Search

Aluminum oxide clusters (AlOCs) possess high surface areas and customizable pore structures, making them applicable in the field of environmental remediation. However, their practical use is hindered by stability issues, aggregation tendencies, and recycling challenges. This study presents an in -situ synthesis of AlOCs on cellulose using a solvent thermal method. The resulting adsorbent's structural and property profiles were thoroughly characterized using multiple analytical techniques. Batch adsorption experiments were performed to assess the adsorbent's capacity and kinetics in removing selected dyes from aqueous solutions. Additionally, both real-environment simulation and regeneration experiments have been conducted to thoroughly assess the adsorbent's reliability, stability, and practical applicability. The aim was to engineer an effective and recyclable adsorbent specifically tailored for dye-contaminated wastewater treatment. [ABSTRACT FROM AUTHOR]

This research develops and evaluates a recyclable corrugated cardboard vibration isolation box reinforced with balsa wood as an alternative to traditional open trench methods for mitigating ground-borne environmental body waves. This study includes designing and testing scaled prototypes, laboratory analyses, prototype fabrication, and full-scale field experiments. In soft ground conditions, ensuring slope stability during deep excavations is a key engineering challenge for open trenches. For this purpose, scaled prototypes were subjected to laboratory tests to assess the resistance of the wave barrier's wall surface. Numerical analyses were also conducted to evaluate the strength of the internal lattice structure under various loads. A prototype was fabricated for on-site experiments simulating real-world conditions. Field experiments evaluated the vibration isolation performance of the proposed barrier. Accelerometer sensors were strategically placed to gather data, analyzing ground surface vibrations for free field motions to assess the vibration shielding efficiency of both the open trench method and the corrugated vibration isolation box, with and without Styrofoam infill. This study concludes that the recyclable corrugated vibration isolation box is a viable alternative, offering comparable or improved vibration isolation efficiency in soft soil conditions while promoting environmental sustainability using recyclable materials. [ABSTRACT FROM AUTHOR]

Solar‐driven steam generation has emerged as a sustainable technology for addressing freshwater scarcity. However, significant challenges still exist in developing high‐performance, multifunctional evaporators that are adept at both efficiently evaporating water and degrading pollutants, primarily because of the trade‐offs among functional designs. Here, a self‐floating solar evaporator is reported by functionalizing balsa wood with solar‐thermal conversion material carbon nanotubes and catalytic manganese dioxide (MnO2) nanoflowers for simultaneous solar evaporation and pollutant degradation. MnO2 nanoflowers are rich in oxygen vacancies that can effectively activate peroxymonosulfate to generate reactive oxygen species for efficient organic pollutant degradation. A distinctive non‐wetted porous interior structure and a precisely targeted water pathway are spontaneously established in the multifunctional evaporator, ensuring fast water supply, thermal insulation, efficient mass transfer, and high buoyancy. The resulting evaporators successfully combine an impressive evaporation rate of 2.74 kg m−2 h−1, a high pollutant degradation efficiency (98.3% for 100 mg L−1 tetracycline and 97.4% for 200 mg L−1 Methyl orange), and stable self‐floating and self‐standing capabilities that ensure long‐term operation stability even in complex real‐world environments. This work provides an approach to design multifunctional solar evaporators, ensuring strong alignment with practical requirements while expanding their potential application scenarios. [ABSTRACT FROM AUTHOR]

Utilizing natural balsa wood as the raw material, cellulose was prepared using microwave-assisted chlorocholine chloride/lactic acid deep eutectic solvents (DES) in synergy with H2O2, followed by further preparation of cellulose nanocrystals (CNCs) via ultrasound treatment. Initially, the optimal process for balsa wood cellulose preparation was explored through single-factor and response surface experiments involving microwave-assisted DES in synergy with H2O2 treatment. Subsequently, cellulose nanocrystals were prepared using ultrasound, and the resulting materials were characterized and analyzed for their chemical composition, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nanoparticle size distribution, transmission electron microscopy (TEM) analysis, and thermogravimetric-differential scanning calorimetry (TG-DSC). The results indicate that the yield of cellulose after microwave-assisted DES in synergy with H2O2 treatment can reach 42.96%. Furthermore, the cellulose nanocrystals obtained after ultrasound treatment exhibit a particle size ranging from 10 to 20 nm, with an average length of 515.9 nm, a crystallinity of 86.72%, and demonstrate good dispersion and thermal stability. Highlights: Microwave-assisted deep eutectic solvent (MaDES) is able to effectively remove lignin and hemicellulose from balsa wood. Determining optimal MaDES treatment conditions through response surface analysis. MaDES cellulose exhibits high cellulose purity with H2O2 treatment. Cellulose nanocrystals prepared from MaDES cellulose purified with H2O2 exhibit high aspect ratio and high crystallinity. Preparation of Cellulose Nanocrystals from Balsa wood Using MaDES with H2O2 treatment produces high-value cellulose nanocrystals while being environmentally friendly and sustainable. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ochroma pyramidale (Cav. Ex Lam.) is a rapidly growing pioneer tree native to the Americas. This species is important for rehabilitating degraded areas as well as commercially due to the wood`s low density and high resistance, making it useful for producing structural cores and lightweight plywood, as well as in the wind energy industry. For at least 50 years, two varieties of this species have been recognized by botanists as well as the Lacandon people of Chiapas, Mexico. This study provides comparative data regarding three years of growth of the white and red varieties of Ochroma pyramidale, indicating ideal soil and climatic conditions for commercial plantations. The white variety had a greater rate of growth and thrives with a high average annual precipitation (2330–3236 mm) and Luvisol or Leptosol with a neutral pH and a high P content. The red variety appears to be the most widely used in other regions of the world, while the white variety is rarely used commercially.

