Search

Developing an eco-friendly, efficient and cost-effective wood modification technique should be prioritised due to increasing environmental concerns. In this study, the effect of temperature on tin-based metal bath modification of Cunninghamia lanceolata wood properties was investigated. The wood was treated at 150°C and 210°C for 120min and 480min and the mechanical (modulus of elasticity and rupture, impact bending, compression strength and hardness) and physical (contact angle, colour and water absorption) properties of the wood were compared with the untreated. The results showed that with increased modification temperature and time, the modulus of elasticity and rupture, impact bending, compression strength, hardness and water absorption decreased. In contrast, contact angle and colour increased significantly after thermal modification. Tin-based metal bath modification technology was an effective treatment method and the treatment of the wood at high temperature significantly impacted the properties of the wood. [ABSTRACT FROM AUTHOR]

Those who work with wood should have a basic knowledge of wood anatomy and chemistry so they can understand how different anatomical and chemical features influence wood properties and, in turn, how these properties contribute to different treatments and final wood utilization. However, little attempt has been made to map global research trends in wood anatomy and chemistry. This paper presents a bibliometric review of research trends in wood anatomy and chemistry to determine research trends and gaps in these research areas. A total of 183 publications on wood anatomy and chemistry from 1974 to 2023 were reviewed. The analysis was done with the VOSviewer software (version 1.6.13). The analysis focused on the bibliographic coupling of countries, co-authorship of authors, citation of documents, and co-occurrence of keywords, which were presented as network visualization maps. The findings revealed that the wood anatomy and chemistry publication trends, although not completely gradient, have been upwards since 2000. Countries including Germany, the United States, Switzerland, the United Kingdom, Brazil, the Netherlands, China, Italy, Mexico, Spain, the Czech Republic, Canada, Australia, Chile, Finland, France, Sweden, and Japan had a great impact on this research area. It also became evident that African countries lag in this area of research. Only one data source - Scopus - was used. It has a wide coverage of publications from diverse areas and provides researchers with information on the most important academic literature in any specific scientific domain. Therefore, the representation of publications presented in this study is limited to only the Scopus data source. [ABSTRACT FROM AUTHOR]

Wood waste, which constitutes an important component of solid waste, is produced by the wood industry, and especially in the processing one. The wood industry includes tree bark, sawdust, planer shavings, sander dust etc. produces unwanted products and/or wastes. This study investigated the usability of sawdust of fruit trees in the production of Medium Density Fiberboard (MDF) and some technological properties of the produced MDF panels. Sawdust of fruit trees was mixed to beech fibers at the ratio of 10, 20 and 30% by weight. The mats were manually formed using 13% urea formaldehyde and pressed at a temperature of 185°C for 8 min in a computer control press. The MDF panel samples of water absorption (WA), thickness swelling (TS), surface hardness, surface roughness, MOR and MOE were investigated. It was determined that the values of WA and TS decreased with increasing the ratio of sawdust. Modulus of rupture (MOR), modulus of elasticity (MOE), surface hardness, surface roughness parameters (Ra, Rq and Rz) values of panel samples increased with increasing the ratio of sawdust from panels. Based on these results, it is advisable that wood sawdust fruit-trees can be used as an alternative raw material source in MDF production. [ABSTRACT FROM AUTHOR]

This research delves into the unexplored territory of using CT image processing techniques to assess capillary flow in freshly felled Scotch pine logs during the drying process. Leveraging a high-resolution CT scanner, the study captures intricate details of the wood's internal structure, which were then quantified using image processing algorithms. The findings confirm the efficacy of CT image processing in accurately determining capillary flow in wood. This opens up new opportunities for non-destructive testing methods and contributes to a deeper understanding of wood properties. The implications of these findings are farreaching, offering substantial advancements in quality control and processing optimization in the wood industry. [ABSTRACT FROM AUTHOR]

Wood is a widely used material in industry due to its sufficient loadcarrying capacity, obtaining from sustainable sources and easiness in its processing, etc. Plywood is a wood panel manufactured from layers of wood veneer and combined under pressure with an adhesive. Plywood panels are widely used in the furniture and construction industry. In this study, the nonconformities during the plywood production process are analyzed using statistical process control methods. First, check sheet are created. p-quality control chart is created using this data. p-control chart is evaluated to investigate whether the process provides the desired quality level. In addition, the tree diagram and the cause-effect diagram are created after the information obtained by brainstorming technique. Also, in order to control the improvements in the process, an additional data including 15 days of data were collected in the 2nd Stage and a p-control chart was created. In this research, the nonconformities of plywood production process and their possible causes are analyzed. [ABSTRACT FROM AUTHOR]

Shorter processes and lower temperatures are critical to reducing thermally modified wood costs. In this study, the exogenous H3PO4 was infiltrated into poplar (Populus × euramaricana) and then heated at low temperatures of 130–170 °C to speed up the thermal modification process of wood with better performance. The hygroscopicity was analyzed by dynamic vapor sorption detection and its constituents of modified wood were characterized by high-performance liquid chromatography and solid-state CP/MAS 13C NMR. The results showed that acid combined with low-temperature thermal modification (acid-LTM) resulted in lower equilibrium moisture content compared with the high-temperature thermal modification (HTM) wood. The addition of H3PO4 triggered severe degradation of the carbohydrates in the wood, and the mass loss of cellulose and hemicellulose were 11.9% and 24.1% when modified with 3.0% H3PO4 at 150 °C, respectively, thereby reducing the quantities of water sorption sites. Besides, the degradation products of carbohydrates crosslinked with the thermally stable lignin to form "pseudo-lignin" substances, leading to an increase in the lignin content of acid-LTM wood. The increase in the crystalline index and crystallite size of cellulose in acid-LTM wood was also conducive to reducing the wood hygroscopicity. The better hydrophobicity of acid-LTM poplar was further verified by its decrease in the water sorption site density and the theoretical OH content compared with HTM wood and unmodified wood. This study will offer a potential process to manufacture thermal-modified wood at a low cost. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the changes occurring in the wood cellulose of the fast-growing poplar (Populus deltoides × maximowiczii) under the influence of steam explosion (SE) pretreatment. Cellulose from native wood and after pretreatment at 160 and 205 °C was isolated. Cellulose polymerization degree by size exclusion chromatography (SEC) and cellulose crystallinity index by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) were determined. The profiles of sugars in the native wood and in the solid fraction after pretreatment (using the acid hydrolysis method) were also determined. In addition, the profile of monosaccharides in the liquid fraction obtained after steam explosion and in the liquid fraction after acid hydrolysis of the oligosaccharides were investigated using high-performance liquid chromatography (HPLC). This allowed to determine the change in the yield of hexoses and pentoses in the studied material. The behavior of cellulose in wood subjected to steam explosion at 160 and 205 °C and isolated by the Kürschner–Hoffer method was studied by determining the absorption bands of FTIR-ATR spectra. The lateral order index (LOI) of cellulose was calculated from the ratio of the intensity of the corresponding absorption bands A1422/A896 cm−1. Total crystallinity index (TCI) of cellulose was calculated from the ratio of the intensity of absorption bands A1372/A2900 cm−1. TCI of Kürschner-Hoffer cellulose isolated from wood subjected to steam explosion at 160 and 205 °C decreased by 5.6 and 5.0%, respectively, with regard to the applied temperature. LOI increased in cellulose isolated from wood subjected to steam explosion at 160 °C (by 0.7%) and at 205 °C (by 19.2%) in relation to the index of cellulose isolated from native wood. Kürschner–Hoffer cellulose isolated from wood subjected to steam explosion at 160 and 205 °C exhibited, respectively, a reduced degree of polymerization of about 11% and about 8%. Polydispersity index in Kürschner–Hoffer cellulose was 1% lower after both pretreatments than native sample. [ABSTRACT FROM AUTHOR]

