Search Results (251)

In gas-condensate reservoirs, the phase behavior of reservoir fluids is inherently dynamic during pressure depletion. When the rate of external pressure decline exceeds the intrinsic relaxation rate governing phase equilibrium, the system deviates from thermodynamic equilibrium and exhibits pronounced non-equilibrium effects. These transient behaviors significantly influence fluid properties; meanwhile, conventional equilibrium models neglect phase transition lag, resulting in inaccurate phase behavior and biased production predictions. In this study, a non-equilibrium dynamic phase transition model is developed to quantitatively couple the pressure depletion rate with the relaxation kinetics of the system. This model, established based on controlled non-equilibrium phase transition experiments performed on the condensate-gas fluid investigated in this work, provides an analytical framework for describing the temporal evolution of phase behavior under dynamic conditions. Model validation through integrated experimental measurements and numerical simulations shows good agreement between calculated and measured results for the studied condensate-gas system, with average relative errors below 5%. Results reveal that accelerated pressure depletion strengthens non-equilibrium effects. At a rate of 15 MPa/h, the relative volume and retrograde condensate saturation decrease by 9.09% and 5.38%, respectively, while condensate recovery improves by 13.85%. Moreover, the characteristic relaxation time toward equilibrium exhibits a strong dependence on the depletion rate, increasing as the depletion rate rises. This work provides an experimentally constrained analytical framework for describing rate-dependent non-equilibrium phase behavior during pressure depletion and for interpreting its impact on condensate recovery in the specific condensate-gas system studied. Although the governing framework may be transferable to other rate-sensitive hydrocarbon systems after fluid-specific recalibration, the parameterized analytical model and validation presented in this study are limited to the investigated condensate-gas fluid, and its applicability to other hydrocarbon fluid types remains to be evaluated in future studies. Full article

Transcriptional bursting, the stochastic production of mRNA in episodic pulses, is a fundamental source of cell-to-cell heterogeneity. In pluripotent stem cells (PSCs), these bursting dynamics at core pluripotency loci are not just noise but critical determinants of identity maintenance and lineage commitment. This review synthesizes current quantitative frameworks for dissecting bursting kinetics and elaborates on the multilayered regulatory hierarchy that governs them, ranging from promoter-intrinsic features and 3D genome architecture to the formation of transcriptional condensates via liquid–liquid phase separation (LLPS). By integrating findings from genomic profiling and live-cell imaging, we highlight how the integrated action between super-enhancers and epigenetic states shapes the unique bursting dynamics in PSCs. Furthermore, we explore the functional consequences of these kinetics in pluripotency surveillance and cell fate decisions. Collectively, this review establishes a unified regulatory framework, providing novel insights for understanding stem cell heterogeneity and offering key insights for regenerative medicine. Full article

The efficient adsorption and storage of gases within nanoporous materials are critical for technologies such as adsorbed natural gas systems and energy storage. A paramount goal is to maximize the adsorbent’s gas uptake capacity. However, the fundamental relationship between pore structure and adsorption performance in disordered aerogels remains unclear, hindering rational material design—specifically, where within the complex pore network adsorption predominantly occurs and how the pore size distribution (PSD) should be engineered to enhance capacity. To address this, we conduct molecular dynamics simulations investigating nitrogen adsorption in silica aerogels with tunable PSDs (achieved via tensile deformation) and varied gas–solid interaction strengths (ε). Our results reveal a kinetic-capacity trade-off: microporous-dominated structures saturate rapidly but have limited total uptake, whereas structures with developed mesoporosity (2–10 nm) achieve higher equilibrium capacity via capillary condensation, despite slower kinetics. The interaction strength ε is identified as a key factor governing both capacity and selectivity. Synthesizing these insights, we establish dual design guidelines: to maximize storage capacity, a hierarchical network combining micropores and interconnected mesopores is essential; for optimal reversible performance in cyclic applications like adsorbed natural gas, prioritizing open mesopores with moderately tuned surface chemistry is key. This work clarifies key aspects of the structure–performance relationships and provides evidence-based design guidelines for designing advanced aerogel adsorbents tailored for efficient, low-pressure gas storage. Full article

