Defense Date

1968

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Physiology and Biophysics

First Advisor

Stephen F. Cleary

Abstract

The mechanical breakage of tobacco mosaic virus (TMV) due to the action of acoustic transients has been investigated. The acoustic transients were produced by transient heating of a Prussian blue dye solution (attenuation coefficient of 1000 per cm) when a ruby laser light (20 x 106 watts) was incident on the dye surface. A quartz piezoelectric transducer was used to determine the amplitude and form of the acoustic wave. The production of acoustic waves by transient heating is discussed, and the theoretical form of the acoustic wave determined for various boundary and initial conditions are compared to the experimentally measured values.

The electron microscope was used to compare particle length distributions of control TMV solutions and solutions exposed to the acoustic transients. Two conditions of exposure have been studied by varying the boundary conditions of the TMV solutions. In one case the TMV solution was exposed to a single acoustic transient whereas in the other case the solution was exposed to an acoustic transient which was reflected within the solution. Significantly greater breakage was produced in the latter case demonstrating the importance of boundary conditions in the biological effects of pressure transients.

Calculations were made of the magnitude of hydrodynamical forces producing tensions in the TMV particle. A laser intensity of 1.6 x 108 watts per cm2 incident on the absorbing dye solution was found to be sufficient to cause significant breakage at the 5 percent level (Kolmogorov-Smirnov test). The corresponding tension on the TMV particle was calculated to be 6.3 x 10-5 dynes.

Comments

Scanned, with permission from the author, from the original print version, which resides in University Archives.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

3-22-2017

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