Heritage Institute of Technology, popularly known as HITK or HIT, is a private autonomous engineering college located in Anandapur, Kolkata near the East Kolkata Township, West Bengal, India.It is affiliated to West Bengal University of Technology, Kolkata.This institute is ranked among the top five engineering colleges in West Bengal. Wikipedia.
Paik S.P.,Sundarban Mahavidyalaya |
Ghatak S.K.,University of Calcutta |
Dey D.,Heritage Institute of Technology |
Sen K.,University of Calcutta
Analytical Chemistry | Year: 2012
Fluorescence in poly(ethylene glycol) (PEGs 400-12000) solutions is reported here for the first time. PEG solutions form a vesicular organization with the hydrophilic groups attached at both ends which arrange themselves beyond a particular concentration and offer electron-dense regions at the center of the vesicle. These vesicles provide an inherent site for fluorescence generation in PEG solutions. Fluorescence emission was observed at ∼380 nm with an excitation wavelength of 300 nm. PEG of molecular weight 6000 was found to show maximum emission intensity at a particular concentration. The formation of PEG vesicles (∼1 nm size) was confirmed by dynamic light scattering (DLS) and confocal laser microscopy. On addition of metal ions the polymeric vesicle breaks up to monomeric PEG, and hence, the fluorescence intensity decreases with a red shift. Fluorescence lifetime measurements indicate the nature of complexation of the metals with PEG. Since PEGs are used as one of the phases in aqueous biphasic systems (ABS) of liquid-liquid extractions, the nature of the fluorescence emission spectrum of the PEG phase after extraction was studied. Metal extraction in the PEG-rich phase of an ABS leads to quenching of fluorescence in PEG. © 2012 American Chemical Society.
Pal S.,Heritage Institute of Technology |
Mitra M.,University of Calcutta
Measurement: Journal of the International Measurement Confederation | Year: 2012
Here an effort is made to use human electrocardiogram as a tool of biometric analysis for authentication. The proposed method is based on first accurate extraction of characteristic features from each ECG and then design of a suitable classification methodology to comment on the authenticity. As the feature matrix is a huge one, Principal Component Analysis (PCA) is applied to avoid handling of large amount of data. Next, the reduced features from PCA are fitted into a quadratic polynomial model by the method of least square. Then the fitted values for the allowed set of data is obtained and the range over which they vary, provides the signature matrix of a person. Finally the classification is done by a comparison based on nearest neighbor method. The method is tested on ECG of 20 individuals taken from PTB database. This method has accuracy more than 95% with the best fit modeling which becomes only 80% without data modeling proving the importance of best fit modeling of data before classification. This accuracy is comparable with conventional biometric techniques; moreover, ECG biometric can be used with other authentication scheme, with ECG providing liveliness proof. © 2012 Published by Elsevier Ltd. All rights reserved.
Chakrabarty I.,Heritage Institute of Technology |
Chakrabarty I.,Institute of Physics, Bhubaneswar
European Physical Journal D | Year: 2010
In this work we study a state which is a random mixture of a two qubit subsystem of a N-qubit W state and GHZ state. We analyze several possibilities like separability criterion (Peres-Horodecki criterion [M. Horodecki, P. Horodecki, R. Horodecki, Phys. Lett. A 223, 1 (1996); A. Peres, Phys. Rev. Lett. 77, 1413 (1996)]), non violation of Bell's inequality [J.F. Clauser, M.A. Horne, A. Shimony, R.A. Holt, Phys. Rev. Lett. 23, 80 (1969)] (M(ρ)<1) and teleportation fidelity [N. Gisin, Phys. Lett. A 210, 157 (1996); R. Horodecki, P. Horodecki, M. Horodecki, Phys. Lett. A 200, 340 (1995); S. Massar, S. Popescu, Phys. Rev. Lett. 74, 1259 (1995); S. Popescu, Phys. Rev. Lett. 72, 797 (1994); C.H. Bennett, G. Brassard, C. Crepeau, R. Jozsa, A. Peres, W.K. Wootters, Phys. Rev. Lett. 70, 1895 (1993)] (F max>2/3 for this state. We also obtain a relationship between N (number of qubits) and p (the classical probability of random mixture) for each of these possibilities. Finally we present a detailed analysis of all these possibilities for N=3,4,5 qubit systems. We also report that for N=3 and in(0.75,1], this entangled state can be used as a teleportation channel without violating Bell's inequality. © 2010 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.
