RESUMO
In many areas of research the measured spectra consist of a collection of "peaks"--the sought-for signals--which sit on top of an unknown background. The subtraction of the background in a spectrum has been the subject of many investigations and different techniques, varying from filtering to fitting polynomial functions, have been developed. These techniques yield results that are not always satisfactory and often even misleading. Based upon the rules of probability theory, we derive a formalism to separate the background from the signal part of a spectrum in a rigorous and self-consistent manner. We compare the results of the probabilistic approach to those obtained by two commonly used methods in an analysis of particle induced x-ray emission spectra.
RESUMO
Previous studies on the role of trace elements (TE) in the development of calcium oxalate (CaOx) human kidney stones by nuclear microprobe (NMP) investigated the mechanisms and role of TE in the buildup of urinary CaOx concretions. In the present work, microanalysis of the previously reported series of recurrent human kidney stones was further expanded. Interest was focused on determining levels of directional variability in elemental concentrations of Ca and TE throughout selected micro-regions of single stones by Dynamic Analysis (DA).