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• An approach for the conservation of waterlogged wood veneered in ivory is described. • Dual evaluation performed on samples prepared in laboratory and on one original piece. • Laboratory samples were artificially degraded putting them in contact with brown rot. • Drying conditions were highly important for the success of the entire treatment process. • Approach applicable where suitable conservation methodology needs to be set-up. This work describes how a conservation method making use of aqueous solutions of lactitol and trehalose (9:1) was chosen to treat several elements of wood furniture veneered in ivory carved in bas-relief and preserved in waterlogged condition. These elements were discovered during the excavations carried out in Villa dei Papiri, the most famous of the luxury villas of Herculaneum. The approach described was based on a dual evaluation. It was carried out: (a) on probe wood specimens produced in the laboratory capable of simulating both the impregnability by consolidants and the deformation of decayed waterlogged wood; (b) on one archaeological element belonging to the original furniture, representative of the material to be treated. The probe specimens produced in the laboratory were artificially degraded by placing them in contact with the brown rot fungus Coniophora puteana , in order to obtain a material of variable decay, similar to that of the original archaeological furniture elements. Three experimental factors were considered when treating probe specimens: (a) the type of substrate, (b) the initial and final consolidant concentration and (c) the drying regime. Three types of substrates were considered: specimens covered with a polycarbonate sheet to simulate the ivory veneer and wrapped in gauze; specimens only wrapped in gauze; and naked specimens, that is, with no obstacles for consolidant penetration. Considering consolidant concentration, the probe specimens were impregnated by full immersion, increasing the concentration of lactitol/trehalose in four combinations: from 15 to 50%, 15 to 60%, 30 to 50%, and 30 to 60%. Last, three drying regimes were considered: 50 °C in an oven, 30 °C/35% RH and 20 °C/65% RH. Results showed that probe specimens whose impregnation started with 30% consolidant in the solution and finished in 60%, and dried under 30 °C and 35% RH exhibited limited volume variations after drying equivalent to those obtained by drying at 50 °C. Drying conditions were important factors in the success of the entire treatment process. As was consolidant uptake, in relation to the extent of decay of the archaeological material. Moreover, the presence of the physical barriers simulating the existence of the ivory veneers and gauzes did not disturb the efficacy of the treatment, as long as sufficient time was given to allow the water-consolidant exchange process to be completed. In the end, the treatment conditions selected on the basis of these probing tests, that is, start with initial concentration of 30%, final concentration of 60%, and drying at 30 °C/35% RH, showed to be successful for treating the representative element of the archaeological furniture. [ABSTRACT FROM AUTHOR]

This paper constitutes an attempt at using FT-IR spectroscopy for the dating of historical and artistic artefacts made of poplar wood. It was decided to do the tests only on poplar (Populus spp.) to reduce a part of the typical wood variability, while poplar was chosen because it is widely present in Italian heritage, such as panel paintings, statues and furniture, and these objects cannot be dated by dendrochronology; also because 14C methodology has major limitations. Poplar artefacts from the fourteenth to the nineteenth century were selected, dated by means of documents, by attributions, or stylistically. In addition, recent poplar samples were selected as a reference. Wood flour were taken from the selected samples, discarding the surface layers that could have been influenced by oxidation phenomena. Before taking measurements with FT-IR, the wood meal was dried and the chemical extractives were removed. The results show the presence of a time-related trend, but the time factor is certainly not the only one that causes the variations within the spectra. After a discussion, it is therefore considered that the results do not allow at the current state to definitely produce a reliable reference for dating poplar wood artefacts through this methodology. [ABSTRACT FROM AUTHOR]

This work is aimed at showing the results of a work of identification of the wood species used for the construction of the mechanical components of a historic pipe organ. The instrument was built in 1895 in Pistoia (Tuscany, Italy) for a church of a small municipality in the north-west of Tuscany, the summer residence of a family of ancient European nobility; it is therefore a large monumental organ, still original. During the restoration operations, and consequently on the disassembly, it was possible to carry out a complete sampling of the wooden components that are normally not directly accessible. The sampling was performed under the supervision of the restorer, through the cut and drawing of very small samples and with minimally invasive criteria. The identification was performed by observing thin sections, manually cut, by means of an optical microscope. The results of the identification carried out on the 25 samples are reported. The identified timbers are not very numerous and the most represented one is poplar (Populus sp.). [ABSTRACT FROM AUTHOR]

