3,583 research outputs found
Cordyceps sinensis mycelium induces MA-10 mouse Leydig tumor cell apoptosis by activating the caspase-8 pathway and suppressing the NF-kappa B pathway.
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Optimisation and Evaluation of La0.6Sr0.4CoO3 –δ Cathode for Intermediate Temperature Solid Oxide Fuel Cells
No full textIn this work, La0.6Sr0.4CoO3 –δ/Ce1 – xGdxO2 –δ (LSC/GDC) composite cathodes are investigated for SOFC application at intermediate temperatures, especially below 700 °C. The symmetrical cells are prepared by spraying LSC/GDC composite cathodes on a GDC tape, and the lowest polarisation resistance (Rp) of 0.11 Ω cm2 at 700 °C is obtained for the cathode containing 30 wt.-% GDC. For the application on YSZ electrolyte, symmetrical LSC cathodes are fabricated on a YSZ tape coated on a GDC interlayer. The impact of the sintering temperature on the microstructure and electrochemical properties is investigated. The optimum temperature is determined to be 950 °C; the corresponding Rp of 0.24Ωcm2 at 600 °C and 0.06Ωcm2 at 700 °C are achieved, respectively. An YSZ-based anode-supported solid oxide fuel cell is fabricated by employing LSC/GDC composite cathode sintered at 950 °C. The cell with an active electrode area of 4 × 4 cm2 exhibits the maximum power density of 0.42 W cm–2 at 650 °C and 0.54 W cm–2 at 700 °C. More than 300 h operating at 650 °C is carried out for an estimate of performance and degradation of a single cell. Despite a decline at the beginning, the stable performance during the later term suggests a potential application.In this work, La0.6Sr0.4CoO3 –δ/Ce1 – xGdxO2 –δ (LSC/GDC) composite cathodes are investigated for SOFC application at intermediate temperatures, especially below 700 °C. The symmetrical cells are prepared by spraying LSC/GDC composite cathodes on a GDC tape, and the lowest polarisation resistance (Rp) of 0.11 Ω cm2 at 700 °C is obtained for the cathode containing 30 wt.-% GDC. For the application on YSZ electrolyte, symmetrical LSC cathodes are fabricated on a YSZ tape coated on a GDC interlayer. The impact of the sintering temperature on the microstructure and electrochemical properties is investigated. The optimum temperature is determined to be 950 °C; the corresponding Rp of 0.24Ωcm2 at 600 °C and 0.06Ωcm2 at 700 °C are achieved, respectively. An YSZ-based anode-supported solid oxide fuel cell is fabricated by employing LSC/GDC composite cathode sintered at 950 °C. The cell with an active electrode area of 4 × 4 cm2 exhibits the maximum power density of 0.42 W cm–2 at 650 °C and 0.54 W cm–2 at 700 °C. More than 300 h operating at 650 °C is carried out for an estimate of performance and degradation of a single cell. Despite a decline at the beginning, the stable performance during the later term suggests a potential application
Optimisation and Evaluation of La0.6Sr0.4CoO3-delta Cathode for Intermediate Temperature Solid Oxide Fuel Cells
No full textIn this work, La0.6Sr0.4CoO3-delta/Ce1-delta Gd2O2-delta (LSC/GDC) composite cathodes are investigated for SOFC application at intermediate temperatures, especially below 700 degrees C. The symmetrical cells are prepared by spraying LSC/GDC composite cathodes on a GDC tape, and the lowest polarisation resistance (R-p) of 0.11 Omega cm(2) at 700 degrees C is obtained for the cathode containing 30 wt.-% GDC. For the application on YSZ electrolyte, symmetrical LSC cathodes are fabricated on a YSZ tape coated on a GDC interlayer. The impact of the sintering temperature on the microstructure and electrochemical properties is investigated. The optimum temperature is determined to be 950 degrees C; the corresponding R-p of 0.24 Omega cm(2) at 600 degrees C and 0.06 Omega cm(2) at 700 degrees C are achieved, respectively An YSZ-based anode-supported solid oxide fuel cell is fabricated by employing LSC/GDC composite cathode sintered at 950 degrees C The cell with an active electrode area of 4 x 4 cm(2) exhibits the maximum power density of 0.42 W cm(-2) at 650 degrees C and 0.54 W cm(-2) at 700 degrees C. More than 300 h operating at 650 degrees C is carried out for an estimate of performance and degradation of a single cell Despite a decline at the beginning, the stable performance during the later term suggests a potential application
Die “ek” in (‘YK’): Die desentralisasie van die subjek in Breyten Breytenbach se digbundel (‘YK’)
No full textIn Breyten Breytenbach’s poetry the “I” is complex. “I” and “you”, the writer and the reader, are not represented with constituted meanings but as signifiers and as part of language production. This article reflects on the development process of the writer as the textual “I”, the “I” narrator in the poetic text – the “I” of language that is not homogeneous or constant. The text is regarded as a pluriform in dialogue (often incomplete) with a variety of texts, the writer and his text, the texts of the reader and the texts of society and history. The author discusses the decentralisation of the subject in Breytenbach’s poetry with respect to his prison collection (‘YK’), and especially the poem “nekra” (a neologism recalling “necro”)
Ergosterol and Its Metabolites Induce Ligninolytic Activity in the Lignin-Degrading Fungus Phanerochaete sordida YK-624
