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oai:www.ideals.illinois.edu:2142/20285 2023-07-10 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Dunn, Floyd Zhang, Jian 2011-05-07T12:34:51Z 2011-05-07T12:34:51Z 10000-01-01 1990 The influences of structural factors of biological media on the acoustic nonlinearity parameter B/A were studied at tissue, cellular and molecular levels, using both the thermodynamic method and the finite amplitude method. Experiments were designed to measure the B/A changes by altering structural factors of media physically and biochemically, while keeping chemical compositions unchanged. Evidences were found to support significant structural dependences of the B/A at all three levels. Further analysis suggests that about 26% of dry weight contribution to the total B/A, the B/A value with water contribution subtracted, is due to cell-cell adhesive force in liver tissues, 20% to the hepatocyte cellular structure, and 15% to the molecular structure of protein. No significant B/A changes were observed between the in vivo and in vitro B/A values in cat livers and during the digestion of protein. In addition, it is found that B/A exhibits an unusually large value near the phase transition regions of liposomes, suggesting the effect of relaxational processes on the B/A value. Finally, implications of the above findings are discussed in the light of the previous studies on the compositional dependence of B/A, and a possible rationale by which the B/A depends on both the chemical composition and structural factors is suggested. Made available in DSpace on 2011-05-07T12:34:51Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9021780.pdf: 5404107 bytes, checksum: 01d0d04d81dec2a892c34d48dda6bbad (MD5) Previous issue date: 1990 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:42:52Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:18:41-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9021780 (UMI)AAI9021780 http://hdl.handle.net/2142/20285 eng Copyright 1990 Zhang, Jian Engineering, Biomedical Biophysics, Medical Influences of biological structural features on the acoustic nonlinearity parameter B/A text Electrical and Computer Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.