Search Results (1,071)

One-part geopolymers (OPG) offer a low-carbon alternative to Portland cement, yet mix design remains largely empirical. This study couples machine learning with SHAP (Shapley Additive Explanations) to quantify how mix and curing factors govern performance in Ca-containing OPG. We trained six regressors—Random Forest, ExtraTrees, SVR, Ridge, KNN, and XGBoost—on a compiled dataset and selected XGBoost as the primary model based on prediction accuracy. Models were built separately for four targets: compressive strength at 3, 7, 14, and 28 days. SHAP analysis reveals four dominant variables across targets—Slag, Na₂O, Ms, and the water-to-binder ratio (w/b)—while the sand-to-binder ratio (s/b), temperature, and humidity are secondary within the tested ranges. Strength evolution follows a reaction–densification logic: at 3 days, Slag dominates as Ca accelerates C–(N)–A–S–H formation; at 7–14 days, Na₂O leads as alkalinity/soluble silicate controls dissolution–gelation; by 28 days, Slag and Na₂O jointly set the strength ceiling, with w/b continuously regulating porosity. Interactions are strongest for Slag × Na₂O (Ca–alkalinity synergy). These results provide actionable guidance: prioritize Slag and Na₂O while controlling w/b for strength. The XGBoost+SHAP workflow offers transparent, data-driven decision support for OPG mix optimization and can be extended with broader datasets and formal validation to enhance generalization. Full article

To effectively address the issues of poor ventilation, light deficiency, increased pest and disease pressure, and declining fruit quality in closed-canopy walnut orchards, this study was conducted in a standard, densely planted ‘Xinwen 185’ walnut orchard. Three treatments were established: an unthinned control (CK), a 1-year thinning treatment (T1), and a 2-year thinning treatment (T2). All parameters were uniformly investigated during the 2023 growing season to analyze the effects of thinning on orchard population structure, microenvironment, leaf physiological characteristics, fruit quality, and yield. The results demonstrated that tree thinning significantly optimized the population structure: crown width expanded by 6.22–6.76 m, light transmittance increased to 27.74–33.64%, and orchard coverage decreased from 100% to 75.94–80.51%. The microenvironment was improved: inter-row temperature increased by 2.34–4.08 °C, light intensity increased by 5.38–25.29%, and relative humidity decreased by 2.15–3.30%. Furthermore, leaf physiological functions were activated: in the T2 treatment, the chlorophyll content in outer-canopy leaves increased by 15.23% and 12.45% at the kernel-hardening and maturity stages, respectively; the leaf carbon-to-nitrogen ratio increased by 18.67%; the net photosynthetic rate (Pn) during fruit expansion increased by 34.21–46.10%; and the intercellular CO₂ concentration (Ci) decreased by 10.18–10.31%. Fruit quality and yield were synergistically enhanced: single fruit weight increased by 23.39~37.94%, and kernel weight increased by 26.79–41.13%. The total sugar content in inner-canopy fruits increased by 16.50–16.67%, while the protein and fat content in outer-canopy fruits increased by 0.69–12.50% and 0.60–2.18%, respectively. Yield exhibited a “short-term adjustment and long-term gain” pattern: the T2 treatment (after 2 years of thinning) achieved a yield of 5.26 t·ha⁻¹, which was 20.38% higher than the CK. The rates of diseased fruit and empty shells decreased by 65.71% and 93.22%, respectively, and the premium fruit rate reached 90.60%. This study confirms that tree thinning is an effective measure for improving the growing environment and enhancing overall productivity in closed-canopy walnut orchards, providing a scientific basis for sustainable orchard management and increased orchard profitability. Full article

Nitrate, as one of the important nutrients in seawater, influences the constant ratio of nitrogen to phosphorus, which is closely related to phytoplankton survival. In this work, a Cu-nanosphere-modified gold microwire electrode was used as the working electrode for determining nitrate in an artificial seawater sample with salinity of 35‰ by a differential pulse voltammetry technique. Under the optimized conditions, the detection linear range is from 1 μM to 2000 μM, the limit of detection is 0.33 μM, and the response time for a single sample is 5 min. Then, to reduce the influence of factors such as temperature, humidity, and microbial environment during sample transporting on the nitrate concentration in real seawater, a portable electrochemical system was introduced for on-site detection. Rapid field determination results show that nitrate levels correlate with tides, proving the portable system’s reliability. Full article

