Geologic materials and hydrogeologic characteristics in the Fire Lakes-Eklutna area, Anchorage, Alaska

1983 ◽  
Author(s):  
Henry R. Schmoll ◽  
Richard P. Emanuel
Keyword(s):  
Geologic Materials

A method to measure pores and fissures in geologic materials under S.E.M. by digital image processing

1978 ◽  
Vol 36 (1) ◽  
pp. 212-213
Author(s):  
L. Montoto ◽  
M. Montoto ◽  
A. Bel-Lan
Keyword(s):  
Image Processing ◽  
Optical Microscopy ◽  
Digital Image Processing ◽  
Digital Image ◽  
Digital Processing ◽  
Free Surfaces ◽  
Geologic Materials ◽  
Automatic Information ◽  
Detector Output ◽  
Rock Specimens

INTRODUCTION.- The physical properties of rock masses are greatly influenced by their internal discontinuities, like pores and fissures. So, these need to be measured as a basis for interpretation. To avoid the basic difficulties of measurement under optical microscopy and analogic image systems, the authors use S.E.M. and multiband digital image processing. In S.E.M., analog signal processing has been used to further image enhancement (1), but automatic information extraction can be achieved by simple digital processing of S.E.M. images (2). The use of multiband image would overcome difficulties such as artifacts introduced by the relative positions of sample and detector or the typicals encountered in optical microscopy.DIGITAL IMAGE PROCESSING.- The studied rock specimens were in the form of flat deformation-free surfaces observed under a Phillips SEM model 500. The SEM detector output signal was recorded in picture form in b&w negatives and digitized using a Perkin Elmer 1010 MP flat microdensitometer.

SURFICIAL GEOLOGIC MATERIALS AND INTERPRETATIONS IN THE LITTLE RIVER VALLEY, NORTHERN VERMONT

2018 ◽  
Author(s):  
Katelyn A. Czyzyk ◽  
◽  
Amanda M. Rossi ◽  
Justin P. Sarkis ◽  
Stephen F. Wright
Keyword(s):  
River Valley ◽  
Geologic Materials

Physicochemical Gas–Solid Sorption Properties of Geologic Materials Using Inverse Gas Chromatography

Langmuir ◽  
2021 ◽  
Author(s):  
Elizabeth H. Denis ◽  
Carlos G. Fraga ◽  
Nicholas L. Huggett ◽  
William C. Weaver ◽  
Lydia A. Rush ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Inverse Gas Chromatography ◽  
Sorption Properties ◽  
Geologic Materials

Comparison of two micro-analytical methods for detecting the spatial distribution of sorbed Pu on geologic materials

2001 ◽  
Vol 47 (2-4) ◽  
pp. 211-218 ◽  
Author(s):  
M.C. Duff ◽  
D.B. Hunter ◽  
I.R. Triay ◽  
P.M. Bertsch ◽  
J. Kitten ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Analytical Methods ◽  
Geologic Materials

Effects of material texture and packing density on the interfacial polarization of granular soils

Geophysics ◽  
2021 ◽  
pp. 1-58
Author(s):  
Hang Chen ◽  
Qifei Niu
Keyword(s):  
Electrical Conductivity ◽  
Packing Density ◽  
Characteristic Frequency ◽  
Effective Permittivity ◽  
Scale Up ◽  
Interfacial Polarization ◽  
Granular Soils ◽  
Geologic Materials ◽  
Effective Electrical Conductivity ◽  
Material Texture

Many electrical and electromagnetic (EM) methods operate at MHz frequencies, at which the interfacial polarization occurring at the solid-liquid interface in geologic materials may dominate the electrical signals. To correctly interpret electrical/EM measurements, it is therefore critical to understand how the interfacial polarization influences the effective electrical conductivity and permittivity spectra of geologic materials. We have used pore-scale simulation to study the role of material texture and packing in interfacial polarization in water-saturated granular soils. Synthetic samples with varying material textures and packing densities are prepared with the discrete element method. The effective electrical conductivity and permittivity spectra of these samples are determined by numerically solving the Laplace equation in a representative elementary volume of the samples. The numerical results indicate that the effective permittivity of granular soils increases as the frequency decreases due to the polarizability enhancement from the interfacial polarization. The induced permittivity increment is mainly influenced by the packing state of the samples, increasing with the packing density. Material textures such as the grain shape and size distribution may also affect the permittivity increment, but their effects are less significant. The frequency characterizing the interfacial polarization (i.e., the characteristic frequency) is mainly related to the electrical contrast of the solid and water phases. The model based on the traditional differential effective medium (DEM) theory significantly underestimates the permittivity increment by a factor of more than two and overestimates the characteristic frequency by approximately 1 MHz. These inaccurate predictions are due to the fact that the electrical interactions between neighboring grains are not considered in the DEM theory. A simple empirical equation is suggested to scale up the theoretical depolarization factor of grains entering the DEM theory to account for the interaction of neighboring grains in granular soils.

scholarly journals Microanalysis of Geologic Materials Exposed to Surface Conditions on the Planet Venus

2017 ◽  
Vol 23 (S1) ◽  
pp. 2188-2189
Author(s):  
Brandon G. Radoman-Shaw ◽  
Ralph P. Harvey ◽  
Gustavo C. C. Costa ◽  
Nathan S. Jacobson ◽  
Amir Avishai ◽  
...  
Keyword(s):  
Surface Conditions ◽  
Geologic Materials
Sign in / Sign up

Export Citation Format

Share Document