Search Results (219)

Cold-air pooling (CAP) and frost risk represent significant climate-related hazards in karstic and agricultural environments, where local topography and surface cover strongly modulate microclimatic conditions. This study focuses on the Mohos sinkhole, Hungary’s cold pole, situated on the Bükk Plateau, to investigate the formation, structure, and persistence of CAPs in a Central European karst depression. High-resolution terrain-based modeling was conducted using UAV-derived digital surface models combined with multiple GIS tools (Sky-View Factor, Wind Exposition Index, Cold Air Flow, and Diurnal Anisotropic Heat). These models were validated and enriched by multi-level temperature measurements and thermal imaging under various synoptic conditions. Results reveal that temperature inversions frequently form during clear, calm nights, leading to extreme near-surface cold accumulation within the sinkhole. Inversions may persist into the day due to topographic shading and density stratification. Vegetation and basin geometry influence radiative and turbulent fluxes, shaping the spatial extent and intensity of cold-air layers. The CAP is interpreted as part of a broader interconnected multi-sinkhole system. This integrated approach offers a transferable, cost-effective framework for terrain-driven frost hazard assessment, with direct relevance to precision agriculture, mesoscale model refinement, and site-specific climate adaptation in mountainous or frost-sensitive regions. Full article

The vegetable sweetpotato (Ipomoea batatas L.) is a novel, specialized type, cultivated for its tender stems and leaves, which are rich in nutrients and bioactive compounds. To clarify its growth adaptation to weak light conditions often encountered during cultivation, this study examined the impact of 70% shading on 12 representative cultivars from 4 leaf color types. Agronomic traits, color, and nutritional and antioxidant properties were assessed in both young and mature leaves. Shading promoted leaf expansion, plant height, and vine length, but reduced stem thickness and dry-matter content. Leaf shape shifted from lobed to more cordate, with the foliage becoming darker green and lighter red due to elevated chlorophylls and reduced anthocyanins. Shading generally reduced soluble protein, sugar, cellulose, total phenols, flavonoids, and total antioxidant capacity. Antioxidant capacity correlated most strongly with soluble sugar and dry-matter content, followed by total phenols and flavonoids. Gene expression analysis of key light- and leaf color-related genes revealed up-regulation of chlorophyll genes and down-regulation of anthocyanin genes under shading, with light-responsive genes potentially affected by pigment feedback. These results elucidate the sweetpotato’s adaptive responses to deep shading and provide valuable guidance for optimized cultivation and breeding of vegetable sweetpotato in light-limited environments. Full article

Cities need photovoltaic (PV) systems to meet climate-neutral goals, yet dense urban forms and variable weather limit their output. This review synthesizes how machine learning (ML) models capture both static factors (orientation, roof, and façade geometry) and dynamic drivers (irradiance, transient shading, and meteorology) to predict and optimize urban PV performance. Following PRISMA 2020, we screened 111 records and analyzed 61 peer-reviewed studies (2020–2025), eight Horizon-Europe projects, as well as market reports. Deep learning models—mainly artificial and convolutional neural networks—typically reduce the mean absolute error by 10–30% (median ≈ 15%) compared with physical or empirical baselines, while random forests support transparent feature ranking. Short-term irradiance variability and local shading are the dominant dynamic drivers; roof shape and façade tilt lead the static set. Industry evidence aligns with these findings: ML-enabled inverters and module-level power electronics increase the measured annual yields by about 3–15%. A compact meta-analysis shows a pooled correlation of r ≈ 0.966 (R² ≈ 0.933; 95% CI 0.961–0.970) and a pooled log error ratio of −0.16 (≈15% relative error reduction), with moderate heterogeneity. Key gaps remain, such as limited data from equatorial megacities, sparse techno-economic or life-cycle metrics, and few validations under heavy soiling. We call for open datasets from multiple cities and climates, and for on-device ML (Tiny Machine Learning) with uncertainty reporting to support bankable, city-scale PV deployment.” Full article

