Wooden Artefacts Research Articles

Shellac/nanoparticles dispersions as protective materials for wood

Wood is a natural material that finds numerous and widespread applications, but is subject to different decay processes. Surface coating is the most common method used to protect wood against deterioration and to improve and stabilize its distinctive appearance. Shellac is a natural resin that has been widely used as a protective material for wooden artefacts (e.g. furniture, musical instruments), due to its excellent properties. Nevertheless, diffusion of shellac-based varnishes has significantly declined during the last decades, because of some limitations such as the softness of the coating, photo-degradation, and sensitivity to alcoholic solvents and to pH variations. In the present study, different inorganic nanoparticles were dispersed into dewaxed natural shellac and the resulting materials were investigated even after application on wood specimens in order to assess variations of the coating properties. Analyses performed by a variety of experimental techniques have shown that dispersed nanoparticles do not significantly affect some distinctive and desirable features of the shellac varnish such as chromatic aspect, film-forming ability, water repellence, and adhesion. On the other hand, the obtained results suggested that some weak points of the coating, such as low hardness and poor resistance to UV-induced ageing, can be improved by adding ZrO2 and ZnO nanoparticles, respectively.

Melamine polymerization in organic solutions and waterlogged archaeological wood studied by FTIR spectroscopy

Abstract Melamine resins are extensively used as chemical consolidate agents in the preservation of different waterlogged archaeological wood artifacts. For successful consolidation, it is essential to control the rate of melamine polymerization. Currently, the understanding of melamine polymerization in waterlogged archaeological wood is qualitative, and is based on the experiences and skills of the conservators-restorers. In this study, we have tested different environmental conditions and additives that influence the rate of Kauramin 800 polymerization in waterlogged archaeological wood by Fourier transform infrared (FTIR) spectroscopy. The results show a fast polymerization reaction of Kauramin 800 at pH values below 7. The polymerization rate of Kauramin 800 increased in the presence of glycine and archaeological wood. On the other hand, slower polymerization was observed with the addition of Kraft lignin. The results indicate that FTIR spectroscopy is a powerful tool in monitoring the process of Kauramin 800 polymerization during the preservation of archaeological waterlogged wood.

The use of chitosan in protecting wooden artifacts from damage by mold fungi

Background: Many buildings in Egypt e.g. museums, mosques and churches, do not possess controlled environments for minimizing the risks of damage of wooden artifacts due to the growth of fungi. Fungal damage usually appears as change in wood color, appearance of stains, and sometimes deformation of wooden surfaces. In this study we focused on the effect that some fungi exert on the properties of wooden artifacts and evaluated the effectiveness of different concentrations of chitosan on their protection against damage by mold fungi. Results: Samples were collected from different monuments and environments, and fungi growing on them were isolated and identified. The isolated Penicillium chrysogenum, Aspergillus flavus and Aspergillus niger strains were used for the infestation of new pitch pine samples. The results revealed that the lightness of samples infected with any of the tested fungi decreased with increasing incubation times. XRD analysis showed that the crystallinity of incubated samples treated individually with the different concentrations of chitosan was lower than the crystallinity of infected samples. The crystallinity index measured by the first and the second method decreased after the first and second months but increased after the third and fourth months. This may due to the reducing of amorphous part by enzymes or acids produced by fungi in wooden samples. Conclusions: The growth of fungi on the treated wood samples decreased with increasing the concentration of chitosan. Hence, it was demonstrated that chitosan prevented fungal growth, and its use could be recommended for the protection of archeological wooden artifacts. Normal 0 21 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria,serif; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US; mso-fareast-language:JA;}

Recurrent Mesolithic–Neolithic occupation at Sise (western Latvia) and shoreline displacement in the Baltic Sea Basin

