Search Results (1,875)

Despite the widespread adoption of the Leadership in Energy and Environmental Design (LEED) rating system, there is limited empirical research examining how different sustainability categories are implemented in practice or how methodological patterns influence certification outcomes. This study contributes to this understanding by analysing LEED v4 Building Design + Construction certification patterns across 1252 newly constructed buildings in the United States to understand the methodological foundations and identify improvement opportunities for the LEED framework. Using credit achievement degree (CAD) analysis, regional variation assessment, and correlation analysis, we examined category adoption patterns across nine US climate regions, investigated relationships between LEED categories, and analysed certification level influences. The analysis reveals significant disparities in category adoption, with innovation (80.7%) and regional priority (66.6%) achieving high implementation rates while the category of material and resources (41.1%) consistently underperforms. Statistically significant regional variations exist across eight of nine categories (p < 0.05), with location and transportation showing the highest variability (CV = 20.1%). The category of energy and atmosphere demonstrates the strongest relationship with overall project performance (R² = 0.38), explaining 43% of total score variation and serving as the primary driver of higher certification levels. Most critically, inter-category correlations are weak (typically R² < 0.05), indicating that projects treat sustainability domains as separate challenges rather than integrated systems. Positive skewness across all certification levels (z-scores > 1.96) provides statistical evidence of strategic “point-chasing” behaviour, where teams target minimum thresholds rather than maximising comprehensive sustainability performance. These findings reveal fundamental methodological patterns that may limit LEED’s effectiveness in promoting holistic sustainability approaches. The compartmentalised implementation patterns and threshold-focused strategies suggest opportunities for structural refinements, including enhanced integration incentives, region-sensitive benchmarking, and certification frameworks that reward comprehensive rather than minimal compliance. This research contributes empirical evidence for evidence-based improvements to green building certification methodology and provides insights for more effective sustainability assessment tools. Full article

This study advances the understanding of atmospheric microplastic (MPs) exposure across urban (US), suburban (SS), and rural (RS) areas of Madrid, Spain, for the first time. Air pollution from MPs remains an understudied issue with broad implications for environmental and human health. Recent evidence highlights the need for multipoint studies to accurately establish atmospheric exposure to MPs, especially during winter seasons in the city. To address this issue, this work conducted active sampling of ≤10 μm aerosol particles, following EN 12341:2014 standards, during the 2024–2025 winter season. A quantitative innovative method using UV-assisted optical microscopy was applied to assess daily MPs exposure. To trace the potential sources and transport pathways, air mass back trajectories were modelled using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) software. The results showed an average exposure (n = 4) of 80 ± 20; 55 ± 9 and 46 ± 20 MPs·m⁻³·day⁻¹ during the sampling period in US, SS, and RS, respectively; and an average exposure (n = 4) of 61 ± 11 MPs·m⁻³·day⁻¹ throughout the winter period between November and December 2024 and January and February 2025. The polymers detected as constituents of MPs were polystyrene, polyethylene, polymethyl methacrylate, and polyethylene terephthalate, achieving a correct identification ratio of 100% for the detected microplastic particles. The HYSPLIT results showed diffuse sources of MPs, especially local, regional, and oceanic sources, in the US. In contrast, microplastic contributions in SS and RS areas originated from local or regional sources, highlighting the need for advanced studies to identify the sources of emissions and transport routes that converge in the occurrence of microplastics in the areas studied. These results demonstrate the atmospheric exposure to microplastics in the city, justifying the need for specialized studies to define the health impacts associated with the inhalation of these emerging pollutants. The findings of this research provide clear evidence of exposure to atmospheric microplastics in urban, suburban, and rural environments in Madrid, suggesting the need for further specialized research to rigorously assess the potential risks to human health associated with microplastic inhalation by the city’s population. Full article

