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Machine learning classifiers are increasingly widely used. This research note explores how a particular widely used classifier, the Random Forest, performs when faced with samples which are imbalanced and noisy data. Both are known to affect accuracy, but if their effects are independent or not has not been explored. Based on an experiment using synthetic data generated for the study we find that the effects of noise and sample balance interact with each other; classification accuracy is worse when faced with both noisy data and sample imbalance. This has implications for the use of RF in market research, but also for how methods to address either sample imbalance or noise are assessed. [ABSTRACT FROM AUTHOR]

Cellulose, as the most abundant natural polymer on Earth, has long captured researchers' attention due to its high strength and modulus. Nevertheless, transferring its exceptional mechanical properties to macroscopic 2D and 3D materials poses numerous challenges. This review provides an overview of the research progress in the development of strong cellulose-based materials using both the "bottom-up" and "top-down" approaches. In the "bottom-up" strategy, various forms of regenerated cellulose-based materials and nanocellulose-based high-strength materials assembled by different methods are discussed. Under the "top-down" approach, the focus is on the development of reinforced cellulose-based materials derived from wood, bamboo, rattan and straw. Furthermore, a brief overview of the potential applications fordifferent types of strong cellulose-based materials is given, followed by a concise discussion on future directions. [ABSTRACT FROM AUTHOR]

Large tropical trees are rightly perceived as supporting a plethora of organisms. However, baseline data about the variety of taxa coexisting on single large tropical trees are lacking and prevent a full understanding of both the magnitude of biodiversity and the complexity of interactions among organisms in tropical rainforests. The two main aims of the research program "Life on Trees" (LOT) are (1) to establish baseline knowledge on the number of eukaryote species supported/hosted by the above-ground part of a single tropical tree and (2) to understand how these communities of organisms are assembled and distributed on or inside the tree. To achieve the first goal, we integrated a set of 36 methods for comprehensively sampling eukaryotes (plants, fungi, animals, protists) present on a tropical tree. The resulting LOT protocol was conceived and implemented during projects in the Andean Amazon region and is proposed here as a guideline for future projects of a similar nature. To address the second objective, we evaluated the microclimatic differences between tree zones and tested state-of-the-art terrestrial laser scanning (TLS) and positioning technologies incorporating satellite and fixed base station signals (dGNSS). A marked variation in temperature and relative humidity was detected along a 6-zones Johansson scheme, a tree structure subdivision system commonly used to study the stratification of epiphytic plants. Samples were collected from these six zones, including three along the trunk and three in the canopy. To better understand how different tree components (e.g., bark, leaves, fruits, flowers, dead wood) contribute to overall tree biodiversity, we categorized observations into communities based on Johansson zones and microhabitats. TLS was an essential aid in understanding the complex tree architecture. By contrast, the accuracy of positioning samples in the tree with dGNSS was low. Comprehensively sampling the biota of individual trees offers an alternative to assessing the biodiversity of fewer groups of organisms at the forest scale. Large old tropical trees provide a wealth of microhabitats that encompass a wide range of ecological conditions, thereby capturing a broad spectrum of biodiversity. [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]

The separation of leaf and wood points remains challenging due to the diversity of tree species and structures. We propose an automatic leaf-wood separation method from tree point clouds, leveraging trees' shape information, growing patterns, and topological information for higher separation accuracy. First, the tree point clouds are roughly classified into initial planar, linear, and scattered points based on the dimensional structure of each point. Then, a slicing strategy combined with the DBSCAN (density-based spatial clustering of application with noise) clustering algorithm is used to exploit the potential wood clusters in each layer. A novel dynamic region growing algorithm based on an energy function is proposed for extracting tree trunk and large branches from initial planar points, incorporating the geometric features and growing patterns of trees. Finally, a novel inner-to-outer region growing method is proposed to extract the tiny branches based on voxel density and the principal direction. Twelve tree samples covering twelve species and locating tropical, temperate, and boreal areas are used to evaluate the method's performance. The mean separation accuracy and kappa coefficient of the proposed method are 0.942 and 0.805, respectively. Experimental results indicate that the proposed method exhibits a strong ability to distinguish the wood and leaf points for various trees with different species and structures. [ABSTRACT FROM AUTHOR]

ABSTRACT Invertebrates and microorganisms are important but climate‐dependent agents of wood decomposition globally. In this meta‐analysis, we investigated what drives the invertebrate effect on wood decomposition worldwide. Globally, we found wood decomposition rates were on average approximately 40% higher when invertebrates were present compared to when they were excluded. This effect was most pronounced in the tropics, owing mainly to the activities of termites. The invertebrate effect was stronger for woody debris without bark as well as for that of larger diameter, possibly reflecting bark‐ and diameter‐mediated differences in fungal colonisation or activity rates relative to those of invertebrates. Our meta‐analysis shows similar overall invertebrate effect sizes on decomposition of woody debris derived from angiosperms and gymnosperms globally. Our results suggest the existence of critical interactions between microorganism colonisation and the invertebrate contribution to wood decomposition. To improve biogeochemical models, a better quantification of invertebrate contributions to wood decomposition is needed. [ABSTRACT FROM AUTHOR]

This current investigation explored the thermal conversion process of castor wood into biochar, which was subsequently harnessed for removing naproxen from pharmaceutical industrial effluent via adsorption. Surface composition analyses conducted through scanning electron microscopy–energy dispersive X‐ray, laser‐induced breakdown spectroscopy, and Fourier‐transform infrared studies unveiled the presence of nano MgO particles within the adsorbent material. Employing optimization techniques such as response surface methodology facilitated a refined approach to batch study. The optimized conditions for batch naproxen sodium (NPX) adsorption on nano‐MgO‐modified biochar were identified as pH 4, 1.5 g/L adsorbent dosage, and a 120‐min contact time maintaining a constant NPX concentration of 10 mg/L. The adsorption capacity was calculated to be 123.34 mg/g for a nano‐magnesium oxide‐modified castor wood biochar (modified biochar) and 99.874 mg/g for pristine castor wood biochar (pristine biochar). Fenton's reagents comprising 15 mM of FeSO4 (7H2O) and 25 mM of H2O2 have been scrutinized under conditions of pH 3.0, a reaction time of 30 min, a temperature of 30°C, and stirring at 120 rpm, followed by batch adsorption treatment. The COD, NH3–N, NO3−, PO43−, and NPX removal percentages was found to be 90%, 87%, 79%, 80%, and 90%, respectively. Thus nano MgO‐modified biochar holds promise of treatment of pharmaceutical effluent. [ABSTRACT FROM AUTHOR]

