Search Results (2,557)

This study aims to investigate the perspectives of aquaculture producers in the Western Mediterranean Region (operating in Antalya, Burdur, and Isparta provinces) on climate change, examine the impacts of climate change on regional aquaculture, and develop solution proposals. Within the scope of this objective, the socioeconomic and demographic characteristics of the aquaculture producers in the Western Mediterranean Region, along with their knowledge levels regarding climate change, were obtained through a questionnaire technique. The results indicate that producers, who are predominantly engaged in rainbow trout aquaculture, are under severe economic pressure due to high-exchange-rate-driven input costs and the abolition of government subsidies. While all participants (100%) perceived that climate change has decreased production tonnage, the most prominent impact of the climate crisis is perceived as drought and the decline of water resources, with a response rate of 37.2%. Multivariable analysis further showed that aquaculture experience and satisfaction with aquaculture income were significantly associated with producers’ future outlook, highlighting the importance of socioeconomic factors in shaping perceived sectoral vulnerability. Due to both rising costs and environmental risks, 50% of the producers view the future of the sector pessimistically and do not recommend this profession to future generations. Consequently, these results emphasize the critical need for integrated land and water resource management policies, alongside targeted climate adaptation strategies, to ensure the long-term socio-ecological sustainability of forest inland aquaculture in the region. Full article

Reverse osmosis (RO) desalination is a major technology for freshwater production in arid regions, but its energy demand becomes more challenging when the system is supplied by variable renewable energy. This study presents an offline digital-twin-assisted decision-support framework for dynamic RO under Kuwait solar-availability conditions. Within this framework, the predictive models are driven primarily by the dynamic RO process variables, while NASA Prediction Of Worldwide Energy Resources (POWER) data provide the Kuwait solar-availability context, and the PV power margin serves as a scenario-level energy indicator. The purpose is to predict instantaneous permeate flow rate, estimate specific energy consumption, and identify energy-efficient operating conditions using machine learning. Kuwait City was used as the solar case-study location. Hourly solar and meteorological data were obtained from NASA POWER, while dynamic RO membrane data were obtained from the open experimental wave desalination dataset published by the National Renewable Energy Laboratory (NREL) through Data.gov and the Marine and Hydrokinetic Data Repository. The RO dataset includes steady-state, ramp, sinusoidal, and Wave Energy Converter SIMulator (WEC-Sim) pressure/flow experiments. The process-flow image used in the system description was also taken from the same NREL dataset and is cited in the figure caption. The raw RO files were cleaned, harmonized, and transformed into a process-informed modeling dataset. Derived features included pressure rate, recovery ratio, salt rejection, estimated pump power, specific energy consumption (SEC), PV power margin, and rolling pressure/flow features. Three supervised regression models were tested: Gradient Boosting, Random Forest, and XGBoost. A representative subset of 60,000 records was used to preserve the main experimental conditions while reducing redundancy in the densely sampled sequential data. Results show that permeate flow rate can be predicted with high accuracy using Gradient Boosting (R² = 0.981; RMSE = 0.161 L/min). The moderate energy prediction performance yielded an R² of 0.654 and RMSE of 7.570 kWh/m³ for Random Forest. The accuracy of permeate conductivity predictions was lower (R² = 0.257; RMSE = 245.44 µS/cm) because membrane and feed characterizing parameters should be included for an adequate water quality control. The proposed approach is best suited as an offline decision-support framework for dynamic RO process analysis. Full article

