Elemental Concentration and Natural Radioactivity Studies for Some Biological and Geological Samples Taken from Selected Zone of Ethiopia by the Method of Instrumental Neutron Activation Analysis(INAA)

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2015-06

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a

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This dissertation is devoted to the use of NAA to be applied for the determination of the qualitative and quantitative elemental analysis of selected samples. It involves the use of the knowledge of nuclear reaction particularly (n; ) reaction and implement its practical applications to determine element types and their concentrations in the sample. In lab, a total of Five di erent biological and geological samples were studied, four samples were studied for their qualitative and quantitative elemental analysis and one soil sample was studied for its natural radioactivity. Long lived and short lived radionuclides spectra were measured using HPGe gamma detector. Using known values of gamma-ray energies ema- nating from calibrating point gamma sources, an energy calibration curve and full energy peak e ciency curve were determined and plotted. The best t line matched the data with a least squares t, R2, of approximately equal to 1. A gamma spectrum is created by taking measurements of emitted gamma-rays from dif- ferent radio nuclei which emit many gammas of di ering energies. Special softwares, acquisition software MAESTRO and analysis software WINSPAN, installed in comput- ers identify an unknown radioisotope by measuring features on the gamma spectrum and comparing them to known spectra, and calculate the concentrations of the elements which gives out the gamma radiation. The peaks of di erent energies in the spectrum were tested analytically using the half lives of radionuclides whether the assignment of an element to each peak by the analysis software is correct. The analysis methodologies were validated by analyzing the IAEA-multi elemental standard having the same matrices as the sample. The irradiation facility used was the Nigeria Research Reactor-1 (NIRR-1) at the Center for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria. A high resolution gamma-ray spectrometer comprising of HPGe detector coupled with asso- ciated electronics and basic spectroscopy softwares were employed in the analysis. From the analysis of samples of biological and geological origin, di erent concentrations of el- ements were obtained and an e ort is made to explain the function of the elements for human or animals. In this dissertation a mineral soil was measured for its radioactivity and the concentration of radioactive materials were analysed and the level of radiation hazard due to the soil is calculated

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Fermion-Antifermion bound States

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