Search Results (207)

Urban morphology plays a decisive role in regulating microclimate and outdoor thermal comfort in arid cities, where extreme heat and intense solar radiation amplify thermal stress. This study examines the influence of four contrasting urban fabrics in Béchar (Algerian Sahara): the vernacular Ksar, the regular-grid colonial fabric, a modern large-scale residential estate, and low-density detached housing, on local microclimatic conditions. An integrated methodological framework is adopted, combining qualitative morphological analysis, quantitative indicators including density, porosity, height-to-width ratio, and sky view factor, in situ microclimatic measurements, and high-resolution ENVI-met simulations performed for the hottest summer day. Results show that compact urban forms, characterized by low sky view factor values, markedly reduce radiative exposure and improve thermal performance. The vernacular Ksar, exhibiting the lowest SVF, records the lowest mean radiant temperature (approximately 45 °C) and the most favorable average comfort conditions (PMV = 3.77; UTCI = 38.37 °C), representing a reduction of about 3 °C, while its high-thermal-inertia earthen materials ensure effective nocturnal thermal recovery (PMV ≈ 1.06; UTCI = 27.8 °C at 06:00). In contrast, more open modern fabrics, including the colonial grid, large-scale estates, and low-density housing, experience higher thermal stress, reflecting vulnerability to solar exposure and limited thermal inertia. Validation against field measurements confirms model reliability. These findings highlight the continued relevance of vernacular bioclimatic principles for sustainable urban design in arid climates. Full article

A series of novel Ce-modified MnCoAl layered double oxides (Ce/MCA LDOs) were prepared using solvothermal and impregnation methods for NH₃-SCR denitration. Various characterizations, such as X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and H₂ temperature-programmed reduction (H₂-TPR) were used to investigate their structural properties and the mechanism of ammonia selective catalytic reduction (NH₃-SCR). The incorporation of Ce was found to effectively integrate into the LDO framework and enhance the catalytic activity over a wide temperature window. Moreover, the thermal stability and resistance of H₂O and SO₂ were evaluated. In situ DRIFTS studies revealed that the reaction follows both the “Langmuir–Hinshelwood” (L–H) and “Eley–Rideal” (E–R) mechanisms. This work provides systematic insights into the design of LDO-based catalysts, demonstrating their potential for practical application in denitration. Full article

This study presents an environmentally sustainable finishing approach for hemp fabrics by combining soy protein isolate (SPI) pretreatment with an in situ infrared (IR)-assisted synthesis of zinc oxide nanoparticles (ZnO NPs). IR heating was employed to reduce energy consumption while promoting efficient nanoparticle formation compared to conventional thermal processing, while SPI acted as a bio-based stabilizer to enable uniform ZnO NP distribution on the fabric surface. Transmission electron microscopy revealed predominantly spherical to polyhedral ZnO NPs with minimal agglomeration, and X-ray diffraction confirmed their characteristic wurtzite crystalline structure. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy mapping further verified the homogeneous deposition of ZnO NPs on hemp fibers. The treated fabrics exhibited multifunctional performance, showing significantly enhanced ultraviolet (UV) protection with a UV protection factor (UPF) of 50+ compared with untreated hemp. Antibacterial activity against Staphylococcus aureus and Escherichia coli was confirmed by the AATCC TM147 test, while a quantitative AATCC TM100 assessment demonstrated an excellent antibacterial efficiency of 99.99% bacterial reduction against S. aureus. Additionally, the incorporation of 2 wt% SPI significantly improved fabric hydrophilicity and wettability. Overall, this work demonstrates a green and effective strategy for producing antibacterial and UV-protective hemp textiles. Full article

