检索结果-南通市图书馆

Analysis of molten metal spreading and solidification behaviors utilizing moving particle full-implicit method

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2021年第4期15卷 959-973页

作者： Ryo YOKOYAMA Masahiro KONDO Shunichi SUZUKI koji OKAMOTO Department of Nuclear Engineering and Management The University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan Research Center for Computational Design of Advanced Functional materials(CD-FMat) Department of Materials and ChemistryNational Institute of Advanced Industrial Science and Technology(AIST)Central 21-1-1UmezonoTsukubaIbaraki 305-8568Japan Institute of Engineering Innovation School of EngineeringThe University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan Nuclear Professional School The University of Tokyo2-22 ShirakataTokai-muraIbaraki 319-1188Japan

To retrieve the fuel debris in Fukushima Daiichi Nuclear Power Plants(1F),it is essential to infer the fuel debris *** particular,the molten metal spreading behavior is one of the vital phenomena in nuclear severe accidents because it determines the initial condition for further accident scenarios such as molten core concrete interaction(MCCI).In this study,the fundamental molten metal spreading experiments were performed with different outlet diameters and sample amounts to investigate the effect of the outlet for spreading-solidification *** the numerical analysis,the moving particle full-implicit method(MPFI),which is one of the particle methods,was applied to simulate the spreading *** the MPFI framework,the melting-solidification model including heat transfer,radiation heat loss,phase change,and solid fraction-dependent viscosity was developed and *** addition,the difference in the spreading and solidification behavior due to the outlet diameters was reproduced in the *** simulation results reveal the detailed solidification procedure during the molten metal *** is found that the viscosity change and the solid fraction change during the spreading are key factors for the free surface condition and solidified ***,it is suggested that the MPFI method has the potential to simulate the actual nuclear melt-down phenomena in the future.

关键词： molten metal spreading solidification particle method severe accident fuel debris decommissioning

A Study on Development of a Hybrid Aerial/Terrestrial Robot System for Avoiding Ground Obstacles by Flight

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2019年第1期6卷 327-336页

作者： Chinthaka Premachandra Masahiro Otsuka Ryo Gohara takao Ninomiya Kiyotaka Kato IEEE the Department of Electronic Engineering Gradu-ate School of EngineeringShibaura Institute of Technology the Department of Electrical Engineering Graduate School of EngineeringTokyo University of Science

To date, many studies related to robots have been performed around the world. Many of these studies have assumed operation at locations where entry is difficult, such as disaster sites, and have focused on various terrestrial robots, such as snake-like, humanoid, spider-type, and wheeled units. Another area of active research in recent years has been aerial robots with small helicopters for operation indoors and outdoors. However,less research has been performed on robots that operate both on the ground and in the air. Accordingly, in this paper, we propose a hybrid aerial/terrestrial robot system. The proposed robot system was developed by equipping a quadcopter with a mechanism for ground movement. It does not use power dedicated to ground movement, and instead uses the flight mechanism of the quadcopter to achieve ground movement as well. Furthermore, we addressed the issue of obstacle avoidance as part of studies on autonomous control. Thus, we found that autonomous control of ground movement and flight was possible for the hybrid aerial/terrestrial robot system, as was autonomous obstacle avoidance by flight when an obstacle appeared during ground movement.

关键词： Ground movement/flight control hybrid aerial/terrestrial robot obstacle avoidance by flight obstacle recognition

A Blowdown Cryogenic Cavitation Tunnel and CFD Treatment for Flow Visualization around a Foil

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2005年第4期14卷 346-351页

作者： Yutaka ITO Kazuya SAWASAKI Naoki TANI takao NAGASAKI Toshio NAGASHIMA Tokyo Institute of Technology G3-334259Nagatsuta-choMidori-kuYokohama226-8502Japan Honda Motor Co.Ltd. 2-1-1Minami-AoyamaMinato-kuTokyo107-8556Japan Japan Aerospace Exploration Agency 2-1-1SengenTsukuba305-8505Japan University of Tokyo 7-3-1HongoBunkyo-kuTokyo113-8656Japan

Cavitation is one of the major problems in the development of rocket engines. There have been few experimental studies to visualize cryogenic foil cavitation. Therefore a new cryogenic cavitation tunnel of blowdown type was built. The foil shape is “piano-convex”. This profile was chosen because of simplicity, but also of being similar to the one for a rocket inducer impeller. Working fluids were water at room temperature, hot water and liquid nitrogen. In case of Angle of Attack （AOA）=8°, periodical cavity departure was observed in the experiments of both water at 90℃ and nitrogen at -190℃ under the same velocity 10 m/sec and the same cavitation number 0.7. The frequencies were observed to be 110 and 90 Hz, respectively, and almost coincided with those of vortex shedding from the foil. Temperature depression due to the thermodynamic effect was confirmed in both experiment and simulation especially in the cryogenic cavitation.

