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    Vibrational analysis of the fullerene family using tersoff potential

    , Article Current Applied Physics ; Volume 17, Issue 1 , 2017 , Pages 72-77 ; 15671739 (ISSN) Nejat Pishkenari, H ; Ghaf Ghanbari, P ; Sharif University of Technology
    Using Tersoff bond order potential, a vibrational analysis of the spherical fullerene family, namely C60, C80, C180, C240, C260, C320, C500, and C720 was performed. To evaluate the validity of our results, we have compared our simulation results with available experimental data and also with DFT B3LYP/6-31G(d) calculations. In general, molecular stiffness tends to decrease with increasing size, but its variation is limited in cases where mostly the tension-compression interaction sites are active such as the breathing mode. Furthermore, the bond length of each molecule is derived and compared with experimental and theoretical values calculated for graphene. Finally, vibrational frequencies... 

    Investigation of conductivity effects on capacitance measurements of water liquids using a cylindrical capacitive sensor

    , Article Journal of Applied Sciences ; Volume 10, Issue 4 , 2010 , Pages 261-268 ; 18125654 (ISSN) Behzadi, G ; Golnabi, H ; Sharif University of Technology
    In this study by using a Cylindrical Capacitive Sensor (CCS), the Electrical Conductivity (EC), effects on the capacitance measurements of the water liquids was investigated. Theoretical values of the capacitance measurements of water liquids with the cylindrical length in the range 0.5-5 cm are calculated. Our obtained results indicate that measured capacitance value by CCS depends on the liquid capacitance and reactance capacitance. Liquid capacitance value of the distilled water for permittivity of 80 is about 33.5 pF and reactance capacitance value is about 0.290 μF, when the cylindrical length value is about 1.6 cm. The reactance capacitance for the mineral, tap and dilute salt water... 

    Strain and stress concentrations in elastomers at finite deformations: effects of strain-induced crystallization, filler reinforcement, and deformation rate

    , Article Acta Mechanica ; Volume 227, Issue 7 , 2016 , Pages 1969-1982 ; 00015970 (ISSN) Khajehsaeid, H ; Reese, S ; Arghavani, J ; Naghdabadi, R ; Sharif University of Technology
    Springer-Verlag Wien 
    Strain and stress concentrations are studied for elastomers at finite deformations. Effects of strain-induced crystallization, filler reinforcement and deformation rate are also investigated, and micromechanical descriptions are provided for the observed results. A simple problem is subjected to finite element simulations to show the results evidently. Material parameters are obtained from experimental tests conducted on standard tensile samples of filled and unfilled natural rubber (NR) as well as styrene–butadiene rubber (SBR) as crystallizing and non-crystallizing rubbers, respectively. In all simulations, the strain concentration factor KE is shown to decrease monotonically where the... 

    Higher order statistics for modulation and STBC recognition in MIMO systems

    , Article IET Communications ; Volume 13, Issue 16 , 2019 , Pages 2436-2446 ; 17518628 (ISSN) Khosraviyani, M ; Kalbkhani, H ; Shayesteh, M. G ; Sharif University of Technology
    Institution of Engineering and Technology  2019
    Identification of modulation and space-time block code (STBC) is an important task of receivers in applications such as military, civilian, and commercial communications. Here, we consider multiple-input multiple-output (MIMO) systems. We propose two methods for STBC identification when the modulation is known. We also introduce a method for joint identification of code and modulation. Additionally, we present an enhanced zero-forcing (ZF) equaliser to improve the separation between the features of different classes. Higher order cumulants are used as the statistical features. In the first method of STBC identification, after the proposed equalisation, received data samples are segmented,... 

    Thermo-hydrodynamic modeling of a single bubble nozzle-diffuser phase change micropump

    , Article 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008, Darmstadt, 23 June 2008 through 25 June 2008 ; Issue PART B , June , 2008 , Pages 1237-1243 ; 0791848345 (ISBN); 9780791848340 (ISBN) Saidi, M. S ; Saeedi, M. H ; Pirouzpanah, S ; Nikparto, A ; ASME ; Sharif University of Technology
    Nowadays, the potential of phase change process in liquids at micro scale attracts the scientists to fabricate this type of micropumps. Such micropumps have widely found applications in industrial and medical equipments such as recent printers. Not using mechanical parts such as valves, and having small sizes and high and controllable mass flow rates are the advantages of these micropumps. In the nozzle diffuser phase change micropump a heat pulse generates a bubble in a chamber; therefore, the pressure pulse which is generated by the bubble, causes the bubble to expand suddenly with high rate, then the pressure of bubble reduces to the vapor pressure and causes negative rate of expansion to...