We report the synthesis of the new compound 2-chloro-4,5,6,7-tetrafluoro-2-(methylthio)-1H-indene-1,3(2H)-dione (Compound 3), which presents an important type of fluoro-containing heterocycles and is a useful intermediate product in organic synthesis. The structure of the compound was confirmed by the NMR and elemental analysis. A quantum-chemical comparison (DFT) of 2-chloro-2-(methylthio)-1H-indene-1,3(2H)-dione (with C-H bonds, compound 4) and its 4,5,6,7-tetrafluoro derivative (with C-F bonds, compound 3) at the M06-2X/6-311++G(d,p) level in THF showed that the introduction of four fluorine atoms into the benzene ring causes a systematic shortening of the C=O, C-Cl, and C-C bonds of the five-membered ring, as well as an almost twofold decrease in the dipole moment. Replacing hydrogen with fluorine leads to a simultaneous stabilization of the frontier orbitals and a narrowing of the HOMO–LUMO energy gap, while the electron affinity increases by 0.39 eV and the electrophilicity index increases from 2.77 to 3.24 eV, making compound 3 a strong electrophile. Analysis of donor–acceptor interactions (NBOs) and condensed Fukui indices confirms that perfluorination selectively increases the electrophilicity of the sp³-carbon center of C-Cl, making it more susceptible to nucleophilic attack. At the same time, the isodesmic reaction with 1,2,4,5-tetrafluorobenzene yields a positive free energy change (ΔG = +13.4 kcal/mol), indicating that the increased reactivity of compound 3 is kinetic rather than thermodynamic in nature. The synthesized 1,3-indandione derivative thus represents a promising precursor for tetrafluoroninhydrin and can be considered a biologically active compound. Thus, perfluorination of the indandione skeleton is an effective tool for targeted enhancement of electrophilic properties without fundamentally changing the geometry of the molecule, which opens up prospects for the design of new highly reactive reagents. Full article

Submicron particulate matter in the 0.1–1.0 µm range is difficult to remove using conventional air pollution control devices because of its low capture efficiency. Condensation-induced particle enlargement has therefore been proposed as a preconditioning method to increase particle size before collection. This study aims to numerically investigate the condensation-induced growth of submicron particles in a cylindrical tube under different pressure-recovery conditions and to clarify how pressure-controlled supersaturation affects droplet-growth kinetics. A three-dimensional computational fluid dynamics (CFD) model was developed in ANSYS Fluent by coupling the Discrete Phase Model (DPM) with a custom User-Defined Function (UDF) growth law to predict droplet growth, condensation time, and associated heat and mass transfer characteristics. Initial particle diameters of 0.1–1.0 µm were examined for growth to a target diameter of 5 µm under initial pressure conditions of 0.5–0.9 bar followed by recovery to 1 atm, corresponding to calculated nominal supersaturated RH values of 202.65–112.58%, respectively. The results show that pressure-induced supersaturation is the dominant factor controlling condensation kinetics. Lower initial pressures resulted in shorter condensation times and higher mass and heat transfer rates. For an initial diameter of 0.5 µm, the condensation time decreased from approximately 0.1434 s at 0.9 bar to 0.0167 s at 0.5 bar, corresponding to an 88.35% reduction. These findings indicate that pressure-controlled supersaturation can significantly accelerate submicron particle enlargement and provide design guidance for condensation-assisted fine-particle removal technologies. Full article

Addressing the challenges of fluctuating renewable energy integration and stable green ammonia production, this study develops and optimizes a deeply integrated system comprising Solid Oxide Electrolysis Cells (SOEC), Liquid Air Energy Storage (LAES), Air Separation Units (ASU), and Haber–Bosch (HB) synthesis. We constructed a simulation model in Aspen Plus incorporating Ru/C catalyst kinetic parameters to analyze key subsystem parameters and optimize operating conditions based on maximized economy and efficiency. At the integrated system level, a parametric analysis of ammonia condensation temperature was further conducted to investigate the coupling characteristics. Using real power output data from Inner Mongolia, we formulated a dynamic energy scheduling strategy satisfying 24-h self-balancing constraints. Results indicate that a system producing 1415 tons of ammonia per day achieves a maximum hourly integrated profit of 69,838 CNY under optimal conditions: a hydrogen-to-nitrogen ratio of 2.98:1, operating pressure of 169 bar, reactor inlet temperature of 380 °C, and ammonia condensation temperature of −9 °C. Increasing the LAES throttle valve outlet pressure from 1 bar to 9 bar improved round-trip efficiency from 52.65% to 72.18%. The integrated-level parametric analysis reveals that the specific electricity consumption per unit mass of ammonia exhibits a non-monotonic trend with a minimum of 8.67 kWh/kg at −10 °C, reflecting the trade-off between refrigeration power consumption and cold energy recovery. In dynamic scheduling scenarios, the system maintains a maximum constant load of 45.78 MW with a steady-state liquid ammonia output of 6543 kg/h. This work optimizes both economic performance and system stability, providing a significant reference for the large-scale development of green ammonia systems. Full article