A major assemblage of Mesolithic and Neolithic wooden artefacts has been recovered from the bed of the River Užava at Sise, in the coastal belt of western Latvia. New archaeological investigation has also produced wooden remains and other evidence of occupation on the riverbank. On the basis of multi-proxy environmental data and radiocarbon dating, this article offers a first attempt to place the human activity in a palaeolandscape context. The earliest evidence of human presence is provided by wooden artefacts dated to c. 10,500–9700 cal. BP, during the Ancylus Lake transgression. These remains are thought to reflect fishing activities in the shallows of the Ventspils Bay, which existed during the transgression. The regression that followed brought a return to river-valley conditions at the site, and the next recorded period of human activity, evidenced by 14C-dated antler tool finds, is associated with the beginning of the Littorina Sea transgression, culminating c. 7500 cal. BP. With the formation of a new Ventspils Bay/Lagoon, the Sise site, at or near the river mouth, would have regained its status as an advantageous fishing location. Archaeological finds indicate continued human activity c. 6000–4000 cal. BP, even though the sea level was now lower and this was no longer a river-mouth location. Such a pattern of recurrent human occupation during the early to middle Holocene, associated with repeated shifts of the shoreline, appears to be characteristic of the central region of the Baltic Sea Basin.

The earliest Near Eastern wooden spinning implements

Abstract

A non-invasive approach to identifying wood species in historical musical instruments

Abstract Identifying the wood species is an important step in the process of studying and preserving historic wooden artefacts. Identification procedures normally applied in cultural heritage contexts are unsuitable for musical instruments, as sampling might alter the aesthetics and functionality of these historically and culturally valuable instruments. Furthermore, macroscopic identification, through the naked eye or a lens, is often inadequate. It is necessary, therefore, to adopt a non-invasive approach, which renders visible the greatest number of anatomical features possible. The purpose of this study was to evaluate the feasibility and reliability of identifying the wood of historical artefacts using microscopes with high magnification and reflected light together with polarized light filters. A total of 117 musical instruments from the “Luigi Cherubini” Conservatory's collection, preserved at the “Galleria dell’Accademia” Museum in Florence (Italy) were examined as case study. The collected data here presented demonstrate that many anatomical features of the wood can be observed in situ, thanks to the portability of the instruments, and that identifying can be done indeed (in almost 6000 observations, only 8% gave no results). In cases where identifying was not possible, the problems involved: the presence of very thick coats of clear varnish, which makes it virtually impossible to see the structure of the underlying wood; the presence of a patina that conceals the wooden surface; and poor surface quality of the wood, which can falsify the appearance and size of wood cells.

Possible Radiation-Induced Damage to the Molecular Structure of Wooden Artifacts Due to Micro-Computed Tomography, Handheld X-Ray Fluorescence, and X-Ray Photoelectron Spectroscopic Techniques

This study was undertaken to ascertain whether radiation produced by X-ray photoelectron spectroscopy (XPS), micro-computed tomography (μCT) and/or portable handheld X-ray fluorescence (XRF) equipment might damage wood artifacts during analysis. Changes at the molecular level were monitored by Fourier transform infrared (FTIR) analysis. No significant changes in FTIR spectra were observed as a result of μCT or handheld XRF analysis. No substantial changes in the collected FTIR spectra were observed when XPS analytical times on the order of minutes were used. However, XPS analysis collected over tens of hours did produce significant changes in the FTIR spectra.

A ‘North Atlantic island signature’ of timber exploitation: Evidence from wooden artefact assemblages from Viking Age and Medieval Iceland

Throughout history, wood has been of key importance to many human communities both as a source of fuel and as material for construction. This applies not only in areas with plentiful woodlands or forests, but also in more marginal island environments where limited native wood resources are available. In such environments, the use of ‘exotic’ timber such as driftwood or imported wood plays a key role in resource provision. The exploration of patterns of use of both native and ‘exotic’ woods in wood-poor environments has great potential to contribute to discussions of resource management and control and human response to landscape change. Using Iceland as a case study, this paper compares wood anatomical analyses of artefact assemblages from across Europe to determine the likely origin of wood (native, imported, drifted) from archaeological sites in the North Atlantic islands, and demonstrates the emergence of an ‘island signature’ in wood utilisation patterns in this region. The paper also highlights the potential pitfalls of the categorisation of wood remains through taxonomic determination, and examines how these obstacles might be overcome in future research.

A 600-year-old Boomerang fragment from Riwi Cave(South Central Kimberley, Western Australia)

A small fragment of a carefully shaped wooden artefact was recovered from Riwi Cave (south central Kimberley, Western Australia) during 2013 excavations. Directly dated to 670 ± 20 BP, analysis of the artefact’s wood taxon, morphology, manufacturing traces, use wear, and residues, in addition to comparison with ethnographic examples of wooden technology from the Kimberley region, allowed for the identification of the tool from which it originated: a boomerang. In particular, this artefact most closely resembles the trailing tip of a hooked boomerang, providing rare insights into the presence of these iconic fighting and ceremonial items in the Kimberley some 600 years ago.

