Wood science and technology

This study aimed to determine the influence of increased temperature on the mass loss, chemical composition, and colour of pine wood because of the lack of such information. The colour was measured on samples of wood, extracted sawdust, holocellulose, and lignin isolated from the extracted sawdust of pine heartwood and sapwood. A wood sample labelled 20 • C was considered as wood with the original composition. Subsequently, we verified the measured values with the proposed mixing colour model. Pine heartwood and sapwood samples were thermally treated at temperatures of 100, 150, 200, 220, 240, and 260 • C for 1, 3, and 5 h. It was found that sapwood degraded faster than heartwood. The thermal treatment of wood increases lignin content and decreases holocellulose content, especially at 260 • C. The maximum extractive content of 3.60% was at 1 h and a temperature of 260 • C for both parts of the wood. Lightness values decreased with increasing temperature and time of treatment. The coordinate a* of heartwood showed a positive slope until one hour of treatment duration and a temperature of 240 • C. Then, it decreased for the subsequent duration of treatment. The same course was shown for the coordinate b* of sapwood at a temperature of 200 • C. The proposed model of mixing colours proved that changes in both parts of a wood-extracted substance, holocellulose, and lignin content, were responsible for the changing colour of extracted wood.

This study aimed to determine the influence of increased temperature on the mass loss, chemical composition, and colour of pine wood because of the lack of such information. The colour was measured on samples of wood, extracted sawdust, holocellulose, and lignin isolated from the extracted sawdust of pine heartwood and sapwood. A wood sample labelled 20 • C was considered as wood with the original composition. Subsequently, we verified the measured values with the proposed mixing colour model. Pine heartwood and sapwood samples were thermally treated at temperatures of 100, 150, 200, 220, 240, and 260 • C for 1, 3, and 5 h. It was found that sapwood degraded faster than heartwood. The thermal treatment of wood increases lignin content and decreases holocellulose content, especially at 260 • C. The maximum extractive content of 3.60% was at 1 h and a temperature of 260 • C for both parts of the wood. Lightness values decreased with increasing temperature and time of treatment. The coordinate a* of heartwood showed a positive slope until one hour of treatment duration and a temperature of 240 • C. Then, it decreased for the subsequent duration of treatment. The same course was shown for the coordinate b* of sapwood at a temperature of 200 • C. The proposed model of mixing colours proved that changes in both parts of a wood-extracted substance, holocellulose, and lignin content, were responsible for the changing colour of extracted wood.

Two important streams are visible in the upper part of the city of Salerno (Italy), which are buried under the city, feeding the underground aquifer of the historic center. Until the beginning of the last century, this water was collected with wells present in churches and convents and fed mills, fountains, wash houses, thermae, and balnea. The most important testimony of the Roman period is the frigidarium discovered seven meters below the palatine chapel of Prince Arechi in 1970. In the underground area, frescoes from an early Christian church have also been brought to light. In the upper part of the underground area up to above street level, the formation of saltpetre efflorescence is observed. In this work, the plausible origin of these efflorescences was investigated through the isotopic determination of nitrogen. Moreover, through the chemical analysis of waters, which of the two main streams (the Rafastia and the Fusandola) fed the ancient frigidarium was identified.

Using chemical fingerprints for timber species identification is a relatively new, but promising technique. However, little is known about the effect of pre-processing spectral data parameter settings on the timber species classification accuracy. Therefore, this study presents an extensive and automated analysis method using the random forest machine learning algorithm on a set of highly valuable timber species from the Meliaceae family. Metabolome profiles were collected using direct analysis in real-time (DART™) ionisation coupled with time-of-flight mass spectrometry (TOFMS) analysis of heartwood specimens for 175 individuals (representing 10 species). In order to analyse variability in classification accuracy, 110 sets of data pre-processing parameter combinations consisting of mass tolerance for binning and relative abundance cut-off thresholds were tested. Furthermore, for each set of parameters (designated "binning/threshold setting"), a random search for one hyperparameter of interest was performed, i.e. the number of variables (in this case ions) drawn randomly for each random forest analysis. The best classification accuracy (82.2%) was achieved with 47 variables and a binning and threshold combination of 40 mDa and 4%, respectively. Entandrophragma angolense is mostly confused with Entandrophragma candollei and Khaya anthotheca, and several Swietenia species are confused with each other due to the high similarity of their chemical fingerprints. Entandrophragma cylindricum, Entandrophragma utile, Khaya ivorensis, Lovoa trichilioides and Swietenia macrophylla are easy to discriminate and show less misclassifications. The choice of parameter settings, whether it is in the data pre-processing (binning and threshold) or classification algorithm (hyperparameters), results in variability in classification accuracy. Therefore, a preliminary parameter screening is proposed before constructing the final model when using the random forest algorithm for classification. Overall, DART-TOFMS in combination with random forest is a powerful tool for species identification.

