Calamine brass Calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even though the alloyed calamine brass was in use for centuries, and metallic zinc was produced directly via reducing-atmosphere smelting in India and China from the 12th century CE onwards. Brass is an alloy of copper and zinc and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists wishing to produce brass thus used calamine (actually
Average variance extracted Average variance extracted In statistics (classical test theory), average variance extracted (AVE) is a measure of the amount of variance that is captured by a construct in relation to the amount of variance due to measurement error. The average variance extracted was first proposed by Fornell & Larcker (1981). The average variance extracted can be calculated as follows: Here, formula_2 is the number of items, formula_3 the factor loading of item formula_4 and formula_5 the variance of the error of item formula_4. The average variance extracted has often been used to assess discriminant validity based on the following "rule of