Search Results (678)

Background/Objectives: Mechanical power (MP) quantifies the energy delivered to the respiratory system during ventilation and serves as a promising marker for ventilator-induced lung injury (VILI). According to its original definition by Gattinoni, MP reflects the energy transferred from the ventilator to the respiratory system under conditions of deep sedation, passive breathing, neuromuscular blockade, and volume-controlled ventilation. Its role in coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome (ARDS) remains under investigation. This systematic review aimed to synthesize the available evidence on the association between MP and VILI, complications related to mechanical ventilation (MV), and mortality in adult patients with COVID-19 undergoing invasive mechanical ventilation (IMV). Methods: A systematic review was conducted using PubMed-MEDLINE (Medical Literature Analysis and Retrieval System Online) for studies published in recent years, focusing on adult COVID-19 patients undergoing IMV. Inclusion criteria centered on studies reporting MP and its association with VILI, complications, or mortality. Ten studies met eligibility criteria after screening 356 retrieved articles. Results: Most included studies were retrospective and observational, encompassing critically ill COVID-19 patients. Elevated MP was correlated with more severe outcomes, including increased 28-day mortality, prolonged MV, and weaning failure. Franck et al. demonstrated strong correlations between MP and driving pressure, elastance, and positive end-expiratory pressure, emphasizing the importance of calculation methods. González-Castro et al. identified a threshold of 17 J/min, above which mortality risk increased. Stalla et al. highlighted that dynamic MP reductions during prone positioning were associated with survival. Registry-based analyses confirmed that both magnitude and cumulative exposure above 18 J/min increased intensive care unit mortality. Novel indices combining MP with oxygenation parameters improved prognostic accuracy. While absolute MP at initiation provided limited predictive value, temporal trends and individual components were strongly linked to VILI. Conclusions: Higher MP has been associated with adverse clinical outcomes in patients with COVID-19 receiving invasive mechanical ventilation, supporting its potential role as a prognostic indicator. Its dynamic assessment, thresholds, and integration with ventilatory strategies such as prone positioning enhance risk stratification and may guide individualized, lung-protective ventilation. Continuous monitoring and standardized calculation are recommended to optimize clinical decision-making. Full article

The global energy sector is undergoing rapid and, in many respects, irreversible transformation driven by the convergence of digital disruption, sustainability mandates, and shifting investor expectations. Technologies such as artificial intelligence (AI), blockchain, and digital twin systems are fundamentally reshaping energy operations and strategic decision-making, while ESG governance quality and renewable energy adoption have emerged as two of the most consequential determinants of corporate financial competitiveness and equity valuation. Despite growing practitioner and regulatory interest in these dynamics, limited empirical evidence exists on how ESG governance, renewable adoption, and digital disruption jointly influence financial performance and environmental outcomes across multiple sectors simultaneously. This study addresses that gap using panel data from 26 large-cap US-listed firms across five sectors over 2015–2022 (N = 208 firm-year observations for Revenue/Market Cap/ROA models; N = 91 for the CO₂ model). A multi-method econometric framework is employed, comprising Fixed Effects and Random Effects panel regression with Hausman specification testing, Difference in Differences quasi-experimental analysis, and sequential OLS path analysis with HC3 robust standard errors. Three of four hypotheses are supported. ESG governance quality generates a significant market capitalisation premium of approximately 10–14% per unit Bloomberg ESG Score improvement, after controlling for firm size and R&D intensity; no significant revenue channel effect is found once firm size is properly accounted for. Renewable energy adoption shows a marginal association with market capitalisation at the 10% significance level (FE β = 0.019, p = 0.086; RE β = 0.016, p = 0.077), suggesting capital markets may price clean energy adoption as a forward-looking signal. ESG governance quality drives within-firm CO₂ emission reduction substantially more powerfully than renewable energy quantity alone, with the Fixed Effects estimator identifying a governance-led eco-efficiency mechanism. Firm profitability functions as a cross-model financial capacity moderator, enabling simultaneous ESG investment and environmental improvement. The findings carry direct implications for corporate managers, institutional investors, and policymakers aligned with SDG 7, SDG 9, and SDG 13. Full article

