Microgravity conditions

In the converse situation free of gravity, a drop assumes a perfectly spherical shape. At one point, the U.S. Space program tested this idea with the solidification of ball bearings from molten metal drops in microgravity conditions. 

Zhao L, Rezkallah KS (1993), Gas-hquid flow patterns at microgravity conditions. Int J Multiphase Flow 19 751-763... 

Candle and Jet Diffusion Flames Mechanisms of Combustion under Gravity and Microgravity Conditions... 

Voorhees s experimental study of low-volume-fraction-solid liquid+solid Pb-Sn mixtures carried out under microgravity conditions during a space shuttle flight enabled a wider range of solid-phase volume fractions to be studied without significant influence of buoyancy (flotation and sedimentation) effects [13]. The rate of approach to the steady-state particle-size distribution in 0.1-0.2 volume-fraction... 

Consider an isothermal, steady gas-solid laminar pipe flow under the microgravity condition. The flow is regarded as axisymmetric. Both the gas and particle phases can be treated... 

Baumann, T., Kreis, W., Mehrle, W., Hampp, R. and Reinhard, E. (1990) Regeneration and characterization of protoplast-derived cell lines from Digitalis lanata Ehrh. and Digitalis purpurea L. suspension cultures after electrofusion under microgravity conditions, in Proceedings of the 4th European Symposium on Life Sciences. ESA Publications Div., ESTEC, Nordwijk, pp. 405-10. 

Fig. 57. Photographs of (a) initial sample and products (TiC) synthesized in (b) terrestrial and (c) microgravity conditions (Adapted from Shteinberg etal., 1991).

Tomiyama, A., Kataoka, L, Zun, 1. Sakaguchi, T. 1998 Drag coefficient of single bubbles under normal and microgravity conditions. The J.S.M.E. International Journal 41, 472-479. 

We want to give only two examples of interfacial relaxation methods. The whole field of interfacial relaxations and rheology is so broad and of strong practical relevance that this topic deserves a whole book. At first, two examples, a harmonic and a transient experiment will be shown as example for slow relaxation experiments, while as second we will present results of experiments performed under ground and microgravity conditions, respectively, based on the principle of oscillating bubbles. 

The comparison of the two figures shows that the characteristic bubble frequency for ground conditions is two times smaller than that for microgravity conditions. The most probable reason for the decrease of the characteristic bubble frequency under ground conditions is the bubble shape deformation due to gravity on which the characteristic frequency strongly depends. 

Fig. 4.47. Phase shift between the externally imposed volume variation and the measured pressure variation vs. frequency obtained microgravity conditions C]2DMPO concentrations 0 ( ) 0.005 ( ), 0.01 ( ), 0.02 (X) and 0.04 ( ) mol/m .

Rationale for laboratory measurements under microgravity conditions... 

Neichitailo G, Gordeev A. Efifea of artificial elearic firelds on plants grown under microgravity condition. Adv Space Res 2001 28 629-631. 

Brooks DE, Bamberger SB, Harris JM, Van Alstine JM, Snyder RS (1986) In Proceedings of the 6th European Symposium on Materials Science under Microgravity Conditions. Bordeaux, France, December 2, ESA Publication No. SP-256, p 131... 

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