Studies of Vibration-Induced Multi-Phase Fluid Phenomena and Pulsating Heat Pipe Performance Under Microgravity

2003 ◽  
Author(s):  
Masahiro Kawaji
Keyword(s):  
Space Shuttle ◽  
Space Station ◽  
Heat Pipes ◽  
Solid Particles ◽  
Protein Crystals ◽  
Microgravity Environment ◽  
Pulsating Heat Pipe ◽  
Two Phase ◽  
Theoretical Investigations ◽  
Multi Phase

High quality semi-conductor and protein crystals can be grown in space by utilizing the microgravity environment in which natural convection and sedimentation effects are suppressed. But some vibrations exist on space platforms such as Space Shuttle and International Space Station that can induce crystal and fluid motions, affecting the quality of the crystals grown in space. Since the effects of small vibrations (called g-jitter) on crystal growth are not yet precisely known in space, experimental and theoretical investigations are being conducted to better understand the vibration effects on the motion of protein crystals and solid particles in liquid-filled cells. Another topic under investigation is the operation of pulsating heat pipes under microgravity. A recent experiment performed on a parabolic airplane has shown the positive effect of reduced gravity on the pulsating motion of vapour-liquid two-phase flow and heat transport in pulsating heat pipes.

A HIERARCHICAL MODEL FOR MULTI-PHASE FRACTAL MEDIA

Fractals ◽  
2010 ◽  
Vol 18 (01) ◽  
pp. 53-64 ◽  
Author(s):  
MAOFEI MEI ◽  
BOMING YU ◽  
JIANCHAO CAI ◽  
LIANG LUO
Keyword(s):  
Distribution Function ◽  
Pore Space ◽  
Fractal Dimensions ◽  
Solid Particles ◽  
Two Phase ◽  
Fractal Media ◽  
Proposed Model ◽  
Three Phase ◽  
Multi Phase ◽  
Good Agreement

The size distributions of solid particles and pores in porous media are approximately hierarchical and statistically fractals. In this paper, a model for single-phase fractal media is constructed, and the analytical expressions for area, fractal dimension and distribution function for solid particles are derived. The distribution function of solid particles obtained from the proposed model is in good agreement with available experimental data. Then, a model for approximate two-phase fractal media is developed. Good agreement is found between the predicted fractal dimensions for pore space from the two-phase fractal medium model and the existing measured data. A model for approximate three-phase fractal media is also presented by extending the obtained two-phase model.

scholarly journals The effects of real and simulated microgravity on cellular mitochondrial function

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hong Phuong Nguyen ◽  
Phuong Hoa Tran ◽  
Kyu-Sung Kim ◽  
Su-Geun Yang
Keyword(s):  
Oxidative Stress ◽  
Respiratory Chain ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Simulated Microgravity ◽  
Space Shuttle ◽  
Parabolic Flight ◽  
Space Station ◽  
Microgravity Environment ◽  
Mitochondrial Stress

AbstractAstronauts returning from space shuttle missions or the International Space Station have been diagnosed with various health problems such as bone demineralization, muscle atrophy, cardiovascular deconditioning, and vestibular and sensory imbalance including visual acuity, altered metabolic and nutritional status, and immune system dysregulation. These health issues are associated with oxidative stress caused by a microgravity environment. Mitochondria are a source of reactive oxygen species (ROS). However, the molecular mechanisms through which mitochondria produce ROS in a microgravity environment remain unclear. Therefore, this review aimed to explore the mechanism through which microgravity induces oxidative damage in mitochondria by evaluating the expression of genes and proteins, as well as relevant metabolic pathways. In general, microgravity-induced ROS reduce mitochondrial volume by mainly affecting the efficiency of the respiratory chain and metabolic pathways. The impaired respiratory chain is thought to generate ROS through premature electron leakage in the electron transport chain. The imbalance between ROS production and antioxidant defense in mitochondria is the main cause of mitochondrial stress and damage, which leads to mitochondrial dysfunction. Moreover, we discuss the effects of antioxidants against oxidative stress caused by the microgravity environment space microgravity in together with simulated microgravity (i.e., spaceflight or ground-based spaceflight analogs: parabolic flight, centrifugal force, drop towers, etc.). Further studies should be taken to explore the effects of microgravity on mitochondrial stress-related diseases, especially for the development of new therapeutic drugs that can help increase the health of astronauts on long space missions.