Eucommia ulmoides wood is renowned for its high quality, however, there is a lack of research regarding the assessment of its structure and properties. This gap was addressed in the present study by examining three clones of E. ulmoides [Huazhong 12 (HZ), Cili (CL), and Miye (MY)] to compare their growth and structural characteristics, chemical components, and physical and mechanical performance. We employed a comprehensive evaluation model, combining the coefficient of variation method and rank sum ratio comprehensive evaluation method, to comprehensively assess the wood samples' structures and properties. The results reveal significant differences at the P < 0.05 level among the three clones in various parameters including tree height, ground diameter, number of internodes, cell wall area ratio, number of vessels per unit area of early and late wood, wood fiber lumen diameter and double wall thickness, fiber length and width, hemicellulose content, lignin content, air-dried density, dry shrinkage properties, wet expansion properties, compressive strength, bending strength, and bending elastic modulus. Among HZ, CL, and MY woods, CL exhibited superior development as well as physical and mechanical properties. HZ showed exceptional chemical properties, while MY demonstrated the finest cell morphology. By utilizing the proposed evaluation model, we comprehensively assessed the structures and properties of three different clones of E. ulmoides wood. All samples were categorized into upper, middle, and lower grades based on their respective characteristics. HZ was found to be distributed across all three grades, with the highest presence in the upper grade. MY was primarily distributed in the middle and lower grades; CL was predominantly found in the third grade. Among the clones, HZ showed the highest comprehensive score while MY showed the lowest score. The evaluation results indicate that among the three wood clones, HZ achieved superior quality for the fiber industry, CL and HZ are more suitable raw materials for construction industry. The findings of this study may contribute to a theoretical foundation for the selection, grading evaluation, and added value enhancement of E. ulmoides wood. [ABSTRACT FROM AUTHOR]

Anthraquinone has been widely utilized in the pulp and paper industry as a catalyst for alkaline cooking; however, its application has been recently restricted due to its potential carcinogenic effects. Hence, safer alternatives to anthraquinone have been explored. Agro-industrial by-products have been utilized as sustainable sources of value-added materials. In this study, teak (Tectona grandis) wood waste from Gunung Kidul, Indonesia, which naturally contains lapachol, was utilized as a biocatalyst to enhance delignification and improve pulp yield in alkaline cooking for pulp and paper production. The use of lapachol as a cooking catalyst was investigated for kraft, soda, and prehydrolysis soda cooking. Lapachol accelerated delignification and retained carbohydrate in all three alkaline cooking methods, with its effect being more pronounced in kraft cooking than in soda cooking. This study demonstrates that teak wood extractives with lapachol are promising sustainable catalysts for alkaline cooking. [ABSTRACT FROM AUTHOR]

Wood contains abundant extractives and volatile oils, which release strong odors and hazardous volatile organic compounds (VOCs). The emission of VOCs can be minimized by degrading and mineralizing wood extractives. Wood powder is widely used as raw material for chemical industry, building materials, wood-based boards, and other products. In this study, China fir wood powder was used as object to remove wood VOCs by the ozonation and ozone-activated persulfate (O3/PS) systems, and their VOC removal efficiencies were evaluated using gas chromatography–mass spectrometry (HS-SPME/GC–MS). The result showed O3/PS system exhibited higher VOC removal efficiency. The mechanism of different ozone processes in wood treatment was explored, which contributed to the evaluation of the removal efficiency of VOCs and the degradation pathway of VOC components. The PS dosage, O3 concentration, and pH had varying effects on the O3/PS system. When the pH increased to 10, the removal rate of wood VOCs decreased. The VOC removal rate did not increase with the increasing free-radical concentration. When the PS concentration increased from 5 to 20 mM, the VOC removal efficiency gradually increased from 49.91 to 72.39%. However, when the PS concentration increased to 40 mM, the VOC removal efficiency of PS slightly decreased because the excess PS immediately produced a large amount of hydroxyl radical (·OH) and sulfate radical (SO4·−), which led to quenching reactions between radicals. The results revealed that the O3/PS process promoted indirect oxidation. Under the synergistic effect of O3, ·OH, and SO4·−, the VOC removal efficiency was significantly improved, the intermediate product was lower, and the total VOC removal rate VOCs by O3/PS was more than 70%. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable biomass utilization, this study investigates the hydrothermal treatment of birchwood and its subsequent impact on enzymatic hydrolysis lignin (EHL). Additionally, birchwood undergoes processing with NaOH (4% w/w) within a Parr reactor to precipitate lignin from the black liquor, resulting in lignin-rich substrates (LRSs) which are then subject to thorough characterization. Notably, EHL produced after hydrothermal pretreatment at 190 °C exhibits the highest lignin content at 67%, while kraft lignin (KL) obtained at 140 °C (pH 1.5) produces 65% lignin content. Among these LRSs, the KL sample produced at 190 °C (pH 4) stands out, displaying a robust aromatic skeletal structure and an abundance of methoxyl groups, primarily owing to its high purity. Furthermore, for these LRSs' it is shown that chemical configuration influences their thermal behaviour, allowing the lignin to be tailored for diverse applications, from low melting point materials to carbonaceous materials capable of withstanding temperatures exceeding 700 °C. This comprehensive understanding of the chemical, thermal, and physical attributes of LRSs not only enriches our knowledge of lignin-rich substrates but also paves the way for the development of sustainable bio-based materials, marking a step towards sustainable materials development. [ABSTRACT FROM AUTHOR]

Previous research found that some organosilicon treatments proved effective in stabilizing waterlogged wood dimensions during drying. The present research aimed to determine the mechanism of wood stabilization by these chemicals to understand their mode of action. The study used chemically (ChP) and biologically degraded (BP) model Scots pine wood treated with Methyltrimethoxysilane (MTMS), (3-Mercaptopropyl) trimethoxysilane (MPTMS), or 1,3-Bis(diethylamino)-3-propoxypropanol)-1,1,3,3-tetramethyldisiloxane (DEAPTMDS). Synchrotron-based X-ray fluorescence microscopy (XFM) was used to investigate the penetration of organosilicons into the wood cellular structure and cell walls, and nanoindentation was used to study the mechanical properties of the treated wood cell walls. All treatments resulted in high volumetric anti-shrink efficiency (ASEV) values of 74–82%, except for MTMS-treated ChP with an ASEV of 52%. The multiscale XFM results revealed that all applied organosilicons penetrated throughout the whole wooden blocks and deposited in both cell lumina and cell walls. The retention of all applied organosilicons was highest in BP wood, and so was the dimensional stabilization effect. MTMS-treated ChP had the lowest measured cell wall infiltration, which likely contributed to its lower ASEv. DEAPTMDS treatments plasticized the cell walls and resulted in lowered nanoindentation elastic modulus (EsNI) and hardness (H) for all types of wood. MTMS and MPTMS had modest effects on cell wall mechanical properties, and the effect depended on the type of wood. The final effect of organosilicon treatment on the dimensional wood stabilization and mechanical properties of wood cell walls depended not only on the type of the applied organosilicon but also the type of wood degradation. This means that the treatment cannot be considered universal, and specific approaches are needed for the conservation of individual wooden objects. Although some mechanisms are now better understood, such as the need for organosilicons to infiltrate the cell walls and the plasticizing effect of DEAPTMDS, other aspects will benefit from a more detailed analysis of the molecular interactions between organosilicons and wood polymers. [ABSTRACT FROM AUTHOR]

To investigate the effect of Fe-addition on the Cs+-adsorption ability (Cs+-AA) of woody charcoal, charcoal samples were prepared from Japanese cedar (JC) and Japanese oak (JO) wood impregnated with Fe3+ at 600 and 800 °C. The residual functional groups of the charcoal samples were examined using infrared-photoacoustic spectroscopy. OH groups were observed in the charcoal made at 600 °C, and no vibrational bands were detectable in the charcoal synthesized at 800 °C. The observation of Raman D-, G-, and G´-bands revealed that all charcoal samples contained sp2-carbon atoms but graphitization occurred only in the iron-loaded charcoal made at 800 °C. The Cs+-AA of the JC and JO charcoal samples were evaluated based on the adsorption isotherms of an aqueous CsCl (Cs+: 33 mg/L) solution. The addition of Fe3+ to wood had a negative effect on the Cs+-AA of the JO charcoal made at 600 °C, but a positive effect on the Cs+-AA of the JC charcoal prepared at 800 °C. [ABSTRACT FROM AUTHOR]