The sustainable development of the ceramics industry is severely impeded by its intensive energy consumption and the concomitant deficits in cooling and freshwater resources. To address these bottlenecks, this study proposes an integrated ejector refrigeration (ER)–humidification–dehumidification (HDH) hybrid system, harnessing ceramic waste heat as the driving energy source to improve overall energy efficiency. A thermodynamic model was developed to analyze the heat transfer characteristics of the ER-HDH system. Comprehensive investigation focuses on the influences of key operating parameters on refrigeration performance, desalination output and overall system efficiency. The results demonstrate that the proposed ER–HDH hybrid system facilitates the efficient thermodynamic cascading of waste heat from both flue gas and internal thermodynamic processes, achieving a high energy utilization factor (EUF) of 0.64 and an exergy efficiency η_Ex of 15.7%. The freshwater yield significantly outperforms that of a standalone HDH system, with the gain output ratio (GOR) more than tripling. The system performance is optimized under elevated generator and evaporator temperatures (T_g and T_e), coupled with a reduced condenser temperature T_c. Across their respective tested ranges, the EUF increases by averages of 19.1%, 45.1% and 38.9%. Furthermore, raising the feed seawater temperature T_{sw_in} significantly elevates the moist air humidity ratio, which in turn drives substantial enhancements in GOR and EUF, by over 83.2% and 58.1%, respectively. T_e and T_{sw_in} should be prioritized to enhance refrigeration and freshwater productions, respectively, while T_c serves as the key determinant for maximizing η_Ex. This study introduces an open dual-cascade ER-HDH system for mid/low-grade flue gas utilization and elucidates the distinct thermodynamic mechanisms governing subsystem interactions, and it addresses a critical knowledge gap in prevalent closed-loop solar-driven ER-HDH systems. Full article

The transportation sector is a major contributor to global greenhouse gas emissions, driving the need for low-carbon energy solutions. Hydrogen is increasingly recognised as a promising option for decarbonising heavy-duty and long-distance transport; however, hydrogen storage systems contribute significant environmental burdens through material production, manufacturing and end-of-life challenges. This study presents a comparative life cycle assessment of a conventional Type IV composite pressure vessel and a novel additively manufactured, internally reinforced titanium alloy pressure vessel concept for heavy-duty vehicle applications. The two pressure vessel designs were compared within the same available packaging volume on a heavy-duty vehicle. A cradle-to-grave system boundary was applied, covering production, manufacturing, transport, use and end-of-life stages. The environmental assessment was limited to cumulative energy demand and CO₂ emissions, which were used as the metrics for comparing the two hydrogen storage systems. Across the entire life cycle, the Type IV pressure vessel exhibited approximately 16% lower energy demand and CO₂ emissions that the titanium alloy pressure vessel. The use phase dominated both energy demand and environmental impacts, contributing more than 75% of the total life cycle impacts for both pressure vessel designs due to the high energy demand for hydrogen production. For the manufacturing phase, when normalised per kilogram of pressure vessel, the Type IV vessel produced 21.9 kgCO₂eq/kg, compared with 80 kgCO₂eq/kg for the titanium alloy vessel. Material production dominated the cradle-to-gate impact of the titanium alloy pressure vessel, primarily because of the energy-intensive primary production of titanium. Although the use of recycled titanium was also assessed, it reduced the manufacturing stage impacts by only 9%, and the overall impacts remained higher than those of the composite alternative. Full article

Digital transformation is crucial to the sustainable development of industries in locked-in specialized peripheral regions. Taking Longyan in Fujian Province as a case study, this study draws on county-level panel data covering the period 2008–2022 and employs the entropy weight method, kernel density estimation, location quotient analysis, Necessary Condition Analysis (NCA), and panel-data qualitative comparative analysis (PD-QCA) to identify the constraints and multiple pathways through which digital transformation drives industrial upgrading in peripheral regions. The findings are threefold. First, industrial upgrading in Longyan has continued to advance, while disparities in industrial development across counties and districts have generally tended to converge. Second, industrial upgrading in Longyan has primarily involved the extension of existing industrial foundations into knowledge-intensive fields, including energy conservation and environmental protection, advanced equipment, and new materials. Third, digital infrastructure, digital transformation environment, core enterprises’ digital technology application, digital technology innovation, intra-regional innovation collaboration, and cross-regional innovation collaboration combine to form five pathways to industrial upgrading. The findings demonstrate that digital transformation can enable peripheral regions to achieve knowledge recombination, functional upgrading, and the reconstruction of development paths on the basis of their existing industrial foundations. Full article

