Biorheology - Volume 5, issue 3

Authors: Palfrey, A.J. | White, J.B.

Article Type: Research Article

Abstract: A cone and plate viscometer, the Weissenberg rheogoniometer, is used to study the viscosity of synovial fluid from the radiocarpal joint of cattle. A sinusoidal movement of low amplitude is applied to the lower conical platen and the movements of both platens are recorded. The movement detected at the upper platen is shown to increase markedly about the natural frequency of the torsion head, and there is also a change in the phase difference between the movements of the two platens. The viscosity of the fluid is calculated and shown to decrease as the frequency of the oscillation is …increased; there is a discontinuity of the plot on either side of the natural frequency, which persists even after the application of correction factors. The results are also difficult to interpret at the highest frequencies. A comparison is made with results obtained by rotational testing, and they are seen to correspond closely. At the lowest frequencies the fluid behaves in in a non-Newtonian fashion. Show more

DOI: 10.3233/BIR-1968-5301

Citation: Biorheology, vol. 5, no. 3, pp. 189-198, 1968

Authors: Fukada, Eiichi

Article Type: Research Article

Abstract: In a number of biological substances, mechanical strain and electrical polarization are closely linked together by piezoelectric effect, which is usually assigned to the property of crystals. Stress induced polarization and field induced strain were investigated in wood (cellulose), bone and tendon (collagen). The matrix of piezoelectric moduli was determined. Recently, the effect was also confirmed in soft tissues such as blood vessels, intestines, and trachea. Physiological meaning of the piezoelectric effect in biopolymers was noticed in connection with growth mechanism of bone and with the tactual sense. The study in synthetic polypeptides suggested some molecular interpretation of the effect.

DOI: 10.3233/BIR-1968-5302

Citation: Biorheology, vol. 5, no. 3, pp. 199-208, 1968

Authors: Ehrly, A.M.

Article Type: Research Article

Abstract: Sodium oleate, representing substances that disrupt erythrocyte aggregates, has been found to considerably decrease the low shear viscosity of blood in optimal concentrations of 20–40 mg per cent. Evidence suggests that this effect is due to reversible morphological changes in the erythrocytes which facilitate disaggregation of erythrocyte aggregates. High and physiologically unbearable concentrations of 60 mg per cent and above cause an increase in the viscosity, apparently through crenation and stiffening of the red cells.

DOI: 10.3233/BIR-1968-5303

Citation: Biorheology, vol. 5, no. 3, pp. 209-214, 1968

Authors: Balasubramaniam, E. | Whiteley, K.J.

Article Type: Research Article

Abstract: The phenomenon of stress relaxation in animal fibres, such as wool, is analysed with reference to proposed structural models for keratin. Rate of stress relaxation in wool is analysed by treating stress relaxation as a unimolecular reaction process. In general, the data fit this system reasonably well. Rate constants are given for the two samples under test. The variation in rate constants between the two samples is discussed in terms of the biological aspects of sulphur content. It is evident that the solution of problems which can be studied by special techniques applicable only to textile protein fibres …can throw considerable light on problems of structure and rheology of enzymes, viruses, hormones, and muscles. The different types of inter and intra molecular bonds can be recognized and the relationship to mechanical, physical, chemical and even physiological behaviour interpreted. Show more

DOI: 10.3233/BIR-1968-5304

Citation: Biorheology, vol. 5, no. 3, pp. 215-225, 1968

Authors: Larcan, A. | Stoltz, J.F. | Stoltz, M.

Article Type: Research Article

Abstract: Considérant la théorie des suspensions colloïdales et la nature des forces d’attraction ct de répulsion interglobulaires, le potentiel zeta des éléments figurés est susceptible d’intervenir dans la stabilité du sang. La mobilité électrophorétique plaquettaire est influencée par l’ADP, l’ATP et la Noradrenaline in vitro . Mais l’effet de ces différentes substances est diphasique pour l’ATP et l’ADP, et il existe une nette corrélation entre cette mobilité, le potentiel zeta et la dose de produit utilisée. Un essai de corrélation in vivo réalisé sur la circulation mésentérique du rat permet de reconnaître que les doses de substances proagrégantes …et désagrégantes prévues en fonction du potentiel zeta donnent bien les résultats escomptés. Show more

DOI: 10.3233/BIR-1968-5305

Citation: Biorheology, vol. 5, no. 3, pp. 227-235, 1968

Authors: Navari, R.M. | Gainer, J.L.

Article Type: Research Article

Abstract: A method is presented for calculating the variation of the viscosity of blood with tube radius in flow through capillaries.

DOI: 10.3233/BIR-1968-5306

Citation: Biorheology, vol. 5, no. 3, pp. 237-239, 1968

Authors: Oka, Syoten

Article Type: News

DOI: 10.3233/BIR-1968-5307

Citation: Biorheology, vol. 5, no. 3, pp. 241-244, 1968

Article Type: Abstract

DOI: 10.3233/BIR-1968-5308

Citation: Biorheology, vol. 5, no. 3, pp. 245-252, 1968