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The possibility of using an aqueous extract of bark-containing mass of wastewater formed during wood processing as growth stimulator for various crops was considered. The proposed technological solution meets the modern requirements to improve the environmental efficiency of enterprises in woodworking industry, contributes to the expansion of the range of goods which can be used in related industries, including the agroindustrial complex to increase its productivity. Studies on testing extractive substances of bark-containing mass at various dilutions as a growth stimulant for a number of test crops (spring common wheat cv. Rada and garden cress cv. Azhur) were carried out. The cambium layer of wood contains all the necessary substances required for higher plants and is most susceptible to destruction under the influence of water and mechanical forces during wood processing at the stage of bark separation. In this regard, the possibility of using aqueous extracts from the bark of various wood species as growth stimulants was investigated. The purpose of the research was to study the effect of a complex of bark extractives on biometric parameters of the test crops depending on the dilution factor of the concentrated bark-containing wastewater from wood processing. It was established that specially prepared aqueous extracts from the bark have pronounced growth-s timulating effects (significant increase in root length by 3540 % and sprouts - by more than 4244 %) and can be used as growth stimulants in seed preparation. The method of producing growth stimulants based on bark-containing wastewater is protected by a patent.

Abstract Background Wood carbon fractions (CFs)—the proportion of dry woody biomass comprised of elemental carbon (C)—are a key component of forest C estimation protocols and studies. Traditionally, a wood CF of 50% has been assumed in forest C estimation protocols, but recent studies have specifically quantified differences in wood CFs across several different forest biomes and taxonomic divisions, negating the need for generic wood CF assumptions. The Intergovernmental Panel on Climate Change (IPCC), in its 2006 “Guidelines for National Greenhouse Gas Inventories”, published its own multitiered system of protocols for estimating forest C stocks, which included wood CFs that (1) were based on the best available literature (at the time) and (2) represented a significant improvement over the generic 50% wood CF assumption. However, a considerable number of new studies on wood CFs have been published since 2006, providing more accurate, robust, and spatially- and taxonomically- specific wood CFs for use in forest C estimation. Main text We argue that the IPCC’s recommended wood CFs and those in many other forest C estimation models and protocols (1) differ substantially from, and are less robust than, wood CFs derived from recently published data-rich studies; and (2) may lead to nontrivial errors in forest C estimates, particularly for countries that rely heavily on Tier 1 forest C methods and protocols (e.g., countries of the Global South with large expanses of tropical forests). Based on previous studies on this topic, we propose an alternative set of refined wood CFs for use in multiscale forest C estimation, and propose a novel decision-making framework for integrating species- and location-specific wood CFs into forest C estimation models. Conclusion The refined wood CFs that we present in this commentary may be used by the IPCC to update its recommended wood CFs for use in forest C estimation. Additionally, we propose a novel decision-making framework for integrating data-driven wood CFs into a wider suite of multitiered forest C estimation protocols, models, and studies.

Abstract Purpose Wood comprises different cell types, such as fibers, tracheids and vessels, defining its properties. Studying cells’ shape, size, and arrangement in microscopy images is crucial for understanding wood characteristics. Typically, this involves macerating (soaking) samples in a solution to separate cells, then spreading them on slides for imaging with a microscope that covers a wide area, capturing thousands of cells. However, these cells often cluster and overlap in images, making the segmentation difficult and time-consuming using standard image-processing methods. Results In this work, we developed an automatic deep learning segmentation approach that utilizes the one-stage YOLOv8 model for fast and accurate segmentation and characterization of macerated fiber and vessel form aspen trees in microscopy images. The model can analyze 32,640 x 25,920 pixels images and demonstrate effective cell detection and segmentation, achieving a $$\hbox {mAP}_{0.5-0.95}$$ mAP 0.5 - 0.95 of 78 %. To assess the model’s robustness, we examined fibers from a genetically modified tree line known for longer fibers. The outcomes were comparable to previous manual measurements. Additionally, we created a user-friendly web application for image analysis and provided the code for use on Google Colab. Conclusion By leveraging YOLOv8’s advances, this work provides a deep learning solution to enable efficient quantification and analysis of wood cells suitable for practical applications.

According to the strategy for the development of the forestry complex of the Russian Federation until 2030, approved by Order of the Prime Minister of Russia no. 312r dated February 11, 2021, the contribution of the forestry industry to the country’s economy should increase by 2 times, including through deep wood processing. To this end, enterprises for deep processing of wood raw materials will be actively developed. Consequently, there will be a shortage of wood raw materials, which will lead to an urgent need to expand the raw material base of these industries. Despite this, as the analysis of the practical experience of modern logging enterprises has shown, today, during logging operations, only the stem part of the tree is removed from the cutting area, and the rest of the biomass in the form of stumpwood, branches, twigs and tops is burned or buried, although these parts of the tree are valuable raw materials for the production of many types of products of wood processing enterprises. This state of affairs is due to the lack of effective technology for processing potential raw materials in the places of their formation and a complex of mobile machines for its implementation. As a result, a technology for the production of wood and coniferous flour, technological chips and semi-finished wood-fiber products, as well as mobile equipment for its implementation, has been proposed for the processing of logging waste in the form of tops, branches and twigs. The article presents technological solutions and equipment models built in the SolidWorks computer-aided design system. The introduction of the proposed technologies, machines and mechanisms will increase the share of harvested raw materials per unit area, reduce the environmental load from the logging process, and increase the efficiency of the industry.

Abstract Wood constantly interacts with the surrounding, locally varying climate, leading to changes in the moisture content. Advanced simulation tools can predict the two-dimensional moisture distributions caused by these changing climate conditions within wood cross sections over time. However, there is a notable absence of systematic simulation results for diverse climatic conditions and various wood cross sections. This study seeks to bridge this gap in research. Here, we present moisture fields in three solid timber and three glued laminated timber cross sections in Austria and show the effect of the location and the altitude on the moisture content distribution. The results reveal decreasing influence of the location on the moisture content development with increasing cross section size, and primarily the altitude affecting the moisture content. In addition, the results are compared with the standard for the design of timber–concrete composite structures (ONR CEN/TS 19103), revealing appropriate values in most of the cases. Only for cross sections with a width of 14 cm and larger, assigned to a specific region, the standard value is assumed underestimated. Furthermore, the distribution of moisture gradients, which are related to the crack depth development, are analyzed for Austria, demonstrating the influence of mountain areas in the moisture gradient development.

