Entity

Time filter

Source Type


Saha G.,Jadavpur University | Sarkar K.K.,Jadavpur University | Sarkar K.K.,Barrackpore Rastraguru Surendranath College | Datta P.,Jadavpur University | And 2 more authors.
Polyhedron | Year: 2010

The reaction of CuX (X = Cl, Br, I) with a mixture of PPh3 and 1-alkyl-2-(naphthyl-α/β-azo)imidazole has synthesized mixed ligand complexes of the composition, [Cu(α/β-NaiR)(PPh3)X]. The spectroscopic characterization (IR, UV-Vis, 1H NMR) supports this formulation. The single crystal X-ray diffraction study of [Cu((α-NaiMe) (PPh3)I] (7a) (α-NaiMe = 1-methyl-2-(naphthyl-α-azo) imidazole) shows a distorted tetrahedral geometry about Cu(I). Cyclic voltammograms of the complexes show a high potential Cu(II)/Cu(I) couple and azo reductions. The [Cu(α/β-NaiR)(PPh3)I] complexes show an additional oxidative response at 0.4 V that is assigned to I/I- A sharp anodic peak at ∼-0.2 V is assigned to the oxidation of metallic Cu, deposited on electrode surface upon scanning to the negative side of the SCE. DFT and TD-DFT computations of [Cu((α-NaiMe)(PPh3)I] (7a), [Cu((α-NaiMe)(PPh3)I]+ (7a+) and [Cu((α-NaiMe)(PPh3)I]- (7a-) were carried out to examine the electronic configuration and to explain the spectral and redox properties of the complexes. © 2010 Elsevier Ltd. All rights reserved. Source


Ghosh D.,Barrackpore Rastraguru Surendranath College
Indian Chemical Engineer | Year: 2015

Carotenoids are the most common pigments in nature possessing high nutraceutical value. The objective of the present work was to obtain a good yield of carotenoids from pumpkin tissues, using cellulase and pectinase enzymes. Various parameters such as concentration of enzymes and time of incubation were optimised, to improve the yield of carotenoid from pumpkins. Enzyme-aided extraction of carotenoid from whole pumpkins under optimised conditions resulted in an increase in the carotenoid yield by 33.3% (w/w) in cellulase-treated sample and 28.6% (w/w) in case of pectinase-treated sample. Extraction from pumpkin peel under optimised conditions showed a remarkable increase in the yield of carotenoid by 77.7% (w/w) and 71.4% (w/w), for cellulase- and pectinase-treated samples, respectively. © 2015 Indian Institute of Chemical Engineers Source


Chakraborty A.,Barrackpore Rastraguru Surendranath College | Mandal J.K.,Kalyani University
Advances in Intelligent Systems and Computing | Year: 2015

Clustering is considered as one of the most important unsupervised learning problem which groups a set of data objects, in such way, so that the data objects belongs to the same group (known as cluster) are very similar to each other, compared to the data objects in another group (i.e. clusters). There is a wide variety of real world application area of clustering. In data mining, it identifies groups of related records, serving as the basis for exploring more detailed relationships. In text mining it is heavily used for categorization of texts. In marketing management, it helps to group customers of similar behaviors. The technique of clustering is also heavily being used in GIS. In case of city-planning, it helps to identify the group of vacant lands or houses or other resources, based on their type, value, location etc. To identify dangerous zones based on earth-quake epi-centers, clustering helps a lot. In this paper, a set of data objects are clustered using two connected graph based techniques – MST based clustering and Tree Based clustering. After considering a lot of test cases, at the end of the paper, the second technique is found to be more suitable for clustering than the first one. © Springer International Publishing Switzerland 2015. Source


Som S.,Barrackpore Rastraguru Surendranath College
2012 National Conference on Computing and Communication Systems, NCCCS 2012 - Proceeding | Year: 2012

In present age chaos based cryptosystem has gained attention in research of information security and number of chaos based image encryption algorithms has been proposed. In this paper, a new symmetric image encryption algorithm based on multiple chaotic maps is proposed. In the proposed algorithm, the plain image is first scrambled using generalized Arnold Cat Map. Further, the scrambled image at a particular iteration is encrypted using chaotic sequences generated by one-dimensional Logistic Map after preprocessing them to integers. The experimental results depicts that the proposed algorithm can successfully encrypt and decrypt grayscale images with secret keys. The simulation analysis also exhibit that the proposed method is loss-less, secure and efficient measured in terms of statistical tests, key sensitivity test and some well known tests like NPCR, UACI and entropy. © 2012 IEEE. Source


Ghosh D.,Barrackpore Rastraguru Surendranath College | Biswas P.K.,BCKV
Indian Chemical Engineer | Year: 2016

Carotenoids are the most common pigments in nature possessing high nutraceutical value. The objective of the present work was to obtain a good yield of carotenoids from pumpkin tissues, using cellulase and pectinase enzymes. Various parameters such as concentration of enzymes and time of incubation were optimised, to improve the yield of carotenoid from pumpkins. Enzyme-aided extraction of carotenoid from whole pumpkins under optimised conditions resulted in an increase in the carotenoid yield by 33.3% (w/w) in cellulase-treated sample and 28.6% (w/w) in case of pectinase-treated sample. Extraction from pumpkin peel under optimised conditions showed a remarkable increase in the yield of carotenoid by 77.7% (w/w) and 71.4% (w/w), for cellulase- and pectinase-treated samples, respectively. © 2015 Indian Institute of Chemical Engineers. Source

Discover hidden collaborations