Quantitative characterization of degradation processes in situ by means of a bioreactor coupled flow chamber under physiological conditions using time-lapse SRµCT

Abstract. An instrumented sample holder was developed for time-lapse microtomography of snow samples to enable in situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass transport properties were evaluated during a 4-day test run. This instrument allows the experimental characterization of metamorphism of snow undergoing structural changes with time.

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The use of Rheed Intensities for the Quantitative Characterization of Surfaces

MRS Proceedings ◽

10.1557/proc-399-3 ◽

1995 ◽

Vol 399 ◽

Cited By ~ 1

Author(s):

Y. Ma ◽

S. Lordi ◽

J. A. Eades

Keyword(s):

Quantitative Characterization ◽

Important Method ◽

Stepped Surfaces ◽

Methods Of Calculation ◽

Improved Methods

ABSTRACTRHEED is an important method for the in situ characterization of surfaces. Until recently, this characterization has not used the intensities of RHEED reflections. Improved methods of calculation have made it possible to simulate RHEED patterns from bulk-terminated, reconstructed and stepped surfaces. From the comparison between simulated and experimental patterns, it is now possible to refine the positions of atoms in surfaces and to determine the density of steps on surfaces (well almost).

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Quantitative Characterization of Dislocation Structure coupled with Electromigration in a Passivated Al (0.5wt%Cu) Interconnects

MRS Proceedings ◽

10.1557/proc-766-e1.2 ◽

2003 ◽

Vol 766 ◽

Cited By ~ 1

Author(s):

R.I. Barabash ◽

N. Tamura ◽

B.C. Valek ◽

R. Spolenak ◽

J.C. Bravman ◽

...

Keyword(s):

Plastic Deformation ◽

Dislocation Structure ◽

Rotation Axis ◽

Early Stage ◽

Middle Region ◽

Quantitative Characterization ◽

X Ray ◽

Interconnect Lines

AbstractNew synchrotron x-ray microbeam methodology is used to analyze and test the reliability of interconnects. The early stage of plastic deformation induced by electromigration before any damages become visible has been recently revealed by white beam scanning X-ray microdiffraction during an accelerated test on Al interconnect lines. In the present paper, we provide a quantitative analysis of the dislocation structure generated in several micron-sized Al grains in both the middle region and ends of the interconnect line during anin-situelectromigration experiment. We demonstrate that the evolution of the dislocation structure during electromigration is highly inhomogeneous and results in the formation of randomly distributed geometrically necessary dislocations as well as geometrically necessary boundaries. The orientation of the activated slip systems and rotation axis depends on the position of the grain in the interconnect line. The origin of the observed plastic deformation is considered in view of constraints for dislocation arrangements under applied electric field during electromigration. The coupling between plastic deformation and precipitation in the Al (0.5% wt. Cu) is observed for the grains close to the anode/cathode end of the line.

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Form and function in hillslope hydrology: in situ imaging and characterization of flow-relevant structures

Hydrology and Earth System Sciences ◽

10.5194/hess-21-3749-2017 ◽

2017 ◽

Vol 21 (7) ◽

pp. 3749-3775 ◽

Cited By ~ 23

Author(s):

Conrad Jackisch ◽

Lisa Angermann ◽

Niklas Allroggen ◽

Matthias Sprenger ◽

Theresa Blume ◽

...

Keyword(s):

Soil Moisture ◽

Hydraulic Conductivity ◽

Soil Water ◽

Time Lapse ◽

Saturated Hydraulic Conductivity ◽

Form And Function ◽

And Function ◽

Hillslope Scale

Abstract. The study deals with the identification and characterization of rapid subsurface flow structures through pedo- and geo-physical measurements and irrigation experiments at the point, plot and hillslope scale. Our investigation of flow-relevant structures and hydrological responses refers to the general interplay of form and function, respectively. To obtain a holistic picture of the subsurface, a large set of different laboratory, exploratory and experimental methods was used at the different scales. For exploration these methods included drilled soil core profiles, in situ measurements of infiltration capacity and saturated hydraulic conductivity, and laboratory analyses of soil water retention and saturated hydraulic conductivity. The irrigation experiments at the plot scale were monitored through a combination of dye tracer, salt tracer, soil moisture dynamics, and 3-D time-lapse ground penetrating radar (GPR) methods. At the hillslope scale the subsurface was explored by a 3-D GPR survey. A natural storm event and an irrigation experiment were monitored by a dense network of soil moisture observations and a cascade of 2-D time-lapse GPR trenches. We show that the shift between activated and non-activated state of the flow paths is needed to distinguish structures from overall heterogeneity. Pedo-physical analyses of point-scale samples are the basis for sub-scale structure inference. At the plot and hillslope scale 3-D and 2-D time-lapse GPR applications are successfully employed as non-invasive means to image subsurface response patterns and to identify flow-relevant paths. Tracer recovery and soil water responses from irrigation experiments deliver a consistent estimate of response velocities. The combined observation of form and function under active conditions provides the means to localize and characterize the structures (this study) and the hydrological processes (companion study Angermann et al., 2017, this issue).

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On the evolution of the elastic properties of organic-rich shale upon pyrolysis-induced thermal maturation

Geophysics ◽

10.1190/geo2015-0514.1 ◽

2016 ◽

Vol 81 (3) ◽

pp. D263-D281 ◽

Cited By ~ 17

Author(s):

Adam M. Allan ◽

Anthony C. Clark ◽

Tiziana Vanorio ◽

Waruntorn Kanitpanyacharoen ◽

Hans-Rudolf Wenk

Keyword(s):

Elastic Properties ◽

Elastic Anisotropy ◽

Time Lapse ◽

Source Rocks ◽

Thermal Maturity ◽

Thermal Maturation ◽

Confining Pressures ◽

Acoustic Velocities

The evolution of the elastic properties of organic-rich shale as a function of thermal maturity remains poorly constrained. This understanding is pivotal to the characterization of source rocks and unconventional reservoirs. To better constrain the evolution of the elastic properties and microstructure of organic-rich shale, we have studied the acoustic velocities and elastic anisotropy of samples from two microstructurally different organic-rich shales before and after pyrolysis-induced thermal maturation. To more physically imitate in situ thermal maturation, we performed the pyrolysis experiments on intact core plugs under applied reservoir-magnitude confining pressures. Iterative characterization of the elastic properties of a clay-rich, laminar Barnett Shale sample documents the development of subparallel to bedding cracks by an increase in velocity sensitivity to pressure perpendicular to the bedding. These cracks, however, are not visible through time-lapse scanning electron microscope imaging, indicating either submicrometer crack apertures or predominant development within the core of the sample. At elevated confining pressures, in the absence of pore pressure, these induced cracks close, at which point, the sample is acoustically indistinguishable from the prepyrolysis sample. Conversely, a micritic Green River sample does not exhibit the formation of aligned compliant features. Rather, the sample exhibits a largely directionally independent decrease in velocity as load-bearing, pore-filling kerogen is removed from the sample. Due to the weak alignment of minerals, there is comparatively little intrinsic anisotropy; further, due to the relatively directionally independent evolution of velocity, the evolution of the anisotropy as a function of thermal maturity is not indicative of aligned compliant features. Our results have indicated that horizons of greater thermal maturity may be acoustically detectable in situ through increases in the elastic anisotropy of laminar shales or decreases in the acoustic velocities of nonlaminar shales, micritic rocks, or siltstones.

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