Search Results (146)

This study presents an integrated approach to sustainable soil and crop management by evaluating the individual and combined effects of cow manure (CM), rice husk biochar (RHB), and potassium humate (KH)—three underutilized, low-cost organic amendments derived from agricultural byproducts. Uniquely, it investigates how these amendments simultaneously affect soil physical and chemical properties, plant growth, and the accumulation of bioactive compounds in sunflower sprouts, thereby linking soil health to crop nutritional quality. The application of 2% w/w KH alone resulted in the greatest increases in macroaggregation (+0.51), soil pH (from 6.8 to 8.6), and electrical conductivity (+298%). The combination of 1% w/w CM and 2% KH led to the highest increases in soil organic carbon (OC, +62.9%) and soil respiration (+56.4%). Nitrate and available phosphorus (P) peaked with 3% w/w RHB + 2% KH (+120%) and 1% w/w CM + 0.5% KH (+35.5%), respectively. For plant traits, 0.5% w/w KH increased the total leaf area by 61.9%, while 1% w/w CM enhanced shoot and root biomass by 60.8% and 79.0%, respectively. In contrast, 2% w/w KH reduced chlorophyll content (−43.6%). Regarding bioactive compounds, the highest total phenolic content (TPC) was observed with 1% w/w KH (+21.9%), while the strongest DPPH antioxidant activity was found under 1% w/w CM + 1% w/w KH (+72.6%). A correlation analysis revealed that biomass production and secondary metabolite accumulation are shaped by trade-offs arising from resource allocation under stress or nutrient limitations. Potassium, P, soil microbial respiration, and OC emerged as key integrators connecting soil structure, fertility, and plant metabolic responses. Overall, the combination of 1% w/w CM with 0.5–1% w/w KH proved to be the most effective strategy under the tested conditions. Full article

Aiming at the problems of serious pavement temperature diseases, low efficiency and high loss of ice-breaking methods, high occupancy rate of waste tires and the low utilization rate and insufficient durability of rubber particles, this paper aims to improve the service level of roads and ensure the safety of winter pavements. A pavement material with high efficiency, low carbon and environmental friendliness for active snow melting and ice breaking is developed. Firstly, NaOH, NaClO and KH550 were used to optimize the treatment of rubber particles. The hydrophilic properties, surface morphology and phase composition of rubber particles before and after optimization were studied, and the optimal treatment method of rubber particles was determined. Then, the optimized rubber particles were used to replace the natural aggregate in the polyurethane gel mixture by the volume substitution method, and the optimum polyurethane gel dosages and molding and curing processes were determined. Finally, the influence law of the road performance of RPGM was compared and analyzed by means of an indoor test, and the ice-breaking effect of RPGM was explored. The results showed that the contact angles of rubber particles treated with three solutions were reduced by 22.5%, 30.2% and 36.7%, respectively. The surface energy was improved, the element types on the surface of rubber particles were reduced and the surface impurities were effectively removed. Among them, the improvement effect of the KH550 solution was the most significant. With the increase in rubber particle content from 0% to 15%, the dynamic stability of the mixture gradually increases, with a maximum increase of 23.5%. The maximum bending strain increases with the increase in its content. The residual stability increases first and then decreases with the increase in rubber particle content, and the increase ranges are 1.4%, 3.3% and 0.5%, respectively. The anti-scattering performance increases with the increase in rubber content, and an excessive amount will lead to an increase in the scattering loss rate, but it can still be maintained below 5%. The fatigue life of polyurethane gel mixtures with 0%, 5%, 10% and 15% rubber particles is 2.9 times, 3.8 times, 4.3 times and 4.0 times higher than that of the AC-13 asphalt mixture, respectively, showing excellent anti-fatigue performance. The friction coefficient of the mixture increases with an increase in the rubber particle content, which can be increased by 22.3% compared with the ordinary asphalt mixture. RPGM shows better de-icing performance than traditional asphalt mixtures, and with an increase in rubber particle content, the ice-breaking ability is effectively improved. When the thickness of the ice layer exceeds 9 mm, the ice-breaking ability of the mixture is significantly weakened. Mainly through the synergistic effect of stress coupling, thermal effect and interface failure, the bonding performance of the ice–pavement interface is weakened under the action of driving load cycle, and the ice layer is loosened, broken and peeled off, achieving efficient de-icing. Full article