Diagnostic latency limits time-sensitive care and early detection, and exhaled breath provides a rapid, repeatable window into metabolic and inflammatory chemistry. We review real-time breath sampling and analytical technologies and evaluate their readiness for clinical adoption, with emphasis on molecular pathways reflected in the breath volatilome and in exhaled breath condensate. Real-time mass spectrometry enables kinetic VOC profiling and targeted quantification, while humidity-aware sensors and wearable condensate platforms extend monitoring beyond the laboratory. Pathway-anchored interpretation links breath readouts to ketone handling, isoprenoid metabolism, nitric oxide signaling, lipid peroxidation, uremic nitrogen handling, and microbiome–host co-metabolism, but performance remains vulnerable to confounding, drift, and non-representative comparators. Translation requires standardized breath fraction control, traceable features, robust quality systems, and governed device algorithm stacks so that breath outputs inform decisions and outcomes. Full article

The transition to renewable carbon resources has positioned lignocellulosic biomass as a key feedstock for sustainable fuel and chemical production; however, its intrinsic recalcitrance limits efficient conversion. Dilute acid pretreatment functions as a homogeneous Brønsted acid catalytic system that selectively depolymerizes hemicellulose and disrupts lignin–carbohydrate complexes, while competing with consecutive sugar dehydration reactions, thereby enhancing downstream processing. This review presents a feedstock-specific analysis of acid catalyzed biomass deconstruction across agricultural residues, woody biomass, and energy crops, with xylose yield employed as a kinetically and mechanistically relevant descriptor of catalytic performance. By correlating proton activity, reaction severity, diffusion constraints, lignin chemistry, and mineral interference with observed conversion behavior, the work establishes a structure–reactivity–performance framework for biomass dependent hydrolysis. Particular attention is given to competing dehydration and condensation pathways that reduce pentose selectivity and generate fermentation inhibitors. The analysis identifies optimal severity windows for maximizing catalytic efficiency while suppressing degradation reactions and provides guidance for feedstock-tailored pretreatment and next-generation acid catalytic systems and reactor configurations in integrated biorefineries. Full article

Environmental fires pose a serious threat to energy security, ecosystems and public safety, whilst traditional halogenated flame retardants suffer from limitations such as high environmental residue risks and insufficient flame-retardant efficacy. In this study, sodium alginate (SA) was utilised as the matrix, with the incorporation of ammonium polyphosphate (APP) and phytic acid (PA), in conjunction with SiO₂-APTES surface modification, to prepare nitrogen–phosphorus synergistic bio-based flame-retardant gels. The present study systematically investigated the influence of the N/P molar ratio on the gelation kinetics, rheological behaviour, microstructure and flame-retardant performance of the gel. The study revealed a nitrogen–phosphorus coupled gas–solid two-phase synergistic flame-retardant mechanism. The results indicate that at an N/P ratio of 1/4, the gel forms a stable dual-network structure comprising ionic cross-links and Si–O–P covalent bonds. In the gas phase, the thermal decomposition of APP releases inert NH₃, which dilutes oxygen and quenches gas-phase radicals (·OH, ·H). In the condensed phase, the phosphate groups of PA-catalysed SA form Si–O–P covalent bonds with SiO₂ under the mediation of APTES, creating a dense, insulating char layer. In comparison with the control group (N/P = 0/0), the optimal gel sample (N/P = 1/4) demonstrated a 33% increase in shear stress, a 10% reduction in the peak heat release rate (HRR), a 75% decrease in total smoke production (TSP), and a 150% increase in char layer thickness after combustion, while maintaining adequate mechanical strength, thermal stability, and environmental friendliness. This work provides novel insights and strategies for the development of green, highly efficient flame-retardant materials for environmental fire prevention and control. Full article

