PIXE, definition

Pion, summary of properties, 11-1 to 55 Pitch, in musical scales, 14-47 PIXE, definition, 12-1 to 4 pK... 

A distribution in more than one variable may be illustrated by the function describing the distribution of matter in a sphere with its center at the origin of a cartesian system. If the radius is c and density p, then the distribution of matter Pix y z) is a function of three variables with the definition that P Xjy,z) dx dy dz is the amount of matter in the element of volume bounded by the set of six cartesian planes through the points x,y,z) and (x + dx, y + dy, z + dz). The mass-distribution function P x,yyZ) is then equal to the density p, for all points satisfying the condition x + / + 2 c. If we are interested in the distribution of matter in only two dimensions, we can obtain a function P(x,y) from P(x,yjz) by integrating over all z ... 

For natural waters TXRF should definitely be the choice though PIXE also gives good possibilities. The number of reliably determined elements does not exceed 16. 

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