Abstract: Olefin metathesis using ruthenium carbene complexes is a useful method in synthetic organic chemistry. Enyne metathesis is also catalyzed by these complexes and various carboand heterocycles could be synthesized from the corresponding enynes. Dienyne metathesis, cross enyne metathesis and ring-opening enyne metathesis have been further developed. Various complicated compounds, such as...

The advancement of residual fluid catalytic cracking (RFCC) is significantly influenced by the development heavy metals passivation technology. Resids often include larger concentrations (Ni, V, and Fe) than gas oils, primarily in form porphyrin complexes salts organic acids. Under conditions, metals, especially Ni V residues oil deposit on catalyst induce adverse dehydrogenation reactions. cat...

The Third International Congress on Catalysis, organised most eficiently by the Royal Dutch Chemical Society, took place in Amsterdam from July 20 to 25. It was attended by 828 active members from 31 countries including 141 from the USA, 29 from the USSR, and 115 from Great Britain. Of the ninety-eight papers presented, twenty-seven refer to the use of the platinum group metals as catalysts, an...

A three-pitcher (locally known as ‘3-Kolshi’) water filtration system made from locally available materials was tested for its efficacy in removing arsenic, other trace metals and anions from the groundwater of Bangladesh and the disposal of the filtering materials after the breakthrough was studied. In this filter, the first Kolshi has cast iron turnings, and sand, the second Kolshi has wood c...

This account reviews transition metal-catalyzed C–C bond formation reactions using alkyl halides, which have rarely been used as carbon sources in conventional transition metal-catalyzed systems. In the reactions, ate complexes formed by the reaction of transition metals with a Grignard reagent play important roles as the active catalytic species. The reactions mentioned here are mechanisticall...

AEROSPACE ENGINEERING engineering.tamu.edu/aerospace Abstract Ductile fracture in metals is an area of active research. While the mechanism of failure (void nucleation, growth and coalescence) in ductile materials is well-understood, the existing models still have several limitations in an accurate prediction of this phenomenon. These models need to be enriched with a more precise understanding...

Hydroxyl radicals (HO*) are derived in Fenton reaction with ferrous salt and H2O2 in acid medium, and at neutral pH, metal-oxyl radicals (M-O*) predominate. Evidence is accumulating that M-O* radicals are also active in oxidation reactions, in addition to metal-oxo (M=O) now shown in many publications. Reactivity of these radicals gives selective oxidized products useful in cellular activities,...

Landfill leachates are potential threats for environmental degradation. This study was conducted to determine the leachate quality, to identify the dominant pollutants and to evaluate the leachate pollution potential of an active and closed dumping ground of an uncontrolled municipal solid waste landfill site in Kolkata, India using leachate pollution index. The results of the physico-chemical ...

A general concept in risk assessment is that a threshold of exposure exists above which adverse effects are initiated. Toxicity related to the target-site concentration or biologically active dose. Although it often huge challenge measure specific dose metric metal toxicity, significant progress has been obtained approach closer concentration. Such developments reviewed present study. In additi...

When and how did galaxies form and their metals accumulate? Over the last decade, this has moved from an archeological question to a live investigation: there is now a broad picture of the evolution of galaxies in dark matter halos: their masses, stars, metals and supermassive blackholes. Galaxies have been found and studied in which these formation processes are taking place most vigorously, a...