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For efficiently measuring ultraviolet transmission through clothing materials for a large number of samples, an automated measuring system with a broad-band method has been built and calibrated against a spectroradiometer based instrument. The apparatus can be used to test 60 samples in 25 min. A selection of clothing materials of known composition, weave, color and state have been tested, using the broad band method and the automated measuring system together with a solar ultraviolet simulator. Variations of about eleven times for different weave structure, about two times in the ultraviolet transmittance for different colors, and about 20 times for some stretched samples were observed. For wet conditions, an increment in ultraviolet transmittance for cotton and lycra materials and a decrement for polyester and polyester(65%)/cotton(35%) were also observed.

Neisseria meningitidis was recovered from the urethra of nine and from the anal canal of seven men, and from the cervix of two women. Twelve of the 16 men were admitted homosexuals. Seven men had no symptoms, while the remainder had mild to moderate symptoms. One woman was asymptomatic and the other was in hospital with acute salpingitis. Reports of previous isolations of meningococci from the urethra, cervix, or anal canal are reviewed. It is concluded that in men, these infections are usually mild and self-limited, but in women, meningococcal genital infections frequently proceed to severe disease.

The results of a programme of research on nitrogen doped green-emitting diffused VPE LEDs are reported. The purpose of this work was to establish whether the recombination processes which control final device efficiencies occur on the p or n side of the junction. To do this we have used a novel technique which involves fabricating diodes down a bevelled epitaxial “sandwich” structure consisting of a nitrogen doped region between non nitrogen doped ones. We find that the light output from the n side is approximately a factor 1.5 times the p side output. Hence both the p and n regions of these diffused structures yield significant light outputs, although the contribution from the n side usually dominates. The above result together with cathodoluminesence efficiency measurements on p - and n -type material suggests the device injection ratio (β), defined as the ratio of injected hole and electrom currents, is β = J h / J e ∼ 3 − 4.5. Attempts at calculating β for these LEDs have shown that the effects of high level injection, built-in field and breakdown of the depletion approximation must be taken into account if realistic device modelling is to be carried out. The results of this work are believed to have important practical implications because they suggest that significant improvements in device efficiencies can be obtained by modifying the doping profile to increase the electron injection efficiency into the higher luminescence efficiency p -type material.

A group of 200 Queensland adults without known health problems had in-vivo estimation of finger bone lead concentrations using X-ray fluorescence analysis (XRF). Forty of these subjects had elevated levels of bone lead of 25 ppm or more, consistent with exposure to the metal. Although the correlation between Queensland residence during childhood and raised bone lead levels was not significant, there were significant correlations between childhood residence in a painted wooden house and raised levels, and between occupational exposure and raised levels. Of the 40 subjects with elevated lead levels only two had neither a history of occupational exposure or childhood residence in a wooden house, whereas 11 of the 25 who had a history of both occupational and residential exposure were positive. The data are consistent with lead in housepaint, or absorbed during occupational exposure, being the two major sources of raised bone lead concentrations.