Magnetic and acoustic characteristics of steel 30CrMnSiA after rolling and pressing

A group of magnetic and acoustic parameters of the cold-deformed 30CrMnSiA steel is determined. It has been revealed that the coercive force of this steel starts to decrease steadily at degrees of plastic deformation higher than 6%. A hypothesis is put forward on the relaxation of stresses of the first kind as a result of flat pressing after rolling of steel plates. To test the possibility of determining the degree of deformation of the 30CrMnSiA steel by ultrasound measurements, the propagation velocities of longitudinal, transverse, and Rayleigh waves are determined. The change in the velocity of longitudinal ultrasonic waves is 0.8% at deformation degrees ranging from 10 to 20%. The velocity of transverse and Rayleigh ultrasonic waves increases monotonically over the entire range of deformations, with a change in their velocity of 2.5% and 2.2% respectively. Thus, the most suitable parameter for determining the degree of deformation is the propagation velocity of transversal ultrasonic waves. © 2018 Author(s)

Dynamic distortion at the exit of a subsonic diffuser of a mixed compression inlet

Measuring distortion characteristics at engine face station of axisymmetric inle

Cole-Hopf Like Transformation for Schr\"odinger Equations Containing Complex Nonlinearities

We consider systems, which conserve the particle number and are described by Schr\"odinger equations containing complex nonlinearities. In the case of canonical systems, we study their main symmetries and conservation laws. We introduce a Cole-Hopf like transformation both for canonical and noncanonical systems, which changes the evolution equation into another one containing purely real nonlinearities, and reduces the continuity equation to the standard form of the linear theory. This approach allows us to treat, in a unifying scheme, a wide variety of canonical and noncanonical nonlinear systems, some of them already known in the literature. pacs{PACS number(s): 02.30.Jr, 03.50.-z, 03.65.-w, 05.45.-a, 11.30.Na, 11.40.DwComment: 26 pages, no figures, to be appear in J. Phys. A: Math. Gen. (2002

The NuMI Neutrino Beam and Potential for an Off-Axis Experiment

The Neutrinos at the Main Injector (NuMI) facility at Fermilab is under construction and due to begin operations in late 2004. NuMI will deliver an intense $\nu_{\mu}$ beam of variable energy 2-20 GeV directed into the Earth at 58 mrad. Several aspects of the design are reviewed, and potential limitations to the ultimate neutrino flux are described. In addition, potential measurements of neutrino mixing properties are described.Comment: talk given at NuFact '02, Imperial College London, proceedings to appear in J. Phys. G, revised to add a referenc

Comment on ``the Klein-Gordon Oscillator''

The different ways of description of the $S=0$ particle with oscillator-like interaction are considered. The results are in conformity with the previous paper of S. Bruce and P. Minning.Comment: LaTeX file, 5p

Direct and inverse source problems for degenerate parabolic equations

Degenerate parabolic partial differential equations (PDEs) with vanishing or unbounded leading coefficient make the PDE non-uniformly parabolic, and new theories need to be developed in the context of practical applications of such rather unstudied mathematical models arising in porous media, population dynamics, financial mathematics, etc. With this new challenge in mind, this paper considers investigating newly formulated direct and inverse problems associated with non-uniform parabolic PDEs where the leading space- and time-dependent coefficient is allowed to vanish on a non-empty, but zero measure, kernel set. In the context of inverse analysis, we consider the linear but ill-posed identification of a space-dependent source from a time-integral observation of the weighted main dependent variable. For both, this inverse source problem as well as its corresponding direct formulation, we rigorously investigate the question of well-posedness. We also give examples of inverse problems for which sufficient conditions guaranteeing the unique solvability are fulfilled, and present the results of numerical simulations. It is hoped that the analysis initiated in this study will open up new avenues for research in the field of direct and inverse problems for degenerate parabolic equations with applications