Search Results (902)

Urban parks play an increasingly important role in supporting social interaction, ecological services, and everyday well-being in rapidly urbanizing cities, yet prevailing planning practices still rely on equal-provision logics and linear modeling frameworks, implicitly assuming that park vitality increases proportionally with facilities and surrounding services. Such assumptions overlook the possibility that park vitality responds to built-environment factors in nonlinear, threshold-based, and configuration-dependent ways. This study develops an interpretable machine learning approach to identify the nonlinear effects and structural configurations that drive urban park vitality in Changsha, China. We integrate Baidu Huiyan population heat data with AOI-defined park boundaries and multi-source POI indicators to characterize internal facilities and surrounding built-environments for 147 parks in the city’s main urban area. An XGBoost model is trained to predict park vitality, and SHAP values, partial dependence analysis, and bivariate interaction plots are employed to examine variable importance, threshold behaviors, and synergistic or substitutive relationships among key factors. The results show that sports and leisure facilities are the most influential driver of vitality, followed by shopping services and government service facilities. Their impacts are strongly nonlinear: sports and leisure facilities and public amenities display clear saturation thresholds, while high-density shopping services generate substantial gains in vitality only beyond specific concentration levels. Interaction effects further indicate that park vitality emerges from particular configurations of internal facilities and surrounding residential and service environments, rather than from the additive accumulation of isolated factors. These findings demonstrate the value of interpretable machine learning for shifting urban park planning from equal-provision paradigms toward structurally informed configuration strategies and more efficient public space governance. Full article

Quinoa (Chenopodium quinoa Willd.) is increasingly valued as a climate-resilient crop due to its nutritional quality and adaptability; however, there is limited information on the nutritional composition of heat-tolerant genotypes grown in tropical environments or the potential of quinoa leaves as an additional nutrient source. This study assessed the nutritional composition of leaves and grains from three heat-tolerant quinoa genotypes (Ames 13746 (Pison), Ames 13748 (Copacabana), and Ames 13745 (Kaslae)) to support their use as multipurpose crops in warm regions. Crude protein, amino acid, dietary fiber fraction, total fat, total starch, and mineral (Ca, Mg, P, K, Fe, and Zn) concentrations were quantified using AOAC, AACCI, and AOCS standardized methods. The grains exhibited a balanced essential amino acid profile, with lysine concentrations exceeding those of most staple cereals. The protein contents in the leaves and grains did not differ among genotypes (p > 0.05), although combustion analysis yielded consistently higher values than the Kjeldahl method. The leaves differed significantly in insoluble and total dietary fiber (p < 0.05), with Kaslae presenting the highest levels. In grains, the dietary fiber, total fat, total starch, and mineral contents did not vary among genotypes. The leaf mineral composition differed in terms of Ca and P, while Mg, Fe, K, and Zn levels remained similar across genotypes. These findings underscore quinoa’s potential as a nutrient-dense, multipurpose crop for food production in tropical environments. Full article

PM_2.5 pollution has become one of the major environmental issues in Shandong Province in recent years. High concentrations of PM_2.5 not only reduce atmospheric visibility but also induce respiratory and cardiovascular diseases, and significantly increase health risks. Source apportionment of PM_2.5 is important for policy makers to determine control strategies. This study analyzed regional and sectoral PM_2.5 sources across 17 Shandong cities during the 2017–2018 winter heating season, which is selected because it is representative of severe air pollution with an average PM_2.5 of 65.75 μg/m³ and hourly peak exceeding 250 μg/m³. This air pollution episode aligned with key control policies, where seven major cities implemented steel capacity reduction and coal-to-gas/electric heating, as a baseline for evaluating emission reduction effectiveness. The particulate matter source apportionment technology in the Comprehensive Air Quality Model with extensions (CAMx) was applied to simulate the source contributions to PM_2.5 in 17 cities from different regions and sectors including industry, residence, transportation, and coal-burning power plants. The meteorological fields required for the CAMx model were generated using the Weather Research and Forecasting (WRF) model. The results showed that all cities besides Dezhou city in Shandong Province contributed PM_2.5 locally, varying from 39% to 53%. The emissions from Hebei province have a large impact on the PM_2.5 concentrations in Shandong Province. The non-local industrial and residential sources in Shandong Province accounted for the prominent proportion of local PM_2.5 in all cities. The contribution of non-local industrial sources to PM_2.5 in Heze City was up to 56.99%. As for Zibo City, the largest contribution of PM_2.5 was from non-local residential sources, around 56%. Additionally, the local industrial and residential sources in Jinan and Rizhao cities had relatively more contributions to the local PM_2.5 concentrations compared to the other cities in Shandong Province. Finally, the emission reduction effects were evaluated by applying different reduction ratios of local industrial and transportation sources, with decreases in PM_2.5 concentrations ranging from 0.2 to 26 µg/m³ in each city. Full article