Recycled wood fiber (RWF) obtained through the multi-stage processing of waste wood serves as an eco-friendly green construction material, exhibiting lightweight, porous, and high toughness characteristics that demonstrate significant potential as a cementitious reinforcement, offering strategic advantages for environmental protection and resource recycling. In this study, high-performance sulfoaluminate cement (SAC)-RWF composites prepared by modifying RWFs with nano-silica (NS) and a silane coupling agent (KH560) were developed and their effects on mechanical properties, shrinkage behavior, hydration characteristics, and microstructure of SAC-RWF composites were systematically investigated. Optimal performance was achieved at water–cement ratio of 0.5 with 20% RWF content, where the KH560-modified samples showed superior improvement, with 8.5% and 14.3% increases in 28 d flexural and compressive strength, respectively, compared to the control groups, outperforming the NS-modified samples (3.6% and 8.6% enhancements). Both modifiers improved durability, reducing water absorption by 6.72% (NS) and 7.1% (KH560) while decreasing drying shrinkage by 4.3% and 27.2%, respectively. The modified SAC composites maintained favorable thermal properties, with NS reducing thermal conductivity by 6.8% through density optimization, whereas the KH560-treated specimens retained low conductivity despite slight density increases. Micro-structural tests revealed accelerated hydration without new hydration product formation, with both modifiers enhancing cementitious matrix hydration product generation by distinct mechanisms—with NS acting through physical pore-filling, while KH560 established Si-O-C chemical bonds at paste interfaces. Although both modifications improved mechanical properties and durability, the KH560-modified SAC composite group demonstrated superior overall performance than the NS-modified group, providing a technical pathway for developing sustainable, high-performance recycled wood fiber cement-based materials with balanced functional properties for low-carbon construction applications. Full article

This study extends the method of pseudo-dynamic analysis based on the Mononobe-Okabe (M-O) method by comprehensively incorporating the seismic acceleration response characteristics of backfill soil and the cohesive properties of the fill. The proposed method is adapted for backfill soils by incorporating the cohesion c and internal friction angle φ (including scenarios with non-horizontal backfill surfaces). Theoretical formulas for the active earth pressure coefficient and its distribution on rigid retaining walls under the most unfavorable conditions are derived. The rationality of the proposed formulas is preliminarily verified using model test data from the relevant literature. A detailed parametric sensitivity analysis reveals the following trends: The active earth pressure coefficient K_a increases with increases in the amplification factor f_a, wall backface inclination angle θ, backfill slope inclination i, lateral vibration period T, and horizontal seismic acceleration coefficient k_h; K_a decreases with an increasing internal friction angle φ and cohesion/unit weight ratio c/γH. The failure wedge angle α_a increases with increases in φ, θ, and c/γH, decreases with increases in f_a, the soil–wall friction angle δ, i, T, k_h, and the vertical seismic acceleration coefficient k_v. Calculations are carried out to further identify the critical tensile stress depth in cohesive backfill soils using c and φ. The proposed analysis highlights the necessity of considering the seismic acceleration amplification factor f_a, backfill cohesion c, and soil–wall adhesion c_w in active earth pressure calculations. This study recommends that the seismic design of retaining walls should involve appropriate evaluation of the the actual cohesion of backfill materials and fully account for the acceleration amplification effects under seismic loading. Full article

