Search Results (5,245)

To address the peak-fluctuating cooling load of ocean-going fishing vessels and the dependency of traditional refrigeration systems on fuel-driven power, this study proposes an exhaust waste-heat-driven ammonia water absorption–compression hybrid refrigeration system. The proposed system was thermodynamically analyzed and simulated based on the principles of heat and mass transfer. Considering the full-cycle cooling demand, an objective optimization model with the goal of minimizing the total operating cost was established and solved using the Northern Goshawk Optimization (NGO) algorithm. Using real data from a fishing company, a voyage cycle of Lu Huang Yuan Yu 105 was selected as a case study. Results showed that NGO outperformed the Genetic Algorithm and Particle Swarm Optimization, achieving the smallest cooling deficit and faster convergence. Compared with the independent compression refrigeration system, the hybrid system reduced the cooling deficit by 9.7%, improved cooling capacity by over 35% during voyage, 5% during fishing, and 2% during processing, while lowering fuel consumption by 10% and efficiently utilizing exhaust heat. Sensitivity analysis identified optimal ranges for ammonia concentration and circulation ratio and highlighted the significant influence of cooling water temperature on system performance. This study provides a valuable reference for the design and optimization of low-grade waste-heat-driven hybrid refrigeration systems in maritime applications. Full article

An eighteen-year record of in situ surface meteorology and computed bulk air–sea fluxes of heat, freshwater, and momentum from an ocean site windward of the Hawaiian Islands is presented. Observations were logged every minute. The one-minute, one-hour, and one-day time series statistics are presented. The daily-averaged time series provide an overview of this trade wind site, with mean wind of 6.8 m s⁻¹ toward the west–southwest, mean ocean heat gain of 23.2 W m⁻², and freshwater loss of 1.2 m yr⁻¹. Energetic variability was found at the higher sampling rates, evidenced by spectral peaks in solar insolation and sea-level pressure and by striking transient signals including short-lived insolation values higher than clear-sky values, short periods with air warmer than the sea surface, and by series of downdrafts of dry air. At longer periods, the presence of moist air accompanying low winds and sunny skies enhanced ocean heating. Winter events with dry air and wind, resulting in large latent and net heat loss, led to ocean cooling. Signals of two hurricanes, Darby and Douglas, were recorded. Normalized by their duration, short-lived events have the potential to make significant contributions to the heat, freshwater, and mechanical energy exchanges. Full article

Selective laser melting (SLM), a pivotal additive manufacturing (AM) technology for titanium alloys, enables near-net-shape forming of complex structures with relative densities of up to 99.9%, making it indispensable in aerospace, biomedical, and marine engineering. This review comprehensively updates the state of the art on SLM-fabricated TC4 (Ti-6Al-4V) alloy, addressing critical gaps in previous studies by integrating novel research progress, in-depth mechanistic analyses, and multi-dimensional comparisons. The core focus is on the unique thermal cycle (10⁶–10⁸ °C/s heating/cooling rates) of SLM, which induces a predominant needle-like martensitic α′ phase (99.7%) and minimal β phase (0.3%), leading to intrinsic anisotropy and low ductility. Room-temperature tensile strength reaches 1315.32 MPa with 9.6% elongation, and high-cycle fatigue limits the range from 417 to 829 MPa, strongly dependent on process parameters and post-treatment. Corrosion anisotropy is systematically analyzed: the XY plane (parallel to scanning direction) exhibits superior corrosion resistance in 1 M HCl (fewer pits and lower corrosion current density) and 3.5% NaCl (more stable passive film) compared to the XZ plane (deposition direction). Novel insights include: (1) synergistic effects of SLM process parameters (laser power–scanning speed–hatch spacing) on defect evolution and microstructure uniformity; (2) atomistic mechanisms of α′→α + β phase transformation during post-heat treatment; and (3) corrosion–mechanical coupling behavior in harsh environments (e.g., marine and biomedical). Post-treatment strategies are refined: annealing at 800 °C for 2 h achieves 1099 MPa tensile strength and 17.4% elongation, while hot isostatic pressing (HIP) reduces porosity from 0.08% to 0.01% and weakens fatigue anisotropy. This review also identifies unresolved challenges (e.g., in situ defect monitoring and multi-field regulated performance) and proposes future directions (e.g., AI-driven process optimization and functional gradient structures). Full article

