Search Results (2,260)

In the development of carbonate reservoirs via water flooding huff-n-puff, the osmotic pressure effect is frequently overlooked, and existing models inadequately quantify the matrix imbibition and oil expulsion driven by salinity gradients. To address this issue, this study establishes a coupled oil–water two-phase huff-n-puff flow model for carbonate reservoirs that incorporates the interplay between salt concentration and osmotic pressure, which, for the first time, fully couples the van ’t Hoff osmotic pressure equation with solute transport equations for fractured-vuggy carbonate huff-n-puff, filling the gap that prior tight/shale reservoir low-salinity flow models fail to adapt to cyclic injection-soaking production regimes of carbonates. Based on the IMPES (implicit pressure–explicit saturation) numerical simulation method, an equivalent single-nucleus model is adopted to characterize the fractured-vuggy reservoir architecture. The model integrates the osmotic pressure formula, solute transport equation, and two-phase seepage governing equations, enabling a systematic analysis of the mechanisms by which osmotic pressure affects the multi-stage seepage process and the influence of key parameters on development performance. Quantitative simulation reveals three core laws controlled by salinity-induced osmosis: first, osmotic pressure drives water molecules to spontaneously migrate from the high-permeability fracture inner core toward the tight matrix pores, thereby modifying the water saturation distribution, expanding the water sweep region, and smoothing the saturation gradient between the inner and outer cores, which effectively mitigates water channeling in fractured reservoirs. Under the base case (injected water salinity = 1000 mg/L, inner-core permeability = 1000 mD, shut-in time = 80 d), the oil recovery factor with osmotic pressure considered reaches 13.46%, representing a 3.50% increment over the case without osmotic pressure. The recovery factor decreases monotonically with increasing injected water salinity, while it increases with longer shut-in time and higher inner-core permeability, both exhibiting pronounced diminishing marginal returns; the optimal shut-in time is approximately 80 d under the simulated conditions. This work delivers a fully coupled numerical tool and quantitative evaluation standard for osmotic imbibition mechanisms in fractured-vuggy carbonates. The quantified recovery increment and optimal soaking window established herein can directly guide field parameter optimization of injection water salinity, shut-in cycle and fracture reconstruction scale, balancing oil increment revenue and water treatment/well shutdown operation costs for on-site low-salinity huff-n-puff design. Full article

With the increasing environmental concerns about carbon dioxide emissions and the pressing demand for sustainable resources, photosynthetic microorganisms have gained considerable attention as alternative platforms for the environmentally friendly production of fuels and chemicals. These organisms function as green cell factories capable of directly converting carbon dioxide into organic carbon metabolites using solar energy, offering a promising platform for more sustainable biomanufacturing. Among these organisms, cyanobacteria, and particularly Synechocystis sp. PCC 6803, have emerged as particularly attractive hosts due to their relatively simple cellular organization, efficient photosynthetic metabolism, and amenability to genetic manipulation. In addition to rational metabolic engineering approaches, Adaptive Laboratory Evolution (ALE) has recently been proposed as a powerful strategy to improve Synechocystis strain robustness, enhance tolerance to environmental and metabolic stresses, and optimize cellular performance under specific growth conditions. By selecting beneficial spontaneous mutations over successive generations, ALE could complement genetic engineering strategies and further expand the potential of cyanobacterial platforms for efficient and sustainable bioproduction. Full article

Background/Objectives: Postharvest fungal decay caused by Botrytis cinerea and Monilinia fructicola poses major threats to global fruit security. Driven by the need for sustainable crop protection agents, this work presents the systematic synthesis, biological evaluation, and computational modeling of a comprehensive 33-compound library of 3-acyl-bromoindole regioisomers (series 4a–k, 5a–k, and 6a–k) to establish clear structure–activity relationship (SAR) design rules. Methods: The regioisomeric library was assembled via a microwave-assisted catalytic protocol in an ionic liquid, expanding the known chemical space with seven newly synthesized 4-bromoindole derivatives (4d–f, 4h–k). Primary in vitro data were modeled using Hansch QSAR and Principal Component Analysis (PCA). Postharvest in vivo efficacy was evaluated on fresh ‘Lapins’ sweet cherries inoculated with M. fructicola. Molecular docking and 100 ns molecular dynamics (MD) simulations were performed against succinate dehydrogenase (SDH) and M. fructicola catalase 2 (MfCat2). Results: In vitro screening demonstrated marked target selectivity: parent core 4 displayed high mycelial suppression against M. fructicola (EC₅₀ = 7.05 µg/mL), whereas C3-acylation with a four-carbon linear chain (4c) achieved optimal broad-spectrum dual action (98% and 86% spore germination inhibition). In vivo cherry bioassays proved that bromoindoles 4, 6a, and 6d significantly suppressed Brown Rot severity to 44–47% (a 20–27% reduction vs. untreated control). Docking and MD trajectories confirmed stable multi-target binding within SDH and MfCat2 active sites (RMSD < 2.0 Å). Conclusions: Bromine regiochemistry dictates pathogen selectivity and life-stage targeting. The novel 4-bromoindole derivatives and multi-target profile establish these scaffolds as promising leads for postharvest crop protection. Full article

