|
Technart 2009 proposed to present and promote the use of the state-of-the-art analytical techniques in the field of cultural heritage, offering an opportunity to exchange knowledge on the latest advances in analytical instrumentation, methodology and application. Particle (neutrons and ions) and photon probes, generated in large infrastructures, bench-top or even mobile instruments, but also mass spectrometry and separation techniques, implemented separately or in a combined and synergistic methodology, offer nowadays a unique mean for advanced and non-destructive characterisation, imaging and remote sensing of cultural heritage materials. The contributions highlighted these new developments and the multidisciplinary character on the emerging field of analytical techniques in cultural heritage, presenting studies of objects and materials in the context of archaeology, art history and conservation science. Technart 2009 followed the previous organisation of Technart 2007 in Lisbon, Portugal. The next edition will take place in Berlin, Germany in 2011. More than 150 delegates, 11 invited speakers and 51 regular speakers from different countries attended the four days conference. Additionally, more than 100 posters were presented in two sessions. Selected contributions will be published in a special issue of Analytical Biochemical Chemistry (ABC). During the intense four days, eleven main sessions covered different aspects of non-destructive and microanalytical techniques in art and cultural heritage: “Innovative techniques & methodologies”, “Confocal X-ray microanalysis and imaging”, “Optics and lasers”, “Neutrons”, “Synchrotron radiation”, “Diagnostic techniques and conservation”, “Mobile spectroscopy”, “Organic materials”, “Combined non-destructive techniques”, “Sensing and spectroscopy” and “X-ray microanalysis and complementary techniques”.
On the first day the opening remarks were made by Andreas-Germanos Karydas and Demetrios Anglos. The first session “Innovative techniques & methodologies” started with G. Demortier and a polemic presentation entitled “The construction of the big monuments in ancient Egypt: new insight from elemental and structural analyses”, focusing on the Chéops pyramid and the construction technique applied: the use of limestone aggregates. The following invited speaker, B. Kanngieβer, presented a work about the application of confocal X-ray microscopy on the study of art and cultural heritage using 3D micro-XRF and micro-PIXE analysis combined, with experimental features focusing on the possibilities and restrictions of both methods. The next speaker, R. J. Clark focused on the application of Raman microscopy to several art and historical works such as codex, painting, archaeological finds, stuccoes, manuscripts, ceramics or miniatures, showing many examples of pigment analysis and how this technique made such an impact on different areas. The last invited speaker was I. Nakai with the communication “On site analysis of artefacts excavated from Egypt by using newly developed portable diffractometer and fluorescence spectrometer”. The speaker brought a case study about the use of this instrument in the analysis of blue pigments from ancient Egypt; the results revealed the existence of two different pigments: Egyptian blue and cobalt blue.
Regarding the first session other contributions were made focusing on various techniques applied to several materials: neutron imaging (renaissance bronzes), X-ray tomographic spectroscopy (paint cross-sections), fluorescence and vibrational spectroscopy (natural varnishes), nuclear magnetic resonance (NMR) spectroscopy (molecular characterization of organic compounds) and automated eXpert spectral image analysis (AXSIA) multi-spectral imaging (ancient manuscripts). Two other presentations were made focusing on the use of combined techniques in the analysis of craft large bronzes masterpieces and the analysis of painting techniques and conservation of wall paintings. The second session “Confocal X-ray microanalysis and imaging” included three presentations: “Non-destructive, depth resolved investigation of historical glass objects by 3D micro X-ray fluorescence analysis – X-ray tube and synchrotron radiation measurements”, “3D imaging with a confocal µ–PIXE arrangement” and “3D micro-XRF analysis of ancient Attic black glazed ceramics”. The first method enables a three-dimension resolved, non-destructive investigation of elemental distribution in samples in the micrometer regime while the second method allows, in principle, the determination of 3D concentration distributions down to a micron spatial resolution, which can be applied to the study of samples such as pictorial layers, gemstones inclusions or glazed ceramics. The first day ended with Poster Session I - with 50 posters being presented - regarding case studies of the conference themes. After the poster session a welcome reception was offered by the organising committee. “Identification and topography of pigments and varnishes by different optical techniques” by M. Elias was the second day’s first presentation of the session “Optics and lasers”. The study was based on the need of a non-destructive, contactless and portable method that leads to results in real-time, allowing the simultaneous identification of pigments and varnishes in the same instrument. Several examples were showed such as the study of Gioconda, imaging of varnished violins or stratified pictorial layers. The results in real time are an important help for restorers who can choose the location