Supercritical CO2 offers an alternative method of removing wood moisture and reducing cellular collapse compared to traditional drying techniques. The technique has been previously demonstrated for Pinus radiata and Eucalyptus nitens dewatering and was modified in this study for New Zealand red beech (Nothofagus fusca) heartwood, which is notoriously difficult to dry without causing excessive distortion. The technique was also successfully extended to drying below the fibre saturation point. A specific dewatering and drying schedule was developed for N. fusca because of negligible dewatering using a schedule previously designed for wood with an open hydrofluidic network of interconnected vessels. An anatomical assessment confirmed lumen pathways were occluded with tyloses and polyphenol resins. A fluid dynamics assessment concluded that permeability measurements are recommended together with tortuosity and porosity information for improved wood species dewatering characterisation. Using the dewatering and drying schedule, collapse was successfully reduced by 92% for both normalised internal wood area and void collapse when compared to oven-dried samples. The beech specimens took 18 days to reach 17.3% moisture content (MC) but displayed some checking from early dewatering depressurisation, compared to air-dried control specimens which showed no collapse or checking but took 6 months to reach 12% MC. Supercritical CO2 dewatering and drying could be combined with extractives separation, preservative treatment, and mechanical forming of wood in one plant to make a potentially economically viable process with improved energy, environmental and carbon footprints. A techno-economic analysis is suggested to fully compare supercritical drying of wood against conventional drying operations. [ABSTRACT FROM AUTHOR]

This research aimed to assess the improvements in dimensional stability and resistance to wood decay by treating the wood with a solution of glycerol–maleic anhydride mixture (GLY-MA) without a catalyst, at four concentrations (10%, 15%, 20%, and 25%), followed by heat treatment at 170 °C for 4 h. Four wood species were selected for property testing: two locally grown in Egypt, namely Tree of heaven (Ailanthus altissima, heartwood) and Cypress (Cupressus sempervirens, sapwood), and two imported species, European beech (Fagus sylvatica) and Norway spruce (Picea abies), both heartwood. The treatment conditions reported here proved the effectiveness in enhancing the stabilization against water absorption for all four wood species. All four concentrations improved dimensional stability, with the highest improvement observed with the 25% treatment for all wood species. Although the treatments had a slight effect on decreasing compressive strength and hardness, a clear significant difference was observed at a concentration of 25% compared to untreated samples. The hardness at a 25% concentration was 4434.7 N, 2440 N, 5220 N, and 1440 N for Tree of heaven, Cypress, Beech, and Spruce, respectively. Across all species studied, the use of the four concentrations demonstrated a shift in wood resistance against white rot and brown rot fungi from nonresistant to moderately resistant. Therefore, in terms of cost-effectiveness, it is recommended to use the low concentration, 10% to enhance decay resistance, as this concentration effectively achieves the desired outcome without the need for higher concentrations, in addition to being environmentally friendly. [ABSTRACT FROM AUTHOR]

The critical role of auxin on secondary vascular development in woody plants has been demonstrated. The concentration gradient of endogenous indole-3-acetic acid and the cellular and molecular pathways contributing to the auxin-directed vascular organization and wood growth have been uncovered in recent decades. However, our understanding of the roles and regulations of auxin influx in wood formation in trees remains limited. Here, we reported that a microRNA, miR7833, participates in the negative regulation of stem cambial cell division and secondary xylem development in Populus tomentosa. The miR7833 is mainly expressed in the vascular cambium during stem radical growth and specifically targets and represses two AUX/LAX family auxin influx carriers, AUX5 and AUX6 , in poplar. We further revealed that poplar AUX6 , the most abundant miR7833 target in the stem, is preferentially enriched in the developing xylem and is a positive regulator for cell division and differentiation events during wood formation. Moreover, inhibition of auxin influx carriers by 1-naphthoxyacetic acids abolished the regulatory effects of miR7833 and AUX6 on secondary xylem formation in poplar. Our results revealed the essential roles of the miR7833- AUX6 module in regulating cellular events in secondary xylem development and demonstrated an auxin influx-dependent mechanism for wood formation in poplar. [ABSTRACT FROM AUTHOR]

The thermo-chemical conversion of biomass wastes is a practical approach for the value-added reclamation of bioenergy in large quantities, and pyrolysis plays a core role in this process. In this work, poplar (PR) and cedar (CR) were used as staple wood biomasses to investigate the apparent kinetics of TG/DTG at different heating rates. Secondly, miscellaneous wood chips (MWC), in which PR and CR were mixed in equal proportion, were subjected to comprehensive investigations on their pyrolysis behavior and product evolution in a fixed bed reactor with pyrolysis temperature, catalyst, and the flow rate H2O steam as influencing factors. The results demonstrated that both PR and CR underwent three consecutive pyrolysis stages, the TG/DTG curves shifted to higher temperatures, and the peak temperature intervals also enhanced as the heating rate increased. The kinetic compensation effect expression and apparent reaction kinetic model of CR and PR pyrolysis were obtained based on the law of mass action and the Arrhenius equation; the reaction kinetic parameter averages of Ea and A of its were almost the same, which were about 72.38 kJ/mol and 72.36 kJ/mol and 1147.11 min−1 and 1144.39 min−1, respectively. The high temperature was beneficial for the promotion of the pyrolysis of biomass, increased pyrolysis gas yield, and reduced tar yield. This process was strengthened in the presence of the catalyst, thus significantly increasing the yield of hydrogen-rich gas to 117.9 mL/g-biomass. It was observed that H2O steam was the most effective activator for providing a hydrogen source for the whole reaction process, promoted the reaction to proceed in the opposite direction of H2O steam participation, and was beneficial to the production of H2 and other hydrocarbons. In particular, when the flow rate of H2O steam was 1 mL/min, the gas yield and hydrogen conversion were 76.94% and 15.90%, and the H2/CO was 2.07. The yields of H2, CO, and CO2 in the gas formation were significantly increased to 107.35 mL/g-biomass, 53.70 mL/g-biomass, and 99.31 mL/g-biomass, respectively. Therefore, H2 was the most dominant species among gas products, followed by C-O bond-containing species, which provides a method for the production of hydrogen-rich gas and also provides ideas for compensating or partially replacing the fossil raw material for hydrogen production. [ABSTRACT FROM AUTHOR]

Aims The work presented here was conducted to characterize the biodiversity of a collection of bacterial isolates, mainly wood endophytes, as part of a research project focused on exploring their bioprotective potential for postharvest biological control of fruits. Methods and results This work was the basis for the development of a tailored method combining 16S rDNA sequencing and Rep-PCR to differentiate the isolates and identify them to genus level or below. More than one hundred isolates obtained from wood and roots of different grapevine genotypes were cultured on appropriate growth media and then subjected to the specified multistep molecular identification. Conclusions We have obtained good dereplication for grapevine-endophytic bacteria, together with reliable genetic identification. Both are essential prerequisites to properly characterize a biome bank and, at the same time, beneficial prerequisites to subsequently perform a correct bioprotection assessment. [ABSTRACT FROM AUTHOR]

