The temperature and pressure in the plasma parallel plate accelerator

This paper presents the results of plasma temperature and pressure calculations in the parallel plate accelerator during the accelerating process. The plasma pressure is calculated by means in Dalton's law.     

On the solutions of a functional equation of dhombres

Continuous solutions of the functional equation ?(x?(x)) = (?(x))² for x ∈ [0,∞) have been characterized by Dhombres. They form a simple, two-parametric family and the result can be easily extended to solutions on the whole real line. However, the class of all solutions is much larger. We show that there is a solution ? whose graph has, among others, the full outer two-dimensional Lebesgue measure. It turns out that partial restrictions, like boundedness, monotonicity and/or continuity on a subinterval do not imply the continuity of solutions. In particular, the class of monotonic solutions has interesting properties. We provide some techniques of constructing such solutions and show that, among others, there is a strictly increasing solution ? whose points of discontinuity form a dense set in R.     

Wind tunnel simulation of air pollution dispersion in a street canyon

Physical simulation was used to study pollution dispersion in a street canyon. The street canyon model was designed to study the effect of measuring flow and concentration fields. A method of C02-laser photoacoustic spectrometry was applied for detection of trace concentration of gas pollution. The advantage of this method is its high sensitivity and broad dynamic range, permitting monitoring of concentrations from trace to saturation values. Application of this method enabled us to propose a simple model based on line permeation pollutant source, developed on the principle of concentration standards, to ensure high precision and homogeneity of the concentration flow. Spatial measurement of the concentration distribution inside the street canyon was performed on the model with reference velocity of 1.5 m/s.     

Cylindricity of tangent bundles of strongly parabolic metrics and strongly parabolic surfaces

It is proved that if the intrinsic zero-index of the Sasaki metric of a tangent bundleTM ⁿ isk, thenk is even andM ⁿ is the metric product of a Riemannian manifoldM ^n–k/2 by a Euclidean spaceE ^k/2, whileTM ⁿ is the metric product ofTM ^n–k/2 byE ^k . An expression is obtained for the second fundamental forms of the imbeddingTF ^l TM ⁿ in terms of the second fundamental forms of the imbeddingF ^l M ⁿ and the curvature tensor ofM ⁿ . It is proved thatTF ^l is totally geodesic inTM ⁿ if and only ifF ^l is totally geodesic inM ⁿ .Translated from Ukrainskií Geometricheskií Sbornik, Issue 28, 1985, pp. 12–32.     

Yttrium aluminate crystals for slabs

The methods of growing YAG:Nd crystals with a flat interface and YAP:Nd crystals with a sharp conical interface are described. The form of the interface was controlled by the He and H₂O content in the reducing atmosphere composed mainly of Ar and H₂ as well as by axial temperature gradient above the melt level. The crystals of 120–180 mm in length were machined to the high-quality slabs.     

Non-steady state homogeneous nucleation in glass-forming systems: Dimensionless kinetic equation

The kinetic equation of the classical homogeneous nucleation theory is rewritten in dimensionless form and it is shown that the numerical computation of the dimensionless kinetic equation is approximately 20 times faster in comparison with the original kinetic equation. The results are compared with known analytical results and with previous numerical results in the case of the constant and variable temperature for the model Li₂O.2 SiO₂ melt. It is shown, e.g., that under non-isothermal conditions the nucleation rate is greater than the quasistationary nucleation rate and the cluster distribution function is greater than the corresponding quasiequilibrium cluster distribution function.     

Rigidity of codimension two indefinite spheres

We describe all isometric immersions f:S _n ^s S _s ⁿ +2/S _s ⁿ n–s4, whenever the set of totally geodesic points does not disconnect S _s ⁿ , where S _n ^s denotes the complete n-dimensional indefinite Riemannian space form of constant positive curvature 1 and signature s.     

Sensitivity of hydrodynamic system of the Obukhov type

The paper deals with the regime of advanced Bénard instabilities (described usually by the Lorenz system) in a more general system formulated firstly by Obukhov. It has been shown that triplet co-operation leads to characteristic courses where some new regularities occur.