The degradation and erosion of wood and its products caused by microorganisms remains a persistent challenge, which leads to significant economic and property losses and poses a potential health threat to users due to the presence of pathogenic microorganisms. In light of the recent COVID-19 pandemic, this issue has become increasingly urgent to address in modern society due to the increasing focus on private health. In this work, the carboxymethyl chitosan nano-silver (CMCS-Ag) was prepared through a microwave-assisted method, where the CMCS-Ag was ultrasonically blended with waterborne paint to obtain a waterborne antimicrobial wood coatings. Compared with commercial nano-silver with the same particle size, due to the unique system, the CMCS-Ag exhibited superior antibacterial efficacy and lower Ag+ release. CMCS-Ag exhibited effective dispersion within waterborne coatings, leading to a significant improvement in both the mechanical and antimicrobial performance of the coatings. With a CMCS-Ag content of 10 wt%, the coating films exhibit high elastic modulus, tensile strength and shore hardness, 78%, 33% and 69% higher than the control, respectively. Moreover, antimicrobial tests confirm that CMCS-Ag wood coatings inhibit Escherichia coli (24 h sterilization rate: 99.99%), Aspergillus niger (28 days without erosion), and soil decay fungi (56 days undecayed), while minimizing wood product appearance deterioration and mass loss from microbial erosion. These findings not only provide valuable insights into enhancing the antimicrobial of wood and its products but also reduce possibilities for people exposed to pathogens.
The increasing demand for sustainable road infrastructure necessitates alternative materials that enhance soil stabilization while reducing environmental impact. This study investigated the application of organosilane-based nanotechnology to improve the structural performance and durability of road corridors in Peru, offering a viable alternative to conventional stabilization methods. A comparative experimental approach was employed, where modified soil and asphalt mixtures were evaluated against control samples without nanotechnology. Laboratory tests showed that organosilane-treated soil achieved up to a 100% increase in the California Bearing Ratio (CBR), while maintaining expansion below 0.5%, significantly reducing moisture susceptibility compared to untreated soil. Asphalt mixtures incorporating nanotechnology-based adhesion enhancers exhibited a Tensile Strength Ratio (TSR) exceeding 80%, ensuring a superior resistance to moisture-induced damage relative to conventional mixtures. Non-destructive evaluations, including Dynamic Cone Penetrometer (DCP) and Pavement Condition Index (PCI) tests, confirmed the improved long-term durability and load-bearing capacity. Furthermore, statistical analysis of the International Roughness Index (IRI) revealed a mean value of 2.449 m/km, which is well below the Peruvian regulatory threshold of 3.5 m/km, demonstrating a significant improvement over untreated pavements. Furthermore, a comparative reference to IRI standards from other countries contextualized these results. This research underscores the potential of nanotechnology to enhance pavement resilience, optimize resource utilization, and advance sustainable construction practices.
This work demonstrates the development of room-temperature curable and durable anti-soiling coating using fluorine functionalized mesoporous silica (F-SiO2) and silicone resin-based hydrophobic coatings. The use of silicone resin with a catalyst enabled room-temperature curing of the coating and enhanced its mechanical properties. The coating prepared from mesoporous silica and F-SiO2 exhibited contact angles of 102 degrees and 122 degrees, indicating a significant improvement in the wettability of F-SiO2-based coatings. Additionally, the transmittance values were 93 % and 94 %, respectively, which are comparable to those of bare PV cover glass. A soiling study of the fabricated coating was conducted in an outdoor environment for over one month. The results confirmed that the F-SiO2-based hydrophobic coatings showed a minimal transmittance loss compared to non-coated PV cover glass. The durability of the F-SiO2-based coating was confirmed by mechanical properties like adhesive strength (1.86 MPa) and hardness (4H). The photo-conversion efficiency of the F-SiO2 coated PV module was measured in an indoor soiling environment using wind cleaning action. It was observed that the module regained its photoconversion efficiency after only one minute of wind cleaning. These results indicate that the prepared coatings have a significant potential for practical application in PV industry.
The demand for seed-based restoration and revegetation of degraded drylands has intensified with increased disturbance and climate change. Invasive plants often hinder the establishment of seeded species; thus, they are routinely controlled with herbicides. Herbicides used to control invasive plants may maintain soil activity and cause non-target damage to seeded species. Activated carbon (AC), which has a high adsorption of many herbicides, has been incorporated into seed pellets and coatings (seed technologies) to limit herbicide damage. Though various AC seed technologies have been examined in numerous laboratory and field studies, questions remain regarding their effectiveness and how to improve it, and what causes variation in results. We synthesized the literature on AC seed technologies for dryland restoration and revegetation to attempt to answer these questions. AC pellets compared to seed coatings were more thoroughly tested in the field and generally provide strong herbicide protection. However, greater amounts of AC in seed coatings appear to increase their effectiveness. Seed coatings show more potential for use than pellets because they are less logistically challenging to use compared to pellets, but need more field testing and refinement. Results often differ between laboratory and field studies, suggesting that field studies are critical in determining realized effects. However, seedling establishment failures from other barriers make it challenging to evaluate the effectiveness of AC seed technologies in the field. AC seed technologies are an innovative tool that with continued refinement, especially if other barriers to seedling establishment can be overcome, may improve the restoration and revegetation of degraded drylands.
