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Solid oxide fuel cells (SOFCs) with flat-tubular structure were successfully fabricated by ceramic wet processing. The SOFCs had three or four internal channels for fuel gas flow and were supported by the fuel electrode. The SOFCs were composed of 8 mol Y 2 O 3 -ZrO 2 (YSZ) electrolyte, Ni-YSZ fuel electrode, and La 0.8 Sr 0.2 MnO 3 air electrode. Fuel gas was uniformly supplied to fuel electrodes with fuel gas pipes made of a heat-resistant alloy. The SOFCs had an active area of 50 cm 2 and were operated to achieve a maximum power density of 0.23 W/cm 2 at 1000 °C. The effect of the fuel gas pipe on cell performance was recognized; the performance was twice as high as that of an SOFC without the fuel gas pipe. The performance of the SOFC with four channels was slightly higher than that with three channels. It also appeared that the performance of the SOFC with three channels decreased steeply with increasing fuel utilization.

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Wholly aromatic para-linked copolyamides of poly( p-phenyleneterephthalamide) have been prepared by direct polycondensation via a phosphorylation reaction using various amounts of p-aminobenzoic acid, toluene-pdiamine or nitroterephthalic acid (NTA) as comonomer. Viscosity number, perhaps degree of polymerization as well, increased with increasing comonomer content, whereas crystallinity of copolymers decreased. In particular, a bulky nitro group decreased crystallinity and the copolymers with NTA content >50 mol% were amorphous and similar to poly (p-pheneylenenitroterephthalamide). Melting point was not greatly changed by copolymerization. Thermal decomposition temperatures of copolymers containing NTA were lower than those of other copolymers by ca. 100 "C.