Search

High variations in juvenile wood properties in the radial direction and its worse performance than mature wood make it less suitable for some applications and often treated as waste material. This study aimed to assess how thermal modification affects the chemical composition and the physical, mechanical and swelling properties of Scots pine juvenile and mature wood. An additional goal was to evaluate if the modification can equalise the differences in selected properties of juvenile wood to those of mature wood so that from waste material, juvenile wood can become a fully-fledged raw material for various industrial applications. Thermal treatment at 220 °C influenced wood chemical composition, degrading mainly hemicelluloses but also affecting cellulose and lignin, which resulted in a reduction of hydroxyls and carbonyl/carboxyl groups. These changes were more pronounced for mature than juvenile wood. It reduced mass loss and swelling rate, and increased swelling pressure in the tangential and radial directions to a higher degree for juvenile than mature wood. Changes in mechanical properties in compression were statistically significant only for mature wood, while wood hardness remained unaffected. Although the applied heat treatment improved the performance of juvenile wood by reducing its swelling rate, it did not equalise the examined properties between juvenile and mature wood. Since higher juvenile wood proportion is expected in the wood supply from the future intensively managed forests, there is still a need to find suitable modification methods or better processing techniques so that instead of being thrown away as waste, it could be used broadly in various industrial applications. [ABSTRACT FROM AUTHOR]

Densified wood (DW) is a carbon-negative and energy-saving structural material with promising applications in high-rise timber buildings. However, its fire safety issues restrict its applications. In this paper, a bio-material, phytic acid, based flame retardant PPBNOH was prepared to improve the flame retardancy of DW. The structure characteristics, thermal stability, flammability, combustion behavior and mechanical performance of flame-retardant DW (PPBNOH/DW) were studied. Results show that the decomposition of PPBNOH catalyzes char formation and enhances thermal stability. Thus, PPBNOH/DW has a 57% reduced peak mass loss rate and a 27.9% increased char yield. Both the wood dense structure and PPBNOH catalyzation synergistically promote the formation of phosphorus-containing, crosslinked and aromatic char during wood combustion, which hinders heat/mass transfers and enhances flame retardancy. Thus, PPBNOH/DW has a 53.2% limiting oxygen index, a V-0 rating of UL-94 test. It presents delayed ignition time, reduced heat release characteristics and lower heat of combustion (5.37 MJ kg−1) in the cone calorimeter test. BNOH improves the smoke suppression performance of PPBNOH/DW with a 38.6% reduced total smoke production. The compatible and thermally insulating char also enhances the high-temperature heating resistance of PPBNOH/DW as it has the highest remaining mechanical strengths after heating. [ABSTRACT FROM AUTHOR]

Worldwide, silicified woods are found in many geological formations. Significantly, the organic materials of wood are no longer dominant; almost all wood fossils have been mineralized into inorganic silica materials. These unique geological processes must be understood to develop better understanding on organic material fossilization, particularly in the micron scale. Therefore, our aim was to characterize the composition of silicified wood using comprehensive microanalysis. The methods utilized were XRF, ICP-MS, XRD, FTIR, and FE-EPMA. Specimens are from Jasinga, West Java, Indonesia. The results showed that wood silicification was controlled by the infiltration of silica from the host rock into the spaces of the wood structure. In Jasinga, they are controlled by Pliocene tuffaceous sedimentary rocks. The ratio of silica phases revealed a trend in the degree of silicification. Besides silica, the distribution of trace elements also demonstrates the geochemical interaction between the wood fossil and host rock. Wood fossils are affected by the gradual replacement of organic carbon-based materials with silica through silicification. Silica enrichment occurs in the internal of wood, facilitates permineralization and recrystallization. Silica replaces organic material and preserves the wood structures. The microanalytical approach provides comprehensive perspectives on wood petrification, leads to better insights for paleontological studies. [ABSTRACT FROM AUTHOR]

Wood degradation by termites is a major concern for researchers, builders of timber-frame houses and stored wood products. This study aimed to determine the wood-degrading Isopterofauna in the cities of Yaoundé and Douala, Cameroon. Woods deposits and joineries workshops in the two cities were investigated monthly over 12 months, and termites were collected from wood species identified by their vernacular names. A total of 44 samples of wood-attacking termites were collected, grouped into two families (Rhinotermitidae, Termitidae), six subfamilies (Rhinotermitinae, Apicotermitinae, Coptotermitinae, Macrotermitinae, Nasutermitinae and Termitinae) and nine species. The species Nasutitermes arborum (14 samples) and Schedorhinotermes putorius (12 samples) were the most common in the city of Yaoundé. Only three species were found in Douala, mainly Coptotermes sp. (three samples). Of the 21 wood species examined in the two cities, Entandrophragma cylindricum hosted the highest termite species richness (six species). These findings are a milestone in the study of termites on lumber in storage and could be used by researchers and agents in the timber industry to make decisions regarding the application of pesticides on wood. [ABSTRACT FROM AUTHOR]

In the present study, with a view to decreasing the inherent fire risk associated with the usage of wood, the flame-retardant efficacies of some additives for wood samples were investigated. The additives included: 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), triphenylphosphine (TPP), diammonium hydrogen phosphate ((NH4)2HPO4) and sodium carbonate (Na2CO3). The test samples incorporating the flame-retardant additives were primarily evaluated by thermo-gravimetric analysis (TGA). It was found that the presence of DOPO imparted some beneficial effects, especially, in terms of increased energetic needs for the second-stage decomposition of the lingo-cellulosic material, coupled to an enhanced production of char residues. However, with the other additive systems, such as TPP, Na2CO3 and (NH4)2HPO4, the flame-retardant effect seemed to arise from increased char production with a concomitant effect on the energetic requirements for the decomposition pathways, especially, at a high temperature. In terms of to the conversion degrees, for samples PFC2, PFC3 and PFC4, stage one was found to extend over the conversion range of 0 ≤ α ≤ 0.65, corresponding to temperatures from 30 to 350 °C. In contrast, for samples PFC5, PFC6 and PFC7, stage one seemed to span over a conversion range of 0 ≤ α ≤0.55, during the same temperature range. Additionally, PFC2 exhibited maximum char residue, indicating it may represent a more effective formulation. Furthermore, a detailed kinetic analysis would be processed in the future. [ABSTRACT FROM AUTHOR]

This study investigated self-heating and off-gassing of Scots pine (Pinus sylvestris) wood pellets made from sawdust generated from separated mature and juvenile wood. The pellets were produced at an industrial scale and stored in large piles of about 7.2 tonnes. The production process involved drying the sawdust using three different methods and to varying moisture contents. The results indicated significant influences of both raw material type (F(6) = 61.97, p < 0.05) and drying method (F(2) = 65.38, p < 0.05) on the self-heating of the pellets. The results from the multiple regression analysis further showed that both the raw material type and pellet moisture content significantly influenced the temperature increase, with strong correlations observed for pellets produced using low-temperature drying (F(3, 14) = 83.52, multiple R2 = 0.95, p < 0.05), and medium temperature drying (F(3, 13) = 62.05, multiple R2 = 0.93, p < 0.05). The pellets produced from fresh mature wood sawdust were found to be more prone to self-heating and off-gassing while steam drying the sawdust at high temperature and pressure led to a significant reduction in heat and gas generation across all materials. The heightened self-heating and off-gassing in mature wood pellet can be attributed to a higher proportion of sapwood in the raw material. The probable explanations to the observed differences are in line with biological mechanisms for self-heating and off-gassing, as well as the chemical oxidation of fatty and resin acids. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