Highlights • The wooden foundations of Ponte di Rialto were analysed in order to determine the tree species used for its construction and to examine the timber's present-day physical and mechanical properties. • The foundations underwent micro-morphological, physical, chemical and mechanical analyses. • The footings of the bridge's foundations, mostly consisting of alder wood, were shown to be in a good condition generally. • Two periods of construction were determined. The later dating corresponds to the construction of the stone bridge that still exists today, while the other period probably refers to the foundations of the initial Ponte della Moneta. Abstract The wooden foundations of Ponte di Rialto (Rialto Bridge), the oldest and most famous of the four bridges spanning the Grand Canal in Venice, Italy, were analysed in order to determine the tree species used to construct the foundation, to examine the timber's present-day physical and mechanical properties and to identify construction periods. The material recovered during geotechnical surveys underwent micro-morphological, physical, chemical and mechanical analyses. The radiocarbon method was used for dating purposes. The footings of the bridge's foundations, mostly consisting of alder wood, were shown to be in good overall condition generally. A comparison of normal and polarised light images of wooden cross-sections showed abundant crystalline cellulose within the cell walls, indicating that the state of conservation of the waterlogged samples is very close to that of sound alder wood. Only one alder sample showed signs of severe bacterial attack, mostly concentrated in the fibre cell walls. Radiocarbon dating identified two distinct construction periods. One sample dates to 1570 AD ± 85, whilst another dates to the year 960 AD ± 59. The later dating corresponds to the construction of the stone bridge that still exists today. The earlier period, around the year 1000, likely refers to the foundations of the first bridge, built after several pontoon bridges, and corresponding to the initial Ponte della Moneta. [ABSTRACT FROM AUTHOR]

Abstract The study of an ancient musical instrument should take into account various approaches, which include historical sources, study of materials and dendrochronological analysis. Very often, an ancient musical instrument has been subject to repairs, substitutions and restorations that have modified its original setting. This study takes into account the "Mango Longo guitar", a masterpiece of 17th century Neapolitan art. It has been analysed from a historical, organological and xylo-chronological perspective to investigate and describe the cultural context of its creation, the wood species used for its construction and various restoration works to which it has been subjected. The Mango Longo guitar belongs to the typology of the Baroque guitars of the seventeenth century, attributed to the lute-maker of German origin Magnus Lang, from which the name derives. The most recent tree-ring identified on the instrument belly is dated dendrochronologically to 1737, terminus post quem. This means that the actual soundboard may be considered a replacement, due to a restoration in the first half of 18th century. The analysis of dendroprovenance of the actual soundboard shows strong analogies with Italian production of the period and identifies the probable sources for wood as being in the Alps. Our results confirm the intensive and well-organized trade of valuable timber used for musical instruments at that time. [ABSTRACT FROM AUTHOR]

The analyses to determine the state of preservation of waterlogged archaeological wood follow three different directions: anatomical analyses, physical evaluation and chemical characterisation. Physical parameters (densities and moisture content) are the ones most frequently found in the specialised literature. The measurement of moisture content is normally referred as maximum water content (MWC) in the case of archaeological wood in waterlogged conditions, because wood has been long-time preserved by the lack of oxygen in waterlogged conditions. Aim of the paper is the comparison of three pre-measurement treatments in the calculations of MWC: without any vacuum-pressure treatment, after 300 mbar vacuum pressure and after 50 mbar impregnation in water. The evaluations were performed on 240 samples of waterlogged archaeological wood coming from different excavation sites and including different wood species (both hardwoods and softwoods) in different state of preservation, from low to very high decay. The three tested methodologies to measure the maximum water content on waterlogged archaeological wood provided substantially equivalent results. Nevertheless, a deeper analysis of the results showed that the MWC values of 300 mbar impregnations were rather low compared to MWC standard measurements. Thus, this impregnation was a little bit harsher, causing most probably an anatomical damage on a portion of most degraded samples. The opposite result was obtained after the 50 mbar impregnation procedure. In this case, the MWC values were slightly higher. This means that this treatment seemed to be more effective in subtracting even the smallest air bubbles trapped inside waterlogged archaeological wood samples. Some suggestions on how to measure MWC on waterlogged archaeological wood are detailed at the end of conclusions. [ABSTRACT FROM AUTHOR]

This paper deals with the identification of the wood species used for the production of wooden tools in an ancient plant for manual paper production. After a quick historic contextualisation of the importance of the paper industry developed in the Pescia district (Tuscany, Italy), this paper describes the process of manual paper production and the different tools, mostly wooden, used by the workers. The historic plant "Le Carte" still preserves these tools, which were sampled to scientifically identify the timber species. Samples were drawn from any wooden component of the equipment involved in the whole manual paper making process. Sampling was performed on any portion of the artefact where the species of origin was not clearly and reliably identifiable by eye, or aided by a manual magnifying lens. In total, 1223 identifications were performed and 25 timber types observed. Most of timber identifications regard the large mould collection (434 artefacts, 1154 identifications, 17 timbers), while the equipment included fewer artefacts, identifications and timbers. Obtained results are then technologically discussed, considering the features of each species and the specific needs of each final use. [ABSTRACT FROM AUTHOR]

Examining the timber structure supporting the roof of Giotto's bell tower in Florence, this paper discusses the combination of non-destructive (NDT), wave-based methods for the characterization of timber structural elements. In particular, it analyses the on-site applicability of selected wave-based techniques for the identification of decay, damage, defects, and moist areas in structural timber. The applied NDT techniques are IR termography, microwave reflectometry, time-of-flight tomography, and mapping by means of elastic waves. Experimental results are compared with data obtained by means of consolidated NDT techniques, such as the electric resistance method for moisture content estimation and the drill-resistance test for decay characterization. These can be considered non-destructive, although they are invasive. The wave-based NDT methods are found to be a value-added complement to routine methodologies for a holistic diagnosis of timber members. Normal practice based on visual inspection, decay detection through point measurements of drill resistance, and moisture content estimation through local readings of electric resistance, can be substantially improved through full-field, multi-sensor, multi-resolution imaging. Nevertheless, while the diverse NDT methods illustrated here can be useful for screening large areas in a completely non-invasive way, local measurements (i.e., the drill resistance and the electric resistance measurements) are still necessary. [ABSTRACT FROM AUTHOR]

