Frequency dependence of AC magnetic susceptibility over a wide range of frequencies for analyzing grain-size distribution of magnetic particles in environmental materials

2012 ◽  
Vol 279-280 ◽  
pp. 250
Author(s):  
Kazuto Kodama
Keyword(s):  
Grain Size ◽  
Magnetic Susceptibility ◽  
Frequency Dependence ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Magnetic Particles ◽  
Ac Magnetic Susceptibility ◽  
Wide Range ◽  
Environmental Materials

scholarly journals Grain size distribution, clay mineralogy and chemistry of bottom sediments from the outer Thermaikos Gulf, Aegean Sea, Greece

2004 ◽  
Vol 5 (1) ◽  
pp. 43
Author(s):  
K.G. PEHLIVANOGLOU ◽  
G. TRONTSIOS ◽  
A. TSIRAMBIDES
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Clay Minerals ◽  
Grain Size Distribution ◽  
Bottom Sediments ◽  
Clay Mineralogy ◽  
Aegean Sea ◽  
Wide Range ◽  
Differential Settling ◽  
Interstratified Phase

The Thermaikos Gulf constitutes the NW part of the North Aegean Sea and is limited eastward from the Chalkidiki Peninsula and westward from the Pieria Prefecture. Its plateau covers an area of 3,500 km2. The mechanisms responsible for the grain size distribution into the Gulf, the clay mineralogy and the chemistry of some bottom sediments from the outer Thermaikos Gulf, are examined. Source mixing during transportation, flocculation, differential settling processes and organic matter appear to be the main mechanisms for the distribution of clay minerals in shallow waters. All grain size fractions studied present a wide range of values confirming the extreme variations of the discharged load and the variability in marine processes. Plagioclases predominate over K-feldspars, while quartz is the most abundant mineral present. In addition, micas, chlorites, amphiboles and pyroxenes exist as primary and/or accessory minerals in all samples. Among clay minerals, illite predominates over smectite and smectite over chlorite (+ kaolinite). The ordered interstratified phase of I/S, with 30-35% S layers, is present in the 2-0.25µm fraction. The randomly interstratified phase of I/S, with 50% S layers, is present in the <0.25& micro; m fraction. On average the clay mineral content of the studied samples is: 48% I, 23% S, 17% Ch (+K) and 12% others for the 2-0.25µm fraction and 50% I, 30% S and 20% Ch (+K) for the <0.25 µm fraction. All these minerals are the weathering products of the rocks from the drainage basins of the rivers flowing into the Gulf, as well as of the Neogene and Quaternary unconsolidated sediments of the surrounding coasts. The terrigenous input, the water mass circulation and, to a lesser extent, the quality of the discharged material and the differential settling of grains, control the grain size distribution within the outer Thermaikos Gulf. The chemical composition of the analysed samples is generally in agreement with their mineral composition and signifies their terrigenous origin presenting discretely clastic character.

Frequency Dependence of Complex Permeability of Polycrystalline Ferrites Based on the Realities of Microstructure

2013 ◽  
Vol 543 ◽  
pp. 507-510 ◽  
Author(s):  
Janis Jankovskis ◽  
Nikolajs Ponomarenko ◽  
Deniss Stepins
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
Frequency Dependence ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Complex Permeability ◽  
Absorption Component ◽  
Resonance Character ◽  
Explicit Relation

Complex permeability spectra of polycrystalline ferrites are analyzed on the basis of the model accounting for the effects of their grain size distribution (GSD). The model allows for explicit relation for absorption component. It shows, that by change of only one parameter (related with GSD) it is possible to turn from the relaxation to resonance character of spectrum, that spectra of ferrites, sintered at low temperature, tend to the most theoretical type - symmetrical one.

scholarly journals Quantifying grain size distribution of pedogenic magnetic particles in Chinese loess and its significance for pedogenesis

2005 ◽  
Vol 110 (B11) ◽  
Author(s):  
Qingsong Liu ◽  
José Torrent ◽  
Barbara A. Maher ◽  
Yongjae Yu ◽  
Chenglong Deng ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Magnetic Particles ◽  
Chinese Loess

scholarly journals Influence of grain size distribution on the mechanical behavior of light alloys in wide range of strain rates

2017 ◽  
Author(s):  
Vladimir A. Skripnyak ◽  
Natalia V. Skripnyak ◽  
Evgeniya G. Skripnyak ◽  
Vladimir V. Skripnyak
Keyword(s):  
Grain Size ◽  
Mechanical Behavior ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Strain Rates ◽  
Light Alloys ◽  
Wide Range

From monodisperse to polydisperse: the influence of grain size distribution on the mechanical behavior of porous synthetic rocks

2021 ◽  
Author(s):  
Lucille Carbillet ◽  
Michael Heap ◽  
Fabian Wadsworth ◽  
Patrick Baud ◽  
Thierry Reuschlé
Keyword(s):  
Grain Size ◽  
Mechanical Behavior ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Glass Beads ◽  
Size Distributions ◽  
Porous Rocks ◽  
Wide Range ◽  
Grain Size Distributions ◽  
Final Porosity

&lt;p&gt;&lt;span&gt;Sedimentary crustal porous rocks span a wide range of grain size distributions &amp;#8211; from monodisperse to highly polydisperse. The distribution of grain size depends on the location and conditions of rock formation, the chemico-physical processes at play, and is influenced by subsequent geological processes. Well-sorted granular rocks, with a grain size distribution close to monodisperse, and granular rocks with a more polydisperse grain size distribution, have repeatedly been subjected to laboratory experiments. And yet the natural variability from sample to sample and structural heterogeneity within single natural samples all conspire to prevent us from constraining the effect of grain size polydispersivity. While a few studies have focused on the influence of grain size, the control of grain size distribution on the mechanical behavior of rocks has scarcely been studied, especially in the laboratory. In this study, we address this knowledge-gap using synthetic samples prepared by sintering glass beads with controlled polydisperse grain size distributions. When heated above the glass transition temperature, the beads act as viscous droplets and sinter together. Throughout viscous sintering, a bead pack evolves from an initial granular discontinuous state into a solid connected porous state, at which the microstructural geometries and final porosity are known. Variably polydisperse individual samples were prepared by mixing glass beads with diameters of 0.2, 0.5, and 1.15 mm in various proportions, which were sintered together to a final porosity of 0.25 or 0.35. Hydrostatic and triaxial compression experiments were performed for each combination of polydispersivity. The samples were water-saturated, deformed at room temperature, and deformed under drained conditions (with a fixed pore pressure of 10 MPa). Triaxial experiments were conducted at a constant strain rate at effective pressure corresponding to the ductile (compactive) regime. Our mechanical data provide evidence that polydispersivity exerts a significant control on the compactive behavior of porous rocks. Insights into the microstructure were gained using scanning electron microscopy on thin sections prepared from samples before and after deformation. These data allow for the observation of the different deformation features, and by extension the deformation micro-mechanisms, promoted by the different type and degree of polydispersivity. Overall, our data show that, at a fixed porosity, increasing polydispersivity decreases the stress required for compactant failure.&lt;/span&gt;&lt;/p&gt;

scholarly journals Grain size distribution of pedogenic magnetic particles in Chinese loess/paleosols

2004 ◽  
Vol 31 (22) ◽  
Author(s):  
Qingsong Liu ◽  
Michael J. Jackson ◽  
Yongjae Yu ◽  
Fahu Chen ◽  
Chenglong Deng ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Magnetic Particles ◽  
Chinese Loess
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