BACKGROUND Contact dermatitis is one of the common work-related dermatoses. Among bricklayers, cement can cause both allergic contact dermatitis and primary contact irritative dermatitis. The personal protective equipment (rubber gloves) may favor the development of allergic contact dermatitis. OBJECTIVES 1) to evaluate the frequency of allergic contact dermatitis among construction workers b...

In this paper, we present our research into the interruption performance of vacuum circuit breakers in aviation intermediate-frequency (360 Hz to 800 Hz) power supply systems. Intermediate-frequency vacuum arc experiments were carried out in interrupters with a diameter of 41 mm and CuCr50 alloy contact material. The results show that, as the frequency and peak value of the current increase, bo...

Ocular microtremor (OMT) is a physiological high frequency (up to 150Hz) low amplitude (150-2500nm) involuntary tremor of the human eye. It is one of the three fixational ocular motions described by Adler and Fliegelman in 1934 as well as microsaccades and drift. Clinical OMT investigations to date have used eye-contacting piezoelectric probes or piezoelectric strain gauges. Before contact can ...

Studies of frequency resolving power in budgerigars (Melopsittacus undulatus) have shown that this species has excellent discrimination abilities for both simple and complex sounds falling in the region of 2 to 4 kHz--the frequency range of their contact call. In four experiments, frequency discrimination by budgerigars of short tones similar to elements found in the contact call was examined. ...

BACKGROUND Contact with primary care and psychiatric services prior to suicide may be considerable, presenting opportunities for intervention. However, there is scant knowledge on the frequency, nature and determinants of contact. METHOD Retrospective cohort study-an analysis of deaths recorded as suicide by the Northern Ireland Coroner's Office linked with data from General Practice patient ...

Sera from 495 pregnant women were examined for toxoplasma antibodies by indirect fluorescent antibody testing (IFAT). Antibodies were positive in 32.7%. Seropositivity was not increased significantly with age but showed a statistically significant rise in accordance with frequency of parity, abortion and contact with cats. The high rate of seronegativity (67.3%) observed in pregnant women ...

The vertical and rocking impedances of a rigid foundation resting on a semi-infinite transversely isotropic medium are obtained in the frequency domain. In the present approach, the contact pressure distribution on the soil foundation-interface is approximated by a linear combination of known pressure patterns. It is shown herein that the approximate solutions of spatial displacement distributi...