The rapid development of electric vehicles has increased the need for a better understanding of the relationships between vehicle dynamics, energy consumption and control strategies. This study presents an experimental investigation of the acceleration and coasting characteristics of a 2024 Kia Niro EV. Road tests were combined with laboratory measurements of the vehicle mass properties, including the centre of gravity. Vehicle motion parameters were recorded using a GNSS/INS measurement system, while electric powertrain data were acquired from the vehicle CAN bus using proprietary software developed by the authors. The influence of driving mode, accelerator pedal position and regenerative braking intensity was analysed. The results showed that the selected driving mode significantly affects the acceleration characteristics only at intermediate accelerator pedal positions, whereas identical maximum performance is obtained with the accelerator pedal fully depressed. The energy required to accelerate the vehicle to 90 km/h remained nearly constant under most operating conditions, indicating high electric powertrain efficiency. During coasting, regenerative braking recovered up to 50% of the energy previously required for acceleration. The obtained results provide valuable experimental data for the validation of vehicle dynamics and energy consumption models and support the development of more efficient electric vehicle control strategies. Full article

This study quantifies whether vehicle electrification reduces greenhouse gas emissions on one of the world’s most fossil-intensive electricity grids. A transparent, ISO 14040/14044-conformant cradle-to-grave life cycle assessment compares a mid-size battery electric vehicle (BEV, 60 kWh) with a comparable gasoline car over 225,000 km, using a fully source-traceable process-sum inventory and life cycle (well-to-wheel) emission factors for both energy carriers. On the 2024 Saudi grid (692 g CO₂e/kWh, 99.8% fossil) the BEV emits 37.8 t CO₂e (168 g CO₂e/km) against the gasoline car’s 50.6 t (225 g CO₂e/km)—a 25% reduction, with the BEV’s 1.9 times higher production emissions repaid at 76,000 km, approximately three years of typical Saudi driving. The advantage rises to 44% on the world-average grid, 53% under Saudi Arabia’s 50% renewable-electricity target for 2030, and 66–80% on the EU and French grids; grid parity would require 991 g CO₂e/kWh, above any national grid. The result is robust to hot climate energy consumption (+15%, advantage 25%), Gulf-sourced materials (break-even shortens to 68,000 km), battery capacity (40–80 kWh), and 10,000-run Monte Carlo uncertainty propagation (BEV superior in 99.6% of draws). Electrification is therefore a sound climate strategy even in fossil-grid economies, and its benefit roughly doubles with the announced power-sector transition. Full article

Tourism is carbon-intensive, with transport and mobility driving much of its greenhouse-gas emissions, yet destination-level evidence on carbon hotspots and decarbonization from a supply-chain perspective remains scarce, especially in developing regions. This study examines low-carbon tourism supply chain management in seven purposively selected provinces of Northeastern Thailand (Isan) using a qualitative-dominant convergent mixed-methods design that integrates demand- and supply-side evidence. A visitor survey yielded 74 open-ended responses (60 complete questionnaires), alongside seven semi-structured key-informant interviews with tourism supply chain operators across the seven provinces. Quantitative data were analyzed with descriptive statistics, and qualitative data with thematic analysis using qualitative data analysis software, drawing on code-frequency and co-occurrence analysis; the two strands were triangulated in joint displays. Visitors reported moderate satisfaction (grand mean 3.91 on a five-point scale) but rated environmental management and safety lowest, engaging with sustainability through visible service cues rather than emissions. Key informants identified perceived carbon hotspots, carrying capacity, and seasonality as dominant concerns, attributing the destination’s footprint chiefly to transport dependence (informant-reported estimates ranging from approximately 80% to nearly 100% private-car arrivals, amid limited public transport) and accommodation energy; these hotspots reflect stakeholder perceptions rather than measured emissions, as no carbon accounting, environmentally extended input–output analysis, or life-cycle assessment was conducted. Integration revealed a demand–supply perception gap and five proposed, interdependent low-carbon pathways: coordinated mobility, accommodation energy efficiency, strengthened local procurement, carrying-capacity and waste management, and multi-stakeholder governance. The findings offer a developing-region, supply-chain-oriented basis for future tourism decarbonization research and practice. Full article

