In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Popu...In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.展开更多
Wood,recognized as a renewable and environmentally sustainable material,plays a crucial role as an alternative energy resource within the construction industry.However,it is highly susceptible to mold and decay fungi,...Wood,recognized as a renewable and environmentally sustainable material,plays a crucial role as an alternative energy resource within the construction industry.However,it is highly susceptible to mold and decay fungi,which can lead to surface discoloration and potentially compromise the structural integrity of wood.The advancement of nanotechnology has introduced innovative strategies for wood protection,enhancing its performance while imparting additional properties.Various approaches including nanosized metals,polymer nanocomposite and coating treatments are actively being explored in this field.Furthermore,integrating bio-based materials with nanotechnology offers a green and sustainable method for wood preservation.This paper provides an analysis,discussion,and synthesis of the applications of nanotechnology in wood protection along with its antifungal mechanisms,thereby contributing novel insights into the research landscape surrounding this topic.展开更多
The impregnation of nanoparticles magnetified into wood had been developed by different methods,like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles(NPs).However,there is...The impregnation of nanoparticles magnetified into wood had been developed by different methods,like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles(NPs).However,there is a lack of information on the best method to coprecipitation NPs.Then,the present study has the objective to measure the effects of the impregnation process of wood veneers through two in situ processes(immersion and vacuum-pressure)using a solution of FeCl_(3)·6H_(2)O,FeCl_(2)·4H_(2)O and ammonia in three tropical species(Pinus oocarpa,Vochysia ferruginea and Vochysia guatemalensis).It was measured the degree of synthesis of iron NPs using weight and density gains,Fe^(3+) absorption,emission scanning electron microscope(SEM),Fournier transform infrared spectroscopy(FT-IR)and for magnetic properties were measured using vibrating sample magnetometry(VSM).After 5-layer veneer panels were fabricated,we evaluated their physical and mechanical properties.Wood samples impregnated by vacuum-pressure methods showed the higher amount of Fe_(3)O_(4)NPs formation,which was observed in the SEM,X-ray diffraction(XDR),FT-IR and VSM.Vacuum-pressure on treatment presented higher ferrite signals and better magnetic properties.Vochysia ferruginea presented the greatest magnetization properties.The magnetization treated causes probably a degradation of the cell wall,which weakens its mechanical properties,especially internal bonding.展开更多
By means of X ray and gas chromatography analysis, the crystalline structure of untreated wood , alkali treated wood and benzylated wood and their liquefaction in toluene and tetrahydrofufan with HCl as a catalyst we...By means of X ray and gas chromatography analysis, the crystalline structure of untreated wood , alkali treated wood and benzylated wood and their liquefaction in toluene and tetrahydrofufan with HCl as a catalyst were studied .The upper solution of benzylated wood was also studied by GC MS analysis. It proved that the introduction of bulky benzyl group in wood significantly changed the crystalline structure of wood ,enlarging the free volume which facilitated the penetration of solvent into the matrix of treated wood, thus tremendously enhancing thesolubility in solvent,compared to untreated wood and alkali treated wood. The percentage of residue decreased and the combined solvent increased with the increase of weight gain revealed that the liquefaction process became easy. Furthermore, the factors that influenced the liquefaction of benzylated wood were investigated. It showed that the liquefaction performance was improved with the increase of liquefaction time and the amount of catalyst when toluene was used as a solvent, especially in the presence of THF as solvent, there existed the optimum liquefaction time and the amount of catalyst .展开更多
Studies presenting long-term observations of the recruitment and mobility of large wood in mountain watercourses are scarce,but they can considerably contribute to the knowledge of river/riparian forest interactions a...Studies presenting long-term observations of the recruitment and mobility of large wood in mountain watercourses are scarce,but they can considerably contribute to the knowledge of river/riparian forest interactions and the assessment of flood hazard resulting from wood mobility during floods.Widespread dieback of riparian forest along the headwater course of Kamienica Stream in the Polish Carpathians,caused by bark beetle infestation of spruce trees,has raised concerns about potential increases of large wood recruitment to the stream and of the flood hazard to downstream valley reaches.In October 2009,429 trees growing along three sections of the stream were tagged with numbered metal plates and monitored over 10 years to determine the timing and causes of their delivery to the channel and the lengths of their displacement during individual flood events.Moreover,in 2012 the mode of location of wood deposits and a degree of wood decay were determined in the second-to fourth-order stream reaches.The monitoring of tagged trees indicated that trees were recruited to the channel during highintensity meteorological and hydrological events,mostly as a result of bank erosion during floods or windthrow.With 22%of tagged trees recruited to the channel during 10 years,the rate of turnover of the riparian trees was estimated at 45 years.As the riparian area is overgrown with trees with ages up to^160 years,the rate evidences substantial intensification of large wood recruitment to the channel in the recent period.Results of large wood inventory and the 10-year-long monitoring of tagged trees indicated variable mobility of large wood along the upper course of the stream.Wood mobility was negligible in the second-order stream reach,very small in the third-order reach,and greater,but still limited in the fourth-order reach.Wood is transported longer distances only during major floods.However,the advanced state of decay of most pieces leads to their disintegration during floods,precluding distant transport.Thus,large wood retained in the upper stream course does not constitute an important flood hazard to downstream,inhabited valley reaches.展开更多
The objective of this study was to evaluate the effect of heat treatment on decorative properties including glossiness,color coordinates including lightness(L),blue-yellow(b^(*))and red-green(a^(*)),hardness(shore-D)m...The objective of this study was to evaluate the effect of heat treatment on decorative properties including glossiness,color coordinates including lightness(L),blue-yellow(b^(*))and red-green(a^(*)),hardness(shore-D)morphological characterization and thermal properties of some exotic wood species.Heat treatment of anigre(Aningeria altissima),cedrorana(Cedrelinga catenaeformis),cemara(Casuarina sumatrana)and coronilla(Scutia buxifolia)wood materials were performed in an oven with a programmable controller at 210°C for 3 h.The obtained samples were conditioned in a climate cabin and the decorative properties,morphological characterization with scanning electron microscopy(SEM)and thermal properties with thermogravimetric analyzer(TGA)of the obtained samples were determined.The test results showed that color got darker with heat treatment,specifically L and b^(*)decreased,and a^(*)increased for anigre and cedrorana but a^(*)decreased for cemara and coronilla.The glossiness for all samples generally increased from 20°to 85°but heat treatment decreased the glossiness.The density generally decreased with heat treatment and decrease ratio in the density was found to be in range from 5.6%to 10.6%.According to the SEM analysis,some cracks,pit aspiration and layer decomposition in the micro level of the wood structure were detected.TGA showed that heat treatment makes thermally more stable wood.As a result,it can be said that heat treatment improved the decorative properties of the exotic wood.展开更多