X-ray computed microtomography and the identification of wood taxa selected for archaeological artefact manufacture: Rare examples from Australian contexts

Wooden artefacts are seldom recovered from Australian archaeological contexts, limiting our understanding of an important component of past Indigenous socio-economic systems. When recovered, the taxa used for construction are very rarely identified, and when undertaken, taxonomic identifications are generally unsubstantiated. For wood taxa to be identified, the microscopic elements of the xylem structure need to be observed and described from three planes. Conventional microscopy methods require physical sectioning, which is a complex, time-consuming process, whereas X-ray computed microtomography is non-invasive and expeditious. Here we describe the use of X-ray microtomography to identify the material of two wooden implements, the negative component of a fire drill and an artefact fragment, both recovered from Riwi cave in the southern Kimberley of Western Australia. By drawing on archaeobotanical analyses conducted at Riwi cave (wood charcoal and other macrobotanical remains), we are able to illustrate that the past inhabitants of Riwi selected certain woods for specific purposes within the last 1000years of occupation at the site.

Woodwork from Ancient Rus Chernihiv (Materials of Excavations on the Territory of Chernihiv Dytynets in 2006)

The article deals with the analysis of woodwork found in one of the structures on the territory of Chernihiv dytynets in 2006. The stratigraphic data allow the authors to interpret the structure as a recessed part (basement) of a large building. It can be dated within the 13th century. Wooden objects found in the filling of the building included a chiseled dish, fragments of other chiseled and carved vessels, two hollowed containers, the bottom of the cooperage vessel, fragmented products made of bark, a spoon, and the remains of a loom. Some details of construction of the building were also found. Besides the usual visual examination, wooden artifacts were studied to determine the feedstock for every kind of product. Diagnosis of timber was conducted based on the specifics of its microstructure. The investigated set of wooden utensils from Chernihiv is traditional for Ancient Rus material culture. Among the findings are the products of home crafts (remains of loom and hollowed containers) and professional artisans (chiseled, carved and cooperage products) are both presented. They were made of local wood species, such as: pine (Pinus sylvestris), oak (Quercus sp.), maple (Acer sp.), lime (Tilia sp.), poplar/aspen (Populus sp.), and willow (Salicaceae). When using different species of wood, their properties and their conformity to products with different functions were taken into account

Decay of softwood in archaeological wooden artifacts

Hardwoods and softwoods were used side by side throughout Egyptian history, and importing softwoods that had an attractive color and texture was common. Over the decades, artifacts based on hardwoods and softwoods underwent deterioration phenomena, sometimes reaching either a level of brittleness or turning into a wood powder that may easily crumble. These levels of decay/degradation are often difficult to handle in terms of conservation treatments. To study or identify the reasons for decay has always been a point of interest for conservation purposes, but to assess decay and choose an appropriate treatment according to the state of preservation for the sake of keeping an artifact intact has become a subject of major importance. It is difficult at times to understand the deterioration process, because hardwoods and softwoods are different in structure, properties, and chemical composition. For this preliminary study, decayed samples from three commonly used softwood types, cypress (Cupressus sp.), cedar (Cedrus sp.), and pine (Pinus sp.), were identified and chosen. Scanning electron microscopy (SEM) of the samples indicated the degree of decay. Decayed and non-aged samples of the same wood type were analyzed using Fourier transform infrared spectroscopy (FTIR), and all the major carbohydrate and lignin bands were recorded. The strong hydrogen bonded (O–H) stretching absorption associated with water linked by hydrogen bonds to the –OH groups of cellulose and hemicelluloses in all decayed samples increased with decay. The brown powdery, fragile samples that had been evidently affected by microbial decay had a higher amount of lignin. The lignin/carbohydrate ratio was calculated and results compared. The increase of either lignin percentage or extractives in some of the samples had caused a darkening of color in both cypress and cedar samples, but the pine sample did not have the same texture and appearance. In cases where the lignin percentage decreased the samples had changed to a slightly lighter color. FTIR results explained the decay phenomena observed in SEM micrographs and helped assess wood decay and also confirmed results that had been previously obtained while applying traditional chemical analysis on wood.

