Search Results (171)

Non-exhaust emissions (NEEs), particularly brake wear particles (BWPs), have become a dominant source of traffic-related particulate matter (PM), accounting for approximately 77% of PM10 and 60% of PM2.5 emissions. Accurate quantification of these emissions is essential under increasingly stringent regulations such as Euro 7. However, measurement reliability is strongly influenced by particle transport and sampling losses. This review provides a state-of-the-art analysis of laboratory-scale methodologies for investigating BWP emissions, focusing on pin-on-disc (PoD) tribometers and inertia dynamometer systems. Particular attention is given to chamber design, airflow management, sampling configurations, and the mechanisms governing particle transport efficiency. The literature indicates that PoD systems are often affected by complex and non-uniform flow fields, leading to incomplete particle capture and reduced representativeness, whereas inertia dynamometers, especially when coupled with constant volume sampling (CVS), provide more controlled and reproducible conditions. Key loss mechanisms, including inertial deposition, diffusion, gravitational settling, and non-isokinetic sampling effects, are major contributors to uncertainty. The reviewed studies highlight that aerodynamic limitations in PoD systems, particularly box-shaped chambers, promote flow recirculation and particle losses. Advanced optimization approaches that combine artificial neural networks (ANNs) with computational fluid dynamics (CFD) simulations show strong potential to improve system design and measurement reliability. Full article

The Kubuqi Desert serves as a critical zone for both renewable energy development and ecological management in China. Large-scale photovoltaic (PV) deployment has fundamentally altered the regional underlying surface, impacting near-surface wind–sand dynamics. To elucidate these disturbance mechanisms, we selected three representative surfaces—a PV area, a resource base, and Qixing Lake—and conducted field observations from September to December 2023 using meteorological towers and wind erosion sensors. Results indicate that all surfaces significantly attenuated near-surface wind speeds by over 30% through modified flow field structures. A strong linear positive correlation existed between wind speed and friction velocity (R² ≈ 0.99). Notably, for the same friction velocity, the actual wind speed required to initiate sand movement was lowest in the PV zone (high k) and highest at Qixing Lake (low k), signifying enhanced surface stability due to PV infrastructure and moisture. Threshold analysis revealed distinct initiation speeds: >6.0 m·s⁻¹ in peripheral quicksand, >4.3 m·s⁻¹ in inter-panel zones, and >4.6 m·s⁻¹ beneath panels. The tilted PV panels accelerate airflow downward, generating cyclonic vortices that intensify sand particle impacts under and between panels. This study reveals the tri-dimensional mechanism of wind regulation–sand suppression–stability enhancement, providing theoretical support for mitigating wind–sand disasters while advancing green energy in desert regions. Full article

Indoor air quality (IAQ) plays a critical role in the health and cognitive performance of students, making its assessment essential for sustainable building design in educational environments. This study evaluates whether the ventilation flow rates prescribed by the Spanish Regulation for Thermal Installations in Buildings (RTIB), together with the occupancy densities defined by the Technical Building Code (TBC), are sufficient to maintain CO₂ concentrations within regulatory limits in classrooms and library reading rooms. A validated three-dimensional CFD model was developed to simulate airflow patterns and CO₂ distribution under typical operating conditions. The model was experimentally validated using measurements from a dedicated test room in the KUBIK experimental building of Tecnalia, demonstrating high predictive accuracy with average relative errors between 14% and 20%. Results indicate that, under current RTIB and TBC design criteria, (modelled for a 36 m² classroom with 24 occupants and a fresh air supply of 1080 m³/h), CO₂ levels frequently exceed the 910 ppm regulatory thresholds established by the RTIB’s direct method, highlighting potential shortcomings in existing standards for educational spaces. Additionally, two mechanical ventilation configurations were analyzed, revealing that floor-supply ventilation promotes more homogeneous pollutant dispersion and lower concentration peaks compared with ceiling-mounted systems. These findings underline the need to reconsider ventilation design strategies in educational buildings and demonstrate the value of CFD modelling as a tool to support evidence-based decisions toward healthier and more sustainable indoor environments. Full article