of the analysis and repeat it at will. The following communications were on the application of terahertz time-domain-spectroscopy (THz-TDS) in art particularly, in the analysis of painting materials, the study of red lakes in wall paintings by Masolino, the compositional depth-profiles of excavated marble patinas and its use in authenticity investigations and the multifunctional encoding system for assessment of movable cultural heritage. The session on “Neutrons” had three speakers that presented studies on Japanese artworks of Tokugawa age, on the content of ancient Tibetan metallic Buddha statues and on archaeological objects using neutron diffraction, neutron transmission radiography and a combination of prompt gamma activation imaging (PGAI) and neutron radiography-tomography (NR/NT). W. Kockelmann, invited speaker, made a presentation on non-destructive neutron analysis at ISIS (UK) focusing on the characterisation of metal objects. The main advantage of this technology is the extraction of the element, phase and microstructural information from an intact object. The afternoon started with the session on “Synchrotron radiation” and the presentation entitled “Combined use of X-ray milli and microprobes for non-destructive analysis of large cultural heritage artifacts”. K. Janssens, invited speaker, brought a case study on Van Gogh’s paint “Patch of grass”. The performed exams revealed that most elements found corresponded to the pigments on the top layer but two elements were directly related to a covered area. This exam allows to obtain information about burial layers in a non-destructive manner. The following presentations were on the study of the Dead Sea scrolls, Italian armours and Celtic ceramic sherds. After the coffee break started the 6th session on “Diagnostic techniques in conservation” with presentations on indoor museum environment and its impact on complex organic materials, the use of near infrared spectroscopy to characterise historic silks, a study on roman rostrum and a combined application of energy dispersive X-ray fluorescence (EDXRF) and Fourier transformed infrared spectroscopy (FTIR) to the study of archaeological artworks from Crete, in order to identify pigments from Hellenistic figurines, to characterize Late Minoan metallic finds, to analyse mortars and plasters from Minoan to Turkish domination period and to assess the efficiency of stone consolidating agents. The day ended with a guided tour through the city of Athens and to the Acropolis. A. Markowickz started the third day with a lecture entitled “The IAEA activities related to applications of nuclear analytical techniques for characterization and protection of cultural heritage objects”. The International Atomic Energy Agency (IAEA) provides support in applications of nuclear analytical techniques in the field of cultural heritage through coordinated research projects, technical cooperation projects, training and development of prototype instruments. The session on “Mobile Spectroscopy” continued during the first part of the morning and the first part of the afternoon with several presentations: “Quantitative X-ray fluorescence analyse of an Egyptian faience pendant and comparison with PIXE”, “Novel extensions of pulsed Raman and laser induced breakdown spectroscopy (LIBS) in art conservation”, “A novel portable XRF spectrometer: first application to a gilded bronze from the Florence baptistery”, “A portable, vacuum-chamber equipped XRF-instrument, designed for the sophisticated needs of the KHM, Vienna”, “A combined use of FORS, XRF and Raman spectroscopy in the study of mural paintings in the Aosta Valley (Italy)” and “Micro-XRF and LIBS analysis of gilded bronze figurines at the National Archaeological Museum of Damascus”. The main idea, besides the application of non-destructive techniques in the analysis of art works, was also the need of a reliable, versatile and practical instrumentation that can be used in situ, without any sample preparation. Some comparisons were made between PIXE and XRF, showing similarly accuracy of the results. The XRD technique can be applied for the mineralogical characterisation of materials; generally the technique is applied with non-transportable instruments, limiting the field of application to small dimension objects or the need to collect samples in objects that can not be transferred to laboratories. The presentation of F. P. Romano brought the latest results on the non-destructive portable XRD system that has been upgraded in LANDIS laboratories and applied in the characterisation of ancient pigments in Roman frescoes. “Since ancient times, a wide variety of natural organic materials have been used as adhesives, sealants, painting and coating materials. Proteins, oils, gums, natural resins and resinous materials have intrinsic properties that enable them to be used not only as painting materials, adhesives, hydro-repellent coatings and sealing agents, but also as flavours, incense, ingredients for cosmetics, medicine and mummification balms”. This was the introduction to the second morning session on “Organic materials” by M. P. Colombini with a very interesting presentation on “Macromolecules in art and archaeology”. The study of these materials is a hard task due to the complexity of their chemical composition, the use in mixtures, the change of the chemical composition and the degradation due to ageing. The lecture reviewed the most significant results obtained by the application of analytical procedures, mainly based on mass spectrometry