Matrix. Calcifications or mineralization within a bone lesion may be an important clue in the differential diagnosis. There are two kinds of mineralization: a chondroid matrix in cartilaginous tumors like enchondromas and chondrosarcomsa and an osteoid matrix in osseus tumors like osteoid osteomas and osteosarcomas.
Oil refinery jobs will have one set of required qualifications, while other jobs may have different qualification requirements. You will need to complete a high school education in order to become a refinery operator in most cases. Once you finish high school, it is a wise decision to enroll in an associate's degree program that will train you for work as a refinery operator.
United States of America. The United States possesses the biggest refinery capacity in the world with 139 operating refineries as of January 2013. Its refinery capacity stood at 17.38 million barrels per day at the end of 2012, accounting for approximately 18.8% of the world's total refinery capacity.