Characterization of Coalbed Methane Reservoirs at Multiple Length Scales: A Cross-Section from Southeastern Ordos Basin, China

A computational characterization technique is presented for assessing the spatial heterogeneity of two reactant phases in a three-phase chemically reactive composite. This technique estimates the reaction yield on multiple microstructure length scales based on the segregation of the two reactant phases and the expected reaction stoichiometry. The result of this technique is a metric, quantifying the effectiveness of phase mixing in a particular microstructure as a function of length scale. Assuming that the proportionate mixing of reactant phases on multiple length scales will enhance reaction kinetics and the overall level of reaction completion, this tool can subsequently be used as a figure-of-merit for optimizing microstructure via appropriate processing. To illustrate this point, an example is shown where a bimodal three-phase microstructure has a higher reaction yield at every length scale when compared with a monomodal three-phase microstructure with the same constituent loading.

Download Full-text

Mechanical characterization of Ti-6Al-4V titanium alloy at multiple length scales using spherical indentation stress-strain measurements

Materials & Design ◽

10.1016/j.matdes.2016.09.016 ◽

2016 ◽

Vol 111 ◽

pp. 463-472 ◽

Cited By ~ 26

Author(s):

Jordan S. Weaver ◽

Surya R. Kalidindi

Keyword(s):

Titanium Alloy ◽

Mechanical Characterization ◽

Spherical Indentation ◽

Stress Strain ◽

Length Scales ◽

Strain Measurements ◽

Multiple Length Scales

Download Full-text

Fractal and Lacunarity Analyses: Quantitative Characterization of Hierarchical Surface Topographies

Microscopy and Microanalysis ◽

10.1017/s1431927615015561 ◽

2016 ◽

Vol 22 (1) ◽

pp. 168-177 ◽

Cited By ~ 8

Author(s):

Edwin J. Y. Ling ◽

Phillip Servio ◽

Anne-Marie Kietzig

Keyword(s):

Processing Parameters ◽

Surface Structures ◽

Quantitative Characterization ◽

Sem Images ◽

Length Scales ◽

Sem Image ◽

Multiple Length Scales ◽

Surface Topographies ◽

Lacunarity Analysis

AbstractBiomimetic hierarchical surface structures that exhibit features having multiple length scales have been used in many technological and engineering applications. Their surface topographies are most commonly analyzed using scanning electron microscopy (SEM), which only allows for qualitative visual assessments. Here we introduce fractal and lacunarity analyses as a method of characterizing the SEM images of hierarchical surface structures in a quantitative manner. Taking femtosecond laser-irradiated metals as an example, our results illustrate that, while the fractal dimension is a poor descriptor of surface complexity, lacunarity analysis can successfully quantify the spatial texture of an SEM image; this, in turn, provides a convenient means of reporting changes in surface topography with respect to changes in processing parameters. Furthermore, lacunarity plots are shown to be sensitive to the different length scales present within a hierarchical structure due to the reversal of lacunarity trends at specific magnifications where new features become resolvable. Finally, we have established a consistent method of detecting pattern sizes in an image from the oscillation of lacunarity plots. Therefore, we promote the adoption of lacunarity analysis as a powerful tool for quantitative characterization of, but not limited to, multi-scale hierarchical surface topographies.

Download Full-text

HRTEM simulation of interfacial structure in amorphous multilayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154305 ◽

1989 ◽

Vol 47 ◽

pp. 466-467

Author(s):

Margaret L. Sattler ◽

Michael A. O'Keefe

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Cross Section ◽

High Resolution Electron Microscopy ◽

Interfacial Structure ◽

Multilayer Sample ◽

Resolution Electron ◽

Multilayered Materials ◽

Simulated Images

Multilayered materials have been fabricated with such high perfection that individual layers having two atoms deep are possible. Characterization of the interfaces between these multilayers is achieved by high resolution electron microscopy and Figure 1a shows the cross-section of one type of multilayer. The production of such an image with atomically smooth interfaces depends upon certain factors which are not always reliable. For example, diffusion at the interface may produce complex interlayers which are important to the properties of the multilayers but which are difficult to observe. Similarly, anomalous conditions of imaging or of fabrication may occur which produce images having similar traits as the diffusion case above, e.g., imaging on a tilted/bent multilayer sample (Figure 1b) or deposition upon an unaligned substrate (Figure 1c). It is the purpose of this study to simulate the image of the perfect multilayer interface and to compare with simulated images having these anomalies.

Download Full-text

Physical Failure Analysis Techniques for Front-End-of-Line Defect Analysis

ISTFA 2016: Conference Proceedings from the 42nd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2016p0182 ◽

2016 ◽

Author(s):

Dirk Doyle ◽

Lawrence Benedict ◽

Fritz Christian Awitan

Keyword(s):

Cross Section ◽

Focused Ion Beam ◽

Ion Beam ◽

Gate Oxide ◽

Top Down ◽

New Techniques ◽

First Case ◽

Transmission Electron ◽

Scanning Transmission

Abstract Novel techniques to expose substrate-level defects are presented in this paper. New techniques such as inter-layer dielectric (ILD) thinning, high keV imaging, and XeF2 poly etch overflow are introduced. We describe these techniques as applied to two different defects types at FEOL. In the first case, by using ILD thinning and high keV imaging, coupled with focused ion beam (FIB) cross section and scanning transmission electron microscopy (STEM,) we were able to judge where to sample for TEM from a top down perspective while simultaneously providing the top down images giving both perspectives on the same sample. In the second case we show retention of the poly Si short after removal of CoSi2 formation on poly. Removal of the CoSi2 exposes the poly Si such that we can utilize XeF2 to remove poly without damaging gate oxide to reveal pinhole defects in the gate oxide. Overall, using these techniques have led to 1) increased chances of successfully finding the defects, 2) better characterization of the defects by having a planar view perspective and 3) reduced time in localizing defects compared to performing cross section alone.

Download Full-text