85 research outputs found
Experimental study for local air/water flow structure of bubbly and slug flow regime
Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.A study for local hydraulic characteristics of water and air/steam mixture flow is a very challenging topic for advanced thermal hydraulic analysis code development. Recently, many researchers made efforts in the study of mechanistic feature related to the two phase dynamics such as an interfacial area transport model. The mechanistic study for the interfacial area needs a lot of understanding for the bubble/drop dynamics and flow propagation phenomena. To generate an experimental data base for a modeling, an air/water test was performed in this study. The facility has a cylindrical acryl test section of which the diameter and height are 80 mm and 10m, respectively. The major local parameters to be measured are the void fraction, bubble/liquid velocities, interfacial area concentration and bubble size. To investigate the transport phenomena of the twophase parameters, a local probe and an impedance void meter(IVM) are installed at three axial elevations of the test section. (L/D=12.2, 42.2, 100.7) The test range covers 0.5~2.8 m/s and 0.04~1.2 m/s of the superficial liquid and gas velocity, respectively, which corresponds to the bubbly and slug flow regimes. The system pressure conditions are 0.2~0.3 MPa at the L/D=12.2.dc201
Hydraulic characteristics of smart reactor for a nominal condition
Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.SMART (System-integrated Modular Advanced ReacTor) is an integral-type reactor being developed, which has major components including core, pumps, steam generators and a pressurizer inside the reactor vessel. In order to analyze the various safety features of the reactor, the quantification for the flow and pressure distributions are very important. A test facility, named âSCOPâ, was designed based on the conservation of Euler number which is a ratio of pressure drop to dynamic pressure with a sufficiently high Reynolds number. In order to preserve the flow distribution characteristics, the SCOP is linearly reduced with a scaling ratio of 1/5. For the present work, a total of 9 tests were performed for a nominal SMART flow condition. By using the test results, a statistical final flow distribution for the SMART reactor were presented. The current data could be applied for the validation of a CFD analysis method as well as reactor safety and system performance analyses.dc201
Hydraulic characteristics of smart reactor for a nominal condition
SMART (System-integrated Modular Advanced ReacTor) is an integral-type reactor being developed, which has major components including core, pumps, steam generators and a pressurizer inside the reactor vessel. In order to analyze the various safety features of the reactor, the quantification for the flow and pressure distributions are very important. A test facility, named âSCOPâ, was designed based on the conservation of Euler number which is a ratio of pressure drop to dynamic pressure with a sufficiently high Reynolds number. In order to preserve the flow distribution characteristics, the SCOP is linearly reduced with a scaling ratio of 1/5. For the present work, a total of 9 tests were performed for a nominal SMART flow condition. By using the test results, a statistical final flow distribution for the SMART reactor were presented. The current data could be applied for the validation of a CFD analysis method as well as reactor safety and system performance analysesPaper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012
Photocatalytic Ohmic layered nanocomposite for efficient utilization of visible light photons
The WO3/W/PbBi2Nb1.9Ti0.1O9 photocatalyst was fabricated by depositing the tungsten clusters over the p-type perovskite base material with the chemical vapor deposition method, and later partly oxidizing the surfaces of these clusters to obtain n-type WO3 overlayers and W metal layer as an Ohmic junction. This NCPC showed unprecedented high activity for the photocatalytic oxidation of water, photocurrent generation, and acetaldehyde decomposition under visible light irradiation (lambda >= 420 nm). (c) 2006 American Institute of Physicsclose313
Band gap tuning of lead-substituted BaSnO3 for visible light photocatalysis
The Pb substitution effect was investigated experimentally and theoretically on the crystal structure of BaSnO3 and on the photo-oxidation activity of H2O. The chemically doped Pb in BaSnO3 induced a concentration-dependent redshift of the experimental band gap (BG). The BaPb0.8Sn0.2O3 system produced 32 mu mol/h of O-2 under lambda >= 420 nm photons, but no O-2 for BaSnO3. The DFT calculations of BaPbxSn1-xO3 (x=0,0.5,1) by using generalized approximation, implying the BG alteration and the photocatalytic activity of BaPbxSn1-xO3, are due to the induced Pb 6s orbital in the BG of BaSnO3. Thus Pb modified the insulating nature of BaSnO3 to semiconducting and semimetallic. (c) 2007 American Institute of Physicsclose343
Perceptions of the appropriate response to norm violation in 57 societies
Norm enforcement may be important for resolving conflicts and promoting cooperation. However, little is known about how preferred responses to norm violations vary across cultures and across domains. In a preregistered study of 57 countries (using convenience samples of 22,863 students and non-students), we measured perceptions of the appropriateness of various responses to a violation of a cooperative norm and to atypical social behaviors. Our findings highlight both cultural universals and cultural variation. We find a universal negative relation between appropriateness ratings of norm violations and appropriateness ratings of responses in the form of confrontation, social ostracism and gossip. Moreover, we find the country variation in the appropriateness of sanctions to be consistent across different norm violations but not across different sanctions. Specifically, in those countries where use of physical confrontation and social ostracism is rated as less appropriate, gossip is rated as more appropriate.info:eu-repo/semantics/publishedVersio
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