The wood industry is undergoing a significant transformation driven by evolving consumer expectations, stringent regulatory requirements, and increasingly complex production processes. This paper explores the role of Artificial Intelligence (AI) in quality management across the entire lifecycle of wood products, from raw material assessment to final product validation. By harnessing machine learning, predictive analytics, and real-time data processing, AI-powered systems can detect defects with greater accuracy, streamline inspection procedures, and facilitate data-driven decision-making. These advancements not only reduce production costs but also enhance regulatory compliance and improve product reliability, ensuring a competitive advantage for industry stakeholders. The findings highlight how AI-driven approaches contribute to higher efficiency and consistency in quality control, offering valuable insights for manufacturers, researchers, and policymakers in the wood sector.

The conference aimed to transfer knowledge and good practices from the field of economics and management of the forest-based sector. Topics under consideration and discussion are sustainability and circular economy in forest and wood-based sectors, economic, financial, and logistics perspectives. management, investment, and innovation, artificial inteligence and digital innovation, market trends, marketing, and customer engagement, policy, legal framework, and esg reporting, technological innovations in production and construction.

The article describes the first results of a digital project dedicated to the preservation and systemization in the form of a dataset of crumbling reindeer rock carvings in the valley of the Pegtymel River for subsequent data development by other researchers. The collection, processing and cataloging of reindeer images were carried out, methodological aspects of clustering of features for the classification of reindeer were determined. The authors also attempt to solve the scientific problem of cultural clusters identification of Pegtymel petroglyphs based on the style of depiction of reindeer: by dates of creation, belonging to culture and people, differentiation of individual style and a single typology.

O conhecimento da composição química da madeira possibilita o entendimento de seu comportamento como matéria-prima para diversos usos, principalmente para a indústria de polpa celulósica, indústria de painéis, além de conferir propriedades preservativas face aos agentes bióticos e abióticos. Dentre as espécies do gênero Eucalyptus, destaca-se o Eucalyptus urophylla por apresentar o maior potencial de crescimento em termos de área plantada e em função da resistência ao fungo Cryphonectria cubensis, causador do cancro do eucalipto. O objetivo da pesquisa em tela foi analisar a possibilidade de propor um modelo sistemático de identificação para madeiras do gênero Eucalyptus por Ressonância Magnética Nuclear do 13 C (RMN 13 C). Neste trabalho, utilizaram-se os extratos ciclo-hexano de madeiras de clones de E. urophylla, devido a uma vasta diferença em deslocamento químico dos carbonos moleculares. O estudo está sendo aplicado também a outras espécies do gênero Eucalyptus. Os dados de RMN 13 C mostraram que os espectros dos extratos ciclo-hexano do cerne foram os mais representativos para o estudo de clones de E. urophylla, devido ao maior número de absorções existentes. Com esses resultados, foi possível traçar o perfil espectral comum para a espécie E. urophylla de cada região (alburno, zona de transição e cerne) da madeira.

This research aimed to study various physical and mechanical properties of the specie of paricá (Schizolobium parahyba var amazonicum), with a view to its application in the construction sector as well as its ranking as the mechanical strength. These properties were obtained from trees with 6, 10, 19 and 28 years old. The specie showed medium density of 0.311 g/cm3, having increased according to the age of the tree. Analogous to this, resistance to parallel compression to the fibers also showed this trend. Moreover, it was observed a loss of tensile strength parallel to and normal to the fiber along the age. The shear strength was equivalent between the ages, and this equivalence was also observed in the resistance to compression parallel to the fibers (20 MPa), to the cracking (0.35 MPa) and to the inlay II Congresso Brasileiro de Ciência e Tecnologia da Madeira Belo Horizonte 20 a 22 set 2015 parallel to the fibers (6.73 MPa). The modulus of elasticity by compression parallel to t...

This paper aims to present a preliminary proposal for a cross laminated solid wood panel better suited to the State of São Paulo forestry resources and timber industry. At first, the main features of the State of São Paulo's forestry and timber industry were analysed in order to create an overall picture of the possibilities and restraints offered by the local forestry sector. After, a preliminary proposal for a cross laminated round-wood solid panel was developed. Then, the proposal was analysed and topics for further research on the theme were presented. It was found that a better suited cross laminated solid wood panel in the State of São Paulo should favour the use of young Eucalyptus round-wood in a labour intensive production process.

For several years, the Timber Export Industry in Ghana has concentrated its activities on primary and secondary processing to the detriment of higher-value processing. While this focus has generated positive cashflows for some operations, the lack of a solid in-state value-added wood processing sector denervates the higher export earnings potential by the country and minimizes employment. Studies have shown that the secondary processing of timber concerning lumber (air-dried and kiln-dried), veneer, and plywood remains the most exported product in terms of volume and value for the past two decades (TIDD 2022). New studies have highlighted recent trends in processing emerging forest products such as Bamboo, Rubberwood, smaller-diameter logs, and other Asian and plantation species such as Teak and Cedrella. Indeed, as raw material, wood provides a resilient basis for various conversion processes, which are widely untapped in most African forested countries (FAO, 2013, Adeyoju 1975) such as Ghana. The Forest Development Master Plan (FDMP) 2016-2036 aims to transform the industry into a high-value-added product manufacturer and exporter seeking to re-tool, retain, and standardize by 2030, where downstream processing activities would contribute 60% of the processing chain. This policy brief provides a comprehensive analysis of the latest data on machinery and empirical evidence in the timber trade, to set out transformational insights and pathways for promoting value addition, maximum wood utilization and stimulating investments. The study is part of the monitoring and evaluation framework for the FDMP to monitor the progress of the achievements of financial and technical targets and critical results of Ministry of Lands and Natural Resource (MLNR) operations (FDMP 2016-2036).

