Development of Oxygen Supply and Recovery System for Closed Environment in a Space -Approach to Low Power Consumption at Cultivating-

作为开发利用钝顶螺旋藻（Spirulinaplatensis）光合作用的供氧系统的基础研究，我们研究了在微重力条件下利用低离心力形成螺旋藻养殖场的可能性。在地面和微重力条件下，我们观察到了容器侧壁附近的气泡行为。在2000年的结果中，发现材料表面的评价、滑动面的形成、气泡的大小和频率的控制是最重要的。地面实验：接触角用液滴法测定。在这项工作中，我们测试了接触角的气泡测量。我们使用该测量值评估了各种表面的特性。地面实验：在北海道工业综合研究所进行了微重力实验，建立了气泡大小和频率的控制程序。利用日本微重力中心的实验装置，对微重力条件下容器侧壁附近的气泡行为进行了观测。结果表明，气泡行为可分为三种模式。(1)空气分散在水中，气泡不接触侧壁。(2)空气在水中不分散，大气泡在侧壁上接触。(3)空气在水中不扩散，在侧壁上形成空气层，每种形态都对应着接触角的大小。因为我们在实验上证实了模式（3），所以我们的过程证明了功率降低的可能性。

As a basic research for developing an Oxygen Supply system used photosynthesis of blue-green algae, Spirulina platensis, we investigated the possibility of power decreasing formed Spirulina Cultivated field, which used low centrifugal force, under microgravity. We observed a bubble behavior near the sidewall of vessel on the ground and under microgravity. In the results at 2000, it was found that the evaluation of a material surface, formation of slipping surface and the controlling of a bubble size and its frequency were the most important.Experiments on the ground :Contact angle was measured by liquid drop. In this work, we tested that contact angle was measured by bubble. We evaluated the characteristic of the various surfaces using this measurement value. We prepared the new surface that was more excellent than Teflon.Experiments on the ground :We established a controlling procedure of bubble size and its frequency by microgravity experiments at Hokkaido National Industrial Research Institute. We observed the bubble behavior near the sidewall of vessel under microgravity, which was created by Japan Microgravity Center. It was found that bubble behaviors were divided three patterns.(1) Air disperses in water and bubble does not contact on the sidewall.(2) Air does not disperse in water and large bubble contact on the sidewall.(3) Air does not disperse in Water and air layer forms on the sidewall.Each pattern corresponded to the value of the contact angle. Because we experimentally confirmed pattern (3), the possibility of power decreasing was proved by our procedure.