Search

Accepted: 2018-05-26, 資料番号: SA1180054000

We compared the thermal performance of two configuration types of Oscillating Heat Pipe (OHP) experimentally to investigate making heat transfer routing more adaptable. One type of OHP has the conventional configuration of closed-loop multiple-serpentine routing that uses U-shaped turns of 3.75 mm radius. The other type has the proposed circular ring configuration with a much larger radius of 1289 mm. Both types have the same pipe length so that the circular OHP can be considered an “unfolded” layout of the serpentine OHP. The circular OHP has alternating heated and cooled sections at locations corresponding to the sections of the serpentine model. Each type has ten sets of these sections with check valves; the OHPs were oriented horizontally. The working fluid was HFC-134a. Both types of samples functioned normally, and their thermal resistances were almost identical. Each OHP showed traveling pressure waves during operation, which indicated a phase difference at each measuring point. The experiment showed that OHPs, with check valves and alternating heated and cooled sections, can transfer heat without the need for a serpentine configuration and that heat transfer routing can be designed more adaptably.

A low-power, large-scale, and efficient cooling system has been developed to cool lithium-drifted silicon [Si(Li)] detectors distributed in a balloon payload of the General Anti-Particle Spectrometer (GAPS). The system is composed of a multi-loop heat pipe, a reservoir, auxiliary heaters, and a backup pump, all of which are based on state-of-the-art thermal control technologies. Basic functions of this unique system have been verified by environmental testing, in-flight tests, and numerical analyses. This novel cooling concept can be applied to similar situations where distributed heat sources must be cooled.

Experiments aiming to directly detect dark matter (DM) particles have yet to make robust detections, thus underscoring the need for complementary approaches such as searches for new particles at colliders, and indirect DM searches in cosmic-ray spectra. Low energy (< 0.25 GeV/n) cosmic-ray antiparticles such as antideuterons are strong candidates for probing DM models, as the yield of these particles from DM processes can exceed the astrophysical background by more than two orders of magnitude. The General Antiparticle Spectrometer (GAPS), a balloon borne cosmic-ray detector, will perform an ultra-low background measurement of the cosmic antideuteron flux in the regime < 0.25 GeV/n, which will constrain a wide range of DM models. GAPS will also detect approximately 1000 antiprotons in an unexplored energy range throughout one long duration balloon (LDB) flight, which will constrain < 10 GeV DM models and validate the GAPS detection technique. Unlike magnetic spectrometers, GAPS relies on the formation of an exotic atom within the tracker in order to identify antiparticles. The GAPS tracker consists of ten layers of lithium-drifted silicon detectors which record dE/dx deposits from primary and nuclear annihilation product tracks, as well as measure the energy of the exotic atom deexcitation X-rays. A two-layer, plastic scintillator time of flight (TOF) system surrounds the tracker and measures the particle velocity, dE/dx deposits, and provides a fast trigger to the tracker. The nuclear annihilation product multiplicity, deexcitation X-ray energies, TOF, and stopping depth are all used together to discern between antiparticle species. This presentation provided an overview of the GAPS experiment, an update on the construction of the tracker and TOF systems, and a summary of the expected performance of GAPS in light of the upcoming LDB flight from McMurdo Station, Antarctica in 2020., 4 pages, 3 figures, The 39th International Conference on High Energy Physics (ICHEP2018), Seoul, Korea

The oscillating heat pipe (OHP) is a novel heat-transfer technique used in thermal engineering. Although the OHP offers many technical advantages, it has not yet been actually used in the sky. Motivated by the need to develop a cooling system for use in the balloon-borne General Anti-Particle Spectrometer (GAPS) project, we are developing OHP technologies. To demonstrate the thermal performances of an OHP in real balloon flight conditions, a scaled-down OHP model was launched by a stratospheric balloon in Japan. In this study, we report the results of the flight demonstration.

Multilayer insulation blankets are used in various sizes for thermal control of space systems. These multilayer insulation blankets are processed, usually by being seamed and patched. It is qualitatively understood that the thermal performance of small size multilayer insulation is more or less deteriorated. The effects of size of space use multilayer insulation blankets on thermal performance are known qualitatively, but not quantitatively. In this study, the thermal performance of limited size multilayer insulation blankets was measured by using the boil-off calorimeter method with liquid nitrogen. The temperature distribution on a rectangular multilayer insulation was also measured in order to investigate the nonuniformity of the local heat flux across the rectangular multilayer insulation. Thermal performance declines with the decrease of multilayer insulation area. This is because the local heat flux drastically increases in the hem region and the gap between the edge of blanket and base plate. Based...

