Crossed-polarized light

Polypropylene molecules repeatedly fold upon themselves to form lamellae, the sizes of which ate a function of the crystallisa tion conditions. Higher degrees of order are obtained upon formation of crystalline aggregates, or spheruHtes. The presence of a central crystallisation nucleus from which the lamellae radiate is clearly evident in these stmctures. Observations using cross-polarized light illustrates the characteristic Maltese cross model (Fig. 2b). The optical and mechanical properties ate a function of the size and number of spheruHtes and can be modified by nucleating agents. Crystallinity can also be inferred from thermal analysis (28) and density measurements (29). 

Cross-coupling reactions, alkyl, 12 835 Cross-dyeing, 9 198 Crossed cylinder test, 9 714 Crossed-immunoelectrophoresis, 9 755 Crossed-polarized light (XPL),... 

Figure 1. Optical micrograph of an as-grown crystal of Py-D3C exhibiting a characteristic truncated octahedral shape. Domains are apparent in transmitted cross-polarized light.

Figure 5. Optical micrograph of a thin section of a Py-D3C crystal in cross-polarized light. Regions A-D show in detail the parallel domain arrays.

Figure 5b. Same view as 5a except under cross-polarized light to show birefringent ingredients. The less stained walls are the most birefringent.

Figure 4.3. Bright field optical microscope images for epoxy composites containing 0.05 wt% SWNT (a), 0.05 wt% SWNT, and 2 wt% clay (c), images (b) and (d) are the same respective positions, but under cross-polarized light condition. Reprinted with permission from ref (41).

Fig. 18 Optical micrographs under cross-polarized light of (a) a pattern of CaCO discrete crystals, (b) a pattern of CaCO film, grown on patterned thin films of PHEMA-b-PMPS-b-PHEMA. Reproduced with permission from [77] Pof>escu et al., (2006) Angew Chem Int Ed 45 1762-1767. Wiley-VCH Verlag GmbH Co...

Figure 1 Common petrographic textures in peridotite xenoliths. Other textural details given in Table 1. (a) Coarse texture in cross-polarized light of garnet peridotite containing olivine (ol), orthopyroxene (opx), and garnet (gt). (b) Mosaic porphyroclastic texture in plane polarized light of garnet peridotite. Both samples are from the Torrie kimberlite. Slave Province (scale bar is 1 mm).

Figure 5. Photomicrograph of mammillary calcite in cross-polarized light. Note the closely packed comb structure of the crystals with the teeth (T) of the comb meeting the back (B) of the comb at an acute angle. White arrow indicates direction to the substrate.

Figure 2.4. Photomicrographs of various shock textures of the samples recovered after being shocked at 14.8 GPa preheated at 611°C (a), 22.6 GPa at 607 C (b), 13.1 GPa at 849 C (c), and 22.8 GPa at 863 °C (d). hi (b) and (d), plagioclases are totally converted into glass phases. Planar fractures (and PDF ) can be seen in pyroxenes in (a), (b) and (c). Widths are 220 pm. Crossed polarized light Px pyroxene PI plagioclase Pl-g plagioclase glass.

Figure 7.6. Plagioclase glass in the Asuka-881757 lunar meteorite is surrounded by radiating expansion cracks in pyroxene, (a) reflected light, (b) transmitted light, and (c) cross polarized light. The scale bar is 200 pm...

Figure 43.1. Compacted parenchymal amyloid plaque in APP transgenic mouse hippocampus. Section was stained with Congo red and viewed with cross-polarized light. Total magnification x 400.

Fig. 8.6 Desolvation of p-estradiol hemihydrate. This photomicrograph was taken at 90°C. Partially crossed polarized light.

The effect of additives on the asphaltene from the Catalytic Incorporated (Cat. Inc.) coal liquid product was studied. Asphaltene is defined as the pentane insoluble but benzene soluble part of the coal liquid. The fractionation procedure has been described in detail elsewhere(l) and is shown schematically in Figure 1. Some work was also done with A240 petroleum pitch. Elemental analysis for the Wyoming sub-bituminous coal. Cat. Inc. coal liquid product, and Cat. Inc. asphaltene and A240 petroleum pitch are shown in Table I. Measured amounts of the additive compounds to be studied were added to the Cat. Inc. asphaltene and petroleum pitch. The samples were pyrolyzed and the pyrolysis residues examined by cross polarized light microscopy. Elemental analyses of the residues were done. 

Pleochroism presence or absence weak or strong colour With transmitted crossed-polarized light ... 

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