Pump-turbines often experience performance deterioration under high-load conditions beyond their best efficiency point, while the underlying flow mechanisms remain insufficiently understood. In this study, we investigate the relationship between internal flow structures and energy performance in a pump-turbine operating at a rated head of 202 m over a range of guide vane openings. Energy losses are evaluated using an average kinetic energy-based method and compared with an entropy production approach. A threshold-independent rigid vorticity method is adopted for vortex identification, and a streamline-based coordinate system is introduced for spatial quantification of energy loss and blade loading. The results show that hydraulic losses are mainly concentrated in the draft tube (66–75%) and runner (25–30%) under high-load conditions. A coupled vortex system formed by separation vortices and horseshoe vortices governs localized dissipation in the runner. In the draft tube, a columnar vortex rope generates strong shear layers that dominate energy loss in the cone and elbow regions. At high flow rates, negative incidence induces pressure-side separation, forming negative torque regions that reduce net runner torque and lead to output power deterioration. These findings highlight the dominant role of coupled vortex structures and pressure redistribution in performance degradation under high-load operation. Full article

The development of efficient photocatalysts for hydrogen production is a key challenge for sustainable energy technologies. In this study, strontium titanate (SrTiO₃) was synthesized via a citrate-assisted sol-gel method and subsequently modified by deposition-precipitation using nominal HAuCl₄ precursor concentrations of 1.0, 1.5, and 2.0 mM. The resulting materials were characterized by XRD, Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy, SEM with EDS, and X-ray fluorescence (XRF). Au incorporation did not produce detectable changes in the SrTiO₃ crystalline phase or its optical band gap, which remained at 3.19–3.20 eV. The additional absorption band centered near 550 nm was consistent with the localized surface plasmon resonance of metallic Au nanoparticles. Microscopy indicated increasing surface coverage and aggregation at the highest nominal precursor concentration. Under irradiation with a low-pressure Hg lamp, all Au-containing materials presented substantially greater H₂ evolution than pristine SrTiO₃, whereas the comparatively small differences among the Au-modified samples indicated an apparent activity plateau across the evaluated concentration range. Because the Au-associated absorption band near 550 nm lies outside the main 254 nm emission of the lamp and the SrTiO₃ band gap remained mostly unchanged, the enhanced H₂ evolution is consistent with improved interfacial charge separation in the Au/SrTiO₃ system. A Schottky-junction-mediated pathway is proposed based on the observed activity trends and the electronic properties reported for Au/SrTiO₃ interfaces, rather than to a plasmonic or band-gap-tuning effect. The selected STO/Au 2.0 mM material retained approximately 97% of its initial apparent H₂ evolution rate after three consecutive cycles, indicating favorable short-term activity retention. Overall, this comparatively simple synthesis route provides a practical baseline for investigating the influence of nominal Au precursor concentration on H₂ evolution over SrTiO₃. Full article

The corrosion behavior of N80 steel in a simulated coalbed–methane environment was investigated in a high-temperature, high-pressure autoclave. Uniform corrosion and maximum pit depth were quantified by weight-loss measurements and ultra-depth-of-field three-dimensional microscopy, respectively, while SEM, EDS, and XRD were used to characterize the morphology, elemental composition, and crystalline phases of the surface corrosion products. A one-factor-at-a-time design was applied at a constant total pressure of 10 MPa to evaluate the effects of nominal CO₂ partial pressure (0.10–1.00 MPa), nominal O₂ partial pressure (0–0.40 MPa), Cl⁻ concentration (3–187 g/L), and temperature (40–75 °C). Increasing the nominal CO₂ partial pressure raised the uniform corrosion rate from 0.712 to 0.930 mm/a but reduced the maximum pitting corrosion rate from 1.691 to 0.280 mm/a, while FeCO₃-containing surface coverage increased. Increasing the nominal O₂ partial pressure intensified both corrosion modes; at 0.40 MPa, the uniform and maximum pitting corrosion rates reached 1.446 and 2.202 mm/a, respectively, and the corrosion-product layer exhibited extensive cracking and spallation. Increasing the Cl⁻ concentration reduced the uniform corrosion rate from 1.078 to 0.839 mm/a but increased the maximum pitting corrosion rate from 0.474 to 1.807 mm/a, indicating a shift in the principal damage risk from average metal loss to localized penetration. The uniform corrosion rate reached a maximum of 1.516 mm/a at 60 °C, whereas the maximum pitting corrosion rate increased continuously to 2.202 mm/a at 75 °C. XRD identified Fe, FeCO₃, Fe₂O₃, Fe₃O₄, and FeOOH. The persistent Fe substrate reflections, interpreted together with the SEM observations, revealed spatially heterogeneous corrosion-product coverage. These results show that the protective contribution of FeCO₃-containing products depends on their surface coverage and visible integrity rather than on phase presence alone. The findings support stringent oxygen-ingress control, targeted pitting protection in high-salinity environments, and enhanced corrosion surveillance of intermediate- and high-temperature well sections. Full article

