Layer properties

Brown Kraft paper is generally used on mineral wool products to give added tensile strength, ease handling, aid positive location between studs or rafters, or prevent contamination when used under concrete screeds. Paper is often laminated with polyethylene to give vapor control layer properties. 

The behavior of the Hg/pc interface is very similar to the Hg/DMF interface 294,301,310 It can be qualitatively described by a multistate model.291 However, although the model can reproduce the electric field and temperature dependencies of the inner-layer properties, the shortcomings of the approach should not be overlooked. 1... 

The temperature dependence of the inner-layer properties has been studied by Vaartnou etal.m m over a wide interval, -0.15°C < T< 50°C. The inner-layer integral capacitance Kh a curves have been simulated using the Parsons308 and Damaskin672,673 models. The experimental Kj, T dependence has a minimum at T = 20°C. The influence of the potential drop in the metal phase has been taken into account. 

Hamelin, A. Double-Layer Properties at sp and sd Metal Single-Crystal Electrodes 16... 

Lead, electrical double layer properties, tabulated, 96... 

Non-situ and ex situ studies can provide important information for understanding the properties of metal/electrolyte interfaces. The applicability of these methods for fundamental studies of electrochemistry seems to be firmly established. The main differences between common electrochemical and UHV experiments are the temperature gap (ca. 300 vs. 150 K) and the difference in electrolyte concentration (very high concentrations in UHV experiments). In this respect, experimental research on double-layer properties in frozen electrolytes can be treated as a link between in situ experiments. The measurements of the work functions... 

Thermodynamic discussions of surface-layer properties rely on the assumption of adsorption equilibrium (i.e., on the assumption that for each component the chemical potential in the surface layer is equal to that in the bulk phase, = [ip). When... 

Catalyst layer architecture As a consequence of the diminishing remrns from ever higher dispersion, the effort to increase the active catalyst surface area per unit mass of Pt has centered in recent years primarily on optimization of catalyst layer properties, aiming to maximize catalyst utilization in fuel cell electrodes based on Pt catalyst particle sizes of 2-5 nm. High catalyst utilization is conditioned on access to the largest possible percentage of the total catalyst surface area embedded in a catalyst... 

Oedegaard A, Hebling C, Schmitz A, Mpller-Holst S, Tunold R. 2004. Influence of diffusion layer properties on low temperature DMFC. J Power Sources 127 187-196. 

Although it was elear that separation of an interface into surface and bulk components as in Eq, (19) is artifieial and must disappear in a consistent microscopic analysis, electronic effects were initially diseussed in terms of a compact layer and its capacitance C, It was apparent early on that the eleetrons strongly influence double layer properties [28-33],... 

The heat transfer efficiency is significantly affected by the slag layer properties and behavior therefore, those factors other than slag phenomena that affect HTE are presented in Table 5. As for the PCR, it is desirable to keep the HTE as high as possible. An increase in HTE at the same PCR decreases fuel consumption (Fruehan et al., 1989 Keogh et al.,... 

Many of the processes that are familiar from ordinary electrochemistry have an analog at ITIES so these form a wide field of study. We limit ourselves to a brief introduction into a few important topics thermodynamics, double-layer properties, and charge-transfer reactions. Further details can be found in several good review articles... 

When we discussed the double-layer properties of metal electrodes in contact with an electrolyte solution, we introduced the notion of an ideally polarizable interface, which is marked by the absence of charge-... 

Davis, J. A., James, R. O. and Leckie, J. O. (1978). Surface ionization and complexation at the oxide/water interface. I. Computation of electrical double layer properties in simple electrolytes, J. Coll. Inter/. Sci., 63, 480-499. 

Fig. 4.16 provides an illustration of the adsorption of a neutral polymer, polyvinyl alcohol, on a polar surface, and the resulting effects on the double layer properties. Adsorption of anionic polymers on negative surfaces - especially in the presence of Ca2+ or Mg2+ which may act as coordinating links between the surface and functional groups of the polymer - is not uncommon (Tipping and Cooke, 1982). 

Harding, I. H., and T. W. Healy (1985), "Electrical Double Layer Properties of Amphoteric Polymer Latex Colloids", J. Coll. Interf. Sd. 107, 382-397. 

What is the likely future use of MC and MD techniques for studying interfacial systems Several promising approaches are possible. Continued investigation of double layer properties, "hydration forces", "hydrophobic effects", and "structured water" are clearly awaiting the development of improved models for water-water, solute-water, surface-water, and surface-solute potentials. 

From the preceding contributions in this volume it is evident that the techniques of modelling the electrical double layer properties at the oxide/electrolyte interface have been well developed (2, 11). However, the problem still contains a certain amount of " art form in the sense that there is more than one school of thought as to how the various modelling techniques should be applied. 

Since the metal can be treated as a nearly perfect conductor, C is high compared with C, and cannot influence the value of the measured doublelayer capacitance. The role of the metal in the double layer structure was discussed by Rice, who suggested that the distribution of electrons inside the metal decides the properties of the double-layer. This concept was later used to describe double-layer properties at the semiconductor/electrolyte interface. As shown later, the electron density on the metal side of the interface can be changed under the influence of charged solution species (dipoles, ions). ... 

Electrical and thermal conductivity are important diffusion layer properties that affect the fuel cell s overall performance. The maferial chosen to be the DL in a fuel cell must have a good electrical conductivity in order for the electron flow from the FF plates to the CLs (and vice versa) to have the least possible resistance. Similarly, the DL material must have good thermal properties so that heat generated in the active zones can be removed efficiently. Therefore, in order to choose an optimal material it is critical to be able to measure the electrical and thermal conductivity. In this section, a number of procedures used fo measure fhese paramefers will be discussed. 

J. P. Owejan, T. A. Trabold, D. L. Jacobson, M. Arif, and S. G. Kandlikar. Effects of flow field and diffusion layer properties on water accumulation in a PEM fuel cell. International Journal of Hydrogen Energy 32 (2007) 4489-4502. 

S. Escribano, J. P. Blachot, J. Etheve, A. Morin, and R. Mosdale. Characterization of PEMFCs gas diffusion layers properties. Journal of Power Sources 156 (2006) 8-13. 

Most of the other novel PV technologies suggested so far can be categorized as high-efficiency approaches, which can be divided between approaches that modify and tailor the properties of the active layer to match it better to the solar spectrum versus approaches that modify the incoming solar spectrum and are applied at the periphery of the active device (without fundamentally modifying the active layer properties). 

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