Due to their light weight, low stiffness, and large range of tilt angle changes, flexible-support photovoltaic structures are highly sensitive to wind loads. Therefore, it is necessary to study the wind load characteristics under large tilt angles and determine reasonable design wind loads. This paper investigates the wind load characteristics of large-span flexible-support PV arrays with different tilt angles through wind tunnel pressure measurements. The results indicate that, in terms of mean wind pressure coefficient, 0° and 180° are the most unfavorable wind direction angles. The first row at the edge of the array is the most unfavorable location, and its shape coefficient is recommended to be 1.3 (for wind pressure) or −1.25 (for wind suction), with subsequent rows of PV panels being appropriately reduced based on this value. The tilt angle of the PV panels significantly affects the shading effect, and under large tilt angle conditions, there is an abrupt drop in the mean wind pressure coefficient and fluctuating wind pressure coefficient of the second row facing the wind. Under large tilt angles, the critical wind direction angles for local extreme wind loads are within the ranges of 15–45° and 135–165°, and the most unfavorable locations occur in the corner areas at the edges of the array. Local extreme wind loads should be considered in the design. Full article

The urbanisation process of cities disrupts the natural energy balance and surface radiation, making cities relatively warm. While vegetation has been widely recognised as a key factor in mitigating urban heat, its effectiveness is shaped by interactions with urban morphology, surface cover types, and the background climate. This paper presents a bibliometric analysis of studies examining the role of vegetation in mitigating urban heat, with a particular focus on its interactions within the urban environment across four major Köppen–Geiger climate groups: tropical, arid, temperate, and cold. A total of 130 publications were reviewed, categorised, and analysed according to geographic distribution, study period, and methodological approaches. This review identifies underexplored areas, synthesises key findings, and summarises the most significant results. Vegetation and water bodies emerged as primary contributors to heat mitigation, along with building configuration, wind speed, and shading. Temperate climates were the most frequently studied. Remote sensing was the predominant methodological approach, followed by fixed in situ observations. Meso-scale studies, examining entire cities and their surroundings, dominated in terms of spatial scale. This review offers methodological recommendations for analysing urban vegetation within the context of urban climate research. As climate change intensifies, it is increasingly important to design and implement adaptation strategies that incorporate but are not limited to vegetation. Such strategies are essential to supporting sustainable and resilient urban development in diverse climatic contexts. Full article

The research results show that urban form has a significant impact on urban building energy consumption. Therefore, it is of great significance to study the relationship between urban form and urban building energy consumption. This study selects 26 cities in China across four climate zones and studies the relationship on a macro scale. In terms of urban building energy consumption, this study summarizes a set of data collation methods for calculating the total energy consumption of residential buildings and public buildings. In terms of urban form, this study constructed three types of urban form indicators (basic indicators, two-dimensional indicators, and three-dimensional indicators) and proposes a set of methods for calculating the urban built-up area, the total urban building area, the urban residential building area, and the urban public building area. This research finds that in the four climate zones, total urban building energy consumption is extremely strongly correlated with indicators such as resident population, GDP, total building area, building base area, and built-up area, and urban building energy consumption per unit area is extremely strongly correlated with indicators such as clustering, building intensity, urban building orientation, shading factor, and shape coefficient of building, but the relevant indicators are not exactly the same in each climate zone. Full article

Background: The aesthetic performance of single-shade polymer-based restorative materials (SPRs) can be compromised by extrinsic stains. Understanding the effects of novel whitening interventions on SPRs is crucial. Objective: This in vitro study aimed to evaluate the effects of different whitening interventions, including a novel purple tooth serum and charcoal-based whitening toothpaste with and without in-office bleaching, on the color of a new coffee-stained SPR. Materials and Methods: Seventy disc-shaped SPR specimens were prepared, stained, and then divided into seven groups (n = 10). Three groups were subjected directly to 2500 cycles of brushing simulation with regular toothpaste (control), charcoal toothpaste, or purple tooth serum. The rest were divided into bleaching groups, and the four groups underwent a simulation of bleaching and then brushing with the three products. The color parameters were recorded at the stained baseline, after brushing, after bleaching, and after post-bleaching brushing. The color change (ΔE00) was calculated, and the data were analyzed statistically using the Kruskal–Wallis test and Dunn–Bonferroni pairwise comparisons (p < 0.05). Results: In-office bleaching without brushing had a statistically significantly higher ΔE00 value than all other groups (p < 0.001). Post hoc tests indicated that the ΔE00 values of the brushed specimens were not significantly different from each other when assessed with and without bleaching (p > 0.05). When using the charcoal toothpaste, the post-bleaching brushed specimens had a noticeable color change above the PT. Conclusions: Bleaching improved the stained SPR color initially, but other treatments may offer longer-lasting aesthetics. The charcoal toothpaste showed promising results when combined with bleaching. The purple serum showed limited effectiveness. Full article