The tight sandstone gas reservoir in Qingshimao gas field has the characteristics of complex gas–water distribution, low reservoir quality, low porosity, low permeability and high water saturation. Single-well productivity is low, the production and pressure decrease rapidly, the stable production period is short and economically viable development remains challenging. Therefore, considering the reservoir physical properties and development characteristics of the Qingshimao area, physical experiments and numerical simulations were conducted to investigate the reserve utilization characteristics of complex tight water-bearing gas reservoirs and to evaluate the effectiveness of CO₂ injection in restoring reservoir pressure and enhancing gas recovery after depletion. The results show that: (1) The movable-water saturation of Type I and Type II reservoirs ranged from 2 to 18% and 3–21%, respectively, while increasing water saturation reduced cumulative gas production and increased gas-flow resistance. Type III and Type IV reservoirs are limited by low permeability and fine pore throat. The movable-water saturation is less than 8% and 6% respectively under high water saturation conditions, and the gas–water flow is obviously limited. (2) Both continuous CO₂ injection and post-injection soaking can promote residual-gas recovery after depletion. Post-injection soaking prolongs the contact time between CO₂ and residual methane, whereas fractured cores exhibit more rapid pressure recovery but earlier CO₂ breakthrough. (3) Pore scale and two-dimensional visualization experiments show that after CO₂ injection, the pressure is transferred from the injection inlet to the production outlet, and the depleted low-pressure area is supplemented. The incremental recovery factor of the two-dimensional models after CO₂ injection ranged from 22.81 to 25.28 percentage points. (4) The numerical simulation results show that permeability, water saturation, and the injection and production rates jointly control pressure restoration and gas recovery during CO₂ injection. The high-permeability reservoir achieves a higher recovery factor but experiences earlier CO₂ breakthrough. High water saturation and high injection and production rates will weaken the effective sweep. In field application, the layers with good connectivity and moderate water saturation should be preferred, and the injection and production rates should be reasonably controlled to reduce the risk of gas channeling. Overall, post-depletion CO₂ injection can effectively restore reservoir pressure, mobilize residual methane, and enhance gas recovery in tight water-bearing gas reservoirs. The experimental results support post-depletion CO₂ injection as a potential approach for improving the development performance of tight water-bearing gas reservoirs. Full article

Energy transitions reshape not only energy supply and demand but also the broader socio-technical, environmental, and economic conditions that influence the resilience of European economies. This study examines whether selected energy and environment-related indicators are associated with employment-rate dynamics in 26 European countries over the period 2005–2022. Harmonised Eurostat indicators from the Sustainable Development Goals monitoring framework are used as empirical proxies for system-level characteristics, rather than as normative measures of SDG implementation. Employment rate by citizenship is treated as an observable indicator of labour-market adjustment within the broader process of sustainable energy-system transformation. The empirical analysis applies a dynamic panel-data model with autoregressive and distributed lag components, estimated using weighted least squares. The results indicate that employment-rate dynamics are associated with energy demand, import dependency, energy productivity, household energy conditions, transport structure, recycling capacity, and environmental pressure. Import dependency shows a negative long-term association, whereas final energy consumption is positively associated with employment-rate dynamics. The study contributes to energy-sustainability research by interpreting labour-market adjustment as one dimension of a resilient and just energy transition. Full article