Experimental Investigation on Air-Solid Two-Phase Mixture Discharge under AC Voltage

2011 ◽  
Vol 383-390 ◽  
pp. 4955-4961
Author(s):  
Wen Jun Yao ◽  
Zheng Hao He ◽  
He Ming Deng
Keyword(s):  
Gas Flow ◽  
Volume Fraction ◽  
Fundamental Problem ◽  
Solid Particles ◽  
Two Phase ◽  
The Common ◽  
Phase Mixture ◽  
Multi Phase ◽  
Inception Voltage ◽  
Statistical Rule

Multi-phase mixture (MPM) discharge has the common characteristics of randomness with air but more complex. How about the statistical rule of MPM discharge ? This is not only a fundamental problem for discharge research, but it has its own strong applied and practical characteristics. The air-solid two-phase mixtures(ASTPM) are employed to study and carry out some experiments for investigating the development and breakdown of MPM discharge under AC voltage. The results from experimental data show that the AC breakdown voltage and corona-inception voltage will drop when the solid particles are added to the discharge chamber with different permittivity and volume fraction. And there is no influence in gas flow and the corona current.

Experiment Study on a Novel Foam System for Enhanced Oil Recovery

2011 ◽  
Vol 311-313 ◽  
pp. 396-405 ◽  
Author(s):  
Zhao Min Li ◽  
Zu Peng Liu
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Control Agent ◽  
Solid Particles ◽  
Mobility Control ◽  
Two Phase ◽  
Orthogonal Experiments ◽  
Profile Control ◽  
Multi Phase ◽  
Micro Sphere

Abstract. Foam, as a mobility control agent in enhanced oil recovery, is becoming more and more attractive. However, this method may be inefficient when water channeling appears in the reservoir due to its heterogeneity. Therefore, it is reasonable to block its flow through preferential channels by an enhanced foam system. A novel foam system is developed by the combination of general two phase foam system with solid particles to improve its performance for deep conformance control in reservoirs. This new foam system involves gas, liquid and particles. Firstly, micro-sphere shape and morphological distribution of particles have been observed through the microscope. Destruction mechanism and stability of multi-phase foam were analyzed in theory. In addition, the concentration of polymer and solid micro-sphere used as the foam agent were determined by orthogonal experiments. Next, micro-sphere displacement experiment shows that it can not only block throats but also migrate through throats by deformation, which can be represented by the pressure curves. Multi-phase foam system presents a similar pressure fluctuation with micro-sphere flooding. Finally, the parallel core experiments were conducted to investigate pressure distribution of two phase foam and multi-phase foam system in porous media respectively. The results show that multi-phase foam can effectively improve the profile control ability and it is adaptable for deep conformance in reservoir.

scholarly journals Space Flight Effects on Antioxidant Molecules in Dry Tardigrades: The TARDIKISS Experiment

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Angela Maria Rizzo ◽  
Tiziana Altiero ◽  
Paola Antonia Corsetto ◽  
Gigliola Montorfano ◽  
Roberto Guidetti ◽  
...  
Keyword(s):  
Space Shuttle ◽  
Space Station ◽  
Total Content ◽  
Thiobarbituric Acid ◽  
Space Experiment ◽  
Microgravity Environment ◽  
Dna Integrity ◽  
Ros Scavenging ◽  
And Control ◽  
Control Samples

The TARDIKISS (Tardigrades in Space) experiment was part of the Biokon in Space (BIOKIS) payload, a set of multidisciplinary experiments performed during the DAMA (Dark Matter) mission organized by Italian Space Agency and Italian Air Force in 2011. This mission supported the execution of experiments in short duration (16 days) taking the advantage of the microgravity environment on board of the Space Shuttle Endeavour (its last mission STS-134) docked to the International Space Station. TARDIKISS was composed of three sample sets: one flight sample and two ground control samples. These samples provided the biological material used to test as space stressors, including microgravity, affected animal survivability, life cycle, DNA integrity, and pathways of molecules working as antioxidants. In this paper we compared the molecular pathways of some antioxidant molecules, thiobarbituric acid reactive substances, and fatty acid composition between flight and control samples in two tardigrade species, namely,Paramacrobiotus richtersiandRamazzottius oberhaeuseri. In both species, the activities of ROS scavenging enzymes, the total content of glutathione, and the fatty acids composition between flight and control samples showed few significant differences. TARDIKISS experiment, together with a previous space experiment (TARSE), further confirms that both desiccated and hydrated tardigrades represent useful animal tool for space research.

