Neutralization of Bacterial Aerosols by Aerodynamic Shocks in a Novel Impactor System: An Integrated Computational and Experimental Study

Abstract

Neutralization of bacterial aerosol releases is critical in countering bioterrorism. We investigate the mechanical instabilities of the bacterial cell envelope as the bacteria pass through aerodynamic shocks To carry out this fundamental investigation, a novel experimental impactor system is built to simultaneously create a controlled shock and to collect the bacteria after they pass through the shock. Experimental measurements of the pressure in the impactor system compare well with computational fluid dynamics simulations used to characterize the aerodynamic shocks. The bacteria experience relative deceleration because of sharp velocity changes in the aerodynamic shock created in the impactor system. Computational model results indicate that vegetative E. coli cells require a critical acceleration of 3.0x10A8 m/sA2 compared to 3.9-16x10A9 m/sA2 for B. atropheus spores to breakup. Computed accelerations in the impactor system reach 5.9x10A9 m/sA2 which predict breakup of both vegetative cells and spores. Experimentally, aerosolized E. coli cells and B. atropheus spores that pass through aerodynamic shocks created in the experimental impactor system are an order of magnitude less likely to retain viability than those that pass through the impactor at conditions which do not lead to the generation of an aerodynamic shock.

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Document Details

Document Type
Technical Report
Publication Date
Oct 15, 2010
Accession Number
ADA531377

Entities

People

  • Panagiotis D. Christofides
  • Patrick R. Sislian

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Advanced Electronics
  • C4I
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aerosols
  • Bacterial Aerosols
  • Biological Aerosols
  • Boundary Layer
  • Chemical Engineering
  • Chemistry
  • Computational Fluid Dynamics
  • Computational Science
  • Dispersions
  • Dynamics
  • Equations Of Motion
  • Fluid Dynamics
  • Fluid Flow
  • Gas Flow
  • Heat Transfer
  • Measurement
  • Pressure Measurement

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Combustion Dynamics and Shock Wave Physics.
  • Microbial Pathology