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Funerary cremations in Roman times were important rites of passage that involved the use of fire to accompany the dead into the afterlife. In the present study, we investigated the wood fuel that was used to build cremation pyres and the foodstuffs involved in offerings and funerary feasts in a necropolis of Barcino (present-day Barcelona), dated to the 1st century CE and located at the Sant Antoni Market site. Our approach began with the analysis of wood charcoal and fruit/seed remains, which were preserved over time through carbonisation. These archaeobotanical remains offer valuable insights into the selection of woody species and the condition of wood logs used for cremations. Additionally, they shed light on the food composition of offerings and feasts in this area of the Mediterranean coast, where data on such practices are scarce. The anthracological analysis of different combustion structures revealed that the principal taxon used for the stacks was evergreen oak, with deciduous oak playing a significant role during the initial use of the necropolis. Dendro-anthracological analysis indicated that medium to large diameters wood logs of deciduous oak obtained from mature individuals were commonly employed. Moreover, charcoal analysis suggested the use of pruning remains from fruit trees such as olive, grapevine, walnut, plums, and members of the apple family, providing evidence of arboriculture practices in the city. Additionally, various minor woody species (Aleppo and mountain pines, juniper, cypress, mastic, and rockroses) may have had several functions, including symbolic sensory aspects relating to smell and good flammability, the constitution of small objects or furniture placed on the stack (boxwood), and fire kindling or decoration (mastic, rockroses, honeysuckle, and laurustinus). Carpological analysis indicated that the most abundant offerings and/or feast remains consisted primarily of cultivated fruits such as figs, walnuts, and grapes, while pulses and cereals were comparatively scarce or absent. Finally, a noteworthy quantity of Arbutus berry remains was recorded, marking the first occurrence of such findings in similar Roman contexts to date. [ABSTRACT FROM AUTHOR]

Luminescent lanthanide-doped phosphates have never been introduced as potential materials for wood functionalization. Wood–ceramic composites (WCC) may enable the extensive use of wood in construction due to different functionalization. Hence, this work proposes the inorganic GdPO 4 ·H 2 O:Eu3+ compound as an alternative and innovative method to increase wood chemical resistance and confer new optical properties. Scots pine (Pinus sylvestris L.) sapwood – ceramic composite was obtained through in situ hydrothermal synthesis and compared with the untreated sapwood specimens. The enhanced characteristics of the WCC samples were demonstrated using scanning electron microscopy (SEM), x-ray computed micro-tomography (μCT), and thermogravimetric (TG) analysis. Optical properties were determined by luminescence analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Using the innovative wood activation system NaOH/CS 2. • Application of ATRP polymerisation to the in-situ growth of hydrophobic chains on wood surfaces. • Long-term hydrophobic stability. Balsa wood, despite being a cost-effective insulation material, has limited applications due to its inherent hydrophilicity. This study introduces an innovative technique for the in-situ growth of low surface energy long alkyl chain segments on balsa wood using the atom transfer radical polymerization (ARGET-ATRP) method, which not only provides durable and stable hydrophobicity but also preserves its natural texture, mechanical strength, and thermal insulation. The resulting hydrophobic wood demonstrated exceptional hydrophobicity in diverse environments, with a water contact angle up to 141.3° and a contact angle decrease of no more than 10.47 % after 150 min, confirming its hydrophobic stability. Furthermore, axial thermal conductivity of the wood was as low as 0.1012 W/m·K, the axial compressive strength decreased by only 12.8 %, further evidencing the retention of its mechanical properties. This simple yet effective strategy of in-situ alkyl chain growth on balsa wood not only preserves its structure but also opens new avenues for the multifunctional development of biomaterials. [ABSTRACT FROM AUTHOR]

In this study, Kraft lignin was modified by ammonium dihydrogen phosphate (ADP) and urea for achieving phosphorylation and carbamylation, aiming to protect wood against biological and fire attack. Scots pine (Pinus sylvestris L.) sapwood was impregnated with a water solution containing Kraft lignin, ADP, and urea, followed by heat treatment at 150 °C, resulting in changes in the properties of the Kraft lignin as well as the wood matrix. Infrared spectroscopy, 13C cross-polarisation magic-angle-spinning (MAS) nuclear magnetic resonance (NMR), and direct excitation single-pulse 31P MAS NMR analyses suggested the grafting reaction of phosphate and carbamylate groups onto the hydroxyl groups of Kraft lignin. Scanning electron microscopy with energy dispersive X-ray spectroscopy indicated that the condensed Kraft lignin filled the lumen as well as partially penetrating the wood cell wall. The modified Kraft lignin imparted fire-retardancy and increased char residue to the wood at elevated temperature, as confirmed by limiting oxygen index, microscale combustion calorimetry, and thermogravimetric analysis. The modified wood exhibited superior resistance against mold and decay fungi attack under laboratory conditions. The modified wood had a similar modulus of elasticity to the unmodified wood, while experiencing a reduction in the modulus of rupture. [Display omitted] [ABSTRACT FROM AUTHOR]

Vascular cambium in tree species is a cylindrical domain of meristematic cells that are responsible for producing secondary xylem (also called wood) inward and secondary phloem outward. The poplar (Populus trichocarpa) WUSCHEL (WUS)-RELATED HOMEOBOX (WOX) family members, PtrWUSa and PtrWOX13b , were previously shown to be expressed in vascular cambium and differentiating xylem cells in poplar stems, but their functions remain unknown. Here, we investigated roles of PtrWUSa, PtrWOX13b and their close homologs in vascular organization and wood formation. Expression analysis showed that like PtrWUSa and PtrWOX13b , their close homologs, PtrWUSb , PtrWUS4a/b and PtrWOX13a/c , were also expressed in vascular cambium and differentiating xylem cells in poplar stems. PtrWUSa also exhibited a high level of expression in developing phloem fibers. Expression of PtrWUSa fused with the dominant EAR repression domain (PtrWUSa-DR) in transgenic poplar caused retarded growth of plants with twisted stems and curled leaves and a severe disruption of vascular organization. In PtrWUSa-DR stems, a drastic proliferation of cells occurred in the phloem region between vascular cambium and phloem fibers and they formed islands of ectopic vascular tissues or phloem fiber-like sclerenchyma cells. A similar proliferation of cells was also observed in PtrWUSa-DR leaf petioles and midveins. On the other hand, overexpression of PtrWOX4a-DR caused ectopic formation of vascular bundles in the cortical region, and overexpression of PtrWOX13a-DR and PtrWOX13b-DR led to a reduction in wood formation without affecting vascular organization in transgenic poplar plants. Together, these findings indicate crucial roles of PtrWUSa and PtrWOX13a/b in regulating vascular organization and wood formation, which furthers our understanding of the functions of WOX genes in regulating vascular cambium activity in tree species. • Vascular tissues in tree species are organized into a highly ordered cylinder that is produced and maintained by the activity of vascular cambium. • The CLE41-PXY-WOX4 signaling pathway regulates the dynamic balance between vascular cambium cell proliferation and differentiation. • We have demonstrated roles of PtrWUSa and PtrWOX13a/b in regulating vascular organization and cambial activity in poplar. • Our findings further our understanding of the functions of WOX genes in regulating vascular cambium activity in tree species. [ABSTRACT FROM AUTHOR]

Surface molecularly imprinted materials on wood-based carriers were prepared using silane-modified deligninized balsa wood to specifically recognize and adsorb OVA. [Display omitted] • Silane-modified wood as a novel carrier to construct MIPs@KW-Si for adsorbing OVA. • The porous structure of wood enhance the adsorption capacity of MIPs@KW-Si. • MIPs@KW-Si exhibits a dual response to temperature and pH to enhance ad/desorption. • MIPs@KW-Si can be used as a novel separation medium for rapid adsorption of OVA. Suitable imprinting methods and carriers for preparing molecularly imprinted materials can improve both the adsorption capacity and selectivity of proteins. In this study, surface molecularly imprinted materials on wood-based carriers (MIPs@KW-Si) were successfully constructed, with temperature/pH dual-responsive ability and dynamic adsorption for selective recognition of ovalbumin (OVA) template molecules. Balsa wood was delignified, modified by silane and was used as a porous carrier to obtain MIPs@KW-Si. The MIPs@KW-Si can well recognize OVA at a pH of 8.5 and a temperature of 25 °C, showing an OVA adsorption capacity of 23.96 mg·g−1 and a high recognition capacity (imprinting factor of 4.26) at a short adsorption equilibrium time of 60 min. The OVA adsorption process of MIPs@KW-Si followed the Pseudo-second-order model and Langmuir model, meaning a monolayer chemisorption with a maximum saturated adsorption of 35.91 mg·g−1. MIPs@KW-Si also had strong specific adsorption capacity for OVA, and the selection factors (α) for bovine serum albumin (BSA) and bovine hemoglobin (BHB) could reach 6.47 and 45.5, and the adsorption capacity remained above 86 % of the equilibrium adsorption capacity after five repeated regeneration experiments. Additionally, a filter constructed by MIPs@KW-Si can achieve a filtration process for fast adsorbing OVA, with an excellent adsorption/desorption effect. The study shows that MIPs@KW-Si is an ideal molecularly imprinted material for OVA with broad potential applications. [ABSTRACT FROM AUTHOR]

