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In many areas of science and technology, the measurement of impulse trains is an important sampling scheme. For example, wireless data transmission has grown enormously due to the recent developments in ultra wide band technology, where the information is represented as impulse trains. In this letter, we present a new approach for sampling of the impulse train using parallel exponential filters (EFs), whose outputs are measured simultaneously. We show that with 2 parallel EFs, it is possible to reconstruct impulses with different amplitudes and appearance times within one sampling period. The reconstruction algorithm is manageable on microprocessor and VLSI circuits. Several applications of the parallel EF network are outlined.

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The zinc content of cancellous bone from the iliac crest was determined by the X-ray fluorescence technique in an autopsy series of 28 women and 66 men. The bone-zinc content was statistically related to age, but there was a large variation. It reached a maximum value in the fifth decade and thereafter decreased with age in both sexes. Men with a chronic disease had a lower zinc content than those who had died suddenly. There was a significant correlation between the zinc content and the bone strength in women (p less than 0.01) and in men (p less than 0.05). Zinc is thought to play a part in osteoporosis.

A prototype of the electrical impedance spectroscopy (EIS) device for the measurement of internal moisture gradients in wood was developed. The EIS device consists of a hand-held probe connected to a control unit interfaced with a portable personal computer and a power unit. In the measurement, parallel flat electrodes of the measuring probe are laid against the wood specimen and the sine wave excitation is applied in the frequency range 1–100 kHz. The measured amplitude and phase spectral data were analyzed using the model based on constant phase elements. A spectral analysis software package was designed for measurement of subsurface transverse moisture gradients. The EIS device was tested with many types of uniform, desorption, and absorption gradients in lumber, pulpwood, and log specimens from spruce, pine, and birch. The EIS device can be easily transferred in a small case allowing field measurements.