Electrical conductivity, patterns

Krisztian K, Mustonen T, Toth G, Jantunen H, Lajunen M, Soldano C, Talapatra S, Kar S, Vajtai R, Ajayan PM. (2006) Inkjet printing of electrically conductive patterns of carbon nanotubes. Small 2 1021-1025. 

Scientist of NASA Johnson Space Center (NASA Tech Briefs, 2008) demonstrated flexible, electrically conductive patterns on textile substrate for many applications including high-speed digital circuits, antennas, and RF circuits. E-textile circuits... 

NASA Tech Briefs, 2008. Making Complex Electrically Conductive Patterns on Cloth. NASA (www.techbriefs.com). 

An electrically conductive pattern film can be produced by electrochemical polymerization of thiophene or its derivatives on a gold film that can act as an electrode in a desired pattern on a changable substrate by electrochemical oxidation the gold is then dissolved to form the pattern film [156]. Printing on insulating material can be realized with a lipophilic ink on an isolating material covered with a layer of electrically conductive PT [157]. 

Graphite bisulfates are formed by heating graphite with a mixture of sulfuric and nitric acids. In the reaction, the graphite planes are partially oxidized. There is approximately one positive charge for every 24 carbon atoms, and the HS04 anions are distributed between the planes, (a) What effect is this oxidation likely to have on the electrical conductivity (b) What effect would you expect it to have on the x-ray diffraction pattern observed for this material Refer to Major Technique 3 on x-ray diffraction, which follows this set of exercises. 

The patterns of isotherms of the internal mobilities in binary systems consisting of two monovalent cations and a common anion could provide useful insight into the mechanism of electric conductance. The patterns may be classified into two types. In Fig. 2 the isotherms are schematically shown versus the mole fraction of the larger cation, Xj. 

The percolation model of adsorption response outlined in this section is based on assumption of existence of a broad spread between heights of inter-crystalline energy barriers in polycrystals. This assumption is valid for numerous polycrystalline semiconductors [145, 146] and for oxides of various metals in particular. The latter are characterized by practically stoichiometric content of surface-adjacent layers. It will be shown in the next chapter that these are these oxides that are characterized by chemisorption-caused response in their electrophysical parameters mainly generated by adsorption charging of adsorbent surface [32, 52, 155]. The availability of broad spread in heights of inter-crystalline barriers in above polycrystallites was experimentally proved by various techniques. These are direct measurements of the drop of potentials on probe contacts during mapping microcrystal pattern [145] and the studies of the value of exponential factor of ohmic electric conductivity of the material which was L/l times lower than the expected one in case of identical... 

The black lines that appear on the C-PVC plate after scanning by the laser beam were found to consist essentially of carbon and were thus expected to exhibit some electrical conductivity. Indeed, when a low voltage was applied to both ends of the laser tracks, the tiny filament turned bright red and even incandescent when a potential over 30 V was applied. This clearly shows that the laser irradiation can transform an insulating polymer like C-PVC into a conductive material. Thus, it becomes possible to write high resolution conductive patterns with this light-pencil which can be easily visualised since they appear as well contrasted black tracks. 

The major function of a bipolar plate, or simply called "plate," is to connect each cell electrically and to regulate the reactant gas (typically, hydrogen and air in a hydrogen fuel cell) or reactant liquid (typically, methanol in a DMFC) and liquid or gas coolant supply as well as reaction product removal in desired patterns. This plate must be at least electrically conductive and gas and/or liquid tightened. Considering these important functions and the larger fraction of volume, weight, and cost of the plate in a fuel cell, it is worthwhile to construct this chapter with emphasis on the current status and future trend in bipolar plate research and development, mainly for the plate materials and fabrication process. 

The very thick and electrically highly conductive weathering residuum in Australia limited the use of conventional geochemical techniques. Nevertheless, the Elura Zn-Pb-Ag massive sulfide body in New South Wales showed trace element, and conductance patterns in the A and B horizon soils over more than 100m of overburden similar to those found in Canada (Govett etal. 1984). 

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