Microgrooves

Wayner et al. (1976) developed a simple procedure to obtain the heat transfer coefficient for the interline region of an adsorption controlled wetting film. Xu and Carey (1990) developed an analytical model to predict the heat transfer characteristics of film evaporating on a microgroove surface. 

In a similar design, DArrigo et al. [78] also used porous silicon as the DL in a fuel cell. The porous silicon was deposited by chemical vapor deposition (CVD) on top of a silicon wafer that already had microgrooves machined on it. Then, catalytic particles were deposited on top of fhe porous silicon layer. Unfortunately, no performance-related data indicating whether the cell was acceptable or not were published for fhis design. 

Now as to the microtechniques which have proved useful for infrared spectrometry, there are several types available in the literature, such as microcells for solutions (9, JO), microgrooved plates for confined films 7,11), suspended particles on a membrane filter 12,13), microspecular spectrometry (14), the various micropellet procedures 15,16,17,18,19, 20, 21, 22, 23, 24, 25), and multiple internal reflectance (5,12,15,26,27). Then, of course, there is multiple scan interference spectrometry 28) with computer storage and handling of the data. It is with this technique... 

Figure 3. Cross-sectional micrographs (a) microstructures with alternative regions of A1 and porous AI2O3 obtained after localized porous-type anodization, (b) trapezoidal metallic features obtained after chemical etching of porous AI2O3. Two while arrows show the depth of microgrooves (D) and undercut (U).

Cosse et al. showed that EF decreases as the thickness of anodized Al-0.5%Cu films increases from 3 to 10 J.m.32 Kikuchi et al. reported that EMM of Al specimens resulted in the hemispherical 20-pm-deep microgrooves.40 In this case, porous-type anodization of patterned Al substrates was isotropic. These results suggest that localized anodization becomes isotropic as the anodization process proceeds. These conclusions are consistent with those obtained with other EMM methods, which indicate that EF decreases as the depth of metal removal increases.13,17... 

Figure 4.24 SEM micrographs of osteoblasts (a type of bone cell) on the microgrooved surface of calcium phosphate.

The surface relief can be approximated with a series of microgrooves of depth H and width d H= (d/2)tan y, where % is the angle between idealized flat surface and a side wall of the groove. If the surface is rough, the real surface area, Srea, is greater than that of the idealized surface, 5 idea. The ratio of the real surface area to the area of its projection onto an idealized flat surface is referred to as the coefficient of roughness, kr [27] ... 

Microgroove - A small groove scribed into the surface of a solar photovoltaic cell which is filled with metal for contacts. 

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