Thermal energy storage wood has been rapidly developed as a green and renewable energy-saving building material. In this study, bio-based Schiff bases (VF) were prepared from vanillin and furfurylamine via aldehyde–amine condensation and used as a small molecule fixative. Subsequently, VF and dodecylamine were mixed uniformly and impregnated into rubberwood under pressure, affording thermal energy storage wood (TESW-x%VF). The results revealed that TESW-x%VF exhibited adjustable enthalpy (41.67–88.23 J g−1) and room-temperature phase transition (25°C–27°C). Moreover, the addition of VF improved the antileakage performance of TESW. According to density functional theory calculations, this is because the adsorption energy between VF and dodecylamine molecules has increased by 3–8 times compared to dodecylamine molecules. The above results provide a solution for the leakage issue associated with organic phase-change materials and aid in the future development of energy-saving wood building materials, which also improves the high-value utilization of chemical components in agricultural and forestry crops. [Display omitted] • Small molecule fixing agents (VF) help to improve the high-value utilization of chemical components inforest resources. • VF and dodecylamine were mixed and impregnated into rubberwood to obtain a bio-based thermal management material. • VF plays a role similar to a crosslinking agent though hydrogen bonding interaction in the fatty amine phase change system. • Thermal energy storage wood (TESW) exhibited room-temperature phase transition and adjustable enthalpy. [ABSTRACT FROM AUTHOR]

Industrial gaseous emissions of volatile organic compounds (VOCs) may result in adverse effects to environment and human health, thus must be removed from flue gas before emitted to the atmosphere. Here we present a study of a real-world testing of a novel hybrid gas-to-particle conversion system targeting VOC removal from the ventilation air originating at wood processing facilities. Terpenes (primarily a-pinene, ppinene, and «-terpineol) were targeted as the prevailing VOCs. The system was realized as a single-pass reactor having multiple stages of plasmolysis/ozonolysis, photolysis, nucleation, coagulation and agglomeration of aerosols, as well as precipitation of agglomerates in an electrostatic field. The VOC removal efficiency in terms of total VOCs (TVOCs) has reached 92.8%, while 100% removal efficiency of a-pinene, ppinene, and a-terpineol was achieved with the non-thermal plasma (NTP) operating at a specific energy input (SEI) of 3.6 J/L (42 J/L of entire system). The advanced gas-phase oxidation system proved to be competitive in treating VOC polluted flue gases in terms of removal efficiency and relatively low energy input. The results hereafter promote faster development and extensive industrial application of gas-phase advanced oxidations systems based on the gas-to-particle conversion process. [ABSTRACT FROM AUTHOR]

In this work, a reactive multiphase particle-in-cell model based on the Eulerian-Lagrangian framework is developed to numerically investigate the wood gasification process in a three-dimensional air-blown bubbling fluidized bed gasifier with the reactive charcoal as bed material. After the model validation, the impacts of gas velocity and initial bed height on the physical and thermophysical properties of gas-solid reacting flow are studied. The results show that lighter particles suspend at the upper part of the dense region with a larger rising velocity due to the density- and size-induced segregation. The vertical dispersion of both particle species is two orders of magnitude larger than the horizontal one. Large heat transfer coefficient (HTC) of solid phase appears in the rising path of biomass. Superficial gas velocity significantly affects the composition and the thermal properties of gas species. Heavy charcoal particles mainly distribute in the dense region with a high temperature and small HTC. Enlarging the superficial gas velocity increases the CO 2 concentration whereas decreases the yields of combustible gas species. Initial bed height exerts an insignificant effect on the thermal property of gas phase, especially in the dense region. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are commonly utilized as an effective pretreatment method for biomass materials, particularly for enhancing the value of lignocellulosic biomass. However, to the best of our knowledge, the utilization of DESs for in situ pretreatment of wood samples has been seldom reported. In this study, the ability of five DESs systems to in-situ pretreatment of balsa wood samples was investigated. Among of them, the Choline Chloride-Ethylene Glycol-P-Toluenesulfonic Acid (ChCl-EG-PTSA) system showing an excellent lignin removal rate (the lignin removal of 87.34 % and cellulose retention of 86.32 %), which is significantly better than the delignification effect of the traditional acid chlorite method (lignin removal of 72,13 % and cellulose retention of 64.57 %). In addition, in the subsequent enzymatic saccharification experiments, after the wood samples were pretreated in situ by the ChCl-EG-PTSA system, the enzymatic saccharification yield of cellulose reached 75.46 %, and the enzymatic saccharification yield of xylose reached 92 %. At the same time, this study also used SEM, FTIR, XPS, TGA and other testing technologies to conduct detailed analysis and characterization of the pretreated samples. This comprehensive analysis unequivocally demonstrated the viability of the ChCl-EG-PTSA system as an environmentally sustainable and efficient approach for pretreating forest biomass. Significantly, this in-situ wood pretreatment strategy significantly lays a robust research groundwork for the development of multifunctional wood fiber composites in subsequent stages. [Display omitted] • In-situ pretreatment of wood samples using DESs systems. • The ChCl-EG-PTSA system removed 87.34 ％ lignin. • Cellulose yielded 75.46 % enzymatic saccharification, while xylose yielded 92 %. [ABSTRACT FROM AUTHOR]

T. dolabrata is a valuable conifer and an essential forestry species endemic to Japan. The essential oil extracted from the wood has a unique relaxing woody fragrance and possesses antifungal, and anti-allergic potentials. Given the potential of the plant wood to serve as a rich source of bioactive compounds and pharmacology, there is a need for a comprehensive understanding of the current state of knowledge on this medicinal plant. A systematic review adopting the PRISMA 2020 protocol with emphasis on studies carried out from January 2000 to December 2023 was conducted. The review focused on extraction techniques, phytochemistry, and therapeutic applications of wood biomass. Findings from the review have revealed the presence of various phytochemicals in the wood with terpenoids (Thujopsene and Hinikitiol) being the most abundant compounds. Among the methods reviewed, supercritical fluid extraction was reported as the method with the best extraction yield, and maceration was the cheapest and easiest method. The isolation methods used are mainly HPLC and column chromatography. The review also identified studies supporting the pharmacological potentials which include psychological and physiological activity, antifungal and antimicrobial activity, anti-allergic activity, cytotoxicity, and anti-tumor activity. However, there is a need for further research to unveil yet-to-be-identified compounds, optimize extraction methods using green techniques, and further validate therapeutic applications. T dolabrata wood emerges as a promising source of bioactive compounds, prompting exploration for sustainable extraction practices and expanded medicinal applications. • The extraction methods applied to T. dolabrata wood include both conventional and modern techniques. • The major compounds currently identified in the woods of T. dolabrata are mainly terpenoids and the most abundant compounds are thujopsene and hinokitol. • The current research on the pharmacological potentials of T. dolabrata wood includes allergy, antimicrobial, psychological, physiological, cytotoxicity, and anti-tumor activity. • Thujopsene and Hinokitiol are responsible for the major pharmacological potential of the wood. [ABSTRACT FROM AUTHOR]

