Atmosphere water vapor

Sihcon dioxide layers can be formed using any of several techniques, including thermal oxidation of siUcon, wet anodization, CVD, or plasma oxidation. Thermal oxidation is the dominant procedure used in IC fabrication. The oxidation process selected depends on the thickness and properties of the desired oxide layer. Thin oxides are formed in dry oxygen, whereas thick (>0.5 jim) oxide layers are formed in a water vapor atmosphere (13). 

A model describing moisture sorption for a deliquescent solid in a pure water vapor atmosphere is developed in this section. Under such conditions there is no... 

The solutions for moisture uptake presented in this section are based on the experimental condition of a pure water vapor atmosphere. In the next section a derivation of moisture uptake equations is based on both heat and mass transport that are characteristic of moisture uptake in air. The final section of this chapter presents the results of studies where heat transport is unimportant and mass transport dominates the process. Thus, we will have a collection of solutions covering models that are (1) heat transport limited, (2) mass transport limited, (3) heat and mass transport limited, and (4) mass transport limited with a moving boundary for the uptake of water by water-soluble substances. 

Oxygen vacancies could play the same role in a water vapor atmosphere giving rise to the following equilibrium ... 

This procedure can be succeeded by the ultrastabilization process, which is one of the basic operations in the industrial production of acid catalysts, consisting of a controlled dealumination process produced by thermal treatment in a water vapor atmosphere, which increases the thermal stability of the zeolite. 

Fig. 4.11. Left (a) Optical microscope image of an OLED working at a luminance of 100 cd/m2 under water vapor atmosphere. Non-emitting dark spots can be seen clearly, (b) SEM image of the bubbles formed on the aluminum cathode in the dark spot area, (c) Correlation between dark spot growths (taken from the increase in diameter) and total current density [110]. Right (a) Shown here is the random pattern of carbonized areas on the surface of the cathode after operation, shown in wide field, (b) At higher resolution, the structure of one of these areas becomes more apparent, (c) and (d) show nanoscale views of carbonized areas with the extrusion of the polymer through the cathode and the resulting void underneath [111].

Sn-doped In203 (ITO) is the most widely used transparent conducting oxide (TCO) material. This can be satisfactorily prepared by pyrolitic oxidation of a mixture of ln(dpm)3 and Sn(n-Bu)2(OAc)2 at 550 °C in a oxygen-nitrogen or nitrogen saturated with water vapor atmosphere," 6 [Equation (3.1.3) dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate ]. 

Inamdar, A. K. and Ramanathan, V. (1998). Tropical and global scale interactions among water vapor, atmospheric greenhouse effect, and surkice temperature.7 GVop/iys. Res. 103(D24), 32177-32194. 

Although most hydrates exhibit a whole-number-ratio stoichiometry, an unusual case is the metastable hydrate of caffeine, which contains only 0.8 moles of water per mole of caffeine. Only in a saturated water vapor atmosphere will additional amounts of water be adsorbed at the surface of the 4/5-hydrate to yield a 5/6 hydrate [59]. 

J. F. Cullinan, The oxidation of carbon-carbon composites between 300 °C and 900 °C in oxygen and oxygen/water vapor atmospheres , M.S. Thesis, University of Pittsburgh, Pittsburgh, PA, 1989. 

We can also see from the data presented in Fig. IV.9 that, as the particle size is reduced, the difference between the adhesive forces obtained in a water vapor atmosphere and in a carbon tetrachloride (or acetone) vapor atmosphere becomes less pronounced since the absolute magnitude of the adhesive force increases with decreasing size, and the realtive magnitude of the capillary forces decreases. 

Fig. 3.49. Thickness of a crystalline surface layer in dependence of tempering time for different treatments (A) untreated, (B) coated with Ti02, (C) tempered in a water vapor atmosphere...

On the other hand, we consider that low CO2 pressure and high water vapor pressure cause the formation of hydroxide from carbonate. During this process, so-called Hedvall effect would accelerate the reaction. In order to solve this problem, the experiments are preferred to be performed in pure water vapor atmosphere. However, the vapor pressure of water was not precisely described in the literatures cited above. Chen et al. [8] generated the water vapor witii bubbling and supplied it to the horizontal tubular furnace using a carrier gas. This procedure seems to be generally used in this kind of experiments [9-11]. It seemed that the water vapor with less than 1 atm of partial pressure was supplied to the furnace. Therefore, we developed the apparatus for the experiments under I atm of pure water vapor. In this study, the thermal decomposition of CaC03 and... 

Experimental apparatus. Fig. 1 shows the experimental apparatus of a vertical electric furnace with a silica tube and a conical flask for the generation of water vapor. The double distilled water in the flask was boiled by a heater to feed the water vapor into the silica tube with temperature of 100 °C and pressure of 1 atm. The superheated steam atmosphere in the silica glass tube was achieved. The sample was put in a silica glass cup, which was then set at the center of the furnace using inner silica tube. The sample was heated under the superheated stream with 1 atm. For comparison, the reaction was also performed in air and in Ar gas Reaction under water vapor atmosphere. Reagent grade CaCOs,... 

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