12 research outputs found

    Investigation of Wind Effects on Tall Buildings through Wind Tunnel Testing

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    There has been significant increase in tall building construction in Turkey in the last decade. As the height of building increase, wind effects become more pronounced. Wind can interact with flexible buildings and can significantly magnify the wind loads and wind induced oscillations. Wind tunnel tests have been widely utilized for estimating the wind effects on buildings. In order to perform a successful test, however, flow conditions inside the tunnel must represent the actual conditions rather closely. In this study, passive devices were designed to create wind profiles defined in wind codes inside Ankara Wind Tunnel that has a short test section. The performance of the designed passive devices was investigated through numerical and experimental studies. Then, wind effects on a rectangular shaped building were examined with high frequency base balance technique. The effect of turbulence intensity, vortex shedding and wind attack angle on wind loads were questioned. Finally base moments calculated from test results were compared with the results of various wind codes

    The mean field model with P-2 theta(2) coupling for the smectic A-smectic C* phase transition in liquid crystals

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    Using mean field theory with a P(2)theta (2) coupling term in the free energy expansion, we calculate the polarization as a function of temperature for the smectic A-smectic C* phase transition in a liquid crystalline material. Our calculated polarization values are in good agreement with the experimental data

    Renal carcinoma associated with a novel succinate dehydrogenase A mutation: a case report and review of literature of a rare subtype of renal carcinoma

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    Renal cell carcinoma (RCC) linked to germline mutation of succinate dehydrogenase subunits A, B, C, and D (SDHA, SDHB, SDHC, and SDHD, respectively) has been recently included as a provisional entity in the 2013 International Society of Urological Pathology Vancouver classification. Most SDH-deficient tumors show SDHB mutation, with only a. small numbei- of RCC with SDHC or SDHD having been reported to date. Only one case of SDH-deficient renal carcinoma known to be SDHA mutated has been previously reported. Here we report an additional RCC harboring an SDHA mutation occurring in a 62-year-old man with right flank pain and nodal metastasis. The tumor was characterized by an infiltrative pattern with solid, acinar, and papillary components. Loss of SDHA and SDHB protein by immunohistochemistry confirmed the diagnosis. Hybrid capture based comprehensive genomic profiling identified 3 genomic alterations in tumor tissue: (i) a novel single-nucleotide splice site deletion in SDHA gene, (ii) single-nucleotide deletion in NF2 gene, and (iii) EGFR gene amplification of 19 copies. This is the second report of SDHA-mutated RCC. With increased awareness, this rare tumor can be recognized on the basis of distinctive morphology and confirmation by immunohistochemistry and genomic profiling. (C) 2015 Elsevier Inc. All rights reserved

    Different developmental histories of beta-cells generate functional and proliferative heterogeneity during islet growth.

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    The proliferative and functional heterogeneity among seemingly uniform cells is a universal phenomenon. Identifying the underlying factors requires single-cell analysis of function and proliferation. Here we show that the pancreatic beta-cells in zebrafish exhibit different growth-promoting and functional properties, which in part reflect differences in the time elapsed since birth of the cells. Calcium imaging shows that the beta-cells in the embryonic islet become functional during early zebrafish development. At later stages, younger beta-cells join the islet following differentiation from post-embryonic progenitors. Notably, the older and younger beta-cells occupy different regions within the islet, which generates topological asymmetries in glucose responsiveness and proliferation. Specifically, the older beta-cells exhibit robust glucose responsiveness, whereas younger beta-cells are more proliferative but less functional. As the islet approaches its mature state, heterogeneity diminishes and beta-cells synchronize function and proliferation. Our work illustrates a dynamic model of heterogeneity based on evolving proliferative and functional beta-cell states
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