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Numerical analysis of cavitation cloud shedding in a submerged water jet

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Journal of Hydrodynamics 2016年第6期28卷 986-993页

作者： Guoyi PENG 杨从新 Yasuyuki OGUMA seiji shimizu Department of Mechanical Engineering College of Engineering Nihon University School of Energy and Power Engineering Lanzhou University of Technology

Focused on the unsteady behavior of high-speed water jets with intensive cavitation a numerical analysis is performed by applying a practical compressible mixture flow bubble cavitation model with a simplified estimation of bubble radius. The mean flow of two-phase mixture is calculated by unsteady Reynolds averaged Navier-Stokes （URANS） for compressible flow and the intensity of cavitation in a local field is evaluated by the volume fraction of gas bubbles whose radius is estimated with a simplified Rayleigh- Plesset equation according to pressure variation of the mean flow field. High-speed submerged water jet issuing from a sheathed sharp-edge orifice nozzle is treated. The periodically shedding of cavitation clouds is captured in a certain reliability compared to experiment data of visualization observation and the capability to capture the unsteadily shedding of cavitation clouds is demonstrated. The results demonstrate that cavitation takes place near the entrance of nozzle throat and cavitation cloud expands consequentially while flowing downstream. Developed bubble clouds break up near the nozzle exit and shed downstream periodically along the shear layer. Under the effect of cavitation bubbles the decay of core velocity is delayed compared to the case of no-cavitation jet.

关键词： cavitation bubble dynamics submerged water jet two-phase flow turbulent flow

Periodic Behavior of Cavitation Cloud Shedding in Submerged Water Jets Issuing from a Sheathed Pipe Nozzle

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Journal of Flow Control, Measurement & Visualization 2018年第1期6卷 15-26页

作者： Guoyi Peng Ayaka Wakui Yasuyuki Oguma seiji shimizu Hong Ji Department of Mechanical Engineering College of Engineering Nihon University Koriyama Japan Graduate School of Engineering Nihon University Koriyama Japan College of Energy and Power Engineering Lanzhou University of Technology Lanzhou China

The behavior of cavitation cloud shedding in submerged water jets issuing from a sheathed pipe nozzle is investigated experimentally by high-speed camera visualization observation. Experiments are carried out under different cavitation numbers decreased to 0.01 with increase of the injection pressure, and the frequency spectrum of cavitation cloud shedding is evaluated by statistical analysis of a sequence of high-speed camera images. Experiments demonstrate that cavitation clouds appear when the cavitation number σ decreases to the level of 0.5-0.7 and developed cavitation clouds shed downstream periodically at multiple frequencies. The low frequency components of cavitation cloud shedding is basically dependent upon the pressure pulsation of plunger pump, which is often employed in various industry application of water jets. However, the high frequency components are closely related to the shedding of vortexes and the collapsing of cavitation clouds, which are dependent on the flow structure of submerged jets and the property of cavitation clouds consisted of numerous bubbles.

关键词： Water Jet Cavitation Cavitation Cloud Visualization Image Analysis

Design and construction of the cooperation support agent for face-to-face class and e-learning

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通讯和计算机（中英文版） 2009年第12期6卷 28-32页

作者： Misako Urakami Masaaki Kunishige seiji shimizu Yasukuni Okataku Nobukazu Yoshioka Oshima National College of Maritime Technology Yamaguchi 742-2193 Japan Chugoku Bureau of Telecommunications Ministry of Internal Affairs and Communications Naka-ku. Hiroshima 730-8795 Japan National Institute of lnformatics Tokyo 101-8430 Japan

E-learning study mainly helps acquisitions of knowledge. However, the effect acquired from dialog on a face-to-face class is not expectable. Thus, Blended-learning which combined a face-to-face class and e-learning attracts attention. Although the blend of ideal Blended-learning should be used by learners on consideration of their capabilities and learning records, the realization is difficulty. In this paper, we proposed and built a mobile agent system which offers cooperation support with a face-to-face class and e-learning. The mobile agents operating autonomously indicate the learner"s weak points and contents which should be learned from a learning plan (learning policy) given by the contents creator and a personal learning record. Therefore, the mobile agents can support the Blended-learning by creating the personal learning result data in consideration of personal capability and personal learning records.

关键词：电子学习合作移动代理系统面类设计混合学习学习内容学习计划

Drug-induced mucosal alterations observed during esophagogastroduodenoscopy

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World Journal of Gastroenterology 2024年第16期30卷 2220-2232页

作者： Masaya Iwamuro seiji Kawano Motoyuki Otsuka Department of Gastroenterology and Hepatology Okayama University Graduate School of MedicineDentistryand Pharmaceutical SciencesOkayama 700-8558Japan

Several features of drug-induced mucosal alterations have been observed in the upper gastrointestinal tract,i.e.,the esophagus,stomach,and *** include pill-induced esophagitis,desquamative esophagitis,worsening of gastroesophageal reflux,chemotherapy-induced esophagitis,proton pump inhibitor-induced gastric mucosal changes,medication-induced gastric erosions and ulcers,pseudomelanosis of the stomach,olmesartan-related gastric mucosal inflammation,lanthanum deposition in the stomach,zinc acetate hydrate tabletinduced gastric ulcer,immune-related adverse event gastritis,olmesartan-associated sprue-like enteropathy,pseudomelanosis of the duodenum,and lanthanum deposition in the *** endoscopists,acquiring accurate knowledge regarding these diverse drug-induced mucosal alterations is crucial not only for the correct diagnosis of these lesions but also for differential diag-nosis of other *** minireview aims to provide essential information on druginduced mucosal alterations observed on esophagogastroduodenoscopy,along with representative endoscopic images.