Improving cropland carbon performance while maintaining food security is central to China’s agricultural transition and climate goals This study examines low-carbon cropland use performance (PCLU) and its model-implied interprovincial association network across 31 Chinese provinces from 2010 to 2023. A global super-efficiency slacks-based measure model estimated PCLU by incorporating agricultural output, carbon emissions, nonpoint-source pollution, and crop sequestration; annual directed networks were constructed with a modified gravity model and analyzed using social network analysis, a temporal exponential random graph model (TERGM), and complementary quadratic-assignment analyses. Mean PCLU increased from 0.524 to 0.861, while the interquartile range widened from 0.146 to 0.310; network density declined before partially recovering as hierarchy increased, indicating improvement without provincial convergence and reconnection within a more differentiated multi-hub structure. Persistence (β = 4.510) and reciprocity (β = 2.376) dominated network evolution, whereas shared partners produced neither additional triadic closure nor expanding open chains; similarities in urbanization and planting structure favored ties, while rural-income differences reflected socioeconomic complementarity. External validation showed moderate overall correspondence with green-technology patent collaboration (mean annual QAP r = 0.335) but limited overlap among the strongest dyads. Overall, China’s low-carbon cropland transition combined rising but increasingly uneven performance with a path-dependent and selective interprovincial structure, providing an empirical basis for differentiated coordination based on provincial performance and network position. Full article

Carbon dioxide water-alternating-gas (CO₂-WAG) flooding simultaneously enables carbon emission mitigation, improved oil displacement efficiency, and expanded gas sweep coverage. Nevertheless, the field performance of this technology remains significantly constrained by gravity override effects, especially in ultra-thick oil reservoirs. In this work, a synthetic heterogeneous dipping mechanistic reservoir model is constructed. Using a quantitative metric for gravity override index in WAG processes, the variation patterns of gravity override under various operational factors are systematically analyzed. Furthermore, the eXtreme Gradient Boosting (XGBoost) machine learning algorithm is employed to conduct feature importance analysis of the controlling factors, identifying parameters with the most substantial impacts. The results indicate that well spacing, oil production rate, WAG injection strategy, and WAG slug duration all exert pronounced effects on both gravity override index and oil recovery factor. Gravity override is confirmed as the dominant factor governing the production performance of WAG flooding in ultra-thick reservoirs. In addition, an optimal combination of operational parameters exists that counterbalances the adverse effects of gravitational and viscous forces, thereby maximizing gas sweep efficiency, delaying gas breakthrough, and enhancing oil recovery. This study provides valuable insights and technical guidance for gas channeling mitigation, vertical gas sweep improvement, and efficient development of analogous ultra-thick reservoirs. Full article

Land use reconfiguration can substantially alter regional carbon source–sink patterns, yet integrated evidence remains limited for spatially constrained island systems where development and ecological land are closely juxtaposed. Using Hainan Island (HI) as a case, this study applied an integrated analytical framework linking land use mix, coefficient-based land use carbon emission (LUCE) accounting, spatial redistribution, spatially varying associations, interaction detection, and decoupling analysis across 18 administrative units from 2000 to 2023. Estimated LUCEs increased more than sevenfold during the study period, with emission growth concentrated mainly in coastal development areas, while the interior remained comparatively low in emissions. The spatial distribution of LUCEs gradually expanded inland, and socioeconomic development, built-up land, terrain, and their interactions exhibited heterogeneous associations with LUCEs across the island. The decoupling relationship between land mixed use and LUCEs generally improved after 2005 but remained unstable in several coastal cities. These results indicate that island-wide LUCE evolution is characterized by spatially differentiated relationships between land development and ecological land configuration rather than by a uniform regional process. By integrating land use structure, coefficient-based carbon accounting, spatial redistribution, heterogeneity in factor associations, and decoupling within a common coast–interior framework, this study provides an analytical perspective that can support comparable land use carbon assessments in islands and coastal regions experiencing concentrated development and strong ecological constraints. Full article

