Search Results (2,551)

Lattice structures produced by additive manufacturing are increasingly used in lightweight, load-bearing applications, yet their mechanical performance is strongly influenced by geometry, process parameters, and boundary conditions. This study investigates the compressive behavior of body-centered cubic (BCC) 316L stainless steel lattices fabricated by laser powder bed fusion (LPBF). Four relative densities (20%, 40%, 60%, and 80%) were achieved by varying the strut diameter, and specimens were built in both vertical and horizontal orientations. Quasi-static compression tests characterized the elastic modulus, yield strength, energy absorption, and mean force, while finite element simulations reproduced the deformation and hardening behavior. The experimental results showed a direct correlation between density and mechanical properties, with vertically built specimens performing slightly better due to reduced processing defects. Simulations quantified the effect of strut–joint rounding and the need for multi-cell configurations to closely match the experimental curves. Regardless of the boundary conditions, for a density of 20%, simulating a single cell underestimated stiffness because of unconstrained strut buckling. For higher densities and thicker struts, this sensitivity to boundary conditions strongly decreased, indicating the possibility of using a single cell for shorter simulations—a point rarely discussed in the literature. Both experiments and simulations confirmed Gibson–Ashby scaling for elastic modulus and yield strength, while the tangent modulus was highly sensitive to boundary conditions. The combined experimental and numerical results provide a framework for the reliable modeling and design of metallic lattices for energy absorption, biomedical, and lightweight structural applications. Full article

Non-photochemical quenching (NPQ) is a key photoprotective mechanism in Symbiodiniaceae, enabling photosystem II (PSII) to dissipate excess excitation energy under stress. The balance between regulated (Φ_NPQ) and unregulated (Φ_NO) energy dissipation influences thermal tolerance, yet the temperature thresholds at which this balance shifts remain poorly defined. Here, we used the Phenoplate, a high-throughput fluorometric platform integrating rapid light curves with controlled temperature ramping, to examine short-term thermal responses in Breviolum minutum across 6–71 °C. We identified a sharp transition at 41 °C where Φ_NPQ collapsed and was replaced by Φ_NO, indicating loss of regulated photoprotection. This switch coincided with a pronounced drop in PSII effective quantum yield (Φ_II) and substantial reductions in cell density, marking a thermal Achilles’ heel in the photoprotective capacity of this species. Despite this regulatory breakdown, a fraction of cells persisted for at least three days post-exposure. These results demonstrate that B. minutum maintains regulated photoprotection up to a discrete threshold, beyond which unregulated becomes the dominant pathway and survival is compromised. Identifying such thermal inflection points in coral symbionts provides mechanistic insight into their vulnerability under acute heat stress and may inform early-warning indicators for coral bleaching susceptibility. Full article

Predicting how vegetation–debris interactions reshape alternate sandbars under a steady subcritical flow remains poorly understood in laboratory-to-field scaling. This study quantified how vegetation density and layout interact with debris geometry to control scouring and deposition and developed an empirical tool to predict normalized bed-level changes. Flume experiments investigated how vegetation–debris interactions regulate the hydromorphodynamics of non-migrating alternate sandbars under a steady subcritical flow (Q = 0.003 m³/s; slope = 1/200). Vegetation patches were configured in two spatial layouts—upstream (apex) and river line (edge), at varying densities, with and without debris (I-type: wall-like; U-type: horseshoe-shaped). Results indicated that dense upstream vegetation combined with I-type debris produced the strongest morphodynamic response, generating maximum scour, corresponding to the maximum bed-elevation changes (Δz) normalized by water depth (h) (dimensionless Δz/h) values of −1.55 and 1.05, and sustaining more than 70% of the downstream morphodynamic amplitude. In contrast, U-type debris promoted distributed deposition with a milder scour, while sparse vegetation yielded weaker, more transient responses. Debris geometry-controlled flow partitioning: the I-type enhanced frontal acceleration, whereas the U-type facilitated partial penetration and redistribution. To integrate these findings into predictive frameworks, an empirical regression model was developed to estimate Δz/h from the vegetation density, distribution, and debris geometry, with an additional blockage index to capture synergistic effects. The model achieved 87.5% prediction within ±20% error, providing a practical tool for anticipating scour and deposition intensity across eco-hydraulic configurations. These insights advance intelligent water management by linking morphodynamic responses with predictive modeling, supporting flood-resilient river engineering, adaptive channel stability assessments, and nature-based solutions. Full article

