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Inducing adventitious root (AR) formation in mature walnut species (Juglans L.) is challenging. However, the AR formation of mature trees can be improved by rejuvenation. In rejuvenated cuttings, exogenous indole-3-butyric acid (IBA) is essential for AR formation, and the underlying mechanism is still not well understood. Therefore, we utilized transcriptome sequencing to investigate the mechanism of IBA-induced AR formation. Our results revealed that, in comparison to the control group, IBA treatment (9 mmol • L-1) significantly increased the endogenous indole-3-acetic acid (IAA) content, leading to an enhanced rooting rate. We performed RNA sequencing to identify differentially expressed genes (DEGs) between the IBA-treated and control (CK) groups at 1, 2, 3, and 5 days after cutting (DAC). The results showed that, compared to the control cuttings, there were 1 539, 889, 785, and 984 up-regulated genes and 2 791, 2 936, 3 017, and 1 752 down-regulated genes, at 1, 2, 3, and 5 DAC, respectively. Analysis of RNA-seq data revealed that G-type ATP-binding cassette 36/37 (ABCG36/37) and ATP-binding cassette subfamily D 1 (ABCD1), associated with IBA transport, were down-regulated in the rejuvenation cuttings. In contrast, PIN-FORMED (PIN) and PINOID (PID), associated with auxin efflux, were up-regulated. We identified 49 auxin/indole-3-acetic acid (AUX/IAA)-encoding genes, including IAA1, IAA3, IAA5, IAA6, IAA8, IAA11, IAA12, IAA19, and IAA20, which were up-regulated at 1e5 DAC in the rejuvenated cuttings. This study highlights that the overexpression of JrWOX5/11 in poplar significantly enhance AR growth, as evidenced by increased root length, surface area, volume, and quantity. Moreover, the co-expression network analysis involving JrWOX11 and JrWOX5 in walnut cuttings elucidates complex genetic interactions, underscoring their pivotal role in the formation of AR. Our data supported the following molecular mechanism of IBA-induced adventitious root formation. Firstly, IBA is converted to free IAA in peroxisomes. Then, the highly concentrated IAA in the procambium and parenchyma cells induces WUSCHEL-related homeobox 11 (WOX11) expression at two days. Finally, WOX11 acts redundantly to up-regulate WOX5, initiating the development of root primordia cells. [ABSTRACT FROM AUTHOR]

The forestry and pulp industry in Chile has been a significant contributor to the country's gross domestic product (GDP), accounting for over 1.2% between 2018 and 2022. This sector is expected to continue growing in the coming years. The purpose of this study was to assess the environmental performance of the production of 1 tonne of short fibre bleached cellulose using the Kraft process in Chile. The assessment focused on quantifying the impact in 10 life-cycle impact categories, utilising the ReCiPe 2016 Midpoint (H) V.1.03 impact method. The evaluation followed a cradle-to-gate approach, considering the various stages including forestry activities involving biocides, fertilisers, and machinery, as well as transportation, and the subsequent industrial stage encompassing chemicals consumption, electricity usage, fuel consumption, and waste disposal. The assessment adhered to the life-cycle assessment guidelines specified in ISO 14040-44:2006 and utilised primary data from 2017, with a base year production of 1,495,000 tonnes of pulp. The results revealed that the industrial stage had the most significant environmental impact in eight out of the ten categories studied. Notably, the Global Warming Potential (GWP) reached 784 kg CO2eq/tonne of cellulose, which is noticeably higher in comparison to other countries but consistent with domestic and Ecoinvent 3.4 results. Additionally, biogenic emissions reached 3140 kg CO2biogenic/tonne of cellulose, primarily due to the combustion of waste wood and black liquor for energy recovery and electricity generation delivered to the national grid. The forestry stage was found to be the primary contributor to marine eutrophication (MAEU) and stratospheric ozone depletion (SOD), accounting for up to 86% of this environmental impact category. These results can be attributed to the usage of chemicals such as nitrogen-based fertilisers and biocides (fungi and herbicides). These findings provide quantified information that can facilitate informed comparisons with similar processes and aid in decision-making to improve the forestry-industrial sector. Emphasis should be placed on those activities that have the most significant impacts on the Chilean pulp sector, thereby promoting sustainable practices and mitigating environmental consequences. [ABSTRACT FROM AUTHOR]

The efficient use of softwood in biorefineries requires harsh pretreatment conditions to overcome biomass recalcitrance. Following harsh pretreatments, the hemicellulose is solubilized. Here, we studied the material characteristics of Norway spruce following steam pretreatment at six different severities, relating chemical and structural information to the enzymatic hydrolyzability. Steam pretreatment conditions were defined by two different temperatures (180 °C and 210 °C), with and without the addition of various acids (CH3COOH, H3PO4, H2SO4, SO2). Structural knowledge of the streams is a cornerstone for developing an efficient saccharification process. This study combines advanced structural characterizations to gain fundamental understanding of the influence of severity of pretreatment on spruce. Structural knowledge is a cornerstone in developing an effective saccharification process by modulating pretreatment conditions and enzymes employed. Overall structural properties were assessed by scanning electron microscopy. The effect of stream pretreatment severity on lignin and lignin-carbohydrate bonds was investigated by two-dimensional heteronuclear single quantum correlation nuclear magnetic resonance. Finally, cellulose ultrastructure was studied by applying small/wide-angle X-ray scattering. The structural characteristics of the six pretreated softwood substrates were related to the enzymatic hydrolyzability. With increasing pretreatment severity, surface defibrillation, and lignin depolymeryzation were observed. Further, lignin-carbohydrate complexes signals were detected. Cellulose analysis revealed the rearrangement of microfibrils leading to the formation of larger microfibril aggregates. This microfibril rearrangement likely contributed to the observed increase in enzymatic hydrolysis yields as better enzyme accessibility resulted. [ABSTRACT FROM AUTHOR]