Zhang Q.,New Jersey Institute of Technology |
Wang Y.,New Jersey Institute of Technology |
Meng X.,New Jersey Institute of Technology |
Dhar R.,Heritage Institute of Technology |
Huang H.,New Jersey Institute of Technology
Analytical Chemistry | Year: 2013
8-Oxo-7,8-dihydroguanine (8-oxoG, or OG) as a free base has been widely considered as a biomarker for DNA oxidative damage. Currently no fluorescence sensor has been developed to directly detect 8-oxoG less than 100 nM. In this study, two triple-stranded DNAs were selected as the scaffolds to rationally design DNA aptamer sensors for 8-oxoG. The cavity was created by deleting the 8-oxodG nucleoside in a triplex containing an A·OG-C triad or a C·OG-A triad. The results showed that the fluorescence of both sensors were completely quenched by 8-oxoG. The detection ranges of the two sensors were different, while the combined range was comparable to the detection range of an antibody-based method. This result is expected to enable a fast, low-cost, and reusable method to measure 8-oxoG concentration. © 2012 American Chemical Society.
Mahapatra N.,Indian Institute of Technology Kharagpur |
Panja S.,Indian Institute of Technology Kharagpur |
Mandal A.,Heritage Institute of Technology |
Halder M.,Indian Institute of Technology Kharagpur
Journal of Materials Chemistry C | Year: 2014
In this study, we have demonstrated a facile, simple one-pot and low cost method for the synthesis of 3-mercaptopropionic acid (MPA)-capped, water-soluble CdS quantum dots (QDs) with highly tunable optical properties. Initially Cd2+ coordinates with MPA at about pH 5, and the CdS QDs were then formed at a higher pH (7-12) under refluxing conditions through the disruption of coordination interaction with the release of sulfur. Here MPA played a dual role, as both, a source of sulfur and as a stabilizer. The particle size and the optical properties of the as-prepared CdS QDs were found to be dependent on the refluxing time for a given concentration ratio of the reactants and pH of the initial mixture. The broadness and large Stokes shift of emission of MPA-CdS QDs are due to the surface-trap state photoluminescence (PL). The PL peak around 510 nm-650 nm is due to the recombination of shallow trapped electrons in sulfur vacancy defect states with holes in the valence band, and a ∼665 nm peak (shoulder) arises from deep-trap states. The origin of the longer lifetime is presumed to be due to the involvement of surface-trap states and their environment. Use of MPA as a capping agent eventually enhances the water solubility as well as the stability of CdS QDs, which makes them useful for the ultra-sensitive detection of Co2+ and Ni2+. The selective coordination interaction of Co2+ and Ni2+ with MPA-CdS QDs through the carboxyl group of MPA provides a turn-off photoluminescence-based assay for sensitive detection of these metal ions without any interference of other commonly coexisting metal ions. The limit of detection (LOD) is 10 nM for Co2+ ions and 50 nM for Ni2+ ions. Co2+-induced color (from colorless to yellow) and UV-vis spectral change of MPA-CdS QDs is the simple way to distinguish Co2+ from Ni2+ in a higher concentration range (more than 5 M). On the other hand the lower stability of the Co(ii)-MPA complex than the Ni(ii)-MPA complex provides a disodium salt of ethylenediaminetetraacetic acid (EDTA)-induced, time dependent turn-on photoluminescence-based technique to distinguish Co2+ from Ni 2+ in the entire range of concentrations. EDTA-induced time dependent PL recovery of MPA-CdS QDs occurs via rapid dissociation of Co2+ ions from the surface of QDs than that of Ni2+. Thus our synthesized MPA-CdS QDs offer a very simple, rapid, cost-effective, turn-off-on photoluminescence-based technique for ultra-sensitive and selective detection of either Co2+ or Ni2+ in aqueous solution without interference of other common metal ions. This journal is © the Partner Organisations 2014.