Abstract: A heat exchanger includes a plurality of plates bonded by transition liquid phase (TLP) bonding. Since the plates are bonded by the transition liquid phase bonding a good bonding portion may be formed reducing defects therein, thereby enabling the heat exchanger to have a high quality. In addition, since the bonding process is performed under a mild condition, it is possible to easily employ a bonding condition and more improve production efficiency.

Abstract: Provided is a process of manufacturing a bio-ceramic ball, the process including the steps of pulverizing a raw material containing 35% of coal sludge remaining after ion milling, 15% of a ceramic material consisting of quartz, 5% of peridot having evening emerald components, 4% of emerald which is a green precious stone and 41% of approximately 40 sorts of other minerals, including elvan, into less than or equal to 700 mesh, mixing the pulverized raw material with extracts containing 30% of pine leaves, 20% of mugwort, 15% of motherwort, 10% of Polygoni multiflori Radix and 25% of approximately 30 sorts of other plant medicines, and agitating in a tank, primarily heating the mixed and agitated materials in a crucible at a temperature of approximately 1300° C.