Soil erosion is an increasingly severe problem and a global focus. As one of the countries facing relatively serious soil erosion, China encounters significant ecological challenges. This study focuses on the carbon sink benefits of comprehensive soil and water conservation management in the red soil erosion area of southern China, conducting an in-depth analysis using the Ziyang small watershed in Shangyou County, Jiangxi Province, as a typical case. Research methods involved constructing an integrated monitoring approach combining basic data, measured data, and remote sensing data. Changes in soil and vegetation carbon storage in the Ziyang small watershed across different years were determined by establishing a baseline scenario and applying inverse distance spatial interpolation, quadrat calculation, feature extraction, and screening. The results indicate that from 2002 to 2023, after 21 years of continuous implementation of various soil and water conservation measures under comprehensive watershed management, the carbon storage of the Ziyang small watershed increased significantly, yielding a net carbon sink of 54,537.28 tC. Tending and Management of Coniferous and Broad-leaved Mixed Forest, Low-efficiency Forest Improvement, and Thinning and Tending contributed substantially to the carbon sink, accounting for 72.72% collectively. Furthermore, the carbon sink capacity of the small watershed exhibited spatial variation influenced by management measures: areas with high carbon density were primarily concentrated within zones of Tending and Management of Coniferous and Broad-leaved Mixed Forest, while areas with low carbon density were mainly found within zones of Bamboo Forest Tending and Reclamation. The increase in watershed carbon storage was attributed to contributions from both vegetation and soil carbon pools. Comprehensive management of soil erosion demonstrates a significant carbon accumulation effect. The annual growth rate of vegetation carbon storage was higher than that of soil carbon storage, yet the proportion of soil carbon storage increased yearly. This study provides a theoretical basis and data foundation for the comprehensive management of soil and water conservation in small watersheds in the southern red soil erosion region of China and can offer technical and methodological support for other soil and water conservation carbon sink projects in this area. Full article

Industrial wastewater can serve as a low-cost nutritional source for sustainable microalgal biomass production. This study investigated the biomass of Chlorella vulgaris var. vulgaris TISTR 8261 grown in untreated wastewater collected from four food industry factories in Phra Nakhon Sri Ayutthaya Province, Thailand. Among them, wastewater from a processed food production plant (PFPP) supported the highest algal growth. Supplementation with 17.4 mM sodium acetate significantly improved algal biomass yield. Further optimization with 3.7 mM NH₄Cl, 1.0 mM KH₂PO₄, 0.2 mM MgSO₄, and a moderate concentration of trace minerals enhanced the specific growth rate and chlorophyll concentration. Scaled-up cultivation in 3.5 L culture bottles in optimized PFPP yielded a maximum biomass yield of 8.436 ± 0.378 g L⁻¹, comparable to 6.498 ± 0.436 g L⁻¹ in standard TAP medium. Biomass composition analysis after 15 days of cultivation revealed 42.70 ± 1.40% protein, 17.10 ± 1.60% carbohydrate, and 1.90 ± 0.10% lipid on a dry weight basis. These findings demonstrate that optimized PFPP wastewater can effectively support high-density cultivation of C. vulgaris var. vulgaris TISTR 8261, yielding nutritionally rich biomass, and offering a cost-effective and environmentally sustainable strategy for industrial-scale microalgal production. Full article

Corn stunt complex, transmitted by the corn leafhopper (Dalbulus maidis), poses significant yield risks to corn production. This study evaluated the effects of two corn hybrids and top-dressed nitrogen (N) and potassium (K) fertilization on D. maidis incidence and corn stunt symptom expression under field conditions. Eighteen treatments were tested in a randomized complete block design with six replications over two seasons. Leafhopper populations were monitored using yellow sticky traps, and symptom incidence and severity were assessed at R₁ and R₃ stages, respectively. While D. maidis populations varied substantially between seasons, neither N nor K fertilization, nor hybrid selection, significantly affected vector abundance. Importantly, symptom frequency and severity were not directly proportional to leafhopper density. Top-dressed fertilization, particularly with K, reduced the visual expression of corn stunt symptoms although it did not prevent infection. Hybrid responses to fertilization varied, with a genotype exhibiting greater symptom mitigation. Grain yield was not significantly influenced by nutrient rates or hybrid choice. These findings suggest that balanced N and K fertilization enhances crop resilience to corn stunt disease without directly suppressing vector populations. Integrating nutritional management with hybrid selection presents a promising strategy to add in corn stunt control and deepens our understanding of the environmental factors that mitigate severe symptoms. Full article

