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Abstract  

Infrared absorption spectra of HNO3 solutions in UO2(NO3)2(TBP)2 have been taken. The formation of a hydrogen bond between HNO3 and nitrate or phosphoryl group in UO2(NO3)2(TBP)2 has been established. On extracting Pu(IV) and Np(IV) by 30% TBP-dodecane, dependence of the distribution coefficients on concentration has been found at UO2(NO3)2 concentrations in the aqueous phase upwards from 0.4M. This dependence appeared in the temperature interval 0–60°C. Such effects may be caused by ordered structure of saturated uranyl nitrate solutions in TBP.

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Abstract  

The present paper reviews briefly the recent advance in radioanalysis of low level plutonium in environmental and biological samples. Lots of new radiochemical methods for determination of plutonium in aerosols, natural waters, soil, sediments and various biological materials have been developed. The use and prospects of several radiochemical procedures are discussed.

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Abstract  

The solvent extraction of the rare earth elements, yttrium and scandium with trioctylphosphine oxide in the presence of strong complexing and various salting-out agents has been studied. As a result, a technique was developed for the extractionchromatography recovery of the rare earth elements and yttrium with simultaneous purification practically from all the elements, including scandium, usually present in the mineral samples.

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Abstract  

The luminescence properties of crystallophosphors on the base of NaBi/WO4/2 activated by americium, plutonium and neptunium have been studied. The synthesis of crystallophosphors is described. Crystallophosphors luminescence in the near infra-red region. The excitation and luminescence spectra of crystallophosphors are considered. The dependence of luminescence yield is linear in the wide interval of activator concentration.

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Abstract  

In the studies of nuclear reactions of heavy ions with heavy nuclei it is often necessary to determine the yields of TPE. Trioctylphosphine oxide (TOPO) has high selectivity with respect to trivalent TPE and rare earths. The possibility of using target or catcher materials as salting-out agents in the extraction of TPE with TOPO from solutions containing DTPA and lactic acid was investigated. The influence of the concentration of Pb, Bi, Cu, Ni, nitric acid and TOPO on the distribution coefficients was established. The advantages of application of the method for the extraction chromatographic separation of TPE and rare earths from the other elements produced in the interaction of ions with heavy elements are shown.

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Journal of Thermal Analysis and Calorimetry
Authors:
V. Logvinenko
,
A. Minina
,
Yu. Mikhaylov
,
Yu. Yukhin
, and
B. Bokhonov

Abstract  

Two bismuth salts, Bi6O4(OH)4(C17H35COO)6 and Bi6O4(OH)4(C17H35COO)6 nC17H35COOH, were synthesized. The thermogravimetry under quasi-isothermal conditions denotes the multi-step character of decomposition processes for both compounds. The thermogravimetry under linear heating was used for kinetic studies. Thermogravimetric data (obtained at different rates of linear heating) were processed with 'Netzsch Thermokinetics' computer program. Kinetic parameters were calculated only for the first decomposition step for both salts, the process is described by different nucleation equations (with and without autocatalysis).

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Abstract  

An improvement of -energy resolution for determining low level plutonium has been investigated using combined solvent extraction-low level liquid scintillation counter. In the present work, -energy resolution of 270–290 keV for liquid scintillation spectra of236Pu and239Pu is attained. Thus the simultaneous determination of low level plutonium with -liquid scintillation spectrometry may be practized.

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Abstract  

Low level90Sr in environmental and biological samples is determined using a combined HDEHP solvent extraction-liquid scintillation procedure. Yttrium-90 is selectively extracted from nitric acid solution into 5% di(2-ethylhexyl) phosphoric acid (HDEHP) in toluene, and90Y in the organic phase is measured directly using an ultra low level liquid scintillation spectrometer.The working program of the Quantulus counter has been optimized. As the counting efficiency using liquid scintillation counting is high and the stripping and precipitation of Yttrium-90 oxalate is omitted, this procedure is simpler and more timesaving than traditional methods. The chemical recoveries of90Y were 85.1% for soil, 75.7% for milk and 65.3% for bone. The detection limit is 8 mBq.

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Abstract  

The possibility of substoichiometric displacement in ion association systems of metal halogenide anions (chlorides and iodides) and extraction reagent cations is demonstrated. Tetrephenylarsonium halogenide, ternary amines and quaternary ammonium halogenides were used as extraction reagents. The method was applied to the determination of several impurities in aluminium by activation analysis.

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Abstract  

A mathematical model is suggested for the approximation of the monoenergetic gamma-ray spectra obtained by a Ge(Li) detector. Some features of the instrumentation monoline spectra in the energy range upto 2 MeV are considered in detail. Computer program “APPROXIMATSIYA” is described. The program allows to determine the parameters of the mathematical model with the purpose to construct a making up standard spectrum library. The results of the monoline spectrum processing are discussed.

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