Commercial kitchen towels (basis weight 39 to 56 g/m²) made of virgin and recycled fiber, produced by Through-Air-Drying (TAD), and conventional Yankee cylinder drying (with creping) were analyzed. The properties of these commercial tissue products were compared to those of handsheets made from them. Laboratory tissue handsheets were also prepared from northern bleached softwood kraft (NBSK), eucalyptus, bamboo, and straw pulp. Fibers were refined with up to 5000 revolutions of a PFI mill. Commercial kitchen towels (kitchen tissue) absorbed 9 to 14 g water per 1 g of fiber, with higher absorption by virgin fibers, and when using TAD. The tensile index (dry) was 3 to 14 Nm/g. Laboratory tissue handsheets made of commercial samples absorbed less water, but the tensile index (dry) was higher in most cases. Higher beating levels (tested at NBSK, eucalyptus, bamboo, straw pulp) increased tensile index. Curl, bulk, softness, absorption capacity, and suction lift were reduced with refining. Best values for absorption capacity (almost 8 g/g), bulk (almost 5 cm³/g), and softness were observed in laboratory bamboo tissue sheets made of non-refined fibers. After refining (2000 revolutions), the tensile index of such tissue sheets made of bamboo increased from 10 to 30 Nm/g. [ABSTRACT FROM AUTHOR]

Wood chips and sawdust are used for cultivating Ganoderma lucidum mushrooms. In Northern Europe, side-streams of Pinus sylvestris are highly abundant, however as cultivation substrate they inhibit the growth of G. lucidum. To identify the changes in lignocellulosic composition after fungal degradation, the major lignocellulosic components in P. sylvestris and an optimal substrate for G. lucidum, Populus tremula were analyzed. Populus tremula was evenly degraded while the glucan fraction of P. sylvestris was not degraded and its lignin fraction was consumed almost completely. Despite not being an optimal substrate, P. sylvestris was successfully delignified by G. lucidum. [ABSTRACT FROM AUTHOR]

The hypothesis was that low residual alkali after cooking would cause lignin re-precipitation during washing and in turn affect the subsequent oxygen delignification stage negatively. To test the hypothesis, kraft cooks were performed in lab-scale to different residual alkali levels, ranging from 5 to 15 g/L and the pulps were subjected to washing with either water or 0.1 M NaOH and then oxygen delignified. The results show that even at low residual alkali and washing with water, the pH in the liquor after washing was above 11 which is sufficiently high to keep lignin in solution. No effect of residual alkali level was observed on the performance of the oxygen delignification stage. [ABSTRACT FROM AUTHOR]

Soft clay is a problematic type of soil because it has high water content, low shear strength, low bearing capacity, and high compressibility. This study explores the effectiveness of stabilizing soft clay using a combination of coir fiber, coconut husk ash, and wood ash. This research investigated the impact of incorporating 0.75% coir fiber and varying levels of a coconut husk ash-wood ash mixture (ranging from 0% to 10%) on the shear strength properties of soft clay. The study applied two different curing times: seven and 21 days. An unconsolidatedundrained triaxial test was conducted following ASTM D2850-03. The results demonstrated that combining coir fiber reinforcement with chemical stabilization through the ash mixture significantly enhanced the deviatoric stress, cohesion, internal friction angle, shear strength, and elastic modulus of soft soil. Specifically, an 8% ash content with a 21-day curing time achieved the highest deviatoric stress and shear strength. This highest shear strength value was 210% greater than soil solely reinforced with coir fiber. [ABSTRACT FROM AUTHOR]

Plastic recycling, waste minimization such as process outfall valorization promotes a circular economy. Herein, food trays have been produced in the moulded pulp thermoforming process. To this end, high-density polyethylene (HDPE) outfall has been dispersed in water via Poly vinyl alcohol (PVA) addition in a Northern Bleached Softwood Kraft Pulp (NBSKP) slurry. Samples physical and mechanical properties have been evaluated. With an increasing HDPE content, parts air permeability was drastically reduced to a minimum of 2.4 ± 0.8 mL min−1. In addition, water and grease hold out properties have been increased with minimum water Cobb1800 value of 10.9 ± 5.4 gm−2 and oil Cobb1800 value of 13.18 ± 6.5 gm−2. Samples with high HDPE content demonstrated hydrophobic surface with water contact angle value above 90°. HDPE melting and binding to wood pulp fibers was monitored by SEM images. Regarding the mechanical properties, HDPE induced plastic deformation with a reduced Young modulus by 17 %. Moreover, the addition of HDPE increased wet strength by 81 %. However, the produced food tray composites with high HDPE content demonstrated low repulpability index. [ABSTRACT FROM AUTHOR]

A fundamental requirement for analysing timber structures under fire is to consider the degradation of material properties with temperature. Therefore, the objective of this study is to propose a model that accounts for the variation of the thermo-physical properties, the development of char, and its evolution with temperature. This model integrates a sequential coupling of heat transfer analysis with structural response. The degradation of the material properties is accounted for through the regulatory approach recommended in Eurocode 5. The stress analysis employs an elasto-plastic model with nonlinear isotropic hardening. Implementation of the model is achieved within the Abaqus suite of finite element software using external subroutines. The model's predictions align well with experimental data, accurately reproducing both thermal and structural responses. Specifically, the model accurately predicts temperature profiles, displacements, and the depth of the charred layer, which initiates above 300 °C. Additionally, for rectangular sections, it was observed that exposure of all faces to fire results in a non-rectangular residual section. Furthermore, employing the temperature-dependent thermal property curves suggested by EC5 yields satisfactory results when predicting the fire resistance of softwood timber structures. [ABSTRACT FROM AUTHOR]

