Effective mass (solid-state physics) from both sides gives where is the th element of , is the th element of , and are the th and th elements of , respectively, and is the total energy of the particle according to the Planck–Einstein relation. The index is contracted by the use of Einstein notation (there is an implicit summation over ). Since Newton's second law uses the inertial mass (not the gravitational mass), we can identify the inverse of this mass in the equation above as the tensor This tensor expresses the change in group velocity due to a change in crystal momentum. Its
Enzyme multiplied immunoassay technique is a branch of the U.S. Department of Health and Human Services). The setting of reasonable cutoff limits help reduce false positive results that occur from assay limitations. Because of the social and legal consequences, a positive test result must be confirmed by an alternative method, usually Gas Chromatography/Mass spectrometry. As an example the SAMHSA cutoffs for cannabinoids are 50 ng/ml for the immunoassay and 15 ng/ml as confirmed by GC/MS. Immunoassays that do not conform with SAMHSA, featuring a cutoff of 20 ng/ml, have been shown to produce false positives from passive inhalation of marijuana smoke. Enzyme multiplied immunoassay