Search Results (944)

The growing demand for renewable biomass energy has driven in-depth research into pyrolysis, in which particle size has emerged as a key factor influencing reaction kinetics and gas release. In this study, beech wood with four different sizes were prepared. A thermogravimetric analyzer (TGA 4000) and a Fourier transform infrared spectrometer (FTIR) were used to analyze the thermal behavior of the biomass under a high-purity N₂ atmosphere at heating rates of 10, 20, and 40 K/min. Conversion rates and activation energies were calculated from the thermogravimetric data using two model-free methods, while infrared spectroscopy was employed to analyze gas composition and release characteristics. The experimental results indicate that changes in particle size significantly affect the DTG curves: as particle size increases, the maximum rate of weight loss gradually rises. In terms of pyrolysis kinetic parameters, the activation energy of the biomass samples increased from 166.42 kJ/mol to 176.07 kJ/mol. Gas release peaks also exhibited a trend of shifting toward higher temperature regions. The primary gaseous products were classified into six functional group/gas categories, with their yields ranked in descending order as follows: CO₂ > CH₂O > CH₃OH > H₂O > CH₄ > CO. Except for CO₂, the yields of all other components increased with increasing particle size. These research findings provide data and guidance for the recovery and reuse of biomass resources, as well as for the modeling of biomass pyrolysis reactors, and the classification, pretreatment, and process optimization of biomass materials, thereby accelerating their practical application. Full article

Strawberries are among the most water-sensitive horticultural crops because of their shallow root systems and high transpiration rates, making them particularly vulnerable to rising temperatures, irregular rainfall, and increased vapor pressure deficits under climate change. This review paper synthesizes methods for quantifying water-use efficiency (WUE) in strawberry production, including empirical equations, crop models (AquaCrop, DSSAT, and HYDRUS), and remote sensing approaches. It examines how water use, crop productivity, and WUE respond to environmental conditions and management practices. Earlier studies show that rising temperatures, altered precipitation patterns, and increased atmospheric water demand can often reduce WUE, although responses vary depending on cultivar, management practices, and environmental conditions. In contrast, practices such as deficit irrigation, mulching, and microclimate modification may help maintain water productivity. Remote sensing tools such as the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Surface Energy Balance Algorithm for Land (SEBAL), and Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) are increasingly used to evaluate evapotranspiration, crop condition, and irrigation performance from field to regional scales. Collectively, these approaches improve understanding of strawberry water use and support irrigation management under changing climatic conditions. Full article

Soil moisture is a key indicator of agricultural and hydrological drought, but its meteorological controls vary across temporal scales. Using ESA CCI soil moisture products from 2010 to 2022, this study investigated soil moisture variability in the Yangtze River Basin at weekly, monthly, and annual scales. The product was first validated using ground observations and ERA5 reanalysis data, and a generalized additive model (GAM) was then applied to quantify the relative contributions of precipitation, temperature, wind speed, and VPD under normal conditions and during three extreme drought events. The validation showed that ESA CCI soil moisture captured basin-scale variations well, with mean absolute deviations of 0.0460, 0.0434, and 0.0072 m³/m³ in the upper, middle, and lower reaches, respectively, and a basin-wide RMSE of 0.0127 m³/m³ against ERA5. The attribution results revealed a clear scale-dependent shift in soil moisture controls. At the weekly scale, VPD dominated soil moisture variability, with a basin-wide average contribution of 47.04% and a maximum contribution of 55.92% in the lower reaches, indicating that short-term soil drying is mainly driven by VPD. At the monthly scale, precipitation became the primary control, with a basin-wide average contribution of 36.62% and a maximum contribution of 44.65% in the upper reaches, reflecting the role of accumulated rainfall recharge in maintaining soil moisture storage. During extreme drought events, the monthly-scale dominance of precipitation weakened, and precipitation, VPD, temperature, and wind speed each contributed approximately 20–30%, suggesting that drought development results from the combined effects of reduced water input and enhanced atmospheric water loss. These findings indicate that precipitation-based drought monitoring may underestimate rapid soil drying risks, whereas incorporating atmospheric demand indicators such as VPD can improve drought early warning and water resource management under a warming climate. Full article