This study presents a novel integrated manufacturing approach that combines fused deposition modeling (FDM) 3D printing with in situ electrospinning to fabricate hierarchical composite structures composed of polylactic acid (PLA) reinforced with polyacrylonitrile (PAN) nanofibers. A mounting fixture was employed to enable layer-by-layer nanofiber deposition directly onto printed PLA layers in a continuous automated process, eliminating the need for prefabricated electrospun nanofiber mats. The influences of nozzle temperature (210–230 °C) and electrospinning time (5–15 min per layer) on mechanical, thermal, and morphological properties were systematically investigated. Optimal performance was achieved at an FDM nozzle temperature of 220 °C with 5 min of electrospinning time (sample E1), showing a 36.5% increase in tensile strength (71 MPa), a 33.3% increase in Young’s modulus (2.8 GPa), and a 62.0% increase in flexural strength (128 MPa) compared with the neat PLA. This enhancement resulted from the complete infiltration of molten PLA into the thin nanofiber mats, creating true fiber–matrix integration. Excessive nanofiber content (15 min ES) caused a 36.5% reduction in strength due to delamination and incomplete infiltration. Thermal analysis revealed a decrease in glass transition temperature (1.2 °C) and onset of thermal degradation (5.3–15.2 °C) with nanofiber integration. Fracture morphology confirmed that to achieve optimal properties, it was critical to balance the nanofiber reinforcement content with the depth of infiltration, as excessive content created poorly bonded interleaved layers. This integrated fabrication platform enables the production of lightweight hierarchical composites with multiscale, custom-made reinforcement for applications in biomedical scaffolds, protective equipment, and structural components. Full article

Buildings account for a substantial share of global energy use, with cooling and heating systems contributing significantly to this demand. Conventional fixed setpoint temperatures overlook occupants’ thermal adaptability, often resulting in unnecessary energy consumption. Although adaptive setpoint temperatures have been investigated in residential and conventional office buildings, their applicability to public buildings, where occupancy is highly variable and indoor–outdoor thermal exchange occurs frequently, remains insufficiently explored. This study examines the performance of an adaptive cooling setpoint strategy in a public building in South Korea through simulation and in situ evaluation. A calibrated simulation model was used to compare cooling energy consumption between fixed and adaptive setpoint temperatures. Simulations indicated an overall 9.0% reduction in cooling energy use, with monthly savings exceeding 11.0% during cooling-dominant months. Validation results confirmed a 7.7% daily energy reduction, while survey results verified that occupant thermal comfort was maintained. The study findings indicate that adaptive thermal comfort-based setpoint temperature control shows promise for effective application in public buildings with similar operational characteristics, improving energy efficiency without compromising occupant comfort. This approach offers a practical pathway for sustainable HVAC operation in buildings with dynamic occupancy and operation features. Full article

In the realm of composite solid propellant research, the enhancement of energy performance without altering the underlying formulation holds paramount significance. This investigation employed an in situ displacement technique to establish a highly reactive interface, successfully synthesizing the [nCu+nCo+nFe]/μAl composite material, which considerably augmented the energy performance of RDX/AP. The decomposition pathways of ammonium perchlorate (AP) and RDX were optimized, resulting in a reduction in their thermal decomposition temperatures by 1.3 °C and 22.4 °C, respectively. Simultaneously, the highly reactive interface promoted efficient oxygen transport, thereby facilitating more rapid and complete reactions of aluminum. Moreover, the distinct dual-catalyst efficacy of the composite significantly enhanced the combustion efficiency of the composite energy micro-unit. Consequently, the [nCu+nCo+nFe]/μAl+RDX/AP composite energetic micro-units exhibited a notable decrease in combustion duration (from 1.58 s to 1.07 s) and elevated combustion flame temperatures (ranging from 1712.8 °C to 2205.6 °C) alongside an expanded combustion area, thus underscoring its potential for advanced propulsion applications. Full article

