Abstract: A carbon fiber-reinforced carbon composite material, wherein carbon fibers are oriented substantially in the thickness direction, the ratio of the thermal conductivity in the thickness direction to the thermal conductivity in a direction perpendicular to the thickness direction is at least 2, and the thermal conductivity in the thickness direction is at least 3 W/cm.multidot..degree.C.

Abstract: A grid structure is presented in which grid cells are formed by orthogonally intersecting straps prefitted in the longitudinal direction with a plurality of slitted spring frame members. Therefore, when the straps are assembled, the spring frame members are also orthogonally intersected. The spring frame members are made of Inconel and provided with welding tabs while the straps are made of zircalloy and provided with their own welding tabs. Therefore, welding can be performed to firmly join the spring frame members to each other while the straps can also be welded firmly to weld the like metals. The spring sections are thus firmly joined and attached to the straps which are firmly joined. The grid of this configuration thus provides an excellent service life without the losing The fuel rod retaining power, which would result from neutron radiation and thermal damages on holding devices made of zircalloy.

Abstract: A fuzzy controller is provided which enables even an unskilled operator to easily adjust various conditions in a glass pipe sealing process. The fuzzy controller has a fuzzy control processor including an image processing unit for processing and calculating image information as a softened state change value of the glass pipe and a combustion state value of burner flame, and a fuzzy control processing unit for calculating and outputting, by receiving a result of this calculation, a suitable control value for controlling parameters relating to the burner flame by fuzzy inference. The fuzzy controller may further has a fuzzy diagnosis support processor which, if there is an abnormality in the sealed portion of the glass pipe and if the state of the glass pipe after sealing is input to the manipulation instruction data input support processor by the operator, automatically ascertains the cause of the abnormality by using fuzzy inference and displays it on a CRT.