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1.
《文物保护研究》2013,58(4):308-313
AbstractThe oak timbers of the Swedish warship Vasa are deteriorating. High amounts of oxalic acid have been found along with a low pH and low molecular weight cellulose deep in the wood timbers. The iron-rich surface wood differs from the interior wood in that it displays higher pH and cellulose with higher molecular weight. The objective of this study was to determine why there is a difference in cellulose degradation, pH, and oxalic acid amount between the surface region and the interior of the Vasa timbers. Analysis of cellulose weight average molecular weight by size exclusion chromatography was performed, as well as quantification of oxalic acid and iron by high-performance anion exchange chromatography and atomic emission spectroscopy, respectively. It was found that a decrease in iron content coincides with an increase in oxalic acid concentration and a drop in pH at a certain depth from the wood surface. When iron-rich surface wood samples from the Vasa were mixed with an aqueous solution of oxalic acid, a fast increase of pH over time was observed. Neither interior wood poor in iron nor the fresh oak reference showed the same neutralizing effect during the time of measurement. This indicates that the presence of iron (rust) causes a neutralization of the wood, through the formation of iron(III) oxalato complexes, thus protecting the wood from oxalic acid hydrolysis. This effect was not observed to the same extent for other acids observed in Vasa wood (sulfuric, formic, glycolic, and acetic acids). 相似文献
2.
《文物保护研究》2013,58(4):274-284
AbstractA survey of stored waterlogged archaeological timbers from the Mary Rose revealed that 2% of these timbers were infested by larvae of the wharf-borer beetle, Nacerdes melanura L. Timber species attacked included oak, poplar and pine, with moisture contents ranging between 130 and 670%. In addition, scanning electron microscope studies demonstrated that wood tunnelled by the larvae was microbially decayed. The larvae and their life-cycle were studied and emerging adults were observed penetrating the 500 gauge polyethylene used to wrap timbers. Studies showed that 60 Nylon/100I Surlyn, 70 Nylon/125I Surlyn, T 1–19v, T 1–25x and Camvac were more suitable wrapping materials. 相似文献
3.
《文物保护研究》2013,58(2):118-122
AbstractThis paper deals with the materials used in conservation treatments in the first half of the twentieth century for the preservation and consolidation of wooden art objects from the Saxony region in Germany. The use of such materials must be seen as early attempts to find a conservation treatment for wood. The documentation of conservation treatments provides a reference to the application of oils and oil–resin mixtures. The results from the chemical analysis of samples of historic preservatives from the beginning to the middle of the twentieth century (so-called 'Puckelin') carried out by gas chromatography–mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) analysis confirm the use of tung oil as a drying oil, whereas the use of linseed oil cannot be excluded. Colophony and, probably, amber varnish were used as resinous constituents. There are indications that a conservation material dating from the second half of the twentieth century most likely contained rapeseed oil. 相似文献
4.
Wood artefacts are subject to damage by biologic infestations due to bacteria, insects, and fungal species. One of the worst feared attacks is due to the xylophagous insects whose larvae feed on wood by boring galleries, at the expense of building timbers and worked woods. These beetles are responsible for daily destruction of the world’s wooden cultural heritage, and their elimination has been always a big problem for conservation of wood. The need to avoid the use of chemical methods in conservation for pest control has led to the development of various non-chemical, non-toxic treatments. Among these, heating with microwaves (MW) seems to be one of the most promising, since it has already shown its high efficacy in destroying pests. Insect-infested wood remediation by MW heating in conservation is based on the larger thermal increment induced in larvae than in wood, due to their different dielectric permittivity in the GHz frequency range. However, the side effects that may occur due to MW heating of wood, such as dehydration, have never been discussed so far. Here we study the possible application of microwave heating as a remediation method for wood samples infested by the larvae of the insect Hylotrupes bajulus. We show that it is possible to set up exposure conditions able to achieve 100% of larvae death and that are sufficiently mild not to induce significant dehydration of the exposed wood from which shrinkage effects may derive. Indeed, under these conditions, MW-induced wood dehydration on cubic and parallelepiped sweetgum samples can be kept under control and to percentages as low as 0.4% (w/w). 相似文献
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6.