The use of recycled concrete and oyster shells as partial cement and aggregate replacements is ongoing research to solve this multifaceted problem of concrete waste in the construction industry as well as waste from o...The use of recycled concrete and oyster shells as partial cement and aggregate replacements is ongoing research to solve this multifaceted problem of concrete waste in the construction industry as well as waste from oyster shell farming. However, there is a lack of evidence on the possibility of producing a fully recycled composite consisting of recycled concrete and oyster shell without the need for new cement and natural aggregates. In this study, recycled concrete powder (RCP) and oyster shell were used to produce a green composite. Separate ground and combined ground (separate ground and co-ground) RCP and oyster shells are used to determine the effects of grinding approaches on the mechanical and chemical properties of the composite. The composite samples were molded via press molding by applying 30 MPa of pressure for 10 minutes. The results revealed that the composite prepared via the combined ground approach presented the highest flexural strength compared to the separate ground and unground samples. The FTIR and XRD characterization results revealed no chemical or phase alterations in the raw materials or the resulting composites before and after grinding. SEM analysis revealed that combined grinding reduced the particles’ size and improved the dispersion of the mixture, thereby increasing the strength.展开更多
Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The ...Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The results showed modifiers could raise the bonding strength of wood fiber with polymer and improve the mechanical properties of the composites. Different modifiers had different effects on the properties of wood-polymer composites, and comparatively the modifier of isocyanate produced a better result. Wood-polymer composite takes not only the advantages of both wood fiber and polymer, but waterproof, dimensional stability and dynamic strength are also significantly improved. Key word Wood fiber - Thermoplastic polyester - Wood-polymer composites - Modifier - Mechanical properties CLC number TB332 Document code A Foundation item: This study was supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).Biography: XU Min (1963-), Female, Associate professor in Material Science and Engineering College, Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Chai Ruihai展开更多
This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determine...This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.展开更多
Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the produc...Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the products is the wood sponge.The key to successfully producing wood sponges lies in an optimal multistage delignification process,which is particularly influenced by wood species,solvent,time,and temperature.The aim of this research was to analyze the characteristics of wood sponge derived from sengon wood(Falcataria moluccana Miq.)after multistage delignification.The process involved delignification using NaOH and Na_(2)SO_(3) solutions at 100℃ for 8,9 and 10 h,followed by further delignification in H_(2)O_(2) solution at 100℃ for 1,2,3,and 4 h.The samples were then frozen at -20℃ for 24 h and freeze-dried at -53℃ for 48 h.The results showed that wood sponges treated at 100℃ exhibited lower density,larger pore diameters,brighter color,and superior absorption capacity compared to untreated wood and sponges treated at room temperature for 24 h.FTIR analysis confirmed a decrease in wavelength between 1032–1035 cm^(-1),indicating the degradation of hemicellulose and lignin.XRD analysis revealed that crystallinity increased as amorphous content decreased with prolonged delignification.The wood sponges demonstrated good porosity,with an absorption capacity ranging from 0.65 to 2.24 g/g.The optimal treatment suggested in this research was multistage delignification using NaOH and Na_(2)SO_(3) solution for 10 h,followed by a 1 h treatment with H_(2)O_(2) solution.展开更多
Infrastructure in mountainous regions is particularly vulnerable when exposed to socio-natural hazards associated with extreme events,especially flood events involving the transport of large volumes of sediment and wo...Infrastructure in mountainous regions is particularly vulnerable when exposed to socio-natural hazards associated with extreme events,especially flood events involving the transport of large volumes of sediment and woody debris.In this context,understanding how such processes affect the structural stability of bridges is crucial for effective risk management and the planning of resilient infrastructure.This study examines the impacts of river floods,including large wood and sediment transport,on the“El Blanco Bridge”over the Blanco River in Chaitén,Chilean Patagonia,and the resulting susceptibility of the structure.The 2D Iber model,which solves the shallow water equations,was employed to simulate different flood scenarios as bi-phasic flows(i.e.,water,inorganic and organic sediments,the latter are referred to as large wood,LW),evaluating the hydrodynamic loadings(i.e.pressure distributions and forces)on piers and their susceptibility to sliding,overturning and scouring.Critical flood scenarios that could pose a potential risk of infrastructure failure were identified by separately determining the associated peak discharge,sediment transport rates,LW loads and bed elevation changes.Compared to clear water flows,LW transport resulted in a reduction of the factor of safety against overturning and sliding,indicating higher hydrodynamic loads on the exposed structure.When sediment transport was considered,increasing flood flows slightly augmented maximum scour depth at the base of the piers.This study underscores the significance of hydrodynamic modeling of the Blanco River for natural risk management,and highlights the importance of considering LW transport when quantifying the safety of structures,especially in catchments where easily transportable LW sources may be found(e.g.,in catchments following fires or volcanic eruptions).展开更多
