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  • Author or Editor: B. Constantinescu x
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Abstract  

Twenty-one gold coins of koson type, considered to be the only kind of gold coins issued by Dacians, were analyzed using EDXRF and PAA methods. Three groups of coins of different compositions were found, corresponding to coins with simple monogram, complex monogram and no monogram. The gold of koson coins is not a natural one (electrum) from present Romania's territory, but is similar to the gold of pseudo-Lysimachan staters. Some possible historical conclusions are discussed.

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Abstract  

Results of post-Chernobyl measurement on some foodstuff samples /eggs, meat, fruit, honey, medicinal herbs/ from South-Eastern Roumania are presented. Gamma-ray spectrometry was used; the radioactive concentration values are given in nCi.kg–1 wet weight. A strong decrease in concentrations for eggs from 6–7 May /3.0–7.4 nCi for131I, 0.25–0.40 nCi for134Cs, 0.40–0.85 nCi for137Cs per one egg, mainly in the yolk/ to 19–25 May /0.3–1.0 nCi for131I, 0.15–0.25 nCi for134Cs, 0.25–0.40 nCi for137Cs/ was observed. The mean values for lamb meat /joint muscle/ were 500 nCi.kg–1 for131I, 12 nCi.kg–1 for134Cs, 22 nCi.kg–1 for137Cs /18–25 May/. Relatively reduced values were found for fruits, e.g. compared to dairy products1. In May–June 1986, the food consumption in Roumania was strictly limited and controlled by competent authorities.

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Abstract  

We present results on the determination of phosphorus, sulfur, fluorine and chlorine in various matrices and some consideration about the possbility of using fast neutrons in elemental analysis based on the variable energy U-120 Cyclotron of the Institute of Atomic Physics (IAP).

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Abstract  

Zinc and nickel hexacyanoferrates (II) present a high affinity for223Fr and no retention for223Ra in hydrochloric acid solutions with concentrations greater than 0.5N. Hydrated antimony pentoxide is the best sorbent for223Ra. Incorporated in a composite exchanger, it could be used for decontamination purposes.

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Abstract  

Various samples from the south-east region of Roumania/greens, fodder, cheese/were analyzed for131I,134Cs and137Cs concentrations in May and July 1986 by -ray spectrometry. The concentrations are reported in nCi. kg–1 wet weight. For greens, a considerable decrease was observed for131I/to 3.0–7.0 nCi. kg–1/,134Cs/to 0.5–2.0 nCi.kg–1/ and137Cs /to 1.0–4.0 nCi. kg–1/ from the first half /5–15 May/ till the end of May 1986. For cheese, maximum values were measured between 5 and 15 May /sheep cottage cheese: 500–800 nCi.kg–1 for131I, 25–50 nCi. kg–1 for134Cs, 40–80 nCi. kg–1 for137Cs/; at the beginning of July a considerable decrease /to 5–10 nCi. kg–1 for131I, 1.2–2.0 nCi.kg–1 for134Cs, 2.2–3.0 nCi. kg–1 for137Cs/ was observed. In autumn 1986 a small increase up to 2.0–3.0 nCi. kg–1 for134Cs and 3.4–5.0 nCi. kg–1 for137Cs /in November/ was reported. The population's internal possible contamination was strongly limited by the authorities' severe control of the food-stuff.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: Z. Szeglowski, L. Guseva, Dinh Thi Lien, V. Domanov, B. Kubica, G. Tikhomirowa, O. Constantinescu, M. Constantinescu, and A. Yakushev

Abstract  

The short-lived isotopes of W and their descendants have been separated from nuclear reaction products arising in the bombardment of samarium target with24Mg ions at the U-400 cyclotron of JINR-Dubna. Chemical separations were performed using previously elaborated fast and continuous ion exchange. In similar way products of235U fission, obtained at the microtron MT-25 during irradiation of235U target with photoneutrons were separated.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: R. Bugoi, B. Constantinescu, F. Constantin, D. Catana, D. Plostinaru, and A. Sasianu

Abstract  

Quantitative analyses of various silver coins from the first century BC, found on current Romanian territory (Thasian tetradrachmae, Apollonia and Dyrrachium drachmae, Roman republican denarii) were performed using PIXE (3 MeV external proton beam) and XRF (1.1 GBq241Am source). The elemental analysis provided evidence of a great variety of monetary alloys and helped Romanian archaeologists to classify the coins, in terms of their provenance, as originals, copies or imitations minted in different areas of the Balkan-Carpathian region.

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Abstract  

A method for deep decontamination of high spin178m2Hf isomer from microquantities of Sc, Fe, Co, Ni, Sb and Ag was elaborated using ion exchange separation on Dowex-1 in Hf and CH3COOH–HCl media.

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Abstract  

The reaction14N(p, n)14O(71 s) is used, with a proton beam of 14 MeV energy and 100 nA intensity. The14O activity is detected by means of its characteristic 2.312 MeV gamma-ray (9.4%), with a NaI(T1) detector. The intensity ratio of gamma-rays to that of the incident particles for the sample, related to a similar ratio in adequate standards determines the nitrogen content in the sample. The measurement is completely automated. If we protect the embryo region during irradiation, the future germination of the analyzed seeds will be normal. Good correlation has been obtained between the results of the present method and those of the chemical Kjeldahl method.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: R. Bugoi, V. Cojocaru, B. Constantinescu, F. Constantin, D. Grambole, and F. Herrmann

Abstract  

Several fragments of ancient gold objects coming from an Eneolithic hoard and from Pietroasa Cloca cu Puii de Aur (The Golden Brood Hen with Its Chickens) hoard, unearthed on Romanian territory, and two Romanian native gold nuggets samples were analyzed using micro-PIXE technique. The purpose of the study was to clarify the metal provenance. Trace and minor elements (Cu, Te, Sn, Pb, Ti, Cr, V, Mn, Ta) and platinum group elements (PGE) concentrations were estimated. The presence of inclusions (micrometer size areas of composition different from the surroundings) was investigated. We found Si and Ca inclusions on two Eneolithic samples, and Ta inclusions on two samples from Pietroasa hoard. The measurements suggested an alluvial origin of gold for the Eneolithic samples and give indications for the possible gold ore sources of Pietroasa hoard.

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