Certification tests currently employed by some industrialized nations to certify respirators require that when challenged with air flow at a constant suction head of 25 mmH2O, the leakage into the facepiece from the exhalation valve(s) should not exceed 30 ml min(-1). However, the test alone might not reflect the leakage rate under different levels of vacuum. To study the characteristics of lea...

The mechanics of lung ventilation in frogs and aquatic salamanders has been well characterized, whereas lung ventilation in terrestrial-phase (post-metamorphic) salamanders has received little attention. We used electromyography (EMG), X-ray videography, standard videography and buccal and body cavity pressure measurements to characterize the ventilation mechanics of adult (post-metamorphic) ti...

The present study investigated the timing of backchannel onsets within speaker’s own and dialogue partner’s breathing cycle in two spontaneous conversations in Estonian. Results indicate that backchannels are mainly produced near the beginning, but also in the second half of the speaker’s exhalation phase. A similar tendency was observed in short non-backchannel utterances, indicating that timi...

Heijkenskjöld Rentzhog, C. 2016. Towards Improved Diagnostics and Monitoring in Childhood Asthma. Methodological and Clinical Aspects of Exhaled NO and Forced Oscillation Technique. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1262. 79 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9710-1. Background: Asthma is a heterogeneous disease. Diag...

A rapid method for directly determining the exhalation rate of thoron from material surfaces was studied. Thoron accumulated with the accumulation chamber is detected with the scintillation cell. The alpha counting efficiency of the scintillation cell was estimated by the Monte Carlo calculation. Measurements were carried out in a sandy loam and different building materials. The results show th...