This study investigates the influence of hole diameter and hole spacing on the fractionation performance using an industrial scale pressure screen. The objective is to increase the quality of the long fiber fraction during dissolving pulp production by separating cellulosic fines from unbleached softwood sulfite pulp containing 8% (w/w) primary fines (fibrous particles shorter than 0.200 mm fiber length). Different screen basket designs were applied, using the same hole spacing while varying hole diameter, and vice versa. This allowed a comparison of the separate influence of hole diameter and hole spacing on the separation efficiency. Production parameters of screening devices are always a compromise between separation efficiency, runnability/plugging, and throughput. High aperture velocity, high feed consistency and low reject rate were identified as the crucial operating parameters for high cellulosic fines removal efficiency, which turned out to be positive in terms of throughput. Considering the different hole diameters, the industrial trials showed that smaller holes yielded better fractionation results. Whereas reduced hole spacing resulted in a denser fiber network on the screen, reducing the amount of fines and short fibers passing, thereby leading to worse fractionation results. By choosing suitable screening conditions, we found that the weight-weighted fines content was reduced more than 50 percent using a one stage fiber fractionation screen set up under industrial conditions. The lowered fines content in the long fiber fraction is expected to allow a reduced purification effort and a lower chemical demand in the subsequent processes of dissolving pulp production. By reducing the fines fraction, consisting of short fibers, fiber fines, as well as mainly short-chain alkali-soluble carbohydrates (hemicelluloses), improvements in process efficiency and dissolving pulp quality can be achieved. [ABSTRACT FROM AUTHOR]

Abstract There are numerous wooden historical artifacts in Kyoto and other parts of Japan, including Buddhist statues or Shinto deities. The identification of wood species in these historical artifact is desirable for both repair and maintenance purposes. The most common method of identifying wood species involves examining samples taken from the artifacts. However, intentional sampling from old cultural artifacts is prohibited in Japan. As a result, we attempted to determine the wood species of old statues non-destructively using near-infrared spectroscopy (NIRS). In this article, we developed the softwood and hardwood separation model using NIRS to compare the prediction accuracy for few algorithms. The model was created based on wood samples stored in the xylarium of the Forestry and Forest Products Research Institute (TWTw). We then applied this model to old Buddhist statues in order to classify them as either softwood or hardwood. These Buddhist statues were housed in Nazenji temple and are believed to have been carved during the Heian period (8th–12th century). For the near-infrared (NIR) measurements, we collected diffuse reflectance spectra from TWTw sample and Buddhist statues using same spectrometer. Initially, we used the soft independent modeling of class analogy method (SIMCA), partial least squares discriminant analysis (PLS_DA), and support vector machine to analyze the NIR spectra obtained from the TWTw wood samples. Subsequently, we applied the NIR spectra obtained from several Buddhist statues in Nazenji temple to the aforementioned separation model and determined whether spectra data were classified as the softwood or hardwood. Finally, wood specimens detached naturally from the Buddhist statues over time were observed under microscopic analysis to identify the wood species. As comparing the prediction accuracy of few algorithms, SIMCA had a poor result, but PLS_DA had a good result. PLS_DA had better discrimination because it performed calculations to improve regression from both explanatory variables and objective variables.

Because of the association with other complex polysaccharides, extracting and utilizing cellulose from lignocellulosic materials requires the combined action of a broad range of carbohydrate‐active enzymes, including multiple glycoside hydrolases (GHs) and lytic polysaccharide monooxygenases (LPMOs). The interplay between these enzymes and the way in which Nature orchestrates their co‐existence and combined action are topics of great scientific and industrial interest. To gain more insight into these issues, we have studied the lignocellulose‐degrading abilities of an enzyme from Caldibacillus cellulovorans (CcLPMO10‐Man5), comprising an LPMO domain, a GH5 mannanase domain and two family 3 carbohydrate‐binding modules (CBM3). Using a natural softwood substrate, we show that this enzyme promotes cellulase activity, i.e., saccharification of cellulose, both by removing mannan covering the cellulose and by oxidatively breaking up the cellulose structure. Synergy with CcLPMO10‐Man5 was most pronounced for two tested cellobiohydrolases, whereas effects were smaller for a tested endoglucanase, which is in line with the notion that cellobiohydrolases and LPMOs attack the same crystalline regions of the cellulose, whereas endoglucanases attack semi‐crystalline and amorphous regions. Importantly, the LPMO domain of CcLPMO10‐Man5 is incapable of accessing the softwood cellulose in absence of the mannanase domain. Considering that LPMOs not bound to a substrate are sensitive to autocatalytic inactivation, this intramolecular synergy provides a perfect rationale for the evolution of modular enzymes such as CcLPMO10‐Man5. The intramolecular coupling of the LPMO with a mannanase and two CBMs ensures that the LPMO is directed to areas where mannans are removed and cellulose thus becomes available. [ABSTRACT FROM AUTHOR]

The potential of oxygen delignified fibers to replace fully bleached fibers in tissue products was investigated on softwood pulps. The absorption, mechanical properties and softness of laboratory tissue hand sheets from one commercial fully bleached pulp and five unbleached oxygen delignified lab pulps were compared. The pulps with different lignin content and total fiber charge were evaluated with and without PFI refining. The pulps subjected to oxygen delignification resulted in pulps with much higher total fiber charge content that led to higher swelling and higher wet strength when compared to the commercial fully bleached pulp. Some unbleached oxygen delignified pulps showed great potential in the absorption capacity, while others showed a much higher wet tensile strength when compared to the commercial pulp. Compared to the commercial bleached pulp, a similar softness for a higher wet and dry tensile index in the unbleached fibers was observed for the oxygen delignified pulps. Unbleached pulps subjected to an extended oxygen delignification proved to be a suitable alternative to fully bleached pulps in tissue grades, depending on the desired property (absorption or wet strength). [ABSTRACT FROM AUTHOR]

