Image analysis techniques

Aspect Ratio. The aspect ratio of mica is determined with electromicroscopic image analysis techniques. 

Two general methods have evolved. One uses a stirred tank system, while the other depends on the measurement of particle size or surface area change via particle counting or image analysis techniques. 

Recently, Razumovskid441 studied the shape of drops, and satellite droplets formed by forced capillary breakup of a liquid jet. On the basis of an instability analysis, Teng et al.[442] derived a simple equation for the prediction of droplet size from the breakup of cylindrical liquid jets at low-velocities. The equation correlates droplet size to a modified Ohnesorge number, and is applicable to both liquid-in-liquid, and liquid-in-gas jets of Newtonian or non-Newtonian fluids. Yamane et al.[439] measured Sauter mean diameter, and air-entrainment characteristics of non-evaporating unsteady dense sprays by means of an image analysis technique which uses an instantaneous shadow picture of the spray and amount of injected fuel. Influences of injection pressure and ambient gas density on the Sauter mean diameter and air entrainment were investigated parametrically. An empirical equation for the Sauter mean diameter was proposed based on a dimensionless analysis of the experimental results. It was indicated that the Sauter mean diameter decreases with an increase in injection pressure and a decrease in ambient gas density. It was also shown that the air-entrainment characteristics can be predicted from the quasi-steady jet theory. 

Immiscibility of polymers in the melt is a common phenomenon, typically leading to a two-phase random morphology. If the phase separation occurs by a spinodal decomposition process, it is possible to control the kinetics in a manner that leads to multiphase polymeric materials with a variety of co-continuous structures. Common morphologies of polymer blends include droplet, fiber, lamellar (layered) and co-continuous microstructures. The distinguishing feature of co-continuous morphologies is the mutual interpenetration of the two phases and an image analysis technique using TEM has been described for co-continuous evaluation.25... 

The porosity of the sialon ceramics was determined using a combination of the water immersion method and the image analysis technique. The porosity of the rest of the materials was either obtained from the manufacturers data sheet (SiC-C and SiC-S) or quoted from literature (SN-F and SN-C) (Becher et al., 1998). 

Since image analysis techniques are not as widely used as laser diffraction techniques, the common tendency is to compare all size data back to laser diffraction... 

Liquid density and other characteristics. Profile measurements for a symmetrical sessile drop can be used to calculate its volume and hence its density if the original mass is known and there has been no significant loss due to evaporation. As for the measurement of drop profile coordinates and numerical integration by using image analysis techniques (Naidich and Grigorenko 1992). Alternatively, the... 

Parma, M. Simple Pore Geometry Characterization from Digital Image Analysis Technique, 1985, ARCO Oil Gas Co. 

The microscopic high-speed video recording method has recently been developed further and used to investigate the combustion wave microstructure in the Ti-Si and Ti-N2 systems (Mukasyan et al., 1996 Hwang et al., 1997). The location of the combustion front was estimated using image analysis techniques, and its shape and propagation were characterized quantitatively. 

This paper presents results from a study of assemblies composed of glass fibre reinforced epoxy composites. First, tests performed to produce mixed mode fracture envelopes are presented. Then results from tests on lap shear and L-stiffener specimens are given. These enabled failure mechanisms to be examined in more detail using an image analysis technique to quantify local strain fields. Finally the application of a fracture-mechanics-based analysis to predict the failure loads of top-hat stiffeners with and without implanted bond-line defects is described. Correlation between test results and predictions is reasonable, but special attention is needed to account for size effects and micro-structural variations induced by the assembly process. 

Fracture mechanics characterisation tests have been performed to determine the mixed mode fracture envelope of an epoxy bonded glass/epoxy composite. Analysis of lap shear, and L-stiffener geometries has shown that for this relatively brittle adhesive reasonable first estimations of failure loads can be obtained for both cracked and uncracked specimens. An image analysis technique has been developed which enables failure mechanisms to be... 

Table I Morphological parameters determined on digitalized SEM micrographs by using the image analysis technique.

Table 2 shows that the induction times determined by pNMR were the longest, while those determined by the image analysis technique were the shortest. Therefore, with the image analysis approach, we were able to detect some early crystallization events beyond the sensitivity of the other methods. The higher sensitivity demonstrated allowed for the detection of early crystallization events, possibly in the vicinity of the true nucleation events. 

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