Electrical resistivity of fabrics

As discussed in Chapter 10, a wide variety of additives is used in the polymer industry. Stabilizers, waxes, and processing aids reduce degradation of the polymer during processing and use. Dyes and pigments provide the many hues that we observe in synthetic fabrics and molded articles, such as household containers and toys. Functional additives, such as glass fibers, carbon black, and metakaolins can improve dimensional stability, modulus, conductivity, or electrical resistivity of the polymer. Fillers can reduce the cost of the final part by replacing expensive resins with inexpensive materials such as wood flour and calcium carbonate. The additives chosen will depend on the properties desired. 

The solid oxide fue( cell (SOFC) have been under development during several decades since it was discovered by Baur and Preis in 1937, In order to commercialise this high temperature (600 - 1000°C) fuel cell it is necessary to reduce the costs of fabrication and operation. Here ceria-based materials are of potential interest because doped ceria may help to decrease the internal electrical resistance of the SOFC by reducing the polarisation resistance in both the fuel and the air electrode. Further, the possibility of using less pre-treatment and lower water (steam) partial pressure in the natural gas feed due to lower susceptibility to coke formation on ceria containing fuel electrodes (anodes) may simplify the balance of plant of the fuel cell system, and fmally it is anticipated that ceria based anodes will be less sensitive to poising from fuel impurities such as sulphur. 

Some ideas and experimental results related to the effect of switching magnetic domain walls in three- and four-arm nanostructures, fabricated from ferromagnetic (Ga,Mn)As layers, are presented. Changes in electrical resistance of those structures, accompanying switching, could be used in spintronic devices. 

The product of PV for a low-density gas is said to be a thermometric property in that to each value of FV there corresponds only a single value of temperature. The ideal gas thermometer is not convenient to use. however, because of both its mechanical construction (see Fig. 1.4-3) and the manipulation required to make a measurement. Therefore, common thermometers make use of thermometric properties of other materials—for example, the single-valued relation between temperature and the specific volume of liquid mercury (Problem 1.2) or the electrical resistance of platinum wire. There are two steps in the construction of thermometers based on these other thermometric propenies first, fabrication of the device, such as sealing liquid mercury in an otherwise evacuated tube and second, the calibration of the thermometric indi-... 

Figure 9 shows data for the dependence of electrical resistance of a surface of a fabric DDA from a degree of transformation of acetate groups (C) after treatment by alkalis with a various size of cations. 

At alkaline treatment of PETP electrical resistance of filaments does not change [29], because as a result of hydrolysis on a surface of filaments we have all same PETP (Table 2). Stress load and stress elongation during alkaline treatment of a filament are reduced (Table 2), however alkali treatment considerably reduces dry dirt adherence of a fabric (Kubelka-Munk index decreases with 1.00 up to 0.6) It is ought to mark that the alkaline treatment results in considerable improvement of a fabric dye color deepness [29]. Using the data of kinetic researches, it is possible to find optimal conditions of alkaline processing of a PETP fabric [2,5.29]. That the destmction happened at the surface layer, specific tensile a keeps almost constant value ... 

The effect of mechanical stress on screen-printed sensors fabricated upon differing electrode substrates has been studied by Wang et al. [80]. The different substrates utilised within the study included Mylar, polyethylene naphthalate (PEN) and Kapton. In this instance, the bending of the electrodes to extremely small radii of curvature was determined to have minimal effect upon the electrochemical behaviour, resulting in only a small increase in the electrical resistance of the sensors. Additionally, the study determined that the electrochemical signal was not adversely impacted from cyclic bending this illustrates the robust nature of screen-printed electrodes upon flexible substrates [80],... 

Fig. 35. Surface resistance of various textile products. The electrical properties of fabrics are measured by the surface or sheet resistance and expressed in ohms/square (/2/D). Although volume resistance or volume conductance of the composite structure may be determined, these values are relatively meaningless as textiles, like foams, may contain large amounts of air.

The heat conductivity of cotton is high, and cotton fabrics feel cool to the touch. Cotton has excellent heat characteristics, and its physical properties are unchanged by heating at 120°C for moderate periods. The electrical resistivity of cotton is low at moderate relative humidities, and the fiber has low static electricity buildup characteristics. 

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