Calicut, India
Calicut, India

The University of Calicut is an affiliating university located at Thenjipalam in Malappuram district of Kerala state in India. The University has a number of off-campus centres in neighbouring districts especially Kozhikkode, Wayanadu, Thrissur, Palakkad and Lakshadweep islands and it conducts courses and examinations for the students of the affiliated colleges. The main campus in Thenjipalam has departments in most of the science and humanities areas. The departments offer post graduate courses and research programmes. However, the main business in the campus is administration and conduct of examinations for all the affiliated colleges which number above 250. In 2013 it is ranked as the 26th best university of India. Wikipedia.

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Pradeep S.,University of Calicut | Benjamin S.,University of Calicut
Journal of Hazardous Materials | Year: 2012

This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC-MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil - either singly or in consortium - completely consumed intact DEHP physically bound to BB by static submerged growth (28 °C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass (~0.15-0.35 g/g BB; OD ~7 at 600. nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large scale through a batch process in alleviating the plactics waste management issue. © 2012 Elsevier B.V.

Ramesan M.T.,University of Calicut
Polymer Engineering and Science | Year: 2014

This article reports the facile synthesis of copper sulfide (CuS)/polyaniline (PANI) nanocomposites by in situ polymerization. The composites were characterized by scanning electron microscopy (SEM), UV-visible and Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). SEM analysis showed that the metal sulfide nanoparticles were uniformly dispersed in the polymer matrix. The characteristic peaks in FTIR and UV-vis spectra of PANI were found to be shifted to higher wave numbers in PANI/CuS composite, which is attributed to the interaction of CuS nanoparticles with PANI chain. XRD pattern revealed the structurally ordered arrangement of polymer composite and this regularity increases with increase in concentration of nanoparticles. Glass transition temperature of the nanocomposite increased with increase in the concentration of nanoparticles and it indicated the ordered arrangement of the polymer composite than PANI. TGA studies indicated excellent thermal stability of polymer nanocomposite. The electrical properties of nanocomposites were studied from direct current and alternating current resistivity measurement. Conductivity, dielectric constant, and dissipation factor of the nanocomposite were significantly increased with the increase in CuS content in the nanocomposite. The enhancement of these properties suggests that the proposed PANI/CuS nanocomposites can be used as multifunctional materials for nanoelectronic devices. © 2013 Society of Plastics Engineers.

Ramesan M.T.,University of Calicut
Journal of Applied Polymer Science | Year: 2013

Nanocomposites of polypyrrole (PPy) containing copper sulfide (CuS) were synthesized by an in situ chemical oxidative polymerization. The nanocomposites were characterized by FTIR, SEM, XRD, DSC, TGA, and conductivity studies. The FTIR spectra ascertained the chemical interlinking of polypyrole with metal sulfide nanoparticles. Morphological analysis showed that the nanoparticles were uniformly covering the entire substrate. The XRD pattern reveals that the nanoparticle incorporated polypyrrole showed a crystalline nature and the crystallinity of the polymer increases with increase in concentration of CuS nanoparticles. From DSC, an increase in glass transition temperature shows the increased orderness in the polymer composite than in the pure polypyrrole. Thermal analysis (TGA) of the composite showed a progressive increase in the thermal stability with increase in content of CuS. The frequency dependent electrical properties (a.c. conductivity) of the nanocomposites were higher than that of polypyrrole. The d.c. electrical conductivity increased with increase in amount of nanoparticles in the polymer matrix. The results obtained for these composites have greater scientific and technological interest. © 2012 Wiley Periodicals, Inc.

Stanly Jacob K.,University of Calicut | Parameswaran G.,University of Calicut
Corrosion Science | Year: 2010

A heterocyclic Schiff base furoin thiosemicarbazone was tested for its corrosion inhibition towards mild steel in 1 M HCl solution using weight loss, Tafel polarization and electrochemical impedance spectroscopy techniques. Furoin thiosemicarbazone revealed good corrosion inhibition efficiency even at low concentrations towards mild steel in HCl medium. Comparison of corrosion inhibition efficiency of Schiff base and its parent amine and effect of temperature on inhibition efficiency were also investigated. The adsorption of furoin thiosemicarbazone on mild steel surface obeys Langmuir isotherm. © 2009 Elsevier Ltd. All rights reserved.

Ramesan M.T.,University of Calicut
Polymer Composites | Year: 2012

Conducting polymer nanocomposites of polyindole (PIN)/copper sulfide (CuS) were fabricated by in situ polymerization of indole with different concentration of CuS nanoparticles. These composites were examined by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and electrical studies. XRD analysis confirmed that the composite began to crystallize by the incorporation of CuS nanoparticles. The IR spectrum shows the intermolecular interaction between PIN and CuS. SEM images revealed that the nanoparticles were uniformly embedded in the entire substrate. Glass transition temperature was found to be increased with increase in concentration of nanoparticles, which showed an ordered structure of the samples. TGA results indicated that the fabricated PIN/CuS composite attains better thermal stability than pure PIN. The dc conductivity of nanocomposite was significantly increased with increase in content of CuS nanoparticle. An increase in ac electrical conductivity and dielectric properties of the composite were observed with increase in molar concentration of CuS nanoparticles. Thus, enhancements in these properties suggest that the fabricated PIN/CuS nanocomposite has potential application in the field of nanotechnology. © 2012 Society of Plastics Engineers.

