01773naa a2200289 a 450000100080000000500110000800800410001910000230006024500670008326000090015052009630015965000090112265000090113165000120114065300330115265300280118565300260121365300320123965300180127165300140128965300150130365300130131870000180133170000180134970000230136777300930139010264262013-01-18       1997    bl ---       0--  u    #d1 aOLIVEIRA, J. C. M.  aImproved soil particle-size analysis by gamma-ray attenuation.  c1997  aThe size distribution of particles is useful for physical characterization of soil. This study was conducted to determine whether a new method of soil particle-size analysis by gamma-ray attenuation could be further improved by changing the depth and time of measurement of the suspended particle concentration during sedimentation. In addition to the advantage of nondestructive, undisturbed measurement by gamma-ray attenuation, as compared with conventional pipette or hydrometer methods, the modifications here suggested and employed do substantially decrease the total time for analysis, and will also facilitate total automation and generalize the method for other sedimentation studies. Experimental results are presented for three different Brazilian soil materials, and illustrate the nature of the fine detail provided in the cumulative particle-size distribution as given by measurements obtained during the relatively short time period of 28 min.  asoil  aSolo  aTamanho  aAgricultural instrumentation  aAtenuacao por raio gama  aGamma-ray attenuation  aInstrumentacao agropecuaria  aParticle-size  aParticula  aTechniques  aTecnicas1 aVAZ, C. M. P.1 aREICHARDT, K.1 aSWARTZENDRUBER, D.  tSoil Science Society of America Journal, Madisongv. 61, n. 1, p. 23-26, Jan./Feb. 1997.