Barium hexafemte doped with iridium was synthesized by two methods: the citrate gel and the polyacrylamide gel methods. The nature of phases obtained and the specific surface area were determined after heat treatments in air at 700°C, 900°C and in air containing 10% humidity at 1200°C. The catalytic activity in the combustion of methane was measured after heat treatment at 900°C. These hexaferr...

The Tetrahymena group I ribozyme requires a hierarchical folding process to form its correct three-dimensional structure. Ribozyme activity depends on the catalytic core consisting of two domains, P4-P6 and P3-P7, connected by a triple-helical scaffold. The folding proceeds in the following order: (i) fast folding of the P4-P6 domain, (ii) slow folding of the P3-P7 domain, and (iii) structure r...

The hammerhead ribozyme is a small catalytic RNA motif capable of endonucleolytic (self-) cleavage. It is composed of a catalytic core of conserved nucleotides flanked by three helices, two of which form essential tertiary interactions for fast self-scission under physiological conditions. Originally discovered in subviral plant pathogens, its presence in several eukaryotic genomes has been rep...

this research evaluates the efficiency of nanosized zno in the catalytic ozonation of 4-chloro-2-nitrophenol and determines the effect of ph on heterogeneous catalytic ozonation. the combined use of ozone and zno catalyst leads to conversion of 98% 4-chloro-2-nitrophenol during 5 min. in addition, it was found that in zno catalytic ozonation, the degradation efficiency of 4-chloro-2-nitrophenol...

The discovery of naturally occurring catalytic RNA (RNA enzymes, or ribozymes) in the 1980s immediately revised the view of RNA as a passive messenger that solely carries information from DNA to proteins. Because DNA and RNA differ only by the absence or presence of a 2'-hydroxyl group on each ribose ring of the polymer, the question of 'catalytic DNA?' arises. Although no natural DNA catalysts...

in this research iron manganese oxide nanocomposites were prepared by co-precipitation, sol-gel and mechanochemical methods by using iron (iii) nitrate, iron (ii) sulfate and manganese (ii) nitrate as starting materials. these nanocomposites were prepared in the presence of various catalyst beds. the polyvinyl pyrrolidon (pvp) was used as a capping agent to control the agglomeration of the nano...

In this manuscript, the experimental setup was designed and fabricated for optimizing the parameters of a catalytic converter of INDICA V2 exhaust system. Three turbulence intensify devices, namely Swirl Venturi, Swirl Blades and Swirl Contour, were close-fitted before the catalytic converter. The heating element is embedded in its body and thermocouples are used for knowing the performance at ...

in this paper, labo3 perovskite type catalyst formulations were prepared by sol-gel auto combustion method using citric acid as the fuel. activity of catalysts was tested in catalytic oxidation of toluene as a model of volatile organic compounds. lacoo3 perovskite formulation showed the highest activity among labo3 (fe, mn and co) perovskite catalysts. so, lacoo3 perovskite based catalyst was s...

a general overview on the prospective of various oxidation and combined processes in the treatment of tannery industry effluent are reported. various oxidation and combined processes such as uv/h2o2/hypochlorites, fenton and electro-oxidation, photo-chemical, photo-catalytic, electro-catalytic oxidation, wet air oxidation, ozonation, biological followed by ozone/uv/ h2o2, coagulation or ele...