Depth of visibility

Additional information can be obtained, if one calculates the smallest thickness difference Ad of sf eel - for instance the depth of a crack - which can be discerned on a radiograph whose granularity is just as high as the limiting value a, of the respective class of the standard EN 584-1. For this estimation the well known relation for the (optical) density difference AD (visible contrast) which results from a difference of thickness Ad in steel is used ... 

All three techniques probe 500 A to 1 pm or so in depth for opaque materials, depending on the penetration depth of the incident light. For transparent materials, essentially bulk properties are measured by PL and Modulation Spectroscopy. All three techniques can be performed in ambient atmosphere, since visible light is used both as incident probe and signal. 

When gas concentrations are high, burning is characterized by the presence of a tall, turbulent-diffusion, flame plume. At points where the cloud s vapor had already mixed sufficiently with air, the vertical depth of the visible burning zone is about equal to the initial, visible depth of the cloud. 

The purity and the depth of the color of phthalocyanines arise front an isolated band (Q band) in the far-red end of the visible spectrum of light near 670 nm, with a molar absorption often exceeding 10s cm2 mol-1.77 321 A second absorption (B band), near 340 nm, extending to the blue of the visible spectrum is generally much less intense. Absorption spectra of 1,4-oc-tahcxyl-substitutcd PcNi322 and 1,4-octahexyl-substituted PcH2,323 both dissolved in chloroform, are shown below. 

Clearly, unless monomer is the intended photoinitiator, it is important to choose an initiator that absorbs in a region of the UV-visible spectrum clear from the absorptions of monomer and other components of the polymerization medium. Ideally, one should choose a monochromatic light source that, is specific for the chromophorc of the photoinitiator or photosensitizer. It is also important in many experiments that the total amount of light absorbed by the sample is small. Otherwise the rate of initiation will vary with the depth of light penetration into the sample. 

Surface features can also be revealed by etching, which permits identification of points of intersection of line dislocations with the surface, and this is valuable in determining the role of these imperfections in chemical processes [45,214] and, in particular, nucleus formation. Smaller topographical details can be rendered visible by the evaporation of a thin (<0.5 nm) film of gold onto the surface [215,216]. Heights and depths of surface features can be determined by interferometry [203—205]. Microcinematography has also been used [217] to record the progress of solid phase reactions. 

In a Japanese plasma wind tunnel, SPA specimens were tested up to 3.8 MW/m2 at 0.7 bar aerodynamic pressure (Fig. 12). After a test duration of 60 s, no obvious damage was visible. The surface temperature of about 2600°C was reduced to 100°C within 20 min. Further analysis showed a maximum charred depth of the ablator of 15 mm. The carbonization process did not change the geometric dimensions, the new heat protection system can be considered absolutely stable to deformation. The carbonized layer still has a noticeable pressure resistance and transfers the load applied by the dynamic pressure to the structure. 

The GPR survey data showed a consistent zone of resistance located at 0.5-1 m below the surface for each of the five E-W transects. Stacking the graphical images of the transect data, according to their locations on the plan, reveals a tongue-shaped structure of resistance that extends southwards (down slope) at least 200 m visible on all five transects. The depth of resistance is consistent with a sub surface enrichment of calcrete. 

This aspect of the Work is called the redemption of the personality, whereby the unregenerate aspects in the depths of our unconscious are evoked to visible appearance, brought into the unifying light of consciousness, and thereby absorbed from their state of separation back into the integrated personality. Jungian psychology calls this... 

The mixture of these two types of light is what meets the eye, and the ratio of these two components affects the perceived depth of color. The higher the ratio of specular reflection, then the less the apparent color depth3. Additionally, any relatively large areas of specular reflection can generate visible points of light when oriented to reflect from point sources these cause the fibers or fabrics to glitter. 

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