Circa 500 . Cast iron was produced for the first time by the Chinese during the Zhou dynasty (1046-256 .). Prior to that, it had not been possible to raise the temperature of the ore sufficiently to melt the iron and the only available iron was wrought iron created by heating iron ore in a furnace with carbon as the reducing agent and hammering the resulting spongy iron output. Furnaces of the day could reach temperatures of about 1300°C which was enough to melt copper whose melting point is 1083°C but not enough to melt iron whose melting point is 1528°C. By a combination of the addition of phosphorus to the ore which reduced its melting point, the use of a bellows to pump air through the ore to aid the exothermic reduction process and the use of improved high temperature refractory bricks forming the walls of the furnace to withstand the heat, the Chinese were able to melt the iron and cast it into functional shapes ranging from tools and pots and pans to heavy load bearing constructional members as well as fine ornamental pieces.
Conclusion(s): The purpose of this study was to assess the differences of blood perfusion in those who scored in the upper compared to the lower quartiles of mania symptomology. Analyses denoted significant differences in blood perfusion of those with a range of mania symptom severity. Specifically, self-reported mania symptomology appears to be indicative of lower levels of blood perfusion in subcortical regions. These results indicated that SPECT analysis could potentially be useful in the neurological aspect of research on mania symptomology. Ensuing research will aim to distinguish the relationship between brain areas and their associated specific symptoms.