Daylighting plays a pivotal role in mosques, shaping their sacred atmosphere and enhancing the spiritual experience for worshippers. Beyond a mere architectural consideration, the integration of natural light into mosque design fundamentally influences the ambiance and functionality of these religious spaces. This study investigates the key factors that enhance daylight levels and visual comfort within prayer halls. It specifically evaluates illuminance levels, light distribution, and glare in four domed mosques located in Saudi Arabia. Field measurements were conducted beneath the domes of these prayer spaces, each featuring clerestory windows of varying forms and dimensions. Based on architectural specifications and material properties, daylight simulations and modeling were performed using the RADIANCE engine integrated with Grasshopper. The simulation results were validated against on-site illuminance measurements to ensure model accuracy and reliability. The primary objective was to assess whether the existing daylighting conditions comply with the recommended illuminance standards for reading and prayer, typically ranging from 150 to 500 lux. This study revealed that the illuminance levels in the central dome area exceeded the recommended values, reaching over 3000 lux. To improve daylight distribution, shading systems such as flat and curved shelves were added to the drum’s windows. This research concludes that the light shelves and vacuum double glazing significantly improved indoor daylight performance by preventing direct sunlight entry into the prayer hall and redirecting it towards the dome. This intervention successfully reduced excessive illuminance levels to a more optimal level of around 447–774 lux during the noon prayer period, ensuring a balanced and comfortable environment for worshippers. Full article

Medieval Islamic bustān gardens in the western Mediterranean played a crucial role in preserving and enriching rose diversity through the cultivation of species from the eastern Mediterranean and western Asia. These gardens, particularly in Al-Andalus, maintained distinctive rose varieties characterized by diverse flower morphology—ranging from white to deep crimson and near-black hues, including various yellow shades—and complex fragrance profiles with multiple olfactory nuances. The botanical heritage from these medieval Islamic gardens demonstrates remarkable persistence, with several of these cultivated rose species still found today in abandoned cortijos and aldeas throughout the mountains of eastern Spain. This study examines the transmission of rose culture through medieval Islamic bustān gardens, analyzing how these gardens served as repositories for ancient cultivars while introducing new varieties from eastern regions. Through examination of historical texts, iconographic evidence, and field documentation of surviving populations, we trace the continuity of medieval Islamic rose cultivation practices and their lasting impact on the rural landscape of eastern Spain. Flower scent is prominent as the leading factor determining preferences for medieval heritage rose cultivars, together with color and shape. The survival of these roses in abandoned settlements provides unique insight into the durability of medieval horticultural systems and the adaptation of cultivated species to semi-wild conditions over centuries. Full article

Shaded-pole induction motors are the most frequently used single-phase electric motors in low power applications. Their main advantages are reliability, robustness, low level of noise and vibration, relatively simple manufacturing technology and cost effectiveness. These motors are the driving units of choice in the applications where the variable speed and high starting torque are not of utmost importance, in spite of the fact that they are characterized by inferior efficiency, power factor and starting torque compared to their single-phase counterparts. They are equipped with auxiliary massive copper coils at the stator side, which makes them self-starting, and strongly influence the motor characteristics. This study deals with the numerical modeling and analysis of a shaded-pole induction motor with a C-shaped stator frame. The analysis was performed using 2D finite element-based transient magnetic numerical modeling. The primary objective was to investigate the influence of the number and size of the auxiliary shaded coils on the output torque speed characteristic. We explored the possibility of reducing the amount of material used while preserving the crucial/nominal properties of the motor. Our results have important implications in manufacturing simplification, which may be important for the eco-design of small motors and actuators, including their recycling and/or reuse process. Full article

One of the goals of Agenda 2030 is to increase the share of renewable energy in the global energy mix. In this context, photovoltaic systems play a key role in the transition to clean energy. According to the International Energy Agency, in 2023, solar photovoltaic alone accounted for three-quarters of renewable capacity additions worldwide. Designing a performing photovoltaic system requires careful planning that takes into account various factors, both internal and external, in order to maximize energy production and optimize costs. In addition to the technical characteristics of the system (internal factors), the positions and the shapes of external buildings and surrounding obstacles (external factors) have a significant impact on the output of photovoltaic systems. However, given the complexity of these environmental factors, they cannot be treated accurately in manual design practice. For this reason, this paper proposes a Building Information Modeling-based workflow for the design of a photovoltaic system that can guide the professional step-by-step throughout the design process, starting from the embryonic phase to the definitive, and therefore more detailed, one. The developed methodology allows for an in-depth analysis of the shading, the photovoltaic potential of the building, the performance of the photovoltaic system, and the costs for its construction in order to evaluate the appropriateness of the investment. The main aim of the paper is to create a standardized procedure applicable on a large scale for photovoltaic integration within Building Information Modeling workflows. The methodology is tested on two case studies, characterized by different architectural features and geographical positions. 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

