Resolving the controversies about the 'nearly cubic' and other phases of Sr(1-x)Ca(x)TiO(3) (0≤x≤1): I. Room temperature structures.

Results of a powder x-ray diffraction study are presented to show that the so-called 'nearly cubic' phase region of Sr(1-x)Ca(x)TiO(3), in fact, corresponds to two different types of crystal structures. The 'nearly cubic' phase occurring in the composition range 0.35

New mechanism for the alpha to omega martensitic transformation in pure titanium.

We propose a new direct mechanism for the pressure driven alpha-->omega martensitic transformation in pure titanium. A systematic algorithm enumerates all possible pathways whose energy barriers are evaluated. A new, homogeneous pathway emerges with a barrier at least 4 times lower than other pathways. The pathway is shown to be favorable in any nucleation model.

Tuned limiter for receiver amplifier in a fast-recovery pulsed NMR spectrometer.

A simple tuned limiter is described which limits the rf voltage amplitude at the input of the receiver amplifier of a pulsed NMR spectrometer. This device prevents overload of the receiver amplifier during the high-power rf pulse and thereby allows fast recovery of the spectrometer following the pulse. When used with Avantek unit amplifiers at 24 MHz, a recovery time of 2.5 mus is achieved.