuracies are evaluated and compared with the least-squares filters.     

Introduction of biochemical wastewater purification at OOO Mechel-Koks (stage I)

Systems for mechanical and biological wastewater purification have been introduced at OOOMechel-Koks. This represents the first stage of a two-stage project to introduce biochemical purification. Results obtained in the adjustment and debugging of the systems are presented.     

Algorithm for adaptive control of bag filters

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 7, p. 25, July, 1989.