Faculty Publications

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    Preparation and characterization of CdxZn1-xS thin films by spray pyrolysis technique for photovoltaic applications
    (2009) Raviprakash, Y.; Bangera, K.V.; Shivakumar, G.K.
    CdxZn(1-x)S (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) thin films were deposited by the chemical spray pyrolysis technique using a less used combination of chemicals. Depositions were done at 573 K on cleaned glass substrates. The composition, surface morphology and structural properties of deposited films were studied using EDAX, SEM and X-ray diffraction technique. XRD studies reveal that all the films are crystalline with hexagonal (wurtzite) structure and inclusion of Cd into the structure of ZnS improved the crystallinity of the films. In the entire compositions, the (0 0 2) diffraction peak is prominent which gives lattice matching to the chalcogenide semiconductor such as CuInxGa1-xSe2 and CuIn (s1-xSex)2, which are used in photovoltaic devices. The value of lattice constant 'a' and 'c' have been observed to vary with composition from 0.382 to 0.415 nm and 0.625 to 0.675 nm, respectively. The band gap of the thin films varied from 3.32 to 2.41 eV as composition varied from x = 0.0 to 1.0. It was observed that presence of small amount of cadmium results in marked changes in the optical band gap of ZnS. © 2009 Elsevier Ltd. All rights reserved.
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    Growth and morphology of mixed K1-x(NH4)xH2PO4 crystals
    (Elsevier Ltd, 2010) Shenoy, P.; Bangera, K.V.; Shivakumar, G.K.
    Mixed crystals of ammonium dihydrogen orthophosphate (ADP) and potassium dihydrogen orthophosphate (KDP), i.e., potassium ammonium dihydrogen phosphate, K1-x(NH4)xH2PO4 have been grown by slow evaporation from the supersaturated solution at an ambient temperature 26 ± 1 °C for ammonium concentration x in the range 0.0 ? x ? 1.0. The morphology changes from tetragonal prism to needles when the concentration of either of the components approaches that of the other. Induction periods were measured for various compositions of mixed crystals of ADP and KDP by the direct vision method. Crystal compositions were determined by flame atomic absorption spectroscopy and also by chemical analysis. Results of the X-ray analysis of the grown crystals are also reported. Maximum size of the grown mixed crystal was around 16 × 10 × 4 mm3. © 2010 Elsevier B.V. All rights reserved.
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    Growth and thermal studies on pure ADP, KDP and mixed K 1-x(NH4)xH2PO4 crystals
    (2010) Shenoy, P.; Bangera, K.V.; Shivakumar, G.K.
    The investigations on the formation of mixed crystals of ammonium dihydrogen orthophosphate (ADP) and potassium dihydrogen orthophosphate (KDP) i.e. potassium ammonium dihydrogen phosphate, K1-x(NH 4)xH2PO4 have been presented in this paper. Pure and mixed crystals of ADP and KDP have been grown by slow evaporation technique from the supersaturated solution at an ambient temperature 26±1 °C for ammonium concentration x in the range 0.0 ? × ? 1.0 in the case of mixed crystals. Crystal compositions were determined by flame atomic absorption spectroscopy and chemical analysis. The results of the X-ray analysis of the grown crystals are also reported. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study the kinetic process of dehydration and the high temperature phase behaviour. DTA showed the distinct thermal events attributed to dehydration of ADP, KDP and K1-x(NH4)xH2PO4. The results of thermal analysis and chemical analysis are consistent with each other. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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    Global water quality indices for river Gurpur, Karnataka State, India
    (2010) Rajagopal, B.; Shrihari, S.; Dwarakish, G.S.
