{"thcode":2,"term":{"code":678,"name":"magnetic hysteresis analysis","parent":860,"scope":"Nondestructive evaluation of ferromagnetic materials.  The evaluation is based on measurement of the variation of intensity of magnetization within an applied magnetic field due to changes in the magnetic domain structure of the materials under study."},"uf":[{"name":"hysteresis","usewith":false}],"bt":[{"code":860,"name":"paleomagnetic analysis","parent":619,"scope":"Determination of the intensity and direction of residual magnetism in rocks to study changes in the earth's magnetic field during past geologic time."},{"code":619,"name":"laboratory methods","parent":734,"scope":"Techniques to analyze and test samples in a place equipped and designed for the work."},{"code":734,"name":"methods","parent":1,"scope":"Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":470,"name":"geophysics","parent":291,"scope":"Branch of geology studying the physical characteristics and phenomena of the earth and its atmosphere."}]}