This article discusses the evolution and diversity of secondary cell walls (SCWs) in seed plants. The study used cryoSEM to analyze macrofibrils in 33 different angiosperm and gymnosperm species. The results showed that angiosperms generally have narrower macrofibrils compared to gymnosperms, but there are exceptions. The findings provide insights into wood nanostructure and cell wall composition, which can be useful for selecting or engineering desirable wood properties and improving carbon sequestration in plantation forests. The study also examines the evolution of macrofibril size in seed plants, specifically focusing on angiosperms and gymnosperms. The researchers found that large macrofibrils are characteristic of gymnosperms, while small macrofibrils are characteristic of angiosperms. However, they also discovered an intermediate macrofibril size in the Liriodendron genus. The researchers speculate that this may be due to differences in cell wall composition or environmental factors. Further research is needed to investigate these factors and their impact on carbon sequestration and storage by plants. [Extracted from the article]

The wood duck (Aix sponsa) consistently ranks within the top 5 harvested duck species for both Illinois and the Mississippi Flyway. While substantial research has been done on wood ducks, especially their breeding ecology, few studies have investigated the postbreeding ecology of the species. We captured and marked wood ducks with either a very high frequency (VHF) radio transmitter or a solar‐charged global system of mobile communication (GSM) transmitter during the postbreeding period from August through September 2018–2020. Capture locations were within the La Grange Pool of the Illinois River extending from near Pekin, Illinois to the La Grange Lock and Dam near Meredosia, Illinois, USA. We used conventional radio‐telemetry techniques to track wood ducks to determine cover type use, home range size, daily movement patterns, survival, and migration chronology. Home range size (95% minimum convex polygon) for wood ducks averaged 6,820 ± 572 ha (SE) and we did not find evidence for a difference by age, sex, or transmitter type. Daily movement distance in August (2,031 ± 51 m) was similar to daily movement distance in September (1,922 ± 44 m), but daily movement distances for August and September were less than daily movement distance for October (3,509 ± 53 m) and November (3,347 ± 106 m). Wood ducks primarily used wetlands with woody (45.0%) and emergent vegetation (40.4%), and the most commonly used wetland types by wood ducks were impounded wetlands (53.8%), lakes (17.6%), and ponds (10.7%). Model‐derived survival during the postbreeding period was 0.79 (95% CI = 0.74–0.84). Daily survival was positively related to increased river level and had a mean increase of 4.06 ± 0.67% for every 0.3‐m increase in the Illinois River level at low river levels (1.5–3.0 m) and a mean increase of 1.38 ± 0.32% for every 0.3‐m increase in the Illinois River level at high river levels (4.0–5.5 m). Average departure date of wood ducks leaving the Illinois River Valley was 27 October (range =13 August–15 December), and adult male wood ducks left the study area 11–16 days earlier than the other age and sex cohorts (H2 = 11.6, P = 0.01). Providing additional waterfowl sanctuaries that contain wooded wetlands, especially in years of low river levels, may increase survival for wood ducks during the postbreeding period. [ABSTRACT FROM AUTHOR]

The Hymenochaetales is an order with most species as wood-inhabiting fungi that have high phylogenetic complexity and morphological diversity. Species in this order play important roles in forest ecosystems and include wood decomposers, pathogens, and those that form ectomycorrhizal associations. However, we have limited knowledge of the patterns of large-scale evolutionary history of the order. In this study, using 171 genomes, including 113 newly assembled, we reconstructed the phylogenomic relationships, divergence times, biogeographic patterns, morphological evolution of basidiomata, and patterns of speciation/extinction in the Hymenochaetales. The phylogenomic relationships of 12 families within the Hymenochaetales suggested that 10 families can be accepted, and 2 families rejected. Molecular clock dating analyses suggested that the Hymenochaetales possibly started a rapid family-wide and genus-wide radiation during the early Cretaceous to late Jurassic and Cretaceous, respectively. Reconstruction of the ancestral state implied that Hymenochaetales probably originated from the temperate regions of Asia, with the basidiomata of the common ancestor likely being a corticioid species that rapidly transformed between the early Cretaceous and late Jurassic, coinciding with radiations at the family level. Furthermore, we detected a gradually increasing trend of speciation, extinction, and net diversification rates. We provided large-scale genomes of the Hymenochaetales and revealed evolutionary history patterns, which are key to understanding the evolution of fungi. [ABSTRACT FROM AUTHOR]

The study explored the post-wildfire elemental composition of parts (wood, bark, branch, cone, trunk, litter, twig, needle, sward, fallow, sapling, etc.) and by-products (biomass ashes, partly burnt parts, and char) of different woody species in the Bohemian Switzerland National Park, Czech Republic, and considered their effects on soils. Multi-elemental analysis of the fire by-products of the woody species was determined with inductively coupled plasma-optical emission spectrometry and mass spectrometry and compared with control biomass samples unaffected by wildfire. Most fire by-products were slightly alkaline, with acidic ashes obtained from blueberry wood. The by-products of the wildfire were characterized by varied total contents of macro (P, Ca, K, Mg, and S), micro (Na, Mn, Fe, Cu, and Zn), and other elements (B, Co, Mo, and V) vital to soil fertility and plant growth. The mean content of macro elements in the biomass ashes was up to 4.16 P, 23.5 Ca, 2.48 Mg, 63 K, and 5.57 S g kg−1. These values were comparatively lower than published data for ashes obtained under optimized conditions, e.g., those combusted in power generation facilities. Conversely, partly burnt parts—an indication of incomplete combustion—had higher 9.22 P, 79 Ca, and 5.99 Mg g kg−1 contents in spruce needles than in biomass ashes and the control. Variations in woody species and anthropogenic activities in areas of wildfires produced varied As, Cd, Cr, Ni, and Pb contents above EU fertilizer regulation. Caution in applying biomass ashes from wildfires on fields is required due to risk/toxic elements input from anthropogenic activities. Wildfire effects on the elemental composition of woody species can provide information on plant parts most suitable for biomass ashes for soil and ecosystem safety. [ABSTRACT FROM AUTHOR]

Variability in Eucalyptus wood density and chemical properties is crucial to understanding important factors for the forest-based industry, such as sampling methods and wood suitability as raw material. This study aimed to evaluate the basic density and chemical composition of the radial positions of young wood from the Eucalyptus urophylla clone grown under different precipitation levels. Trees from E. urophylla clonal plantations were collected in Inhambupe, Jandaíra and Itanagra, Bahia State, Brazil. Trees’ basic density and chemical composition (total extractive, lignin, hemicelluloses and α-cellulose) were determined based on the basal log of each tree, at four radial positions (1, 2, 3 and 4). It was found that the basic density and α-cellulose of wood are influenced by the cambial age and the site rainfall. There was greater increase in sections close to the bark (positions 1 and 4) and in more humid environments (sites Itanagra and Jandaríra). This finding highlights the association between wood basic density and chemical composition, mainly in the holocellulose content. [ABSTRACT FROM AUTHOR]