Volvariella volvacea, a fungal species of Volvariella within the Pluteaceae family, is predominantly cultivated in southern China. Polysaccharides, the primary bioactive constituents of V. volvacea, exhibit diverse pharmacological activities. However, current cultivation practices face challenges due to the genetic heterogeneity of strains, leading to inconsistent content and compositional variability of polysaccharides and other functional components. ARTP, denoting atmospheric and room-temperature plasma, is a technology capable of generating plasma jets at ambient pressure with temperatures ranging from 25 to 40 °C. These jets feature high concentrations of highly reactive species, including but not limited to excited-state helium atoms, oxygen atoms, nitrogen atoms, and OH radicals. This study aims to develop high-yielding exopolysaccharide (EPS) strains through integrated ARTP mutagenesis and genome shuffling, thereby overcoming current cultivation bottlenecks. ARTP mutagenesis and genome shuffling significantly boosted EPS production in V. volvacea. ARTP generated nine stable mutants with >20% higher EPS yields. Subsequent genome shuffling (three rounds of protoplast fusion) produced the hybrid strain SL212, which achieved 46.85 g/L of EPS, an 111.67% increase over that of the parent strain under identical conditions. Metabolomics and transcriptomics analyses revealed that differential metabolites and genes were mainly enriched in galactose metabolism, ABC transporter pathways, and the tricarboxylic acid cycle. These pathways enhance monosaccharide biosynthesis and generate ATP, providing both precursors and energy for polysaccharide polymerization, thereby driving EPS overproduction. Preliminary mechanistic analysis identified the key contributing factors driving the elevated polysaccharide biosynthesis. Full article

Additive manufacturing (AM) is an Industry 4.0 technology that assists or replaces the conventional manufacturing (CM) of complex geometries in various sectors, including transport, steel, aerospace, military, and architecture. The aim is to improve processes, reduce energy consumption, atmospheric emissions, and solid waste, and streamline stages while complying with the new environmental regulations. The main objective of this work was to carry out a cradle-to-gate Life Cycle Assessment (LCA), considering the raw material extraction, pre-processing, manufacturing, and post-processing stages, comparing two manufacturing methods for the same ER-90 metal flange part, conventional forging and wire and arc additive manufacturing (WAAM), all following the requirements and operations proposed by the ISO 14040/44 standard. WAAM is a Directed Energy Deposition (DED) technology that uses welding techniques to produce 3D objects with more complex geometries. Compared to the forging industry, which requires a lot of heat and kinetic energy in its metal part production stages, WAAM is a more sustainable and modern alternative because it does not require high temperatures and energy to produce the same parts. The environmental indicators compared in the process stages were energy consumption, greenhouse gas (GHG) emissions, and solid waste. The total energy consumption in AM was 18,846.61 MJ, the GHG emissions were 864.49 kgCO₂-eq, and the solid waste generated was 142.34 kg, which were 63.8 %, 90.5%, and 31.6% lower than the environmental indicators calculated for CM, respectively. Full article

As a sessile wax scale insect, Ericerus pela heavily relies on its host plant for nutrition. While E. pela utilizes the nitrogen-poor plant sap as its primary nutrient source, the mechanisms by which this insect overcomes the nitrogen deficiency are poorly understood. In this study, we first confirm the nitrogen fixation capability of E. pela through isotopic tracer experiments and the acetylene reduction assay, which demonstrate that female adults exhibit an efficient nitrogen fixation rate. High-throughput sequencing further revealed 42 nitrogen-fixing bacterial species in the tissues of E. pela, most notably including Rhizobiales and Methylobacterium as the dominant species converting atmospheric nitrogen to ammonia. Several critical genes involved in nitrogen fixation, ammonia transporting, amino acid synthesis, and transportation were determined to be transcriptionally active across different developmental stages of E. pela. In addition, the symbiotic fungus Ophiocordyceps—located in the fat body of E. pela—was found to be capable of synthesizing all amino acids, including the essential amino acids required for the survival of E. pela. Taken together, this study demonstrates that E. pela has evolved a highly effective nitrogen acquisition system driven by symbiotic microorganisms, ensuring a sufficient nitrogen supply and enabling it to thrive on nitrogen-deficient food sources. Our findings reveal a unique evolutionary adaptation in which E. pela leveraged both bacterial nitrogen fixation and fungal amino acid synthesis to bolster its growth and development. Full article