Foundation piles are a noteworthy example of waterlogged wood still constituting load bearing structures. Micromorphological analysis, investigation of physical properties (water content, residual basic density), compressive tests in wet conditions and chemical analyses (lignin, holocellulose) were carried out on samples taken in Venice. Obtained results demonstrated that both mass and strength were lost due to decay, but the residual strength loss was greater than the residual mass. It is also shown that this occurrence was due to the holocellulose decrease. Present results point out that basic density and holocellulose amount could be used as possible predictors of woodpiles residual strength. [ABSTRACT FROM AUTHOR]

The present paper deals with wood from Venice historic centre foundation elements. Samples were taken from both piles and planking (horizontal elements positioned above the pile heads), in 5 out of 6 districts of Venice. Considering the watery milieu, the diagnostic methodology for waterlogged archaeological wood was adopted, performing anatomical, chemical and physical characterisations. Our results show that the wood used for Venetian foundation elements belong to a small group of 5–6 species (alder, larch, oak, pine, elm and spruce, although the latter was probably of more recent introduction). Most of the analysed samples evidenced decay, which in some cases was high (residual basic densities of only 32%, and values of the ratio holocellulose to lignin as low as 0.3). It was evidenced how the state of preservation of wood was related to several factors, including: thickness of the element, depth of burial, horizontal/vertical position, and wood species. It was also shown how ash content does not reflect the state of preservation of waterlogged material, as it is sometimes reported in the literature. The diffuse decay was apparently not related to the general stability of the buildings under study. [ABSTRACT FROM AUTHOR]

Paper deals with the scientific identification of timbers utilised for the production of the sculptures preserved within the collection of the National Museum of the “Palazzo di Venezia” in Rome, Italy. After a brief description of the Museum and its sculpture collections, and, more specifically, the wooden sculpture collection which is the largest in Italy, the sampling of the artwork is discussed and described, together with the methodology used for the identification of wood species following the Italian standard UNI 11118:2004. The 12 identified timbers are listed together with their distribution within the cultural provenance of the sculptures. The discussion deals with the timber species utilised by the artists from the four cultural European provenances most represented within the collection: Italy, Alps, central-southern Germany and Lowlands around the Rhine delta. In the different Italian regions, several wood species were utilised and among them mostly poplar and limewood, while the alpine sculptors mostly used Swiss stone pine and the German artists, limewood. Finally in the Rhine delta, most of the sculptures were made out of deciduous oak. [ABSTRACT FROM AUTHOR]

Abstract: Artefacts made of wood coming from archaeological excavations provide insights into human cultural behaviour of the past. They show how man utilised natural resources and how the development of woodworking techniques and artistic endeavour were developed. Within archaeological contexts, waterlogged anaerobic conditions generally preserve the appearance of artefacts, although wood is subject to severe decay processes. The said conditions can transform the original material into a new one, thus demonstrating specific differences from those of the “fresh” wood of the same species. In order to assess these new properties correctly, an integrated diagnostic approach is needed, one which includes a multidisciplinary (micromorphological, physical and chemical) evaluation of the state of preservation. This paper reports several diagnostic results regarding wood artefacts coming from a series of archaeological excavations carried out in Italy. Different types of artefacts – ships, furniture, foundation piles, etc. – that date to different eras (Roman times, the Middle Ages, the Renaissance) have been included in this study. In addition, several species of wood at different levels of decay were analysed. Our study provides evidence of how a multidisciplinary approach, based on anatomical (micromorphological), physical and chemical analyses, avoids goes beyond the limits of each single type of analysis, thus contributing to a complete and reliable evaluation of the state of preservation of these archaeological artefacts. [Copyright &y& Elsevier]

This paper describes the study of a 31-year-old Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) stand located in Southern Italy, which was thinned 19 years after planting. The aim of the study is to evaluate the influence of three thinning treatments (unthinned, selective, and geometrical) performed twelve years later on wood density (WD), moisture content, shrinkage, ring width (RW), latewood proportion (LW%), modulus of elasticity, compression (CS), and bending strength (BS). The WD was higher in the unthinned stand. LW% and BS were lowest in the selective thinning and in the geometrical thinning, respectively. No significant differences were found in other variables. In addition, the thinning processes mostly affected the medium tree class more than the dominant and suppressed ones. Regression analysis established a correlation between mechanical characteristics and WD, RW and LW%. Mechanical strength is strongly correlated with WD than other variables. The stepwise model showed that WD and RW are most closely related to the behavior of CS, whereas only WD explained variation in BS. Stand density reduction may improve the development of stands without greatly affecting wood quality. [ABSTRACT FROM AUTHOR]