The creep properties of 15Kh2NMFAA nuclear WWER (water–water energetic reactor) vessel steel in the range of 500–1200 °C temperatures, which may appear during severe nuclear reactor accidents, were investigated. The present paper attempts to analyze the creep curves obtained from tensile testing at high temperatures using the Larson–Miller parametric technique. The power law rate and material coefficient of Norton’s equation with the Monkman–Grant relationship coefficient were found for each test temperature. It is shown that in accordance with the Monkman–Grant relationship coefficient values, changing the creep type from dislocation glide to high temperature dislocation climb occurs in the temperature range of 600–700 °C, which leads to a slope change in the Larson–Miller parameter plot and the conversion of steel creep behavior. It is also shown that in the range of $A_1$–$A_3$ temperatures, a stepwise change in creep characteristics occurs, which is associated with phase transformations. In addition, the constancy of the product of the time to rupture ${\tau }_r$ and the minimum creep rate ${\dot{ϵ}}_{min}$ in the ranges of 600–700 °C and $A_3$—1200 °C was noted. The proposed approach improves the accuracy of time to rupture estimation of 15Kh2NMFAA steel by at least one order of magnitude. Based on the research results, the calculated dependence of the steel’s long-term strength limit on temperature was obtained for several time bases, allowing us to increase the accuracy of material survivability prediction in the case of a severe accident at a nuclear reactor. Full article

This study investigates the mechanical performance of epoxy resin composites reinforced with silane coupling agent-modified Al₂O₃ nanoparticles (m-Nano-Al₂O₃/epoxy). Three silane coupling agents (KH550, KH560, and KH570) were employed to functionalize the Al₂O₃ nanoparticles, and their chemical structures were confirmed via Fourier transform infrared spectroscopy (FTIR). The microstructure and elemental distribution of the composites were characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Mechanical properties, including tensile strength and hardness, were evaluated using a universal testing machine and a Rockwell hardness tester, respectively. The incorporation of m-Nano-Al₂O₃ significantly enhances the mechanical properties of the epoxy matrix. Compared to pure epoxy, the KH570-modified composites demonstrate a remarkable 49.1% improvement in tensile strength and an 8.8% increase in hardness. These findings highlight the potential of surface-modified Al₂O₃ nanoparticles as effective reinforcements for high-performance epoxy composites. Full article

In this study, rice husk (RH, 15wt%) served as a carbonizing agent, and ammonium polyphosphate (APP) served as an acid and gas source. These were combined with polylactic acid (PLA) to develop a high-strength and flame-retardant PLA-based composite. The APP surface was modified with silane coupling agents (KH550 and KH570) to enhance the compatibility with the PLA matrix and improve both mechanical and flame-retardant properties. The composite was evaluated using UL-94 flame retardancy tests, limiting oxygen index (LOI) measurements, and mechanical properties assessments. The findings demonstrated that both PLA/RH-APP10% and PLA/RH-APP15% composites met the UL-94 V-0 standard. Increasing APP content enhanced flame retardancy but reduced mechanical strength. Compared to unmodified PLA composite, the PLA/KAPP5% composite exhibited an 18.7% increase in tensile strength, an elongation at break improvement from 3.26% to 4.09%, and a LOI of 27.9%. The silane modification significantly improved APP dispersion within the PLA matrix, increasing interfacial contact and improving overall mechanical properties. The flame retardancy improvements were attributed to reduced thermal decomposition rates and increased carbon residue formation. Full article

Basalt with columnar jointing can act as a good groundwater conductor. In areas with limited water resources in sedimentary rock, such as the Deccan Traps in India and the Columbia River basalt formations in Washington State (USA), large quantities of groundwater are abstracted from such basalt formations for drinking water supply and irrigation. The hydraulic properties of basaltic formations are difficult to quantify. To obtain a better understanding of their hydraulic properties, intensive field campaigns in Iceland were combined with a conceptual groundwater model in MODFLOW. The field experiments enabled us to derive the upper boundary conditions, like precipitation surplus, and obtain reliable ranges for the k_h (0.01–0.3 m d⁻¹) and k_v (0.01–10 m d⁻¹) of the basalt formations. The main objective was to test the concept of representative elementary volumes (REVs) for such basaltic regions. Precipitation excess for the Vestragil and Eystragil catchments was calculated by taking into account the orographic effect of precipitation. It was found that at higher elevations (600 m + msl) the precipitation was twice the amount compared to the base camp rain gauge at 100 m + msl. Calculated evapotranspiration (1–2 mm d⁻¹) is in line with the literature. In the MODFLOW model, best results were obtained when the top layer (organic soil, peat, and regolith) was considered to be most conductive (up to 10 m d⁻¹), with a gradual reduction in hydraulic conductivity with depth in the basaltic aquifers. This study shows that, when larger elementary volumes are used, a good model representation of basaltic regions can be created. Full article

