Force action of a shock wave on a solid body

Approximate engineering methods for determining the forces acting on solid bodies upon interaction with shock waves are proposed. These methods are verified experimentally with the use of a shock tube. The forces acting on bodies are measured by fast–response acceleration transducers. Good correspondence between measurement data and calculation results obtained by exact and approximate methods is observed.     

Flow structure in a flat vortex chamber

We investigate a flow in a flat vortex chamber in which the distance between the end walls is smaller than the radius of the chamber. The study was mainly performed by optical methods: a Töpler device was employed, with the Foucault knife replaced by a diaphragm. It is shown that the flow in the chamber has a complicated spatial structure. In addition to the basic helical flow, an intense “transverse” rotation of the type of Taylor-Görtler vortices occurs. In contrast to previously studied flows, where these vortices were observed near a concave surface, in the motion considered transverse vortices occur in the entire working volume of the chamber. In this case, four parallel vortex filaments are formed. The high intensity of the vortices has allowed one to visualize them by the Töpler method and by “tinting” the flow by highly disperse particles. Quantitative dependences of the dimensions of the vortex cells on the flow regime, i.e., on the pressure of gas deceleration, were obtained.     

An asymptotic method for studying nonequilibrium systems

The following is a well-known problem of statistical physics: can a dynamic system of oscillators with nonlinear coupling be described approximately by statistical laws? This problem was studied for the first time by Fermi, Ulam, and Pasta [1] for the following system of equations describing coupled oscillators:

$$\begin{gathered} x^{..} _i = x_{i + 1} - 2x_i + x_{i - 1} + \alpha [(x_{i + 1} - x_i )^2 ] - (x_i ..x_{i - 1} )^2 ], \hfill \\ (i = 1,...,N;\alpha< 1).(0.1) \hfill \\ \end{gathered} $$     

Glycosylation of the methyl ester of carbobenzoxy-L-serine and of n-nonyl alcohol

Conclusions The methyl ester of O-[2-acetamido-3,4,6-tri-O-acetyl-2-deoxy--D-glucopyranosyl]-N-carbobenzoxy-L-serine and n-nonyl 2-acetamido-4-O- (2-acetamido-2-deoxy--D-glucopyranosyl)-2-deoxy-jS-D-glucopyranoside have been synthesized by the oxazoline method.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, p. 2622, November, 1969.