A preliminary result employing neutron activation tomography in the study of the diffusion of a preservative in a sample of Scots pine is presented. The ability to determine the spatial distribution of elements within the wood without recourse to destructive sectioning makes this a better technique than others currently available.
Authors:O. Akanle, F. Balogun, J. Owa, and N. Spyrou
Instrumental neutron activation analysis (INAA) and proton induced X-ray emission (PIXE) analysis were used to determine the concentration of 13 elements in the breast milk collected within the first week of lactation and after morning feed from 16 pre-term mothers and 20 term mothers. The results of the study show that pre-term milk has a significantly higher concentration of Cl, Cu, Fe, K, Mg, Mn, Na and Zn while term mothers have a significantly higher concentration of P and Br. No significant differences were, however, found in the mean concentration of Al, Ca, I and Rb. Furthermore, the mean concentration for most of the elements found in the breast milk fall within the range of the concentrations obtained for the commercial infant milk formulae.
Authors:M. Fasasi, P. Tchokossa, J. Ojo, and F. Balogun
The radioactivity of the Opa river — irrigated farmlands in the south western Nigeria was determined using an HpGe based,
low-level passive gamma-counting system. With the exception of two isotopes, the main radionuclides analysed in the sample
were the progenies of238U and232Th. The other two isotopes were the naturally occurring40K and the anthropogenic137Cs. The result obtained showed elevated levels of radioactivity from all detected radionuclides compared to the published
data for this area. Enhanced levels of naturally occurring radionuclides is attributed to the use of phosphatic fertilizers
for dry season vegetable cultivation along this river banks. The presence of the fission product137Cs could be traced to the fallouts occasioned by the various French nuclear tests in the Sahara desert, and probably, some
effect of the more recent nuclear reactor accident at Chernobyl in 1986.
Authors:F. Balogun, A. Nwankpa, F. Ibitoye, C. Adesanmi, I. Tubosun, and S. Owolabi
A combination of Semi-absolute Fast Neutron Activation Analysis (SFNAA) and Energy Dispersive X-ray Fluorescence (EDXRF) analysis has been employed to determine 35 inorganic elements in coals from four different mines across the minefields of Nigeria. A plot of certified against measured values of elemental constituents in a National Bureau of Standard coal reference material, SRM 1632 a, with a regression coefficient of r=0.894, is used to demonstrate the efficacy of this technique. With a complimentary application of the EDXRF technique, better precision is obtained for short-lived isotopes reducing the need for a more sophisticated transfer system and cyclic activation analysis in the situation under discussion.
Authors:F. Balogun, I. Tubosun, A. Akanle, J. Ojo, C. Adesanmi, J. Ajao, and N. Spyrou
A complementary use of the comparative and the semi-absolute variations of instrumental neutron activation analysis (INAA) has enabled us to determine 22 different elements in a sample of natural fluorite originating from the younger granite province of Nigeria. The mineral has a brownish purple appearance with some veinlets having a deep purple coloration. Of all the 22 elements measured, Fe (851.36 ppm), Sb (7.69 ppm), Ag (87.4 ppm), Hg (2.71 ppm) and Se (1.97 ppm) are found to be exclusive to the veinlets while Au (109.15 ppm), Co (2.15 ppm) and W (173.20 ppm) are concentrated in the main matrix of the fluorite. With the aid of the semi-absolute method, it was possible to measure the Au concentration in the IAEA Soil-7 reference material to be 56.83±5.87% ppm. A qualitative electron microprobe analysis (EMA) showed that the bulk of the matrix is composed mainly of Ca and F, as expected.