Search Results (148)

Background: Fragrance-free policies are increasingly adopted to improve indoor air quality and reduce fragrance exposure linked to adverse health outcomes and accessibility barriers. This scoping review mapped the evidence on fragrance-free policies across sectors. Methods: Following Arksey and O’Malley’s framework and PRISMA-ScR guidelines, we searched five peer-reviewed databases and grey literature sources. Documents describing formal scent-free or fragrance-free policies or guidance in workplaces, healthcare, educational, or public settings were included. Data were charted on policy characteristics, enforcement mechanisms, implementation supports, and governance features. Results: Sixty-three documents were included. Findings revealed substantial variability in terminology, scope, and enforcement. Many policies relied on voluntary compliance and awareness-based strategies, with limited integration of structural supports such as procurement controls, staff training, and evaluation frameworks. Enforcement mechanisms were predominantly reactive, responsibilities were inconsistently defined, and consequences for non-compliance were limited. Although many policies referenced multiple chemical sensitivity or fragrance sensitivity, accommodation pathways and accountability structures were frequently lacking. Four key themes indicate that many fragrance-free policies function as accommodation tools rather than integrated environmental health interventions. Conclusions: Strengthening definitional clarity, institutional accountability, and structural integration may enhance effectiveness and support more consistent, equitable, and evidence-informed approaches to reducing fragrance-related exposures in indoor environments. Full article

Concerns regarding poor air quality in communities experiencing disproportionately high levels of air pollution frequently motivate formation of community–academic partnerships. Low-cost air monitors can assess air pollution but require specific training. The RISE Communities program was created to support partnerships in air quality training and community-engaged research. The RISE Communities program in-person training took place in Cincinnati, OH, in summers 2023 and 2024. The training included hands-on workshops, lectures, and monthly webinars with continued expert guidance for one year following the in-person training. A mixed method evaluation included pre-, post-, and one-year follow-up surveys, webinar evaluation surveys, and focus groups at the conclusion of each cohort. Participants reported significantly increased confidence in describing the health impacts of air pollution and using low-cost air sensors. Subjective feedback commented on the need for more tailored and interactive webinars and data training. Participants agreed that the goals of the RISE Communities training program were met and skills were sustained. This mixed method evaluation study demonstrates that an immersive training program for academic and community partners resulted in significantly higher confidence levels related to community partnership, data analytics, data visualization, and achieving project planning outcomes. Full article

Provincial power systems must decarbonize while sustaining rapid demand growth and improving air quality; yet, few integrated assessments separate the contributions of renewable expansion and carbon capture, utilization, and storage (CCUS) for China’s less-developed regions. We apply the Low Emissions Analysis Platform (LEAP) to model Guangxi’s power system to 2060 under four scenarios—Reference (BAS), Renewable-driven (RES), CCUS-intensive (CCS), and an Integrated comprehensive-policy scenario (ICS). Under ICS, solar photovoltaic generation rises from 38 TWh in 2025 to 408 TWh in 2060 (close to half of all generations), non-fossil capacity grows by about 730%, and power-sector CO₂ falls by roughly 95% relative to BAS. A counterfactual decomposition shows that CCUS provides about 75% of the CO₂ reduction along the coal-retaining CCS pathway but only about 5% along the renewables-led ICS pathway and reduces neither SO₂ nor NO_x. The air-quality co-benefits—up to 82%, 78%, and 73% lower SO₂, NO_x, and PM_2.5 than BAS—arise mainly from renewable substitution, which also abates carbon more cheaply (about 120–190 versus 300 CNY t⁻¹ CO₂) while sharply raising flexibility needs. Once avoided fuel and carbon-market costs are included, the renewables-led pathways become net cost-saving on a full-system basis and yield a monetized air-quality health co-benefit roughly twice that of the CCUS-intensive route. The findings give policy-relevant guidance for sustainable low-carbon transitions in Guangxi and comparable emerging regions. Full article