Inconsistent yield of subtropical table grape across seasons is often associated with low carbohydrate reserves during flowering. In an attempt to increase TNC and thus yield, sucrose was injected into treated trunks during periods of high carbohydrate demand (i.e., between budburst and flowering). Total non-structural carbohydrate (TNC) concentration dynamics were assessed in the grapevine root and trunk tissues of both control and treated vines. In the control (untreated) vines, the TNC concentration in root and trunk tissues was 13.5% and 7.5% w/dw at leaf fall and 7.2% and 3.7% w/dw at flowering, respectively. This decrease in carbohydrate reserve was estimated at ~500 g/vine and is associated with the re-establishment of the plant canopy in early spring. Carbohydrate reserves remained stable or rose slightly between flowering and harvest and recovered between crop harvest and leaf fall. In treated vines, a constantly pressurised low-pressure in situ trunk injection system (69 kPa) with 5% w/v sucrose solution over 45 days from budburst (to flowering), in each of the two seasons, delivered a widely variable amount of sucrose into each vine with variation ascribed to the amount of internal dead wood in the trunk. In the best circumstances, an average of 150 g sucrose/vine/season was injected, and sucrose-injected vines had higher trunk TNC reserve (4.1% compared to 3.6% w/dw in the control) at flowering. A δ13C (‰) analysis confirmed the presence of injected sucrose in the shoot at flowering. However, the correlation between the amount of loaded sucrose and δ13C in young shoot tissue was poor, indicative of variable partitioning patterns. Inflorescence number per vine and berry yield were markedly higher in sucrose-injected vines, but differences were not significant given the high variation between vines. The addition of KCl to the sucrose solution and use of the healthy vines are recommended to increase sucrose loading using the injection method to address inconsistent yielding of subtropical table grape. [ABSTRACT FROM AUTHOR]

• Determination of cellulose, hemicellulose, and lignin contents of three species of archaeological wood in the Quanzhou Song shipwrecks. • Characterisation of salt-forming elemental compositions of the three species of archaeological wood in the Quanzhou Song Shipwrecks. • Changes in the mechanical properties of the amorphous components (amorphous cellulose, hemicellulose, and lignin) of the three waterlogged archaeological wood samples were compared with those of sound wood based on molecular dynamics simulations. • The molecular mechanisms underlying the effects of soluble salts (sodium chloride) on the mechanical properties of water-soaked archaeological wood were revealed. Sodium chloride (NaCl) is the main soluble salt component of marine waterlogged archaeological wood, and it causes deterioration of wood fibres. In this study, a molecular dynamics simulation of three types of archaeological wood from the Quanzhou Song Shipwreck was employed to investigate the impact of NaCl on the mechanical properties of amorphous components consisting of amorphous cellulose, hemicellulose, and lignin. The findings revealed that water molecules bound to the fibres enhanced the mechanical performance of the woody fibres. However, NaCl affected the stability and mechanical properties of the amorphous components. By using molecular dynamics simulations, 24 sets of amorphous fibre models, consisting of fir, pine, and camphorwood with salt concentrations ranging from 0 % to 7 %, were constructed to further analyse the influence of salt content on the mechanical properties of the amorphous components. The results showed that all three species of archaeological wood exhibited similar trends, with the adsorption energy and radial distribution function between wood fibres and water molecules decreasing with increasing NaCl concentration, leading to the gradual rupture of hydrogen bonds in water molecules. Consequently, more water molecules engage in ion hydration, resulting in an increase in the amount of free water within the amorphous regions. This, in turn, degrades the mechanical properties of the amorphous components. This study contributes significantly to a comprehensive understanding of the mechanical properties of marine archaeological wood and is important for decision-making in studies related to the preservation and evaluation of marine waterlogged wooden artefacts. [Display omitted] [ABSTRACT FROM AUTHOR]

• Canvases made with fine linen are difficult to observe in the radiograph. • Canvases made with jute and hemp are easily detectable with radiography. • White lead pigment affects the identification of the canvas. The historical techniques of panel painting manufacturing involve the preparation of boards to be used as painting support. The high affinity of wood for water can cause dimensional variations, deformations, and internal tensions. The application of a canvas over the boards, besides the choice and treatment of wood, is useful to minimize and guarantee the stability and preservation of the painting over time. The detection of the fabric is ensured with different imaging techniques, such as macro photography and radiography. The latter is mainly used to obtain information about the characteristics of the wood, the number of boards, the assembly system, and for the evaluation of the conservation state. The main advantage is the non-invasiveness of the analysis, which is a fast, simple, and widespread method. The limitations are related to different factors, such as the capacity of the materials to absorb the radiation. Despite canvas has a low radiopacity, in several cases it was possible its identification in the radiograph. This is important to investigate the technique of the artists. In our laboratory, we analyzed different panel paintings and while in some cases the fabric is easily detectable, in others it's not visible. Different variables can limit the observation of the canvas. This study is aimed at the comprehension of how acquisition parameters and painting characteristics can affect the detection of incamottatura through radiography. [ABSTRACT FROM AUTHOR]

• Iron deposits in Nanhai I shipwreck wood were hydroxyl iron oxide and pyrite. • Near-neutral DTPA and amidoxime cellulose had high iron deposit removal efficiency. • Na 2 S 2 O 4 improved the iron deposits removal efficiency of EDTA-2Na. Iron deposits are commonly found in marine archaeological wood, causing acidification, degradation, and mechanical damage to marine archaeological wood. This study focused on extracting iron deposits from loose wood samples taken from the Nanhai Ⅰ shipwreck. The removal efficiency of iron deposits in wood using materials, such as EDTA-2Na, DTPA, C 6 H 17 N 3 O 7 , Na 2 C 2 O 4 , amidoxime cellulose, DFO, EDTA-2Na-H 2 O 2 , DTPA-H 2 O 2 , EDTA-2Na-Na 2 S 2 O 4 , and DTPA-Na 2 S 2 O 4 , was evaluated. Analysis using scanning electron microscopy/energy dispersive spectroscopy and X-ray diffraction identified the presence of iron deposits in the wood of the Nanhai I shipwreck including goethite (FeOOH) and pyrite (FeS 2). The removal efficiency was evaluated by ICP-AES and results showed that amidoxime cellulose and DTPA had higher removal efficiency for iron deposits in wood. The difference between the iron deposits removal efficiency of DTPA and EDTA was significant after the addition of oxidant (H 2 O 2) and reductant (Na 2 S 2 O 4) to the systems, respectively. The addition of oxidant H 2 O 2 to DTPA improved the iron deposits removal efficiency of DTPA from wood within 30 days. Furthermore, the addition of reductant Na 2 S 2 O 4 to EDTA-2Na significantly improved the iron deposits removal efficiency of EDTA-2Na from wood. These findings provide a valuable reference for developing efficient methods for removing iron deposits during the practical protection of the Nanhai I shipwreck. [ABSTRACT FROM AUTHOR]

The research on a novel preparation method for functional scaffolds from natural cellulose has attracted widespread attention in science and engineering. In order to obtain cellulose board which is similar to wood board in structure and mechanical properties, ice template, phase inversion under low temperature, and hot pressing were employed to fabricate board from natural cellulose. During preparation, ice template was used to control cellulose molecules arrange forming excellent orientation in the scaffold. Then, prepared scaffold was immersed in ethanol under −20 °C to remove salt ions used in cellulose resolve process, and keep the direction arrange of molecules in scaffold. Finally, prepared scaffold was treated by hot pressing for pushing off air in pores to form density board. Scanning electron microscopy image showed that prepared scaffold has directional cellulose arrange structure which was similar to that of wood. After hot pressing, the density of scaffold is increased. The mechanical properties of cellulose boards are enhanced with the increase of cellulose concentration, and the tensile strength can reach about 45 MPa, which has great potential in replacing natural wood boards. Our study provides new tactics for the use of natural cellulose in our life. [ABSTRACT FROM AUTHOR]

Greater diversity in functional morphology should be associated with the evolution of greater ontogenetic diversity, an expectation difficult to test in most long-lived wild organisms. In the cells derived from the wood meristem (vascular cambium), plants provide extraordinary systems for reconstructing ontogenies in often long-lived organisms. The vascular cambium produces files of cells from the stem center to the periphery, with each cambial derivative "deciding" which of four cell types it differentiates into. Wood cell files remain in place, allowing tracing of the ontogenetic "decisions" taken throughout the life of a stem. We compared cell files from the Pedilanthus clade (genus Euphorbia), which span a range of growth forms from small trees and shrubs of tropical habitats to desert succulents. Using language theory, we represented wood cell types as "letters" and combinations of cell types in cell files as "words," allowing us to measure the diversity of decisions based on word frequency matrices. We also used information content metrics to compare levels of predictability in "decision-making." Our analyses identified a wider array of developmental decisions in woody trees as compared to succulent shrubs, illustrating ways that woody plants provide unparalleled systems for studying the evolution of ontogeny in long-lived, non-model species. [ABSTRACT FROM AUTHOR]