techniques, to painting and archaeological samples. The other presentations were focused on the study of egg-tempera and oil on canvas in Post-Byzantine period, the identification of protein media used in coloured glazes on silver leaf, the characterisation and deterioration of parchment and a comparative study on the extraction methods for the analysis of natural dyes in historical textiles. The afternoon started with the second part of the “Mobile spectroscopy” session and ended with four presentations on “Combined non-destructive techniques” focusing on the combined use of optical microscopy, X-ray diffraction and X-ray fluorescence on the study of tesserae from mosaics, the use of micro-XRF and Raman spectroscopy for non-invasive analysis of art works, the use of ionoluminescence to characterise lapis lazuli provenance and the use of a diamond cell for FTIR characterisation of binding and pigments in contemporary paintings. Poster Session II ended the third day sessions, with other 50 posters being presented by the authors. The day ended with a gala dinner in a restaurant in the centre of Athens. The fourth and last day was dedicated to “Sensing and spectroscopy” and “Ion-beam analysis and complementary techniques” in the morning and “X-ray microanalysis and complementary techniques” in the afternoon. G. Karagiannis presented a study on “Non-destructive identification of art objects using multispectral images and spectra combined with acoustic microscopy”. This technique is based on the combination of acoustic microscopy and diffuse reflectance spectroscopy and imaging from the ultraviolet up to the mid infrared area of the spectrum (UV/VIS/nIR/mIR). The final result is material mapping images for the upper layer and the existing under layers. Two more studies were presented regarding the non-invasive identification of organic materials in wall paintings and the composition, identification and thickness of different lining glues used in paintings using non-linear measurements. The second session focused on the study of Venetian-type glass from Lezha (Albania), glass beads from Thebes (Greece), a bronze statue (Croatian Apoxiomenos) discovered in the North Adriatic sea in 1999, the silver analysis of coins from the hoard of Beçin and the non-destructive determination of the silver content in Roman coins dated 308-311 A.D. During the four-day conference and after many presentations, the lecture on the Croatian Apoxiomenos bronze statue by D. Mudronja, was probably one of the most interesting lectures, focusing not only on the laboratorial studies necessary to material characterisation and art history approach but also on the seek to define an accurate methodology for the statue’s conservation and restoration. It was a clear and practical application of science to art. The statue was found in the sea with the majority of the surface being covered with a layer of corrosion products and organic limestone. These deposits protected the bronze from electro-chemical deterioration although the back of the statue that was buried in the sand revealed a large corroded area. After the desalinisation process, the restoration and conservation started in 2000 and was completed in 2005. During all this process an extensive investigation that included many physical and chemical methods was carried out. The afternoon started with M. L. Carvalho and a communication entitled “µ-EDXRF and XRD on lead-based glazes”. The investigation intends to be an initial output for the results expected for lead-based glazes, since the complete study will be extended to ancient faiences fragments from Coimbra (Portugal) from the 16th to 19th centuries. The analysis of the elemental and compositional profile will allow the attribution of the manufacturing technique, since there are still some doubts regarding the date and place of production, e.g. Coimbra’s production is often attributed to Lisbon. Apart from this study several other applications of µ-EDXRF were presented. The final communications of the last session were on the application of X-ray micro-analysis in outdoor copper monuments, glazed ceramics, Indonesian paintings and copper-based pigments. The final remarks were made by some of the members of the international scientific committee and the local organising committee. For those who could stay another day, Friday was reserved to a one day cruise in the islands near the coast. As a final note, it should be highlighted the perfect organisation of the conference and the social events. Despite the high number of participants, the majority were physicists and chemists and for a conference that aimed to promote the bridge between art and science the presence of historians, archaeologists, conservators and restorers was rather scarce, maybe because many of the presentations were too focused on technological aspects of the equipments or maybe the purpose of some studies is yet far from a concrete and practical application. The reading of the abstracts (already online) and the future articles is strongly recommended.
About the author:
Ana Bidarra has a Degree in Conservation-Restoration and a Master Degree in GeoSciences on white structured pigments for restoration. Currently she is a PhD candidate researching the compositional and technological aspects of gold leaf from Portuguese baroque altarpieces. She works as conservator-restorer in private practice since 1999. ▲TOP
To save this article please
Download this article
Permanent link to this resource: http://www.e-conservationline.com/content/view/769 |
||||||||