Recent research has focused on developing environmentally friendly flame-retardant coatings to improve the fire resistance of wood. In this study, phytic acid–guanazole (PG), a dual-functional compound synthesized through an ionic reaction between phytic acid and guanazole, was added to KH550-modified urea–formaldehyde resin (KUF) as both a curing agent and flame retardant. The $-{\mathrm{PO}}_4^{3-}$ groups from phytic acid act as an acid source to accelerate char formation during combustion, while the −NH₂ groups introduced by guanazole release non-combustible gases to dilute oxygen in the air, synergistically enhancing flame retardancy. Additionally, the hygroscopic $-{\mathrm{PO}}_4^{3-}$ groups absorb free water in the resin, reducing the curing temperature and accelerating coating solidification. The KH550 coupling agent improves compatibility between KUF and PG while introducing silicon, which forms SiO₂ during combustion to strengthen the char layer and further enhance flame resistance. Evaluations showed that PG outperforms conventional tannic acid (TA) in curing efficiency and fire resistance. Comprehensive analyses, including Differential Scanning Calorimetry (DSC), Limiting Oxygen Index (LOI), vertical flame tests, and cone calorimetry, confirmed PG’s dual functionality. Scanning Electron Microscope (SEM) and Raman spectroscopy revealed that PG-modified coatings form denser post-combustion char layers, directly linked to improved fire resistance. As a multifunctional additive, PG eliminates the need for separate curing agents and utilizes bio-based phytic acid, offering cost-effective and sustainable advantages for industrial applications. Full article

Objective: Prolonged microgravity environments impair skeletal muscle homeostasis by triggering fiber-type transitions and metabolic dysregulation. Although exercise and nutritional interventions may alleviate disuse atrophy, their synergistic effects under microgravity conditions remain poorly characterized. This study investigated the effects of an 8-week ketogenic diet combined with aerobic exercise in hindlimb-unloaded mice on muscle fiber remodeling and metabolic adaptation. Methods: Seven-week-old male C57BL/6J mice were randomly divided into six groups: normal diet control (NC), normal diet with hindlimb unloading (NH), normal diet with hindlimb unloading and exercise (NHE), ketogenic diet control (KC), ketogenic diet with hindlimb unloading (KH), and ketogenic diet with hindlimb unloading and exercise (KHE). During the last two weeks of intervention, hindlimb unloading was applied to simulate microgravity. Aerobic exercise groups performed moderate-intensity treadmill running (12 m/min, 60 min/day, and 6 days/week) for 8 weeks. Body weight, blood ketone, and glucose levels were measured weekly. Post-intervention assessments included the respiratory exchange ratio (RER), exhaustive exercise performance tests, and biochemical analyses of blood metabolic parameters. The skeletal muscle fiber-type composition was evaluated via immunofluorescence staining, lipid deposition was assessed using Oil Red O staining, glycogen content was analyzed by Periodic Acid–Schiff (PAS) staining, and gene expression was quantified using quantitative real-time PCR (RT-qPCR). Results: Hindlimb unloading significantly decreased body weight, induced muscle atrophy, and reduced exercise endurance in mice. However, the combination of KD and aerobic exercise significantly attenuated these adverse effects, as evidenced by increased proportions of oxidative muscle fibers (MyHC-I) and decreased proportions of glycolytic fibers (MyHC-IIb). Additionally, this combined intervention upregulated the expression of lipid metabolism-associated genes, including CPT-1b, HADH, PGC-1α, and FGF21, enhancing lipid metabolism and ketone utilization. These metabolic adaptations corresponded with improved exercise performance, demonstrated by the increased time to exhaustion in the KHE group compared to other hindlimb unloading groups. Conclusions: The combination of a ketogenic diet and aerobic exercise effectively ameliorates simulated microgravity-induced skeletal muscle atrophy and endurance impairment, primarily by promoting a fiber-type transition from MyHC-IIb to MyHC-I and enhancing lipid metabolism gene expression (CPT-1b, HADH, and PGC-1α). These findings underscore the potential therapeutic value of combined dietary and exercise interventions for mitigating muscle atrophy under simulated microgravity conditions. Full article