In recent years, ancient wooden building fires have been a hot issue that has not been properly solved. The existing ancient wood buildings objectively have serious natural ageing phenomenon, among which the dry and wet alternating ageing phenomenon of wood caused by water is the most serious. However, the phenomenon of dry and wet alternating ageing pays less attention to the influence of wood combustion. Therefore, this study took the typical wood species of ancient wooden buildings as the research object, based upon the natural ageing phenomenon of these buildings, determining the artificial acceleration of dry and wet alternate ageing method, to obtain dry and wet alternate ageing wood. The thermal diffusion coefficient of dry and wet ageing wood was analysed by thermal property experiments. Using differential scanning calorimetry experiment, we appraised the change law of heat flow in the combustion process of dry and wet ageing wood, determined the characteristic peak intensity and stage continuous temperature of dry and wet ageing wood, and mastered the change characteristics of wood in different thermal release stages affected by dry and wet alternating ageing. Finally, the apparent activation energy distribution of ageing wood in different exothermic stages was calculated and analysed by isoconversion method. The influence mechanism of alternating dry and wet ageing on wood combustion thermal release behaviour was revealed. The results show that the main thermal release of dry–wet ageing is the stage of volatiles precipitation. The alternate ageing of dry and wet has the greatest impact on the energy demand of thermal response in the accelerated thermal release stage. The influence of alternating dry and wet ageing on different types of wood in the rapid exothermic stage is quite different. [ABSTRACT FROM AUTHOR]

In the process of poplar fermentation for ethanol, different methods are adopted to achieve efficient treatment and resource utilization of fermentation residues, which meets the current demand for green energy and carbon neutrality. Therefore, this work aims to establish an evaluation method on energy consumption, pollutant emissions, and cost expenditures in the production process for biofuels from poplar wood and residue. The process was simulated with commercial software (Aspen Plus for chemical production simulation and cost estimation and eBalance for LCA). Results showed that compared to FCE, it made a higher conversion efficiency of CFG because of the biojet fuel and gasoline from the gasification and conversion of residual lignin. And the flash evaporator, hydrolysis reactor, and fermentation reactor were components with the highest exergy loss. The economic cost of CFG was 9.63% less than that of FCE, and cellulase enzymes and poplar wood in variable costs were main factors in the total cost. Comparing environmental impacts from four perspectives, it was found that the total comprehensive impact of FCE was higher than that of CFG under each weight. The degree of influence of the first level indicator layer was energy consumption, environmental impact, and economic cost in descending order. [ABSTRACT FROM AUTHOR]

Reducing the ignition temperature of aromatic volatile organic compounds (VOCs) is a long-term pursuit for environmental pollution treatment and industrial application. In this paper, the toluene catalytic combustion was ignited at ultra-low temperature of 73 °C over a poplar wood monolithic catalyst with highly dispersed Pd particles coated by nano-thick graphited carbon layer via in-situ carbonization. Combing the characterizations and DFT calculations, the satisfying catalytic performance could be attributed to two aspects: (i) the unrestricted mass transfer of reactant and the high dispersity of Pd were simultaneously ensured in the straight micrometer-channel with abundant surface anchoring groups of poplar wood; (ii) the nano-thick graphited carbon layer on Pd significantly enhanced the oxygen activation. Given the low cost of economic wood and facile preparation technique, this work opened up new alternative for the preparation of highly dispersed noble metal catalyst and the low temperature catalytic combustion of aromatic VOCs in industry. [ABSTRACT FROM AUTHOR]

In this research, microblasting with powdered vegetable particles (almond and hazelnut husks, cork saw dust and rice husks) and cellulosic fibres was used to analyse their usefulness for cleaning unpainted wooden cultural heritage and their effects on surface morphology. Tests were made on mock-ups of old pine wood from wooden boards with original soiling. Before cleaning powdered particles were characterised by SEM–EDS to analyse their morphology and elemental composition. Wood surfaces were analysed before and after cleaning by means of digital microscope (white and UV light) and SEM–EDS to evaluate cleaning effectiveness, assess effects on the wood surface, and determine eventual soiling and powdered particles larger than 1 µm that might remain in the surface after the procedure. Results indicate that microblasting with powdered vegetable and cellulosic media is a useful and safe technique to remove soiling from wood, including micrometric particles embedded in its texture, with negligible surface changes. Furthermore, residues left after the cleaning procedure are very scarce and chemically compatible with the substrate because they are mainly composed of cellulose, hemicellulose and lignin, the main components of wood. [ABSTRACT FROM AUTHOR]

The differential swelling seen between softwood opposite wood (OW) and its neighbouring compression wood (CW) developed in branches prompts several engineering issues such as dimensional instability and cracking. For a more efficient use of resources, the inevitable CW and OW should not be discarded or used as fuel, but incorporated into engineered wood products. Swelling is a hygroelastic phenomenon, where both the swelling and elastic properties of CW and OW are needed in order to make proper structural predictions. In this paper, swelling coefficients and moisture dependent elastic moduli for both CW and OW in the three principal material directions are provided along with measurements of moisture content, density, and microfibril angle. The small deformations necessitate the use of precise X-ray micro-computed tomography for measurements. The results indicate that CW and OW from Norway spruce branches differ in swelling, especially in longitudinal direction at low moisture content. It is noted that CW is a wood type with less pronounced anisotropic behaviour than both OW and normal wood from the stem, with the elastic moduli less sensitive to moisture changes in both longitudinal and transverse directions. [ABSTRACT FROM AUTHOR]

Indoor pollution is a major health issue. In particular, urea pollution is drawing significant attention. Herein, we designed functional wooden window with the unique ability to photocatalytically degrade indoor pollutants, specifically urea. The transparent wooden window has been prepared via one-pot hydrothermal polymerization on a chemical-treated wood in order to incorporate resorcinol–formaldehyde. A hybrid wood denoted as resorcinol–formaldehyde-wood composite capable of photocatalytically degrading urea has been obtained. Mechanism study shows that the urea is degraded on composite interface via the as-formed hydroxyl radicals (·OH) generated from hydrogen peroxide. Further employing a large-scale (150 mm × 200 mm) resorcinol–formaldehyde-wood window for control of toilet urea pollution, a 100% urea removal efficiency was achieved in less than one hour. [ABSTRACT FROM AUTHOR]