Preservative systems based on vegetable seed oils and natural waxes from renewable sources may confer protection to wood under exposure to various environmental conditions. These, as non-toxic substances, can form an environmentally friendly and efficient protective layer on the wood surfaces, with beneficial effects on their water resistance and dimensional stability. Thus, these natural coatings may hinder biodegradation of wood products to a certain degree. In present paper, softwood samples (from Abies alba fir tree species), prepared as dried discs (25 to 30 mm diameter, 8 to 10 mm thickness), were surface impregnated by dipping using vegetable oils, namely Asclepias syriaca seed oil, and soybean oil, respectively. Beeswax treatment was also applied for comparison purposes. Surface chemistry and morphology, biodegradation process under controlled and simulated natural conditions, and water sorption behavior of wood samples were investigated. Fourier Transform Infrared spectroscopy, X-ray diffraction, and scanning electron microscopy methods were used for investigation of surface changes in wood samples before and after impregnation with natural based products, as well as under biodegradation conditions in soil burial tests.

The goal of this work was to characterize potential biological agents responsible for biodeterioration in heritage buildings identified as Costa Rican Caribbean architecture using a multidisciplinary approach. First, an inventory of buildings of Caribbean architecture from Limón City was elaborated. Then, a multi-criteria evaluation system was used to define priority scores to select buildings for sampling and analysis. Selected buildings were sampled for potential biological agents responsible for biodeterioration. Wood samples were taken from sections showing visual damage and fungi were isolated and characterized using Sanger sequencing. A basic profile of Costa Rican Caribbean architecture was established. A preliminary identification of 101 buildings that satisfied the basic profile of characteristics was con-ducted. Subsequently, these buildings were classified into 4 typologies from which 23 buildings belonging to Typologies 1 and 2 were chosen for the collection and registration of data. Applying the multi-criteria evaluation, 6 buildings with final scores higher than 60 points were selected from which the 1st (Casa Misionera Bautista) and 3rd (Antigua Capitanía de Puerto) in the classification were selected for further characterization of biological agents. From the sampling conducted on these two buildings. A total of 36 fungi were isolated. All fungi identified belonged to the fungal group Ascomycota phylum, the most common genera being Trichoderma, Fusarium, and Penicillium. The study shows how multidisciplinary studies can improve the process of decision-making in the preservation of heritage with the use of a ranking obtained for each building in the multi-criteria evaluation and the use of advanced techniques for the identification of biological agents.

Abstract This study presents a novel approach to fabricating interdigitated capacitive (IDC) touch sensors using graphite-based pencils on a wood substrate. The sensors were designed to detect touches and pressure variations, offering a cost-effective and environmentally friendly solution for sensor fabrication. The fabrication process involved abrasion of graphite pencils on a wooden substrate to create conductive traces, followed by the integration of interdigitated electrode structures. Capacitance variations resulting from touch interactions were investigated to calibrate sensor responses for tailored tasks. The sensitivity of the sensor was found to be 1.2 pF/kPa, highlighting its responsiveness to pressure variations. Additionally, the sensors were interfaced with an Arduino Uno microcontroller board to demonstrate practical applications, such as replicating arrow key functionality. Additionally, the sensors exhibit sensitivity to environmental factors, with the relative change in capacitance increasing from 0.1 to 0.65 as relative humidity ranges from 30 to 90%. Furthermore, variations in temperature from 30 to 60ºC result in a relative change in capacitance increasing to approximately 0.5. The results indicate the feasibility and versatility of using wood-based substrates and graphite-based pencils for fabricating IDC touch sensors, offering promising prospects for sustainable and accessible sensor technology.

Bioeconomy is becoming a more interesting field for investments in the Republic of Croatia, especially in its small regions and local administrative units. Vukovar-Srijem county is one such unit in eastern Croatia with noticeable potential for development in a circular, carbon-neutral, and sustainable bioeconomy. Due to the nature potential represented by one of the largest forest reservoirs in Europe-Spačva basin, forestry is one of the most important county branches. Aiming to provide more inputs on the wood biomass management, the study on the biomass flow of Vukovar-Srijem county was conducted in 2020 by collecting data from local stakeholders and official reports. The study results have shown that Vukovar-Srijem county has the potential to increase the efficiency level of biomass use, but specific actions on the value-chain strengthening, finalisation of wood products, and innovative ecosystem establishment are still needed. The results highlight the predominant use of sawdust for heating purposes in the VSC region, suggesting potential for optimizing its utilization towards a circular, carbon-neutral, and sustainable bioeconomy, thus offering novel insights for future research and initiatives aiming to maximize economic and environmental benefits from wood biomass residues.

Abstract Efforts to characterize microbial life across diverse environments have progressed tremendously, yet the microbiome of Earth's largest biomass reservoir—the wood of living trees—has been largely unexplored. Current understanding of the tree microbiome is largely confined to roots and leaves, with little attention given to the endophytic microbiome of wood, even though emergent studies have indicated this zone as a niche for unique taxa, of consequence for ecosystem health and global biogeochemical cycles. The lack of investigation derives partly from the physical recalcitrance of wood, which presents challenges during sampling, homogenization, and the extraction of nucleic acids. In response to these issues, we present an optimized method for processing wood for use in microbial analyses, from sampling through to downstream analyses. Using methane‐cycling taxa as model endophytes, we assess losses in recovery during our method, and determine a limit‐of‐detection of approximately 500 cells per 100 mg of (dry) wood. For all six species evaluated—which represented several diverse taxa of hardwoods and softwoods—PCR inhibition proved minimal, and we expect this method to be applicable for a majority of tree species. The methods presented herein can facilitate future investigation into the wood microbiome and global microbial ecology of methane cycling.

A 29-year-old right-handed woman presented to an outside emergency department with right small finger pain, swelling, and concern for a retained wooden splinter. Diagnosis and treatment were delayed for 2 weeks due to the inability to identify the foreign body clinically or radiographically. Ultimately, ultrasonography by a fellowship-trained specialist was used to localize the wooden splinter. It was embedded within the flexor tendon sheath but had migrated away from its initial point of entry. The patient underwent subsequent surgical extraction, irrigation, and debridement. Two weeks following surgery, she had regained full range of motion through her digit without signs of infection. This case highlights the use of diagnostic ultrasound to identify a radiolucent foreign body, such as a wooden splinter, and to guide subsequent surgical extraction.