Silane-based passivation films have been widely utilized for corrosion protection in metal materials. In order to further improve the anticorrosion performance of the silane passivation film, this paper adopts the hydrolysis method to add graphene oxide (GO) to the silane coupling agent (3-(2,3-glycidoxy)propyltrimethoxysilane) (KH560). The synthesized KH560-GO passivation solution was then mixed with epoxy resin (EP) to prepare a silane composite passivation film layer (KH560-GO/EP) containing GO and epoxy resin. For comparison, EP and KH560-GO films were also prepared, and the corrosion performance of the composite film was compared with that of the single film. The structure of the KH560-GO film was characterized by X-ray diffraction analyzer (XRD) and infrared spectroscopy (FTIR). The microstructure of the composite film was analyzed by scanning electron microscopy (SEM), while its corrosion resistance was tested through polarization curves and electrochemical impedance spectroscopy (EIS). Additionally, neutral salt spray tests were conducted to evaluate the corrosion resistance of the samples, and rubber wiping tests were performed to assess the adhesion of the film. The results demonstrated that the KH560-GO/EP film exhibited a higher corrosion potential (E_corr) of −0.239 V compared to the EP and KH560-GO films, along with the lowest self-corrosion current density (I_corr) of 6.157 × 10⁻⁷ A/cm². These findings indicate that the KH560-GO/EP film possesses excellent corrosion resistance. The results showed that the corrosion potential (E_corr) of the KH560-GO/EP film was higher than that of EP and KH560-GO film layer is −0.239 V, and the self-corrosion current density (I_corr) is the smallest, which is 6.157 × 10⁻⁷ A/cm². The KH560-GO/EP film layer shows excellent corrosion resistance. Experiments show that the KH560-GO/EP passivated film has excellent bonding properties and corrosion resistance. Full article

Ships and offshore equipment operating in marine environments often face issues such as seawater corrosion and biofouling, leading to significant economic losses. To address the corrosion problems of ships and offshore equipment, heavy-duty anticorrosive coatings are widely used for corrosion protection in marine environments due to their long-term effectiveness, cost-efficiency, and excellent applicability. In this study, silane coupling agent (KH-560) was employed to modify sodium silicate, and the modified sodium silicate was then incorporated as a reinforcing phase into polyurethane to ultimately prepare a modified sodium silicate/polyurethane coating. The feasibility of the modified sodium silicate/polyurethane coating was investigated by characterizing its conventional physicochemical properties, weather resistance, acid and alkali resistance, and salt spray corrosion resistance. Experimental results indicate that the silane coupling agent acts as a bridge between the organic and inorganic interfaces through the hydrolysis and condensation reactions of its bifunctional groups, forming an interfacial layer connected by hydrogen bonds and covalent bonds, thereby improving the compatibility between the organic resin and inorganic sodium silicate. Comprehensive performance analysis revealed that when the content of modified sodium silicate was 60 wt%, the coating hardness reached 4H. Additionally, electrochemical tests demonstrated that the coating exhibited higher impedance (9.62 × 10⁴ Ω/cm²) and lower corrosion current density (5.82 × 10⁻⁷ A/cm²). This study provides a theoretical and experimental basis for the development of high-performance anticorrosive coatings for marine applications. Full article