    Three water quality indices viz. Drinking Water Quality Index (DWQI), Health Water Quality Index (HWQI) and Acceptability Water Quality Index (AWQI) were developed by United Nations Environment Programme (UNEP) under the Global Environment Monitoring System (GEMS)/Water for global comparison of quality of water sources. In this paper these three global water quality indices were determined for River Gurpur, in Karnataka state of India. Gurpur is one of the important west flowing rivers of India and is the source for industrial needs of fast developing Mangalore city. River water samples were collected from Gurpur River at Gurpur Bridge on National Highway -13 near Mangalore monthly from November 2006 to October 2007. The samples were analyzed for sixteen physico-chemical and bacteriological parameters. The global water quality indices determined for river Gurpur can be designated as 'Fair' during the study period. The seasonal variation in global water quality indices ranged from 'Marginal' to 'Excellent'. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
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    Analytical properties of p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone: Spectrophotometric determination of palladium(II) in alloys, catalysts, and complexes
    (2011) Karthikeyan, J.; Parameshwara, P.; Nityananda Shetty, A.N.
    p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone (CEABT) is proposed as a new, sensitive, and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium(II) in the pH range 1-2 to form a yellow-colored complex. Beer's law is obeyed in the concentration range up to 2.64 ?g cm-3. The optimum concentration range for minimum photometric error as determined by Ringbom's plot method is 0.48-2.40 ?g cm-3. The yellowish Pd(II)-reagent complex shows a maximum absorbance at 395 nm, with molar absorptivity of 4.05 × 104 dm3 mol-1 cm-1 and Sandell's sensitivity of the complex from Beer's data, for D= 0.001, is 0.0026 ?g cm-2. The composition of the Pd(II)-CEABT reagent complex is found to be 1:2 (M-L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes, water samples, and synthetic alloy mixtures with a fair degree of accuracy. © 2010 Springer Science+Business Media B.V.
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    Association of chlorophyll in a multi-parametric shallow marine environment off the Karnataka-Kerala coast
    (2011) Raghavan, B.R.; Shylini, S.K.; Deepthi, T.; Kumaraswami, M.; Ashwini, S.; Chauhan, P.; Raman, M.; Venkat Reddy, D.
    Cluster analysis is a useful data analyzing method to obtain detailed information on the state of the shallow marine environment. The objective of this analysis is to appreciate the clustering patterns of the data of case II shallow marine environment of the eastern Arabian Sea. R-mode cluster analysis was resorted to appreciate the relation of the physical, chemical and biological oceanographic parameters represented as dendograms. A set of 14 parameters were retrieved from seven seasons of the coastal waters from Bekal (North Kerala) to Karwar (North Karnataka). This study exhibits diverse clustering patterns reflecting the heterogeneous behavior of the surface waters of the shallow Arabian Sea enforced by the physical, chemical and biological oceanography of the shallow marine environment. © 2011 CAFET-INNOVA technical society. All right reserved.
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    Assessment of water quality of river Ganga along ghats in Varanasi city, U. P., India
    (2011) Thomas, T.; Mishra, M.; Thomas, H.; David, A.A.; Bharose, R.; Venkat Reddy, D.
    Assessment of water quality was done in holy River Ganga district of Varanasi, (U.P.) India in 2009. Water samples were collected from fives different sites namely (S 1)- Samne Ghat, (S 2)- Assi Ghat, (S 3)- Harishchandra Ghat, (S 4)- Dasaswamedh Ghat, (S 5)- Dr. Rajendra Prashad Ghat. The Ganga, one of the world's major rivers, has been venerated as the holiest and is bound with countless beliefs and faiths especially in India and adjacent countries. Its water has traditionally been regarded as pure and holy in nature gift to human. Recent experiences however do not warrant such complacency. The water resources are strained to a non-sustainable level due to rapid population growth, urban development, industrialization; livestock and power production on the Ganga Ghats at Varanasi city. The severe pollution stress and causes to which its water is subjected to the contents and quality of water and possible remedial measures. According to the result obtained by analyzing various Physico-chemical parameters of Ganga river in Varanasi City, maximum BOD recoded in (S 2)- Assi Ghat and minimum in (S 1)- Samne ghat whereas maximum DO was observed in Samne Ghat and minimum in (S 2)- Assi Ghat during Jan to March 2009 period respectively. On the basis of our experimental results it can be concluded that (S 2)- Assi Ghat exhibited higher pollution index than other ghats due to higher values of Turbidity, pH, BOD, Hardness, Alkalinity and Nitrate disposal occurring at (S 2)- Assi Ghat as well as disposal of industrial sewage in the (S 2)- Assi Ghat. Regular monitoring of Ganga river water quality is necessary to have a check on surface water quality for the sake of human life & to maintain a balanced aesthetical value of religious. We have to restore the environmental quality of Ganga which is amended by policy makers of Indian constitution. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
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    Synthesis and characterization of schiff base metal complexes and reactivity studies with malemide epoxy resin
    (Korean Chemical Society sunlee@kcsnet.or.kr, 2012) Lakshmi, B.; Shivananda, K.N.; Prakash, G.A.; Isloor, A.M.; Mahendra, K.N.
