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Thirugnanam K.,SUTD | Kumar P.,IIT GuwahatiAssam
2015 IEEE International Transportation Electrification Conference, ITEC-India 2015 | Year: 2015

Due to increasing peak power demand and decreasing quality of power delivery to consumers, the penetration of Electric Vehicles (EVs) are highly acceptable for grid support. If the EVs are exchange active and reactive power to grid during parking hours, then the peak power demand has reduced and quality of power delivery has improved. The EVs are discharged at a place to be called as a Grid Supporting Station (GSS). The GSS have multiple Discharging Units (DUs) which transfers active and reactive power from EVs' batteries to grid. In this paper, a fuzzy based control method is described for EVs which regulate the active and reactive power for grid support. The active and reactive power flow from EVs to grid based on the node voltage and amount of energy available in the GSS. Each DU is designed for a maximum power handling capacity of 80VA. The performance of the GSS is analyzed with five set of EVs which is connected through point of Common Coupling (PCC) of distribution node. Simulation studies show that the GSS could effectively exchange the power for grid support during the peak hours. © 2015 IEEE. Source

Hosseini S.J.,Islamic Azad University at Tehran | Aghaie H.,Islamic Azad University at Tehran | Ghaedi M.,Yasouj University | Dashtian K.,Yasouj University | Purkait M.K.,IIT GuwahatiAssam
Environmental Progress and Sustainable Energy | Year: 2016

Silver nanoparticles (Ag-NPs) were synthesized viz. a green method in the presence of trisodium citrate as reducing agent and L-cysteine as acceptor and capping agent for removal of Pb2+ ion. Central composite design (CCD) under response surface methodology (RSM) was applied for simultaneous optimization of the importance variables for synthesis of Ag-NPs and its applicability for Pb2+ ion removal. The effects of the variables, such as pH, amount of reagent (such as L-cysteine concentration) and contact time on the Pb2+ ion removal and subsequent elution steps were efficiently examined. The maximum of Pb2+ ion removal was obtained while concentration of sodium citrate, silver nitrate, lead nitrate and L-cysteine was 0.05 M, 0.005 M, 27.78 mg L−1 and 0.25 M, respectively. The optimized resulting of Ag-NP were applicable for removal of a large content of Pb2+ ion (105.4 mg g−1) from samples with high Pb2+ ion concentration in short reasonable time. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 743–749, 2016. © 2016 American Institute of Chemical Engineers Environ Prog Source

Rao C.V.,IIT GuwahatiAssam | Golder A.K.,IIT GuwahatiAssam
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2016

The doping of semiconductor materials is conventionally carried out in chemical and energy intensive processes to have the visible light responsive photocatalytic activity. Herein, we first time report a new and green technique of metal doping viz., bio-mediated doping (BMD) of Ag on onto TiO2 (Ag/TiO2) using the aqueous extract of Sechium edule. The immobilization efficiency of Ag+ at the neutral pH was around 71–84% with the initial amount of Ag varying from 0.25 to 2% (w/w w.r.t. TiO2) and, the immobilized Ag+ was completely doped as no Ag+ ions were detected owing to BMD. The BMD technique had dramatically shifted the optical absorption (∼500 nm) to the visible domain and, the band gap of TiO2 was reduced to 2.5 eV. The crystallite size of TiO2 with the increase in Ag-loading was increased significantly because of Ag+ induction into the Ti4+ lattice and, there was about 10% (maximum) phase transformation. In the case of Ag/TiO2, the absolute value of zeta-potentials increased notably at pH > pHzpc that had resulted from the rise in oxygen vacancies and, Ag/TiO2 were mostly present as an individual nonclustered unit in water. Ag/TiO2 exhibited 98% degradation of Congo red dye under the visible light illumination. The electron spin resonance spectra confirmed that O2[Formula presented]− formed caused the high photocatalytic activity of BMD Ag/TiO2. © 2016 Elsevier B.V. Source

Bharti A.,IIT GuwahatiAssam | Banerjee T.,IIT GuwahatiAssam
Fuel Processing Technology | Year: 2016

n-Octanol is a new promising fuel which is considered as an alternative to conventional diesel. In order to understand the combustion characteristics of n-octanol, reactive molecular dynamics (ReaxFF MD) simulation of n-octanol has been carried out at temperatures from 2000 to 4000 K with equivalence ratios ranging from 0.5 to 2.0. Ethylene and formaldehyde have been found to be major intermediates in the oxidation of n-octanol which is in agreement with the available experimental data. Reaction mechanisms have been proposed for the formation of major intermediates (C2H4 and CH2O) and final products (CO and CO2) from where it is revealed that intermediates are mainly consumed by the build-up of hydroxyl and hydroperoxyl radicals. It was observed that the CO and CO2 formation from formaldehyde and ethylene starts with the attack of molecular oxygen or hydroxyl radical or hemolytic [Formula presented] bond cleavage. Overall, a good qualitative agreement with the available experimental data in terms of product distribution has been found. The results indicate that ReaxFF MD simulations can give a detailed description of the reaction mechanism and product distribution for the combustion for oxygenated fuel such as octanol. © 2016 Elsevier B.V. Source

Maddirala A.K.,IIT GuwahatiAssam | Shaik R.A.,IIT GuwahatiAssam
Proceeding - 2015 IEEE International Circuits and Systems Symposium, ICSyS 2015 | Year: 2015

The electroencephalogram (EEG) signals often contaminated by muscle or electromyogram (EMG) artifacts. The presence of these artifacts obscure the desired information in the EEG signal. In this paper, we proposed an efficient subspace based technique named singular spectrum analysis (SSA), to remove the EMG artifacts from the single channel EEG signals. For this we proposed a new grouping technique to extract efficiently the desired component from the contaminated EEG signal by setting a threshold. Firstly, single channel signal is mapped into multichannel signal or data, called embedding. Next, the orthogonal eigenvectors are estimated from the covariance matrix of the multichannel data by singular value decomposition (SVD). Since the local variations of eigenvectors corresponding to the EEG signals are low compare with the EMG signals, we set an arbitrary threshold (0.275) to find these eigenvectors, which are used to create the subspace corresponding to the EEG signals. After identifying the subspace, the EEG signals are extracted by simply projecting the multichannel data onto this subspace followed by reverse process of embedding step. Finally, the proposed method is applied on synthetic noisy sinusoidal signals and EEG signals contaminated by the EMG artifacts. The results shows that the proposed method can efficiently removes the EMG artifacts without altering the desired components. © 2015 IEEE. Source

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