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	Provedor de dados Scientia Agricola (2) Autor BACCHI,O.O.S. (1) Bacchi,Osny Oliveira Santos (1) Elias,Elimoel Abraão (1) NIELSEN,D.R. (1) OLIVEIRA,J.C.M. (1) REICHARDT,K. (1) Reichardt,Klaus (1) Mais... Palavra-chave Gamma attenuation (2) Gamma radiation (1) Granulometry (1) Soil mechanical analysis (1) Soil texture (1) Soil water retention (1) Mais... Tipo do documento Info:eu-repo/semantics/article (2) Ano 1999 (1) 1998 (1) País Brazil (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última EXACT EQUATIONS FOR SOIL PARTICLE-SIZE ANALYSIS BY GAMMA-RAY ATTENUATION Scientia Agricola Elias,Elimoel Abraão; Bacchi,Osny Oliveira Santos; Reichardt,Klaus. Soil particle-size analysis by gamma-ray attenuation was first suggested in 1992 and improved in 1997 by diminishing the measurement time and adapting it for automation. It is here demonstrated that when the mass attenuation coefficient <FONT FACE="Symbol">m</font>w and the density Dw are replaced by <FONT FACE="Symbol">m</font>s and Ds (where the subscripts w and s stand for water and solution) in the approximate equations used to estimate the concentration of suspended particles, they become exact. The demonstration is based by treating the dispersant and water solution as one single medium, instead of treating them as two media. In this way, six variables are reduced to only three. Physical considerations suggest that the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Granulometry; Soil mechanical analysis; Soil texture; Gamma attenuation. Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161999000100014 Gamma-ray beam attenuation as an auxiliary technique for the evaluation of the soil water retention curve Scientia Agricola BACCHI,O.O.S.; REICHARDT,K.; OLIVEIRA,J.C.M.; NIELSEN,D.R.. The soil water retention curve is fundamental for the hydraulic characterization of a soil and has many applications in agricultural research as well as in practical agriculture. A new procedure for soil moisture and soil bulk density evaluation inside closed pressure chambers through gamma-ray beam attenuation is presented. The proposed procedure presents several advantages in relation to the traditional process: avoids the need of continuous sample manipulation; minimizes the problem of hysteresis; allows a more precise evaluation of soil moisture by taking into account changes of soil bulk density due to swelling or shrinking on addition or removal of water; allows frequent evaluation of soil moisture without the need of opening the pressure chamber;... Tipo: Info:eu-repo/semantics/article Palavras-chave: Gamma attenuation; Gamma radiation; Soil water retention. Ano: 1998 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161998000300019 Registros recuperados: 2 Primeira ... 1 ... Última

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