The aim of the present study is to evaluate the impact of chromium (Cr) supplementation on glucose and lipid metabolism in breast muscle in broilers under heat stress. A total of 220 day-old broiler chicks were reared in cages. At 29 days old, 180 birds were randomly assigned to three treatments (0, 400, and 800 µg Cr/kg, as chromium picolinate) and transferred to climate chambers (31 ± 1 °C, 60 ± 7% humidity) for 14 days. Growth performance, carcass traits, serum biochemical indices, fasting glucose and insulin, homeostasis model assessment of insulin resistance (HOMA-IR), as well as muscle metabolomic profiles and gene expression related to energy and lipid metabolism were analyzed. The results showed that, compared with the heat stress group, the groups supplemented with 400 and 800 µg Cr/kg showed higher dry matter intake and average daily gain, breast muscle ratio, and lower feed conversion ratio and abdominal fat ratio; chickens supplemented with 400 and 800 µg Cr/kg showed significantly lower serum corticosterone (CORT), free fatty acids, and cholesterol levels compared with the heat stress (HS) group (p < 0.05). Fasting blood glucose and HOMA-IR were also significantly reduced, while fasting insulin was significantly increased in the Cr-supplemented groups (p < 0.05). Metabolomic analysis revealed that Cr supplementation regulated lipid and amino acid metabolism by altering key metabolites such as citric acid, L-glutamine, and L-proline, and modulating pathways including alanine, aspartate, and glutamate metabolism, and glycerophospholipid metabolism. Furthermore, Cr supplementation significantly upregulated the expression of Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1 α (PGC-1α), ATP Binding Cassette Subfamily A Member 1 (ABCA1), Peroxisome Proliferator-Activated Receptor α (PPARα), and ATP Binding Cassette Subfamily G Member 1 (ABCG1) in both the hepatic and muscle tissue. This paper suggested that chromium supplementation may enhance energy metabolism and lipid transport like the findings of our study suggested. Full article

Normal concrete exhibits poor resistance to chloride penetration, often leading to reinforcement corrosion and premature structural failure. In contrast, ultra-high-performance concrete (UHPC) demonstrates superior resistance to corrosion caused by chloride salts. The chloride diffusion behaviour of UHPC was investigated via long-term immersion (LTI) and rapid chloride migration (RCM) tests. Additionally, this study presents the first development of a time-dependent diffusion model for UHPC under chloride corrosion, as well as the proposal of a performance-based design method for calculating the protective layer thickness. Results show that the incorporation of steel fibers reduced the chloride diffusion coefficient ($D$) by 37.9%. The free chloride content (FCC) in UHPC increased by 92.0% at 2 mm after 300 d of the action of LTI. $D$ decreased by up to 91.0%, whereas the surface chloride concentration ($C_{\mathrm{s}}$) increased by up to 92.5% under the action of LTI. The time-dependent models of $D$ and $C_{\mathrm{s}}$ followed power and logarithmic functions, respectively. An increase in UHPC surface temperature, relative humidity, and tensile stress ratio significantly diminishes the chloride resistance of UHPC. The minimum UHPC protective layer thicknesses required for UHPC-HPC composite beams with design service lives of 100 years, 150 years, and 200 years are 30 mm, 37 mm, and 43 mm, respectively. Full article