Remediating complex-contaminated soils demands the synergistic optimization of efficiency, cost-effectiveness, and carbon emission reduction. Currently, ultra-high-temperature thermal desorption technology is mature in terms of principle and laboratory-scale performance; however, ongoing efforts are focusing on achieving stable, efficient, controllable, and cost-optimized operation in large-scale engineering applications. To address this gap, this study aimed to (1) verify the energy efficiency and economic benefits of removing over 98% of target pollutants at a 7.5 × 10⁴ m³ contaminated site and (2) elucidate the mechanisms underlying parallel scale–technology dual-factor cost reduction and energy–carbon–cost optimization, thereby accumulating case experience and data support for large-scale engineering deployment. To achieve these objectives, a “thermal stability–chemical oxidizability” classification criterion was developed to guide a parallel remediation strategy, integrating ex situ ultra-high-temperature thermal desorption (1000 °C) with persulfate-based chemical oxidation. This strategy was implemented at a 7.5 × 10⁴ m³ large-scale site, delivering robust performance: the total petroleum hydrocarbon (TPH) and pentachlorophenol (PCP) removal efficiencies exceeded 99%, with a median removal rate of 98% for polycyclic aromatic hydrocarbons (PAHs). It also provided a critical operational example of a large-scale engineering application, demonstrating a daily treatment capacity of 987 m³, a unit remediation cost of 800 CNY·m⁻³, and energy consumption of 820 kWh·m⁻³, outperforming established benchmarks reported in the literature. A net reduction of 2.9 kilotonnes of CO₂ equivalent (kt CO₂e) in greenhouse gas emissions was achieved, which could be further enhanced with an additional 8.8 kt CO₂e by integrating a hybrid renewable energy system (70% photovoltaic–molten salt thermal storage + 30% green power). In summary, this study establishes a “high-temperature–parallel oxidation–low-carbon energy” framework for the rapid remediation of large-scale multi-contaminant sites, proposes a feasible pathway toward developing a soil carbon credit mechanism, and fills a critical gap between laboratory-scale success and large-scale engineering applications of ultra-high-temperature remediation technologies. Full article

To address the inherent limitations of easy oxidation and unstable electrical properties in two-dimensional MXene-based flexible sensors, this study developed a MXene/GO/rGO (reduced graphene oxide) textile-based flexible sensor using a lamination method and in situ steam reduction technology. The sensor was constructed on a high-elasticity knitted polyester fabric, with MXene as the primary conductive layer, graphene oxide (GO) as the adhesive layer, and reduced graphene oxide (rGO) as the protective encapsulation surface layer. The tensile strain-sensing and electrothermal properties of the resulting e-textile were systematically characterized. The MXene/GO/rGO textile demonstrated outstanding electrical and mechanical performance, achieving a conductivity of 39.7 S·m⁻¹, a gauge factors ranging from –3 to –1.6, and a controllable electrothermal heating range from 43 °C to 85 °C under currents of 0.02–0.05 A. Experimental results demonstrated that under applied currents of 0.02, 0.03, 0.04, and 0.05 A, the fabric reached temperatures of 43, 56, 73, and 85 °C, respectively, and remained constant over extended periods. In terms of strain sensing, the sensor exhibited a short response time (65 ms), high discriminability for different strain levels and stretching rates, and a consistent relative resistance change (ΔR/R0) under various stretching speeds (0.5, 1, 2, 4, and 6 mm/s). Compared with sensors based on a single conductive material, the MXene/GO/rGO polyester fabric sensor shows superior electrothermal and strain-sensing performance, indicating promising potential for applications in intelligent wearable textiles such as medical thermal therapy, sports monitoring, and health management. Full article

This study addresses the stability and deformation control of the Xiling auxiliary shaft in the Sanshandao Gold Mine during excavation, under the complex geological conditions of high in situ stress, high pore pressure, and elevated geothermal gradients. A thermal–hydraulic–mechanical (THM) coupling numerical model is developed to investigate the stress distribution, deformation mechanisms, and long-term stability of the surrounding rock under multi-physical interactions. Meanwhile, the influence of excavation rate on rock stability is analyzed. The results indicate that excavation induces significant stress redistribution, with stress concentrations in high-elastic-modulus strata, where the maximum compressive and tensile stresses reach 15.9 MPa and 14.1 MPa, respectively. The maximum displacement occurs in low-stiffness rock layers (around 1400 m depth), with a total magnitude of 1139 mm, primarily resulting from unloading relaxation, pore pressure reduction, and thermal contraction. Excavation rate strongly affects the temporal evolution of deformation: faster excavation leads to greater instantaneous displacements, whereas slower excavation suppresses displacement due to the sustained influence of thermal contraction. Based on these findings, particular attention should be paid to the low-stiffness strata near 1400 m depth during the construction of the Xiling auxiliary shaft. A combined support system consisting of high-prestress rock bolts, lining, and grouting is recommended for deformation-concentrated zones, while excavation rates should be optimized to balance efficiency and safety. Furthermore, long-term monitoring of temperature, pore pressure, and displacement is essential to achieve dynamic risk control. These results provide valuable theoretical and engineering insights for the safe construction and stability management of deep mine shafts. Full article

