Record Display for the EPA National Library Catalog


Main Title Off-Center Spherical Model for Dosimetry Calculations in Chick Brain Tissue.
Author Gonzalez, G. ; Nearing, J. C. ; Spiegel, R. J. ; Joines, W. T. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC. ;Miami Univ., Coral Gables, FL.
Year Published 1986
Report Number EPA/600/J-86/170;
Stock Number PB87-113429
Additional Subjects Brain ; Dosimetry ; Electric fields ; Chickens ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB87-113429 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 15p
The paper presents calculations for the electric field and absorbed power density distribution in chick brain tissue inside a test tube, using an off-center spherical model. It is shown that the off-center spherical model overcomes many of the limitations of the concentric spherical model, and permits a more realistic modeling of the brain tissue as it sits in the bottom of the test tube surrounded by buffer solution. The effect of the unequal amount of buffer solution above the upper and below the lower surfaces of the brain is analyzed. The field distribution is obtained in terms of a rapidly converging series of zonal harmonics. A method that permits the expansion of spherical harmonics about an off-center origin in terms of spherical harmonics at the origin is developed to calculate in closed form the electric field distribution. Numerical results are presented for the absorbed power density distribution at a carrier frequency of 147 MHz. It is shown that the absorbed power density increases toward the bottom of the brain surface. Scaling relations are developed by keeping the electric field intensity in the brain tissue the same at two different frequencies. Scaling relations inside, as well as outside, the brain surface are given.