Search Results (217)

Photovoltaic (PV) systems are the core technology for implementing net-zero carbon emissions by 2050. The performance of PV systems is strongly influenced by environmental factors, including irradiance, temperature, and shading, which makes it difficult to characterize the nonlinear and multi-coupling behavior of the systems. Accurate modeling is essential for reliable performance prediction and lifespan estimation. To address this challenge, a novel metaheuristic algorithm called shuffled puma optimizer (SPO) is deployed to perform parameter extraction and optimal configuration identification across four PV models. The robustness and stability of SPO are comprehensively evaluated through comparisons with advanced algorithms based on best fitness, mean fitness, and standard deviation. The root mean square error (RMSE) obtained by SPO for parameter extraction are 8.8180 × 10⁻⁴, 8.5513 × 10⁻⁴, 8.4900 × 10⁻⁴, and 2.3941 × 10⁻³ for the single diode model (SDM), double diode model (DDM), triple diode model (TDM), and photovoltaic module model (PMM), respectively. A one-factor-at-a-time (OFAT) sensitivity analysis is employed to assess the relative importance of undetermined parameters within each PV model. The SPO-based modeling framework enables high-accuracy PV performance prediction, and its application to sensitivity analysis can accurately identify key factors that lead to reduced computational cost and improved adaptability for integration with energy management systems and intelligent electric grids. Full article

To determine optimal light conditions for Hopea hainanensis Merr. & Chun seedling growth, this study examined growth and physiological parameters under four shading treatments (0%, 30%, 60%, and 90% irradiance reduction) over 12 months. Shading significantly affected the growth adaptability of seedlings. As shading increased, height, leaf traits (area, length, width), and light saturation point all initially increased, peaked at 30% shading, and then decreased. Conversely, basal diameter, leaf thickness, the maximum net photosynthetic rate, net photosynthetic rate, photosynthetic quantum efficiency, transpiration rate, and stomatal conductance progressively declined as shading increased. Biomass accumulation (in stems and roots), dark respiration rate, and light compensation point exhibited a U-shaped response to shading, being minimized under low or moderate shading. All shading treatments significantly reduced biomass and photosynthetic performance compared to controls. Multivariate analysis identified 0%–30% shading as optimal for cultivation, with 30% shading enhancing photomorphogenic responses while maintaining photosynthetic efficiency. The study findings suggest a novel seedling cultivation protocol for nursery use, in which initial establishment occurs under 30% shading to maximize vertical elongation, followed by the progressive reduction in shading to stimulate radial growth and optimal biomass partitioning. This approach mimics natural canopy gap dynamics, effectively mimicking natural regeneration in tropical rainforest ecosystems. Full article

Improving the quality of compounds in medicinal and aromatic plants is crucial due to their uses in the pharmaceutical, cosmetics, and food sectors. One way of influencing plant composition is through exposure to different light conditions. Therefore, a two-year field study (2023–2024) was conducted to investigate the impact of coloured shading nets on the physiology, essential oil (EO) content, and composition of three Mentha genotypes: Mentha × piperita ‘Multimentha’, Mentha × piperita ‘Fränkische Blaue’, and Mentha rotundifolia ‘Apfelminze’. In addition to an unshaded control, the Mentha plants were grown under red and blue shading nets. Plant height and vegetation indices were collected weekly. Biomass accumulation, EO content, and composition were determined for each harvest. Both red and blue shading were found to influence the physiological responses and EO compositions of the plants, with red shading promoting slightly higher p-menthone levels in ‘Fränkische Blaue’ and ‘Multimentha’, while blue shading slightly increased carvone levels in ‘Apfelminze’. While EO content varied across harvest seasons (spring, summer, and autumn), ‘Fränkische Blaue’ responded to red shading, demonstrating an increased EO content. The findings suggest that targeted use of coloured shading nets can modulate EO quality. However, genotype-specific responses highlight the necessity of further research to define shading applications for different species and genotypes. Full article