Об'єктом дослідження є процес переривчастого різання лезами з керамічних та надтвердих матеріалів. Предмет дослідження – скінчено-елементна модель процесу різання лезами, зміцненими іонно-променевою імплантацією. Мета даної науково-дослідної роботи розроблення методики підвищення ресурсу різальних лез із керамічних і надтвердих матеріалів, які працюють в умовах переривчастого різання, за рахунок визначення їх оптимальної геометрії на основі імітаційного моделювання робочого процесу в замкненій технологічній системі верстат-пристосування-інструмент-заготовка. Основні результати полягають у тому, що удосконалено методику моделювання процесів різання у податливій технологічній системі шляхом врахування контактної взаємодії на стиках. Виконані розрахунки та доведено працездатність моделі. Експериментально доведено, що зпрогнозована деформація ТС за розробленою моделлю процесу стругання менша за реальну по причині як заниженої сили різання, так і неврахуванням зазорів у з’єднаннях. Р...

Calamus merrillii. The anatomical, physical, chemical and mechanical properties of cultivated Calamus merrillii were determined. These properties were used as basis for determining the optimum cycle age of rattan plantations. Stand age did not affect the basic properties of rattan cane. Cane properties were uniform throughout the age groups (7, 8, 10, 11, 14, 15, 18, 20 years). In wood, age-related variability in properties could be attributed to the secondary growth of stems. Rattan does not undergo secondary growth, thus, age-related variability in properties was not evident. Unlike trees where the cutting age is predetermined due to the presence of juvenile wood, the cutting age of cultivated C. merrillii is more flexible. Harvesting could start as early as 7 years after cultivation. However, it could only be used for splits due to its low modulus of rupture (class 3). Nonetheless, with rattan, plantation investors have more flexibility in assigning the appropriate cutting age of the stand. Hence, they would have more control over the rate of return of their investments.

This paper aims to document the conservation processes of a polychrome wooden coffin in the Dahshur archaeological area dating back to the late period. The exterior part of the coffin is decorated with a painted layer. Visual observation, 2D Program, and Optical Microscopy (OM) were used. wood identification. The coffin was in a bad condition. It was covered with a thick layer of dust, losing parts of the painted and gesso layers, as well as other parts of these layers, were lost. Some parts were missing from the head area of the lid coffin. The conservation processes of the wooden coffin included mechanical and chemical cleaning, reattachment of the separated parts of the ground layer and painted layers, filling the edge of the painted layer, and consolidating the painted layer. The conservation process included mechanical cleaning using soft brushes, chemical cleaning using ethyl alcohol and distilled water for painting, stabilization of the separated gesso layer using Paraloid B72, filling cracks of the gesso layers using glass microballoon with Paraloid B72 and consolidating the painted layer with calcium oxide nanoparticles with Klucel G (hydroxypropyl cellulose) 0. 5%

Chemically-modified laminated veneer lumbers (LVLs) were produced and their physical properties and biological resistance were evaluated. For the chemical modification, the vapor-phase formalization and the pad-dry-cure treatment ofveneers with some cross-linking agents were employed prior to lamination of the treated veneers. The vapor-phase formalization was conducted for 5, 10 and 24 hours using tetraoxane as a source offormaldehyde, and the pad-dry-cure treatments with glutaraldehyde and dimethylol dihydroxy ethylene urea (DMDHEU) were made after impregnation of their 2.5,5 and 10% aqueous solutions. Sulfur dioxide was used as a catalyst in both treatments. Laboratory tests with a brown-rot and a white-rot fungus revealed that decay was almost completely suppressed at the high levels of treatment, and fairly eliminated at the low levels of treatment. The treatment could reduce the weight loss of specimens caused by termite attack, but the effectiveness in resisting it was not as sufficient as was decay resistance. All treated LVLs were very stable to water soaking even in the 2-hour boiling on thickness swelling as well as linear expansion along tangential direction.

Tijekom arheoloskih istraživanja na Starom gradu u Varaždinu, a iskopavanja suprovedena kao dio Projekta BASTION u sklopu međunarodnog INTERREG III A programa, otkriveni su dijelovi dviju drvenih konstrukcija. U sjevernom jarku bili su pronađeni ostaci mosta ili prilazne rampe, koja je vodila prema vratima srednjovjekovne cetvrtaste kule, a u zapadnom unutarnjem jarku otkriveni su ostaci drvene obrambene ograde - palisade. Na osnovi raspoloživihpovijesnih podataka bilo je procijenjeno da drvo pripada konstrukcijama s vremenskim rasponom nastanka od 13. do sredine 16. stoljeca. Nakon vađenja iz zemlje drvo je bilo odgovarajuce pohranjeno u podrumu muzeja u Varaždinu pa se nije osusilo niti je doživjelo ostecenja. Prema uputama Odsjeka za drvnu tehnologiju Univerziteta u Ljubljani, pripremljeni su manji uzorci koji su poslani na dendrokronolosku analizu u Ljubljanu. Tamo je drvo fino obrađeno te su provedeni identifikacija i dendrokronolosko datiranje u skladu s važecom metodologijom ...

