Phase boundary between ilmenite and perovskite structures in MnGeO3 determined by in situ X-ray diffraction measurements

In situ X-ray observations of the phase transition from ilmenite to perovskite structure in MnGeO₃ were carried out in a Kawai-type high-pressure apparatus interfaced with synchrotron radiation. The phase boundary between the ilmenite and perovskite structures in the temperature range of 700–1,400°C was determined to be P (GPa) = 16.5(±0.6) − 0.0034(±0.0006)T (°C) based on Anderson’s gold pressure scale. The Clapeyron slope, dP/dT, determined in this study is consistent with that for the transition boundary between the ilmenite and the perovskite structure in MgSiO₃.     

Effect of isolation on fragility curves of highway bridges based on simplified approach

The trend of isolating highway bridges is on the rise after the recent large earthquakes in Japan, the United States, and other countries. Recent investigation shows that isolated systems perform well against seismic forces as the substructures of such systems experience less lateral forces due to energy dissipation of the isolation device. Hence, it is anticipated that there might be an effect on fragility curves of highway bridges due to isolation. In this study, 30 isolated bridge models were considered (and they were designed according to the seismic design code of highway bridges in Japan) to have a wider range of the variation of structural parameters, e.g. pier heights, weights, and over-strength ratio of structures. Then, fragility curves were developed by following a simplified procedure using 250 strong motion records, which were selected from 5 earthquake events that occurred in Japan, the USA, and Taiwan. It is observed that the level of damage probability for the isolated system is less than that of the non-isolated one for a lower level of pier height. However, having the same over-strength ratio of the structures, the level of damage probability for the isolated system is found to be higher for a higher level of pier height compared to the one of the non-isolated system. The proposed simple approach may conveniently be used in constructing fragility curves for a class of isolated bridge structures in Japan that have similar characteristics.     

Tsunami Assessment for Risk Management at Nuclear Power Facilities in Japan

The present study focuses on evaluation of the maximum and minimum water levels caused by tsunamis as risk factors for operation and management at nuclear power facilities along the coastal area of Japan. Tsunamis generated by submarine earthquakes are examined, basing literature reviews and databases of information on historical tsunami events and run-up heights. For simulation of water level along the coast, a numerical calculation system should be designed with computational regions covering a particular site. Also the calculation system should be verified by comparison of historical and calculated tsunami heights. At the beginning of the tsunami assessment, the standard faults, their locations, mechanisms and maximum magnitudes should be carefully estimated by considering historical earthquake-induced tsunamis and seismo-tectonics at each area. Secondly, the range of errors in the model parameters should be considered since earthquakes and tsunamis are natural phenomena that involve natural variability as well as errors in estimating parameters. For these reasons, uncertainty-induced errors should be taken into account in the process of tsunami assessment with parametric study of the tsunami source model. The element tsunamis calculated by the standard fault models with the errors would be given for the design. Then, the design tsunami can be selected among the element tsunamis with the most significant impact, maximum and minimum water levels, on the site, bearing in mind the possible errors in the numerical calculation system. Finally, the design tsunami is verified by comparison with the run-up heights of historical tsunamis, ensuring that the design tsunami is selected as the highest of all historical and possible future tsunamis at the site.     

Studying air pollution with kitt peak solar flux atlas — analysis method and results of observation

For the measurement of atmospheric NO2 vertical column density (VCD), Kitt Peak Solar Flux Atlas can be substituted as an extraterrestrial solar radiation. Compared with differential analysis method, the Taylor expansion of integrated transfer equation underestimates the VCD. This underestimation is as large as 35% when the amount of NO2 is 1 × 1017 cm－2 and observation is conducted with an air mass factor of 10. Even when the VCD is 2 × 1016 cm－2 and the air mass factor is 4, the relative error of the retrieved VCD is still no less than 3%. If the observation is restricted under the small air mass factor condition (≤4), with Kitt Peak Solar spectrum as an extraterrestrial solar radiation, only an atmospheric layer of 2 km thick from ground can be studied, which will make the absorption too weak to be detected by normal instruments.The VCD in winter Tokyo area was observed and analyzed by differential method, which shows a good precision even when the absorption is as low as 3%. The largest average VCD was about 1.3 × 1017 cm－2, and the lowest was about 1.3 × 1016 cm－2. The trend of its variation was almost the same as the ground level observation by Saltzman reagent method.     