Debris flows pose significant risks to mountainous regions, and quick, accurate volume estimation is crucial for hazard assessment and post-disaster response. Traditional volume estimation methods, such as ground surveys and aerial photogrammetry, are often limited by cost, accessibility, and timeliness. While remote sensing offers wide coverage, existing optical and Synthetic Aperture Radar (SAR)-based techniques face challenges in direct volume estimation due to resolution constraints and rapid terrain changes. This study proposes a Super-Resolution Shape from Shading (SRSFS) approach enhanced by a Non-local Piecewise-smooth albedo Constraint (NPC), hereafter referred to as NPC SRSFS, to estimate debris-flow erosion volume using single high-resolution optical satellite imagery. By integrating publicly available global Digital Elevation Model (DEM) data as prior terrain reference, the method enables accurate post-disaster topography reconstruction from a single optical image, thereby reducing reliance on stereo imagery. The NPC constraint improves the robustness of albedo estimation under heterogeneous surface conditions, enhancing depth recovery accuracy. The methodology is evaluated using Gaofen-6 satellite imagery, with quantitative comparisons to aerial Light Detection and Ranging (LiDAR) data. Results show that the proposed method achieves reliable terrain reconstruction and erosion volume estimates, with accuracy comparable to airborne LiDAR. This study demonstrates the potential of NPC SRSFS as a rapid, cost-effective alternative for post-disaster debris-flow assessment. Full article

To address the escalating urban heat stress driven by global warming and rapid urbanization, this study integrates multi-source remote sensing data to assess the spatiotemporal dynamics of summer thermal comfort across the Yangtze River Delta Urban Agglomeration (YRDUA) from 2000 to 2020. By combining 2D landscape pattern metrics with 3D building morphological features, this study employs an XGBoost model enhanced with SHAP and PDP techniques to reveal the nonlinear and threshold effects of landscape configurations on the Universal Thermal Climate Index (UTCI). The results show the following: (1) during the study period, over 90% of the region experienced strong or extreme heat stress, and 76.8% of the area exhibited a rising UTCI trend, with an average increase of 0.09 °C per year; (2) forest coverage exceeding 50% reduced the UTCI by approximately 2.5 °C, and an increased water area lowered the UTCI by around 1.5 °C, while highly clustered cropland intensified the UTCI by about 1.5 °C; and (3) a moderate increase in building height and shape complexity improved ventilation and shading, reducing the UTCI by roughly 0.5 °C. These findings highlight that optimizing the blue–green infrastructure and 3D urban form are effective strategies to mitigate urban heat stress, offering scientific guidance for sustainable urban planning. Full article

The aim was to assess the blending effect of universal-shade resin-based composites (RBCs) (Omnichroma—OC; Clearfil Majesty Universal–CM; Venus Pearl—V; Transcend—T) used for repair for lithium disilicate blocks. Fifteen parallelepiped-shaped (10.5 × 10.5 × 3 mm) specimens with four cavities (3 mm in diameter and 2 mm in depth) were designed from lithium disilicate CAD/CAM blocks (CEREC Tessera HT A3) and milled. Specimens were then randomly divided into five groups based on the five resin composite materials for cavity restoration (n = 12): Group 1, control group (F); Group 2 (T); Group 3 (OC); Group 4 (V); and Group 5 (CM). After surface conditioning, composite resins were applied to the ceramic surface. Color measurements were taken with a colorimeter in the center of the resin restoration and on the CAD/CAM block. Tristimulus values were converted to CIELab color coordinates and color differences were expressed in ΔE₀₀ units using the CIEDE-2000 formula. F showed significantly better color matching (ΔE₀₀ = 2.51 ± 0.64) in comparison to single-shade RBCs except T (ΔE₀₀ = 2.55 ± 0.64). All groups exceeded perceptibility and acceptability thresholds. The control group presented higher color matching than the single shade universal composites except for Transcend. Full article