Massive cultural objects made of wood are often situated in historic interiors in which they experience uncontrolled dynamic variations of relative humidity (RH). Although the objects usually have acclimatized to the natural climate variability, preventing risks related to any kind of modification of their environment requires an understanding of the object's response to the expected changes. In the present study, an analysis of the risk of cracking related to continuous or intermittent heating, or the transfer to hypothetically ideal conditions in a conservation studio was performed for the case of elements of Veit Stoss' altarpiece (1477–1489) preserved in St. Mary's Basilica in Krakow, Poland. Massive sculptures carved in lime wood and approximately one meter in diameter were analysed. The study aimed at determining safe margins of environment modifications that would not cause propagation of cracks that are known to have accumulated in wood during centuries of the altarpiece's existence. The mechanical properties of lime wood were determined experimentally to feed the numerical model. The energy release rates around the tips of cracks of various depths in a wooden sculpture were calculated using the finite element analysis and compared with the critical value of the parameter triggering the fracture propagation in the material, derived from the fracture energy measurement. It was shown that the church interior housing the altarpiece can be heated to 11 °C during the cold season to provide human comfort. The allowable duration of intermittent heating events to more comfortable 18 °C that would induce drops in RH of up to 40% was assessed as 12 h. The study demonstrated that moving the sculptures to the conservation studio would have to be done with extreme caution as it would be connected with risks depending on the depth of existing cracks and the duration of the RH change. [ABSTRACT FROM AUTHOR]

Pentachlorophenol (PCP) is a manmade chemical that is widely present in the environment and is mostly used as a wood preservative. Therefore, to conduct remediation studies, it is imperative to determine the most effective PCP analytical technique. PCP can be analyzed using a variety of analytical tools, including non-destructible methods like X-ray fluorescence spectrometry (XRF) and electrochemical sensors (EC), destructible tools like gas chromatography (GC), thin layer chromatography (TLC), colorimetry, ultraviolet–visible and infrared spectroscopy (UV–vis/IR), and high-performance liquid chromatography (HPLC). the colorimetric approach is less recommended because of its low sensitivity and precision, whereas TLC offers superior recovery rates and precision but is expensive, takes longer, and is unable to resolve complicated combinations. Higher recovery rates, sensitivity, precision, and superior separation are all offered by HPLC; however, its effectiveness is impacted by time, money, and solvent compatibility. The most favored destructible approach is GC because it is efficient in terms of both cost and time and offers superior precision and separation. Although XRF is frequently used in the wood industry to test PCP in treated wood and treating solutions, scientific research has avoided using it because of its high cost and ability to identify chemicals based only on their elemental composition—in the case of PCP, it is chloride. Among all methods, EC is shown to be more dependable than the other methods listed because it is extremely specialized, less expensive, and offers a faster response. It is possible to make more changes to the current analytical techniques, such as enhancing extraction techniques, creating a universal HPLC column, developing more affordable and high-precision EC electrodes, and evaluating a larger variety of samples from different matrices. This review has shed light on the many analytical tools available for determining PCP and the knowledge gaps in the field of study. [ABSTRACT FROM AUTHOR]

Highlights: An innovative class of versatile form-stable composite phase change materials (CPCMs) was fruitfully exploited, featuring MXene/phytic acid hybrid depositing on non-carbonized wood as a robust support. The wood-based CPCMs showcase enhanced thermal conductivity of 0.82 W m−1 K−1 (4.6 times than polyethylene glycol) as well as high latent heat of 135.5 kJ kg−1 (91.5% encapsulation) with thermal durability and stability throughout at least 200 heating and cooling cycles. The wood-based CPCMs have good solar-thermal-electricity conversion, flame-retardant, and electromagnetic shielding properties. Phase change materials (PCMs) offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization. However, for organic solid–liquid PCMs, issues such as leakage, low thermal conductivity, lack of efficient solar-thermal media, and flammability have constrained their broad applications. Herein, we present an innovative class of versatile composite phase change materials (CPCMs) developed through a facile and environmentally friendly synthesis approach, leveraging the inherent anisotropy and unidirectional porosity of wood aerogel (nanowood) to support polyethylene glycol (PEG). The wood modification process involves the incorporation of phytic acid (PA) and MXene hybrid structure through an evaporation-induced assembly method, which could impart non-leaking PEG filling while concurrently facilitating thermal conduction, light absorption, and flame-retardant. Consequently, the as-prepared wood-based CPCMs showcase enhanced thermal conductivity (0.82 W m−1 K−1, about 4.6 times than PEG) as well as high latent heat of 135.5 kJ kg−1 (91.5% encapsulation) with thermal durability and stability throughout at least 200 heating and cooling cycles, featuring dramatic solar-thermal conversion efficiency up to 98.58%. In addition, with the synergistic effect of phytic acid and MXene, the flame-retardant performance of the CPCMs has been significantly enhanced, showing a self-extinguishing behavior. Moreover, the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs, relieving contemporary health hazards associated with electromagnetic waves. Overall, we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs, showcasing the operational principle through a proof-of-concept prototype system. [ABSTRACT FROM AUTHOR]

The histogenesis of reaction wood in woody plants is a promising area of exploration for emerging wood technology products and for a generalized understanding of stress physiology. The activity of total protein and antioxidant enzymes were measured during the development of normal and reaction wood (opposite wood and tension wood) in the bole of poplar trees (Populous alba L.) induced by two levels of sustained bending stress to produce moderate and severe reaction wood. Four-year-old poplars were induced to produce reaction wood by sustained bending to 0, 35 and 80° from the vertical position. The activity of antioxidant enzymes was studied with repeated sampling during one growing season. Severe reaction wood showed higher levels of H2O2 and enzymes than moderate reaction wood. Tension wood showed a higher accumulation of total protein than opposite wood at the beginning and end of the bending treatment and opposite wood showed higher enzymatic activity. H2O2 and antioxidant enzymes were also sensitive to mechanical bending stress; compared to normal wood, tension wood and opposite wood which showed higher enzymatic activity coupled with higher amounts of total H2O2. Ascorbate peroxidase was more active than glutathione peroxidase in both tension and opposite wood at some periods of sampling. [ABSTRACT FROM AUTHOR]

Efficient forest operations are essential for forest enterprises, who provide wood and numerous ecosystem services for the society. Important factors influencing the efficiency of forest operations, and thus the harvesting costs, are the level of mechanization, the harvesting method applied, the forest road network, and the training of the labourers. The cost of labour, i.e. salaries, is another important driver of harvesting costs. However, its effect on and relative importance for overall harvesting costs is poorly described in the scientific literature. Thus, this study aims to analyse the influence of labour costs in more detail, especially on the country-wide wood harvesting potentials. In addition, we aimed to cross-compare the effect of labour costs with the effect of switching to a more efficient harvesting method. For this purpose, we calculated timber harvesting costs with varying salaries for all sample plots of the Swiss National Forest Inventory (NFI) for both, the currently applied harvesting method recorded in the NFI, and the potential best suitable harvesting method. A 1% change in labour costs affects harvesting costs by 0.33–0.77%, depending on the harvesting method applied. The influence is larger for systems that involve a large share of motor-manual work and for cable-based methods. Changing labour costs by ± 30% affects the number of plots for which timber harvesting is economically feasible, by 5 to 15 percent points. The effect of switching from the current to the best suitable harvesting method is comparable to that of reducing labour costs by 15–30%. These results indicate that the efficiency of wood harvesting can be increased with further mechanization and does not require cutting salaries of forestry personnel. In that, our results may inform forestry planning and policy making at regional to national level. [ABSTRACT FROM AUTHOR]