High-energy-consuming and high-emission industries have made enormous contributions to economic development, but their carbon emissions are also substantial. To achieve the “dual carbon” goals as early as possible, this study takes Hainan Province, China, as the study area and employs the LMDI method to decompose the factors influencing carbon emissions. The Tapio model is also used to analyze the decoupling relationship between the driving factors and carbon emissions. The results show the following: (1) Carbon emissions in Hainan Province from 2007 to 2022 exhibited an overall upward trend, with an average annual growth rate of 5.75%. Various oil products accounted for an average share of over 40.11%, but the share of electricity increased, while that of oil decreased. The sectors, ordered from the highest to lowest carbon emissions, are: industry > transportation > residential > agriculture, forestry, animal husbandry, and fishery. (2) The decomposition results indicate that economic output, energy structure, and population size have positive effects on carbon emissions, while energy intensity and industrial structure have negative effects. At the sectoral level, the energy structure factor has a negative effect only on the transportation sector, and positive effects on all other sectors. The energy intensity factor has negative effects on all sectors except “other sectors” and the residential sector, with a cumulative contribution of 2003.65 × 10⁴ tonnes of carbon emissions. The industrial structure factor has negative effects on carbon emissions across all sectors, with a cumulative contribution of 1568.23 × 10⁴ tonnes. The economic output factor promotes emissions in all sectors, with a cumulative increase of 5787.35 × 10⁴ tonnes, of which 2740.88 × 10⁴ tonnes are from the industrial sector. The population factor also promotes emissions across all sectors, with a cumulative contribution of 549.21 × 10⁴ tonnes. (3) The decoupling model analysis shows that from 2007 to 2008, the decoupling state was predominantly an unfavorable negative decoupling. From 2008 to 2010, it shifted to a favorable positive decoupling, but from 2010 to 2011 it returned to an unfavorable negative decoupling. From 2011 to 2022, the decoupling index declined from 1.43 to 0.13, indicating an overall favorable weak decoupling state. (4) The decoupling effects of individual influencing factors reveal that in the 2007–2008 period, the carbon emission decoupling index was mainly composed of the energy intensity effect and the economic output effect. In the 2012–2013 period, the energy structure effect did not change significantly and remained in a weak decoupling state, while the energy intensity effect declined markedly, changing the decoupling state from weak to strong decoupling. The industrial structure effect remained in a strong decoupling state. In 2017–2018, the economic output effect changed from an expansive coupling state to a weak decoupling state, while the other effects all showed relatively favorable positive decoupling states. In 2021–2022, all effects exhibited favorable positive decoupling states, among which the energy structure and energy intensity effects showed strong decoupling. Finally, this study provides a case study for the development of Hainan as a Free Trade Port, a tourism island, a petroleum- and aviation-fuel-intensive province, and a pilot ecological civilization zone. Full article

The rapid growth of computing-intensive and latency-sensitive applications, including augmented reality, virtual reality, and self-driving systems, has increased the demand for low-latency and energy-efficient processing solutions. Mobile edge computing (MEC) has evolved as a transformative paradigm by relocating computation to the network edge, closer to end users. Unmanned aerial vehicles (UAVs) further strengthen MEC by offering flexible deployment, mobility, and reliable line-of-sight communication, making them suitable for temporary high-demand scenarios. Moreover, such latency-sensitive applications often generate numerous repetitive tasks and, thus, storing the results of these tasks can reduce both communication overhead and computational workload. However, jointly addressing the caching of task-results alongside offloading and resource allocation decisions in UAV-aided MEC networks remains a non-trivial challenge. In this study, an integrated task offloading and resource allocation with data caching (JORC) framework is proposed to address these challenges. The offloading and resource allocation problems are formulated as a Markov decision process and solved using the soft actor–critic reinforcement learning algorithm. In addition, dynamic and adaptive caching manages limited storage and reduces redundant computations by using a hybrid strategy that integrates the least-frequently used and least-recently used policies to reduce computational redundancy. Simulation results confirm that the proposed JORC framework substantially reduces latency, energy consumption, and overall system cost, while increasing the successful task completion ratio compared to existing baseline approaches. Full article