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.

In this article, the properties and working methods of the tools and machines for wood carving are analyzed, starting with the simplest and primitive tools for processing materials up to the most complex machines. Wood is one of the oldest materials practiced in sculpture, and the following traditional tools are used for its processing: chisels, hammers, saws, abrasives. Along with the development of the industrial era, tools and machines for processing materials also developed. Therefore, it is found that the use of both traditional and modern utensils provides an opportunity to bring out the shape, texture, color and beauty of the sculpture. The working tools chosen by the artist, whether simple or complex, depend on the material used to make the work. This dependence has contributed to the development and modernisation tools and machinery for processing the materials used in sculpture, with the discovery and increasing knowledge of the ideational value offered by the material, be it clay, wood, stone, metal or unconventional materials.

The wood was used as raw material to obtain the wood skeleton by matrix-removal. And the high-strength wood-based composite hydrogels with PVA/PAM double network structure were constructed by in-situ polymerization. The change rules of macro/micro functional morphological characteristics, mechanical properties, optical properties and chemical composition of the wood-based composite hydrogels were systematically investigated by adjusting the mass ratio of PVA and PAM in the hydrogel system. The results show that introducing a small amount of PVA into the PAM/wood skeleton composite hydrogels and constructing a double network structure can effectively enhanced the mechanical properties of the wood-based composite hydrogels. As a result, the wood-based composite hydrogels show tensile properties with a maximum tensile strength and fracture elongation of 16.47 MPa and 11.61%. Furthermore, the wood-based composite hydrogel is used as a flexible substrate with a conductivity of 1.8 S/m to assemble and build sensor components. The results indicate that the flexible sensor exhibits stable and repeatable relative current signal changes under a variety of deformations.

Abstract Samples of Eucalyptus globulus wood were processed in a reaction media made up of 1-pentanol, water, and diluted acid catalyst. The effects of selected variables (proportion of 1-pentanol in the reaction media, catalyst charge and temperature) on wood solubilization and on the composition of the various phases from treatments (solids containing cellulose, pentanol-rich phase containing depolymerized lignin, and the aqueous phase concentrating the hemicellulose-derived products) were assessed by Response Surface Methodology. Numerical optimization based on the statistical models allowed the identification of the best operational conditions, under which extensive removal of both lignin and hemicelluloses was reached at good selectivity toward cellulose solubilization. The treated solids achieved near stoichiometric conversion upon enzymatic hydrolysis performed under diverse operational conditions, and the lignin structural analysis provided data typical for hardwoods. The experimental results confirmed the potential of 1-pentanol as a solvent for Eucalyptus globulus wood-based biorefineries.

Relevance. The need for an ecological and geochemical assessment of the mercury intake characteristics into pine wood in order to identify the factors determining the accumulation of the element by trees. Aim. Quantitative evaluation of mercury content in the annual rings of Scots pine (Pinus sylvestris L.) in the Tomsk region, as well as identification of geoecological and climatic factors affecting the accumulation of pollutant. Object. Annual rings of Scots pine (Pinus sylvestris L.) widely used in world science to obtain information about environmental pollution by chemical elements. Methods. Pine core sampling, samples drying at room temperature. Determination of the number, width of annual rings and growth of wood on the LINTAB device (TSAP-Win and LIGNOVISION software) at the Institute of Monitoring of Climatic and Ecological Systems SB RAS (Tomsk). Determination of concentrations on the mercury analyzer RA-915+, by atomic absorption (pyrolysis method) on the basis of the Engineering School of Natural Resources of Tomsk Polytechnic University. Calculation of ecological and geochemical indicators: concentration coefficient, temporal allowable concentration, noosphere clark, normalization according to B. Markert, enrichment factor. To assess the climatic response of mercury accumulation by trees, the average daily data for 1933–2021 from the Tomsk weather station were used. Results. The authors have obtained the data on the gross content and geochemical features of mercury accumulation by Scots pine wood in the territory of the Tomsk region. The results of calculations of the main geoecological indicators of the mercury load indicate an excess of element concentrations relative to the background, the average for terrestrial plants, as well as according to scandium rationing data. The paper highlights the period of increased mercury concentration in pine wood (1941–1974) as a result of the influence of the city industry. A similar pattern of pollutant accumulation for 1970–1986 was revealed in the study area, with an excess of 1.6–1.8 times relative to adjacent environments (soil, solid snow sediment, pine needles, mosses). Hg accumulation by wood is affected by the precipitation amount, both per year and during the growing season and during the period with positive temperatures, as well as the duration of precipitation during the year and the growing season.

The use of nanoparticles has attracted widespread attention in surface science to improve the characteristics of substrates such as thermal stability, corrosion resistance, self-cleaning, and antibacterial effects. Nonetheless, porous materials like wood have received limited attention due to their inherent absorbency. This study aims to evaluate the antibacterial and photo-activity of modified wood employing Ag-doped TiO2 coating applied on the wood surface. The main characteristics of the modified wood were measured through XRD, SEM, AFM, TGA, and DRS analysis to determine structure and crystallinity, shape of particles, physical modifications of the wood surface, degradation rate, band gap alterations, and light absorbance, respectively. Methylene blue indicator witnessed a photo-degradation rate of 90 percent under UV irradiation after 21 h. This rate was observed at around 38 percent under irradiation of visible light. All in all, the modified wood underwent less color change whereas the parent wood witnessed a major change regarding its color. The antibacterial properties of wood were also measured. Two bacterial infections, S. Aureus and E. Coli, were employed for the following experiments. The results illustrated that the coating was able to reduce the amount of colonization and adhesion of E. Coli by 50 % and S. Aureus to zero.

To investigate and compare hardwood species based on their carbon (C) and nitrogen (N) storage capacity, a study of the C and N content of the bark and wood of nine common hardwood broadleaves in Novi Pazar, southwestern Serbia, was conducted. Compared with sycamore maple, Norway maple, common ash, common hornbeam, black locust, European beech, Turkey oak, and sessile oak, field maple has the highest C/N ratio in wood (37.05 ± 3.23), representing the best hardwood species for biomass production.

