Search

White-rot fungi are vital microorganisms that can decay lignocellulosic biomass. This study investigated the ability of white-rot fungus found on rotten wood to produce ligninolytic enzymes and their enhancement using nanoparticles (NPs). Phanerochaete chrysosporium was isolated from decayed wood. Its ability to produce ligninolytic enzymes, namely CMCase, FPase, Laccase, and MnPase, was recorded. The enzymes' productivity was enhanced via utilization of the surfactant polysorbate 80 with optimum concentration 0.20 mL/L for maximum CMCase (201.33 ± 2.31 U/mL) and FPase (66.33 ± 0.58 U/mL), whereas the corresponding value was 0.15 mL/L for laccase and MnPase production. Mn2O3NPs and CuONPs enhanced the enzymes' productivity but with different levels according to their concentrations, where the maximum productivity of CMCase (220.67 ± 2.31 U/mL) and (FPase 74.63 ± 3.51 U/mL) were at 50 ppm, but MnPase (0.52 ± 0.01 U/mL) and laccase (2.88 ± 0.01U/mL) were at 25 ppm and 75 ppm of CuONPs, respectively. Mn2O3NPs at 75 ppm enhanced the productivity of CMCase (219.33 ± 1.15 U/mL) and FPase (74.63 ± 3.51U/mL); but at 25 ppm and 75 ppm enhanced the productivity of laccase (2.40 ± 0.04U/mL) and MnPase (0.73 ± 0.03 U/mL), respectively. Thus, NPs were found to play a vital role in improving the productivity of ligninolytic enzymes. [ABSTRACT FROM AUTHOR]

The acoustic emission analysis method was used to determine the activity of very young Hylotrupes bajulus larvae in their long-term development. In the laboratory conditions the simulated scenario of a fresh, intense infestation inside the construction wood was evaluated. The sounds generated by the insects during their feeding on the wooden samples were processed by the measurement system, which was able to detect and count the larva-originated sound pulses and calculate related energy. So far, no one has examined possibilities of detecting infant larvae of Hylotrupes bajulus L. This work is a continuation of research on the influence of the insect mass on its AE-based detection. The experiments performed with multiple wood samples analyzed through the period of one year have shown dependency between the mass of the larva and the intensity of the sound generated by them. The moment of the earliest possible detection of infestation in the wooden structure was evaluated. In the appropriate conditions (large number of young larvae inside the wood and optimal temperature) the insects reach the mass of tens of mg, which makes them detectable using the AE method. [ABSTRACT FROM AUTHOR]

Wooden structures are becoming increasingly popular in the construction world. However, these structures often rely on synthetic adhesives, raising concerns about the environmental risks associated with their chemical composition. In response to these concerns, this study aims to explore sustainable alternatives, particularly focusing on polyurethane adhesives that incorporate proteins from industrial byproducts. The investigation involved three protein sources: soybean meal, shrimp shells, and skim milk, modified under mild alkaline conditions to obtain protein concentrates. These concentrates were then incorporated into the adhesives at varying protein contents: 5%, 10%, and 15%. Additionally, two isocyanate systems were examined, one being petrochemical-based and the other a partially bio-based blend. Chemical, thermal, optical, and mechanical characterizations were conducted to evaluate the adhesive performance. This study demonstrates that the adhesives’ thermal properties remain unaffected by both the protein content and the isocyanate system. However, these factors influence the adhesive penetration into the wood substrate. Ultimately, the results suggest that higher protein content offers superior retention of mechanical strength in adhesives compared to the petrochemical reference when subjected to humid conditions. Overall, this research demonstrates the potential of proteins from industrial byproducts as sustainable adhesive allies, providing valuable insights into their interactions with different isocyanates.

Laboratory and field experiments were performed to examine the feasibility of using Time Domain Reflectometry (TDR) to monitor moisture content (MC) of wood and standing trees. The TDR was used to detect the electromagnetic wave propagation time of four tree species (Betula platyphylla, Tilia tuan, Picea asperata, and Fraxinus mandshurica) at different MCs. During the TDR test, effects of probe insertion depths on MC predictive accuracy were considered. The best results were obtained at an insertion depth of 8 cm. At the selective 8 cm insertion depth, a species-specific MC prediction model (0.94 ≤ R2 ≤ 0.98), a generalized model for the four species (R2 = 0.65), and a hybrid model for the species with similar densities (0.80 ≤ R2 ≤ 0.96) were constructed, respectively. Overall, the species-specific MC prediction model showed good predictive ability for both tree and wood disc samples, including that TDR can be used to detect wood and standing tree MC. If possible, the hybrid model can be used for species with similar density.

Wood structures generally rely on synthetic adhesives for their strength and versatility. However, environmental concerns linked to the chemical composition of these adhesives have stimulated the search for more environmentally friendly adhesives. Researchers have explored replacing petroleum-based constituents with natural raw materials such as lignins, tannins, and proteins. Of these alternatives, proteins, being biological macromolecules, are recognized for their capacity to enhance adhesion to wood substrates. This study considered the development of protein-based adhesives derived from diverse sources, including soybean meal, microbrewery spent grains, shrimp shells, and skim milk powder. These raw materials were subjected to mild alkaline conditions to yield protein concentrates. The resulting adhesives were formulated at various protein content levels: 5%, 10%, 15%, and 20%. The study's findings showed that the incorporation of proteins into the polyurethane adhesive system not only can preserve but also augment adhesive performance. This enhancement encompasses deeper penetration into wood substrates and an overall improvement in mechanical strength. These results underscore the promise of proteins as a sustainable alternative to petroleum-based polyols in adhesive formulations.

