475 research outputs found

    Full-scale collapse testing of a steel stiffened plate structure under axial-compressive loading triggered by brittle fracture at cryogenic condition

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    This paper is a sequel to the authors’ earlier article Paik et al. [2020a. Full-scale collapse testing of a steel stiffened plate structure under cyclic axial-compressive loading, Structures, https://doi.org/10.1016/j.istruc.2020.05.026]. The aim of the paper was to present a test data on the ultimate compressive strength characteristics of a full-scale steel stiffened plate structure at cryogenic condition which may be due to unwanted release of liquefied gases. The test structure was fabricated in a shipyard using exactly the same welding technology as used in today’s shipbuilding industry. It is observed that the test structure reaches the ultimate limit states triggered by brittle fracture, which is totally different from typical collapse modes at room temperature. Details of the test database are documented as they can be used to validate computational models for the structural crashworthiness analysis involving brittle fracture at cryogenic condition

    Kinetic roughening of ion-sputtered Pd(001) surface: Beyond the Kuramoto-Sivashinsky model

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    The kinetic roughening of Ar+ ion-sputtered Pd(001) surface was investigated. The facet formation on the sputtered surface was studied by tracing the extradiffraction peaks or satellites around the diffraction peaks corresponding to the sample surface. The morphological evolution of the sputtered Pd(001) surface was also investigated by an scanning tunneling microscopy (STM). It was shown that the nanoscale adatom islands form and grow with increasing sputter time.open313

    Long-term annual primary production in the Ulleung Basin as a biological hot spot in the East/Japan Sea

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    Although the Ulleung Basin is an important biological hot spot in East/Japan Sea (hereafter the East Sea), very limited knowledge for seasonal and annual variations in the primary productivity exists. In this study, a recent decadal trend of primary production in the Ulleung Basin was analyzed based on MODIS-derived monthly primary production for a better annual production budget. Based on the MODIS-derived primary production, the mean daily primary productivity was 766.8 mg C m-2 d-1 (SD=+/- 196.7 mg C m-2 d-1) and the annual primary productivity was 280.2 g C m-2 yr-1 (SD=+/- 14.9 g C m-2 yr-1) in the Ulleung Basin during the study period. The monthly contributions of primary production were not largely variable among different months, and a relatively small interannual production variability was also observed in the Ulleung Basin, which indicates that the Ulleung Basin is a sustaining biologically productive region called as hot spot in the East Sea. However, a significant recent decline in the annual primary production was observed in the Ulleung Basin after 2006. Although no strong possibilities were found in this study, the current warming sea surface temperature and a negative phase PDO index were suggested for the recent declining primary production. For a better understanding of subsequent effects on marine ecosystems, more intensive interdisciplinary field studies will be required in the Ulleung Basin

    Alteration of the bZIP60/IRE1 Pathway Affects Plant Response to ER Stress in Arabidopsis thaliana

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    The Unfolded Protein Response (UPR) is elicited under cellular and environmental stress conditions that disrupt protein folding in the endoplasmic reticulum (ER). Through the transcriptional induction of genes encoding ER resident chaperones and proteins involved in folding, the pathway contributes to alleviating ER stress by increasing the folding capacity in the ER. Similarly to other eukaryotic systems, one arm of the UPR in Arabidopsis is set off by a non-conventional splicing event mediated by ribonuclease kinase IRE1b. The enzyme specifically targets mature bZIP60 RNA for cleavage, which results in a novel splice variant encoding a nuclear localized transcription factor. Although it is clear that this molecular switch widely affects the transcriptome, its exact role in overall plant response to stress has not been established and mutant approaches have not provided much insight. In this study, we took a transgenic approach to manipulate the pathway in positive and negative fashions. Our data show that the ER-resident chaperone BiP accumulates differentially depending on the level of activation of the pathway. In addition, phenotypes of the transgenic lines suggest that BiP accumulation is positively correlated with plant tolerance to chronic ER stress

    Urinary Transforming Growth Factor-beta 1 as a marker of response to immunosuppressive treatment, in patients with crescentic nephritis

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    BACKGROUND: Crescentic nephritis is characterized by formation of cellular crescents that soon become fibrotic and result in irreversible damage, unless an effective immunosuppressive therapy is rapidly commenced. TGF-β(1 )is involved in the development of crescents through various pathways. The aim of this study was to identify whether the determination of urinary TGF-β(1 )levels in patients with crescentic nephritis could be used as a marker of response to treatment. METHODS: Fifteen patients with crescentic nephritis were included in the study. The renal expression of TGF-β(1 )was estimated in biopsy sections by immunohistochemistry and urinary TGF-β(1 )levels were determined by quantitative sandwich enzyme immunoassay (EIA). TGF-β(1 )levels were determined at the time of renal biopsy, before the initiation of immunosuppressive treatment (corticosteroids, cyclophosphamide and plasma exchange). Twelve patients with other types of proliferative glomerulonephritis and ten healthy subjects were used as controls. RESULTS: Improvement of renal function with immunosuppressive therapy was observed in 6 and stabilization in 4 patients (serum creatinine from 3.2 ± 1.5 to 1.4 ± 0.1 mg/dl and from 4.4 ± 1.2 to 4.1 ± 0.6 mg/dl, respectively). In 5 patients, with severe impairment of renal function who started on dialysis, no improvement was noted. The main histological feature differentiating these 5 patients from others with improved or stabilized renal function was the percentage patients with poor response to treatment were the percentage of glomeruli with crescents and the presence of ruptured Bowman's capsule and glomerular necrosis. Urinary TGF-β(1 )levels were significantly higher in patients who showed no improvement of renal function with immunosuppressive therapy (930 ± 126 ng/24 h vs. 376 ± 84 ng/24 h, p < 0.01). TGF-β(1 )was identified in crescents and tubular epithelial cells, whereas a significant correlation of TGF-β(1 )immunostaining with the presence of fibrocellular cresents was observed (r = 0.531, p < 0,05). CONCLUSION: Increased TGF-β(1 )renal expression and urinary excretion that is related to the response to immunosuppressive therapy was observed in patients with crescentic nephritis. Evaluation of urinary TGF-β(1 )levels may be proved a useful marker of clinical outcome in patients with crescentic nephritis

    High-performance flexible perovskite solar cells exploiting Zn2SnO4 prepared in solution below 100 degrees C

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    Fabricating inorganic-organic hybrid perovskite solar cells (PSCs) on plastic substrates broadens their scope for implementation in real systems by imparting portability, conformability and allowing high-throughput production, which is necessary for lowering costs. Here we report a new route to prepare highly dispersed Zn2SnO4 (ZSO) nanoparticles at low-temperature (<100 degrees C) for the development of high-performance flexible PSCs. The introduction of the ZSO film significantly improves transmittance of flexible polyethylene naphthalate/indium-doped tin oxide (PEN/ITO)-coated substrate from similar to 75 to similar to 90% over the entire range of wavelengths. The best performing flexible PSC, based on the ZSO and CH3NH3PbI3 layer, exhibits steady-state power conversion efficiency (PCE) of 14.85% under AM 1.5G 100 mW . cm(-2) illumination. This renders ZSO a promising candidate as electron-conducting electrode for the highly efficient flexible PSC applications.ope
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