Abstract Equipping otherwise passive surfaces with electronic functionality enables advanced interactive robotics, consumer products, sensor skins, and structural health monitoring. Concurrently, the rapidly growing number of electronic devices fuels the search for sustainable materials and processes that aid in reducing electronic waste. Wood is CO2‐neutral, omnipresent in the construction industry, in furniture, musical instruments, or packaging, yet so far, its potential for direct integration with electronics remains largely unexplored. Complications arise as traditional methods of equipping wood with electronics often compromise structural integrity and thus limit applications requiring load‐bearing capabilities. Here, seamless fabrication methods that allow the direct enhancement of wooden surfaces with electrically conducting structures, sensors, and microelectronic components based on screen printing of conducting inks or physical vapor deposition of thin metal films in conjunction with laser engraving are presented. Such electronic circuits imperceptibly operate on the surface of structural elements or as parts of decorative wooden furniture. These types of electronic wooden surfaces enable touch‐sensing applications, monitoring temperature, or the curing of varnishes without compromising functionality and mechanical stability. This multidisciplinary approach opens up new avenues for the development of smart wooden structures with embedded electronics, revolutionizing the way it is monitored, controlled, and interacted with wood‐based constructions.

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.

Introduction. The paper discusses the advantages and features of the main existing methods of connecting wooden columns and crossbars.Materials and methods. It was proposed to increase the load-bearing capacity and reduce the deformability of joints by modifying the joints with the introduction of epoxy resin between the screw and the wood and between the overlay and the end of the wooden element to which it is attached and modifying the design of the overlays.Results. As a result, a constructive solution for connecting wooden columns and crossbars was developed, which has increased reliability compared to the studied connections and is free of their disadvantages. This result was achieved due to the presence of an adhesive layer between the screw and the wood, as well as between the overlay and the wooden element, the making of notches on the sides of the overlays attached to the wooden elements, the increased length of the screws screwed into the overlay with a groove, compared to the length of the screws screwed into an overlay with a tenon, placement of holes for screws at an angle of 90° to the surface of the overlay into which the screws are screwed.Conclusions. An urgent issue is the development of constructive solutions for connections of wooden elements, in particular the interfaces of columns and crossbars. The paper discusses the advantages and features of the main existing methods of connecting wooden columns and crossbars.

Abstract The genus Melia is known for its secondary metabolites and recently, this genus is being explored for its timber. There are vast differences among its species. For instance, Melia azedarach is reported to be invasive and while another species, M. dubia, has diverse utility with complex germination and regeneration characteristics. Researchers globally have been working on various aspects of this genus; In this study, using topic modelling and science mapping approach, we attempted to understand research facets on this genus. The literature corpus of the Web of Science database was explored using a single keyword—“Melia” which yielded 1523 publications (1946–2022) and after scrutiny metadata of 1263 publications were used in the study. Although nine individual species were cited in the publications, only three species are accepted viz., M. dubia, M. azedarach, and M. volkensii. This implies taxonomic uncertainty, with potential confusion in assigning scientific findings to particular species. Thus, a taxonomic relook on this genus is warranted for a better assessment of the economic utility in many countries. More importantly, our results indicate that the research interests have recently shifted from the secondary metabolite constituents towards growth, biomass, wood properties, germination, plantation, and green synthesis. The shift in research focus toward wood properties of Melia sp. can impact the wood demand–supply at a global scale owing to its fast growth and the possibility of cultivation over a wider geographical range.

Abstract To assess the damage and fracture behavior of wood under load, a wood damage assessment method was proposed based on acoustic emission (AE) b-values and seismic magnitude difference entropy. First, AE signals from Pinus sylvestris var. mongolica (softwood) and Zelkova schneideriana (hardwood) specimens were collected separately at a sampling frequency of 500 kHz in a three-point bending test. Then, 52 dB was taken as the threshold of the AE event, and the b-value and seismic magnitude difference entropy were calculated at 4-s intervals. Finally, by comparing with the load‒time curve, the b-value and seismic magnitude difference entropy were used to evaluate the damage fracture degree. The results showed that an increase in the b-value indicates the accumulation of strain energy, and vice versa, corresponding to the concentrated release of strain energy. At the same time, the test process can be divided into three stages—elastic, elastic‒plastic and plastic—based on the level of the seismic magnitude difference entropy.

Tree wood is a natural material that is one of the oldest materials used by the artists of many ancient civilizations, as well as by the sculptors of modern and contemporary arts. In this research, the researcher relied on the natural color of wood, each with its own characteristics. He chose the wood blocks, each by its nature in terms of porosity, color, and different sectors, and tried to employ them to serve the subject of the research. The research, despite the difference in formations between vertical and horizontal, the researcher incited to achieve unity in the artistic work where the use of one raw material and one artistic processors, and he also used the technique of direct carving on wood, with the requirements of each stage of machines

Buprestidae is a group of beetles of important conservation and phytosanitary value that is poorly studied in the Tuscan Archipelago and the limited faunistic knowledge available refers to a few scant historical records.The present contribution increments the species documented in the Archipelago from 27 to 51, providing more than 300 georeferenced occurrence records, derived from both direct field research and citizen science via iNaturalist. Of particular importance is the discovery of Eurythyrea quercus on Isola d'Elba, an uncommon and localised species currently critically endangered.

Due to their durability, versatility, and aesthetic value, wood and wood-based composites are widely used as building materials. The fact that these materials are flammable, however, raises a major worry since they might cause fire hazards and significant loss of life and property. The article investigates the variables that affect fire performance as well as the various fire-retardant treatments and their mechanisms. The current developments and challenges in improving the fire performance of wood and wood-based composites treated with fire-retardant materials are summarized in this paper. Nanoparticles, organic chemicals, and densification are some recent developments in fire-retardant treatments that are also emphasized. Key points from the review are summarized, along with potential areas for further research and development.

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.

