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Abstract  

For this work, a parallel plate avalanche counter was used, filled with ketone gas within the ionization chamber, to obtain CEM spectra for non-conducting samples: -Fe2O3, Fe3O4, Fe(NH4)2(SO4)2·6H2O, and a mineral sample (clay). The samples were prepared by three alternative methods. The Mössbauer parameters for CEM and transmission spectra were compared.

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Abstract  

Solid amorphous zirconium phosphate /ZPa/ and hafnium phosphate /HPa/ are mixed with an excess of solid oxalic acid dihydrate and are digested in molten oxalic acid. Then oxalic acid is removed by extraction or by heating. The residue is washed with dilute HCl /0.01M/ and redistilled water. By this method -ZP and -HP is formed from amorphous ones.

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Summary Some aromatic based conjugated polymers having carbon-carbon triple bonds moiety were synthesized and carbonized. The polymers were efficiently carbonized by heating up to 900°C under an argon atmosphere, affording porous carbons in high yields. The polymer characteristics were appropriate to form nano-structured carbons in the pyrolytic carbonization process. The carbon materials were consisted of 2-4 nm sized graphitic crystallites and had slit-shaped micropores with ca. 0.7 nm pore width. Structural defects in the pre-carbon materials caused generation of mesopores with ca. 4 nm pore width after carbonization.

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Abstract  

The use of halogenated organic compounds under the effect of ionizing radiation requires a comprehensive knowledge of their radiation stability. There is little experimental evidence on the radiolysis of fluorine-containing organic compounds in the literature, while a theoretical generalization enabling one to predict the main radiolysis pathways is completely lacking. This paper is concerned with the identification of stable radiolysis products of trichloromethyl-1,1,2-trifluoro-2,2-dichloroethyl ether (C3F3Cl5 O), γ-irradiated separately and the extraction system based on tributyl phosphate. Practically all the C3F3Cl5O radiolysis products were identified with the aid of gas-liquid chromatography, GC-MS, IR, UV and NMR spectroscopy and elemental analysis. Upon C3F3Cl5O radiolysis, the formation of CCl4, Cl2, COCl2, C2 Cl6, freons of various composition and long-chained ethers like CFCl2−CF2−O−CCl2−CCl3 takes place. The identification of radiolysis products allows to draw well-founded conclusions on the mechanism of C3F3Cl5O radiolysis, representing a wide class of chlorine- and fluorine-containing organic compounds.

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Abstract  

An environment friendly method, thermal catalytic pyrolysis of used isobutyl isoprene rubber was investigated. In this method, the used inner butyl tube rubbers were catalytically pyrolyzed into valuable hydrocarbons and carbon black. In this method, the tube rubber was pyrolyzed both thermally (with out catalyst) and catalytically in a batch reactor under atmospheric pressure. The effect of temperature, the amount of catalyst, and the reaction time on the yields of the pyrolyzed products were investigated. Char yield decreased with increase of pyrolysis temperature while total gas and liquid yields increased. The liquid fraction was obtained with boiling point up to 478 K. At optimum conditions, the liquid product was collected and analyzed for different fuel properties. Typical analysis of the used isobutyl isoprene rubber oil for both the cases of parent and refluxed oil has been performed. Phenols and carbonyls were quantitatively determined by spectrophotometric methods using folin-denis and phenyl hydrazine reagents, respectively. The distillation data showed that ~100% of oil has boiling point <473 K which is the boiling point for 80% of distilled product in commercial kerosene. Its specific gravity, viscosity, freezing point, Cetane number, and diesel index were also within the limits of kerosene.

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