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Abstract  

Results of several IAEA intercomparison runs organized over the last 8 years are analyzed from the point of view of contribution and performance of NAA as compared to other techniques. It is shown that NAA is the method of good accuracy and precision providing on average greater share of results than any other single analytical technique. The prominent position of NAA among other methods used in trace analyses seems to be firmly established and there are no signs that there might be any change of the trend in the nearest future.

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Summary  

Neutron activation analysis (NAA) offers advantages for detecting impurity levels of select isotopes that have suitable neutron cross sections. Secondary ion mass spectrometry (SIMS) on the other hand detects most isotopes, but suffers various molecular interferences and covers only a small beam size volume per run. These two methods are combined here to study a large number of isotopes in titanium thin films in an electrolytic cell experiment. Nine isotopes are covered by NAA and over 50 with SIMS. An overlap in the data sets allows a normalization of SIMS data to the more accurate NAA measurements.

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Abstract  

Ion-exchange and solvent extraction procedures that can enable the use of NAA for the determination of trace elements from gallium matrix, using pre-irradiation separations are discussed. Matrix separation coefficients of the order of 103–106 are obtained.

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Abstract  

The k 0-standardization method (k 0-NAA) is known as one of the most remarkable progresses of the NAA with its many advantages. For the application of k 0-NAA method at the NAA #1 irradiation position where the neutrons are well thermalized in the HANARO research reactor, KAERI, Korea, the determination of the reactor neutron spectrum parameters such as α and f have been carried out. The measured values of α and f using the “Cd-ratio” triple monitor method were 0.127±0.022 and 1010±70, respectively. To evaluate the applicability of k 0-NAA in our analytical system, the analysis of three kinds of SRMs was executed. The analytical results showed that the relative error of most of the elements was less than 10% and the U-scores were within 2. It is turned out that the procedure of the k 0-NAA in the HANARO research reactor is available for a practical application in the environmental fields.

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Abstract  

This study intended to demonstrate the use of k 0-IAEA software with the NAA#3 irradiation hole in the HANARO research reactor and the gamma-ray spectrometers at the NAA laboratory in the Korea Atomic Energy Research Institute (KAERI). NIST SRM 2586-Soil was chosen as a sample to validate the analytical protocol by using the k 0-IAEA software. Twenty four elements were determined and the resultant deviations between the experimental results and the certified values were all within 10% except for Dy. In addition, an analysis of three types of synthetic multielement standards (SMELS) prepared by the Institute for Reference Materials and Measurements (IRMM) and Institute of Nuclear Science (INW) in Belgium was executed. The analytical results agreed well with the assigned values and the U-scores for most of the elements were lower than 2.

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Abstract  

The International Centre for Environmental and Nuclear Sciences (ICENS) has been involved in conducting multipurpose geochemical surveys, the results of which were published in "A Geochemical Atlas of Jamaican Soils". The primary analytical tool for these studies was neutron activation analysis (NAA) using the SLOWPOKE-2 reactor at the Centre. The neutron flux of the SLOWPOKE-2 reactor is extremely stable, thus allowing a semi-absolute method for quantitative NAA. This has several advantages, but requires preparation and measurement of the single- or multi-element standards for each gamma-spectroscopy system (GSS). The NAA laboratory at ICENS operates three GSSs. The primary ("master") GSS was standardized using single element standards for over 50 elements, naturally occurring in most geological and biological materials. The standardization of the secondary GSS's was achieved by transferring of the elemental sensitivities of the master GSS using an instrumentation-free standardization approach. The paper describes the implementation of this methodology and its utilization in the routine analytical work.

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Abstract  

A NAA-PIXE combined analysis has been applied to the precise measurement of the concentrations of Nb and Ti in Nb–Ti alloy ingot. The ingot is used in the production of superconductors and the concentration should be controlled very strictly. The ingot cross section could be analyzed with an accuracy of better than 1% by the use of NAA for the preparation of standard samples and PIXE for the nondestructive rapid scan of the surface. The radial and azimuthal concentration profiles of the ingot could be obtained.

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Abstract  

Neutron activation analysis is one of many analytical techniques used at the National Institute of Standards and Technology (NIST) for the certification of NIST Standard Reference Materials (SRMs). NAA competes favorably with all other techniques because of it's unique capabilities for high accuracy even at very low concentrations for many elements. In this paper, instrumental and radiochemical NAA results are described for 25 elements in two new NIST SRMs, SRM 1515 (Apple Leaves) and SRM 1547 (Peach Leaves), and are compared to the certified values for 19 elements in these two new botanical reference materials.

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Abstract  

The concentrations of Cl, K and Na were analyzed in human body fluids (whole blood and serum) using NAA, resulting in the first biochemical baseline values for the Brazilian population. These data permitted us a discussion about the advantages and limitations of using this analytical technique for clinical chemistry.

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Abstract  

Concentrations of Br, Ca, Cl, K and Na in whole blood of dystrophin-deficient mouse [the Dmdmdx line] were determined using NAA, resulting in reference values that are relevant for clinical blood investigation. The comparison with human being whole blood values was also performed in order to establish possible indexes and similarities among the experimental and clinical applications.

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