Increased market demand for plant herbs has prompted growers to ensure a continuous and assured supply of superior nutritional quality over the years. Apart from the nutritional value, culinary herbs contain phytochemical benefits that can improve human health. However, a significant amount of research has focused on enhancing yield, frequently overlooking the impact of production practices on the antioxidant and phytonutritional content of the produce. Thus, the study aimed to evaluate the yield, phytonutrients, and essential mineral profiling in selected aromatic herbs and their intricate role in nutritional quality when grown under different production systems. Five selected aromatic herbs (coriander, rocket, fennel, basil, and moss-curled parsley) were evaluated at harvest when grown under three production systems: in a gravel-film technique (GFT) hydroponic system and in soil, both under the 40% white shade-net structure, as well as in a soilless medium using sawdust under a non-temperature-controlled plastic tunnel (NTC). The phytonutritional quality properties (total phenolic, flavonoids, β-carotene-linoleic acid, and condensed tannins contents) as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) were assessed using spectrophotometry, while vitamin C and β-carotene were analyzed using HPLC-PDA, and leaf mineral content was evaluated using ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry). The results show that the health benefits vary greatly owing to the particular culinary herb. The fresh leaf mass (yield) of coriander, parsley, and rocket was not significantly affected by the production system, whereas basil was high in soil cultivation, followed by GFT. Fennel had a high yield in the GFT system compared to in-soil and in-soilless cultivation. The highest levels of vitamin C were found in basil leaves grown in GFT and in soil compared to the soilless medium. The amount of total phenolic and flavonoid compounds, β-carotene, β-carotene-linoleic acid, and DPPH, were considerably high in soil cultivation, except on condensed tannins compared to the GFT and soilless medium, which could be a result of Photosynthetic Active Radiation (PAR) values (683 μmol/m²/s) and not favoring the accumulation of tannins. Overall, the mineral content was greatly influenced by the production system. Leaf calcium and magnesium contents were highly accumulated in rockets grown in the soilless medium and the GFT hydroponic system. The results have highlighted that growing environmental conditions significantly impact the accumulation of health-promoting phytonutrients in aromatic herbs. Some have positive ramifications, while others have negative ramifications. As a result, growers should prioritize in-soil production systems over GFT (under the shade-net) and soilless cultivation (under NTC) to produce aromatic herbs to improve the functional benefits and customer health. Full article

Facing rapid urbanization, rising temperatures, and a residential sector that accounted for 38% of Egypt’s electricity use in 2022, middle-income housing presents a critical yet underexplored opportunity for energy efficiency improvements. This study investigates how the integration of passive design strategies and rooftop photovoltaic (PV) systems can enhance energy performance in this segment, using the Sakan Masr housing project in New Cairo as a case study. Addressing a research gap—namely the limited analysis of combined strategies in Egypt’s middle-income housing—the study follows a four-phase methodology: identifying dominant building orientations; simulating electricity demand and thermal comfort using DesignBuilder; optimizing the building envelope with passive measures; and evaluating PV system performance across south-facing and east–west configurations using PV-SOL. Results reveal that passive strategies such as improved glazing and shading can enhance thermal comfort by up to 10% and reduce cooling loads. Also, east–west PV arrays outperform south-facing ones, producing over 14% more electricity, reducing costs by up to 50%, and avoiding up to 168 tons of CO₂ emissions annually. The findings highlight that passive improvements with smart PV integration—offer a cost-effective pathway toward Net Zero Energy goals, with significant implications for national housing policy and Egypt’s renewable energy transition. Full article

Limited comparative research exists on evaluating the performance of tomato rootstocks under different growing methods, resulting in growers facing challenges when deciding which rootstock and growing method to use for improved yield. The effect of growing methods (scion of a single stem or double stems and non-grafted plant as the control) and rootstock cultivars (Goldbac, SVTX6258, and Booster) on the yield and quality of tomatoes grown in a plastic tunnel and a shade net structure was investigated. The splice grafting method was followed. In a plastic tunnel experiment, grafting and rootstock cultivar did not significantly affect the total soluble solids (TSS), pH, and electrical conductivity (EC) of the tomato juice, as well as percentage weight loss, yield, and fruit firmness. However, the Booster rootstock with a scion of 2 stems had high fruit Mg, K, P, and Fe contents, while the Goldbac rootstock with a scion of 1 stem and 2 stems had high fruit Ca and Fe contents compared to other treatments. The Goldbac and Booster rootstocks grafted to a scion of 2 stems had a high marketable yield. In a shade net experiment, the Booster rootstock with a scion of 2 stems had a high early harvest and total yield of tomatoes, followed by the Goldbac rootstock with a scion of 2 stems. Higher incidences of fruit cracking were noticed on the Booster rootstock grafted with a scion of a single stem. Generally, grafted plants on Booster and Goldbac had improved Mg, K, and P contents, unlike SVTX6258 with a scion of 1 stem. The Booster rootstock with a scion of 2 stems had significantly higher Mg, K, and P contents, while the sodium (Na) fruit content was high on the SVTX6258 rootstock with a scion of 1 stem. Grafting did not significantly affect fruit physiological disorders, weight loss, and TSS, or pH and EC of tomato juice. Grafting with a scion of two stems at the seedling stage significantly improved the tomato fruit mineral content and the total and marketable yield in a plastic tunnel and a shade net structure. Full article