Plants vary in number of chromosomes (ploidy levels), which can influence morphological traits, including the size and density of stomata cells. Although biologists can detect these differences under a microscope, the process is often time-consuming and tedious. This study aims to automate the classification of blackcurrant (Ribes nigrum L.) ploidy levels—diploid, triploid, and tetraploid—by leveraging deep learning techniques. Convolutional Neural Networks and Vision Transformers are employed to perform microscopic image classification across two distinct blackcurrant datasets. Initial experiments demonstrate that these models can effectively classify ploidy levels when trained and tested on subsets derived from the same dataset. However, the primary challenge lies in proposing a model capable of yielding satisfactory classification results across different datasets ensuring robustness and generalization, which is a critical step toward developing a universal ploidy classification system. In this research, a variety of experiments is performed including application of augmentation technique. Model efficacy is evaluated with standard metrics and its interpretability is ensured through Gradient-weighted Class Activation Mapping visualizations. Finally, future research directions are outlined with application of other advanced state-of-the-art machine learning methods to further refine ploidy level prediction in botanical studies. Full article

JP-10 (exo-tetrahydrodicyclopentadiene) is a high-energy-density hydrocarbon broadly used in advanced aerospace propulsion as a regenerative cooling fluid; in this study, we aimed to clarify how fuel pressure affects its thermal degradation (oxidative and pyrolytic) in near-isothermal flowing reactor. Experiments were performed under oxidative conditions (wall temperature 623.15 K, p = 0.708–6.816 MPa) and pyrolytic conditions (wall temperature 793.15 K, p = 2.706–7.165 MPa); carbon deposits were quantified by LECO analysis, oxidation activity was assessed by temperature-programmed oxidation (TPO), and morphology was performed by FESEM and EDS. Results show that oxidative coking is minimal (5.37–14.95 μg·cm²) and largely insensitive to pressure in the liquid phase (1.882–6.816 MPa), whereas at 0.708 MPa (gas/phase-change conditions), deposition increases, implicating phase and local heat-transfer effects. Under oxidative conditions, deposits are predominantly amorphous carbon with a disordered structure, formed at relatively low temperatures, with only a few fiber-like metal sulfides identified by EDS. In contrast, under pyrolysis conditions, the deposits are predominantly carbon nanotubes, exhibiting well-defined tubular morphology formed at elevated temperatures via metal-catalyzed growth. The pyrolysis coking yield is substantially higher (66.88–221.89 μg·cm⁻²) and increases with pressure. The findings imply that the pressure influences the coking of JP-10 via phase state under oxidative conditions and residence time under pyrolytic conditions, while basic morphologies of coke deposits remain similar; operationally, maintaining the working pressure higher than the saturated vapor pressure can mitigate oxidation coking associated with phase transitions, and minimizing residence time can mitigate pyrolytic coking. Full article

Polyploidization is a rapid breeding strategy for producing new varieties with superior agronomic traits. Kenaf (Hibiscus cannabinus L.), an important fiber crop, exhibits high adaptability to diverse stress conditions. However, comprehensive studies on polyploid induction, screening, and genetic identification in kenaf remain unreported. This study first established an optimal tetraploid induction system for diploid kenaf seeds using colchicine. The results showed that a 4-h treatment with 0.3% colchicine yielded the highest tetraploid induction rate of 37.59%. Compared with diploids, tetraploid plants displayed distinct phenotypic and physiological characteristics: dwarfism with shortened internodal distance, increased stem thickness, larger and thicker leaves with deeper green color and serration, as well as enlarged flowers, capsules, and seeds. Physiologically, tetraploid leaves featured increased chloroplast numbers in guard cells, reduced stomatal density, and larger pollen grains, elevated chlorophyll content. Further analyses revealed that tetraploid kenaf had elevated contents of various trace elements, enhanced photosynthetic efficiency, prolonged growth duration, and superior agronomic traits with higher biomass (54.54% higher fresh weight, 79.17% higher dry weight). These findings confirm the effectiveness of colchicine-induced polyploidization in kenaf, and the obtained tetraploid germplasm provides valuable resources for accelerating the breeding of elite kenaf varieties with improved yield and quality. Full article

Cover crops and mulches are widely used techniques for limiting weeds and pests’ effects on crops. This study compared six practices over two growing seasons in two organic farms in Cuneo province, North-West Italy: two bio-based biodegradable mulch sheets (BM01 and BM02), dead mulch (hazelnut shells), living mulch (Trifolium repens L.), mechanical control, and an untreated control. Spring crops included Lactuca sativa L. var. capitata, Allium cepa L. cv. ‘Tropea’, and Brassica oleracea L. var. italica, while autumn crops were Lactuca sativa L. var. capitata, Allium fistulosum L., and Brassica oleracea L. var. italica. Weed infestation was evaluated through density (n/m²), biomass (g/m²), and diversity (Shannon Index), alongside crop yield and quality. Biodegradable mulch sheets provided the greatest weed suppression, followed by hazelnut shells, while living mulch and untreated control showed the highest weed pressure. Crop yield varied significantly among practices and species: BM01 and BM02 resulted in the highest yields, while living mulch consistently produced the lowest. Lettuce displayed the best quality across both farms, whereas onion quality varied by site. The highest quality scores were observed under biodegradable mulches and mechanical control, while living mulch and untreated control yielded the poorest results. Overall, biodegradable mulches emerged as the most effective balance between weed suppression, crop yield, and quality in organic systems. Full article

Hydrogen energy offers high energy density and carbon-free combustion, making it a promising fuel for next-generation propulsion and power generation systems. Hydrogen offers approximately three times more energy per unit mass than natural gas, and its combustion yields only water as a byproduct, making it an exceptionally clean and efficient energy source. Materials used in hydrogen-fueled combustion engines must exhibit high thermal stability as well as resistance to corrosion caused by high-temperature water vapor. This study introduces a novel ceramic matrix composite (CMC) designed for such harsh environments. The composite is made of yttria-stabilized zirconia (YSZ) fiber-reinforced silicoboron carbonitride [Si(B)CN]. CMCs were fabricated via the polymer infiltration and pyrolysis (PIP) method. Multiple PIP cycles, which help to reduce the porosity of the composite and enhance its properties, were utilized for CMC fabrication. The Si(B)CN precursor formed an amorphous ceramic matrix, where the presence of boron effectively suppressed crystallization and enhanced oxidation resistance, offering superior performance than their counter part. Thermogravimetric analysis (TGA) confirmed negligible mass loss (≤3%) after 30 min at 1350 °C. The real-time ablation performance of the CMC sample was assessed using a hydrogen torch test. The material withstood a constant heat flux of 185 W/cm² for 10 min, resulting in a front-surface temperature of ~1400 °C and a rear-surface temperature near 700 °C. No delamination, burn-through, or erosion was observed. A temperature gradient of more than 700 °C between the front and back surfaces confirmed the material’s effective thermal insulation performance during the hydrogen torch test. Post-hydrogen torch test X-ray diffraction indicated enhanced crystallinity, suggesting a synergistic effect of the oxidation-resistant amorphous Si(B)CN matrix and the thermally stable crystalline YSZ fibers. These results highlight the potential of YSZ/Si(B)CN composites as high-performance materials for hydrogen combustion environments and aerospace thermal protection systems. Full article

The Inner Mongolian Plateau is a critical region for the development of herbivorous animal husbandry in China. However, its harsh climate and poor soil quality have constrained the sustainable growth of the alfalfa industry. This 3-year field study investigated the effects of potassium (K) fertilizer on the productivity and forage quality of alfalfa (Medicago sativa L. cv. ‘WL168’) in such specific conditions of the region. Five rates of K fertilizer (0 (CK), 100, 200, 300, and 400 kg ha⁻¹ of K₂O) were applied in three split applications. Forage harvests occurred three times annually in 2023 and 2024, and yield, yield components, and forage quality were determined. The results showed that the forage yield of alfalfa increased initially and then decreased with the rising K application rates, which paralleled the changes in the plant density, and plant height, especially the mass shoot⁻¹; forage yield was mainly correlated with mass shoot⁻¹. Appropriate K fertilizer improved forage quality, especially in 2024. With increasing application, crude protein (CP) and total digestible nutrients (TDNs) first rose then declined, whereas neutral detergent fiber (NDF) and acid detergent fiber (ADF) decreased steadily, leading to a consistent rise in the relative feeding value (RFV). Comprehensively considering both yield and quality under such condition, a K fertilizer application rate of 273.2 kg ha⁻¹ of K₂O is suggested as a reference for this region. Full article