Drying method is a key factor influencing the nutritional quality and flavor characteristics of Chenpi. In this study, peels of Citrus reticulata ‘Chachi’ (Xiaoqinggan) were subjected to natural air drying (NAD), hot-air drying (HAD), and vacuum drying (VD) to evaluate changes in physicochemical properties, free amino acids, and volatile compounds. VD exhibited superior retention of total flavonoids and soluble sugars, resulting in the best overall physicochemical quality. NAD preserved the highest total free amino acid content and amino acid diversity, whereas HAD was characterized by a predominance of bitter amino acids, contributing to a pronounced bitter taste. In contrast, VD maintained a more balanced amino acid composition with relatively high proportions of sweet amino acids and effective retention of aroma precursors. A total of 75 volatile compounds were identified by GC–MS, with olefins representing the dominant class. NAD exhibited the highest total volatile content, while VD retained the greatest diversity of volatile compounds and a more balanced aroma composition. Odor activity value (OAV) analysis revealed that key aroma-active compounds were effectively preserved in VD-treated samples, with linalool identified as the major contributor to citrus peel aroma. Overall, VD achieved the most favorable balance between nutritional quality, taste characteristics, and aroma preservation. These findings provide scientific guidance for optimizing drying technologies and improving the quality of Chenpi products. Full article

Vertical greenery is increasingly applied in modern cities for environmental improvement and landscape enhancement. Given the insufficient coverage of recent developments in research and practice by prior reviews, this paper conducts a systematic review based on literature from Web of Science and global patent databases following PRISMA guidelines, with CiteSpace used for bibliometric analysis. This study summarizes the theoretical achievements of vertical greenery in ecological environment, building energy efficiency and technical materials. It also analyzes practical innovations via patent mining—a new supplement compared with traditional reviews. The environmental impacts of both outdoor and indoor vertical greenery are elaborated on: outdoor systems improve urban microclimate, noise control and air quality; indoor systems enhance indoor comfort, air purification and people’s mental status. Current innovations are categorized into structure and equipment, intelligent management, and social–cultural values. The outcomes of this work offer practical guidance for the design, construction and maintenance of vertical greenery in real projects. This paper also identifies future research priorities for the long-term development of vertical greenery. Full article

Indoor air quality (IAQ) research remains divided across three separate streams: sensor-based monitoring, CFD simulation, and occupant-centered evaluation. This separation limits how readily technical measurements translate into actionable building guidance. To assess this divide, a systematic review and critical synthesis of 192 peer-reviewed studies was conducted, with each study categorized by which domain or domains it addressed. This categorization shows that fewer than 8% integrate all three—a figure derived directly from the classification rather than asserted independently of it. Accuracy itself proves uneven: under specific operational and environmental conditions reported in the literature, low-cost particulate sensors have been found to underestimate PM_2.5 by as much as 50%, and wall-mounted placements often misrepresent breathing-zone exposure. These limitations carry into simulation, where the k–ω SST model persists as the practical standard despite Large Eddy Simulation’s superior accuracy at two orders of magnitude greater computational cost. Building these findings, the review proposes a Tripartite IAQ Assessment Framework (TIAF) synchronizing sensor protocols, simulation outputs, and occupant surveys, addressing a regulatory tendency to privilege instrument metrics over lived experience. Implications extend to IAQ-responsive digital twins and post-pandemic governance, resolving the “stuffy-but-clean” paradox through validated, cross-domain integration. Full article

