The partial pressure of oxygen in Earth's atmosphere has increased dramatically through time, and this increase is thought to have occurred in two rapid steps at both ends of the Proterozoic Eon (∼2.5-0.543 Ga). However, the trajectory and mechanisms of Earth's oxygenation are still poorly constrained, and little is known regarding attendant changes in ocean ventilation and seafloor redox. We h...

rapid industrialization, installation of mega-desalination plants and suspected trace metals discharges in the kuwait marine environment instigated us to determine the trace metals toxicity on the body structures (first dorsal fin, otolith and scales) of the commercially relished mullet fish, liza klunzingeri. 96 h toxicity test with fe, cd, ni, as, showed the body structure of l. klunzingeri t...

this study assesses the effect of major trace metals levels in wastewater discharges and sedimentfrom twenty four permanent and five semi-permanent wastewater drain outlets into the kuwait coast. theeffect of trace metals levels released from untreated wastewater discharges to euchelus asper, gastropod was also determined. results showed high trace metal levels in e. asper tissues, followed by ...

Microbial methane from coal beds accounts for a significant and growing percentage of natural gas worldwide. Our knowledge of physical and geochemical factors regulating methanogenesis is still in its infancy. We hypothesized that in these closed systems, trace elements (as micronutrients) are a limiting factor for methanogenic growth and activity. Trace elements are essential components of enz...

Introduction: The compositional variations [1 and references therein] in the zoned metal grains from the CH and CB chondrites are generally interpreted as unequivocal evidence for their condensation from a parcel of H 2-rich gas with solar or somewhat increased dust/gas (D/G) ratios [2,3]. Although different origins of such gas are discussed [e.g., 4-7], its high enrichment in H 2 [8] and low a...

the concentrations of some heavy metals in sediment from the sinop coasts of the black sea were measured to monitor metal pollution in 2013. the distribution of the heavy metals in sediments of the black sea shows a variable pattern. the objectives of the present study were to elucidate the distribution heavy metals such as cu, pb, zn, ni, mn, fe, as, cd, cr, hg and co in sediment from sinop co...

There are many processes that can transport gas from the galaxies to their environment and enrich the environment in this way with metals. These metal enrichment processes have a large influence on the evolution of both the galaxies and their environment. Various processes can contribute to the gas transfer: ram-pressure stripping , galactic winds, AGN outflows, galaxy-galaxy interactions and o...