Search Results (163)

This study aimed to address the limited infiltration capacity of the double ridge–furrow mulching system (DRFM) under heavy rainfall on the Loess Plateau, which exacerbates surface runoff and mid-summer soil water deficits in semi-arid rainfed areas. By incorporating infiltration holes to optimize the system, we evaluated their effects on soil water storage, maize growth, and water use efficiency (WUE). A two-year field experiment (2021–2022) comprised four treatments: conventional flat planting (CK), the traditional ridge-furrow system (CWC), the double ridge-furrow system (DWC), and the double ridge-furrow system with infiltration holes (DWCR). The experimental periods represented a normal precipitation year (2021, 410 mm) and a dry year (2022, 270 mm). Results indicated that the DWCR treatment established preferential flow pathways, significantly enhancing deep soil water storage and its utilization efficiency during critical phenological stages, particularly under drought. This improved deep water accelerated crop growth and boosted yield. Compared to the CK, CWC, and DWC treatments, the DWCR treatment significantly increased plant height, aboveground dry matter (ADM), yield, and WUE. Specifically, the DWCR treatment improved yield and WUE by 0.24–20.04% and 2.75–26.27%, respectively. In the dry year, the yield of the DWC treatment increased by 12.72% compared to its yield in the normal year, whereas the DWCR treatment achieved a greater increase of 19.18%. Root analysis confirmed that the DWCR treatment significantly increased root weight density in the 20–60 cm soil layer under drought, optimizing root spatial distribution and thereby enhancing deep water uptake and drought resistance. In conclusion, incorporating infiltration holes into the DRFM is an effective strategy for optimizing soil water distribution, improving crop drought tolerance and WUE, and promoting sustainable semi-arid rainfed agriculture. Full article

The ongoing decarbonisation of power systems is displacing synchronous generators (SGs) with converter-based plants, requiring a consistent assessment of grid-following inverters (GFLIs) and grid-forming inverters (GFMIs). Using an openly available four-bus root-mean-square (RMS) benchmark modelled in DIgSILENT PowerFactory, this work compares three generation configurations: (i) a single local SG connected at the point of common coupling; (ii) the same generator combined with a GFLI; and (iii) the generator combined with a GFMI. These configurations are evaluated under three disturbance scenarios: (1) a balanced load step, (2) an unbalanced double line-to-ground fault at low short-circuit ratio (SCR) with temporary islanding and single-shot auto-reclose, and (3) full islanding with under-frequency load shedding (UFLS), partial resynchronisation, and staged restoration. For the tested tuning ranges and within this RMS benchmark, the grid-forming configuration behaves as a low-impedance source at the point of common coupling in the phasor sense, yielding higher frequency nadirs during active-power disturbances and faster positive-sequence voltage recovery under weak and unbalanced conditions than the SG-only and SG+GFLI cases. During islanding, it supports selective UFLS, secure resynchronisation, and orderly load restoration. Rather than introducing new control theory, this work contributes a reproducible RMS benchmarking framework that integrates low-SCR operation, unbalance, and restoration sequences with a documented cross-technology tuning procedure. The findings indicate system-level improvements in frequency resilience and voltage recovery for the tested benchmark relative to the alternative configurations, while recognising that instantaneous device-level effects and broader generality will require electromagnetic-transient (EMT) or hybrid EMT/RMS validation in future work. Full article

Atrium spaces are widely applied in university buildings. However, achieving effective energy reduction while maintaining adequate daylighting and indoor comfort remains a major challenge at the early design stage. This study identifies key building form design variables significantly influencing atrium daylighting, energy use, and thermal comfort, including building orientation, atrium width-to-depth ratio, atrium aspect ratio, atrium bottom area ratio, and skylight–roof ratio. A multi-objective optimization (MOO) framework is proposed to balance daylight performance, energy consumption, and thermal comfort under fixed envelope parameters. Using typical single- and double-atrium teaching buildings in cold regions as case studies, this research adopts Useful Daylight Illuminance (UDI), Energy Use Intensity (EUI), and Discomfort Time Percentage (DTP) as key indicators to evaluate the interactions between design parameters and building performance. Based on the Pareto-optimal results for the studied prototypes, a south-by-west orientation, moderately slender atrium proportions, relatively compact atrium bottom areas, and medium skylight–roof ratios together yield a balanced performance. Compared with the reference to the initial solution, the optimized solutions reduce EUI by up to 5.66% while also improving UDI and DTP. These results are intended as quantitative references and optimization for early-stage geometric forms design of atrium teaching buildings in cold regions. Full article

