Sciencia Acta Xaveriana

11 - 19

Authors: A.Chandrasekaran, R.Ravisankar, A.Naseerutheen, G.Raja Annamalai

Firing is the key proces in potery production. Firing temperature analysis of the poteries may be used to ases the basic properties of the matrix and its temper. TGA-DTA study is commonly employed to thermal studies of potsherds to estimate the firng temperature. In the present work, thermogravimetry (TG) and diferential thermal analysis were caried out for potery samples recovered from the ancient setlements of Odugathur. The TG–DTG curves were obtained in the temperature range 0–100°C. Thermal analysis results howed larger mas los at dehydration than dehydroxylation and the organic material is used in the making of the potery. From the analysis Odugathur potsherds were fired below 80°C.

29 - 40

Authors: P.Eswaran, D.Prem Anand, A.Chandrasekaran, R.Ravisankar, A.Rajalakshmi

FT-IR spectroscopy is apowerful tol for asesing the mineralogical compositon of the soils. In the present study an atempt has ben made to investigate soils of Yelagir Hils, Tamilnadu India by Fourier transform infrared (FT-IR) spectroscopy. Qualitative analyses were caried out to determine the major and minor constiuent minerals present in the samples from the band positon or location of the peaks. From the prominent IR absorption peaks, the minerals identifed with the available literature are quartz, microcline, orthoclase, kaolinite, montmorilonite, ilite, and organic arbon. XRD confirms the presence of these minerals in soils. The interpretation of results is made from the characteristics of IR absorption bands. The results how that he FT-IR technique is apotential tol for the characterization of soil minerals.

51 - 58

Authors: J.Madhavan, M.Victor Antony Raj, D.Prem Anand

Quantum mechanical calculation is an efective tol to study the molecular behavior. L-Arginine maleate(LArM) an eficient NLO material is analyzed quantum mechanicaly by ab inito and Density Functional(DFT) method. It’s found that first order hyperpolarizabilty of the molecule is 6.3061527×10- 30esu and the large value of hyperpolarization along zdirection shows asubstantial delocalization of charges in these directions. Highest Ocupied Molecular Orbital (HOMO) energy and Lowest Unocupied Molecular (LUMO) energy were calculated and molecular energy gap is found to be 0.04638 a.u. This HOMO is mainly localized on the malate anion so that its energy is indicative of the donating character and LUMO is localized on L- Arginine cation. Strong donating group leads to high Polarizabilty values. Second Harmonic Generating eficiency depends on high hyperpolarizabilty of the material.

65 - 71

Authors: M Presheth, S.Stanly John Xavier, S R Bheeter, J Prema Kumari

Manganese(I), iron(II), cobalt(I), nickel(I), coper(I) and zinc(I) complexes of phloroglucinol have ben prepared and characterized by molar conductivity, magnetic susceptibilty measurements, estimation of metal ion and by their IR and electronic absorption spectra. The analytical data shows that al the complexes are of octahedral geometry. The non electrolytic and electrolytic nature of these complexes is evidenced by their magnetic susceptibilty and conductance data. The electronic and IR spectral data sugests octahedral geometry and cordination mode of the ligand.

79 - 93

Authors: Arockiam Thaddeus, G.Sumathi

Biological diversity is one of the functional atributes of an eco system. The nature of Soil on the diversity indices of earthworms were studied during the year 2010-2012. 168 study fields include eight stations of Theni district such as Periyakulam (S1), Theni (S2), Andipati (S3), Bodinaykanur (S4), Chinamanur (S5), Utamapalayam (S6), Kambam (S7), and Myladumparai (S8) were selected for the curent investigation. 52 species of earthworms were found in various ecosystems of al the 8 stations. Soils of the respective study areas were analyzed for their physico-chemical parameters uch as pH, Ec, N, P, K, Fe, Mn, Zn, and Cu. The nature of soil related to species abundance was also analyzed using regresion analysis. It was found that he earthworm species abundance decreases with increase in the level of pH, Zn & cu. In other words they both are inversely proportional to each other. The positve sign of the coeficient of Ec, N, P, K, Fe and Mn indicates that he earthworm species abundance directly depends upon the foresaid parameters. Biodiversity of Earthworm species were studied by Shanon wiener and evenes index and was found to be greater in station 7 (Kambam).

