Pattern film thickness-dependent phase

In compact geometries the heat transfer coefficient depends on the two-phase flow pattern (51-67). For low condensation rates, the heat transfer is gravity controlled, and the heat transfer coefficient depends on the liquid film thickness. For higher condensation rates, the heat transfer coefficient depends on the vapor shear effect, and for small passages the liquid-vapor interaction leads to high heat transfer coefficients. 

The mean size of the crystallites of linear-chain carbon films calculated from the width of their electron diffraction maximums depends on the film thickness (Table 11.1). As can be seen from Table 11.1 the mean crystal size of the films is comparable with the film thickness if that thickness is about 4.0 nm. In this case, the films become highly oriented and there are sharp reflections in their diffraction pattern (Figure 11.1(a)). If the thickness of the films increases to 16.0 nm, the orientation still takes place. In films with a thickness greater than 60 nm amorphization is observed, with the formation of inter-chain bounds. This is clearly seen by increasing the intensity of diffraction maximums corresponding to the three-dimensional amorphous carbon phase and finally by the complete disappearance of diffraction maximums corresponding to the sp phase. 

In an effervescent atomizer, pressurized gas is injected into the liquid feed to form a two-phase flow upstream the nozzle orifice [24]. As a consequence, the atomization gas occupies a significant amount of the cross sectional area and thereby reduces the thickness of the liquid film within the nozzle orifice. After emerging from the nozzle orifice, the atomization gas disrupts the liquid film as it expands [21]. From this, it is obvious that the spraying performance depends on the two-phase flow pattern inside the mixing chamber [41]. 

Thin solid films are layers that are present on a surface and have their top interface exposed to the environment Their extreme thinness in comparison with their lateral dimensions makes them systems that are infinite in two dimensions and are confined between an infinite gaseous phase and an infinite solid phase in the third one. As a result the global property of a layer is a combination of bulk and interface properties thus, one has to take into accoimt the thickness of the layer and the nature of the substrate when designing a coating for a specific application. Thin layers can be used for various purposes, depending on their surfece and/or bulk intrinsic properties. They can be dense, porous, patterned, multilayered, composite, and so on. Sol-gel films can be found in many different application domains such as optics (e.g., antireflection, self-cleaning, smart windows, and conductive transparent layers), electronics (e.g., microfabrication, low-/ , and self-assembled monolayers (SAMs)), protection (e.g., anticorrosion, anti-abrasion, and antistatic), and analysis (e.g., selective sensors). In most of these applications, the function must be identical on the whole surface of the substrate, and thus the thickness has to be controlled as much as possible and must be as uniform as possible. 

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