نتایج جستجو برای: natural catalyst
تعداد نتایج: 524102 فیلتر نتایج به سال:
This paper argues that Information Technology (IT) needs to be demystified, through critical consciousness, for educators to focus on IT as a means to enhance learning. It goes on to define the technical, sociohistorical and political-ideological levels of IT and to identify four theoretical constructs: tutorial, machine-as-human, tool kit and catalyst. Pervading these constructs is the underst...
An environmentally benign and clean synthesis of aryl-hydrazones by reacting variety of carbonyl compounds with thiosemicarbazide, semicarbazide, aminoguanidine, and phenyl hydrazine has been achieved using aqueous extract of Acacia concinna pods as a natural surfactant type catalyst. We found that the aqueous extract of Acacia concinna pods could be effectively used for the synthesis of aryl-h...
The super-Brownian motion X % in a super-Brownian medium % constructed in DF96a] is known to be persistent (no loss of expected mass in the longtime behaviour) in dimensions one ((DF96a]) and three ((DF96b]). Here we ll the gap in showing that persistence holds also in the critical dimension two. The key to this result is that in any dimension (d 3); given the catalyst, the variance of the proc...
determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...
Methane is a hydrocarbon compound that can be used for various purposes. Currently, methane widely as fuel, and continues to developed synthetic gas material petrochemical products have added value, one of which formaldehyde. This study aimed the partial catalytic oxidation reaction formaldehyde using MoO 3 /zeolite catalyst. Reactant stream consisting pure O 2 CH 4 were contacted with rate rat...
In this study, Cu nanoparticles were immobilized on the surface of natural bentonite using Thymus vulgaris extract as a reducing and stabilizing agent. The natural bentonite-supported copper nanoparticles (Cu NPs/bentonite) were characterized by FTIR spectroscopy, X-ray diffraction (XRD), X-ray fluorescence (XRF), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spe...
The stereoselective synthesis 4′,6′-dually branched carbocyclic nucleosides was accomplished in this study. The introduction of a methyl group in the 6′(α)-position was accomplished by Felkin-Anh controlled alkylation. The construction of the required 4′(α)-quaternary carbon was carried out using a [3,3]-sigmatropic rearrangement. Bis-vinyl 6 was successfully cyclized using a Grubbs’ catalyst I...
Cyclopropanation reaction is an important tool for obtaining interesting compounds and can be catalyzed by metalloporphyrins with high syn/anti ratio. The catalyst cannot be recycled and is usually lost during chromatographic separation from the two isomeric products. In this paper a meso-tetraphenylporphyrin rhodium(III) chloride was bound to a Merrifield resin and used to catalyze the cyclopr...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید