Radioactive Indicator Method Research Articles

Fe3O4-decorated MXene for the effective removal of 133Ba and 137Cs: synthesis, characterization, and optimization via response surface methodology (RSM)

The potential activity of Fe3O4 decorated MXenes in the removal of highly toxic 133Ba and 137Cs using a radioactive indicator method.

Radiogeochemical studies of the features of radionuclide distribution at the sites of dumping of radioactive wastes of the Novaya Zemlya Archipelago

This paper presents the results of the studies performed from aboard the R/V Akademik Boris Petrov of the Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, in 2002–2004 aimed at surveying the sites of dumping of potentially dangerous objects in Stepovoy, Abrosimov, and Tsivol’ka bays of the Kara Sea. These studies coupled the instrumental facilities of acoustic survey with the visual examination of the objects recovered and also included sampling of the bottom sediments and near-bottom water in the vicinity of the objects and away from them. Subsequently, the samples collected were analyzed using direct gamma spectrometry and radiochemical concentrating selected radionuclides. This allowed us to obtain a statistically reliable database on the specific concentrations of radionuclides (cesium, strontium, cobalt, and plutonium) in the water column and in the bottom sediments. In selected parts of Stepovoy and Abrosimov bays, at the sites where containers were located, local areas with contaminated bottom sediments were registered in the immediate vicinity of the objects, in which significant concentrations of Cs-137 were detected. We also carried out experiments with the samples of the collected bottom sediments on the determination of the kinetic parameters of sorption in the sediment-solution system using the method of radioactive indicators. Taking into account the hydrological conditions, the results obtained allow one to explain particular features of radioactivity distribution in selected aquatic areas. Based on a comparison between the results of the studies performed in 1992–1994 and 2002–2004, we estimated the dynamics of the changes in the mean level of specific concentrations of radionuclides in the regions of the location of sunken objects in shallow-water bays of the Novaya Zemlya Archipelago. The registration of elevated concentrations of corrosive elements in the surface layers of the bottom sediments in these zones suggests a necessity of a multidisciplinary study consisting of regular repeated measurements at reference points in different areas aimed at before-the-fact prevention of possible leakages of radioactive substances from the sunken objects, which might result in a significant contamination of the environment.

The effect of complexing anions on the formation of polynuclear hydroxocomplexes of Cr(III) in aqueous solution

The effect of anions on the hydrolysis of cations with the formation of polynuclear hydroxocomplexes was investigated by applying a complex mixture of physical–chemical methods including dialysis, ultrafiltration, centrifugation, pH-metric titration, method of radioactive indicators and spectrophotometry. A series of anions chosen for investigation included iodide, iodate, phosphate, oxalate, and EDTA. It has been shown that the effect of the anions on the formation of polynuclear hydroxocomplexes of chromium(III) depends on the stability of their complexes with Cr 3+-cation. Thus, the iodide-anion, formed weak complexes with Cr 3+-cations, but did not interact with polynuclear hydroxocomplexes of chromium(III) under all conditions investigated. The effect of IO 3 −, SO 4 2− and PO 4 3−-anions was that they did not decrease the total content of polynuclear hydroxocomplexes in solution and, at the same time, were able to join chromium(III) polynuclear hydroxocomplexes, causing the formation of bigger particles precipitated by centrifugation. The effect of oxalate- and EDTA-anions was determined by their high complexing ability with respect to Cr 3+-cations. The anions were able to hinder the formation of polynuclear hydroxocomplexes and to decrease their content in solution such that the polymerization reaction was stopped.