Most spacecrafts flown today are covered with multilayer insulation blankets as the most efficient thermal control element. This study was performed to investigate the influence of various processing methods for space use multilayer insulation on thermal performance. The latter was measured by the calorimetric method using a liquid nitrogen cryostat and it was verified that the thermal performance of the multilayer insulation blankets that were processed in the most conventional manner for space use was found to be deteriorated considerably by hem processing such as overlap, seam, and patch. An estimation of the deterioration of the thermal performance of processed multilayer insulation blankets is given in this report.

Accepted: 2014-01-23, 資料番号: SA1004913000

A meter-scale Oscillating Heat Pipe (OHP) has been developed for the General Anti-Particle Spectrometer (GAPS) project. Two types of OHP routing, U-shaped and O-shaped, have been investigated. For the operation at low temperature, R410A was used as the working fluid. As the result of the investigation, we verified for the first time that both the meter-scale U-shaped and O-shaped OHPs can transfer heat under gravity in a wide temperature range between 20°C and -60°C. Generally, the O-shaped OHP showed better performance than the U-shaped OHP. Both OHP models showed good thermal conductance and a good amount of heat transport under the particular sets of conditions which meet the design requirements. In order to clarify the drive force to operate OHP to further improve the OHP design, the performance difference between the U-shaped and the O-shaped models has been interpreted in terms of the gravity effect and the pressure loss.

The Space Infrared Telescope for Cosmology and Astrophysics (SPICA) is a pre-project of JAXA in collaboration with ESA to be launched around 2025. The SPICA mission is to be launched into a halo orbit around the second Lagrangian point in the Sun-Earth system, which allows us to use effective radiant cooling in combination with a mechanical cooling system in order to cool a 3m large IR telescope below 6K. The use of 4K / 1K-class Joule-Thomson coolers is proposed in order to cool the telescope and provide a 4K / 1K temperature region for Focal Plane Instruments (FPIs). This paper introduces details of the thermal design study for the SPICA payload module in the Risk-Mitigation-Phase (RMP), in which the activity is focused on mitigating the mission’s highest risks. As the result of the RMP activity, most of all the goals have been fully satisfied and the thermal design of the payload module has been dramatically improved.

Meter-scale Oscillating Heat Pipe (OHP) has been developed for the General Anti Particle Spectrometer (GAPS) project. Two types of the OHP routing have been investigated. One is a U-shaped routing and the other is an O-shaped routing. For the operation at low temperature, R410A was used as the working fluid. As the result of the investigation, we verified for the first time that both the meter-scale O-shaped and U-shaped OHPs can transfer heat in gravity at low temperature. Between the heat input section and the radiator section, the thermal conductance larger than 10 W/K was achieved under particular sets of conditions. In terms of thermal characteristics, the O-shaped OHP showed better performance than the U-shaped OHP. The O-shaped OHP started up more quickly than the U-shaped OHP at low temperature. The temperature uniformity of the O-shaped-OHP heating section was also better without drying-out at around the top of the heating section. The U-shaped OHP could transfer heat at temperatures above around 240 K, and the O-shaped OHP could transfer heat at temperatures above around 210 K. We consider the O-shaped OHP utilizes the gravity to assist the circulation of the working fluid resulting in better performance.

Right thoracotomy is an alternative surgical technique for mitral valve reoperation. The purpose of this study is to determine whether right thoracotomy for mitral valve reoperation affects its perioperative outcomes and complications.We investigated the perioperative events in consecutive mitral valve reoperations between January 2006 and November 2009. Demographic, intraoperative and postoperative data were collected and analyzed retrospectively.Five right thoracotomy cases and 22 repeated sternotomy cases were included. Thoracotomy group needed more platelet transfusion (median, 20 units in thoracotomy; 10 units in sternotomy; P=0.047). We had a higher frequency of adrenaline administration (60% in thoracotomy; 4.6% in sternotomy; P=0.005) and needed more doses of dobutamine in thoracotomy group (median, 16.0 microg x kg(-1) x min(-1) in thoracotomy ; 7.5 microg x kg(-1) x min(-1) in sternotomy; P=0.037) to wean them from cardiopulmonary bypass. Right thoracotomy did not reduce cardiopulmonary bypass time (median, 265 min in thoracotomy ; 199 min in sternotomy; P=0.126). We experienced two serious complications requiring reoperation in thoracotomy group, but diagnosed them with intraoperative transesophageal echocardiography.When we choose right thoracotomy for mitral valve reoperation, we should prepare more blood products and inotropic agents and should evaluate cardiac function by using intraoperative transesophageal echocardiography.