No full textWhite-rot fungi are the most important group of lignin biodegraders. Phanerochaete sordida YK-624 has higher ligninolytic activity than that of model white-rot fungi. However, the underlying mechanism responsible for lignin degradation by white-rot fungi remains unknown, and the induced compounds isolated from white-rot fungi for lignin degradation have never been studied. In the present study, we tried to screen ligninolytic-inducing compounds produced by P. sordida YK-624. After large-scale incubation of P. sordida YK-624, the culture and mycelium were separated by filtration. After the separation and purification, purified compounds were analyzed by high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance. The sterilized unbleached hardwood kraft pulp was used for the initial evaluation of ligninolytic activity. Ergosterol was isolated and identified and it induced the lignin-degrading activity of this fungus. Moreover, we investigated ergosterol metabolites from P. sordida YK-624, and the ergosterol metabolites ergosta-4,7,22-triene-3,6-dione and ergosta-4,6,8(14),22-tetraen-3-one were identified and then chemically synthesized. These compounds significantly improved the lignin-degrading activity of the fungus. This is the first report on the ligninolytic-inducing compounds produced by white-rot fungi
RNA-Seq analysis of <i>Phanerochaete sordida</i> YK-624 degrades neonicotinoid pesticide acetamiprid
No full textAcetamiprid (ACE) belongs to the group of neonicotinoid pesticides, which have become the most widely utilised pesticides around the world in the last two decades. The ability of Phanerochaete sordida YK-624 to degrade ACE under ligninolytic conditions has been demonstrated; however, the functional genes involved in ACE degradation have not been fully elucidated. In the present study, the differentially expressed genes of P. sordida YK-624 under ACE-degrading conditions and in the absence of ACE were elucidated by RNA sequencing (RNA-Seq). Based on the gene ontology enrichment results, the cell wall and cell membrane were significantly affected under ACE-degrading conditions. This result suggested that intracellular degradation of ACE might be mediated by this fungus. In addition, genes in metabolic pathways were the most enriched upregulated differentially expressed genes according to the KEGG pathway analysis. Eleven differentially expressed genes characterised as cytochrome P450s were upregulated, and these genes were determined to be particularly important for ACE degradation by P. sordida YK-624 under ligninolytic conditions.</p
Analysis and Reconstruction of Shipwreck YK 11 (c. Seventh Century A.D.) from the Theodosian Harbor at Yenikapı in Istanbul, Turkey
No full textSince 2004, the Istanbul Archaeological Museums have conducted salvage archaeological excavations at the construction site of an underground railway station at Yenikapı in Istanbul, Turkey. These excavations have unearthed the remains of Constantinople’s Theodosian Harbor (Portus Theodosiacus), including 36 Byzantine shipwrecks. The detailed study of eight of these wrecks was allocated to a small international team under the direction of Cemal Pulak from the Institute of Nautical Archaeology (INA) at Texas A&M University. One of these shipwrecks, YK 11, was a small, heavily-repaired, pine-built merchantman abandoned as a derelict at the western end of the harbor early in the seventh century. This dissertation serves as a detailed record of the YK 11 hull remains, provides a theoretical reconstruction of the vessel, compares the ship’s construction with that of contemporaneous vessels, and explores the ship’s historical context.
The YK 11 hull was excavated, dismantled, and removed from the construction zone at Yenikapı in 2008. The author conducted the post-excavation documentation of the ship’s timbers between 2009 and 2012, following methods established by Fred van Doorninck and J. Richard Steffy of INA in their work with Mediterranean shipwrecks. This documentation revealed that YK 11 had undergone a series of significant repairs over the ship’s lifetime. In these repairs, much of the ship’s original planking, edge fastened with unpegged mortise-and-tenon joints below the waterline, was replaced with planks lacking edge fasteners; a considerable number of the ship’s frames were also replaced. These repairs to YK 11 significantly complicated the interpretation of its original construction.
The paucity of edge fasteners, presence of caulking, and attachment of frames to the keel might be taken as evidence that YK 11 was built after a skeleton-based tradition. However, with the detailed documentation of each component timber, a careful analysis of fastening patterns, the identification of repairs, and a thorough study of the preserved surface detail, it is clear that YK 11, although exhibiting evidence of both shell-first and skeleton-first techniques, was initially designed and built as a primarily shell-based vessel. As such, this study of YK 11 contributes valuable new information toward a better understanding of the transition from shell-based to skeleton-based shipbuilding in the Mediterranean
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