Wood is an invaluable asset to human society due to its renewable nature, making it suitable for both sustainable energy production and material manufacturing. Additionally, wood derived from forest trees plays a crucial role in sequestering a significant portion of the carbon dioxide fixed during photosynthesis by terrestrial plants. Nevertheless, with the expansion of the global population and ongoing industrialization, forest coverage has been substantially decreased, resulting in significant challenges for wood production and supply. Wood production practices have changed away from natural forests toward plantation forests. Thus, understanding the underlying genetic mechanisms of wood formation is the foundation for developing high‐quality, fast‐growing plantation trees. Breeding ideal forest trees for wood production using genetic technologies has attracted the interest of many. Tremendous studies have been carried out in recent years on the molecular, genetic, and cell‐biological mechanisms of wood formation, and considerable progress and findings have been achieved. These studies and findings indicate enormous possibilities and prospects for tree improvement. This review will outline and assess the cellular and molecular mechanisms of wood formation, as well as studies on genetically improving forest trees, and address future development prospects. [ABSTRACT FROM AUTHOR]

Wood is a naturally porous material prone to microbial erosion and degradation in outdoor environments. Therefore, the development of an environmentally friendly wood preservative with excellent antibacterial effects and low toxicity is urgently needed. In this study, nitrogen-doped carbon quantum dots (N-CQDs) with excellent antifungal performance and fluorescent properties were synthesized using a one-step hydrothermal method with chitosan quaternary ammonium salt (HACC) as the raw material. The fluorescence characteristics of N-CQD preservatives can help track their position and distribution in wood. The minimum inhibitory concentration (MIC) of N-CQDs is 1.8 mg/mL, which was nearly 22 times lower than that of HACC (40.0 mg/mL) in the PDA medium. The decay resistance test demonstrated that wood treated with N-CQDs showed a considerably reduced decay degree and its mass loss rate decreased from 46 ± 0.5% to 3.8 ± 0.5%. Biological transmission electron microscopy revealed that N-CQDs effectively destroyed fungal cell structures, thereby hindering the growth of Coriolus versicolor. N-CQDs synthesized using the one-step hydrothermal method can be used as an efficient wood preservative that can effectively improve the utilization and service life of wood. [ABSTRACT FROM AUTHOR]

The construction of networks within natural wood (NW) lumens to produce porous wood aerogels (WAs) with fascinating characteristics of being lightweight, flexible, and porous is significant for the high value-added utilization of wood. Nonetheless, how wood species affect the structure and properties of WAs has not been comprehensively investigated. Herein, typical softwood of fir and hardwoods of poplar and balsa are employed to fabricate WAs with abundant nanofibrillar networks using the method of lignin removal and nanofibril's in situ regeneration. Benefiting from the avoidance of xylem ray restriction and the exposure of the cellulose framework, hardwood has a stronger tendency to form nanofibrillar networks compared to softwood. Specifically, a larger and more evenly distributed network structure is displayed in the lumens of balsa WAs (WA-3) with a low density (59 kg m−3), a high porosity (96%), and high compressive properties (strain = 40%; maximum stress = 0.42 MPa; height retention = 100%) because of the unique structure and properties of WA-3. Comparatively, the specific surface area (SSA) exhibits 25-, 27-, and 34-fold increments in the cases of fir WAs (WA-1), poplar WAs (WA-2), and WA-3. The formation of nanofibrillar networks depends on the low-density and thin cell walls of hardwood. This work offers a foundation for investigating the formation mechanisms of nanonetworks and for expanding the potential applications of WAs. [ABSTRACT FROM AUTHOR]

Effective early fire detection is crucial for preventing damage to people and buildings, especially in fire-prone historic structures. However, due to the infrequent occurrence of fire events throughout a building's lifespan, real-world data for training models are often sparse. In this study, we applied feature representation transfer and instance transfer in the context of early fire detection using multi-sensor nodes. The goal was to investigate whether training data from a small-scale setup (source domain) can be used to identify various incipient fire scenarios in their early stages within a full-scale test room (target domain). In a first step, we employed Linear Discriminant Analysis (LDA) to create a new feature space solely based on the source domain data and predicted four different fire types (smoldering wood, smoldering cotton, smoldering cable and candle fire) in the target domain with a classification rate up to 69% and a Cohen's Kappa of 0.58. Notably, lower classification performance was observed for sensor node positions close to the wall in the full-scale test room. In a second experiment, we applied the TrAdaBoost algorithm as a common instance transfer technique to adapt the model to the target domain, assuming that sparse information from the target domain is available. Boosting the data from 1% to 30% was utilized for individual sensor node positions in the target domain to adapt the model to the target domain. We found that additional boosting improved the classification performance (average classification rate of 73% and an average Cohen's Kappa of 0.63). However, it was noted that excessively boosting the data could lead to overfitting to a specific sensor node position in the target domain, resulting in a reduction in the overall classification performance. [ABSTRACT FROM AUTHOR]

This paper tackles the issue of moisture variation in wood-based materials, explicitly focusing on melamine-coated particleboard (hereafter referred to as melamine) and medium-density fiberboard (MDF) used in the third phase of wood industry transformation. The approach involves a comprehensive strategy for predicting moisture content variation, incorporating numerical simulation, experimental testing, and the application of artificial neural network (ANN) technology to enhance accuracy in furniture manufacturing. The developed ANN models are tailored to predict moisture content changes under specific thermal comfort conditions. Remarkably, these models demonstrate high precision, with an average error margin of only 1.40% for 8% moisture content (MC) and 2.85% for 12% MC in melamine, as well as 1.42% for 8% MC and 2.25% for 12% MC in MDF. These levels of precision surpass traditional models, emphasizing this study's novelty and practical relevance to the industrial context. The findings indicate that ANN models adapt to diverse environmental conditions, presenting a robust tool for optimizing moisture management in wood-based materials. This research contributes valuable insights for improving the reliability and efficiency of moisture content predictions in the wood industry. [ABSTRACT FROM AUTHOR]

In transitioning to a carbon‐neutral chemical industry, the intake of fossil feedstocks will have to be reduced by maximizing end‐of‐life product recycling and introducing alternative feedstocks based on renewable carbon. This perspective article analyses the potential of domestically grown and sourced woody biomass for the supply of renewable carbon for chemicals in Europe. The European chemical industry can become a major consumer of woody biomass in a context where burning wood for energy production is viewed as an unsustainable practice. [ABSTRACT FROM AUTHOR]

Carbon fraction (CF) of trees is essential for quantifying forest carbon (C) stocks. Considerable attention has been paid to CF variations at various levels with the exception of inter- and intra-growth rings. Herein, the inter- and intra-growth ring variation of CF in Pinus tabuliformis was investigated. Elemental analysis was performed to obtain CF values of the earlywood and latewood in each growth ring of the xylem. Patterns of CF variation at the growth ring level were evaluated using mixed-effect models. The results showed that latewood CF, 50.6 %, was significantly higher than earlywood CF, 49.9 % (p < 0.01). In particular, inter-growth ring variations of CF differed between heartwood and sapwood, as well as between juvenile wood and mature wood. CF values decreased nonlinearly with cambium age toward the heartwood or juvenile wood, with estimated least-squares means of 50.4 % and 51.8 %, respectively. While CF values were almost unaltered in sapwood, and slightly decreased in mature wood, with estimated least-squares means of 50.0 % and 50.2 %, respectively. It indicates that patterns of CF variation between juvenile wood and mature wood are important to estimate the C stock of P. tabuliformis. This research provides insights into C uptake dynamics to support forest management and wood utilization. [ABSTRACT FROM AUTHOR]

