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Entropy generation in bypass transitional boundary layer flows

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Journal of Hydrodynamics 2014年第5期26卷 669-680页

作者： GEORGE Joseph owen Landon D. XING Tao MCELIGOT Donald M. CREPEAU John C. BUDWIG Ralph S. NOLAN Kevin P. Department of Mechanical Engineering College of EngineeringUniversity of IdahoMoscowIdaho 83843USA University of Idaho Idaho FallsIdaho 83402USA University of Idaho BoiseIdaho 83702USA Imperial College London London SW7-28ZUK

The primary objective of this study is to evaluate the accuracy of using computational fluid dynamics （CFD） turbulence models to predict entropy generation rates in bypass transitional boundary layers flows under zero and adverse pressure gradients. Entropy generation rates in such flows are evaluated employing the commercial CFD software, ANSYS FLUENT. Various turbulence and transitional models are assessed by comparing their results with the direct numerical simulation （DNS） data and two recent CFD studies. A solution verification study is conducted on three systematically refined meshes. The factor of safety method is used to estimate the numerical error and grid uncertainties. Monotonic convergence is achieved for all simulations. The Reynolds number based on momentum thickness, Reo, skin-friction coefficient, Cf, approximate entropy generation rates, S, dissipation coefficient, Cd , and the intermittency, y, are calculated for bypass transition simulations. All Reynolds averaged Navier-Stokes （RANS） turbulence and transitional models show improvement over previous CFD results in predicting onset of transition. The transition SST k - ω 4 equation model shows closest agreement with DNS data for all flow conditions in this study due to a much finer grid and more accurate inlet boundary conditions. The other RANS models predict an early onset of transition and higher boundary layer entropy generation rates than the DNS shows.

关键词： entropy generation bypass transition Reynolds averaged Navier-Stokes (RANS) transitional boundary layer turbulence models

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Late upper urinary tract urothelial carcinoma following radical cystectomy,presenting as page kidney

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Asian Journal of Urology 2021年第4期8卷 442-443页

作者： Asmaa Ismail Hazem Elmansy Walid Shahrour owen Prowse Ahmed Kotb Department of Urology Northern Ontario School of MedicineThunder BayOntarioCanada

Dear Editor,We are describing a rare case presenting with page phenomenon,9 years post radical cystectomy for muscle invasive bladder *** kidney was developed secondary to a late recurrent urothelial tumour in the left renal *** case is a fifty-seven-year-old gentleman presented with poorly controlled hypertension and left dull aching loin *** blood pressure(BP)was 180/80 mmHg at diagnosis and was down to 150/80 mmHg using angiotensin converting enzyme(ACE)inhibitor and beta blocker *** underwent a radical cystectomy(RC)and ileal conduit urinary diversion 9 years *** of his cystectomy specimen was localized urothelial carcinoma with negative resection margin and negative lymph nodes(T2N0M0).Examination showed a palpable mobile mass in the left hypochondrium.

关键词： urinary cystectomy kidney

ENSO and Southeast Asian biomass burning modulate subtropical trans-Pacific ozone transport

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National Science Review 2021年第6期8卷 120-127页

作者： Lian Xue Aijun Ding owen Cooper Xin Huang Wuke Wang Derong Zhou Zhaohua Wu Audra Mc Clure-Begley Irina Petropavlovskikh Meinrat O.Andreae Congbin Fu Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric SciencesNanjing University Jiangsu Provincial Collaborative Innovation Center for Climate Change Cooperative Institute for Research in Environmental Sciences University of Colorado Chemical Sciences Division NOAA Earth System Research Laboratory Department of Earth Ocean and Atmospheric SciencesFlorida State University Global Monitoring Division NOAA Earth System Research Laboratory Max Planck Institute for Chemistry Scripps Institution of Oceanography University of California

Trans-Pacific transport of enhanced ozone plumes has been mainly attributed to fossil fuel combustion in Asia in spring, but less attention has been paid to vegetation fires in Asia. Here we show that the El Ni?noSouthern Oscillation(ENSO)-modulated fires in Southeast Asia, rather than Asian fossil fuel plumes,dominate the interannual variability of springtime trans-Pacific transport of ozone across the entire North Pacific Ocean. During El Ni?no springs, the intensified fires from both the Indochinese Peninsula and Indonesia, together with large-scale circulation anomalies, result in enhanced ozone plumes that stretch over 15 000 km in both the lower-middle and upper troposphere. This enhancement is also observed in the in situ measurements of ozone concentration, with an almost 10% increase at Mauna Loa Observatory,Hawaii, a unique site to monitor the long-distance transport over the North Pacific. This study reports an unexpectedly strong influence of vegetation fires, linked with climate variability, on global tropospheric chemistry and proves once more how complex the interactions in the climate system are.