Climate warming is reshaping the phenology of plants in recent decades,with potential implications for forest productivity,carbon sequestration,and ecosystem functioning.While the effects of warming on secondary growt...Climate warming is reshaping the phenology of plants in recent decades,with potential implications for forest productivity,carbon sequestration,and ecosystem functioning.While the effects of warming on secondary growth phenology is becoming increasingly clear,the influenceof environmental factors on different developmental phases of xylem remains to be quantified.In this study,we investigated the temporal dynamics of xylem cell enlargement,wall-thickening,and the interval between these events in twelve temperate tree species from Northeast China over the period 2019–2024.We found that both cell enlargement and wall-thickening advanced significantlyin response to climate warming,with species-specific variations in the rate of advancement.Importantly,the advancing rate of wallthickening was greater than that of cell enlargement,leading to a shortening of the interval between these two events.Linear mixed-effects models revealed that photoperiod,forcing temperature,and precipitation were the primary environmental drivers influencingthe timing of both cell enlargement and wall-thickening,with photoperiod emerging as the most important factor.These results suggest that climate warming accelerates the heat accumulation required for the transition from xylem cell enlargement to wall-thickening,thereby shortening the time interval between these two developmental stages.Beyond contributing valuable multi-year xylem phenological data,our results provide mechanistic insights that enhance predictions of wood formation dynamics under future climate scenarios and improve the accuracy of forest carbon models.展开更多
As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(H...As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(HKL)is limited due to its poor crosslinking reactivity.Hence,for the first time,the present study reports the facile oxidation of HKL involving a redox reaction with silver-ammonia complexes([(AgNH3)2]+),primarily focusing on oxidation to produce reactive quinones and promote C-C linkages during reaction.This study aims to increases reactivity of oxidized HKL for effective crosslinking with monoethanolamine(MEA)for the development of bio-based wood adhesives.The characterization,including 13C-nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy,confirms the oxidation reaction,such as the formation of quinones(C=O)and subsequent crosslinking between the oxidized HKL molecules and MEA.Additionally,gel permeation chromatography(GPC)confirms the C-C and C-O linkages with increased molecular weight after oxidation,and is supported by differential scanning calorimetry(DSC)which shows the exothermic reaction due to the crosslinking of the oxidized HKL molecules via condensation to form C-C and C-O linkages.The crosslinked HKL/MEA-based adhesives underwent mild reaction and achieved a maximum dry shear strength of 0.77 MPa,which exceeds the standard requirement of 0.6 MPa.These findings demonstrate not only a one-pot oxidation for improving the reactivity of HKL using silver complexes,but also its facile crosslinking with MEA for sustainable bio-based wood adhesives.展开更多
More than 30%of the earth's land surface is covered by the forest.Increase in population undergoes activities like construction,grazing,agriculture activities,and industrialization causing permanent clearing of la...More than 30%of the earth's land surface is covered by the forest.Increase in population undergoes activities like construction,grazing,agriculture activities,and industrialization causing permanent clearing of land to make room for something besides the forest,which is called deforestation.Considering this scenario,the mathematical model is framed for studying the dynamics with using four compartments such as deforestation of the dense forest,deforestation of the urban forest,population growth and wood industrialization.Using the dynamical phenomenon,the boundedness of the system is proposed.The proposed model has five equilibria.Behaviour of the system around all feasible equilibria is scrutinized through local stability theory of diferential equations.The 3d phase portrait gives the chaotic behavior of each compartment.Basic reproduction number value assists the bifurcation and the sensitivity analysis.Bifurcation analysis gives the ideal value,then the comparison of threshold and ideal value suggests the permissible situation of the compartment.For these findings,analytics results are verified through numerically validated data.展开更多
Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy.Herein,Co_(9)S_(8)/CoS heterojunctions were rationally encapsulated in S,N-codoped carb...Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy.Herein,Co_(9)S_(8)/CoS heterojunctions were rationally encapsulated in S,N-codoped carbon((Co_(9)S_(8)/CoS)@SNC)microleaf arrays,which are rooted on S-doped carbonized wood fibers(SCWF).Benefiting from the synergistic electronic interactions on heterointerfaces and the accelerated mass transfer by array structure,the obtained self-supporting(Co_(9)S_(8)/CoS)@SNC/SCWF electrode exhibits superior performance toward alkaline oxygen evolution reaction(OER)with an ultra-low overpotential of 274 mV at 1000 mA/cm^(2),a small Tafel slope of 48.84 mV/dec,and ultralong stability up to 100 h.Theoretical calculations show that interfacing Co_(9)S_(8)with CoS can upshift the d-band center of the Co atoms and strengthen the interactions with oxygen intermediates,thereby favoring OER performance.Furthermore,the(Co_(9)S_(8)/CoS)@SNC/SCWF electrode shows outstanding rechargeability and stable cycle life in aqueous Zn-air batteries with a peak power density of 201.3 mW/cm^(2),exceeding the commercial RuO_(2)and Pt/C hybrid catalysts.This work presents a promising strategy for the design of high-current-density OER electrocatalysts from sustainable wood fiber resources,thus promoting their practical applications in the field of electrochemical energy storage and conversion.展开更多
Improving consumer satisfaction with the appearance and surface quality of wood-based products requires inspection methods that are both accurate and efficient.The adoption of artificial intelligence(AI)for surface ev...Improving consumer satisfaction with the appearance and surface quality of wood-based products requires inspection methods that are both accurate and efficient.The adoption of artificial intelligence(AI)for surface evaluation has emerged as a promising solution.Since the visual appeal of wooden products directly impacts their market value and overall business success,effective quality control is crucial.However,conventional inspection techniques often fail to meet performance requirements due to limited accuracy and slow processing times.To address these shortcomings,the authors propose a real-time deep learning-based system for evaluating surface appearance quality.The method integrates object detection and classification within an area attention framework and leverages R-ELAN for advanced fine-tuning.This architecture supports precise identification and classification of multiple objects,even under ambiguous or visually complex conditions.Furthermore,the model is computationally efficient and well-suited to moderate or domain-specific datasets commonly found in industrial inspection tasks.Experimental validation on the Zenodo dataset shows that the model achieves an average precision(AP)of 60.6%,outperforming the current state-of-the-art YOLOv12 model(55.3%),with a fast inference time of approximately 70 milliseconds.These results underscore the potential of AI-powered methods to enhance surface quality inspection in the wood manufacturing sector.展开更多