Resin production in wood tissues is a regular feature of pine wood species, including southern pine. High resin contents of southern pine wood may increase wood resistance against decay fungi. The current study investigated the effect of resin contents in southern pine wood on decay resistance by exposing non-extracted heartwood, mixed wood (sapwood + heartwood), and sapwood blocks with varying resin content to brown rot, Fomitopsis ostreiformis in a laboratory decay test. Matching blocks of each wood type were successively extracted in a Soxhlet using three solvents to determine resin content and were exposed to decay fungus in parallel. Results showed that mass losses in non-extracted heartwood and mixed wood depended on resin content levels, and very shallow or no mass losses were observed in blocks containing more than 31 % resin content. Sapwood experienced high mass losses, but the presence of resinous extractives significantly increased the decay resistance. All solvent-extracted blocks experienced high mass loss (53–55 %). Scanning electron microscopy showed that penetration of brown rot hyphae and cell damage depended on the resin contents of blocks. Most of the identified compounds through GC-MS belonged to oleoresins, among which monoterpene hydrocarbons, oxygenated monoterpenoids, and sesquiterpenes were more abundant in heartwood than sapwood. [ABSTRACT FROM AUTHOR]

In this study, the influence of "bear claw" or indented growth ring anatomical patterns on the vibro-mechanical behavior of spruce wood have been investigated, particularly in the context of utilizing these singularities/specific features for the construction of violins. By employing vibrometry and modal analysis followed by finite element model updating, the vibro-mechanical properties (specific stiffness in longitudinal (L) and radial (R) directions and shear LR plane, and associated damping) of the indented growth rings spruce were identified and implemented in a numerical model of a violin. Results have revealed a significant increase in specific moduli in R direction and LR plane and decrease in L direction of spruce wood in the presence of indented growth rings, therefore accompanied by a reduction in anisotropic elastic properties, in comparison to spruce without these patterns. These properties led to changes in violin dynamics, globally increasing resonance frequencies and changing the shape of the vibration modes. The simulated frequency response function of the violin at the bridge suggested a global shift of the admittance of the bridge toward higher frequencies. These results suggest a potential impact of indented growth rings of spruce on the acoustic properties of instruments. [ABSTRACT FROM AUTHOR]

The time domain nuclear magnetic resonance (TD-NMR) technique was employed to distinguish various water states, and the moisture migration during Elm wood (Ulmus rubra) heartwood vacuum drying was quantitatively analyzed. The transverse relaxation time (T2) was employed to establish the correlation between drying time and moisture migration. Additionally, the longitudinal relaxation time (T1) was utilized to identify two types of water states within the cell wall: OH bound water (B-water) and more freely bound water (C-water). Meanwhile, the changes in these two types of bound water during the drying were investigated. The results demonstrated an exponential decrease in the content of OH bound water and more freely bound water with drying time. OH bound water within the cell wall predominated, with only a small portion of more freely bound water experiencing migration loss when the moisture content (MC) dropped below 20 %. Furthermore, OH bound water exhibited higher migration rate compared to more freely bound water at 10–20 % MC, while the motion of OH bound water molecules became highly restricted and stronger binding to cell walls than more freely bound water at a MC level of below 10 %. These findings yield a theoretical foundation and empirical support for optimizing drying methods. [ABSTRACT FROM AUTHOR]

The hygroscopic and moisture-dependent mechanical characteristics of small-leaved lime wood (Tilia cordata) were investigated experimentally. This study includes sorption, swelling and shrinkage experiments, as well as tension and compression tests in the three principal anatomical directions at four relative humidity levels. Four sample groups from trees of three different locations in Germany were used. The findings are comparable to those of earlier studies. The hygro-expansion anisotropy is relatively small. Young's moduli at tension/compression decreased by about 52 %/64 % in radial, 19 %/48 % in tangential and 16 %/58 % in longitudinal direction for an increase of moisture content from 10 % (65 % RH) to 20 % (95 % RH). Tension strengths/compression yield stresses decreased by about 25 %/45 % in radial, 9 %/42 % in tangential, and 32 % (compression) in longitudinal direction, respectively. These parameters increased with an increasing density. Based on the mechanical tests, Young's modulus, tension strength and compression yield stress were derived as density- and moisture-dependent material model parameters. Shear modulus and shear strength were estimated by a theoretical approach. The experimental and modelling study was accompanied by a literature survey on characteristics of lime wood relevant for hygro-mechanical material modelling. [ABSTRACT FROM AUTHOR]

Summary: Deladenus tonekabonensis sp. n. was isolated from dried wood of the Tree of Heaven (Ailanthus altissima) from the Sehezar forests in Tonekabon city in Mazandaran Province. The new species is characterised by a body length of 655 (561-777) and 592 (488-735) μ m for mycetophagous females and males, respectively, a short stylet (7.5-8.8 μ m) with three knobs backward. Lateral field with ten incisures, and an excretory pore toward the anterior part of the neck, located at 27.5 (22.0-35.5) and 28.0 (21.0-38.0) μ m from the anterior end of the mycetophagous females and males, respectively. The distance of the excretory pore to the hemizonid is 66.0 (59.0-71.0) and 61.0 (57.0-67.5) μ m for the mycetophagous females and males, respectively. Adults have a long overlapping dorsal pharyngeal gland, lacking a post-uterine sac (PUS), and in some specimens a very short post-uterine sac, 2.4-5.1 μ m long, and a conical tail, narrowing towards the tail tip. Males are frequent with slender tylenchoid spicules and a leptoderan bursa reaching the tail tip. Molecular phylogenetic analyses based on 28S rDNA placed the new species close to Deladenus and Anguillonema species in a clade with 0.99 posterior probability support. The measurements, line illustration and light microphotographs are given for the new species. [ABSTRACT FROM AUTHOR]

Models estimating decomposition rates of dead wood across space and time are mainly based on studies carried out in temperate zones where microbes are dominant drivers of decomposition. However, most dead wood biomass is found in tropical ecosystems, where termites are also important wood consumers. Given the dependence of microbial decomposition on moisture with termite decomposition thought to be more resilient to dry conditions, the relative importance of these decomposition agents is expected to shift along gradients in precipitation that affect wood moisture.Here, we investigated the relative roles of microbes and termites in wood decomposition across precipitation gradients in space, time and with a simulated drought experiment in tropical Australia. We deployed mesh bags with non‐native pine wood blocks, allowing termite access to half the bags. Bags were collected every 6 months (end of wet and dry seasons) over a 4‐year period across five sites along a rainfall gradient (ranging from savanna to wet sclerophyll to rainforest) and within a simulated drought experiment at the wettest site. We expected microbial decomposition to proceed faster in wet conditions with greater relative influence of termites in dry conditions.Consistent with expectations, microbial‐mediated wood decomposition was slowest in dry savanna sites, dry seasons and simulated drought conditions. Wood blocks discovered by termites decomposed 16–36% faster than blocks undiscovered by termites regardless of precipitation levels. Concurrently, termites were 10 times more likely to discover wood in dry savanna compared with wet rainforest sites, compensating for slow microbial decomposition in savannas. For wood discovered by termites, seasonality and drought did not significantly affect decomposition rates.Taken together, we found that spatial and seasonal variation in precipitation is important in shaping wood decomposition rates as driven by termites and microbes, although these different gradients do not equally impact decomposition agents. As we better understand how climate change will affect precipitation regimes across the tropics, our results can improve predictions of how wood decomposition agents will shift with potential for altering carbon fluxes. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Owing to the serious natural ageing phenomenon of ancient wooden buildings, to better explore the effect of drying and wet ageing degree on the exothermic behaviour of wood combustion, firstly, wood treated with different degrees of dry and wet ageings was obtained by artificially accelerating the dry and wet ageing method. The pore characteristics, along with the capacity of the heat transport of wood treated and wood combustion heat flow with different dry and wet ageing degrees, were analysed by scanning electron microscopy, thermophysical property, and thermal analysis test. Finally, according to Friedman's differential equivalent conversion method, the reaction process of the distribution of apparent activation energy of wood in various exothermic stages was computed and appraised, revealing the mechanism of the effect of the wood treated with dry and wet ageings on thermal reaction process. In the accelerated exothermic stage, the initial dry and wet ageing process (10 to 30 times) led to the opposite change in the trend of the apparent activation energy of wood and the fresh wood as a whole. The effect of the dry and wet ageings on the energy demand of the oxidation reaction at the end of prompt exothermic stage could decrease with the deepening of the ageing degree. [ABSTRACT FROM AUTHOR]

