Shape characteristics of biological spores

摘要

Calculation of scattering properties of biological materials has classically been addressed using numerical calculationsbased on T-matrix theory. These calculations use bulk optical properties, particle size distribution, and a limited selectionof shape descriptors to calculate the resulting aerosol properties. However, the most applicable shape available in T-matrix codes, the spheroid, is not the best descriptor of most biological materials. Based on imagery of the spores ofBacillus atrophaeus and Bacillus anthracis, capsule and egg shapes are mathematically described and programmed intothe Amsterdam Discrete Dipole Approximation (ADDA). Spectrally dependent cross sections and depolarization ratiosare calculated and a comparison made to spheroidal shapes of equivalent sizes.