The epithermal neutron shape factor (α) was determined in the permanent cadmium lined irradiation channel installed in the large outer irradiation site of the Nigeria Research Reactor-1 (NIRR- 1) by the cadmium cover...The epithermal neutron shape factor (α) was determined in the permanent cadmium lined irradiation channel installed in the large outer irradiation site of the Nigeria Research Reactor-1 (NIRR- 1) by the cadmium covered multimonitor method using the monitors Al-0.1% Au, Zr and Zn thin foils and Mo thin wire and was found to be -0.137 ± 0.018. The high negative value of α indicates a hardened epithermal neutron spectrum in the cadmium lined irradiation channel. The α value obtained was used in the single comparator method of ENAA (ko-ENAA) for the determination of the concentrations of elements in the standard reference material NIST 1515 Apple leaves using Al-0.1% Au thin foil as the single comparator. The concentrations of the elements Sm and Br were determined in the NIST 1515 Apple leaves because of their high Qo values and are in good agreement with the certified values.展开更多
Samples of the food legumes, cowpeas (Vigna unguiculata), soya beans (Glycine max) and groundnuts (Arachis hypogaea) collected from rural farmers in four rural villages around Zaria, Nigeria were analysed for the conc...Samples of the food legumes, cowpeas (Vigna unguiculata), soya beans (Glycine max) and groundnuts (Arachis hypogaea) collected from rural farmers in four rural villages around Zaria, Nigeria were analysed for the concentrations of the major, minor and trace elements by the ko-ENAA and INAA methods. Irradiation and γ-ray counting were performed using the NIRR-1 and associated facilities. The NIST 1515 Apple leaves were used as the quality control material. The concentrations of the elements Se, Br and Rb were determined by ko-ENAA while those of Na, K, Zn, La, Br, Sm and Sc were determined in INAA in the food legumes. The concentrations of Zn found in all the legumes are within the limit specified in international guidelines. The concentrations of Se found in the food legumes are above the limit specified in international guidelines. The food legumes are good sources of the elements Na, K, Zn which can meet adequate dietary requirements provided the legumes are not refined. Bromine is not at toxic levels in the food legumes.展开更多
文摘The epithermal neutron shape factor (α) was determined in the permanent cadmium lined irradiation channel installed in the large outer irradiation site of the Nigeria Research Reactor-1 (NIRR- 1) by the cadmium covered multimonitor method using the monitors Al-0.1% Au, Zr and Zn thin foils and Mo thin wire and was found to be -0.137 ± 0.018. The high negative value of α indicates a hardened epithermal neutron spectrum in the cadmium lined irradiation channel. The α value obtained was used in the single comparator method of ENAA (ko-ENAA) for the determination of the concentrations of elements in the standard reference material NIST 1515 Apple leaves using Al-0.1% Au thin foil as the single comparator. The concentrations of the elements Sm and Br were determined in the NIST 1515 Apple leaves because of their high Qo values and are in good agreement with the certified values.
文摘Samples of the food legumes, cowpeas (Vigna unguiculata), soya beans (Glycine max) and groundnuts (Arachis hypogaea) collected from rural farmers in four rural villages around Zaria, Nigeria were analysed for the concentrations of the major, minor and trace elements by the ko-ENAA and INAA methods. Irradiation and γ-ray counting were performed using the NIRR-1 and associated facilities. The NIST 1515 Apple leaves were used as the quality control material. The concentrations of the elements Se, Br and Rb were determined by ko-ENAA while those of Na, K, Zn, La, Br, Sm and Sc were determined in INAA in the food legumes. The concentrations of Zn found in all the legumes are within the limit specified in international guidelines. The concentrations of Se found in the food legumes are above the limit specified in international guidelines. The food legumes are good sources of the elements Na, K, Zn which can meet adequate dietary requirements provided the legumes are not refined. Bromine is not at toxic levels in the food legumes.