ABSTRACTConservation of wooden objects exposed outdoors is extremely difficult and complex due to their constant exposure to fluctuating weather conditions and biological degradation. Filling the gaps in such objects requires the use of specific materials that in particular can adapt to changes in wood dimensions in response to humidity variations. Various materials have been used so far for filling voids in wooden artefacts but none of them was entirely suitable. Therefore, the authors have attempted to provide the basic characteristics of the selected commonly used filling materials based on pine wood powder or glass microballoons as fillers and Paraloid® B-72, Klucel® G, or glutin glue as binders, as the first step in research aiming at developing new and more appropriate gap-fillers. Special attention was paid to the dimensional stability of filling materials upon drying and exposure to water vapour and liquid water. The overall results indicate that among the examined fills those consisting of Paraloid® B-72 and glass microballoons revealed best properties as they were relatively dimensionally stable upon drying and exposure to moisture – despite high absorption of water – and were quite easy to finish. Generally, better properties were observed for filling materials containing higher concentrations of adhesives and these materials will be modified in the next step of the research. Since the main drawbacks of the examined gap-fillers were low water resistance, poor dimensional stability upon drying or exposure to water vapour or liquid water, and fragility or friability, future research into their modification will head towards improvement of the above-mentioned properties. 相似文献
7.
Microfibril angle (MFA) – the orientation of cellulose fibres in the S2 layer of the secondary cell wall – is a key determinant of the stiffness and strength of timber. The microfibril angle depends on the way in which the timber was grown and its position within the tree. Microfibril angle can be measured by X-ray diffraction and other methods, but the methods in current use are slow or require advanced instrumentation. The aim of this study was to explore the use of polarised Fourier transform infrared (FTIR) microscopy as a relatively fast and inexpensive method for measuring MFA in historic Scots pine (Pinus sylvestris L.). The FTIR measurements were calibrated against X-ray measurements of MFA in modern Scots pine. We observed a wide range in MFA values and a radial pattern of MFA similar to modern Scots pine in undecayed Scots pine heartwood from sixteenth and seventeenth century beams in Scottish secular buildings. The density of the heartwood was also similar to modern plantation-grown Scots pine despite the much slower growth rate recorded in the ring widths of the historic timber. The sapwood, which had been attacked by both insect pests and fungi, showed an erratic reduction in density and a large increase in MFA compared to the modern material. The increased sapwood MFA was attributed to selective destruction of the S2 layer of the wood cell walls by fungal decay. Using MFA measurements in conjunction with density offers the possibility to estimate the mechanical properties of sound historic pine timber, to detect fungal decay more sensitively than by density alone, and to distinguish between pest and fungal attack in a way that relates directly to the remaining mechanical performance of the timber. 相似文献
8.
《文物保护研究》2013,58(3):133-142
AbstractThis study considers the impregnation of wood by two acrylic monomers, methylmethacrylate and butylmethacrylate, and examines their subsequent polymerization in wood samples initiated chemically and by gammaradiation. The results of the polymerization were assessed on the basis of the resultant polymer content of the wood, and it was found that polymerization initiated by gammaradiation was more effective. The influence of the consolidation by monomer polymerization upon the properties of the wood (hygroscopicity, water absorption, swelling andcompression strength alorig the fibres) was found to depend on the polymer content of the wood, on the polymercomposition and on the type and structure of the wood. Copolymerization of methylmethacrylate and butylmethacrylate has no benefit on the properties of the wood. 相似文献
9.
Natural polymers as alternative consolidants for the preservation of waterlogged archaeological wood
In recent years, there has been increased interest in examining alternative polymers for the conservation of archaeological artefacts, particularly waterlogged timbers, providing better, renewable, greener alternatives to poly(ethylene glycol) (PEG). The degradation of PEG consolidants in the timbers of the sixteenth century warship Mary Rose has been examined and the rheological and thermal properties of PEG have been compared with its monomethyl and dimethyl ethers and several polysaccharide consolidants (chitosan, guar, and 2-hydroxyethyl cellulose) in order to evaluate their potential as alternative consolidants for the conservation of waterlogged wooden artefacts. Additionally, the effect of the polymers on the archaeological wood was characterised by thermogravimetric analysis and solid-state nuclear magnetic resonance spectroscopy. The results suggest that the future of conservation technologies lies with polysaccharide consolidant materials, which show enhanced compatibility with wooden artefacts with no detectable side effects while also being cheap, with extremely low toxicity, renewable, and sustainably resourced. 相似文献
10.
