17 research outputs found

    Analysis of Parameter Effects on Transport Phenomena in Conjunction with Chemical Reactions in Ducts Relevant for Methane Reformers

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    Various transport phenomena in conjunction with chemical reactions are strongly affected by reformer configurations and properties of involved porous catalyst layers. The considered composite duct is relevant for a methane steam reformer and consists of a porous layer for the catalytic chemical reactions, the fuel gas flow duct and solid plate. In this paper, a fully three-dimensional calculation method is developed to simulate and analyze reforming reactions of methane, with purpose to reveal the importance of design and operating parameters grouped as three characteristic ratios. The reformer conditions such as mass balances associated with the reforming reactions and gas permeation to/from the porous catalyst reforming layer are applied in the analysis. The results show that the characteristic ratios have significant effects on the transport phenomena and overall reforming reaction performance

    Transport Phenomena Coupled by Chemical Reactions in Methane Reforming Ducts

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    Mass, heat and momentum transport processes are strongly coupled with catalytic chemical reactions in a methane steam reforming duct. In this paper, a three-dimensional calculation method is developed to simulate and analyze reforming reactions of methane, and the effects on various transport processes in a steam reforming duct. The results show that the design and operating parameters grouped as characteristic ratios have significant effects on the transport phenomen

    The Evolution of Research on C&D Waste and Sustainable Development of Resources: A Bibliometric Study

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    Construction and demolition (C&D) waste is steadily increasing as both urbanization and the construction industry advance. Therefore, numerous studies on C&D waste have been conducted. In this paper, the literature published in the field of C&D waste and sustainable development from 2002 to 2022 was utilized to examine the current state of research and potential future research hotspots via the bibliometric method. Herein, 3550 studies found in the literature were analyzed using Citespace and VOSviewer, two efficient visual analysis programs, for the annual quantitative distribution, contribution and cooperation of authors, influential and productive countries/regions and institutions, keyword co-occurrence analysis, literature co-citation analysis and identification of research frontiers. The findings show an exponential rise in publications on construction waste and sustainable resource development, while the research focus has clearly shifted from recycling and reduction of C&D waste to harmless and resourceful treatment in the last five years. The keywords “optimization”, “implementation” and “strategy” also indicate that more emphasis is being placed on the research of management method realization mechanisms, technological optimization schemes and policy strategies. The research results of this paper will help participants in the construction industry to grasp the current research hotspots and development trend in the field of C&D waste and the sustainable development of resources. It also plays a positive role in formulating relevant regulations and policies, reducing resource waste and construction project costs

    Synthesis and experimental study of novel double perovskite Ba2NixCo2−xO6 as promising oxygen carrier materials for CO2 capture application

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    Novel oxygen-deficient double-perovskite type oxide Ba2NixCo2−xO6 was applied to produce O2/CO2 mixed stream gas for oxyfuel combustion application. A series of different Co concentration substituted Ba2NixCo2−xO6 was synthesized by an EDTA-citrate sol-gel combustion method. The oxygen carriers, Ba2Ni0.25Co1.75O6, Ba2Ni0.45Co1.55O6, Ba2Ni0.65Co1.35O6 and Ba2Ni0.85Co1.15O6 were c\characterized by scanning electron microscopy and cyclic oxygen adsorption/desorption experiments. The results showed that the capacity of provided O2 was improved by the partial substitution of Ni by Co. In addition, the synthesized perovskites exhibit good regeneration ability. The optimal degree of Co substitution was x = 0.25 for Ba2NixCo2−xO6 with consideration of oxygen desorption ability. Therefore, Ba2Ni0.25Co1.75O6 was selected to examine the influence of the operating parameters on the oxygen release performance. It was found that the desorption temperature and CO2 partial pressure are the two main operating parameters for the oxygen desorption performance. Further, the proposed novel double perovskite Ba2Ni0.25Co1.75O6 provided excellent performance, the O2 production of Ba2Ni0.25Co1.75O6 can still reach 120 mg/g after 10 cycles

    Design and Implementation of the Optimization Algorithm in the Layout of Parking Lot Guidance

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    The information guidance system for parking spaces in large- and medium-sized parking lots is not efficient at present. It tends to be difficult to find an empty parking space in parking lots in big cities. One of the problems is the large amount of calculation in the traditional Dijkstra algorithm. In this paper, an improved Dijkstra algorithm is presented and optimized to find the best parking path with the purpose of looking for the nearest free parking space based on the layout model in parking lot parking guidance. The experiments show that the improved Dijkstra algorithm can find the optimal parking space and the optimal parking path and improve the parking efficiency