The accurate estimation of corn canopy structure and light conditions is essential for effective crop management and informed variety selection. This study introduces CCSNet, a deep learning-based semantic segmentation model specifically developed to extract fractional coverages of soil, illuminated vegetation, and shaded vegetation from high-resolution corn canopy images acquired by UAVs. CCSNet improves segmentation accuracy by employing multi-level feature fusion and pyramid pooling to effectively capture multi-scale contextual information. The model was evaluated using Pixel Accuracy (PA), mean Intersection over Union (mIoU), and Recall, and was benchmarked against U-Net, PSPNet and UNetFormer. On the test set, CCSNet utilizing a ResNet50 backbone achieved the highest accuracy, with an mIoU of 86.42% and a PA of 93.58%. In addition, its estimation of fractional coverage for key canopy components yielded a root mean squared error (RMSE) ranging from 3.16% to 5.02%. Compared to lightweight backbones (e.g., MobileNetV2), CCSNet exhibited superior generalization performance when integrated with deeper backbones. These results highlight CCSNet’s capability to deliver high-precision segmentation and reliable phenotypic measurements. This provides valuable insights for breeders to evaluate light-use efficiency and facilitates intelligent decision-making in precision agriculture. Full article

Photovoltaic (PV) technology is essential for achieving net-zero emissions by 2050. PV system efficiency is highly sensitive to irradiance, temperature, and shading. However, accurate parameter identification is critical for modeling, as PV models often exhibit multi-modal and strongly coupled characteristics. In addition, commercial datasheets typically lack sufficient parameter information, making precise parameter extraction difficult and limiting the accuracy of maximum power point predictions. To address these challenges, this research employs a novel metaheuristic algorithm called Puma Optimizer (PO) to optimize the parameters of multiple PV models. The PO’s performance is benchmarked against four advanced metaheuristic algorithms using convergence curves, error bars, and boxplots to evaluate its robustness. Results show that PO demonstrates strong adaptability and reliable performance in PV parameter optimization. Lastly, the research analyzes parameter sensitivity to help reduce computational resource usage. Visual analysis confirms that the PO parameter optimization approach provides an effective and practical solution for enhanced energy management and stable grid integration as solar adoption continues to expand. Full article

As a widely cultivated warm-season turfgrass, bermudagrass (Cynodon spp.) faces significant challenges in shaded environments due to its inherent low-light sensitivity. While improving photosynthetic adaptation represents a promising strategy to address this limitation, the associated regulatory mechanisms remain insufficiently characterized. In this study, we found that the overexpression of CdGLK1 significantly improved low-light tolerance in bermudagrass by increasing shoot weight, root weight, chlorophyll a, chlorophyll b, net photosynthetic rate (Pn), and maximum quantum yield of photosystem II (Fv/Fm). Furthermore, coordinated upregulation of both C₃ and C₄ pathway enzymes was observed under low-light stress, accompanied by enhanced antioxidant capacity and reduced photoxidative damage. Transcriptomic profiling further revealed CdGLK1-mediated activation of photosynthetic machinery components spanning light harvesting, electron transport, and carbon fixation modules. These findings establish CdGLK1 as a master integrator of photoprotection and metabolic adaptation under light-limiting conditions, providing both mechanistic insights and practical strategies for developing shade-resilient turfgrass cultivars. Full article