    A novel malemide epoxy containing Co(II), Ni(II) and Cu(II) ions have been synthesized by curing malemide epoxy resin (MIEB-13) and Co(II), Ni(II) and Cu(II) complexes of macrocyclic bis-hydrazone Schiff base. The Schiff base was synthesized by reacting 1,4-dicarbnyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol. The Schiff base and its Co(II), Ni(II) and Cu(II) complexes have been characterized by elemental analyses, spectral (IR, 1H NMR, UV-vis., FAB mass, ESR), thermal and magnetic data. The curing reaction of maleimide epoxy compound with metal complexes was studied as curing agents. The stability of cured samples was studied by thermo-gravimetric analyses and which have excellent chemical (acid/alkali/solvent) and water absorption resistance. Further, the scanning electron microscopy (SEM) and definitional scanning colorimetric (DSC) techniques were confirmed the phase homogeneity of the cured systems.
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    Simple glucose reduction route for one-step synthesis of copper nanofluids
    (Springer Nature, 2014) Shenoy, S.U.; Nityananda Shetty, A.
    One-step method has been employed in the synthesis of copper nanofluids. Copper nitrate is reduced by glucose in the presence of sodium lauryl sulfate. The synthesized particles are characterized by X-ray diffraction technique for the phase structure; electron diffraction X-ray analysis for chemical composition; transmission electron microscopy and field emission scanning electron microscopy for the morphology; Fourier-transform infrared spectroscopy and ultraviolet–visible spectroscopy for the analysis of ingredients of the solution. Thermal conductivity, sedimentation and rheological measurements have also been carried out. It is found that the reaction parameters have considerable effect on the size of the particle formed and rate of the reaction. The techniques confirm that the synthesized particles are copper. The reported method showed promising increase in the thermal conductivity of the base fluid and is found to be reliable, simple and cost-effective method for preparing heat transfer fluids with higher stability. © 2012, The Author(s).
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    Influence of redmud on the mechanical, damping and chemical resistance properties of banana/polyester hybrid composites
    (Elsevier Ltd, 2014) Veerasimman, V.; Marimuthu, M.; Manikandan, V.; Nagarajan, N.; Jeyaraj, P.
    A novel hybrid composite was developed with the addition of redmud as secondary reinforcing filler with banana fiber reinforced polyester composites (BFRPCs). The effect of varying parameters such as particle size (4, 6 and 13. ?m) and weight percentage (2, 4, 6, 8 and 10. wt%) of redmud were analyzed on static mechanical, free vibration and chemical resistance properties of hybrid composites. The addition of redmud shown enhanced performance compared to the virgin BFRPCs in all the above said properties. The maximum increase of 50% in mechanical strength was observed for the BFRPCs with the addition of redmud having 4. ?m particle size and 8. wt% of filler content compared to pure BFRPCs. The increased value of fundamental natural frequencies with associated modal damping characteristics of redmud filled BFRPCs were found using half-power band width method. All the fabricated composites performed well against various chemicals and it indicates that the resistance to the weight loss is due to the uniformly distributed redmud. To study the effect of redmud on interfacial bonding between the banana fiber and polyester matrix the Scanning Electron Microscope (SEM) image analysis was performed. © 2014 Elsevier Ltd.