Coating plays an important role in advancing sensing technology by significantly enhancing sensitivity, stability, and response time. The unique properties of nanostructures, including high surface-to-volume ratio and tunable porosity, make them suitable candidates for improving sensor performance. By optimizing nanostructure coatings, advancements in high-precision humidity sensing devices are achievable, enabling a wide range of industrial applications, especially in humidity-controlled industries. In this study, the effects of annealing time, annealing temperature, and the number of coating layers on the properties of additive-enhanced SnO₂ nanostructure were investigated. The experiment was carried out by subjecting the additive-enhanced SnO₂ nanostructure to different annealing times and annealing temperatures to analyze its impact on crystallinity, porosity, and moisture adsorption properties. Upon optimizing the annealing parameters, multilayer coatings were carried out to assess the effect of the total number of coating layers on hygroscopic behavior. A hygroscopicity test was carried out on each sample to evaluate its moisture adsorption and desorption capabilities. The results demonstrated that controlled annealing conditions significantly improve the nanostructure’s hygroscopic properties, and the optimized coating layers further enhanced the moisture retention, making the developed SnO₂ nanostructure a promising candidate for advanced sensing applications. Full article

Hakka traditional vernacular dwellings embody regionally specific climatic adaptation strategies. This study takes the Meizhou Guangludi enclosed house as a case study to evaluate its climate adaptability with longevity and passive survivability factors of the Hakka three-hall enclosed house under subtropical climatic conditions. A mixed research method is employed, integrating visualized parametric modeling analysis and on-site measurement comparisons to quantify wind, temperature, solar radiation/illuminance, and humidity, along with human comfort zone limits and building environment. The results reveal that nature erosion in the Guangludi enclosed house is the most pronounced during winter and spring, particularly on exterior walls below 2.8 m. Key issues include bulging, spalling, molding, and fractured purlins caused by wind-driven rain, exacerbated by low wind speeds and limited solar exposure, especially at test spots like the E8–E10 and N1–N16 southeast and southern walls below 1.5 m. Fungal growth and plant intrusion are severe where surrounding trees and fengshui forests restrict wind flow and lighting. In terms of passive survivability, the Guangludi enclosed house has strong thermal insulation and buffering, aided by the Huatai mound; however, humidity and day illuminance deficiencies persist in the interstitial spaces between lateral rooms and the central hall. To address these issues, this study proposes strategies such as adding ventilation shafts and flexible partitions, optimizing patio dimensions and window-to-wall ratios, retaining the spatial layout and Fengshui pond to enhance wind airflow, and reinforcing the identified easily eroded spots with waterproofing, antimicrobial coatings, and extended eaves. Through parametric simulation and empirical validation, this study presents a climate-responsive retrofit framework that supports the sustainability and conservation of the subtropical Hakka enclosed house. Full article

School buildings in hot-humid climates encounter considerable difficulties in balancing energy use and thermal comfort due to this environment, necessitating optimized design strategies to reduce energy consumption while enhancing occupant comfort. This study presents sustainable design strategies for educational structures in hot-humid regions, aiming to optimize energy efficiency and thermal comfort for environmental preservation and occupant welfare. The present work introduces a multi-objective optimization framework for window design in school buildings situated in hot-humid climates, targeting a balance between Energy Use Intensity (EUI) and Thermal Comfort Time Ratio (TCTR). Exploring multi-objective optimization through NSGA-II genetic algorithms, the study conducts Sobol sensitivity analysis for parameter assessment and applies Gaussian Process Regression (GPR) for effective model validation, identifying optimal window configurations that reduce energy consumption while enhancing thermal comfort. It finds that the Window-to-Wall Ratio (WWR) and Solar Heat Gain Coefficient (SHGC) are the most significant factors, with WWR and SHGC accounting for 28.1% and 23.7% of the variance in EUI and TCTR, respectively. The results reveal a non-linear trade-off between the objectives, with the Balanced Solution offering a practical compromise: a 6.7% decrease in energy use and a 14.3% enhancement in thermal comfort. The study examined various ranges of window parameters, including WWR (0.1–0.50), SC (0.20–0.80), K (1.0–2.5 W·m⁻²·K⁻¹), SHGC (0.1–0.4), Shading width (0.3–2.0 m), and Shading angle (0°–90°). The recommended compromise, known as the Balanced Solution, suggests optimal values as follows: WWR = 0.40, SC = 0.30, SHGC = 0.40, K = 1.2 W·m⁻²·K⁻¹, Shading width = 1.22 m, and Shading angle = 28°. The GPR model exhibited high predictive precision, with R² values of 0.91 for EUI and 0.95 for TCTR, underscoring the framework’s effectiveness. This research offers actionable insights for designing energy-efficient and comfortable school buildings in hot-humid climates, enriching sustainable architectural design knowledge. Full article