This study aimed to understand the difference in forest transpiration (T) between slope positions and to separate the contributions of main influencing factors to improve the accuracy of forest transpiration estimation at the slope scale by up-scaling the results measured at the plot scale, especially in semiarid regions with significant soil moisture differences along slope positions. Two plots of larch plantation were established, one at the lower position and another at the upper position of a northwest-facing slope in the semiarid area of the Liupan Mountains in northwest China. The sap flow velocity ($J_S$, mL·cm⁻²·min⁻¹) of sample trees, meteorological parameters in the open field, and soil water potential in the main root zone (0–60 cm) were monitored simultaneously in the growing season (from July to September) of 2015. However, only the transpiration data of 59 selected effective days were used, after excluding the days with rainfall and missing data. Based on the relative sap flow velocity (the ratio of instantaneous sap flow velocity to its daily peak value), the impacts of terrain shading and soil water potential on sap flow velocity at varying slope positions were quantitatively disentangled. The reduction in $J_S$ at the lower slope plot, attributed to terrain shading, exhibited a positive linear correlation with solar radiation intensity. Conversely, the $J_S$ reduction at the upper slope plot demonstrated a quadratic functional relationship with the differential in soil water potential between the two plots. Subsequently, employing the relationship whereby transpiration is equivalent to the product of sap flow velocity and sapwood area, we conducted a quantitative analysis of the contributions of soil water potential, sapwood area, terrain shading, and their interaction to the disparity in transpiration between the two slope positions. The total transpiration of the 59 effective days was 41.91 mm at the lower slope plot, slightly higher than that at the upper slope plot (37.38 mm), indicating a small difference (4.53 mm) due to the offsetting effects of multiple factors. When taking the upper slope plot as a reference, the plot difference in soil water potential increased the total transpiration for the 59 days at the lower slope plot by 16.40 mm, while the differences in sapwood area and terrain shading and the interaction of the three factors decreased the total transpiration at the lower slope plot by 6.61, 2.86, and 2.40 mm, respectively, making a net increase of 4.53 mm. Based on the pilot study under given conditions of location, soil, climate, and vegetation, the contributions of the influencing factors to the stand transpiration differences between the upper and lower slopes are as follows: soil moisture (soil water potential) > stand structure (sapwood area) > solar radiation (terrain shading) > interaction of all factors. All these impacts should be considered for the accurate prediction of forest transpiration at the slope scale through up-scaling from measurement at the plot scale, especially in semiarid regions. Full article

Ethnographic sources from Finland and Estonia in the 18th to early 20th centuries often mention alder bark as a dye source. The bark of grey alder (Alnus incana) and black alder (Alnus glutinosa) was used to dye wool and linen yarns reddish, paint leather red, and darken linen fishing nets. These recipes were simple folk craft and are not represented in dye books. Combining various sources, a selection of ethnographic and historical recipes was reconstructed through dyeing experiments to deepen the knowledge of alder bark dyeing practices and to recreate a colour palette based on past recipes. To understand the properties of the alder bark dye, the dyed textile samples were tested according to the ISO standards for washing, rubbing, and light fastness, and colour was recorded with the CIELab values. Our results show that it was possible to obtain different shades of brown, reddish brown, and dark brown. The colour fastness of dyed wool samples was moderate or good. Slight colour changes in the washed samples compared to the untreated ones were observed, which can be due to the standard’s heavily alkaline detergent. Full article

Agrophotovoltaic (APV) systems represent innovative agricultural farms and solar power plants, capable of producing electricity and crops simultaneously. Since the solar radiation required to optimize harvests varies by crop type, traditional PV panels face challenges in efficiently adjusting the shading ratio of APV systems. This study evaluates the economic viability of APV systems integrated with building-integrated photovoltaic (BIPV) systems for biofuel production. Specifically, it assesses the production forecast for corn-based biofuel—demand for which is rising due to the mixed-fuel use policy of the Korean government—and the economic feasibility of production in the APV system enhanced by BIPV integration (i.e., the APV–BIPV system). To this end, LCOE (levelized cost of energy) and NPV (net present value) are employed as performance indicators. Additionally, yield data from corn and corn stover harvested in actual APV facilities are utilized to predict bioenergy production. Consequently, the study will analyze the impact of renewable energy production from the proposed APV–BIPV system on achieving the Korean government’s renewable energy production goals and will provide guidelines on the potential benefits for farmers involved in renewable energy production and energy crop harvesting. Full article