The screening of exopolysaccharides (EPS) produced by 52 isolates of endophytic and basidiomycete fungi was studied on two different media, PDB and PYGM. There were five isolates that could produce dried exopolysaccharide of more than 4 g/L (S. commune LF01962, LF01001, LF01581, Pycnoporus sp. MMCR00271.1, Pestalotiopsis sp. PP0005). The molecular weights of these exopolymers were found to be in the range of 2.5–500 kDa. These five exopolysaccharides, produced by five different fungal isolates, showed non-cytotoxic activity against NCTC clone 929 and HDFn cell lines. The selected fungal isolate of S. commune LF01962 was used for further optimization of different medium compositions affecting exopolysaccharide production using statistical methods. Among four conditions tested in the first step (xylose + peptone, glucose + (NH₄)₂HPO₄, fructose + peptone, and mannose + yeast extract), mannose + yeast extract resulted in the highest exopolysaccharide production of 5.10 ± 2.00 g/L. In the second step using Plackett–Burman design, the optimal medium for S. commune exopolysaccharide production was found to consist of 40 g/L glucose, 5 g/L mannose, 20 g/L (NH₄)₂HPO₄, 5 g/L yeast extract, 3 g/L monosodium glutamate, 0.5 g/L KH₂PO₄, 0.5 g/L K₂HPO₄, 0.2 g/L MgSO₄, 1 mL/L trace elements, and 3 mL/L vitamin solution, which resulted in 8.16 g/L exopolysaccharide production. Exopolysaccharide production in a 5 L bioreactor using small pellets as seed inoculum was found to produce 18.28 g/L exopolysaccharide. Full article

In order to address the issue of wind leakage leading to spontaneous coal combustion in goafs during gob-side entry mining, a KH570 silane coupling agent (SCA)-modified vinyl acetate–ethylene (VAE)/cement-based flexible spraying sealing material was developed. The mechanical properties and wind leakage sealing performance of the material were evaluated using specialized testing equipment. Furthermore, molecular dynamics simulations and microstructural characterization techniques were utilized to assess and model the interface compatibility of the material. The experimental results demonstrate that KH570 significantly enhanced the material’s mechanical properties. Following modification, the material exhibited increases in the maximum tensile strength, compressive strength, and flexural strength by 53%, 38%, and 29%, respectively. KH570 not only promotes the formation of additional calcium silicate hydrate (C-S-H) gel through cement hydration, but also establishes Si-O-Si chemical bonds with cement hydration products and hydrogen bonds with the VAE emulsion. This functions as a “molecular bridge”, significantly enhancing the interface performance of the composite. The interaction between the organic and inorganic phases contributes to the formation of an interpenetrating network structure, imparting excellent compressive, flexural, and tensile deformation resistance to the material. The wind leakage of the spray-modified material was reduced by 2.7 times compared to the unmodified material, significantly improving its sealing performance under mining-induced pressure conditions. This enhancement effectively minimizes spontaneous combustion in mined-out coal areas caused by wind leakage, thereby ensuring safer mining operations. Full article

In modern agriculture, fertilizers are commonly used to increase crop yields; however, their negligent use can lead to environmental pollution and the waste of essential nutrients such as inorganic phosphate (Pi). Encapsulated fertilizers are a feasible alternative that could prevent these issues, as they can protect Pi from leaching and extend the interval between applications. In this study, we developed and tested innovative fertilizers (IFs) manufactured with KH₂PO₄, encapsulated with chitosan modified via high-frequency ultrasound treatment. The characterization of these fertilizers consisted of Fourier-transform infrared spectroscopy analysis and scanning transmission electron microscopy to determine their sizes and forms. In addition, we evaluated the phosphate release profile using electrical conductivity. The IFs were spheroidal microcapsules with an average diameter of 0.5–2 μM and showed slow-release behavior. Their efficacy was assessed via in vivo and in vitro assays, using Arabidopsis thaliana as a study model. As expected, the IFs promoted the growth of seedlings. One of the IFs showed enhanced growth promotion, contrasting with the control. This phenotype was likely promoted by this fertilizer due to the synergistic effect of Pi and the modified chitosan used as an encapsulant matrix. Our results highlight the potential of these formulations, which have unique properties and could be used on a large scale. Full article