This study aimed to develop a waterborne stain (WBS) that protects against weathering and increases resistance of wood to fungi when exposed to heavy rainfall. The WBS was prepared using an antibacterial agent, insect repellent, and copper nanoparticle solution (CN) as a surface coating agent. The WBS was applied on larch and hemlock wood, and changes in color and wettability due to natural and artificial weathering were evaluated. A gray-blue spot developed on the untreated wood surface within 30 d of outdoor exposure, which then spread over the entire wood surface, and the wood eventually turned black. Resistance to fungi increased when CN alone was applied; however, the CN surface was oxidized and turned gray after 30 d and 90 d for larch and hemlock, respectively. The water contact angle was increased due to leaching. The application of CN followed by WBS prevented wood discoloration under ultraviolet light and the wood showed excellent weathering resistance capacity. The prevention of wood discoloration and resistance to fungi by CN were confirmed, which could guide the development of a paint that can prolong protection from weathering of wood exposed to heavy rainfall events. [ABSTRACT FROM AUTHOR]

The existing research primarily focuses on wood-concrete composite beams, with limited studies on the bending performance and effective width of wood-concrete composite slabs. A full-scale composite slab with screw connections was constructed and subjected to static load testing. The study extensively investigated the ultimate bearing capacity, loaddeflection curves, interface slips, strain distributions of cross-section and effective width of the wood-concrete composite slab. It was found that the failure mechanism of the composite slab involved both bending and tensile failure of the wood beams. As the applied load intensified, a marked augmentation in the longitudinal strain of the concrete slab was observed; along the width direction, the longitudinal strain of concrete slab manifested a curved distribution. The precise determination of the effective width of the concrete slab within the composite floor could be accurately achieved via the utilization of a simplified computational approach. In order to simplify the analysis, the M-shaped section of composite slab was approximated as T-section composite beams when evaluating the bending behavior. The linear-elastic model was shown to be accurate in predicting the bending stiffness and load-carrying capacity of composite slabs. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the correlation between the mass loss (ML) of wood due to thermal modification and the equilibrium moisture content (EMC) of thermally modified wood. After thermal modification of larch lumber under various temperature and time conditions, ML according to treatment temperature and time was measured, and the (EMC) of the thermally modified wood was evaluated for each treatment condition. As the treatment temperature increased and the treatment time became longer, the ML of wood due to thermal modification increased. In addition, as the treatment temperature increased, the difference in EMC between the non-treated wood and the thermally modified wood tended to increase. Finally, a robust logarithmic correlation was observed between the ML due to thermal modification and the EMC of the thermally modified wood. These results suggest that the EMC of thermally modified wood can be predicted by simply measuring the weight of wood before and after thermal modification. [ABSTRACT FROM AUTHOR]

The dimensional stability and equilibrium moisture content (EMC) of thermally modified hardwoods were studied. Lumber of yellow-poplar (Liriodendron tulipifera); red oak (Quercus borealis); white ash (Fraxinus americana), red maple (Acer rubrum); hickory (Carya glabra), and black cherry (Prunus serotina) were modified in industrial thermo-vacuum system. The water absorption rate, EMC, swelling, anti-swelling efficiency, shrinkage, anti-shrinkage efficiency, and anisotropy of the specimens were measured and compared to unmodified wood. The results show that thermal modification significantly decreased water absorption of wood which leads to improved dimensional stability. Specifically, thermally modified wood showed reduced EMC (22% in hickory to 59% in red maple), increased water absorption repellent (14.9% in black cherry to 29.6% in yellow-poplar), increased anti-swelling efficiency (14.2% in hickory to 71.4% in ash), increased anti-shrinkage efficiency (23.5% in red maple to 65.6% in ash), and reduced anisotropy coefficient (4.7% in red oak to 31.9% in black cherry). [ABSTRACT FROM AUTHOR]

Wood structures generally rely on synthetic adhesives for their strength and versatility. However, environmental concerns linked to the chemical composition of these adhesives have stimulated the search for more environmentally friendly adhesives. Researchers have explored replacing petroleum-based constituents with natural raw materials such as lignins, tannins, and proteins. Of these alternatives, proteins, being biological macromolecules, are recognized for their capacity to enhance adhesion to wood substrates. This study considered the development of protein-based adhesives derived from diverse sources, including soybean meal, microbrewery spent grains, shrimp shells, and skim milk powder. These raw materials were subjected to mild alkaline conditions to yield protein concentrates. The resulting adhesives were formulated at various protein content levels: 5%, 10%, 15%, and 20%. The study's findings showed that the incorporation of proteins into the polyurethane adhesive system not only can preserve but also augment adhesive performance. This enhancement encompasses deeper penetration into wood substrates and an overall improvement in mechanical strength. These results underscore the promise of proteins as a sustainable alternative to petroleum-based polyols in adhesive formulations. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate whether the chemical composition of wood and its crystallinity can help in the analysis of degradation by fungi and insects in logs of Amazonian wood species stored in a stockyard. For this study, wood from five commercial species that had been stored in an open yard for six months was used. The scale of degradation by fungi and insects, the moisture content of the logs, the total extractive content, lignin, holocellulose and the crystallinity were evaluated. It was concluded that the position of the logs in the stacks, associated with the storage time, influenced the evaluated characteristics. It was also observed that X-ray diffraction has potential for analysis of the degradation by fungi and insects in logs of Amazonian species stored in the stockyard. [ABSTRACT FROM AUTHOR]

To enhance the synergistic effect of phosphorus (P) and nitrogen (N) on flame retardant property, four different phytic acid-based NP flame retardants (FR-PAN) were manufactured using phytic acid and urea with various molar ratios, ranging from 1:3 to 1:12. The FR-PAN water solution was used to impregnate poplar wood under vacuum condition, and the thermal degradation performance of the FR-PAN treated wood were investigated. Compared to untreated wood, the PAN-6 (molar ratio is 1:6) group showed a reduction of 57.1% in total heat release and 80.0% in total smoke release. In the combustion, due to the introduction of P and N, FRPAN generates O=P/C-O/C-P/C-N bonds, forming highly graphitized char residues, which effectively isolate the entry of oxygen and heat and play a good protective role in the condensed phase. Morphological and chemical analysis of the residual char layer revealed that the introduction of P and N elements formed a more stable hybrid structure, significantly improving the thermal stability of the char layer. Among them, the PAN-6 group exhibited the highest char layer stability, indicating optimal synergistic effects of nitrogen and phosphorus under these conditions. [ABSTRACT FROM AUTHOR]

