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  • Author or Editor: G. Guzzi x
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Abstract  

The behaviour of 66 radio-ions towards 11 exchangers and 11 solutions under standardized experimental conditions has been evaluated and classified in order to have the possibility of a rapid assessment of radiochemical separation procedures. Two systems of utilizing the bulk of data obtained have been devised and employed. The first is based on the use of a deck of cards similar to those used for fast retrieval of bibliographic information, in which the behaviour of ions is coded by means of punched holes; the second is based on the treatment of the data by means of an electronic computer. The operational modes of the two systems and examples of their practical applications are presented.

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Abstract  

Trace element analysis has been carried out on standard biological reference samples such as bovine liver, orchard and tomato leaves. Computer aided instrumental neutron activation analysis and, in some cases, preliminary chemical group separation followed by NAA were used. For Ca, Mg, Ni and Si special chemical separation and Cerenkov counting were applied. *** DIRECT SUPPORT *** A1353068 00003

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Abstract  

Three different computer systems for gamma-spectrometric data-handling have been developed at the Joint Nuclear Research Center of Ispra. The systems are: (1) batchwise treatment of the data with a large computer, (2) time-shared teleprocessing by means of a centralised computer, (3) use of a small computer at the laboratory site. The paper describes both hardware and software of the three systems with emphasis on their practical use and on advantages and disadvantages in routine application. A partial analysis of the running costs of the systems is also presented.

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Abstract  

In a framework of a more intensive study of the oceanographic phenomenology of the Northern Adriatic Sea, recently undertaken by the O. G. S. of Trieste, the present paper provides some insight into the determination of trace elements in sea water and bottom sediment matrices. Sampling procedure using continuous pumping and filtering and neutron activation analytical techniques are presented and the obtained results briefly discussed. Accounting for the physiography of the basin, for the oceanographic processes and for the different freshwater input, several samples were collected of filtered water in order to set up their properties. Results were obtained throughout the settlement only for long-lived radionuclides based on routine neutron activation: Cr, Ag, Co, Cs, Rb, Sb, Sc, Sr, Zn, U. For each of them, the concentration range was determined and discussed. Results indicate that the Cs, Rb, Sr and U concentration range is readily comparable with that assessed at open seas. On the contrary, for the other elements such as Cr, Ag, Co, Sc, Sb and Zn concentrations are noticeably higher than those found at open seas, mainly as far as samples collected near the sea bottom are concerned. The concentration increase is surely related to the burden of pollutants suffered by rivers. Moreover, the positive concentration gradient experienced toward the bottom, is fully in agreement with the estuarine character of the investigated area and in accordance with the strong decomposition of organic matter taking place in the bottom layer of the basin. Finally, the complexity of the sedimentary pattern in the Northern Adriatic renders it difficult to properly define the element concentration in bottom sediment. Only four samples were chosen as representative of the different sediments and analysed. Long-lived elements obtained are: Ce, Co, Cs, Cr, Rb, Sc, Tb, Yb. Their concentration was found to be related to the geochemical features of the activated matrix.

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Abstract  

Cerenkov counting efficiencies for a large number of radionuclides formed by (n, γ) reactions and used in the field of activation analysis have been obtained by two different experimental procedures. A comparison between the Cerenkov counting technique and scintillation low-resolution gamma-ray spectrometry is also presented. Results are summarized in tables and briefly discussed.

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Abstract  

Three different analytical techniques: INAA, X-ray fluorescence and atomic absorption spectrometry were used at the JRC Ispra to test the total homogeneity of four candidate botanic reference materials supplied by NBS. Without adopting complex statistical formalities a “degree of inhomogeneity” was estimated in each sample for the elements considered in the test. The operating procedures and the results obtained are presented and discussed.

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