10 research outputs found

    Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport

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    【Abstract】The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gasesandliquids underasteady-stateapplied pressure,nearlyeliminate fouling,and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores’ deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles.This work was supported by the National Natural Science Foundation of China (grant no. 21673197), the Young Overseas High-level Talents Introduction Plan, the 111 Project (grant no. B16029). 研究工作得到国家自然科学基金委(项目批准号:21673197)和厦门大学校长基金(项目批准号:20720170050)等资助与支持

    Exploration on Application of High Pressure Water Jet Cleaning Technology

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    at present, the three-dimensional cleaning machine involved in tank car cleaning technology in China has full-automatic function, which includes two main structures: three-dimensional positioning machine and high-pressure cleaning machine. However, the tank car cleaning process used in the railway field still has many shortcomings. For example, serious pollution, serious energy consumption, insecurity, etc. In order to improve such defects, it is necessary to introduce new processes and improve the previous cleaning processes. The introduction of new technology can reduce environmental pollution and save capital cost. It can adapt to the development of the times and meet people's needs. Therefore, this paper expounds and analyzes the high-pressure water jet cleaning technology in railway tank cars from the aspects of application and improvement, and puts forward the corresponding improvement measures for reference

    A Thermophilic GH5 Endoglucanase from Aspergillus fumigatus and Its Synergistic Hydrolysis of Mannan-Containing Polysaccharides

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    In this study, we isolated and identified a thermophilic strain of Aspergillus fumigatus from the “Daqu” samples. Transcriptomic analysis of A. fumigatus identified 239 carbohydrate-active enzymes (CAZy)-encoding genes, including 167 glycoside hydrolase (GH)-encoding genes, 58 glycosyltransferase (GT)-encoding genes, 2 polysaccharide lyase (PLs)-encoding genes and 12 carbohydrate esterase (CEs)-encoding genes, which indicates that the strain has a strong potential for application for enzyme production. Furthermore, we also identified a novel endoglucanase gene (AfCel5A), which was expressed in Pichia pastoris and characterized. The novel endoglucanase AfCel5A exhibited the highest hydrolytic activity against CMC-Na and the optimal activity at 80 °C and pH 4.0 and also showed good stability at pH 3.0–11.0 and below 70 °C. The Km and Vmax values of AfCel5 were 0.16 ± 0.05 mg·mL−1 and 7.23 ± 0.33 mol mg−1·min−1, respectively, using CMC-Na as a substrate. Further, the endoglucanase exhibited a high tolerance toward NaCl as well as glucose. In addition, the finding that the endoglucanase AfCel5A in combination with β-mannanse (ManBK) clearly increased the release of total reducing sugars of glucomannan by up to 74% is significant

    Characterization of a Novel Thermophilic Mannanase and Synergistic Hydrolysis of Galactomannan Combined with Swollenin

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    Aspergillus fumigatus HBFH5 is a thermophilic fungus which can efficiently degrade lignocellulose and which produces a variety of glycoside hydrolase. In the present study, a novel β-mannanase gene (AfMan5A) was expressed in Pichia pastoris and characterized. AfMan5A is composed of 373 amino acids residues, and has a calculated molecular weight of 40 kDa. It has been observed that the amino acid sequence of AfMan5A showed 74.4% homology with the ManBK from Aspergillus niger. In addition, the recombined AfMan5A exhibited optimal hydrolytic activity at 60 °C and pH 6.0. It had no activity loss after incubation for 1h at 60 °C, while 65% of the initial activity was observed after 1 h at 70 °C. Additionally, it maintained about 80% of its activity in the pH range from 3.0 to 9.0. When carob bean gum was used as the substrate, the Km and Vmax values of AfMan5A were 0.21 ± 0.05 mg·mL−1 and 15.22 ± 0.33 U mg−1·min−1, respectively. AfMan5A and AfSwol showed a strong synergistic interaction on galactomannan degradation, increasing the reduction of the sugars by up to 31%. Therefore, these findings contribute to new strategies for improving the hydrolysis of galactomannan using the enzyme cocktail

    Waste Substitution Extraction of Coal Strip Mining Pillars

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    In order to solve problems of environmental pollution caused by waste rock emission, low recovery rate of strip mining, a green mining approach for pillars extraction with waste backfill is presented. The physical composition, density, and the compaction deformation characteristics of the waste rock were evaluated by laboratory tests. The stress-strain curve and the stress-compaction degree curve were obtained and that the grain size of 0 similar to 50mm was elected to be the optimum gradation. Then, the strata movement and ground subsidence situation of different mining designs were predicted by a numerical study and a physical simulation, and then, the optimum design was obtained. Field test showed that the deformation of ground buildings could be controlled to meet the grade I standard; about 125000 tons of waste rock could be disposed and about 125000 tons of coal be recovered every year using this technology; the waste rock produced in the heading face could be disposed as backfill material without being transported to the ground, which can reduce environmental damage to a certain extent and achieve good economic benefits