Dried ginger slices are widely used for both culinary and medicinal applications. It is worth noting that a systematic model describing the dynamics of flavor profile changes during the drying of ginger has not been established. This study aimed to investigate the effects of hot-air drying on the volatile composition and odor-active compounds of ginger. Sensory evaluation revealed a shift in the aroma profile from pungent, floral, and herbal notes in fresh ginger toward predominantly roasted and woody notes in dried samples. In this study, molecular sensory science was employed. The results showed that 92 volatile compounds were tentatively identified, with terpenes showing a pronounced increase in relative proportion after drying. Nineteen compounds with flavor dilution (FD) ≥ 8 and odor activity value (OAV) ≥ 1 were confirmed as key aroma contributors, with zingiberene, linalool, geraniol, citronellal, 1,8-cineole, myrcene, and (E)-nerolidol exhibiting the highest FD values. These findings provide a quantitative basis for understanding aroma modulation during ginger drying and may offer practical guidance for the quality control of dried ginger products. Full article

Smart city environmental monitoring depends on sparse air quality sensor networks and analytics services that remain reliable under node additions, outages, and missing streams. We propose an operational deep learning framework for citywide cross-location forecasting from a limited set of sensors, delivering low-latency, real-time concentration heatmaps at unsensed locations by combining temporal prediction with spatial regression. We formulate single-stage spatiotemporal forecasting and benchmark nine recurrent, convolutional, and multilayer architectures against classical baselines. The framework forecasts ${\mathrm{O}}_3$, ${\mathrm{NO}}_2$, ${\mathrm{PM}}_{2.5}$, and ${\mathrm{PM}}_{10}$ over horizons from 1 h to 10 days. Using open monitoring data from Madrid (Spain) and Cali (Colombia), we evaluate generalization by holding out stations, reflecting deployment to new sensor nodes and sparse coverage regimes. We further compare missing data handling strategies and show that common imputation can substantially degrade accuracy, increasing RMSE by up to 74% in some settings. Beyond prediction, the framework provides a basis for guiding sensor network densification; confidence estimates can highlight locations where additional sensors may be most beneficial. These results provide actionable guidance for deploying AI-enabled sensing services with robust performance under realistic sensor reliability constraints while supporting real-time citywide mapping. Full article

Against the backdrop of the dual-carbon strategy, China’s civil aviation industry, as a high-energy-consumption and high-carbon-emission sector, faces mounting pressure for low-carbon transformation. As the dominant airlines within China’s civil aviation system, Air China, China Eastern Airlines, and China Southern Airlines play a pivotal role in guiding the industry’s high-quality development. Employing the Global Malmquist–Luenberger (GML) index model, this study constructs a global production frontier incorporating undesirable outputs to systematically measure the dynamic evolution of total factor productivity (TFP) for the three major airlines in the period 2005–2023, and further applies a combined static-dynamic regression framework to identify the firm-level heterogeneous mechanisms through which explanatory factors operate. The results reveal significant heterogeneity in TFP trajectories: China Southern Airlines exhibits the most stable efficiency with the lowest volatility; China Eastern Airlines displays the greatest volatility but the strongest post-crisis rebound; and Air China occupies an intermediate position in both efficiency level and volatility. This differentiation stems from fundamental differences in market positioning, strategic orientation, and resource allocation patterns. Market competitiveness exerts a significantly positive effect on TFP for both Air China and China Eastern Airlines. Technological innovation investment generates short-run negative effects across all three airlines, albeit with divergent magnitudes. Human capital accumulation acts as a positive driver for Air China but produces a negative effect for China Southern Airlines, attributable to a structural mismatch between aggressive talent upgrading and organizational absorptive capacity. Shifting the unit of analysis to the firm level, this study identifies three heterogeneous strategic archetypes—market-led, scale-expansion, and regional-deepening—and constructs a differentiated “one firm, one policy” framework to provide targeted policy guidance for improving airline efficiency and facilitating low-carbon transition under carbon constraints. Full article

