Date of Award

Spring 1980

Document Type

Dissertation

Degree Name

Doctor of Engineering Science in Chemical Engineering

Department

Chemical Engineering and Chemistry

First Advisor

Ching-Rong Huang

Second Advisor

Angelo J. Perna

Third Advisor

David S. Kristol

Fourth Advisor

Hung T. Chen

Fifth Advisor

P. Hrycak

Abstract

The rheological property of whole blood from various human subjects was studied with a Weissenberg Rheogonio-meter, modified with a continuously variable speed drive. Experimental data showed a hysteresis loop in the shear stress versus the shear rate plot and a torque-decay in the shear stress versus the shearing time plot which is under a constant shear rate. The rheological equation previously developed by Huang was employed to define the thixotropic parameters of each whole blood sample based upon the recorded rheograms.

The altered thixotropic parameters for the blood from patients with open heart surgery at different clinical stages were quantitatively determined. The viscosity by non-Newtonian contribution during the stage of cardiopulmonary bypass showed tremendously high values for the expired patients. Effect of temperature on the blood from normal healthy adults may imply a particular thixotropic temperature existing in a thixotropic system, at which the thixotropic properties reach minimum. It also reveals that 37°C is the optimal temperature for human subjects at normal physiological conditions. The rheological behaviors of blood affected by normal linear alkanols were mainly determined by the solubilities of alkanols in water and chemical speciality of the red blood cell. Both hydrophilic and hydrophobic: alkanols tended to increase blood thixotropic properties, Amphiphilic alkanols increased blood thixotropy at low concentration and, hemolysed blood to a Newtonian. fluid at high concentration.

A theoretical analysis of the artifacts of the torsion head to the experimentally obtained rheograms of torque‑decay curve-and hysteresis loop demonstrated the dynamic behaviors of the torsion head as well predicted the real rheograms of the tested fluid. The experimental data which have been proved from the study are true hemorheological properties and involve no artifacts.

This investigation has shown the significance of the rheological test of whole human blood. It can be developed as a clinical test, which will supply diagnostic information beyond the standard clinical tests available at this time.

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