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de S.K.,Midnapore College Autonomous | Sana S.S.,Bhangar Mahavidyalaya
Journal of Intelligent Manufacturing | Year: 2016

This paper investigates a hill type economic production-inventory quantity (EPIQ) model with variable lead-time, order size and reorder point for uncertain demand. The average expected cost function is formulated by trading off costs of lead-time, inventory, lost sale and partial backordering. Due to the nature of the demand function, the frequent peak (maximum) and valley (minimum) of the expected cost function occur within a specific range of lead time. The aim of this paper is to search the lowest valley of all the valley points (minimum objective values) under fuzzy stochastic demand rate. We consider Intuitionistic fuzzy sets for the parameters and used Intuitionistic Fuzzy Aggregation Bonferroni mean for the defuzzification of the hill type EPIQ model. Finally, numerical examples and graphical illustrations are made to justify the model. © 2016 Springer Science+Business Media New York Source

De S.K.,Midnapore College Autonomous | Beg I.,Lahore School of Economics
Journal of Intelligent and Fuzzy Systems | Year: 2016

This article deals with a new novel defuzzification method for the dense fuzzy sets. In our study, we first define the dense fuzzy set for triangular fuzzy numbers. Then new defuzzification methods have been formulated with crisp convergence tests. Cauchy sequence has been utilized for better illustrations. We show the usefulness and the global justification of newly introduced methods. Applications of new methods in decision making, psychological test, military selection, cryptography, photography, crime research, filtering of noisy environment and risk analysis have been given as its key indexes. © 2016 - IOS Press and the authors. Source

Sasmal D.,Midnapore College Autonomous | Singh R.P.,Indian Institute of Science | Tripathy T.,Midnapore College Autonomous
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2015

Amylopectin-g-poly(acrylamide-co-N-methylacrlymide) [AP-g-poly(AM-co-NMA)] was prepared in presence of potassium persulfate (K2S2O8) as the initiator by solution polymerization technique. The synthesised graft copolymer was characterized by various characterization techniques like FTIR, 1H NMR and 13C NMR spectroscopy, thermal analysis and SEM. Biodegradation of the graft copolymers was carried out by enzyme hydrolysis. Flocculation performance of the graft copolymer was evaluated in 1.0wt% coal, 1.0wt% silica, 1.0wt% kaolin, 0.25wt% iron ore and 1.0wt% bentonite clay suspensions. The flocculation efficiency of the graft copolymer was also evaluated by the colour removal capacity from aqueous solution of a synthetic dye, malachite green. A comparative study of the flocculation performance AP-g-poly(AM-co-NMA) was also made with another laboratory synthesised graft copolymer namely amylopectin-g-polyacrylamide (AP-g-PAM) and some commercially available flocculants in the same suspensions and also in the malachite green solution. The results showed that the graft copolymer AP-g-poly(AM-co-NMA) showed better flocculation performance than that of AP-g-PAM as well as to some of the commercial flocculating agents. © 2015 Elsevier B.V. Source

Kolya H.,Midnapore College Autonomous | Tripathy T.,Midnapore College Autonomous
Polymer International | Year: 2015

Synthesis of amylopectin-graft-poly[(N,N-dimethylacrylamide)-co-(acrylic acid)] was carried out using solution polymerization technique with potassium persulfate as the initiator. The graft copolymer was characterized by measuring molecular weight using size exclusion chromatography, thermal analysis and Fourier transform infrared (FTIR) spectroscopy. The synthetic graft copolymer was used for the removal of some potentially toxic metal ions, Cu(II), Zn(II) and Ni(II), from their aqueous solutions. Various operating parameters like the amount of adsorbent, solution pH, contact time and temperature were studied. The adsorption data were well described by the pseudo-second-order and Langmuir isotherm models. Metal complexation studies were carried out experimentally using cyclic voltammetry and UV-visible and FTIR spectroscopies. The metal complex structure was also studied theoretically using density functional theory with the Gaussian 09 program and the geometry of the complex structure was optimized. The metal complexation ability of the graft polymer was in the order Cu(II) > Ni(II) > Zn(II). Calculation of the various thermodynamic parameters was also done. The negative value of free energy change indicates the spontaneous nature of the adsorption. © 2015 Society of Chemical Industry. Source

Das S.,Midnapore College Autonomous | Pandey A.,Midnapore College Autonomous | Pal S.,Indian School of Mines | Kolya H.,Midnapore College Autonomous | Tripathy T.,Midnapore College Autonomous
Journal of Molecular Liquids | Year: 2015

In this study, eco-friendly, non-toxic gold nanoparticles (AuNPs) were synthesized by green technique using a novel biodegradable graft copolymer based on hydroxy ethyl starch (HES) and methylacrylate (MA). The graft copolymer was prepared by first grafting of MA onto HES backbone by solution polymerization technique using potassium persulfate (K2S2O8) as the initiator followed by alkaline hydrolysis. The graft copolymer was characterized by FTIR and 1H NMR spectroscopy and XRD and SEM studies and by measuring saponification equivalent (S.E.). Biodegradation of the graft copolymer was studied by enzyme hydrolysis. AuNPs prepared by this method were characterized by UV-VIS spectroscopy and XRD, HR-TEM and EDAX analyses. The formation of AuNPs was confirmed by a visual color change (colorless to purple) and appearance of SPR band at 529 nm. The prepared AuNPs are globular in shape with an average particle size of 16-20 nm. Antibacterial activity of the green synthesized AuNPs was studied against two gram negative bacteria namely Shigella flexneri and Proteus mirabilis and two gram positive bacteria namely Bacillus cereus and Bacillus subtilis by agar well diffusion method. AuNPs synthesized by using the graft copolymer had a significant antibacterial effect against gram positive bacteria at very low concentration of nanoparticles. © 2015 Elsevier B.V. Source

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