Quantitative anatomical characteristics and their radial variation in compression (COW), lateral (LAW), and opposite (OPW) woods of Agathis loranthifolia and Pinus merkusii stem woods growing in Indonesia were observed and compared to understand wood quality. The length, diameter, wall thickness, and lumen diameter of tracheids and ray height and numbers were observed using optical microscopy. In both species, COW had the shortest tracheid length, smallest tracheid and lumen diameter, thickest cell wall, and highest ray numbers among the parts, while LAW and OPW showed comparable or variable values in quantitative characteristics. In A. loranthifolia, COW had the highest ray height, whereas, in P. merkusii, it had the lowest uniseriate and fusiform ray heights. No significant difference was observed in ray numbers and heights between LAW and OPW. In both species, the tracheid length and lumen-to-diameter ratio in COW, LAW, and OPW tended to increase from near the pith to near the bark while the wall-to-diameter ratio decreased. The ray heights of all parts increased with increasing distance from the pith, whereas the ray number decreased. [ABSTRACT FROM AUTHOR]

This study identified the wood species and evaluated the weathering and biological degradation of historical timber from a traditional Turkish house in Konuralp, Türkiye. The wood material was obtained from the floorboards, window frames, cabinets, cripple studs, ceiling boards, and joists. The species were identified as Pinus spp. for the cabinet, window frame, and cripple stud, Abies spp. for the floorboards, Populus spp. for the ceiling boards, and Quercus spp. for the joist. The macroscopic observation revealed multiple types of degradation caused by weathering, fungi, and insect attacks. The cripple studs made of pine and the floorboards made of fir had become completely unusable due to insect damage. Relatively less biological damage was observed on the cabinet made of pine wood and the ceiling boards made of poplar wood. [ABSTRACT FROM AUTHOR]

In this study, the influence of the diameter of round steel nails, the guiding bores, and the wood sections on the nail holding performance of Pinus massoniana and Cunninghamia lanceolata dimension lumber was explored. The results showed that the nail-holding power of round steel nails mainly came from their friction with wood fibers, while the radial and tangential sections were also affected by the shearing action of wood fibers. The tangential section reached the largest nail-holding power, followed by the radial section and cross section. Greater wood density was associated with higher nail holding power. Under a large nail diameter, however, high-density wood was prone to plastic cracking, which influenced the nail holding power greatly. Prefabricated guiding bores could prevent plastic cracking in wood to some extent and improve the nail holding power of Pinus massoniana and Cunninghamia lanceolata dimension lumber when diameter of round steel nails was more than 3.0 mm. For Cunninghamia lanceolata characterized by low density and rigidity, the wood fiber was in close contact with the round steel nail and internal cracking could not be easily generated under a large diameter of round steel nails. [ABSTRACT FROM AUTHOR]

The article presents the impact of drying process and selected parameters on the color changes on the surface of pine wood (Pinus sylvestris L.). Three predetermined process conditions (modes), mild, normal, and intensive, were investigated. The experiments were conducted using a semi-industrial scale dryer designed at the Gdańsk University of Technology with a loading capacity of 0.55 m3. The drying process was applied to pine wood grown in the northern part of Pomeranian region in Poland. The specimens were selected taking into consideration the radial angle of the growth rings. During each drying mode, 25 pieces of wood with dimensions (thickness, width, length) of 0.03 m, 0.2 m, and 1.5 m, respectively, were dried. The total color change (E) after drying process and color saturation (h*) before and after drying processes of the wood surface was determined using the normalized CIELAB methods. The obtained results indicated that the color change of the pine wood surface increased simultaneously with the intensification of the drying process. However, the normalized wood quality after drying under intensive drying process conditions remained within the standard limits. The application of intensive drying process conditions remarkably changes the surface color of the obtained material, while remarkably reducing the drying process duration. [ABSTRACT FROM AUTHOR]

This study analyzed the diversity of physical properties and mechanical properties of white jabon (Neolamarckia cadamba (Roxb.) Bosser) from various locations and ecological conditions in West Java and Banten Indonesia. White jabon wood samples were taken from 8 locations in West Java and the Banten region. Tree ages ranged from 5 to 6 years. This wood was then tested to compare physical characteristics (density or specific gravity) and mechanical characteristics (modulus of rupture (MOR) and modulus of elasticity (MOE)). The results showed that wood density ranged from 0.29 to 0.43 g.cm-3, MOR ranged from 361 to 641 kg.cm-2, and MOE ranged from 31,117 to 58,910 kg.cm-2. The highest density average (0.43 ± 0.004 g.cm-3) was produced from Cianjur, and the lowest density average (0.29 ± 0.010 g.cm-3) was from Tanjungsari Sumedang. Environmental factors (precipitation and altitude) affect the density of wood. Separately, rainfall has a low effect and a negative relationship to jabon wood density, while altitude has a high influence and a negative relationship to jabon wood density. Andosol soil types tend to produce low density wood. [ABSTRACT FROM AUTHOR]

Laminated veneer lumber (LVL) and laminated veneer board (LVB) panels from jabon wood (Neolamarckia cadamba) were impregnated with fire retardation substances, namely diammonium phosphate (DAP) and sodium silicate (SS). Prior to testing, the boards were conditioned in relative humidity (RH) of 65% and a temperature of 25 °C. The moisture content (MC), bending strength tests in flat wise position, and bonding tests were conducted in accordance with the Japanese Agricultural Standard (JAS:2008). Density tests and hardness tests were conducted in accordance with ASTM D143 standard (2003) in 50 mm x 50 mm. Thickness-swell shrinkage tests were conducted in accordance with the standard BS EN 317:1993, and fire resistance was tested under PS 1-19 standard. The use of 20% DAP and SS solution on jabon wood using impregnation methods affected some of the properties of the panels, especially the moisture content, density, and bonding strength of LVL and LVB compared to the control panels. Both DAP and SS impregnation increased the density. The treatments showed promise for resisting fire, as well as increasing the moisture content and increasing the density compared to the control. [ABSTRACT FROM AUTHOR]

Using phase change materials (PCMs) is an efficient solution for reducing energy consumption in buildings. These materials have a large capacity for storing thermal energy, making them an appealing option for energy management purposes. Phase change materials have been successfully incorporated into various construction materials such as concrete, brick, or plaster. The primary objective of this review is to examine previous studies conducted on the application of PCMs in wood. The initial section presents an overview of the direct impregnation techniques utilized for wooden materials. This is followed by a discussion on the implementation of macroencapsulated PCMs in wooden structures that are typically present in residential buildings. In addition, the use of shape-stabilized PCM/wood composites, preventing potential leaks during the phase change transition, is explored. Finally, patents related to the use of PCMs in wood are described. Future challenges include the incorporation of PCMs into wood composites to improve their thermal properties. This literature review shows that there is a gap in knowledge regarding the utilization of phase change materials in wood-based panels such as oriented strandboards, fiberboards, and particleboards. This provides an opportunity for future research to improve the performance of the products manufactured by the wood-based panels industry.

