Electromagnetic Energy Absorption and Its Distribution for Man and Animals at Different Frequencies under Various Conditions.

Abstract

The whole-body absorption of electromagnetic waves by biological bodies is strongly dependent on the orientation of the electric field (E) relative to the longest dimension (L) of the body. The highest rate of energy deposition occurs for E parallel L orientation for frequencies (65-70 MHz for an adult human being) such that the major length is approximately 0.36 to 0.4 times the free-space wavelength. Peaks of whole-body absorption for the other two configurations (major length oriented along the direction of propagation (K parallel L) or along the vector of the magnetic field (H parallel L) occur for wavelength on the order of 4 pi b, where 2 pi b is the weighted average circumference of the animals. Numerical calculations for a realistic block model of man shown a fine structure to whole-body absorption at frequencies higher than the whole-body resonant frequency. Minor peaks in the supraresonance region are ascribed to maxima of energy deposition in the various body parts such as the arm and the head. For the E parallel L, supraresonant region, an average 1/f dependence of the whole-body absorbed dose is obtained theoretically and experimentally to frequencies on the order of 4-8 times the resonance frequency.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1978
Accession Number
ADA100029

Entities

People

  • John A. D'andrea
  • Mark J. Hagmann
  • Om P. Gandhi

Organizations

  • University of Utah

Tags

Communities of Interest

  • Biomedical
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption
  • Animals
  • Birds
  • Dielectric Permittivity
  • Electric Fields
  • Electromagnetic Fields
  • Electromagnetic Radiation
  • Frequency
  • Geometry
  • Health Services
  • Laboratory Animals
  • Magnetic Fields
  • Mechanical Jamming
  • Radio Frequency
  • Resonant Frequency
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Nuclear and Radiation Engineering.
  • Spectroscopy.

Technology Areas

  • Space
  • Space - Orbital Debris