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.
The pipe thickness used on pipeline is usually less than that used in refinery piping and the pipe ends of a pipeline are machine beveled whereas pipe ends of a refinery piping joint are manually cut and beveled. These two factors play a major role in determining the opposite welding techniques.