Spin-wave excitations in amorphous ferromagnets

Mössbauer measurements have been performed on a number of metallic glasses. The temperature dependence of average hyperfine or internal magnetic fieldH _eff(T) arises from long wavelength spin wave excitations in these glasses. Values ofB _3/2 andC _5/2 are in general much higher than those observed for crystalline ferromagnets indicating higher density of states for spin waves in amorphous ferromagnets.     

Fracture characteristics of a burst tested maraging steel rocket motor case

A 0.3 m diameter, 2 m long and 0.0015 m thick, 18 nickel 1800 MNm^–2 grade maraging steel motor case was designed, fabricated and burst tested to gain experience for using the steel as booster case material in satellite launch vehicles. The bursting occurred at 15.2 MPa for which the effective hoop stress worked out to be 1754 MNm^–2 almost equal to the ultimate tensile strength (1764 MNm^–2) of the material in the solution treated and aged condition. The failure analysis revealed that the material failed due to normal tensile overload fracture. The burst test data was used to arrive at fracture mechanics parameters like crack size, gross section area stress and the stress for leak before bursting.     

Neue Steuerprinzipien für das Reibschweißen

New adjustments for friction welding of different solids The article describes the laws of most favourable selection system by friction welding of different materials. The aim is the welding, with a minimum of energy, time and other burden world's around, when the retail trade is slightly for important and different materials in the industries productions. However, the terms Friction Moment and Temperature are significant for Action one the surfaces of the partners. The article shows the development of Friction Moment in the time and gives points for the estimation optimal parameters for friction welding. Most importent variables are the differential coefficient the Friction Moment, the Temperature, the waste and the efficiency. The last term is the area between funktion M and time axis. The author shows that the term $ \frac{{{\rm dM}}}{{{\rm dt}}}\,{\rm R}\,{\rm or}\,\frac{{{\rm dT}}}{{{\rm dt}}}\,{\rm R} $ are going through a maximum and then in a low material. The friction welding is perfect by optimal conditions.     

Simulation and analysis of pollen coronas

By numerical simulation of light scattering by birch and pine pollen grains, we create color plates of coronas with vertical elliptical shapes and strong brightenings, respectively. The shape of the pollen is modeled by the union of n ellipsoids. The Fraunhofer integral is solved by the use of the fast Hartley transform. The sensitivity of the patterns to pollen orientation, Sun elevation, and pollen shape and size is discussed. Good agreement is obtained with amazing photographs made by a Finnish network of amateur astonomers, in the case of strong vertical orientation of the pollen axis.     

Mirror system for collecting Thomson-scattered light in a tangential direction

We describe an optical system for collecting Thomson-scattering light in the tangential direction of a tokamak. The key part of the optics is a set of mirrors arranged as a Venetian blind. This system makes it possible to look around the corner of the tokamak vessel. Design considerations and test performance are presented.