Brain-derived neurotrophic factor (BDNF) impacts parasympathetic nervous system function by increasing the excitability of cardioinhibitory parasympathetic neurons in the brainstem, ultimately lowering heart rate (HR) and heightening resting parasympathetic tone. Yet, whether BDNF and its high-affinity receptor—tropomyosin receptor kinase B (TrkB)—also act more distally, i.e., at the level of cholinergic-sensitive intrinsic cardiac ganglia (ICGs), remains unclear. Hence, we conducted morphological and functional studies in neural crest-specific BDNF knockout mice (ncBDNF KO), a model that selectively ablates BDNF signaling in neural crest-derived autonomic structures, including the intrinsic cardiac nervous system. ncBDNF mice exhibited a significant rise in resting heart rate with unchanged baseline contractile performance, thus supporting the role of endogenous BDNF in maintaining physiological parasympathetic restraint. When examining the ICGs, immunofluorescence analysis revealed a highly compartmentalized organization, with BDNF being predominantly confined to cholinergic neuronal somata and TrkB mainly clustered instead in S100-positive satellite glial cells, thus unveiling a previously unrecognized neuron–glia BDNF/TrkB ICG pattern. Next, we directly infused BDNF in Langendorff-perfused isolated WT mouse hearts and observed a rapid and reproducible bradycardic response that was abrogated by atropine but potentiated by neostigmine, hence attesting to the cholinergic nature of such bradycardia. Of note, BDNF maintained its positive inotropic effects under muscarinic blockade, as witnessed by the enhanced left ventricular developed pressure, maximal dP/dt, and rate-pressure product, congruent with direct BDNF-evoked myocardial TrkB agonism. Thus, ICGs are additional relevant relay stations interposed between BDNF/TrkB signaling and parasympathetic modulation of heart function. Although through different molecular paths, BDNF-mediated modulation of ICG firing can coordinate with the previously reported BDNF positive inotropy/lusitropy to adapt cardiac performance to increased workload and/or stress conditions. Full article

Offshore wind energy droughts are quantified at eight strategic sites using a Standardized Renewable Energy Production Index referenced to an 86-year-ERA5 baseline. Events are extracted via multi-threshold run theory and projected to 2100 using bias-corrected CMIP6 models under SSP2-4.5 and SSP5-8.5. Drought climatology shows that mean drought duration and severity exhibit spatial heterogeneity, peaking in the Aegean–Cretan sector. Under future warming, a robust, false-discovery-rate-controlled intensification is predominantly concentrated in the central–western basin, associated with structural shifts toward weaker, heavy-tailed wind distributions. The Sicily Channel and Gulf of Lion emerge as hotspots for drought intensification, exhibiting consistent annual total duration increases of up to 20% and 15%, respectively, under the SSP5-8.5 scenario. Winter droughts across the basin are associated with a complex interplay of the AO, NAO, EA, and EA/WR teleconnections, alongside a pronounced winter MOI influence in the west. Summer droughts in the Aegean–Cretan sector are strongly coupled with the weakening of the MOI, reflecting the collapse of the basin-scale pressure gradient that sustains the Etesian winds. The central–western Mediterranean emerges as a key region for adaptive, long-duration energy storage planning, whereas the climatology of the eastern basin remains a defensible baseline for future capacity design. Full article

Spent automotive catalysts represent an important secondary resource for platinum group metals, offering environmental and economic advantages over primary mining. This review evaluates bioleaching-based recovery strategies of these metals as sustainable alternatives to conventional pyrometallurgical and hydrometallurgical processing. The cyanogenic bioleaching using Chromobacterium violaceum, Pseudomonas fluorescens, and Bacillus megaterium, and acidophilic bioleaching using Acidithiobacillus spp. for washcoat degradation and base-metal removal are discussed through the one-step, two-step, spent-medium, and decoupled systems. The analysis shows progressive improvement of recovery as process separation increases. Sequential pretreatment involving ultrasound-assisted acid leaching, thermal oxidation, and pressure-enhanced processing improved recovery by removing competing base metals and increasing PGM accessibility. Kinetic analyses indicate that diffusion through the porous catalyst support matrix becomes the dominant rate-controlling mechanism at high conversion, which impacts reactor design. Despite sustainability potential, industrial implementation remains constrained by low pulp density, cyanide stability, reactor productivity, and scale-up limitations. Routes to commercialisation require feasibility studies of process designs that integrate viable process flow diagrams combining pretreatment, biological lixiviant generation, intensified bioleaching, and downstream metal purification. Full article

