The reaction of sulphuric acid with titanium raw materials runs violently with simultaneous emission of gases. Such run of
reaction creates danger of explosion. This process is very complicated from the reason of complexity of reactions and variety
of compounds in reaction mixture. To determine safe conditions of reaction with high efficiency, it is necessary to investigate
phase composition products of reaction.
Products of reaction were investigated by using X-ray diffraction. However reaction products show high amorphy and this is
the reason of difficulties to determine all phases. For this reason also was used additional method — ‘drop’ calorimeter.
This method is used for determination of average specific heat of liquid or solid samples. In this case, this method was used
for verification of phase composition of products of reaction.
On the basis of investigation the phase composition of reaction product is following: titanyl sulfate, iron(III) sulfate,
monohydrated iron(II) sulfate, magnesium sulfate and unreacted remainders of ilmenite and magnesium silicate.
A solvent extraction procedure for rapid separation of uranium from complex nuclear reaction product mixtures is suggested. The procedure has been tested in batch experiments with tracer amounts of representative elements. It has also been tested with fission products and uranium tracer using the continuous chemical separation system SISAK at the Mainz TRIGA reactor.
The complex thermal analysis was used in the investigations of the carbonate reaction products in the residue after Al leaching
from calcium aluminate-12CaO7Al2O3 and Selfdisintegrated Powder. The conversion of Al was calculated basing on a content of Al in the pregnant solution as well
as in a residue obtained from the kinetic investigations. The third method of measurements of a conversion of Al was presented
and discussed. Results show, that the proposed method can be used for conversion estimations with 95% of confidence level
as well as for the detection of carbonate products and is useful for an interpretation of the new approach for kinetic mechanism
of Al leaching.
Authors:Yuan-Fang Liu, Cheng Luo, K. Moody, D. Lee, G. Seaborg, and H. Von Gunten
Two procedures are described for fast separations of berkelium from complex mixtures of reaction products arising from heavy
ion reactions, such as18O+248Cm. The first procedure uses a combination of several extraction steps with a final separation on a cation exchanger, the
second procedure starts with an anion exchange column which is followed by multiple extractions in different media. The elements
separated in the different steps were analyzed and overall decontamination factors are given.
Authors:E. Testani, V. Giannetti, M. Boccacci Mariani, and P. Mannino
In the present work, three volatile Maillard reaction products (maltol, furfuryl alcohol, and furfural) were considered for their supposed ability to act as process markers of dry durum wheat pasta. Hence, a commodity investigation was performed on Made in Italy pasta products and the HS-SPME/GC-MS technique was adopted to detect the target compounds in sixty samples. The analysis of variance (ANOVA) was used to evaluate whether the relative abundance of the flavour compounds can differentiate pasta samples processed through mild technologies (traditional methods) from that submitted to intense thermal stress during their elaboration (industrial methods). Results showed that the analysed products were efficiently discriminated according to their claimed manufacturing method by maltol, furfuryl alcohol, and furfural, which thus can serve as reliable pasta process indicators.
Authors:Małgorzata Janicka, Ernő Tyihák, Ágnes Móricz, and Barbara Ościk-Mendyk
A group of thirteen newly synthesized potential herbicides,
-aryltrichloroacetamides or 2-(chlorophenoxy)acyl derivatives, have been initially investigated by reversed phase (RP) TLC. The lipophilicity of the substances was described by retention factors in water, log
, calculated from experimental RP TLC data, and by log
values calculated by use of software. Biological activity was examined by use of the BioArena system of TLC separation then (micro)biological detection. The potential role of formaldehyde (HCHO) in the toxic antibacterial action of substances against
bacterial cells was investigated. The effect of HCHO capturers (L
-arginine and reduced glutathione) and Cu
ions on the bioactivity and mechanism of toxicity of the substances was examined. It was established that HCHO and its potential reaction products (e.g.
) are crucial in the mechanism of action of these molecules. Correlations between the lipophilicity and bioactivity of the test compounds were also analyzed. It seems that hydrophobicity is not the decisive factor affecting the bioactivity of these substances.
Authors:Yang Weifan, Yuan Shuangui, Xiao Yonghou, and Xu Yanbing
Protactinium was produced by the reaction of 60 MeV/nucleon 18O with natural uranium. A simple, relatively fast radiochemical procedure was developed, which can be used for the extraction separation of protactinium from uranium and from the complex reaction products using 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and tri-iso-octylamine as extractants. Measurements of the gamma-ray spectra for the separated protactinium fractions were performed with a HPGe detector. The measured g-ray spectrum of protactinium shows that the decontamination from the main impurity elements, especially zirconium and niobium, is quite satisfactory.
A method for separation and chemical identification of products formed in nuclear reactions or nuclear decay is to slow down
the recoil products in a gas and to transport them to a trap, where a detecting system is arranged. The sources for the recoil
products are252Cf and224Ra. As transport phase we used nitrogen or argon and added chemical reagents such as methyl and ethyl radicals, chlorine,
oxygen, carbon monoxide or methane. The chemical additives lead to selective and fast separation of certain elements. As examples
the results of two experiments are presented:224Ra with ethyl radicals, and252Cf with chlorine-oxygen-nitrogen mixtures. The registration of the recoil products at the trap was measured as a function
of temperature, pressure and composition of the reactive gas.
High-energy bremsstrahlung from high-intensity electron linacs can produce activation through a variety of photonuclear reactions.
A great range of activities by half-lives can be used. Some discrimination between target elements can be obtained through
the choice of bremsstrahlung end-point energy. The high resolution of Ge(Li) gamma-ray spectrometers permits much of the analysis
to be accomplished without chemical separation of resulting nuclei; hence, non-destructive analysis can be applied to many
materials. To facilitate the use of such analysis, a compilation of photonuclear reactions with their resulting gamma-rays
has been prepared.