Vegetation in urban green spaces plays a critical role in mitigating surface heat, yet the magnitude of this effect remains uncertain across scales and measurement methods. This study assesses the cooling performance during the summer of 94 green spaces in three Chilean cities—classified in three types according to their size—combining satellite-derived land surface temperature (LST) data with high-resolution in situ thermal imaging. We performed comparisons of the cooling effects of green spaces and their components (vegetation, impermeable and semi-permeable surfaces). Spearman’s correlation analysis, the Mann-Whitney U test and Kruskal-Wallis and Dunn post hoc were used to evaluate associations and differences. Results demonstrate that vegetation quantity and composition—particularly tree and shrub cover—are key determinants of cooling performance. In situ measurements reveal that green spaces are on average 9.3 °C cooler than their urban surroundings, substantially exceeding differences captured by LST. Additionally, shaded surfaces within green spaces exhibit temperature reductions of 12 °C to 17 °C compared to sun-exposed areas, underscoring the role of vegetation in mitigating surface heat extremes. These findings challenge the sole reliance on remote sensing for urban heat assessments and highlight the value of integrating ground-based observations. This study advances understanding of vegetation’s localized cooling potential in Latin American cities and provides actionable insights for urban climate resilience planning. Full article

The energy-saving performance of the building envelope, which plays a pivotal role in energy conservation and thermal insulation, has been the subject of extensive research. In the context of China’s high-quality green development, this study proposes a building energy-saving strategy based on optimal thermal comfort. It analyzes the impact of factors such as regional dwell time and PMV types on energy-saving effects, summarizes the optimal comfort parameters under the highest energy efficiency rate, and sets relevant parameters in the DeST building energy simulation software to analyze a typical public building. The analysis examined the impact of changing the heat transfer coefficients of exterior walls and windows on the annual cumulative heating and cooling loads. It established the relationship between the thermal transmittance of building envelopes and energy consumption and assessed the carbon emissions during the building’s operation and maintenance phase. The results indicate that as building envelope thermal transmittance coefficient decreases, particularly that of external windows and walls, overall cumulative heating and cooling loads decline accordingly. Notably, the reduction in external windows’ thermal transmittance coefficient has the most significant impact on total building thermal load. Furthermore, as the envelope thermal transmittance coefficient decreases, seasonal heating and cooling demands decline simultaneously, with the most substantial effect on heating load reduction during winter. Total annual building carbon emissions also decrease with the reduction in envelope thermal transmittance coefficient, particularly external wall thermal transmittance coefficient. Based on the findings of this study, the building envelope of the public building was redesigned, taking into account construction costs, the owner’s requirements, and energy efficiency alongside the reduction in carbon emissions. Comparisons of the redesigned building’s envelope thermal performance, experimental testing, and in situ measurements confirmed that it fulfilled the engineering requirements. This study also demonstrates that DeST software provides reliable technological support for low-carbon building design, retrofitting, and operation. Full article

Backfilling mining methods control the surrounding pressure and ground subsidence by backfilling goaf and managing the ground pressure, providing a safety guarantee for mining in complex environments and serving as a key means of achieving the deep mining of metal minerals. However, in the design of backfill strength, material mix ratios are determined under indoor standard constant temperature and humidity conditions, which differ significantly from the in situ curing environment. Strength measurements obtained from field samples are notably higher than those from indoor test specimens. To address this issue, this study designed a curing device simulating the in situ thermal-hydraulic multi-field environment of the mining site and tested the strength and porosity of the backfill under different curing temperatures, curing pressures, and pore water pressures. The results indicate that curing pressure and pore water pressure significantly altered the pore structure of the specimens. Specifically, when the curing pressure increased to 750 kPa, the maximum pore diameter decreased from 3110.52 nm to approximately 2055 nm, accompanied by a continuous reduction in porosity. Pore water pressure exhibited a positive linear correlation with specimen porosity, which increased continuously as the pore water pressure rose. With increasing curing temperature, the strength of the backfilled specimens first increased and then decreased, reaching a maximum at 45 °C. As the curing pressure increased, the strength of the backfilled specimens rose, but the rate of increase gradually slowed. With increasing pore water pressure, the strength of the backfilled specimens showed a gradual decreasing trend. Full article