21 - 34

Authors: A. Lourdusamy

The t-pebbling number, ft(G), of a connected graph G, is the smallest positive integer such that from every placement of ft(G) pebbles, t pebbles can be moved to a specified target vertex by a sequence of pebbling moves, each move taking two pebbles off a vertex and placing one on an adjacent vertex. We say a graph G satisfies the odd 2t–pebbling property if, for any arrangement of pebbles with at least 2ft (G) – r + 1 pebbles, where r is the number of vertices with an odd number of pebbles in the arrangement, it is possible to put 2t pebbles on any target vertex using pebbling moves. We study the odd 2t-pebbling property of graphs.

71 - 74

Authors: C. Sanjeeviraja, J.T. Anandhi, V. Anslin Ferby, A. Moses Ezhil Raj

Lanthanum Aluminum Oxide nanoparticles have been synthesized by an auto-combustion method for different oxidant to fuel (O/F) ratios (0.5, 1.0 and 1.5). Lanthanum nitrate and Aluminum nitrate were used as oxidants, Citric acid as fuel and Ammonia as buffer to adjust the pH of the solution. Crystallinity and crystalline phases of the prepared samples were analyzed using X-ray diffraction and the reflection planes (100), (110), (111), (200), (210), (211), (220), and (300) revealed the rhombohedral phase as comparable to the JCPDS standards (Card No. 85-0848). FTIR spectra again confirmed the single phase formation of compound by the noticeable metal-oxygen (AlO6 octahedra) ligand formation band in the lower frequency region at about 665 cm-1. In the higher frequency region, the band appeared at 440 cm-1 was assigned to the La-O coordination of the samples. Optical measurement revealed absorption in the low wavelength region that corresponds to the optical absorption edge, 4.95eV, 4.77eV, 4.88eV respectively for the LaAlO3 samples prepared for three different F/O ratios.

81 - 86

Authors: J. Madhavan, S. Arulmozhi

Optical absorption of 2-Amino 5-Chloro Benzophenone (2A5CB) single crystal has been measured and its direct band gap was found. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the nonlinearity of 2A5CB has been investigated by Kurtz and powder technique. Thus optical characterization of 2A5CB reveals the various application oriented properties of the material.

91 - 98

Authors: C.Krishnan, S.G.Rejith

In this work we evaluate structural and optical properties of Zn-Doped CuO nanoparticles grown by microwave assisted solvothermal method. The formation of Zn-Doped CuO nanoparticles were confirmed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and UV-Visible spectroscopy. The average particle size have been found to be about 40 to 80 nm , The SEM image showed that the prepared product consists of spherical nanoparticles with narrow size distribution. The UV-Visible spectrum of Zn doped-CuO nanoparticles shows a strong blue shift compared to that of bulk and also shows the band edgeabsorption peak and is found to be at 350 nm. The obtained band gap value is 2.65 eV for Zn-Doped CuO nanoparticles.

103 - 110

Authors: Alphy Pius Stanly, John Xavier S, Selvakumar M.S, Prem Anand D

Green synthesis of nanoparticles is an emerging branch of nanotechnology. The characterization and sensing application of microwave synthesized and silver nanoparticles are reported in this work. The formation of silver nanoparticles was verified by UV-Vis spectroscopy and characterized by TEM and XRD analyses. The silver nanoparticles were used to detect Hg2+ ions colorimetrically by visible color change in aqueous medium. At higher pH value the deprotonated second 2+ions thereby inducing AgNP aggregation. The prepared silver nanoparticles were successful in sensing of mercury (II) ion even in a very low concentration of the order of 10-10 mol L-1 with high selectivity and sensitivity over K+, Mg2+, Mn2+, Na+, Fe3+, Zn2+, Ni2+, Co2+ and Ba2+ ions.