Deactivation of the coolant of the holding basins of a nuclear power plant by an inorganic zirconium phosphate sorbent

During the operation of a nuclear power plant, especially during conservation or decommissioning, appreciable quantities of radionuclides accumulate in the water of the holding basin for the spent fuel. This results in a high radiation background during maintenance work and creates a potential danger that the radionuclides will escape into the external environment as a result of a break in the seal of the basin casing. In particular, at the Beloyarskaya nuclear power plant, the radioactivity of the water in both regulation holding basins reached -20 GBq/m 3. The radionuclides 137Cs and t34Cs make the main contribution to the total specific radioactivity of the water: 9% and 1%, respectively. The radioactivity of other biologically toxic nuclides, such as, 9~ and 6~ is insignificant and does not exceed 0.13% of the total activity. The most efficient method for deactivation of the holding-basin water is a sorption technology. However. because of the high specific radioactivity of water and the large volume of the basins (2200 m 3 each), the traditional organic cationites will hardly be useful for purification because of their low radiation resistance [1, 2]. This justifies the interest in the synthetic inorganic sorbents, which have a high radiation resistance and selectivity [3-8]. Specifically, the granulated synthetic mordenite extracts more than 95% of ~37Cs and 134Cs and 75% of the ll0mAg from the water in the basin, after passage through 16,000 column volumes, for storage of spent fuel [3]. According to the data of [4-6], a promising inorganic sorbent for these purposes is zirconium phosphate, which is characterized by high capacity and selectivity with respect to cesium isotopes and can remain functional for a long time in the dynamic regime [5]. Its sorption capacity does not decrease under irradiation with 3' rays with a dose of 3.107 Gy [9] and neutrons with a dose of 8-105 Gy [10]. In the present paper we describe the sorpt~on-selective properties and the results of model tests of spherogranulated thermooxide-3A zirconium phosphate for the removal of 137Cs, in the circulation regime, from the simulator of the water in the holding basin of a Beloyarskaya nuclear power plant. This phosphate (the chemical composition is Zr(HPO4)2"H20 (the ratio P/Zr = 2)) was synthesized by the sol-gel method [5]. Externally, it consists of spherical 0.4-1 mm glassy granules, with a bulk density of 1.1 g/cm 3, a moisture content of 32% if dried at ll0~ and a mechanical strength of 15 4- 3 MPa. The pH-metric tritration curves for alkali (Na + and Cs +) and alkaline-earth cations (Ca 2 +. Mg 2 +) for pH ranging from 2 to 8 were measured in order to investigate the sorption-selective properties, and the distribution coefficients (Dg) of 137Cs (no carrier) sorbed from 0 05 moles/liter of a NaNO 3 solution with different filling of the sorbent volume with Na +, Ca 2+, and Mg 2+ as well as the internal diffusion coefficient of cesium cations in the pores of the sorbent were determined. The titration curves were obtained by the method of separate measured quantities of the chloride solution with a constant ionic strength of the solutions 0.1 N. the solid:liquid ratio equal to 1 g:50 cm 3 for alkali cations and 0.2-0.4 g:50 cm 3 for alkalineearth cations, and a solution holding time of six days. Solid magnesium oxide was used to change the pH in the system H+--Mg 2 +. and solutions of the corresponding alkali were used for the other cations. The method of radioactive indicators was used to determine the equilibrium concentration of alkali metals. The alkahne-earth metals in the solutions were analyzed by the trilonometric method [11]. The distribution coefficient of 137Cs (no carrier) was found in a system with 0.05 moles/liter of NaNO 3 with continuous mixing for 24 h. The ",/activity of the liquid phase was measured on a Roboton 20040 radiometer. using a scintillation detector.

Diffusion of sulphur, selenium and bismuth in HTSC YBa 2Cu 3O 7− δ and (Pb xBi 1−x) 2 Ca 2Sr 2Cu 3O y ceramics

Diffusion of sulphur, selenium and bismuth in HTSC YBa 2Cu 3O 7− δ and (Pb x Bi 1−x) 2 Ca 2Sr 2Cu 3O y ceramics was studied by a method of radioactive indicators. It is supposed that two types of diffusion processes are related to with surface (quick) and volume (slow) diffusion. A change in diffusion mechanism of sulphur observed in the range of 300 °C is explained by a vacancy generation in a basal CuO plane. Such parameters as Ea activation energy and Do diffusion coefficient of sulphur, selenium and bismuth in HTSC ceramics are determined. Maximum solubility concentration of sulphur and selenium are found in the present work.

