Category Archives: SEAHA student publication

SEAHA and ISH research on epidemiology for heritage collections published in Heritage Science journal

Former Institute for Sustainable Heritage (ISH) student, presently SEAHA student Cristina Duran-Casablancas has recently published a series of papers on wear and tear in archival and library collections in the journal Heritage Science, with her supervisors Dr. Josep Grau-Bové, Prof. Tom Fearn and Prof. Matija Strlič.

An intrinsic value of archival collections is that they are physically used, which undoubtedly leads to a certain level of wear and tear. This reasearch explores whether differences in individual items might explain patterns of decay across a population, as well as how reliable different groups of objects are.

In ‘Accumulation of wear and tear in archival and library collections. Part I: exploring the concepts of realibility and epidemiology’ the authors explore how realibility theory, the method that deals with failure in complex systems, and epidemiology, which explores deseases in defined populations, could be applied in the heritage field to provide quantitative evidence of patterns of decay on large heritage collections.

Part II of the study, ‘Accumulation of wear and tear in archival and library collections. Part II: a epidemiological study’, proposes a new methodology to collection surveying based on epidemiology. The results show that appropriate survey methods and statistical methods of data analysis can reveal the factors that can lead to wear and tear.

Read the two papers below:

  1. ‘Accumulation of wear and tear in archival and library collections. Part I: exploring the concepts of reliability and epidemiology’
  2. ‘Accumulation of wear and tear in archival and library collections. Part II: a epidemiological study’

This article is part of the SEAHA CDT collection in the journal Heritage Science.

SEAHA student Cristina Duran presenting research on epidemiology for heritage collections at the 18th ICOM-CC Triennial Conference, September 2017, Copenhagen. Read the paper presented at the conference ‘Data mining in collections: from epidemiology to demography’ here.

 


Cristina Duran-Casablancas is a SEAHA student based at the Institute of Sustainable Heritage at the University College London. Supported by National Archief (NL) and Helicon Conservation Support, her present research explores the use of System Dynamics and related mathematical modelling techniques to evaluate the effect of preservation actions during the lifetime of collections.

Header Image: Repositories at the Amsterdam City Archives (© Stadsarchief Amsterdam).

Lucie Fusade publishes paper on curing conditions of lime mortars in Journal of Cultural Heritage

SEAHA alumna Lucie Fusade has recently published an article in the Journal of Cultural Heritage with supervisor Heather Viles called ‘A comparison of standard and realistic curing conditions natural hydraulic lime repointing mortar for damp masonry: Impact on laboratory evaluation’.

The setting and hardening process of fresh mortar is governed by the temperature and the relative humidity (RH) of the environment. Environmental conditions therefore have an impact on the early days development of the porosity and structure of lime mortar in a masonry which can affect its performance and function. This combination of temperature and relative humidity in the environment in which lime mortar will harden is called the curing condition. It is therefore essential to understand better what differences, if any, various external environmental conditions would make to the internal structureand durability of repointing lime mortar.

Throughout the centuries, lime mortars have been used under a very wide range of environmental conditions. In England, where the climate is often wet, lime mortar is found in many types of historic masonry built before the 1850s. One of the main roles of pointing mortar – the mortar at the surface of the joint in a masonry wall- is to absorb moisture from the surrounding stones, helping the overall masonry to dry out by evaporation. Failure or weathered original pointing mortar or previous inappropriate interventionscan lead to more rainwater and moisture ingress through the joints. In these cases, mortar needs to be replaced by a repointing mortar.

Realistic curing conditions (as likely found on site) of 15 °C, 85 % RH, representing an average of summer climate in Devon were compared with standard recommended laboratory conditions of 20 °C 65 % RH. The study evaluates the development of the internal structure of mortar samples (mechanical properties, pore structure, water absorption and desorption behaviour) after curing for 28 and 90 days, producing early and medium-aged mortars respectively, under those two curing conditions. The research also evaluates the implication for laboratory characterisation: whether it is of significant importance to use realistic curing conditions if the mortar is later to be applied on a specific site or building. A range of mortar mixes, representing some conservation repointing mortars, was prepared using natural-hydraulic lime (NHL 2, St Astier), quartz sand, and crushed Portland limestone.

Results show that significant differences are found in laboratory evaluations of mechanical properties of the same NHL mortar exposed to different curing conditions, especially at early age and for mortar made with quartz sand. Findings show that laboratory evaluation should be made on samples cured under realistic conditions if information on the early to medium-term (up to 90 days) characteristics of NHL mortar is required. Overall, humid curing conditions could help NHL mortars gain good internal structure more quickly, minimising the risk of early failure of repointing mortar exposed in a harsh humid environment.

Read the article here.


Lucie Fusade is a SEAHA alumnus who was based at the School of Geography and the Environment at the University of Oxford. Lucie’s project looked at traditional materials, such as lime mortar, with the aim to design a repair pointing mortar which can mitigate driving-rain ingress to historical buildings. Lucie was supported by partners Historic England, and The Churches Conservation Trust.

Ian Maybury publishes on imaging Armenian manuscripts in journal Heritage Science

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

Sarah Hunt, heritage science research - battery-operated prototype sensor board for the PQC acetic acid sensors to detect acid in museum display cases

Acetic acid sensors for museum display cases – Sarah Hunt guest blog

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 Pocobelli presenting research on BIM for heritage science at the SEAHA conference 2017

Danae Pocobelli publishes on BIM in journal Heritage Science

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.