Annamalai University

About: Annamalai University is a education organization based out in Chidambaram, Tamil Nadu, India. It is known for research contribution in the topics: Lipid peroxidation & Antioxidant. The organization has 8098 authors who have published 10758 publications receiving 203872 citations.

An Interesting Correlation between Crystalline Perfection and Second Harmonic Generation Efficiency on KCl-and Oxalic Acid-Doped ADP Crystals

Abstract: The effect of dopants (over a concentration range from 1 to 10 mol %), namely KCl and oxalic acid (C2H2O4·2H2O, Oxa), on the growth process, crystalline perfection, and nonlinear optical (NLO) properties of ammonium dihydrogen phosphate (NH4H2PO4, ADP) single crystals grown by a slow evaporation solution growth technique has been investigated. The high-resolution X-ray diffraction (HRXRD) studies used to evaluate crystalline perfection reveal some interesting features on the ability of accommodating the dopants by the crystalline matrix. The remarkable and systematic increase in the broadness and asymmetry of the diffraction curves as the concentration increases clearly indicates that the dopants predominantly occupied the interstitial positions in the crystalline matrix. Due to the larger size of the Oxa molecule, the crystalline matrix could not accommodate these dopants, which led to the formation of a very low angle (tilt angle <1′) internal structural grain boundaries at high concentrations. The rela...

Evaluation of water quality pollution indices for heavy metal contamination monitoring: a case study from Curtin Lake, Miri City, East Malaysia

Abstract: An integrated approach of pollution evaluation indices and statistical techniques was employed to assess the intensity and sources of pollution in Curtin Lake water, Miri City, East Malaysia. Fe, Pb and Se concentrations in most of the water samples exceed the maximum admissible concentration. The heavy metal evaluation index (HEI) shows strong correlations with heavy metal pollution index (HPI) and degree of contamination (C d), and gives a better assessment of pollution levels. Samples from all the 25 locations in the lake were classified as high in C d and low in HPI compared with the respective critical values. The modified schemes of HPI and C d show comparable results with HEI and indicate that about 48 % of the samples with values lower than mean were classed as low contamination and the remaining samples (52 %) with values greater than the mean were classed as medium contamination. Cluster analysis, principal component analysis and pollution indices reveal that the quality of water is mainly controlled by natural/geogenic processes with minor anthropogenic input. US Salinity Laboratory plot and EC classification were also been used to assess the suitability of lake water for agricultural purpose. The current distribution level of heavy metal in the lake water is of environmental and health concerns and needs attention.