Precipitation leaches soil organic matter (SOM), transporting it downward where it accumulates at the soil–bedrock interface. Intensive agriculture, particularly tillage, accelerates this process. Microbial decomposition of SOM generates CO₂, forming a gas-rich soil layer (GRSL)—a phenomenon long hypothesized but never directly confirmed until now. Drilling on the Harbechy Plateau (Moravian Karst) revealed a GRSL with a thickness of ~0.8 m, CO₂ concentrations averaging 1.5–3 vol. % (peaks of 4–6 vol. %), and isotopic signatures (δ¹³C) indicating a mix of biogenic (−25‰) and atmospheric (−8‰) CO₂. These findings necessitate re-evaluation of carbon cycling models in karst agroecosystems. Full article

The livestock sector significantly contributes to atmospheric emissions of various pollutants, such as ammonia (NH₃) and particulate matter of diameter under 2.5 µm (PM2.5) from activity and barn management. The objective of this study was to evaluate the reliability of low-cost sensors integrated with an IoT system for monitoring PM2.5 concentrations in a dairy barn. To this end, data acquired by a PM2.5 measurement device has been validated by using a high-precision one. Results demonstrated that the performances of low-cost sensors were highly correlated with temperature and humidity parameters recorded in its own IoT platform. Therefore, a parameter-based adjustment methodology is proposed. As a result of the statistical assessments conducted on this data, it has been demonstrated that the analysed sensor, when corrected using the proposed correction model, is an effective device for the purpose of monitoring the mean daily levels of PM2.5 within the barn. Although the model was developed and validated by using data collected from a dairy barn, the proposed methodology can be applied to these sensors in similar environments. Implementing reliable and affordable monitoring systems for key pollutants is crucial to enable effective mitigation strategies. Due to their low cost, ease of transport, and straightforward installation, these sensors can be used in multiple locations within a barn or moved between different barns for flexible and widespread air quality monitoring applications in livestock barns. Full article

Space-based, photon-counting lidar instruments are effective tools for observing cloud and aerosol layers in the atmosphere. Cloud phases and several different kinds of aerosols are presently identified and typed using sophisticated, fine-tuned classification algorithms that operate using processed lidar data. We present a deep neural network semantic segmentation model that was trained using raw, uncalibrated photon count data and data products from the Cloud/Aerosol Transport System’s (CATS) 1064 nm lidar. Our approach successfully types layers in complex scenes using only raw photon counts, bin altitudes, and ground surface type at 14 to 171 times the spatial resolution of the CATS operational data product. We observe comparable cloud detection and phase determination to the CATS operational algorithm while also exhibiting a 15-point improvement in finding tenuous aerosol layers. Because the model is lightweight, does not rely upon ancillary information, and is optimized to leverage GPU computing, it has the potential to be deployed on-instrument to perform cloud and aerosol typing in real time. Full article

Using multiple reanalysis datasets, this study investigates the decadal variability in the relationship between Northeast Pacific Sea surface temperature (SST) and Arctic stratospheric ozone (ASO), with a focus on the role of atmospheric dynamics in mediating this connection. A significant decadal shift is identified around the year 2000, characterized by a weakening of the previously strong negative correlation between January–February SST anomalies and February–March ASO. Prior to 2000 (1980–2000), warm SST in the northeastern Pacific suppressed upward planetary wave propagation, resulting in decreased stratospheric wave activity and a weakened Brewer–Dobson circulation. The weakened BD circulation reduced poleward transport of tropical ozone and heat, yielding a colder, ozone-poor polar vortex. The strong relationship enabled skillful seasonal predictability of ASO using SST precursors in a linear regression model. However, post-2000 (2001–2022), the weakened planetary wave response to SST anomalies resulted in a breakdown of this relationship, yielding non-significant predictive skill. The findings highlight the non-stationary nature of ocean-stratosphere coupling and underscore the importance of accounting for such decadal shifts in climate models to improve projections of Arctic ozone recovery and its surface climate impacts. Full article

