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Bruggeman-Nannenga M.A.,Griffensteijnseplein 23 | Manjula K.M.,Zamorins Guruvayurappan College | Manju C.N.,Zamorins Guruvayurappan College
Lindbergia | Year: 2016

The African Fissidens enervis Sim is reported from the Western Ghats (India). This is the first Asian record. © 2016 The Authors.

Ummathur M.B.,Unity College | Babu D.K.,Zamorins Guruvayurappan College | Krishnankutty K.,University of Calicut
Journal of the Serbian Chemical Society | Year: 2014

The coupling of diazotized 2-aminothiazole and 2-aminobenzothiazole with cyclohexane-1,3-dione yielded a new type of tridentate ligand system (HL). Analytical, IR, 1H-NMR, 13C-NMR and mass spectral data indicate the existence of the compounds in the intramolecularly hydrogen bonded azo-enol tautomeric form. Monobasic tridentate coordination of the compounds in their [CuL(OAc)] and [ML2] complexes [M = Ni(II) and Zn(II)] was established based on the analytical and spectral data. The Zn(II) chelates are diamagnetic while the Cu(II) and Ni(II) complexes showed a normal paramagnetic moment. © 2014 Copyright SCS.

Krishnankutty K.,University of Calicut | Ummathur M.B.,Unity College | Babu D.K.,Zamorins Guruvayurappan College
Journal of the Serbian Chemical Society | Year: 2010

The coupling of diazotized 2-aminobenzothiazole with 1,3-dicarbonyl compounds (benzoylacetone, methyl acetoacetate and acetoacetanilide) yielded a new series of tridentate ligand systems (HL). Analytical, IR, 1H-NMR, 13C-NMR and mass spectral data indicated that the compounds exist in the intramolecularly hydrogen bonded azo-enol tautomeric form in which one of the carbonyl groups of the dicarbonyl moiety had enolised and hydrogen bonded to one of the azo nitrogen atoms. The compounds formed stable complexes with Ni(II), Cu(II) and Zn(II) ions. The Cu(II) complexes conform to [CuL(OAc)] stoichiometry while the Ni(II) and Zn(II) complexes are in agreement with [ML2] stoichiometry. Analytical, IR, 1H-NMR, 13C-NMR and mass spectral data of the complexes are consistent with the replacement of the chelated enol proton of the ligand with a metal ion, thus leading to a stable six-membered chelate ring involving a cyclic nitrogen, one of the azo nitrogens and the enolate oxygen. The Zn(II) chelates are diamagnetic while Cu(II) and Ni(II) complexes showed a normal paramagnetic moment.

Reshmi C.P.,Zamorins Guruvayurappan College | Reshmi C.P.,Indian National Institute for Interdisciplinary Science and Technology | Savitha Pillai S.,Kerala University | Vasundhara M.,Indian National Institute for Interdisciplinary Science and Technology | And 3 more authors.
Journal of Applied Physics | Year: 2013

Magnetization (M), Magnetocaloric effect (MCE), and Magnetoresistance (MR) in Co substituted La0.67Sr0.33Mn1-xCo xO3 (x = 0.03, 0.05, and 0.1) samples have been investigated. All the studied samples were crystallized into a single phase rhombohedral structure with R3̄c space group. The Curie temperature (TC) is found to decrease with the increase of Co content and for the composition x = 0.1, a cluster glass-like nature is observed. Temperature variation of magnetic entropy change (ΔSM) shows a positive peak at TC for the composition x = 0.1 with ΔS M = 3.1 J/kg K and relative cooling power, RCP=155J/kg at a magnetic field of 50 kOe. Again, the critical analysis of the paramagnetic to ferromagnetic transition and the scaling behaviour of field dependence of MCE for x = 0.1 composition is also reported. Furthermore, the temperature dependence of electrical resistivity under the magnetic fields up to 50 kOe is reported along with the values of 20% enhancement in MR at room temperature for the Co substituted samples. © 2013 AIP Publishing LLC.

