2021-(I)-A new evaluation Q-factor to be calculated for suction geometries as a basis for smooth suction in the operating field to ensure the highest possible blood integrity for re-transfusion systems

I. Iwanowski, J. Böckhaus , P. Richardt, I. Kutschka, G.G. Hanekop, M.G Friedrich: A new evaluation Q-factor to be calculated for suction geometries as a basis for smooth suction in the operating field to ensure the highest possible blood integrity for re-transfusion systems

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2018-(II)-Surface Tension in Critical Mixtures

Parameters which have been obtained from ultrasonic spectrometry, dynamic light scattering and shear viscosity are presented in Table (5.9). It is a fascinating aspect of the dynamic scaling theory of ultrasonic attenuation that, due to scaling of frequency data of different critical mixtures fall on one scaling function.  However, the most curious specific system parameter is the characteristic relaxation rate amplitude Γ_0, which according to Bhattacharjee-Ferrell theory, corresponds with the mutual diffusion coefficient D and the fluctuation correlation length ξ.  In Table (5.9) parameters Γ_0  and ξ_0  are listed for various binary mixtures with critical demixing point. The isobutoxyethanol-water system exhibits by far the smallest amplitude Γ_0 in the relaxation rate of order parameter fluctuations. In comparison, with the system n-pentanol-nitromethane, Γ_0 is 35 times larger.  Assuming, that the life time of fluctuations τξ  = Γ_0^−1, as inverse characteristic relaxation rate reflects intermolecular properties as well the geometry of considered components the strong variation of Γ_0  of various liquids can be understood. In addition, due to the Coulombic interactions, relaxation from a local nonequilibrium distribution of electrical charges into thermal equilibrium will involve extensive redistribution of ions in ionic solutions and may, therefore, proceed with a smaller relaxation rate than a molecular liquid mixture at the same reduced temperature.  A quantity, which may be taken to summarize the above mentioned molecular properties, is the surface tension σ. If considering critical fluctuations, reflected by the fluctuation relaxation rate Γ_0  , to depend on the  surface  tension,  a correlation  between  both  quantities  should  exist.           

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2018-(I)-Critical Contribution, Dynamic Scaling and Crossover Theory

The following project deals with the dynamic scaling aspects within the framework of Bhattacharjee-Ferrell theory. Furthermore, relationships between the critical sound attenuation and the dynamic scaling function are presented. Moreover, crossover effects for binary and ternary fluids are presented.

Bhattacharjee-Ferrell scaling hypothesis - binary systems:

Critical phenomena, as all continuous phase transitions, Show universal characteristics of their thermodynamic properties, if they belong to the same universality class and if their dimension is identical. The concepts and consequences of critical slowing down have been presented in 2005-(II)-Critical Phenomena and Universality.  In particular, the light scattering is well represented and described by dynamic scaling theories, resulting from the mode-coupling considerations. However, the treatment of critical ultrasonic attenuation necessitates the development of new theories in order to get an access to critical fluctuations in a sound field. Bhattacharjee and Ferrell have presented a general theory of the critical ultrasonic attenuation, based on an extension of the concept of the frequency-dependent specific heat. This conception was firstly introduced by Herzfeld and Rice in 1928.

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