The vertical distribution of volatile organic compounds (VOCs) within the planetary boundary layer (PBL) is critical for understanding ozone (O₃) formation, yet knowledge remains limited in complex urban environments. In this study, vertical measurements of 117 VOC species were conducted using an unmanned aerial vehicle (UAV) equipped with a VOC multi-channel sampling system, up to a height of 500 m in Shenzhen, China. Results showed that total VOC (TVOC) concentrations decreased with altitude in the morning, reflecting the influence of surface-level local emissions, but increased with height at midday, likely driven by regional transport and potentially stronger photochemical processes. Source apportionment revealed substantial industrial emissions across all altitudes, vehicular emissions concentrated near the surface, and biomass burning primarily impacting higher layers. Clear evidence of enhanced secondary formation of oxygenated VOCs (OVOCs) was observed along the vertical gradient, particularly at midday, indicating intensified photochemical processes at higher altitudes. These findings underscore the importance of considering vertical heterogeneity in VOC distributions when modeling O₃ formation or developing measures to reduce emissions at different altitudes, and also demonstrate the potential of UAV platforms to provide high-resolution atmospheric chemical data in complex urban environments. Full article

Quantifying land–atmosphere transport remains crucial for advancing climate prediction and weather forecasting efforts. To improve turbulent flux estimation, the anisotropy of turbulence is taken into consideration. The parameters $x_B$ and $y_B$, which quantify anisotropy degrees across motion scales, form trajectories in the barycentric map. Using the Hilbert–Huang transform, the scale-dependent properties of anisotropy in observational data from multiple sites are investigated. Analysis reveals consistent patterns in the average $y_B-x_B$ trajectories across stratification conditions: as scale increases, $x_B$ increases from 0.4 to 0.9, while $y_B$ initially climbs from 0.5 to 0.7 before declining to 0. Meanwhile, individual case trajectories sometimes deviate from this pattern, indicating contamination by non-turbulent motions that typically cause turbulent flux overestimation. Crucially, identifying the scale at which deviations occur allows effective separation of atmospheric turbulence from non-turbulent motions, which enables the reconstruction of turbulence data. Results demonstrate that corrected fluxes reduce overestimation inherent in traditional eddy covariance systems by approximately 30%, with enhancements for CO₂ and air pollutants reaching 45–83%. Furthermore, the correlation between anisotropy and stratification suggests potential for refining similarity theories into a broader scope, such as carbon cycle assessment and pollution control. Therefore, anisotropy shows promise in quantifying the land–atmosphere transport. Full article

The Amazon River Basin (ARB) experienced an extreme drought from summer 2023 to spring 2024, driven by complex interactions among multiple climatic and environmental factors. A detailed investigation into this drought is crucial in understanding the entire process of the drought. Here, we employ drought indices derived from the Gravity Recovery and Climate Experiment (GRACE), GRACE Follow-On (GFO), and Swarm missions to reconstruct the drought’s progression, combined with reanalysis datasets and extreme-climate indices to analyze atmospheric and hydrological mechanisms. Our findings reveal a six-month drought from September 2023, reaching a drought peak of −1.29 and a drought severity of −5.62, with its epicenter migrating systematically from the northwestern to southeastern basin, spatially mirroring the 2015–2016 extreme drought pattern. Reduced precipitation and abnormal warming were the direct causes, which were closely linked to the 2023 El Niño event. This event disrupted atmospheric vertical movements. These changes led to abnormally strong sinking motions over the basin, which interacted synergistically with anomalies in land cover types caused by deforestation, triggering this extreme drought. This study provides spatiotemporal drought diagnostics valuable for hydrological forecasting and climate adaptation planning. Full article