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Citric acid can be used as a bio-based binding agent in composites made from lignocellulosic material due to its crosslinking ability with hydroxyl groups via ester formation. Even though plenty of research has investigated diverse manufacturing conditions, with a focus on citric acid content and pressing temperature, an apparent knowledge gap persists regarding their effect on the properties of particleboards made from softwood sawdust. Furthermore, the optimal temperature for particleboards crafted from mostly non-wood lignocellulosic materials was found to be 180–200°C which is lower than that observed for softwood material in a prior study. This study aimed to systematically examine the effects of citric acid content and pressing temperature on particleboards derived from softwood sawdust. Results highlighted a positive correlation of both citric acid content and pressing temperature with mechanical and hygroscopic properties of the particleboards, the best results being achieved at 20 wt% citric acid and 220°C, exhibiting a thickness swelling of 9%, internal bonding strength of 0.77 MPa and a modulus of rupture of 4.3 MPa. This study served as a foundational framework for future investigations into the addition of other chemicals, offering a comprehensive understanding of their interactions with citric acid in particleboard manufacturing. [ABSTRACT FROM AUTHOR]

Wood branches subjected to bending develop reaction wood to accommodate both tensile and compressive stresses. For softwood, such as Norway spruce and Scots pine, compression wood (CW) develops in the lower parts, while opposite wood (OW) develops on the upper parts of the branch. It is likely that the ratio of CW to OW is optimised for mechanical load bearing by nature. This hypothesis was tested with an analytical beam model using experimental data of stiffness and strength of CW and OW at CW fractions from 0 to 100%. It was found that there is indeed a maximum bending moment capacity around 35% CW, like literature values of CW content in softwood branches. For all compositions, compressive or tensile strength of OW was governing the behaviour. [ABSTRACT FROM AUTHOR]

Bronze artifacts often suffer from "bronze disease" due to the presence of chloride ions, which result from copper chlorides forming on their surfaces during storage. Therefore, reinforced protection is essential for these unearthed cultural artifacts, and new materials for the reinforced protection of fragile bronzes are urgently needed. In this study, cuprammonium solvent and nanocellulose (CNC) were utilized as reinforcement materials to protect fragile bronzes. The chemical and aesthetic properties before and after reinforcement were analyzed using ultra-depth field microscopes, SEM-EDX, XRD, and Raman spectroscopy. The results indicated that at a nano-cuprammonium reinforcer concentration of 2.5 mol/L, the optimal reinforcement effect on simulated bronze powdery rust samples was achieved.Mechanical strength increased by an average of 77.59%. The mass growth rate reached 84.8%, while the color difference Δ E remained below 4.0. Additionally, aging resistance significantly improved, aligning with cultural artifact protection standards.Meanwhile, a compact and stable protective membrane formed on the surface of the bronzes, isolating the bronze matrix from direct contact with the external environment, which delayed bronze corrosion and contributed to long-term stable preservation. [ABSTRACT FROM AUTHOR]

Background: 2-Naphthol, a carbocation scavenger, is known to mitigate lignin condensation during the acidic processing of lignocellulosic biomass, which may benefit downstream processing of the resulting materials. Consequently, various raw materials have demonstrated improved enzymatic saccharification yields for substrates pretreated through autohydrolysis and dilute acid hydrolysis in the presence of 2-naphthol. However, 2-naphthol is toxic to ethanol-producing organisms, which may hinder its potential application. Little is known about the implications of 2-naphthol in combination with the pretreatment of softwood bark during continuous steam explosion in an industrially scalable system. Results: The 2-naphthol-pretreated softwood bark was examined through spectroscopic techniques and subjected to separate hydrolysis and fermentation along with a reference excluding the scavenger and a detoxified sample washed with ethanol. The extractions of the pretreated materials with water resulted in a lower aromatic content in the extracts and stronger FTIR signals, possibly related to guaiacyl lignin, in the nonextractable residue when 2-naphthol was used during pretreatment. In addition, cyclohexane/acetone (9:1) extraction revealed the presence of pristine 2-naphthol in the extracts and increased aromatic content of the nonextractable residue detectable by NMR for the scavenger-pretreated materials. Whole-slurry enzymatic saccharification at 12% solids loading revealed that elevated saccharification recoveries after 48 h could not be achieved with the help of the scavenger. Glucose concentrations of 16.9 (reference) and 15.8 g/l (2-naphthol) could be obtained after 48 h of hydrolysis. However, increased inhibition during fermentation of the scavenger-pretreated hydrolysate, indicated by yeast cell growth, was slight and could be entirely overcome by the detoxification stage. The ethanol yields from fermentable sugars after 24 h were 0.45 (reference), 0.45 (2-naphthol), and 0.49 g/g (2-naphthol, detoxified). Conclusion: The carbocation scavenger 2-naphthol did not increase the saccharification yield of softwood bark pretreated in an industrially scalable system for continuous steam explosion. On the other hand, it was shown that the scavenger's inhibitory effects on fermenting microorganisms can be overcome by controlling the pretreatment conditions to avoid cross-inhibition or detoxifying the substrates through ethanol washing. This study underlines the need to jointly optimize all the main processing steps. [ABSTRACT FROM AUTHOR]

The object of this study is the process of roasting iron ore pellets. The study solves the task of replacing fossil fuel with plant-based fuel in order to reduce environmental load and ensure the stable quality of pellets, which is necessary for use in blast furnaces. The influence of biofuel content at a given temperature and air speed on the strength of pellets after roasting was studied. As a result of the research, it was established that the fuel content has a decisive effect on the strength of pellets. Among all types of fuel that were investigated, pellets with the addition of sunflower husks and wood had the highest strength that meets the requirements for blast furnace melting of 200 kilograms. The use of wheat straw and charcoal does not make it possible to completely replace solid fuel in the layer of pellets. The results show that the use of up to 0.36 % of sunflower husk makes it possible to increase the strength of burned pellets compared to samples without biofuel content. Adding all other considered types of fuel reduced the strength of the pellets. These results are explained by the different content of lignin, cellulose, and hemicellulose, which determines the characteristics of the biomass. The high content of cellulose and hemicellulose allows for high hydrophilicity due to the high number of OH groups and positively affects the formation of raw pellets. Volatile substances released during the combustion of biofuel contribute to the formation of spherical pores, as well as their uniform distribution, which prevents the propagation of cracks under load. Research results make it possible to establish the optimal roasting mode, decrease harmful emissions, and bring down costs by reducing fossil fuel consumption [ABSTRACT FROM AUTHOR]