The use of double-phase medium (2F) gave beneficial effects in the propagation of woody plants belonging to the Rosaceae family. Despite this, it appears that such research has not yet been carried out in relation to (Amelanchier sp.). Thus, the efficiency of such a technique in micropropagation of three cultivars of serviceberry (Amelanchier sp.)—‘Autumn Brilliance’, ‘Ballerina’, ‘Snowcloud’—was evaluated. The 2F medium was obtained by pouring the liquid MS solution (10 mL) onto the solid (1F) medium (50 mL) after inoculation of the explants. Generally, the response of the in vitro cultures to 2F medium was positive but clone-dependent. This medium stimulated, to various extents, the elongation and proliferation of the shoots. The use of 2F medium did not significantly increase hyperhydricity, whereas it lowered shoot tip necrosis frequency during the multiplication stage. However, the residual effect of 2F medium on the in vitro rooting of shoots and acclimation was adverse in the case of two out of three studied clones. Considering the efficiency of the three micropropagation stages, the use of 2F medium was only favorable in the case of one clone (‘Ballerina’), yielding over 90% more acclimated plantlets in comparison to the control (1F medium). Full article

The use of artificial oxygenation to counteract the effects of hypoxia and improve living standards in high-altitude, low-oxygen settings is widespread. A recognized consequence of this intervention is that it elevates the risk of fire occurrence. In this study, we simulated a real fire environment with low-pressure oxygen enrichment in a plateau area. A new multi-measuring apparatus was constructed by integrating an electronic control cone heater and a low-pressure oxygen enrichment combustion platform to enable the simultaneous measurement of multiple parameters. The combined effects of varying oxygen concentrations and thermal irradiance on the combustion behavior of wood plastic composites (WPCs) under specific low-pressure conditions were investigated, and alterations in crucial combustion parameters were examined and evaluated. Increasing the oxygen concentration and heat flux significantly reduced the ignition and combustion times. For instance, at 50 kW/m², the ignition time decreased from 75 s to 16 s as the oxygen concentration increased from 21% to 35%. This effect was suppressed by higher heat fluxes. Compared with low oxygen concentrations and low thermal radiation environments, the ignition time of the material under high oxygen concentrations and high thermal radiation conditions was shortened by more than 78%, indicating that its flammability is enhanced under extreme conditions. Higher oxygen concentrations enhanced the heat feedback to the fuel surface, which accelerated pyrolysis and yielded a more compact flame with reduced dimensions and a color transition from blue-yellow to bright yellow. This intensified combustion was further manifested by an increased mass loss rate (MLR), elevated flame temperature, and a decline in residual mass percentage. The combustion of WPCs displayed distinct stage characteristics, exhibiting “double peak” features in both the MLR and flame temperature, which were attributed to the staged pyrolysis of its wood fiber and plastic components. Full article

This study presents a comprehensive evaluation of levulinic acid purification schemes from a circular economy perspective, integrating resource-based indicators with economic and environmental metrics. Twelve alternatives, ranging from conventional distillation sequences to intensified hybrid systems, were assessed using indicators such as Relative Material Impact, total annual cost, Eco-Indicator 99, fuel demand, and CO₂ emissions. The novelty of this work lies in extending the assessment beyond purification infrastructure to include upstream systems that supply energy demand, such as fuel extraction and steam generation. The configurations considered incorporate thermal couplings, dividing wall columns, and decanters, which influence energy efficiency, process complexity, and resource depletion. Among these, the TDWS-D configuration (Thermally Coupled Double Dividing Wall Column System with Decanter) exhibits the highest values in DMR, TAC, and CO₂ emissions, driven by its elevated energy demand and complex infrastructure. Conversely, the TCS2 configuration (Thermally Coupled Sequence, featuring selective heat integration between distillation columns) achieves the lowest impact across all metrics, demonstrating that selective and strategic intensification (rather than maximalist design) can yield superior sustainability outcomes. Across all scenarios, the boiler stage was identified as the main contributor to material depletion, followed by fuel extraction and purification equipment. Notably, some conventional designs proved superior to intensified ones in terms of circularity, challenging the assumption that intensification inherently guarantees sustainability. Overall, the integration of circular economy indicators enables a multidimensional evaluation framework that supports more responsible and resource-efficient process design. Full article