This paper outlines the physical characterisation of findings of woods from the excavation of the Etruscan–Roman ancient harbour of Pisa. The physical characterisation deals with measurements of wood density, shrinkages and maximum water content. The measurements are performed with a methodology specifically set up for the archaeological wet material, not applicable as standardised international methodologies. Physical characterisation is necessary to measure the wood decay, through a useful decay index, and to define the consolidation strategies for the recovery of the wooden findings, for their conservation and enjoyment. Results confirm the high decay of wood samples, probably due to the almost complete loss of the cellulose fraction of the cell walls, shown by the very low basic density (average value less than 0.2 g/cm3) and the high water content (more than 500%). The parameter of the residual basic density seems less useful for the identification of the consolidation strategy. [Copyright &y& Elsevier]

• EDTA-2Na, EDTA-4Na and citric acid used to extract iron in oak wood (Quercus spp.). • ESEM, FT-IR and DMA used to characterise samples after the extraction treatments. • Alkaline agents have an impact on both chemical and viscoelastic characteristics. • Modification and loss of hemicelluloses increases the viscous behaviour of treated wood. • Results are generalizable to the various wood treatments where high pH is adopted. The process of extracting iron from waterlogged wood was simulated on non-degraded oak wood (Quercus spp.) with the aim of evaluating the effect of three levels of pH (acid / close to neutral / alkaline, obtained using three products normally used to extract iron) on both the composition and the viscoelastic mechanical properties of wood samples. The three products were disodium-ethylenediaminetetraacetic acid (EDTA-2Na), tetrasodium-EDTA (EDTA-4Na), and citric acid, and they were used at different concentrations and different extraction durations. Environmental Scanning Electron microscopy (ESEM) was used to observe the microstructure before and after extraction, ATR-FTIR was used to analyse the chemical composition and Dynamical Mechanical Analysis (DMA) was used to assess the storage and loss moduli and the loss factor of samples after treatment. Mass loss measurements after treatments were also carried out. The results indicated that chelating agents inducing alkaline conditions could have an impact on both chemical and viscoelastic characteristics of wood, whereas neutral or acidic conditions did not appreciably affect the considered characteristics. The observed effects are related to modifications of hemicelluloses composition (with partial mass loss of wood), which provoked a clear increase of the viscous behaviour of the treated material. These modifications were only limitedly and indirectly detectable using the other considered techniques. Being induced by the obtained alkaline conditions, present results are generalizable to the various treatments where high pH is adopted, and hence not only limited to the iron removal process. Thus, based on the knowledge attained in this research, conservators can be aware of the potential impact of these treatments on the wood structure, and this should help in gaining greater control over this process. [ABSTRACT FROM AUTHOR]

Multidisciplinary diagnostic methods were applied to evaluate the preservation state of waterlogged archaeological wood (WAW) from ancient Chinese shipwreck Nanhai No.1. The characterisation combines micromorphological, physical, and Fourier transform infrared (FTIR) analyses to overcome limitations of using a single analysis. The micromorphological analysis used the whole-slide imaging (WSI) method to identify wood species and determine the decay class. The collected samples were graded as Class 2 (moderate decay) or Class 3 (severe decay). Bacterial and fungal attacks on wood tissues were evident, and the decay pattern of erosion bacteria (EB) was verified. The maximum water content obtained from the oven-drying and freeze-drying methods confirmed that the micromorphological features can be used to grade the decay class. In tandem with hierarchical cluster analysis, FTIR measurements classified four clusters, including moderate and severe decay groups. FTIR also revealed that the chemical alteration of WAW was mainly due to the depletion of polysaccharides. Increased knowledge of WAW degradation and feasible diagnostic methods are beneficial for further conservation strategies. [ABSTRACT FROM AUTHOR]

Thermogravimetry (TG) is used to measure the change of sample mass versus temperature or time under a program controlling temperature. It is a common thermal analysis tool with a precise built-in balance, and accurate data can be obtained through a small amount of sample at the level of milligrams. The feasibility of the TG method for determining maximum water content (MWC) measurement of waterlogged archaeological wood was studied. Simulated waterlogged wood and waterlogged archaeological wood were used to determine the test condition for the TG method. MWC data obtained through the oven-dry and TG methods with different mass gradients from 0–10 mg to >50 mg were analyzed statistically. Deviation, error bar, and coefficient of variation were evaluated. According to the results, when sample mass is no less than 30 mg, and holding time at 105°C is no less than 40 min, data deviation between these two methods is less than 5%. Effect of sampling depth and presence of inorganic deposits were also investigated. Specimens were taken from an archaeological wood with a sampling depth from 2 to 6 mm, then MWC was measured through the TG method. The results indicate MWC of the samples taken from a depth of 2–4 mm is higher than that taken from a depth of 0–2 mm and is lower than that taken from a depth of 4–6 mm, which is related to inorganic deposits. The presence of deposits was verified through SEM-EDX. MWC of three archaeological wood samples from China and five archaeological wood samples from Italy were measured to verify the effectiveness of the TG method when wood species and degradation degree are different. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the diagnostic analysis performed on the different timber structures of the Nativity Church. The surveys were performed in agreement with the Italian standards UNI 11161:2007 and 11119:2004. The uniqueness of some structures made it necessary also the analysis and description of structural typologies. The results allow describing the different timbers utilised, the state of preservation, mechanical and biotic decays and finally to determine the present strength of each wooden element, obtained through the combination of the evaluation of the defectiveness and the measurement of the residual sections. The results of the diagnostic survey will influence the design of the structural restoration and of the maintenance operations. [Copyright &y& Elsevier]