In recent years, diagnostic technologies that utilize noninvasively collected sweat have garnered significant interest. However, the concentration of components in sweat is lower than that in blood, making the introduction of a concentration step as a sample pretreatment crucial for achieving highly sensitive detection. In this study, we developed a PDMS-based microchannel filled with silica gel, a desiccant particle, to concentrate liquid samples at room temperature without requiring an external power source or heating. The evaluation of the basic characteristics of the fabricated microchannel confirmed that filling it with silica gel efficiently removed the solvent vapor from the liquid samples. In concentration tests using the fluorescent dye uranine as a model for sweat sugar, a maximum 1.4-fold concentration was achieved in DPBS solution and a 1.2-fold concentration in artificial sweat at room temperature. In contrast, no similar concentration effect was observed in microchannels without silica gel packing. The proposed silica-gel-packed PDMS microchannel features a simple structure and requires no external equipment, making it easily integrable with existing microfluidic devices as a sample pretreatment module. This method is considered useful as a passive and simple sample concentration technique for the analysis of low-molecular-weight components in sweat. Full article

As a reliable peak-shaving power source, coal-fired boilers’ flexible operation technology has become a key support for achieving the low-carbon transition. To enhance the peak-shaving capacity of the boiler, it is urgent to explore the transient mechanisms of flow, combustion, and heat transfer under dynamic conditions. In this study, the heat transfer characteristics of the burner under varying load conditions and the combustion characteristics in boilers under low and dynamic load conditions are investigated by CFD numerical simulation technology based on a 10 MW coal-fired test bench. The results indicate that at load rates of 2%/min and 4%/min, heat flux density remains mostly consistent across the upper wall of the furnace. At 6%/min, the heat flux near dense pulverized coal flow exceeds that near fresh coal flow. At 60% load, the flow fields are symmetrical, optimizing flame filling and distribution. As the load drops to 40%, the upper flow field begins to distort, and by 20% load, turbulence and uneven temperature distribution arise. At 20% load, the one-layer burner demonstrates superior flow field stabilization compared to the two-layer configuration, with particle concentration remaining lower near the wall above the burner but higher in the cold ash hopper, while high-temperature zones predominantly concentrate in the furnace center with minimal areas exceeding 1900 K. A boiler designed for concentration separation enhances airflow and decreases wall particle concentration at 20% load, resulting in a more uniform temperature distribution with high-temperature zones further from the walls. Full article

Incorporating hydrophobic flavonoids such as naringenin into food systems is challenging due to their poor water solubility and instability. Effective delivery systems are essential to improve solubility, dispersibility, and controlled release during digestion. This study developed a food-grade encapsulation system using basil seed gum water-soluble extract (BSG-WSE) combined with proteins, sodium caseinate (NaCas) and whey protein isolate (WPI), via pH-driven and mild heat treatments in aqueous media, without the use of organic solvents, to ensure safety and sustainability. BSG-WSE and NaCas were tested at mass ratios of 1:1, 1:3, and 1:5 under pH conditions of 4, 5, and 7, followed by heat treatments at 60 °C or 80 °C for 30 min. The total biopolymer concentrations were 0.15%, 0.3%, and 0.45% (w/v). The most stable colloidal system was obtained at a 1:1 ratio, pH 4, and 60 °C, which was further evaluated for two additional flavonoids (rutin and quercetin) and with WPI as an alternative protein source. The highest loading capacity (11.18 ± 0.17%) and encapsulation efficiency (72.50 ± 0.85%) were achieved for naringenin under these conditions. Quercetin exhibited superior performance, with a loading capacity of 14.1 ± 3.12% and an encapsulation efficiency of 94.36 ± 5.81%, indicating a stronger affinity for the delivery system. WPI showed lower encapsulation efficiency than NaCas. Ternary systems (BSG-WSE, NaCas, and naringenin) formed under different pH and heat treatments displayed distinct morphologies and interactions. The pH 4 system demonstrated good dispersion and pH-responsive release of naringenin, highlighting its potential as a delivery vehicle for hydrophobic flavonoids. BSG-WSE significantly improved the stability of protein-based complexes formed via pH-driven assembly. Physicochemical characterization, rheological analysis, and release studies suggest that this system is particularly suitable for semi-solid food products such as yogurt or emulsions, supporting its application in functional food development. Full article