The problems of excessive nitrogen fertilizer application and mismatch between varieties and planting density are common in potato production in the dryland farming areas of Loess Plateau, and it is of great significance to select suitable nitrogen application rates and planting densities for the green and sustainable production of dryland potatoes in this area. In this study, Longshu 16 was selected as the potato variety, and we investigated two nitrogen application rates: 200 kg·hm⁻² (N1), 300 kg·hm⁻² (N2); and three planting densities: 37,500 plants·hm⁻² (D1), 52,500 plants·hm⁻² (D2), 67,500 plants·hm⁻² (D3). The effects of different nitrogen fertilization rates and planting densities on photosynthetic characteristics, leaf carbon and nitrogen metabolism enzyme activities, and yield and quality of potato were measured and analyzed. The results showed that during the tuber swelling stage, the activity of ribose-1,5-diphosphate carboxylase oxygenase (Rubisco) in potato leaves was increased by 9.05%. During the starch accumulation stage, the activity of glutamine synthetase (GS) in potato leaves was increased by 3.02~22.34% in N1D2 treatment compared with other treatments, and the activity of glutamate synthase (GOGAT) was increased by 2.83~7.35% compared with other treatments. During the starch accumulation stage, the activity of ADP-glucose pyrophosphorylase (AGPase) in potato leaves was increased by 7.85~31.17% in N1D2 treatment compared with other treatments. The contents of protein, starch, vitamin C, and calcium in potato tubers in N1D2 treatment were the highest, and the yield was the highest in N1D2 treatment. In conclusion, the recommended nitrogen application rate of 200 kg·hm⁻² and planting density of 52,500 plants·hm⁻² in dry-fed potato production improved the yield and quality of potato by enhancing activities of GAPDH, GS, and AGPase. Full article

Soybean (Glycine max (L.) Merr.) is one of the most important global economic crops, extensively utilized in the production of food, animal feed, and industrial raw materials. As the demand for soybeans continues to rise, improving both the yield and quality of soybeans has become a central focus of agricultural research. To accelerate the genetic improvement of soybean, genome selection (GS) and genome-wide association studies (GWAS) have emerged as effective tools and have been widely applied in various crops. In this study, we conducted GWAS and GS model evaluations across five soybean phenotypes (Glycitin content, Oil, Pod, Total isoflavone content, and Total tocopherol content) to explore the effectiveness of different GWAS methods and GS models in soybean genetic improvement. We applied several GWAS methods, including fastGWA, BOLT-LMM, FarmCPU, GLM, and MLM, and compared the predictive performance of various GS models, such as BayesA, BayesB, BayesC, BL, BRR, SVR_poly, SVR_linear, Ridge, PLS_Regression, and Linear_Regression. Our results indicate that markers selected through GWAS, when used in GS, achieved a prediction accuracy of 0.94 at a 5 K density. Furthermore, Bayesian models proved to be more stable than machine learning models. Overall, this study offers new insights into soybean genome selection and provides a scientific foundation for future soybean breeding strategies. Full article

Climate change poses serious challenges to Mediterranean crops such as the olive tree (Olea europaea L. subsp. europaea), underscoring the need for cultivars with improved drought tolerance and disease resistance. This study investigates variability in leaf and wood traits among Moroccan and introduced olive cultivars and their crossbreed genotypes grown under similar conditions. Specifically, we assessed (1) variation in key functional traits, (2) the effects of crossbreeding combinations, and (3) trait syndromes shaped by selection. Results showed substantial intraspecific variation in leaf traits, including specific leaf area (SLA), specific leaf water content (SLWC), stomatal size (SS), and density (SD), indicating diverse strategies for resource use and plasticity. Crossbreed genotypes generally displayed higher SLWC and lower SLA, reflecting adaptation to water stress. Wood traits, particularly vessel size (SVS) and number (NVS), also varied, revealing trade-offs between hydraulic efficiency and safety. Notably, an increase in vessel size and hydraulic conductivity was correlated with oil content (OC%), while OC% increased with higher vessel and stomatal densities. Larger stomata increased conductance and fruit growth, while lower SLA was linked to higher yield. Multivariate analysis distinguished two genotype groups, consistent with parental combinations. Overall, crossbreeding generated novel functional diversity that may enhance adaptive potential. These findings highlight the value of integrating functional and anatomical traits into olive breeding programs to improve resilience and productivity under climate change. Full article