The purpose of this study was to determine the effect of four different age groups on wood properties, i.e., anatomical, physical, and mechanical, of Himalayan birch (Betula alnoides Buch.-H.ex D.Don). The correlation between the properties was also discussed. The results indicated age influences the anatomical, physical, and mechanical properties of Himalayan birch. Results were comparable with other plantation species. Moreover, mechanical properties were highly correlated with the fibre morphology in Himalayan birch. Results from this present study indicate that the 15-, 20-, and 25-year-old Himalayan birch are suitable to be used for parquet, furniture, and other products. Generally, plantation-grown Himalayan birch has the potential to be a raw material to fulfill the demand for the timber industry.

With the application of bleaching treatments, the color of the wood material changes. When different bleaching agents are applied to the same wood, different results are likely to be obtained. In this study, wood species doussié (Afzelia africana), iatandza (Albizia ferruginea), merbau (Intsia bijuga (Colebr.) O. Kuntze), mahogany (Swietenia mahagoni L.), and hornbeam (Carpinus betulus L.) along with one and two component (B-One-C and B-Two-C) wood bleaching chemicals were applied to the wood material surfaces with sponge technique. Then, color parameters (ho: hue angle, a*: red color tone, b*: yellow color tone, C*: chroma, and L*: lightness) were determined on bleached and unbleached materials. According to the results obtained, B-One-C application increased ho, a*, b*, C*, and L* values in all wood species. The highest ∆E* values were determined in mahogany, doussié, hornbeam, and merbau wood species treated with B-Two-C. The chemicals used in the study showed different results on the same wood.

Using phase change materials (PCMs) is an efficient solution for reducing energy consumption in buildings. These materials have a large capacity for storing thermal energy, making them an appealing option for energy management purposes. Phase change materials have been successfully incorporated into various construction materials such as concrete, brick, or plaster. The primary objective of this review is to examine previous studies conducted on the application of PCMs in wood. The initial section presents an overview of the direct impregnation techniques utilized for wooden materials. This is followed by a discussion on the implementation of macroencapsulated PCMs in wooden structures that are typically present in residential buildings. In addition, the use of shape-stabilized PCM/wood composites, preventing potential leaks during the phase change transition, is explored. Finally, patents related to the use of PCMs in wood are described. Future challenges include the incorporation of PCMs into wood composites to improve their thermal properties. This literature review shows that there is a gap in knowledge regarding the utilization of phase change materials in wood-based panels such as oriented strandboards, fiberboards, and particleboards. This provides an opportunity for future research to improve the performance of the products manufactured by the wood-based panels industry. [ABSTRACT FROM AUTHOR]

Wood density is a crucial factor in determining the quality of wood in boreal ecosystems within the Northern Hemisphere. Climate variables play a significant role in shaping wood density, posing challenges for forest managers and stakeholders in the wood industry to adapt amidst climate change. However, our current understanding of these effects remains incomplete. This systematic literature review explores the multifaceted influences on wood density in the boreal zone, encompassing both climate-related and non-climatic factors. The findings demonstrate that warmer temperatures can cause both increases and decreases in wood density, primarily due to their impact on tracheid lignification and cell wall thickening. Nonetheless, the outcome depends on various factors, including species type, age, soil conditions, presence of pests and diseases, fire, windstorms, and silviculture practices. The quantification of complex relationships between these factors and wood density has been insufficient in existing literature. Understanding the impacts of both climate and non-climate factors on wood density is essential for fostering a sustainable wood industry, while effectively mitigating adverse effects and maximizing benefits. Forest managers can leverage this knowledge to optimize wood production strategies, ensuring long-term ecological resilience amidst the increasingly variable climate challenges. [ABSTRACT FROM AUTHOR]

Color change was compared through artificial and outdoor weathering tests according to wood species and stain type. In the artificial weathering tests, the color change ΔE was the highest for the initial 200 hour, and teak solvent-based stain was the most effective in preventing color change. Outdoor weathering tests also showed a rapid color change until the initial 60 days, and the uncoated larch specimens exhibited graying after 120 days. Teak solvent-based stain had the highest preventing color effect, whereas water-based white semi-transparent stain had the highest contact angle. It is difficult to check the color change of wood due to the addition of pigment in teak, as its resistance to moisture is rapidly reduced and its surface protection effect is poor. Water-based white semitransparent stain prevented color change and maintained a contact angle of 57.1° for up to 150 days, confirming the effect of moisture resistance. This study aimed to provide basic data on weather resistance by wood species and to suggest that the development direction of outdoor exposed wood is a water-based semi-transparent stain. [ABSTRACT FROM AUTHOR]

Bio-damaged wood was studied as a potential raw material for the production of hydrolytic degradation cellulose products. Conditions for obtaining fine-dispersed microcrystalline cellulose (MCC) based on hydrolytic treatment of cellulose from bio-damaged wood were determined. A comparative analysis of the quantitative values of the degree of polymerization of default commercial cellulose and cellulose from damaged wood was performed. The objective of the work was to study the possibilities of obtaining MCC from bio-damaged wood possessing quantitative characteristics close to those obtained from the commercial wood, reducing the concentration of inorganic acid during the hydrolytic degradation. The experimental analysis showed that with an increase in the pulp refining degree from 15 °SR to 75 °SR, the time for the hydrolysis process decreased from 150 to 90 min, the temperature of chemical treatment decreased from 100 °C to 80 °C, and acid concentration by 0.5 N. The polymerisation degree of microcrystalline cellulose, regardless of the type of raw material, also decreased with an increase in the refining degree. [ABSTRACT FROM AUTHOR]