关键词： cavitation tunnel cryogen CFD visualization simulation foil.

Favorable effect of modest alcohol consumption to fatty liver disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第32期19卷 5393-5394页

作者： Masahide Hamaguchi takao kojima Department of Experimental Immunology World Premier International Immunology Frontier Research CenterOsaka University Department of Gastroenterology Murakami Memorial HospitalAsahi University

We previously reported that modest alcohol consumption was significantly inversely associated with fatty liver *** et al pointed out a discrepancy of statistical significance between our current larger scale cohort and a previous ***,the prevalence of non-alcoholic fatty liver disease was higher in non or minimal drinkers than those in light drinkers in both *** also argue that some potential co-factors such as soft drink consumption and genetic variations should be discussed.

关键词： Alcohol Fatty liver disease Obesity Diabetes Metabolic syndrome

Computational Fluid Dynamics Benchmark of an Impulse Turbine with Fixed Guide Vanes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2004年第2期13卷 109-113,108页

作者： Ajit THAKKER Fergal HOURIGAN T. SETOGUCHI M. takao Wave Energy Research Team Department of Mechanical and Aeronautical Engineering University of Limerick Limerick IrelandWave Energy Research Team Department of Mechanical and Aeronautical Engineering University of Limerick Limerick IrelandDepartment of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502 JapanDepartment of Control Engineering Matsue National College of Technology 14-4 Nishiikuma-cho Matsue-shi Shimane 690-8518 Japan

This paper presents the comparison of a three dimensional Computational Fluid Dynamics (CFD) analysis with empirical performance data of a 0.6 m impulse turbine with fixed guide vanes used for wave energy power conversion. Pro-Engineer, Gambit and Fluent 6 were used to create a 3-D model of the turbine. A hybrid meshing scheme was used with hexahedral cells in the near blade region and tetrahedral and pyramid cells in the rest of the domain. The turbine has a hub-to-tip ratio of 0.6 and results were obtained over a wide range of flow coefficients. The model yielded a maximum efficiency of approximately 54% as compared to a maximum efficiency of around 49% from experiment. A degree of insight into flow behaviour, not possible with experiment, was obtained.

关键词： wave energy impulse turbine computational fluid dynamics CFD hybrid mesh.

Slip Flow on Graphene:Current Status and Perspective

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第4期31卷 1115-1134页

作者： CHEN Kuan-Ting LI Qin-Yi TAKAHASHI koji Department ofAeronautics and Astronautics Kyushu UniversityFukuoka 819-0395Japan International Institute for Carbon-Neutral Energy Research(WPI-I2CNER) Kyushu UniversityFukuoka 819-0395Japan

Fast fluid transport on graphene has attracted a growing body of research due to a wide range of potential applications including thermal management,water desalination,energy harvesting,and ***,we critically review the theoretical,simulational,and experimental progress regarding the fluid slippage on *** on the summary of the past studies,we give perspectives on future research directions towards complete understanding and practical applications of slip flow on graphene.

关键词： slip flow graphene nanochannel simulation experiment

Tourist preferences for agricultural landscapes:a case study of terraced paddy fields in Noto Peninsula,Japan

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2016年第10期13卷 1880-1892页

作者： CHEN Bixia QIU Zhenmian NAKAMURA koji Faculty of Agriculture University of the Ryukyus1 SenbaruNishihara TownOkinawa Prefecture903-0213Japan Fujian Normal University Fuzhou 350108China Kanazawa University Kanazawa CityIshikawa Prefecture920-1192Japan

