To explore the sedimentation process in the Terengganu coastal water, 30 cm sediment cores was studied by measuring the stable element lead (Pb). Applying the 210Pbexcess method, average sedimentation rates of 0.21 cmyr-1 was obtained. The estimated sedimentation rates obtained was comparable to other related studies in South China Sea and other coastal areas elsewhere. Assuming that the sedimentation rate values are accurate, this implies that the sediments in the upper 30 cm were deposited during the last 143 years ago.
Fluorobenzothiazole comprising sulfonamido pyrazole derivatives have been synthesized and evaluated for their antimicrobial activity. Structures of these products have been established by IR, 1HNMR data. Significant antimicrobial activities were observed for some members of this series.
An epoxy-furfural-methylethylketone matrix resin (FM resin) system has been developed to prepare glass reinforced composites. The polycondensation reaction of furfural and methyl ethyl ketone which derived furfural-methylethylketone resin (FM resin) in a single step under different experimental condition. This FM resin is used for blending with epoxy resin i.e diglycidyl ether of bisphenol A (DGEBA) in presence of various catalysts such as triethylamine (TEA), Diamino diphenylmethane (DDM) and p-toluene sulphonic acid (PTS). Glass reinforced composites based on FM resin and epoxy resin were prepared and characterized by measuring its mechanical and chemical resistance properties
Owing to the pollution implications of the volatile organic compounds (VOCs or organic solvents) present in coating resins, the current focus of the surface coating industries is towards the use of low VOC binders. Since alkyds are the workhorse of the paint industries, they were chosen for the study. Present study is aimed at optimising the ingredients of alkyd resin emulsions so as to have low VOC, shelf stable and performance oriented coatings. Various experimental sets were designed by changing the oil length, surfactants amount, and organic phase to water phase ratios. The resulting emulsions were studied for their stabilities. Also the films were coated on test panels and their performance was compared with their solvent based counter parts.
The films were evaluated for adhesion, flexibility, impact resistance, scratch hardness, chemical resistance as well as drying performance at ambient temperature. The study revealed certain excellent features of alkyd emulsion [low VOC] as surface coating binders.
Cyclodehydration of thiocarbohydrazide with substituted benzoic acid gives, 5-Aryl-4-amino-3-mercapto-1,2,4 triazole. The requisite 3-Aryl-1,2,4-triazolo-8-methyl-thiadiazepin-6-ones were prepared by refluxing ethyl acetoacetate and 5-Aryl-4-amino-3-mercapto-1,2,4-triazole. The screening results are correlated with the structural features of the tested compounds.
The relation between turbidity and the Total Dissolved Solids (TDS) was measured basing on the flow rate of the Godavari water during the period pre- mansoon (July 2005) to post-mansoon (November 2005). It is observed that, in pre mansoon season during heavy rainfall, the flow rate of the Godavari water increases causing decrease in TDS and increase in turbidity, where as in post mansoon season due to decrease in flow rate of water turbidity decreases and TDS value increases.
The heavy flow rate of river water neither allows settling the turbid soil nor does allow the salts to dissolve in water. Hence turbidity in water increases, simultaneously the TDS value decreases. The soil sample of the Godavari was also analyzed and found low Total Soluble Salts (TSS) in pre mansoon and high in post mansoon season.
6-Chloropurine which was obtained commercially was used as the precursor for the preparation of 6-anilinopurine and of 6-piperidinopurine. Fluorescence studies were carried out in 75% ethanol, acetonitrile and ethyl acetate. Both compounds showed the highest fluorescence peak in ethyl acetate whereby 6-piperidinopurine showed fluorescence peak at 373 nm, when excited at 315 nm, and 6-anilinopurine showed fluorescence peak at 447 nm when excited at 321 nm. The fluorescence intensity of 6-anilinopurine and 6-piperidinopurine decreased with time.
The reaction of 2-Amino-6,8-diphenyl-5-oxo-pyrimido [4,5-d] pyrimidine-7-thions with a-halo ketones offers 2-Aryl-1,3-diazolo-(3, 2-b)-pyrimido [4,5-d]-5,7-diaryl-8-oxo-pyrimidine-7-thiones, which on bromination results their bromo analogues 2-Aryl-3,9-dibromo-1,3-diazolo-(3, 2-b)-pyrimido [4,5-d]-5,7-diaryl-8-oxo-pyrimidine-7-thiones.
Mixed ligand complexes of Ln (III) chlorides and nitrates possessing the general formula [Ln LL' x (H2O)n], where Ln = La, Pr, Nd and Sm, X = Cl, NO3, n = 3 in chtoro complexes of La, Pr, Nd, n = 1 in chloro complex of Sm, n = 2 in nitrato complexes of La, Pr, Nd, n = 0 in nitrato complex of Sm, LH = 2 - acetyl pyridyl - pyrazine carboxylic hydrazone (apph) and L' H = 2 thiophene acetic acid (taa), have been prepared and characterized on the basis of analytical, conductance, magnetic, spectral and thermal data. The complexes are nonelectrolytic in nature. IR spectra suggest that both the ligands are bidentate in nature. The complexes have been found to possess antibacterial activity.
Condensation of 4-bromo-3-aryl pyrazol-5(4H)-one (1) with 3-substitued-4-amino-5-mercapto-1,2,4-triazoles (2) in ethanol in the presence of pyridine afforded 3,8-disubstitued-5H-s-triazolo (3,4-b) pyrazolo (5,4-e) -1,3,4- thiadiazines (3). The antifungal and antibacterial activity of synthesized compounds have also been evaluated.