Rapid inversion of coarse-scale parameters is important for history matching in reduced-order reservoir models, yet conventional methods require repeated simulation and iterative updating. This study proposes a residual conditional generative adversarial network (Res-cGAN) to reconstruct structured control-pore-volume parameters from well liquid production rate (WLPR), well oil production rate (WOPR), and pressure responses. The methodological contribution is a response-conditioned inversion framework that directly maps multivariate production responses to the structured CPV representation, combining residual feature learning, cross-level feature fusion, conditional adversarial learning, and local matrix-continuity regularization. A dataset of 3000 samples was generated using the interwell numerical simulation model (INSIM), with training sets of 600, 1200, 1800, and 2400 samples and fixed validation and test sets of 300 samples each. Increasing the training size reduced mean squared error (MSE) from 0.0128 to 0.0059 and increased the coefficient of determination (R²) from 0.9120 to 0.9670. With 2400 training samples, Res-cGAN achieved an MSE of 0.0059, mean absolute error (MAE) of 0.0493, mean absolute percentage error (MAPE) of 5.18%, and R² of 0.9670, outperforming the baseline conditional GAN (Base-cGAN). These results suggest the potential of Res-cGAN for rapid post-training CPV initialization and candidate screening for reduced-order history matching workflows, while field validation and cross-reservoir testing remain necessary. Full article

Ultra-high-temperature ceramic (UHTC) coatings offer a promising route to extending cutting tool service life under severe conditions. This work evaluates the tribological behaviour and wear regime transitions of ZrB₂–SiC/ZrO₂ coatings, deposited by physical vapour deposition (PVD) onto ASSAB-17 high-speed steel tool bits, during dry turning of Ti-6Al-4V. Structural, microstructural, mechanical, and tribological characterisation was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindentation, and pin-on-disc testing under three pressure–velocity (PV) severity levels, with worn surfaces analysed by SEM and profilometry. The coating exhibited a nanostructured ZrB₂/β-SiC/t-ZrO₂ architecture with a hardness (H) of 24 ± 3 GPa, a hardness-to-reduced-elastic-modulus ratio (H/Er) of 0.100, and an elastic resistance to plastic deformation (H³/Er²) of 0.240 GPa. Three tribological regimes were identified: running-in, steady-state sliding, and progressive degradation, with the highest severity (PV = 6.0 N·m/s) triggering degradation beyond approximately 620 m, a more than one-order-of-magnitude rise in wear rate, and the only case exceeding the tool-life criterion of maximum flank wear (VBmax = 0.30 mm) according to ISO 3685. The main advantage of the proposed approach is that it condenses tool-life-relevant behaviour into a single, easily measurable severity parameter, the PV product, directly applicable to coating design and the selection of safe machining-condition windows. The overall behaviour is consistent with a mechanism governed by the stability and regeneration capacity of a protective tribofilm. As the composition of this layer was not directly characterised, this mechanism is proposed as a phenomenological interpretation, from which a PV threshold is derived as a design criterion for UHTC coatings. Full article

