The goal of this article was to review the hypometabolic efficacy of 3-iodothyronamine (T1AM) in both in vivo and in vitro models from our past and current studies. T1AM is known to be a natural derivative of thyroid hormone. In the in vivo studies, a single-dose injection of T1AM to ICR mice decreased metabolic rate (MR) and body temperature by ~55% and 7℃, respectively, and lowered respiratory quotient from 0.85 to 0.7. Repeated injections of T1AM successfully induced two 2-d torpor bouts, separated by 1-d interbout arousal. In the in vitro studies, T1AM-treated C2C12 myotubes decreased the MR to 36%, and upregulated activation of AMP-activated protein kinase and acetyl-CoA carboxylase, but inhibited signaling activities associated with glycolytic activity. Thus, T1AM could induce hypometabolism in both the animal and cell models and promoted catabolism of lipid over carbohydrate as a fuel. For these outcomes closely mimic key features of true hibernators, T1AM may have potential applications to emergency medicine and long-term manned spaceflights.
In this paper several important thermal management aspects of propellant storage tanks are investigated. Special attention is devoted to the heat and mass transport, fluid flow and phase change phenomena that govern tank pressurization and pressure control under 1G and microgravity conditions in terms of three computational-experimental case studies. In the first study, 1G pressurization of a simulant low-boiling point fluid in a small scale transparent tank is considered in the context of the Zero-Boil-Off Tank (ZBOT) Experiment. It is shown that computational predictions of tank pressure and temperature evolution for this moderate Ra and high Bo number regimes are in excellent temporal and spatial agreement with their experimental counterparts. Next, 1G pressurization and pressure control of the large-scale K-site liquid hydrogen tank experiment is considered where the high Bo number - high Ra number flow regimes challenge our ability to predict the vapor phase turbulent heat and mass transfer and their impact on the tank pressurization correctly. Finally, we examine pressurization results from the small scale simulant fluid Tank Pressure Control Experiment (TCPE) and ZBOT Experiment, both performed in microgravity, to show that we have a fairly good ability to simulate the tank self-pressurization rates for low Bo number low Ra regimes encountered in reduced gravity. Unfortunately these results also indicate that accurate tank heat loss and precise knowledge of low and high frequency residual accelerations are all necessary for proper and direct quantitative model validation against microgravity data.
The Aerospace Plane Research Center of Muroran Institute of Technology is now developing the small-scale supersonic flight experiment vehicle. In this system, the application of propellant supplying system for Bioethanol and liquid oxygen (LOX) by pressurant gas has been under consideration. Since LOX is a cryogenic liquid, the pressurant gas is cooled by the liquid during discharge of the propellant. When the pressurized gas is cooled in the tank, the gas tends to shrink, and the amount of pressurized gas required to maintain the tank pressure increases. In the design of the propellant supply system, it is necessary to predict the consumption of pressurant gas to determine its amount to be carried. The pressurant gas consumption in the rocket propellant supply system is expressed as a collapse factor, and its empirical value is available. However, since the configuration of the aircraft tank system is different from that of a rocket, it is necessary to establish the technology for predicting the collapse factor of the present small-scale supersonic flight experiment vehicle.
The final goal of this research is to develop a design technology for the propellant supply system of the cryogenic propellant tank for the small-scale supersonic flight experiment vehicle. The purpose of the present study was to understand the thermal and fluid behavior in the tank during discharge of the propellant with the pressurant gas supply. The thermal and fluid analysis in the tank was conducted using Computational Fluid Dynamics (CFD), and the verification tests of the propellant discharge by simulated cryogenic fluid with pressure control by pressurized gas were also conducted.