An investigation of the use of cellulose-based materials to gap-fill wooden objects

The conservation of wooden objects is complicated by their response to changes in their environment. In particular, filling voids in wooden objects can be difficult when their dimensions might be expected to alter over time. A short survey of conservators showed that a wide variety of materials have been, and are being used for this purpose. Following conservation work undertaken on a wooden coffin, the author wished to investigate the properties of cellulosic materials and their suitability in the conservation of wooden objects. This paper shares the results of experiments that were conducted to determine the way in which hydroxypropyl cellulose (HPC) and paper pulp fills respond in various conditions, as compared to other fill materials used by conservators. The compatibility of the HPC and paper pulp fills with wood is satisfactory enough to be able to recommend their use in the conservation of wooden artefacts, but ideally further experiments would be carried out, and on a wider variety of fill materials.

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.

Wooden Artifacts from Asx̂aana x̂ Cave, Islands of the Four Mountains, Alaska

Asxaana x Cave, a burial cave in the Islands of the Four Mountains, was excavated in 1990. One radiocarbon date for a burial in the front area of the cave is 700±60 BP (Beta-39962). Due to the conditions in the cave, there was excellent preservation of organic materials, though these had been considerably disturbed. Wooden artifacts include boat parts and paddles, bent-wood and carved trays, bowls and baskets, netting tools, and ceremonial objects. The iqya-x (baidarkas) are definitely Unangan but with peculiarities unique to the Islands of the Four Mountains; the carved Halibut bowl and many of the ceremonial objects bear strong resemblance to artifacts from Karluk One on Kodiak. The distribution of the wooden artifacts within the cave deposits suggests that the three areas excavated within the cave were used for burial by different family groups.

Nondestructive wood discrimination: FTIR – Fourier Transform Infrared Spectroscopy in the characterization of different wood species used for artistic objects

Wooden artifacts represent a significant component of past cultures. Successful conservation of wooden artifacts depends on the knowledge of wood structure and types. It is critical that conservators know the category of wood that they are treating in order to successfully conserve it. Recently, vibrational spectroscopy has been successfully applied to determine the chemical structure of wood and to characterize wood types. FTIR (Fourier Transform Infrared) is a useful nondestructive or micro-destructive analytical technique providing information about chemical bonding and molecular structure. Its application in the discrimination between softwoods (conifers) and hardwoods (broad-leafs) has already been reported. The aim of the present study was to investigate the potential of FTIR as a tool for the discrimination between different wood types belonging to the same genus. Three different hardwood species, namely poplar (Populus spp), lime (Tilia spp) and birch (Betula spp), were investigated by means of FTIR spectroscopy. The woods were first inspected using a light microscope to certify the wood essence types through micrographic and morphoanatomical features. The FTIR spectra in the 4000 cm[Formula: see text] to 450 cm[Formula: see text] region were recorded using a Perkin-Elmer Spectrum 100 spectrometer. To enhance the qualitative interpretation of the IR spectra, second derivatives of all spectra were calculated using the Spectrum software to separate superimposed bands and to extract fine spectral details. To obtain a comprehensive characterization, the essences under investigation were also analyzed by means of Raman Spectroscopy. Clear differences were found in the spectra of the three samples confirming FTIR to be a powerful tool for wood type discrimination.

Деревянные находки из могильника Цзяохэ (Яр-Хото) в Турфанской впадине в Синьцзяне: аналогии и датировки

The ancient city of Jiaohe (Yar-Hoto) is situated 10 km to the west from the city of Turfan, the center of the Xinjiang - Uygur province in the autonomous region of the People’s Republic of China. In the beginning of the 90-s of the 20th century the excavation was made of a burial ground to the north of the city. About 40 wooden pieces were found. Among them are arrows, quivers, knives, wallets, pencil cases, clasps, buckles, figurines, tableware and other categories. Chinese archaeologists consider the culture of the Jiaohe burial grave to be of the local Turpan type. Analysis of ceramics allows agreeing with this opinion, but the dating attributed by Chinese researchers of the monument exclusively to the Han time is a matter of doubt. Many wooden artifacts, primarily related to the armament objects, bone (horn) details of harness and especially saddle accessories from Jiaohe have direct analogies in the Russian territory, especially in the monuments of the Pazyryk culture. This makes it possible to attribute many of the burials to the 4th century BC. Another part of the wooden findings has analogies in the monuments of the Hun-Sarmatian time, so that the burial ground in the north of the ancient city of Jiaohe turns out to be different in the time and culture.