The demand for solid wood is high in the construction and manufacturing industries, and the quality of the wood is crucial. Defects in solid wood can result in hazardous accidents or financial loss. While manual visual inspection of defects is time consuming and labor intensive, Automated Optical Inspection (AOI) systems provide a solution that is hindered by defect variations and environmental factors such as moisture content and lighting conditions. AOI systems coupled with machine learning algorithms have emerged as a promising approach for inspecting wood defects. Despite their promising results compared to manual visual inspection and AOI systems, machine learning algorithms have shown several limitations in terms of complex image processing methods, feature engineering, and hyperparameter dependence. Deep learning algorithms have tremendous potential and have become trends in wood defect inspection in recent years, particularly Convolutional Neural Networks (CNNs), single-shot detectors (SSD), You Only Look Once (YOLO), and faster region-based neural networks (Faster R-CNN) algorithms. The coupling of machine vision technology with deep learning algorithms can enhance the efficiency and accuracy of wood defect inspection, and their impact has been proven in several studies. This study aims to provide a comprehensive overview of wood defect inspection approaches by analyzing related studies on machine learning-based and deep learning-based defect inspection methods. Their principles, procedures, performance, and limitations were compared and discussed. Subsequently, future trends and challenges in wood defect inspection are also discussed to provide a detailed understanding and direction for related fields.

Wood is one of the most important materials that has been used for several millennia. It is therefore not surprising that wood plays an important role in the cultural and technical heritage of several European countries and beyond. An excellent example of cultural and technical heritage is a wooden mill, almost 100-year-old, near Cazin in Bosnia and Herzegovina. These mills played an important role, especially in times of Bosnian war (1992- 95), when this region was cut off from electricity. The microscopic analysis of the wood materials used in the mills revealed that the mills were made of chestnut (Castanea sativa) and oak (Quercus sp.) wood. Sufficient durability of these wood species resulted in good structural integrity of the mills. The surface of the wood materials in the mills showed partial degradation patterns caused by weathering over the years. However, the interior parts of the wood materials were intact probably due to smoke deposits from the open fireplace. It is suggested that the roofing in the mills should be maintained regularly to prevent possible leaks to protect this heritage for future generations.

This research presents the fabrication and characterization of an interdigitated capacitive (IDC) sensor on a wooden substrate using pencil traces. The resistance of the pencil traces decreased from 100 kΩ to 5 kΩ as the pencil grade shifted from HB to 8B. Concurrently, capacitance measurements revealed an increase from approximately 5 pF for a 5-finger IDC made with HB pencil to around 32 pF for an 8B pencil counterpart. Increasing the number of pencil traces from 10 to 50 resulted in a significant decrease in resistance and a proportional increase in capacitance. Application of the IDC sensor demonstrated notable changes in capacitance upon proximity and touch, with a significant decrease upon removal. The interdigitated capacitance sensor exhibits good proximity effects and contact sensitivity in touch, with capacitance increasing exponentially from 0.3 pF (7 cm) to 1.2 pF (direct contact), highlighting its ability to detect objects with high precision. Additionally, environmental factors such as temperature and humidity influence capacitance values. These findings underscore the potential of pencil-drawn IDC sensors for responsive and adaptable applications in various fields.

Illegal activities associated with deforestation for the lumber and furniture industries pose significant threats to plant and animal biodiversity, as well as natural resources. Accurate identification of wood sources is vital, yet traditional laboratory techniques often fall short in precisely determining the chemical composition of samples for classification. This study aims to leverage ATR-FTIR spectroscopy alongside machine learning algorithms to construct a robust model for discerning the geographical origins of wood samples from India. By systematically comparing various machine learning classifiers, we address the limitations of subjective visual interpretation and evaluate their accuracy using wood spectral data. Logistic regression emerges as the most effective classifier for distinguishing Eucalyptus (75 % accuracy), Dalbergia (68 % accuracy), and Populus (81.5 % accuracy) species. Through a methodology encompassing data pre-processing, classifier selection, and performance evaluation, this research offers promising tools for combating challenges posed by illegal wood trafficking and transportation. The outcomes hold significant potential for enhancing wildlife crime prevention efforts by facilitating the tracing illicit timber sources, apprehension of perpetrators, and implementation of preventive measures.

In this study, the effects of applying wax on the colour, glossiness, and whiteness index (WI*) values of American black cherry (Prunus serotina Ehrh.) wood were investigated. Wax was applied to wooden material surfaces using a brush in one, two, and three layers. Tests were then conducted on surfaces with and without wax. The results were statistically significant according to the multivariate variance analysis. It was determined that the application of wax led to a decrease in L*, ho, and WI* values on the wooden material surfaces (parallel and perpendicular to the fibres), while the a*, b*, and C* parameters increased. In measurements parallel and perpendicular to the fibres, increases were observed in gloss values for two- and three-layer wax applications at 60° and 85°. The ∆L* values were negative when wax was applied in one, two, and three layers, whereas the ∆a*, ∆b*, and ∆C* values were positive. The ∆E* values were determined as 8.41 for one layer of wax, 11.29 for two layers, and 11.59 for three layers. Given the similarity between the ∆E* values of two and three layers of wax, it can be inferred that a third layer may not be necessary.

Ghana’s forest is fast depleting as a result of over-dependency on the traditionally known timber species and high demand for wood products for structural works. This study seeks to determine the chemical properties and basic density of Terminalia catappa wood and its potential for structural application. Three mature trees of Terminalia catappa were acquired based on the diameter at the breast height (dbh) greater than 40 cm. In this study 160 samples of wood were used for the chemical properties and density tests. Chemical analyses were performed by using the TAPPI standards. The study revealed that there were higher cellulose and hemicellulose contents in the sapwood than in heartwood, and in the branchwood than in stemwood. Lignin and extractives content were higher in the heartwood than in sapwood, and in the stemwood than in branchwood. The basic density of the sapwood ranged from 473 to 649 kg/m³ and in the heartwood from 444 to 579 kg/m³ being the highest in the base portion and the lowest in the branches. The difference in wood density, which is greater in the base area than the branches, emphasizes how crucial it is to take wood quality into account for the best possible use across various tree portions. The study also clarifies the wood's suitability for structural and non-structural uses. These findings have the potential to influence sustainable forest management strategies and encourage the use of alternative timber to supplement the resource base.