Studying Air Pollution with Kitt Peak Solar Flux Atlas—Analysis Method and Results of Observation

l.Introducti0nTwoflightsoftheSAGEIIIinstrumentwereplanedbeinglaunchedinJune2O00byRussianMeteor-3Mandin2002byInternationalSpaceStation(ISS).Itisexpectedthattheywouldofferinformationofalmostglobalcoverage.Theseinstrumentswillutilizetheselfcal-ibratingsolaroccultationtechniquetomeasureprofilesofaerosoIextinctionfrom0to4Okm,ozonefrom6to85km,nitrogendioxidefroml0to5Okm,andwatervaporfrom0to5Okm,andutilizelunaroccultationobservati0nstomonitorthekeynighttimesPecies,nitrogentrioxidefrom22to55k…     

Localized changes in geomagnetic total intensity values prior to the 1995 Hyogo-ken Nanbu (Kobe) earthquake

Changes in total geomagnetic field intensity, of 2–3 nT, were observed prior to the 1995 Hyogo-ken Nanbu (Kobe) earthquake at the Amagase (AMG) site, located approximately 70 km from the epicenter. We examined whether the observed variations are local signals arising from the Earth's crust, or global variations that are unlikely to originate from the crust. To remove global-scale variations in total geomagnetic intensity data, we employed a regional geomagnetic field model. Using data recorded at five reference sites in Japan, we estimated global-scale variations in total geomagnetic intensity, and removed them from the observed total geomagnetic intensity at the AMG site. The reminder still showed variations during the period prior to the Kobe earthquake. In addition, these pre-seismic variations include two of the largest shifts recorded during the entire observation period at the AMG site, raising the possibility that these variations were indeed related to the earthquake. These variations cannot be interpreted as signals arising from the area close to the seismic source because of the large distance between the epicenter and the site. Therefore, our results raise the possibility that the physical state of the Earth's crust shows marked changes over a wide region in the lead-up to a seismic event.     

Modeling of 500-year tsunamis for probabilistic design of coastal infrastructure in the Pacific Northwest

This paper describes the development of tsunami scenarios from the National Seismic Hazard Maps for design of coastal infrastructure in the Pacific Northwest. The logic tree of Cascadia earthquakes provides four 500-year rupture configurations at moment magnitude 8.8, 9.0, and 9.2 for development of probabilistic design criteria. A planar fault model describes the rupture configurations and determines the earth surface deformation for tsunami modeling. A case study of four bridge sites at Siletz Bay, Oregon illustrates the challenges in modeling of tsunamis on the Pacific Northwest coast. A nonlinear shallow-water model with a shock-capturing scheme describes tsunami propagation across the northeastern Pacific as well as barrier beach overtopping, bore formation, and detailed flow conditions at Siletz Bay. The results show strong correlation with geological evidence from the six paleotsunamis during the last 2800 years. The proposed approach allows determination of tsunami loads that are consistent with the seismic loads currently in use for design of buildings and structures.     

Energy Balance of Irrigated Intercropping Field in the Middle Reaches of Heihe River Basin

1 Introduction Most of the solar radiation that ecosystem seizes is con- sumed on latent, sensible and soil heat flux. Among them, latent heat flux shares the biggest part (Gutierrez and Meizer, 1994; Ham et al., 1991; Rachidi et al., 1993). The radiation budget and the energy balance are crucial to water conversion and effective water utilization. Also, they are important parts of research of water-saving ag- riculture (Mo et al., 1997). At present, the researches on radiation budget and e…