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.
Rule 49 CFR Parts 192 and 195 - Impact on Operators and Contractors. The rule places a significant compliance burden on operators and contractors. Pipeline operators and technicians must be qualified and certified as of October 28, 2002, in order to keep working in this industry. Contractors will have to have a qualified workforce that is able to perform activities for multiple operators and they must be qualified and certified under each operator's plan.