Although many of the structures and organelles of vegetative cells are comparable to those of animal tissues, significant differences between the two kingdoms require modifications in histological techniques for both tissue processing steps and histochemical staining techniques. The authors investigated the challenges of working with plant tissues by collecting various flora to represent the four main plant organs: leaf, stem, root, and flower/fruit. Triplicate samples for each specimen were placed into formalin for paraffin embedding, placed into formalin for later frozen sections, and used fresh to undergo immediate frozen sectioning. Frozen sections of plant tissues were more difficult to obtain than formalin-fixed paraffin-embedded (FFPE) sections, exhibited tissue loss during staining, and were inferior morphologically to FFPE sections. Although, historically, plant tissue fixation and processing has employed several different reagents compared with those used in animal tissue processing and took significantly longer times, the current investigation determined reagents and protocols from a modern histology laboratory which processes mammalian tissues can be applied to plant tissue processing with only slight modifications in respect to reagent timing. Additionally, staining techniques were compared and while it is well known that plant cell walls stain well with safranin O, the current investigation determined the uptake of safranin O can be accelerated by incubating at 60°C. [ABSTRACT FROM AUTHOR]

The process of formation of aromatic components for agarwood in Aquilaria sinensis is closely related to endophytic fungi and the result of complex multiple long-term joint interactions with them. However, the interactions between the aromatic components and endophytic fungi remain unclear during the formation of agarwood. In this study, precise mixed solution of hormones, inorganic salts, and fungi was used to induce its formation in A. sinensis, and sample blocks of wood were collected at different times after inoculation. This study showed that the aromatic compounds found in the three treatments of A. sinensis were primarily chromones (31.70-33.65%), terpenes (16.68-27.10%), alkanes (15.99-23.83%), and aromatics (3.13-5.07%). Chromones and terpenes were the primary components that characterized the aroma. The different sampling times had a more pronounced impact on the richness and diversity of endophytic fungal communities in the A. sinensis xylem than the induction treatments. The species annotation of the operational taxonomic units (OTUs) demonstrated that the endophytic fungi were primarily composed of 18 dominant families and 20 dominant genera. A linear regression analysis of the network topology properties with induction time showed that the interactions among the fungal species continued to strengthen, and the network structure tended to become more complex. The terpenes significantly negatively correlated with the Pielou evenness index (p < 0.05), while the chromones significantly positively correlated with the OTUs and Shannon indices. [ABSTRACT FROM AUTHOR]

Herein, we successfully modified wood sponge (WS) with Fe3O4 (MWS) to enhance its ability to adsorb five different oils, eight organic solvents, metal ions, and degrade methylene blue (MB) from wastewater. MWS, possessing over 96% porosity, exhibited remarkable sorption capacities of 26.79 g g− 1 for CCl4 and 21.00 g g− 1 for pump oil. Notably, MWS maintained high sorption capacity even after repeated use. Furthermore, MWS effectively removed toxic metal ions including As3+, Cr6+, and Pb2+ from real industrial wastewater, at pH 4 and 50 °C to levels suitable for drinking water. Also, MWS demonstrated excellent photocatalytic properties for degrading methylene blue dye. The photodegradation process involved the generation of superoxide anion radicals and the participation of hydroxyl radicals. The magnetic properties of MWS allow for easy remote retrieval using a magnet, making it a cost-effective and reusable solution for environmental remediation. [ABSTRACT FROM AUTHOR]

The study investigates the horizontal fuel size effect on free-burning fires for PMMA plates and wood cribs. The fuel size effect on mass burning flux and flame behavior is mainly discussed and compared with typical pool fires. For the PMMA plate and liquid pool, when the fuel size is small (< 10 cm), either the 3D sidewall burning of PMMA or the container wall heated by flame can promote the burning flux at the horizontal projection area. As the fuel size increases, these side wall burning or heating effects decrease, causing the drop in burning flux with fuel scale for both the PMMA plate and liquid pool. For small-scale wood cribs, fire cannot self-sustain due to the large airflow cooling. With the increase in wood crib size, the burning rate first remains constant and then gradually increases, driven by the enhanced internal radiation. As the fuel size increases above 20–30 cm, the flame radiation dominates the burning flux for all fuel types. Fire dynamics simulator (FDS) was adopted to simulate the horizontal size effect by setting a varied fire source (horizontal projection) area. First, the flame geometry and heat release rate (HRR) of simulations were validated against experimental results. Subsequently, the validated fire model generates cases covering a broad range of fire scales. Finally, a new correlation of flame height with the fire heat release rate and fuel size is proposed, and its prediction capability is validated in the numerical fire modeling. This study quantifies the size effect on the burning rate for common solid fuels and provides valuable information for the numerical modeling of multi-scale fires. [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]

Asymmetric timber trade between least-developed countries with large forest resources but backward processing industries and emerging economies has led to an uneven distribution of value in international timber commodity chains. Selling their raw timber with no domestic value added contributes little to socio-economic development and is associated with high rates of deforestation. The Lao PDR has served as a raw timber frontier for advanced timber industries in neighboring countries, leading to forest loss and related environmental problems. In response, since 2015, the Lao government has adopted drastic policy measures to end forest degradation and upgrade its timber industry (e.g., log export ban). Using teak as an example, our study provides empirical ex-post evidence on the effectiveness of state-imposed timber industry upgrading policies. The study relies on expert interviews with key policy actors at national and local levels, as well as an enterprise survey and cluster analysis conducted in Xayyabouly province. These drastic policies had far-reaching implications for the structure of the timber industry and the configuration of the timber value chain and rural development. [ABSTRACT FROM AUTHOR]