Curly (Karelian) birch is a special variety of Betula pendula Roth distributed in the northwestern part of Europe. Karelian birch is well-known for its valuable figured curly wood also known as "wooden marble". The genetic basis underlying curly wood formation has been debated since last century, however, there was no data about loci responsible for the curly wood trait. In the present study, we analyzed two full-sibs populations derived from experimental crosses of curly birches and segregating for the trait. RADseq genotyping was applied to reveal how many loci are involved in 'curliness' formation and to search for genetic variants associated with this trait. One single interval on chromosome 10 was detected containing possible candidate genes. InDel marker BpCW1 was suggested for the first time for marker-assisted selection of trees with curly wood at their earliest stages of development. [ABSTRACT FROM AUTHOR]

This study presents a superficial analysis of different wood polymer composites (WPC) comprising polystyrene (WPSC), poly(furfuryl alcohol) (WPFAC), and pine resin (WPRC) when exposed to artificial weathering. The study investigates the influence of resin type on the composites, focusing on their chemical, colorimetric, morphological, and thermal properties. The main findings indicate WPSC exhibits poor resistance to weathering, allowing ultraviolet radiation damage on the lignocellulosic component of the composite, leading to oxidized groups formation. Conversely, WPFAC and WPRC demonstrate good wood protection capabilities by preventing significant deterioration of holocellulose and acting as filters for radiation and moisture. Moreover, WPFAC exhibits the lowest decrease in carbonyl index and O/C ratio, with reductions of 2.6 and 11.6%, respectively. These findings are significant as they demonstrate that poly(furfuryl alcohol) and pine resin can be used to produce WPCs that delay and mitigate wood degradation by weathering, contributing to the increased potential utilization of bioresins. [ABSTRACT FROM AUTHOR]

This work aims to use experimental data from thermal characterization and adsorption/desorption isotherms of two tropicals woods species (Ayous and Tali) to propose an empirical model of thermal conductivity as a function of air relative humidity. A static gravimetric method was used to determine the adsorption isotherms of Tali and Ayous at 30 °C, and 40 °C. The GAB, Henderson and Nelson models were used to predict the isotherms. Exponential models of thermal conductivity and volumetric heat capacity with air relative humidity were proposed. The influence of hysteresis phenomenum was studied on these properties. The reliability of the developed empirical correlation between thermal properties and air relative humidity was evaluated by comparing the experimental and predicted curves. The relative errors were less than 8% for both Ayous and Tali. The correlation coefficients obtained were greater than 99% for both species in adsorption and desorption. There was also an increase in the equilibrium water content of both species with the increase in water activity at constant temperature. The correlation coefficients between GAB model and sorption experimental data were lower than 99% when Ayous was subjected to a temperature of 40 °C in adsorption and Tali to a temperature of 40 °C in desorption. [ABSTRACT FROM AUTHOR]

Aiming at the problems of low milling efficiency, low machining precision and high manual labor intensity of the outer frame of passive European-style wood windows, a double end milling machining center for passive European-style wood windows was designed and used for high-efficiency and high-precision milling of the outer frame of passive European-style wood windows. Through the analysis of the milling process of wood windows, the detailed design of the machining center structure was carried out using computer-aided design methods. Solidworks software was used for three-dimensional modeling of the machining center, and finite element analysis software was used to analyze the strength and stiffness of the key support parts. Virtual experimental methods was used to verify the machining efficiency of the machining center. The results showed that the theoretical machining efficiency of the machining center was about 400 fans/ day, compared with the manual machining efficiency of 350 fans/ day, the efficiency was improved by 14. 28%, and the maximum stress of the key support parts was far less than the permissible stress of the material, which met the requirements for use. [ABSTRACT FROM AUTHOR]

In order to explore the effect of heat treatment of vegetable oil wax on the physical properties and dimensional stability of wood of different tree species, Abies nephrolepis Maxim., Larix gmelinii and Diospyros celebica were taken as the research objects, and the independently prepared vegetable oil wax solution was used as the heating medium. The wood was heat treated at different temperatures (140, 170, 200 ℃ ) for 4 hours, and then the vegetable oil wax was fully cooled to ensure that it entered the interior of the wood. The internal structure was observed by scanning electron microscope. The results showed that the room temperature cooling stage was the key of wood oil wax heat treatment. At this stage, a large amount of vegetable oil wax entered the interior of wood, which was mainly reflected in the change of wood specimen weight percentage gain (WPG). The maximum color change (ΔE ∗ ) of three kinds of wood after combined heat treatment with vegetable oil and wax were 48. 24, 40. 67, 5. 95. The surface hydrophobicity was improved steadily, and the water contact angle (WCA) was increased to about 70°. The tangential and radial moisture expansion rates and volume expansion rates of different tree species were reduced to varying degrees, and the anti swelling efficiency (ASE) was effectively improved, with the maximum increase of 49. 64%, 48. 24% and 38. 86% for the three kinds of wood, indicating that vegetable oil wax heat treatment can improve the dimensional stability of wood. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of including teak wood in recycled high-density polyethylene wood plastic composites (WPC) with pine wood on their resistance to degradation caused by termite attack and accelerated weathering. A 23 factorial experimental design was conducted with three repetitions in the center to analyze the weight loss and termite mortality during the experiments. The factors studied were the days of exposure to accelerated weathering, days of exposure to termite attack, and the concentration of teak wood in the composite. Surface characterizations (SEM and FTIR) were carried out to analyze the exposed surfaces and determine the chemical modification of the composite components. The results showed that the WPC manufacturing process promotes a heterogeneous distribution of the wood particles, being greater within the center of the samples than on the surface. Specimens exposed to both accelerated weathering and termite attack resulted in a certain weight loss and termite mortality, depending on the material, conditions of exposure, and the content of teak wood in the WPC. When those compounds were subjected to accelerated weathering followed by termite attack they exhibited a higher termite attack. The presence of teak wood in the WPC produced a reduction in the effects of termite attack and accelerated weathering on weight loss and an increase in termite mortality compared to the WPC with only pine wood, as teak wood contains extractables with termiticidal action. The lowest value of weight loss (0.06%) was observed for the WPC with the highest amount of teak wood with termite attack, resulting in a termite mortality rate of 100% after 17 days of exposure. [ABSTRACT FROM AUTHOR]

