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Catalytic exchange technology is state-of-the-art to enrich hydrogen isotopes in nuclear wastewater through platinum (Pt)-based catalyst. Most researchers focus on developing hydrophobic supports to inhibit direct coverage of Pt by liquid water, while the structure-activity relationship between active sites and water vapor is ignored. Herein, we prepare a series of Pt-based model catalysts (Pt/MON-t) by crystal engineering of Pt to determine the effect of water vapor. Combining the results of X-ray diffraction characterization, density functional theory calculation, and catalyst evaluation, the quantitative results of water vapor adsorption behavior are found to show a linear correlation with catalytic efficiency (R2 = 0.94), proving the water vapor adsorption behavior is mainly responsible for the difference in efficiency, and the weaker water vapor adsorption is more favorable to achieve higher catalytic efficiency. As the weakest adsorption energy of water molecule, Pt/MON-120 exhibits the highest catalytic efficiency with 91.4% at 353.15 K, and maintains excellent stability. • Structure-activity relationship between active sites and water vapor was explored. • By crystal engineering of Pt active sites, hydrophobic model catalysts were prepared. • Water vapor adsorption behavior on Pt crystals were quantified by integrating facets. • Weaker water vapor adsorption was favorable to obtain higher catalytic efficiency. • Hydrophobic catalysts Pt/MON-t exhibited excellent stability. [ABSTRACT FROM AUTHOR]

Porous carbon derived from lignin holds immense potential for use in supercapacitors, due to its abundant pore structure and high specific surface area. In this research, lignin, which is selected due to its renewable and abundant nature compared to traditional carbon sources, was used as the precursor for producing lignin-derived carbon materials through a carbonization-activation process. The resulting porous carbon materials underwent rigorous characterization using SEM, BET, Raman, XRD and XPS to uncover their morphological and structural intricacies. This study delves into the influence of purified lignin (PL) and the type of activator on the microstructure and electrochemical properties of the porous carbon. Notably, the optimal product, achieved with a mass ratio of EL to KOH at 1:2 and activation temperature at 750 °C, emerges as an excellent electrode material for high-performance supercapacitors. This superior carbon material boasts a remarkable specific surface area of 2615.5 m2 g−1, demonstrating an electrochemical capacitance up to 350 F/g at 1 A/g, which surpasses many existing carbon materials in performance. By harnessing raw materials sourced from agricultural byproducts, this study not only presents a cost-effective solution but also proposes a novel approach towards the high-value utilization of biomass wastes. The successful preparation of activated carbon with exceptional performance from these renewable resources paves the way for the development of low-cost, high-performance supercapacitors, contributing significantly to the advancement of sustainable energy storage systems. • Porous carbon with good pore structure and electrochemical properties was successfully synthesized from biomass waste. • The effects of purification on the structure and electrochemical properties of lignin-based porous carbons were investigated. • The relationship between the microstructure and electrochemical performance of lignin derivatives by different activators. [ABSTRACT FROM AUTHOR]