Rapeseed is an important oil crop in the world. Wood vinegar could increase the yield and abiotic resistance of rapeseed. However, little is known about the underlying mechanisms of wood vinegar or its valid chemical components on rapeseed. In the present study, wood vinegar and butyrolactone (γ-Butyrolactone, one of the main components of wood vinegar) were applied to rapeseed at the seedling stage, and the molecular mechanisms of wood vinegar that affect rapeseed were studied by combining transcriptome and metabolomic analyses. The results show that applying wood vinegar and butyrolactone increases the biomass of rapeseed by increasing the leaf area and the number of pods per plant, and enhances the tolerance of rapeseed under low temperature by reducing membrane lipid oxidation and improving the content of chlorophyll, proline, soluble sugar, and antioxidant enzymes. Compared to the control, 681 and 700 differentially expressed genes were in the transcriptional group treated with wood vinegar and butyrolactone, respectively, and 76 and 90 differentially expressed metabolites were in the metabolic group. The combination of transcriptome and metabolomic analyses revealed the key gene-metabolic networks related to various pathways. Our research shows that after wood vinegar and butyrolactone treatment, the amino acid biosynthesis pathway of rapeseed may be involved in mediating the increase in rapeseed biomass, the proline metabolism pathway of wood vinegar treatment may be involved in mediating rapeseed's resistance to low-temperature stress, and the sphingolipid metabolism pathway of butyrolactone treatment may be involved in mediating rapeseed's resistance to low-temperature stress. It is suggested that the use of wood vinegar or butyrolactone are new approaches to increasing rapeseed yield and low-temperature resistance. [ABSTRACT FROM AUTHOR]

Light detection and ranging (LIDAR) sensors using a polarization-diverse receiver are able to capture polarimetric information about the target under measurement. We demonstrate this capability using a silicon photonic receiver architecture that enables this on a shot-by-shot basis, enabling polarization analysis nearly instantaneously in the point cloud, and then use this data to train a material classification neural network. Using this classifier, we show an accuracy of 85.4% for classifying plastic, wood, concrete, and coated aluminum. [ABSTRACT FROM AUTHOR]

As a mature non-destructive testing technology, near-infrared (NIR) spectroscopy can effectively identify and distinguish the structural characteristics of wood. The Wood Defect One-Dimensional Visual Geometry Group 19-Finite Element Analysis (WD-1D-VGG19-FEA) algorithm is used in this study. 1D-VGG19 classifies the near-infrared spectroscopy data to determine the knot area, fiber deviation area, transition area, and net wood area of the solid wood board surface and generates a two-dimensional image of the board surface through inversion. Then, the nonlinear three-dimensional model of wood with defects was established by using the inverse image, and the finite element analysis was carried out to predict the elastic modulus of wood. In the experiment, 270 points were selected from each of the four regions of the wood, totaling 1080 sets of near-infrared data, and the 1D-VGG19 model was used for classification. The results showed that the identification accuracy of the knot area was 95.1%, the fiber deviation area was 92.7%, the transition area was 90.2%, the net wood area was 100%, and the average accuracy was 94.5%. The error range of the elastic modulus prediction of the three-dimensional model established by the VGG19 classification model in the finite element analysis is between 2% and 10%, the root mean square error (RMSE) is about 598. 2, and the coefficient of determination (R2) is 0. 91. This study shows that the combination of the VGG19 algorithm and finite element analysis can accurately describe the nonlinear defect morphology of wood, thus establishing a more accurate prediction model of wood mechanical properties to maximize the use of wood mechanical properties. [ABSTRACT FROM AUTHOR]

Modeling the dynamic properties of wood and wood-based composites is a challenging task due to naturally growing structure and moisture-dependent material properties. This paper presents the finite element modeling of plywood panels' dynamic properties. Two panels differing in thickness were analyzed: (i) 18 mm and (ii) 27 mm. The developed models consisted of individual layers of wood, which were discretized using three-dimensional finite elements formulated using an orthotropic material model. The models were subjected to an updating procedure based on experimentally determined frequency response functions. As a result of a model updating relative errors for natural frequencies obtained numerically and experimentally were not exceeding 2.0%, on average 0.7% for 18 mm thick panel and not exceeding 2.6%, on average 1.5% for 27 mm thick panel. To prove the utility of the method and at the same time to validate it, a model of a cabinet was built, which was then subjected to experimental verification. In this case, average relative differences for natural frequencies of 6.6% were obtained. [ABSTRACT FROM AUTHOR]

Cold-temperate forests (CTFs) are not only an important source of wood but also provide significant carbon storage in China. However, under the increasing pressure of human activities and climate change, CTFs are experiencing severe disturbances, such as logging, fires, and pest infestations, leading to evident degradation trends. Though these disturbances impact both regional and global carbon budgets and their assessments, the disturbance patterns in CTFs in northern China remain poorly understood. In this paper, the Genhe forest area, which is a typical CTF region located in the Inner Mongolia Autonomous Region, Northeast China (with an area of about 2.001 × 104 km2), was selected as the study area. Based on Landsat historical archived data on the Google Earth Engine (GEE) platform, we used the continuous change detection and classification (CCDC) algorithm and considered seasonal features to detect forest disturbances over nearly 30 years. First, we created six inter-annual time series seasonal vegetation index datasets to map forest coverage using the maximum between-class variance algorithm (OTSU). Second, we used the CCDC algorithm to extract disturbance information. Finally, by using the ECMWF climate reanalysis dataset, MODIS C6, the snow phenology dataset, and forestry department records, we evaluated how disturbances relate to climate and human activities. The results showed that the disturbance map generated using summer (June–August) imagery and the enhanced vegetation index (EVI) had the highest overall accuracy (88%). Forests have been disturbed to the extent of 12.65% (2137.31 km2) over the last 30 years, and the disturbed area generally showed a trend toward reduction, especially after commercial logging activities were banned in 2015. However, there was an unusual increase in the number of disturbed areas in 2002 and 2003 due to large fires. The monitoring of potential widespread forest disturbance due to extreme drought and fire events in the context of climate change should be strengthened in the future, and preventive and salvage measures should be taken in a timely manner. Our results demonstrate that CTF disturbance can be robustly mapped by using the CCDC algorithm based on Landsat time series seasonal imagery in areas with complex meteorological conditions and spatial heterogeneity, which is essential for understanding forest change processes. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) have theoretically ideal properties for bio-based composite applications; however, the incorporation of these materials into polymers is made challenging by the strong binding of water to CNFs and the irreversible agglomeration of CNFs during drying. Previous methods used "contact dewatering", wherein the addition of wood flour (WF) to CNFs facilitated the mechanical removal of water from the system via cold pressing, which showed potential in producing dried CNF fibrils attached to wood fibers for biocomposite applications. In this work, the viability of contact dewatering with poly(lactic) acid (PLA) powder for PLA/CNF composites was evaluated. The energy efficiency of dewatering, preservation of nanoscale CNF morphology, and mechanical properties were examined by mixing wet CNFs with pulverized PLA at various loading levels, pressing water out of the system, and compression molding and shear mixing composites for testing. The most impressive results from this dewatering method were the preservation of micron-to-nanoscale fibers with high aspect ratios in PLA-CNF composites; increased strength and modulus of 1.7% and 4.2%, respectively, compared to neat PLA; equivalent or better properties than spray-dried nanocellulose at similar loading levels; and an 11-194x reduction in drying energy compared to spray-drying CNFs. [ABSTRACT FROM AUTHOR]