This study investigated techniques of coating zeolitic imidazolate framework-8 (ZIF-8) particles on the surface of blocks of pine (Pinus densiflora) and a method for effectively preventing termite access. ZIF-8 was synthesized by the reaction of 2-methylimidazole (2-MeIm) and Zn2+ in methanol media. Treatment of the wood blocks was carried out by immersing wood blocks in aqueous dispersions of ZIF-8 (0.1–0.3%) and in aqueous solutions of 2-MeIm (0.01–0.3%). Subterranean termite (Reticulitermes speratus) prevention experiments were carried out using choice and no-choice tests according to AWPA standard (E1-17). In the no-choice test, termites would not eat the wood block treated with aqueous dispersions of ZIF-8 prepared at a concentration of 0.1% or more, and all died within 28 days of the experiment, 100% mortality. In the choice test performed for 28 days, the termites did not eat the treated block and ate only the untreated wood block and showed the same low mortality as the control group, and there was no damage to the treated wood block. The results of experiments performed with wood blocks treated with 2-MeIm aqueous solutions were similar to those of ZIF-8. In conclusion, ZIF-8 and 2-MeIm showed very effective anti-termite agent performance. [ABSTRACT FROM AUTHOR]

Background: Wood products continue to store carbon sequestered in forests after harvest and therefore play an important role in the total carbon storage associated with the forest sector. Trade-offs between carbon sequestration/storage in wood product pools and managed forest systems exist, and in order for forest sector carbon modeling to be meaningful, it must link wood product carbon with the specific forest system from which the products originate and have the ability to incorporate in situ and ex situ carbon synchronously over time. Results: This study uses elements of a life cycle assessment approach, tracing carbon from US southern pine timber harvests to emission, to create a decision support tool that practitioners can use to inform policy design around land- and bioproduct-based mitigation strategies. We estimate that wood products from annual loblolly and shortleaf pine timber harvests across the southern US store 29.7 MtC in the year they enter the market, and 11.4 MtC remain stored after 120 years. We estimate fossil fuel emissions from the procurement, transportation, and manufacturing of these wood products to be 43.3 MtCO2e year−1. We found that composite logs, used to manufacture oriented strand board (OSB), were the most efficient log type for storing carbon, storing around 1.8 times as much carbon as saw logs per tonne of log over 120 years. Conclusions: Results from our analysis suggest that adjusting rotation length based on individual site productivity, reducing methane emissions from landfills, and extending the storage of carbon in key products, such as corrugated boxes, through longer lifespans, higher recycling rates, and less landfill decomposition could result in significant carbon gains. Our results also highlight the benefits of high site productivity to store more carbon in both in situ and ex situ pools and suggest that shorter rotations could be used to optimize carbon storage on sites when productivity is high. [ABSTRACT FROM AUTHOR]

Trees in breeding programmes are often selected at 1/4–1/3 of rotation, called 'early selection', which is typically between 8 and 10 years in radiata pine. However, differences between populations and genotypes selected for either basic density or wood stiffness are already apparent at age 2. We report the application of very early screening techniques for wood properties in the New Zealand Radiata Pine Breeding Programme deployment populations. Approximately 3000 trees representing three populations with 92 families and 10 clones were grown in a common garden trial, leaning for 21 months to separate compression and opposite wood. The trees were harvested and analysis carried out separately by wood type. The trial showed the existence of large variability in wood properties at early age, in some cases similar to variability near rotation age, and moderate to high degree of genetic control ( 0.35 ≤ h 2 ≤ 0.71 ). The genetic association between traits was strong, particularly between wood stiffness and longitudinal shrinkage ( - 0.69 ) and between longitudinal and volumetric shrinkage (0.83), suggesting that improving stiffness would also have a strong effect on improving dimensional stability. Basic density was also associated with stiffness and shrinkage, but with lower predictive capacity. These results can be used for roguing deployment populations-which already contain superior growing trees-and quickly upgrade the wood quality of seeds and clones currently available to New Zealand forest growers. We discuss necessary modifications to turn this research work into operation to screen any new material before commercial release. [ABSTRACT FROM AUTHOR]

The aim of this work is to evaluate two quantitative methods, based on the external calibration applied in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis, known as (i) analytical curve and (ii) one-point calibration, using the concept of matrix matching to quantify three potentially toxic elements (PTEs) in wood samples. These can biologically register changes in the abiotic environment and be applied to monitoring climate change or environmental toxicity. In this case, standard sample preparation was evaluated to prepare the standard pellets using Pinus taeda species as a matrix-matching concept. Six pellets of P. taeda, with different Pb, Cd, and Ba concentrations, were prepared to build the analytical curve and one-point calibration strategies. The LA-ICP-MS parameters were optimised for 206Pb, 208Pb, 112Cd, 114Cd, 137Ba, and 138Ba isotope analysis in wood samples. The two calibration strategies provided 74–110% analytical recovery from certified reference materials and similar results to those obtained by ICP-MS through the acid digestion of environmental wood samples from São Paulo City (Brazil). This demonstrated the applicability of the one-point calibration strategy in quantifying PTEs in wood samples, which could be used with environmental analyses. Differences observed between the Ba isotope results obtained via LA-ICP-MS and ICP-MS quantification were related to sampling by LA-ICP-MS and the ICP-MS sample introduction, as well as to laser matrix and transport effects because of the difference between the wood species evaluated. [ABSTRACT FROM AUTHOR]

Wood is a primary building tool for ancient buildings and structures, but for those that survive to date, naturally aged wood may pose a noteworthy fire hazard. There are potential risks to health, safety, and substantial cultural loss if fire risks in such buildings are not mitigated. We obtained several samples of aged wood commonly used in ancient structures (elm, pine, and aspen), and compared the kinetic and thermal characteristics to fresh wood examples to determine potential methods of enhancing safety. Differential scanning calorimetry was used to establish the heat release characteristics of the fresh and aged samples, and the characteristics of the thermal reaction stages were characterized using the temperature range and heat release laws for each reaction stage. The heat release characteristics during combustion were investigated for different heating rates, and the influence of aging on temperature change and heat release rate characteristics during different exothermic stages was assessed. Finally, using heat flow data, the apparent activation energy (AAE) of the samples and their distributions during different exothermic stages were calculated and analyzed via the Friedman differential iso-conversion method. Results showed that the exothermic energy of the aged samples was higher than that of the fresh samples, indicating that aging does impact the thermal reaction process. The aged samples in this study had a greater heat diffusion capacity, transmitted more heat, were more susceptible to burning (by spreading that heat), and generally posed a greater fire hazard. During the rapid exothermic phase, the AAE of aged wood increased as the reaction progressed, and exhibited lower AAE with a greater sensitivity to fire than fresh samples. A sound linear relationship between pre-exponential factor and AAE and the kinetic compensation effect was obvious. This study provided a rudimentary theoretical basis for the prevention of fires in timber-framed ancient buildings. [ABSTRACT FROM AUTHOR]