《文物保护研究》2013,58(4):327-369
AbstractThe restoration of the Hedin altar in Rothenburg o.d.T., dated 1466, is described. The polychromed sculptures were cleaned and loose paint was fixed. Methods and materials used in the restoration of the paintings, the areas polychromed in various techniques and the brocade reliefs are mentioned. The altar was protected from direct sunlight. The construction of the shrine and the technique of carving are extensively discussed. Sculptures made from one piece of lime wood were hollowed out and closed with a plank. Traces of rough finishing are visible. Shrine and predella were polychromed after a preliminary assembly of the sculptures. The various techniques used in the undisfigured polychromy are described as they are observed with the unaided eye. It can be shown that the working methods were rational. The fabrication of relief brocades and the various patterns used are discussed in detail. The treatment of the various paintings on the wings, the predella and the reverse of the shrine is reported. The question is raised to what extent the painter Herlin can also have been responsible for the polychromy. 相似文献
11.
《文物保护研究》2013,58(3):34-40
AbstractIn preparation for a major exhibition at the National Gallery of Scotland in 2005, a thorough technical examination of VISION OF THE SERMON by Paul Gauguin was undertaken for the first time since the painting's acquisition in 1925. An inter-disciplinary approach to the research was adopted in an attempt to assess how innovative were the materials and techniques employed by Gauguin in this iconic work. The importance of the unique customs and religious piety of Brittany in 1888 to the iconography of Vision is discussed, as well as the various ways in which the original appearance of the painting has altered over time. Changes have occurred through both the natural ageing of materials and as a result of human intervention, particularly an aqueous lining and reframing. Analysis suggests that the paint medium consists of several different drying oils, confounding years of speculation that it may contain wax. The discovery that the original surface coating contains beeswax and tallow has grave implications for the feasibility of future conservation treatments. Following Gauguin's accusation of plagiarism by Emile Bernard, a tentative comparison is made between Vision and the latter's Breton Women in the Meadow. This reveals that while compositional similarities exist, Vision is far more complex, both in conception and execution. 相似文献
12.
《文物保护研究》2013,58(3):143-154
AbstractSince 1980, much research in the field of treatment and conservation of archaeological wood has been carried out at the Conservation Department, Faculty of Archaeology, Cairo University. Materials and methods used in conservation have been changing gradually over the years worldwide. It was necessary to study critically previous masters and doctoral dissertations on Egyptian archaeological and historic wood, all written in Arabic. This review of them includes a brief history of the Conservation Department at Cairo University and five main focal points of past research: types of wood used throughout Egyptian history, assessment of wood decay, wood properties and composition, treatment and conservation of decorated wood, and the evaluation of chemicals and polymers used in the treatment of archaeological wood and composite objects containing wood. 相似文献
13.
《文物保护研究》2013,58(2):114-117
AbstractProblems were encountered when preparing objects from the Pacific islands for exhibition. These specimens were of wood with shell inlay. Cleaning with non-ionic detergent and distilled water had no effect on the dull shell surface; solvents were little better;finally, glass fibre brushes were tried with very good results. Precautions should be taken when using glass fibre brushes; these include the wearing of protective gloves, dust masks, and the provision of a vacuum cleaner to remove fragments of broken glass fibre and dust from the shell surface. 相似文献
14.
《文物保护研究》2013,58(3):124-136
AbstractIn this study, the following methods of treatment have been studied: bulking with PEG 4000 in water, methanol and t-butanol solvents; bulking with PEG 540 blend in water; bulking with rosin in acetone; freeze-drying from different concentrations of PEG 400 with various methods of pre-freezing; in situ polymerization with glycol methacrylate and with a melamine formaldehyde resin; water displacement with methylene chloride followed by rosin impregnation. They have all been carried out with five groups of waterlogged wood representative of different species and various states of degradation. Freezedrying, PEG 4000 impregnation in t-butanol and PEG 540 blend impregnation in water gave the most satisfactory results, based on appearance and shrinkage. 相似文献
15.
