Ground water is an important source of water supply throughout the world. Its use in irrigation, industries, municipality and rural areas continues to increase. The need of the groundwater exceeds the groundwater potential and water scarcity exists. It becomes essential to evaluate qualitative and quantitative assessment of existing ground water resources. Mailam Block of Tindivanam Taluk, Villupuram District, falls between the latitudes 79⁰26' to 79⁰44'N and longitudes 12⁰3' to 12⁰19' E and forms part of survey of India Top sheet No.57 P/12. Ground water sample from 30 locations have been collected and analyzed and brought into a digital output using a simple program HYCH. From the digital output, thematic maps such as Total Dissolved Solids (TDS), Total Hardness, Corrosivity ratio, USSL Classification and Groundwater Classification have been prepared using the GIS environment. It is inferred that the quality of groundwater is very poor in central part of the study area. High TDS water occurs in locations near eastern and western part of this region. Groundwaters in many parts of the study area are of hard water type. Entire northern and central portion has highly corrosive water. C5S4 water occurs in central zone is unfit for the agricultural use rest of the area have better quality of water which can be used for certain agricultural purposes. Designing of recharging wells along the central region will result in considerable improvement both in the quality and quantity of groundwater.
 

The present manuscript includes study of composition and stability constants of mixed ligand complexes of Cd (II) ion with tryptophan and some bicarboxylic acids (Tartaric, Succinic, Maleic, Malonic and Malic acid) voltammetrically. In each case the reduction of the Cd (II) ion is found reversible and diffusion-controlled, involving two electrons in each case. Deford and Hume's method is used to calculate the stepwise formation constants of simple systems while the stability constants of mixed complexes i.e. MXY, MXY₂ and MX₂Y have been evaluated by the method of Schaap and McMasters. With the help of stability constants of these complexes statistical and electrostatic effects have been investigated.
 

Reaction of 2-chloro-4,6-dimethylpyridine-3-carbonitrile (2) with each of hydrazine hydrate, hydroxylamine and anthranilic acid afforded the corresponding pyrazolo, isoxazolo and pyridoquinazoline derivatives (3), (4) and (5) respectively. Alkylation of 2-mercapto-4,6-dimethylpyridine-3-carbonitrile (7) with ethyl chloroacetate and/or phenacyl bromide followed by cyclisation in NaOH gave thienopyridine derivatives (9) and (12). Diazotization of ethyl 3-amino-4,6-dimethylthio[2,3-b]pyridince-2-carboxylate (9) followed by reaction with thiourea, guanidine carbonate and/or hydroxylamine hydrochloride gave the corresponding thienopyridine derivatives (15), (16) and (17) respectively. The biological activity of some new compounds has been discussed.
 

A polarographic study of In(III) with some amino acids and Phthalic acid have been carried out separately at ionic strength kept constant (µ = 1) by using KCl at 298K. DeFord and Hume's method is used to calculate the stepwise formations constants of simple systems (In-amino acids and In-Phthalic acid) while the stability constants of mixed complexes have been evaluated by the method of Schaap & McMaster's. The reduction of In(III) ion is found to be quasireversible and diffusion controlled involving three electrons in each case. The statistical and electrostatic effects have also been discussed by using these stability constants. The mixing constant (Km) and stabilization constant (Ks) were measured for comparative study of simple and mixed ligand complexes.
 

Reaction of Amoxicillin & Alanine with certain biologically active metal ions, in binary & ternary systems have been traced conductometrically & spectrophotometrically. Formation of M : Ala : Amox, 1 : 1 & 1 : 2 complexes and M : Ala : Amp. 1 : 1: 1 complex is indicated, structures of the isolated mixed complexes with the metal : Alanine : Amoxicillin in 1 : 1: 1 molar ratio have been ascertained on the basis of analytical data and physico-chemical properties. The results of the study appear to support the hypothesis that formation of metal bridged-drug-receptor complex is formed during antibiotic activity of the drug.

Piper betel plant is one among the great herbals used in folk and tribal medicines in India. It belongs to the family Piperaceae used as ingredients in a chew commonly known as pan. Chemically piper betel containing chavi betel, chavicol, eugenol, cadinene, alkaloids, sugar, tannin, diastase, betel oil, terpene, sesquiterpene. Biologically Piper betel have broad spectrum activities like antifungal, antibacterial, antitumour, hypotensive, respiratory depressant, anthelmintic, cardiotonic and antifertility. We have used liver slice culture model to demonstrate hepatoprotective activity of PBLE in vitro. CCl₄ (20mM) has been used as a hepatotoxin and the cytotoxicity of CCl₄ is estimated by quantitating the release of LDH in the medium. CCl₄ induces twice the amount release of LDH from the liver as compared to the cells from untreated liver tissue and this was significantly reduced in presence of Plant extract (10µg/ml). Our results clearly point out that PBLE mitigates the CCl₄ induced liver damage by decreasing L

Reaction of 3-hydrazino-4,5,6-triphenyl pyridazine 3 with phenacyl bromide afforded triazolopyridazine 4, while, reaction of 3 with different aldehydes gave the corresponding 3-arylidinhydrazinopyridazine derivatives 5a-c which on reaction with Br₂/Na₂CO₃ gave the corresponding triazinopy-ridazines 6a-c. Also, fusion of 3 with ethyl acetoacetate, ethyl benzoylacetate, diethyl malonate and/or ethyl phenyl acetoacetate gave the corresponding pyrazolo and triazinopyridazine derivatives 10, 11, 12 and 13 respectively. The antimicrobial activity of some new compounds has been discussed.