Phase change material (PCM) with outstanding thermal energy storage and temperature regulation, holds tremendous interest in energy conservation and management. However, the application of conventional PCMs is limited due to issues of liquid leakage, poor mechanical properties, and insufficient photothermal conversion efficiency. In this work, inspired by the powerful muscle system, we developed a shape-stable PCM via in-situ polymerization of polyurethane in the wood. This wood-based PCM could reach a tensile strength of 96.5 MPa along the longitudinal direction, up to 3–50 times that of reported PCMs, due to a unique aligned fiber array and energy dissipation system. Meanwhile, this composite had a high enthalpy of 95.4 J/g and a photothermal conversion efficiency of 83.2 %. It is believed that such an eco-friendly and ultrastrong wood-based PCM with efficient solar energy utilization will be a novel option for building energy collection, storage, and regulation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A stable and flexible semi-dissolved wood PAA ionogels is achieved. • Ionogels prepared from natural wood via top-down strategy are anisotropic. • Translucency, anti-drying and fatigue resistance are demonstrated. • Wood ionogel sensor exhibits excellent electrical conductivity and high sensitivity. Ionogels exhibit outstanding ionic conductivity, thermal stability, and non-volatility, positioning them as highly promising for sensor devices rivaling hydrogels. However, the inherent limitation of most existing ionogels is that their strength and toughness are not ideal, which significantly hinders their widespread application. One possible method is using natural wood with anisotropic properties to reinforce ionogels. Herein, we reported a top-down approach to obtain a semi-dissolved wood template, in which the delignified balsa wood was heated and impregnated in an ionic liquid to partially dissolve the cellulose in the wood skeleton. Finally, acrylic acid was infiltrated into the wood template, and the wood-based ionogels with a dual network were successfully synthesized by in-situ polymerization. The prepared wood-based ionogels were significantly anisotropic with longitudinal strength up to 9.0 MPa and radial strength of 0.97 MPa. These wood ionogels also have translucency (53.9 %), anti-drying (remain stable at room temperature for more than 30 days), fatigue resistance (>500 loading cycles), and flexibility. In addition, they have excellent electrical conductivity (3.8 μS cm−1) with high sensitivity (GF = 8.6), making them ideal candidates for strain sensors capable of detecting a wide range of human activities. The preparation of gel using semi-dissolved wood as a template provides an advanced strategy for producing biomass-based flexible gel materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dissolved BrC fractions account for approximately 1/3-1/2 of DOC formulae. • Dissolved BrC shows high levels of OS C , DBE, and AI mod than those of DOC. • CRAMs-like structures are the most abundant species in DOC and dissolved BrC. • Molecular compositions of DOC and dissolved BrC show similarities and differences. Recently, extreme wildfires occur frequently around the world and emit substantial brown carbon (BrC) into the atmosphere, whereas the molecular compositions and photochemical evolution of BrC remain poorly understood. In this work, primary smoke aerosols were generated from wood smoldering, and secondary smoke aerosols were formed by the OH radical photooxidation in an oxidation flow reactor, where both primary and secondary smoke samples were collected on filters. After solvent extraction of filter samples, the molecular composition of dissolved organic carbon (DOC) was determined by Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). The molecular composition of dissolved BrC was obtained based on the constraints of DOC formulae. The proportion of dissolved BrC fractions accounted for approximately 1/3–1/2 molecular formulae of DOC. The molecular characteristics of dissolved BrC showed higher levels of carbon oxidation state, double bond equivalents, and modified aromaticity index than those of DOC, indicating that dissolved BrC fractions were a class of organic structures with relatively higher oxidation state, unsaturated and aromatic degree in DOC fractions. The comparative analysis suggested that aliphatic and olefinic structures dominated DOC fractions (contributing to 70.1%-76.9%), while olefinic, aromatic, and condensed aromatic structures dominated dissolved BrC fractions (contributing to 97.5%-99.9%). It is worth noting that dissolved BrC fractions only contained carboxylic-rich alicyclic molecules (CRAMs)-like structures, unsaturated hydrocarbons, aromatic structures, and highly oxygenated compounds. CRAMs-like structures were the most abundant species in both DOC and dissolved BrC fractions. Nevertheless, the specific molecular characteristics for DOC and dissolved BrC fractions varied with subgroups after aging. The results highlight the similarities and differences in the molecular compositions and characteristics of DOC and dissolved BrC fractions with aging. This work will provide insights into understanding the molecular composition of DOC and dissolved BrC in smoke. [ABSTRACT FROM AUTHOR]

For the high-value utilization of wood, a novel non-cytotoxic bifunctional wood (NBW) was synthesized in this study for simultaneous adsorption and detection of Pb(II). Adsorption experiments showcased the remarkable maximum adsorption capacity of NBW, measuring 211.6 mg/g. The adsorption isotherm followed the Langmuir model, and concurrently, adsorption kinetics adhered to the pseudo-second-order model. Critically, NBW exhibited exceptional reusability, maintaining 81.0% of its initial adsorption capacity even after undergoing six consecutive adsorption/desorption cycles. Additionally, it demonstrated notable temporal stability, preserving more than 84.2% of its initial adsorption capacity after a fifteen-week storage period. Furthermore, NBW was used for selective and sensitive detection of Pb(II), yielding a low limit of detection of 0.13 μg/L. The fluorescence quenching of NBW resulted from both the internal filtering effect and dynamic quenching. Importantly, the cost analysis demonstrated that the expense of removing Pb(II) per gram using NBW was only CNY 0.50, significantly lower than the cost associated with activated carbon, totaling CNY 2.11. This study lays the groundwork for the development of a long-term stable, reusable, cost-effective, and multifunctional adsorbent. [Display omitted] ● A novel non-cytotoxic bifunctional wood (NBW) was synthesized. ● NBW simultaneously has efficient adsorption and sensitive detection abilities. ● Maximum adsorption capacity of the NBW for Pb(II) ion was 211.6 mg/g. ● NBW had sensitive detection ability with low detection limit of 0.13 μg/L. [ABSTRACT FROM AUTHOR]

Recovery and analyses of perishable non-charred archaeological wood is extremely rare. Traceological analyses in general are still scarce and mainly focused on waterlogged remains. Ancient desiccated wood from the Canary Islands offers an exceptional opportunity to identify the processes and techniques of the indigenous populations prior to the arrival in the 14th and 15th centuries AD of European colonists. This paper offers xylological and morpho-technological data linked to artefacts recovered in cliffside Prehispanic communal granaries in Gran Canaria (Canary Islands, Spain). The findings gleaned from a combination of xylological and traceological analyses are for the moment the first of their type of the archipelago's indigenous contexts. The data suggest the widespread exploitation of pine (Pinus canariensis) and fig tree (Ficus carica) and advances several analytical categories for wood artefacts and fragments. The identification and description of the different traces is followed by hypotheses as to the technical actions and the nature of the active edges of the stone tools. Thus, work-waste is identified and linked to several technical actions with the aim of reconstructing the chaînes opératoires. Moreover, further experimental research could offer a better understanding of the functions of these wooden artefacts. [ABSTRACT FROM AUTHOR]

• Comprehensive investigation into pyrolysis kinetics of different wood samples using DAEMs. • High model fit accuracy exceeding 98% demonstrated in all three distribution models. • Identified increased cellulose content in naturally aged wood, influencing resource utilization. • Weibull model exhibited superior predictive power in capturing the complexities of pyrolysis process. • Recognition of key parameters ln A and E as influencers over accurate DAEMs establishment. Recycling and reusing biomass is an effective strategy to enhancing bioenergy utilization and minimizing resource waste. This study aims to investigate the pyrolysis mechanisms and kinetic predictions of typical Cypress Wood (CW), Fir Wood (FW), Old Cypress Wood (OCW), and Old Fir Wood (OFW) samples, Distributed Activation Energy Models (DAEMs) were employed to fit the pyrolysis processes of the two types of wood before and after natural aging. For this purpose, three activation energy distributions, Gaussian, Logistic, and Weibull, were selected to investigate the optimal reaction function model. Each model was simultaneously fitted the extracted experimental α and d α /d T data at three heating rates. Important features and relationships of the models were discussed, and the best model was chosen. Additionally, the isoconversional method was used to validate the optimal model, and the sensitivity of the best parameters were estimated. The result shows that the Weibull distribution is more effective in predicting the trend of the conversion rate against the activation energy. In addition, the most obvious effects of the pre-exponential factor and activation energy on the pyrolysis process. [ABSTRACT FROM AUTHOR]

