Flow-field in a vortex with breakdown above sharp edged delta wings

The behavior of vortex-flow, accompanied with breakdown, formed above sharp-edged delta wings, was studied experimentally as well as theoretically. Emphasis is placed particularly on the criterion for the breakdown at sufficiently large Reynolds number

Fermion masses in SUSY SO(10) with type II seesaw: a non-minimal predictive scenario

A predictive framework for fermion masses and mixing is given by the supersymmetric SO(10) model with one 10, one bar126, one 126 and one 210 Higgs representations, and type II seesaw dominating the neutrino mass matrix. We investigate the origin of the tension between this model and lepton mixing data and refine previous numerical analyses. We discuss an extension of the minimal model that includes one 120 Higgs chiral superfield representation. This exhausts the possible renormalizable contributions to the Yukawa sector. In spite of the increase in the number of parameters the predictivity of the minimal setting is not spoiled. We argue that the contributions to fermion masses due to the doublet components of 120 can be naturally small compared to those of 10 and 126, thus acting as a perturbation in the fermion mass generation. The antisymmetric nature of the 120 Yukawa coupling affects at leading order the determination of the mixing angles and it allows to remove the inconsistencies between predictions and data on the neutrino parameters. An improvement in the experimental bound on |Ue3| can tell this scenario from the minimal model.Comment: 11 pages, 3 figures; Note and references added on new KamLAND dat

Influence of climate change on storm surges in the Ariake sea

The influence of climate change on storm surges in the Ariake Sea was evaluated using the stochastic\ud typhoon model. The Ariake Sea is located in the middle of Kyushu Island, Japan and has been attacked by severe\ud typhoons many times. There are many lowland coastal farmlands along the coastline of the Ariake Sea as a result of\ud many reclamation projects since ancient times. These coastal farmlands are at risk of even more severe storm surges due\ud to typhoons caused by climate change. The deviations of tides due to storm surges were simulated by an experimental\ud typhoon model employing the Myers model. The stochastic typhoon model generated the tracks and attributes of\ud typhoons over the next 2,000 years. Meanwhile, the tracks of typhoons in the case of the climate after climate change\ud were generated by shifting the start points of typhoons 0.9 degrees further north and 1.9 degrees further east. The\ud number of typhoons after climate change was set to 0.79 times that of typhoons in the present climate. These changes in\ud the tracks and number of typhoons in the future were decided according to the results of numerical simulations of\ud climate change using the AGCM model based on the A1B scenario. The non-exceedance probabilities of the yearmaximum\ud anomaly rise were compared to evaluate the change due to climate change. The simulation suggested that the\ud height of the year-maximum anomaly rise due to storm surges in the future climate will be similar to or slightly lower\ud than the present height

Damages caused by 3/11 Great East Japan earthquake on coastal drainage pumping stations along Sendai bay

On March 11, 2011, a tsunami struck low-lying land along Sendai Bay, where no tsunami had hit in the past 200 years. These coastal lowlands were equipped with drainage pumping stations for paddy areas, but the pumping stations were destroyed by the tsunami, thus preventing drainage of the sea water inundation.There are two kinds of pumps, motor and diesel pumps. Even diesel pumps need electricity to start up and control their power. If a pump is inundated by salt water, all electric parts will be short-circuited. Although the diesel mechanisms can be reused after being washed by fresh water, the electric parts of both types of pump must be replaced. The switchboard for the pumps must also be replaced. If damages are caused only by salt inundation, the electric parts of both types of pump must be replaced. Temporary recovery was done by manually controlling the pumps because the automatic pump control system was difficult to restore. The mean recovery time was one month for electric pumps and two months for diesel pumps. For pumps that were broken by external force, quick recovery was abandoned.Past studies on tsunami have shown that concrete structures are strong enough to withstand tsunami surges. In the present study, a few concrete pumping stations located near the coast were damaged. The damages to buildings were mainly governed by the type of material and location on the coast. At some pumping stations, the tank for desorption prevented external forces from acting on the buildings.These results show that the tsunami safety of drainage pumping stations could be improved by increasing the resistance to salt inundation and appropriately locating the tank for desorption

Oxidation of Nickel in AlCl3-1-Butylpyridinium Chloride at Ambient Temperature

We have studied in detail the electrochemical reaction of nickel in several kinds of molar ratio-controlled molten salts consisting of AlCl(3) and 1-butylpyridinium chloride (BPC) at 40°C. We observed NiCl(2) as an oxidation product from nickel on the surface of the electrode in slightly acidic AlCl(3)/BPC salts with molar ratios of 1.05/1.0 and 1.1/1.0. However, in strongly acidic salt with the ratio of 1.5/1.0, NiCl(2) deposits on the electrode less than when in the above salts, and no NiCl(29) is observed in basic and neutral salts with the ratio of 1.0/1.0 or less AlCl(3) content. This suggests that [NiCl(4)](2−) ions form as the oxidation of nickel in such neutral and basic AlC(3)/BPC (salts)