Developable surfaces

Several techniques for VOC removal have been investigated such as thermal incineration, catalytic oxidation, condensation, absorption, bio-filtration, adsorption, and membrane separation. VOCs are present in many types of waste gases and are often removed by adsorption [1]. Activated carbon (AC) is commonly used as an adsorbent of gases and vapors because of its developed surface area and large pore volumes [2]. Modification techniques for AC have been used to increase surface adsorption and hence removal capacity, as well as to improve selectivity to organic compounds [3]. 

The first type of materials, i.e. KOH activated carbons constitute an interesting class of capacitor electrodes due to their highly developed surface area of the order of 3000 m2/g. Especially, inexpensive natural precursors are well adapted for this process. The activation process is strongly affected by the C KOH ratio, temperature and time. The optimal ratio seems to be 4 1 and the temperature for activation ca. 800°C. The total activation process is quite complicated and proceeds via different pathways and by-products. The... 

One of the main problems in the development of air gas-diffusion electrodes for metal-air cells is to find active and stable catalysts for the electrochemical reduction of oxygen. Carbon-based catalysts are mostly used, because of their highly developed surface area and capability for adsorption of 02, suitable morphology, chemical stability, good electric conductivity and comparatively low price. 

Porous zinc electrodes with highly developed surface are elaborated in this laboratory, which show extremely high discharge rate capability in wide temperature range (down to -40°C). The self-discharge of the zinc is well suppressed without the use of any unacceptable mercury and a high amper-hour capacity of these zinc electrodes is achieved. 

Strain in dents may be estimated using data from deformation in-line inspection (ILI) tools or from direct measurement of the deformation contour. Direct measurement techniques may consist of any method capable of describing the depth and shape terms needed to estimate strain. The strain estimating techniques may differ depending on the type of data available. Interpolation or other mathematical techniques may be used to develop surface contour information from ILI or direct measurement data. Although a method for estimating strain is described herein, it is not intended to preclude the use of other strain estimating techniques. See also Fig. D-l. 

Although a family of OgS - Jig8 values are allowed under Equation 7 the actual equilibrium state of the oxide/solution interface will be determined by the dissociation of the surface groups and the properties of the electrolyte or the diffuse double layer near the surface. For surfaces that develop surface charges by different mechanisms such as for semiconductor, there will be an equation of state or charge-potential relationship that is analogous to Equation 7 which characterizes the electrical response of the surface. 

The thermal properties of C3 materials at high temperatures are most remarkable if protected from oxidation. This issue is discussed below in more detail. If they are not oxidized, the C3 materials exhibit similar stability data as ceramics [22], in particular at temperatures above 1500 K where protective coatings applied behave like a plastic and close developing surface cracks against air attack. C3 materials expose the advantages of their hierarchical structure being present in both filler and binder phase and develop wood-like properties under ambient conditions. A descriptive pa-... 

Ya.B. considered that the most important adsorbents—porous coal, silica gel, and the powdered manganese dioxide which he had studied experimentally—are amorphous substances, i.e., they do not have clearly articulated crystalline structure. Only thus is it possible to obtain a large developed surface—the most important feature of an adsorbent. In this case, it is natural to consider all the possible values of adsorption activity and a smooth distribution function of surface sectors according to their level of activity. 

Hydrogen interaction with the carbon nanostructural materials (nanotubes, nanofibers, fullerenes C60 and C70 has been intensively studied over the last years. A developed surface of nanotubes and nanofibers induced a considerable applied interest aimed at hydrogen storage and reduced consumption of organic fuel in modem industry. For the academic studies, of interest is the nature of the hydrogen interaction with the carbon nanomaterials. 

The coming decade probably will be the scene of still further reliability and productivity improvements as local microprocessor instrument control and data handling become more pervasive and complex. Unlike the past decade, however, for which the ultimately developed surface analysis techniques were well recognized at the outset (JL), the coming decade may be the... 

Various surface analysis techniques show that silicate glasses rapidly develop surface compositional profiles when exposed to water. When water is present as a vapor an alkali-rich layer (presumably a hydrated alkali carbonate) forms over the SiOj-rich layer. Water as a liquid dissolves the alkali and leaves the silica-rich film. As long as this SiC -rich film is stable the rate of corrosion due to diffusion is reduced with exposure time. Addition of multi-valent species to the glass or reactant results in formation of a complex protective surface layer in the glass which may be stable over a wide range of environmental conditions. 

As mentioned earlier, there are a large variety of surface-modification techniques for achieving a desired surface architecture. Due to lack of sophisticated instrumental facilities, the researchers in the past had to compromise with techniques that were less surface-specific and offered little control over the process. However, with system automation, it is possible to develop surfaces with well-defined properties and morphologies, avoiding tedious processes. 

Fig. 6 shows how one can measure conductivity s and capacitance C of an obsidian which is expected to develop surface charges. It is unwise to directly apply the metal electrodes onto the sample because this would only lead to shortcircuiting. Instead, as shown by the detail, we insert two fused silica microscope cover glasses (0.1 mm thick). 

Here we report a technique of direct synthesis of the photocatalytically active mesoporous composites Ti02/M (M = Cu, Ni, Co, Fe, Zn, Ag etc.) via photochemical reduction of the metal cations adsorbed on highly developed surface of a mesoporous titanium dioxide. The Ti02/M composites were found to be efficient photocatalysts of hydrogen evolution from water-alcohol mixtures. 

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