Developing a moisture-stable structural material with high toughness is essential for improving the stability of packaging and building materials. Wood is a pervasive structural material with naturally good mechanical properties. However, insufficient moisture stability and toughness compromises its safety and structural requirements. Herein, we constructed a moisture-stable wood veneer with high toughness by assembling the choline chloride-ethanolamine delignified wood with alkali lignin, followed by hot-pressing to densify the material. Lignin can be assembled into the microchannel of the delignified wood as a filler and binder for reducing molecular transportation and increasing internal bonding. The enhanced tensile strength (582.0 MPa) and strain (3.6%) are accompanied by a significant increase in the toughness to 11.1 MJ/m3, which is 37 times higher than that of natural wood. The excellent mechanical property can be preserved to a large extent after retaining in tropic moisture conditions (38 °C, 90% RH) with retention of 66.2% and 60.8% for tensile strength and toughness, respectively. A stable water contact angle on the surface and limited water adsorption of reconstructed wood indicate a lowered water infiltration velocity, suggesting highly improved moisture stability as needed for structural materials. [ABSTRACT FROM AUTHOR]

In Japanese households, it is customary to walk barefoot on wooden floors. Previous reports on the psychological and physiological relaxing effects of feet contact with uncoated solid wood have already been published. However, there are no studies on the effects of feet contact with coated wood, which is commonly used for residential floors. This study aimed to validate the psychological and physiological relaxing effects of sole contact with oil-finished wood. In total, 27 women university students (mean age: 21.9 ± 1.9 years) participated in this study. Psychological indices such as the modified semantic differential method and the Profile of Mood States Second Edition were used. The oxyhemoglobin (oxy-Hb) concentrations in the prefrontal cortex were determined using near-infrared time-resolved spectroscopy. The sympathetic nervous activity and the parasympathetic nervous activity were measured using heart rate variability. The flat plate for tactile stimulation was oil-finished wood, and uncoated wood and marble were used for comparison. The sole of the feet of each participant touched each material for 90 s. Feet contact with oil-finished and uncoated wood had relaxing effects on psychological and physiological responses compared with marble. The relaxing effects of oil-finished wood and uncoated wood were similar. That is, they significantly increased subjective feelings of comfort and relaxation, improved mood states, and decreased oxy-Hb concentration in the left prefrontal cortex compared with marble. However, there were no statistically significant differences in terms of right prefrontal cortex and sympathetic nervous activities between oil-finished wood and marble. Oil-finished wood had a slightly weaker physiological relaxation effect than uncoated wood. [ABSTRACT FROM AUTHOR]

Owing to variation of moisture content, the larch wood basic density near-infrared (NIR) prediction model shows reduced accuracy and robustness, or even model failure. To solve this technical problem, a multi-verse-algorithm-optimized BP neural network (MVO-BPNN) prediction model is proposed to improve the accuracy of the model. The preprocessing effects of the Savitzky–Golay smoothing, detrending, and 15-point moving average smoothing method were compared. The synergy interval partial least squares was used to extract the feature bands of the NIR spectra. Results showed that the prediction model based on MVO-BPNN was better than those based on BPNN and the genetic algorithm-optimized BPNN. It indicated that the NIR model based on the MVO-BPNN could effectively predict the basic density of wood with different moisture contents. [ABSTRACT FROM AUTHOR]

Considering the bioactive composition and therapeutic interest of Ficus carica, much research has been conducted on its fruits and leaves. However, there has been relatively little investigation regarding the wood bark, despite its potential as a rich source of phytochemical compounds with diverse biological activities. The aim of this work is the determination of the phenolic composition of the wood bark extracts of F. carica from three cultivars (Aberkane, Aghanime, and Bakour) and the assessment of their potential cytotoxicity and bioactive capacities such as antioxidant, anticancer, and anti-inflammatory activities. The phytochemical compounds were identified and quantified using UPLC-ESI-MS. The results revealed that Aberkane wood bark cultivar had the highest content of total polyphenols and ascorbic acid, while Aghanime cultivar had the highest content of flavonoids. The wood bark of the Aberkane cultivar exhibited the highest DPPH and ABTS scavenging activities (48.55% and 71.81%, respectively). This extract exhibited strong cytotoxic effects against cancer cell lines MCF-7 (IC50 143.30 µg/mL) and carcinoma HepG2 (IC50 240.18 µg/mL), as well as potent anti-inflammatory activity demonstrated by the BSA assay and inhibition of NO production in RAW 264.7 cells. Aghanime wood bark extract exhibited the highest ORAC value (446.078 µmol TE/g). However, the Bakour wood bark cultivar was particularly noteworthy for its iron-chelating properties. The UPLC-ESI-MS analysis revealed the presence of various phenolic compounds, notably chlorogenic acid and rutin. These findings demonstrate that the wood bark extract of fig possesses a diverse range of beneficial biological activities, which are associated with its phytochemical composition. [ABSTRACT FROM AUTHOR]

Wood is a structural material of biological origin that undergoes thermal degradation when exposed to high temperatures. Additionally, wood shows an anisotropic behavior in terms of thermal expansion and thermal conductivity along and across fiber direction. This work reports thermophysical measurements of beech wood from room temperature up to 900 °C. The wooden material was investigated in different states: moist, dry, charred and during pyrolysis. A push-rod dilatometer was used to measure thermal expansion, from which temperature dependent density was derived. Specific heat was determined by differential scanning calorimetry. A laser flash apparatus was applied to measure thermal diffusivity. Thermal conductivity was calculated from thermal diffusivity, specific heat, and density. The measurements of thermal expansion and thermal diffusivity were performed along and across fiber direction to consider the anisotropic behavior of wooden material. The results of the thermophysical properties are reported from room temperature to 200 °C for the beech wood, during pyrolysis, and up to 900 °C for the charred material. It was found that thermal expansion of beech wood across fiber direction is greater than along fiber direction in the order of a magnitude. In contrast, thermal expansion of charred material is rather independent on fiber direction. Thermal conductivity of beech wood along fiber direction was found to be approx. 2 to 3 times higher than across fiber direction. In the case of the charred material the relative difference is smaller. [ABSTRACT FROM AUTHOR]

Optically transparent wood has been fabricated by structure-retaining delignification of wood and subsequent infiltration of thermo- or photocurable polymer resins but still limited by the intrinsic low mesopore volume of the delignified wood. Here we report a facile approach to fabricate strong transparent wood composites using the wood xerogel which allows solvent-free infiltration of resin monomers into the wood cell wall under ambient conditions. The wood xerogel with high specific surface area (260 m2 g–1) and high mesopore volume (0.37 cm3 g–1) is prepared by evaporative drying of delignified wood comprising fibrillated cell walls at ambient pressure. The mesoporous wood xerogel is compressible in the transverse direction and provides precise control of the microstructure, wood volume fraction, and mechanical properties for the transparent wood composites without compromising the optical transmittance. Transparent wood composites of large size and high wood volume fraction (50%) are successfully prepared, demonstrating potential scalability of the method. Optically transparent wood composites are commonly prepared by delignification of wood and subsequent infiltration of thermo- or photocurable polymer resins but the fabrication is still limited by the intrinsic low mesopore volume of the delignified wood. Here, the authors report a facile approach to fabricate transparent wood using wood xerogel which allows solvent-free infiltration of resin monomers into the wood cell wall under ambient conditions.' [ABSTRACT FROM AUTHOR]