In the manufacturing of carbon fiber/epoxy composites, different stacking sequences have different effects on the void inside materials. In this paper, the double-vacuum-bag (DVB) process was utilized to fabricate laminates with different stacking sequences, including different angles, different thicknesses and plain weave prepregs, and the single-vacuum-bag (SVB) process was set as the control group. The void content of different laminates in the cross-section was counted by image analysis software, and material thickness, density, and fiber volume fraction were measured by experiments. Three-point bending and short-beam-shear tests were conducted to evaluate the material mechanical properties. The results show that the void contents of laminates prepared by the DVB process are all less than 1% with different stacking sequences, while the laminates manufactured by the SVB process contain a large number of voids inside. The density and fiber volume fraction of the DVB process are higher than those of the SVB process. In terms of mechanical properties, the flexural strength and interlayer-shear-strength (ILSS) of the DVB process are higher than those of the SVB process. The results of this paper expand the application of the DVB process and provide a reference for low-cost manufacturing of composite materials. Full article

The long-term accumulation of polyethylene terephthalate (PET) in marine environments may drive the evolution of microbial degradation capabilities, positioning the ocean as a valuable reservoir for discovering novel PET-degrading microorganisms. In this study, we isolated 305 marine-derived microorganisms with potential PET-degrading capability from samples collected from mangrove areas of Zhanjiang and the intertidal zones of Daya Bay, Shenzhen, China, using PET powder as a major carbon source. Subsequent evaluation of degradation performance via scanning electron microscopy and Fourier-transform infrared spectroscopy analysis identified 14 isolates capable of degrading PET film. These 14 strains belonged to 14 distinct species, none of which, to the best of our knowledge, has been previously documented as PET degraders. Among them, Microbacterium aurum SCSIO 85700 exhibited the most potent PET-degrading activity, achieving a weight loss of 2.1 mg (2.1%) and a 6.5% increase in relative crystallinity over 30 days. Genome analysis revealed the genetic basis underlying PET degradation and associated metabolic pathways in strain SCSIO 85700. Notably, genome mining and structural modeling identified two candidate polyester hydrolases, MA2267 and MA2443, possessing conserved His–Asp–Ser catalytic triads and exposed substrate-binding clefts resembling those of characterized PET-degrading enzymes, suggesting their potential involvement in PET depolymerization. Collectively, this study expands the recognized diversity of marine PET-degrading microorganisms and provides microbial resources for sustainable PET bioremediation. Full article

Low seawater temperatures constrain the operation of open rack vaporizers (ORVs) and intermediate fluid vaporizers (IFVs), while also increasing pumping-related emissions at LNG terminals. This study establishes a carbon-oriented framework for an expanded ORV–IFV regasification system sharing a fixed-speed seawater pump network and evaluates thermal discharge from an adjacent power plant as a supplementary heat source. Using measured LNG composition, we developed an Aspen HYSYS model based on the Peng–Robinson equation of state and steady-state energy balances, which was validated against field data. Electricity-related CO₂ emissions from seawater pumps and auxiliaries were quantified using the regional grid emission factor, while pump scheduling was formulated as a mixed-integer nonlinear programming (MINLP) problem. Model predictions differed from measurements by approximately 2%. Lower seawater temperatures increased emissions and restricted maximum regasification capacity to 80% and 57% of the design value at 3–4 °C and 2–3 °C, respectively. For LNG throughputs of 300, 500, and 700 t/h, CO₂ reduction increased with warm-seawater flow and inlet temperature; maximum reductions reached approximately 50–55% under 3–7 °C ambient seawater conditions and 40% under 6–20 °C conditions, with a 95% confidence interval of ±3.9 percentage points. Monthly discharge data indicated reductions of approximately 20% in winter and 45% in summer. Integrating power-plant waste heat with load-dependent pump scheduling can improve the carbon performance of LNG regasification. Full article

