Measurements of air-ice drag coefficient over the ice-covered Sea of Okhotsk   总被引：1，自引：0，他引：1  

Ayumi Fujisaki  Hajime Yamaguchi  Takenobu Toyota  Akio Futatsudera  Masaru Miyanaga 《Journal of Oceanography》2009,65(4):487-498

The air-ice drag coefficient under neutral stratification C _DN was measured with the eddy correlation method in the southern Sea of Okhotsk. The disturbance of the wind field caused by the ship’s structure was evaluated by computational fluid dynamics (CFD), and two types of correction methods were applied to estimate the error span of C _DN : one is based on the results of CFD, and the other is based on the parameterization of C _DN over open water suggested by Taylor and Yelland (2001). The C _DN × 10³ values finally obtained ranged from 1.9 to 5.4 with a mean value of 2.7 by the CFD correction and from 1.5 to 5.0 with a mean value of 3.1 by the other method. This is somewhat larger than the value of 2.5 suggested by Shirasawa (1981), and in the same range as 2.2–4.0 over rough ice and 3.1–5.0 over very rough ice, values which were complied by Guest and Davidson (1991) for first year ice. Most of the ice conditions were characterized by broken floes with a diameter less than 100 m and raised rims, which made the surface rougher than flat, level ice. The relation between C _DN and ice concentration was not clear, mainly because the contribution of the form drag caused at the freeboard was undetectable due to the great variation of ice surface condition. The roughness length z _M was also evaluated using the model developed for snow covered ice in a previous study.  相似文献   

Production of the Blood Pressure Lowing Peptides from Brown Alga （ Undaria pinnatifida ）     

Sato Minoru Oba Takashi Hosokawa Takao Yamaguchi Toshiyasu Nakano Toshiki Saito Tadao Muramoto Koji Kahara T akashi Funayama Katsura Kobayashi Akio Nakano Takahisa 《中国海洋大学学报(英文版)》2005,4(3):209-213

Brown alga （ Undaria pinnatifida） was treated with alginate lyase and hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for the angiotensin-I-converting enzyme （ACE） was measured. Four hydrolysates with potent ACE-inhibitory activity were administered singly and orally to spontaneously hypertensive rats （SHRs）. The systolic blood pressure of SHRs decreases significantly after single oral administration of the brown alga hydrolysates by pro- tease S ＇ Amano＇ （from Bacillus stearothermophilus） at the concentration of 10 （mg protein） （kg body weight）^ - 1. In the 17 weeks of feeding experiment, 7-week-old SHRs were fed standard diet supplemented with the brown alga hydrolysates for 10 weeks. In SHRs fed 1.0 and 0.1% brown alga hydrolysates, elevating of systolic bloodpressure was significantly suppressed for 7 weeks. To elucidate the active components, the brown alga hydrolysates were fractionated by 1-butanol extraction and HPLC on a reverse-phase column. Seven kinds of ACE-inhibitory peptides were isolated and identified by amino acid composition analysis, sequence analysis, and LC-MS with the results Val-Tyr, Ile-Tyr, Ala-Trp, Phe-Tyr, Val-Trp, Ile-Trp, and Leu-Trp. Each peptide was determined to have an antihypertensive effect after a single oral administration in SHRs. The brown alga hydrolysates were also confirmed to decrease the blood pressure in humans.  相似文献   

The Meteoritical Bulletin,No. 92, 2007 September     

Harold C. Connolly  Caroline Smith  Gretchen Benedix  Luigi Folco  Kevin Righter  Jutta Zipfel  Akira Yamaguchi  Hasnaa Chennaoui Aoudjehane 《Meteoritics & planetary science》2007,42(9):1647-1694

Abstract— In this edition of The Meteoritical Bulletin, 1394 recognized meteorites are reported, 27 from specific locations within Africa, 133 from Northwest Africa, 1227 from Antarctica (from ANSMET, PNRA, and PRIC expeditions), and 7 from Asia. The Meteoritical Bulletin announces the approval of four new names series by the Nomenclature Committee of the Meteoritical Society, two from Africa and one from Asia, including Al Haggounia, from Al Haggounia, Morocco, which is projected to be on the order of 3 metric tons of material related to enstatite chondrites and aubrites. Approved are two falls from Africa, Bassikounou (Mauritania) and Gashua (Nigeria). Approved from areas other than Antarctica are one lunar, two Martian, 32 other achondrites, three mesosiderites, two pallasites, one CM, two CK, one CR2, two CV3, one CR2, and four R chondrites. The Nomenclature Committee of the Meteoritical Society announces 48 newly approved relict meteorites from two new name series, Österplana and Gullhögen (both from Sweden).  相似文献   

