Physico-Chemical Characteristics of Waterlogged Archaeological Wood

Passialis, Costas

doi:10.1515/hfsg.1997.51.2.111

Cited by 37 publications

(31 citation statements)

References 11 publications

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“…The diffractograms were used to calculate the crystallinity index, CrI % (Passialis 1997), and the crystallite length, L hkl (Jahan and Mun 2005):…”

Section: Methodsmentioning

confidence: 99%

Juvenile and mature wood of Abies pinsapo Boissier: sorption and thermodynamic properties

et al. 2015

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For industrial processes, it is important to study the hygroscopicity and thermodynamic properties of juvenile and mature wood. Samples of Abies pinsapo Boiss. collected in the natural areas of the species in Spain were used to study these properties in both types of wood. The equilibrium moisture contents were obtained, and the 15, 35 and 50°C isotherms were plotted following the Guggenheim-Anderson-Boer-Dent model. The thermodynamic parameters were calculated using the integration method of the Clausius-Clapeyron equation. Chemical analyses, infrared spectra and X-ray diffractograms were applied to assess chemical modifications and possible changes in the cell wall structure. The chemical composition of the mature wood shows a decrease in the lignin and hemicelluloses content and an increase in the extracts and a-cellulose. The sorption isotherms for the three temperatures studied are higher in the mature wood than in the juvenile wood. Causes of this include the higher content of a-cellulose, the higher crystallinity index and the shorter crystallite length in the mature wood. No difference was found between the juvenile and mature wood in relation to the point of inflexion where the multilayer starts to predominate over the monolayer (approximately 30 %). In terms of the thermodynamic properties, the heat involved is greater in desorption than in adsorption, and more heat is involved in the mature wood than in the juvenile wood.

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“…The diffractograms were used to calculate the crystallinity index, CrI % (Passialis 1997), and the crystallite length, L hkl (Jahan and Mun 2005):…”

Section: Methodsmentioning

confidence: 99%

Juvenile and mature wood of Abies pinsapo Boissier: sorption and thermodynamic properties

et al. 2015

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“…In relation to the crystallinity index, one factor that directly contributes to the decrease it undergoes is the increase of lignin. Passialis [29] showed that in wood submerged for thousands of years the lignin content increases up to 3.6 times in comparison with new wood. Although the wood in the present study was not submerged, natural ageing may have caused changes in the chemical composition by decreasing the fraction of carbohydrate composites in favour of the lignin content.…”

Section: H Emc a Emc D ---------------=mentioning

confidence: 99%

“…This affirmation is related to the degree of crystallinity, as the ability of wood to take up water by sorption decreases as the degree of crystallinity of the material increases [24]. Some studies have been done on the degree of crystallinity and its possible implications in the hygroscopic response [29,37].…”

Section: Introductionmentioning

confidence: 99%

Comparison of the hygroscopic behaviour of 205-year-old and recently cut juvenile wood fromPinus sylvestrisL.

et al. 2006

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-The hygroscopic response of the juvenile wood of Pinus sylvestris L. from recently cut trees from the Valsaín Forest in Segovia, Spain (new wood) was compared to that of the juvenile wood of the same species used in roof rafters installed at the end of the eighteenth century (old wood), which came from the same forest. The 35 ºC isotherms were plotted using the saturated salts method, and the mathematical fit used was the GAB model. The infrared spectrums and the X-ray diffractograms were used in order to study the possible chemical variations and crystallinity indices of the cell wall. The adsorption-desorption loop of the old wood is above the loop of the new wood, although the hysteresis coefficient is higher in the old wood. The peaks corresponding to the -OH groups are similar, although the degree of crystallinity is significantly lower in the old wood. While cellulose crystallinity differs between the old and new wood, and has a major influence on wood hygroscopicity, other modifications in the amorphous components of the cell wall may have contributed to the changes in hygroscopicity between the old and new wood. hygroscopicity / sorption isotherm / juvenile wood / Fourier transform infrared spectroscopy (FTIR) / X-ray diffraction (XRD)Résumé -Comparaison du comportement hygroscopique d'un bois juvénile de Pinus sylvestris L. âgé de 205 ans avec celui d'un bois juvénile récemment coupé. La réponse hygroscopique du bois juvénile de Pinus sylvestris L. provenant d'arbres récemment coupés de la forêt de Valsaín en Segovia, Espagne (bois récent) a été comparée à celle de bois juvénile de la même espèce utilisé comme bois de charpente à la fin du XIII e siècle (vieux bois), originaire de la même forêt. Les isothermes de sorption à 35 ºC ont été obtenus par la méthode des sels saturés, et l'ajustement mathématique utilisé était le modèle GAB. La spectrographie infrarouge et la diffractométrie par rayons X-ont été utilisées pour étudier d'éventuelles différences de composition chimique et d'indices de cristallinité de la paroi cellulaire. La boucle d'adsorption-désorption du vieux bois est au-dessus de celle du bois récent, tandis que le coefficient d'hystérésis est plus élevé dans le vieux bois. Les pics correspondant aux groupes -OH sont similaires, bien que le degré de cristallinité soit significativement plus bas dans le vieux bois. Bien que ces différences de cristallinité puissent expliquer pour une bonne part le contraste hygroscopique entre bois vieux et actuel, des modifications au niveau des composés amorphes de la paroi peuvent également être invoquées. hygroscopicité / isotherme de sorption / bois juvénile / spectroscopie infrarouge par transformée de Fourier / diffraction par rayons X

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“…The research shows a positive correlation between severities of degradation of ancient wood and the relative extraction content of 1%NaOH solution in ancient wood compared with healthy wood [5]. The content of holocellulose can relatively be more accurate in reflecting the rotten degree of waterlogged wood [6][7][8]. The white rot fungi, which can degrade lignin, belong to aerobic fungi.…”

Section: Chemical Components Of Waterlogged Woodmentioning

confidence: 99%

Degradation assessment of waterlogged wood at Haimenkou site

Jingran¹,

Li²,

Qiu³

et al. 2014

Frattura Ed Integrità Strutturale

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ABSTRACT. Haimenkou site is the largest railing-enclosed wooden architecture settlement site on the waterfront in current China. This research conducts degradation assessment of waterlogged wood at Haimenkou site with various methods, including maximum moisture content analysis, basic density analysis, shrinkage measurement, swelling analysis, chemical composition analysis, measurement of compression strength parallel to grain, SEM microstructure analysis and measurement of crystallinity, providing scientific guidance for the subsequent formulation of proper methods of reinforcement.

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Physico-Chemical Characteristics of Waterlogged Archaeological Wood

Cited by 37 publications

References 11 publications

Juvenile and mature wood of Abies pinsapo Boissier: sorption and thermodynamic properties

Juvenile and mature wood of Abies pinsapo Boissier: sorption and thermodynamic properties

Comparison of the hygroscopic behaviour of 205-year-old and recently cut juvenile wood fromPinus sylvestrisL.

Degradation assessment of waterlogged wood at Haimenkou site

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