Taking the conventional drying process of Pinus sylvestris square wood with pith as the research material, based on the Back Propagation (BP) neural network algorithm, a model was constructed using the real-time online-measurement data. Softening treatment time and temperature, variable treatment time and temperature, initial moisture content of wood, and position of wood core and sapwood were used as model inputs. Wood drying rate and longitudinal cracking degree were used as outputs to indicate wood drying quality. The results showed that with a suitable model structure of 6-9-2 (input layer-hidden layer-output layer), the coefficient of determination R² and mean square error of the test samples were 0.96, 0.99, and 0.00605, respectively, indicating that the neural network model has good generalization ability. Compared with the experimental value, the predicted value basically conforms to the change law and size of the experimental value, and the error distribution is approximately 2%. This shows that the BP neural network model can simulate the drying rate and longitudinal cracking degree in the drying process and realize the prediction of the drying process. [ABSTRACT FROM AUTHOR]

Thermal modification of wood changes its chemical, physical, and structural properties, which may affect adhesive bondline quality and bonding performance. This research compared the effect of thermal modification on the adhesive bonding performance of poplar (Liriodendron tulipifera) wood. Samples were prepared from thermally modified and unmodified yellow poplar using one-component polyurethane (PUR) and polyvinyl acetate (PVA), as they are adhesives used in wood products. Microscopic properties of the bondlines were investigated to understand shear performance and durability. Adhesive line thickness, penetration, shear strength, and moisture durability were measured, and failure modes were recorded. Thermal modification negatively affected the wood and adhesive interaction by reducing penetration (31.2% in PUR and 29% in PVA), therefore creating a thicker adhesive line (70% in PUR and 2% in PVA) and consequently causing a significant reduction in the shear strength of both adhesive types (27% in PUR and 36% in PVA) compared with non-modified specimens. The PUR adhesive had higher shear strength than PVA by 2.7% in non-modified and 14% in thermally modified wood. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of brutian pine (Pinus brutia Ten.) wood impregnation with nanoclay in different concentrations on the chemical and thermal changes, and their impact on the physical and mechanical properties. The samples were impregnated with nanoclay in concentrations of 1%, 3%, and 5%, for 2, 24, and 48 h. Fourier transform infrared spectroscopic analysis revealed a shift in the typical peaks of cellulose, hemicellulose, and lignin depending on the impregnation time and nanoclay ratio. Thermogravimetric analysis and the limiting oxygen index indicated that the samples impregnated with clay solutions exhibited higher thermal stability than the unimpregnated wood. Impregnation with nanoclay caused a decrease water absorption and thickness swelling of the sample groups. The modulus of elasticity, modulus of rupture, and compression strength strength values of samples were improved via impregnation. In conclusion, the applied nanoclay are suitable substances to increase the durability and thermal stablity of brutian pine wood. [ABSTRACT FROM AUTHOR]

The present study aims to identify the most suitable tree species for monitoring and reducing strontium (Sr) pollution. Strontium is a heavy metal that is extremely harmful to human and environmental health even at low concentrations and is listed as a priority pollutant by the Agency for Toxic Substances and Disease Registry due to its potential harm. Samples were taken from Pinus pinaster, Cupressus arizonica, Picea orientalis, Cedrus atlantica, and Pseudotsuga menziesii species grown in Düzce, a location reported as one of the top 5 cities having the most polluted air in Europe by the World Air Pollution Report. The changes in Sr concentration over the last 40 years were evaluated by species, organ, direction, and age range. The results indicate that Sr pollution significantly increased due to traffic sources. This study also showed that the transfer of Sr within the wood is limited in all the species under consideration; hence, all these species can be used in monitoring the changes in Sr pollution. The most suitable species for reducing Sr pollution were Cupressus arizonica and Picea orientalis, which have the highest capacity to accumulate the most Sr in their wood. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effect of four different age groups on wood properties, i.e., anatomical, physical, and mechanical, of Himalayan birch (Betula alnoides Buch.-H.ex D.Don). The correlation between the properties was also discussed. The results indicated age influences the anatomical, physical, and mechanical properties of Himalayan birch. Results were comparable with other plantation species. Moreover, mechanical properties were highly correlated with the fibre morphology in Himalayan birch. Results from this present study indicate that the 15-, 20-, and 25-year-old Himalayan birch are suitable to be used for parquet, furniture, and other products. Generally, plantation-grown Himalayan birch has the potential to be a raw material to fulfill the demand for the timber industry. [ABSTRACT FROM AUTHOR]

With the application of bleaching treatments, the color of the wood material changes. When different bleaching agents are applied to the same wood, different results are likely to be obtained. In this study, wood species doussié (Afzelia africana), iatandza (Albizia ferruginea), merbau (Intsia bijuga (Colebr.) O. Kuntze), mahogany (Swietenia mahagoni L.), and hornbeam (Carpinus betulus L.) along with one and two component (BOne- C and B-Two-C) wood bleaching chemicals were applied to the wood material surfaces with sponge technique. Then, color parameters (ho: hue angle, a*: red color tone, b*: yellow color tone, C*: chroma, and L*: lightness) were determined on bleached and unbleached materials. According to the results obtained, B-One-C application increased ho, a*, b*, C*, and L* values in all wood species. The highest ΔE* values were determined in mahogany, doussié, hornbeam, and merbau wood species treated with B-Two-C. The chemicals used in the study showed different results on the same wood. [ABSTRACT FROM AUTHOR]

Thermal treatment of pine wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 hours. The highest mean values were, for specific gravity (0.492), moisture content (29.1%), and maximum moisture content (191%), whereas the lowest mean values were for specific gravity (0.418), moisture content (1.20%), and maximum moisture content (127%). The maximum mean values were for shrinkage in longitudinal plane (0.42%), radial plane (4.63%), volumetric shrinkage (9.28%), and maximum mean value tangential plane (3.67%). The minimum mean values were for shrinkage in longitudinal plane (0.04%), radial plane (2.22%), tangential plane (1.55%), and volumetric shrinkage (4.88%). Maximum mean values were for swelling in longitudinal (0.41%), radial (5.22%), and tangential plane (3.15%) and maximum mean volumetric swelling (7.71%), while minimum mean values were for swelling in longitudinal plane (0.08%), radial plane (2.26%), and tangential plane (1.29%) and minimum mean volumetric swelling (3.15%). The highest mean values were for tensile strength (57.3 MPa) and compression parallel to the grain (50.3 MPa), the maximum mean value of bending strength (84 MPa) and compression strength perpendicular to grain (27 MPa), whereas the lowest values were for tensile strength (42.7 MPa), bending strength (7.33 MPa), compression parallel to the grain (7.33 MPa) and compression strength perpendicular to grain (12.3 MPa). [ABSTRACT FROM AUTHOR]