Bio-Optical Relationship of Case I Waters: The Difference between the Low- and Mid-Latitude Waters and the Southern Ocean     

Toru Hirawake  Hiroo Satoh  Takashi Ishimaru  Yukuya Yamaguchi  Motoaki Kishino 《Journal of Oceanography》2000,56(3):245-260

Both historic and currently operational chlorophyll algorithms of the satellite-borne ocean color sensors, such as SeaWiFS, were evaluated for in situ spectral radiation and chlorophyll data in some Case I waters, including the waters in the Indian Ocean sector of the Southern Ocean. Chlorophyll a concentration of the data set (n = 73) ranged from 0.04 to 1.01 mg m^–3. The algorithms had higher accuracy for the low- and mid-latitude waters (RMSE: 0.163–0.253), specifically the most recently developed algorithms of OCTS and Sea WiFS showed 0.163 and 0.170 of Root Mean Square Errors, respectively. However, these algorithms had large errors (0.422–0.621) for the Southern Ocean data set and underestimated the surface chlorophyll by more than a factor of 2.6. The absorption coefficients in the blue spectral region retrieved from remote sensing reflectance varied in a nonlinear manner with chlorophyll a concentration, and the value in the Southern Ocean was significantly lower than that in the low- and mid-latitude waters for each chlorophyll a concentration. The underestimation of chlorophyll a concentration in the Southern Ocean with these algorithms was caused by the lower specific absorption coefficient in the region compared with the low- and mid-latitude waters under the same chlorophyll a concentration.  相似文献   

Tracing depositional consequences of environmental radionuclides (137Cs and 210Pb) in Slovenian forest soils     

Ryoko Fujiyoshi  Takayuki Yamaguchi  Naoki Takekoshi  Kazumasa Okamoto  Takashi Sumiyoshi  Ivan Kobal  Janja Vaupotič 《Central European Journal of Geosciences》2011,3(3):291-301

Depth distribution profiles of environmental radionuclides (¹³⁷Cs and ²¹⁰Pb) have been investigated in soil to elucidate the underlying environment of semi-natural temperate deciduous and/or coniferous forest soils in Slovenia (?irovski vrh, Idrija, Ko?evski Rog, Pohorie, Gori?nica and Rakitna). Surface enrichment of both nuclides was observed at all the sites investigated in this study, suggesting that the soils had undergone little natural or anthropogenic disturbance for at least the last several decades. Apparent annual burial rates of ¹³⁷Cs (0.1–0.2 cm y^??1) were estimated to be about 1.3 times higher than those of ²¹⁰Pb at individual sites of different lithology, which suggests strong affinity of ²¹⁰Pb to soil organic matter. Variability of the vertical distribution profiles of these nuclides depends not only on “in situ” pedology but also on geographical and meteorological conditions, especially precipitation and wind direction.  相似文献   

Variability of wave-induced ripple migration in wave-flume experiments and its implications for sediment transport   总被引：1，自引：0，他引：1  

Naofumi Yamaguchi  Hideo Sekiguchi 《Coastal Engineering》2011

A thorough discussion of results from laboratory experiments with regular waves sheds light on the gap that lies between the sediment transport associated with ripple migration and the performance of a standard bedload transport formula in terms of bed shear concept. It is found that the extent of deviations of the bedload transport formula by Ribberink (1998) from the measured rate of sediment transport associated with ripple migration becomes systematically apparent under conditions of increasing settling time factor Ω_s (= η/(w₀T); η is the ripple height, w₀ the settling velocity and T the wave period). Re-examination of previous two field studies demonstrates a further reinforcement for phase-lag argument addressed in this paper.  相似文献   