Thermodynamic cycles used with external combustion are typically based on compression, heating, expansion and cooling, admitting variants to enhance efficiency or power. This paper carries out a thorough theoretical study of isochoric heating and non-adiabatic expansion processes and proposes a new thermodynamic cycle based on three instead of four stages. The compressor is removed because the working fluid (a gas) is pressurized by heating it isochorically. A novel concept of an engine is proposed (patent ES2992009A, WO 2025/257447), and it shows potential for power generation that has to be explored. Full article

Under global climate warming, the impact of extreme high temperatures on carbon exchange in paddy rice ecosystems remains unclear, yet they exert a profound influence on the carbon cycle in agricultural ecosystems. The characteristics of carbon dioxide (CO₂) fluxes and their response to temperature were explored at two sites (Jurong and Jiangdu) across the lower reaches of the Yangtze River in China using open-path eddy covariance observations in 2021–2024. During the rice-growing season, considerable inter-annual spatial variability in high temperature was observed, with a higher frequency and larger intensity in Jurong relative to Jiangdu and more severe heat stress in 2022 relative to 2023. The jointing–booting stage was identified as the hotspot exposed to the highest frequency and longest duration of high temperature across multiple years. There was obvious variation in net ecosystem CO₂ exchange (NEE) throughout the rice-growing season, with the cumulative values being −462.2 ± 55.2 gC·m⁻² in 2021–2023 at Jurong and −362.4 ± 43.0 gC·m⁻² in 2022–2024 at Jiangdu. The period from jointing to flowering was identified as the most sensitive time slice for NEE variation, with a daily average value of −6.3 ± 0.2 gC·m⁻²·d⁻¹ in jointing–booting and −5.2 ± 2.2 gC·m⁻²·d⁻¹ in booting–flowering at Jurong, as well as −4.0 ± 0.7 gC·m⁻²·d⁻¹ in jointing–booting and −5.7 ± 1.1 gC·m⁻²·d⁻¹ in booting–flowering at Jiangdu. The respective correlation coefficients were −0.59 and −0.37 between periodical NEE and mean air temperature at Jurong and Jiangdu, meaning that NEE showed a decreasing trend as temperature increased, owing to the simultaneous but heterogeneous changes in gross ecosystem CO₂ exchange and ecosystem respiration. When the temperature was lower than 38 °C, the corresponding correlation coefficient reached −0.85 at Jurong and −0.52 at Jiangdu, suggesting that extreme high temperature prevented a decline in NEE. The response of NEE to temperature highlighted that NEE ceased to decrease when temperature surpassed 38 °C, implying that a critical threshold existed for limiting the carbon sink under extreme high temperature. These findings could provide insight for understanding carbon cycling in agricultural systems under an extreme climate. Full article

This study investigates the integration of a molten salt thermal energy storage (TES) system into a 330 MW coal-fired power unit to enhance its operational flexibility and exergy-based performance. Using EBSILON Professional (version 13) software, several heat storage and heat release schemes were modeled and analyzed to assess their effects on turbine performance, coal consumption rate, heat rate, and exergy losses under various load conditions. The results reveal that coupling TES with conventional thermal units can effectively decouple heat and power generation, enabling deep peak-shaving operation while maintaining system efficiency. The six heat storage schemes and seven heat release schemes considered in this study were selected based on the physical characteristics of the 330 MW reheat-steam cycle and the practical constraints of integrating a molten salt TES system into an existing coal-fired unit. Specifically, the schemes were designed to represent all feasible pathways for redirecting thermal energy within the boiler–turbine system, including steam extraction from different turbine stages, reheater-side interventions, and electric-heating-assisted charging options. These schemes also reflect the operational boundaries of the unit, such as allowable extraction fractions, steam temperature limits, and turbine safety margins. The findings demonstrate that molten salt TES can serve as a feasible and efficient pathway for retrofitting existing coal-fired power units to improve load-following capability, reduce fuel consumption, and support grid flexibility under renewable-dominated energy scenarios. Full article