Today, using one-component polyurethane (1c-PUR) adhesives in the manufacturing of engineered wood products from spruce is common practice. However, the use of other wood species can require the application of a primer to fulfill normative requirements. Previous research shows the primers' effectiveness, especially in moist environments. However, the primers' exact mode of action remains not yet fully understood. We hypothesize a reduction in the hygroscopic behavior of the primer-treated wood—intensity and kinetics—that could reduce the formation of stresses in the bond line region. To test this hypothesis, two commercially available primers, based on Polysorbate 20 and poly(ethylene glycol), and the hydroxymethylated resorcinol (HMR) primer are examined with wood from beech, birch, larch, and Douglas fir. Swelling experiments show that of each primer a portion infiltrates and swells the wood cell walls, affecting the wood's hygroscopic and mechanical properties. In stepwise sorption experiments, it is seen that the primers influence differently the amount of moisture uptaken by the wood (adsorption). The rate at which the moisture spreads within the wood (diffusivity) also changed differently for the primers, while the rate at which the moisture moves through the wood (permeability) remains unchanged. The application of all primers improves the bulk flow behavior and thus the void penetration of the adhesive into the lumina in the interphase region, which in turn leads to a reduced bond line thickness. All three primers improve the tensile shear strength. The hygroscopic changes caused by the primers appear too small to be claimed as the sole and primary cause of their functionality, whereas more relevance is seen in the primers' cell wall infiltration and the increased adhesive's void penetration. [ABSTRACT FROM AUTHOR]

Poor dimensional stability, sensitivity to microorganisms, and flammability restrict the application of wood in certain areas where these properties are critical. Although furfurylation can improve the physical and mechanical properties of wood, the heat and smoke release of furfurylated wood during combustion are dramatic and need to be addressed. As a kind of halogen-free phosphorus flame retardant, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives exhibit excellent performance in polymer composites. In this study, DOPO was dissolved in furfuryl alcohol (FA) and used to modify wood. The effect of DOPO on the thermal stability, combustion behavior, and physical and mechanical properties of furfurylated wood was investigated. The chemical structure, morphology, and char residue after combustion were also characterized. The studies show that DOPO can react with the FA polymer and is incorporated and homogeneously dispersed in the wood structure. Compared to untreated wood, furfurylated wood has a much higher heat and smoke release during combustion. The addition of DOPO remarkably reduces the heat release of furfurylated wood, and this effect increases as the amount of DOPO increases. When the amount of introduced DOPO of furfurylated wood is 7%, its total heat release is reduced by 37.4% and becomes comparable to the untreated wood. However, DOPO does not suppress smoke production effectively. DOPO improves the thermal stability of furfurylated wood by promoting char formation and inhibiting the diffusion of oxygen and the escape of pyrolysis products. The addition of DOPO has little effect on the physical and mechanical properties of furfurylated wood. The results indicate that the combination of DOPO and furfurylation could be an efficient way to prepare highly stable and fire-resistant wood materials. [ABSTRACT FROM AUTHOR]

Recent advances in wood treatment include the use of eco-friendly coatings to improve the wood's dimensional stability and appearance. Assessing coating performance during its service life is critical for establishing a knowledge base for product optimization. Numerous approaches, including microimaging, are available for analyzing coating behavior. In addition to conventional microscopic techniques, high-resolution X-ray microtomography is a tool that provides nondestructive imaging of coatings and their substrates. In this study, we performed two-dimensional (2D) and three-dimensional (3D) visualization of tomographic reconstruction images of two coating types, spray and brush, to observe and assess the distribution of several commercial Japanese coating materials in Fagus crenata. X-ray images and plot profiles were used to determine the penetration depths and thicknesses of coatings. Each coated sample was scanned using X-ray microtomography, which allowed successful visualization and quantification of the coating penetration depth. Chemical content and concentration of the coating materials influenced penetration depth and amount. [ABSTRACT FROM AUTHOR]

Fireproof coatings are the simplest, most efficient, and oldest method for protecting a wide range of flammable products, such as wood. Furthermore, surface ignition is the initial phase, so surface protection is essential to reduce fire propagation. Furthermore, delaying the spread of flames can help to save someone when a fire starts. This project synthesized flame-resistant resin starting from tetraallyloxysilane monomer as a halogen-free monomer, an intrinsic flame retardant co-curing agent. The following step synthesized polyester resin using terephthalic acid as a heat-resistant resin. Unsaturated polyester was used by bulk radical polymerization. FT-IR and 1H-NMR analysis showed the successful synthesis of the desired monomer and polymeric compound. The thermal degradation and flame retardancy of pure unsaturated polyester resin (UPE) and allyloxysilane-unsaturated polyester (AUPE) were investigated by thermogravimetric analysis (TGA/DTG/DSC). The burning test and the thermal stability of the coating layers were evaluated using standard UL 94. Physical properties of resins were evaluated using Heat Deflection Temp tests (HDT) ISO 75-A, ASTM 648, Hardness ASTM D2583, Volumetric shrinkage ASTM 3521, and Water absorption ASTM D570. The results of the tests show the successful synthesis and their flame retardant properties. [ABSTRACT FROM AUTHOR]

The current study aims to improve the thermal and energetic performances of building materials used in construction field and especially to meet the heating and cooling needs required by the Moroccan thermal building regulations (RTCM 2015). The study aims to investigate the possibility of incorporating wood ashes or crushed waste from traditional pottery into the formulation of eco-friendly bricks. Laboratory-scale experiments were conducted on different mixtures to determine the optimal dosage that would result in optimal thermal characteristics for the brick blocks. The percentage of wood ashes and crushed pottery waste was varied from 0 to 50% relative to the total mass of the dry mixture. Samples of the clay were used to create brick blocks and cylindrical specimens with dimensions of 5 cm in diameter and 10 cm in height. The optimal dosage of wood ashes was found to be 5% in combination with the clay. The addition of crushed pottery waste improved the absorption of these blocks, and the highest thermal resistance values were recorded with a dosage of 20% pottery waste. By replacing 5% of the clay with wood ashes or 20% with crushed pottery waste, it was possible to produce eco-friendly blocks with an increase in thermal resistance comparable to that of traditional building materials. In addition, simulations study of the dynamic thermal behaviour of a room with a single thermal zone was investigated in order to determine the effect of the introduced building material on heating and cooling loads in Morocco. Two climate zones are considered: Agadir recognized by its humid climate (zone 1) and Marrakech city recognized by its dry climate (zone 5). The study aims to compare numerically the heating and cooling demands of hollow brick, hollow block as a common construction material and a comparison with using the introduced material as an energy-efficient material. The results found show that the studied composite material meets the requirements of thermal regulation in building of Morocco (RTCM2015). [ABSTRACT FROM AUTHOR]