Flame retardancy was induced in maple (Acer velutinum) and ash (Fraxinus excelsior) wood and bark by means of mixtures consisting of bio-based materials such as starch (S) and glue (G) and water-based paint, MINWAX (M) in two different combined formulations with perlite (P) as the main fire retardant. The selected wood species as solid wood with two different treatable surfaces (with and without bark) were examined. The lowest and the highest mass loss occurred in the untreated-ash and untreated-maple wood samples with bark, while the lowest weight percent gain was related to PSGM-treated ash wood samples with bark, and the highest weight percent gain was related to PSGM-treated maple wood samples without bark. The lowest time to ignition and glowing point time were measured in the untreated-maple wood samples without bark, and the highest of them were measured in the PSGM-treated ash wood samples without bark. The effect of bark in the treated- and untreatedmaple samples on the time to ignition and glowing point time was greater than the bark of treated- and untreated-ash samples, respectively. There was not any significant relationship between actual retention, weight percent gain, and mass loss for all treatments. However, there was significant difference between the individual and interaction agents on fire retardancy of treated and untreated samples. [ABSTRACT FROM AUTHOR]

Different types of wood defects correspond to different processing methods. Good classification means can transform defective boards into practical boards after appropriate processing. The detection accuracy of the wood surface defects is particularly important for improving the utilization rate and speed of processing the boards. The RegNet stands out in the field of computer vision. It automatically designs the network model based on the design space and applies it to wood defect detection, which can improve the classification accuracy. When the convolutional structure of the RegNet network is applied to industrial detection and classification, the problems of long real-time detection time and large algorithm parameters persist. This study focuses on collecting wood material images of common coniferous and broad-leaved trees in Northeast China with three types of defects: wormholes, slip knots, and dead knots. To improve the allocation of computing resources, based on the RegNet network model, an attention mechanism module was added, and the Ghostconv structure was introduced. The structure quickly and accurately highlighted the types of wood defects, improved the classification accuracy, reduced the parameters of the network, and exhibited generalization ability. To verify the performance of the improved network, MobileNet-v2, EfficientNet, and Vision-Transformer networks were introduced for comparative analysis. The improved RegNet network had smaller weight and higher accuracy, with a classification accuracy of 96.58%. [ABSTRACT FROM AUTHOR]

Specimens of European beech wood (Fagus sylvatica L.) charred at 250 °C (4 min), 300 °C (2 min), and 350 °C (1 min) in combination with linseed oil coating were studied. The influence of the surface charring process and artificial weathering on surface discoloration, water absorption, and decay resistance were analyzed. Discoloration analysis showed a decrease in all parameters L*, a*, and b* due to the charring process. Coating with linseed oil caused a decrease in the L* parameter. An influence on parameters a* and b* was also demonstrated. As a result of the artificial weathering, the L* parameter increased in almost all groups. The group charred at 350 °C showed a decrease in L*. The parameters a* and b* were also affected. The effect of oil coating on discoloration during artificial weathering was negligible. The average water absorption of uncoated charred specimens decreased more than 50%. Damage due to artificial weathering disrupted the effect of the charring process. The effect of oil coating decreased depending on the length of partial immersion. Surface charring and oil impregnation slightly reduced the loss of beech wood mass caused by T. versicolor and P. placenta but could not fully protect the wood. [ABSTRACT FROM AUTHOR]

Water availability is an important issue all over the world, and membrane filtration technology is one of the most effective measures for remediation. As a sustainable and renewable biomass material, natural wood has a hierarchical and three-dimensional interconnected microstructure, which provides an alternative for water filter design. Longitudinal filtration could take advantage of the micropores, while the treatment speed is severely limited. This study examined a wood filter in which muddy wastewater can be transported into the microchannels and out of the vertically stacked micropores. The filter takes full advantage of the pores present in the wood without sacrificing the speed of hydraulic flow within the main transport channels, exhibiting excellent performance for mud removal. In this manner, water flux, decolorization, and turbidity are highly dependent on the groove number, groove depth, and thickness of the filter. Due to the reorientation of the water transport pathways, the clogging of micropores could be easily alleviated, thus promoting the filter lifecycle. The design of the cross-flow wood filter can provide an available platform for various wastewater treatment cases with different impurities, displaying an application prospect in the wastewater treatment field. [ABSTRACT FROM AUTHOR]

Cerrado is the second largest Brazilian morphoclimatic domain. Despite being a region of great ecological importance, it has been the target of constant threats caused by anthropogenic activities, mainly those related to agriculture and livestock farming. With a rich biodiversity still not fully known and constantly being devastated, the Cerrado lacks studies. The objective of this study was to microscopically analyze the wood of Cerrado tree species. Wood samples were collected from nine tree species in a Cerrado area located in Monte Carmelo, Minas Gerais. Microscopic analyses were carried out on permanent histological slides and macerated material, following IAWA Committee standards. This work provided information on species whose wood had not been previously described in the literature, such as Machaerium opacum and Eugenia dysenterica, as well as on previously described species. [ABSTRACT FROM AUTHOR]

Beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) wood specimens were heat-treated separately at three different temperatures (170 °C, 190 °C, and 210 °C) with steam treatment method (STM), oil treatment method (OTM), and hot-air treatment method (HTM). Then, the specimen surfaces were coated with water-based, polyurethane-based, and oil-based varnishes according to industrial applications. The study results show that both hardness and adhesion strength values of STM and HTM treated specimens were similar for both wood species. In contrast, these values were generally lower in OTM-treated specimens. For all applied methods, heat treatment temperature had no significant effect on hardness values. Varnish adhesion strength decreased in all heat-treated wood specimens compared to untreated specimens. Adhesion strength also decreased in STM- and HTM-treated specimens with increasing heat treatment temperature. Hardness values increased in all specimens coated with polyurethane- and water-based varnish compared to the specimens without varnish. However, hardness decreased in the specimens coated with oil-based varnish. In contrast, the highest adhesion resistance was determined in the specimens coated with oil-based varnish under all heat treatment conditions. In addition, the heat treatment method is more effective relative to the hardness values and the treatment temperature is more effective relative to the adhesion strength of varnished pine and beech specimens. [ABSTRACT FROM AUTHOR]

