Analyses of hydrogen distribution around fatigue crack on type 304 stainless steel using secondary ion mass spectrometry

Secondary Ion Mass Spectrometry (SIMS) analyses were carried out on type 304 austenitic stainless steel. On annealed specimen exposed to hydrogen (10 MPa, 358 K), Element Depth Profiles SIMS mode was able to describe quantitatively the hydrogen profile content computed by the Fick’s law. Based on SIMS analyses on the wake of a fatigue crack (propagation in hydrogen gas at 0.6 MPa and RT), it was possible to compute an apparent diffusivity and solubility in the crack tip region. The apparent solubility and diffusivity in the deformed regions were two times and five orders of magnitude higher than the ones on annealed material, respectively. High hydrogen content was found around the crack tip, where the plastic deformation was well developed (pronounced slip activity). The high apparent diffusivity is presumed to result from enhanced hydrogen transport induced by cyclic plastic activity at the crack tip.a Arts et Me´tiers ParisTech, I2M, UMR CNRS 5295, Universite´ de Bordeaux, Esplanade des Arts et Me´tiers, 33405 Talence Cedex, France b Department of Mechanical Engineering, Kyushu University, Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan c Research Center for Hydrogen Industrial Use and Storage, National Institute of Advanced Industrial Science and Technology (HYDROGENIUS), Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan d CNRS, UMR 5395, I2M, Universite´ de Bordeaux, Arts et Me´tiers ParisTech, Talence, Franc

Numerical Analysis of Outdoor Thermal Environment in City Block Area Using Coupled Simulation of Convection and Radiation -Part 2 CFD Study on of Outdoor Thenna1 Environment sing Modified κ-ε model -

In this study, velocity, temperature and humidity fields in urban area were analyzed using CFD technique developed by the authors. Spatial distribution of SET* is calculated in order to assess pedestrian comfort from the CFD predictions. It was darified that 1) revised κ-ε model can predict the velocity field and temperature field more accurately　than does the stndard κ-ε model， 2) greening is effective for relaxation of thermal environment on the urban area in summer，3) coupled simulation of radiation and convection with incorporating of moisture transport is very powerful tool for eva1uating the outdoor environment

Numerical Analysis of Outdoor Thermal Environment in City Block Area Using Coupled Simulation of Convection and Radiation -Part 2 CFD Study on of Outdoor Thenna1 Environment sing Modified κ-ε model -

In this study, velocity, temperature and humidity fields in urban area were analyzed using CFD technique developed by the authors. Spatial distribution of SET* is calculated in order to assess pedestrian comfort from the CFD predictions. It was darified that 1) revised κ-ε model can predict the velocity field and temperature field more accurately　than does the stndard κ-ε model， 2) greening is effective for relaxation of thermal environment on the urban area in summer，3) coupled simulation of radiation and convection with incorporating of moisture transport is very powerful tool for eva1uating the outdoor environment

High Resolution Crystal Structure of KD-247, a Humanized Antibody that Inhibits HIV Entry [abstract]

Comparative Medicine - OneHealth and Comparative Medicine Poster SessionHighly active antiretroviral therapy (HAART) has been very efficient in reducing the rate of mortality of human immunodeficiency virus type 1 (HIV-1) infected patients. However, resistance to clinically used drugs inevitably develops and impairs the potency of these drugs. There is also no vaccine available to prevent the spread of the virus. Our collaborators, Dr. Shuzo Matsushita and his colleagues have developed a monoclonal antibody, KD-247, that is currently in Phase Ib clinical trials for the treatment of HIV-1 infections. KD-247 blocks virus entry into host cells by binding to the V3 loop of the surface glycoprotein of HIV. It is the first humanized antibody shown to neutralize a wide range of subtype B HIV viruses (Matsushita et al. Hum. Antibodies, 14, 81) and to prevent HIV infection in cell culture and in a chimpanzee model (Eda et al. J. Virol., 80, 5563). KD-247 reacts exclusively with subtype B viruses (Eda et al. J. Virol., 80, 5552). In order to understand the molecular basis of this specificity we have solved the crystal structure of KD-247 at 1.5 Å resolution, the highest resolution structure for any humanized antibody reported to date. The present structure reveals in atomic detail the molecular boundaries of a pocket formed by the antigen-binding region of the antibody. Molecular docking experiments of a pre-existing structure of the V3-loop target at the presumed binding pocket on KD-247 suggest possible molecular interactions involved in HIV resistance to KD-247 and clade B specificity. A G314E V3 loop mutation that has been reported to confer resistance to KD-247 (Yoshimura et al., AIDS 20, 2065) appears to result in steric interactions between the tip of the V3 loop and residues of the heavy chain of KD-247. Further, Arg315, a residue critical for clade B specificity, appears to form extensive interactions with multiple residues of KD-247. Analysis of these interactions has provided insights into the design of second-generation antibodies with broader subtype specificity and improved ability to evade resistance mutations. This work is a product of collaborations between the University of Missouri and researchers at Kumamoto University, an academic institution in Japan, and the Chemo-Sero-Therapeutic Research Institute, an industrial partner in Japan, working to commercialize the antibody and further its progress in clinical trials