Understanding, modeling, and reducing the cycle-to-cycle variability (CCV) of combustion in internal combustion engines (ICE) is a critical challenge to design engines of high efficiency and low emissions. A high level of CCV may contribute to partial burn, misfire, and knock in extreme engine cycles, which affects engine performance and eventually damages the engine. The origins of CCV have been studied both experimentally and numerically, and the variability of in-cylinder aerodynamics is recognized as one of the most important sources of CCV. However, a detailed and quantitative explanation of how in-cylinder flow CCV is generated is not yet clear. The objective of the present study is to develop a methodology to localize inside the chamber of a spark-ignition engine (SIE) the origins of flow variabilities and to identify some driving mechanisms leading to combustion variabilities. Multi-cycle wall-modeled large-eddy simulations (LES) for the TU Darmstadt optical engine under fired conditions are performed using the CFD solver Converge 3.0. The evolution of organized large-scale structures and the small-scale turbulence of the in-cylinder flow are analyzed using a developed methodology that includes the empirical mode decomposition (EMD) method adapted for 2D and 3D flow fields, and a vortex identification tool Γ 3 p. The contributions of different parts of the flow to CCV are quantified. In Part I of this work, the LES framework is validated against experimental data, and CCV of large-scale structures is characterized at spark timing. In Part II, the overall flow development during compression and intake strokes are quantitatively analyzed, and links are built between different engine phases to establish the cause-and-effect chain. Other CCV factors, such as spray injection and exhaust gas recirculation, are not included in the current study. However, the developed methodology for in-cylinder flow analysis could be used in studies on other engine configurations to improve the development of engine designs. Novelty and significance statement In this work, the cycle-to-cycle variability (CCV) of combustion in a spark ignition engine is investigated to give a deeper understanding of CCV generation. The present study focuses on CCV caused by the stochastic nature of internal turbulent flow structures. LES approach is chosen due to its ability to capture CCV. The LES methodology was validated in a motored case in Ding et al. (2023). In the present study, it is validated in a reactive case against experimental in-cylinder pressures and velocity fields. A first novelty is the application of EMD methods combined with topology-based techniques to reactive LES results to characterize flow structures of different scales in the three-dimensional domain and to quantify separately their impacts on combustion. A second novelty and important finding is that a link is established between the combustion speed and the tumble formation and destabilization near BDC. Throughout our analyses in Part I and II, starting from the spark-ignition timing and going back to the early intake phase, a cause-and-effect chain is finally established between the development of in-cylinder flow and the combustion variability. [ABSTRACT FROM AUTHOR]

In this work, the phenomenon of cycle-to-cycle variability (CCV) of combustion in a spark ignition engine is investigated to give a deeper understanding of CCV generation. The main objective is to localize within the cylinder and all along the engine cycle the flow variabilites and identify some driving mechanisms originating in the flow structures and leading to combustion variabilites. In Part I , the application of empirical mode decomposition methods combined with topology-based techniques to the LES flow results allowed the extraction of the large-scale flow motion from the small-scale turbulence and the follow-up of their evolution during compression stroke [1]. A link was then established between the combustion process and the tumble formation and destabilization near BDC. In the present paper, the overall tumble motion development during compression and intake strokes is quantitatively analyzed, and links are built between different engine phases to establish the cause-and-effect chain. Other CCV factors, such as spray injection and exhaust gas recirculation, were not included in the current study. However, the developed methodology for in-cylinder flow analysis could be used in studies on other engine configurations to improve the development of engine designs. Novelty and significance statement In this work, the cycle-to-cycle variability (CCV) of combustion in a spark ignition engine is investigated to give a deeper understanding of CCV generation. The present study focuses on CCV caused by the stochastic nature of internal turbulent flow structures. LES approach is chosen due to its ability to capture CCV, and advanced flow analysis tools are developed and applied to LES results to characterize instantaneous flow structures of different scales in the three-dimensional domain and separately quantify their impacts on combustion. A first important finding is that flow-wall interactions near BDC determine the tumble evolution. A second novelty is the characterization of several 3D dominant flow interactions during intake yielding large-scale flow variability. A third novelty and important finding is that links are found between the flow organization during intake, the tumble development, and destabilization during early compression and the combustion. Throughout our analyses starting from the spark timing and going back to the early intake phase, a cause-and-effect chain is finally established between the development of in-cylinder flow and the combustion variability. [ABSTRACT FROM AUTHOR]

Abstract: An analytical model for channel potential and subthreshold swing of the symmetric and asymmetric double-gate Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is presented. Two-dimensional Poisson equation is solved analytically using series method and channel potential is obtained. The analytical expression for subthreshold swing is achieved. Model results are compared with Medici simulation results, both of them turn out to agree very well. The results show the variation of channel potential and subthreshold swing with channel length, gate bias, and oxide thickness, which will provide some guidance for the integrated circuit designs. [Copyright &y& Elsevier]

