753 Soil Sci. Soc. Am. J. 74:753–761 Published online 29 Mar. 2010 doi:10.2136/sssaj2009.0284 Received 3 Aug. 2009. *Corresponding author ([email protected]). © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photoco...

Laboratory measurements of three predicted wave types (two compressional or P-waves and one shear S-wave) have been made in artificial soils. The Type-I P and S-wave are predicted to be most sensitive to the macroscopic elastic properties of the frame, whilst the Type 11 P-wave is predicted to be most sensitive to the hydrodynamic material properties. A loudspeaker source has becn used for the ...

abstract earthworms are an important component of soil fauna, and play a crucial role in the improvement of soil properties. however, very little is known of the interactive influence of earthworms and organic materials on soil enzyme activities, particularly in arid and semi-arid soils. the low organic matter content and the significant role of earthworms in stimulating microbiological and bio...

Many soils have clay-enriched horizons that are thought to result from pedogenic processes. Various hypotheses are proposed for expected clay size-distributions in soil profiles. The average size of clay crystallites determined by the amount of broadening of x-ray diffraction peaks ranged from 160 to >2000A 0 , but the lack of trends in four loess-de• rived soils did not permit the hypotheses t...

hydroxyapatite is a biocompatible ceramic and reinforcement for bone implantations. seva/hap composite content hap filler with difference particle sizes were designed. mechanical tests like tensile modulus, uts, strain at break and biodegradation were investigated. results illustrated much increase tensile modulus of composites content hap nano powders ratio to micro powders. also uts analysis ...

soil is a nonrenewable source that needs considerable management to prevent physical deteriorationby erosion and compaction. compacted soil causes low fertility and yield. the purpose of this study isto investigate the effect of viscoelastic properties of soil and to determine important factors oncompaction. furthermore, stress distribution, prediction of soil compaction and simulation of its e...

In order to implement MEPDG hierarchical inputs for unbound and subgrade soil, a database containing subgrade M R , index properties, standard proctor, and laboratory M R for 140 undisturbed roadbed soil samples from six different districts in Indiana was created. The M R data were categorized in accordance with the AASHTO soil classifications and divided into several groups. Based on each grou...

Manganese (Mn) contamination of drinking water may cause aesthetic and human health problems when concentrations exceed 50 and 500 μg l, respectively. In the UK, the majority of Mn-related drinking water supply failures originate from unpolluted upland catchments. The source of Mn is therefore soil, but the exact mechanisms by which it is mobilised into surface waters remain unknown. Elevated M...

Enzyme-mediated decomposition of soil organic matter (SOM) is controlled, amongst other factors, by organic matter properties and by the microbial decomposer community present. Since microbial community composition and SOM properties are often interrelated and both change with soil depth, the drivers of enzymatic decomposition are hard to dissect. We investigated soils from three regions in the...