Ensuring product integrity across Malaysia’s East Malaysian states (Sabah and Sarawak) requires a cold chain that is resilient to tropical heat, long multimodal routes, intermittent power, and dispersed rural populations. This paper proposes a sustainability-first architecture for vaccine and blood component logistics that combines World Health Organization and the United Nations International Children’s Emergency Fund Effective Vaccine Management (EVM 2.0) criteria with energy-aware transport planning, solar-hybrid edge refrigeration, phase-change materials, and digital temperature monitoring compliant with ISO 23412 for temperature-controlled delivery services. In this study, a mixed-methods methodology was employed, including (1) route and mode optimization under temperature risk and carbon intensity constraints; (2) equipment right-sizing using duty-cycle energy models and IEC 60068 environmental tests as design baselines; (3) governance with real-time earned value management (EVM) and key performance indicators (KPIs); and (4) scenario analysis for riverine, road, air, and drone last-mile segments relevant to remote East Malaysian communities. Results from realistic logistic scenarios indicate a 45–65% reduction in dose-weighted temperature-excursion minutes, 28–41% reduction in CO₂e per successful dose delivered, and 35–52% reduction in product loss compared with status quo planning. For blood components, solar-hybrid storage and mixed-mode routing reduced breach risk by 37% while maintaining red cells (2–6 °C), platelets (20–24 °C, continuous agitation surrogate), and fresh frozen plasma (≤−18 °C) requirements aligned with WHO guidance and Malaysia’s national transfusion policies. We provide a reference architecture, implementation bill of materials, and an EVM-aligned KPI dashboard to guide scale-up. Full article

Infertility affects a substantial proportion of women of reproductive age and is frequently associated with impaired endometrial receptivity. Successful implantation depends on tightly regulated hormonal, immune, apoptotic, and stress-response pathways within the endometrium. This pilot study aimed to evaluate the expression and distribution of granulocyte colony-stimulating factor (G-CSF), bone morphogenetic proteins 2/4 (BMP-2/4), heat shock protein 70 (HSP-70), apoptosis, progesterone, estrogen, and pentraxin-3 (PTX-3) in the endometrium of infertile women across different menstrual cycle days. A descriptive cross-sectional analysis was performed on endometrial tissue samples obtained from six infertile women aged 21–49 years at various menstrual cycle days. Routine histology, immunohistochemistry, TUNEL assay, and chromogenic in situ hybridization were used to assess tissue morphology, protein expression, apoptotic activity, and PTX-3 gene expression. Quantitative evaluation was applied to immunohistochemical markers and apoptosis, while PTX-3 expression was assessed semi-quantitatively. G-CSF expression showed low-to-moderate levels with a relative mid-cycle increase. BMP-2/4 demonstrated the highest overall positivity across most cycle days, with marked inter-sample variability. HSP-70 exhibited pronounced cycle-dependent variability. Apoptotic activity increased toward mid-to-late cycle days. Progesterone and estrogen positivity was heterogeneous and limited to selected cycle days. PTX-3 gene expression was highest during mid-cycle days and decreased toward later phases. No clear association with patient age was observed. Conclusions: The findings indicate distinct and cycle-dependent patterns of immune, morphogenetic, apoptotic, hormonal, and inflammatory markers in the endometrium of infertile women. These results highlight the dynamic nature of endometrial regulation and suggest that altered temporal coordination of these pathways may contribute to impaired endometrial receptivity. Full article

The electrochemical reuse of spent graphite from the negative electrodes of lithium-ion batteries is influenced by regeneration-induced changes in near-surface chemical and defect states. These states govern solid electrolyte interphase (SEI) re-formation, particularly when bulk contaminants are suppressed. Acidic malic-acid leaching and ethylenediaminetetraacetic acid chelation under alkaline conditions (pH 8.7) were compared under similar operating parameters to isolate the role of the leaching environment. This was followed by heat treatment at 1200 °C to decouple chemical cleaning from structural restoration. Both methods reduced the total impurities from 217.85 ppm to ~1.8 ppm, approaching that of commercial graphite. Despite the comparable bulk purity, depth-resolved X-ray photoelectron spectroscopy after formation cycling revealed distinct outermost surface states relevant to SEI re-formation: acidic processing yielded a more oxygenated carbon signature and higher LiOH fraction at the outermost surface (~16%), whereas alkaline chelation produced a more graphitic, carbonate-dominated surface with lower LiOH (~7%). Electrochemical and impedance measurements were consistent with these differences, suggesting that after the bulk impurities were minimized, resistance development was largely governed by the leaching-conditioned near-surface state, which biased the SEI composition. The comparison under matched conditions linked the regeneration environment to SEI-relevant surface speciation and provided a mechanistic basis for selecting regeneration routes to reuse spent graphite as a negative-electrode active material. Full article