Furfurylation,a renowned chemical modification technique,uses furfuryl alcohol to enhance the properties of wood.This technology can be further refined by incorporating renewable tannins,which promote cross-linking wi...Furfurylation,a renowned chemical modification technique,uses furfuryl alcohol to enhance the properties of wood.This technology can be further refined by incorporating renewable tannins,which promote cross-linking with furfuryl alcohol.This study investigates the effects of furfurylation and tannin-modified furfurylation on the physical and mechanical properties of tropical Gmelina wood(Gmelina arborea Roxb.).Experiments involved impregnating Gmelina wood with aqueous solutions of furfuryl alcohol(FA)at 40%and 70%concentrations,as well as FA-tannin combinations(FA 40%-TA and FA 70%-TA),followed by polymerization at 103℃.The results demonstrated that both FA and FA-tannin treatments significantly improved the wood’s physical and mechanical properties.Notably,FA-tannin treatments achieved anti-swelling efficiency comparable to FA alone.However,the addition of tannins(FA 70%-TA)enhanced leaching resistance by up to 47%,contributing to a more environmentally sustainable modification process.Mechanically,the inclusion of tannins in FA 70%-TA slightly increased the modulus of elasticity(14%~8732 kg/cm^(2))and the modulus of rupture(9%~40.9 kg/cm^(2)).Furthermore,the tannin addition imparted a darker color to the modified wood,enhancing its aesthetic appeal.This study highlights the potential of tannin-modified furfurylation to advance wood modification technology,combining improved performance with environmental benefits.展开更多
High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of subs...High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of substrate and active metal particles,enabling excellent catalytic properties and stability.Herein,the optimization strategy of delignification and 2,2,6,6-tetramethylpyperidine-1-oxyl(TEMPO)oxidization was developed to modify the porous structure and active groups of wood substrate,and Ru doped Co/CO_(2)P(Ru-Co/CO_(2)P)nanoparticles were encapsulated into the optimized wood carbon substrate(Ru-Co/CO_(2)P@TDCW)for the efficient pH-universal hydrogen evolution reaction(HER).The nanopore and carboxyl groups were produced by delignification and TEMPO oxidation,which accelerated the dispersion and deposition of Ru-Co/CO_(2)P nanoparticles.The RuCo alloy and RuCoP nanoparticles were produced with the doping of Ru,and more Ru-Co/CO_(2)P nanoparticles were anchored by the delignified and TEMPO oxidized wood carbon(TDCW).As anticipated,the Ru-Co/CO_(2)P@TDCW catalyst exhibited excellent pH-universal HER activity,and only 16.6,93,and 43 mV of overpotentials were required to deliver the current density of 50 mA cm^(-2)in alkaline,neutral,and acidic electrolytes,outperforming the noble Pt/C/TDCW catalyst significantly.In addition,Ru-Co/CO_(2)P@TDCW catalyst presented excellent stability for more than 600 h working at 100 mA cm^(-2)in alkaline solution(1.0 M KOH).Density function theory(DFT)results revealed that energy barriers for the dissociation of H_(2)O and the formation of H_(2)were decreased by the doping of Ru,and the conductivity and efficiency of electron migration were also enhanced.This work demonstrated a strategy to optimize the structure and properties of wood carbon substrate,providing a promising strategy to synthesize high-efficiency catalyst for H_(2)production.展开更多
The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance...The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance of low-durable wood species.Wacapou(Vouacapoua americana.,Fabaceae)is a well-known Guianese wood spe-cies commonly used in local wood construction due to its outstanding natural durability,which results from the presence of a large panel of extractives compounds.In addition,its industrial processing generates large amounts of residues.Wacapou residues were extracted by maceration using four different solvents(water/ethanol,ethyl acetate,hexane and dichloromethane/methanol),separately and successively.The yield of each extractive fraction was determined,and their chemical compositions were analyzed by Liquid Chromatography-Mass Spectrometry(LC-MS).Ethyl acetate led to the highest extraction yield,and the active compounds were identified in the obtained extractive fraction.In this sense,the fungicidal and termite-repellent properties of these extractives were then tested using a screening laboratory(with temperate and tropical microorganisms),according to the solution concentration(1%,2.5%,5%,8%and 10%).Finally,Virola michelii Heckel wood samples(low durable species)were impregnated with the 8%concentration solution.The impregnated wood samples were then exposed to a soil bed test.The results highlighted that the nature of the solvent used during wood maceration affects the con-tent of the obtained extractive fractions.Ultra-Performance Liquid Chromatography–High-Resolution Mass Spectrometry(UHPLC-HRMS)analyses showed the influence of extraction parameters on the nature of the extracted molecules.Wacapou extracts(from ethyl acetate maceration)showed good anti-fungal and anti-termite activities.Additionally,the concentration in extractives had an impact on the anti-termite activity level for Reti-culitermesflavipes and Cryptotermes sp.Formulations based on Wacapou extractives showed a good potential for valorization in eco-friendly preservatives,aiming to confer better durability to local low-durability wood species.展开更多
This article presents research focused on developing and scientifically substantiating a technology for producing environmentally friendly glued structures fromwood treated through a two-stage process.Themethodology i...This article presents research focused on developing and scientifically substantiating a technology for producing environmentally friendly glued structures fromwood treated through a two-stage process.Themethodology involves preliminary thermal modification followed by high-frequency low-temperature plasma treatment.Thermal modification enhances performance characteristics such as resistance to rot,lowers hygroscopicity,and increases dimensional stability.However,it can diminish the adhesive properties of wood,complicating the bonding process.To address this challenge,the study introduces high-frequency low-temperature plasma treatment,which activates the wood surface,improving wettability and adhesion while minimizing glue consumption.Experimental results indicate that plasma treatment reduces the contact angle by 46%and adhesive consumption during bonding by 24%,thereby enhancing the environmental friendliness of the glued structures.Furthermore,this dual treatment process increases the shear strength of adhesive joints by 22.7%and bending strength of glued beams by 66.6%,demonstrating a 30%lower carbon footprint compared to conventional methods.The findings affirm the efficacy of this technology in producing building materials,particularly glued beams for large-span structures.展开更多
文摘In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.
基金sponsored by Key Lab.of Biomass Energy and Material,Jiangsu Province(JSBEM-S-202305)Guangdong Academy of Forestry(2022-GDFS-KJ-03).
文摘Wood,recognized as a renewable and environmentally sustainable material,plays a crucial role as an alternative energy resource within the construction industry.However,it is highly susceptible to mold and decay fungi,which can lead to surface discoloration and potentially compromise the structural integrity of wood.The advancement of nanotechnology has introduced innovative strategies for wood protection,enhancing its performance while imparting additional properties.Various approaches including nanosized metals,polymer nanocomposite and coating treatments are actively being explored in this field.Furthermore,integrating bio-based materials with nanotechnology offers a green and sustainable method for wood preservation.This paper provides an analysis,discussion,and synthesis of the applications of nanotechnology in wood protection along with its antifungal mechanisms,thereby contributing novel insights into the research landscape surrounding this topic.