This study assessed the possibility of using wood as a building material for the construction of houses. A comprehensive method was used, which consisted of analysing environmental management regulations, applying the life cycle assessment method to minimise the carbon footprint; using software to calculate the carbon footprint of a wooden house at different stages of the life cycle. The object of study is the carbon footprint of a house built of wood. The Life Cycle Assessment method was used as a methodology for assessing the life cycle. Using the One Click Life Cycle Assessment and Life Cycle Cost software, the carbon footprint of a log house was calculated for the product life cycle stage mentioned above (A1-A3). When calculating the carbon footprint of wood-based building materials, carbon emissions were taken into account not only from the finished products, but also from all other products obtained as a result of logging. When calculating the carbon footprint, greenhouse gas emissions from all activities are estimated. We have obtained data on the life cycle cost of a wooden house in terms of electricity use. Accordingly, we obtained a value of global warming potential (A1-A3) of 0.51 kg CO2 e/kWh. We also obtained data on the life cycle cost of a wooden house in terms of diesel consumption. According to the results of the LCA, the value of the global warming potential due to meeting the water supply/sewage needs is (A1-A3) 0.69 kg CO2 e/m3. The value of the global warming potential due to meeting the heat supply needs of production needs is (A1- A3) 0.13 kg CO2 e/kWh. Based on the information obtained, we can conclude that it is advisable to use a wooden log house as a building material, as the carbon footprint is smaller than that of a brick building. The final section presents the results of calculating the life cycle cost of a wooden house by discount factor and inflation, the results of the life cycle cost of a wooden house by percentage of energy costs, and the results of assessing the life cycle cost of a wooden house (displaying parameters according to the European energy certification scale). Based on the carbon footprint assessment (using the Life Cycle Assessment methodology), economic comparison (Life Cycle Cost and total construction costs), and expert assessment (based on technical and ergonomic parameters) of the two construction technologies, the feasibility and possibility of using wood as a building material was established. The study proves the feasibility of applying the LCA method in the construction industry.

A low-density wood fiber insulation panel (WIP) composite was developed with 100 % petrochemical-free, bio-based binder with high mechanical strength, water resistance and thermal insulation properties. This study investigated the manufacturing process of composite WIPs made with mechanical pulp fibers with cellulose nanofibrils (CNFs), lignin-containing CNFs (LCNFs), hybridized CNFs-LCNFs, and CNFs-starch as a binder on different scales and evaluated the effects of binder type and content on the panels’ physical, mechanical, and thermal properties. All panels had excellent thermal resistivity values, which increased with the decrease in density. The WIPs made with LCNFs as binder had lower mechanical properties, but it was possible to replace 20 % CNFs with LCNFs to obtain the same performance as neat CNFs as the binder. Untreated panels had poor water resistance but the water absorption properties were significantly improved with the addition wax. The WIPs made with 5 % and 7.5 % binder content and 2 % wax addition could fulfill the criteria of regular and structural wall sheathing applications, respectively. Overall, the results confirm the potential of CNFs and LCNFs to be used as 100 % bio-based adhesives to produce eco-friendly composite WIPs with excellent thermo-mechanical properties to be used for regular and structural wall sheathing applications.

The hand-held power sander is a frequently used tool in woodworking, and it is a significant source of risk in terms of dust, vibration, and, notably, noise. The purpose of a hand-held power sander manufacturer’s noise emission statement is to provide information that is useful for assessing the risks associated with noise exposure and should assist users in selecting a hand-held power sander with reduced noise emissions. The stated levels of emitted noise obtained in accordance with a harmonized test procedure may not, in all circumstances, give a reliable indication of the actual risk of noise exposure during the typical use of a hand-held power sander. The aim of this work was to investigate the difference between the values declared by the manufacturers of hand-held power sanders and the measured noise values during actual use. The measurements of the equivalent sound pressure levels were carried out using an integrating–averaging sound level meter (B&K, model 2245) during the sanding of beech and spruce wood with different types of hand-held electric sanders (belt, random orbital, and orbital) with abrasives of coarse, medium, or fine grit. Upon comparing the measured and declared noise values, differences ranging from −6.3 dB to 19 dB(A) were identified for distinct sander types. The results of this study show that the use of declared noise emission values during risk assessments underestimates the magnitude of operator noise exposure.

In this study, which aims to improve the waterproofing performance of Calabrian pine (Pinus brutia Ten.) wood by the thermal bio-oil dipping technique, it was used castor oil (Ricinus communis L.), linseed oil (Oleum linii), and mixed oil (50% castor oil + %50 linseed oil), and the thermal method (hot-cold dipping method). Retention amount, water absorption, water repellent activity, and volumetric swelling properties of the samples were determined. Among the oils, the highest retention amount, 42.90%, was obtained in wood samples treated with flax oil. The water uptakes of the treated samples were lower than that of the control samples. The lowest water absorption values was found at 19.20% in the treatment with linseed oil. For water-repellent activity, better results were obtained in the linseed oil treatment than in the castor oil and mixed treatments. All treated wood samples showed a significant hydrophobic property. For all three oils, the volumetric swelling values of the treated samples were lower than that of the control samples. All these show that the hot-cold bio-oil dipping treatment improves the waterproofing performance of the Calabrian pine wood, which is given a hydrophobic qualification by positively affecting these physical properties. According to these results, it would be beneficial to apply thermo-bio-oil immersing treatment before use in environments that will be exposed to the effect of water/humidity, for Calabrian pine wood. For this reason, it would be suggested to apply Calabrian pine sapwood with the thermal bio-oil dipping process in the production of final waterproof wood material for indoor use.

Introduction. The article considers the prerequisites for the development and application of new construction technology with the use of renewable natural resource — wood. The problem of providing construction with raw materials for production is relevant. Objectives of the research — determination of the main advantages and disadvantages of CLT-panels as a material used in load-bearing frames; feasibility of CLT-panels in relation to other traditional building materials; identification of the main technological features of construction production with the use of cross-glued panels technology, determination of the advantages of the technology; necessity of research activities on the construction material for updating the relevant building regulations; analysis of foreign experience in the field of construction of wood-based panels.Materials and methods. The review and analysis of domestic and foreign literature, scientific papers, normative documents, information sources on the basis of eLIBRARY.RU were performed. Comparison and systematization of the obtained data. Earlier studies were also taken as a basis.Results. On the basis of the conducted analysis of information sources the description of the main properties and characteristics, as well as production technology of CLT-panels is given; positive and negative sides of the material application, advantages of construction technology of building frames erection are determined. The comparative analysis of domestic and foreign experience in wooden house building is carried out. The problems of cross-glue panel technology development in Russia are defined.Conclusions. The results obtained through the conducted research determine the feasibility of using CLT-panels as a building material for load-bearing structures, characterized by the presence of a list of properties significant for the industry: environmental friendliness, renewability, high rates of work production, reduction in the cost of construction of objects due to the reduction of labour intensity of the construction process.