Coal-bearing tight gas and deep coalbed methane (CBM) widely co-occur in China, and integrated commingled production outperforms separate development. Conventional separated simulation fails to capture coupled reservoir–wellbore gas–water flow. This study develops an integrated geomechanical coupled numerical model with multi-scale fractures and multi-phase wellbore flow: tight gas reservoirs use a stress-sensitive single-porosity model, deep CBM adopts a dual-porosity model for matrix desorption, and EDFM characterizes non-Darcy flow in hydraulic fractures. The Gray gas column and liquid column methods calculate layered bottomhole pressure according to reservoir vertical distribution, and matrix bordering solves the whole coupled system. Validated by field data of Well C-1 in Shanxi, the model yields average relative errors of 8.76% for daily gas output and 2.92% for daily water output. Sensitivity analysis on Well C-2 indicates vertical reservoir stacking controls interlayer pressure difference, and commingled gas curves show dual peaks with shifting dominant gas sources over production stages. A 3.9% rise in deep coalbed methane gas content significantly boosts mid-term peak production and cumulative gas output, making reservoir gas content the dominant geological factor governing commingled production performance. A 120.0% increase in tight gas saturation only delivers a slight uplift in cumulative production under low-porosity conditions. Elevated reservoir stress sensitivity triggers a cumulative gas production reduction of over 50%. Cumulative gas output varies proportionally with hydraulic fracture length, while fracture network width brings mismatched production improvement due to pressure drawdown funnel effects. Therefore, hydraulic fracturing operations should prioritize extending artificial fractures to expand the drainage area of commingled wells. Schemes with constant bottomhole flowing pressure and constant gas rate exert marginal influences on ultimate cumulative production and can be flexibly switched on site. To stabilize daily gas deliverability throughout the early, middle and late production stages, a bottomhole pressure drawdown rate of 0.05 MPa/d or a fixed daily gas rate of 4000 m³/d is recommended. This work provides theoretical support for optimizing commingled development of superimposed tight gas and deep CBM reservoirs. Full article

High-volume, long-duration flowback in ultra-deep fractured wells couples pressure, rate, water production, fracture conductivity, and stress-sensitive reservoir properties, making it difficult for pressure transient analysis (PTA), flowing material balance (FMB), and rate transient analysis (RTA) to maintain parameter continuity across flowback stages. This study proposes a physics-constrained artificial-intelligence (AI)-assisted workflow centered on FMB. PTA provides permeability, fracture half-length, and fracture-conductivity priors; RTA, Blasingame, and Agarwal–Gardnerdiagnostics provide production-dynamic constraints; and machine-learning models perform anomaly screening, stage recognition, time-series correction, type-curve discrimination, and multi-method fusion. The workflow was applied to Well Baitan 1, an ultra-deep fractured gas well with eight-stage fracturing and multi-regime flowback data. Isolation forest preprocessing removed 32 abnormal records, random forest (RF) drainage-type classification reached 93% accuracy, and long short-term memory (LSTM) correction improved production-forecast fitting from 87% to 95%. Neural-network fusion yielded matrix permeability of 0.49 mD and dynamic reserves of 1.93 × 10⁴ m³, reducing static geological-volume validation error to 2.8%. The results show that AI improves productivity evaluation when constrained by diagnostic flow models and geological validation, providing a traceable basis for optimizing flowback intensity, monitoring frequency, and stabilized deliverability estimation. Full article

Strawberries are among the most water-sensitive horticultural crops because of their shallow root systems and high transpiration rates, making them particularly vulnerable to rising temperatures, irregular rainfall, and increased vapor pressure deficits under climate change. This review paper synthesizes methods for quantifying water-use efficiency (WUE) in strawberry production, including empirical equations, crop models (AquaCrop, DSSAT, and HYDRUS), and remote sensing approaches. It examines how water use, crop productivity, and WUE respond to environmental conditions and management practices. Earlier studies show that rising temperatures, altered precipitation patterns, and increased atmospheric water demand can often reduce WUE, although responses vary depending on cultivar, management practices, and environmental conditions. In contrast, practices such as deficit irrigation, mulching, and microclimate modification may help maintain water productivity. Remote sensing tools such as the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Surface Energy Balance Algorithm for Land (SEBAL), and Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) are increasingly used to evaluate evapotranspiration, crop condition, and irrigation performance from field to regional scales. Collectively, these approaches improve understanding of strawberry water use and support irrigation management under changing climatic conditions. Full article