Aswin V.S.,National Institute of Technology Calicut | Awasthi A.,National Institute of Technology Calicut | Anu C.,Zamorins Guruvayurappan College
Procedia Engineering | Year: 2015

In this paper, three different numerical schemes are described to approximate the solution of the convection-diffusion equation. The methods are based on differential quadrature and finite difference. In the first scheme, time derivative is approximated using forward difference and the space derivatives using polynomial based differential quadrature method (PDQM). In the second scheme, the discretization of the time and space derivatives are done using PDQM and central difference respectively, while in the third scheme only PDQM is used for the discretization of both time and space derivatives. The validation and comparison of the schemes are done through the simulation of two classic examples of convection-diffusion problem having known exact solution. It is found that the numerical schemes are in excellent agreement with the exact solution. We conclude with the realization that the third scheme, i.e. PDQM in time and space produce more accurate results among these three schemes. © 2015 The Authors.

Arun Kumar T.K.,Zamorins Guruvayurappan College | Manimohan P.,University of Calicut
Mycotaxon | Year: 2013

Nuclear LSU rDNA sequence analysis unequivocally places an agaric currently designated as Megacollybia virosa in Cantharocybe. Based on this molecular evidence, Cantharocybe virosa comb. nov. is proposed. This transfer results in the recognition of a third distinct species of Cantharocybe. The collections from India form the first record of the genus outside the North American continent. Phenetically, C. virosa shares with the type species of the genus, C. gruberi, the clitocyboid habit, distinct cheilocystidia, convex pileus with an inrolled margin, subdecurrent to decurrent lamellae, thickset stipe, ellipsoid, thin-walled, hyaline, smooth and inamyloid basidiospores, clamped hyphae, subregular to regular lamellar trama, a cutis-type pileipellis disrupted to form trichodermal patches, pileipellis hyphae with plasmatic pigment, and cystidioid terminal cells. A key to the known species is provided. © 2013. Mycotaxon, Ltd.

Manju C.,Zamorins Guruvayurappan College | Rajesh K.,Zamorins Guruvayurappan College | Madhusoodanan P.,University of Calicut
Acta Botanica Hungarica | Year: 2011

Chiloscyphus chinnarensis sp. nova, an autoicous, epiphytic leafy liverwort, with prostrate thin leafy shoot, closely imbricate, bluntly bilobed leaves in some branches, deeply 2-lobed underleaves which varies in size and cell arrangements, both margin usually with one additional tooth below, and having non-ciliate bracts in female inflorescence is described from the tropical wet evergreen forests of the Western Ghats of India.

Manju C.N.,Zamorins Guruvayurappan College | Manju C.N.,Ga College Po | Prakashkumar R.,Ga College Po | Prajitha B.,Ga College Po | And 2 more authors.
Taiwania | Year: 2012

Trichosteleum stigmosum Mitt. a rare moss is reported from Silent Valley National Park in the Western Ghats of India.

Ramani T.,Indian Institute of Chemical Technology | Leon Prasanth K.,Zamorins Guruvayurappan College | Sreedhar B.,Indian Institute of Chemical Technology
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2016

Air stable colloidal copper nanoparticles are synthesized by a simple chemical reduction method using octadecylsilane as a reducing agent and octadecylamine as a stabilizing agent in toluene without any inert gas. The formation of nanosized copper was confirmed by its characteristic surface plasmon absorption peaks in UV-visible spectra. The transmission electron microscopic (TEM) images show that the resulting copper nanoparticles are distributed uniformly with a narrow size distribution. The X-ray diffraction (XRD) demonstrated that the obtained copper nanoparticles are single crystalline nanoparticles. Fourier transform infra-red (FT-IR) spectroscopic data suggested that the silane Si-H is responsible for the reduction of copper ions. And also the resulting colloidal copper nanoparticles exhibit large surface-enhanced Raman scattering (SERS) signals. © 2015 Elsevier B.V. All rights reserved.

Ramani T.,Indian Institute of Chemical Technology | Umadevi P.,Indian Institute of Chemical Technology | Prasanth K.L.,Zamorins Guruvayurappan College | Sreedhar B.,Indian Institute of Chemical Technology
European Journal of Organic Chemistry | Year: 2013

ortho-Benzoylation of phenols with aryl aldehydes to afford the substituted 2-hydroxybenzophenones can be catalyzed efficiently by Fe3O 4 nanoparticles under ligand-free conditions. This method is useful for the preparation of xanthones in good yields. The catalyst can be magnetically removed and recycled easily over four cycles without a significant decrease in activity. The applicability of magnetically retrievable Fe 3O4 nanoparticles in the oxidative coupling of aryl aldehydes with phenols under ligand free conditions is demonstrated. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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