The automotive panoramic roof exhibits a large-size and thin-wall geometry, with a length-to-thickness ratio approaching the thousand level. This geometric feature makes its forming quality highly sensitive to forming conditions. During the glass molding process, variations in temperature evolution, loading, and cooling parameters may lead to residual stress accumulation and springback deformation, thereby affecting dimensional accuracy and final forming quality. In this study, a full-process finite element model was established and combined with an L16(4^5) orthogonal design to investigate the effects of five key process parameters—heating temperature, holding time, quenching air velocity, quenching air pressure, and quenching time—on the mean residual stress and mean springback displacement in the glass molding process (GMP). The results showed that, within the given parameter ranges, heating temperature, holding time, and quenching time had relatively pronounced effects on the mean residual stress; the mean residual stress was relatively low when the heating temperature was 680 °C, the holding time was 3 s, and the quenching time was 12 s. Heating temperature, quenching air velocity, and quenching time had relatively pronounced effects on the mean springback displacement; the mean springback displacement was relatively low when the heating temperature was 677.5 °C, the quenching air velocity was 13 m/s, and the quenching time was 10 s. Based on the orthogonal analysis, regression models for the mean residual stress and mean springback displacement were further developed, and parameter combinations were screened using the NSGA-III method. Experimental validation showed that the relative error of the mean residual stress was controlled within 15%, indicating that the established model could, to some extent, capture the relationship between process parameters and forming quality indicators, thereby providing guidance for precision forming and process optimization of large-scale thin-walled automotive panoramic roofs. Full article

Reliable air pollution monitoring remains a major challenge in Sub-Saharan Africa (SSA), limiting the assessment of population exposure and the development of effective mitigation strategies. Recent advances in low-cost (LC) sensors offer promising opportunities, but their deployment in low-infrastructure settings still faces significant technical and logistical challenges. This study presents the experience gained from deploying LC sensor networks in Burkina Faso, Niger, and the Republic of Guinea, focusing on the practical challenges of installing and maintaining these systems under demanding conditions. In Burkina Faso, an LC station was co-located with a reference-grade instrument, enabling field calibration. In Niger, factory-calibrated LC sensors were deployed across urban, semi-urban, and rural settings, while in Guinea they were installed in a remote area. Several practical issues and challenges emerged, including unstable power supplies, limited internet connectivity, safety, and logistical constraints. Careful planning and involvement of local expertise proved essential for the long-term sustainability of LC sensors. Knowledge transfer to local partners supported ongoing maintenance and strengthened data ownership. Overall, this study demonstrated that the reliability of LC air quality networks in SSA depends not only on technology, but also on adaptive strategies, robust calibration, and strong local engagement, offering practical guidance for future scalable and sustainable implementations in resource-limited settings. Full article

A high quality factor, denoted as the Q-factor, is crucial for micromachined disk resonator gyroscopes, commonly referred to as DRGs, to suppress thermomechanical noise and improve bias stability. However, the coupled energy dissipation mechanisms under low-pressure conditions impose significant limitations on further Q-factor enhancement. This paper establishes a rigorous multiphysics damping analysis framework for DRGs and quantitatively investigates the contributions of air damping, thermoelastic damping, and anchor loss. A free-molecular squeeze-film damping model is derived based on kinetic gas theory and molecular energy transfer mechanisms, avoiding the continuous fluid assumption of the classical Reynolds equation, which fails in low-pressure regimes. Due to the highly symmetric ring structure and central anchor design, finite element method simulations reveal an extremely high anchor-loss-limited quality factor, Q_anchor, of approximately 1.85 × 10¹², indicating negligible anchor-induced dissipation. Under an operating pressure of 0.1 Pa, air damping is validated as the absolute dominant energy dissipation mechanism with a gas quality factor, Q_air, of approximately 1.105 × 10⁵, which is significantly lower than the thermoelastic damping quality factor, Q_TED, evaluated at 8.98 × 10⁵. To break the classical trade-off between squeeze-film damping suppression and capacitive drive efficiency, a decoupled gap optimization strategy is proposed. By maintaining the drive electrode gap, gap_e, at 7.2 µm while increasing only the parasitic ring-to-suspended-mass gap, gap_m, to 12 µm, the squeeze-film-damping-limited Q-factor is improved by approximately 25% to 1.381 × 10⁵ without degrading electromechanical coupling efficiency. In addition, the optimal anchor radius is determined to be approximately 160 µm. The proposed framework provides practical design guidance for high-Q DRGs and other MEMS resonant inertial sensors. Full article