文摘The impregnation of nanoparticles magnetified into wood had been developed by different methods,like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles(NPs).However,there is a lack of information on the best method to coprecipitation NPs.Then,the present study has the objective to measure the effects of the impregnation process of wood veneers through two in situ processes(immersion and vacuum-pressure)using a solution of FeCl_(3)·6H_(2)O,FeCl_(2)·4H_(2)O and ammonia in three tropical species(Pinus oocarpa,Vochysia ferruginea and Vochysia guatemalensis).It was measured the degree of synthesis of iron NPs using weight and density gains,Fe^(3+) absorption,emission scanning electron microscope(SEM),Fournier transform infrared spectroscopy(FT-IR)and for magnetic properties were measured using vibrating sample magnetometry(VSM).After 5-layer veneer panels were fabricated,we evaluated their physical and mechanical properties.Wood samples impregnated by vacuum-pressure methods showed the higher amount of Fe_(3)O_(4)NPs formation,which was observed in the SEM,X-ray diffraction(XDR),FT-IR and VSM.Vacuum-pressure on treatment presented higher ferrite signals and better magnetic properties.Vochysia ferruginea presented the greatest magnetization properties.The magnetization treated causes probably a degradation of the cell wall,which weakens its mechanical properties,especially internal bonding.
文摘By means of X ray and gas chromatography analysis, the crystalline structure of untreated wood , alkali treated wood and benzylated wood and their liquefaction in toluene and tetrahydrofufan with HCl as a catalyst were studied .The upper solution of benzylated wood was also studied by GC MS analysis. It proved that the introduction of bulky benzyl group in wood significantly changed the crystalline structure of wood ,enlarging the free volume which facilitated the penetration of solvent into the matrix of treated wood, thus tremendously enhancing thesolubility in solvent,compared to untreated wood and alkali treated wood. The percentage of residue decreased and the combined solvent increased with the increase of weight gain revealed that the liquefaction process became easy. Furthermore, the factors that influenced the liquefaction of benzylated wood were investigated. It showed that the liquefaction performance was improved with the increase of liquefaction time and the amount of catalyst when toluene was used as a solvent, especially in the presence of THF as solvent, there existed the optimum liquefaction time and the amount of catalyst .
基金financed by the statutory funds of the Institute of Nature Conservation,Polish Academy of Sciencesby the project FLORIST(Flood risk on the northern foothills of the Tatra MountainsPSPB no 153/2010)supported by a grant from Switzerland through the Swiss Contribution to the Enlarged European Union。
文摘Studies presenting long-term observations of the recruitment and mobility of large wood in mountain watercourses are scarce,but they can considerably contribute to the knowledge of river/riparian forest interactions and the assessment of flood hazard resulting from wood mobility during floods.Widespread dieback of riparian forest along the headwater course of Kamienica Stream in the Polish Carpathians,caused by bark beetle infestation of spruce trees,has raised concerns about potential increases of large wood recruitment to the stream and of the flood hazard to downstream valley reaches.In October 2009,429 trees growing along three sections of the stream were tagged with numbered metal plates and monitored over 10 years to determine the timing and causes of their delivery to the channel and the lengths of their displacement during individual flood events.Moreover,in 2012 the mode of location of wood deposits and a degree of wood decay were determined in the second-to fourth-order stream reaches.The monitoring of tagged trees indicated that trees were recruited to the channel during highintensity meteorological and hydrological events,mostly as a result of bank erosion during floods or windthrow.With 22%of tagged trees recruited to the channel during 10 years,the rate of turnover of the riparian trees was estimated at 45 years.As the riparian area is overgrown with trees with ages up to^160 years,the rate evidences substantial intensification of large wood recruitment to the channel in the recent period.Results of large wood inventory and the 10-year-long monitoring of tagged trees indicated variable mobility of large wood along the upper course of the stream.Wood mobility was negligible in the second-order stream reach,very small in the third-order reach,and greater,but still limited in the fourth-order reach.Wood is transported longer distances only during major floods.However,the advanced state of decay of most pieces leads to their disintegration during floods,precluding distant transport.Thus,large wood retained in the upper stream course does not constitute an important flood hazard to downstream,inhabited valley reaches.
文摘The objective of this study was to evaluate the effect of heat treatment on decorative properties including glossiness,color coordinates including lightness(L),blue-yellow(b^(*))and red-green(a^(*)),hardness(shore-D)morphological characterization and thermal properties of some exotic wood species.Heat treatment of anigre(Aningeria altissima),cedrorana(Cedrelinga catenaeformis),cemara(Casuarina sumatrana)and coronilla(Scutia buxifolia)wood materials were performed in an oven with a programmable controller at 210°C for 3 h.The obtained samples were conditioned in a climate cabin and the decorative properties,morphological characterization with scanning electron microscopy(SEM)and thermal properties with thermogravimetric analyzer(TGA)of the obtained samples were determined.The test results showed that color got darker with heat treatment,specifically L and b^(*)decreased,and a^(*)increased for anigre and cedrorana but a^(*)decreased for cemara and coronilla.The glossiness for all samples generally increased from 20°to 85°but heat treatment decreased the glossiness.The density generally decreased with heat treatment and decrease ratio in the density was found to be in range from 5.6%to 10.6%.According to the SEM analysis,some cracks,pit aspiration and layer decomposition in the micro level of the wood structure were detected.TGA showed that heat treatment makes thermally more stable wood.As a result,it can be said that heat treatment improved the decorative properties of the exotic wood.
文摘The use of recycled concrete and oyster shells as partial cement and aggregate replacements is ongoing research to solve this multifaceted problem of concrete waste in the construction industry as well as waste from oyster shell farming. However, there is a lack of evidence on the possibility of producing a fully recycled composite consisting of recycled concrete and oyster shell without the need for new cement and natural aggregates. In this study, recycled concrete powder (RCP) and oyster shell were used to produce a green composite. Separate ground and combined ground (separate ground and co-ground) RCP and oyster shells are used to determine the effects of grinding approaches on the mechanical and chemical properties of the composite. The composite samples were molded via press molding by applying 30 MPa of pressure for 10 minutes. The results revealed that the composite prepared via the combined ground approach presented the highest flexural strength compared to the separate ground and unground samples. The FTIR and XRD characterization results revealed no chemical or phase alterations in the raw materials or the resulting composites before and after grinding. SEM analysis revealed that combined grinding reduced the particles’ size and improved the dispersion of the mixture, thereby increasing the strength.