To improve the processing quality of wood products, the effects of different wood microstructure on the cutting quality of cherry wood were studied in the experimental process of gas-assisted laser processing. Based on the absorption ability of wood relative to laser wavelength, the composite processing of CO2 laser and inert gas was carried out. Kerf width and surface roughness were used as evaluation indexes, with analysis by factor experiments. The results showed that under the same parameter conditions, due to the difference in internal structure of wood, the cavity structure in the tracheid was more conducive to the diffusion and absorption of laser energy during perpendicular cutting. In addition, the kerf width and surface roughness of parallel cutting were smaller than that of perpendicular cutting. The microscopic morphology and surface carbon content of the kerf surface showed that during perpendicular cutting, due to the plugging effect of small holes, heat accumulation was not conducive to the flow of flue gas and carbide; thus carbon particles remained in the tracheid, and the carbon content of kerf surface was higher. [ABSTRACT FROM AUTHOR]

Thermally modified Scots pine samples were impregnated with lauric acid (LA) and myristic acid (MA) as phase change material (PCM) by vacuum process. The LA-MA mixture was prepared at a eutectic ratio of 66 to 34 wt%. Some properties of the wood samples such as hygroscopicity, mechanical, thermal energy storage (TES), and lab-scale thermoregulative performance were investigated. Fourier transform infrared spectroscopy (FT-IR) was utilized to analyze the physicochemical characteristics of wood samples that underwent thermal treatment. The thermal degradation stability, cycling chemical/thermal reliability, and TES properties of the samples were assessed through TG (thermogravimetric analysis) and DSC (differential scanning calorimetry) analyses. The DSC results of thermally modified wood (TMW)/LA-MA samples showed good energy storage or release capacity with appropriate phase. These analyses also indicated that TMW samples infused with PCM exhibited reduced residue compared to the control samples. The experimental evaluation conducted on a small scale demonstrated that the PCM integrated within the wood effectively retains excess heat within the surrounding environment, thereby restricting heat dissipation. Moreover, the presence of PCM visibly decreased water absorption and enhanced the dimensional stability in wood. The impregnation with LA-MA improved mechanical properties of thermally modified wood despite the thermal modification that normally decreases mechanical properties. [ABSTRACT FROM AUTHOR]

As a biodegradable material, wood is subject to deterioration if proper conservation techniques are not observed. Thus, several buildings, especially those of historical heritage, present pathological manifestations that can cause accidents. The interventions in these constructions must be planned to maintain the original elements and the aesthetics of the environment, with the indication of fixing additional elements in the degraded structure. The modification of the section of structural elements is commonly observed in the literature; however, few studies have been intended to analyze the effects of reinforcement in these geometrically discontinuous elements. Furthermore, the use of screwed steel plates guarantees greater ease of execution, even though it is not yet a method that has been well explored in the scientific literature. The objective of this study was to propose an equation for estimating the flexural stiffness of wooden beams with loss of cross-section that are then reinforced with screwed steel plates using a regression model. The considered variables correlated the elastic modulus of the wood and the reinforcement, the configuration of the defect, and the reinforcement. It was possible to identify that the properties of the wood and the position of the defect were variables with a significant impact on the stiffness of the reinforced beam. [ABSTRACT FROM AUTHOR]

A silane-siloxane based water-repellent substance (S-WR) was used as an impregnation material for Scots pine (Pinus sylvestris L.), black pine (Pinus nigra Arnold), sessile oak (Quercus petraea Liebl.), and cedar (Cedrus libani A. Rich). In the impregnation process, the immersion method was carried out for various periods (30 min, 3 h, and 24 h). Following impregnation, physical properties of the wood (retention, contraction, expansion, water intake rate, specific gravity, etc.) were determined. The retention was highest in sessile oak wood (0.96%) and lowest in black pine wood (0.24%). The highest specific gravity value was found in stemless oak (0.86 g/cm³) impregnated for 24 h, and the lowest air-dry specific gravity value was found in Scots pine (0.40 g/cm³) impregnated for 30 minutes Absolutely dry (0% humidity) specific gravity was highest in sessile oak for 24 h (0.83 g/cm³). Shrinkage was highest in the sessile oak control sample (13.5%). The expansion amount was highest in the cedar wood control sample (17.5%) and lowest in sessile oak wood (1.66%). The highest water uptake rate (SAO) was determined in Scots pine wood at 96 h (105%), and the lowest in sessile oak wood in 24 h (8.80%). In summary, silane-siloxane based water-repellent impregnation material was found to be effective in providing dimensional stability in wood. [ABSTRACT FROM AUTHOR]

As a typical orthotropic material, the mechanical properties of wood in the parallel and perpendicular-to-grain directions are very different. Based on mathematical orthogonality, mechanical force balance condition, and energy comparability, the deformation energy decomposition method of planar wood element is proposed, and then the quantitative and visual analysis of the basic deformation performance of wood structure is realized. The basic deformation performance of wood structure and isotropic structure is analyzed using the deformation energy decomposition method, and the seismic performance of wood frame structure and concrete frame structure is compared. The results show that the lateral resistance and beam ductility of wood frame are greater than those of concrete frame under seismic load. However, the reduction of deformation energy proportion of wood frame beam leads to greater deformation energy of the frame column, so it is suggested to take targeted strengthening measures to the bottom of the wood frame column and the joint area. [ABSTRACT FROM AUTHOR]