Many agricultural landscapes have been formed through the interaction and co-evolution of nature and people, and represent the living landscapes shaped over time through intensive and continuous human cultivation. Terraced paddy fields are being re-evaluated to take into account the multiple functions they fill beyond only rice cultivation, particularly their contribution to the national biodiversity strategy of Japan. Since the 1990 s, terraced paddy fields have been considered a representative cultural landscape of Japan and, at the same time, multi-stakeholder conservation activities have been conducted throughout Japan to reverse the increasing abandonment of terraces. Shiroyone Senmaida is an outstanding cultural landscape and a major tourist attraction in Noto Peninsula, Ishikawa Prefecture, which was designated through an initiative by the Food and Agriculture Organization(FAO) as a Globally Important Agricultural Heritage Systems(GIAHS) pilot site in 2011. It is important to clarify tourist preference for terraced paddy field landscapes to contribute to future policy making toward improved agricultural landscape conservation. A key finding of this study is that tourists visiting toenjoy the agricultural landscape are also concerned on the sustainability of the farming methods and preferred to maintain the naturalness of the landscape. Respondents with higher educational levels and greater concern for the biological and traditional farming knowledge aspects of the rice terraces were also more inclined to favor sustainable farming practices. Tourists preferred to maintain the naturalness and rurality of the agricultural landscape, and indicated that construction of excessive tourist facilities would cause the landscape to deteriorate. It was suggested that the local community and surroundings, including rural settlements, hills, and forests, should also be conserved together with the scenic terrace.

关键词： Agricultural landscape Landscape aesthetics Landscape naturalness Terraced land Traditional farming Tourist preference

Effects of Kampo medicine, Keishi-ka Shakuyaku-to (TJ-60) on alteration of diacylglycerol metabolism in gastrointestinal smooth muscle of diabetic rats

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2002年第12期23卷 120-127页

作者： NOBE koji,MOMOSE Kazutaka,SAKAI Yasushi Showa University 1-5-8 Hatanodai Shinagawa-ku Tokyo 142-8555 Japan Division of Physiology Department of Occupational Therapy Shool of Nursing and Rehabilitation Sciences Showa University 1865 Taka-Ichiba Department of Pharmacology Midori-ku Yokohama Kanagawa 226-8555 Japan School of Pharmaceutical Sciences Showa University 1-5-8 Hatanodai Shinagawa-ku Tokyo 142-8555 Japan Department of Pharmacology School of Pharmaceutical Sciences

AIM: To examine the effects of Kampo medicine, Keishi-ka-Shakuyaku-to (TJ-60) on the signal transduction in diabetic gastrointestinal dysfunction. METHODS: Experimental diabetic models were prepared using streptozotocin (STZ)-treated Wistar rats. Randomly selected STZ rats were treated with insulin (12 U·kg-1·d-1) or TJ-60 (1% of food intake). Diacylglycerol (DG) and DG kinase activities were quantified in isolated aortic smooth muscle tissue. RESULTS: One of the key element of the Pi-turnover, DG kinase activity in resting state in gastric smooth muscle was significantly increased compared to the control value, and carbachol (CCh)-induced response was not detectable, but it was detected in the control rats. On the other hand resting activity in ileum did not differ from the control, but the CCh-induced responses were suppressed. Treatment with TJ-60 indicated resistant effects for the alteration of DG kinase activities in diabetic intestinal tissues. In order to reveal the mechanism of the effects, t

关键词： diabetes mellitus Keshi-ka-Shakuyaku-to gastrointestinal smooth muscle herbal medicine muscle contraction diacylglycerol kinase signal transduction

Model Analysis of Radar Echo Split Observed in an Artificial Cloud Seeding Experiment

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2016年第3期30卷 386-400页

作者： MASAKI Shimada KIKURO Tomine koji Nishiyama Department of Earth and Ocean Sciences National Defense Academy Faculty of Engineering Kyushu University

An artificial cloud seeding experiment was performed over the Japan Sea in winter to show how massive seeding could be effective to mitigate heavy snowfall *** results showed that 20 min after cloud seeding,a portion of the radar echo beneath the seeding track was weakened to divide the radar echo into two *** order to analyze the results,a numerical simulation was conducted by using the Weather Research and Forecasting model verion *** this simulation,the seeding effects were represented as phenomena capable of changing rain particles by accreting cloud ice and snow to form graupel particles and by changing cloud liquid water to snow *** graupel particles fell rapidly,thus temporarily intensifying the rainfall,which subsequently ***,the weakened radar echo in the field experiment is deemed to have been caused by the increase in rapidly falling graupel particles.

关键词： heavy snowfall artificial cloud seeding numerical experiment