Cellulose acetate polymers were developed from pretreated cotton stalk (cellulose). The cellulose was acetylated through reaction with acetic acid and acetic anhydride in the presence of sulphuric acid as catalyst. The relationship between reaction time, catalyst loading and temperature on the weight percent gain and percent acetyl content of the cellulose acetate were investigated. Optimization of process conditions for acetylation via response surface methodology (RSM) revealed that the maximum weight percent gain (WPG) and percent acetyl content (PAC) were 50.79% and 43.73% respectively. The corresponding optimum operating conditions were 2.76 hrs, 6.09 wt% and 40.07 o C, for reaction time, catalyst loading and temperature respectively, while glacial acetic acid to cellulose ratio and acetic anhydride to cellulose ratio were 6:1 and 4.36:1 respectively. The result revealed that acetylation of cellulose extracted from cotton stalk was successful as indicated by the characteristic ...

This study examined the mechanical properties of Turkey oak (Quercus cerris L.) wood before and after combined steam and thermal treatments under vacuum conditions. Wood was steamed at 100 to 110°C and thermally treated under vacuum at 160°C by the press-vacuum or thermo-vacuum process. Treated material was characterized in terms of the modulus of elasticity (MOE) and compression strength of heartwood and sapwood. The MOE was established using a nondestructive technique based on the measurement of ultrasonic pulse propagation. Results differed depending on the treatment or combination of treatments, and showed that the steaming process strongly affected the MOE. Thermo-vacuum treatment increased the compression strength, whereas steaming had the opposite effect.

This paper presents significant findings on the variation in the anatomical properties of Anthocleista grandiflora wood, which could greatly influence its utilization in various products. Cubic-shaped heartwood and sapwood specimens were extracted at the base, middle, and top of boles from 38-, 43-, and 47-year-old trees. The variations in cell morphology and anatomical characteristics were meticulously assessed. The specimens were prepared into 3 mm x 10 mm fragments, macerated, and viewed under a microscope using Motic Image plus 2.0 ML software. The following parameters were determined: average values of fiber length, fiber diameter, lumen width, double fiber wall thickness, Runkel ratio, aspect ratio, coefficient of rigidity, and coefficient of flexibility of trees at the base, middle, and top. Notably, there were more vessels in sapwood than in heartwood, and the vessel areas increased with increasing vessel lengths. The results also revealed that in the heartwood region, the fraction of vessel lumen increases with tree age in the base, middle, and top sections. These findings are significant as they provide a comprehensive understanding of the anatomical properties of A. grandiflora wood, which is classified as wood from numerous vessels, a common characteristic of noble woods. The wood exhibited anatomical properties suitable for cellulose, paper, and fiber-based products, highlighting its potential in various industries.

This paper presents significant findings on the variation in the anatomical properties of Anthocleista grandiflora wood, which could greatly influence its utilization in various products. Cubic-shaped heartwood and sapwood specimens were extracted at the base, middle, and top of boles from 38-, 43-, and 47-year-old trees. The variations in cell morphology and anatomical characteristics were meticulously assessed. The specimens were prepared into 3 mm x 10 mm fragments, macerated, and viewed under a microscope using Motic Image plus 2.0 ML software. The following parameters were determined: average values of fiber length, fiber diameter, lumen width, double fiber wall thickness, Runkel ratio, aspect ratio, coefficient of rigidity, and coefficient of flexibility of trees at the base, middle, and top. Notably, there were more vessels in sapwood than in heartwood, and the vessel areas increased with increasing vessel lengths. The results also revealed that in the heartwood region, the fraction of vessel lumen increases with tree age in the base, middle, and top sections. These findings are significant as they provide a comprehensive understanding of the anatomical properties of A. grandiflora wood, which is classified as wood from numerous vessels, a common characteristic of noble woods. The wood exhibited anatomical properties suitable for cellulose, paper, and fiber-based products, highlighting its potential in various industries.

Wer vor der Wahl eines neuen Bodenbelags steht, hat oft die Qual der Wahl: Soll es ein hochwertiger Parkettboden oder ein moderner Vinylboden sein? Beide Varianten haben ihre Vor- und Nachteile. Der folgende Vergleich soll helfen, die richtige Entscheidung zu treffen.