Silver fir (Abies alba L.) wood samples were charred on one surface using an enhanced version of the traditional Japanese Yakisugi method. The 15 charred boards obtained from five charring chimneys were divided into three different zones and investigated for their physical properties. The density profile, water absorption after 24 h of water submersion, and Brinell hardness were analyzed. In general, the temperature-time regime, which causes inside surface carbonization, was more evident at the bottom than at the top of the chimney. The density profile of the specimens revealed that the surface charring treatment decreased the surface density of the wood significantly. A gradient was visible from 383 kg/m² at the bottom to 424 kg/m² at the top. Water absorption measurements showed that a thicker carbonized layer could take up more water as a result of increased porosity. While 3,684 g/m² were absorbed at the bottom, the top accounted for only 2,533 g/m². Furthermore, with increasing thickness of the charred layer, the hardness gradually decreased. The average of the charred specimens reached only 3.2% of the hardness of the uncharred back side of the specimens. [ABSTRACT FROM AUTHOR]

The aim of the conducted experiments was to determine the effect of selected machining parameters on power consumption and surface quality obtained during the milling of beech wood using a computerized numerical control woodworking machine. Surface roughness was tested using the contact roughness measurement method, while roughness parameters Ra and Rz were recorded and cutting energy was determined. Tests were conducted for two variants of cutting speed (7.5 and 15 m•s-1) as well as three variants of chip thickness (0.10, 0.06, and 0.02 mm); additionally, the tests examined different cross-sections of wood. It was found that greater chip thickness and feed speed caused an increase in surface roughness and cutting power. In turn, cutting speed had no effect on surface roughness, whereas its increase resulted in increased cutting power. Surface roughness at the radial and tangential cross-sections was comparable, while it was greater at the transverse cross-section. It was also found that cutting power was lowest at the radial cross-section, while it was greater at the tangential and the greatest at the transverse crosssection. [ABSTRACT FROM AUTHOR]

Currently, there is a big issue with waste, its processing and subsequent use. While there are many initiatives to replace materials that are poorly biodegradable, it is necessary to process and ideally use the waste that is already produced. In this study, the properties of composite boards made of waste materials and biodegradable polymer were investigated. The composite boards were made from wood and plastic waste using high-energy milling technology. This technology for material preparation is promising, as it includes controlling the morphology of particles, homogenizing the mixture, and drying the material during the milling process. The results showed higher flexural strength of high-density fiberboard (HDF) boards compared with tested composites with one exception. Wood/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [PHBV] composite exhibited 30% higher modulus of elasticity (MOE) than HDF due to the higher modulus of PHBV. The lowest thickness swelling (3%) and water absorption (12%) were measured for wood/recycled high density polythene (rHDPE) composite. The HDF boards recorded the lowest dimensional stability. The highest water absorption of tested composites was measured for wood/PHBV composite. The resistance to wood-rotting fungi was greatest for wood/PHBV composite containing marble powder, which corresponded to the results of scanning electron microscopy.

This review article discusses the use of organosilane (OS) compounds and their derivatives to modify wood materials. The emphasis in this work is on trialkoxysilanes and effects of their reactions with hydroxyl groups at wood surfaces. The versatile properties of OS make them ideal for improving the water resistance, weather resistance, antibacterial properties, and dimensional stability of wood. This article provides an overview of recent techniques and methods used to modify wood substrates with OS, highlighting the main findings and advancements in the field. Additionally, the article suggests future research directions, including innovative modification mechanisms, strategies to control the pollution caused by biomaterial-based silanes, and the investigation of the influence of wood permeability on silane modification.

Despite the progress in synthetic polymer industries, wood is one of the main materials in making musical instruments because of its unique characteristics. Many instrument makers try to improve the acoustic properties of wood by traditional treatments. In this study, the changes in the acoustic properties of walnut wood during the processes of fermentation pretreatment, water washing, and organic solvent washings were evaluated. For this, the samples were divided into two groups of 20. For the first group, de-extraction was started with fermentation pretreatment, while the second group samples directly underwent stepwise extraction, using hot water and ethanol-acetone solvents. The results showed a decrease in density, dynamic modulus of elasticity, and damping factor due to the soaking process. But the elastic stiffness did not change. The values of the acoustic coefficient and the acoustic conversion efficiency increased due to the soaking process. The values of density, dynamic modulus of elasticity, elastic stiffness, and damping factor decreased due to ethanol-acetone washing, while the acoustic coefficient and acoustic conversion efficiency showed a significant increase. In general, soaking process and ethanol-acetone washing with fermentation pretreatment improved the acoustic properties of walnut wood.

Wood is an indispensable renewable material for national economic development. As a bio-organic material, wood is subject to deterioration due to climatic, biological, and chemical factors, which greatly limit the advantages of wood products and increase the difficulty of conserving historical wood. To preserve the historical and cultural heritage, extend the historical life of ancient wooden structures, and promote the efficient and sustainable utilization of wood resources, this paper provides an overview of the main degradation and destruction forms and biochemical changes of wood in ancient architecture, unearthed relics, and antique ship wood from the perspective of wooden structure, historical applications, and their forms of destruction. The conservation strategies and consolidation methods of ancient wood are reviewed, with emphasis on the summary and analysis of the properties and uses of different consolidation materials and their methodological characteristics for the conservation of historical wood. In the context of the development of biomaterials, polymer chemistry and nanotechnology, biomass nanocomposites are applied gradually in the field of consolidation. To provide a strong basis for the effective use of reinforced wood, this paper presents the theoretical foundation for the research and development of green, efficient, and environmentally friendly wood consolidation and protection technologies. [ABSTRACT FROM AUTHOR]

Wood-based additive manufacturing (AM), some examples of which are called 3D printing, is a promising technology for reducing the environmental impact of manufacturing and increasing the sustainability of the construction industry. This review paper provides an overview of various AM methods, including commonly used wood-based techniques and the mechanical and physical properties of their products. The paper also discusses challenges related to precision and surface finish in woodbased AM and identifies areas for future research, including the effects of wood species, particle size, and processing parameters on the mechanical properties and dimensional stability of wood-based AM products. The review concludes by discussing the potential implications of wood-based AM for sustainable materials and the construction industry, along with recommendations for future research such as the development of new wood-based AM techniques and exploration of new applications for this technology. This paper provides valuable insights into the current state of wood-based AM research and its potential to revolutionize sustainable manufacturing practices. [ABSTRACT FROM AUTHOR]