Background: Chronic Obstructive Pulmonary Disease (COPD) is a progressive, incurable condition marked by irreversible airflow limitation and systemic inflammation. Cardiovascular comorbidities, particularly pulmonary hypertension (PH), exacerbate disease severity. While cigarette smoke is a well-known trigger, non-smoking-related inflammatory pathways remain underexplored. This study investigates vascular remodeling in a murine model of inflammation induced by chronic exposure to house dust mite Farinae (HDM). Methods: Female C57BL/6 mice were sensitized with HDM in Freund’s Complete Adjuvant and challenged intranasally with HDM for six weeks. Lung inflammation, mucus hypersecretion, and vascular remodeling were evaluated via BAL, histology, immunofluorescence, echocardiography, gene expression, proteomics, and FlexiVent pulmonary function tests (FlexiVent system). Results: HDM exposure induced a mixed inflammatory response, with elevated neutrophils, monocytes, and lymphocytes in BALF. Mucus hyperproduction (increase in MUC5AC/MUC5B) and impaired lung function (reduced FEV0.1/FVC) were observed. Vascular remodeling was evidenced by increased wall thickness, α-SMA expression, and collagen deposition. Proteomic analysis revealed dysregulation of endothelial markers and protease/antiprotease imbalance. HIF1-α was significantly upregulated in lung tissue and correlated with vascular and epithelial remodeling. Conclusions: Chronic HDM exposure in mice recapitulates key features observed in subsets of COPD and PH, including inflammation-driven airway and vascular remodeling. HIF1-α emerges as a central regulator, linking hypoxia to structural changes. This model offers insights into the effect of non-smoking-related inflammatory pathways on bronchial and vascular remodeling that are potentially relevant for subgroups of COPD patients and highlights HIF1-α as a potential therapeutic target. Full article

Asthma is a chronic airway disease characterized by inflammation, bronchial hyperresponsiveness, and airflow limitation, highlighting the need for novel bronchodilator agents. Cryptotanshinone (CT), a bioactive diterpenoid derived from Salvia miltiorrhiza, exhibits anti-inflammatory and vasodilatory properties; however, its direct effects on airway smooth muscle remain poorly characterized. This study investigated the bronchodilatory activity of CT and its pharmacological mechanisms. Molecular docking was performed to evaluate potential interactions with M₃ muscarinic receptors and L-type calcium channels. Functional experiments were conducted using isolated guinea pig tracheal smooth muscle preparations. The relaxant effects of CT (10⁻⁷–3 × 10⁻⁴ M) were evaluated against carbachol (1 µM)- and high-K⁺ (80 mM)-induced contractions. Docking predicted favorable binding of CT to the M₃ receptor and L-type Ca²⁺ channel, with binding energies of −9.854 and −9.951 kcal/mol, respectively. In vitro, CT produced concentration-dependent relaxation of CCh-induced contractions, reaching a maximal effect of 41.9 ± 2.58% at 3 × 10⁻⁴ M (pEC₅₀ = 4.60). CT produced minimal relaxation in high-K⁺-induced contractions, suggesting receptor-mediated rather than non-selective smooth muscle inhibition. CT also produced a parallel rightward shift of the CCh concentration–response curve at 10⁻⁵ M, whereas a higher concentration (10⁻⁴ M) altered the maximal contractile response, suggesting concentration-dependent pharmacological effects. Pharmacological inhibition studies indicated the involvement of muscarinic receptor-mediated mechanisms, with additional contributions from calcium channel-related mechanisms and partial involvement of the NO/cGMP pathway, while β₂-adrenergic signaling and potassium channels were not significantly involved. These findings suggest that CT exerts bronchodilatory effects through the involvement of multiple pharmacological pathways relevant to airway smooth muscle regulation and provide preliminary mechanistic evidence supporting further investigation. Full article

Methane (CH₄) is a highly potent greenhouse gas whose accurate detection and quantification are essential for climate mitigation and compliance with emerging environmental regulations. Conventional monitoring approaches, including fixed monitoring stations and satellite-based observations, often exhibit limitations in terms of spatial resolution, operational flexibility, and accessibility for localized measurements. This paper presents CH4SCOUT, a modular unmanned aerial vehicle (UAV)-based platform designed for methane detection, environmental monitoring, and georeferenced data acquisition. The proposed system integrates a methane sensing module, environmental sensors, controlled airflow sampling, onboard data acquisition, and wireless communication capabilities within a UAV-compatible architecture. A three-stage signal-conditioning pipeline based on Median filtering, Hampel outlier suppression, and Exponential Moving Average (EMA) smoothing is implemented to improve measurement stability under dynamic flight conditions. Initial real-world validation flights demonstrate stable methane concentration measurements under realistic environmental conditions while maintaining reliable data transmission and telemetry synchronization. Results indicate that low-cost UAV-assisted sensing architectures can provide operationally useful methane measurements when supported by appropriate calibration and deterministic signal conditioning. Future work will focus on advanced plume localization algorithms, autonomous navigation strategies, and enhanced methane emission quantification capabilities. Full article