Wood is an abundant source of biomass and an important biomaterial for renewable resources and industrial products worldwide. Fasciclin-like arabinogalactan proteins (FLAs) are essential for plant growth, development, and responses to various abiotic stresses and are also closely associated with wood formation. However, the biological roles of FLAs in trees remain largely unclear. Here, we identified the FLA family in the ironwood tree (Ostrya rehderiana) and elucidated its possible function in poplar. Our results showed that OreFLAs underwent significant gene expansion due to multiple duplication events, leading to apparent functional redundancy. Among these genes, OreFLA11 was highly expressed in the xylem and roots. Overexpression of OreFLA11 in Populus alba var. pyramidalis altered xylem structure and cell wall composition, such as thickening the xylem and secondary cell wall (SCW), decreasing lignin contents and increasing cellulose contents, resulting in increased stem tensile strength but decreased salt tolerance, suggesting that OreFLA11 plays a negative role in the salt stress response. The mutant Palfla11 generated using CRIPSR-Cas9 methods showed the opposite phenotype compared to that of OreFLA11-OE poplars, indicating that the orthologues function similarly in wood formation. Furthermore, the transcriptome analysis showed that genes such as PME , BGAL and BGLU , related to cell wall biosynthesis, were up-regulated while the genes associated with salt stress resistance (CYSB , TSPO , RCI2B and CIPK6) were down-regulated in OreFLA11-OE poplars. These results indicated that OreFLA11 promotes wood formation and modulates stem mechanical properties but decreases tolerance to salt stress by decreasing the transcript abundance of salt-responsive genes in trees. • The FLA gene family has expanded in woody plants, and OreFLAs showed functional redundancy in Ostrya rehderiana. • OreFLA11 promoted wood formation by impacting stem biomechanics and cell wall composition. • OreFLA11 negatively regulated salt tolerance by decreasing the transcript abundance of salt-responsive genes. • The function of the ortholog PalFLA11 from Populus alba var. pyramidalis was similar to that of OreFLA11 in wood formation and the salt stress response. [ABSTRACT FROM AUTHOR]

During major floods, rivers erode their banks and thus recruit large wood pieces from the riparian zones. There is still a lack of knowledge about the transport of large wood, the volumes involved and the flux distribution, i.e. the large wood connectivity at catchment scale. During storm Alex (October 2020), the French Roya catchment (394 km2) experienced a paroxysmal morphogenic flood involving massive bank erosion. The riparian vegetation was largely recruited, with large wood contributing to logjams and bridge destruction. This paper presents a methodology for volumetric assessment of the large wood fluxes involved. Simple approaches are used to (i) quantify the inputs from stand density data from the national forest inventory and from source areas based on diachronic analysis of active channels highlighting the erosion of 87 ha of wooded areas; and (ii) quantify the volumes deposited via an exhaustive manual digitisation of 16,846 pieces of large wood deposited on 59 km of channels on the Roya and its tributaries. This catchment-scale, large wood connectivity analysis shows that the flood recruited and transported downstream a volume of around 14,000 m3 of large wood (uncertainty range: 7000–29,500 m3). Drone observations of the Roya River mouth in Italy and satellite images showing a raft of driftwood, several km long, drifting off the Roya River mouth in the aftermath of the flood corroborate our findings. • Storm Alex (Oct. 2020) triggered dramatic geomorphic changes in the Roya River (FR). • We quantified the volume of large wood (LW) eroded, conveyed and deposited. • Large wood production is deduced from eroded forest maps and forest stand density. • Large wood deposition is estimated by digitizing logs on aerial pictures. • Circa 14,000 m3 of LW were recruited, 900 m3 deposited, the rest went to the sea. [ABSTRACT FROM AUTHOR]

Severe climate change and urgent climate action have raised concerns about wood. Overharvesting and increased wood waste are putting immense pressure on sustainable forest management and the global carbon budget. In Germany, a vital wood supplier and user in Europe, the wood supply chain's production, consumption, trade, and recycling have been insufficiently investigated. To tackle this challenge, we conducted a comprehensive dynamic wood flow analysis from 1991 to 2020. Approximately 2143 million cubic meters of standing timber were felled in German forests over the past three decades, with 80% used for materials and 20% for energy purposes. Wood flow patterns were susceptible to market demand and forest disturbances like drought, storms, and insect infestations. The storm in 2007 left a notable impact, leading to the highest figures ever recorded for various wood products. Notably, the net forest carbon sink, carbon storage in forest products, and energy substitution effect (replacing fossil energy with wood) reached 160, 332, and 343 million tons of carbon, respectively. However, the transition to renewable energy, wooden buildings, and wood and paper packaging demands further strains the wood supply chain. To promote sustainable forest management and achieve climate neutrality, we propose potential strategies for consideration. [Display omitted] [ABSTRACT FROM AUTHOR]

The use of mass timber framing as a sustainable material, particularly in high-rise buildings, requires detailed structural fire performance calculations. Thermal models describing only the solid phase are cost-effective alternatives to provide information to structural behavior models. Their accuracy depends on an adequate description of drying, pyrolysis, charring and eventually flaming phenomena. While in recent years there have been considerable contributions to the development of such models, there are still open questions. This work proposes a thermal model which incorporates char oxidation, describing both the kinetic- and diffusion-controlled regimes. The model was used to replicate two sets of experimental results which used standard fire calorimeters to study the ignition of thick wood specimens within a range of incident heat fluxes and oxygen concentrations, respectively. The model yields adequate temperature predictions in the early heating stages, but fails to replicate the behavior at later stages, when the effect of the surface combustion is noticeable. In terms of mass loss rates, a poorer performance is observed. To change from one oxidation regime to another, a Damköhler number is proposed, based on char oxidation reaction rates. It is found that for compartment fire conditions, char oxidation will mostly occur develop under diffusion-controlled conditions. • The model for char oxidation considers kinetic- and diffusion-controlled regimes. • Temperature predictions are accurate in early heating stages. • In fires, char oxidation will more frequently be controlled by oxygen diffusion. [ABSTRACT FROM AUTHOR]

A fundamental understanding of the composition of archaeological wood stored under oxygen-limited environments, such as waterlogged sediments, is needed to inform preservation conditions of remains and to evaluate the validity of sediment and tree core-derived proxies of past environmental conditions. For this purpose, we determined chemical changes along the radial direction of archaeological (∼2000 yrs old) and modern (growth period 1948 to 2018 CE) wood of the Chinese swamp cypress (Glyptostrobus pensilis), an ethnobotanically important species in subtropical China, using conventional analytical pyrolysis (pyrolysis-gas chromatography-mass spectrometry; Py-GC-MS), pyrolysis with in situ methylation (thermally assisted hydrolysis and methylation; THM-GC-MS), and Fourier-transform infrared (FTIR) spectroscopy. The results showed 1) excellent preservation of the archaeological wood expressed by significant contributions of levoglucosan to the polysaccharides fingerprint after Py-GC-MS; 2) considerable chemical differences between archaeological and modern wood, i.e. archaeological wood samples yield relatively small proportions of lignin and large proportions of polysaccharides and terpenoids; 3) major differences in chemical characteristics of sapwood (more polysaccharides) and heartwood (more lignin). Furthermore, some tested decay proxies show large differences between sap- and heartwood (and are therefore of little value), yet the 4-acetylguaiacol/total guaiacol ratio (4AG/G; Py-GC-MS) of heart- and sapwood are similar, implying that this ratio is a more suitable proxy for decay assessment. Data comparison allowed to identify discrepancies and complementarities of Py-GC-MS, THM-GC-MS and FTIR for the characterization of different wood constituents and their preservation during long-term storage under waterlogged conditions. These results expand our understanding of the chemical composition of decomposing trunks of archaeological wood in general, and of G. pensilis in particular. [Display omitted] • Archaeological and modern Glyptostrobus pensilis wood analyzed by Py-GC-MS, THM-GC-MS and FTIR. • Post-depositional decay reflected by preferential decay of polysaccharides and preservation of lignin. • Clear evidence of lignin alteration in archaeological wood from parameters such as 4-acetylguaiacol/guaiacol. • Significant compositional differences between heartwood and sapwood influence potential decay proxies. • Application and cross-validation of multiple techniques recommended to identify pitfalls. [ABSTRACT FROM AUTHOR]