Air pollution episodes caused by particulate matter (PM) persist in and around Kraków even after the city’s ban on solid fuels. We examine how household wealth and the ongoing replacement of old heat sources with modern, energy-efficient units affect these emissions. Years of hourly data from a network of low-cost sensors for neighboring municipalities are combined with the Poland building emissions register specifying the number and type of heating devices and municipal personal income tax records. Two distinct emission patterns emerge. Episodes of elevated concentrations near houses with old hand-loaded stoves follow pronounced behavioral cycles tied to residents return home hours and the nightly sleep cycle, whereas elsewhere the pattern is smoother—consistent with modern heating sources or with advection from dispersed upwind sources. Municipalities that recorded per capita income growth also showed declines in average PM concentrations, suggesting that rising incomes accelerate the transition to cleaner, more efficient heating. Our findings suggest that economic development is linked to the shift towards cleaner and more efficient energy, and that providing targeted support for low-income households should not be overlooked in completing the transition. Full article

Against the global backdrop of urbanization and sustainable development, urban parks—key public spaces for carbon sequestration, heat island mitigation, and public health promotion—have made their service performance a critical metric for evaluating urban human settlement quality. However, traditional evaluations relying on static questionnaires and aggregate indicators often fail to capture the spatiotemporal dynamics of park usage and complex supply–demand relationships. To address this gap, this study developed a three-dimensional dynamic evaluation model (“Vitality Level, Demand Matching, Service Supply”) for 59 urban parks in Gongshu District, Hangzhou, integrating multi-source data (mobile phone signaling, POIs, park vectors, demographic statistics). The model includes nine indicators (e.g., Temporal Activity Difference, Vitality Stability Index) with weights determined via the entropy weight method. Empirical results show: (1) Gongshu’s park service performance presents a “core-periphery” spatial disparity, with high-performance parks concentrated in central areas (e.g., West Lake Culture Square) due to convenient transportation and diverse functions; (2) Performance levels vary significantly between weekdays and weekends, with higher stability on weekdays and more pronounced supply–demand mismatches on weekends; (3) Time-series cross-validation and Monte Carlo simulations confirmed the model’s robustness. This framework shifts park research from “static quantitative description” to “dynamic performance diagnosis,” providing a scientific basis for refined planning and efficient management of parks in high-density cities. Full article

This paper analyzes smoke control strategies in high-rise building stairwells, with particular focus on their application to existing buildings without smoke exhaust openings at the top of the stairwell. This study is necessary to support the optimization of fire safety in a wide range of existing high-rise buildings in Bucharest, Romania, where stairwells operate without upper smoke vents. The scientific challenge addressed is the comparative evaluation of natural ventilation and mechanical pressurization applied at the lower part of the stairwell in order to assess their influence on smoke and heat propagation. The motivation of this work is related to emergency response, as firefighters require a clear understanding of smoke movement and evacuation conditions depending on the fire location and ventilation mode. Three-dimensional CFD simulations were performed, using a fire source validated against experimental data, to analyze temperature, pressure, airflow velocity, visibility, and toxic gas concentration for different fire-floor locations. The results show that natural ventilation alone is ineffective, while single-point mechanical pressurization improves conditions only during the early fire stage. The findings contribute to better-informed firefighter decision-making by clarifying stairwell conditions during intervention in existing high-rise buildings. Full article