The rapid development of intelligent high-speed railways (HSRs) has significantly improved the transportation efficiency of modern transit systems, while also imposing higher bandwidth demands on mobile communication systems. Free-space optical (FSO) communication technology, as a promising solution, can effectively meet the high-speed data transmission requirements in intelligent HSR scenarios. In this paper, we consider an intelligent HSR system based on beamwidth-adaptive FSO communication and investigate the coverage performance of the system. Different from the circular cells used in traditional radio frequency wireless communication systems, this paper focuses on the coverage problem of narrow-strip-shaped cells in HSR systems based on FSO communication. When the transmitter emits a wide beam, the channel gain includes geometric loss, atmospheric attenuation, and atmospheric turbulence. When the transmitter emits a narrow beam, the channel gain includes pointing error, atmospheric attenuation, and atmospheric turbulence. To adapt the width of the transmitter’s beam, we propose a beamwidth-adaptive HSR system and a beamwidth-adaptive method. Furthermore, we derive closed-form expressions of the edge coverage probability (ECP) and the percentage of cell coverage area (CCA), where the ECP is the probability that the received signal-to-noise ratio at the cell edge is greater than or equal to a given threshold, and the percentage of CCA dictates the percentage of locations within a cell that are not in outage. The accuracy of the derived theoretical expressions is validated through Monte-Carlo simulations. The average relative error of the ECP between theoretical and simulation results is only 0.035%, and the corresponding error of the percentage of CCA is 0.087%. In addition, the impacts of factors such as cell diameter, transmission power, signal-to-noise ratio threshold, and weather visibility on coverage performance are also discussed. Full article

The rainy season characteristics are directly modulated by atmospheric circulation and moisture transport dynamics. Focusing on the characteristics of the rainy season onset date (RSOD), this study aims to advance the understanding and prediction of climate change impacts on agricultural production and disaster mitigation strategies. Based on rainfall data from 66 meteorological stations in northeast China (NEC) from 1961 to 2020, this study determined the patterns of the RSOD in the region and established its mechanistic linkages with atmospheric circulation and water vapor transport mechanisms. This study identifies a climatic regime shift around 2000, with the RSOD transitioning from low to high interannual variability in NEC. Further analysis reveals a strong correlation between the RSOD and atmospheric circulation characteristics: cyclonic vorticity amplifies before the RSOD and dissipates afterward. Innovatively, this study reveals a significant transition in the water vapor transport paths during the early rainy season in NEC around 2000, shifting from eastern Mongolia–Sea of Japan to the northwestern Pacific region. Moreover, the advance or delay of the RSOD directly influences the water vapor transport intensity—an early (delayed) RSOD is associated with enhanced (weakened) water vapor transport. These findings provide a new perspective for predicting the RSOD in the context of climate change while providing critical theoretical underpinnings for optimizing agricultural strategies and enhancing disaster prevention protocols. Full article

In the summer of 2022, central and eastern China experienced prolonged extreme high temperatures and severe drought, leading to significant economic losses. To gain a more profound understanding of this drought event and furnish a reference for forecasting similar events in the future, this study examines the circulation anomalies associated with the drought. Employing a diagnostic method focused on temperature and moisture anomalies, this study introduces a novel approach to quantify and compare the relative significance of moisture transport and warm air dynamics in contributing to the drought. This study examines the atmospheric circulation anomalies linked to the drought event and compares the relative contributions of water vapor transport and warm air activity in causing the drought, using two parameters defined in the paper. The results show the following: (1) The West Pacific Subtropical High (WPSH) was more intense than usual and extended westward, consistently controlling the Yangtze River Basin. Simultaneously, the polar vortex area was smaller and weaker, the South Asian High area was larger and stronger, and it shifted eastward. These factors collectively led to weakened water vapor transport conditions and prevailing subsiding air motions in the Yangtze River Basin, causing frequent high temperatures. (2) By defining I_q and I_t to represent the contributions of moisture and temperature to precipitation, we found that the drought event in the Yangtze River Basin was driven by both reduced moisture supplies in the lower troposphere and higher-than-normal temperatures, with temperature playing a dominant role. Full article