Chemical glycolysis can convert waste poly(ethylene terephthalate) (PET) into bis(2-hydroxyethyl) terephthalate (BHET), but recyclable heterogeneous catalysts derived from circular carbon sources and showing low metal release remain limited. Here, post-consumer expanded polystyrene (EPS) was transformed into a hypercrosslinked polymer (HCP) and carbonized with Fe to produce Fe@graphitic-carbon (Fe@C) catalysts for PET glycolysis. The catalysts are denoted mFe@EPS-HCP₈₀₀, where m represents the nominal Fe loading (wt.%), and 800 is the carbonization temperature (°C). The optimized 5Fe@EPS-HCP₈₀₀ contained graphitic carbon layers, bamboo-like carbon nanotube (CNT) domains, hierarchical porosity, and Fe-rich domains associated with graphitic carbon coverage. Under atmospheric-pressure conditions (PET, 2.00 g; ethylene glycol, 20.00 g; catalyst, 0.20 g; 200 °C; 2 h), it achieved complete PET conversion and 94.6% BHET yield. The catalyst also maintained BHET yields of ca. 90–94% over ten reuse runs, and post-reaction microscopy confirmed the retention of graphitic carbon layers and Fe-containing domains. Fe was below the detection limit in the product solutions for the 1, 3, and 5 wt.% Fe catalysts, whereas 7Fe@EPS-HCP₈₀₀ released 9.1 mg kg⁻¹ Fe, consistent with incomplete carbon coverage at excessive Fe loading. Conversion profiles followed an Avrami–Erofeev/Weibull model, giving an apparent activation energy of 205.6 kJ mol⁻¹. The data support a two-stage pathway in which external graphitic carbon/CNT domains promote primary PET chain scission to soluble oligomers, followed by Fe@C interfacial secondary glycolysis to BHET. This work demonstrates dual waste-polymer valorization by using EPS waste as catalytic infrastructure for PET chemical recycling. Full article

The growing demand for energy in agro-industrial systems has increased the need for forest biomass in regions of expanding commercial forestry, such as Mato Grosso State, Brazil. However, information on how genetic material and harvest age influence the energy properties of eucalyptus wood under local edaphoclimatic conditions remains limited. This study evaluated the energy potential of wood from different eucalyptus clones and harvest ages intended for industrial combustion in Mato Grosso. Clones H13, VM01, and H15 were assessed at 54 months of age. To investigate the effect of harvest age, clone VM01 was also evaluated at 54, 108, and 144 months. All samples were collected from a commercial plantation located in Brasnorte, Mato Grosso, Brazil. Morphological, physical, chemical, and energy-related wood properties were determined. Among the evaluated clones, VM01 showed the highest energy potential, with energy production reaching 674.62 Gcal ha⁻¹, approximately 53% higher than H15. Clone H13 presented the highest lignin and fixed carbon contents, while H15 exhibited the highest extractives content. Regarding harvest age, wood maturation led to increases in basic density (15.9%), extractives content, and fixed carbon content, along with reductions in ash content, volatile matter, and the elemental ratios H/C, N/C, and O/C, indicating a gradual improvement in biomass energy quality with increasing harvest age. These results provide technical support for clone selection and harvest age optimization, contributing to more efficient use of eucalyptus wood as a renewable energy source in tropical regions where commercial forestry is expanding. Full article

Artificial intelligence (AI) data centers are creating large, power-dense loads, often faster than transmission lines, substations, transformers, and grid interconnections can be expanded. This review assesses whether solid oxide fuel cells (SOFCs) can provide dependable on-site power during these grid delivery constraints and remain competitive after grid capacity becomes available. We critically synthesized evidence on AI electricity demand, competing power supply options, SOFC efficiency and durability, commercial deployments, environmental impacts, thermal and electrical integration, and hybrid SOFC–battery–grid systems. We also performed a screening-level levelized cost of electricity sensitivity analysis covering natural gas prices, carbon costs, stack replacement, grid electricity prices, and the avoided cost of delayed grid access. The evidence indicates that commercial SOFC systems can achieve approximately 50–60% net electrical efficiency and scale modularly from 325 kW units to a planned deployment of up to 2.45 GW. A nominal 100 MW installation would require approximately 308 such modules and at least 3600 m² of direct equipment area, excluding auxiliary systems and safety setbacks. However, multi-year durability targets of about 40,000 h, fuel and carbon price exposure, slow transient response, lifecycle methane emissions, and limited opportunities to use high temperature exhaust heat remain important constraints. The economic analysis indicates that avoided grid delay costs can justify SOFCs as bridge assets, whereas long-term retention requires competitiveness without this temporary benefit. SOFCs are therefore most suitable for sites that prioritize rapid access to firm power, modularity, reliability, and low local air pollutant emissions, rather than as a universal alternative to grid expansion. Full article