When a long distance HVDC transmission system discharges current into the earth through its grounding electrode, ground potential differences appear in a large area. And therefore part of the DC current may flow into nearby pipelines which may be dangerous to the equipment and personnel, and may aggravate corrosion. In this paper, an equivalent circuit based on the method of moments is introduced to calculate the current and potential distributions along a pipeline with damaged anticorrosive coating. The current-dependent electrochemical polarization potential between soil and the metal pipe, due to the damage of the anticorrosive coating, is taken into account by using the Newton-Raphson scheme. The circuit is verified through a reduced scale experiment. By examining the circuit, the effect of the damaged anticorrosive coating on the leakage current and the pipe potential with respect to soil along the pipeline is analyzed.
Mycelium-based composites are a promising avenue for innovating sustainable materials from the hyphae of fungi. This study focuses on the use of fibers from four local fungal species, namely, Pleurotus ostreatus, Pleurotus sajor-caju (Fr. Singer), Auricularia auricula-judae, and Schizophyllum commune Fr., to produce mycelium-based composites from water hyacinth. An inoculum of each of the mushroom species was cultivated on PDA medium at 25 and 30 degrees C to determine the optimal temperature based on the growth rate. The obtained optimal condition was used to grow the fungi on water hyacinth (WH) mixed with rice bran in different proportions (100% WH, 70% WH, and 50% WH) with various numbers of fungal inocula (10, 20, and 30 plugs). The obtained composites were coated with a solution of either starch, chitosan, or epoxy resin. Schizophyllum commune Fr. exhibited the highest growth rate and fiber density, with a growth rate of 1.45 +/- 1.92 mm/day at 30 degrees C. Ten inocula of Schizophyllum commune Fr. incubated at 30 degrees C for seven days on a mixture of 50% WH and 50% rice bran gave the optimal composite. Coating the obtained composite with chitosan improved its mechanical properties, but coating it with epoxy resin improved its water absorbency. Buried in soil, the composite coated with a chitosan solution decomposed within 30 days. The results indicate that Schizophyllum commune Fr. can be used as a binder to produce mycelial composites on a substrate of WH mixed with rice bran. The implications of these results will enable the further development and tuning of mushroom-based materials, especially for the production of sustainable bio-construction materials derived from local mushrooms and bio-waste.
Hylastes species are known to cause damage to conifers in plantations in northern Sweden, and in recent years an increase in seedling damage has been observed in southern Sweden. However, there are few studies on Hylastes spp and the damage it can cause, so there is a lack of knowledge regarding pest management. In order to investigate an eventual interaction between damage by Hylastes spp and the more well-known Hylobius abietis (L) we registered damage by these species. Unprotected spruce seedlings were compared with seedlings protected from Hylobius abietis by a mechanical coating or with an insecticide. The effect of mechanical site preparation (MSP) was studied, with half of the seedlings being planted in unprepared soil and the other half after MSP. Both seedling protection and MSP significantly reduced the level of damage caused by Hylastes spp. MSP reduced the proportion of affected and killed seedlings and reduced the level of damage at the root collar. Protecting the seedlings reduced the level of damage, and no difference was found between seedlings treated with an insecticide and those provided with a coating. Similar responses were observed with both containerized and plug plus seedlings. In conclusion, measures against Hylobius abietis seem to also prevent damage by Hylastes spp.
Plastic-coated paper straws are insufficient to solve the plastic pollution problem because microplastics are formed during their degradation. In this study, upgraded paper straws were prepared by coating with biodegradable sodium alginate/cellulose nanofiber/stearic acid (SA/CNF/STA) on the surface of paper without additional adhesives. The tensile strength of the paper was enhanced synergistically by the coated SA and CNF after cross-linking with Ca2+ ions, reaching a maximum (26.46 MPa) when the mass ratio of SA to CNF was 4:1. The straws were prepared by spirally winding coated paper into tubes. Subsequent STA modification with different concentration (1-40%) improved the water stability of the paper straws. The paper straws exhibited excellent mechanical properties (including 13.45 MPa of flexural strength, 13.30 MPa of compressive strength) and hydrophobicity (103.67 degrees of maximum water contact angle). After 130 days of soil burial, the paper straws were completely degraded. The comprehensive performance of prepared straws exceeds that of commercially available products in the same category, and they are safe and biodegradable. Paper straw in the work is in line with the concept of green and low-carbon development.
The extremely hot and dense environment on Venusian surface will degrade almost any material via atmosphere-surface interactions, therefore the exploitation of its soil and atmosphere is very challenging. Exploring rovers are designed with mostly mechanical parts, and the knowledge of the effect of Venusian exposure on mechanical and tribological systems is very important for the longevity of the missions. Herein, we studied the effect of 3-day Venusian exposure on selected interfaces. It was found that diamond-like carbon (DLC) and Ti-doped molybdenum disulfide (TiMoS2) experienced negligible morphological changes, whereas polycrystalline diamond (PCD) and PS400 (plasma sprayed Ni-alloy) formed few-microns thick sulfur-containing reacted surface layers after exposure. Also, PCD retained its structural integrity, while the mechanical properties of DLC deteriorated the most, manifested as 49% decrease in hardness. The hardness of PS400 and TiMoS2 degraded to a lesser degree, with 8 and 26% decrease, respectively. The above coatings could be candidate materials to coat structural and bearing systems in the rovers, probes, and drills for future missions to Venus. (c) 2024 COSPAR. Published by Elsevier B.V. All rights reserved.