Microgravity Science and Technology
Springer Science+Business Media
About: Microgravity Science and Technology is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Convection & Heat transfer. It has an ISSN identifier of 0938-0108. Over the lifetime, 1624 publications have been published receiving 15302 citations.
Papers published on a yearly basis
TL;DR: The working principle, technology and control modes will be explained, an overview of the previously used and available experiment systems will be presented and the option to provide partial gravity control modes simulating for instance Mars or Moon gravity will be discussed.
Abstract: A Random Positioning Machine (RPM) is a laboratory instrument to provide continuous random change in orientation relative to the gravity vector of an accommodated (biological) experiment. The use of the RPM can generate effects comparable to the effects of true microgravity when the changes in direction are faster than the object’s response time to gravity. Thus, relatively responsive living objects, like plants but also other systems, are excellent candidates to be studied on RPMs. In this paper the working principle, technology and control modes will be explained and an overview of the previously used and available experiment systems will be presented. Current and future developments like a microscope facility or fluid handling systems on the RPM and the option to provide partial gravity control modes simulating for instance Mars or Moon gravity will be discussed.
TL;DR: It is evident that further systematic studies are required to generate a meaningful body of knowledge of the heat and mass transport mechanism in these devices for practical applications in cooling devices or energy systems.
Abstract: A bibliographical review on the heat and mass transfer in gravity assisted Closed Loop Two Phase Thermosyphons (CLTPT) with channels having a hydraulic diameter of the order of some millimetres and input power below 1 kW is proposed. The available experimental works in the literature are critically analysed in order to highlight the main results and the correlation between mass flow rate and heat input in natural circulation loops. A comparison of different experimental apparatuses and results is made. It is observed that the results are very different among them and in many cases the experimental data disagree with the conventional theory developed for an imposed flow rate. The paper analyses the main differences among the experimental devices and try to understand these disagreements. From the present analysis it is evident that further systematic studies are required to generate a meaningful body of knowledge of the heat and mass transport mechanism in these devices for practical applications in cooling devices or energy systems.
TL;DR: The results for a solid, a hollow, and a hollow-porous microcarriers show that with a denser microcarrier material, the hollow or hollow- porous spherical microcar carriers are preferable in order to increase the suspension time and decrease the maximum shear stress.
Abstract: Rotating-wall vessel (RWV), a low-shear, low turbulence microcarrier culture system provides a simulated microgravity environment suitable for 3-dimensional tissue culture. In this paper, the motion of a microcarrier particle in the rotating fluid has been analytically/numerically studied. If the microcarrier is less dense than the surrounding liquid medium, it eventually migrates towards an equilibrium state in the fluid. This state corresponds to a stationary location in the inertial frame of reference or equivalently, a circular orbit about the rotational axis in a rotating frame. If the particle is denser, it may move away indefinitely to reach or collide with the outer wall of the rotating vessel (outer boundary of the rotating fluid). Such a collision may damage the cells and could be undesirable for tissue culture. We have calculated migration times for a denser microcarrier to reach the outer wall of the vessel. Several factors--rotational speed, fluid viscosity, density difference between that of the microcarrier and the fluid, microcarrier radius, and the initial position of the microcarrier--were found to affect this migration time. We have also evaluated the variation of the fluid shear stress on the microcarrier surface. Decreasing the density difference between the microcarrier and the fluid, and decreasing the size of the microcarrier, can both decrease the maximum shear stress. The results for a solid, a hollow, and a hollow-porous microcarrier show that with a denser microcarrier material, the hollow or hollow-porous spherical microcarriers are preferable in order to increase the suspension time and decrease the maximum shear stress. The results of this study are thought to be useful for the development of optimal conditions for cell growth and metabolism in RWVs.
TL;DR: SJ-10 program as mentioned in this paper provides a mission of space microgravity experiments including both fields of microgravity science and space life science aboard the 24th recoverable satellite of China, which will be launched in the end of 2015 or a bit later.
Abstract: SJ-10 program provides a mission of space microgravity experiments including both fields of microgravity science and space life science aboard the 24th recoverable satellite of China. Scientific purpose of the program is to promote the scientific research in the space microgravity environment by operating the satellite at lower earth orbit for 2 weeks. There are totally 27 experiments, including 17 ones in the field of microgravity science (microgravity fluid physics 6, microgravity combustion 3, and space materials science 8) and 10 in the field of space life science (radiation biology 3, gravitational biology 3, and space biotechnology 4). These experiments were selected from more than 200 applications. The satellite will be launched in the end of 2015 or a bit later. It is expected that many fruitful scientific results on microgravity science and space life science will be contributed by this program.
TL;DR: In this paper, cold atom interferometers were used for measuring the diagonal elements of the gravity gradient tensor and the spacecraft angular velocity. But they were not used to detect time-varying signals in the gravity field.
Abstract: We propose a concept for future space gravity missions using cold atom interferometers for measuring the diagonal elements of the gravity gradient tensor and the spacecraft angular velocity. The aim is to achieve better performance than previous space gravity missions due to a very low white noise spectral behavior and a very high common mode rejection, with the ultimate goals of determining the fine structures of the gravity field with higher accuracy than GOCE and detecting time-variable signals in the gravity field better than GRACE.