基金Supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).
文摘Wood-polymer composites (WPC) were prepared from wood fiber and four kinds of plastics such as PE, PS, ABS, and SAN. The effects of different modifiers on the mechanical properties of the composites were studied. The results showed modifiers could raise the bonding strength of wood fiber with polymer and improve the mechanical properties of the composites. Different modifiers had different effects on the properties of wood-polymer composites, and comparatively the modifier of isocyanate produced a better result. Wood-polymer composite takes not only the advantages of both wood fiber and polymer, but waterproof, dimensional stability and dynamic strength are also significantly improved. Key word Wood fiber - Thermoplastic polyester - Wood-polymer composites - Modifier - Mechanical properties CLC number TB332 Document code A Foundation item: This study was supported by the Harbin Technology Tackle Key Plan (Development Research of Wood-Polymer Composites with High Wood Matrix) and by Heilongjing Nature Science Fund (Composite Mechanism Study of the Wood Polymer).Biography: XU Min (1963-), Female, Associate professor in Material Science and Engineering College, Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Chai Ruihai
文摘This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.
基金funded by New Energy and Industrial Technology Development Organization of Japan(NEDO)—NET ZERO EMISSION TA 2023 BATCH-2—with the Grant Number 28/Ⅲ.5/HK/2023Research Program by Research Organization of Nanotechnology and Materials,National Research and Innovation Agency(Grant Number B-1484/Ⅲ.10/TK.01.00/2/2024)Research Program by Research Assistant,National Research and Innovation Agency(Grant Number B-6932/Ⅱ.5/S1.06.01/9/2023).
文摘Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the products is the wood sponge.The key to successfully producing wood sponges lies in an optimal multistage delignification process,which is particularly influenced by wood species,solvent,time,and temperature.The aim of this research was to analyze the characteristics of wood sponge derived from sengon wood(Falcataria moluccana Miq.)after multistage delignification.The process involved delignification using NaOH and Na_(2)SO_(3) solutions at 100℃ for 8,9 and 10 h,followed by further delignification in H_(2)O_(2) solution at 100℃ for 1,2,3,and 4 h.The samples were then frozen at -20℃ for 24 h and freeze-dried at -53℃ for 48 h.The results showed that wood sponges treated at 100℃ exhibited lower density,larger pore diameters,brighter color,and superior absorption capacity compared to untreated wood and sponges treated at room temperature for 24 h.FTIR analysis confirmed a decrease in wavelength between 1032–1035 cm^(-1),indicating the degradation of hemicellulose and lignin.XRD analysis revealed that crystallinity increased as amorphous content decreased with prolonged delignification.The wood sponges demonstrated good porosity,with an absorption capacity ranging from 0.65 to 2.24 g/g.The optimal treatment suggested in this research was multistage delignification using NaOH and Na_(2)SO_(3) solution for 10 h,followed by a 1 h treatment with H_(2)O_(2) solution.
基金funded by the ANID Fondecyt Nr.1200091"Unravelling the dynamics and impacts of sediment-laden flows in urban areas in southern Chile as a basis for innovative adaptation(SEDIMPACT)"by principal investigator Bruno Mazzorana.
文摘Infrastructure in mountainous regions is particularly vulnerable when exposed to socio-natural hazards associated with extreme events,especially flood events involving the transport of large volumes of sediment and woody debris.In this context,understanding how such processes affect the structural stability of bridges is crucial for effective risk management and the planning of resilient infrastructure.This study examines the impacts of river floods,including large wood and sediment transport,on the“El Blanco Bridge”over the Blanco River in Chaitén,Chilean Patagonia,and the resulting susceptibility of the structure.The 2D Iber model,which solves the shallow water equations,was employed to simulate different flood scenarios as bi-phasic flows(i.e.,water,inorganic and organic sediments,the latter are referred to as large wood,LW),evaluating the hydrodynamic loadings(i.e.pressure distributions and forces)on piers and their susceptibility to sliding,overturning and scouring.Critical flood scenarios that could pose a potential risk of infrastructure failure were identified by separately determining the associated peak discharge,sediment transport rates,LW loads and bed elevation changes.Compared to clear water flows,LW transport resulted in a reduction of the factor of safety against overturning and sliding,indicating higher hydrodynamic loads on the exposed structure.When sediment transport was considered,increasing flood flows slightly augmented maximum scour depth at the base of the piers.This study underscores the significance of hydrodynamic modeling of the Blanco River for natural risk management,and highlights the importance of considering LW transport when quantifying the safety of structures,especially in catchments where easily transportable LW sources may be found(e.g.,in catchments following fires or volcanic eruptions).
基金supported by the Ministry of Science and Technology(No:2019FY101602).
文摘Climate warming is reshaping the phenology of plants in recent decades,with potential implications for forest productivity,carbon sequestration,and ecosystem functioning.While the effects of warming on secondary growth phenology is becoming increasingly clear,the influenceof environmental factors on different developmental phases of xylem remains to be quantified.In this study,we investigated the temporal dynamics of xylem cell enlargement,wall-thickening,and the interval between these events in twelve temperate tree species from Northeast China over the period 2019–2024.We found that both cell enlargement and wall-thickening advanced significantlyin response to climate warming,with species-specific variations in the rate of advancement.Importantly,the advancing rate of wallthickening was greater than that of cell enlargement,leading to a shortening of the interval between these two events.Linear mixed-effects models revealed that photoperiod,forcing temperature,and precipitation were the primary environmental drivers influencingthe timing of both cell enlargement and wall-thickening,with photoperiod emerging as the most important factor.These results suggest that climate warming accelerates the heat accumulation required for the transition from xylem cell enlargement to wall-thickening,thereby shortening the time interval between these two developmental stages.Beyond contributing valuable multi-year xylem phenological data,our results provide mechanistic insights that enhance predictions of wood formation dynamics under future climate scenarios and improve the accuracy of forest carbon models.
基金supported by the National Research Foundation(NRF)of Korea,funded by the Korean Government(MSIT)(Grant No.RS-2023-00240043).
