Microstructure Characterization of Ceramics by Fractal Geometry

1997 ◽  
Vol 492 ◽  
Author(s):  
Z. X. Xiong ◽  
K. Z. Baba-Kishi ◽  
F. G. Shin

ABSTRACTFollowing Mandelbrot's fractal theory, the irregular characteristics of the microstructural features of ferroelectric Pb(Sc0.5 Ta0.5)O3 ceramics, including grain boundaries and dislocation networks, were investigated. The microstructural features were imaged by electron microscopy. The fractal analyses were carried out manually and by image processing techniques, which show the value of the fractal dimension, D, varies according to the regularity of the microstructure. The value of, D, close to unity is an indication of an increasing degree of microstructural regularity, which is in good agreement with the simulated results.

2019 ◽  
Vol 29 (1) ◽  
pp. 1226-1234
Author(s):  
Safa Jida ◽  
Hassan Ouallal ◽  
Brahim Aksasse ◽  
Mohammed Ouanan ◽  
Mohamed El Amraoui ◽  
...  

Abstract This work intends to apprehend and emphasize the contribution of image-processing techniques and computer vision in the treatment of clay-based material known in Meknes region. One of the various characteristics used to describe clay in a qualitative manner is porosity, as it is considered one of the properties that with “kill or cure” effectiveness. For this purpose, we use scanning electron microscopy images, as they are considered the most powerful tool for characterising the quality of the microscopic pore structure of porous materials. We present various existing methods of segmentation, as we are interested only in pore regions. The results show good matching between physical estimation and Voronoi diagram-based porosity estimation.


Author(s):  
Arman Molki ◽  
Lyes Khezzar ◽  
Afshin Goharzadeh

This paper outlines a proposed experimental setup and image processing techniques using MATLAB for the characterization of the average dynamic behavior of the air/water mixture under the free surface of water penetrated by a plunging jet. The proposed setup focuses on the dynamics of air entrainment below the free surface and the identification of the major regimes related to the entrainment process of bubbles in water, namely: (a) no-entrainment, (b) incipient entrainment, (c) intermittent entrainment, and (d) continuous entrainment. The experimental setup allows students to observe the flow behavior below the free liquid surface and determine the penetration depth of the bubble plumes using image processing techniques in MATLAB. The focal point of the experiment is image analysis for qualitative and quantitative characterization of the bubble plume.


2011 ◽  
Vol 172 (1) ◽  
pp. 308-314 ◽  
Author(s):  
Ana Ferraz ◽  
Vitor Carvalho ◽  
Filomena Soares ◽  
Celina P. Leão

Author(s):  
R. Anthony Crowther

Neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, pose an increasingly severe burden for individuals and society in an ageing population. The causes and mechanisms of the diseases are poorly understood and as yet there are no effective treatments. Some of the molecular complexes involved in degeneration have been identified and electron microscopy has provided an essential tool in the investigations. The focus of this review is to show how electron microscopy has contributed historically to the understanding of disease and to summarize the most striking current advances. It does not seek to cover in detail the recent technical developments in microscopy, involving better microscopes, better electron detectors and more powerful image processing techniques, which have made possible the new insights. In many instances pathological filament assemblies are associated with brain cells that die in the disease, causing the observed symptoms such as dementia or movement disorders. Using electron microscopy it is now possible to go beyond morphological descriptions to produce atomic structures of many of the filaments. This information may help to understand the seeding and assembly of the filaments, with the aim of finding small molecule inhibitors that could potentially provide a form of treatment for the diseases.


1998 ◽  
Vol 26 ◽  
pp. 319-323 ◽  
Author(s):  
F. Sabot ◽  
M. Naaim ◽  
F. Granada ◽  
E. Suriñach ◽  
P. Planet ◽  
...  

Seismic signals of avalanches, related video images and numerical models were compared to improve the characterization of avalanche phenomena. Seismic data and video images from two artificially released avalanches were analysed to obtain more information about the origin of the signals. Image processing was used to compare the evolution of one avalanche front and the corresponding seismic signals. A numerical model was also used to simulate an avalanche flow in order to obtain mean- and maximum-velocity profiles. Prior to this, the simulated avalanche was verified using video images. The results indicate that the seismic signals recorded correspond to changes in avalanche type and path slope, interaction with obstacles and to phenomena associated with the stopping stage of the avalanche, suggesting that only part of the avalanche was recorded. These results account for the seismic signals previously obtained automatically in a wide avalanche area.


1990 ◽  
Vol 183 ◽  
Author(s):  
J. Reyes-Gasga ◽  
R. Perez ◽  
M. Jose-Yacaman

AbstractImage processing techniques applied to HREM images of decagonal quasicrystalline phases are carried out. A comparison between these processed images, simulated images based on the multislice method and density wave techniques and also experimental STM images of the decagonal phase [9] suggest some insights on their structure.


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