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.

This paper presents research into the possibilities of using laser perforation to enhance the decorative properties of Siberian fir (Abies sibirica) wood. Fir wood is characterized by fairly modest physical and mechanical properties and featureless appearance, which is why it is in low demand. With enhanced decorative properties, fir wood could find its use in the production of finish materials. The literature review reveals that the existing wood dyeing technologies are not really effective for the hard-to-impregnate fir wood. Therefore, laser perforation was used to achieve higher wood impregnation and its controlled coloring to form the texture. The study also explored the features of dyeing laser-perforated fir wood, depending on the set parameters of impregnation and wood structure. To do so, the fir samples (with the size of 165×65×32 mm) were laser perforated to form slots up to 0.2 mm in diameter and 15 mm deep. Then the samples were impregnated in an autoclave. The set parameters were determined in accordance with the two-factor experiment schedule: the pressure standing at 0.2, 0.5 and 0.8 MPa, with the impregnation time of 30, 225 and 480 min. The study showed that when perforated wood is impregnated, the dyeing solution penetrates the laser-cut slots first and mainly spreads along the wood fibers. Depending on the impregnation time and pressure applied, the dye moves from the perforated slots along the wood fibers covering a distance of 10.9 mm to 24.6 mm. The dye does not spread as well across the fibers, only coloring a total width of 1.3 to 1.7 mm both ways from the slot depending on applied pressure and time of impregnation. It was found that, first and foremost, the set parameters affect the size of colored areas along the wood fibers and make little difference to lateral coloring in absolute values. Pressure applied to perforated wood during impregnation was determined to have the biggest impact on the size of colored areas. The study proves it possible to use the developed technology in forming artificial wood textures, including those that imitate valuable wood species. For citation: Eliseev S.G., Ermolin V.N., Duk D.V. Using Laser Perforation to Enhance Decorative Properties of Siberian Fir (Abies sibirica) Wood. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 151–163. (In Russ.). https://doi.org/10.37482/0536-1036- 2023-5-151-163

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.

Introduction. A distinctive feature of CLT panels is the cross arrangement of planks (lamellae) in different layers of the board. Due to the anisotropy of wood, this design allows for high strength and stiffness in different directions of stress action, which has made this material one of the most promising to be studied in recent decades. This article examines the influence of the thickness of transverse and longitudinal layers in five-layer slabs of cross-glued timber boards, or CLT panels, on the deformation and distribution of the resulting normal and tangential stresses. The relevance of the work is conditioned by the necessity of obtaining calculated data to analyze changes in the strength characteristics of boards with different variations in the thickness of longitudinal and transverse layers in order to choose the most effective configuration of the board.Materials and methods. The studies were carried out by numerical methods using SCAD+ PC using FEM (Finite element method). At the same time, the three-dimensional finite elements are parallelepipeds. The design scheme is defined as a general-type system, whose deformations and its main unknowns are represented by linear displacements of nodal points along the X, Y, Z axes and rotations around these axes. As a design structure, a five-layer slab with cross-directed layers was chosen in such a way that the outer (1, 5) and central inner (3) layers are longitudinal, and the remaining inner (2, 4) are transverse. The simplified design scheme is a pivotally supported beam.Results. The results of the study and calculations made using SCAD+ were applied to make tables and graphs showing dependence of deflection, distribution of normal and tangential stresses on the thickness of transverse and longitudinal layers of the board.Conclusions. The obtained data allow us to evaluate the influence of thickness on deformability and stress distribution in five-layer CLT panels. The significance of the conducted research is in the expansion of scientific and technical knowledge base in the field of wooden structures.

Indonesia merupakan salah satu negara dengan sumber daya alam berupa kayu yang melimpah, Salah satu sumberdaya alam yang melimpah adalah kayu. Dan salah satu daerah di Indonesia yang memiliki Kawasan hutan yang cukup besar adalah Pulau Papua. Dari sekian banyak jenis kayu yang ada, hanya sebagian kecil saja yang telah diketahui sifat dan kegunaannya. Maka selanjutnya akan dilakukan pengujian kuat lentur terhadap kayu yang tidak dikeringkan dan kayu yang mengalami proses pengeringan, hal ini bertujuan untuk melihat seberapa besar pengaruh kadar air terhadap kuat lentur dari kayu yang beredar di Kota Sorong – Papua Barat Daya. Setelah dilakukan pengujian kadar air dan kuat lentur, maka diketahui bahwa semakin rendah kadar air dari kayu maka nilai kuat lentur dari kayu akan semakin tinggi, Hal ini dikarenakan jika kadar air kayu berkurang (semakin kering) maka kayu akan mengalami penyusutan dan membuat kayu tersebut semakin padat hingga kerapatannya lebih tinggi dan membuat kayu semakin kuat menahan gaya lentur. Hal ini sejalan dengan standar SNI 7973:2013 yang mensyaratkan kayu harus memiliki kadar air dibawah 30% untuk bisa dipakai sebagai material konstruksi.

ABSTRACT: Introduction. This study aims to carry out comprehensive comparative research of thermal degradation and inflammation parameters of timber covered with fire resistant biological flame retardants of different chemical composition. We also looked at the efficiency and the action mechanism of the latter. Materials and methods. As the objects of research, the means were selected – phosphorase-containing water-soluble compounds of the nanoscale series, complex biocides and special bioplasticizers (Agent 1) and water-soluble nanoscale diammonium hydrophosphate (Agent 2) applied to pine wood by surface treatment and deep impregnation methods. Results and discussion. Thermogravimetric studies of wood treated with flame retardants have shown that its decomposition occurs in the following temperature ranges: 30–150°C – the process of loss of moisture by wood; 150–400°C – the effect of protective mechanisms of the compositions, as well as the process of decomposition of the main components of wood (hemicellulose, cellulose, lignin) and the formation of a coke layer; 400–800°C – the process of gradual burnout of the coke layer taking into account its thermophysical characteristics up to the ash residue. It has been established that both flame retardants act by the mechanism of catalytic dehydration and reduce the rate of decomposition of wood from 29 to 10%/min. Conclusion. The features of the thermal decomposition of wood protected by two different chemical composition and method of its processing means are determined. The parameters of the flammability of pine wood treated with fire-protective compounds by surface and deep impregnation were obtained, which indicate their high efficiency, which is confirmed by the values of the coke residue at 400°C, the nature of DTG peaks and DSC curves. The possibility of using the obtained materials from wood for interior decoration and cladding of facades of buildings that meet regulatory requirements for their safe use is shown

