concentrations of elements (as, co, cu, ni, mo, pb, v, cd, cr and zn) are studied in the surface sediments of bakhtegan lake, northwest of nyriz city, iran, to assess metal contamination. the average abundance order of trace elements content in bakhtegan lake sediments is cr>ni> v> zn> cu> co> as> pb> mo>cd. the comparison of trace elements concentration in bakhtegan lake sediments with toxicol...

We report on the fabrication of responsive double hydrophilic block copolymers (DHBCs)-based dual fluorescent chemosensors for Zn(2+) ions and temperatures and investigate the effects of thermo-induced micellization and detection conditions on the probing sensitivity and binding reversibility of Zn(2+) ions. A novel quinoline-based polarity-sensitive and Zn(2+)-recognizing fluorescent monomer (...

The objective of this study was to determine if exposure to divalent cations, Cd(2+), Ni(2+), and Co(2+) would lead to malformations in Xenopus laevis embryos, and whether addition of Mg(2+) and Zn(2+); separately and in combination, would reduce their toxicity and teratogenicity on the embryos of Xenopus laevis as assessed by 96-h FETAX tests. Results indicate that exposure to Cd(2+), Ni(2+) o...

Present study consists geochemical variations and spatial distribution of trace elements (Fe, Mn, Cr, Co, Cu, Ni, Pb and Zn) of the ocean floor sediments collected along the continental shelf off East coast Tamil Nadu (Chennai to Velanganni) during the 2009 southwest monsoon period. Results indicate sand dominance with abundant calcareous debris and shell fragments. Normalisation of trace metal...

A sensitive method for the preconcentration and determination of trace amounts of Co, Cu and Zn by energy-dispersive X-ray fluorescence spectrometry (EDXRF) has been developed. The method is based on the fact that 4-(2-pyridylazo)-resorcinol (PAR) loaded Dowex anion-exchange resin (PAR-resin) can effectively adsorb Co, Cu and Zn at pH 9.0 to form PAR-metal complexes. The detection limits for Co...

A series of novel photocatalysts Zn/Cr LDH with different Zn/Cr molar ratios (2 : 1, 3 : 1, 4 : 1 and 2 : 1-CO(3)) were fabricated by a co-precipitation method and evaluated for photodecomposition of water using visible light irradiation. Various characterization methods were employed to investigate the structures, morphologies and photocatalytic properties. In comparison to Zn/Cr (2 : 1) LDH, ...

The potential of naphthol blue–black-modified Amberlite IRA-400 anion-exchange resin for separation of heavy metal pollutants has been explored. The distribution coefficients (Kd) of metal ions in several acidic solvent systems have been studied. The effect of the dissociation constant of the solvent on the distribution coefficient of metal ions has also been investigated. On the basis of Kd va...

We present evidence demonstrating the capability of Phaeocystis antarctica colonies to substitute cobalt (Co) and zinc (Zn) as micronutrients, in which Co limitation is alleviated by additions of Zn and vice versa. Maximal growth rates and biomass were determined by fluorescence and the values obtained under replete Zn and no added Co conditions were significantly higher than under replete Co a...

Pheophorbide a was prepared from a mixture o f chlorophylls a and b by differential extrac­ tion with HC1 and saponification. The insertion o f the following metal ions was investigated: Mg, Zn, Co, Cu, Ni. In the enzyme test with chlorophyll synthetase, the metallopheophorbides fall into two categories: the Mgand Zn-complexes are good substrates, the Co-, Cuand Ni-complexes are neither substra...

We present the results of a computational study of ZnO in the presence of Co and Mn substitutional impurities. The goal of our work is to identify potential ferromagnetic ground states within the (Zn,Co)O or (Zn,Mn)O material systems that are also good candidates for piezoelectricity. We find that, in contrast to previous results, robust ferromagnetism is not obtained by substitution of Co or M...