This research develops and evaluates a recyclable corrugated cardboard vibration isolation box reinforced with balsa wood as an alternative to traditional open trench methods for mitigating ground-borne environmental body waves. This study includes designing and testing scaled prototypes, laboratory analyses, prototype fabrication, and full-scale field experiments. In soft ground conditions, ensuring slope stability during deep excavations is a key engineering challenge for open trenches. For this purpose, scaled prototypes were subjected to laboratory tests to assess the resistance of the wave barrier’s wall surface. Numerical analyses were also conducted to evaluate the strength of the internal lattice structure under various loads. A prototype was fabricated for on-site experiments simulating real-world conditions. Field experiments evaluated the vibration isolation performance of the proposed barrier. Accelerometer sensors were strategically placed to gather data, analyzing ground surface vibrations for free field motions to assess the vibration shielding efficiency of both the open trench method and the corrugated vibration isolation box, with and without Styrofoam infill. This study concludes that the recyclable corrugated vibration isolation box is a viable alternative, offering comparable or improved vibration isolation efficiency in soft soil conditions while promoting environmental sustainability using recyclable materials.

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

The use of residues from human activities has been currently gaining ground in the national and international markets, aiming toward the production of more sustainable materials that are less aggressive to the environment. Reusing and adding value to new products has also become an important factor in reducing production costs and the best alternative for this is process optimization. The choice for residual balsa wood was due to its rapid growth and low density, as well as for its ease of engineering and determining the ideal amount of resin for different types of panels. This study aims to investigate the influence of the content variation of castor oil-based polyurethane resin on the physical and mechanical properties of OSB board particles made from residual balsa wood in reforestation areas. The panels were produced with 8, 10, and 12 % commercial castor oil-based polyurethane resin and 9 mm long particles; their physical and mechanical characterizations followed international normative recommendations. The results indicated that the panels with resin contents higher than 10 % reached the minimum regulatory requirements for type 2 OSB panels, suitable for structural application. On the other hand, the panels produced with 8 % resin reached the minimum requirements for type 1 OSB panels, suitable for non-structural use by the furniture industry, such as linings and partitions. Therefore, our study concludes that the variation of resin contents for OSB panels of residual balsa wood allowed us to achieve optimal levels for the use of castor oil-based polyurethane resin, reaching minimum values recommended by regulations for OSB panels type 1 and 2 and a great possibility of application of this product for engineered materials. [ABSTRACT FROM AUTHOR]

Wood-based functional materials have developed rapidly. But the flammability significantly limits its further application. To improve the flame retardancy, the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold, and then alternately immersed in CaCl2 ethanol solution and NaHCO3 aqueous solution under vacuum. The high porosity and wettability resulting from delignification benefited the following mineralization process, changing the thermal properties of balsa wood significantly. The organic-inorganic wood composite showed abundant CaCO3 spherical particles under scanning electron microscopy. The peak of the heat release rate of delignified balsa-CaCO3 was reduced by 33% compared to the native balsa, according to the cone calorimetric characterization. The flame test demonstrated that the mineralized wood was flame retardant and selfextinguish. Additionally, the mineralized wood also displayed lower thermal conductivity. This study developed a feasible way to fabricate a lightweight, fire-retardant, self-extinguishing, and heat-insulating wood composite, providing a promising route for the valuable application of cellulosic biomass. [ABSTRACT FROM AUTHOR]

