The purpose of this study was to explore the feasibility of re-treating artifacts previously conserved by PEG impregnation with alkoxysilanes. The study tried to evaluate pros and cons of re-conserving artifacts with this type of silanes. A series of experiments were conducted focusing on small, wood samples from the Vasa Museum Collection, to test different re-conservation methods. Three different procedures involving alkoxysilanes were implemented in order to re-conserve the samples. The study revealed the techniques are an efficient re-conservation method in which highly satisfactory results can be achieved. The re-treated samples present minimal volumetric distortion without significant collapse or shrinkage of the wood structures. This minimal distortion is primarily produced by the transition from swollen waterlogged wood to a dry conserved wood, and not as a result of collapse or shrinkage during treatment. Due to the negligible thickness of the polymer coating (a few microns), the samples acquire physical properties extremely close to the original dry wood. Moreover, other physiochemical properties are obtained from the consolidation with alkoxysilanes; the re-conserved wood becomes hydrophobic, chemically inert, resistant to chemical attacks (e.g., acids or bases), and resistant to ultraviolet light. These newly acquired characteristics drastically reduce the preventive conservation measures needed in museum display cabinets or during transport. Despite the excellent results, the procedure is not reversible, thus does not comply with one of the main premises traditionally accepted in conservation. Therefore, a careful study assessing benefits and disadvantages in a case-by-case basis should be assessed by conservators, restorers, and curators before applying this method to waterlogged material culture.

第23回名古屋大学年代測定総合研究センターシンポジウム平成22(2010)年度報告

Les bois gorgés d’eau sont des découvertes rares en archéologie, du fait des conditions inhérentes à leur conservation. Quand ils nous parviennent, ils livrent de nombreuses données sur la place de ce matériau pour les populations anciennes.L’Auvergne est un contexte privilégié pour leur conservation. Des milliers de bois issus de découvertes fortuites ou de fouilles archéologiques sont datés du Néolithique à l’époque moderne, mais le corpus couvre surtout le Second âge du Fer jusqu’au Moyen Âge.La diversité des bois permet d’appréhender les différents usages selon leur destination respective. Le bon état de nombreux éléments renseigne de différentes étapes de façonnage de l’abattage de l’arbre à sa mise en œuvre.Chaque bois est détaillé spécifiquement par domaine et catégorie pour être comparé aux vestiges d’autres régions. L’approche technologique et typologique est traitée le plus exhaustivement possible.Le spectre taxonomique renseigne les pratiques de collecte et leur évolution sur un espace forestier impacté par l’homme.L’apport de la dendrochronologie renseigne les évolutions des approvisionnements, principalement pour la construction, et dégage certains traits des pratiques sylvicoles sur les peuplements forestiers exploités. / Waterlogged woods are rare discoveries in archeology because of the conditions inherent in their conservation. When they reach us, they give a lot of data on the importance of this material for past populations.Auvergne is a privileged context for their conservation. Thousands of woods from fortuitous discoveries or archaeological excavations are dated from the Neolithic to the modern era, however the corpus covers mostly the Second Iron Age until the Middle Ages.The diversity of the woods enables a better understanding of different uses according to their respective destination.The state of conservation of many elements gives information about the different stages of shaping, from the felling of the tree to its implementation.Each wood is detailed specifically by field and category to be compared with the remains of other regions. The technological and typological approach is treated as exhaustively as possible.Taxonomic diversity documents collection practices and their evolution in a forest area impacted by humans.The contribution of dendrochronology informs the evolutions of supplies, mainly for the construction, and releases certain features of the silvicultural practices in the exploited forest stands.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21277号 / 農博第2293号 / 新制||農||1062(附属図書館) / 学位論文||H30||N5141(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 杉山 淳司, 教授 吉村 剛, 教授 渡邊 隆司, 教授 高妻 洋成 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

No / The use of Fourier-transform Raman spectroscopy for characterising lignocellulosics has increased significantly over the last twenty years. Here, an FT-Raman spectroscopic study of changes in the chemistry of waterlogged archaeological wood of Pinus sp. and Quercus sp. from a prehistoric assemblage recovered from northern Greece is presented. FT-Raman spectral features of biodeteriorated wood were associated with the depletion of lignin and/or carbohydrate polymers at various stages of deterioration. Spectra from the archaeological wood are presented alongside spectra of sound wood of the same taxa. A comparison of the relative changes in intensities of spectral bands associated with lignin and carbohydrates resulting from decay clearly indicated extensive deterioration of both the softwood and hardwood samples and the carbohydrates appear to be more deteriorated than the lignin. The biodeterioration of the archaeological timbers followed a pattern of initial preferential loss of carbohydrates causing significant loss of cellulose and hemicellulose, followed by the degradation of lignin.