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Neutron resonance-capture analysis applied to some prehistoric metal objects

Hans POSTMA1 / Peter SCHILLEBEECKX2 / Luc AMKREUTZ3 (1Delft-University of Technology, Delft, the Netherlands / 2EC-JRC-IRMM, Geel, Belgium / 3National Museum of Antiquities (RMO), Leiden, the Netherlands) Outline: non-destructive analytical method for precious cultural heritage objects Neutron resonance capture analysis (NRCA) is based on peaks occurring in the absorption spectrum of neutrons as a function of their energy. These so-called “resonance” peaks are specific for each element/isotope and therefore suitable to recognize and to quantify elements in objects. Neutrons can penetrate thick layers of materials, and therefore this method provides bulk compositions. The energies of captured neutrons can be readily determined with the time-of-flight method using a pulsed source of neutrons. NRCA is the latest member of neutron-based methods for analyzing objects and materials. It is developed in the EC-JRC-IRMM research centre in Geel (B) using the pulsed source of neutrons and time-of-flight systems of its GELINA facility. NRCA is a fully non-destructive method; it is not necessary to take samples. The activation is low directly after the measurement and negligible after a short waiting period. NRCA has been applied in the study of ancient bronze objects. Recently two objects, on loan from the National Museum of Antiquities in Leiden (NL) have been analyzed, the Buggenum sword, and the Jutphaas dagger. Both objects are in excellent condition and have likely been served as ceremonial objects in the Mid to Late Bronze Age period in Europe. They have been found at locations in the Netherlands far from their probable production areas. For the study of their compositions it was not allowed to use analytical methods, which need samples to be taken from objects. For this reason they were studied by NRCA at the GELINA facility. This research is part of the European Ancient Charm project. Keywords: Neutrons, analytical method, bronze-age...

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Neutron Resonance Imaging Experiments at the ISIS pulsed neutron source

Enrico PERELLI CIPPO / ANCIENT CHARM Collaboration (Milano-Bicocca University, Italy) Outline: A new equipment for 3D neutron resonance analysis of small objects is now available at the ISIS pulsed neutron source. One of the key developments in the Ancient Charm project was the construction of a new equipment for 3D neutron resonance analysis of small objects to be used at the ISIS pulsed neutron source. The system is now available for users and was first applied to a number of test objects and archaeological samples. Neutron resonance analysis exploits the unique properties of many isotopes to resonantly capture neutrons at characteristic energies. A combined detector array is used to measure either the gamma-ray emission following neutron absorption or the attenuation of the neutron beam. In the latter case the neutron detector is made from a matrix of 10×10 pixels and the beam attenuation for each pixel is measured as a function of neutron energy thus providing a map of the elemental composition of the object. The neutron energy is determined by measurement of the neutron time of flight; i.e. neutrons are emitted simultaneously by the pulsed source but arrive at different times at the object depending on their energy. The method is particularly suited for metal artifacts, because many metals (typically Cu, Sn, Zn, Ag, Au, Sb, Pb, As) have strong neutron absorption resonances. Examples of results obtained from test objects of known composition will be shown illustrating the method and its limitations. Both 2D (radiography) and 3D (tomography) analyses will be presented. Keywords: Neutron analysis, neutron resonances, elemental...

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Virtual 3D Reconstruction of the East Pediment of the Temple of Zeus at Olympia

András PATAY-HORVÁTH (Univ. Eötvös Loránd, Budapest, Hungary) The arrangement of the five central figures of the east pediment of the temple of Zeus at Olympia has been the subject of scholarly debates since the discovery of the fragments more than a century ago. More than four substantially different reconstructions were put forward in drawings, but they were hardly tested in three-dimensional form because of the monumental scale of the statues. Most recently the author has started a project to produce digital models of the statues by scanning the originals. The scanning (with Breuckmann Tritos structured light scanner) of the white marble statues was made difficult by many technical problems: the pieces are not only of huge dimensions, but they are also not movable and are placed very close to the museum wall. The poster focuses on these technical difficulties encountered during the scanning campaign in the Museum of Olympia and gives an overview of the work in progress: on the basis of the scanned fragments, the original statues are tentatively reconstructed and placed in their original architectural setting. For the virtual reconstruction a new 3D modelling software (Leonar3do) was used. As the preliminary results presented in the poster can clearly demonstrate, the virtual 3D reconstruction will enable archaeologists to compare the various arrangements both from technical and from aesthetical aspects. On the other hand every detail of the world-famous statues is now more thoroughly documented than ever before. The data will be stored both at the university and by the enterprize (Tondo), which carried out the scanning. A copy of the 3D models is provided for the museum. Keywords: 3D scanning, classical Greek marble...