The focus of this study is the experimental assessment of the mechanical behaviour of balsa wood and its sandwich structures, where balsa serves as the core, supported by carbon fibre-epoxy skin layers. A comprehensive characterisation is conducted on the mechanical behaviour of balsa wood and carbon fibre-epoxy balsa core sandwich structures subjected to a range of low strain rates. Initially, the study undertakes a consistent procedure for sample preparation. Subsequently, the characterisation of the manufactured composite structures is performed experimentally. A stereo microscope is employed for a detailed visual inspection of the internal structure of the balsa wood and the sandwich structures. Furthermore, the mechanical characterisation is carried out with three-point bending tests at a range of strain rates from 0.1 % to 6 % strain per minute. This research reveals key findings about balsa wood and its sandwich structures, highlighting their performance and their sensitivity even under low strain rates.

Solar-driven absorption has been emerging as a promising technology to clean up crude oil. The photothermal performance of porous absorbents reduces the viscosity of crude oil and allows in-situ oil absorption and desalination when exposed to solar irradiation. However, the process of crude oil recovery (e.g., squeeze) will inevitably damage the properties of the absorbent, seriously reducing its long-term efficacy. Herein, an innovative strategy is designed for in-situ solar-driven crude oil recovery and desalination technology for long-term efficacy without any surface degradation or biofouling. A dual-function photothermal aerogel (PCM@WA) was prepared by modifying delignified wood with polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and molybdenum dioxide (MoO2). The aerogel displays an efficient crude oil absorption of 35.4 g/g under one sun irradiation. In multiple absorption-recovery cycles, the decline in oil absorption ability promotes the water transport capacity of the aerogel, providing PCM@WA with excellent solar steam generation performance. It exhibits a high and stable evaporation rate of 1.96 kg/m2/h and the total metal removal efficiency is over 99.8%. The strategy combining crude oil absorption with seawater desalination not only extends the device life but also fully exploits the photothermal conversion technology to handle environmental pollution and energy crisis. [ABSTRACT FROM AUTHOR]

The development of new materials for the construction sector is a global trend, and products that use by-products in their composition and have also incorporated technology are commercially competitive. Microparticles have large surface areas and can modify the microstructure of materials, positively affecting their physical and mechanical properties. In this context, this study aims to investigate the effect of incorporating aluminium oxide (Al2O3) microparticles on the physical and mechanical properties of oriented strand boards (OSBs) made from reforested residual balsa and castor oil polyurethane resin and to evaluate their durability performance under accelerated aging conditions. The OSBs were produced on a laboratory scale with a density of 650 kg/m3, strand-type particles measuring 90 × 25 × 1 mm3, using castor oil-based polyurethane resin (13%) and Al2O3 microparticle content ranging from 1% to 3% of the resin mass. The physical and mechanical properties of the OSBs were determined following the EN-300:2002 recommendations. The results obtained indicated that the OSBs with 2% Al2O3 presented thickness swelling significantly lower (at the 5% significance level) after being subjected to accelerated aging and internal bonding of the particles higher than the values obtained for the references, evidencing the positive effect of including Al2O3 microparticles in balsa OSBs. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • N-doped porous carbon materials (WNPC) were derived by ZIF-8 modified balsa wood. • WNPC showed excellent H 2 O 2 generation capability in electro-Fenton system. • WNPC has a good selectivity for two electron oxygen reduction reaction. • Hydroxyl radicals were the main active substances for efficient TC degradation. Efficient electrochemical advanced oxidation processes (EAOPs) based on carbon catalysts are highly promising candidates for green environmental remediation technologies. Wood derived N-doped porous carbon (WNPC) was prepared the balsa wood with in-situ growth of zeolitic imidazolate framework-8 (ZIF-8) was used as precursor. WNPC acted as self-supporting electric Fenton cathode with high yield and selectivity (96 %) of in-situ H 2 O 2 generation, which effectively avoided the use binder for powder material. Owing to abundant N-doping and oxygen functional groups, the H 2 O 2 yield of WNPC was three times that of balsa wood derived carbon (WC) in electro-Fenton system. The graphite-N promoted the electron transfer, while the pyridinic-N could enhance the selectivity of the 2e-ORR for H 2 O 2 generation. Furthermore, the specific surface area of WNPC was 10 times of WC, with improved hydrophilicity and accelerated electron transfer. The removal efficiency of tetracycline hydrochloride (TC) achieved 91 % within 120 min in electro-Fenton system with WNPC and Fe2+, which was much higher than that with WC (63 %). Free radical scavenging and electron paramagnetic resonance experiments confirmed that ·OH and O 2 –· were the main active substances for TC degradation in electro-Fenton system. In addition, WNPC has good stability, reusability, and comparable degradation performance of various organic pollutants, and also had efficient degradation performance with actual water. This research proposed a novel strategy to construct efficient electro-Fenton catalyst with wood as precursor, which provides an advancing electrocatalytic methods to achieve efficient and environmentally conscious water purification. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present materials record greatest usage of composites in automotive and aircraft industry. Parts of aircrafts are experimenting materials with respect to mechanical properties which should have more strength to weight ratio, resistance to buckling, high ultimate tensile strength, high resistance to vibration, and high fatigue. Composite materials filled the requirement for making high strength to weight ratio components. This paper aims to study the Mechanical Characterization of Balsa wood, Depron and Glass fiber. The fabricated composites is highly suitable for manufacturing of floors in aircrafts instead of carbon fiber reinforced epoxy composite. Also, it will be used for luggage compartment. Using Hand Layup process specimens were prepared and the tensile test, Temperature Test and Flexures test has been performed as per ASTM standard. We observed 12%-17% more bending strength from this experiment which suits well for aircraft floor panel. [ABSTRACT FROM AUTHOR]

