Medium density (3×109 cm−3) and high density (3×1012 cm−3) plasmas, generated by low and medium power rf techniques, have been used for the implantation of 10–20 keV nitrogen ions into mild steel targets which were immersed in the plasma and biased to −20 kV. Use of the high density plasma resulted in significant damage to the surface by arcing. At medium densities the nitrogen was implanted to a depth and dose consistent with expectations, there was no arcing damage, and tests showed improved wear and hardness compatible with the level of implantation.

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Since December 1992, CSIRO and BHP have been field trialing rf HTS SQUID magnetometers for mineral prospecting applications. Ten field trials in widely varying environments (from -16°C to +4OoC ambient temperatures) in mostly remote locations saw the development of a system which can be operated in many configurations including ground based and airborne Transient ElectroMagnetics (TEM). The magnetometer system has been developed to a point where, at late times in TEM applications, the SQUID system has a higher signal-to-noise level than the competing traditional coil technology. In some trials, a SQUID magnetometer detected anomalies at later times than were observed with the coil system, indicating an enhanced ability to detect highly conductive targets. This paper reviews development of our 3-axis SQUID magnetometer. SQUID systems as B field sensors have advantages over coils which are dB/dt type sensors. We will discuss the importance of these advantages for mineral prospecting in regions with a conducting soil cover or overburden typical of the Australian landscape.

SYNOPSIS An account is given of the uterine anatomy of virgin Glossina austeni Newstead and this is compared with the anatomy of the female tract both during mating and after the mating act has been completed. Notes on the functional morphology of the male genitalia are included.

The male accessory glands of Glossina austeni Newst. contain an apical secretion-a dense, opaque, whitish secretion at the apical end of the gland, and a diffuse secretion-a bulkier, more mobile, translucent, whitish secretion occupying nearly all the remainder of the gland. There is also a plug of clear solidified accessory material preventing the outflow of secretions from the resting gland. By immersing the whole accessory gland in a saline medium at pH 2-2, and then transferring the specimen to distilled water, the apical secretion can be separated manually from the rest of the gland, as an apical body. Measurements of the apical body in virgin male flies show that the apical body increases in width according to the equation: Age = constant X width 2 -5 , but individual deviations from this relation were considerable. Immediately after mating the apical body is long and thin; recovery to approximately the resting condition is complete after 48 h, but, on average, mated males have thinner apical bodies than virgin males of the same age. The use of apical secretion measurements to assess mating frequency under field conditions might be possible if adequate samples of males were available.