Influence of structural features of polygenols on their dissolving power

The solubility of cesium perchlorate in glycols: ethylene glycol (EG), diethylene glycol (DEGH), triethylene glycol (TEG), tetraethylene glycol (TTEG), polyethylene glycol with mol. wt. of 300 (PEG-300) and 400 (PEG-400), was studied by the method of radioactive indicators in the temperature range of 298.15-333.15/sup 0/K. The main factor determining the solubility of a salt in a series of solvents is the structure of the solvent. This is shown by the temperature dependent solubility coefficients, and thermodynamic characteristics of the dissolution and solvation process.

Differential Measurements in Fields of Air-Flow

Air-condition of rooms (working rooms, school rooms, refrigerating chambers, car cabins, and so on) depends upon ventilation (flow of air, exchange of air). In praxi projects of air-condition systems are optimized by means of investigation of real flow fields. A measuring method including a mathematical model and an instrument set is evolved on behalf of an automobile manufacturing plant. It is a differential radioactive indicator method. Measured results are transition functions relative to air transport between marked cell and measured cells.

Study of the conversions of hexoses during the synthesis of carbohydrates from formaldehyde with the aid of radioactive indicators

1. The method of radioactive indicators with the use of labeled glucose has been used to show that under the conditions for the synthesis of carbohydrates from formaldehyde the rate of the retroaldol splitting of the hexoses is significantly lower than the rate of synthesis. 2. Under the conditions for the condensation of the formaldehyde, a significant portion of the carbohydrates heavier than the hexoses forms as a result of the cocondensation and self-condensation of low-molecular-weight carbohydrates and possibly by means of the disproportionation of carbohydrates with the participation of hexoses and low-molecular-weight carbohydrates.

Use of the radioactive indicator method to determine mean gas velocity through a porous medium

Use of the radioactive indicator method to determine mean gas velocity through a porous medium

Determination by the radioactive indicator method of the retention and stability of thiabendazole in treated Valencia oranges

Thiabendazole residues were determined by the radioactive indicator method in peel and pulp of oranges which had been dipped in a 0.1% aqueous suspension of the fungicidal agent thiabendazole, and then stored for periods up to four weeks. Whole peel from these oranges retained an average of ≃46 μg of thiabendazole/g after four weeks of storage. Inner peel contained only 8–21% of these levels, suggesting a slow inward diffusion of drug. The edible portion was virtually free of thiabendazole. Practically all of the applied agent was still present as intact thiabendazole after four weeks of storage.

Investigating mobility of carbon atoms and interatomic interaction in alloys by radioactive indicator method: P. L. Gruzinet al., U.S.S.R.

Investigating mobility of carbon atoms and interatomic interaction in alloys by radioactive indicator method: P. L. Gruzinet al., U.S.S.R.

The Determination of the Stability of Vitamin B12 in Multivitamin Mixture by a Radioactive Indicator Method

By means of cobalt 60 labeled vitamin as radioactive tracer, the stability of vitamin B12, after thirteen months' storage in four different multivitamin combinations, has been determined. The cobalt 60 labeled vitamin B12, prepared by microbial synthesis, was extracted from the multivitamin preparations by using three separate solvents, and determined by its radioactivity.

Determination of Dissociation Constants of Complex Ions by a Radioactive Indicator Method1a

Determination of Dissociation Constants of Complex Ions by a Radioactive Indicator Method^1a

Studies on the Lymphocyte Production. Investigations on the Nucleic Acid Turnover in the Lymphoid Organs

Summary.The importance of the various lymphoid organs as a source of blood lymphocytes is studied by determinations of the rate of desoxyribose nucleic acid formation in the organs under examination. The rate of formation of nucleic acid is estimated by means of the radioactive indicator method. The animal material is normal albino rats in different age groups.A large nucleic acid turnover is observed in the lymphoid organs. The greatest renewal takes place in the thymus, the rate of renewal in mature animals being 5–6 per cent during the 3 hours' experimental period. The corresponding figures for the lymph nodes and the spleen are only 1–2 per cent.Various considerations lead to the assumption that the desoxyribose nucleic acid turnover affords an estimate of the lymphocyte production in the different lymphoid organs. According to this conception, calculations show that the thymus must be the most important lymphocytopoietic organ except in old age when the weight of the organ is markedly reduced. Compared with the high thymic activity the other lymphoid organs possess only a slight lymphocytopoietic function.