This study explores lignin-retaining transparent wood biocomposite production through a lignin-modification process coupled with epoxy resin. The wood's biopolymer structure, which includes cellulose, hemicellulose, and lignin, is reinforced with the resin through impregnation. This impregnation process involves filling the voids and pores within the wood structure with resin. Once the resin cures, it forms a strong bond with the wood fibers, effectively reinforcing the biopolymer matrix and enhancing the mechanical properties of the resulting biocomposite material. This synergy between the natural biopolymer structure of wood and the synthetic resin impregnation is crucial for achieving the desired optical transparency and mechanical performance in transparent wood. Investigating three distinct wood species allows a comprehensive understanding of the relationship between natural and transparent wood biocomposite properties. The findings unveil promising results, such as remarkable light transmittance (up to 95%) for Aspen transparent wood. Moreover, transparent wood sourced from White Spruce demonstrates excellent stiffness (E = 2450 MPa), surpassing the resin's Young's modulus. Also, the resin impregnation enhanced the thermal stability of natural wood. Conversely, transparent wood originating from Larch showcases superior impact resistance. These results reveal a clear correlation between wood characteristics such as density, anatomy, and mechanical properties, and the resulting properties of the transparent wood. [ABSTRACT FROM AUTHOR]

The aim of this study was to reveal the strength mechanism of the mortise-and-tenon (M–T) joint at a deeper level. The effects of tenon fit on bending and withdrawal load resistances, and strain distributions outside and inside beech (Fagus sylvatica) wooden round-end M–T joints were experimentally investigated using mechanical testing synchronizing digital image correlation method (DICM). The results showed that (1) the tenon fit had greater significance on withdrawal properties than that of bending properties of M–T joints; (2) the bending load resistance was linearly proportional to withdrawal load resistance based on both theoretic analysis and regression methods; (3) strain distributions outside M–T joints during the loading process were not sufficient to evaluate the mechanical behaviors of the M–T joint; (4) strain distributions inside M–T joints showed that the maximum strains on top and bottom parts of the tenon were significantly greater than that of middle part, but the difference decreased with the growth of tenon fit; (5) the method of determining the optimal tenon fit of the M–T joint based on the DICM was proposed, and optimal tenon fit of beech wooden round-end M–T joint evaluated ranged from 0.4 to 0.5 mm. [ABSTRACT FROM AUTHOR]

This paper presents a comparative analysis of the blind test outcomes of two independent methods for the identification of tropical wood species in pulp and paper products. Both, the established anatomical and the relatively new chemotaxonomic method support the European Deforestation Regulation 2023/1115 (EUDR), which aims to ensure that only legally harvested timber that has not contributed to deforestation is traded in the EU. The blind test involved 570 decisions on 15 test sheets of 37 self-manufactured mixed tropical hardwood pulps and an industrial beech pulp, used as a matrix. Both detection techniques demonstrated robust performance with over 80 % hit rates. The results show that the synergies and combination of the strengths of both methods can be utilized and lead to even better combined performance. In order to establish the chemotaxonomic identification method as a complement to the conventional anatomy-based method, statistical analyses were performed to assess its intermediate precision between three different GC-MS systems. In most cases, the method gave consistent results independent of the instrument used. [ABSTRACT FROM AUTHOR]

The anatomical description of wood and charcoal for a wide variety of purposes is an essential tool for compiling databases to correctly identify species. This study describes and compares the anatomy of the wood and charcoal of Manilkara sp., collected in a protected area in the Pará state, Brazil. The qualitative anatomical characteristics of the wood, such as diffuse-porosity; vessels in radial multiples; alternate intervessel pits; axial parenchyma in lines or reticulate; rays uniseriate or biseriate, not storied, are corroborated in the literature. Moreover, this work reports the presence of helical thickenings in the vessel elements and possible helical thickenings in fibres in Manilkara. After the carbonization process, there were morphometric changes in the anatomical elements, as an increase in vessel frequency between 23 % and 141 %, and in ray frequency between 2.8 % and 12.9 %; while ray height decreased and ray width increased. Overall, some anatomical variations could be related to, or a result of the interaction between species plasticity, genetics, age and environmental factors. These characteristics enabled the identification of the samples at the genus level and the anatomical description of the wood and charcoal can be useful for forest inspections. [ABSTRACT FROM AUTHOR]

The control authorities of timber trade lack quick and easy methods to verify the legality of the traded product. This includes the clear identification of the timber species. In this study, a simple genetic method, the macroarray technique, was modified and optimised for this purpose. The internal transcribed spacer (ITS) was used as barcode region. Specific probes were designed and tested using this barcode of trade-relevant, CITES protected wood species and their look-alikes. The results reveal that 61 of these probes are suitable for identification purposes. Hence, 32 of the 50 investigated species can be clearly identified using the developed macroarray. Additional 15 species are represented by probes in groups of two to three species, which enables a delimitation of the species present. For four species, no identification was possible applying the probes created. The findings indicate the potential of time and cost savings compared to currently established methods in species control in the timber trade. [ABSTRACT FROM AUTHOR]

A general solution technique for hygrothermo-electroelastic problems in bodies with D∞ symmetry is developed. The displacement and electric field are expressed in terms of their respective potential functions, and the hygrothermo-electroelastic field quantities are expressed in terms of elastic and piezoelastic potential functions, each of which satisfies a Laplace equation with respect to the appropriately transformed spatial coordinates, combined with the two hygrothermoelastic displacement potential functions. As an application of this technique, a theoretical analysis of an infinite cylinder subjected to distributions of moisture content, temperature, and stress was performed, and the significance of the hygrothermo-electroelastic analyses was demonstrated. [ABSTRACT FROM AUTHOR]

Part II of this two‐part article investigates the impact of thermocouple insulation failure on temperature measurement data in forensic fire‐death scenarios. Two different models of glass fiber‐insulated thermocouple wires (GG‐K‐24‐SLE and HH‐K‐24 from Omega Engineering) were passed through a ceramic kiln at temperatures up to 1093°C to measure an ice bath at a constant 0°C. In a separate experiment, the same two models of thermocouple wire plus a BLMI‐XL‐K‐18U‐120 mineral‐insulated metal‐sheathed thermocouple probe were passed through a wood pallet fire to measure an ice bath. In the ceramic kiln, the effect on measurement errors was determined for short vs. long exposure lengths and clean insulation vs. insulation contaminated with pork fat. Glass fiber‐insulated thermocouple wires showed severe failure in both experiments, with errors ranging from −270°C to almost 2200°C. The metal‐sheathed probe showed no evidence of insulation failure and continued to accurately measure the ice bath temperature within expected margins of error around 0°C. This study highlights how exposure of inadequate thermocouples to fire‐level temperatures produces severe errors in temperature data. Consequently, it will not be possible to use this data to draw any accurate conclusions about the effects of fire exposure to human donors or animal proxies. [ABSTRACT FROM AUTHOR]

