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    Experimental investigation of the roles of blood volume and density in finger photoplethysmography

    , Article IEEE Sensors Journal ; Volume 13, Issue 5 , 2013 , Pages 1397-1398 ; 1530437X (ISSN) Keikhosravi, A ; Zahedi, E ; Attar, H. M ; Aghajani, H ; Sharif University of Technology
    2013
    Abstract
    Using simultaneous photoplethysmogram (PPG) and pulse transducer signals from the same finger, a high correlation (Mean: 98.6, STD: 1) is obtained between the AC part of the PPG and estimated volume changes (after normalization). These results point to the fact that in the resting fingertip, PPG signal variations are only due to volume changes and that blood density does not change thus has no contribution  

    Mixed convection cooling of a heated circular cylinder by laminar upward-directed slot jet impingement

    , Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 46, Issue 2 , 2009 , Pages 225-236 ; 09477411 (ISSN) Amiri, S ; Habibi, K ; Faghani, E ; Ashjaee, M ; Sharif University of Technology
    Abstract
    An experimental and numerical study has been carried out to investigate the heat transfer characteristics of a horizontal circular cylinder exposed to a slot jet impingement of air. A square-edged nozzle is mounted parallel with the cylinder axis and jet flow impinges on the bottom of the cylinder. The study is focused on low Reynolds numbers ranging from 120 to 1,210, Grashof numbers up to Gr = 10Re2 and slot-to-cylinder spacing from 2 to 8 of the slot width. The flow field is greatly influenced by the slot exit velocity and the buoyancy force due to density change. A Mach-Zehnder Interferometer is used for measurement of local Nusselt number around the cylinder at 10° interval. It is... 

    Measurement and calculation of 13C and 15N NMR chemical-shift tensors of a push-pull ethylene

    , Article Canadian Journal of Chemistry ; Volume 87, Issue 4 , 2009 , Pages 563-570 ; 00084042 (ISSN) Amini, S. K ; Tafazzoli, M ; Jenkins, H. A ; Goward, G. R ; Bain, A. D ; Sharif University of Technology
    2009
    Abstract
    Methyl 3-dimethylamino-2-cyanocrotonate (MDACC) has a remarkably weak carbon-carbon double bond. It has strong electron-withdrawing groups on one end and electron-donating groups on the other: a so-called push-pull ethylene. To investigate this unusual electronic structure, we have determined the crystal structure and measured both the 13C and 15N NMR chemical-shift tensors. These measurements are supplemented by shielding-tensor calculations done with density functional methods. The large difference (approximately 100 ppm) between isotropic chemical shifts of the two alkenyl carbons reflects a large charge release from the electron-donating side of C=C double bond to the...