Escalating climate change and the increasing frequency of weather extremes pose a threat to the resilience of urban environments and human health, highlighting the urgent need for implementing energy-efficient interventions and reducing building cooling loads. This study investigates the passive building envelope retrofit technologies of external shading, electrochromic windows, and thermochromic windows through a multi-criteria evaluation analysis based on energy savings, economic performance, and indoor thermal comfort improvement. Thermochromic windows are discerned by a mean colour transition temperature of 34 °C and operate throughout the entire year, while electrochromic windows are activated only during cooling periods. Both technologies present total solar transmittance indices of 72.6% and 8.4% in the bleached and tinted state, respectively. External shading devices are either static or movable, applied with an inclination angle, and are either standalone interventions or combined with chromogenic glazing. Eight retrofit scenarios are investigated for a single-story, fully electrified residential building in Athens, Greece. The building features south- and east-oriented windows, which is an appropriate case to assess the effectiveness of these passive envelope cooling technologies in regulating solar heat gains. Thermal comfort is assessed using Fanger’s PMV (predicted mean vote) and PPD (Predicted Percentage of Dissatisfied) indices. The combination of electrochromic windows and movable external shading yields the highest annual electricity savings at 22.2% and reduces the PPD by 15.8%. Local static shading, on the other hand, ranks as the optimal retrofit solution in terms of economic performance, with a life-cycle cost of €6378, a 9.3% improvement in thermal comfort, and a corresponding reduction of 626 thermal discomfort hours. While the proposed multi-criteria framework can be applied to other buildings and climates, the quantitative results reported here are linked to the specific case examined: a residential building with south- and east-facing glazing in Athens, Greece, representing Mediterranean climatic conditions. Full article

The aqueous phase (AP) produced during hydrothermal liquefaction (HTL) contains high organic loads and a chemically complex mixture of dissolved intermediates, posing significant environmental management challenges. Aqueous phase recycling (APR) has emerged as a strategy to enhance bio-crude yield, improve energy recovery, and reduce freshwater consumption by reintroducing reactive water-soluble species into subsequent cycles. However, repeated recycling can lead to the accumulation of N-containing compounds and phenolics, potentially diminishing bio-crude quality and heating value through secondary polymerization and condensation reactions. Simultaneously, the carbon and nutrient-rich character of AP presents opportunities for valorization via anaerobic digestion, microalgae cultivation, and supercritical water gasification. Despite growing interest, APR-HTL research remains feedstock-specific, and a systematic understanding of AP compositional evolution across multiple recycling cycles is limited. This review synthesizes recent progress, highlighting mechanistic linkages between AP composition, bio-crude performance, and integrated biorefinery strategies. Full article

Ascorbate peroxidase (APX) is a heme-containing enzyme involved in hydrogen peroxide (H₂O₂) detoxification within the ascorbate–glutathione (AsA–GSH) cycle. In this study, the full-length genomic DNA and cDNA of an APX1 gene (VsAPX1) were cloned and characterized from Vicia sativa. The genomic sequence of VsAPX1 is 2425 bp in length and comprises 10 exons separated by nine introns, with the first intron located within the 5′ untranslated region (5′UTR). The corresponding cDNA is 1010 bp long and includes a 61 bp 5′UTR, a 753 bp open reading frame, and a 196 bp 3′UTR. VsAPX1 encodes a predicted cytosolic APX protein of 250 amino acids, with a molecular weight of 27.1 kDa and a theoretical isoelectric point (pI) of 5.60. Bioinformatics analysis revealed that the deduced VsAPX1 protein shares high sequence similarity with cytosolic APX1 proteins from other plant species, contains conserved APX domains, and clusters within the cytosolic APX clade in phylogenetic analysis. Quantitative real-time PCR analysis showed that VsAPX1 expression exhibits transient and moderate changes in response to abiotic stress and phytohormone treatments. Transcript levels increased at early time points following heat stress (42 °C), abscisic acid, and salicylic acid treatments, and after 4 h of jasmonic acid exposure, whereas hydrogen peroxide treatment resulted in a gradual down-regulation of expression. Overall, this study provides the first molecular and expression characterization of a cytosolic APX1 gene from Vicia sativa and establishes a foundation for future functional analyses of antioxidant genes in this species. Full article

