Composites based on natural cellulose fibres are susceptible to moisture. The fibres as well as the composite will inevitably soften and swell as moisture is absorbed. The intention of the present paper is to shed some light on the mechanisms behind softening and swelling. Also references to modelling work are made, to predict the moisture-induced dimensional stability. Characterisation techniq...

Two electronic moisture analyzers were critically evaluated with regard to their suitability for determining moisture in small amounts (< or = 200 mg) of various environmental matrices such as leaves, needles, soil, peat, sediments, and sewage sludge, as well as various biological reference materials. To this end, several homogeneous bulk materials were prepared which were subsequently employed...

Low temperature calorimetry (LTC) is usually applied to characterize the porosity of cement-based materials with a total water saturated state. By recording the heat flow of the sample at different testing temperatures, the ice content in the freezing and the melting process can be analyzed. In order to investigate the state of the water during the freezing/melting process of unsaturated porous...

BACKGROUND Quantification of lacrimal total protein content (TPC) is an important tool for clinical scientists to understand disease pathogenesis, identify potential biomarkers and assess response to therapy, among other applications. However, TPC is not only affected by disease state but also by the method used for tear collection. Thus, the purpose of this study is to determine the impact on ...

To prevent indoor fungal growth, understanding the moisture relations of fungi is a key element. Indoor moisture is quantified by the relative humidity (RH). RH controls the water activity of the indoor materials that fungi grow on, a well-studied parameter known to limit fungal growth. RH, however, also controls the amount of water present in these materials, the moisture content. The signific...

Determination of an effective rate constant and activation energy allowed the application of steady-state theory to predict concentrations of compound A from sevoflurane concentrations, fresh gas flow rate, absorbent temperature and amount of absorbent. Studies by eight research groups were compared. Lower concentrations of compound A than predicted were observed at low flow rates, suggesting t...

We propose a generalization of the notion of the absorbent element of aggregation operators. Our construction involves tuples of values that are absorbent, that is, that decide the result of aggregation. We analyze some basic properties of this generalization and determine the absorbent tuples of some popular classes of aggregation operators.

403 The Journal of The South African Institute of Mining and Metallurgy JULY/AUGUST 2003 Introduction Coal preparation is used to upgrade run-ofmine coal before it is utilized by the end-user, primarily electric utility power plants. According to Fonseca1, the coal preparation process reduces the amount of noncombustible mineral impurities, acid-rain precursor sulphur-bearing minerals and hazar...

In most materials, there exists a coupling effect between heat and moisture during their transient diffusion. In particular, the coupling effect gives a significant change in the distributions of temperature and moisture concentration in some porous materials and resin composites (Chang, et al., 1991). Moreover, it is known that the absorption of moisture by hygroscopic materials under high-tem...