Blue–green spaces are essential for mitigating urban heat islands. The matching between their supply and demand affects the fairness and effectiveness of urban cooling facilities. This study focuses on the third ring area of Urumqi, Xinjiang, China. Cooling supply indicators and cooling demand indicators for blue–green spaces are established. Using coupling coordination and bivariate spatial autocorrelation models, it evaluates the cooling supply-demand relationship during 2010–2020. Results show that: (1) There is a “suburban cold sources dominated, urban supply turned positive” pattern in the cooling supply of Urumqi’s blue–green spaces. (2) Cooling demand has a significant “dual-core spatial separation”. The physical demands are concentrated in the high-temperature patches around the city, while the social demands are mainly distributed in the core area of the urban district. (3) There is a severe supply–demand spatial mismatch, with extremely low coupling coordination. The core issue is that high-supply cropland cold sources are far from the high-social-demand urban area. This study provides an important scientific basis for formulating effective cooling strategies for oasis cities through the analysis of the supply and demand matching of blue and green space. It uniquely helps safeguard ecological security and residents’ health in arid-zone cities. Full article

This work proposes the design, construction, and field test of a vacuum seawater desalination system (VSDS) driven by an evacuated tube solar collector (with a total absorption area of 1.86 m²) under tropical climatic condition (Thailand ambient at latitude 13°43′06.0″ N, longitude 100°32′25.4″ E). The VSDS prototype was designed and constructed to be driven by hot water, which is produced by two heat source conditions: (1) an electric heater for laboratory tests and (2) an evacuated tube solar collector for field tests under real climatic conditions. A comparative experimental study to assess the ability to produce fresh water between a conventional dripping/pipe feed column and spray falling film column is proposed in the first part of the discussion. This is to demonstrate the advantage of the spray falling film distillation column. The experimental method is implemented based on the batch system, in which the cycle time (distillation time) considered is 10–20 min so that heat loss via the concentrated seawater blow down is minimized. Later, the field test with solar irradiance under real climatic conditions is demonstrated to assess the freshwater yield and the system performance. The aim is to provide evidence of the proposed vacuum desalination system in real operation. It is found experimentally that the VSDS working with spray falling film provides better performance than the dripping/pipe feed column under the specified working conditions. The spray falling film column can increase the distillated freshwater volume from 1.33 to 2.16 L under identical cycle time and working conditions. The improvement potential is up to 62.4%. The overall thermal efficiency can be increased from 33.7 to 70.8% (improvement of 110.1%). Therefore, the VSDS working with spray falling film is selected for implementing field tests based on real solar irradiance powered by an evacuated tube solar collector. The ability to produce fresh water is assessed, and the overall performance via the average distillation rate and the thermal efficiency (or Gain Output Ratio) is discussed with the real solar irradiance. It is found from the field test with solar time (8.00–16.00) that the VSDS can produce a daily freshwater yield of up to 4.5 L with a thermal efficiency of up to 19%. The freshwater production meets the requirement for international standard drinking water criteria, indicating suitability for household/community use in tropical regions. This work demonstrates the feasibility of VSDS working under real solar irradiance as an alternative technology for sustainable fresh water. Full article

Microwaves have been used as a heat source in various chemical processes, and their application range is expanding to include high-temperature processes. Existing microwave-based methods for glass syntheses predominantly involve coating and drying. Moreover, microwaves have rarely been applied to glass melting, which consumes a large amount of energy. In this study, the raw materials required for preparing optical glass were heated using microwaves to reduce the energy consumption of the glass-melting process. Microwaves were applied to the raw materials of a typical optical glass, i.e., borosilicate crown glass (BK7). The results indicated that the raw materials rapidly reached the target temperature of 1000 °C and were heated particularly well at temperatures above 500 °C. This was reflected in the high microwave absorption of BK7 above 500 °C, as confirmed by dielectric-constant measurements in the high-temperature range using resonance perturbation. Additionally, BK7 was heated on a 100 g scale in a large microwave-concentrated hexagonal furnace. The obtained glass exhibited a refractive index of 1.5155 (d-line of helium: λ = 587.56 nm), which is comparable to that obtained via conventional heating. Our findings are expected to help reduce the time needed for glass melting considerably and conserve energy, thus contributing to a sustainable society. Full article

