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Abstract  

A novel method that spent nuclear fuel is converted into nitrates with N2O4, and then nitrates are extracted with TBP in supercritical CO2 (SC-CO2), has been developed for reprocessing of spent nuclear fuel, which has a potential prospect because of its potential to decrease generation of the secondary liquid waste. In this paper, conversion of Nd2O3 with N2O4 into its nitrate under various conditions and extraction of the conversion product with TBP in SC-CO2 were investigated. When temperature was 60–120 °C, the molar ratio of H2O to Nd2O3 was from 1 to 6, and molar ratio of N2O4 to Nd2O3 was above 8, complete conversion of Nd2O3 into its nitrate was achieved. The conversion product was characterized by thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR) and Raman spectroscopy. Quantitative extraction of the conversion product with TBP in supercritical CO2 was also achieved under experimental conditions.

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England in years 1973–1974) CACs are applied to structural concrete much less often than Portland cements [ 1 – 3 ]. The deterioration of strength is related with a process of conversion of aluminate hydrates. In case of CACs the nature of hydration

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Kenichiro Inoue, Kiyomi Okabe, Megumu Inaba, Isao Takahara, and Kazuhisa Murata

biomass-derived materials such as bio-ethanol for the problems of exhaustion of petroleum resources and global warming. Therefore, propylene production from bio-ethanol is highly desirable. Processes for the conversion of methanol to olefins (MTO) are well

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Photosynthetic energy conversion in the diatom Phaeodactylum tricornutum

Measuring by calorimetry, oxygen evolution and pulse-amplitude modulated fluorescence

Journal of Thermal Analysis and Calorimetry
Authors: Steffen Oroszi, Torsten Jakob, Christian Wilhelm, Hauke Harms, and Thomas Maskow

a sample in the presence of DTT (0.5 mM) Discussion The aim of this study was to compare the photosynthetic energy conversion in the diatom P. tricornutum measured by photocalorimetry and by

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Introduction Iso-conversional methods are used for non-isothermal analysis, in which the transformation rate at a constant extent of conversion is only a function of temperature as suggested by Vyazovkin et al. [ 1 – 4 ] and

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method, which can not detect the complex nature of the solid-state reaction, has been replaced by multiple scan method at different heating rates using iso-conversional and iso-temperature calculation procedures [ 12 – 14 ]. Among the iso-conversional

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Abstract  

Characterization of the solid-state form (hydrate or polymorph) of a pharmaceutical active is a key scientific and regulatory requirement during development of and prior to seeking approval for marketing of the drug product. A variety of analytical methods are available to perform this task. By nature of the fundamental information it provides, TG-DTA offers advantages over other methods in regards to monitoring and quantitation of hydration state changes. In a single experiment with only a few milligrams of sample, TG-DTA perceives minor changes in phase, quantitates total water content and percent conversion, and illustrates hydrate type. All of this is accomplished without the necessity of generating time-consuming standard curves representing the differing ratios of hydrated to anhydrous forms. This study describes the use of TG-DTA to monitor and quantitate humidity induced solid–solid phase conversion of nitrofurantoin and risedronate. Percent conversion was qualitatively observed by both TG and DTA signals and quantitated by the TG.

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Journal of Thermal Analysis and Calorimetry
Authors: S. X. S. Costa, M. R. Galvão, D. P. Jacomassi, M. I. B. Bernardi, A. C. Hernandes, A. N. de Souza Rastelli, and M. F. Andrade

employed, as well as to the composite resin composition and degree of conversion [ 6 ]. Composite resins are set via exposure to light of a certain wavelength and an intensity that initiates the generation of free radicals that propagate

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Abstract  

The applicability of instrumental activation analysis by the conversion radiation of impurities in matrices with high specific gamma-activity has been studied. An iron-free toroidal magnetic β-spectrometer with 2 per cent resolution and 20 per cent transmission for 4 was used for measurement. The spectrometer was made at the Activation Analysis Laboratory of the Academy of Sciences of the Kazakh SSR. Comparative gamma- and beta-spectra of samples of amorphous selenium thin films with palladium, cadmium, indium and mercury impurities were obtained. It was established that the analysis by the spectra of internal conversion electrons enables to increase the detection sensitivity of these elements in selenium as compared to the gamma-spectrometric method. The procedure of mercury determination in amorphous selenium films was developed and by this method the investigation of the dependence of photoconductive properties of the film upon the total mercury content and its distribution on the film surface was carried out.

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Introduction With the shortage of petroleum resources and the high price of crude oil, the conversion of CH 4 (main component of natural gas) to chemicals of high demand has received much attention [ 1 ]. Aromatic compounds

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