Bioactive glass (BAG) S53P4 is a clinically approved bone substitute with antibacterial, osteoconductive and osteostimulatory properties. Its antibacterial effect is associated with ion release, local pH elevation and osmolality, but the precise biochemical and biophysical mode-of-action is unclear. This study investigates the antibacterial mechanism of BAG S53P4 eluates. BAG eluates, collected at 2, 4, 8, and 24 h, eradicated Staphylococcus aureus. Elemental analysis revealed an early increase in concentrations of Si and Na, a later rise in Ca, depletion of P over time and rapid loss of Mg. Membrane disturbances occurred within 5 min, evident by permeability for SYTOX, aligning with time-kill kinetics for S. aureus and Bacillus subtilis. In B. subtilis, 2h-BAG-eluate induced rapid delocalization of marker proteins for cell division and DNA repair, signaling membrane potential collapse and nucleoid condensation. Transcriptomics revealed early transcription remodeling reflecting ionic and energetic imbalance, including disruption of central metabolism, redox homeostasis, and translational stability. Scanning electron microscopy revealed severe cell surface damage and particulate deposits on S. aureus. Transmission electron microscopy showed cell envelop disruptions and cytoplasmic leakage. Energy dispersive X-ray analysis identified Si on bacterial cell surface at 4 h and intracellular accumulation in punctured, empty cells at 24 h. Overall, BAG ionic dissolution products kill bacteria through a stepwise mechanism involving membrane damage, protein delocalization and metabolic impairment, accompanied by Si deposition on bacterial surfaces and loss of Mg. This finally leads to cell wall degradation, cytoplasmic content leakage and further Si deposition on the cells and inside cell ghosts. Full article

The orange juice industry generates large amounts of waste, leading to significant environmental impacts. Within the framework of a citrus biorefinery, this study evaluates an integrated pilot-scale scheme combining essential oil extraction with hydrolysis of orange waste. A self-designed modular system was used, characterized by ease of operation and maintenance, consisting of a 20 L sealed reactor and a condenser with water recirculation. Essential oil extraction was carried out by hydrodistillation, producing 35 mL of essential oil per run and a yield of 2.57 mL per 100 g of orange peel. Hydrolysis was investigated using a 2³ factorial design considering time (30 and 60 min), waste type (with and without pulp), and H₂SO₄ concentration (0 and 0.25% v/v). ANOVA results showed that the waste type was the dominant factor, while the acid concentration had no significant effect. The optimal hydrolysis condition was waste with pulp, 0% acid, and 30 min, achieving 108.5 g/L of glucose and 30.4 g/L of xylose. Under these conditions, the kinetics of glucose and xylose release were determined. The energy consumption was 45.96 MJ, equivalent to 70.61 kJ/g of glucose and 236.59 kJ/g of xylose, with corresponding costs of 0.0017 and 0.0057 USD/g, respectively. Orange waste containing pulp, obtained directly from juice-processing facilities, exhibits greater valorization potential than orange waste without pulp to produce essential oil, glucose, and xylose within a biorefinery scheme. Full article

Neurodegenerative diseases feature diverse pathological protein aggregates, including Lewy bodies in Alzheimer’s disease (AD) and skein-like filaments in amyotrophic lateral sclerosis (ALS). The physical mechanisms underlying this morphological diversity remain unclear. Here, we demonstrate that aggregation of the prion-like domain of hnRNPA1 (A1PrD), implicated in AD and ALS, is driven by solution composition and phase transition dynamics. Utilizing 3D timelapse and fluorescence lifetime imaging microscopy, we show that solution conditions modulate phase separation, gelation, and fibrillation, resulting in distinct structures such as fibril, gel, and starburst morphologies. Homotypic and heterotypic interactions between A1PrD and RNA were observed to shift the balance between pathological and physiological condensates. Importantly, amyloid-rich starbursts displayed prion-like infection capabilities toward amyloid-poor condensates. Our findings highlight how the interplay between solution composition and kinetic balances of liquid-liquid phase separation, gelation, and fibrillation shapes the diverse pathological aggregate morphologies characteristic of neurodegenerative diseases. Full article