This review comprehensively assesses the clinical applications and future potential of alpha-emitting radionuclides available for targeted alpha-particle therapy (TAT) in cancer treatment. The approval of radium-223 therapy in 2013 marked a significant advancement in alpha-emitting therapeutic radiopharmaceuticals, which are primarily used in treatment of prostate cancer. The EU SECURE project was introduced as a major initiative to enhance the sustainability and safety of medical alpha-emitting radionuclides production in Europe. This literature review was conducted by a multidisciplinary team on selected radionuclides, including actinium-225, bismuth-213, astatine-211, lead-212, terbium-149, radium-223 and thorium-227. These were selected based on their clinical significance, as identified in the EU PRISMAP project and subsequent literature searches. The review process involved searching major databases using specific keywords related to alpha-emitter therapy and was limited to articles in English. For each selected radionuclide, the physical characteristics, the radiochemistry, and the pre-clinical and clinical studies are explored. Actinium-225 is the most widely studied alpha emitter, with several preclinical and clinical studies on prostate cancer and neuroendocrine tumours. Other types of tumours (such as glioblastoma) still require preclinical and clinical development. Bismuth-213 bound to antibodies, peptides and nanobodies has shown optimal results in preclinical and clinical studies, with increased median survival and no significant toxicity. Astatine-211 differs from most other α-emitters relevant to TAT, since it yields one α-particle per decay. This offers certain translational advantages, including the simplification of radiation dosimetry calculations and quality control (QC). Lead-212 has the advantage of being an in situ generator with likely widespread availability. Although clinical data are limited, the findings are promising at this stage. The unconventional production of Terbium-149 is the primary reason it has not yet progressed to clinical trials. Overcoming this production obstacle would allow more detailed preclinical investigations. Optimal results with Thorium-227-labelled agents have been observed in preclinical studies, including delays in cellular growth, multiple double-strand breaks and complete regression. Intermediate phase I trial results have also been reported, demonstrating safety and tolerability, as well as an objective response rate of 25%.: The results highlight the advantages of alpha particles in targeting cancer cells with minimal radiation to normal tissue, emphasising the need for high specificity and stability in delivery mechanisms, as well as suggesting that the full clinical potential of alpha particle therapy remains unexplored. Theranostic approach and dosimetric evaluations still represent relevant challenges. Full article

This study investigates the bidirectional bending performance of double- and triple-spliced steel-ribbed composite slabs for substation applications. Full-scale experiments and numerical parametric analyses were conducted to evaluate ultimate load, ductility, stiffness, failure modes, and load-transfer mechanisms. Results indicate that double-spliced slabs exhibit better performance than triple-spliced slabs, showing a 24.5% higher ultimate load and 65.3% greater ductility, with well-developed orthogonal cracks and yielding of both longitudinal prestressing steel and transverse reinforcement. Triple-spliced slabs display partial bidirectional behavior due to reduced transverse integrity, with stresses in edge slabs concentrated at the corners. Compared with monolithic slabs, spliced slabs show nearly identical stiffness at cracking onset but progressively reduced stiffness, load capacity, and ductility in the mid-to-late loading stages. Joint-crossing reinforcement is critical for transverse load transfer, and increasing its diameter is more effective than increasing its strength in preventing premature joint-controlled failure. These findings provide significant theoretical guidance and technical support for the prefabricated construction of high-voltage substation floor systems. Full article