Primary Photochemical Processes in Solution

The effect of an inert solvent on the efficiency of photodissociation processes is discussed. It is shown on theoretical considerations that under the usual experimental conditions a close analogy between reactions in solution and in the gas phase cannot be accounted for by assuming a symmetrical retardation of both the dissociation and recombination processes by the solvent. It is shown experimentally by means of the radioactive indicator method that even in the ideal case of chlorine in carbon tetrachloride the atoms produced in the photodissociation process do not react with the solvent.

Exchange Reactions of Iodine Compounds

JULIUSBURGER, Topley and Weiss1 found by the artificial radioactive indicator method that an exchange takes place between sodium iodide (c. 0.5M) and methyl iodide (c. 2M) in alcoholic solution at room temperature ; the exchange is complete in a minute or two. Under similar conditions, allyl iodide exchanges with sodium iodide, but ethyl, propyl, isopropyl and methylene iodides do not ; nor does iodoform exchange in acetone solution. Further, Gluckauf and Fay's2 successful concentration of active iodine from methyl iodide after neutron bombardment shows that no appreciable exchange occurs between iodine and methyl iodide in the absence of a solvent.

EXCHANGE REACTIONS OF IODINE BY THE METHOD OF RADIOACTIVE INDICATORS*

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEXCHANGE REACTIONS OF IODINE BY THE METHOD OF RADIOACTIVE INDICATORS*D. E. Hull, C. H. Shiflett, and S. C. LindCite this: J. Am. Chem. Soc. 1936, 58, 3, 535Publication Date (Print):March 1, 1936Publication History Published online1 May 2002Published inissue 1 March 1936https://doi.org/10.1021/ja01294a506RIGHTS & PERMISSIONSArticle Views38Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (112 KB) Get e-Alerts Get e-Alerts

Interchange of Heavy Atoms in Organo-Metallic Compounds

THE interchange of heavy atoms in organo-metallic compounds, reported by Mrs. Leigh-Smith and Dr. Richardson1, using the radioactive indicator method, is in line with work done by Hilpert and Gruttner2, who, however, found evidence of detachment of the organic radicals from the metal. They found that a reversible reaction took place between mercury diphenyl and metallic bismuth, with formation of a little diphenyl, at 250° in hydrogen.

Interchange of Heavy Atoms in Organo-Metallic Methyls

USING the radioactive indicator method in which radioactive isotopes are used to indicate transference of atoms, we have obtained evidence which suggests that both lead and bismuth, deposited, presumably as oxides, on a metallic surface, can exchange with lead in lead tetra-methyl and bismuth in Bi(CH3)3 in ether solution at room temperature.

Lead Content of Rocks

PROF. AETHUB HOLMES points out that there is a serious discrepancy between the data for lead in rocks (a) as given by Prof. Hevesy and Dr. Hobble and (b) as cited by him in the letters on this subject which appeared in NATURE of Dec. 19, 1931. The latter figures (under Pb on p. 1040) refer to the preliminary results obtained by the gravimetric method, whereas those announced on p. 1039 are the final results obtained by the use of the radioactive indicator method. Both sets of figures will appear in a forth-coming detailed record of the investigation. It appears that Prof. Hevesy substituted the final results for the preliminary figures after Prof. Holmes had passed the proofs of his own letter. The effect of the corrections, however, is to emphasise the validity of the conclusions based on the original figures. It now appears that in the composite sample of granitic rocks the total lead is eight (not five) times the radioactively generated lead. Thus, if the atomic weight of the lead originally present in the earth be taken as 207.22, that of the lead now present in granitic rocks should be about 207.19. Actual determinations on ore-lead correspond very closely with these figures.