The anatomical structure of the annual rings of Scots pine, formed before and after the Kyshtym accident, is analyzed. In trees growing closer to the central axis of the East Ural radioactive trace (EURT), a decrease in the number of cells in the annual ring, as well as a decrease in the diameter of the lumens and the thickness of the cell walls, was noted. It is assumed that radiation-induced damage to the photo-assimilation apparatus of trees led to disturbances in physiological processes that were reflected in the anatomical structure of wood. [ABSTRACT FROM AUTHOR]

During the dehydration of waterlogged archaeological wood (WAW), shrinkage inevitably occurs due to capillary force and hydrogen bond recombination as WAW loses free and adsorbed water. Existing drying techniques, including solvent displacement, freeze-drying, and supercritical fluid drying, only take effect by reducing or eliminating the surface tension of liquid. Nonetheless, the contribution of hydrogen bond recombination in shrinkage has long been neglected and a countermeasure concerning this problem is needed. In this study, we propose a simple aqueous phenylboronic acid (PBA) treatment that can help improve dimensional stability and reduce hygroscopicity of WAW. Analysis by Fourier transform infrared spectroscopy, density functional theory calculation and dynamic vapour sorption reveal that PBA can incorporate with hydroxyl groups (–OH) on cellulose through coordination and hydrogen bonds, occupy the water-cellulose binding sites, and possibly inhibit the formation of hydrogen bonds between adjacent cellulose chains. [ABSTRACT FROM AUTHOR]

In the engine of heavy trucks, the built-in fuel filter assumes the role of "lungs". The core of the filter, namely the fuel filter paper, acts as a filter for small impurities and separates oil and water. In order to be able to separate minute impurities from the fuel, in this study, we prepared a novel fuel oil filter paper with high efficiency and high dust holding capacity based on wet-laid forming by laminating PBT/PP two-component melt-blown nonwoven material and cellulose nanocrystals (CNC)-doped cellulose wood fiber pulp with the fiber mesh combination forming technology. The effects of the CNC mixing ratio, surface density of melt-blown nonwoven material layer, surface density of cellulose wood pulp paper layer and calendaring pressure on the pore size and filtration performance of the composite samples were investigated, and the filtration efficiency of the composite samples on the tiny impurities in the fuel were also studied. The results showed that the novel composite fuel filter paper material prepared by the combined forming technology of fibrous web had high filtration efficiency and dust holding capacity, and the filtration efficiency of the composite samples could respectively reach 99.90% and 99.52% for particles larger than 14 μm and 4 μm in diameter in the fuel. At the same time, the dust holding capacity of the composite sample can reach up to 27.63 mgcm−2. [ABSTRACT FROM AUTHOR]

This paper describes the development and characterisation of wood-filled polylactic acid (PLA) composite filaments for application in fused filament fabrication three-dimensional (3D) printing. Four different wood-polymer composite filaments for 3D printing were prepared, and specimens were 3D-printed with the obtained materials. The composite filaments consisted of wood particles (10% or 20% mass ratio) and a PLA polymer matrix. Wood particles were prepared by grinding and sieving non-modified beech wood and thermally modified (TM) (at 200 °C) beech wood. Thermal modification of wood affected particle preparation and smaller particles with lower aspect ratios were obtained. Filaments with TM wood particles were extruded better than with non-modified wood particles, with lower surface roughness and lower porosity. With a higher wood ratio, the surface roughness and porosity of the filament increased. Non-homogenous filaments also affected extrusion in 3D printing and reduced the properties of 3D-printed parts. Parts 3D-printed from filaments with TM particles had better tensile strength than from filaments with non-modified particles, but were lower than from pure PLA filaments. The tensile strength of the injection-moulded specimens was 18–69% higher than that of the 3D-printed specimens, depending on the filament composition. The results indicate some positive effects of thermal modification of wood particles on the properties of filaments and 3D-printed parts. Nevertheless, further optimisation of particle preparation and extrusion parameters is needed to obtain quality filaments with this size of wood particles. [ABSTRACT FROM AUTHOR]

To solve the problem of poor texture decorative effects and inferior functional properties of a fast-growing wood, a combined dyeing and superhydrophobic modification method was proposed and applied. The pretreated wood (P-wood) was dyed based on the permeability variation of the earlywood and latewood. After the dyeing of the wood, the variation in color between the earlywood and latewood was significantly enhanced, and the value of texture contrast of the wood increased from 19.15 to 61.43, indicating that the texture decorative effect of the wood was effectively improved. Furthermore, dyed-superhydrophobic wood (DS-wood) was fabricated by depositing a superhydrophobic coating on the surface of dyed wood (D-wood) to improve its functional properties. The contact angle (WCA) and sliding angle (SA) of the wood were 153.1° and 7°, respectively. Because of the protection of superhydrophobic coating, the wood exhibited excellent color fastness to washing and light aging. In addition, DS-wood exhibited superior thermal stability and physical–mechanical properties. Additionally, DS-wood exhibited excellent abrasion resistance and chemical stability. This modification method of functional wood is simple, inexpensive, and environmentally friendly and has great potential for architectural and furniture applications. [ABSTRACT FROM AUTHOR]

This article sets out to analyse how and why the wood industry in France has recently responded to various calls for its economic models to fit better with the demands of climate change and ecological transition. By adopting a 'politics of industry' approach to the linkages between business practices and their regulation by the European Union, the state, and regional authorities, it unpacks the structuration of this industry, then examines the political work undertaken either to change or conserve it. The study draws upon interviews with public, private, and collective actors from throughout the industry, documentary analysis, and observation of stakeholder meetings. First, we show that in this industry, access to markets and to its factors of production (natural and financial capital) has indeed become increasingly driven by environmental criteria and practices of ecological planning. Second, however, the industry is still struggling to make its productive models fit with an institutional order that has only partially transitioned in this direction. In endeavouring to make productive models and this institutional order match up, key actors in the industry are still working politically to reach three objectives that are often contradictory: (i) build cohesion within the industry aligned with decarbonization ambitions, (ii) re-organize value chains that respond to calls for more national sovereignty for wood, and (iii) maintain ties between a productivist model that has taken on board ecological constraints and another, essentially conservationist, one which still resists change to the very definition of the overall objectives of the industry. [ABSTRACT FROM AUTHOR]