Busan’s major port is among the largest trading ports worldwide; however, it is also one of the ten most polluted ports globally. This study aims to assess the effectiveness of satellite-derived aerosol data for monitoring particulate matter levels in Busan. Aerosol optical depth (AOD) from the Visible Infrared Imaging Radiometer (VIIRS) Deep Blue product tends to be sparse near coastlines due to higher retrieval uncertainties. To increase the number of samples along the coastal area, we established optimized quality control criteria, resulting in more than three times the number of samples. The VIIRS AOD showed a positive correlation with surface particulate matter (PM_2.5) measurements (r = 0.42). The ratios of VIIRS AOD to surface PM_2.5 and PM₁₀ were higher in coastal areas, probably due to greater hygroscopic growth of particles. This connection can assist in estimating surface PM concentrations using satellite data. Both VIIRS AOD and surface PM concentrations exhibit a negative correlation with terrain elevation, primarily due to the locations of emission sources and altitude-dependent weather factors such as temperature and humidity. We expect that combining higher-resolution ancillary databases, including digital elevation maps and meteorology, with satellite-based AOD will enhance the detail of air quality evaluations in port cities. Full article

We examined the modulation of ‘Sweet Gold’ and ‘Goldone’ kiwifruit (Actinidia spp.) ripening using modified atmosphere and humidity (MAH), 1-methylcyclopropene (1-MCP), and edible coating treatments up to 35 days after storage (DAS) at room temperature. The 1-MCP and coating treatments decreased [CO₂] in both cultivars, whereas MAH treatment rapidly increased or decreased [CO₂]. Use of 1-MCP highly preserved firmness in both cultivars, followed by coating. MAH sharply reduced approximately 17% of ‘Goldone’ fruit firmness at 7 DAS compared to other treatments. MAH, 1-MCP, and coating reduced weight loss in ‘Sweet Gold’ kiwifruits from 14 to 35 DAS. Coating prevented approximately 14% of weight loss in ‘Goldone’ fruits during storage by strong adherence to the fruit surface. The flesh of control and MAH-treated fruits of both cultivars exhibited reduced acidity during storage, increasing the soluble solids content to acidity ratio. The use of 1-MCP delayed a reduction in L* values of the peel color of ‘Sweet Gold’ kiwifruits, while reduced L* values of flesh color were mostly observed with control and MAH treatment in both fruit cultivars. The use of 1-MCP, coating, and MAH maintained high total phenolics, ABTS, and vitamin C levels in both cultivars at 14 and 28 DAS. Fruit ripening was delayed by coating and promoted by MAH treatment, while maintaining the quality and functional substances of the fruit. Full article

Heat stress induced by high temperature and humidity in southern China during summer reduce goat production efficiency and meat quality. Taurine (TAU), one of the most abundant amino acids in animal tissues, plays a vital role in alleviating heat stress and regulating energy metabolism through its involvement in glucose uptake and glycogen turnover. This study aimed to investigate the effects of rumen-protected (RP)-TAU on the meat quality, hepatic gluconeogenesis, and muscle energy metabolism of heat-stressed goats. During summer, twenty-four male crossbred Gan-xi goats (20.45 ± 2.95 kg) aged 5 months were randomly allocated to two groups treated with or without 0.4% RP-TAU (on a diet weight basis). After feeding for 60 days, six goats per treatment were slaughtered. Compared with the control group, RP-TAU supplementation significantly improved the growth performance of goats, as evidenced by increased final body weight, average daily gain, and average daily feed intake (p < 0.05). The goats in the RP-TAU group showed a reduced splenic index (p < 0.05), lower serum cortisol levels (0.05 < p < 0.1), and decreased muscle crude fat content (p < 0.01). Crucially, meat quality was improved with reduced hardness, gumminess, and chewiness (p < 0.05), indicating better textural properties. Nutritionally, RP-TAU supplementation modulated the muscle fatty acid profile, significantly reducing the concentrations of palmitic (a saturated fatty acid), palmitoleic (a monounsaturated fatty acid), and nervonic acids (p < 0.05), while cystine content was reduced (p < 0.05). RP-TAU supplementation significantly enhanced the muscle contents of glucose and glycogen, glycolytic potential, phosphofructokinase activity, and ATP level, while decreasing the pyruvate level and AMP/ATP ratio (p < 0.05). Gene expression analysis revealed the upregulation of GLUT4 and PYGM and the downregulation of GSK3β in muscle (p < 0.05). These results indicated that dietary supplementation of RP-TAU might be beneficial to improve stress resistance and meat quality by increasing muscle energy supply and glucose uptake in Gan-xi goats. Full article

