Wood Science and Technology最新文献

The study of wood acoustics is relevant to both understanding the biological functions of living trees and designing renewable sound-absorbing materials. This understanding can be enhanced through micromechanical models that relate wood microstructure to its acoustic properties. This paper begins by introducing three-dimensional modeling for microscale wood structures, confirming the elastic properties of wood cell wall layers. The equation of motion, incorporating element stiffness, mass matrices, and the force vector of a single substructure, is analyzed to assemble the global dynamic stiffness matrix of a wood cell. Free wave propagation characteristics are then examined by solving eigenvalue problems within both direct and inverse wave finite element method frameworks. The dispersion relations of positive-going waves are illustrated for a wood cell without a pit. Additionally, the forced response and displacement field of a wood cell without a pit are explored. Finally, wave diffusion, including reflection and transmission coefficients, is examined in a wood cell with a pit. The results demonstrate the proposed approach’s potential for investigating wave propagation and diffusion characteristics in microscale wood structures.

The structural changes of cellulose during a hydrolysis over solid acid catalysts (oxidized carbon Sib450 and sulfonic resin Amberlyst-15) were studied. Cellulose structure alterations were characterized via XRD, FTIR and SEM, among other techniques. It was shown that the hydrolysis of cellulose in an aqueous medium over solid catalysts bearing strong and weak acid species proceeds by different mechanisms, at least under a limited mass-transfer condition. The results are interpreted in terms of the different ability of solid acids to form the electrical double layer—a region near the catalyst surface with a high concentration of hydroxonium ions in an aqueous medium.

As global water scarcity escalates into a pressing environmental challenge, advancing atmospheric water harvesting (AWH) technologies becomes imperative. This study presents a solar-driven wood-based AWH system using an innovative hygroscopic composite material, DW@LiCl. Through selective lignin removal, natural wood is transformed into delignified wood (DW) featuring a three-dimensional microporous architecture and enhanced surface area. Subsequent infusion with lithium chloride (LiCl) creates a biohybrid material that synergizes sustainable biomass properties with high-performance salt hygroscopicity. The composite demonstrates dual-phase functionality: rapid moisture capture (2.06% gravimetric uptake in 10 h at 90% RH during nocturnal adsorption) and efficient solar-triggered water release (75% desorption within 30 min under 1 00000 lx irradiation). Cyclic stability tests reveal exceptional reusability, with the material retaining 92% of its initial water uptake capacity after 10 adsorption-desorption cycles. Distinct from conventional AWH designs, DW@LiCl innovatively bridges ecological sustainability with engineering efficiency, leveraging wood’s inherent capillary transport and LiCl’s deliquescent behavior while circumventing energy-intensive regeneration processes. This biomass-based approach establishes a scalable framework for decentralized water production, particularly, offering a sustainable alternative to synthetic polymer-based systems.

The illegal timber trade results from the confusion whether intentional or not between a species that is banned from harvesting, trade, or destruction and a non-protected species, it was important to find an alternative means of rapidly and reliably identifying species in the Ivorian forest. Near infrared spectroscopy (NIR), being non-destructive, was used to identify five (05) timbers from the Besso classified forest (Côte d’Ivoire). Chemometric tools were used to decode the spectra and reveal trends in the forest species studied. The PLS-DA models effectively differentiated between wood and wood flour. The PLS-DA classification model shows that it is possible to accurately differentiate Côte d’Ivoire woods, with accuracy rates ranging from 0.92 to 0.99 for different types of wood, such as Khaya ivorensis, Mansonia altissima and Nauclea diderrichii. However, the differentiation of certain species, such as Milicia excelsa and Milicia regia, remains more complex due to their similarity, although wood flour from these woods showed better classification results. The reduction in the particle size of wood flour could explain this improvement. The performance of the PLS-R and PLS-DA models is encouraging, with high cross-validation coefficients (R² between 0.79 and 0.92), underlining the effectiveness of NIR spectroscopy combined with chemometric methods to identify and classify wood accurately and quickly. These preliminary results could help control agencies to better monitor timber marketing by developing a more elaborate database of timber species in Côte d’Ivoire, due to the simplicity and reliability of the technology.

The widespread preference for tropical wood species in guitar neck manufacturing is increasingly challenged by the declining availability of these resources, creating an urgent need for sustainable alternatives. This study compared the deflection stability of 17 wood species used for classical guitar necks under long-term string tension and varying humidity conditions, focusing on the performance of tropical woods and potential European alternatives. The effects of the experimental set-ups (tuning key and weight-loaded device) and wood cross-grain orientations (quarter-sawn and flat-sawn) were also examined. The results indicated that the two tropical wood species, mahogany and cedro, exhibited relatively small and consistent deflection variations, especially under changing humidity. Among the tested European-grown wood species, black walnut and alder showed great potential as materials for guitar necks, with some performance indicators surpassing those of tropical woods, making them viable alternatives. Different experimental setups had no significant impact on deflection measurements, and the tuning key device provided a simpler method for evaluating guitar neck stability. Quarter-sawn neck wood samples demonstrated more stable deflection than flat-sawn wood, though this difference was not significant in the majority of tested wood species. Exploring alternative wood species will expand the material selection of the local musical instrument manufacturing industry and contribute to the sustainable use of local-grown wood resources.