Wood identification is a basic information that should interest any wooden artefact. This typically involves invasive sampling, but sometimes sampling is unattainable either because of the object typology or because it is difficult to obtain authorizations. In the present study, reflected light microscopy potential as a non-invasive identification tool for wooden cultural artefacts is assessed on a number of marquetry furniture and small wood carvings. In more than one half of the 13 examined cases accurate wood identification was possible, while the remaining cases yielded information of diagnostic value, making it possible to exclude several potential candidate species. In a number of cases the use of optical filters improved the visibility of character states. Shape and orientation of surfaces influenced the visibility of microscopic characters. The study confirms that reflected light microscopy is a valuable tool for non-invasive wood identification. In many cases it is able to support accurate identification, in others it can anyway provide important information, useful to help decision about supposed species, or to limit the invasiveness of possible further analysis by addressing them on specific features. [ABSTRACT FROM AUTHOR]

Wood degradation in waterlogged conditions, although slow, is relevant in some specific contexts, such as in the case of cultural heritage preservation (e.g., ancient shipwrecks found under the water table). This decay process induces the selective depletion of the biopolymers constituting wood cell walls and mainly of their structural polysaccharides (both cellulose and hemicelluloses). Assessment of residual composition of cell walls is normally carried out using conventional chemical analyses, which, however, require elevated amounts of material. The present work reports on a new approach to quantitatively determine the residual chemical composition of wood (in terms of amount of lignin and holocellulose) and therefore its extent of degradation. This was accomplished by acquiring attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectra on material still in waterlogged conditions, which was simply placed in optical contact with the ATR crystal. Data for the calibration set were obtained by means of wet analyses, and the calibration model was based on multivariate statistical analysis through partial least square regression. Acquired spectra showed signals higher and better resolved than for dry wood. Calibration was selected after comparing two different normalization procedures and after processing signals of two different spectral ranges. Furthermore, the exclusion of some outliers led to a substantial improvement in the error parameters (R2and root mean square error of cross validation) associated with the calibration model, thus allowing for the selection of the best model. The stability of this best model was also established by means of the leave-more-out method. Finally, a procedure of external validation confirmed that the proposed model also could be applied to similar (for instance, belonging to Pinaceae) wood remains from other excavations. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the work is to set up a methodological approach to verify the effectiveness of the treatments of decayed waterlogged archaeological wood and to point out the proper thermo-hygrometric conditions for its preservation after treatment. The treatments were performed on wood samples of maritime pine (Pinus pinaster Aiton), oak (Quercus sp. caducifolia), elm (Ulmus cf. minor) and strawberry tree (Arbutus unedo L.), obtained from stems pertaining to the original vegetation found in the excavation site of the Ancient Ships in Pisa (Italy), and dated from seventh century BC to second century AD The utilised products were: Polyethylene Glycols (PEG) of various molecular weights, a Polypropylene Glycol (PPG 425), Trehalose (α-D-glucopyranosyl-α-D-glucopyranoside), and their mixtures, and also a Hydroxypropylcellulose (Klucel). The main objective to be pursued by the treatments was considered the stabilisation of the original size and shape of samples. The various steps of this approach were: the execution of a preliminary diagnostic survey on untreated samples; the characterisation of treatment solutions ‘as such’ to establish the property to be monitored during the treatment; the evaluation of the main physical characteristics of wood after the treatment were determined. Among the latter, the coefficient of dimensional stability during the exposure to a series of selected thermo-hygrometric conditions and the retention of consolidants after the treatment. These two measurements allowed the definition of the ‘efficacy of a treatment’, φ T , a new parameter firstly utilised in this work. It measures the stabilisation capability of the percent unit of retained product, and its value permits to put in evidence the consolidants that stabilise wood with the lowest amount of product. Conversely, it was not possible to measure the Anti-Shrink Efficiency (ASE), one of the most utilised parameters for the evaluation of treatments, because of the serious distortions and fractures observed in all the heavily degraded untreated samples. [Copyright &y& Elsevier]

The viscoelastic properties of wood samples treated with various consolidants [polyethylene glycols (PEGs), lactitol and trehalose, Kauramin, polydimethylsiloxane (PDMS) and trimethoxymethylsilane (MTMS), rosin and polyethylene-L-tartaramide] were evaluated by means of dynamic mechanical analysis (DMA) in order to clarify their effects with regard to the conservation of wood objects. Two softwoods, medium-decayed silver fir (Abies alba) and highly decayed maritime pine (Pinus pinaster), and two differently decayed oak hardwoods (Quercus spp.) were used. In addition, the selected parameters [retention, volume variations and equilibrium moisture content (EMC)] were evaluated to assess the consolidation efficacy. The results showed that in treated wood, both the storage modulus and tanδ depend upon the level of degradation. The impact of the consolidating product was greater in more degraded wood (a higher product amount inside the artefact) compared to well-preserved material, where also wood played a role (also when the products were applied at high concentrations). The values of the different viscoelastic parameters also depend upon the ability of the products to interact with the wood matrix; this characteristic is fundamental to the nature of each consolidant. Lactitol-treated samples showed the highest stiffness increases, whereas those treated with selected PEG combinations and rosin displayed noticeable tanδ increases (high dissipative behaviour). [ABSTRACT FROM AUTHOR]