Furniture surfaces are prone to the accumulation of bacteria, fungi and other micro-organisms, especially in humid environments such as kitchens and bathrooms. The antimicrobial treatment of coatings has been demonstrated to enhance the performance of wood, prolong its service life, and improve hygiene and safety. Consequently, by investigating the most effective preparation process for antimicrobial microcapsules and incorporating them into the coating, the coating can be endowed with antimicrobial properties, thereby expanding its application range. Microcapsules were prepared using a composite wall material consisting of chitosan (CS) and Arabic gum (AG), with tea tree essential oil (TTO) serving as the core material. The best CS-AG coated TTO microcapsules were prepared when the core–wall ratio was 1.2:1, the emulsifier concentration was 2%, the pH was 3, and the mass ratio of AG to CS (m_AG:m_CS) was 3:1. The m_AG:m_CS was identified as the most significant factor affecting the microcapsule yield and encapsulation rate. With the increase in m_AG:m_CS, the antimicrobial rate of the coating against Escherichia coli (E. coli) exhibited a trend of first rising and then falling, while the antimicrobial rate against Staphylococcus aureus (S. aureus) demonstrated a trend of first rising, then falling, and then rising again. The colour difference (ΔE) and gloss exhibited an overall downward trend, the light loss rate demonstrated a fluctuating upward trend, and the roughness exhibited a trend of first falling and then rising. The visible light band transmittance exhibited minimal variation, ranging from 86.43% to 92.76%. Microcapsule 14# (m_AG:m_CS = 3:1) demonstrated remarkable antimicrobial properties (E. coli 65.55%, S. aureus 73.29%), exceptional optical characteristics (light transmittance 92.12%, 60° gloss 24.0 GU), and notable flexibility (elongation at break 18.10%, modulus 0.10 GPa). The waterborne coating was modified by microcapsule technology, thus endowing the coating with antimicrobial properties and concomitantly broadening the scope of application of antimicrobial microcapsules. Full article

Recycled aggregate concrete refers to concrete made by using recycled aggregates produced from construction waste to replace natural aggregates. The performance of recycled aggregate concrete is extremely unstable. Internal factors such as water–cement ratio, porosity, and the properties of recycled aggregates, as well as external factors like temperature, humidity, environmental erosion, and the addition of improvement materials, may all have an impact on its mechanical properties. The response surface analysis method was employed to investigate the impact of three key factors—the number of dry–wet cycles, the content of stainless steel fibers, and the concentration of Na₂SO₄—on the mechanical properties of stainless steel fiber recycled aggregate concrete (SSFRAC) under dry–wet cycling conditions in the study. By incorporating stainless steel fibers into the cementitious gel network, SSFRAC is conceptualized as a composite material where the metal fibers are integrated into the gel matrix, forming a hybrid system akin to metallogels. The response models for compressive strength durability coefficient S_c and flexural strength durability coefficient S_f are established using Design-Expert software to evaluate the significance of these factors and their interactions. The version of Design-Expert used in this study is Design Expert 13.0. The results demonstrated that both S_c and S_f models exhibit high fitting accuracy, effectively capturing the relationships among the factors. The number of dry–wet cycles exhibit the highest significance, followed by Na₂SO₄ concentration and stainless steel fiber content. The interaction between dry–wet cycle number and Na₂SO₄ concentration has a particularly significant impact on S_c. For S_f, stainless steel fiber content is the most significant factor, followed by dry–wet cycle number and Na₂SO₄ concentration, with the interaction between fiber content and Na₂SO₄ concentration exerting a notably strong influence. This study highlights the potential of cement-based gels as raw materials for synthesizing functional composite materials, where the incorporation of metal fibers enhances mechanical performance and durability under aggressive environmental conditions. The findings provide insights into the design and optimization of hybrid gel–metal systems for advanced construction applications. Full article