关键词： El Niño-Southern Oscillation (ENSO) climate biomass burning tropospheric ozone long-range transport Southeast Asia

Magnetospheric Boundary Layer Structure and Dynamics as Seen From Cluster and Double Star Measurements

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空间科学学报 2013年第6期33卷 577-603页

作者： Y V Bogdanova C J owen M W Dunlop M G G T Taylor A N Fazakerley Space Science and Technology Department RALChiltonDidcotOxfordshireOX11 0QXUK Mullard Space Science Laboratory University College LondonHolmbury St.MaryDorkingSurreyRH5 6NTUK Science and Robotic Exploration Directorate ESA/ESTECNoordwijkThe Netherlands

In this review,we discuss the structure and dynamics of the magnetospheric LowLatitude Boundary Layer(LLBL)based on recent results from multi-satellite missions Cluster and Double *** boundary layer,adjacent to the magnetopause on the magnetospheric side,usually consists of a mixture of plasma of magnetospheric and magnetosheath origins,and plays an important role in the transfer of mass and energy from the solar wind into the magnetosphere and subsequent magnetospheric *** southward Interplanetary Magnetic Field(IMF)conditions,this boundary layer is generally considered to be formed as a result of the reconnection process between the IMF and magnetospheric magnetic field lines at the dayside magnetopause,and the structure and plasma properties inside the LLBL can be understood in terms of the time history since the reconnection *** northward IMF conditions,the LLBL is usually thicker,and has more complex structure and *** observations confirm that the LLBL observed at the dayside can be formed by single lobe reconnection,dual lobe reconnection,or by sequential dual lobe reconnection,as well as partially by localized cross-field *** LLBL magnetic topology and plasma signatures inside the different sub-layers formed by these processes are discussed in this *** role of the Kelvin-Helmholtz instability in the formation of the LLBL at the flank magnetopause is also ***,we conclude that the LLBL observed at the flanks can be formed by the combination of processes,(dual)lobe reconnection and plasma mixing due to non-linear Kelvin-Helmholtz waves.

关键词：边界层结构磁层顶双星群集国际货币基金组织等离子体特性测量拓扑结构

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Rethinking Cultural History

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Rethinking Cultural History

Best Teacher I Ever Had

文明的和谐与共同繁荣——北京论坛（2004）

作者： Stephen owen Harvard University

Theorists of post-modernism have declared the end of history in the sense that it was understood in the preceding *** does not mean,as some have understood it,that we have somehow miraculously removed ourselves from *** our relation to the cultural past has been profoundly changed by technologies of reproduction and ***

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语言教育 1992年第8期 33-34页

作者： David owen 陈可培

Mr. Whiston taught sixth-grade science. On the first day of class, hegave us a lecture about a creature called the cattywam-pus, an ill-adapted nocturnal animal that was wipedout during the Ice Age. He passed around a skull as hetalked. We all took notes and later had a quiz. When he returned my paper, I was shocked. Therewas a big red X through each of my answers. I hadfailed. There had to be some mistake. I had written downexactly what Mr. Whiston said. Then I realized thateveryone in the class had failed. What had happened?

关键词： Teacher mistake lecture skull passed speak nocturnal night haven notes

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乌敢大之医事教育

中华医学杂志 1933年第6期19卷 984-994页

作者： H. B. owen 前乌敢大木拉哥城医学校校长

附志:‘鸟敢大’Uganda在中非洲之东部,为英国之保护国。面邻比属刚果;’面积110,300英方里。人口三百五十万。有铁道横贯其间,止於维克多利亚尼安撒(Victoria Nvanza)湖畔。首都为坎巴拉Kampala而行政中央区,则在恩特比(Entebbe)。出...

附志:‘鸟敢大’Uganda在中非洲之东部,为英国之保护国。面邻比属刚果;’面积110,300英方里。人口三百五十万。有铁道横贯其间,止於维克多利亚尼安撒(Victoria Nvanza)湖畔。首都为坎巴拉Kampala而行政中央区,则在恩特比(Entebbe)。出口货之大宗为兽皮,橡牙,棉,加啡等。

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BER规定:是敌是友?

汽车与配件 2005年第46期 46-47页

作者： Mike owen 英国汽车零售业联合会(RMIF)

英国友刊《CAT》与RMIF英国汽车零售业联合会的Mike owen交谈中,问到了几个有关BER影响的问题。这位思考者要求给他一些时间来考虑。下面是他的书面回复

关键词：维修商经销商贸易商汽车制造商 BER

Rethinking Cultural History

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Rethinking Cultural History