Global regulations are guiding society towards more sustainable material solutions. This increasing awareness of the need for environmentally friendly alternatives has led to a greater emphasis on biocomposites, which combine natural fibers with bio-based polymers. This study investigates how bleached softwood pulp fibers (BSWPF) and unbleached softwood pulp fibers (UBSWPF) affect the characteristics of poly(lactic acid) (PLA)-based biocomposites. UBSWPF is a more cost-effective option because it is manufactured with less processing steps than BSWPF. However, it is largely unexplored as a reinforcement in biopolymers. Through investigating the mechanical, thermal, and morphological aspects of the biocomposites, this study showed that UBSWP increased the modulus and impact strength of the PLA biocomposites better than BSWPF. The impact strength, modulus, and tensile strength of PLA-BSWPF and PLA-UBSWPF improved as the fiber content increased. However, a decrease in tensile strength was seen at higher percentages of UBSWPF in PLA. Despite the decrease in tensile strength at higher UBSWPF concentrations, both types of fibers improved the mechanical properties of the biocomposites, demonstrating a potential sustainable reinforcing material for PLA biocomposites. [ABSTRACT FROM AUTHOR]

Mechanochemical methods for cellulose processing have gained significant attention for the higher efficiency and the potential for special applications. Cellulose pulp fibers from different sources including softwood, hardwood and bamboo were selected as starting materials in this study, because the performance and sustainability of cellulose based materials are highly dependent on their sources. They were successfully defibrillated and functionalized in one-step by 3-aminopropyltriethoxysilane (APTES)-assisted ball milling method. The morphology, chemical structure and crystal structure of the cellulose fibers before and after modification were characterized. Translucent cellulose films with high haze (about 94.8%) were prepared through vacuum-assisted filtration. The test results show that the addition of APTES plays a significant role in enhancing the performance of cellulose films, not only weakening the hydrophilicity (water contact angle of up to 88°), but also enhancing the transparency (transmittance of up to 78%), thermal stability and mechanical properties. These demonstrate that the APTES-assisted ball milling method is an effective way to tailor the structure of cellulose fibers due to its easy operation and wide applicability. In addition, softwood and bamboo films that show relatively higher comprehensive performance on the radar chart have higher application value in the packaging, composite materials and other fields. This work provides guidance for the design and efficient preparation of high-performance cellulose materials. [ABSTRACT FROM AUTHOR]

In this study, the impact of mercerization and PFI refining on the properties of softwood kraft pulp was investigated. Never-dried softwood kraft pulp was treated with 15 wt% NaOH to generate highly hydrated fibers, followed by PFI refining to increase pulp fibrillation and porosity. The original and modified pulp properties were assessed for morphological and chemical composition. Differential scanning calorimetry (DSC) tests and water retention value (WRV) measurements were conducted to evaluate pulp swelling behavior and porosity. Fiber bonding potential and strength properties were evaluated from handsheets of mercerized and unmercerized pulp. Mercerization with 15 wt% NaOH successfully converted cellulose I to cellulose II, leading to slightly increased pulp swelling and micropore volume. However, the mercerization reduced handsheet strength properties. Furthermore, PFI refining resulted in a negligible enhancement of bonding in mercerized pulp, in stark contrast to its significant effect on unmercerized kraft pulp. [ABSTRACT FROM AUTHOR]

The impact of ultimate limit state checks on the fire resistance of the cross-section (element) of softwood structural timber is analyzed in this study, which was found to depend on the cross-sectional area, strength class or material quality expressed through the actual price. The limit state method and the reduced cross-section method were used to obtain numerical results. The established practice suggests that, if the ultimate limit state is satisfied, the softwood structural timber will meet fire resistance according to the load-bearing criterion of 30 min (R30). This study shows that this is not entirely correct and is not always applicable. The main results of this study are precisely related to the above, and it will now be possible to provide much more precise answers to questions related to fire resistance according to the load-bearing criterion. Certainly, the price, which plays a significant role in achieving a certain or required fire resistance, should not be overlooked. This study provides the possibility of optimizing the choice of the cross-sectional area, fire resistance and price, depending on the state of stress to which the cross-section (element) is exposed. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs) have been investigated for biomedical applications in medical imaging due to their fluorescent properties, overall long-term stability, and excellent cytocompatibility and biocompatibility. Lignin is an organic polymer in the tissues of woody plants. It is also considered a byproduct of the wood and pulp industries. Hence, it presents as a renewable source of carbon nanoparticles. In this study, we report the synthesis and material and biological characterization of two colloidal suspensions of CQDs in water derived from lignin-based carbon. One was the native form of CQDs derived from lignin carbon, and the second was doped with nitrogen to evaluate material differences. Material characterization was carried out using various commonly used techniques, including Fourier transform infrared spectroscopy (FTIR), emission and absorbance spectra, zeta potential, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Thin films of CQDs were formed on glass and silicon substrates to assess the in vitro cytocompatibility with human mesenchymal stem cells (hMSCs). Observations suggest that the two forms of CQDs promote cell attachment within 24 h and sustain it for at least 7 days. The overall structure and shape of cells suggest a lack of any adverse or toxic effects of CQDs. The data lay down the novel foundation to support the use of lignin-derived CQDs in tissue engineering applications. [ABSTRACT FROM AUTHOR]