• Integrative transparent fire-retardent coating was facilely constructed. • Integrative coating preserves the texture and structure of the wood. • Introduction of nano-CeO 2 imparts super fire resistance to integrative coatings. • Adding nano-CeO 2 achieves long-term fire protection of integrative coatings. • Integrative coating containing nano-CeO 2 impedes the growth of bacteria. To prevent the coatings applied in historical buildings from aging failure due to environmental factors, an integrative coating with decorative, antibacterial, weather-resistant and flame-retardant properties is particularly important in practical applications. The nanocomposite flame retardants named CPPBs are obtained from the successful grafting of the phosphate esters to the surface of cerium oxide nanoparticles, which are physically blended with film-forming polymer to construct integrative coating named MCPPBs. The results show that adding nano-CeO 2 greatly strengthens the mechanical property, fire protection performances, weather resistance, antibacterial activity of the integrative coatings, and maintains high light transmittance in the meantime. Especially, when the addition of nano-CeO 2 in flame retardant is 0.5 wt.%, the expansion ratio of the MCPPB3 coating increases to 65 and the char index reduces to 15.7cm3, concomitant with a high transparency of 80.3 %. By combining FTIR, SEM and EDS analyses, the MCPPBs char containing nano-CeO 2 is compact and dense. In the accelerated aging test, the back equilibrium temperature of the MCPPB3 coating at 900 s is still less than 220 °C concomitant with a complete surface morphology after 6 aging cycles. In addition, the MCPPB3 coating exerts a negative effect on the growth of E. coli and S. aureus , and the antibacterial activities against E. coli and S. aureus are 92.8 % and 96.2 %, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

The high sulfuric acid concentration used in the hydrolysis of cellulose to isolate cellulose nanocrystals (CNCs) leads to low yields due to the dissolution of both amorphous and semi-crystalline cellulose. The present study explored the use of steam explosion pretreatment before acid hydrolysis to enhance the crystallization of semi-crystalline/ non-crystalline cellulose and generating new CNC precursors with poplar wood as feedstock. The crystallinity of steam exploded poplar wood increased 1.3-fold compared to untreated poplar wood. Consequently, the overall yield of CNCs of steam exploded poplar wood increased 2.5-fold compared to untreated poplar wood. Moreover, the steam explosion pretreatment did not affect the quality of the CNCs with regard to the crystal size, crystallinity, and colloidal stability. Whereas the thermal stability of the CNCs increased due to the steam explosion pretreatment. This study demonstrates a simple and scalable pretreatment step that can significantly improve the CNCs yield from the acid hydrolysis step thereby improving the overall economics and commercial viability. [Display omitted] [ABSTRACT FROM AUTHOR]

Based on click chemistry of poly(methylhydrogen)siloxane (PMHS), an environment-friendly method was proposed for in-situ fabrication of robust, transparent, UV-resistant and hydrophobic silicone resin coating (SRC) at room temperature by simply brushing a mixture of PMHS, tetramethyltetravinyl cyclotetrasiloxane (V4), and Karstedt catalyst on wood surface. The mechanism for click chemistry of PMHS and the continuous curing characteristic of SRC was discussed based on the characterization of SRC by FTIR and XPS. The effects of the mass ratio of PMHS to V4 and curing time on the properties of SRC and the modified wood were investigated. Results showed that SRC with the mass ratio of PMHS to V4 of 5:1 possessed the best mechanical stability, and the mechanical stability increased with curing time and temperature. SRC improved significantly the hydrophobicity and water-repellency of wood by increasing the water contact angle from 27.2° to 123.1° and decreasing the water absorption rate from 103 % to 16 %. SRCs showed excellent transparency with an average transmittance of 92.3 % at 400–1100 nm. The UV resistance of SRC was 6 times higher than that of varnish coating. The click chemistry of PMHS will find great application in rapid fabrication of functional coatings on wood surface by using PMHS and any vinylated reagent or micro-/nano-particles. [Display omitted] • Mechanism of click reaction of PMHS is discussed. • Functional silicone resin coating on wood was prepared by a rapid method. [ABSTRACT FROM AUTHOR]

• Experimental data on wood thermal degradation at TGA and cone calorimeter scales. • Improved kinetic mechanism for wood thermal degradation. • 1D-Modeling of wood thermal degradation at the cone calorimeter scale. Understanding the process of pyrolysis is crucial to achieve continuous progress in the efficient use of wood as a fuel source in various applications. In the literature, a wide range of kinetic models for wood pyrolysis has been introduced, varying from simpler to more complex and predictive. Some of these models are mathematical, with the sole objective of fitting the experimental results. The others are physical models that describe the underlying chemical processes involved in wood thermal degradation, but they tend to be more complex and time-consuming. In our study, a compromise between these two categories of models was established. A new physical and simple kinetic model of wood thermal degradation was proposed. This model was validated using a multi-scale approach. At micro scale, the thermal degradation of wood was studied using thermogravimetric analysis (TGA). TGA experiments were conducted with two wood species, beech and spruce, in an inert atmosphere at five different heating rates. Based on the latter analysis, our kinetic model of wood thermal degradation was established. Its associated kinetic parameters were determined by fitting the experimental mass loss and mass loss rate data. Good agreement was achieved between the experimental and numerical results. At bench scale, tests were performed in a controlled atmosphere chamber placed in front of a cone calorimeter. The thermal degradation of wood was studied at two heat fluxes in an inert atmosphere obtained by a constant argon injection. The kinetic model developed at the micro scale was implemented into a one-dimensional pyrolysis model, taking into account both thermal and mass transfer phenomena within the wood. The validity of the 1D pyrolysis model was established by comparing the numerical results with the mass loss, mass loss rate, and temperature profile measured during cone calorimeter tests. [ABSTRACT FROM AUTHOR]

Two groups of coffins from the Necropolis of Thebes and held in the Egyptian Museum of Florence were analysed to collect information about the woods used in their construction, possible provenance and the technological features. The two groups of coffins belong to burials during the XVIII Dynasty of the New Kingdom and the XXI Dynasty of the Third Intermediate Period. The latter group comes from the well-known tomb of Bab el-Gasus. The analysis confirms that the most frequently utilised timber for the ancient Egyptian wooden coffins was Ficus sycomorus L. (sycamore fig) that was widely available locally at the time of construction. Sycamore fig wood is light and easy to process, and is the only local tree species suitable for making boards of sufficient length for the sides of coffins. Sycamore fig is used almost exclusively in the coffins from Bab el-Gasus. Here very few other woods were detected, but were all local in origin: Acacia sp., acacia; Tamarix sp., tamarisk. In contrast, the precious softwood of Cedrus cf. libani (probably Lebanon cedar) largely appears in the coffins of the New Kingdom. The comparison of the woods from the analysis of the two groups of coffins points out important differences between them. The differences may depend on the variations over time of the workmanship skills and on the higher social status of the deceased in more ancient periods. Most likely the main difference is due to the worst socio-economic situations that drastically reduced the availability of timber during the XXI dynasty period, in that geographical area of Egypt. [ABSTRACT FROM AUTHOR]

In this work, we first discover the new bifunctional abilities of wood for highly selective electrocatalytic CO 2 reduction to formate and highly sensitive electroanalytical detection of myricetin and cadmium (II). The highly developed microchannels in wood ensure most effective reactant and electrolyte transport, great facilitating the electrode reaction. The activated wood electrode displays excellent electrocatalytic CO 2 reduction activity, attained the highest formate Faradaic Efficiency (FE) of 70.8% at −1.8 V with high current density of 53.8 mA cm−2 in aqueous solution, and displayed at least 24 h CO 2 electrolysis durability. Furthermore, the wood is also first utilized as new electrode matrix for electroanalytical detection of drug (myricetin is as an example) and heavy metal ion (cadmium (II) is as an example). Compared with traditional glassy carbon electrode (GCE) and its derived modified electrodes, the wood electrode exhibits a wide linear detection range (0.01–50 μmol dm−3) and a low detection limit (0.002 μmol dm−3, S/N = 3) for myricetin, and displays a wide linear detection range (0.1–20 μg l−1) and a low detection limit (0.05 μg L−1, S/N = 3) for cadmium (II). These remarkable bifunctional performances of low cost wood electrode show great potential for large-scale using in CO 2 electroreduction and electroanalytical detection. Image 1 [ABSTRACT FROM AUTHOR]