We studied the physical properties of some commercially available wood in Nigeria. The wood samples include Gmelina, Mahogany (Khayalvorensis), Black Oak, Iroko (Melicea Excels), Afara, Bamboo (Bambusoideae), Achi, Bitterkola, Ubia and Mba. The wood sample were initially machined and trimmed to about in width and about thickness. The wood samples were then soaked in water in an airtight container for four weeks (these were taken as the wet wood sample). The weights of the wood samples were determined with a digital weighing balance; the lengths were measured with a meter rule. The width and the thickness were measured using a Vernier caliper and micrometer screw gauge respectively. The wood sample were then subjected to a simple cantilever test to determine their Young Modulus which is a measure of the stiffness of the wood. The wood sample were then dried in open air (but not directly under the sun) for eight weeks (these were taken as the dry wood sample) and the experiment repeated. The results of the test showed that stiffness of a wood depends on its specie and hence different wood species have different stiffness characteristics. Iroko wood have the highest Young Modulus when dried while Melina wood is stronger when wet than when dry. The result obtained in this study has provided qualitative/quantitative information on the physical properties of these selected wood species which can be used in determining their applications for either building, construction or for any other purposes such as the in the making of furniture.

Seasonal dynamics of xylem formation were studied at a cellular level in Norway spruce (Picea abies) from the lowland forests Sorsko polje (350 m a.s.l.) and the sub-alpine site Pokljuka (1200 m a.s.l.) in Slovenia during the growing season 2003. Th e pinning technique and sampling of intact tissue were performed at weekly intervals to assess the usefulness of both methods for examining wood formation. Pinning induced desiccation of diff erentiated xylem, necrosis of cambial cells and undiff erentiated xylem derivatives, and formation of callus, traumatic resin canals and wound-wood. Th e border between cambial cells and radially expanding cells located inside the callus was a reliable mark for defi ning the xylem increment reached from the time of wounding. Intact tissue sampling was superior for precise investigations of cambial activity, various developmental stages of tracheids, and for secondary phloem formation.

Proučili smo vpliv eksperimentalnega ogrevanja in hlajenja dela debla navadne smreke (Picea abies) na kambijevo aktivnost in celično diferenciacijo. Poskusa sta potekala 30 dni; ogrevanje od 29.3.2004 do 3.5.2004, hlajenje pa od 14.6.2004 do 20.7.2004. Vzorce floema, kambija in ksilema smo iz dreves odvzeli vsakih 10 dni, pripravili prečne prereze tkiv in preparate opazovali s svetlobnim mikroskopom. Lokalno ogrevanje je po 10 dneh induciralo delitveno aktivnost kambija na floemsko stran, po 20 dneh pa tudi na ksilemsko. Po 30 dneh je pri ogrevanem vzorcu nastalo do 15 celic ranega lesa. V tem času se je redna delitvena aktivnost kambija pri kontrolnem drevesu šele začela. Odziv kambija na hlajenje debla je bil manj izrazit. Anatomskih razlik med kontrolnim in hlajenim vzorcem po 10 in 20 dneh ni bilo. Po 30 dneh je pri hlajenem vzorcu začel nastajati kasni les, pri kontrolnem drevesu pa šele prehodni rani-kasni les. S poskusom smo demonstrirali, da je mogoče pri smreki z umetnim ogrevanjem in hlajenjem debla vplivati na ksilo-in floemogenezo.

Seasonal dynamics of xylem formation were studied at a cellular level in Norway spruce (Picea abies) from the lowland forests Sorsko polje (350 m a.s.l.) and the sub-alpine site Pokljuka (1200 m a.s.l.) in Slovenia during the growing season 2003. Th e pinning technique and sampling of intact tissue were performed at weekly intervals to assess the usefulness of both methods for examining wood formation. Pinning induced desiccation of diff differentiated xylem, necrosis of cambial cells and undifferentiated xylem derivatives, and formation of callus, traumatic resin canals and wound-wood. The border between cambial cells and radially expanding cells located inside the callus was a reliable mark for defining the xylem increment reached from the time of wounding. Intact tissue sampling was superior for precise investigations of cambial activity, various developmental stages of tracheids,and for secondary phloem formation.

System for image analysis Lucia G was used for measuring vessel dimensions of oak wood (Quercus sp.) on macroscopic level. We present the problem of sample preparation as well as capturing and processing of images for automatic measurements of diameters, areas and perimeters of early wood vessels. After testing various methods of sample preparation we found out that the best results were obtained when the samples were sanded with paper of granulation 320 and the surface stained with black alcohol marker. Vessel lumina were then filled with white chalk dust, and finally the images were captured by a digital camera attached to a stereo microscope and saved in TIF format. We improved the images by using digital filters, converted them to binary images and defined measurement frames. The results confirmed that the image analysis system Lucia G enables measurements of early wood vessel dimensions in ring porous species on macroscopic samples with satisfying accuracy.

In paper, two models of formation of lignin macromolecule are described. Random coupling model suggests lignin formation process through coupling of monomer radicals to growing lignin polymer in a near-random fashion. According to the dirigent protein model, process of lignin polymerization is fully controlled by specific dirigent proteins that direct formation of individual bonds. Critical judgements and scientific opinions of both models are given.

