Research Articles

Pre-extraction of hemicellulose from eucalyptus heartwood and sapwood was conducted using the method of KOH extraction. Activated carbons (ACs) with high toluene adsorption capacity were prepared by using KOH as activator and hemicellulose-pre-extracted residue (HPR) as AC precursor. The findings indicated that the pore structure of the ACs could be regulated by adjusting the carbonization temperature. Using the HPR of eucalyptus heartwood as raw material, the activated carbon carbonized at 400 °C exhibited the highest BET surface area (3699 m²·g^-1) and pore volume (1.90 cm³·g^-1). The adsorption capacity of AC for toluene reached 816 mg·g^-1. The results showed that the adsorption capacity of toluene was associated with the micropores (< 2 nm) in the AC. Optimizing the carbonization temperature could enhance the proportion of micropores, thereby significantly enhancing the activated carbon’s adsorption capacity for toluene.

This study focuses on the wooden columns of a historic residential structure to assess their integrity. Employing non-invasive computed tomography (CT) scanning, the internal integrity of these ancient wooden supports was examined. Stress wave analysis, pilot nail testing, and assessments of static bending and compressive mechanical performance were performed to validate and compare the data. The findings revealed substantial variability in the material quality across the columns’ cross-sections, suggesting a loss of mechanical integrity that renders them unsafe for habitation or public access. A comparison between the CT scan outcomes for the Masson’s pine columns and the stress wave data from the dismantled counterparts confirmed a marked degradation in their mechanical characteristics, rendering them unfit for use. The CT scan findings align with the pilot nail test results, both accurately pinpointing the condition and precise locations of defects within the columns. The static mechanical performance tests substantiated the precision and dependability of the CT scanning, pilot nail testing, and stress wave analysis in evaluating the wooden columns’ quality. This research aims to establish a scientific foundation for employing diverse non-destructive testing methods in the preservation and strengthening of traditional wooden structures, thereby safeguarding our cultural heritage.

Fiber-reinforced polymer (FRP) is an external reinforcement solution for wooden structures, where several studies have shown its efficiency in maintenance and design. This solution is not yet among the main topics of literature, although its importance justifies new research on this relevant topic for construction. This systematic literature review involves the FRP as reinforcement in wood-based columns, using Engineering Village and Web of Science databases and PRISMA protocol to follow the procedures and ensure the quality of sampling. Reinforcement dispositions and types of assessments were identified so that the literature synthesis can contribute to identifying behavior models. Different methods of reinforcement sizing studied by the literature were synthesized and detailed as to their respective uses. A positive correlation between the reinforcement index and the increasing the load capacity of timber columns were discussed and statistically analyzed.

Tannin-based biomass foam was prepared through a self-foaming process at room temperature. The material’s density, porosity, microstructure, mechanical properties, thermal stability, limiting oxygen index (LOI), brittleness, as well as water absorption and retention properties, were studied. Adding 2% bamboo fibers in varying forms did not affect the uniformity of the foam cells. The density, porosity, thermal stability, and LOI of the foam material remained largely unchanged. The compressive strength of the unmodified tannin foam was 0.043 MPa, while the addition of 2% bamboo fibers increased the compressive strength by 72%. Even when the effect of density was excluded, the specific compressive strength was enhanced by 60%. Additionally, brittleness, measured as the slagging percentage, was significantly reduced from 16.12% to 4.78%. The modified foam could absorb up to 26.5% of its weight in water, with excellent water retention capabilities of 78.1% after 120 h while retaining its structural integrity under intermittent wetting conditions, making it suitable for vertical greening applications. This demonstrates its suitability for vertical greening applications, where moisture exposure is frequent. In conclusion, the bamboo fiber-reinforced tannin-based foam exhibits excellent mechanical properties and superior water absorption and retention performance.

Molded pulp products (MPP) products can accommodate a variety of fiber types and additives, including agricultural residues. This work showed the industrial scale production of molded pulp food trays made of double lined kraft clipping fibers with the addition of pistachio shell (PS) powder at levels from 5 to 30 wt% and evaluated the mechanical and barrier properties of the trays. The PS powder used to make the trays was ground using an impact mill and a cryo mill to a D50 of approximately 50 microns. Tray compression strength was tested to simulate the wrapping of food trays with plastic wrap. Additionally, the tray material’s basis weight, thickness, density, tensile strength, short span compressive strength, and absorptiveness were determined. The results showed that compared to the control tray sample, the trays containing the cryo-milled pistachio powder had essentially the same engineering properties as the control trays without PS. For the trays made with the impact-milled powder, the tensile strength, bending resistance, and compressive strength increased relative to the control 11.3%, 6.2%, and 13.5%, respectively. The study demonstrates a method to evaluate the incorporation of alternative materials into pulp molded products.

This experiment aimed to test the effectiveness of four antifungal chemicals in controlling mold contamination in edible mushroom production. The antifungal chemicals were terbinafine hydrochloride, prochloraz, azoxystrobin, and sodium dichloroisocyanurate. The inhibitory effects of the chemicals were evaluated for inhibition on Cladosporium sp., Aspergillus niger, and Neurospora sp. The mycelia of the three molds and Morchella sextelata were cultured individually and co-cultured on plates with different concentrations of these chemicals, and then the mycelial growth was observed. By comparing the growth areas under the same conditions, the appropriate concentrations of each chemical were determined. The results indicated that terbinafine hydrochloride and prochloraz significantly inhibited the mycelial growth of all three mold species at certain concentrations, whereas their impact on the mycelial growth of M. sextelata was not significant. These results suggest that these two chemicals are effective in controlling the mycelial growth of the three molds, potentially increasing the yield and quality of M. sextelata and reducing mold contamination during storage and transportation.