In unmanned aircraft applications, electromagnetic wave (EMW) absorbers suffer from defects in narrow absorption bands and poor mechanical properties. To solve the problems, a lightweight multilayer stealth structure with wide broadband absorption performance and excellent mechanical properties was designed and prepared by adjusting microscopically the number of multi-walled carbon nanotubes (MWCNT) and modulating macroscopically the thickness-matching relationship of the structure to promote the absorption of EMW synergistically. Under the MWCNT of 30 wt% and the depletion layer with the thickness of 0.2 mm, the effective absorption bandwidth (EAB) covers the entire Ku-band while maintaining a minimum reflection loss (RL) of −15 dB. Besides, the radar cross-sectional area attenuation is as high as 23.1 dBm2, as well as the mechanical properties of the radar absorbing structures (RAS) were improved significantly due to the reducing structural density from balsa wood and the enhancement effect of glass fiber mats (GFM). The study constructed balsa-based RAS with excellent EMW absorbing and mechanical properties from both micro-nano scale and macro-structure, providing a research route for designing high-performance and lightweight stealth structures. This study designs a lightweight multilayer stealth structure that achieves broadband absorption (Ku-band full absorption), which dues to the interface polarization effect and thickness-tunable absorption mechanism. The structure also shows impressive mechanical properties, making it an ideal candidate for unmanned aircraft stealth applications. [Display omitted] • The electromagnetic parameters of the loss layer can be tuned by adjusting the impregnation rate of MWCNT. • The impedance matching of the structure can be modulated by the thickness of the loss layer. • The MWCNT and GFM has significantly enhanced the mechanical properties of the lightweight multilayer stealth structure. • The RL attains a value of -41 dB, and the EAB reaches 5.6 GHz which encompasses the full Ku bands. [ABSTRACT FROM AUTHOR]

Due to frequent industrial wastewater discharge and oil spills, there is a need to develop sustainable and efficient absorbents and treatment methods. Herein, based on the unique microstructure of wood and functional requirements, super-hydrophobic, recyclable, and renewable wood sponges (SHWSs) with an ultralight density (35.4 mg cm−3) and high porosity (98.68%) were prepared from anisotropic natural balsa wood via a scalable and sustainable silanization reaction using liquid-phase deposition (LPD). The super-hydrophobicity of the SHWSs (contact angle = 159.2°) was due to the formation of polysiloxanes on the surface via silanization. The internal contact angle (CA) reached 137.2°, which was attributed to the uniformity of LPD. The SHWSs exhibited a high absorption capacity for various organic solvents and oils (23–60 g g−1) and reusability, allowing it to reach a contact angle of 150.8° and an absorption capacity of 52 g g−1 for CCl4 after 50 absorption cycles. The SHWSs also showed excellent super-hydrophobicity under acidic, alkaline, and saline conditions, as well as in hot water, demonstrating their excellent durability. A continuous oil/water separation device was made by using the SHWSs, which showed a high separation efficiency, with a flux rate of up to 72.8 L h−1 g−1. This green strategy for treating natural balsa wood with LPD provides a scalable way to produce sustainable oil/water separation materials while also developing high-value-added applications of natural balsa wood. [ABSTRACT FROM AUTHOR]

