Microstructure analysis

Microstructural analysis revealed branched cracks running across the metal grains (transgranular) originating on the external surface. 

Atomic structure and Microstructural analysis of solid materials, providing high lateral resolution... 

The first detailed book to describe the practice and theory of stereology was assembled by two Americans, DeHoff and Rhines (1968) both these men were famous practitioners in their day. There has been a steady stream of books since then a fine, concise and very clear overview is that by Exner (1996). In the last few years, a specialised form of microstructural analysis, entirely dependent on computerised image analysis, has emerged - fractal analysis, a form of measurement of roughness in two or three dimensions. Most of the voluminous literature of fractals, initiated by a mathematician, Benoit Mandelbrot at IBM, is irrelevant to materials science, but there is a sub-parepisteme of fractal analysis which relates the fractal dimension to fracture toughness one example of this has been analysed, together with an explanation of the meaning of fractal dimension , by Cahn (1989). 

D. Balzar, in R. Snyder, J. Fiala, H. J. Bunge (eds.) Defects and Microstructural Analysis by Diffraction, lUCr/Oxford University Press, Oxford, 1999, 94. 

With MAO activation, Zr- and Hf-FI catalysts 1 and 3 exhibit fairly high reactivity toward propylene and produce propylene oligomers [64, 65], Conversely, the corresponding Ti-FI catalyst/MAO 2 forms semicrystalline PP (1 °C polymerization), which displays a peak melting temperature of 97 °C, indicative of the formation of a stereoregular polymer. To our surprise, microstructural analysis by 13C NMR indicates that the resultant polymer is syndiotactic (rr 19%), and that a chain-end control mechanism is responsible for the observed stereocontrol, regardless of the C2 symmetric catalyst ([28] for the first report on syndiospecific propylene... 

C2-symmetric species, which can produce isotactoid and isotactic polymers, are obtainable by occupation of one and two vicinal positions.123 An easy switch between these three polymerization modes has recently been proposed on the basis of a high-resolution 13C NMR microstructural analysis.119d... 

This research was supported by NSERC Discovery Grant s 214602-312584 and 220302-217290 to the second and third authors, with contributions from the Acadia Centre for Microstructural Analysis in the K.C. Irving Environmental Science Centre at Acadia University, and via logistical support and access from Acadian Mining Corporation. 

Bouehon, R, Aguilera, J. M. (2001). Microstructural analysis of frying potatoes. International Journal of Food Science and Technology, 36, 669-676. 

Thomas, L. E., Beyer, C. E. Charlot, L. A. 1992. Microstructural analysis of LWR spent fuels at high bumup. Journal of Nuclear Materials, 188, 80-89. 

The relative content of the three kinds of dyad in a polymer sample can be determined by measuring the peak area ratios of the three kinds of quartets in the H-NMR spectrum taken at 100 MHz in benzene-d6 solution at 70° C. Accuracy of the analysis could be raised to +1-2% by using the data of chemical shifts and coupling constants determined at 220 MHz. Thus, the microstructure analysis by H-NMR spectrum can be used for routine work, because propylene oxide-a-d can be prepared easily. 

Another example is illustrated in the relationship between the specific rotation and the microstructure of polypropylene oxide reported by Price. Optically active propylene oxide and racemic propylene oxide-a-d were polymerized under otherwise identical conditions by the freeze-dried ZnEt2-H20 (1 0.7) catalyst system containing varying amounts of ZnEt2. A linear relationship was observed between specific rotation of the former polymer and the tail-to-tail dyad content of the latter (Fig. 14). This result proves quantitatively that the decrease in the specific rotation of polymer prepared by several catalysts is due to the presence of head-to-head and tail-to-tail linkages, and also provides supporting evidence for our microstructure analysis. 

The method of microstructure analysis with the a-deuterated derivative was successfully applied to poly-tertiarybutylethylene oxide-a-d ((53), but could not be applied to polystyrene oxide due to overlapping of absorption bands (64). 

Rigorously purified EtZnNBu ZnEt alone has practically no catalytic activity for purified propylene oxide and requires a cocatalyst, for example, water, for acquiring catalytic activity. In what manner does the added water affect the rate and stereospecificity of polymerization and the microstructure of polymer The microstructure analysis method by H-NMR techniques was expected to give a relevant answer to this question. 

Oguni.N, Lee,K., Tani,H. Microstructure analysis of polypropylene oxide by 13C-nmr spectroscopy. Macromolecules, in press. 

J. H. Richardson, Sample preparation methods for microstructure analysis, in... 

J. C. McCall and W. M. Mueller, eds., Microstructural Analysis Tools and Techniques, Plenum Press, New York, 1974. 

Now that the top-down internal state variable theory was established, the bottom-up simulations and experiments were required. At the atomic scale (nanometers), simulations were performed using Modified Embedded Atom Method, (MEAM) Baskes [176], potentials based upon interfacial atomistics of Baskes et al. [177] to determine the conditions when silicon fracture would occur versus silicon-interface debonding [156]. Atomistic simulations showed that a material with a pristine interface would incur interface debonding before silicon fracture. However, if a sufficient number of defects were present within the silicon, it would fracture before the interface would debond. Microstructural analysis of larger scale interrupted strain tests under tension revealed that both silicon fracture and debonding of the silicon-aluminum interface in the eutectic region would occur [290, 291]. 

Verbrugge M, Liu P. Microstructural analysis and mathematical modeling of electric double-layer supercapacitors. Journal of the Electrochemical Society 2005 152(5) D79-D87. 

Microstructure analysis Cancer cell identification and differentiation... 

From the above discussion, values of 8, a and D can be manipulated by changing processing conditions or chemical composition. This is demonstrated in the cooling rate case study at the end of this chapter. In this example, the microstructural analysis discussed is used successfully to... 

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