Napier grass (Cenchrus purpureus Schumach) is an important forage crop and livestock feed. However, its yield and quality in Kenya are often limited by Napier grass headsmut and stunt disease. Napier grass genetic improvements through mutation breeding and selection could avail cultivars with increased forage. This study investigated the response of embryogenic calli to different levels of colchicine in inducing polyploidy in the two germplasms of Napier grass; South africa and Bana grass. The experiments were carried out as a factorial experiment in a completely randomized design (CRD). The colchicine concentrations used were 0, 0.05, 0.1, and 0.2%, and the exposure durations were 24, 48, and 72 h. During the shoot regeneration stage, culturing explants on an MS medium (Murashige and Skoog) supplemented with 0.2 mg L⁻¹ Benzyl Adenine (BAP), 0.1 mg L⁻¹ dichlorophenoxyacetic acid (2, 4-D), and 0.1 mg L⁻¹ indole-3-butyric acid (IBA) was more suitable for shoot regeneration. Chromosome doubling was confirmed by genomic DNA and the stomata size and number. Culturing explants on an MS medium supplemented with 1 mg L⁻¹ IBA, 1 mg L⁻¹ 2, 4-D, and 0.5 mg L⁻¹ BAP was more suitable in inducing embryogenic calli in both genotypes. Polyploidy results revealed that a 0.1% concentration of colchicine with two days of treatment established the maximum number of octoploid plantlets induced in vitro, while a 0.2% concentration was very toxic. The stomata size and number of derived octoploid plantlets were bigger with a lower density, a shorter plant height, and a smaller stem diameter, and despite being the first to produce tillers, they were significantly higher than their progenitors. Induced mutants also had a significantly higher number of chromosomes and showed different band patterns and distances during gel electrophoresis. However, we recommend the use of flow cytometry to confirm the ploidy level. The superior mutant plantlets can be selected and recommended for characterization across representative agro-ecologies for large-scale production and used in Cenchrus purpureus breeding programs in Kenya and its environments. Full article

Using a maize planting system with full film mulching on double ridges and furrow sowing in the arid and semi-arid regions of the Loess Plateau, this study aims to explore the optimal proportion of organic fertilizer to replace basal chemical fertilizers; clarify its regulatory mechanism on nitrogen metabolism in maize roots and yield, so as to simultaneously achieve the reduction in chemical fertilizers and stable yield increase; and provide technical support for the global green production of dryland agriculture. Using fully mulched ridge–furrow cropping maize as the research object, four treatments were established with an equal nitrogen application rate (200 kg/hm²): 100% chemical fertilizer (T1), 50% chemical fertilizer + 50% organic fertilizer (T2), 62.5% chemical fertilizer + 37.5% organic fertilizer (T3), and no fertilization (T4). The nitrogen content in roots, metabolic enzyme activities in different soil layers during the filling stage, as well as indicators such as yield and nitrogen use efficiency were measured. The T3 treatment showed the highest root nitrogen content, accumulation, and metabolic enzyme activity in the 0–20 cm soil layer. The nitrogen assimilation amount after flowering was 10.7% higher than that of T1. The grain yield and grain weight per ear were the highest in two years, reaching 6388.9 kg/hm² in 2022, which was 11.8% higher than that of T1. The agronomic utilization efficiency increased by 22.8%, while the partial productivity of nitrogen fertilizer increased by 11.5%. The T2 treatment led to yield loss due to the excessive application of organic fertilizer. Overall, substituting 37.5% of the basal chemical fertilizer with organic fertilizer enhanced root activity and nitrogen metabolism enzyme activities, thereby improving nitrogen uptake and translocation efficiency, which ultimately increased kernel number per ear and kernel weight per ear, leading to higher grain yield. Therefore, this approach can be recommended for the green production of maize in the arid and semi-arid regions of the Loess Plateau. Full article