Large-Scale Synoptic Systems and Fog During the C-FOG Field Experiment     

Dorman  Clive E.  Hoch  Sebastian W.  Gultepe  Ismail  Wang  Qing  Yamaguchi  Ryan T.  Fernando  H. J. S.  Krishnamurthy  Raghavendra 《Boundary-Layer Meteorology》2021,181(2-3):171-202

Boundary-Layer Meteorology - The goal of this work is to summarize synoptic meteorological conditions during the Coastal Fog (C-FOG) field project that took place onshore and offshore of the Avalon...  相似文献   

A Review of Coastal Fog Microphysics During C-FOG     

Gultepe  I.  Heymsfield  A. J.  Fernando  H. J. S.  Pardyjak  E.  Dorman  C. E.  Wang  Q.  Creegan  E.  Hoch  S. W.  Flagg  D. D.  Yamaguchi  R.  Krishnamurthy  R.  Gaberšek  S.  Perrie  W.  Perelet  A.  Singh  D. K.  Chang  R.  Nagare  B.  Wagh  S.  Wang  S. 《Boundary-Layer Meteorology》2021,181(2-3):227-265

Boundary-Layer Meteorology - Our goal is to provide an overview of the microphysical measurements made during the C-FOG (Toward Improving Coastal Fog Prediction) field project. In addition, we...  相似文献   

Microphysics and Optical Attenuation in Fog: Observations from Two Coastal Sites     

Wang  Qing  Yamaguchi  Ryan T.  Kalogiros  John A.  Daniels  Zachary  Alappattu  Denny P.  Jonsson  Haflidi  Alvarenga  Oswaldo  Olson  Alex  Wauer  Benjamin J.  Ortiz-Suslow  David G.  Fernando  Harindra Joseph 《Boundary-Layer Meteorology》2021,181(2-3):267-292

Boundary-Layer Meteorology - A total of 15 fog events from two field campaigns are investigated: the High Energy Laser in Fog (HELFOG) project (central California) and the Toward Improving Coastal...  相似文献   

Petrogenetic implications and geochronology of middle Miocene Tannayama igneous rocks,Goto Islands,Japan Sea southern margin,northwestern Kyushu,Japan     

Yoshimitsu Suda  Kenichiro Tani  Miho Yamaguchi  Susumu Kakubuchi 《Island Arc》2021,30(1):e12390

The subduction of “hot” Shikoku Basin and the mantle upwelling related to the Japan Sea opening have induced extensive magmatism during the middle Miocene on both the back-arc and island-arc sides of southwest Japan. The Goto Islands are located on the back-arc side of northwestern Kyushu, and middle Miocene granitic rocks and associated volcanic, hypabyssal, and gabbroic rocks are exposed. The igneous rocks at Tannayama on Nakadori-jima in the Goto Islands consist of gabbronorite, granite, granite porphyry, diorite porphyry, andesite, and rhyolite. We performed detailed geological mapping at a 1:10 000 scale, as well as petrographical and geochemical analyses. We also determined the zircon U–Pb age dating of the igneous rocks from Tannayama together with a granitic rock in Yagatamesaki. The zircon U–Pb ages of the Tannayama igneous rocks show the crystallization ages of 14.7 Ma ± 0.3 Ma (gabbronorite), 15.9 Ma ± 0.5 Ma (granite), 15.4 Ma ± 0.9 Ma (granite porphyry), and 15.1 Ma ± 2.1 Ma (rhyolite). Zircons from the Yagatamesaki granitic rock yield 14.5 Ma ± 0.7 Ma. Considering field relationships, new zircon data indicate that the Tannayama granite formed at ~16–15 Ma, and the gabbronorite, granite porphyry, diorite porphyry, andesite, and subsequently rhyolite formed at 15–14 Ma, which overlaps a plutonic activity of the Yagatamesaki. The geochemical characteristics of the Tannayama igneous rocks are similar to those of the tholeiitic basalts and dacites of Hirado, and the granitic rocks of Tsushima in northwestern Kyushu. This suggests that the Tannayama igneous rocks can be correlated petrogenetically with the igneous rocks in those areas, with all of them generated by the upwelling of hot mantle diapirs during crustal thinning in an extensional environment during the middle Miocene.  相似文献