Vegetation carbon sinks are an important component of the terrestrial carbon cycle, and net ecosystem productivity (NEP) is widely used to indicate ecosystem carbon-sink strength. However, the long-term dynamics and environmental associations of vegetation carbon sinks in the middle and lower Yellow River Basin remain insufficiently understood. Based on remote-sensing net primary productivity (NPP) and an empirical heterotrophic-respiration model, annual NEP was estimated for 2001–2024. Theil–Sen trend analysis, the Mann–Kendall test, coefficient of variation, optimal-parameter geographical detector (OPGD), and regression residual analysis were applied. Basin-mean annual NEP increased from approximately 214 to 425 g C m⁻² yr⁻¹, with significantly increasing areas accounting for 89.93% of the study area. Areas with NEP above 300 g C m⁻² yr⁻¹ expanded from 18.51% to 78.86%. Precipitation and solar radiation showed the highest explanatory power for NEP spatial differentiation, with mean q values of 0.538 and 0.490, and their interaction reached 0.722. Comparison with a published NEP product, parameter-sensitivity analysis, and an NPP-based robustness test supported the main temporal patterns and factor rankings. The residual-derived non-climatic component exceeded 40% of the combined component-trend magnitude across approximately 94% of the study area, but should not be interpreted as a direct measure of human activities. These findings support regional carbon-sink monitoring, water-constrained ecological restoration, and land-use management. Full article

High-temperature heat pumps are a promising pathway for electrifying industrial process heat, but their application to large-temperature-glide duties remains technically challenging. Milk powder spray drying is one such application, requiring air heating to approximately 200 °C while offering only low-to-medium-temperature waste heat sources. Transcritical CO₂ heat pumps are attractive for this duty because the sensible cooling profile of supercritical CO₂ can be matched to the large temperature glide of air heating. However, the high operating pressures required in transcritical CO₂ cycles lead to substantial expansion losses, creating a potential opportunity for expansion work recovery. This study evaluates ejector- and expander-based expansion work recovery in high-temperature transcritical–transcritical CO₂ heat pump cycles for spray dryer air heating. Baseline and modified cycle configurations were modelled using steady-state thermodynamic analysis and compared using heating coefficient of performance, maximum achievable sink temperature, component-level exergy destruction, and discharge-pressure sensitivity. Under the investigated conditions and assumed component efficiencies, expanders improved the COP of all evaluated cycles. TTX-2 achieved a COP of 2.35, 5.4% above its corresponding TT-2 baseline. TT-2 and the external benchmark TT-4 each achieved a COP of 2.23 at 150 bar for the investigated duty. The comparison with TT-4 is a benchmark comparison, not an evaluation of a TT-4 recovery variant. The improvement was modest, and an upper-bound break-even expander cost of approximately 150 EUR/kW of delivered heat was estimated for the most favourable expander case. Ejector cycles reduced expansion losses in some cases but did not provide a clear cycle-level COP improvement because they altered compressor pressure ratios, gas-cooler outlet conditions, and cascade heat transfer performance. These findings apply to the investigated spray dryer duty and demonstrate that reducing expansion exergy destruction alone is insufficient to guarantee improved whole-cycle performance under the stated operating and component-efficiency assumptions. Full article

Global climate change threatens regional biodiversity, yet multi-model assessments tracking future range shifts of endangered mammals remain limited. This study evaluated future habitat suitability for five legally protected terrestrial mammals in the Republic of Korea (Lutra lutra, Martes flavigula, Prionailurus bengalensis, Naemorhedus caudatus, and Pteromys volans). Using the MaxEnt framework, we projected distributions across four Shared Socioeconomic Pathways (SSPs) and future horizons (2021–2100) using five CMIP6 global climate models (GCMs). Projections revealed distinct, species-specific dynamics across consensus models. Four taxa (L. lutra, P. bengalensis, N. caudatus, and P. volans) exhibited progressive range contractions, with suitable habitats declining by −95% to −100% under high carbon emission scenarios. Conversely, M. flavigula demonstrated expanding trajectories, reflecting high-latitude range-edge responses. Prominent inter-model variations in the INM-CM5-0 and BCC-CSM2-MR models highlighted predictive uncertainties. We conclude that real-world habitat occupancy will be heavily constrained by non-climatic anthropogenic barriers, including fence networks, road systems, and climate-driven extensive wildfires. Consequently, proactive conservation should prioritize reinforcing verified contemporary core habitats along the Baekdudaegan Mountain Range and establishing structural corridors rather than relying solely on volatile bioclimatic projections. Full article