Atmospheric carbon dioxide (CO₂) has reached an unprecedented 430 ppm, warming the planet by 50% compared with pre-industrial times and prompting a search for a quick and effective solution to control CO₂ emissions. As a robust, renewable, biodegradable, and sustainable material, nanocellulose can serve as a strong support for many active molecules. Nanocellulose, whether in suspension, aerogel, or membrane form, is not sufficient for efficient CO₂ capture and separation; hence, active molecules, such as silanes, amines, zeolites, and metal–organic frameworks (MOFs), are introduced via chemical modification, such as grafting, or via physical mixing as fillers or additives to make nanocellulose effective for CO₂ capture and separation. Introducing amine or silane molecules into nanocellulose has proven to be an effective strategy for achieving a satisfactory CO₂ absorption capacity exceeding 6 mmol/g. Nanocellulose membranes, when fabricated with MOFs or zeolites and used as a coating with polyvinyl alcohol (PVA) to create a thin-film composite membrane (TFC), can achieve CO₂ permeance of more than 600 GPU for CO₂ separation from flue gas, with CO₂/N₂ selectivity close to 40. This review provides an overview of nanocellulose-based CO₂ capture and separation materials developed over the last 10 years, along with the related challenges that must be overcome to meet current performance and demand. To facilitate readability, the author has provided a brief introduction to the origin, performance, and scale-up developments of nanocellulose at the start of this review. Full article

External spaces of buildings represent a type of potential space that can supplement the urban public space system under the background of urban renewal. However, as spaces with ambiguous publicness, their design and layout often need to convey stronger welcoming attitudes to attract citizens’ use. This study aims to explore the expression elements of publicness in external spaces of museum buildings. A mixed method approach, including field observation and measurement, questionnaire surveys (with a total sample size of 277), and statistical analysis, was adopted to explore and reveal the design logic of publicness expression in the layout and form of external spaces of museum buildings. Taking nine museum building external spaces located in Beijing’s core area as empirical cases, this study analyzes the influence of spatial layout on publicness expression from six dimensions: leisure atmosphere and activity diversity, spatial quality and perceived safety, landscape creation and spatial comfort, pedestrian friendliness, spatial identity, and boundary treatment and management measures. The study aims to understand the subtle threshold characteristics between the design of external spaces of museum buildings and the expression of publicness, and to explore the benefits of external spaces of buildings in supplementing the urban public space system. This research is expected to respond to public demands for high quality public spaces and improve the refinement of urban space management and optimization. Full article

This study proposes a reproducible methodological framework for deriving potential sustainable urban mobility indicators from open-source traffic microsimulation in data-scarce cities. The approach integrates OpenStreetMap data, targeted manual traffic counts, and SUMO to estimate potential technical and environmental indicators through a four-stage workflow comprising network construction, model configuration, indicator extraction, and spatial visualization. The downtown area of Bahía Blanca (Argentina) is presented as an illustrative proof of concept demonstrating the implementation of the framework rather than a fully calibrated traffic model. Future work includes origin–destination demand estimation, model calibration and validation, and coupling with atmospheric dispersion models. Full article