Exhaust piping in diesel engines is subject to severe thermal stress arising from high-temperature, high-pressure gas flows, and spray cooling with atomizing nozzles has become a widely adopted method to safeguard structural reliability. However, at present, the understanding of the spray fragmentation mechanism of two-phase flow under low inlet pressure is still not comprehensive. This study establishes a three-dimensional model of a gas–liquid impinging-jet nozzle and applies a coupled Volume-of-Fluid to Discrete-Phase-Model (VOF–DPM) approach to resolve the liquid breakup process in detail. High-speed imaging experiments were carried out to validate the numerical results. Orthogonal tests were conducted at five pressure levels for both gas and water—0.28, 0.24, 0.20, 0.16, and 0.12 MPa—producing 25 data pairs of spray cone angle and Sauter Mean Diameter (SMD). Within the 0–0.3 MPa air inlet pressure range explored here, raising the pressure consistently reduced the SMD and widened the cone angle, although both trends weakened as the pressure increased. Water inlet pressure exhibited a nonlinear influence, with local extrema appearing in the higher-pressure region. The overall SMD reached a minimum of 34.12 μm and a maximum of 149.04 μm. Using these 25 data points, a genetic algorithm was employed to optimize the pressure ratio under the constraint of total hydraulic power, yielding optimization strategies for different power budgets. An additional outcome of the simulation was the identification of a structural weakness: by reshaping the original flat impingement surface into a full conical surface, atomization quality improved by 29.36% under identical boundary conditions. These findings clarify the atomization mechanism of gas–liquid impinging jets under low inlet pressure and offer practical guidance for nozzle optimization. Full article

Polymers are increasingly used as structural materials in medical devices due to their lightweight, chemical resistance, and electrical insulation properties. High-density polyethylene (HDPE) is widely applied; however, the fabrication of large or thick components often requires extrusion welding. Since joint performance directly affects structural reliability, controlling welding quality is essential. In this study, the effects of preheating conditions on the mechanical performance of HDPE extrusion-welded joints were systematically investigated. Preheating temperature and hot-air movement speed were selected as key variables, and their influence on tensile, flexural, and elongation properties was evaluated experimentally. The results provide insight into the role of preheating in weld quality and offer guidance for process optimization in medical device applications. Full article

Energy efficiency and positive users’ experiences are key to sustainable healthcare. However, limited research has been conducted to examine the relationship between them. A framework-based systematic literature review using the PRISMA methodology was conducted to identify key links in existing literature between the two dimensions in hospitals. A total of 138 publications including articles, reviews, and conference papers were retrieved from the Scopus database on 23 March 2026. Selected studies were critically appraised for methodological quality and potential bias prior to the analysis and narrative synthesis using the TCCM framework. This review advances the field by reconceptualizing indoor environmental quality as the mediating link between energy efficiency and user experience in hospitals, offering an integrated multi-dimensional framework linking both dimensions. Key linking constructs were identified as spatial, environmental, psychological, behavioral, and organizational. Future pathways must integrate qualitative users’ experiences with quantitative energy efficiency data to enrich the understanding of hospital sustainability. Considering stakeholder priorities, conducting comprehensive evaluations of indoor environmental quality, and adopting holistic and interdisciplinary methodologies and simulations in hospital designs and retrofits are essential to address gaps in healthcare sustainability. Architectural measures must prioritize natural light, acoustic comfort, air quality, and access to views. The findings provide practical guidance for hospital designers, managers, and policymakers on strategies that promote healthcare sustainability through energy efficiency and positive user experiences. Full article