School of Historical and Philosophical Studies - Research Publications
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ItemNo Preview AvailableSpeckle and Conservation(International Seminars, 2008)The aim of this research is to demonstrate the usefulness of speckle, a trait of an expanded laser beam, for the non-destructive testing of artwork in both the imaging of subsurface structure and the quantitative detection of physical movement of canvas. Laser Speckle Contrast Method (LSCI) is a useful method for the viewing of subsurface layers and movement. By investigating the statistical properties of dynamic speckle it is possible to reveal drawings that are hidden beneath scattering layers such as the primary layer of paint or adhered paper. This is achieved by taking a series of speckle images captured in a short time frame and applying one of a number of post processing algorithms. We explore the limitations of this method when applied to various paper samples that have a sketch executed in various media beneath the top layer. The ability to resolve gray scale images was examined as well as looking at the dependence of the contrast of the revealed drawings to the temperature of the surface. Current work is being done on using LSCI to reveal indentations in artwork caused by the application process. The successful use of Electronic Speckle Pattern Interferometry (ESPI) both in the laboratory and in-situ for the detection of in-plane movement of painted canvas due to humidity fluctuations and the out-of-plane movement of paint as it dries has also been demonstrated. Canvas paintings can be very susceptible to movement due to changes of the environment. ESPI is a non-destructive technique yielding sensitive results that can detect displacement on a surface of less than the wavelength of the illuminating coherent light source. While ESPI has been successfully applied to the in-situ study of painted frescoes, previous studies have employed tensile testers as a support for painted canvas. We have shown a portable version of ESPI to be of use in tropical environment in the Philippines, Malaysia and Singapore with original artworks where variations in humidity occur and the samples have not undergone special preparation before analysis, revealing significant directional movements. Furthermore, a simple variation in the direction of beams paths permits the characterisation of out-of-plane movement, specifically as the height of paint shrinks due to the drying process. We have used ESPI to view the drying process of alkyd resin paints over the time period of 24 hours.
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ItemA preliminary understanding of oil paintings in tropical Southeast Asia(Allied Publishers Pvt. Ltd., 2008)
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ItemIn-situ, non-invasive investigation of an outdoor wooden sculpture(International Council of Museums, 2014-09-14)This paper reports on the development of a radio- frequency sensor unit for the non-invasive monitoring of Bruce Armstrong’s outdoor wooden sculpture constructed from River Red gum (Eucalyptus camaldulensis). This technique collects realtime data in situ in outdoor environments. Sensor units employing electromagnetic radiation in the microwave to radio frequency part of the spectrum can detect moisture changes, mould growth and termite infestation in specimen Australian timbers used in works of art. Model experiments using wood samples showed that moisture changes,decay levels, invasion of wood by insects such as termites and wood deterioration due to fungal attack can be detected with both ‘look through’ and radar-based microwave sensors. The monitoring provided information on the time response, temporal and cyclic activity of an outdoor, exposed wooden sculpture to moisture. A radio-frequency sensor is applicable for the monitoring of cultural materials to inform damage functions and dose values.
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ItemFluorescence analysis of the constituent dyes within a daylight fluorescent paint layer via thin layer chromatography: implications for colour matching(The Colour Society of Austrlia, 2009)