The effect of experimental heating and cooling in a part of the stem of Norwayspruce (Picea abies) on cambial activity and cell differentiation was studied. Experiments were performed for 30 days; heating from 29 March 2004 until 3 May 2004 and cooling from 14 June, 2004 until 20 July 2004. Samples ofphloem, cambium and xylem were taken from trees every 10 days, transverse sections of tissue were prepared and observed under light microscope. After 10days, localized heating reactivated cambial cell division on the phloem sideand after 20 days on the xylem side as well. After 30 days up to 15 early wood cells were formed in the heat-treated sample. Regular cambial activity inthe control tree only started after 30 days. Cambial response to the coolingof the stem was less conspicuous. No anatomical differences were detected between the control and cool-treated samples after 10 and 20 days. After 30 days, late wood already started to form in the cool-treated sample and only transition ea...

Les lames de plancher d'ingénierie (LPI) sont des composites multicouches à base de bois. La structure en couches croisées est conçue pour donner aux LPI une bonne stabilité dimensionnelle pendant les changements de conditions environnementales. Toutefois, pendant la saison d'hiver en Amérique du Nord, l'humidité relative dans les habitations peut descendre de façon significative et générer une déformation en tuilage de LPI importante. L'amplitude de cette déformation dépend des propriétés physiques et mécaniques de chaque couche et du changement d'humidité. Le contreplaqué est largement utilisé comme substrat dans la fabrication de LPI. L'industrie canadienne des lames de plancher utilise couramment le contreplaqué de bouleau baltique (CBB [russe et finlandais]) dans leurs constructions de LPI haut de gamme. L'objectif général de ce projet de doctorat était de développer un panneau OSB (Oriented Strand Board) spécial afin de remplacer le contreplaqué utilisé comme substrat dans la

The feasibility of preparing a surface-densified wood product by replacing the traditional time-consuming pressurization stage with only a short vacuum time was investigated. Sugar maple and red oak wood specimens were successfully impregnated with low-viscosity resins of 1,6 hexanediol dimethacrylate and trimethylolpropane trimethacrylate, with or without silicate nanoparticles, using vacuum times of 30 s to 10 min without pressurization. Chemical retention (CR) and vertical density profiles of the treated wood specimens were measured. The CRs obtained with the short vacuum impregnation process, even with a vacuum of 30 s or 60 s, proved comparable to those achieved by the traditional process of 30-min vacuum plus 30-min pressure. A 52-63 wt% CR was found for maple impregnated with neat resin, while the formulations containing nanoparticles achieved 44-55 wt% as the vacuum time was increased 30 s to 10 min. Oak yielded lower CR values. The vertical density profiles indicated better treatability for maple than oak. Examination of the resin and resin/nanoparticle penetration into the wood by scanning electron microscopy revealed successful wood impregnation with both nanoparticles and resin.

The understanding of the interaction between bark extractives and adhesives is fundamental in the manufacture of bark particleboard for optimum adhesive curing, and mechanical and physical properties of the boards. The effect of hot-water treatment on black spruce and trembling aspen bark was investigated to highlight its impact on the bark particles/phenol-formaldehyde adhesive system, and on the physical and mechanical properties of bark particleboard made from hot-water-treated bark of both species. Bark was soaked in hot water maintained at 100°C for 3 h. The results showed that the hot-water treatment affects the physical and chemical properties of the bark by decreasing hydrophilic characteristics, acidity, and the amount of condensable polyphenols that can react with formaldehyde. The mechanical properties, including static bending and internal bond of particleboard made from untreated black spruce and trembling aspen bark, were higher than those of boards made from hot-water-treated bark of the same species. The thickness swelling of particleboard made from hot-water-treated black spruce and trembling aspen bark was higher than that made from untreated bark. One exception occurred for particleboard made from 100% trembling aspen bark for which no significant difference was found between particleboards made from treated and untreated barks.

This study examines the suitability of wood welding technology for producing composite panels for furniture applications with two Canadian hardwood species, sugar maple (Acer saccharum) and yellow birch (Betula alleghaniensis). For each species, twelve 30x225x300 mm panels were manufactured using a panelling machine specifically designed for rotational wood-dowel welding with optimized parameters obtained from a previous study. Six edge-glued panels of the same size were manufactured from each species using a non-structural polyvinyl acetate (PVA) adhesive and tested for comparative purposes. The experimental program included three-point bending at 255-mm span and visual inspection of the panels to assess performance at standard moisture conditions and after an aging cycle with variable relative humidity. Average breaking load of 1.79 kN and 1.70 kN was obtained at standard moisture conditions for welded panels of yellow birch and sugar maple, respectively. Fractures consistently occurred in the dowel's crosssection, whereas no slippage was observed along the welded interface. Delamination between wood slats occurred after the aging cycle, but did not affect the bending properties. Results confirm the suitability of wood-dowel welding for producing furniture panelling with Canadian hardwood species. Further research is needed to design panels with a more efficient position and use of welded dowels and with panel product properties that are comparable or superior to those of glued counterparts.