Waterborne chromated copper arsenate (CCA) is a highly effective, widely used wood preservative. While it does not appear to markedly alter the flaming behaviour of treated wood, there are significant concerns regarding post-fire smouldering. Our understanding of the mechanisms and factors affecting smouldering behaviour is currently insufficiently developed. This study used a multiscale approach to better understand smouldering in slash pine treated to different CCA retentions and investigated reaction kinetics through thermogravimetric analysis (TGA) in addition to Cone Calorimeter smouldering tests. Derivative thermogravimetry (DTG) showed that the temperatures at the onset of pyrolysis and oxidation, and where the maximum rate of decomposition occurred were both lowered by CCA treatment, and effects became more pronounced as CCA retention increased. Bench-scale smouldering tests showed that the smouldering mass loss rate increased with higher CCA retention, lower wood density, and prolonged heat exposure. Smouldering mode changed from a steady to an unsteady pattern as CCA retentions decreased to a threshold from combined pyrolysis and oxidation to isolated char-to-ash oxidation. Once initiated, the reaction can be self-sustaining until all the mass has been consumed regardless of the initial smouldering rate. • Increasing CCA retention lowers the oxidation and pyrolysis temperatures of wood. • Smouldering rates increase with higher CCA retention, lower density, and prolonged heating. • During steady smouldering, a threshold in the reaction mechanism was observed. • Thermogravimetric analysis results can be used to predict smouldering behaviour on a larger scale. [ABSTRACT FROM AUTHOR]

The aim of this work was to model the thermal degradation of wood in an inert atmosphere at the cone calorimeter scale. First, the degradation of spruce wood was studied at the matter scale by TGA and DSC in an inert atmosphere at different heating rates. The kinetic parameters associated with a global multi-reaction mechanism were estimated by fitting the mass loss and the mass loss rate obtained by the TGA. The heats of reaction associated with the reaction scheme were estimated by fitting the heat flux measured by DSC. Then, experiments with an inert material (calcium silicate) were performed at the cone calorimeter scale under an inert atmosphere to characterize the boundary conditions of the developed 3D heat transfer model. The boundary conditions were determined by minimizing the difference between the measured in-depth temperatures and the predictions of the model using a least squares method The results showed good predictions in agreement with experimental data and the convective heat transfer coefficients obtained were realistic. Finally, a 3D pyrolysis model, taking into account the anisotropic nature of wood, was developed by coupling the heat transfer with the kinetic model. The latter model was validated by comparison with tests carried out on spruce wood in an inert atmosphere using a cone heater. • Thermogravimetric analysis of wood. • Experiments at the cone calorimeter using thermally inert material. • 3D-Modeling of wood thermal degradation at the cone calorimeter scale. [ABSTRACT FROM AUTHOR]

[Display omitted] • Online alkali measurement during gasification of wood with fresh bed material mixtures. • The main elements in bed material migrate to the char surface and affect gasification. • Dolomite affects pyrolysis and gasification due to deposition and element migration. • Si-containing materials inhibit gasification and alkali release in the final stage. • Residual Na in sea sand and alumina moves to char surface and catalyzes gasification. Bed materials provide efficient heat transfer and catalytic function in the thermochemical conversion of biomass, but their interactions with the fuel remain incompletely understood. In this study, the effects of bed materials on alkali release and fuel conversion during wood pyrolysis and CO 2 gasification are investigated by online alkali detection combined with thermogravimetric analysis. The investigated bed materials include silica, sea sand, alumina and the natural ores olivine, ilmenite and dolomite. Only dolomite has a significant effect on fuel mass loss and alkali release during wood pyrolysis, while all bed materials influence char reactivity and alkali release during gasification. Sea sand, alumina and dolomite enhance the char gasification during the whole or most of the gasification process, which is related to alkali migration from the bed materials. All bed materials affect char reactivity and alkali release when the conversion approaches completion, and small amounts of some bed materials reduce the alkali release by an order of magnitude. The findings can be understood based on the chemical composition of the different materials. Silicon-rich materials reduce the levels of catalytically active alkali by formation of stable alkali silicates, and a similar explanation applies for ilmenite that captures alkali efficiently. Magnesium and calcium in contrast promote alkali release through their influence on alkali silicate chemistry. Analysis of char surfaces using scanning electron microscopy with energy dispersive spectroscopy indicates that low amounts of several elements are transferred from the bed material to the char where they may be directly involved in the char conversion process. The transferred elements are specific for each bed material and relates to their chemical composition. Mechanisms for material exchange between bed material and char are discussed. [ABSTRACT FROM AUTHOR]

Solar-driven sewage purification was considered to be a promising technique for the alleviation of freshwater scarcity issues globally. However, most steam generation devices focused on ultrahigh photothermal conversion and also neglected to develop the potential functions of natural creatures. Here, a deep eutectic solvent (DES) functionalized wood was designed as the supported substrate decorated with black polypyrrole (PPy) to construct low-cost and efficient solar interfacial evaporator. DES modification selectively removed most of the lignin, which enhanced the hydrophilic wetness of wood for the efficient transportation of water from the bottom to the solar interface. The lignin selective removal lowered the thermal conductivity of the evaporator, facilitating the heat location on the gas-liquid interface for efficient steam generation. Most importantly, more cellulose hydroxyl was exposed on the wood surface by the DES process, which was conducive to the in-situ polymerization of pyrrole on the wood surface by hydrogen bond interaction. The prepared PPy-DES wood evaporator achieved a considerable water evaporation rate of about 1.94 kg m−2 h−1 with a corresponding photothermal conversion efficiency of about 83.4% in one sun, arising from the functionalized design of DES wood and efficient photothermal conversion. For seawater desalination and sewage purification, the prepared evaporator exhibited excellent salt self-cleaning ability and stable wastewater purification performance. It was envisioned that the strategy of functionalized design of natural evaporators would motivate a large-scale application of biomaterials for efficient wastewater purification. [Display omitted] • Deep eutectic solvent technique was employed for the wood functionalization. • Delignification enhanced water pumping capacity and reduced thermal conductivity. • Functionalized wood was conducive to the polymerization of pyrrole on wood surface. • Excellent salt self-cleaning and sewage purification performances were achieved. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is an irreversible brain disorder, which has been found to be associated with neurotoxic amyloid-β oligomers (AβO). The early diagnosis of AD is still a great challenge. Herein, inspired by the hierarchical channel structure of natural wood, we design and demonstrate a low-cost and sensitive wood channel-based fluidic membrane for electrochemical sensing of AβO 1-42. In this design, Zn/Cu-2-methylimidazole (Zn/Cu-Hmim) with artificial peroxidase (POD)-like activity was asymmetrically fabricated at one side of the wood channels by biomimetic mineralization and a subsequent ion exchange reaction. The strong affinity between Cu(II) and AβO 1-42 enables Cu(II) species in Zn/Cu-Hmim to be extracted by AβO 1-42 , thus suppressing the POD-like performance via Zn/Cu-Hmim disassembly. Using Zn/Cu-Hmim to catalyze the oxidation reaction of 2,2′-diazo-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) by H 2 O 2 , the current – voltage (I–V) properties of wood channels are influenced by the generated oxidation product (ABTS•+), thus providing information useful for the quantitative analysis of AβO 1-42. Importantly, the three aggregation states of Aβ 1-42 (AβM 1-42 , AβO 1-42 , and AβF 1-42) can also be identified, owing to the affinity difference and available reaction sites. The proposed wood membrane provides a novel, assessable, and scalable channel device to develop sensitive electrochemical sensors; moreover, the sustainable wood materials represent alternative candidates for developing channel-structured sensing platforms. [Display omitted] • Contra-diffusion technique was used to asymmetrically grow POD-like Zn/Cu-Hmim. • Asymmetric Zn/Cu-Hmim enhanced channels' sensitivity via amplified ionic current. • Aβ 1-42 states was identified based on differences in affinity and reaction sites. [ABSTRACT FROM AUTHOR]