Thermo‐catalytic co‐pyrolysis of paulownia wood and polypropylene mixture were carried out in a fixed bed horizontal reactor system. The biochar obtained from pyrolysis of paulownia wood was activated by steam at 700°C. Activated biochar supported magnesium oxide, nickel oxide and cobalt oxide catalysts were prepared by incipient miosture impregnation and were used to upgrade the bio‐oil. Catalytic pyrolysis reduced the amount of bio‐oil compared with non‐catalytic pyrolysis (59.5% of bio‐oil). The results indicate that the production of aromatic compounds increased from 40.35% to 65.93, 62.12 and 61.56% using Ni, Co and Mg catalysts, respectively. For all three catalysts, the production of furan compounds decreased. It was found that bio‐char based catalysts are suitable for use in the co‐pyrolysis process to improvement the biofuel production. [ABSTRACT FROM AUTHOR]

The aim of this study is to apply a new approach to the quantitative analysis of the formation of gaseous products generated during the thermochemical conversion of wood waste samples of different fineness by using thermogravimetric analysis with mass spectrometry (TGA‐MS). Profiles of the release of gaseous components in the process of thermochemical conversion of wood samples were obtained based on data from the combined use of mass spectrometry and thermogravimetry. The resulting mass spectrometric data were processed according to the proposed methodology and the characteristics of the released gases were noted. The kinetic coefficients of the gases' formation were calculated from the processed data. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass, the most abundant natural resource on earth, can be used for cellulosic ethanol production but requires a pretreatment to improve enzyme access to the polymeric sugars while obtaining value from the other components. γ‐Valerolactone (GVL) is a promising candidate for biomass pretreatment since it is renewable and bio‐based. In the present work, the effect of a pretreatment based on GVL on the enzymatic saccharification of white birch was evaluated at a laboratory scale and the importance of the washing procedure for the subsequent saccharification was demonstrated. Both the saccharification yield and the production of cellulosic ethanol were higher using a noncommercial enzyme crude from Talaromyces amestolkiae than with the commercial cocktail Cellic CTec2 from Novozymes. Furthermore, the production of extracellular cellulases by T. amestolkiae has been optimized in 2 L bioreactors, with improvements ranging from 40% to 75%. Finally, it was corroborated by isoelectric focus that optimization of cellulase secretion by T. amestolkiae did not affect the pattern production of the main β‐glucosidases and endoglucanases secreted by this fungus. [ABSTRACT FROM AUTHOR]

Aim: To test the hypothesis that adaptive shifts leading to the assembly of tropical savannas involved coordination between bark and wood traits and to understand the underlying mechanisms. Location: Tropical South America. Taxon: Angiosperms (woody). Methods: We compiled data on three bark traits (total, inner and outer relative bark thickness), wood density, maximum height, five secondary xylem traits and on species' habitat information (light environment, climate, soil and fire history) for Neotropical savanna, forest and generalist species (biome groups). We tested for pairwise and multivariate associations among traits across species and if biome group and habitat conditions explained species positions along the resulting strategy axes. Results: Traits covaried along four different axes. The first axis was consistent with a trade‐off between fire (thick barks) and shade tolerance (low bark to diameter ratio, high vessel density) and contributed to differentiate the three biome groups according to the preference for shaded environments. Forest species also differed from savanna and generalist species in a separate axis by being more resource acquisitive. Maximum height and wood density did not strongly trade‐off with bark thickness, although maximum height was negatively covaried with relative outer bark thickness. Preference for shaded conditions was the main driver of variation in the two principal strategy axes, but temperature, fire and soil sand content also explained differences in plant stature between savanna and generalist species. Main Conclusions: Allocation to bark is constrained by trade‐offs with wood, opposing shade‐tolerant and acquisitive forest species to fire‐resistant and conservative savanna species. Rather than a single strategy axis, three axes are necessary to understand the functional differences among savanna, forest and generalist species. Because two of these axes are controlled by light availability, the associated traits tend to covary in space and time, but not across species. [ABSTRACT FROM AUTHOR]

Fusarium wilt and gummosis disease is a major concern in Subabul plantations, resulting in quantitative and qualitative wood losses to the paper and pulp industry. Growers currently rely on agrochemicals, which are not environmentally safe. Therefore, developing a sustainable control strategy employing biocontrol agents is necessary. For this, the investigation was performed to identify native Trichoderma strains from Subabul rhizospheric soil having antagonistic, disease control efficiency, and PGPR attributes. Six antagonistic Trichoderma (TR1 to TR6) strains were isolated and their efficacy was tested against Fusarium in-vitro by dual plate technique and volatile metabolites. Among these, Trichoderma strains TR1 and TR2 were found efficient in counteracting the growth of F. equiseti (70–90% inhibition) compared to control. The effectiveness was primarily attributed to the increased production of volatile metabolites, siderophores, and the ability to solubilise the nutrients (P and K). Further, six potent Trichoderma strains were identified as T. asperellum (TR1, TR2, TR3, TR6), and T. hamatum (TR4, TR5) through rDNA ITS gene sequencing and phylogenetic analysis. These isolates were mass-multiplied, formulated using Talc powder followed by bio-priming in rooting media. The application of Trichoderma into rooting media reduced the wilt disease caused by artificial inoculation of F. equiseti. Further, TR1 and TR2 were found promising with conferred protection against wilt, enhanced survival rate (10–15%), and improved growth compared to untreated control. Application of adapted TR1 and TR2 antagonists in rooting media during clonal multiplication has the potential wilt control efficiency, enhanced survival rate, and plant growth promotion in Subabul. [ABSTRACT FROM AUTHOR]