This study looks at wall partition panels with hollow core wood elements and gypsum board as protection in fire conditions. In addition to our previous research, this study on wall partitions considers the effect of steel screws in the assembly of the elements, as well as the filling of the cavity with insulating material. The goal of this work is to calculate the fire resistance time and compare the results using different numerical models. The discussion of the results analyzes the effect of steel screws and the introduction of insulating material inside the cavities. The steel screws are verified with and without threads. The numerical models are based on the finite element method, using thermal and transient analysis with nonlinear materials. The thermal insulation criterion for measuring fire resistance is referenced by the EN 1363-1:2020 standard. The steel screws allow more heat to be concentrated and, therefore, distribute it throughout the wooden wall partition members. Based on the results obtained, the use of steel screws reduces fire resistance by 71.75 min, regardless of whether the wall partition is filled with or without insulating material.

Wood extractives have proven strong anti-oxidative properties which may be used to mitigate surface deterioration caused by photolytic effects and free radical formations. An interesting challenge regarding wood extractives is understanding how they behave in terms of treating natural wood surfaces to reduce anti-oxidative processes that arise from exposure to the main environmental factors. In this study, the possible efficacy of chestnut (Castanea sativa Mill.) extractives derived from native (CH) and thermally modified wood (TMT CH), as a means of protecting against UV exposure in poplar (Populus spp.) and spruce (Picea abies Karst.) wood, was evaluated. Chestnut wood was first thermally modified at 180 °C for 3 h, and the extractives were obtained by the accelerated solvent extraction technique (ASE) and subsequently used to treat wood surfaces. Samples were immersed in extractive solutions and exposed to artificial UV-weathering exposure, then contact angle and colour stability were monitored during the process. An FTIR analysis of the photo-degradation process of poplar and spruce surfaces was also executed. Extractives of TMT chestnut changed the total colour variation in both poplar and spruce wood. A much darker colour compared to the extractives of native wood was observed and an increase in ∆E* from 9.75 to 30.76 and 6.24 to 22.97 in poplar and spruce was calculated. The stability of the colour depended both on the surface wood and the type of extractive. The initial contact angle remained almost unchanged in the poplar wood surface and only slightly increased in spruce regardless of whether they were treated with extractives from native or TMT chestnut wood. A strong reduction in contact angle after the accelerated UV exposure test was observed, especially in spruce treated with CH extractives. FTIR analysis confirmed the lower levels of chemical degradation of surfaces observed by colorimetry, where TMT CH extractives formed more stable chemical bonds than native extractives. The comparative analysis in this study clarified the complex relationships between the effects of high-temperature modification of wood and the potential protective role of TMT extractives on some wood surfaces.

In this study, environmentally friendly and low-cost biomass materials were selected as wood flame retardants. Three polyelectrolyte flame-retardant coatings made from chitosan (CS), tea polyphenols (TP), soybean isolate protein (SPI), and banana peel powder (BBP) were constructed on wood surfaces by layer-by-layer (LBL) self-assembly. The results of SEM-EDS and FT-IR analyses confirmed the successful deposition of CS-TP, CS-SPI, and CS-BPP on the wood surface, and the content of N element increased. The TG results showed that the initial decomposition temperature and the maximum thermal decomposition temperature of the coated wood specimens decreased, while the char residue increased significantly. This is due to the earlier pyrolysis of CS-TP, CS-SPI, and CS-BBP. This shows that the three polyelectrolyte flame-retardant coatings can improve the thermal stability of wood. The combustion behavior of the wood specimen was observed by exposure to combustion; the coated wood could self-extinguish within a certain period of time after ignition, and the flame-retardant performance was improved to a certain extent. SEM and EDS characterization analyses of the carbon residue after combustion showed that the coated wood charcoal layer was denser, which could effectively block heat and combustible gas.

This study outlines a method of utilizing the finite element method and a simple mathematical model to predict the behavior of laminated veneer lumber (LVL) beams strengthened with composite sheets. The numerical models were created using the Abaqus 2017 software. The LVL was considered as a linearly elastic or elastic–plastic material, factoring in Hill’s yield criterion. The composites were simulated as linearly elastic–ideally plastic materials. The mathematical models were predicated on the methodology of transformed cross-section. The theoretical and numerical outcomes were juxtaposed with previous empirical investigations. The comparison encompassed load-bearing capacity, stiffness, and deformation under peak force. Furthermore, presentations of normal stress maps in the LVL and composite have been illustrated. The derived maps were juxtaposed with the delineations of failure modes. An adequate correlation was identified between the theoretical, numerical, and empirical values in the case of beams reinforced with aramid, glass, and carbon sheets. The relative deviation varied from several to multiple percentages. This technique is not applicable for evaluating load-bearing capacity and deformation when only dealing with sheets with low elongation of rupture. This is a consequence of their premature failure. The proposed models may be utilized by researchers and engineers in the design of reinforcements for timber structures.

The increasing global commitment to carbon neutrality has propelled a heightened focus on sustainable construction materials, with wood emerging as pivotal due to its environmental benefits. This review explores the development and application of eco-friendly polymer nanocomposite coatings to enhance wood’s fire resistance, addressing a critical limitation in its widespread adoption. These nanocomposites demonstrate improved thermal stability and char formation properties by integrating nanoparticles, such as nano-clays, graphene oxide, and metal oxides, into biopolymer matrices. This significantly mitigates the flammability of wood substrates, creating a robust barrier against heat and oxygen. The review provides a comprehensive examination of these advanced coatings’ synthesis, characterization, and performance. By emphasizing recent innovations and outlining future research directions, this review underscores the potential of eco-friendly polymer nanocomposite coatings as next-generation fire retardants. This advancement supports the expanded utilization of wood in sustainable construction practices and aligns with global initiatives toward achieving carbon neutrality.