Purpose: In industrial applications, formaldehyde-based wood adhesives have been used extensively because of their low costs and high reactivity. However, their real-world applications are hindered by some main bottlenecks, especially the formaldehyde emission and usage of nonrenewable raw materials. The purpose of this study is the development of sustainable and formaldehyde-free wood adhesive formulation. Design/methodology/approach: In this study, starch and tannin-based wood adhesive were synthesized. Chemical structures and thermal properties of the prepared bio-based resin formulations were elucidated by using Fourier transform infrared and differential scanning calorimetry analysis, respectively. Laboratory scale particleboard production was carried out to determine the performance of the developed resin formulations. Obtained results were evaluated in dry medium (P2) according to European norms EN 312 (2010). Furthermore, the board formaldehyde content was determined by using the perforator method according to the European Norm EN 12460-5. Findings: The results show that the improved starch and tannin-based wood adhesives were successful in their adhesive capacity, and the formaldehyde content of the final product was obtained as low as 0.75 mg/100 g. This paper highlights that the presented adhesive formulations could be a potential eco-friendly and cost-effective alternative to the formaldehyde-based wood adhesives for interior particleboard production. Research limitations/implications: Starch-based resins in the liquid form needed to be continuously mixed throughout their shelf life to prevent the starch from settling because it was not possible to dissolve the precipitated starch again after a while. For this reason, starch was given to the chips in powder form while preparing the particleboard. Practical implications: In conclusion, this study shows that the developed bio-based resin formulations have a high potential to be used for producing interior-grade particleboards instead of commercial formaldehyde-based wood adhesives because the obtained results generally satisfied the interior grade particleboard requirements according to European norms EN 312, P2 class (2010). In addition, it was determined that the produced boards had significantly low formaldehyde content. The low formaldehyde content of the final boards was not because of the resin but because of the natural structure of the wood raw material, press parameters and environmental factors. Social implications: The developed bio-based resin system made it possible to obtain boards with significantly low formaldehyde content compared to commercial resins. Originality/value: The developed bio-based resin formulation made it possible to produce laboratory-scale board prototypes at lower press factors and board densities compared to their counterparts. [ABSTRACT FROM AUTHOR]

This study describes the seasonal changes in cell-to-cell transport in three selected angiosperm tree species, Acer pseudoplatanus (maple), Fraxinus excelsior (ash), and Populus tremula × tremuloides (poplar), with an emphasis on the living wood component, xylem parenchyma cells (XPCs). We performed anatomical studies, dye loading through the vascular system, measurements of non-structural carbohydrate content, immunocytochemistry, inhibitory assays and quantitative real-time PCR to analyse the transport mechanisms and seasonal variations in wood. The abundance of membrane dye in wood varied seasonally along with seasonally changing tree phenology, cambial activity, and non-structural carbohydrate content. Moreover, dyes internalized in vessel-associated cells and 'trapped' in the endomembrane system are transported farther between other XPCs via plasmodesmata. Finally, various transport mechanisms based on clathrin-mediated and clathrin-independent endocytosis, and membrane transporters, operate in wood, and their involvement is species and/or season dependent. Our study highlights the importance of XPCs in seasonally changing cell-to-cell transport in both ring-porous (ash) and diffuse-porous (maple, poplar) tree species, and demonstrates the involvement of both endocytosis and plasmodesmata in intercellular communication in angiosperm wood. [ABSTRACT FROM AUTHOR]

Developing sustainable and lightweight structural materials is a promising strategy for reducing carbon emissions in transportation and buildings. However, producing high‐performance bulk structural materials from sustainable biomass materials while maintaining excellent mechanical strength remains a major challenge, especially for further scale‐up. Herein, a scalable and robust bottom‐up strategy is reported to fabricate bulk wooden plate (W‐plate) with a typical "brick‐and‐mortar" structure from engineered wood particles via moderate delignification and in situ LiCl/DMAc treatment followed by hot‐pressing. The W‐plate constructed by delignified wood particles and regenerated cellulose nanofibers can achieve a confluence of mechanical strengthening and toughening by the ordered lamination structure and multiscale cellulose micro/nanofiber crosslinking interactions, resulting in high flexural strength (225.17 ± 12.18 MPa) and high fracture toughness (4.01 ± 0.53 MPa m0.5) while maintaining a low density (1.34 g cm−3), superior to typical metals and ceramics. Moreover, the W‐plate exhibits advantageous thermal properties, including a low thermal expansion coefficient (<19 × 10−6 K−1) and a high storage modulus (>7.5 GPa) compared to those of petroleum‐based polymers. Coupled with abundant and renewable raw materials, all‐cellulose components, and scalable and recyclable fabrication, the W‐plate can potentially be used as a high‐performance, cost‐effective, and environmentally friendly alternative for engineering applications. [ABSTRACT FROM AUTHOR]

Sepiolite is a silicate mineral that improves the fire properties in solid wood when mixed with a water-based coating. The present study was carried out to investigate and evaluate the effects of sepiolite addition to acrylic-latex paint on the pull-off adhesion strength, as an important characteristic of paints and finishes used in the modern furniture industry and historical furniture as well for preservation and restoration of heritage objects. Sepiolite was added at the rate of 10%, and brushed onto plain-sawn beech (Fagus orientalis L.) wood specimens, unimpregnated and impregnated with a 400 ppm silver nano-suspension, which were further thermally modified at 185 °C for 4 h. The results showed that thermal modification had a decreasing effect on the pull-off adhesion strength, primarily as a result of the thermal degradation of cell-wall polymers (mostly hemicelluloses). Still, a decreased wettability as a result of condensation and plasticization of lignin was also partially influential. Based on the obtained results,thermal modification was found to have a significant influence on pull-off adhesion strength. Sepiolite addition had a decreasing effectin all treatments, though the effect was not statistically significant in all treatments. The maximum and minimum decreases due to sepiolite addition were observed in the unimpregnated control (21%) and the thermally-modified NS-impregnated (4%) specimens. Other aspects of the sepiolite addition, and further studies that cover different types of paints and coatings, should be evaluated before coming to a final firm conclusion in this regard. [ABSTRACT FROM AUTHOR]

Sepiolite is a silicate mineral that improves the fire properties in solid wood when mixed with a water-based coating. The present study was carried out to investigate and evaluate the effects of sepiolite addition to acrylic-latex paint on the pull-off adhesion strength, as an important characteristic of paints and finishes used in the modern furniture industry and historical furniture as well for preservation and restoration of heritage objects. Sepiolite was added at the rate of 10%, and brushed onto plain-sawn beech (Fagus orientalis L.) wood specimens, unimpregnated and impregnated with a 400 ppm silver nano-suspension, which were further thermally modified at 185 °C for 4 h. The results showed that thermal modification had a decreasing effect on the pull-off adhesion strength, primarily as a result of the thermal degradation of cell-wall polymers (mostly hemicelluloses). Still, a decreased wettability as a result of condensation and plasticization of lignin was also partially influential. Based on the obtained results,thermal modification was found to have a significant influence on pull-off adhesion strength. Sepiolite addition had a decreasing effectin all treatments, though the effect was not statistically significant in all treatments. The maximum and minimum decreases due to sepiolite addition were observed in the unimpregnated control (21%) and the thermally-modified NS-impregnated (4%) specimens. Other aspects of the sepiolite addition, and further studies that cover different types of paints and coatings, should be evaluated before coming to a final firm conclusion in this regard. [ABSTRACT FROM AUTHOR]

Fast-growing plants with a high carbon fixation capability are promising candidates for mitigating climate change and serving as a renewable resource to replace fossil fuels. Nonetheless, their short lifespan and extensive use lead to the significant accumulation of underutilized waste. While conventional thermal energy extraction remains dominant in biomass utilization, the lack of appropriate carbon capture and storage techniques results in unavoidable CO2 emissions. In contrast, the fine reforming of lignocellulosic biomass offers the potential to reduce CO2 emissions. However, the polymeric, complex and rigid structure of lignocellulosic biomass poses challenges, necessitating energy-intensive pretreatment, where the balance between wood particle size reduction (and thus energy consumption) and pretreatment duration is often overlooked. Herein, we developed a facile energy-saving microwave-hydrothermal method to advance the utilization of fast-growing Paulownia. The optimized sugars (xylose and glucose) after pretreatment can be further converted to formate via a hybrid electrolysis process with the cogeneration of green hydrogen. Both xylose and glucose can be readily converted to formate with high yield and selectivity. This process can be directly powered by PV panel without the safety concerns of hydrogen crossover because oxygen evolution is greatly suppressed. This solar-driven hybrid electrolysis of pretreated Paulownia suggests a pathway to cogenerate green chemicals and green fuels from fast-growing woods while also storing energy from renewable sources in chemical bonds. Overall, this novel synthesis process for green chemicals contributes to the decarbonization efforts and sustainable development initiatives. [ABSTRACT FROM AUTHOR]