نتایج جستجو برای: buried soils
تعداد نتایج: 59570 فیلتر نتایج به سال:
A bench-top experimental approach is described for estimation of the polarization behaviour of pipeline steel as a function of the time-dependent formation of scale and calcareous deposits in simulated soil leachates. A three-time constant process model provided a common set of parameters for a given soil environment and level of aeration. The parameters estimated could be applied to a broad ra...
An extensive ice body is buried under less than 20 cm to several meters of debris in Beacon Valley (Dry Valleys, Antarctica). The thermal behavior of the upper 20 m of permafrost, including the annually freezing and thawing surface (active layer) in this region of low relative humidity and very low annual precipitation, has great scientific interest. Distinctly different behavior from wet, arct...
Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane ...
rom the detection of buried treasure to the detection of landmines and unexploded ordnance, the history of metal detectors is long and varied. This article reviews the basic technology for detecting metal objects using electromagnetic induction techniques. Working with the U.S. Army Night Vision and Electronic Sensors Directorate and other government agencies, APL has developed a number of adva...
The C/C ratio in pedogenic carbonate (i.e., CaCO3 formed in soil) is a significant tool for investigating C4 biomes of the past. However, the paleoecological meaning of dC values in pedogenic carbonate can change with the scale at which one considers the data. We describe studies of modern soils, fossil soils, and vegetation change in the Chihuahuan Desert of North America and elsewhere that re...
Published in Agron. J. 103:628–643 (2011) Published online 02 Mar 2011 doi:10.2134/agronj2010.0409 Copyright © 2011 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and ret...
High spatial resolution Clementine images are examined to measure the reflectance properties of small and optically immature mare craters that have sampled discrete compositional units. The spectral properties of these relatively crystalline mare materials are compared to associated mature soils to determine the effects of space weathering on specific basalt types. Space weathering is observed ...
Monsanto's "Lasagna" process uses layers of treatment zones spaced between buried electrodes to remove trichloroethylene (TCE) from contaminated soil and groundwater. TCE is used primarily as a metal degreaser as well as in products such as dyes, printing ink, and paint. TCE can eventually make its way into the environment and is prevalent in the water and soil of industrialized nations. Althou...
The density of soil seed banks is normally highest at the soil surface and declines monotonically with depth. Sometimes, for a variety of reasons, peak density occurs below the surface but, except in severely disturbed soils, it is generally true that deeper seeds are older. In seasonally dry habitats that develop deep soil cracks during the dry season, it is possible that some seeds fall down ...
Coastal temperate rainforests from southeast Alaska through to southern Oregon are ecologically distinct from forests of neighboring regions, which have a drier, or more continental, climate and disturbance regimes dominated by fires. The long-term role of fire remains one of the key outstanding sources of uncertainty in the historical dynamics of the wetter and less seasonal forests that domin...
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