103 research outputs found

    Method of calculating a layer gasifier with the determination of chemical products

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    The paper proposes a method for calculating the layered gas generator, which allows calculating not only the yield and composition of the generator gas in the gasification of solid fuels, but the yield and composition of chemical products. The calculation is made based on the proposed method for the coal gasification of the technological grade "G" of OAO «Severny Kuzbass».В работе предложена методика расчета слоевого газогенератора, позволяющая рассчитывать не только выход и состав генераторного газа при газификации твёрдых топлив, но выход и состав химических продуктов. Приведён расчёт по предложенной методике процесса газификации каменного угля технологической марки "Г" ОАО «Северный Кузбасс»

    Pd-based bimetallic catalysts for parahydrogen-induced polarization in heterogeneous hydrogenations

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    Production of hyperpolarized catalyst-free gases and liquids by heterogeneous hydrogenation with parahydrogen can be useful for various technical as well as biomedical applications, including in vivo studies, investigations of mechanisms of industrially important catalytic processes, enrichment of nuclear spin isomers of polyatomic gases, and more. In this regard, the wide systematic search for heterogeneous catalysts effective in pairwise H2 addition required for the observation of parahydrogen-induced polarization (PHIP) effects is crucial. Here in this work we demonstrate the competitive advantage of Pd-based bimetallic catalysts for PHIP in heterogeneous hydrogenations (HET-PHIP). The dilution of catalytically active Pd with less active Ag or In atoms provides the formation of atomically dispersed Pd1 sites on the surface of Pd-based bimetallic catalysts, which are significantly more selective toward pairwise H2 addition compared to the monometallic Pd. Furthermore, the choice of the dilution metal (Ag or In) has a pronounced effect on the efficiency of bimetallic catalysts in HET-PHIP, as revealed by comparing Pd-Ag and Pd-In bimetallic catalysts.</p

    Influence of modifying additives on formation of supported copper nanoparticles

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    The influence of modifying additives of Ce, Zr, La and Cs oxides on changes of electronic state of supported copper during the catalytic reaction of butane complete oxidation has been studied by the methods of IR-spectroscopy of adsorbed CO, XPS, EXAFS and XRD. The modifying additions of cerium and zirconium oxides stabilize the ionic state of copper, while lanthanum and cesium oxides decrease the effective charge of copper ions. The observed effects are caused by variation in metal dispersivity in the modified samples and by electron donor-acceptor interaction of the surface atoms and ions of copper with the modifier

    Effect of Compactin on the Mycotoxin Production and Expression of Related Biosynthetic and Regulatory Genes in Toxigenic Fusarium culmorum

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    Zearalenone (ZEN) and deoxynivalenol (DON) are mycotoxins produced by various species of Fusarium fungi. They contaminate agricultural products and negatively influence human and animal health, thus representing a serious problem of the agricultural industry. Earlier we showed that compactin, a secondary metabolite of Penicillium citrinum, is able to completely suppress the aflatoxin B1 biosynthesis by Aspergillus flavus. Using the F. culmorum strain FC-19 able to produce DON and ZEN, we demonstrated that compactin also significantly suppressed both DON (99.3%) and ZEN (100%) biosynthesis. The possible mechanisms of this suppression were elucidated by qPCR-based analysis of expression levels of 48 biosynthetic and regulatory genes. Expression of eight of 13 TRI genes, including TRI4, TRI5, and TRI101, was completely suppressed. A significant down-regulation was revealed for the TRI10, TRI9, and TRI14 genes. TRI15 was the only up-regulated gene from the TRI cluster. In the case of the ZEN cluster, almost complete suppression was observed for PKS4, PKS13, and ZEB1 genes, and the balance between two ZEB2 isoforms was altered. Among regulatory genes, an increased expression of GPA1 and GPA2 genes encoding &alpha;- and &beta;-subunits of a G-protein was shown, whereas eight genes were down-regulated. The obtained results suggest that the main pathway for a compactin-related inhibition of the DON and ZEN biosynthesis affects the transcription of genes involved in the G-protein-cAMP-PKA signaling pathway. The revealed gene expression data may provide a better understanding of genetic mechanisms underlying mycotoxin production and its regulation

    Crystal structure of phosphonium carboxylate complexes. the role of the metal coordination geometry, ligand conformation and hydrogen bonding

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    © the Partner Organisations 2014. A series of new mononuclear and heteronuclear complexes of carboxylate phosphonium betaines with biologically important metals (Zn(ii), Cd(ii), Hg(ii) and Cu(ii)) were obtained in aqueous media at ambient temperature. X-ray single crystal diffraction showed that carboxylate phosphonium betaines exhibit versatile complexation abilities, producing monomeric, dimeric and tetrameric homonuclear and mixed metal complexes. The binding mode was found to change in the series of Zn(ii), Cd(ii) and Hg(ii) complexes with an increase of the cation radius. Water and chlorine atoms, bound to the metal, play an important role in crystal formation. In the case of α- and β-substituted phosphabetaines, the crystallization of various stereoisomers was observed including a rare case of co-crystallization of two diastereomers in one crystal. This journal i
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