The Complex of Hue Monuments (abbreviated as the Monuments) is well-known for its wealth of scientific materials for research. This paper begins by introducing the features of the Wooden Frame of the Twin-Ridge Beam Building (abbreviated as the Twin-Buildings), which represent the highest level of the Hue Imperial Palaces (abbreviated as the Imperial Palaces). The Twin-Buildings are an important component of the Complex of Hue Monuments, recognized as UNESCO's first World Cultural Heritage site in Vietnam in December 1993. Next, this paper examines the design methods of the Wooden Frame of the Twin-Buildings, which were used exclusively for special functions such as residences in the Palaces, worshiping halls in the Shrines of the ancestors, and the Temples of succeeding Emperors' mausoleums. Designing and constructing the Twin-Buildings represents one of the most challenging techniques among the Monuments. Primarily based on the historic documents of the Nguyen dynasty, surveys of the remaining Twin-Buildings, dimensional analysis, investigations into traditional design methods, interviews with traditional master carpenters, and study results on the floor plan design methods, this research seeks to redefine the design methods of the Wooden Frame of the Twin-Buildings. Through this study, the architectural proportions, design methods, and design processes of the Wooden Frame have been concretely identified. This research provides a comprehensive understanding of the principles behind the wooden frame design of the Twin-Buildings in the Imperial Palaces. Furthermore, the findings published in this paper serve as a valuable reference for researchers, graduate students, and architecture students. They contribute to academic education and scientific research, while also providing an important database and knowledge base for the restoration and reconstruction of the Monuments.

Pieces of fossil wood were discovered near Komenda from the Lower Miocene beds. According to microscopic wood anatomy it corresponds to the family Meliaceae and to the genus Carapoxylon. This is the first identification of Miocene hardwood from Slovenia. Fossil woods of genus Carapoxylon are most common in the Ottnangian to Badenian period in central Europe (North Alpine Molasse Basin). The nearest living relatives of Carapoxylon belong to genus Carapa, Xylocarpus and Entandrophragma.

Attualità 6 Presentato alla fiera "Più Libri Più Liberi" di Roma il numero 133 di Kermes dedicato alla conservazione della plastica nell'arte contemporanea e nel design 8 Restauro in equilibrio tra tecnologia e filologia. Il caso dell'Apollo del Belvedere nei Musei Vaticani 12 Il bronzo di Donatello svelato dopo il restauro 15 Michael Sweerts: «Chi [effettivamente] era costui?» 16 Un libro sulle tavolozze degli artisti 18 Restaurata la conceria di Pompei 33 Il monitoraggio microclimatico dell'ambiente espositivo come azione necessaria al contrasto della migrazione del PEG

By using minerals instead of bioresources in construction, greenhouse gas emissions are nearly doubled. It is vital to transition from this traditional paradigm to a low-carbon model in which woods and bamboos are essential components. To proliferate bio-urbanization, challenges must be overcome in forestry and construction. Our study is a necessary starting point for more sophisticated studies and policies to support the valorization and utilization of bioresources, especially wood and bamboo, in greener construction solutions for a sustainable urbanization. Our main results elucidate examples and benefits of biobased cities and buildings, raise issues and current challenges, and suggest opportune actions to be globally addressed in collaborative proposals. Assertive codes, well-managed resources, resolution of challenges, and clarification campaigns on decarbonization are priority targets in future environmental and societal commitments.

The influence of keyboard instruments on cultural and religious dynamics during the European conquest of Latin America was profound. The surviving harpsichords and clavichords from the 16th to 18th centuries exemplify a fusion of European origins and local craftsmanship. Historical records substantiate the presence and exchange of these instruments between Europe and Latin America, underscoring a rich bidirectional musical and cultural interaction.

The conversion to climate-stable, resilient and productive forests has resulted in an increasing share of mixed stands. Different growth conditions and silvicultural treatments lead to an increased scatter in strength compared to what is expected from monoculture experience. The study (i) quantified the magnitude of variation in strength of European beech timber from stands of different composition and (ii) showed the impact of grading on the characteristic strength value of timber coming from those stands. Strength grading models and machine settings for hardwood tensile classes on over 900 European beech (Fagus sylvatica L.) boards were derived. One model used only the dynamic modulus of elasticity (Edyn), and a more complex model used a knot value in addition. Afterwards, 407 boards from pure beech stands as well as mixed stands of beech with Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), Norway spruce (Picea abies (L.) Karst.), sessile oak (Quercus petraea (Matt.) Liebl.), ...

Controlling the long-term effect of management on the quantity and properties of individual boards is a fundamental challenge for silviculture. Within this basic study on Douglas-fir, we have investigated the sensitivity of the net present value (NPV) to three most common planting densities and a prominent pruning strategy. We therefore have applied an individual tree growth model, which represents intrinsic stem structure as a result of crown competition. The model extrapolated board strength development to the rotational age of 70 years, starting from real and comprehensive data recorded from experimental Douglas-fir plots at the age of 20 years. Total volume production increased from about 1600 m3 ha−1 for 1000 and 2000 trees ha−1 to 1800 m3 ha−1 for 4000 trees ha−1. The economic superiority of the lowest density stands increased considering the NPV at inflation-adjusted interest rates of 0%, 2% and 4%: Given an interest rate of 2% and no pruning, the NPV at 2000 was at about 50%...

