scholarly journals Use of Advanced Imaging Techniques for the Characterization of Oily Skin

2019 ◽  
Vol 10 ◽  
Author(s):  
Patricia M. B. G. Maia Campos ◽  
Maisa O. Melo ◽  
Daiane G. Mercurio
Keyword(s):  
Imaging Techniques ◽  
Advanced Imaging

Characterization of Cement Microstructure for the Immobilization of Nuclear Waste Using Advanced Imaging Methods

2012 ◽  
Vol 1475 ◽  
Author(s):  
D.L. Engelberg ◽  
J.A. Duff ◽  
L. Murray ◽  
L. Dodds ◽  
N. Mobasher ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Pore Space ◽  
Imaging Techniques ◽  
Image Correlation ◽  
Advanced Imaging ◽  
Comprehensive Picture ◽  
X Ray Computed ◽  
Matrix Fraction ◽  
Nuclear Waste Immobilization

ABSTRACTA range of advanced imaging techniques have been brought together to provide a comprehensive picture of cement microstructure for nuclear waste immobilization. Image analysis of Nirex Reference Vault Backfill (NRVB) has been used to characterize the Calcium-Silicate-Hydrate (C-S-H) matrix fraction. Through weight loss measurements and digital image correlation of OPC-based cement blends we have quantified the development of microstructure surface strains during the initial 48 hrs hardening period. The build-up of displacements on the microstructure scale indicated grain-like compressive areas, surrounded by a network of tensile regions. Serial sectioning of NRVB using ultra-microtome cutting has been explored for advanced high-resolution 3D microstructure characterization, while X-ray Computed Tomography (XCT) has been used to obtain information of the 3-D pore space and size distribution of air pores in NRVB non-destructively.

scholarly journals Corrigendum: Use of Advanced Imaging Techniques for the Characterization of Oily Skin

2020 ◽  
Vol 11 ◽  
Author(s):  
Patricia M. B. G. Maia Campos ◽  
Maisa O. Melo ◽  
Daiane G. Mercurio
Keyword(s):  
Imaging Techniques ◽  
Advanced Imaging

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

Coherent electron nanodiffraction from clean silver nano particles in a UHV STEM

1993 ◽  
Vol 51 ◽  
pp. 1058-1059
Author(s):  
J. Liu ◽  
M. Pan ◽  
G. E. Spinnler
Keyword(s):  
Supported Catalysts ◽  
Imaging Techniques ◽  
Nano Particles ◽  
Metal Particles ◽  
Shape Structure ◽  
Dynamical Simulations ◽  
Small Metal Particles ◽  
Extract Information

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.

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