Marine heatwaves (MHWs) are persistent extreme warm events in the ocean that pose substantial threats to marine ecosystems, fisheries, aquaculture, and offshore energy infrastructure. In 2024, the Yellow Sea experienced the most intense MHW on record in terms of cumulative intensity, with sea surface temperature (SST) anomalies exceeding 5 °C and an exceptional duration of 118 days. Using the ERA5 atmospheric reanalysis and GLORYS12V1 ocean reanalysis, this study systematically investigates the characteristics, driving mechanisms, and extremity of this event. Mixed-layer heat budget analysis indicates that enhanced shortwave radiation was the primary contributor to the warming, which is closely linked to the westward-extending and northward-shifting subtropical high. During MHW decay, sea surface cooling is dominated by enhanced latent heat flux, closely linked to typhoon and cold air activities. Further analysis links the positive SST anomalies to the North Atlantic and the Barents Sea warming, which triggered a Eurasian teleconnection wave train. These results highlight the importance of cross-basin climate connectivity in driving regional maritime temperature extremes. Full article

The transition towards circular economy models is driving the transformation of wastewater treatment plants (WWTPs) from energy-intensive facilities into resource recovery systems capable of generating renewable energy. In this context, this study developed an integrated mass and energy balance methodology to assess sludge production, anaerobic digestion performance, biomethane recovery, and electricity generation in a full-scale urban WWTP. The proposed framework integrates the water treatment line, sludge processing line, and energy recovery system, combining primary and secondary sludge management with biogas upgrading and combined heat and power (CHP) generation. Representative operating parameters from the scientific literature were applied to a facility treating 204,000 m³ d⁻¹ and serving approximately 425,000 population equivalents. The results showed that primary sludge accounted for approximately 70% of the volatile solids fed to the anaerobic digester. Methane production was estimated at 1.12 × 10³ kg CH₄ d⁻¹, corresponding to a biogas production of 2.40 × 10³ m³ d⁻¹. Under two alternative valorisation scenarios, the maximum recovered biomethane flow was 1.48 × 10³ m³ d⁻¹, whereas the maximum annual electricity generation potential through CHP was 1.9 × 10⁶ kWh. These findings highlight the potential of integrated sludge valorisation strategies to enhance renewable energy recovery and support the transition of WWTPs towards energy-efficient and low-carbon resource recovery facilities. Full article

To improve braking energy recovery in pure electric vehicles while maintaining a reasonable braking-force distribution, this study proposes a regenerative braking strategy based on a grey wolf optimizer (GWO)-optimized fuzzy control. A single-motor front-wheel-drive pure electric vehicle is modelled in terms of vehicle longitudinal dynamics, motor characteristics, and battery state of charge (SOC). A front–rear braking-force distribution strategy is developed based on the ideal braking-force distribution I-curve and ECE regulation constraints. A Mamdani fuzzy controller is then designed with braking intensity z and battery SOC as inputs and the front-axle regenerative braking-force distribution coefficient k as the output, enabling coordinated allocation between front-axle regenerative braking and mechanical braking. To reduce the dependence of fuzzy rules on expert experience, the GWO is used to optimize 25 fuzzy rules, and the proposed strategy is verified in MATLAB R2023b under a typical urban driving cycle. The results show that all strategies satisfy the braking demand. Compared with the unoptimized fuzzy control strategy, the optimized strategy reduces SOC consumption by 5.15% and increases recovered braking energy by 59.56%, indicating improved regenerative braking performance. Full article