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Integrated geophysical survey to characterize the subsurface properties below and around the area of Saint Andreas church (Loutraki, Greece)

Nikos G. PAPADOPOULOS / Apostolos SARRIS (Laboratory of Geophysical-Satellite Remote Sensing & Archaeo-environment, IMS-FORTH Rethymnon, Greece) Urban archaeological geophysics (U.A.G.) is an emerging field that focuses on the effective geophysical exploration of urbanised areas in order to provide specific solutions concerning the preservation of cultural monuments located in urban territories. U.A.G. can be applied in different urban environments to investigate the integrity of structures, to study the geological stability of the settings where monuments are located and map the archaeological relics. Taking into account the extensive construction works that accompany the inevitable development of new and the expansion of existing modern urban infrastructures it becomes obvious that all these may threaten important archaeological monuments, which are still buried in the subsurface of the urban territories. This work presents an integrated application of the Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods to effectively map the complex changes of the physical environment below and around the area of Saint Andreas church in Loutraki (central Greece). Saint Andrea’s church is a relatively small three-aisled basilica with cupola. The cultural value of the monument is significant, as according to the legend, the stairs at the north side of the church lead to the entrance of a small cave, which was used as a hideaway by Saint Andreas when he was pursued by Romans. The church has been severely damaged by the Alkyonid earthquake in 1981 and the Ministry of Culture is studying a restoration plan of it. The main purpose of this geophysical investigation was to provide the necessary feedback concerning the ground subsurface properties for the future restoration of the monument. High resolution ERT data (electrode spacing of 0.5-1 m) were collected along profiles and in a grid employing two different arrays (Dipole-Dipole & Wenner-Schlumberger) in order to increase the vertical and horizontal resolution. Bentonite contact electrodes were used for the maximum protection of the monument. A dense grid of parallel GPR sections (DX=0.5m, DY=0.1m) was completed in various parts inside and outside the area of the church. Two and three dimensional inversion algorithms were used to reconstruct the true subsurface resistivity. Specific filters (first peak estimation, DC shift,...

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The Mind Maps and archaeological processes

Anna Maria MARRAS (University of Siena, Trento, Italy) Outline:The mind maps in archaeology to organize the data set and compare the archaeological field processes. A Mind Map is a diagram (tree diagram, fishbone diagram, etc) to represent words, ideas, tasks ort other items linked to a central key word or idea. The Mind Maps are used to generate, visualize, and classify ideas. The ideas (elements of Map) are arranged according to the importance of the concepts, and are classified into branches with the goal of representing semantic or other connections between portions of information.. There are a lot of Mind Map software, many are open source and cross platform like FreeMind, WikkaWiki, Vue, Xmind. This kind of software are user friendly, online collaborative, ability to upload/export images, it’s possible to use all kind of software format. The aim of this poster is how to use the Mind Map theory and the Mind Maps software to: Field Project planning Organize the field archive data Compare the different field projects with the different projects Maps Communicate with the image Map the Field Archaeological survey steps Often, unfortunately, the archaeological research, especially in Italy, became a private research, the single project, methodology and data are available only for department or researcher they self, Often is show only the final data of the project, but the different processes of field archaeology such as planning, acquisition and elaboration of data are not standard. Since there are so many variables, it is difficult to find two projects that use the same methodology. In order to evaluate different field archaeological projects we have to compare their final data? Is it more important to consider what kind of data was collected or how it was collected? Planning a field archaeological survey Mind Map is like to build a diagram of romance , the scenes and chapters are organized to follow a chronological development of the story. The scenes of romance are different than other romance, but the organize of chapters are the same. The Mind maps is able to represent the scheme of work and compare different work step-by-step. It is important to have a temporal or...

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Documentation – Demolition – Reconstruction. A “späthistoristischer” wooden pavilion of Vienna

Ingrid MADER1 / Andreas BERTHOLD2 (1Museen der Stadt Wien – Stadtarchäologie, Austria / 2Vienna, Austria) Outline: 3D reconstruction of lost architecture Until 1994 there was a huge pavilion situated on the “Grüner Berg” near Schönbrunn Castle. We don’t know exactly when it was erected. People said that it was once located in the exhibition area of the world exhibition held in Vienna in 1873. But no proof has been found yet. From 1892 onwards it is shown on the city maps of Vienna situated on the “Grüner Berg”. First it was used as a popular restaurant destination. After World Word I two-thirds of the edifice were demolished. The rest of the building remained as changing rooms for the nearby tennis club. It was used in this function until 1994. In the very same year the whole area has been sold. At that moment people remembered the historic pavilion. Almost no wooden buildings from the second half of the 19th century had survived in Vienna! First it was necessary to determine the extent of damage. It was turned out that various pests destroyed most of the fretwork and ornamental elements turned on a lathe. Only a low percentage of the wooden construction could be rescued for rebuilding the pavilion. Later on a small excavation clarified the original dimension of the building. After that a catalogue was created listing up every detail of the structural design. It was the basis for the following demontage of the pavilion. Afterwards the remains were translocated to a protected site where they are still archived. In the end the detailed catalogue, postcards and photographs of the 19th century enabled the digital reconstruction. This poster will show the various phases: rediscovery of a building of Späthistorismus, extent of damage, listing up of details (documentation), demontage and archiving of the leftovers and 3D reconstruction as basis for possible rebuilding. Keywords: Vienna, 19th century, wooden architecture, translocation,...

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