There are numerous wooden historical artifacts in Kyoto and other parts of Japan, including Buddhist statues or Shinto deities. The identification of wood species in these historical artifact is desirable for both repair and maintenance purposes. The most common method of identifying wood species involves examining samples taken from the artifacts. However, intentional sampling from old cultural artifacts is prohibited in Japan. As a result, we attempted to determine the wood species of old statues non-destructively using near-infrared spectroscopy (NIRS). In this article, we developed the softwood and hardwood separation model using NIRS to compare the prediction accuracy for few algorithms. The model was created based on wood samples stored in the xylarium of the Forestry and Forest Products Research Institute (TWTw). We then applied this model to old Buddhist statues in order to classify them as either softwood or hardwood. These Buddhist statues were housed in Nazenji temple and are believed to have been carved during the Heian period (8th–12th century). For the near-infrared (NIR) measurements, we collected diffuse reflectance spectra from TWTw sample and Buddhist statues using same spectrometer. Initially, we used the soft independent modeling of class analogy method (SIMCA), partial least squares discriminant analysis (PLS_DA), and support vector machine to analyze the NIR spectra obtained from the TWTw wood samples. Subsequently, we applied the NIR spectra obtained from several Buddhist statues in Nazenji temple to the aforementioned separation model and determined whether spectra data were classified as the softwood or hardwood. Finally, wood specimens detached naturally from the Buddhist statues over time were observed under microscopic analysis to identify the wood species. As comparing the prediction accuracy of few algorithms, SIMCA had a poor result, but PLS_DA had a good result. PLS_DA had better discrimination because it performed calculations to improve regression from both explanatory variables and objective variables. [ABSTRACT FROM AUTHOR]

The porosity of cell walls, as indicated by diffusion of rhodamine B dye, in the wood of Douglas fir, radiata pine, New Zealand red beech and Shining gum was compared under dynamic conditions using fluorescence recovery after photobleaching. The comparative diffusion rate was estimated using the half-life of fluorescence recovery under water-saturated conditions performed on transverse sections. All four wood species showed similar diffusion behaviour in tracheid or fibre cell walls with slower diffusion in the middle lamella layer compared to the secondary cell wall. Within the S2 layer of the secondary wall two regions were observed, an outer region with a slow diffusion rate and an inner region with a higher diffusion rate. Vessel cell walls showed slightly slower diffusion rates. Diffusion of rhodamine B dye appears to occur primarily along the fibre axis and is probably somewhat different to water in its behaviour. This suggests that pores are aligned with cellulose microfibrils. The dye diffusion rate was estimated to be in the range of 50–100 nm2 s−1. This has implications for understanding wood drying behaviour and chemical modification of wood by infiltration with small molecules as well as water storage in living trees. [ABSTRACT FROM AUTHOR]

In order to determine the suitability of packaging materials made of paper/cardboard and used in different public institutions in charge of Costa Rican documentary heritage, the measurement of the acidity (pH) of the materials was carried out, as well as the use of infrared spectroscopy to study the changes in the crystalline structure of paper cellulose molecules, which influence the oxidation and degradation of cellulose as a consequence of aging (Chiriu et al., 2018). Studying the materials used to package and store documents with historical/heritage value is of high importance since these are the ones that remain in direct contact with the cultural assets for years, even decades. In total, the measurement of the physicochemical properties was carried out in four different aging stages (0, 8, 15 and 28 days), in order to compare the results and establish the changes and degradations in the materials, this to determine which of the sampled materials are more suitable for packaging documentary heritage, both in the short and long term, and according to the parameters analyzed. [ABSTRACT FROM AUTHOR]

Softwood is widely employed in construction and faces high demand. Australia is grappling with substantial timber scarcity, specifically related to radiata pine, which is the dominant structural timber in the construction sector. However, Australia has a significant hardwood population, which can be utilized to reduce the high demand for radiata pine. This paper aims to investigate the bond properties of both Australian softwood (radiata pine) and hardwood (shining gum). It also discusses the potential to combine softwood and hardwood in glue or cross-laminated timber by evaluating the bond properties of the radiata pine–shining gum interface. For hardwood, the effect of primer is also investigated to determine its efficacy in improving failure mode, bond strength, and stiffness. Lastly, both glulam and cross-laminated timber bonding scenarios are simulated for bond testing by examining the effect of relative fibre orientation on the bond properties of the aforementioned species individually and in combination. Instead of conventional block shear testing, which is predominantly used for same-species bond testing, push-out testing is adopted in this study. However, a comparison with block shear testing is also made in this article. The results indicated that the use of primer on hardwood reduced the inconsistencies in the bond properties and improved wood-side failure rates. It was also concluded that the effect of fibre orientation in a CLT scenario with combined hardwood and softwood failure modes can vary significantly, which leads to a higher standard deviation in the results. Nevertheless, this study outlines the challenges and opportunities for producing hardwood–softwood hybrid glue or cross-laminated timber. [ABSTRACT FROM AUTHOR]

The demand for Vaccinium fruits has skyrocketed due to their nutritional and medicinal properties, notably their high content of phenolic compounds and excellent sensory evaluation. The use of Vaccinium plants and its components as dietary supplements and health ingredients has been on the rise across the world. The attractive fruits contain a high content of anthocyanins and antioxidant compounds. In some popular and valuable cultivars, the conventional propagation methods, exploiting hard or soft wood cuttings, are inefficient. The demand for nursery plants can be fulfilled by micropropagation. This review aims to explore advances in the in vitro culture of Vaccinium plants, focusing on effective disinfection, optimized culture media, and the role of growth regulators in plant development and multiplication. By providing a controlled environment, micropropagation allows the large-scale production of these plants in a short time, ensuring availability throughout the year. Additionally, this technique offers the advantage of studying the effects of abiotic stresses on plants, as well as facilitating research on the production of relevant metabolites. This review seeks to provide an updated overview of the most promising methods and techniques for micropropagation of Vaccinium, thereby contributing to the ongoing development of the blueberry production industry and derivative products. [ABSTRACT FROM AUTHOR]