Understanding how much wood we use and how we use it has important implications for forest management, economic policy, and climate action. While individual wood streams are documented by various sources, a comprehensive, economy-wide mapping of wood use has been lacking in Denmark. Our study set out to produce a comprehensive national wood flow analysis for all wood products, to include harvest, import, export, and domestic flows through the economy, as well as to assess the level of circular and cascading wood resource use. We used the Physical Supply-Use Tables compiled by Statistics Denmark in combination with other sources to construct wood flows in m3 solid wood equivalent (SWE), enabling comparison throughout the processing chain with the standing natural resource. We estimated total Danish use of wood fibre in 2018 to be around 17.7 million m3 SWE, of which more than 15 million m3 was used for energy production. Most wood used in Denmark is imported, with a net import of more than 11 million m3 SWE. Apart from energy use the domestic wood processing, construction, and furniture industries are the largest users. By using mass balancing principles, we identified significant undocumented flows of wood from nature to the economy which are currently used for energy purposes, representing more than 1 million m3 SWE per year from 2015 to 2021, and we estimated the output of secondary wood products from the wood industry to be around 400,000 m3 SWE in 2018. According to Eurostat's Circular Material Use rate indicator, 8.4% of wood used is recycled and reused domestically, though with imported wood for energy excluded, the rate would be higher, around 17.8%. The overall cascading factor for wood in the Danish economy was calculated to 1.44, indicating that wood is used almost one and a half times before oxidation or final consumption. Ongoing monitoring of Danish wood flows would permit further analysis of any changes in patterns of use and reuse, and our estimates of wood flows could likely be improved with investigation of currently undocumented streams and country specific conversion factors. [Display omitted] • National physical supply-use tables were used to map Danish wood flows with Sankey diagrams. • Total Danish use of wood fibres in 2018 was more than 2.5 times domestic harvest. • Use of wood fibres for energy was 15 million m3 out of 17.7 million m3 total use. • There are likely significant undocumented flows of wood from nature to the economy. • 8.4% of wood used is recycled, comparable to the EU average of 9.4% for biomass. [ABSTRACT FROM AUTHOR]

Silane coupling agent with its special molecular structure is often used to connect organic and inorganic materials. Due to the hydrophobic nature, silane coupling agents are often applied in wood surface modification instead of cell wall. In this study, poplar wood was modified with γ-methacryloxypropyltrimethoxysilane (MPS) to improve the dimensional stability and mechanical properties of the wood through in situ polymerization and hydrolysis-condensation reactions. The SEM/EDS imaging showed that at low monomer dosage, PMPS was uniformly distributed in the wood cell walls, while parts of PMPS formed a film at the cell lumen surface when modified with high concentrations of MPS. FTIR results indicated that PMPS was grafted onto the wood fibers. The XRD of the modified wood showed that the MPS modification did not affect the crystallinity of the wood. The even-distributed polymers PMPS, together with the original hemicellulose and lignin, act as a binder between microfibrils and was proved to impede the swelling of wood more efficiently than ordinary polymer bulking. Compared with untreated wood, 5% MPS modified wood achieved an ASE value of 48.67 ± 4.65% with the WPG only 5.05 ± 0.48%. The impact strength of 30% MPS wood increased by 45.66% compared with the unmodified wood. The ability to improve both dimensional stability and high mechanical properties with PMPS provided a promising modification solution for the functional improvement of wood. • Cross-linking of polymers and wood improves the physical properties of wood. • Simple and efficient modification method, avoids the hazards of organic reagents. • The mechanism of γ-methacryloxypropyltrimethoxysilane(MPS) in wood modification. [ABSTRACT FROM AUTHOR]

This paper describes fire safety experiments on Australian native timber samples with a special focus on their use in bushfire-prone areas. Nine species were assessed through testing in a cone calorimeter, thermogravimetric analysis and differential scanning calorimetry (DSC). The effects of density, moisture content and chemical extractives content were evaluated. Marked differences in ignition times were found, possibly due to variations in density across species, as well as the chemical extractives content. Analysis of the heat flow through DSC indicated that the type of extractives can influence the fire safety performance and that this aspect of wood properties merits further study. One additional species was identified as a suitable candidate for bushfire-resisting species in the Australian bushfire context. • Determination of flammability of northern Australia timber species. • Multiscale testing of varied density and extractive content. • Assessment for timber use in bushfire attack level 29 zones. • Extractives content and ignition have linear correlation. [ABSTRACT FROM AUTHOR]

The carbonization process induces significant physical, elemental, and structural transformations of wood. In this study, the modification of δ18O in wood during the carbonization process was investigated in conjunction with elemental analysis, infrared spectroscopy (FTIR), and Rock-Eval thermal analysis, to explore the connection between the chemical composition of the materials and the alterations in δ18O. Quercus petraea wood samples were experimentally burned at temperatures ranging from 200 °C to 1000 °C under inert (pyrolysis) and oxidative atmospheres. The results reveal that the modification of δ18O values in charred wood can be described as a sequential two-step process. The initial step, occurring below 300 °C, involves the volatilization and preferential degradation of thermolabile compounds, leading to an increase of +1.6‰ in δ18O. The subsequent step, below 700 °C, results in a decrease in δ18O values of –21.6‰, primarily driven by the thermal degradation of cellulose and lignin, as well as the increase of aromaticity and reorganization. The components and the δ18O of wood undergo distinct changes in combustion mode, due to different carbonization kinetics as evidenced by FTIR and elemental analysis. To assess the intensity of the carbonization process, influenced by temperature, oxygen availability, and wood characteristics, the H/C atomic ratio, a good indicator of aromaticity, is used. A non-linear regression model was established, relating δ18O to the H/C atomic ratio, thereby demonstrating that δ18O values undergo changes as wood aromatization progresses, independent of the carbonization conditions. The second order model has a mean confidence interval of 1.9‰ and a prediction interval of 8.1‰. This work provides a fundamental understanding of the connection between the chemical composition of woody materials, alterations in δ18O, and the carbonization process, offering valuable insights for further studies and applications related to oxygen-related information that may be preserved in charcoals. • Quercus petraea was charred in oxidative and reducing atmospheres. • The carbonization process alters δ18O in two steps due to structural changes. • The δ18O changes follow different pathway in combustion and pyrolysis. • Key chemical parameters for identifying the wood carbonization process are provided. • A non-linear regression model links δ18O to wood aromatization via H/C ratio. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fluorination was applied to massive wood. • Covalent grafting of fluorine atoms onto wood surface decreases their hydrophilicity. • The hydrophobic character acquires thanks to fluorination is durable. • Short fluorination does not impact the wood density, morphology, mechanical properties and photodegradation kinetic. Abstract The main limiting factor for the use of solid wood lies in its highly hydrophilic character which is associated with the loss of its properties after moisture uptake. Therefore for limiting the negative impact of moisture in wooden structures, numerous research have been carried out in order to (i) protect the surface of wood by the addition of varied varnish or protections or to (ii) modify the wooden surfaces structure by the mean of different technologies such as thermal treatments. The former present the disadvantage to protect the wood surfaces for a limited period of time while the later present the disadvantage to reduce the mechanical properties. The aim was investigate how to reduce the hydrophilic character of wood without reducing physical and/mechanical properties. We use dynamic fluorination using F 2 gas applied to wood samples (Douglas and silver fir) for reducing the hydrophilic character. The covalent grafting of fluorine atoms on a wood surface was highlighted by Fourier-Transform infrared spectroscopy and 19F solid state Nuclear Magnetic Resonance. The wood samples acquire a hydrophobic character comparable to that of Polytetrafluoroethylene, thanks to fluorination. The high durability of this treatment was also determined by aging tests under ambient atmosphere and UV irradiation. Moreover, this treatment gives a surface with a hydrophobic character without major structural (morphology, density and colour) and mechanical modifications. Maintaining those properties after fluorination, a dried gas/solid treatment without the use of toxic solvents and high temperatures seems to show a remarkable advantage over other physical chemical wood treatments. [ABSTRACT FROM AUTHOR]

• Each studied wood species presents a specific acoustic activity in terms of emissivity and energy. • The acoustic activity is related to the degree of heterogeneity of the species. • The more the species is heterogeneous, the more the acoustic signatures are specific. • The more the species is heterogeneous, the more the signals statistical classification is effective. The use of wood in civil engineering structures, such as timber bridges, has been increasing in recent years. Unfortunately, our knowledge of their behaviour towards sustainability problems is far from complete and it is necessary to develop monitoring techniques like acoustic Emission (AE) that allow early identification of pathologies. This study focuses on the analysis of the influence of wood species on the acoustic response under bending loading. The results of this experimental study show a correlation between AE signal features and certain failure mechanisms but also that these acoustic signatures are different for each timber species. [ABSTRACT FROM AUTHOR]