The relationship between the mechanical properties of Cunninghamia lanceolata (Chinese fir) wood and the development of fungal decay was investigated with the aim of implementing a statistical model useful as a non-destructive and a fast method for determining the state of conservation of in-service timber structures. Artificial decay due to brown rot fungi was induced on wood specimens and physical and mechanical test were performed periodically, as well as anatomical observation of wood, FT-IR spectroscopic and XRD diffraction analysis. As a result, Chinese fir was confirmed to have a good durability against fungi, showing a mass loss percentage of 7.21% on average after 14 weeks of exposure. On the contrary, the mechanical properties reduced dramatically during the decay test: a 19% decrease was observed for compression strength and 21% for tensile strength. The mechanism of decay was explored and the corresponding damage constitutive model was proposed. [ABSTRACT FROM AUTHOR]

Huaguangjiao І is a Chinese ancient wooden shipwreck of South Song Dyansty (1127–1279 AD). Wood samples from Huaguangjiao І were analyzed in order to evaluate the preservation state of the waterlogged wood. Samples were studied from the anatomical, physical and chemical point of view. Thin slides of cross and longitudinal sections from samples were observed by optical microscope, micromorphological decay was classified into class 3 or class 4 according to the anatomical characters. Water content and basic density were measured. Maximum water content (MWC) of the wood samples is between 300% and 600%, residual basic density is about 50%. The proportion of the α-cellulose decreased to 25% of the normal value, and the content of the ash increased greatly. These results indicate the degradation of the wood is very high. In addition, there is a plenty of inorganic deposit in the wood structure. The inorganic compounds deposited in wood samples were analyzed by XRD and ICP qualitatively and quantitatively. The morphology and composition of the inorganic deposit was characterized through SEM-EDS, the majority were iron sulfide, including pyrite and marcasite (FeS 2 ), and fluorite (CaF 2 ). [ABSTRACT FROM AUTHOR]

Excavations for the construction of thermal pools at Poggetti Vecchi (Grosseto, Tuscany, central Italy) exposed a series of wooden tools in an open-air stratified site referable to late Middle Pleistocene. The wooden artifacts were uncovered, together with stone tools and fossil bones, largely belonging to the straighttusked elephant Paleoloxodon antiquus. The site is radiometrically dated to around 171,000 y B.P., and hence correlated with the early marine isotope stage 6 [Benvenuti M, et al. (2017) Quat Res 88:327-344]. The sticks, all fragmentary, are made from boxwood (Buxus sempervirens) and were over 1 m long, rounded at one end and pointed at the other. They have been partially charred, possibly to lessen the labor of scraping boxwood, using a technique so far not documented at the time. The wooden artifacts have the size and features of multipurpose tools known as "digging sticks," which are quite commonly used by foragers. This discovery from Poggetti Vecchi provides evidence of the processing and use of wood by early Neanderthals, showing their ability to use fire in tool making from very tough wood. [ABSTRACT FROM AUTHOR]

The paper presents the aim and objectives of a research project concerned with the weathering processes of oak (Quercus robur.) and douglas fir (Pseudotsuga menziesii). The project deals with the identification of any synergistic effects between biotic factors such as aerobic bacteria, Basidiomycota, Ascomycota and abiotic factors such as light, temperature and moisture on the weathering of wood surfaces in durability class 3. [ABSTRACT FROM AUTHOR]

Work on thermal pools at Poggetti Vecchi in Grosseto, Italy, exposed an up to 3-meter-thick succession of seven sedimentary units. Unit 2 in the lower portion of the succession contained vertebrate bones, mostly of the straight-tusked elephant, Palaeoloxodon antiquus, commingled with stone, bone, and wooden tools. Thermal carbonates overlying Unit 2 are radiometrically dated to the latter part of the middle Pleistocene. This time span indicates that early Neanderthals produced the human artifacts from Poggetti Vecchi. The elephant bones belong to seven individuals of different ages. Sedimentary facies analysis and paleoecological evidence suggest a narrow lacustrine-palustrine embayment affected by water-level fluctuations and, at times, by hydrothermal water. Cyclic lake-level variations were predominantly forced by the rapid climatic fluctuations that occurred at Marine Isotope Stage (MIS) 6–7 transition and throughout the MIS 6. Possibly an abrupt, intense, and protracted cold episode during the onset of MIS 6 led to the sudden death of the elephants, which formed an unexpected food resource for the humans of the area. The Poggetti Vecchi site adds new information on the behavioral plasticity and food procurement strategies that early Neanderthals were able to develop in Italy during the middle to the late Pleistocene transition. [ABSTRACT FROM PUBLISHER]