In this work we have investigated the effect of surface modification of fibres on the overall mechanical properties of high-density papers. Paper sheets were prepared by a combination of heat-pressing and polyelectrolyte Layer-by-Layer (LbL) modification of different softwood fibres. LbLs of Polyallylamine Hydrochloride (PAH) and Hyaluronic Acid (HA) were adsorbed onto unbleached kraft fibres and bleached Chemo-ThermoMechanical Pulp (CTMP) to improve the strength of the fibre–fibre joints in papers made from these fibres. Additionally, different sheet-making procedures were used to prepare a range of network densities with different degrees of fibre–fibre interaction in the system. The results demonstrate that interfacial adhesion within fibre–fibre joints plays a pivotal role in the network's performance, even at higher paper densities. Hygroexpansion measurements and fracture zone imaging with Scanning Electron Microscopy (SEM) further support the claim that stronger interactions between the fibres allow for a better utilisation of the inherent fibre properties. Surface treatments and network densification significantly improved the paper sheets' mechanical properties. Specifically, LbL-treatments alone increased specific stiffness up to 60% and specific strength by over 100%. This improvement is linked to the build-up of residual stresses during drying. Due to a high interaction between the fibres during water removal the fibres become constrained, leading to increased stretching of fibre segments. Strengthened fibre joints intensify this constraint, further increasing the stretch and, consequently, the paper's strength. [ABSTRACT FROM AUTHOR]

The current research describes the multiplication of Paulownia elongata S. Y. Hu, a timber plant, through the forcing of softwood shoots from epicormic buds under glasshouse conditions in spring and fall seasons. Different growth media were used to compare their effect on the forcing potential of epicormic buds. For this, 25–30-cm-long and 1.2–2-cm-diameter stem segments taken from the lower juvenile portion of a mother plant were placed horizontally in flat trays containing media, i.e., sterilized well-moistened sand, peat moss, perlite, and vermiculite individually. Furthermore, 4–6-cm-long forced softwood shoots were detached and treated with various concentrations of IBA (indole-3-butyric acid) and NAA (α-naphthyl acetic acid) either individually or in combinations for subsequent rooting. The response of shoot forcing was better in spring as compared to fall in terms of shoot length (cm), and number of shoots or leaves; however, an earlier bud break was observed during fall after 30 days of the initial experiment. The use of peat moss and vermiculite proved to be equally suitable for early bud break in both seasons, whereas in terms of shoot and leaf number as well as the shoot length (cm), the best outcome was observed in sand. Best rooting was observed at 3 gL−1 IBA + 3 gL−1 NAA in terms of root number per shoot, root length (cm), and days to root initiation while using sand as the growth medium after 50 days of the rooting experiment. The successfully established plantlets were further shifted to soil at Botanical Garden, University of the Punjab, Lahore, Pakistan, exhibiting an 87.5% survival rate. On the basis of the results obtained, it may be concluded that reasonable softwood shoot forcing in P. elongata may further be exploited for its mass scale nursery propagation as well as use in future in vitro studies. [ABSTRACT FROM AUTHOR]

Laser-induced graphene (LIG) is a versatile form of graphene materials synthesized through direct laser writing (DLW) onto a carbon-rich precursor. Lignin is a promising natural precursor for LIG. However, the lack of understanding of the relationship between lignin chemistry and LIG properties limits the effective utilization of lignin. Herein, we aimed to understand the structural evolution of lignin into few-layer graphene during direct laser writing via the combined experimental investigation and reactive force field molecular dynamics (MD) simulation. Strong correlations were found between structural features of lignin and LIG characteristics, especially the sheet resistance (electrical conductivity) and defects in graphene domains. Specifically, higher molecular weight lignin demonstrated a superior propensity for generating the graphitic structure in the turbostratic matrix of LIG. This phenomenon led to better graphene quality in terms of morphological continuity, conductivity, and graphene domains. The glass transition temperature (Tg) of fractionated lignin was identified to have the strongest linear correlation with both sheet resistance and defect density in LIG. Additionally, the MD simulations shed light on the role of closely positioned carbon atoms in the initial substrate, highlighting their facilitative effect on the formation of large graphene domains. The proposed LIG formation pathway offers a new avenue for lignin biorefinery, facilitating efficient production of graphene materials from renewable resources. [ABSTRACT FROM AUTHOR]

In this study, digital light processing (DLP) was utilized to generate 3D-printed blends composed of photosensitive acrylate-modified polylactic acid (PLA) resin mixed with varying weight ratios of lignin extracted from softwood, typically ranging from 5 wt% to 30 wt%. The microstructure of these 3D-printed blends was examined through X-ray microtomography. Additionally, the tensile mechanical properties of all blends were assessed in relation to the weight ratio and post-curing treatment. The results suggest that post-curing significantly influences the tensile properties of the 3D-printed composites, especially in modulating the brittleness of the prints. Furthermore, an optimal weight ratio was identified to be around 5 wt%, beyond which UV light photopolymerization experiences compromises. These findings regarding acrylate-modified PLA/lignin blends offer a cost-effective alternative for producing 3D-printed bio-sourced components, maintaining technical performance in reasonable-cost, low-temperature 3D printing, and with a low environmental footprint. [ABSTRACT FROM AUTHOR]

Owing to the increasing interest in sustainability and bio-based materials, softwood kraft lignin (SKL) was acetone-fractionated to reduce its heterogeneity and then demethylated to substitute phenol in lignin–phenol–formaldehyde (LPF) resins to be used as bio-based wood adhesives. This study investigated the effect of the demethylation of acetone-soluble SKL (AS-SKL) on the adhesion of LPF resins, where phenol was partially replaced with acetone-soluble demethylated kraft lignin (AS-DKL). Characterization of SKL, AS-KL, and AS-DKL using gel permeation chromatography (GPC), FTIR, and 31P NMR spectroscopy showed that the demethylation was successfully performed; the molecular weight (MW) and the number of methoxy groups decreased, and the number of –OH groups increased. The MW, chemical reactions, and curing behavior of LPF resins synthesized with different AS-DKL levels (10, 20, 30, and 50 wt%) were also characterized. With the increase in AS-DKL content, the viscosity and MW of the resin increased, whereas the gelation time decreased. LPF resins with 10% AS-DKL showed the highest tensile shear strength and lowest peak curing temperature. These results suggest that 10% is an optimal AS-DKL level in LPF resins for plywood bonding and that demethylation is an effective way of utilizing SKL. [ABSTRACT FROM AUTHOR]