文摘As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(HKL)is limited due to its poor crosslinking reactivity.Hence,for the first time,the present study reports the facile oxidation of HKL involving a redox reaction with silver-ammonia complexes([(AgNH3)2]+),primarily focusing on oxidation to produce reactive quinones and promote C-C linkages during reaction.This study aims to increases reactivity of oxidized HKL for effective crosslinking with monoethanolamine(MEA)for the development of bio-based wood adhesives.The characterization,including 13C-nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy,confirms the oxidation reaction,such as the formation of quinones(C=O)and subsequent crosslinking between the oxidized HKL molecules and MEA.Additionally,gel permeation chromatography(GPC)confirms the C-C and C-O linkages with increased molecular weight after oxidation,and is supported by differential scanning calorimetry(DSC)which shows the exothermic reaction due to the crosslinking of the oxidized HKL molecules via condensation to form C-C and C-O linkages.The crosslinked HKL/MEA-based adhesives underwent mild reaction and achieved a maximum dry shear strength of 0.77 MPa,which exceeds the standard requirement of 0.6 MPa.These findings demonstrate not only a one-pot oxidation for improving the reactivity of HKL using silver complexes,but also its facile crosslinking with MEA for sustainable bio-based wood adhesives.
基金Supported by the DST-FIST file(#MSI-097)funded by UGC granted National Fellowship for Other Backward Classes(NFO-2018-19-OBC-GUJ-71790)funded by a Junior Research Fellowship from the Council of Scientific&Industrial Research(09/07(0061)/2019-EMR-I)。
文摘More than 30%of the earth's land surface is covered by the forest.Increase in population undergoes activities like construction,grazing,agriculture activities,and industrialization causing permanent clearing of land to make room for something besides the forest,which is called deforestation.Considering this scenario,the mathematical model is framed for studying the dynamics with using four compartments such as deforestation of the dense forest,deforestation of the urban forest,population growth and wood industrialization.Using the dynamical phenomenon,the boundedness of the system is proposed.The proposed model has five equilibria.Behaviour of the system around all feasible equilibria is scrutinized through local stability theory of diferential equations.The 3d phase portrait gives the chaotic behavior of each compartment.Basic reproduction number value assists the bifurcation and the sensitivity analysis.Bifurcation analysis gives the ideal value,then the comparison of threshold and ideal value suggests the permissible situation of the compartment.For these findings,analytics results are verified through numerically validated data.
基金supported by National Key Research and Development Program of China(No.2023YFD2200503)the Young Elite Scientists Sponsorship Program from National Forestry and Grassland Administration of China(No.2019132614)+1 种基金the Science and Technology Innovation Program of Hunan Province(Nos.2021RC3103 and 2022RC3054)the Scientific Research Project of Hunan Provincial Education Department(Nos.23B0276 and 21B0225).
文摘Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy.Herein,Co_(9)S_(8)/CoS heterojunctions were rationally encapsulated in S,N-codoped carbon((Co_(9)S_(8)/CoS)@SNC)microleaf arrays,which are rooted on S-doped carbonized wood fibers(SCWF).Benefiting from the synergistic electronic interactions on heterointerfaces and the accelerated mass transfer by array structure,the obtained self-supporting(Co_(9)S_(8)/CoS)@SNC/SCWF electrode exhibits superior performance toward alkaline oxygen evolution reaction(OER)with an ultra-low overpotential of 274 mV at 1000 mA/cm^(2),a small Tafel slope of 48.84 mV/dec,and ultralong stability up to 100 h.Theoretical calculations show that interfacing Co_(9)S_(8)with CoS can upshift the d-band center of the Co atoms and strengthen the interactions with oxygen intermediates,thereby favoring OER performance.Furthermore,the(Co_(9)S_(8)/CoS)@SNC/SCWF electrode shows outstanding rechargeability and stable cycle life in aqueous Zn-air batteries with a peak power density of 201.3 mW/cm^(2),exceeding the commercial RuO_(2)and Pt/C hybrid catalysts.This work presents a promising strategy for the design of high-current-density OER electrocatalysts from sustainable wood fiber resources,thus promoting their practical applications in the field of electrochemical energy storage and conversion.
文摘Improving consumer satisfaction with the appearance and surface quality of wood-based products requires inspection methods that are both accurate and efficient.The adoption of artificial intelligence(AI)for surface evaluation has emerged as a promising solution.Since the visual appeal of wooden products directly impacts their market value and overall business success,effective quality control is crucial.However,conventional inspection techniques often fail to meet performance requirements due to limited accuracy and slow processing times.To address these shortcomings,the authors propose a real-time deep learning-based system for evaluating surface appearance quality.The method integrates object detection and classification within an area attention framework and leverages R-ELAN for advanced fine-tuning.This architecture supports precise identification and classification of multiple objects,even under ambiguous or visually complex conditions.Furthermore,the model is computationally efficient and well-suited to moderate or domain-specific datasets commonly found in industrial inspection tasks.Experimental validation on the Zenodo dataset shows that the model achieves an average precision(AP)of 60.6%,outperforming the current state-of-the-art YOLOv12 model(55.3%),with a fast inference time of approximately 70 milliseconds.These results underscore the potential of AI-powered methods to enhance surface quality inspection in the wood manufacturing sector.
基金funded by the Directorate General of Higher Education,Research,and Technology,Ministry of Education,Culture,Research,and Technology,Indonesia,which sponsored the research grant via the National Competitive Basic Research Scheme,No.027/E5/PG.02.00.PL/2024facilitated by IPB University(Bogor Agricultural University)through Research Contract No.22055/IT3.D10/PT.01.03/P/B/2024+1 种基金funded by Research Organization for Nanotechnology and Materials No.3/III.10/HK/2023National Research and Innovation Agency(BRIN),Indonesia.
文摘Furfurylation,a renowned chemical modification technique,uses furfuryl alcohol to enhance the properties of wood.This technology can be further refined by incorporating renewable tannins,which promote cross-linking with furfuryl alcohol.This study investigates the effects of furfurylation and tannin-modified furfurylation on the physical and mechanical properties of tropical Gmelina wood(Gmelina arborea Roxb.).Experiments involved impregnating Gmelina wood with aqueous solutions of furfuryl alcohol(FA)at 40%and 70%concentrations,as well as FA-tannin combinations(FA 40%-TA and FA 70%-TA),followed by polymerization at 103℃.The results demonstrated that both FA and FA-tannin treatments significantly improved the wood’s physical and mechanical properties.Notably,FA-tannin treatments achieved anti-swelling efficiency comparable to FA alone.However,the addition of tannins(FA 70%-TA)enhanced leaching resistance by up to 47%,contributing to a more environmentally sustainable modification process.Mechanically,the inclusion of tannins in FA 70%-TA slightly increased the modulus of elasticity(14%~8732 kg/cm^(2))and the modulus of rupture(9%~40.9 kg/cm^(2)).Furthermore,the tannin addition imparted a darker color to the modified wood,enhancing its aesthetic appeal.This study highlights the potential of tannin-modified furfurylation to advance wood modification technology,combining improved performance with environmental benefits.