The low-light environments under urban viaducts significantly hinder plant growth and development. An in-depth study of the plasticity response mechanisms and survival strategies of plants in these conditions is crucial for selecting appropriate species. This study examined how light intensity affects leaf plasticity in four plants (Ophiopogon japonicus, Pittosporum tobira, Euonymus japonicus, and Ligustrum sinense) under two representative urban viaducts and how they respond to changes in light intensity in Zhengzhou City. The leaf morphology, physiological photosynthesis, and chlorophyll (Chl) fluorescence parameters were analyzed at three light intensities (one natural full-light and two viaduct-shaded low-light environments.): CK (full light), T1 (21.29%–25.99%), and T2 (5.16%–8.20%). The results showed that (1) with decreasing light intensity, most plants showed reductions in leaf thickness (LT), palisade and spongy tissue thickness (PT, ST), net photosynthetic rate (P_n), stomatal conductance (G_s), and F_v/F_m and F_v′/F_m′, while leaf area, Chl content, and malondialdehyde (MDA) content increase, with antioxidant enzyme activity also rising. The photosynthetic indicators of O. japonicus first increased and then decreased. (2) The overall plasticity of the plants ranked from high to low as follows: O. japonicus > E. japonicus > P. tobira > L. sinense. O. japonicus showed the strongest adaptability through comprehensive photosynthetic physiology and antioxidant mechanisms, with a wide light tolerance range. E. japonicus relied more on adjustments in photosynthetic and anatomical structures, as well as leaf area. P. tobira improved light tolerance by modifying leaf area, epidermal structure, and physiological traits. L. sinense had the lowest adaptability, relying on limited antioxidant enzymes and leaf thickness adjustments. (3) In conclusion, plant plasticity is primarily reflected through photosynthetic and physiological traits. High plasticity in these parameters is key for plants to adapt to thrive in dynamic low-light environments. Therefore, when greening viaduct-shaded areas, it is crucial to consider the light environment and the light adaptability range of different plant species. Plants with high photosynthetic and physiological plasticity should be selected to ensure the optimal growth and development of plants in shaded areas. Full article

Soil desiccation cracks in natural clayey soil pose significant risks to the stability of civil and geotechnical structures. Traditional methods for detecting these cracks are often inefficient and prone to inaccuracies. Therefore, we applied a deep learning approach of semantic segmentation based on DeepLabv3+ to detect desiccation cracks. To enhance computational efficiency, a pretrained lightweight network, MobileNetV2, was employed as the backbone for the DeepLabv3+ model. The model was trained and tested on a dataset of natural clayey soil crack images obtained through laboratory tests. Evaluation metrics including precision, recall, F1 score, and intersection over union (IoU) were used to assess the segmentation performance. The model took 17.13 min to train and achieved an inference speed of 0.43 s per image. DeepLabv3+ achieved better performance than the traditional segmentation method, with a precision of 95.76%, a recall of 84.12%, an F1 score of 89.56%, and an IoU of 81.10%. The model also demonstrated the capability to handle images with shading conditions and the presence of spots. DeepLabv3+ with MobileNetV2 as a backbone network was proven to be effective and efficient as a backbone in soil desiccation crack detection and segmentation. Full article

Dynamic building envelopes integrated with renewable energy sources, termed Dynamic and Renewable Source Building Envelopes (DREBE), provide an innovative approach to optimizing building envelope designs. Yet, these systems are not mature enough and not widely adopted in the industry and few literature resources are employed to understand them. These systems dynamically respond and adapt to various environmental, energy, and occupancy demands for higher energy efficiency and comfort levels compared to traditional building envelopes while simultaneously producing energy. Their potential in climate change mitigation and fostering sustainable urban development warrants great attention from industry and urban planners. Especially in positive energy districts, which aim to reach net-positive energy goals through utilizing smart energy efficient building systems on the district level. This paper reviews innovative systems like dynamic photovoltaic shading devices and phase change materials and evaluates their performance by answering two research questions, what are the current DBE trends and are they feasible in achieving net-positive energy consumption? The analysis conducted reveals the dominance of solar-based dynamic renewable energy systems and a great need for alternatives. The study suggests that alternatives like wind as a renewable energy source should be studied with dynamic systems. Moreover, the study highlights current research gaps including insufficient data on long-term application and economic costs associated with such systems. To address this gap, the study suggests exploring in depth some of these systems and then branching into various combinations of dynamic envelope systems with multiple renewable or adaptive components to further enhance the overall building performance. By synthesizing the current body of literature, this paper gives insights into advancing the application of the dynamic building envelope systems and highlights their crucial role in the future of sustainable urban environments. Full article