Rationalized Concise Descriptions of Fluid Motions in an Oscillating/Pulsating Heat Pipe

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Masao Furukawa
Keyword(s):  
Heat Pipes ◽  
Pressure Oscillation ◽  
Angular Frequency ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Two Phase ◽  
Convenient Means ◽  
Oscillation Velocity ◽  
Condensing Heat Transfer

Various ways developed so far in modeling oscillating/pulsating heat pipes (OHPs/PHPs) are briefly reviewed to find which way would be serviceable for design purposes and also be helpful to mathematically plainly describe oscillatory/circulatory motions of the charged working fluid. A selected way basically follows Ma's approach but a theoretically new attempt is made to derive the oscillation angular frequency ratio from two differently represented expressions of the oscillation velocity. A two-phase flow and evaporative/condensing heat transfer analysis is then carried out to get the wave equation of pressure oscillation. Finally obtained are closed-form algebraic expressions, providing us with convenient means of predicting the oscillation frequency- and-amplitude and the wave velocity. To demonstrate the applicability of those expressions, numerical comparisons are extensively done between our predictions and many other ones.

scholarly journals ADVANCED TWO-PHASE PASSIVE THERMAL CONTROL DEVICES: LOOP HEAT PIPES AND PULSATING HEAT PIPES

2006 ◽  
Vol 5 (1) ◽  
pp. 54
Author(s):  
Roger R. Riehl
Keyword(s):  
Heat Pipes ◽  
Experimental Tests ◽  
Thermal Control ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Two Phase ◽  
Space Applications ◽  
Source Temperature ◽  
Loop Heat Pipes ◽  
Control Devices

This paper presents the development of two-phase passive thermal control devices that can be used at both ground and space applications. These devices operate by acquiring heat through their evaporation section and rejecting through their condensation section, keeping a tight control on the heat source temperature without the presence of moving parts. Recent researches with loop heat pipes (LHPs) have showed the great capability of such a device in managing high levels of heat while keeping the source temperature within certain levels. For this case, experimental tests of a LHP are presented, where the behavior related to its operation with power cycles can be evaluated and its performance can be verified. This paper also presents an investigation of a two-phase thermal control device called pulsating heat pipe (PHP) configured as an open loop. Experimental tests with different working fluids are presented, which shows the great capability of the PHP in operating at both horizontal and vertical orientations and promoting the thermal control, which is highly affected by the working fluid and geometric parameters. The experimental results presented for both devices are intended to contribute for the continuous development of these two passive thermal control devices.

Technology of high quality protein crystals’ obtaining aboard the ISS at execution of joint Japanese–Russian experiments

2020 ◽  
pp. 5-25
Author(s):  
Koji INAKA ◽  
Saori ICHIMIZU ◽  
Izumi YOSHIZAKI ◽  
Kiyohito KIHIRA ◽  
Elena G. LAVRENKO ◽  
...  
Keyword(s):  
Drug Design ◽  
International Space Station ◽  
Space Station ◽  
Protein Crystals ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
High Quality ◽  
International Space ◽  
X Ray ◽  
High Quality Protein

A series of space experiments aboard the International Space Station (ISS) associated with high-quality Protein Crystal Growth (PCG) in microgravity conditions can be considered as a unique and one of the best examples of fruitful collaboration between Japanese and Russian scientists and engineers in space, which includes also other ISS International Partners. X-ray diffraction is still the most powerful tool to determine the protein three dimensional structure necessary for Structure based drug design (SBDD). The major purpose of the experiment is to grow high quality protein crystals in microgravity for X-ray diffraction on Earth. Within one and a half decade, Japan and Russia have established an efficient process over PCG in space to support latest developments over drug design and structural biology. One of the keys for success of the experiment lies in how precisely pre-launch preparations are made. Japanese party provides flight equipment for crystallization and ensures the required environment to support the experiment aboard of the ISS’s Kibo module, and also mainly takes part of the experiment ground support such as protein sample characterization, purification, crystallization screening, and solution optimization for microgravity experiment. Russian party is responsible for integration of the flight items equipped with proteins and precipitants on board Russian transportation space vehicles (Soyuz or Progress), for delivery them at the ISS, transfer to Kibo module, and returning the experiments’ results back on Earth aboard Soyuz manned capsule. Due to close cooperation of the parties and solid organizational structure, samples can be launched at the ISS every half a year if the ground preparation goes smoothly. The samples are crystallized using counter diffusion method at 20 degree C for 1–2.5 months. After samples return, the crystals are carefully taken out from the capillary, and frozen for X-ray diffraction at SPring8 facility in Japan. Extensive support of researchers from both countries is also a part of this process. The paper analyses details of the PCG experiment scheme, unique and reliable technology of its execution, and contains examples of the application. Key words: International Space Station, Protein crystals, Microgravity, International collaboration.

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