Outdoor thermal comfort in tropical cities is increasingly threatened by rapid urbanization, high humidity, and insufficient climate-sensitive planning. Despite numerous studies on urban heat mitigation, there is a lack of empirical and numerical research that evaluates the synergistic application of bioclimatic strategies under humid tropical conditions. This paper addresses this gap by analyzing the combined effect of arborization, dry mist systems, water bodies, and sprinklers on outdoor thermal comfort at the Víctor Levi Sasso Campus of the Technological University of Panama. We hypothesized that synergistic application of these strategies provides greater thermal comfort improvements than isolated interventions. The central research question guiding this study was: To what extent can combined bioclimatic strategies enhance outdoor thermal comfort compared to individual strategies in humid tropical environments? To answer this, a hybrid methodology was employed, integrating ENVI-met dynamic simulations with in situ measurements and thermal comfort surveys based on the physiological equivalent temperature (PET) index and subjective comfort scales. The results demonstrate that combined strategies achieve superior reductions in mean radiant and surface temperatures while improving subjective comfort perceptions, highlighting their potential for context-sensitive urban design in tropical regions. Full article

The building sector plays a key role in the transition toward climate neutrality, with national regulations across the EU requiring the construction of nearly zero-energy buildings (nZEBs). However, while energy performance has been extensively studied, less attention has been given to the problem of ensuring user comfort—both indoors and in the surrounding outdoor areas—under nZEB design constraints. This gap raises two key research objectives: (1) to evaluate whether a well-designed nZEB with extensive glazing maintains acceptable indoor thermal comfort and (2) to assess whether residents experience greater outdoor thermal comfort and satisfaction in small, sun-exposed private gardens or in larger, shaded communal green spaces. To address these objectives, a newly built residential estate near Kraków (Poland) was analyzed. The investigation included simulation-based assessments during the design phase and in situ measurements during building operation, complemented by a user survey on spatial preferences. Indoor comfort was evaluated for rooms with large glazed façades, as well as rooms with standard-sized windows, while outdoor comfort was assessed in both private gardens and a shared green courtyard. Results show that shading the southwest-oriented glazed façade with an overhanging terrace provided slightly lower temperatures in ground-floor rooms compared to rooms with standard unshaded windows. Outdoors, users experienced lower thermal comfort in small, unshaded gardens than in the larger, vegetated communal area (pocket park), which demonstrated greater capacity for temperature moderation and thermal stress reduction. Survey responses further indicate that potential future residents prefer the inclusion of a shared green–blue infrastructure area, even at the expense of building some housing units in semi-detached form, instead of maximizing the number of detached units with unshaded individual gardens. These findings emphasize the importance of addressing both indoor and outdoor comfort in residential nZEB design, showing that technological efficiency must be complemented by user-centered design strategies. This integrated approach can improve the well-being of residents while supporting climate change adaptation in the built environment. Full article

The functionalization of textiles with nanomaterials through green synthesis offers a promising pathway for sustainable material innovation. This study explores the in situ green synthesis of silver nanoparticles (AgNPs) onto cotton fabrics using Solanum tuberosum (potato) peel extract as a natural reducing and stabilizing agent. The synthesis conditions were optimized by varying silver nitrate concentration, extract volume, temperature, pH, and reaction time, after which the optimized protocol was applied for fabric treatment. The presence and distribution of AgNPs were confirmed through UV-Visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy and dynamic light scattering. The treated fabrics demonstrated strong and durable antibacterial performance, with inhibition zones of 23 ± 0.02 against Escherichia coli and 16 ± 0.01 against Staphylococcus aureus. Notably, antibacterial activity was retained even after 20 washing cycles, demonstrating the durability of the treatment. Mechanical testing revealed a 32.25% increase in tensile strength and a corresponding 10.47% reduction in elongation at break compared to untreated fabrics, suggesting improved durability with moderate stiffness. Air permeability decreased by 8.8%, correlating with the rougher surface morphology observed in Scanning Electron Microscopy images. Thermal analysis showed a decrease in thermal stability relative to untreated cotton, highlighting the influence of AgNPs on degradation behavior. Overall, this work demonstrates that potato peel waste, an abundant and underutilized biomass, can be used as a sustainable source for the green synthesis of AgNP-functionalized textiles. The approach provides a cost-effective and environmentally friendly strategy for developing multifunctional fabrics, while supporting circular economy goals in textile engineering. Full article