This research presents an advanced characterization of Balsa wood waste to evaluate its potential use as raw material for Oriented Strand Board (OSB) panel. For that, chemical, thermal and microstructural characterization of the Balsa wood particles were performed followed by the production and characterization of OSB agglomerated with castor oil polyurethane resin (Pu-Castor oil). The results indicated that the lignin content of the Balsa wood waste was lower than the content found in Pinus spp. wood, used in the industrial production of OSB panels, demonstrating the need for higher resin contents to ensure a perfect agglomeration of the particles. Microstructural analysis indicated that the Balsa wood presented characteristics to be used as a constituent raw material of OSB with Pu-Castor oil. The physical-mechanical characterization indicated that the material can be classified as OSB type 1 in accordance with the EN 300:2006 guidelines and is suitable for application in internal environments. [ABSTRACT FROM AUTHOR]

Wood can be used for the in situ preparation of wood sponge using chemical treatment, which can be employed as absorbent for sewage treatment and exhibits the advantage of low cost, low density, high porosity, and environmental friendliness. Previous researches on wood sponge mainly focused on its various applications, while the influence rule and mechanism of treatment conditions such as pH and concentration of NaClO2 solution, as well as concentration of NaOH solution have not been fully understood. This challenge limits the manufacturing efficiency and further application of wood sponge for the production of absorption materials and so on. The study presented an effective strategy for preparing wood sponges via using a top–down chemical treatment on low-density balsa wood and paid more attention to the controlling rule of preparation parameters. At the condition that pH of 4.0 (NaClO2 solution), NaOH concentration of 7 wt%, and NaClO2 concentration of 3 wt%, wood sponge with a porosity of 96.47% can be obtained with good resilience and excellent absorption capacity. Excessive concentration of NaOH and NaClO2 will significantly affect the skeletal structure of the wood sponge. After the silylation treatment, the optimal wood sponge was endowed with oil and organic solvents absorption capacity of 2441–17,300 mg g−1; it can be also recycled by simple extrusion. This highly resilient and recyclable wood sponge with high porosity and oil absorption capacity can be potentially applied for environmental protection. [ABSTRACT FROM AUTHOR]

Developing bio-based adsorbents for efficient removal of heavy metal ions from water has attracted increasing attention due to their abundance, low cost, and sustainability. However, most of these adsorbents are in powdered or granular forms, suffering from difficult regeneration and poor recyclability. Here, we report a highly porous three-dimensional amino-functionalized wood aerogel for efficient heavy metal adsorption. The amino-functionalized wood aerogel was prepared from natural balsa wood via a delignification treatment, followed by TEMPO-mediated oxidation of the delignified wood and then grafting polyethylenimine (PEI) onto the oxidized cellulose skeleton. The obtained amino-functionalized wood aerogel possessed a unique porous lamellar structure with a low bulk density of 77.2 mg/cm3 and high porosity of 94.9%. Benefiting from its high porosity and the introduced amino groups on the cellulose skeleton, the amino-functionalized wood aerogel exhibited a maximum Cu(II) adsorption capacity of 59.8 mg·g−1, which was significantly higher than those of the TEMPO-oxidized wood aerogel and natural balsa wood. The adsorption process can be well described by the pseudo-second-order and Langmuir isotherm models, indicating that the Cu(II) adsorption by the PEI@wood aerogel was dominated by a monolayer chemisorption process. The developed amino-functionalized wood aerogel provides new insights for the design of efficient and low-cost monolithic absorbents for heavy metal remediation. [ABSTRACT FROM AUTHOR]

Sandwich composites are special class of materials because of peculiar properties such as lightweight, high energy absorbing capacity, and high damping, etc. These properties make them suitable for their use in aerospace and marine industry. Generally, metal or FRP sheets are used as skin/face sheet and honeycomb, foam and balsa wood, etc. are used as core materials. The elastic properties of the honeycomb are the function of foil thickness and cell size. In the present study, the effect of parameters (Foil thickness and Cell size) of the honeycomb on the energy absorption capacity of the sandwich composite was investigated through experimental and numerical studies. Experiments were carried out on four sandwich composites having a variable combination of foil thickness, and cell size by using the Charpy ASTM E-23 machine. Further, numerical analyses were carried out using finite element (FE) software Abaqus. The experimental and numerical results were found to be in good agreement. The results show that energy absorption to mass ratio increases with the increase in foil thickness and with the decrease in cell size. For the improvement of energy absorption to mass ratio, the effect of change in the foil thickness is significant compared to that of change in cell size. Failure mechanism was discussed through numerical study. The impact force resisted by the sandwich composites was presented by using the impulse-momentum equation. [ABSTRACT FROM AUTHOR]