Thermal performance of a 6m-long Oscillating Heat pipe (OHP) for balloon-borne General Anti-Particle Spectrometer (GAPS) experiment has been investigated. The developed OHP is a closed loop type and U-shaped due to the mission detector requirements. R410A is selected as the working fluid for the use at low temperature. We achieved a thermal conductance of 18.7 W/K for 150 W heat input with 16 turns at +20 deg-C. We also found for the first time that this large-scale OHP can be operated at low temperatures when the cooling section is cooled from +20 deg-C to -60 deg-C. In addition to the well-known advantages of OHP that it can be simply fabricated and has low sensitivity to the orientation, it is found that the OHP has an adjustability and flexibility to 3-dimensional alignment and wide temperature range.

The BepiColombo MMO (Mercury Magnetospheric Orbiter) flight model thermal design and the flight prediction are presented. The MMO Thermal Test Model (TTM) was built according to the design at PDR (Preliminary Design Review). MMO TTM was tested in a series of thermal testing. The geometrical and thermal mathematical models (GMM/TMM) were correlated in accordance with the test results. The flight model (FM) thermal design was modified from the PDR design according to the configuration change after PDR and the outcome of the thermal tests. The GMM/TMM for FM was prepared for the flight prediction for CDR (Critical Design Review) on the basis of the correlation and the hardware modifications. The verification of GMM/TMM for FM will be done by the additional TTM test and the FM thermal test. The final flight prediction will be available between the FM thermal test and the launch.

T = temperature , K t = thickness, m V = volume flow rate, L min -1 Subscripts av = average temperature , K B = boil-off tank or base plate g = vapor Hem = hem of MLI blanket l = liquid MLI = MLI outermost surface, Test MLI N = number of layers, number of test MLI n = number of control MLI blanket (masking MLI blanket) S = outermost surface of MLI Total = total into the boil-off tank, measured from evaporation rate by experiment V = vacuum chamber

Lessons learned and results from BepiColombo/Mercury Magnetospheric Orbiter (MMO) thermal test model testing are presented. The MMO Thermal Test Model (TTM) was elaborately tested in four Thermal Balance Tests (TBTs): TBT with a 1 solar constant simulator at the Tsukuba Space Center in November 2009, TBT with infrared panels at the Institute of Space and Astronautical Science in February 2009, TBT with a 10 solar constant simulator at the European Space Research and Technology Centre (ESTEC) in October 2010, and TBT of the MMO TTM and MOSIF TTM composite at ESTEC in December 2010. This last MOSIF-MMO test was conducted by the European Space Agency.

Remifentanil may be beneficial in patients undergoing cardiac surgery, by attenuating the neurohumoral stress response to surgical stimulation and inflammation evoked by cardiopulmonary bypass (CPB).We retrospectively examined blood glucose monitored every 30 minutes during CPB and insulin dose in patients during CPB under remifentanil anesthesia (remifentanil group) and those under low dose fentanyl anesthesia (fentanyl group) in adult cardiac surgery. Furthermore we also investigated incidence of atrial fibrillation within 72 hours after surgery in both groups.There were 35 patients in remifentanil group and 22 patients in fentanyl group. Although blood glucose at the beginning and the end of CPB in both groups were not different, remifentanil group showed lower maximum blood glucose (median 172 mg x dl(-1), interquatile range 156-205 mg x dl(-1)) during CPB than in fentanyl group (197 mg x dl(-1), 176-219 mg x dl(-1); P = 0.009). Significantly less insulin was administered during CPB in remifentanil group than in fentanyl group. Incidence of postoperative atrial fibrillation was similar between the groups.Maximum blood glucose was lower and less insulin was administered during CPB in remifentanil group. These data may suggest that remifentanil reduce stress response to surgical stimulation in cardiac surgery.

