Station Science Top News: July 14, 2023
Vascular Echo researchers using a 3D ultrasound identified a 35% reduction in the size of the internal jugular vein after crew members wore thigh cuffs for four hours, indicating that thigh cuffs are an effective countermeasure to headward fluid shifts. This finding was not evident with a 2D ultrasound, suggesting that 3D ultrasound is a better choice for measuring cardiovascular anatomy in astronauts.
Ultrasound measurements and the leg cuff are part of Vascular Echo, a Canadian Space Agency (CSA) investigation examining changes in blood vessels and the heart. Bulging of the jugular vein commonly occurs during spaceflight due to pooling of blood, but conventional imaging does not always produce good measurements, especially when users are not medical professionals (such as astronauts). The 3D ultrasound helps non-experts take precise measurements and accurately assess vascular changes during flight.
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Researchers found several parameters that significantly influence the process of flow boiling in microgravity, including some that have effects similar to those seen on Earth and others that are different. Flow boiling is a method of thermal management that circulates a fluid over a surface to remove heat. These results could help researchers identify parameters they might manipulate to improve cooling systems in microgravity.
Thermal management of most systems and components in spacecraft are based on forced liquid convection but more advanced, compact, and lightweight systems are needed for future long-duration missions. Flow Boiling and Condensation Experiment works to develop a model and facility to examine the effects of microgravity on heat transfer and support development of better systems for use in space and on Earth.
Read more here.
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Molten yttrium oxide density measured by the station’s electrostatic levitation furnace (ELF) facility showed good agreement with measurements made with a terrestrial aero-acoustic levitator and with those of other non-glass-forming oxides. Yttrium oxide is used in dental ceramics, superconductors, and other materials. Understanding its thermal properties could expand and improve 3D printing and other manufacturing processes for materials with high melting point and low thermal expansion characteristics.
Japan Aerospace Exploration Agency's (JAXA) ELF facility measures the thermophysical properties of high temperature melts and enables solidification from deeply undercooled melts. Its electrostatic levitation method uses the Coulomb force between charged samples and electrodes. Previous density measurements of molten yttrium oxide used a terrestrial aero-acoustic levitator.
