Thermal Control System to Easily Cool the GAPS Balloon-borne Instrument on the Ground

This study developed a novel thermal control system to cool detectors of the General AntiParticle Spectrometer (GAPS) before its flights. GAPS is a balloon-borne cosmic-ray observation experiment. In its payload, GAPS contains over 1000 silicon detectors that must be cooled below -40^{\circ}\mbox{C}. All detectors are thermally coupled to a unique heat-pipe system (HPS) that transfers heat from the detectors to a radiator. The radiator is designed to be cooled below -50^{\circ}\mbox{C} during the flight by exposure to space. The pre-flight state of the detectors is checked on the ground at 1 atm and ambient room temperature, but the radiator cannot be similarly cooled. The authors have developed a ground cooling system (GCS) to chill the detectors for ground testing. The GCS consists of a cold plate, a chiller, and insulating foam. The cold plate is designed to be attached to the radiator and cooled by a coolant pumped by the chiller. The payload configuration, including the HPS, can be the same as that of the flight. The GCS design was validated by thermal tests using a scale model. The GCS design is simple and provides a practical guideline, including a simple estimation of appropriate thermal insulation thickness, which can be easily adapted to other applications.Comment: 8 pages, 14 figures, 3 table

Usefulness of vitrification device having vitrification solution absorber for cryopreservation of mouse embryos at the blastocyst stage

Vitrification is widely used for cryopreservation of embryos and oocytes in applications of assisted reproductive technology globally. In this study, we evaluated the efficacy of the Kitasato Vitrification System (KVS) as a device for the cryopreservation of mouse embryos and made comparisons with the widely used Cryotop® vitrification device. In Experiment 1, the blastocyst survival rates were significantly higher after vitrification using the KVS than after using Cryotop® devices. In Experiment 2, the cooling and warming rates of Cryotop® increased with decreasing vitrification solution volumes around the embryo and were 336,000 ℃/min and 320,000°C/min at best, respectively. However, the cooling and warming rates of the KVS were 683,000 ℃/min and 612,000 ℃/min, respectively, exceeding those of Cryotop®

Polymer-Stabilized Blue Phase and Its Application to a 1.5 µm Band Wavelength Selective Filter

The use of polymer-stabilized blue phase (PSBP) including a tolane-type liquid crystal was investigated to develop a voltage-controlled wavelength selective filter for wavelength-division-multiplexing optical fiber network. It was found that the tolane-type liquid crystal introduction can increase both a blue-phase temperature range and a Kerr coefficient. A Fabry–Perot etalon filled with PSBP functioned as a wavelength selective filter, as expected. The tuning wavelength range was 62 nm although peak transmission was not as high as expected. Numerical analysis suggested that light absorption in transparent electrodes may cause the issue. Minor change to the etalon structure will result in improved performance