This review provides a comprehensive analysis of advanced control strategies and operational optimization of energy systems, focusing on heat pumps, with an emphasis on their role in enhancing energy efficiency and operational flexibility. The study concentrates on methods supported by artificial intelligence algorithms, highlighting Model Predictive Control (MPC), Reinforcement Learning (RL), and hybrid approaches that combine the advantages of both. These methods aim to optimize both the operation of heat pumps and their interaction with thermal energy storage (TES) systems, renewable energy sources, and power grids, thereby enhancing the flexibility and adaptability of the systems under real operating conditions. Through a systematic analysis of the existing literature, 95 studies published after 2019 were examined to identify research trends, key challenges such as computational requirements and algorithm interpretability, and future opportunities. Furthermore, significant benefits of applying advanced control compared to conventional practices were highlighted, such as reduced operational costs and lower CO₂ emissions, emphasizing the importance of heat pumps in the energy transition. Thus, the analysis highlights the need for digital solutions, robust and adaptive control frameworks, and holistic techno-economic evaluation methods in order to fully exploit the potential of heat pumps and accelerate the transition to sustainable and flexible energy systems. Full article

NO, NO₂, and O₃ were measured for 1 year at a suburban site in the southeast Mediterranean. NO preserved no seasonality, but significant seasonal variations were obtained for NO₂ and O₃. These pollutants exhibited inverse trends with higher NO₂ levels measured during wintertime, whilst higher O₃ levels were measured during summertime. Photochemistry was the primary reason for the opposing variations in both pollutants, although O₃ levels were frequently increased due to O₃-rich plumes travelling from northeast Europe, highlighting the impact of regional contributions in the measured concentrations. Nevertheless, anthropogenic sources were identified and contributed to both NO and NO₂. Diurnal variations analysis showed that NO increased usually in the early morning and was linked with primary emissions from traffic. NO₂ increased simultaneously with NO in the early morning, and besides primary vehicle emissions, it was associated with secondary formation from the emitted NO. Moreover, a significant contribution from domestic heating emissions on NO₂ was identified in the late evening during wintertime. Overall, a relative burden of weekdays was associated with NO (morning rush hours) and NO₂ (morning rush hours, evening), whereas weekends were burdened by O₃ due to the weekend effect. Comparison with European Union air quality standards showed that NO₂ was considerably lower than the limit values, but a significant number of exceedances were identified for O₃, especially during the warmer months. This finding suggested the relative burden of the study site from O₃. In conclusion, NO at the study site was influenced by primary traffic emissions, whereas NO₂ had both primary and secondary contributions, and together with photochemistry, both pollutants governed O₃ diurnal and seasonal cycles. Full article

Nowadays, renewable energy sources are gaining importance, yet global energy demand is primarily met by burning fossil fuels. Fluctuations in fossil fuel availability, driven by geopolitical tensions, supply–demand changes, and natural disasters, can lead to sudden energy price spikes or supply shortages, adversely affecting the global economy. Despite its negative impact on carbon emissions and climate change, Heating Oil (HO) offers advantages over other fossil fuels in efficiency, reliability, and availability. Accurate time series prediction models for HO are crucial for stakeholders. This study proposes a novel hybrid model, integrating the Chaotic Adaptive Fitness-Distance Balance-based Stochastic Fractal Search (AFDB-SFS) algorithm with a Bidirectional Long-Short Term Memory (Bi-LSTM) network, for HO close price prediction. The dataset comprises daily observations of five financial time series (close, open, high, low, and volume) over 4260 trading days, yielding a total of 21,300 data points (4260 days × 5 variables). During the feature extraction stage, financial signal processing methods such as Demand Concentration Curve (DCC) and traditional technical indicators are utilized. A total of 189 features are extracted at appropriate intervals for each indicator. Due to the large number of features, the AFDB-SFS algorithm then efficiently identifies the most compatible feature subsets, optimizing the Bi-LSTM model based on three criteria: maximizing R², minimizing RMSE, and minimizing feature count. Experimental results demonstrate the proposed hybrid model’s superior performance, achieving high accuracy (R² of 0.9959 and RMSE of 0.0364), outperforming contemporary models in the literature. Furthermore, the model is successfully implemented on the Jetson Orin Nano Developer Platform, enabling real-time, high-frequency HO price predictions with ultra-low latency (1.01 ms for Bi-LSTM), showcasing its practical utility for edge computing applications in commodity markets. Full article