A knowledge of the air movement around a worker in a low-speed airflow is important in a number of areas: containment testing of fume cupboards; testing of personal dust samplers; testing of LEV effectiveness; and measurement of worker exposure. Measurements of velocity vectors around the upper torsos of manikins and a human in low-speed airflows have been made using a laser Doppler anemometer....

This research classifies the physical morphology (form and structure) of bioaerosols emitted from open windrow composting. Aggregation state, shape and size of the particles captured are reported alongside the implications for bioaerosol dispersal after release. Bioaerosol sampling took place at a composting facility using personal air filter samplers. Samples were analysed using scanning elect...

It has frequently been claimed that cycling in heavy traffic is unhealthy, more so than driving a car. To test this hypothesis, teams of two cyclists and two car drivers in two cars were equipped with personal air samplers while driving for 4 h on 2 different days in the morning traffic of Copenhagen. The air sample charcoal tubes were analysed for their benzene, toluene, ethylbenzene and xylen...

The goal of steganography is to pass secret messages by disguising them as innocent-looking covertexts. Real world stegosystems are often broken because they make invalid assumptions about the system’s ability to sample covertexts. We examine whether it is possible to weaken this assumption. By modeling the covertext distribution as a stateful Markov process, we create a sliding scale between r...

The counting of fibres on membrane filters could be facilitated by using size-selective samplers to exclude coarse particulate and fibres that impede fibre counting. Furthermore, the use of thoracic size selection would also remove the present requirement to discriminate fibres by diameter during counting. However, before thoracic samplers become acceptable for sampling fibres, their performanc...

The sea surface microlayer (SML) is a thin film located at the interface between oceans and atmosphere. In this study, three SML samplers—polycarbonate membrane (PC), glass plate (GP), drum sampler (DS)—were used to collect microbiological DNA samples for molecular analysis. Among samplers, DS only took half time sample compared GP while PC were able thinnest depth. Biological matter distinct b...

We strengthen the notion of double samplers, first introduced by Dinur and Kaufman [``High dimensional expanders imply agreement expanders,” in Proc. 58th IEEE Symp. on Foundations Comp. Science, IEEE, 2017, pp. 974--985], which are samplers with additional combinatorial properties, whose existence we prove using high-dimensional expanders. The ABNNR code construction [N. Alon et al., Trans. In...

For studies of the biological effects of bioaerosols, large samples are necessary. To be able to sample enough material and to cover the variations in aerosol content during and between working days, a long sampling time is necessary. Recently, a high-volume transportable electrostatic field sampler for collection of fine particles has been described. The aim of this study was to investigate wh...