scholarly journals Methodology and potential of image analysis and unconventional use of GIS tools in determining grain size distribution and fractal dimension: a case study of fault rocks in the Western Tatra Mts. (Western Carpathians, Poland)

2019 ◽  
Vol 63 (2) ◽  
Author(s):  
Maciej KANIA
Keyword(s):  
Grain Size ◽  
Image Analysis ◽  
Fractal Dimension ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Western Carpathians ◽  
Fault Rocks ◽  
Gis Tools ◽  
Tatra Mts

scholarly journals A laboratory study of sediment deformation: stress heterogeneity and grain-size evolution

1996 ◽  
Vol 22 ◽  
pp. 167-175 ◽  
Author(s):  
Neal R. Iverson ◽  
Thomas S. Hooyer ◽  
Roger Leb. Hooke
Keyword(s):  
Grain Size ◽  
Fractal Dimension ◽  
Normal Stress ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Local Stress ◽  
Large Strains ◽  
Self Similar ◽  
Deformation Stress ◽  
Stress Heterogeneity

In shearing sediment beneath glaciers, networks of grains may transiently support shear and normal stresses that are larger than spatial averages. Consistent with studies of fault-gouge genesis, we hypothesize that crushing of grains in such networks is responsible for surrounding larger grains with smaller grains. At sufficiently large strains, this should minimize stress heterogeneity, favor intergranular sliding and abrasion rather than crushing, and result in a self-similar grain-size distribution.This hypothesis is tested with a ring-shear device that slowly shears a large annular sediment sample to high strains. Shearing and comminution of weak equigranular (2.0–3.3 mm) sediment resulted in a self-similar grain-size distribution with a fractal dimension that increased with shear strain toward a steady value of 2.85. This value is significantly larger than that of gouges produced purely by crushing, 2.6, but it is comparable to values for tilts thought to be deforming beneath modern glaciers, 2.8 to nearly 3.0. At low strains, under a steady mean normal stress of 84 kPa, variations in normal stress measured locally ranged in amplitude from 50 to 300 kPa with wavelengths that were 100 times larger than the initial grain diameter. Crushing of grains, observed through the transparent walls of the device, apparently caused the failure of grain networks. At shearing displacements ranging from 0.7 to 1.0 m, the amplitude of local stress fluctuations decreased abruptly. This change is attributed to fine sediment that distributed stresses more uniformly and caused grain networks to fail primarily by intergranular sliding rather than by crushing of grains. Sliding between grains apparently produced silt by abrasion and resulted in a fractal dimension that was higher than if there had been only crushing.A size distribution with a fractal dimension greater than 2.6 is probably a necessary but not sufficient condition for determining whether a basal till has been highly deformed. Stress heterogeneity in subglacial sediment that is shearing through its full thickness should contribute to the erosion of underlying rock.

Influence of SiO2 Content on Fractal of Grain Distribution in Low Silicon Sinter

2011 ◽  
Vol 391-392 ◽  
pp. 269-273
Author(s):  
Qing Jun Zhang ◽  
Li Mei Jiang ◽  
Wen Ling Mo ◽  
Yu Zhu Zhang
Keyword(s):  
Grain Size ◽  
Fractal Dimension ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Fractal Theory ◽  
Fractal Characteristic ◽  
Important Index ◽  
Grain Distribution

Grain size distribution in the sinter is an important index sign to measure the quality of sinter. In this paper, according to the fractal theory and the contrast experiment of sinter, the fractal characteristic of grain size distribution of sinter with low SiO2is discussed. The relation between the fractal dimension and content of SiO2is proposed. Combine with the SEM graphs of the sinter with low SiO2, the relation between the fractal dimension and microstructure of sinter with low SiO2is also analyzed. Pass to the quantificational description of the grain size distribution of sinter with low SiO2, to predict and optimize the grain size constitution of sinter, and offer a new idea, a new way for the further thorough research of sinter ore.

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