Woodworm Disinfestation of Wooden Artifacts by Vacuum Techniques

Wooden artifacts are subject to being heavily damaged by the attack of worms which develop in the wood through the eggs deposited by adult pests before their final transformation into flying insects. Among the most dangerous species are xylophagous (wood-boring) insects, whose larvae are responsible for one of the most efficient wood-destroying mechanisms in wooden cultural heritage. Their elimination has always been a huge problem for the conservation of wood. In this work, we present the experimentation of a simple vacuum technique to disinfest wood from the larval Hylotrupes bajolus . We will also introduce the possibility of treating large-sized wooden artifacts by means of a special vacuum chamber.

Mercaptan계와 Diamine계를 이용한 저수축·절삭력이 우수한 Epoxy Putty의 개발 및 물성에 관한 연구

This study aimed to develop epoxy putty as a multi-purpose connection and restoration material that can be used for material-specific restoration work such as metal, wood, ceramics, earthenware and stone artifacts by replacing synthetic resins currently being used for preservation treatment of cultural assets. Existing synthetic resins have the issue of cutting force resulting from high strength, deflection resulting from long hardening time, contaminating the surface of artifacts through staining on tools or gloves and need for re-treatment resulting from material discoloration. Accordingly, paste type restoration material most widely being used in the field of cultural assets preservation treatment was selected and examined the property to select it as an object of comparison. Based on such process, epoxy putty was developed according to the kind of agent, hardener and filler. For the purpose of solving the issues of existing material and allowing the epoxy putty developed to have similar property, property experiments were conducted by selecting agents and hardeners with different characteristics and conditions. The study findings showed that both kinds are paste type that improved work convenience and deflection issue as a result of their work time of within 5~10 minutes that are about 3~10 times shorter than that of existing material. In regards to wear rate for increasing cutting force, it improved by about 3 times, thereby allowing easy molding. For the purpose of improving the issue of surface contamination that occurs during work process, talc and micro-ballon were added as filler to reduce the issue of stickiness and staining on hand. Furthermore, a multi-purpose restoration material with low shrinkage, low discoloration and high cutting force was developed with excellent coloring, lightweight and cutting force features.

Excavations at Schöningen and paradigm shifts in human evolution

The exceptional preservation at Schöningen together with a mixture of perseverance, hard work, and sheer luck led to the recovery of unique finds in an exceptional context. The 1995 discovery of numerous wooden artifacts, most notably at least 10 carefully made spears together with the skeletons of at least 20 to 25 butchered horses, brought the debate about hunting versus scavenging among late archaic hominins and analogous arguments about the purportedly primitive behavior of Homo heidelbergensis and Neanderthals to an end. Work under H. Thieme's lead from 1992 to 2008 and results from the current team since 2008 demonstrate that late H. heidelbergensis or early Neanderthals used sophisticated artifacts made from floral and faunal materials, in addition to lithic artifacts more typically recovered at Lower Paleolithic sites. The finds from the famous Horse Butchery Site and two dozen other archaeological horizons from the edges of the open-cast mine at Schöningen provide many new insights into the technology and behavioral patterns of hominins about 300 ka BP during MIS 9 on the Northern European Plain. An analysis of the finds from Schöningen and their contexts shows that the inhabitants of the site were skilled hunters at the top of the food chain and exhibited a high level of planning depth. These hominins had command of effective means of communication about the here and now, and the past and the future, that allowed them to repeatedly execute well-coordinated and successful group activities that likely culminated in a division of labor and social and economic patterns radically different from those of all non-human primates. The unique preservation and high quality excavations have led to a major paradigm shift or “Schöningen Effect” that changed our views of human evolution during the late Lower Paleolithic. In this respect, we can view the behaviors documented at Schöningen as a plausible baseline for the behavioral sophistication of archaic hominins of the late Middle Pleistocene and subsequent periods.