With the expansion of global oil and gas resource exploration and development into deep and ultra deep layers, the efficient development of deep carbonate rock fracture cave reservoirs has become the key to ensuring energy security. However, this type of reservoir commonly faces high temperatures, high salinity, and extremely strong heterogeneity, leading to increasingly severe water content spikes caused by dominant water flow channels. Although the existing traditional inorganic plugging agent has good temperature resistance, it has the defects of great brittleness and easy cracking, while the organic polymer gel is prone to degradation failure under high temperature and high salt environments. In order to solve the above problems, a new biochar-enhanced inorganic composite gel system was constructed by using biochar prepared from agricultural and forestry waste pyrolysis as a functional enhancement component. Through rheological testing, high-temperature and high-pressure mechanical experiments, long-term thermal stability evaluation, and dynamic sealing experiments of fractured rock cores, the reinforcement and toughening laws and rheological control mechanisms of biochar on inorganic matrices were systematically studied. Research has found that a biochar content of 0.5 wt% can significantly improve the micro pore structure of the matrix. By utilizing its micro aggregate filling effect and interfacial chemical bonding, the compressive strength of the solidified body can be increased to over 2 MPa, and there is no significant decline in strength after aging at 130 °C for 30 days. More importantly, the unique “adsorption slow-release” mechanism of biochar effectively stabilizes the hydration reaction kinetics at high temperatures, extending the solidification time of the system to 15 h and solving the problem of flash condensation in deep well pumping. This system exhibits excellent shear thinning characteristics and crack sealing ability, and presents a unique “yield reconstruction” toughness sealing feature. This study elucidates the multidimensional strengthening mechanism of biochar in inorganic cementitious materials, providing technical reference for stable oil and water control in deep fractured reservoirs. Full article

This study examines the influence of SO₂ and its hydrate H₂SO₃ on the free energies of the core autocatalytic cycle of the formose reaction. We find that SO₂ and H₂SO₃ readily condense with aldehyde and alcohol functional groups to form bisulfite analogs of formose proto-metabolites under modeled conditions. The bisulfite functional group can provide intramolecular catalytic enhancement in specific isomers towards aldol additions and the retroaldol step that regenerates two equivalents of glycolaldehyde from tetrose. The bisulfite moiety reduces the favorability of the parasitic Cannizzaro side-reaction both thermodynamically and kinetically, thus potentially furnishing more throughput towards forming sugars. As a prebiotic analog to phosphate, we find that bisulfite slightly stabilizes ribose over its C₅ aldose diastereomers thermodynamically, although the effect is modest and may be influenced by solution dynamics. Full article

Linear alkylbenzene (LAB) is the main raw material used to make biodegradable detergents, and its production process is based on aromatic alkylation. HY zeolites that have undergone controlled dealumination and desilication have led industrial standards amongst solid acid catalysts because of their controllable acidity and hierarchical pore structure. Coke formation in such systems can assume a dual role, which is dependent on its condition. Though the over-deposition is known to cause deactivation by blocking the micropores, Bronsted acid-site masking, and diffusion collapse, the low-level deposition could also be done to increase the monoalkylate selectivity by the pore mouth catalysis, steric modulation, and selective suppression of secondary alkylation pathways. The critical review is done on the structural-kinetic interaction that determines the coke evolution in HY-based catalysts. In order to moderate the acid-site density and enhance hydrothermal stability, dealumination (Si/Al optimization of about 2.5 to 30–100) occurs, but to reduce deep-pore coke formation, desilication (interconnected mesopores) is created. The bimodal porosity and regulated acidity are found to be synergistic, as hierarchical HY zeolites produced through successive cycles of steam and alkaline treatments not only show LAB selectivity in excess of 90% but also exhibit much longer catalyst lifetimes. Quantitative research on the beneficial coke regime revealed that it was composed of about 36 wt% hydrogen-rich species, which were localized at the pore mouths, hence enhancing monoalkylation selectivity by 15–40%. Beyond a critical transition window (e.g., 8–12 wt.%), coke formation to condensed polyaromatic and graphitic products leads to fast deactivated coke formation, which is due to percolation limits and transport-controlled kinetics. More advanced techniques of characterization of the coke, e.g., temperature-programmed oxidation (TPO), ²⁷Al MAAS NMR, and UV-Raman spectroscopy, indicate how the coke is changed to highly structured graphitic deposits of high oxidation activation energy. Activity recovery of 85–98% is obtained in regeneration processes, including controlled oxidative calcination, microwave-based and plasma-based processes, and thermal management protocols, and it would be determined by the chemistry of the coke, its spatial distribution, and the regeneration protocols. This paper has developed a mechanistic coke control system by cross-tuning the acidity and development of an effective pore network, which led to a sustainable aromatic alkylation reaction with minimal activity loss, high selectivity, and long life. Full article