Renuka N.K.,University of Calicut
Journal of Alloys and Compounds | Year: 2012

Nanoscale, high surface area spherical cerium oxide was prepared from aqueous cerium nitrate by homogeneous precipitation using ammonia. This synthesis route offers a versatile, low cost and environmental friendly method to produce nano ceria. The specimen powder was characterized with XRD, SEM, HRTEM, and UV-vis spectrophotometry. Cubic cerianite crystallites (CeO 2) were detected by powder XRD pattern, while Ce 3+ was also evident from XPS spectra and DR UV spectroscopy study. XPS spectra indicated that cerium in the nano crystals was predominantly tetravalent. Both Ce 2O 3 as well as oxygen vacancy contributed towards the presence of Ce 3+ in the sample. The particle size of the system was calculated from TEM analysis, XRD study and BET surface area analysis. The characterization revealed the particles to be spherical in shape with typical size 4-5 nm, which is a favourable characteristic feature for many applications. The direct optical band gap estimated from DR UV absorption spectrum was blue-shifted evidently with respect to the bulk material and indicated quantum-size confinement effect in nano crystallites. © 2011 Elsevier B.V. All rights reserved.

Ramesan M.T.,University of Calicut
Polymer - Plastics Technology and Engineering | Year: 2012

This work focused on the preparation, characterization and conductivity studies of copper sulphide nanoparticle incorporated polypyrrole (PPy)/polyvinyl alcohol (PVA) blend by in situ chemical oxidative polymerization. The blend nanocomposites were examined by FTIR, SEM, XRD, TGA and electrical studies. The complexation of CuS with the polymer was confirmed by FTIR. The surface observed in the SEM image clarifies the uniformity in morphology. The XRD pattern reveals that the nanoparticle incorporated PPy and their blend showed a crystalline nature. TGA and conductivity studies indicated that the blend nanocomposites attain better thermal stability and conductivity than original polypyrrole and PPy/PVA blend. © 2012 Copyright Taylor and Francis Group, LLC.

Muraleedharan K.,University of Calicut
Journal of Thermal Analysis and Calorimetry | Year: 2013

The effect of gamma ray irradiation on the rate and kinetics of thermal decomposition of potassium iodate (KIO3) has been studied by thermogravimetry (TG) under non-isothermal conditions at different heating rates (3, 5, 7, and 10 K min-1). The thermal decomposition data were analyzed using isoconversional methods of Flynn-Wall-Ozawa, Kissinger-Akahira- Sunose, and Friedman. Irradiation with gamma rays increases the rate of the decomposition and is dependent on the irradiation dose. The activation energy decreases on irradiation. The enhancement of the rate of the thermal decomposition of KIO3 upon irradiation is due to the combined effect of the production of displacements and extended lattice defects and chemical damage in KIO3. Non-isothermal model fitting method of analysis showed that the thermal decomposition of irradiated KIO3 is best described by the contracting sphere model equation, with an activation energy value of ~340 kJ mol-1. © Akadémiai Kiadó, Budapest, Hungary 2013.

Bannur V.M.,University of Calicut
Physica A: Statistical Mechanics and its Applications | Year: 2015

Mayer's convergence method for virial expansion and condensation is studied using a new generating function for canonical partition function, which directly depends on irreducible cluster integral, βk, unlike Mayer's work where it depends on reducible cluster integral, bl. The virial expansion, criteria for its validity and criteria for condensation, etc. are derived from our generating function. All earlier Mayer's results are obtained from this new generating function. © 2014 Elsevier B.V. All rights reserved.

Ramesan M.T.,University of Calicut
International Journal of Polymeric Materials and Polymeric Biomaterials | Year: 2013

Polypyrrole (PPy)/poly(pyrrole-co-acrylamide) (Poly(Py-co-AAm)/ nanocomposite was prepared by a simple and inexpensive in-situ co-polymerization of pyrrole and acrylamide in the presence of Fe3O4 nanoparticles. The nanocomposites were characterized by FTIR, SEM, XRD, TGA, and conductivity measurements. The FTIR spectra ascertain the chemical interlinking of polypyrrole and copolymer with magnetite nanoparticles. The XRD revealed that crystallinity of the copolymer was increased with weight percentage of the magnetite nanoparticles. SEM analysis showed that the nanoparticles were well shaped and uniformly dispersed in the nanocomposites. Thermal stability and the electrical conductivity of the nanocomposite were higher than that of polypyrrole and the copolymer. © 2013 Copyright Taylor and Francis Group, LLC.

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