• Wood species identification is crucial for a proper evaluation of timber members. • Semi-destructive test provide information regarding possible aging effects. • The effect of ageing (damage of cell wall) lead to a reduction of tensile strength. • In-situ test information should be crossed with wood species information. A proper assessment of the properties of timber members is dependent upon the capacity for acquiring sufficient information onsite. A large part of this depends on the ability to identify wood species which is consequently used for selecting and applying a suitable visual strength grading standard. However, given the wide variability associated with the mechanical properties, normally above 20%, and the possible ageing effects due to load and moisture history, visual grade information should be complemented by information from onsite tests. This paper presents the results of a methodology for assessing old timber members where all information collected from wood identification and semi-destructive testing (wood coring and tensile tests) are combined and analysed. The results stress the importance that the combination of information from different sources can provide in terms of a safer and more reliable assessment of timber members in service. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Wood is the main source of lignin in the world. This generic term "Lignin" describes a large group of aromatic biopolymers, i.e. the second most abundant class of biopolymers on Earth. It accounts for approximately 30% of wood weight while conferring rigidity and antimicrobial properties to wood. Since lignin is combined with cellulose and hemicellulose in biomass, this will constitute a limiting factor in the bioconversion of wood into pulp or second-generation biofuels through the biochemical pathway. These processes generate a huge quantity of lignin as by-products, mainly used as fuels for energy savings. Recently, alternative routes towards lignin's valorization were emphasized (e.g. as bio-based resins, adhesives, or composites), but they strongly depend on lignin's chemical structure, also dependent on fractionation process. Therefore, this review aims to summarize the strong interplay between extraction processes, resource supply, and recent uses of lignin into bio-based materials. [ABSTRACT FROM AUTHOR]

Abstract In this study, pyrolysis of the wood samples with varied C/H ratio on distribution of the products was investigated. The results show that C/H ratio in the biomass drastically affects the yields of char, tar and gas. Poplar has a higher C/H content, and consequently it produces a higher yield of char and the lower yield of tar. Pine wood has the lower C/H ratio, and the pyrolysis produces the lower char but higher gas and tar yields. Furthermore, the C/H ratio in the feedstock affects the elemental composition and the stability of the tar. The higher C/H ratio in biomass resulted in the tar with a higher stability during pyrolysis of the tar. The C/H ratio also affected the formation of the aromatic ring structures in the tar. The pyrolysis of poplar with the highest C/H content produced more aromatics with smaller ring size in the tar, while that from pine with the lowest C/H content produced more aromatics with bigger ring size. The tars produced from the feedstock with the different C/H ratio show a large similarity in terms of distribution of the functionalities but with varied intensities. The TG-MS characterisation showed that the organics in the tar did not reach the equilibrium and could continue to decompose during heating, producing CO 2 via decarboxylation, CO via decarbonylation and H 2 via dehydrogenation reactions. The DRIFTS study of heating char in inert atmosphere showed that the char originated from the different biomasses had distinct stabilities and distinct tendencies towards aromatisation. Highlights • Pyrolysis of poplar with a higher C/H ratio produces more char and less tar. • Pyrolysis of pine with a lower C/H ratio produces less char while more gas and tar. • The C/H ratio also affected formation of the aromatic ring structures in tar. • TG-MS result showed that organics in tar did not reach the equilibrium. • DRIFTS study showed that different char had distinct tendencies towards aromatisation. [ABSTRACT FROM AUTHOR]

Abstract Irradiation with γ rays is widely used in the sterilization of a large variety of products and materials in the field of medical supplies, pharmaceuticals, cosmetics, food industry and cultural heritage. It is also applied on wood materials, with the purpose of improving their shelf-life, by lowering the microbial charge and hence the microbial-related deterioration rate. A fundamental issue when applying γ rays is the preservation of the chemico-physical as well as of the structural and mechanical properties of the materials irradiated, since a significant change of properties may jeopardize the use of the materials for the purpose intended. To this end, in this paper, we analyzed the chemico-physical properties of four different types of wood used for the construction of musical instruments namely fir, maple, poplar and durmast oak under increasing doses of γ rays. In detail, the effect of incremental radiation doses was evaluated by comparing the results obtained by acoustic tests with those providing information at molecular level, i.e., cyclic voltammetry, linear square voltammetry and infrared spectroscopy. Moreover, in this work, the glucose released as a result of the degradation of wood cellulose and hemicellulose, has been analyzed for the first time, with an innovative tool, based on the use of a Gellan gel. The integrated approach presented here, based on both traditional and innovative techniques has proven to be highly efficient in providing a complete picture of wood behavior following γ-ray irradiation, at both the macroscopic and the molecular level. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract The compressive properties of spruce and beech wood species at a large range of strain rates – from 0.001 to 600 s - 1 – under rigid lateral confinement have been investigated, using an original experimental device especially developed for the purpose. The work is motivated by the need to explore the dynamic behavior of wood up to large strains close to 70%. Three experimental apparatus have been used to obtain the compressive responses: the quasi-static tests have been performed using a Sintech 20D test system, the compressive responses at intermediate strain rates have been obtained with an Instron VHS65/20 apparatus and the dynamic tests have been conducted using a Split Hopkinson Pressure Bars (SHPB) system. The strain rate sensitivity of wood is clearly visible on the crushing strength with an increase between 80 and 155% but also on the plastic like behavior. In addition, the entire responses exhibit an elastic-plastic like behavior whereas an elastic brittle behavior could be observed, in the previous Part A which was focused on the compression configuration without lateral confinement. Even if no significant effect of the rigid lateral confinement is observed on the apparent Young modulus and the crushing strength values for both species, the wood energy absorption capability is better when longitudinal failure mechanisms are restricted thanks to the rigid lateral confinement. [ABSTRACT FROM AUTHOR]

Timber-mortar composite structures require rigid, strong, but also ductile connections to optimize their performances. Up to now, the preferred connection systems were based on metal fasteners and notches in wood. In this study, an alternative approach based on a fully glued connection was studied (using an epoxy-based system), and a wood pre-treatment was applied in order to enhance the compatibility and the adhesion properties at the interface between beech wood and mortar. The wood surface was functionalized with a xerogel obtained by means of a sol-gel process, consisting of two layers of silane nanofilms – namely tetra-ethoxysilane and (3-Aminopropyl) triethoxysilane. Chemical analysis of the wood surface confirmed the chemical bonding of the silanes. Microscopy images revealed that the silane pre-treatment also affects adhesive penetration into the wood. In terms of mechanical properties, 3-point bending tests on pre-treated beech wood-mortar samples showed an improved load bearing capacity in comparison to unmodified wood-mortar specimens. [ABSTRACT FROM AUTHOR]

Abstract Weathering leads to rapid depolymerization and modification of wood chemical components. The present study aims to assess the structural and distributional changes in the main wood polymers, such as lignin and polysaccharides, located in the surface layers during weathering exposure. A confocal Raman microscopic technique, which is useful for evaluating the structure of molecules with a high spatial resolution, was utilized to examine the effects of weathering on the chemical composition of wood surfaces at the cellular level. Raman spectra showed that lignin degradation during weathering proceeds with the formation of o - and p -quinones, carbonyl groups, and certain types of C C double bonds such as stilbene derivatives. Comparing the weathering conditions between light only and light plus water exposure, it was found that weathering in the presence of water significantly enhances the degradation of lignin. The Raman images exhibited that the degree of lignin degradation by light only exposure is according to the depth. However, in the case of light plus water exposure, lignin degradation in the outermost cell walls proceeded from both the exposed surface side and the lumen side of the cell walls. This study is expected to potentially promote development of more effective and efficient methods to protect wood surfaces against weathering. Highlights • Effects of weathering on wood surfaces were studied by confocal Raman microscopy. • Lignin polymer was degraded and modified during weathering exposure. • The presence of water significantly accelerated delignification. • Weathering degradation of lignin was inhomogeneous at the cellular level. [ABSTRACT FROM AUTHOR]

In Europe, the volume of waste wood is increasing. Waste wood can be reused, promoting circular economy and avoiding landfills. It can be used as a bioenergy feedstock reducing the use of fossil fuels, or be reused for producing new composite wood material. Only wood with hazardous substances needs to be disposed. To this aim waste wood samples were collected from a panel board company and several recycling centres in Italy and Denmark. The samples were assigned to waste wood categories and analysed by Near Infrared Spectroscopy. Principal Component Analysis was used to investigate sample variability and Soft Independent Modelling of Class Analogies (SIMCA) for classifying the samples according to the appropriate reuse: energy production, panel board production or landfill. The results are good, with a classification rate of 90% for virgin wood material and 86.7% for treated wood material. The classification of waste wood is key for turning it into a secondary resource. • Waste wood composition is the key-point for deciding the best suited applications. • Waste wood were divided into three categories according to the best-suited reuse. • Classification models were developed to separate the material in the three classes. • Results suggest that Near Infrared Spectroscopy can be used for real-time sorting. [ABSTRACT FROM AUTHOR]