Cov ntxaij lim dej sib nqus yog tsim los ntawm cov khoom siv hlau nplaum muaj zog thiab cov ntxaij lim dej thaiv. Lawv muaj kaum npaug ntawm cov nplaum quab yuam ntawm cov khoom sib nqus dav dav thiab muaj peev xwm adsorbing micrometer-loj ferromagnetic pollutants nyob rau hauv ib qho instant kua ntws cuam tshuam los yog siab txaus lub xeev. Thaum ferromagnetic impurities nyob rau hauv lub hydraulic nruab nrab dhau los ntawm qhov sib txawv ntawm cov hlau rings, lawv tau adsorbed mus rau lub nplhaib hlau, yog li ua tiav cov nyhuv lim.