The replacement of synthetic dyes with natural food colorants has become a priority for the food industry, as emerging evidence from in vitro and animal studies on the potential neurotoxic and pro-inflammatory effects of certified dyes converges with consumer pressure for clean-label formulations. Yet despite this, the industrial uptake of natural pigments remains uneven, held back by stability limitations that differ considerably from one pigment class to the next and from one food matrix to another. This review covers the chemistry, industrial applications, and stabilization approaches of the main natural colorant groups: carotenoids, anthocyanins, betalains, chlorophylls, curcuminoids, phycocyanin, and genipin-derived pigments, with particular attention to the physicochemical reasons behind their instability and the practical tools available to address it. Among stabilization strategies, spray-drying microencapsulation with composite protein–polysaccharide wall materials is often the most scalable and cost-effective option, whereas freeze drying may be preferable for high-value pigments or applications in which maximum pigment retention is the priority. Whether the encapsulating matrix remains in a glassy or rubbery state stands out as a key factor governing oxidative degradation across all pigment categories, which makes water activity management a non-negotiable element of any serious formulation effort. Anthocyanins require more than physical encapsulation alone: copigmentation and structural approaches such as acylation and pyranoanthocyanin formation hold degradation routes that no shell material can prevent on its own. For hydrophobic pigments like carotenoids and curcuminoids, lipid-based delivery systems consistently deliver higher bioaccessibility than aqueous or dried formats. pH control, antioxidant incorporation, and modified atmosphere packaging add a useful but ultimately incomplete third line of defense. One development worth attention is the use of pH-responsive pigments in biopolymer packaging films, where color instability, long treated as a drawback, becomes a real-time indicator of food freshness. Bridging the remaining performance gap with synthetic dyes will call for stabilization platforms that tackle the molecular, physical, and environmental dimensions of degradation together, built around the particular chemistry of each pigment and the demands of each application. Full article

The demand for high-precision 3D wind fields in low-altitude weather services is increasing. To improve reconstruction accuracy, the high precision of 2D near-surface single-level products and the vertical structure of 3D numerical model outputs are combined to establish a mapping between 2D observations and 3D atmospheric fields, offering a new approach for 3D wind field reconstruction. A multi-task learning-based downscaling model, WindSD-3D, is proposed. Using single-level near-surface wind and terrain data as input, the model reconstructs high-resolution wind fields at multiple heights from 30 to 200 m. The architecture employs a shared feature extractor and two task-specific branches to decouple U and V wind components, and introduces cascaded Laplacian upsampling layers at the output to progressively recover high-frequency details. Ablation experiments and independent validation in the Beijing–Tianjin–Hebei region show that incorporating terrain data and a multi-stage upsampling strategy effectively enhances the model’s ability to reconstruct the vertical structure of wind fields. Compared to the numerical model product (GRAPES_MESO 3 km), WindSD-3D reduces errors at all evaluated heights, with RMSE improvements of 24.534–33.806% and bias reductions of 47.534–76.156%. The reconstructed wind fields exhibit more stable temporal error evolution across heights, with extreme errors suppressed and growing improvements at higher layers. At 120 m and 180 m, the correlation coefficients with observations increase by 44.989% and 43.913%, respectively, while preserving boundary layer vertical coupling. This method successfully extends the accuracy advantage of near-surface data into the vertical direction, offering a new technical approach for developing high-quality 3D wind field products. Full article

Hydroclimatic evidence is often carried too directly from global-scale attribution studies into local water-resources decisions, despite important differences among variables, methods, and spatial scales. This critical narrative review examines how climate variability, statistical trends, detection, attribution, non-stationarity, and risk should be distinguished when interpreting changes in precipitation, drought, streamflow, floods, groundwater, and water availability. The review compares global assessments, Mediterranean studies, and selected local examples to clarify what each line of evidence can—and cannot—support in adaptation planning. Human influence on global warming is unequivocal, and increases in atmospheric evaporative demand are well supported across many regions; anthropogenic influence has also been detected in several large-scale water-cycle responses. Historical changes in precipitation, river flooding, groundwater, and local drought remain spatially heterogeneous because internal variability interacts with circulation, storage, landscape properties, abstraction, infrastructure, and demand. Statistically significant trends do not by themselves establish hydrological importance or causation, while non-significant local trends do not imply an absence of operational risk. On this basis, the review proposes a scale-aware way of matching hydroclimatic evidence with system vulnerability and the degree of commitment involved in adaptation. Low-regret and adjustable measures can address current vulnerabilities under uncertainty, whereas costly, long-lived, or difficult-to-reverse interventions require stronger local evidence and stress testing across plausible futures. Full article

