Alison Heritage

This article presents the first non destructive measurements of salt ions transport through fired-clay brick during electrokinetic desalination using nuclear magnetic resonance technique. The effect of the strength of an applied electric field on the migration of salt ions is examined by varying the electrical potential gradients from 0.75–2 V cm-1 across the specimens. The measurements show that for electrokinetic to exceed ion transport by diffusion a minimum level of applied voltage is necessary. Below this threshold salt transport by diffusion is dominant over electromigration. The effect of advec-tion on the salt transport is studied by introducing a hydraulic gradient across the specimen. The results show that advection is a major transport process in the materials studied. To assess the relative magnitude of the various active transport processes during electrokinetic desalination, a scale analysis on the basis of dimensionless numbers is presented. The value of these numbers determines which transport mechanism will dominate the desalination process in a given sample length and time scale.

This paper examines some of the current science policy paradigms set at international level to promote open science and participatory research, and discusses how key factors necessary for successful collaboration can usefully contribute to the training of future conservation professionals through group work and research-based learning programmes.

The ICCROM Forum 2013 on Conservation Science resulted in a series of recommendations for improving the relevance and impact of science within cultural heritage conservation. These recommendations are outlined in this paper. Central to the Forum recommendations is the responsibility of conservation science to provide benefit through research and innovation. This relies on shared strategic vision and good governance, to identify priority needs and align efforts accordingly. To enhance the effectiveness of conservation science research, it is imperative to adopt an approach based on needs assessment, collaboration, and sharing. However, to establish whether desired goals are being met, systematic assessment of what is delivered and how it is used is required. Evaluation tools provide a structured way to identify needs and to measure results, offering a basis for learning and improvement. A new initiative is outlined, launched by ICCROM in follow-up to the Forum, to develop a common framework for needs and outcome assessment for heritage conservation science. To achieve this will require participation and support at multiple levels, and collaboration is called for to continue and sustain this effort.

This paper presents preliminary results from the
ICCROM Forum on Conservation Science, which
took place in October 2013. This initiative was organised
by ICCROM in partnership with 15 conservation
research and training institutions spanning
Europe, North America, Latin America and Asia.
Background research undertaken before the Forum
examined research trends, strategy development,
information dissemination, education and training,
job opportunities and the impacts of science
within conservation. These surveys revealed stark
inequalities between countries and regions in regard
to knowledge production and access to scientific
information and services, limited research
opportunities for non-institutional players and a
shortage of job openings for young conservation
scientists. In its conclusions, the Forum stressed
the need for the sector to embrace all relevant sciences,
to place greater emphasis on wider societal
issues and to undertake strategy development.
Building on the Forum experience, ICCROM will
explore options for the regular collection of indicators
for conservation science.

ABSTRACTCellulose poultices are frequently used in stone and wall painting conservation for the purposes of soluble salt extraction, consolidation and cleaning. They have the reputation of being easy and pleasant to work with, have a neutral pH, high water absorption and plasticity, exhibit good conformance and adhesion to the substrate, and in most cases leave minimal residues after clearance. The cellulosic materials from which they are composed range from cotton wool, blotting paper or newspaper, to cellulose powders, the latter now by far the most common form of cellulose used today by conservators. Drawbacks of these products include poor water retention when applied to vertical surfaces, a tendency to redistribute salts further into the object substrate, and poor long-term treatment effectiveness for salt extraction. Hence cellulose poultices are used frequently due to good working properties, but apparently are in some situations not very effective. In this paper, existing knowledge of these poultices is outlined, followed by investigations undertaken to fill some of the knowledge gaps. Investigations include characterization of poultice properties such as pore size distribution and workability, and of moisture transport processes within poultice/substrate systems including moisture penetration depth, moisture distribution, and poultice shrinkage during drying. Cellulose powder products known under the trade name Arbocel®, extensively tested and used in conservation over several decades, were a particular focus. Resulting guidelines include counter-intuitive measures such as (when used for salt extraction purposes) the use of thinner poultices to reduce drying shrinkage and salt redistribution further into the substrate. The relatively uniform pore size distribution (around 10 μm) of Arbocel® poultices makes them more appropriate for salt extraction on substrates with a medium-coarse pore size (i.e. 15 μm and above), while on fine porous substrates (10 μm and below), the extraction will not be as efficient.