基金financially supported by the National Natural Science Foundation of China(32101452)the Research Foundation of Education Bureau of Hunan Province(22B0283)+2 种基金the Hunan Provincial Natural Science Foundation(2022JJ40865)the Talents Research Funding of Central South University of Forestry and Technology(2021YJ007)the Scientific Innovation Fund for Graduate of Central South University of Forestry and Technology(2024CX02005)。
文摘High-performance catalyst is significant for the sustainable hydrogen(H_(2))production by electrocatalytic water splitting.Optimizing porous structure and active groups of substrate can promote the interaction of substrate and active metal particles,enabling excellent catalytic properties and stability.Herein,the optimization strategy of delignification and 2,2,6,6-tetramethylpyperidine-1-oxyl(TEMPO)oxidization was developed to modify the porous structure and active groups of wood substrate,and Ru doped Co/CO_(2)P(Ru-Co/CO_(2)P)nanoparticles were encapsulated into the optimized wood carbon substrate(Ru-Co/CO_(2)P@TDCW)for the efficient pH-universal hydrogen evolution reaction(HER).The nanopore and carboxyl groups were produced by delignification and TEMPO oxidation,which accelerated the dispersion and deposition of Ru-Co/CO_(2)P nanoparticles.The RuCo alloy and RuCoP nanoparticles were produced with the doping of Ru,and more Ru-Co/CO_(2)P nanoparticles were anchored by the delignified and TEMPO oxidized wood carbon(TDCW).As anticipated,the Ru-Co/CO_(2)P@TDCW catalyst exhibited excellent pH-universal HER activity,and only 16.6,93,and 43 mV of overpotentials were required to deliver the current density of 50 mA cm^(-2)in alkaline,neutral,and acidic electrolytes,outperforming the noble Pt/C/TDCW catalyst significantly.In addition,Ru-Co/CO_(2)P@TDCW catalyst presented excellent stability for more than 600 h working at 100 mA cm^(-2)in alkaline solution(1.0 M KOH).Density function theory(DFT)results revealed that energy barriers for the dissociation of H_(2)O and the formation of H_(2)were decreased by the doping of Ru,and the conductivity and efficiency of electron migration were also enhanced.This work demonstrated a strategy to optimize the structure and properties of wood carbon substrate,providing a promising strategy to synthesize high-efficiency catalyst for H_(2)production.
基金PROTEXTWOOD (ID 2202-102) funded through LabEx AGRO ANR-10-LABX-0001-01 (under ISiteUniversité de Montpellier framework)the project PANTHER2-Guyane funded through AgenceNationale de la Recherche (ANR-22-CE43-0019)+2 种基金“Investissement d’Avenir” grant managed by Agence Nationale de la Recherche (CEBA, ref. ANR-10-LABX-25-01)supported by the FEDER (European Regional Development Fund)research project “EcovaloBois” (Project number: GY0015430)by the CNRS peps INSIS2018 research project “GuyavaloFibres”.
文摘The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance of low-durable wood species.Wacapou(Vouacapoua americana.,Fabaceae)is a well-known Guianese wood spe-cies commonly used in local wood construction due to its outstanding natural durability,which results from the presence of a large panel of extractives compounds.In addition,its industrial processing generates large amounts of residues.Wacapou residues were extracted by maceration using four different solvents(water/ethanol,ethyl acetate,hexane and dichloromethane/methanol),separately and successively.The yield of each extractive fraction was determined,and their chemical compositions were analyzed by Liquid Chromatography-Mass Spectrometry(LC-MS).Ethyl acetate led to the highest extraction yield,and the active compounds were identified in the obtained extractive fraction.In this sense,the fungicidal and termite-repellent properties of these extractives were then tested using a screening laboratory(with temperate and tropical microorganisms),according to the solution concentration(1%,2.5%,5%,8%and 10%).Finally,Virola michelii Heckel wood samples(low durable species)were impregnated with the 8%concentration solution.The impregnated wood samples were then exposed to a soil bed test.The results highlighted that the nature of the solvent used during wood maceration affects the con-tent of the obtained extractive fractions.Ultra-Performance Liquid Chromatography–High-Resolution Mass Spectrometry(UHPLC-HRMS)analyses showed the influence of extraction parameters on the nature of the extracted molecules.Wacapou extracts(from ethyl acetate maceration)showed good anti-fungal and anti-termite activities.Additionally,the concentration in extractives had an impact on the anti-termite activity level for Reti-culitermesflavipes and Cryptotermes sp.Formulations based on Wacapou extractives showed a good potential for valorization in eco-friendly preservatives,aiming to confer better durability to local low-durability wood species.
基金funded by the Technostart competition,Agreement No.12-22(2-22)dated 01 February 2022.
文摘This article presents research focused on developing and scientifically substantiating a technology for producing environmentally friendly glued structures fromwood treated through a two-stage process.Themethodology involves preliminary thermal modification followed by high-frequency low-temperature plasma treatment.Thermal modification enhances performance characteristics such as resistance to rot,lowers hygroscopicity,and increases dimensional stability.However,it can diminish the adhesive properties of wood,complicating the bonding process.To address this challenge,the study introduces high-frequency low-temperature plasma treatment,which activates the wood surface,improving wettability and adhesion while minimizing glue consumption.Experimental results indicate that plasma treatment reduces the contact angle by 46%and adhesive consumption during bonding by 24%,thereby enhancing the environmental friendliness of the glued structures.Furthermore,this dual treatment process increases the shear strength of adhesive joints by 22.7%and bending strength of glued beams by 66.6%,demonstrating a 30%lower carbon footprint compared to conventional methods.The findings affirm the efficacy of this technology in producing building materials,particularly glued beams for large-span structures.