    Predicting algorithm of attC site based on combination optimization strategy

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    Site-specific recombination systems are widely used as bioengineering tools. However, the traditional site-specific recombination system requires a consensus sequence for the specific site. Such sequence-level constraints limit effective recombination between sites. Therefore, in order to develop an efficient site-specific recombination system, we investigated the attC site of the bacterial integration subsystem and built a predictive model to infer the important features that contribute to recombination. Here, we design an attC site prediction algorithm based on a combination optimisation strategy. Based on the structural features of attC sites, the prediction algorithm realises the high-precision prediction of the recombination frequencies between sites and the screening of the top 20 important features that play a role in recombination, which are effective for improving the design method of attC sites. The algorithm has better portability and higher prediction accuracy compared with the existing advanced algorithms, among which the Pearson correlation coefficient is 0.87, explained variance score is 0.73, root mean square error is 0.006 and mean absolute error is 0.041. This can not only provide ideas for the research of efficient recombination systems but also provide a theoretical basis for developing genetic engineering further

    Plasma exosomes lncRNA-miRNA-mRNA network construction and its diagnostic efficacy identification in first-episode schizophrenia

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    Abstract Background The exosomal lncRNA-miRNA-mRNA networks in first episode schizophrenia (FOS) have not reported yet. This study examined the lncRNA, miRNA and mRNA expression level in exosome derived from first episode schizophrenia (FOS) patients, and explored the the potential of exosomes as biomarkers for schizophrenia. Methods We recruited 10 FOS patients and healthy controls (HCs) respectively, examined the lncRNA, miRNA and mRNA expression level of plasma exosome by high throughput sequencing, constructed lncRNA-miRNA-mRNA network, and performed correlation analysis, GO and KEGG pathway analysis, PPI network construction and ROC analysis. Results There were 746 differently expressed lncRNA, 22 differently expressed miRNA, and 2637 differently expressed mRNA in plasma exosome in FOS compared with HCs. Then we constructed ceRNA network consisting of 8 down-regulated lncRNA, 7 up-regulated miRNA and 65 down-regulated mRNA, and 1 up-regulated lncRNA, 1 down-regulated miRNA and 4 up-regulated mRNA. The expression level of 1 lncRNA and 7 mRNA in exosomal network were correlated with PANSS score. GO and KEGG pathway analysis showed that 4 up-regulated mRNAs were enriched in neuropsychiatric system function. Down-regulated mRNA EZH2 and SIRT1 were identified as hub gene. Finally, we detected the ROC curve of ENSG00000251562, miR-26a-5p, EZH2, miR-22-3p, SIRT1, ENSG00000251562—miR-26a-5p—EZH2, ENSG00000251562—miR-22-3p—SIRT1, and found that the AUC of ceRNA network was higher than lncRNA, miRNA and mRNA alone. Conclusion We constructed the lncRNA-miRNA-mRNA network in exosome derived from FOS plasma, and found that lncRNA-miRNA-mRNA network has potential as biomarkers for FOS

    Enhancement of osteogenesis using a novel porous hydroxyapatite scaffold in vivo and vitro

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    The repair of large maxillofacial bony defects using regular scaffolds is restricted by the osteogenic effect. It was postulated that a novel porous hydroxyapatite (HA) scaffolds with a 25-30 mu m groove structure (HAG) may counter this limitation. In this study we evaluated the biocompatibility of HAG scaffolds both in vitro and in vivo in beagle dogs by investigating the enhancement of scaffolds bioactivity and osteogenesis. Compared with a regular HA scaffolds, the HAG scaffolds significantly promoted human placenta-derived mesenchymal stem cell (hPMSC) osteogenic differentiation and the maturation of osteoblasts. This is achieved by increasing protein adsorption, as well as promoting directed growth and expression of osteogenic genes in vitro. The compressive strength of HAG scaffolds was significantly greater than HA in both dorsal muscle and the mandibular distraction area after in vivo implantation, with hematoxylin and eosin staining demonstrating new bone formation and vasculogenesis. Immunochemical staining and micro-CT scanning demonstrated increased expression of osteogenic factors (BMP2, OCN and COL-1) and bone density in the HAG scaffolds compared with HA. Based on the above results, we conclude that HAG scaffolds that have a groove structure induce greater osteogenesis and possess improved ostoegenesis which could be utilized in the clinical treatment

    A Natural Compound Containing a Disaccharide Structure of Glucose and Rhamnose Identified as Potential N-Glycanase 1 (NGLY1) Inhibitors

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    N-glycanase 1 (NGLY1) is an essential enzyme involved in the deglycosylation of misfolded glycoproteins through the endoplasmic reticulum (ER)-associated degradation (ERAD) pathway, which could hydrolyze N-glycan from N-glycoprotein or N-glycopeptide in the cytosol. Recent studies indicated that NGLY1 inhibition is a potential novel drug target for antiviral therapy. In this study, structure-based virtual analysis was applied to screen candidate NGLY1 inhibitors from 2960 natural compounds. Three natural compounds, Poliumoside, Soyasaponin Bb, and Saikosaponin B2 showed significantly inhibitory activity of NGLY1, isolated from traditional heat-clearing and detoxifying Chinese herbs. Furthermore, the core structural motif of the three NGLY1 inhibitors was a disaccharide structure with glucose and rhamnose, which might exert its action by binding to important active sites of NGLY1, such as Lys238 and Trp244. In traditional Chinese medicine, many compounds containing this disaccharide structure probably targeted NGLY1. This study unveiled the leading compound of NGLY1 inhibitors with its core structure, which could guide future drug development
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