Hydrogen diffusion in titanium and zirconium alloys

Conclusions The values of the hydrogen diffusion coefficients in titanium and zirconium alloys at temperatures near room temperature obtained by the method of sectioning and spectral analysis are in good agreement with the corresponding coefficients obtained earlier by other methods.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 75–77, April, 1978.     

On subchannel inversion for improvement of power efficiency in OFDM-based systems

The problem of power loading in orthogonal frequency division multiplexing (OFDM)-based systems that provides minimization of the bit-error rate (BER) performance under a fixed transmit power (or equivalently minimisation of the transmit power under a fixed value of the BER) is addressed in this work. A lemma about inversion of subchannel power gains is proved and examples that exhibit its utility are presented. As a result, a non-iterative adaptive power allocation technique is derived. The algorithm combines the recently proposed ordered subcarrier selection method with 'subchannel inversion'. Compared with the original technique, such a combination provides a power gain that depends on the channel statistics.