As they fulfil many ecological and social functions and services better than even-aged monocultures, heterogeneous pure and mixed-species stands are on the advance in Central Europe. Even so, knowledge of how different stands compare in terms of the quantity and quality of the produced wood remains limited, as forest research has been focused on pure stands in the past. Therefore, the still limited comparative studies on timber quality in mixed versus pure stands were reviewed. Further, approximately 100 studies on the morphology of mixed versus pure stands have been reviewed. As is known, the close connection between morphology and timber quality from many studies in pure stands as well as the morphological and structural properties of trees in mixed stands is used as proxies for their timber quality. The number of studies reporting a decrease or increase in timber strength and stiffness in complex stands compared with homogeneous stands was balanced. Knottiness is mostly higher in complex stands. Wood density behaves indifferently. Distortion, as indicated by eccentricity of crown, bending of stems, or irregularity of the tree-ring width, is generally higher in complex forests. This rather ambiguous pattern becomes clearer by typifying the findings depending on the species-specific morphological plasticity of the trees and the spatial conditions they are exposed to. When growing in strong lateral restriction in even-aged pure or mixed-species stands (type 1), trees follow a ''keep abreast'' strategy which results in high-quality Electronic supplementary material The online version of this article

The chemicals distribution of preservatives treated bamboo Gigantochloa scortechinii through soaking, vacuum pressure and high-pressure sap displacement were studied. The distribution of chemicals in the bamboo influences their durability against the attacks of the insects and fungi. This largely depends on the chemicals penetration, location and retention at the tissue and cell wall levels in the bamboo. At optimum retention levels, the preservative performance should be comparable unless the preservative's distribution, substrate susceptibility or fixation product had altered. In evaluating the performance of various treatment methods employed, the distribution of preservatives within the cell walls of treated bamboo must be considered. The results from the energy dispersive x-ray analysis on the bamboo treated with copper chrome arsenic and ammoniacal copper quaternary are analyzed. The G. scortechinii samples were treated by soaking, vacuum pressure impregnating and high-pressure sapdisplacement. Observations were carried out using the transmission electron microscope linked system to an energy dispersive x-ray analyzer. The system enables to detect preservative distribution at the cellular level and measured relative preservative content into the lumen surface, in the S 2 cell wall layer and in the middle lamella.

Wood anatomy is considered to be a precise and rapid method in wood identification. Eucalyptus is a diverse genus of trees in the family of Myrtaceae. Due to the lack of appropriate systematic approaches, timber identification of Eucalyptus species is presently done based on visual observations and personnel skills. Therefore, the authenticity of Eucalyptus species is frequently questioned at the timber market. Identification of Eucalyptus species based on anatomical properties is recognized to be an imperative exercise as it could minimize possible misleads in the timber industry.

Eucalyptus is a diverse genus of trees in the family of Myrtaceae. Many Eucalyptus species are employed in producing timbers in different parts of the world. However due to the lack of information on the mechanical properties of different Eucalyptus species, commercial applications of them is hindered. In the present research, nine Eucalyptus species grown in Sri Lanka namely: E.

Wood is a renewable natural resource used in diverse sectors. Wood processing operations generate a substantial quantity of residues which possess higher potential of alternative uses. Finger-jointing, a method which connects two small pieces of timber together, is identified as a sound technique to minimize wastage. In the present context, where deforestation continues to threaten the existing timber resources, the finger-joint technique has gained higher recognition as a viable tool for sustainable utilization of wood. With the increasing demand and decreasing volume of high-grade timber material, finger-jointing has become an industry with great economic benefits and finger-joint technology will boost the increased utilization of timber materials. The outcomes of this review paper will therefore improve the quality of finger-jointed products through the generated technical information and thereby enhance the finger-jointing industry in practice.

Wood is a leading environmentally friendly construction material due to its renewability, carbon sequestration, and energy-efficient production. Sourced sustainably, it has a lower carbon footprint than concrete and steel while offering natural insulation for energy-efficient buildings. Wood stores as much as 15 times CO 2 released during its manufacture whereas aluminum and steel store negligible amounts. Finger joint is a sustainable technique used to ensure sustainable utilization of small pieces of wood removed as waste. Chemical protection of wood is performed with preservatives, such as insecticides, fungicides and UV protective finishes that are used for wooden materials. Softwood species are highly susceptible to deterioration caused by wood-destroying agents such as fungi, insects, and moisture. Without proper protection, their structural integrity and lifespan can be significantly reduced. Therefore, preservation treatments are essential to enhance durability, improve resistance to decay, and extend the usability of softwood in various applications. The objective of this study has been to evaluate the impact of boron treatment for finger-jointed pine wood samples on enhancing the durability of pine wood planks. Samples of pine wood with 19 mm-long fingers have been used for this study. Average tensile strength values of treated and untreated finger-jointed pine wood samples are higher than the recommended minimum requirement of tensile strength value (≥10 N/mm 2). Failure modes of treated and untreated finger-jointed pine wood samples have also been described. Boron-treated, finger-jointed pine wood planks with 19 mm-long fingers offer improved durability and resistance to decay, making them well-suited for industrial applications. The treatment enhances the wood's structural integrity, extending its lifespan and performance in demanding environments.