Abstract: The present invention addresses the problem of providing: a polycrystalline SiC molded article that has a small volume resistivity despite having a small crystal grain size; and a method for producing the same. The present invention provides a polycrystalline SiC molded body in which the average crystal grain size of 5 ?m or less, a nitrogen concentration of 2.7×1019 to 5.4×1020 (pcs./cm3), and the product of the carrier density×Hall mobility of 4.0×1020 to 6.0×1021 (pcs./cmVsec).

Abstract: A wheel for an omnidirectional moving device includes an annular core body formed by connecting joint members in an annular shape, and free rollers rotatably supported by the core body. Each of the joint members includes a shaft portion having a first end and a second end, a first connecting portion provided at the first end, and a second connecting portion provided at the second end. Each of the free rollers is rotatably supported by the shaft portion of the corresponding joint member. The first connecting portion of each of the joint members is rotatably connected to the second connecting portion of the adjacent joint member. The first end of each of the joint members abuts on the second end of the adjacent joint member so that a rotation range of the adjacent joint members is restricted. A cushioning material is provided between the first end and the second end.

Abstract: Provided is a polycrystalline SiC molded body wherein the resistivity is not more than 0.050 ?cm and, when the diffraction peak strength in a diffraction angle 2? range of 33-34° in an X-ray diffraction pattern is regarded as “A” and the diffraction peak strength of the SiC(111) plane in the X-ray diffraction pattern is regarded as “B”, then the ratio (A/B) is not more than 0.018.

Abstract: Provided is a polycrystalline SiC molded body wherein the resistivity is not more than 0.050 ?cm and, when the peak strength in a wave number range of 760-780 cm?1 in a Raman spectrum is regarded as “A” and the peak strength in a wave number range of 790-800 cm?1 in the Raman spectrum is regarded as “B”, then the peak ratio (A/B) is not more than 0.100.

Abstract: An SiC film having an excellent strength and thermal characteristics. The SiC film is prepared by a CVD process (i.e. CVD-SiC fabrication) and has a thermal conductivity along the direction of the SiC crystal growth between 100 and 300 W/m.multidot.K, and an average grain diameter of the internal structure between 4 to 12 .mu.m. It is preferred that the ratio of the thermal conductivity along the direction of the SiC crystal growth to the thermal conductivity in the perpendicular direction is in a range of 1.10 to 1.40.

Abstract: A reed type valve is operatively secured on the outer surface of the casing of an engine air filter assembly to supply the exhaust system of an engine with secondary air. The reed valve is fluidly connected to an air induction passage formed inside the casing of the air filter assembly. A resonance chamber is also formed inside of the casing and communicates through a communication passage with the air induction passage so as to attenuate a relatively low frequency component of exhaust noise transmitted through the reed valve. The air induction passage, resonance chamber and communication passage are formed as follows: ##EQU1## where, S.sub.o (cm.sup.2)=the cross-sectional area of the air induction passageS(cm.sup.2)=the cross-sectional area of the communication passagel(cm)=the length of the communication passageV(cm.sup.3)=the volume of the resonance chamberM=the number of the engine cylinders of the engine.

Abstract: A reed type valve is operatively secured on the outer surface of the casing of an engine air filter assembly to supply the exhaust system of an engine with secondary air. The reed valve is fluidly connected to an air induction passage formed interior of the casing of the air filter assembly. A resonance chamber is also formed interior of the casing and communicated through a communication passage with the air induction passage so as to attenuate a relatively low frequency component of exhaust noise transmitted through the reed valve. The air induction passage, resonance chamber and communication passage are formed as follows: ##EQU1## where, S.sub.o (cm.sup.2)=the cross-sectional area of the air induction passageS(cm.sup.2)=the cross-sectional area of the communication passagel(cm)=the length of the communication passageV(cm.sup.3)=the volume of the resonance chamberM=the number of the engine cylinders of the engine.