Thermogravimetric analysis (TGA) was performed on five softwood and five hardwood thin wood samples in the longitudinal (L) and radial (R) directions. Dimensional changes were monitored using a charge-coupled device camera under a nitrogen flow. A comparison of the TG and derivative TG (DTG) curves revealed that shrinkage in the R direction began when the weight was reduced to 79–92% at 305–330 °C and 87–96% at 275–290 °C for softwoods and hardwoods, respectively. Hemicellulose is mainly degraded in this temperature range. In contrast, shrinkage in the L direction started at temperatures close to the DTG peaks, i.e., 360–380 °C and 345–370 °C, respectively, at which temperatures cellulose is mainly degraded. In general, the R/L shrinkage anisotropy was greater for hardwoods than for softwoods, but the species variation was large and the magnitude was directly related to the difference in the shrinkage onset temperatures between the R and L directions, regardless of the wood species. Therefore, shrinkage anisotropy can be attributed to the relative reactivity of hemicellulose and cellulose in wood cell walls. The shrinkage mechanism during carbonization is discussed in terms of the cell wall ultrastructure, in which cellulose microfibrils are covered by a hemicellulose–lignin matrix, and the orientation of the cells in the L and R directions. [ABSTRACT FROM AUTHOR]

The transient dimensional changes during hygro-expansion and hydro-expansion of freely and restrained dried, softwood and hardwood sheets and fibers is monitored, to unravel the governing micro-mechanisms occurring during gradual water saturation. The response of individual fibers is measured using a full-field global digital height correlation method, which has been extended to monitor the transient hydro-expansion of fibers from dry to fully saturated. The hygro- and hydro-expansion is larger for freely versus restrained dried and softwood versus hardwood handsheets. The transient sheet-scale hydro-expansion reveals a sudden strain and moisture content step. It is postulated that the driving mechanism is the moisture-induced softening of the so-called "dislocated regions" in the fiber's cellulose micro-fibrils, unlocking further fiber swelling. The strain step is negligible for restrained dried handsheets, which is attributed to the "dislocated cellulose regions" being locked in their stretched configuration during restrained drying, which is supported by the single fiber hydro-expansion measurements. Finally, an inter-fiber bond model is exploited and adapted to predict the sheet-scale hygro-expansion from the fiber level characteristics. The model correctly predicts the qualitative differences between freely versus restrained dried and softwood versus hardwood handsheets, yet, its simplified geometry does not allow for more quantitative predictions of the sheet-scale hydro-expansion. [ABSTRACT FROM AUTHOR]

The cationic cellulose nanofibrils demonstrate outstanding properties and have garnered extensive attention as sustainable materials. However, the large-scale preparation of cationic cellulose nanofibrils was limited since the high crystallinity of plant fibers made them harder to disintegrate and nanofibrillate. In this study, cationic cellulose nanofibrils, HKCF, were produced from softwood bleached kraft pulp (SWBK) with 2,3-epoxypropyltrimethylammonium chloride (EPTAC) by disk milling, followed by high-pressure homogenization. Morphologies and structures of cationic fibers (KCF and CCF) and homogenized products were characterized. The influence of cationization combined with high mechanical shear on the degree of substitution (DS) of cationic fibers was studied. At the same molar ratios of EPTAC to anhydroglucose units and holding time, the DS of KCF was higher than that of CCF. Compared with simple mixing induced by conventional stirring, the high mechanical shear induced by disk milling could increase the cationic efficiency of EPTAC by at least 50%. After high-pressure homogenization, KCF was completely fibrillated to HKCF with nano-scaled dimensions. HKCF dispersion showed a Bingham flow behavior and viscosity-dominating fluid-like behavior. Our study provides a facile and effective industrialized approach for producing highly substituted cationic cellulose nanofibrils. [ABSTRACT FROM AUTHOR]

Developing an environmentally friendly and more efficient pulping process is necessary to cope with the pollution issues created by the current pulp and paper mills. Although Organosolv pulping is considered environmentally friendly compared to kraft or soda pulping, the higher cost hindered the commercialization of the Organosolv process to pulp different raw materials. Therefore, this research aimed to explore the papermaking potential of three raw materials i.e., spruce, beech, and miscanthus, using Acetosolv pulping. This research also includes the determination of properties of the fibers influenced by refining and application potential that could arise for the fibers in terms of strength, barrier, and optical properties. Paper sheets showed excellent air barriers, which justifies their applications in the packaging sector. It was concluded that if the tensile index is the selection criteria, then even miscanthus (a nonwood material) Acetosolv pulp can replace the spruce softwood kraft pulp. Also, transparency and contact angle were found to be maximum for spruce which can facilitate its application as a substrate in green electronics. [ABSTRACT FROM AUTHOR]

The chemoselective hydrodeoxygenation of natural lignocellulosic materials plays a crucial role in converting biomass into value‐added chemicals. Yet their complex molecular structures often require multiple active sites synergy for effective activation and achieving high chemoselectivity. Herein, it is reported that a high‐entropy alloy (HEA) on high‐entropy oxide (HEO) hetero‐structured catalyst for highly active, chemoselective, and robust vanillin hydrodeoxygenation. The heterogenous HEA/HEO catalysts were prepared by thermal reduction of senary HEOs (NiZnCuFeAlZrOx), where exsolvable metals (e.g., Ni, Zn, Cu) in situ emerged and formed randomly dispersed HEA nanoparticles anchoring on the HEO matrix. This catalyst exhibits excellent catalytic performance: 100% conversion of vanillin and 95% selectivity toward high‐value 2‐methyl‐4 methoxy phenol at low temperature of 120 °C, which were attributed to the synergistic effect among HEO matrix (with abundant oxygen vacancies), anchored HEA nanoparticles (having excellent hydrogenolysis capability), and their intimate hetero‐interfaces (showing strong electron transferring effect). Therefore, our work reported the successful construction of HEA/HEO heterogeneous catalysts and their superior multifunctionality in biomass conversion, which could shed light on catalyst design for many important reactions that are complex and require multifunctional active sites. [ABSTRACT FROM AUTHOR]

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