Conducting materials

Let us consider a conductive material of conductivity o in which a long, very narrow discontinuity was machined under the examined material surface The surface examination is accomplished with a transducer with orthogonal coils, the coil parallel to the inspected surface serving as emission coil, and the coil perpendicular to the surface being the reception coil. 

Let us consider a conductive material with the conductivity a, in which have been machined relatively small discontinuities shaped like dead hole. The surface has been inspected with a transducer with orthogonal coils connected in an impedance bridge [11]. 

Anode and cathode have to be made of a conductive material, mostly metal. The insulating material must be joined vacuum-tight and stressproof with the eleetrodes. 

Two parallel plates of conducting material separated by an insulation material, called the dielectric, constitutes an electrical condenser. The two plates may be electrically charged by connecting them to a source of direct current potential. The amount of electrical energy that can be stored in this manner is called the capacitance of the condenser, and is a function of the voltage, area of the plates, thickness of the dielectric, and the characteristic property of the dielectric material called dielectric constant. 

Polysilicon. Polysihcon is used as the gate electrode material in MOS devices, as a conducting material for multilevel metallization, and as contact material for devices having shallow junctions. It is prepared by pyrolyzing silane, SiH, at 575—650°C in a low pressure reactor. The temperature of the process affects the properties of the final film. Higher process temperatures increase the deposition rate, but degrade the uniformity of the layer. Lower temperatures may improve the uniformity, but reduce the throughput to an impractical level. 

Bicomponent technology has been used to introduce functional and novelty effects other than stretch to nylon fibers. For instance, antistatic yams are made by spinning a conductive carbon-black polymer dispersion as a core with a sheath of nylon (188) and as a side-by-side configuration (189). At 0.1—1.0% implants, these conductive filaments give durable static resistance to nylon carpets without interfering with dye coloration. Conductive materials such as carbon black or metals as a sheath around a core of nylon interfere with color, especially light shades. 

Fig. 8. Geometry for float-zoning large-diameter conducting materials.

Surface Resistivity. Resistance is the measure of the conductivity of a material. Conductive materials have the abiUty to dissipate static charges. Therefore, resistance is a good measure of the abiUty of an object to dissipate a static charge. Since static electricity is primarily a surface phenomenon, the resistance along the surface of the object is of most interest. 

Most battery electrodes are porous stmctures in which an interconnected matrix of soHd particles, consisting of both nonconductive and electronically conductive materials, is filled with electrolyte. When the active mass is nonconducting, conductive materials, usually carbon or metallic powders, are added to provide electronic contact to the active mass. The soHds occupy 50% to 70% of the volume of a typical porous battery electrode. Most battery electrode stmctures do not have a well defined planar surface but have a complex surface extending throughout the volume of the porous electrode. MacroscopicaHy, the porous electrode behaves as a homogeneous unit. 

Electrodes. At least three factors need to be considered ia electrode selection as the technical development of an electroorganic reaction moves from the laboratory cell to the commercial system. First is the selection of the lowest cost form of the conductive material that both produces the desired electrode reactions and possesses stmctural iategrity. Second is the preservation of the active life of the electrodes. The final factor is the conductivity of the electrode material within the context of cell design. An ia-depth discussion of electrode materials for electroorganic synthesis as well as a detailed discussion of the influence of electrode materials on reaction path (electrocatalysis) are available (25,26). A general account of electrodes for iadustrial processes is also available (27). 

Use alternate solvent with reduced static potential Use conductive materials of construction Add antistatic agent to nonpolar solvent Check conductivity prior to feeding Use static dissipating linings if applicable... 

Static electricity Inert milling system generation both, Control/interlock with oxygen concentration in mill and con- monitoring veying equipment bond all electrically conductive components Use conductive materials of construction CCPS G-12 CCPS G-23 CCPS G-29 CCPS G-32 ISAS84.01 NFPA 654... 

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