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Sobha A.P.,Vidya Academy of Science and Technology | Narayanankutty S.K.,Cochin University of Science and Technology
Sensors and Actuators, A: Physical | Year: 2015

Abstract Polyaniline (PANI)/functionalised multiwalled carbon nanotube (FMWCNT) based conductive thermoplastic polyurethane (TPU) films were prepared to study their strain sensing property. The composites were prepared by solution casting method using FMWCNT coated with polyaniline. The coating was done by in-situ and ex-situ polymerization of aniline. The composites thus prepared were designated as FMWCNT-PANI/TPU (I) and FMWCNT-PANI/TPU (E), respectively. The electrical resistivity and resistivity - strain behaviour of these composites were measured. The percolation threshold and the strain sensitivity of these films depended on the dispersion of conductive fillers in the polymer matrix. The well-dispersed filler in FMWCNT-PANI/TPU (I) composites resulted in low percolation threshold and improved strain sensitivity. These composites with 2 weight% filler content, showed a gauge factor of 1075 at 100% strain and exhibited high reversibility in resistivity upon elongating to 20%. A coating of PANI on FMWCNT reduced its entanglement and enhanced the interfacial interaction between the nano fillers and TPU, leading to improved strain sensitivity. The experimental data for strain sensing was in good agreement with the theoretical equations derived from a model based on the tunneling theory by Simmons. © 2015 Elsevier B.V.

Balagopalan S.,Vidya Academy of Science and Technology
IET Conference Publications | Year: 2011

Cooperative game theory is relevant for ensuring reliability of power grid of electricity markets, where central objectives of its transmission sector clash with the private incentive of its players. It is a critical component of market engineering as also is differential pricing, which is used here for pricing of transmission. Another tool used in the model for transmission sector, is a power vector to identify coalition partners. This procedural model is explained in three phases of game theory and is illustrated using a 24 bus power system. The results are significant and show that loss, congestion and total power flow in lines decrease considerably, improving efficiency. © 2012 The Institution of Engineering and Technology.

Sobha A.P.,Vidya Academy of Science and Technology | Sobha A.P.,Cochin University of Science and Technology | Narayanankutty S.K.,Cochin University of Science and Technology
IEEE Transactions on Nanotechnology | Year: 2014

Nanocomposites consisting of functionalized multiwalled carbon nanotubes and polyaniline (PANI) were prepared by traditional in-situ polymerization and dynamic interfacial polymerization methods. Morphological and structural analysis showed that synthesis by interfacial polymerization resulted in a well-ordered composite with a uniform core-shell structure, while traditional in-situ dynamic polymerization resulted in composites having a thick core shell structure with many protrusions. Composites synthesized by interfacial polymerization showed better electrical conductivity and seebeck coefficient as compared to composites synthesized by traditional in-situ polymerization. The highly extended and well-aligned PANI chain structure increased the effective degree of electron delocalization between pi bonds in aromatic rings of PANI and graphitic structure of nanotubes and, therefore, enhanced the carrier mobility in PANI. However, there was no corresponding increase in the thermal conductivity of the composite, which was due to phonon scattering effect of nanointerfaces. Thus, the introduction of a large number of nanointerfaces, which scatter phonons very effectively, leads to the development of nanostructured composites with enhanced power factor making it suitable for thermoelectric applications. © 2002-2012 IEEE.

Prabha S.K.,Vidya Academy of Science and Technology | Sathian S.P.,Indian Institute of Technology Madras
International Journal of Thermal Sciences | Year: 2014

Molecular dynamics study of non-reacting and disparate mass binary gas mixture is conducted. To investigate the gas-surface interaction properties of the gas mixture, in non-continuum regime, the rarefied gas confined in a nanochannel is considered. While keeping the bulk number density a constant, the interaction properties of gas mixtures at different molar concentration of individual components are determined. The study discusses the calculation of accommodation coefficients and prediction of the reflected gas distribution using accommodation coefficients. The Maxwell-type model that use calculated values of accommodation coefficients accurately predicts the reflected tangential and normal distributions. The model is validated for different wall-fluid conditions. The velocity correlation of individual gases demonstrates that the individual components of gas mixture are accommodated in different proportion. The result from the study will be beneficial in the analysis and development of potential applications involving the flow of gas mixture in a nanochannel. © 2014 Elsevier Masson SAS. All rights reserved.

In this discussion we show that the significance of the cubic relationship observed in Basu et al. (Scientometrics, 2016. doi: 10.1007/s11192-016-1935-0) can be explained simply—QQCI is a proxy for the normalized form of the exergy term X = (TC2/TP) and so the relationship seen in Nishy et al. (Scientometrics 91(1):245–251, 2012) is just confirmed. The original data is reworked to show explicitly the values of X and h3 and using a correlation test it is shown that there is remarkable agreement between X and h3. © 2016 Akadémiai Kiadó, Budapest, Hungary

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