This study explores the application of immobilized phospholipase A1 (PLA1) on hollow double-layer mesoporous silica nanoparticles (PLA1@NH₂/C₈-HdlMS) for the degumming of crude arachidonic acid (ARA) oil for the first time. The immobilized enzyme was comprehensively characterized, and the reaction conditions were optimized via single-factor experiments. Under the optimized conditions (enzyme dosage 0.3% w/w, 35 °C, water addition 3%, and reaction time 90 min), PLA1@NH₂/C₈-HdlMS achieved a remarkable phosphorus removal rate of 97.9%, reducing the phosphorus content from 441.21 mg/kg to 9.29 mg/kg in 90 min (well below the food-grade standard of <10 mg/kg). The fatty acid composition of the oil remained almost unchanged, while the oxidative induction time of the degummed oil significantly improved by 42%. Notably, PLA1@NH₂/C₈-HdlMS demonstrated broad applicability across crude oils, with initial phosphorus contents ranging from 294.98 mg/kg to 537.44 mg/kg, and it maintained ~93% of its initial activity after 11 reuse cycles. Compared to traditional hydration degumming (with a phosphorus removal rate of 56.3%), this enzymatic method offers superior efficiency at lower temperatures, minimizing energy consumption and the thermal degradation of ARA. This green, efficient, and sustainable method for degumming heat-sensitive oils offers significant potential for the industrial application of high-quality functional oils by preserving PUFA integrity and reducing environmental impact. Full article

Coffea canephora cultivation areas in Brazil are frequently exposed to successive cycles of water deficit, triggering plant stress responses. In addition to water deficit, increased air temperature can act as a second stress factor. The recurrence of these stress factors may induce plant tolerance mechanisms, potentially mitigating future stress responses even of a different stress nature. We hypothesized that repeated cycles of water deficit can trigger tolerance mechanisms that make C. canephora leaves more resilient to supra-optimal temperatures. To test this hypothesis, young C. canephora plants were grown under non-limited water conditions for seven months (Ψ_mSoil > −20 kPa), after which they were subjected to two consecutive cycles of water deficit (Ψ_mSoil < −300 kPa), followed by rehydration. Two clones were used, ‘A1’ and ‘3V’, previously classified as drought sensitive and tolerant, respectively, considering the dynamics of physiological and architectural responses. After the second cycle, leaf discs were collected from completely expanded leaves formed during the two stress cycles and exposed to heat treatments (35 °C, 40 °C, 45 °C, 50 °C, and 55 °C) for 15 min in a water bath. Chlorophyll a fluorescence emission was then monitored, and the results were analyzed using OJIP transient kinetics and the JIP_Test. High temperatures induced negative changes in both OJIP kinetics and JIP_Test-derived parameters. A significant increase in F₀ and a reduction in F_M were observed mainly at 50 °C and 55 °C, due to changes in the stages of the OJIP curve. These changes impacted the “energy connectivity” and consequently the electron transport along the electron transfer chain (ETC), increasing energy dissipation, as confirmed by the JIP_Test variables. Despite the high temperature impacts, previous water deficit induced heat tolerance in clone ‘A1’, while it increased sensitivity in clone ‘3V’. This study suggests that selecting drought-resistant varieties should consider their subsequent response to short high-temperature stress to avoid cross-sensitivity caused by selecting for a single environmental factor. Full article

Addressing the challenges in predicting carbon–water fluxes in cold, temperate coniferous forests—specifically, the strong heterogeneity of driving factors, the significant non-linearity of processes, and the lack of consistency of ecological mechanisms in data-driven models—this paper constructs a Multi-Channel Fusion Attention BiLSTM (MCF-ABiLSTM) model. This model is designed for the joint prediction of Net Ecosystem Exchange (NEE) and Latent Heat Flux (LE). The model adopts a multi-channel structure to separately characterize meteorological, soil, and historical flux information, combining channel attention and temporal attention mechanisms to enhance the identification of key driving factors and critical temporal scales. On this basis, dynamic Water Use Efficiency (dWUE) and Sensitivity of Carbon–Water (SCW) indices are proposed to characterize the synergistic response features of carbon uptake and evapotranspiration under humidity and temperature gradients. The stable ecological relationships revealed by these indices are explicitly introduced into the model training process as ecological process consistency constraints, thereby guiding the model to adhere to known physiological mechanisms while improving prediction accuracy. Experimental results demonstrate that the MCF-ABiLSTM model outperforms various benchmark models in predicting both NEE and LE. Furthermore, flux contribution decomposition results indicate that the model’s response structure to environmental drivers is highly consistent with the known carbon–water coupling mechanisms of cold, temperate coniferous forests. This study achieves organic integration of high-precision carbon–water flux prediction, ecological process constraints, and mechanism analysis, providing a modeling framework that possesses both predictive capability and ecological interpretability for research on the carbon–water cycle in cold, temperate forest ecosystems. Full article