Metrological role of neutron activation analysis. II. Parametric INAA – an ideal back-up for INAA as a primary ratio method of measurement

2002 ◽  
Vol 7 (2) ◽  
pp. 50-54 ◽  
Author(s):  
W. Tian ◽  
Bangfa Ni ◽  
L. Cao ◽  
Yangmei Zhang ◽  
Pingsheng Wang
2017 ◽  
Vol 112 ◽  
pp. 99-154 ◽  
Author(s):  
Alexandra Villing ◽  
Hans Mommsen

To date, the pottery production of Rhodes, Kos and other ‘East Dorian’ islands and coastal areas remains little understood. This article presents and discusses new neutron activation analysis (NAA) of eighth–sixth-century bc vessels found on Rhodes and in related areas, placing them in the wider context of past and present archaeometric research. The results highlight the role of Kos as a leading regional centre of painted pottery production and export in the seventh–sixth centuries bc, notably of ‘East Dorian’ plates. This includes the famous ‘Euphorbos plate’, which can now be attributed to Koan production. Contemporary Archaic pottery workshops on Rhodes, in contrast, had a less ambitious, if diverse, output, ranging from vessels in a Sub-Geometric tradition, imitation Corinthian wares and modest local versions of Koan- and Ionian-style plates to finely potted and richly decorated ‘Vroulian’ cups and black-figured situlae. It was imported mainland and East Greek wares, however, that dominated the island's consumption of Archaic painted wares. This represents a departure from the preceding Geometric period, which was characterised by a local pottery production of considerable scale and quality, although receptivity to external influences remained a consistent feature throughout later periods. As patterns of demand were changing, the island's craft production appears to have concentrated on a different range of goods in which high-quality figured finewares played a lesser role.


2018 ◽  
Vol 14 (2) ◽  
pp. 5564-5573
Author(s):  
Tarek Mohamed Talaat Salama ◽  
N. A. Mansour ◽  
M. Fayez-Hassan

Neutron activation analysis (NAA), based on the comparator method, has the potential to fulfill the requirements of a primary ratio method as defined in 1998 by the Comité Consultatif pour la Quantité de Matière — Métrologie en Chimie (CCQM, Consultative Committee on Amount of Substance — Metrology in Chemistry Studies of Neutron Activation Analysis (NAA) have been carried out on different Egyptian building material samples. The technique of neutron activation analysis is based on the measurement of radiation released by the decay of radioactive nuclei formed by neutron irradiation of the material. The most suitable source of neutrons for such an application is usually a research reactor. The samples that can be analyzed with this method stem from a number of different fields, including medicine, nutrition, biology, chemistry, forensics, the environment and mining. Neutron activation analysis can be performed in a variety of ways. This depends on the element and the corresponding radiation levels to be measured, as well as on the nature and the extent of interference from other elements present in the sample. Most of the methods used are non-destructive, based on the detection of gamma radiation emitted by the irradiated material after or during the irradiation. Next to education and training, neutron activation analysis is the most widely used application of research reactors. Almost any reactor operating at 10-30 kilowatt of thermal power is capable of providing a sufficient neutron flux to irradiate samples for selective applications of this analysis technique. Another method of NAA by using two Am-Be isotopic neutron sources of activity 5 Ci were used in this investigation. The accomplished gamma rays were measured using 70 % HPGe spectrometer. This work demand to estimate the elements contained in cement products and its quality control. X-ray Fluorescence (XRF) measurements were done for confirming our results, and for determining the average neutron flux of 3.7× 103 n/cm2sec. The Natural radioactivities of these samples were measured before the analysis to know the background level of 40K, 238U and232Th nuclei. The results investigated that NAA agree with the results of XRF and the world range of the cement concentration of the essential elements Ca, Al, Na, Fe, Mn, V, Sr and Si.


1972 ◽  
Vol 43 (5) ◽  
pp. 627-637 ◽  
Author(s):  
D. J. Hosking ◽  
M. J. Chamberlain ◽  
J. H. Fremlin

1. The change in total body calcium content after surgery for primary hyperparathyroidism was studied in seven patients by whole body neutron activation analysis. Three patients who remained in the uncontrolled state for up to 12 months were also studied by this technique. 2. The technique and its reproducibility are described. Changes in total body calcium greater than ±4% should be detectable using this method. 3. The change in total body calcium after surgery was variable. Total body calcium content decreased in three cases after apparently successful parathyroidectomy. Not all the cases experiencing an increase in body calcium content had radiological evidence of bone disease. 4. The role of relative hypoparathyroidism due to suppression of normal parathyroid tissue by a functioning adenoma is discussed.


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