The thermal performance of a gas-loaded variable conductance heat pipe (VCHP) is investigated. The VCHP consists of a conventional constant-conductance heat pipe and a reservoir: the reservoir is connected to the end of the condenser of the heat pipe. The heat pipe section of the VCHP is an axial grooved aluminum pipe. The working fluid and the non- condensate gas were 20 ml acetone and air, respectively. The heat load was given to the evaporator section, while the condenser section was water-cooled. By keeping the reservoir temperature constant, the temperature of the adiabatic section was kept constant against the change in the heat load to the evaporator, as well as against the change in the temperature of the condenser section. The temperature of the evaporator section could be regulated by adjusting the heat input to the reservoir: The temperature of the evaporator section could also be kept constant against the change in the temperature of the condenser section, and against the change in the heat load to the evaporator section. conducted on the ETS-III and the ETS-V successfully. 3 However, VCHP has not been used in a Japanese satellite since then. This paper investigates the fundamental thermal performance of a VCHP. The heat load to the evaporator section and the temperature of the condenser section were changed to measure the thermal performance of the VCHP. The fundamental operations of the VCHP were demonstrated. The PID control of the heater on the reservoir is employed to control the temperature of evaporator section. It is certain that VCHP is a useful temperature control device which enables the power reduction for temperature control. II. Gas-controlled heat pipe A conventional heat pipe contains a working fluid which is saturated in it. It is composed of three main parts; an evaporator, a condenser and an adiabatic sections. A wick is put on the inner surface of the pipe. During the operation, the working fluid is vaporized by the heat load to the evaporator section. The vapor flows through the adiabatic section to the condenser section, and it condenses there. The capillary force develops in the vapor-liquid interface in the wick. The capillary force pumps the liquid to the evaporator for re-evaporation. A conventional heat pipe realizes high heat transfer performance and has uniform temperature distribution over its surface by the latent heat exchange. VCHP contains a non-condensable gas along with a working fluid. A gas reservoir is connected to the end of the condenser section. During the operation, the vapor of the working fluid sweeps away the non-condensable gas to the reservoir. At one part of the condenser section, the vapor cannot condense there due to the existence of the non- condensable gas. This portion is inactive part of the condenser section. The non-condensable gas represents a diffusion barrier against the flowing vapor. The vapor can condense at the rest part of the condenser section, which is active part of the condenser section. The active condenser area is changed passively according to the variation of the heat load to the evaporator section and to the thermal condition in the condenser section, i.e. the temperature of T

We experienced the combustion of the endotracheal tube during a bronchoscopic potassium titanyl phosphate laser resection of an intratracheal metastatic tumor. Some preventive precautions have been reported, however, none of them are absolutely perfect. We report the rare occurrence of tracheal tube ignition, preventive measures and treatment strategies for the resultant airway burn.

著者人数: 23名, 資料番号: SA1160215000

The GAPS experiment is designed to carry out a sensitive dark matter search by measuring low-energy cosmic ray antideuterons and antiprotons. GAPS will provide a new avenue to access a wide range of dark matter models and masses that is complementary to direct detection techniques, collider experiments and other indirect detection techniques. Well-motivated theories beyond the Standard Model contain viable dark matter candidates which could lead to a detectable signal of antideuterons resulting from the annihilation or decay of dark matter particles. The dark matter contribution to the antideuteron flux is believed to be especially large at low energies (E < 1 GeV), where the predicted flux from conventional astrophysical sources (i.e. from secondary interactions of cosmic rays) is very low. The GAPS low-energy antiproton search will provide stringent constraints on less than 10 GeV dark matter, will provide the best limits on primordial black hole evaporation on Galactic length scales, and will explore new discovery space in cosmic ray physics. Unlike other antimatter search experiments such as BESS and AMS that use magnetic spectrometers, GAPS detects antideuterons and antiprotons using an exotic atom technique. This technique, and its unique event topology, will give GAPS a nearly background-free detection capability that is critical in a rare-event search. GAPS is designed to carry out its science program using long-duration balloon flights in Antarctica. A prototype instrument was successfully flown from Taiki, Japan in 2012. GAPS has now been approved by NASA to proceed towards the full science instrument, with the possibility of a first long-duration balloon flight in late 2020. Here we motivate low-energy cosmic ray antimatter searches and discuss the current status of the GAPS experiment and the design of the payload., 8 pags, 3 figures, Proc. 35th International Cosmic Ray Conference (ICRC 2017), Busan, Korea