Archaeological excavations in the docking site of Pisa (Central Italy) unearthed several shipwrecks which dated back to the Roman time, from the Republican to the Imperial periods. The recent identification of the woods used for building ships D, E, H, I and P, in addition to data of the previous analysis of ships A, B, C, F, L, revealed the utilization of 18 different taxa . Wood from oaks, both deciduous and evergreen, is mostly represented. 6 different softwood timbers, mostly from maritime and umbrella pine, were also largely used. Some of the hulls were entirely realized with hardwoods, others with softwoods or using a combination of softwoods for planking (mostly pines) and different hardwoods for the frame. The selection of timber indicates a skilful knowledge of the technological properties of the different woods and their suitable utilization in the Roman vessels. The use of woods largely available in the territory surrounding the Pisa docking site, as demonstrated by pollen analysis, does not necessary indicate the local production and/or provenance of the ships, given the spread of the identified wood taxa throughout the North Mediterranean area. [ABSTRACT FROM AUTHOR]

Present work describes the application of NIR spectroscopy coupled with Partial least square (PLS) regression to estimate the residual chemical composition (in terms of holocellulose and lignin) of wood decayed by attack of biotic agents (such as bacteria) when preserved for a long-time in waterlogged conditions. The evaluations allowed assessing how various parameters may influence the predictive ability of calibration models. These parameters include: pre-processing manipulations (first and second derivatives curves, both normalized and not, were compared with baseline corrected spectra), the ranges used for model calibration, the preliminary conditioning of the samples (meals conditioned at both 22 °C/50% r.h. and 60 °C), and the way to take account of the presence of inorganic fillers permeating wood. To such aim, 59 samples from different excavations were considered, with samples belonging to several hardwoods and softwoods ( Alnus sp.p., Cupressus sempervirens , Larix decidua , Picea abies , Pinus sp.p., Quercus sp.p., Ulmus sp.p.), and to different states of preservation and burial environments. Values used for calibration were obtained by conventional wet analyses. Results showed that NIR spectroscopy coupled with PLS multivariate analysis could be used to reliably assess the residual chemical composition of waterlogged decayed wood provided that the calibration range is carefully selected and that original data are suitably pre-processed. However, the best models were different for the two considered components (lignin and holocellulose) and depending on which data set (softwoods or hardwoods) the samples belonged. Finally, it was also shown that the models predictive ability is affected by high ash content (too contaminated samples had to be excluded in order to attain good results). [ABSTRACT FROM AUTHOR]

Objects of this study are the wooden artifacts discovered in the archaeological excavation of Mephitis goddess sanctuary in the Ansanto Valley (Rocca San Felice – AV, Southern Italy). At the moment of discovery, in the mid of last century, woods were waterlogged and mineralized, and they were restored to allow their preservation. Purpose of this work was the wood identification, in order to gain information on some technological aspects, and the analysis of wood preservation state. Wood species were identified by means of magnifiers or optical and scanning electron microscopes, while the state of preservation was studied through microscopy and chemical analyses (FTIR-ATR, ash content and pH measurement). Four different taxa have been identified with certainty among all the findings: Quercus sp. , Fagus sylvatica L., Rosaceae, Populus/Salix . It was not possible to identify the wood of all the findings, because some sampled fragments were too small or because of the deformation of wood tissues. The state of preservation showed a great variability over the analyzed findings. A general damage degree was observed, sometimes also macroscopically visible. The polarized light microscope and FTIR-ATR spectroscopy demonstrated the absence of cellulose in the analyzed samples. The wood cell wall was not detectable by means of SEM because it is completely covered by restoration material. Because of the lack of visibility, it was impossible to identify the type of biological damage occurred to the wood. [ABSTRACT FROM AUTHOR]

This paper reports on the assessment of lignin and holocellulose by means of ATR-FTIR analysis and multivariate PLS regression. The analysis was conducted on 59 samples coming from different excavations where wood had been preserved in waterlogged conditions. A range of results from different wood species ( Alnus sp.p., Cupressus sempervirens , Larix decidua , Picea abies , Pinus sp.p., Quercus sp.p., Ulmus sp.p.), states of preservation, waterlogged environments, and burial times are presented. A calibration model was selected after comparing different reference data (samples extracted and not-extracted, and ash-rich and ash-free bases of calculation for the calibration values), and two different post-acquisition spectroscopic manipulations (both in terms of normalisation procedures and of spectral ranges used for the calibration). Results showed that the best models were different depending on which considered component (lignin or holocellulose) was measured and to which data set (softwood or hardwood) the samples belonged. It is shown that the predictive ability of the models is affected by high ash content (too contaminated samples had to be excluded in order to attain good results, because of excessive overlapping of bands related to the inorganic fraction) but not by the preliminary extraction of sample. Furthermore, the stability of best models is also demonstrated and a procedure of external validation carried out on an external set of samples confirmed the general validity of the identified models. [ABSTRACT FROM AUTHOR]

The paper presents the results of the restoration and conservation work which has been carried out in three archaeological areas in the Autonomous Province of Trento. The areas, which have been opened to the public for more than ten years, are the open-air archaeological site of Monte S. Martino, Roman Tridentum (an underground site under the historical city centre of Trento), and Fiavé (a pile dwelling site in a peat bog). These areas present very different environmental characteristics and have therefore required different interventions according to their specific situation. In order to reduce maintenance and extraordinary costs, appropriate conservation of the archaeological remains is required. This consists of methodologies of conservation according to the characteristics of the environment; continuous monitoring systems and indirect preventive intervention; and annual maintenance planning. [ABSTRACT FROM AUTHOR]

