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Acharjee N.,Jalpaiguri Government Engineering College
Journal of Theoretical and Computational Chemistry | Year: 2014

1,3-dipolar cycloaddition reactions of an electron deficient C-aryl-N-phenyl nitrone to benzylidene derivatives (with different electrophilicities) have been analyzed by density functional theory calculations. The transition states corresponding to the endo and exo approaches along the feasible regioisomeric reaction channels have been located for each cycloaddition. The reactions follow a concerted mechanism with asynchronous transition states. The asynchronicity along the regiochemical reaction modes depends on the β-carbon electrophilicities of the olefins. The regio and stereochemistries predicted from the calculated activation energy barriers (with solvent and higher basis set corrections) of the located transition states are in conformity with the experimental results. The local electrophilicities, softness matching indices and the interaction energies were then calculated to analyze how well these reactivity parameters can interpret the regioselectivities of such reactions. The electronic populations at the reactive sites computed from electrostatic potential-driven atomic charges provided correct and consistent predictions for each theoretical model contrary to the natural orbital based charges. © 2014 World Scientific Publishing Company.

Koner S.,Jalpaiguri Government Engineering College | Pal A.,Indian Institute of Technology Kharagpur | Adak A.,Bengal Engineering and Science University
International Journal of Environmental Research | Year: 2012

The silica gel waste (SGW), after its collection from a local factory (Kolkata, India) was modified with cationic surfactant and was utilized as an adsorbing media for the removal of 2,4- dichlorophenoxyacetic acid (2,4-D) from agricultural runoff of a tea garden. Characterization of base adsorbent and modified adsorbent was carried out. The efficacy of the adsorbent was evaluated through both batch and fixed bed mode. Kinetics and isotherm study were conducted and the parameters were compared with 2,4-D bearing distilled water samples. The values of diffusion coefficients were determined. Presence of electrolyte and solution pH was found to affect the performance of the adsorbent significantly. The removal efficiency of surfactant modified silica gel waste (SMSGW) in case of wastewater was found to be lower than the 2,4-D bearing distilled water sample. The data of column run was analyzed using Logit model. Batch desorption study was carried out using ethanol and acetone. The studies revealed surfactant coated SGW to be an efficient adsorbing media for 2,4-D removal.

Guha D.,Dr. B. C. Roy Engineering College | Roy P.K.,Jalpaiguri Government Engineering College | Banerjee S.,National Institute of Technology Durgapur
Swarm and Evolutionary Computation | Year: 2016

In this article an attempt has been made to solve load frequency control (LFC) problem in an interconnected power system network equipped with classical PI/PID controller using grey wolf optimization (GWO) technique. Initially, proposed algorithm is used for two-area interconnected non-reheat thermal-thermal power system and then the study is extended to three other realistic power systems, viz. (i) two-area multi-units hydro-thermal, (ii) two-area multi-sources power system having thermal, hydro and gas power plants and (iii) three-unequal-area all thermal power system for better validation of the effectiveness of proposed algorithm. The generation rate constraint (GRC) of the steam turbine is included in the system modeling and dynamic stability of aforesaid systems is investigated in the presence of GRC. The controller gains are optimized by using GWO algorithm employing integral time multiplied absolute error (ITAE) based fitness function. Performance of the proposed GWO algorithm has been compared with comprehensive learning particle swarm optimization (CLPSO), ensemble of mutation and crossover strategies and parameters in differential evolution (EPSDE) and other similar meta-heuristic optimization techniques available in literature for similar test system. Moreover, to demonstrate the robustness of proposed GWO algorithm, sensitivity analysis is performed by varying the operating loading conditions and system parameters in the range of ±50%. Simulation results show that GWO has better tuning capability than CLPSO, EPSDE and other similar population-based optimization techniques. © 2015 Elsevier B.V. All rights reserved.

Sultana S.,Dr. B. C. Roy Engineering College | Roy P.K.,Jalpaiguri Government Engineering College
International Journal of Electrical Power and Energy Systems | Year: 2015

Increasing power demand and limited sources of conventional energy enforces the power system network to use sustainable energy sources. Renewable energy sources like biomass, wind and solar cell are the common technologies for sustainable, exhaustless and non-polluting energy. Optimal placement of renewable distributed generator (RDG) is a new challenge for traditional electric power systems. This paper presents, krill herd (KH) algorithm to minimize annual energy losses when different renewable resources are used. Moreover, the opposition-based learning (OBL) concept is integrated in KH algorithm in this article for improving the convergence speed and simulation results of conventional KH algorithm. In order to show the effectiveness the proposed oppositional krill herd (OKH) algorithm is implemented on 33-bus, 69-bus and 118-bus radial distribution networks to find optimal location and optimal size of RDGs to optimize energy losses. Moreover, to validate the superiority, the proposed OKH algorithm is compared with basic KH algorithm and recently developed analytical approach reported in the literature. It is observed from the test results that the proposed OKH algorithm is more efficient in terms of simulation results of energy loss and convergence property than the other reported algorithms. © 2015 Elsevier Ltd. All rights reserved.

Koner S.,Jalpaiguri Government Engineering College | Pal A.,Indian Institute of Technology Kharagpur | Adak A.,Bengal Engineering and Science University
Desalination | Year: 2011

The use of silica gel waste (SGW) as an adsorbent was found to be a very attractive alternative for removal of cationic surfactant (CS) from industrial (textile) wastewater. In the present work, the actual textile wastewater containing 362mg/l CS (in terms of CTAB) was treated by SGW in both batch and continuous modes. In batch mode, the optimum adsorbent dose and equilibrium time were found to be 10g/l and 30min respectively. Under optimized conditions, high removal efficiency of CS was achieved (~87%) and subsequent solubilization of other organic pollutants was found to occur through adsolubilization. The adsorption followed the Freundlich isotherm model. The breakthrough and exhaust times were found to be 6.5 and 13h respectively for a column of depth 50mm, maintaining the loading rate at 1.22m3/m2/h. The value of adsorption rate coefficient (K) and adsorption capacity coefficient (N) were found out. Regeneration of SGW after its exhaustion was efficiently done using 18% hydrochloric acid. The use of a solid waste of a factory as an adsorbent for removal of cationic surfactant and subsequent adsolubilization of organics made the process very cost effective alternative for textile wastewater treatment. © 2011 Elsevier B.V.

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