Rotary tillage–seeding combined operations require stable power take-off (PTO) speed during rotary tillage and accurate tracking of the prescribed travel speed for seeding. Existing energy management strategies for hybrid electric tractors mainly focus on fuel economy and commonly use fixed objective weights, limiting their ability to adjust control priorities under changing operating conditions. To address this issue, an operation-quality-oriented energy management strategy based on model predictive control, termed OQ-EMS/MPC, is proposed. An equivalent combined-operation condition was constructed using the PTO-side rotary-tillage load, drive-side equivalent traction load, segmented travel-speed reference, and equivalent seeding-quality risk. A condition-severity index integrating the PTO-load coefficient of variation, PTO-load impact intensity, and equivalent seeding-quality risk was developed to distinguish steady, fluctuating, and impact-dominated conditions. Based on the identified condition, the weights assigned to PTO-speed regulation, equivalent seed synchronization, and energy economy were adjusted online. These weights were used in the MPC to optimize torque allocation among the engine, motor-generator 1 (MG1), and motor-generator 2 (MG2). The proposed strategy was validated on a dual-side loading bench and compared with a rule-based energy management strategy and a fixed-weight MPC strategy. The overall PTO-speed root-mean-square error (RMSE) was reduced to 1.76 r/min, representing reductions of 58.40% and 45.66% relative to the two comparative strategies, respectively. The equivalent seed-synchronization RMSE was reduced by 69.15% and 52.66%, respectively. Under the impact-dominated condition, the PTO-speed RMSE decreased to 1.65 r/min. The normalized composite cost decreased by 13.53% and 6.26%, while the equivalent fuel consumption increased by 3.40% and 3.76%, respectively. The results demonstrate that the proposed strategy improves PTO-speed stability and equivalent seed-synchronization performance as operating severity increases while accounting for energy economy. Full article

The Huaibei region is a critical grain and energy–chemical base in northern China, characterized by substantial water demand for industrial and agricultural production. Karst groundwater systems constitute the primary water supply source in this area. Under the superimposed impacts of intensive exploitation, climate change, and anthropogenic activities, karst aquifers have encountered a series of geo-environmental problems, including groundwater level decline and expansion of cones of depression. Most previous studies have predominantly focused on water quality assessment and groundwater resource quantification, yet systematic investigations into the multi-scale characteristics and driving mechanisms of karst groundwater level dynamics remain insufficient. In this study, based on long-term groundwater level and rainfall monitoring data (2014–2024) from three monitoring wells representing different types of karst aquifers, continuous wavelet transform (CWT) and wavelet coherence (WTC) approaches are introduced to identify the periodic patterns of karst groundwater levels and reveal the dominant controlling factors of groundwater level dynamics. The results demonstrate that groundwater levels in all types of karst aquifers exhibit distinct multi-scale periodic variations. The groundwater levels of HB01 and HB02 share dominant oscillation periods of 18~19 months and 9 months with regional rainfall, while the groundwater level at HB03 displays a more complex, multi-scale, periodic combination of 41 months, 18~19 months, and 9 months. Periodic variations in regional rainfall serve as the dominant controlling factor for the intra-annual and inter-annual periodic fluctuations of karst water levels, with a prominent resonance relationship identified between the two variables at dominant periodic scales. Distinct heterogeneity is observed in the response magnitude and lag time of different karst aquifer types to rainfall; specifically, the lag time of water level response to rainfall on the annual periodic scale ranges from 2.7 to 2.9 months. The correlation between annual average water level and pumping discharge is moderate for boreholes HB01 and HB03, whereas a strong correlation is detected for borehole HB02, implying that its water level regime is likely subjected to pronounced pumping disturbance. The degree of karst development, aquifer burial depth, and overlying stratum architecture are the key geological factors accounting for such heterogeneous response patterns. For the first time, this study utilizes long-term water level time series data from the karst water exploitation zone of the Huaibei Plain, complemented by synchronous precipitation and pumping records. Integrated with regional hydrogeological settings, wavelet analysis is employed to conduct an in-depth investigation into the dynamic variations in karst water levels in the Huaibei region from the perspective of groundwater recharge–discharge relationships. The results provide a scientific underpinning for the remediation of karst water over-exploitation and the optimal allocation of water resources. Specifically, pumping and artificial recharge schemes can be proactively adjusted based on periodicity forecasts. Zoned management strategies for water resources are put forward: artificial regulation and storage are recommended for zones with sensitive hydrological responses, while preventive protection is prioritized for zones with sluggish responses. By incorporating periodic characteristics and lag durations, targeted pumping strategies for dry and wet seasons can be developed, and a coupled water level–rainfall–pumping early warning system can be established to realize the long-term sustainable regulation of karst water resources. Full article