In contiguous seam mining, the sudden large-scale collapse of a hard roof in an overlying goaf generates violent impact airflow, driving hazardous gases into the underlying working face and seriously threatening production safety. However, quantitative analysis of airflow responses under such transient impacts is rare for conventional exhaust ventilation systems, and proactive control strategies remain lacking. This study hypothesized that replacing exhaust ventilation with a forced ventilation system builds a sufficient counter-pressure gradient across the working face to block the downward migration of hazardous gases. Taking the Longhua Coal Mine as the engineering background, this study combines a theoretical velocity model of roof-collapse-induced impact airflow with numerical simulations and subsequently implements a forced ventilation system on site. Results show that under exhaust ventilation, roof collapse greatly intensifies air leakage in the goaf, causing the CO concentration at the return corner to spike to 5000 ppm within only 0.2 s. In contrast, the field-deployed forced ventilation system effectively suppresses this impact: by keeping the pressure difference across the air regulator within 338–417 Pa, the CO concentration drops from 36 ppm to below 15 ppm. Complemented by a real-time monitoring system for goaf pressure surges and hazardous gases, this strategy successfully shifts disaster control from passive ventilation to active aerodynamic suppression. This study provides a robust theoretical foundation and practical engineering reference for disaster prevention in contiguous seam mining. Full article

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation, chronic airway inflammation, and immune dysregulation, and currently available therapies remain insufficient to effectively halt disease progression. In this study, we used an integrative, hypothesis-generating strategy to investigate the potential mechanisms of baicalein against COPD by combining multi-dataset transcriptomic analysis, single-cell transcriptomics, machine learning-based feature selection, Mendelian randomization (MR), molecular simulation, virtual knockout analysis, and in vitro validation. Putative targets of baicalein were predicted using CTD, SEA, and SwissTargetPrediction, and were intersected with COPD-related genes collected from GeneCards and OMIM. Four GEO datasets (GSE20257, GSE42057, GSE76925, and GSE130928) were integrated after batch-effect correction, yielding a combined cohort of 260 control samples and 250 COPD samples. Candidate genes were prioritized by intersecting the results of LASSO regression, random forest, and support vector machine. Immune-cell infiltration was estimated using CIBERSORT, and single-cell transcriptomic data were used to define the cellular localization of prioritized genes. Formal protein-level MR analysis was conducted for CD163 using deCODE plasma protein pQTL/GWAS summary statistics as the exposure dataset and the IEU OpenGWAS COPD dataset (ebi-a-GCST90018807) as the outcome dataset. Molecular docking, molecular dynamics simulation, and virtual knockout analysis were further used to provide structural and network-level supportive evidence. Finally, LPS-stimulated BEAS-2B cells were used as an epithelial inflammatory model to evaluate the effects of baicalein by CCK-8 assay, wound-healing assay, ELISA, and RT-qPCR. Five core genes were prioritized, namely ABCC1, CD163, CYP1B1, IKBKB, and PIK3CA. Immune infiltration and single-cell analyses suggested that macrophage-associated immune regulation may represent an important mechanistic direction. MR analysis provided supportive genetic evidence for prioritizing CD163 in COPD. Molecular simulation offered preliminary structural support for several target-compound interactions. In LPS-stimulated BEAS-2B cells, baicalein reduced inflammatory cytokine release and modulated the expression of IKBKB, PIK3CA, IL1B, IL6, and IL10, thereby providing epithelial-level support for the predicted network. Taken together, these findings suggest that baicalein may exert anti-inflammatory effects in COPD through a multi-target, immune-associated mechanism, with macrophage-related regulation and CD163 emerging as noteworthy candidate directions for further investigation. This study provides an integrative framework for target prioritization and mechanistic exploration, while the predicted macrophage-centered mechanisms still require dedicated validation in immune-cell and in vivo models. Full article

