A sensitive study of real time storm surge forecast model to meteorological and hydrodynamic fields along the Sanin coast, Japan

In the present study, the performance of the real time storm surge forecast model based on the neural network is examined by forecasting Typhoon Megi storm surge 2003 at Sakai, Japan in terms of a variety of the combinations of data obtained from Typhoons Songda 2004 and Maemi 2003. In the experiments, the data sets are trained with the meteorological data measured at five stations: the sea level pressure, the depression rate of the sea level pressure, the wind speed, the wind direction; the hydroulic data: the sea surface level and the storm surge at Sakai; the typhoon parameters: the typhoon position, the central pressure of the typhoon and the highest wind speed near the typhoon center. In addition, the forecast time spans of 01, 02, 03, 04, 05, 12 and 24 hours are investigated for all cases of the data sets. From the results, It is found that the performance of the real time forecast models shows best when training the neural network with the data set of the storm surge, the sea level pressure, the depression rates of the sea level pressure, the wind speed and the typhoon position at Sakai

Modeling of damage progression for rubble mound revetment

Based on the experimental results for profile change of rubble mound revetment, the modeling of damage progression process is discussed in this study. The ranks that indicate the degree of damage for the revetment are determined and the ratio for each rank of damage level is obtained from the experimental data. Three models based on Markov chain model are applied to the transition process of the ratio. The stationary transition probability is obtained for each model and the damage progression is predicted. The model that includes the transition to more than two ranks can predict the transition process of the ratio well

Atmospheric chemistry of cyclohexanone: UV spectrum and kinetics of reaction with chlorine atoms

Absolute and relative rate techniques were used to study the reactivity of Cl atoms with cyclohexanone in 6 Torr of argon or 800–950 Torr of N 2 at 295 ± 2 K. The absolute rate experiments gave k (Cl + cyclohexanone) = (1.88 ± 0.38) × 10 −10 , whereas the relative rate experiments gave k (Cl + cyclohexanone) = (1.66 ± 0.26) × 10 −10 cm 3 molecule −1 s −1 . Cyclohexanone has a broad UV absorption band with a maximum cross section of (4.0 ± 0.3) × 10 −20 cm 2 molecule −1 near 285 nm. The results are discussed with respect to the literature data. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 223–229, 2008Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58072/1/20291_ftp.pd

Seasonal variation of carbon monoxide in northern Japan: Fourier transform IR measurements and source-labeled model calculations

Tropospheric carbon monoxide (CO) was measured throughout 2001 using groundbased Fourier transform IR (FTIR) spectrometers at Moshiri 44.4N and Rikubetsu 43.5N) observatories in northern Japan, which are separated by 150 km. Seasonal and day-to-day variations of CO are studied using these data, and contributions from various CO sources are evaluated using three-dimensional global chemistry transport model (GEOS-CHEM) calculations. Seasonal maximum and minimum FTIR-derived tropospheric CO amounts occurred in April and September, respectively. The ratio of partial column amounts between the 0–4 and 0–12 km altitude ranges is found to be slightly greater in early spring. The GEOS-CHEM model calculations generally reproduce these observed features. Source-labeled CO model calculations suggest that the observed seasonal variation is caused by seasonal contributions from various sources, in addition to a seasonal change in chemical CO loss by OH. Changes in meteorological fields largely control the relative importance of various source contributions. The contributions from fossil fuel (FF) combustion in Asia and photochemical CO production have the greatest yearly averaged contribution at 1 km among the CO sources (31% each). The Asian FF contribution increases from winter to summer, because weak southwesterly wind in summer brings more Asian pollutants to the observation sites. The seasonal variation from photochemical CO production is small (±17% at 1 km), likely because of concurrent increases (decreases) of photochemical production and loss rates in summer (winter), with the largest contribution between August and December. The contribution from intercontinental transport of European FF combustion CO is found to be comparable to that of Asian FF sources in winter. Northwesterly wind around the Siberian high in this season brings pollutants from Europe directly to Japan, in addition to southward transport of accumulated pollution from higher latitudes. The influences are generally greater at lower altitudes, resulting in a vertical gradient in the CO profile during winter. The model underestimates total CO by 12–14% between March and June. Satellite-derived fire-count data and the relationship between FTIR-derived HCN and CO amounts are generally consistent with biomass burning influences, which could have been underestimated by the model calculations

Two cases of variceal haemorrhage during living-donor liver transplantation

Some patients with cirrhosis experience rupture of venous varices before operation, and liver transplantation is a therapy of last resort for these patients. However, we have experienced two cases of intraoperative rupture in whom no abnormalities of the venous varices were seen on endoscopy before operation. One patient with ruptured gastrointestinal varices was treated by direct surgical ligation and the other with ruptured oesophageal gastric varices, spontaneously recovered with a Sengstaken–Blakemore tube. These cases suggest that acute variceal haemorrhage should always be considered as a possibility during living-donor liver transplantation in patients with a history of upper gastrointestinal bleeding. Careful observation of the nasogastic tube is important during clamping of the hepatic portal vein