《文物保护研究》2013,58(2):65-79
AbstractEnvironmental standards for cultural heritage collections have been much debated in recent years. The interest in the issue has been driven by the growing movement towards green museums, that is, managing indoor museum environments in a responsible and efficient manner, especially in terms of reducing energy consumption and carbon emissions but at the same time maintaining high standards of collection care. Painted wood is among the category of heritage objects most vulnerable to relative humidity and temperature fluctuations. Therefore, scientific understanding of how changes in environmental conditions ultimately affect painted wood is crucial to the development of rational guidelines for the control of climate in museums and historic buildings. This review provides a systematic progression through two fundamental approaches to establish the allowable ranges of climatic variations – an analysis of the mechanical response of painted wood as a complex, multilayer system to climate variations, and an analysis of the historic climate to which the objects have acclimatized. The climate specifications and standards based on both these approaches are reviewed. 相似文献
16.
《文物保护研究》2013,58(4):155-164
AbstractEthnological specimens of many different materials can be dry cleaned mechanically by means of a grit-spraying unit. Plain and painted leather, corroded metal, beadwork, metallic embroidery, wood, ivory, bone, basketry, some paper, pottery, shell, some textiles and stone are items which can be cleaned with less disturbance to the surface than is often occasioned by the use of other methods. A specimen constructed of several materials may be cleaned by this one method rather than by several, thereby also avoiding the use of water, solvents or other chemicals. The powdered abrasives used are calcium magnesium carbonate, sodium bicarbonate, glass beads, and several grades of aluminium oxide. Silicone carbide powder is used occasionally for very hard corrosion products on metal. 相似文献
17.
《文物保护研究》2013,58(4):201-205
AbstractWe have reacted Georgia marble in sulfur dioxide (SO2) enriched atmospheres and calculated the reaction rate constant. This constant was derived from surface reduction data, obtained by leaching thereaction product from samples exposed for different periods of time. Application of this constant to marble weathered in known ambient levels of sulfur dioxide (SO2) and relative humidity, allows the prediction of the thickness of the resulting gypsum crust formed over a given period of time. We have found that the crust grows outwards due to calciumions which migrate from the interior and then react with sulfur dioxide at the sample surface. Thus, anytreatment of the sulfated marble should include the considerations that the crust only masks the marble surface and is not an integral part of the original sculpture, and that cavities exist in the underlying layer of marble from which the calcium ions were selectively depleted. 相似文献
18.
《文物保护研究》2013,58(2):66-75
AbstractIn contrast to fully tanned leather, that used by the Canadian Indians and Eskimos has poor durability. When stored under less than ideal conditions it becomes stiff and brittle, and restoration of such artifacts presents problems. The methods used for sound leather, such as fat liquoring or staking, cannot be used once the skin has deteriorated. A method used successfully is described. It consists of soaking the artifact in water to gain pliability and then replacing the water with organic liquid in order to avoid shrinkage on drying. Flexibility is preserved by permeation with an emulsion containing a stabilized olein soap, neat’s-foot oil and ethyl alcohol. Gut-skin may be treated by a modification of this emulsion. Fur poses a lesser problem because the skin is thin and can easily be permeated with an aqueous emulsion of sulfited sperm oil. Several examples of restoration are given. 相似文献
19.
《文物保护研究》2013,58(3):169-173
AbstractA complete summary of equations for leakage of enclosures is given, including vapour diffusion through still air in openings, and infiltration of air/vapour/particulate mixture. Stack pressure due to temperature and relative humidity difference drives most infiltration. Experiments confirmed the diffusion and infiltration equations for small and medium-size enclosures. Leakage for a carefully made display case with ordinary materials has been reduced to the microbarometric limit of about 0·03 of an air change per day. Simplified tables and charts of leakage are given for 0·1, 1·0 and 10m enclosures, as a function of crack width, hole width, and wall permeability. 相似文献
20.
《文物保护研究》2012,57(1):28-36
ABSTRACTA pre-restoration diagnosis revealed a high amount of pyrite in the wood of the Lyon Saint-Georges 4 shipwreck (end of the second century). The occurrence of this phase is supposed to result from the microbiologically influenced corrosion of the iron fasteners. So, all the nails and metallic elements were removed from the remains before treatment and the wreck was consolidated by polyethylene glycol impregnation coupled to a specific desalination process. Treated and non-treated samples extracted from the wreck were studied in order to identify the iron/sulfur-containing compounds present in the wood before and after treatment and figure out its effect. Sample analyses relied on an original approach combining magnetic characterization methods and more common elemental and structural analysis methods. The results showed that the treatment was effective in removing soluble salts. However, a large amount of unstable iron sulfides remained inside the wood. 相似文献