Background: Asthma is a heterogeneous chronic inflammatory airway disease characterized by recurrent exacerbations and variable airflow limitation. Epithelial-derived alarmins, particularly interleukin-33 (IL-33) and its receptor ST2, play key roles in type 2 inflammation. The soluble form of ST2 (sST2) acts as a decoy receptor regulating IL-33 signaling. Vitamin D is an important immunomodulator influencing airway inflammation, but its interaction with the IL-33/ST2 pathway remains unclear. Objective: To evaluate the association between serum IL-33, sST2, and 25-hydroxyvitamin D [25(OH)D] levels with asthma severity and exacerbation status, and to assess their potential as clinical biomarkers. Methods: This study enrolled 52 adult asthma patients (27 experiencing exacerbation and 25 in remission) and 28 healthy controls. Serum levels of IL-33 and sST2 were measured using enzyme-linked immunosorbent assays, while 25(OH)D concentrations were determined via electrochemiluminescence immunoassay. Results: Serum sST2 levels were significantly higher and 25(OH)D levels significantly lower in asthma patients compared with controls (p < 0.000 for both). Serum IL-33 levels did not differ significantly between groups (p > 0.05). During exacerbation, sST2 levels were markedly elevated compared with remission (p < 0.001), whereas vitamin D levels were significantly reduced (p = 0.038). A significant negative correlation was identified between sST2 and 25(OH)D (r = −0.333, p = 0.016). Conclusions: The presence of asthma and the severity of exacerbations are associated with elevated circulating sST2 levels and reduced vitamin D levels. These findings suggest a regulatory interaction between vitamin D and the IL-33/ST2 axis in airway inflammation and indicate that targeting this axis could be a potential therapeutic strategy. Full article

Depression is a common mental disorder that substantially impairs patients’ daily life and work. To identify natural and safe preventive options, we investigated the preventive effect and underlying mechanism of the Ganoderma lucidum and Rosa roxburghii Tratt formula (GLRRTF) on depression. A total of 72 chemical components in GLRRTF were identified by UHPLC-ESI-Q-Exactive Plus Orbitrap-MS Analysis. GLRRTF (containing 400 mg/kg of G. lucidum extract and 800 mg/kg of R. roxburghii extract per day), administered as a 1-week preventive intervention followed by 4 weeks of co-administration with chronic unpredictable mild stress, prevented the development of depression-like behaviors in male C57BL/6J mice and reduced neuronal damage in the hippocampus. Airflow-assisted desorption electrospray ionization mass spectrometry imaging and enzyme-linked immunosorbent assays showed that GLRRTF corrected abnormalities in neurotransmitter levels. The 16S rRNA sequencing indicated that GLRRTF restored dysbiosis of the gut microbiota. Metabolomic profiling revealed that GLRRTF increased the level of tryptophan and promoted tryptophan metabolism towards the 5-HT and indole pathways in feces and the brain. Western blot demonstrated that GLRRTF increased 5-HT production from tryptophan in the brain by regulating tryptophan hydroxylase 2 and DOPA decarboxylase. GLRRTF activated the PI3K/AKT pathway by regulating brain-derived neurotrophic factor and its receptor tropomyosin receptor kinase B. This research provides a comprehensive mechanistic understanding of GLRRTF’s preventive effect against depression, highlighting its potential as a novel, safe, and preventive functional food formulation. Full article

Urban canyons, integral components of the built environment, significantly influence microclimatic conditions and thermal comfort. This review investigates their combined effects with green infrastructure on thermal comfort, offering a comprehensive framework for supporting urban design and greening strategies. The review is based on a structured literature analysis of peer-reviewed studies retrieved from major scientific databases (Scopus and Web of Science), following defined selection and screening criteria. Urban canyon orientation determines solar exposure and its interaction with prevailing wind patterns, affecting ventilation and heat dissipation. The urban canyon aspect ratio influences shading and airflow regulation, while their sky view factor moderates radiative cooling and daylight availability. Urban greening—encompassing street trees, green roofs, and vertical green walls—complements urban geometry by reducing air temperatures, enhancing evapotranspiration, and modifying local wind dynamics. Tree shading can reduce the physiological equivalent temperature in urban canyons, mitigating extreme heat stress. Key vegetative parameters, such as leaf area index and canopy density, are critical for quantifying cooling contributions. Key findings underscore the role of higher aspect ratios in enhancing shading and ventilation while they emphasize the critical influence of street orientation and sky view factor on microclimatic regulation. Vegetation emerges as a vital component, with tree shading contributing substantially to cooling effects and reducing physiological equivalent temperature. The beneficial synergistic interaction between urban geometry and vegetation optimizes thermal comfort. Tailored strategies based on urban canyon typologies balance urban development with environmental sustainability. The proposed framework provides actionable strategies for designing resilient and thermally optimized urban spaces, promoting climate-adaptive urban planning by addressing the dual challenges of the urban heat island and thermal discomfort in cities. Full article

