SEAHA student Ian Maybury, alongside researchers David Howell, Melissa Terras and Heather Viles has published the paper ‘Comparing the effectiveness of hyperspectral imaging and Raman spectroscopy: a case study on Armenian manuscripts’ in journal Heritage Science.
Hyperspectral imaging was originally developed for remote sensing. It allows the characterisation of a scene by providing a reflectance spectrum for each pixel in an image and is commonly used to provide information on the geography of an area. In this study the efficacy of HSI for the identification of pigments in works of art was investigated. The study compared how well HSI between 400 and 1000 nm was able to differentiate between different pigments compared to an established technique (Raman spectroscopy) using illuminated Armenian manuscripts from the Bodleian Libraries (Oxford University) as a case study to demonstrate the use of the equipment.
The two techniques worked very well together. Raman spectroscopy can identify pigments much more accurately than HSI. This is because a Raman spectrum has characteristic peaks, but a reflectance spectrum in this range has very few distinguishing features. However it takes much longer to sample on a point by point basis and to scan in large areas using Raman spectroscopy. HSI can scan a large area quicker than Raman spectroscopy, and can be used in conjunction with Raman spectroscopy to map different regions of colour within the artwork. In essence, the most effective approach is to use the identification accuracy provided by the Raman spectroscopy, combined with the mapping functionality of HSI, to map the occurrence of individual pigments across a large area. This is useful for feature detection, monitoring for conservation, and investigating an items’ provenance or history.
Read the full article here.
Ian Maybury is a SEAHA student based at the School of Geography and the Environment at the University of Oxford. Ian’s project investigates the use of hyperspectral imaging (HSI) in a heritage context learning how to best use the equipment to extract information such as hidden text, relief details, the presence of organic growth, and signs of deterioration. Ian is supported by partners the Bodleian Library and Headwall Photonics.
Tasty on fish & chips but a problem for museums… SEAHA student Sarah Hunt recently blogged about her work in heritage science detecting acetic acid in The Book and Paper Gathering. Acetic acid is known to be damaging to museum artefacts and is particularly problematic within display cases. As damage occurs below the odour threshold, Sarah blogs about her development of piezoelectric quartz (PQC) crystal sensors to quantify parts per billion concentrations of acetic acid inside display cases.
Sarah also discusses how her work has wide application to museums and heritage objects; PQCs are sensitive to nanogram changes of mass and are also small, affordable, and have fast response times.
Read Sarah’s blog about developing acetic acid sensors here.
Sarah Hunt is a SEAHA student based in the School of Pharmacy at UCL. Supported by the National Physical Laboratory, TA Instruments & the Mary Rose Trust, her project investigates air quality inside museum display cases, with a particular focus on emissions from waterlogged organic collections.
Image: Sarah Hunt, Battery-operated prototype sensor board for the PQC acetic acid sensors. It has the capability to remotely log data from eight sensors.
SEAHA student Danae Phaedra Pocobelli has published a review article ‘BIM for Heritage Science: A Review‘ in journal Heritage Science, with her supervisors Josep Grau-Bové, Jan Boehm, Paul Bryan and James Still.
In contrast with a classical literature review, Pocobelli’s paper explores what Building Information Modelling (BIM) is and how it has been used in heritage buildings to date. Through a review of scholars’ research and analysis of practical case studies, Pocobelli critically assesses work that has been done thus far and what should be achieved in the future. She specifically identifies the need for, and potential impact of, including tools for heritage building condition reporting, as well as condition monitoring and weathering simulation.
Read ‘BIM for Heritage Science: A Review’ here.
Danae Phaedra Pocobelli is a SEAHA student based within the Institute for Sustainable Heritage at UCL. Supported by Historic England, English Heritage & Plowman Craven, her project explores using BIM for heritage.
Image: SEAHA student Danae Pocobelli presenting research on BIM for heritage science at the SEAHA conference 2017.
SEAHA MRes student Rosie Brigham alongside her supervisors has demonstrated that heritage site visitors can use their smartphones to obtain good measurements of colour. The research, which measures the uncertainty of crowd-sourced measurements, has been published in Angewandte Chemie.
Through this research, the quality of crowd-sourced measurements taken by visitors to historic sites has been quantified for the first time. In collaboration with Historic Environment Scotland and UCL Culture, the researchers left signs on display asking visitors to submit pictures via email and twitter. The tweeted pictures were later analysed, colour-corrected, and used to obtain measures of colour of the depicted objects. The results show that colour measurements can be obtained with the help of visitors. The measurements are not as good as those obtained with scientific equipment, but are good enough to see some colour differences that are important for conservation.
This project will continue with research on the use of crowd-sourced smartphone images to measure other parameters of interest, such as shape, and on the development of algorithms for the automation of the measurements.
Read the paper here.
SEAHA student Scott Allan Orr has recently published two research papers on wind-driven rain and the effect on built heritage. Orr’s research has also been featured in The Sunday Times.
Wind-driven rain is a prominent environmental risk to built heritage, but while predicted climate changes are well established, it has been until now uncertain how this will manifest in wind-driven rain.
In the research, Orr and his co-authors combine weather generator predictions with a probabilistic process to create a time series of climate parameters under a high-emissions scenario for 2070-2099 at eight UK sites. They predict that in the late twenty-first century, rain spells will have higher volumes thus impacting façades across all 8 sites and that damage to buildings will occur more frequently.
Periods of wind-driven rain are predicted to become shorter but more intense, posing challenges to infrastructure that could be very costly if they are not managed properly. Of particular concern is the impact on traditional and heritage buildings, as the materials they are built from can be deteriorated by rain in several ways.
Orr and his co-authors are therefore proposing that new metrics for wind-driven must be developed to manage future impacts, with Orr commenting that “we need to ensure that the standards used to evaluate wind-driven rain in this country are incorporating current knowledge and state-of-the-art methods.”
Wind-driven rain implications for built heritage in the UK
Read the two papers below:
‘Wind-driven rain and future risk to built heritage in the United Kingdom: Novel metrics for characterising rain spells’, Science of the Total Environment.
‘Characterisation of building exposure to wind-driven rain in the UK and evaluation of current standards’, Journal of Wind Engineering and Industrial Aerodynamics.
Scott Allan Orr is a SEAHA student based at the School of Geography and Environment at the University of Oxford. Supported by Historic Environment Scotland and Consarc Design Group, his research assesses exposure and response of historic stone masonry to wind-driven rain, using climate models and non-destructive testing.