The experimental study presented in this paper aimed to investigate the effects of bolt number and their pattern on the failure time of minimally fire-protected glulam beam bolted connections. Four full-size glulam beam-end connection configurations reinforced perpendicular to wood grain with self-tapping screws (STS) were experimentally tested under exposure to elevated temperatures that followed the CAN/ULC S101 (Standard methods of fire endurance tests of building construction and materials. Underwriters Laboratories of Canada, Fifth edition, Ottawa, Canada, 2019) standard fire time–temperature curve. All metal connecting components (i.e., bolt heads and nuts and steel plate edges) were fire protected using wood plugs and strips, respectively. Throughout the duration of fire tests, all specimens were subjected to monotonic load causing bending moment equivalent to the maximum moment design capacity of the weakest unreinforced connection configuration. Fire test results show that the failure time of all four proposed wood–steel–wood connection configurations surpassed the 45-min mark, which is the minimum prescribed fire resistance rating for timber connections in applicable codes, with the two configurations that employed six bolts sustained the applied load for more than 60 min in standard fire conditions. Increasing the number of bolts from four to six enhanced the failure time of the proposed connection configurations with time increments more than those due to changing the bolt pattern. Most importantly, test results confirm that reinforcing the connections with STS fully curtailed wood splitting and averted row shear failure that is frequently encountered in similar but unreinforced connection configurations. [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]

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: Educational board games have been receiving attention from educators in recent years. Designing the rules of board games based on cognitive theory, and further analysing educational board games from more dimensions are important issues that warrant further study. Purpose: The research designed a board game called Chemistry Story to promote students' learning of the concept of element combination in chemical substances. The design of the cognitive mechanism of the board game was based on three cognitive design principles, namely schema connection theory, attention, and cognitive scaffolding. Sample: The participants were 48 eighth-grade students in Taiwan. Their average age was 13.8. Design and methods: A one-group pretest-posttest design was adopted. The research explored students' learning achievement, flow, and acceptance after using this board game for learning. Moreover, this research analysed the differences in students' flow while playing with game components made of different materials (paper, wood, and plastic), and explored the relationship with learning achievement, perceived usefulness, and perceived ease of use. Results: The results showed that students' concept of element combination in chemical substances improved through playing this board game. In addition, students had considerable engagement and acceptance of the board game's learning activities with the game components made of different materials. The results of the correlation analysis showed that students with low academic achievement were more likely to feel that Chemistry Story was helpful to their studies. It was also found that the wooden material components brought abetter sense of engagement and game acceptance. Conclusion: When designing educational board game products, we should not only consider the target knowledge of the board game and the design of the game mechanism, but also consider the students' feelings about the materials used to make the components, and choose materials that can bring students a better learning experience, so as to enhance the positive influence on their learning. [ABSTRACT FROM AUTHOR]

N-acetyl-beta-d-glucosaminidase (NAG) is a lysosomal enzyme found in renal tubular epithelial cells, the concentration of which can be measured in blood as a possible diagnostic tool to monitor renal disease; however, no reference values are currently available in reptiles. This study investigated the presence of plasma NAG concentrations in three reptile species. Blood samples were obtained from clinically healthy bearded dragons (Pogona vitticeps; n = 13), corn snakes (Pantherophis guttatus; n = 9) and wood turtles (Glyptemys insculpta; n = 13). To assess renal health further, a biochemistry panel was performed for all animals, and renal biopsies were collected from the bearded dragons and snakes, but not from the turtles. Biopsies were not taken from wood turtles to limit the risk associated with anesthetizing an endangered species. Of the 35 animals sampled, 29 were considered healthy and included in the study. Plasma NAG concentrations in the wood turtles were significantly lower than in the corn snakes (P = 0.004) and plasma NAG concentrations in the corn snakes were significantly higher than in bearded dragons (P = 0.038). Wood turtles had the lowest NAG concentrations, followed by bearded dragons and corn snakes. In conclusion, NAG reference intervals should be established for each reptile species, and analyte validation is needed for this assay in reptiles. Further research is needed to establish NAG reliability as a diagnostic tool in reptiles. [ABSTRACT FROM AUTHOR]

North American conifers exhibit three radial specific gravity (SG) patterns (Type 1, 2, and 3), which balance hydraulic and mechanical requirements. Type 1 and 2 patterns (Pinaceae) have low SG and high microfibril angle (MFA) corewood ensuring compliance, whereas in outerwood high SG/low MFA provide stiffness and strength resisting bending. Hydraulically, corewood, especially in Type 2 species, is resistant to embolism, whereas outerwood has higher specific conductivity. Cupressaceae (Type 3) have hydraulically very efficient, low SG outerwood, facilitating rapid growth. Corewood is flexible, whereas outerwood is mechanically weak and compensated for by more conical stems and durable heartwood (which prevents Brazier buckling). Radially earlywood (EW) decreases, and latewood (LW) increases for all types, whereas %latewood (%LW) increases (Type 1), decreases, then increases (Type 2) and decreases (Type 3). Ring SG increases when increasing LW SG and %LW are sufficient to counteract decreasing EW SG. Shade tolerance, crown recession, hormone gradients, and environmental variation affect patterns. Auxin concentration decreases with increasing distance from juvenile foliage slowing cell division, concomitantly gibberellin concentration (lignification) and carbohydrates (cell wall thickening) increase, producing higher %LW. Across a species range regions receiving relatively high summer rainfall have trees with higher %LW (by ring). [ABSTRACT FROM AUTHOR]

Debris jams contribute to bridge pier failures. Previous investigations showed that a debris jam can constrict the flow cross section, enhance flow intensity, and result in significant scour. Physical modeling was conducted to investigate the influence of debris jams on scour depth. Instead of using a static block to represent a debris jam, dynamic debris jams composed of real tree seedlings were investigated to represent jams forming of woody debris with roots and branches. The dynamic jam was achieved by continuously releasing individual seedlings from upstream. The resulting seedling jams had a typical half-cone shape and generally grew continuously over time, with observed scour increasing with the size of the debris jam. The scour in the presence of a dynamic debris jam could have depth up to twice and volume up to eight times that of a pier without a debris jam. In addition, the dynamic debris jam also induced additional hydraulic head across the cylinder pier, which correlated with the size of debris jam and Froude number. Practical Applications: Scour around a bridge pier is the removal of sediment from the pier foundation by the surrounding flow. This can destabilize the bridge infrastructure, leading to potential failure. The accumulation of wood debris on a bridge pier leads to the formation of a debris jam that can increase scour. Most previous studies measured scour induced by a fixed debris jam geometry of constant size, with no temporal variation. However, in real situations, debris will gradually and often rapidly, especially during floods, accumulate over time around a bridge pier, and the associated scour increases as the debris jam increases in size. This paper presents an experimental study of the temporal evolution of debris accumulation on the model of a bridge pier and the associated progress of scour as a debris jam develops. In contrast to most previous studies that used wooden dowels, the debris is modeled using real seedling trees, which have roughness characteristics more akin to real-world debris. The resulting debris jams are relatively stable due to the interlocking of debris pieces. It was found that the instantaneous scour depth increased in the presence of the developing debris jam and that it was proportional to how much the debris jam blocked the flow. Interestingly, the plan area of the scour hole increased more than that occurring in the absence of the debris; the scour hole volume is hence much greater when a debris jam is present. [ABSTRACT FROM AUTHOR]