Lignin is the most abundant aromatic biomacromolecule on the earth, which is an attractive raw material for producing bio-based chemicals, materials, and fuels. However, the complexity, heterogeneity, and variability of the lignin structure always hinders the value-added application of different sources of raw materials. In this study, double enzymatic lignin (DEL) was isolated from balsa grown for different lengths of time to understand the structural variations of lignin macromolecules during the growth of balsa for the first time. Confocal Raman microscopy and component analysis were used to monitor the lignin accumulation in balsa. Meanwhile, the structural characteristics and chemical reactivity of DELs were synthetically characterized by advanced 2D-HSQC and 31P-NMR techniques. It was found that the balsa lignin is a typical hardwood lignin and it is overwhelmingly composed of C–O bonds (i.e., β-O-4 linkages), whose content is elevated with increasing tree-age. Interestingly, carbon–carbon linkages (e.g., β-β and β-5) in these DELs isolated from 3-and 5-year-old balsa are gradually disappearing. Considering the increasing molecular weight of DELs with tree-age, it was concluded that lignin macromolecules in balsa wood were gradually polymerized within the growth period. Furthermore, abundant C–O linkages with less C–C linkages in the DELs from 3 and 5-year-old balsa wood suggested that these feedstocks are promising in current lignin-first biorefinery and will facilitate the conversion of aromatic chemicals from the lignin macromolecule. In short, a comprehensive understanding of native lignin during the growth of balsa wood will not only advance the understanding of biosynthetic pathways of lignin biopolymer, but also facilitate the deconstruction and value-added applications of this kind of feedstock.

Glycoproteomics is one of the main routes to study protein post-translational modifications, and enrichment is one of the important steps. Many hydrophilic materials have been used for glycopeptide enrichment, however involving complex synthesis procedures, high consumption in cost, time, and chemicals. Here, balsa wood, a naturally available hydrophilic material with highly porous structure, was investigated for immunoglobulin G (IgG) glycopeptide enrichment in a micropipette set-up. Native balsa wood without any pretreatment provided a green alternative to a commercial HILIC product, exhibiting comparable, or even better, enrichment performance for IgG standard and human plasma IgG samples. After delignification, binding capacity and recovery could be improved due to increased hydrophilicity and porosity. The developed method utilizing wood materials introduced an environmentally friendly option for glycoproteomics, saving both costs and chemicals, while exhibiting high performance. [ABSTRACT FROM AUTHOR]

Hydrothermal and electrochemical deposition methods have been employed to fabricate porous wood carbon (PWC)/pseudocapacitive hybrid materials for use as free-standing supercapacitor electrodes. However, their cycling stability is poor because of the inherent storage mechanism of pseudocapacitive materials, and their specific capacitance requires further improvement. In this study, PWC was directly produced as a conductive matrix by pyrolyzing natural balsa wood, and then manganese dioxide (MnO 2) and graphene quantum dots (GQDs) were deposited to fabricate a PWC/MnO 2 /GQDs electrode by a hydrothermal method. GQDs significantly boosts the ions transport, and protects MnO 2 from falling off both the external surface and inside the channel of PWC. Compared with a PWC/MnO 2 electrode, the unique needle-like nanostructures formed by adding GQDs resulted in a better electrochemical performance for a supercapacitor electrode, including a moderate areal specific capacitance (2712 mF cm−2 at a current density of 1.0 mA cm−2), good rate capability, and excellent cycling stability (95.3% retention after 2000 cycles). This indicated that GQDs-decorated composites will promote the development of high-performance energy storage devices. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • Balsa-derived magnetic Fe 3 C/N@BsB was prepared with curcumin as a mediator. • Fe 3 C/N@BsB had dual active sites to activate PMS for catalytic degradation of PFOA. • Degradation and defluorination efficiencies were 82.9% and 71.4% for PFOA at 4 h. • SO 4 − dominated in the system, with maximum accumulation concentration of 29.6 μM. • In-situ magnetized Fe 3 C/N@BsB with cm-size was convenient for recycling for reuse. Perfluorooctanoic acid (PFOA) is one of the most commonly detected perfluorinated compounds, and now poses a significant threat to animal, plant and human health as an emerging pollutant. Using balsa wood as a natural template and potassium ferrocyanide as a precursor, curcumin-mediated Fe 3 C/N-embedded 3D magnetic biochar (Fe 3 C/N@BsB) was obtained in this study via a facile in-situ pyrolysis method. Featured with dual metallic and non-metallic active centers, Fe 3 C/N@BsB was then utilized for activating peroxymonosulfate (PMS) to degrade PFOA in water. The experimental data indicated that a degradation efficiency of 82.9% and defluorination efficiency of 71.4% were achieved for PFOA at room temperature and pH 3.0. Coexisting 50 mM Cl− in water had no significant impact, while HCO 3 − and HA showed inhibitory effects on PFOA degradation. By the identification and quantification of free radicals, SO 4 − was predominant in the Fe 3 C/N@BsB + PMS system with its maximum accumulation concentration of 29.6 μM. Under the attack of active species, PFOA degradation occurred gradually to produce short-chain by-products for subsequent mineralization. Finally, the recyclability of Fe 3 C/N@BsB and its catalytic degradability in tap water and Yellow River water were also evaluated. This study not only demonstrates the enormous potential of Fe 3 C/N@BsB + PMS system for the removal of emerging PFOA in water, but also provides good theoretical support for the resource utilization of balsa wood. [ABSTRACT FROM AUTHOR]