The curing speed of adhesives is crucial in the production of wood-based panels. The Automated Bonding Evaluation System (ABES) is a commonly used method for evaluating the bond strength development of adhesives. However, using polymeric diphenyl methane diisocyanate (pMDI) with ABES can be challenging due to the significant moisture dependence required for proper curing. In this study, a simple and reliable method was developed to enable the use of pMDI with the ABES device. While the ASTM D7998–15 standard provided guidance, certain modifications were required to adapt the method to specific conditions. The results highlight several key factors that influence the curing of pMDI, including the addition of water, the need for higher pressure, and the preference for two-sided adhesive application. In addition, MDI emissions were monitored during ABES measurements and showed detectable but very low levels of emissions. This research opens up new possibilities for assessing the curing kinetics of pMDI adhesive.

Understanding the initiation and expansion of cracks in Caragana korshinskii branches (CKB) is crucial for investigating their cutting mechanisms. In this study, an extended finite element method (XFEM) model was developed to analyze the mechanical behavior associated with crack formation and growth in CKB under the influence of multiple factors. A mechanical model of the cutting tool was also established, and the effects of cutting speed and cutting angle on the cutting force were examined using MATLAB simulations. Beginning with the internal cracks present in the stems, the study employed a response surface methodology to investigate how various parameters affect the stress intensity factor and crack tip propagation. The results revealed that the cracks generally exhibit a mixed mode of type I–II, with mode I (opening mode) being dominant. The stress intensity factor varies significantly with the crack angle and increases with both crack length and applied load. Furthermore, crack propagation displays a characteristic “W”-shaped pattern as influenced by the crack angle and tends to increase with longer crack lengths and higher loads. To optimize crack propagation behavior, a central composite design experiment was conducted to achieve minimal crack expansion and a maximal stress intensity factor. The optimal parameter combination was determined to be a crack angle of 105°, a crack length of 0.5 mm, and a load of 44.62 N, which resulted in a crack expansion length of 6.30 mm and a stress intensity factor of 112.78 MPa·mm^1/2. This study offers a novel approach for analyzing the fracture behavior of CKB and provides valuable insights into optimizing their cutting performance.

Illegal logging is a profitable transnational crime, prompting the development of global reference databases to support tools for identifying wood species and harvest location. While these tools are effective for raw timber, they have not been systematically evaluated for manufactured wood products which undergo high temperature, pressure, and steam treatments. Although it is known that these treatments alter wood's chemical composition, no chemical technique has demonstrated its ability to generalize measurements from raw wood to its manufactured form. This paper examines the impact of heat treatments and plywood manufacturing on metabolomic fingerprints and database recall for timber species identification. Processes included plywood manufacturing of Betula pendula and lab-based heat treatments (72 °C to 250 °C) for Cedrela odorata and Dalbergia nigra (both CITES-listed), as well as Diospyros crassiflora and Araucaria cunninghamii. The database recall for D. crassiflora and D. nigra, both dark woods, were largely unaffected by temperature whereas the database recall decreased with increasing temperatures for C. odorata (species-level database recall dropping below 30% after 24 h at 200 °C and continuing to decline with longer treatments) and A. cunninghamii (species-level database recall dropping below 10% after 24 h at 150 °C and continuing to decline with longer treatments) and due to manufacturing processes of the B. pendula plywood (manufacturer, using a single tree for each plywood batch. The logs were soaked and pressed at 120–135 °C). The findings underscore the need for (1) complementary identification methods for manufactured wood products and (2) further research into how manufacturing processes impact the effectiveness of identification and traceability methods under development.

Fibers are a key component of wood, providing mechanical support to woody plants. Understanding their development is crucial for both tree function and industrial use. We investigated how the transverse surface area of wood fiber bodies increases in Robinia pseudoacacia L. Samples of vascular cambium and differentiating secondary xylem were collected and sectioned using a Tesla ultramicrotome. Zones containing cambium and wood fibers at different stages of differentiation were analyzed for cell transverse surface area, cell wall perimeter, cell width, and thickness. The shapes of fiber bodies were also examined and the obtained data were compared with mathematical considerations regarding the shape of geometric objects and the impact of shape changes on transverse surface area. Our findings show that wood fiber development involves a gradual shape change from rectangular to round, accompanied by increasing thickness and decreasing width. The increase in transverse surface area results from shape changes rather than cell wall growth in the transverse plane. This is supported by the nearly constant cell wall perimeter across the differentiation zones. Obtained results have important consequences for the analysis of xylogenesis in angiosperms, as they stay in sharp contrast to the common understanding of events occurring within differentiating xylem.

Wood production and processing is one of the main industries in Northern Europe. Timber has many uses in construction and daily life; however, timber production creates a significant side-stream – logging residue, which consists of smaller branches and in the case of coniferous trees, needles. This forestry side-stream is commonly used for the production of bioenergy or left untouched creating environmental risks. To reduce the amount of logging residue and create a viable processing strategy, the chemical composition and possible benefits of biomass refining should be examined. The aim of this study was to develop a fractionation approach of non-polar, lipid extract from the logging residue of Norway spruce (Picea abies), demonstrating the application potential of obtained fractions. The raw lipophilic extract was fractionated using short path distillation into 14 fractions with distinct characteristics. Obtained fractions were characterised using UV, FTIR and chemical composition was determined using GC/MS. The prepared fractions contained 206 compounds belonging to monoterpenes, sesquiterpenes, labdanes, abietanes, pimaranes, triterpenoids, sterols and other minor groups of compounds. Fractions were tested to identify antimicrobial, antifungal activities and cytotoxic effects on melanoma cells. It was shown that specific groups of compounds possess specific activities, highlighting the potential application fields. Further research on the undistillable part of the lipophilic extract and its application to achieve zero-waste processing goals is needed. Fractionation of spruce lipophilic extractives has been demonstrated as a processing option to create a multi-product biorefinery approach from logging residue, encouraging circularity and bioeconomy-based solution adoption into the forestry sector.