Forests provide many different ecosystem services (ESs) to society. We divide these services into three main groups: provisioning, regulating and cultural. The services themselves are usually interrelated, so changes in the level of one of these services can affect the others. Depending on the nature of the mutual relationship, a distinction is made between trade-off and synergy. Understanding the relationships between services in a given area, time period and scale can support conscious management of forest resources, taking into account the concept of ES. This article aims to systematically review the literature with the aim of identifying the relationships between the services and the factors that influence these relationships. Particular attention was paid to the provisioning service, i.e., timber harvesting, and its relationships with other services, taking into account different variants of forest management. The literature search was conducted using the SCOPUS database, which was searched for scientific articles published between 2005 and December 2023 containing the following terms: "ecosystem services" AND "forest" AND "bundle" or "ecosystem services" AND "forest" AND "synergy" or "ecosystem services" AND "forest" AND "trade-off". The query resulted in 825 records, of which 55 articles were subjected to a detailed content analysis using a standardised procedure. The results show that most studies analysed the relationships between timber harvesting and biodiversity, carbon storage/sequestration and water erosion. Cultural Ecosystem Services were only examined in a few studies. In most cases, timber harvesting is at trade-off with cultural and regulating services. Many factors influence the supply of services and the relationship between them: climate change, forest management scenarios, temporal and spatial scale of the simulation, species composition and age class or more generally the structure of the forest stand, the history of the study area, its location, habitat productivity and geomorphology. The results show that further work is needed in the area of ES in order to apply this concept in forest management. [ABSTRACT FROM AUTHOR]

Transparent wood has the potential to be a sustainable alternative to glass in the building and construction industry. However, it is crucial to consider the fire hazard in building applications. In this study, we applied a green strategy to treat the wood aerogel with an intumescent flame retardant coating. The coating consisted of positively charged polyethyleneimine (PEI) and melamine, as well as negatively charged phytic acid. The treated wood aerogel demonstrated excellent flame retardancy. Subsequently, we incorporated the flame-retardant wood aerogel into epoxy resin to examine its impact on the thermal stability and fire resistance of the epoxy. The wood aerogel, with two bilayers of PEI + melamine/phytic acid, significantly enhanced the fire resistance of the epoxy. This was evident through notable reductions in peak heat release rate (42%) and total heat release (15%). By characterizing the char residue of the epoxy/wood-2 composite, we observed the formation of a continuous network within the epoxy matrix, effectively impeding the transfer of combustible gases and heat. Our work presents a simple and environmentally friendly approach to producing multifunctional transparent wood. [ABSTRACT FROM AUTHOR]

Wood modification techniques, like densification, can improve the mechanical performance of low-density and undervalued wood species, rendering them suitable for high-value engineering applications. Nevertheless, densified wood (DW) commonly manifests a set recovery (SR) phenomenon when exposed to water, negating the enhancements achieved through densification. Our method addresses the SR issue and the non-recyclability associated with conventionally produced DW using chemical techniques in wood densification. To mitigate SR in DW, an ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate was impregnated as a cellulose plasticizing agent prior to wood densification. This method facilitated permanent deformation within the cellulose network, resulting in negligible SR. Moreover, the DW treated with IL (DW_1w) demonstrated an increase in both modulus of rupture and modulus of elasticity after water washing and subsequent redrying, in comparison to the untreated control (UC). Notably, spectroscopic (FTIR) analyses indicated that the chemical structure of DW_1w remained akin to that of UC. Additionally, the IL leached out during the DW-water washing step can be recovered. This research contributes to advancing sustainable alternatives to less ecologically friendly (chemical) pretreatment methods to reduce SR related issues in DW. [ABSTRACT FROM AUTHOR]

In this work, nanocellulose aqueous dispersions were studied as a bio-inspired consolidating agent for the recovery and conservation of ancient wood and compared with two of the most used traditional consolidants: the synthetic resins Paraloid B-72 and Regalrez 1126. The morphology of crystalline nanocellulose (CNC), determined using Scanning Electron Microscopy (SEM), presents with a rod-like shape, with a size ranging between 15 and 30 nm in width. Chemical characterization performed using the Fourier-Transform Infrared Spectroscopy (FT-IR) technique provides information on surface modifications, in this case, demonstrating the presence of only the characteristic peaks of nanocellulose. Moreover, conductometric, pH, and dry matter measurements were carried out, showing also in this case values perfectly conforming to what is found in the literature. The treated wood samples were observed under an optical microscope in reflected light and under a scanning electron microscope to determine, respectively, the damage caused by xylophages and the morphology of the treated surfaces. The images acquired show the greater similarity of the surfaces treated with nanocellulose to untreated wood, compared with other consolidating agents. Finally, a colorimetric analysis of these samples was also carried out before and after a first consolidation treatment, and after a second treatment carried out on the same samples three years later. The samples treated with CNC appeared very homogeneous and uniform, without alterations in their final color appearance, compared to other traditional synthetic products. [ABSTRACT FROM AUTHOR]

In the past, organ builders used many tree species for the production of wooden organ pipes, and the thicknesses of the pipe walls were also different. From the point of view of the sound of wooden organ pipes, it appears that the type of wood, as well as the thickness of the pipe wall, affect the resulting organ sound. Therefore, this research focused on how the wood species and the thickness of the pipe's wall affect the sound of the organ. Two wood species were selected for our experiment: maple wood, representing hardwood; and spruce wood, representing softwood. The physical and acoustic characteristics (PACHs)—density (ρ), dynamic modulus of elasticity along the wood grain (EL), specific modulus (Esp), speed of sound along the grain (cL), resonant frequency (fr), acoustic constant (A), logarithmic decrement (ϑ), loss coefficient (η), acoustic conversion efficiency (ACE) and sound quality factor (Q)—were determined. Subsequently, the boards were used for making the back wall of the experimental wooden organ pipe with a replaceable back wall. The boards used for the back wall had an initial thickness of 7 mm. The boards were gradually thinned in 1 mm decrements to a final thickness of 1 mm. For each board thickness, the frequency spectrum was recorded at four different air pressures in the windchest, namely, 588 Pa, 716 Pa, 814 Pa and 941 Pa. The results of the experiment showed that at a given back wall thickness, the fundamental tone frequency increases with increasing air pressure. The decrease in the back wall thickness was manifested by a decrease in the fundamental frequency. With increasing air pressure, the intensity of higher harmonic frequencies also increased. [ABSTRACT FROM AUTHOR]