Cross sections microscopic

The cross-section microscope picture shows a microvoid in a random E-glass fiber/unsaturated polyester FRP sample manufactured with VARTM. Also note that there are two different scales of flow pathways for the resin infusion (i.e., the large flow channel between fiber tows and the small flow channel between individual fibers in a fiber tow). 

For elucidation of the role of substituents in adhesion of ceramic materials, these monomers have, thus, been evaluated in terms of adhesion strength toward calcium metaphosphate ceramic (CMP) as a new type of castable ceramic. CMP, like tooth enamel, is a calcium phosphate material derived from the glass with a basic composition of 49Ca052P205. As shown by a cross-section microscopic photograph of CMP in Fig. 1, CMP consists of both crystalline and glass phases, and the crystalline rods are oriented toward the surface. The structure is quite similar to that of tooth enamel, in which the enamel crystalline rods also grow toward the tooth surface. 

The principal fissile nuclei are listed in Table 3.1. In addition, the microscopic fission cross section, microscopic radiative capture cross section, and average number of prompt neutrons released per fission, v, are shown for each nucleus. The cross section values for U233, U235, Pu239, and Pu 241 are thermal cross sections Th232 and U238 are lOMeV values because these isotopes primarily undergo fast fission. 

Figure 5. Cross-sectional microscope images (20X) of hypothesized PpIX fluorescence in rat hippocampus. When compared to control (A), the seizure focus (B) in a rat kindling model of epilepsy shows a dramatic increase in fluorescence at 635 nm using 400 nm excitation light.

One more significant aspect of modem microscopy is the quantitative interpretation of the images in terms of the microstmcture of the object. Although most microscopes include or can be combined with powerful image processing systems, the interpretation of the contrast is still the main problem. On the other hand, reliable micromorpbological information could be easily obtained from a set of thin flat cross sections which reveal only density information, from which case accurate two- and three-dimensional numerical parameters of the internal microstmcture could be calculated. 

Considering existing microscopical techniques, one can find that non-destmctive information from the internal stmcture of an object in natural conditions can be obtained by transmission X-ray microscopy. Combination of X-ray transmission technique with tomographical reconstmction allows getting three-dimensional information about the internal microstmcture [1-3]. In this case any internal area can be reconstmcted as a set of flat cross sections which can be used to analyze the two- and three-dimensional morphological parameters [4]. For X-ray methods the contrast in the images is a mixed combination of density and compositional information. In some cases the compositional information can be separated from the density information [5]. Recently there has been a... 

A first example of application of microtomography is taken from life sciences. Here X-ray microscopy and microtomography allows to reconstruct the internal three-dimensional microstructure without any preparation and sometimes even of living objects. Fig. la shows an X-ray transmission microscopical image of bone (femoral head). Several reconstructed cross-sections are shown in Fig.lb. Fig.lc shows the three-dimensional reconstruction of this bone. 

Light J C, Ross J and Shuler K E 1969 Rate coefficients, reaction cross sections and microscopic reversibility Kinetic Processes in Gases and Piasmas ed A R Hochstim (New York Academic) pp 281-320... 

It is difficult to determine the cross-sectional area of a fiber. Direct observation and measurement of a cross section under a microscope is the most accurate method (15). This is a destmctive test that does not allow subsequent study of fiber mechanical properties, and is slow and tedious. Also, it does not take into account any variations in the cross-sectional area along the fiber length. Measurement of fiber diameters from microscopic observations of longitudinal views is somewhat easier, but the eUipticity of the cross section in certain fibers can lead to serious errors. 

Acryhc and modacryhc fibers are sold mainly as staple and tow products with small amounts of continuous filament fiber sold in Europe and Japan. Staple lengths may vary from 25 to 150 mm, depending on the end use. Eiber deniers may vary from 1.3 to 17 dtex (1.2 to 15 den) 3.2 dtex (3.0 den) is the standard form. The appearance of acryhcs under microscopical examination may differ from that of modacryhcs in two respects. Eirst, the cross sections (Eig. 1) of acryhcs are generally round, bean-shaped, or dogbone-shaped. The modacryhcs, on the other hand, vary from irregularly round to ribbon-like. The modacryhcs may also contain pigment-like particles of antimony oxide to enhance their flame-retardant properties. 

Microscopical Examination. All fibers have distinguishing features which either allow outright identification or classification iato narrower grouping for specialized analysis. Fiber cross sections are particularly usehil for identification. 

Structural Analysis. Some of the optical techniques are also used for stmctural analysis. Microscopic examinations of metallurgical cross sections or of sections through the paint layers of a painting are indeed stmctural examinations, as is ir reflectography. 

Microscopic examination of cross sections through the paint layers gives definite information regarding the paint-layer sequence in the area from which the sample was taken (31,66). This information illustrates the artist s use of underlayers and glazes, superposition of compositional elements, and changes in composition. 

ASTM D629 describes procedures for determining cross-sectional shapes for natural fibers using microscopic analysis. Cross-sectional shape of synthetic fibers also can be verified by using microscopic analysis. 

Fig. 2. A series of progressively closer (scanning electron microscope) SEM photographs of the same membrane cross section, clearly showing skin and...

Measurement of Cross Section with a Scanning Electron Microscope... 

A.STM B487, Std. Test Methodfor Measurement of Metaland Oxide Coating Thickness by Microscopical Examination of a Cross Section, American Society for... 

Close examination of these areas under a low-power microscope revealed smoothly rippled, spherical surfaces in the weld region and a chevron pattern that pointed back to the weld in the plate. Cross sections cut through the weld revealed substantial subsurface porosity and regions where oxidized surfaces prevented metallurgical bonding of the weld (Fig. 

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