Tracing Estuarine Sediments by Neutron Activation

Author(s):  
Richard M. Ecker ◽  
John F. Sustar ◽  
William T. Harvey
2018 ◽  
Vol 10 (1) ◽  
pp. 58
Author(s):  
Ali Arman Lubis

Nuclear analytical technique instrumental neutron activation analysis was employed for the multielemental analysis of sediments collected from Cisadane estuary. This analytical technique provides concentration of 20 elementswhich consist of heavy metals and rare earth elements simultaneously. Two sediments cores were collected using core sampler for determining the distribution of all elements in the depth profiles of sediments. Sediment cores were subdivided into 2 cm increment, dried and sent to reactor for irradiation using thermal flux of ?1013 neutrons.cm-2.s-1 for 20 minutes in Research Reactor Siwabessy, National Nuclear Energy Agency (BATAN), Serpong. Irradiated samples were measured using a multichannel analyzer (MCA) gamma spectrometer coupled with high purity germanium detector. Analysis of particle size was done since uptake of heavy metals by sediments is particle-size dependent. The results are presented and discussed.


1997 ◽  
Vol 218 (2) ◽  
pp. 169-176 ◽  
Author(s):  
A. Kuno ◽  
M. Matsuo ◽  
B. Takano ◽  
C. Yonezawa ◽  
H. Matsue ◽  
...  

Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.


1963 ◽  
Vol 03 (02) ◽  
pp. 175-182 ◽  
Author(s):  
Bo Bergman ◽  
Rune Söremark

SummaryBy means of neutron activation and gamma-ray spectrometry the concentrations in the human mandibular articular disc of the following elements have been determined: Na, Mn, Cu, Zn, Rb, Sr, Cd, W, and Au. The discs were obtained at necropsy from seven men and nine women, ranging in age from 56 to 71 years.The activation was carried out in a thermal neutron flux of about 1.7 XlO12 neutrons × cm−2 × sec.−1 for about 20 hours. A chemical group separationwas performed before the gamma-ray spectrometry. Quantitative data based on the dry weight of the cartilage samples were obtained by comparing the photo-peak area of the identified elements with those of appropriate standards.


2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Guilherme Soares Zahn ◽  
Regina Beck Ticianelli ◽  
Mitiko Saiki ◽  
Frederico Antonio Genezini

In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used for gamma spectrometry in NAA measurements. This material is very practical, but its chemical composition may be troublesome, as it presents large amounts of elements with intermediate atomic number, with attenuation factors for low-energy gamma-rays that must not be neglected. In this study, count rates obtained using different sample holders were compared. To accomplish that, an Am-241 source, with 59-keV gamma emission, was used so that low-energy gamma attenuation differences can be determined. Moreover, in order to study the energy dependence of these differences, a Ho-166m source was also used. From these results, it was possible to analyze the experimental error associated to the variations between sample holders, with the aim of introducing an addictive term to the uncertainty analysis of comparative Neutron Activation Analysis results.


Sign in / Sign up

Export Citation Format

Share Document