Balsa wood is a natural cellular material with an excellent resistance-to-weight ratio that is ideal for manufacturing the core of sandwich structures. In this study, sandwich specimens with a carbon-fiber-reinforced polymer (CFRP) skin and a balsa wood core were tested with static and dynamic loading. Three-point flexural tests in static regime determined the mechanical characteristics of the CFRP-balsa specimens that were needed for subsequent fatigue strength tests. Also, experimental research was performed on the Charpy impact response of the CFRP-balsa sandwich specimens. This study implemented an accelerated fatigue testing method to identify and predict the mean fatigue life of the CFRP-balsa sandwich specimens subjected to cyclic fatigue via three-point flexural tests. Using the accelerated fatigue and the three-point flexural testing methodology on the CFRP-balsa sandwich specimens, the testing period was reduced by 11.9 times, and thus the material costs necessary for the tests were also reduced. Also, the breaking surfaces were analysed to reveal the failure modes of CFRP-balsa specimens subjected to static and fatigue tests at three-point flexural and at impact tests.

Objective: To report a simple and novel method for intra-operative planning of fibula free flap reconstruction by means of a balsa wood (BW) model. Study design: Retrospective chart review. Methods: Between 2010 and 2015, 29 patients underwent mandibular reconstruction by a BW osteotomy design in which a single BW beam (US$4) is cut into segments to match the plate. The segments are then assembled together in a three-dimensional (3D) fashion to conform to the contour of the defect and the angles of attachment. Osteotomies are then performed according to the BW segment lengths and angles. Outcomes were retrospectively analyzed for number of procedures, operative times, and complications between the balsa wood method and more standard techniques, e.g., conventional 3D models. Results: The length of the average mandibular defect was 9.62 cm (4–19), and the mean number of fibula segments was 2.03 ± 0.92 (range 1–4). Only one case (3.4%) necessitated revision surgery. Three patients (10.3%) had minor complications. Comparison of the results of the 13 patients reconstructed solely by BW to the 16 reconstructed by both BW and a 3D-printed model revealed that the use of BW alone did not significantly alter the average number of segments [2.31 (BW) vs 1.69 (combined); P = 0.07] or ischemia time (173 min vs 171 min, respectively, P = 0.938). Conclusion: The use of balsa wood as a model for intra-operative planning of fibula free flap osteotomies is an effective, inexpensive, and safe technique. [ABSTRACT FROM AUTHOR]

Copyright of Dilemas Contemporáneos: Educación, Política y Valores is the property of Dilemas Contemporaneos: Educacion, Politica y Valores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Balsa wood (Ochroma pyramidalei) are widely available in Indonesian market especially in the creative industry. Balsa wood was preferred due to its excellent strength to weight ratio in-line with workability and the simplicity of its color and texture. Balsa composite has increased the economic value of balsa wood and widen its use from merely lightweights and non-structural objects to some efficient super-structures. The development of balsa composite into curved structure add another level of design sophistication and widen the variation of its use. Application of this material in a shell structure allowed the structure to have more strength to weight excellence, since the shell structure itself had already had excellent depth to span ratio. The added value of the application in Indonesia is expected to add significant contribution in national agroforestry and construction sector. However, introducing the material into construction industry required further examination, especially related to the stability of supplies (forestry management), manufacture readiness, and human resources. This paper showed a theoretical and statistical feasibility study of manufacture-scale business establishment in Indonesia. [ABSTRACT FROM AUTHOR]