Rainfall–runoff pollution poses a major challenge to urban water quality management, particularly in rapidly developing regions. However, its spatial variability and source characteristics remain inadequately understood. This study investigates the types, concentrations, and sources of pollutants in rainfall runoff across different urban land-use settings, with the aim of providing insights for more effective water management strategies. By quantifying pollutant occurrence frequencies, comparing reported event mean concentrations, and summarizing literature-reported pollution sources, we evaluated the spatial heterogeneity of runoff contamination from a descriptive perspective. The compiled literature data showed descriptive differences in reported pollution levels among land-use types, with relatively high pollutant concentrations frequently reported in residential and traffic areas. These differences should be interpreted as functional-area-based patterns rather than continuous geographic spatial distributions. Pollutants such as chemical oxygen demand (COD), suspended solids (SS), and total nitrogen (TN) frequently exceeded China’s Class V surface water quality standards. Atmospheric deposition and surface litter were the most frequently reported pollution sources, while traffic-related activities were frequently associated with elevated heavy metal concentrations in the reviewed studies. These findings underscore the urgent need for targeted, land-use-specific pollution control strategies that not only reduce runoff pollution but also improve source-control efficiency for sustainable urban water management. This study offers valuable insights that may be transferable to other urban environments worldwide, with important implications for policy development and urban resilience in the face of increasing environmental pressures. Full article

Urban green spaces (UGSs) are vital for enhancing a city’s resilience and livability; however, their functionality is increasingly jeopardized by drought, particularly in water-scarce regions. This study evaluates drought impact on UGSs in Metropolitan Adelaide, Australia, a representative semi-arid urban system, using satellite-derived Normalized Difference Vegetation Index (NDVI) time-series data spanning 2000–2020. Vegetation dynamics were analyzed through Seasonal-Trend decomposition using Loess (STL), standardized anomaly assessment, lagged Pearson correlation, Ordinary Least Squares (OLS) regression, and Mann–Kendall trend analysis. To isolate climatically sensitive signals, 29 urban lawn patches were examined separately from mixed urban canopy, given their shallow root systems and direct dependence on surface moisture. NDVI declined by approximately 0.09 units during the Millennium Drought (2001–2009), with summer greenness deficits reaching 24% below the 20-year benchmark. Temperature was the dominant driver of lawn NDVI variability (r = −0.863, R² = 74.5%), substantially exceeding the effect of rainfall (r = 0.156, R² = 2.4%). El Niño–Southern Oscillation (ENSO) cycles modulated vegetation responses, with La Niña years supporting recovery and El Niño years amplifying decline. Post-drought recovery remained incomplete, with NDVI deficits of 8–20% persisting through 2020; full recovery was observed only in 2017, coinciding with the highest recorded summer rainfall. No significant directional trend was detected over the full study period (Mann–Kendall τ = 0.005, p = 0.908). These findings demonstrate that heat, rather than water limitation alone, is the primary driver of vegetation stress in urban systems, highlighting the benefits of integrated management strategies that address both warming and moisture deficits to sustain urban green infrastructure under future climate conditions. We introduce the concept of “urban greenery drought,” referring to a form of vegetation stress in managed urban landscapes where greenness is reduced primarily by elevated temperature and atmospheric demand despite water availability. Full article

Accurate short-term rainfall forecasting is essential for disaster mitigation. Although numerical weather prediction models are widely used, their application to short lead times is constrained by computational demands. Data-driven approaches provide an efficient alternative. To better exploit atmospheric water vapor information, this study develops a dual-branch long short-term memory (LSTM) model that integrates Global Navigation Satellite System (GNSS)-derived precipitable water vapor (PWV) with surface meteorological parameters for rainfall forecasting. The model processes historical rainfall and meteorological variables through separate branches. Historical rainfall characterizes precipitation persistence, while PWV, PWV variation (ΔPWV), PWV rate of change (ΔtPWV), and air temperature describe atmospheric moisture evolution and thermodynamic conditions before rainfall. The model was evaluated using hourly observations from 18 GNSS-collocated meteorological stations in Taiwan collected during 2018–2019 and compared with a rainfall history-based LSTM baseline model. Results show that the proposed model achieved accuracies of 89–91% and recalls of 88–90% for 1–3 h forecasts. Its advantages became more evident for longer lead times, with Recall and Threat Score increasing by 6–11% and 4–8%, respectively, for 2–3 h forecasts. These findings demonstrate that integrating GNSS-derived PWV with surface meteorological parameters can improve short-term rainfall forecasting. Full article

