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High-resolution X-ray spectroscopy of bright O-type stars 总被引：1，自引：0，他引：1
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An Integrated Laboratory Method to Measure and Verify Directional Hydraulic Conductivity in Fine‐to‐Medium Sandy Sediments 
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下载免费PDF全文 The constant‐head permeameter test (CHPT) is widely used in sandy samples as a standard method in the laboratory to investigate hydraulic conductivity (K). However, it neither can be used to consistently determine directional hydraulic conductivity (DHC) nor guarantee the comparability of measured K values of samples with different sizes. Therefore, this paper proposes an integrated laboratory method, called modified CHPT (MCHPT), for the efficient determination and verification of consistent DHC values in fine‐to‐medium sandy sediments, based on a new methodological framework. A precise and standardized procedure for preparing the experimental setup of MCHPT was conducted, based on the integrated experimental setup of CHPT and tracer tests. Moreover, a formula was yielded for the time‐optimized sample saturation control. In comparison with grain size‐based methods, the validity of consistent Kh and Kv values determined by MCHPT was convincing. 相似文献
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Werner Ehrmann Gerhard Schmiedl Yvonne Hamann Tanja Kuhnt 《International Journal of Earth Sciences》2007,96(4):769-780
Extensive published data sets and some new data on the clay mineral composition of surface sediments in the Aegean Sea, northeastern
Mediterranean Sea, have been compiled in order to map the distribution patterns of clay mineral assemblages and to decipher
source areas and transport paths. We distinguished six provinces, a Northwest Aegean Province, a Marmara-Dardanelles Province,
a West Turkey Province, a Southeast Aegean Province, a Kithira Province and a Central Aegean Province. The clay mineral assemblages
in the coastal and shelf areas carry the signature of the riverine sediment discharge from southeast Europe and Turkey, respectively.
The southern Aegean Sea is probably influenced by the River Nile discharge and transport of clay minerals by surface currents.
The clay minerals in the central Aegean Sea form a mixed assemblage comprising components of the other assemblages. A dispersion
and dilution of clay minerals by surface currents is obvious. 相似文献
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A hitherto unknown distal volcanic ash layer has been detected in a sediment core recovered from the southeastern Levantine Sea (Eastern Mediterranean Sea). Radiometric, stratigraphic and sedimentological data show that the tephra, here termed as S1 tephra, was deposited between 8970 and 8690 cal yr BP. The high-silica rhyolitic composition excludes an origin from any known eruptions of the Italian, Aegean or Arabian volcanic provinces but suggests a prevailing Central Anatolian provenance. We compare the S1 tephra with proximal to medial-distal tephra deposits from well-known Mediterranean ash layers and ash fall deposits from the Central Anatolian volcanic field using electron probe microanalyses on volcanic glass shards and morphological analyses on ash particles. We postulate a correlation with the Early Holocene ‘Dikkart?n’ dome eruption of Erciyes Da? volcano (Cappadocia, Turkey). So far, no tephra of the Central Anatolian volcanic province has been detected in marine sediment archives in the Eastern Mediterranean region. The occurrence of the S1 tephra in the south-eastern part of the Levantine Sea indicates a wide dispersal of pyroclastic material from Erciyes Da? more than 600 km to the south and is therefore an important tephrostratigraphical marker in sediments of the easternmost Mediterranean Sea and the adjacent hinterland. 相似文献