Delayed neuronal damage can be caused or aggravated after cerebral ischemia–reperfusion (I/R) injury. Recent studies have shown that glymphatic system dysfunction after cerebral ischemia–reperfusion injury is involved in ischemic brain edema and neuroinflammation, thereby regulating cerebral ischemia–reperfusion injury. The aim of this study is to investigate the changes of glymphatic system after cerebral ischemia–reperfusion injury and whether limb remote ischemic postconditioning (LRIP) can improve the function of glymphatic system to protect the brain. To establish a focal brain I/R injury mouse model, this study utilized the middle cerebral artery occlusion/reperfusion (MCAO/R) method. The present study classified eight-week-old C57BL/6 male mice into three groups. The changes in glymphatic function in different periods of ischemia and reperfusion were analyzed through immunofluorescence, transmission electron microscopy (TEM), and Western-Blot (WB) assays. The contents of the evaluation included cerebrospinal fluid flow, swelling degree of brain tissue, aquaporin-4 (AQP4) expression and polarization, and amyloid-β (Aβ) excretion. In the early stages of cerebral ischemia, cerebrospinal fluid (CSF) flow is disturbed, accompanied by a decrease in AQP4 polarization. The polarity of AQP4 decreased from 12 h to 72 h of reperfusion, the Aβ deposition. LRIP can increase the expression of β-DG and AQP4 polarization, reduce the deposition of Aβ, improve the function of the glymphatic system, and reduce the expression of AQP4 to play A protective role in brain. Glymphatic system impaired after cerebral ischemia–reperfusion injury in mice. LRIP may play a neuroprotective role by improving glymphatic function after I/R. [ABSTRACT FROM AUTHOR]

Asymmetric cell division, which plays fundamental roles in generating cell diversity during development, requires elaborate interactions between extrinsic cues and intrinsic cues. However, the precise nature of this type of interaction and its involving signaling mechanisms are poorly understood. Here, we demonstrate that Gαs is present in the proliferative region of ventricular zone in mouse developing neocortex and co-localizes with intrinsic cell fate determinant protein Numb in dividing apical progenitors. Targeted ablation of Gαs subunit in the cortical progenitor causes an alteration from asymmetric to symmetric cell division, consequently leading to increased progenitor proliferation. Mechanistically, we show that Gαs deletion significantly reduces Numb expression and activates notch signaling. Therefore, these results reveal a novel role of Gαs in control of neural progenitor asymmetric cell division via suppressing Numb mediated Notch signaling inhibition. [ABSTRACT FROM AUTHOR]

• Aromatic nitriles were cyanide-freely synthesized under mild conditions. • The aldoxime dehydratase gene OxdF1 was functionally expressed in E. coli. • OxdF1 can efficiently catalyze the dehydration of aromatic aldoximes to nitriles. • OxdF1 contains a ferrous heme as the catalytic center. Aromatic nitriles are important structural motifs that frequently existed in pharmaceutical drugs. Due to the convenient synthesis of aldoximes from aldehydes, the dehydration of aldoximes to corresponding nitriles by aldoxime dehydratases (Oxds) is considered as a safe and robust enzymatic production route. Although the Oxd genes are widely distributed in microbial kingdom, so far less than ten Oxds were expressed and further characterized. In this study, we found 26 predicted putative Oxd genes from the GenBank database using a genome mining strategy. The Oxd gene from Pseudomonas putida F1 was cloned and functionally expressed in Escherichia coli BL21 (DE3). The amino acid sequence of OxdF1 shows high identities of 33∼85 % to other characterized Oxds, and contained a ferrous heme as the catalytic site. The optimum reaction pH and temperature of recombinant OxdF1 were 7.0 and 35 °C, respectively. OxdF1 was stable in pH 7.0 potassium phosphate buffer at 30 °C, and its half-life was approximately 3.8 h. OxdF1 can efficiently dehydrate aromatic and heterocyclic aldoximes to nitriles, such as 2-bromobenzaldoxime, 2-chloro-6-fluorobenzaldoxime, thiophene-2-carboxaldoxime, and pyridine-3-aldoxime. Therefore, the recombinant OxdF1 shows a potential application in the cyanide-free synthesis of aromatic nitriles. [ABSTRACT FROM AUTHOR]