关键词： Diagnosis Esophagogastroduodenoscopy Non-neoplastic lesions Esophageal lesions Gastric lesions Duodenal lesions

Space–time finite element method with domain reduction techniques for dynamic soil–structure interaction problems

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International Journal of Mechanical System Dynamics 2024年第2期4卷 117-130页

作者： Vikas Sharma Shion shimizu Kazunori Fujisawa Division of Environmental Science and Technology Graduate School of AgricultureKyoto UniversityKyotoJapan

Design of earth structures,such as dams,tunnels,and embankments,against the vibrational loading caused by high-speed trains,road traffic,underground explosions,and,more importantly,earthquake motion,demands solutions of the dynamic soil–structure Interaction(SSI)*** paper presents a velocity-based space–time finite element procedure,v-ST/finite element method(FEM),to solve dynamic SSI *** main goal of this study is to present the computation details of implementing viscous boundary conditions of Lysmer–Kuhlemeyer to truncate the unbounded soil ***,additional time-dependent boundary conditions,in terms of the free-field response,are included to facilitate energy flow from the far field to the computation domain at the vertical truncated *** the FEM,seismic input motion is applied to an effective nodal force vector,which can be obtained explicitly in the numerical ***,the response of a concrete gravity dam resting on an elastic half-space to the horizontal component of earthquake motion is computed and successfully compared with the results of semidiscrete FEM using the Newmark-βmethod.

关键词： absorbing boundary domain reduction FEM soil-structure interactions space-time

Mogroside IIE,an in vivo metabolite of sweet agent,alleviates acute lung injury via Pla2g2a-EGFR inhibition

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Food Science and Human Wellness 2024年第1期13卷 299-312页

作者： Weichao Lü Guoqing Ren Kuniyoshi shimizu Renshi Li Chaofeng Zhang State Key Laboratory of Natural Medicines School of Traditional Chinese PharmacyChina Pharmaceutical UniversityNanjing 211198China Sino-Jan Joint Lab of Natural Health Products Research School of Traditional Chinese PharmacyChina Pharmaceutical UniversityNanjing 211198China Faculty of Agriculture Kyushu UniversityFukuoka 819-0395Japan

In the face of increasingly serious environmental pollution,the health of human lung tissues is also facing serious *** IIE(M2E)is the main metabolite of sweetening agents mogrosides from the anti-tussive Chinese herbal Siraitia *** study elucidated the anti-inflammatory action and molecular mechanism of M2E against acute lung injury(ALI).A lipopolysaccharide(LPS)-induced ALI model was established in mice and MH-S cells were employed to explore the protective mechanism of M2E through the western blotting,co-immunoprecipitation,and quantitative real time-PCR *** results indicated that M2E alleviated LPS-induced lung injury through restraining the activation of secreted phospholipase A2 type IIA(Pla2g2a)-epidermal growth factor receptor(EGFR).The interaction of Pla2g2a and EGFR was identified by *** addition,M2E protected ALI induced with LPS against inflammatory and damage which were significantly dependent upon the downregulation of AKT and m TOR via the inhibition of ***2g2a may represent a potential target for M2E in the improvement of LPS-induced lung injury,which may represent a promising strategy to treat ALI.

关键词： Mogroside IIE Acute lung injury Secreted phospholipase A2 type IIA(Pla2g2a) Epidermal growth factor receptor(EGFR)

A plant growth chamber system equipped with aerosol generators for studying aerosol-vegetation interactions

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Particuology 2024年第2期85卷 122-132页

作者： Masao Gen seiji Ikawa Masahiro Yamaguchi Fong Zyin Lim Takeshi Izuta I.Wuled Lenggoro Graduate School of Bio-Applications and Systems Engineering Tokyo University of Agriculture and TechnologyKoganeiTokyo184-8588Japan Institute of Multidisciplinary Research for Advanced Materials Tohoku UniversitySendai980-8577Japan Faculty of Agriculture Tokyo University of Agriculture and TechnologyFuchuTokyo183-8509Japan Graduate School of Fisheries and Environmental Sciences Nagasaki UniversityNagasaki852-8521Japan Institute of Agriculture Tokyo University of Agriculture and TechnologyFuchuTokyo183-8509 Japan Department of Applied Physics and Chemical Engineering Tokyo University of Agriculture and TechnologyKoganeiTokyo184-8588Japan Institute of Global Innovation Research Tokyo University of Agriculture and TechnologyFuchuTokyo183-8509Japan

