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Absorption parameters
  Computes, from experimental data, the diffusion and relaxation parameters for absorption.
2025.Feb.21 21:16:32
Data X •
Data Y •
Constants • Problem constants (fixed parameters. •
Parameters (initial guess) • Problem parameters, to be found. •
scale, tol   (NM = Nelder-Mead) NM: scale for variables; tolerance.
itmax, iprt NM: max. iterations; intermediate test. •
Mode   Mode: audit (verify) or solve. •
Show values ? Shows the graph coordinates.

Computes, from experimental data, vectors X and Y, the parameters, P, of a given function, y = y(x; C, P), with constant(s) C. The total residual (sum of absolutes) is minimized via the Nelder-Mead (NM) algorithm.

In this plate, the problem is (super-)absorption:  'Data X', time (x, min); 'Data Y', fraction swelling (y); 'constant(s)', particle diameter (m); and 'parameters', P = (xF, .kF, .kR), i.e., Fickian diffusion weight, Fickian diffusion rate, and relaxation rate. (For the base problem, a final residual of ~0.04 is expected.)

The graph shows: (red) the experimental points connected by a broken line; and (green) the computed points.

References: Plate: SuperabsorbentParams

• Berens, A. R., H. B. Hopfenberg, 1978, "Diffusion and relaxation in glassy polymer powders: 2. Separation of diffusion and relaxation parameters", Polymer, 19(5):489–496.

• 1908-06-25: Quine, Willard Van Orman (2000-12-25).

 
 
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Created: 2010-06-25 — Last modified: 2010-07-06