Ground source heat pump (GSHP) systems, while energy-efficient, often face persistent soil thermal imbalance in heating-dominated severe cold regions, which undermines their long-term performance and sustainability. This study proposes a TRNSYS-GenOpt framework for the life-cycle cost optimization of hybrid GSHP systems integrating electric boilers and geothermal regulation towers. A transient model for a 5650 m² fire station in Changchun was developed, employing the Hooke–Jeeves algorithm to co-optimize boiler capacity, borehole depth, and geothermal regulation tower airflow under constraints on heating supply temperature and soil thermal balance. Time-of-use electricity pricing was incorporated for realistic operational economics. The optimized configuration (148 m, 864.8 kW, 290,400 m³/h) achieved a minimum 20-year life-cycle cost of CNY 1.13 million. Sensitivity analysis revealed “rigid design, flexible cost” characteristics: optimal parameters remained invariant across discount rate variations (3.5–7.5%) and equipment costs (±20%), while life-cycle cost showed the highest sensitivity to electricity pricing and discount rates. The long-term simulation confirmed compliance with all physical constraints. This methodology demonstrates that thermodynamic constraints supersede economic trade-offs in severe cold climates, providing engineers with a reliable tool for sustainable hybrid geothermal system design. Full article

Mine ventilation network (MVN) regulation faces severe challenges: strong variable coupling, high search dimensionality, and the inherent conflict between energy conservation and safety constraints. To address these issues, we propose a novel airflow optimization framework integrating a Minimum Influence Spanning Tree (MIST), sensitivity attenuation boundaries, and an Improved Dung Beetle Optimizer (IDBO). Initially, high-influence co-tree chords are strategically extracted via MIST to compress the mathematical optimization dimensionality. Subsequently, effective ventilation resistance search intervals are bounded using sensitivity attenuation, preventing the algorithm from performing invalid searches in high-resistance regions. Furthermore, the standard DBO is enhanced via Fuchs chaotic initialization, Golden Sine and Lens Imaging collaborative learning, and differential mutation to minimize system power consumption. A 46-branch MVN case study validates the approach, identifying an 8-dimensional control combination as the absolute minimum requirement for full compliance. Compared to state-of-the-art baselines (DBO, SSA, WOA, DE), IDBO achieved the lowest power consumption. Post-optimization, the airflow constraint satisfaction rate improved from 89.13% to 100%, and total system power decreased by 11.87% (from 185.03 kW to 163.08 kW). Ultimately, this method robustly achieves Ventilation on Demand (VoD), providing a reliable computational tool for intelligent underground mining. Full article

Large-diameter axial ventilation fans are widely used in poultry houses to regulate ai flow, temperature, and air quality. However, conventional induction motors driving these fans typically operate at fixed speed and suffer efficiency degradation under low-speed, high-torque conditions due to slip-induced rotor copper losses. This study presents an experimental investigation of a manufacturing constrained conversion of a commercial induction motor platform into a direct-drive surface permanent magnet synchronous motor (PMSM). Instead of developing a completely new motor design, the proposed approach reuses the existing stator lamination, housing structure, and winding production process while redesigning the rotor electromagnetic structure to incorporate surface-mounted permanent magnets. Experimental testing was conducted using a dynamo meter-based measurement system to evaluate the performance of both the commercial induction motor and the converted PMSM prototype. The results show that the commercial induction motor exhibits significant efficiency degradation at high torque due to increased slip, whereas the PMSM eliminates slip-dependent rotor copper losses and maintains efficiencies above 88% within the typical ventilation operating range of 650–750 rpm. This study further relates airflow demand to rotational speed using fan affinity laws, highlighting the cubic relationship between speed and input power and demonstrating the energy-saving potential of variable-speed PMSM drives. The proposed conversion framework therefore provides a practical pathway for improving the energy efficiency of agricultural ventilation systems while maintaining compatibility with existing motor manufacturing infrastructure. Full article

Thermal management is critical for maintaining the safety and performance of lithium-ion batteries. Phase change materials (PCMs) have been widely studied as passive cooling media due to their high latent heat capacity, but major technical challenges remain due to their relatively low thermal conductivity and nanoparticle sedimentation in composite systems. In this work, a composite phase change material (PCM) consisting of paraffin wax, a microencapsulated phase change material (MicroPCM 28D), and nano carbon black is developed to enhance thermal stability and suppress particle sedimentation through increased viscosity of the PCM matrix. Five capsule geometries fabricated by fused filament fabrication (FFF) 3D printing are experimentally investigated under airflow velocities ranging from 0 to 10 m s⁻¹. Wind tunnel experiments with infrared thermography are used to evaluate the thermal response of the PCM capsules. The results show that airflow velocity and capsule geometry strongly influence heat dissipation behavior. Compared with conventional wax composites, the MicroPCM 28D composite capsules reduce peak temperature by approximately 2–4 °C under airflow velocities of 0–10 m/s. These findings provide insights into geometry-regulated convection and stable composite PCM design for lithium-ion battery thermal management systems. Full article