Water stress represents one of the most critical limiting factors affecting plant distribution, growth rate, biomass accumulation, and crop yield across diverse growth stages. Variations in species’ drought tolerance fundamentally shape global biodiversity patterns by influencing survival rates, distribution ranges, and community composition under changing environmental conditions. This study investigated the physiological responses of six plant species (Haloxylon ammodendron (H.A.), Nitraria tangutorum Bobr. (N.T.B.), Sympegma regelii Bge. (S.R.B.), Tamarix chinensis (T.C.), Potentilla fruticosa (P.F.R.), and Sabina chinensis (Linn.) Ant. (S.C.A.)) to varying water stress levels through controlled water gradient experiments. Four treatment levels were established: W1 (full water supply, >70% field water holding capacity); W2 (mild stress, 50–55%); W3 (moderate stress, 35–40%); and W4 (severe stress, 20–25%). Height growth and leaf mass per area decreased significantly with increasing water stress across all species. S.C.A. consistently exhibited the highest leaf mass per area among the six species, while H.A. showed the lowest values across all treatments. Leaf water content declined progressively with intensifying water stress, with T.C. and P.F.R. showing the most pronounced reductions (T.C.: 16.53%, 18.07%, and 33.37% under W2, W3, and W4, respectively; P.F.R.: 19.45%, 28.52%, and 36.08%), whereas N.T.B. and H.A. demonstrated superior water retention capacity (N.T.B.: 2.44%, 6.64%, and 9.76%; H.A.: 1.44%, 4.39%, and 5.52%). Water saturation deficit increased correspondingly with declining soil moisture. Diurnal leaf water potential patterns exhibited a characteristic V-shaped curve under well-watered (W1) and mildly stressed (W2) conditions, transitioning to a double-valley pattern with unstable fluctuations under moderate (W3) and severe (W4) stress. Leaf water potential showed linear relationships with air temperature and relative humidity, and a quadratic relationship with atmospheric water potential. For all six species, the relationship between pre-dawn leaf water potential and soil water content followed the curve equation y = a + b/x. Under water-deficient conditions, S.C.A. exhibited the greatest water physiological changes, followed by P.F.R. Both logarithmic and power function relationships between leaf and soil water potentials were highly significant (all F > 55.275, all p < 0.01). T.C. leaf water potential was the most sensitive to soil water potential changes, followed by S.C.A., while H.A. demonstrated the least sensitivity. These findings provide essential theoretical foundations for selecting drought-resistant plant species in arid regions of the Qaidam Basin. This study elucidates the response mechanisms of six distinct drought-tolerant plant species under water stress. It provides critical theoretical support for selecting drought-tolerant species, designing community configurations, and implementing water management strategies in vegetation restoration projects within the arid Qaidam Basin. Furthermore, it contributes empirical data at the plant physiological level to understanding the mechanisms sustaining species diversity in arid ecosystems. Full article

To address the limitations of traditional buckling-restrained braces (BRB), which feature a single-stage yielding and inadequate energy dissipation under small earthquakes, this study proposes a novel double-stage yielding buckling-restrained brace (DSY-BRB). The proposed design integrates a sliding friction damper with shape memory alloy (SMA) bolts and conventional BRB components, enabling effective energy dissipation at small deformations and adaptive performance across varying displacement amplitudes compared with traditional BRBs. Leveraging SMA superelasticity, the DSY-BRB also exhibits self-centering capability that distinguishes it from prior DSY-BRB configurations. Experimental investigations were conducted on DSY-BRB specimens with varying core plate widths under cyclic quasi-static loading to evaluate hysteresis behavior, energy dissipation capacity, and self-centering performance. Results demonstrate that DSY-BRBs exhibit symmetric flag-shaped hysteresis curves with enhanced energy dissipation and excellent self-centering capabilities, achieving minimal residual deformation compared to traditional BRBs. Complementary finite element modeling with parametric analysis was performed to establish design guidelines for optimal double-stage buckling behavior. The findings reveal critical stiffness ratio requirements between BRB and SMA bolt-based friction damper components, providing valuable design criteria for engineering applications. This hybrid approach offers significant advantages in seismic energy dissipation and structural resilience compared to existing DSY-BRB systems. Full article