Structural engineers commonly use balsa wood and PVC foam as core materials for sandwich composite structures. These structures are frequently exposed to thermal cycling in sea water. The long-term performance and damage mechanism of these composite sandwich structures under such environmental conditions are still unclear. To simulate these effects, sandwich panels using balsa wood (SB100) and foam core (Airex C70.55) with fiber glass/vinyl ester face sheets were exposed to 100 days of freeze/thaw exposure (−20℃ to 20℃). The freezing and thawing occurred in presence of a saline solution. A total of 150 samples were tested for core shear, core compression, and peel tests. Results confirmed that exposure reduced the balsa wood core shear strength by 14%, compression strength by 36%, and compression modulus by 33%. Interestingly, the PVC foam core shear modulus increased by 25% after exposure, whereas the compression modulus reduced by 12%. Simulated lifetime core shear fatigue curves were developed and evaluated. Additional testing techniques such as scanning electron microscopy, optical microscopy, dynamical mechanical analysis, and X-ray computed tomography were used to rationalize the static and fatigue behavior of the core materials. [ABSTRACT FROM AUTHOR]

Abstract This study evaluated the termite susceptibility of Papua New Guinea (PNG) balsa (Ochroma pyramidale) against Australia's most economically important wood-destroying termite species, Coptotermes acinaciformis. Samples of envelope treated PNG balsa with the insecticide bifenthrin and non-treated balsa, radiata pine (Pinus radiata) sapwood and southern blue gum (Eucalyptus globulus) heartwood were exposed to seven different colonies of C. acinaciformis at a field site in the Northern Territory, Australia. The results indicated that balsa is susceptible to termite attack, with a mean mass loss of 30.9% (range 3.8–99.9%). Mean mass losses for radiata pine and southern blue gum were 90.3 and 98.9% respectively. It was evident that balsa can be successfully protected from termite attack with envelope-treatments of bifenthrin, with the latter proving to be highly efficacious at mass/volume retentions much lower than those specified in AS 1604.1 and typically used in the Australian timber preservation industry. Highlights • PNG balsa is susceptible to wood-destroying termite attack in Australia, with a mean mass loss of 30.9% (range 3.9–99.9%). • Similarly, as a control in the study, the mean mass losses for radiata pine and southern blue gum were 90.3% and 98.9%. • Balsa can be successfully protected from termite attack with envelope-treatments of the insecticide bifenthrin. • The paper reviews the literature for balsa susceptibility to termite species and details the origin of balsa and methods used. [ABSTRACT FROM AUTHOR]

The utilization and transportation of clean energy require efficient energy storage solutions. Gas hydrate represents a promising way for high-density storage under mild conditions. In particular, hydrate induced by confined space has the advantage of being environmentally friendly with rapid nucleation and high mass transfer efficiency. However, the cost of artificial pore-construction methods has hindered its widespread application. In this study, we report a novel approach of hydrate storage in the -SO 3 − modified flexible balsa wood as a naturally porous material. The surface sulfonate groups were successfully grafted by coupling agents which was verified by various techniques. The material's natural porous hierarchical structure allows for efficient fluid flow in porous media, enabling a reduction in induction time by ∼88% and a storage capacity of up to 150.6 v/v by adjusting the load water amount. The 100 wt% water-loaded wood materials exhibited the highest water conversion efficiency. Moreover, the recoverable mechanical properties make it reusable without performance degradation. The inner pore structure and hydrate morphologies were further investigated by X-ray microscopy to clarify the hydrate growth mechanism. The interconnected pores and channels make the hydrate grow in layers inside. In addition, the performance could be adjusted by simply changing the hydrophobicity to regulate the gas flow which may contribute to the large storage systems. The use of natural biomass porous materials provides an environmentally friendly and economically feasible strategy for gas storage. [Display omitted] • The modified flexible balsa wood was synthesized and applied in energy storage. • Methane hydrate induction time was reduced by ∼88% and the storage capacity was enhanced to 150.6 v /v. • The 400 wt% water loaded case exhibited the best storage performance. • The hydrate started to form in axial parenchyma structures verified by X-ray microscopy. • Tunable storage performance based on hydrophobic and hydrophilic modification. [ABSTRACT FROM AUTHOR]

• The samples exhibit higher strength and toughness at θ = 0° or 90°. • The strength and fracture toughness show positive relationship with vessel area. • Vessels can effectively arrest crack propagation at θ = 90°. Balsa wood, as one of the lightest woods available, presents superior mechanical properties, and thus it is one of the most appealing core materials particularly for marine and aerospace applications. However, the strengthening and toughening mechanisms in balsa wood are still poorly understood. The present work indicates that the samples exhibit higher strength and toughness concurrently, provided the loading direction is perpendicular to rays; in this case, vessels with strong walls can provide mechanical support, blunt cracking and stop horizontal cracking, and rays can arrest axial cracking. The present research findings are expected to provide fundamental insight into the design of high-performance bionic materials with a highly fibrous and porous structure. [ABSTRACT FROM AUTHOR]