Micro-cratering

The laser source is a Nd YAG pulsed laser, operating at 1064 nm, which delivers about 10 mJ on the sample surface, in 8 ns. The spatial lateral resolution of the LIBS measurements corresponds to the dimensions of the micro-crater left by the laser on the sample surface. The same dimensions are also a measurement of the damage induced on the pigment. A computer-enhanced enlargement of a typical laser crater is shown in Figure 2 its diameter does not exceed 10 pm, which is practically invisible at naked eye. The reduced size of the crater also allows for a high spatial resolution of the LIBS analysis. 

The fine concave and convex structure is formed by a difference of solubility against alkali between potyester fibers and the particles uniformly dispersed in polyester fibers. The potyester fiber of fine concave and convex structure, Micro crater fiber-SN2000 , provides not only a deeper color shade,but an improvement of luster,a dissolution of glittering under direct rays(for a particular use in the artificial hair), a color brightness of printed fabrics,modifications of hand and handle of fabrics. 

Illumination generates holes within the material of PS and causes photo corrosion of PS that is much faster than that in the dark. Depending on illumination intensity and time, the pore walls in a PS can be thinned to various extents by the photo induced corrosion. This corrosion process is responsible for the etched crater between the initial surface and the surface of PS as illustrated in Figure 28. It is also responsible for the fractal structure of the micro PS formed under illumination. 

In an optical micrograph of a commercially available nitinol stent s surface examined prior to implantation, surface craters can readily be discerned. These large surface defects are on the order of 1 to 10 p.m and are probably formed secondary to surface heating during laser cutting. As mentioned above, these defects link the macro and micro scales because crevices promote electrochemical corrosion as well as mechanical instability, each of which is linked to the other. Once implanted, as the nitinol is stressed and bent, the region around the pits experiences tremendous, disproportionate strain. It is here that the titanium oxide layer can fracture and expose the underlying surface to corrosion (9). 

Meteorites vary greatly in size and so do the craters they make.This tiny crater is the result of a micro-meteor impact on lunar rock.This image, as viewed, is several hundred times the crater s actual size. JLM Visuals. Reproduced by permissKsri. 

Edges of micro-colony are raised higher than center (crater-shape). 

Figure 2 shows the next stage in the attack of bacteria on the surface (in this case by R. rhodochrous) and shows clearly the separation of the developing bacteria from the craters produced in the polymers surface by action-at-a-distance of the micro-organisms noted by other workers. 

Stachowiak G. B. and Stachowiak G. W. (2004), Wear mechanisms in baU-cratering tests with large abrasive particles . Wear, 256,600-7. (doi 10.1016/j.wear.2003.10.029) Stack M. M. and Mathew M. (2003), Micro-abrasion transitions of metaUic materials . Wear, 255,14-22. (doi 10.1016/S0043-1648(03)00204-7)... 

In A, the crater spot generated by the arc is visible, and in this region no carbon nanotubes are present, only micro-spheres deposited during the process. 

Fig. 2(a) shows the SEM micrograph wire EDM micro-grooved of stainless steel part. From the micrographs shown in Fig. 3, it is seen clearly that the craters/depressions present on SS surface have been replicated by the polymer parts, indicating a good replication quality. This suggests that the polymer flows easily on the surface when molding was performed at elevated temperatures and ambient pressures. All the four polymers of this study showed the same response. 

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