Photosynthetic efficiency and dry matter accumulation are essential for achieving high rice yields, yet conventional controlled-release fertilizers often fail to synchronize nitrogen (N) supply with crop demand. In this study, we evaluated a novel double core–shell controlled-release urea (DCSCRU) designed to align with the bimodal N uptake pattern of rice. A two-year field experiment was conducted to compare DCSCRU at three application rates (180, 225, and 270 kg N ha⁻¹) with conventional urea and conventional controlled-release urea (both at 270 kg N ha⁻¹). DCSCRU exhibited a distinct biphasic N release profile, with a rapid initial release peaking at 1.60% d ⁻¹ on day 10 to meet early vegetative demand, followed by a second peak (1.85% d⁻¹ on day 45) supporting reproductive development. Compared with conventional urea, DCSCRU treatments significantly improved photosynthetic efficiency and dry matter accumulation during critical growth stages. The 270 kg N ha⁻¹ DCSCRU treatment achieved a grain yield exceeding 11.50 × 10³ kg ha⁻¹, substantially higher than that of conventional urea. Notably, the 225 kg N ha⁻¹ DCSCRU treatment produced a comparable yield (10.90 × 10³ kg ha⁻¹) to that of the conventional urea treatment (10.83 × 10³ kg ha⁻¹), indicating the potential to reduce N input by 16.7% without compromising yield. The enhanced physiological performance was attributed to improved N availability and optimized canopy function. These findings highlight DCSCRU as a promising strategy for high-yield, resource-efficient, and environmentally sustainable rice production. Full article

Canopy coverage is a key indicator for judging maize growth and production prediction during the seedling stage. Researchers usually use deep learning methods to estimate canopy coverage from maize images, but fully supervised models usually need pixel-level annotations, which requires lots of manual labor. To overcome this problem, we propose ASLNet (Automatic Scribble Labeling-based Semantic Segmentation Network), a weakly supervised model for image semantic segmentation. We designed a module which could self-generate scribble labels for maize plants in an image. Accordingly, ASLNet was constructed using a collaborative mechanism composed of scribble label generation, pseudo-label guided training, and double-loss joint optimization. The cross-scale contrastive regularization can realize semantic segmentation without manual labels. We evaluated the model for label quality and segmentation accuracy. The results showed that ASLNet generated high-quality scribble labels with stable segmentation performance across different scribble densities. Compared to Scribble4All, ASLNet improved mIoU by 3.15% and outperformed fully and weakly supervised models by 6.6% and 15.28% in segmentation accuracy, respectively. Our works proved that ASLNet could be trained by pseudo-labels and offered a cost-effective approach for canopy coverage estimation at maize’s seedling stage. This research enables the early acquisition of corn growth conditions and the prediction of corn yield. Full article

Achieving food security for a growing population under a changing climate is a key concern in Senegal, where agriculture employs 77% of the workforce with a majority of small farmers who rely on the production of crops for their subsistence and for income generation. Moreover, due to the underproductive soils and variable rainfall, Senegal depends on imports to fulfil 70% of its food requirements. In this research, we considered four crops that are crucial for Senegalese agriculture: millet, sorghum, peanuts and rice. We used crop simulation models to explore existing yield gaps and optimal agronomic practices. Improving the N fertilizer management in sorghum and millet resulted in 40–100% increases in grain yields. Improved N symbiotic fixation in peanuts resulted in yield increases of 20–100% with highest impact in wetter locations. Optimizing irrigation management and N fertilizer use resulted in 20–40% gains. The best N fertilizer strategy for sorghum and millet included applying low rates at sowing and in early development stages and adjusting a third application, considering the expected rainfall. Peanut yields of the variety 73-33 were higher than Fleur-11 in all locations, and irrigation showed no clear economic advantage. The best N fertilizer management for rainfed rice included applying 30 kg N/ha at sowing, 25 days after sowing (DAS) and 45 DAS. The best combination of sowing dates for a possible double rice crop depended on irrigation costs, with a first crop planted in January or March and a second crop planted in July. Our work confirmed results obtained in field research experiments and identified management practices for increasing productivity and reducing yield variability. Those crop management practices can be implemented in pilot experiments to further validate the results and to disseminate best management practices for farmers in Senegal. Full article