Understanding aerosol-vegetation interactions is vital in ***,the interactions remain elusive partly due to the lack of suitable plant growth chamber ***,deposition of submicron particles on leaf surfaces is challenging due to its low deposition velocities compared to larger *** this work,we present a plant-growth chamber that was used to study the effect of sub-micron black carbon(BC)particles on the growth and photosynthesis of *** chamber system simultaneously enables the growth of multiple plants in pots and the deposition of submicron particles onto *** spraying methods assisted by ultrasonic and electrostatic forces were employed as aerosol generators to realize the particle *** flow regime inside the chamber was numeri-cally calculated to predict the transportation of aerosol particles,suggesting the optimal operating conditions of the *** gas-phase particle size distribution measurements showed that gener-ated BC particles were suspended in submicron diameter *** aerosol generators were examined in the chamber using three conductor and insulator substrates as a model of plant *** observations and spectroscopic analysis ascertained that submicron BC particles generated from our generators were deposited on all substrate *** the developed chamber system,systematic studies can be performed to advance the fundamental understanding of aerosol-vegetation interactions.

关键词： Aerosol Exposure chamber Spray drying Black carbon

Disruption of neuronal actin barrier promotes the entry of disease-implicated proteins to exacerbate amyotrophic lateral sclerosis pathology

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Neural Regeneration Research 2025年第9期20卷 2589-2590页

作者： Mikio shimizu Tatsusada Okuno Department of Neurology Osaka University Graduate School of MedicineSuitaJapan Department of Neurology Osaka General Medical CenterOsakaJapan

Amyotrophic lateral sclerosis(ALS)is a devastating neurological disease characterized by the accumulation of aberrant proteins in motor neurons of the brain and spinal *** with ALS develop skeletal muscle weakness,resulting in death from respiratory paralysis,which usually occurs 2-4 years after clinical onset(Goutman et al.,2022).

关键词： paralysis sclerosis

Effectiveness of antibiotic prophylaxis for acute esophageal variceal bleeding in patients with band ligation: A large observational study

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World Journal of Gastroenterology 2024年第3期30卷 238-251页

作者： Chikamasa Ichita Sayuri shimizu Tadahiro Goto Uojima Haruki Naoya Itoh Masao Iwagami Akiko Sasaki Gastroenterology Medicine Center Shonan Kamakura General HospitalKamakura 247-8533KanagawaJapan Department of Health Data Science Yokohama City UniversityYokohama 236-0027KanagawaJapan TXP Research TXP Medical Co.Ltd.Chiyoda-ku 101-0042TokyoJapan Department of Clinical Epidemiology and Health Economics School of Public HealthThe University of TokyoBunkyo-ku 113-0033TokyoJapan Department of Genome Medical Sciences Project Research InstituteNational Center for Global Health and MedicineIchikawa 272-8516ChibaJapan Division of Infectious Diseases Aichi Cancer CenterNagoya 464-8681AichiJapan Department of Health Services Research Institute of MedicineUniversity of TsukubaTsukuba 305-8575IbarakiJapan

BACKGROUND Esophageal variceal bleeding is a severe complication associated with liver cirrhosis and typically necessitates endoscopic *** current standard treatment is endoscopic variceal ligation(EVL),and Western guidelines recom-mend antibiotic prophylaxis following ***,given the impro-vements in prognosis for variceal bleeding due to advancements in the management of bleeding and treatments of liver cirrhosis and the global concerns regarding the emergence of multidrug-resistant bacteria,there is a need to reassess the use of routine antibiotic prophylaxis after *** To evaluate the effectiveness of antibiotic prophylaxis in patients treated for *** We conducted a 13-year observational study using the Tokushukai medical database across 46 *** were divided into the prophylaxis group(received antibiotics on admission or the next day)and the non-prophylaxis group(did not receive antibiotics within one day of admission).The primary outcome was composed of 6-wk mortality,4-wk rebleeding,and 4-wk spontaneous bacterial peritonitis(SBP).The secondary outcomes were each individual result and in-hospital mortality.A logistic regression with inverse probability of treatment weighting was used.A subgroup analysis was conducted based on the Child-Pugh classification to determine its influence on the primary outcome measures,while sensitivity analyses for antibiotic type and duration were also *** Among 980 patients,790 were included(prophylaxis:232,non-prophylaxis:558).Most patients were males under the age of 65 years with a median Child-Pugh score of *** composite primary outcomes occurred in 11.2%of patients in the prophylaxis group and 9.5%in the non-prophylaxis *** significant differences in outcomes were observed between the groups(adjusted odds ratio,1.11;95%confidence interval,0.61-1.99;P=0.74).Individual outcomes such as 6-wk mortality,4-wk rebleeding,4-wk onset of SBP,and in-hospital mo

关键词： Esophageal varices Endoscopic hemostasis Antibiotic prophylaxis Liver cirrhosis Inverse probability of treatment weighting