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The use of nanotechnology in different fields is increasing rapidly. Engineered nanoparticles (ENPs) may have adverse effect on human health, but little is known about the exposure levels of ENPs at occupational settings. In this study, exposure levels of cerium oxide (CeO(2)) ENPs were measured during enclosed flame spray process used for coating and surface modification of materials. Particle number concentration, mass concentration, and morphology and composition of the ENPs were studied. The average particle number concentration varied from 4.7·10(3) to 2.1·10(5) 1/cm(3) inside the enclosure, and from 4.6·10(3) to 1.4·10(4) 1/cm(3) outside the enclosure. The average mass concentrations inside and outside the enclosure were 320 and 66 μg/m(3), respectively. A batch-type process caused significant variation in the concentrations, especially inside the enclosure. CeO(2) ENPs were mainly chainlike aggregates, consisting of spherical 20-40 nm primary particles having crystalline structure. In conclusion, enclosure of the process with efficient ventilation seemed to be an effective means to reduce the exposure to CeO(2) ENPs as expected.

Elongation to fracture values higher than 300% were obtained for cold rolled AISI 304 type steel grades in hot tensile tests. The effects of heating rate and carbon content on the elongation of the steels studied are discussed based on internal friction measurements and TEM observations. A slow heating rate to the test temperature and high carbon content of the steel led to a fine and equiaxial grain structure of the steels.MST/6042

Glass and glazes are easy-to-clean surfaces often used in everyday environments where the surface needs to repel soils and deposits. In general, these surfaces have good chemical durability in everyday environments. However, the durability is rapidly degraded in solutions of high or low pH. This kind of surface corrosion has been found to diminish the cleanability. Surface topography has also a certain influence on the soil attachment and cleanability. Self-cleaning and easy-to-clean coatings have been employed to enhance the cleanability of surfaces. In this report surface properties of three coatings reported to enhance the cleanability of glass and glazed surfaces are summarized. The properties discussed are the surface appearance, roughness, wettability, soil attachment and soil removal. Also the chemical and mechanical durability of the coatings are discussed. The coatings studied were a commercial fluoropolymer film applied at room temperature, an experimental sol-gel derived TiO2 coating calcined at 500°C, and an experimental liquid flame sprayed TiO2-Ag coating applied on the substrates at 500-800°C. The advantages of the fluoropolymer coating are easy application and soil good soil repellence, but the coating has limited chemical and mechanical durability. The manufacture of the sol-gel TiO2 coating requires several processing steps. The coated surface showed excellent cleanability, and good chemical and mechanical durability. The liquid flame sprayed coating has potential to be applied online in the material manufacture. However, the processing parameters should be optimized in order to achieve desired improvements in the cleanability.

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