The significant potential loss of proton exchange membrane fuel cells (PEMFCs) at high current densities is primarily attributed to the high mass transfer resistance of the gas diffusion layer (GDL). The underlying mechanism of how structural parameters of the GDL under actual assembly conditions affect oxygen transport resistance remains unclear, particularly the quantitative relationship between the compression ratio (α) and tortuosity (γ). This study systematically evaluated the output performance and mass transfer overpotential of three commercially available GDLs with similar thickness and porosity under different compression ratios (5.4% to 27%) and four inlet humidity conditions (RH0% to RH100%). By accurately extracting and comparing mass transfer overpotentials, it was observed that the mass transfer overpotential initially decreased and then increased with the rising compression ratio, with an optimum observed at 21.6%. An empirical correlation between the compression ratio (α) and tortuosity (γ) was established as γ = 3.42α + 2.1. Based on this, a modified oxygen diffusion equation was proposed to accurately describe oxygen transport behavior within the GDL under compressed conditions. A modified oxygen diffusion equation was proposed to more accurately characterize the oxygen transport process within compressed GDLs. These findings establish a foundation for optimizing GDL design and stack assembly processes. Future work will build upon this study by incorporating multiphysics conditions such as stack clamping pressure, number of cells, intercell contact resistance, and assembly conditions (temperature and relative humidity), with the aim of elucidating the force–thermal–electrical–mass coupling mechanisms within the stack, thereby enhancing the overall performance and reliability of high-power-density proton exchange membrane fuel cell (PEMFC) stacks. Full article

Dew is an important water source for vegetation growth in arid regions and plays a significant role in maintaining ecosystem balance. The characteristics of dew formation vary under different topographic conditions. In response to the challenges posed by climate change to the sustainability of water resources and ecosystems, this study explored the impact of topography on dew formation, and leaf wetness sensors (LWSs) were employed to conduct field observations from April 2023 to April 2025 in typical hilly and gully regions of China’s Loess Plateau. We analyzed the characteristics, influencing factors, and ecological significance of near-surface water vapor condensation. The main conclusions are as follows: (1) During the observation period, dew primarily occurred between 19:00 and 07:00 the next day, peaking between 05:30 and 07:00 in the early morning. The monthly average dew amounts for the hilly region and gully region were 2.15 mm and 3.38 mm, respectively, and the monthly maximum dew amounts were 8.57 mm and 11.88 mm, respectively, both peaking in autumn, with the gully region exhibiting higher dew amounts. (2) Dew formation at a 0.2 m height was favored when relative humidity at 0.2 m exceeded 70%, the air temperature–dew point difference was less than 8 °C, the wind direction was between 150 and 210° and 240 and 270° for the hilly region and gully region, respectively, and the standardized wind speed at a 10 m height was less than 0.5 m/s and 1.5 m/s for the hilly region and gully region, respectively. (3) Moderate rainfall facilitates dew condensation. The monthly average dew-to-precipitation (dew and rain) ratio reached its maximum in November for both the Loess hilly region and gully region, at 12.88% and 18.91%, respectively. (4) The gully region experienced larger dew events more frequently than the hilly region, resulting in a higher overall dew amount in the gully region during the observation period. The dew formation characteristics observed in this study can provide a scientific basis for assessing the future supply potential of non-precipitation water sources in the Loess Plateau under climate change and their supporting role in the ecological environment. Full article