For the utilization of silver birch (Betula pendula Roth) in load-bearing engineered wood products (EWPs), reliable bonding in production is a prerequisite. The current knowledge regarding the bonding of birch in EWP applications is limited. Extractives are considered a general factor of attention when securing bonding quality. Thus, in this study, the effects of hydrophilic extractives on several adhesion-related bulk and surface properties of silver birch wood were studied, e.g., vapor sorption, swelling behavior, microstructure, wettability, and mechanical properties. The extraction procedure slightly affected vapor sorption causing a reduction in swelling pressure. The extraction also led to a lower Young's modulus, as seen by compression tests. Control experiments with vapor-treated specimens, however, indicated that the effects were originating from the water imbibition and not due to the removal of extractives per se. This was supported by X-ray diffraction results, which were similarly affected by both vapor and extraction treatment. Therefore, the results indicate that the hygric history of the specimens was affecting the wood due to plasticization, increasing mobility, and thereby likely allowing biopolymer reconfiguration and subsequent quenching during re-drying, even though surface-free energy and wettability were not considerably affected. The extent to which these changes appear permanently or temporarily remains an open research question. [ABSTRACT FROM AUTHOR]

While the succession of terrestrial plant communities is well studied, less is known about succession on dead wood, especially how it is affected by environmental factors. While temperate forests face increasing canopy mortality, which causes considerable changes in microclimates, it remains unclear how canopy openness affects fungal succession. Here, we used a large real-world experiment to study the effect of closed and opened canopy on treatment-based alpha and beta fungal fruiting diversity. We found increasing diversity in early and decreasing diversity at later stages of succession under both canopies, with a stronger decrease under open canopies. However, the slopes of the diversity versus time relationships did not differ significantly between canopy treatments. The community dissimilarity remained mainly stable between canopies at ca. 25% of species exclusively associated with either canopy treatment. Species exclusive in either canopy treatment showed very low number of occupied objects compared to species occurring in both treatments. Our study showed that canopy loss subtly affected fungal fruiting succession on dead wood, suggesting that most species in the local species pool are specialized or can tolerate variable conditions. Our study indicates that the fruiting of the fungal community on dead wood is resilient against the predicted increase in canopy loss in temperate forests. [ABSTRACT FROM AUTHOR]

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

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

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

In this study, activated PLA/olive wood flour (OWF) composite films were prepared by a solvent casting process with different wood flour contents (0, 1, 3, 5 and 10 wt%). 3% Cinnamon Essential Oil (CEO) is incorporated into the biocomposite film to impart antimicrobial activity. OWF and CEO properties were examined using FTIR and total phenol quantification. Biocomposite films with and without CEO were tested by FTIR and tensile strength. The antimicrobial activity of biocomposite films was tested against four types of fungi and five types of bacteria. CEO and OWF extracts physically interact with PLA, affecting its mechanical and antimicrobial properties. In addition, only 1% of OWF and CEO achieved better performance. The best antifungal inhibition against A. flavus and F. oxysporum was observed in the case of 10% of OWF, and the best antibacterial activity for P. aeruginosa and S. aureus was observed for OWC0 films. The combined use of OWF and CEO showed synergistic antifungal properties. Overall, low content of OWF and CEO could bring antibacterial and antifungal activities to biocomposite PLA/OWF biofilms with satisfactory mechanical properties. The primary use of these films is cereal packaging applications. [ABSTRACT FROM AUTHOR]

In this study, hydrophilic cellulosic wood (Tectona grandis) is modified into superhydrophobic wood with the aid of octadecyltrichlorosilane (OTS) and silica nanoparticles (SiO2) using one-step facile method. The prepared superhydrophobic wood possessed water contact angle (WCA) of 167 ± 2° and the sliding angle was less than 4°. The surface morphology was examined by scanning electron microscopy (SEM) and it showed agglomeration of nanostructures on the surface of superhydrophobic wood. Fourier transform infrared spectroscopy was used to analyse the functional groups present on the produced wood, and the results showed the existence of – CH 2 and – CH 3 groups. The exceptional self-cleaning and stain resistance of modified wood made it suitable for a variety of applications. Also, it is mechanically durable as it underwent and sustained tape peeling, sand abrasion and water jet impact. The modified wood demonstrated excellent durability in exposure to UV and on exposure to solutions of varying pH. This makes the fabricated wood suitable for various applications. [ABSTRACT FROM AUTHOR]

As the amount of oily wastewater discharged from industrial and domestic sources increases, materials used for oil/water separation have received widespread research attention in recent years. However, many reported separation materials with special wetting properties require complex and environmentally unfriendly preparation processes. Therefore, green and efficient materials for oily wastewater and emulsion separation are urgently needed. In this paper, inspired by the scrobiculate and honeycomb-shaped porous structure of natural balsa wood, functionalized wood was designed as an oil/water separation and emulsion purification material by delignification and a simple surface modification process. A deep eutectic solvent (DES) was used to remove the lignin and hemicellulose components. Sodium carboxymethyl cellulose (CMC) and chitosan quaternary ammonium salt (CQA) were used to functionalize and obtain the superhydrophilic/underwater superoleophobic wood material. The water contact angle of the functionalized wood in air reached 0°, while the underwater contact angles for different kinds of oil were greater than 150°. Various oils were effectively separated with a high separation efficiency (> 99.2%). Moreover, the separation efficiency of kerosene from water still reached 99.5% after 30 separation test cycles. After long-term immersion in different pH and salt solutions, the separation efficiency for a kerosene/water mixture was still greater than 99%. Rapid and continuous oil/water separation was achieved conveniently. More importantly, the selective wetting properties and complex porous structure of the functionalized wood enabled the purification of unstable and surfactant-stabilized oil-in-water emulsions with high separation efficiencies. The functionalized wood material also showed promising antibacterial properties, with a good inhibitory effect on the growth of both Gram-positive S.aureus and Gram-negative E.coli. This will effectively prevent contamination and the decrease in separation efficiency caused by mold on the surface. Therefore, this green, efficient, easily prepared, and durable functionalized wood shows excellent potential for application as a separation material for oily wastewater. [ABSTRACT FROM AUTHOR]

Forest management allows the sustained removal of significant amounts of carbon from the atmosphere. Within different activities in the forest, wood utilisation has the most significant man-made environmental impact which affects the carbon balance, which is important to know, to be able to accurately identify its role in climate change. This study aims to determine the carbon footprint of logging during utilisation based on scenario analysis in national default and theoretical assortment structures (11 additional scenarios for each forest stand) within the entire life cycle of raw wood products. Based on a common functional unit (100 m3 of cut wood), a comparative environmental life cycle analysis (LCA) for intermediate and final cutting was performed in shortwood forestry work systems in beech (Fagus spp.), oak (Quercus spp.), spruce (Picea spp.), black locust (Robinia pseudoacacia), and hybrid poplar (Populus x euramericana) stands in Hungary. After obtaining the results, the present study calculated the carbon footprint order for the utilisation life cycle phases and the entire tree utilisation life cycle. The distribution of absolute carbon footprint (ACF: considered emitted CO2 from fossil and biotic origins together) by final cutting exhibited the following order: hybrid poplar (6%)—spruce (8%)—beech (26%)—oak (27%)—black locust (33%). The ACF ranking for the whole technological life cycle (intermediate and final cutting, 400 m3 of cut wood) was hybrid poplar– spruce—oak—beech–black locust. The carbon footprint rankings of the studied stands were expanded to the national level. [ABSTRACT FROM AUTHOR]