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- Giorgi, R., et al.
(författare)
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Nanoparticles of calcium hydroxide for wood deacidification: Decreasing the emissions of organic acid vapors in church organ environments
- 2009
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Ingår i: Journal of Cultural Heritage. - : Elsevier BV. - 1296-2074 .- 1778-3674. ; 10:2, s. 206-213
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Tidskriftsartikel (refereegranskat)abstract
- Acetic and formic acid vapors emitted from woodwork in historical organs are very important corrosive agents for lead pipes. These acids are slowly released from the wood both during playing and when the pipes are silent. To inhibit this emission process. the wood surface can be modified, by creating a protective layer with alkaline features. However, a coating of wood is not recommended since this could modify the appearance and create a layer not perfectly compatible with the substrate. For this reason, we propose to use some innovative nanotechnology that has been successfully applied for the deacidification of wood samples coming from the Vasa shipwreck. Application of calcium (or magnesium) hydroxide nanoparticles, with sizes ranging from 30-150 nm, allowed a homogeneous distribution of particles through the surface layer of wood simply by soaking (or spraying) it in a alcohohc (or mixed with less polar solvents) dispersion of nanoparticies. Nanoparticles do not modify the wood appearance and distribute randomly within the first layers of wood. The small size of particles accounts for the high reactivity with CO2 from the air, to give the alkaline reserve of carbonates that provide high efficacy in the neutralization of gaseous acids. The emission of volatile organic compounds (VOC) from the treated wood was determined by using an emission test cell, Field and Laboratory Emission Cell (FLEC). The results show that the emissions of acetic acid vapor from nanoparticles treated wood was very low (
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| 2. |
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| 3. |
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| 4. |
- Niklasson, Annika, 1977, et al.
(författare)
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Air Pollutant Concentrations and Atmospheric Corrosion of Organ Pipes in European Church Environments
- 2008
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Ingår i: Studies in Conservation. - 0039-3630 .- 2047-0584. ; 53:1, s. 24-40
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: The atmospheric environment inside and outside historical organs in several European regions is reported. In each region, comparisons were made between an instrument suffering organ pipe corrosion and an organ without corrosion problems. Concentrations of acetic acid (ethanoic acid), formic acid (methanoic acid), acetaldehyde (ethanal), formaldehyde (methanal) and other volatile organic compounds in the organ environment were determined using active sampling. Temperature and relative humidity were recorded. In addition, polished metal samples that mimic the material used in the historical organ pipes have been exposed in the organ wind systems for up to 22 months. High concentrations of acetic acid and formic acid vapours are present in the wind system of the corroded organs. Acetaldehyde and formaldehyde are also present in smaller amounts. The main source of acetic acid is the wood from which the wind system is built. In contrast, formic acid is generated in the chruch environment outside the wind system. The results show that the two organic acids play an important role in the atmospheric corrosion of organ pipes. It is suggested that the corrosion of lead pipes in historical organs can be effectively reduced by removing the sources of gaseous acetic acid and formic acid in the wind system and in the chruch environment.
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| 5. |
- Olofsson, Marcus, 1968, et al.
(författare)
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The flux of isoprene from a willow coppice plantation and the effect on local air quality
- 2005
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 39:11, s. 2061-2070
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Tidskriftsartikel (refereegranskat)abstract
- Isoprene fluxes from a Salix viminalis (willow) plantation in western Sweden were measured using the relaxed eddy accumulation (REA) technique. Fluxes of up to 0.23 mu g m(-2) s(-1) could be observed. A standard emission factor at 303 K and a PAR flux of 1000 mu mol m(-2) s(-1) was estimated to 0.98 mu g m(-2) s(-1) by using the G93 algorithm. The chemistry of an air parcel passing over a willow coppice plantation was investigated utilising a Lagrangian box model in which the measured isoprene fluxes were used as input data. Dispersion after the field was accounted for by a procedure based on the Gaussian plume model. The calculations indicate that, in most cases, the isoprene emissions have a small effect on the local air quality.
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