    Characterization of NaA Zeolite Oxygen Permeable Membrane on TiO 2

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    The NaA zeolite membrane was synthesized on the surface of TiO2/α-Al2O3 composite support with TiO2 as modifier of α-Al2O3 porous tubular ceramic membrane support by crystallization method. The structure characterization indicated that the TiO2 of the support surface could effectively improve the surface properties of the support. It didn’t affect the crystallization of NaA synthesis liquid and synthesis process of NaA zeolite membrane. There were no obvious defects between the crystal particles with size of approximate 6μm. The perfect and complete membrane with thickness of approximate 15μm combined closely with support to connection together by TiO2 modified. The oxygen permeability of the membrane on TiO2/α-Al2O3 composite support improves of 47% compared with that of α-Al2O3 support. So the process of TiO2 modifying the surface of α-Al2O3 support should increase the oxygen permeability of the NaA zeolite membrane

    Antioxidant Effects of Roasted Licorice in a Zebrafish Model and Its Mechanisms

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    Licorice (Gan-Cao, licorice) is a natural antioxidant and roasted licorice is the most common processing specification used in traditional Chinese medicine prescriptions. Traditional Chinese medicine theory deems that the honey-roasting process can promote the efficacy of licorice, including tonifying the spleen and augmenting “Qi” (energy). The antioxidant activity and mechanisms underlying roasted licorice have not yet been reported. In this study, we found that roasted licorice could relieve the oxidative stress injury induced by metronidazole (MTZ) and could restrain the production of excessive reactive oxygen species (ROS) induced by 2,2′-azobis (2-methylpropionamidine) dihydrochloride (AAPH) in a zebrafish model. It was further found that roasted licorice could exert its oxidative activity by upregulating the expression of key genes such as heme oxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), glutamate–cysteine ligase modifier subunit (GCLM), and glutamate–cysteine ligase catalytic subunit (GCLC) in the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway both in vivo and in vitro. Furthermore, consistent results were obtained showing that rat serum containing roasted licorice was estimated to reduce cell apoptosis induced by H2O2. Then, the UHPLC-Q-Exactive Orbitrap MS analysis results elucidated the chemical composition of rat plasma containing roasted licorice extracts, including ten prototype chemical components and five metabolic components. Among them, six compounds were found to have binding activity with Kelch-like ECH-associated protein 1 (KEAP1), which plays a crucial role in the transcriptional activity of NRF2, using a molecular docking simulation. The results also showed that liquiritigenin had the strongest binding ability with KEAP1. Immunofluorescence further confirmed that liquiritigenin could induce the nuclear translocation of NRF2. In summary, this study provides a better understanding of the antioxidant effect and mechanisms of roasted licorice, and lays a theoretical foundation for the development of a potential antioxidant for use in clinical practice

    UV and Resonance Raman Spectroscopic and Theoretical Studies on the Solvent-Dependent Ground and Excited-State Thione → Thiol Tautomerization of 4,6-Dimethyl-2-mercaptopyrimidine (DMMP)

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    The vibrational spectra of 4,6-dimethyl-2-mercaptopyrimidine (DMMP) in acetonitrile, methanol, and water were assigned by resonance Raman spectroscopy through a combination of Fourier-transform infrared spectroscopy (FT-IR), FT-Raman UV–vis spectroscopy, and density functional theoretical (DFT) calculations. The FT-Raman spectra show that the neat solid DMMP is formed as a dimer due to intermolecular hydrogen bonding. In methanol and water, however, the majority of the Raman spectra were assigned to the vibrational modes of DMMP­(solvent)<sub><i>n</i></sub> (<i>n</i> = 1–4) clusters containing NH···O hydrogen bonds. The intermolecular NH···O hydrogen bond interactions, which are key constituents of the stable DMMP thione structure, revealed significant structural differences in acetonitrile, methanol, and water. In addition, UV-induced hydrogen transfer isomeric reactions between the thione and thiol forms of DMMP were detected in water and acetonitrile. DFT calculations indicate that the observed thione → thiol tautomerization should occur easily in lower excited states in acetonitrile and water
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