Contents 14 Quantitative image analysis

X-ray diffraction (XRD) results are provided in Table 111 in weight percent. Table IV provides results of Si content in volume percent from three different measurements, namely (1) calculation from density. (2) measured by XRD and converted from weight to volume percent and (3) measured by quantitative image analysis (QIA). In all cases, the amount of carbon in the starting preforms, with similar starting SIC weights, increases as the sample number increases. 

Quantitative analysis of these images is accomplished in the same manner as for any microscope image, depending on the detail of analysis desired. Automated image analysis software can be used to provide a variety of information. Crystal phase volume (solid fat content UNIT D3.i) can be obtained by counting dark pixels (according to some empirical threshold factor). 

Veltri RW, Partin AW, Epstein JE, et al. Quantitative nuclear morphometry, Markovian textrrre descriptors, and DNA content captured on a CAS-200 Image analysis system, combined with PCNA and HER-2/neu immrmohistochemistry for prediction of prostate cancer progression./Cell Biochem (Suppl). 1994 19 249. 

The C/S ratio of C-S-H in a fully reacted C3S may be calculated if CH and CO2 contents are known. Quantitative XRD is used to determine unreacted C3S. Methods such as TG, DTG, semi-isothermal DTG, thermal evolved analysis, DTA, DSC, XRD, IR spectroscopy, image analysis of back scattered electron images, and extraction methods have been applied to estimate lime. Variations in the estimated values are possible depending on the technique. In one study in which C3S paste was prepared at a W/S ratio of 0.45 and stored wet for 25 years at 25°C, the TGA results indicated that 1.15 moles of CH were formed for one mole of C3S. The calculation showed the C/S ratio of C-S-H to be 1.81. PI... 

After the image has been successfully captured, the contents of the buffer memory may be mapped onto the address space of the Unibus of a PDP11/04 minicomputer for quantitive analysis, via a group of programs (SIM-1) (7). Approaches to analysis available to us include least squares fitting (5), eigen analysis (3). and... 

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