Abstract: Some acetone-carried consolidants for waterlogged archaeological wood were tested in order to evaluate treatments able to save time and energy. In details, colophony (rosin), two esterified colophonies (Rosin 100® and Rosin 459®), a mixture of colophony with PEG 3400 and a vinyl acetate - vinyl versate copolymer (Vinavil 8020S®) were tested. The treatments were carried out at temperatures of 20 and 35 °C on waterlogged maritime pine, elm, oak and beech. The materials came from the archaeological site of the ancient ships of Pisa (Tuscany, Italy) and were dated back to VII cent. BC – II cent. AD. To evaluate the processes, equilibrium moisture content and dimensional stability of treated wood samples at different relative humidity, and retention of impregnating products were measured; moreover macroscopic and microscopic examination were also run to respectively assess the shape and appearance of treated wood and the way of deposition of consolidants. The results highlighted that natural and modified colophony treatments gave the most satisfactory results both in the maintenance of shape and dimensions of samples and in the stabilization with respect to RH variations. Moreover, the equilibrium moisture contents of samples treated with R100 and R459 were much reduced in comparison to the other consolidants and to untreated archaeological wood. This fact was related to the high retention values of those products that occluded most of the porosity including the microporosity of cell walls. Therefore, in terms of higroscopicity treated wood was more similar to impregnating substances rather than to decayed wood. This fact was considered helpful in contrasting the moisture-related negative effects in cases of eventual faults in the climate control during e.g. exhibition and in protecting treated wood from the risks of new fungal attacks. [Copyright &y& Elsevier]

multi-technique approach was employed to study a decorated Egyptian wooden sarcophagus (XXV-XXVI dynasty, Third Intermediate Period), belonging to the Museo del Vicino Oriente of the Sapienza University of Rome. Portable non-invasive unilateral NMR was applied to evaluate the conservation state of the sarcophagus. Moreover, using unilateral NMR, a non-invasive analytical protocol was established to detect the presence of organic substances on the surface and/or embedded in the wooden matrix. This protocol allowed for an educated sampling campaign aimed at further investigating the state of degradation of the wood and the presence of organic substances by C cross polarization magic angle spinning (CPMAS) NMR spectroscopy. The composition of the painted layer was analysed by optical microscopy (OM), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Raman and surface enhanced (resonance) Raman spectroscopy (SERS/SERRS), infrared and GC-MS techniques, evidencing original components such as clay minerals, Egyptian green, indigo, natural gums, and also highlighting restoration pigments and alteration compounds. The identification of the wood, of great value for the reconstruction of the history of the artwork, was achieved by means of optical microscopy. [ABSTRACT FROM AUTHOR]

Abstract: Forty years ago in a xxth-century church in Torino, a small fire partially burned some of the decorative external boards of the sound-box of the organ. The focus of this present work was to find a treatment able to consolidate partially burnt wood in dry conditions, in which the external charred layer would be lost if not well preserved because of its incoherence. The product had to be applied onsite on an architectural structure intended to be reused again (and not simply exhibited). This circumstance is rarely encountered in the conservation of wooden Cultural Heritage. The efficacy of treatments was evaluated on the basis of a suitable and original experimental methodology, which took into account both the immediate and long-term behaviour of the various tested products. Although the opportunity to carry out this work came from a real case, both the selected product and the set up evaluation methodology have a general validity and they can be effectively used in other similar situations in which a slight antipowdering effect is required for treatment. [Copyright &y& Elsevier]

One of the problems in marketing the wood of Prosopis and Acacia is the lack of standardization of its qualities. The aim of this paper was to obtain a preliminary detection of some properties of the wood of four species of the genus Prosopis and one species from Acacia grown in Argentina. To accomplish this objective, the content of extractives and some physical and mechanical characteristics were analyzed. The density ρ12 of all the species indicates that these woods range from heavy to very heavy (⩾0.69g/cm3). The total volumetric shrinkage values are low, less than 10%, for all species. The parallel compression strength and the shear strength for all the species indicate a very resistant wood (⩾46.93MPa and ⩾18.35MPa, respectively). Brinell hardness was higher than 5kg/mm2 in all cases. The species with less content of extractives is P. ruscifolia (approximately 9% of anhydrous mass) whereas A. aroma was the one with the greatest content (approximately 25% of anhydrous mass in the heartwood). [Copyright &y& Elsevier]

Abstract: The most frequent dating methods of wooden artefacts are briefly introduced and discussed. Each of them shows merits and shortcomings. Therefore, an integrated approach of different techniques sometimes allows overcoming specific difficulties. The dating of a wooden support of a precious panel painting through a detailed xylological analysis and the joint use of dendrochronological and radiocarbon dating techniques is proposed. While any single dating technique demonstrated ineffective, the simultaneous use of several approaches in the study of the artefact led to excellent results in terms of both reliability and resolution, thus contributing to the inclusion of this painting in a specific historical period. On the basis of the performed dating, supported by the features of the panel and by a chemical-stratigraphic analysis of paint fragments, the artwork cannot be attributed to Cesare da Sesto. [Copyright &y& Elsevier]