CFD Analysis of flowfield around building using revised k-ε models based on mixed time-scale

The flowfields around a front-step and a cubic shaped building model placed within the surface boundary layer were analyzed by using various k-ε models; namely standard k-ε, Durbin’s revised k-ε and revised k-ε with mixed time-scale concept. The calculated results are compared with those of wind tunnel experiment. Turbulent kinetic energy k around the windward corner is overestimated by the standard k-ε and the Ω type revised k-ε models, while it is improved by the S type model and the model proposed by Durbin. However, all revised k-ε models overestimate the reattachment length behind the building in comparison with the experimental data

CFD Analysis of flowfield around a high-rise building using various revised k-ε models

The flowfield around a high-rise building model placed within the surface boundary-layer was analyzed using various revised k-ε models, and these results were compared with the result of DSM and the experimental data. The standard k-ε model could not reproduce the reverse flow on the roof. This drawback was corrected by all revised k-ε models and DSM tested here. However the revised k-ε models except for the model proposed by Durbin overestimated the reattachment length behind the building in comparison with the standard k-ε model. Among the computations using various turbulence models compared here, the result with the Durbin’s revised k-ε model showed the best agreement with the experiment

トシ ニ オケル チヒョウメンオンドサ ノ ブッシツカクサン ニ オヨボス エイキョウ ニ カンスル ジッケンテキケンキュウ

This paper describes the effects of the ground surface temperature difference on gaseous diffusion in built-up area by ndd experiments and by the wind tunnel investigations. In the field experiments, the black panels with high absorbance of solar radiation were used as the model of the ground surface to produce the fully developed thermal boundary layer. It has been confirmed from the field experiments as follows ; (1) the thermal boundary layer is sufficiently developed in small-scale experiments by using the panels ; (2) the turbulent intensity of the air flow on the panels becomes larger in propotion to the total solar radiation on a horizontal plane. In the wind tunnel investigations, the thermal boundary layer observed in the field experiments was simulated by using the hot panel with electrical heaters. The other thermal boundary layers generated by the difference of the surface temperature were studied by changing the arrangement of the Panels. For example, the cool surface zone in "parks and green belts" was also simulated by the cold panel with cold water. The tracer gas was emitted from the stack upwind of the hot panel in order to clarify the effects of the surface temperature difference on gaseous diffusion. It has been confirmed from the wind tunnel investigations as follows ; (3) in the case of setting only the hot panel in the wind tunnel, when the temperature difference between the oncoming air and the surface of the hot panel becomes larger, the maximum concentration on the floor decreases gradually ; (4) when the cold panel is set on the leeward of the hot panel, a large cooled air region is generated on the cold panel. As the result, the maximum concentration appears at higher position from the ground surface than in the case of setting only the hot panel

Study on urban climate analysis based on meso-scale model incorporated with the Urban Canopy Model

特集1 乱流シミュレーションと流れの設計(TSFD

Numerical Analysis of Local Climate in Niigata Area

Velocity and temperature fields in Niigata area were predicted numerically using the turbulence closure model developed by Mellow and Yamada. Two cases of predictions were carried out. In case 1, the present situations of land-use were incorporated into the prediction through the boundary conditions at the ground surface, while values of surface parameters in the area of rice field were changed to the values corresponding to the paved road in case2. Effects of the rice field on local climate in summer season were discussed by comparing the results of these two cases

ジッソク ニ モトヅク シガイチ ノ カゼカンキョウ ノ ヒョウカ

The ground level wind speeds around two projected tall buiIdings in built-up areas were observed over a period of 3 years from the beginning of construction to end. Mean wind speed ratio and gust factor at ground level are obtained. The probability distributions of mean gradient wind in this area are approximated on the basis of the Weibull distribution. The probabilities of exceeding daily maxmum gust speed are calculated from these observed wind data. Then, the evaluation of the acceptability of ground level wind environment are discussed using a proposed pedestrian comfort criteria