01900naa a2200325 a 450000100080000000500110000800800410001910000200006024501350008026000090021530000150022450001420023952008310038165000090121265000180122165000110123965000090125065300070125965300180126665300170128465300200130165300210132165300110134265300090135365300340136265300190139665300100141570000190142577301300144410267952010-03-03       1994    bl ---       0--  u    #d1 aCRUVINEL, P. E.  aUse of proton induced X-ray analysis and image processing for determination of trace-elements distribution in agricultural fields.  c1994  ap.371-376.  aReprinted from ICSI'94 proceedings of the third International Conference on Systems Integration, Sao Paulo, SP, Brazil, Aug. 15-19, 1994.  aA method to study the spatial distribution of trace-elements in soil by using proton induced X-ray analysis (PIXE) and image technique is presented. A large number of trace-elements are present in soils, at concentration values in the range of parts per billion and tenths of parts of million. As for biological samples many elements are of great importance for the nutrition of the plants, while others are toxic, and others have an unknown role. Taking into account the spatial variability on the sampled field the samples were evaluated by PIXE and the concentration of several trace-elements were determined. In addition by using image processing it was possible to interpolate in between sampled points and a grid of trace-elements was establised. In particular the distribution of Ca over the sampled field is presented.  asoil  aProcessamento  aRaio X  aSolo  aCa  aDetermination  aDistribution  aElementos-traco  aImage processing  aImagem  aPIXE  aProton induced X-ray analysis  aTrace-elements  aX-ray1 aMINATEL, E. R.  tIn: INTERNATIONAL CONFERENCE ON SYSTEMS INTEGRATION, 3., Aug. 1994, Sao Paulo, SP. Los Alamitos: IEEE Computer Society, 1994.