Tree-ring chronologies are essential proxies for investigating ecosystem dynamics and reconstructing environmental variability, yet integrative approaches for assessing chronology quality and sampling representativeness across heterogeneous regions remain limited. We analyzed 190 tree-ring chronologies distributed across Mexico and developed two composite indicators: the Signal Quality Index (SQI), integrating internal coherence, interannual sensitivity, common growth signal strength, and the Sampling Representativeness Index (SRI), quantifying the statistical adequacy of sampling efforts. Both indices were standardized and evaluated using Moran’s I, Local Indicators of Spatial Association (LISA), Getis–Ord Gi* hotspot analysis, and correlations with climatic, hydrological, and edaphic variables. Results revealed a marked decoupling between chronology signal quality and sampling representativeness. SQI exhibited significant positive spatial autocorrelation, with clusters of high and low values associated with hydroclimatic gradients. It was strongly related to indicators of water availability and atmospheric evaporative demand, suggesting greater growth coherence under water-limited conditions. In contrast, SRI displayed weak spatial structure and largely non-significant relationships with environmental variables, indicating that representativeness is driven primarily by methodological decisions and sampling design. These findings highlight complementary ecological (SQI) and methodological (SRI) dimensions of dendrochronological networks and provide a practical framework for improving chronology evaluation, comparability, and network development across environmentally heterogeneous regions. Full article

Efficient irrigation management requires complementary information on atmospheric demand, soil conditions, and crop water stress. This study presents a low-power Internet of Things (IoT)-based irrigation system that integrates these components within a unified monitoring and control framework. The system combines LoRa communication, ESP32-based sensor nodes, soil and meteorological sensing, FAO-56 reference evapotranspiration ($E{T}_0$), and canopy-temperature-based Crop Water Stress Index (CWSI). Irrigation decisions rely on the complementary use of $E{T}_0$, in situ soil measurements, and CWSI rather than on a single indicator. A hybrid time-, event-, and query-driven acquisition strategy was implemented to adapt node activity and limit communication overhead. The system was deployed under outdoor conditions in Oujda, Morocco, demonstrating integrated sensing, wireless data transmission, crop-stress monitoring, and automated irrigation control. Energy characterization further showed distinct consumption profiles across sensing, communication, actuation, and low-power operating states, supporting the use of duty cycling to limit active node operation. The results demonstrate the feasibility of integrating environmental, soil, and crop-level information within a low-power IoT framework for adaptive irrigation management. Full article

The growing demand for sustainable energy has intensified interest in converting abundant agricultural residues into renewable fuels. Among these feedstocks, corn stover represents a promising biomass for thermochemical conversion due to its high volatile matter content and widespread availability. This study investigates syngas production and product distribution from corn stover via pyrolysis and steam gasification in an atmospheric fixed-bed tubular furnace at temperatures of 650–850 °C. Furthermore, the effects of steam-to-carbon (S/C) ratio and nickel aluminate (NiAl₂O₄) catalyst loading at 650 °C were also investigated to determine their influence on product distribution and syngas composition. Increasing temperature significantly enhanced gas production in both processes, while steam gasification consistently produced higher gas yields than pyrolysis. At an S/C ratio of 3, the gas yield increased from 37% to 58.6%, with a 55.1% increase in H₂ production after 60 min compared with the pyrolysis baseline. Furthermore, incorporation of NiAl₂O₄ improved the H₂ yield and H₂/CO molar ratio while suppressing CO₂ and CH₄ formation, indicating enhanced catalytic reforming and secondary cracking of pyrolysis vapors. These findings demonstrate that optimizing steam addition and nickel aluminate catalyst loading effectively promotes hydrogen-rich syngas from corn stover and provides valuable insight for the development of efficient biomass-to-fuel conversion technologies. Full article