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Positive- and Zero-Sequence Impedance Estimation of YNyn0+d-Connected Main Power Transformers in Wind Power Applications

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CSEE Journal of Power and Energy Systems 2021年第1期7卷 57-65页

作者： Franklin L.Quilumba Robert E.Jimerson ken Swift Rafael Garc´ıa with Oncor Electric Delivery Fort WorthTX 76102 USA

With the increased penetration of non-conventionalrenewable energy resources, such as wind power plants (WPPs),into the power system, a lot of interest has been placed on studyingtheir impact for system protection, planning and operationsto ensure continued reliability of the electric grid. The impactof WPPs on the grid is typically identified during generationinterconnection studies. One of the challenges faced by protectionand planning engineers, at an early stage in this process, isthat many of the studies involving these power plants must beperformed without specific data available because the equipmentis not built yet. Among all the needed data, a particular interest inthis study is placed on the positive- and zero-sequence impedancesof the main power transformer (MPT) that interconnects a windpower plant to the transmission system due to its contribution toshort-circuit current during ground faults. The most commonlyfound in practice MPT winding configurations is a high-voltagewinding in wye with neutral bushing;a low-voltage windingin wye with neutral bushing without phase shift between thesewindings, and a stabilizing tertiary winding connected in deltathat is not designed for external loading designated as YNyn0+***, this paper proposes a methodology to estimate the sequenceimpedances of YNyn0+d transformers from a statistical point ofview applying clustering and regression analyses on existing MPTtest report data.

关键词： Positive-and zero-sequence impedance estimation power transformers short-circuit analysis threewinding transformer with buried tertiary wind power integration

Multiple Impact Phenomenon in Impact Hammer Testing:Theoretical Analysis and Numerical Simulation

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Acta Mechanica Solida Sinica 2021年第6期34卷 830-843页

作者： Junyin Li ken Lin Yanchao Hu Yuliang Yang Yong Wang Zhilong Huang Department of Engineering Mechanics Zhejiang UniversityHangzhou310027China Hangzhou Zhongpu Technology Co. Ltd.Hangzhou310012China Pengcheng Lab Shenzhen518055China

As conducting an impact hammer testing during experimental modal analysis,the multiple impact phenomenon must be *** is generally recognized that the multiple impact phenomenon is induced by the tester’s improper operation and can be avoided through more careful *** study theoretically and numerically investigates the whole process of the dynamical interaction between the hammer tip and the impacted structure and discovers the intrinsically physical mechanism of the multiple impact *** determination of the interacting process comes down to solve two sets of governing differential equations alternately,and the effectiveness of the theoretical analysis is validated by numerical *** dimensionless parameters governing the interacting process are recognized in the theoretical *** critical stiffness ratio for a given impacted location and the critical impacted location for a given stiffness ratio are analytically *** results can guide impact hammer testing to avoid the occurrence of multiple impact by suggesting the hammer tip and impacted locations.

关键词： Impact hammer testing Modal analysis Multiple impact Theoretical analysis Numerical simulation

Renal amyloidosis as a late complication of Crohn's disease:a case report and review of the literature from Japan

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World Journal of Gastroenterology 2000年第3期6卷 461-464页

作者： Osamu Saitoh Keishi Kojima Tsutomu Teranishi ken Nakagawa Masanobu Kayazawa Masashi Nanri Yutaro Egashira Ichiro Hirata ken-ichi Katsu Second Department of Internal Medicine Osaka Medical CollegeTakatsukiJapan First Department of Pathology Osaka Medical CollegeTakatsukiJapan

INTRODUCTION Secondary amyloidosis is a rare but seriouscomplication of Crohn’s disease(CD).Theincidence of the association of secondaryamyloidosis in patients with CD has been reportedto be 0.5%-8% in Western ***,in Japan,the number of patients with CDcomplicated by amyloidosis is *** of their clinical manifestations andthe incidence of association are ***,we report herein a patient with

关键词： Crohn’s disease/complication renal amyloidosis amyloid deposits

Optimization of fuel consumption and NO_(x) emission for mild HEV via hierarchical model predictive control

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Control Theory and Technology 2022年第2期20卷 221-234页

作者： Yuka Umezawa ken Yamauchi Hiroki Seto Toshiro Imamura Toru Namerikawa Graduate School of Science and Technology Keio University3-14-1 HiyoshiKohoku-ku.YokohamaKanagawa 223-8522Japan Isuzu Advanced Engineering Center Ltd 8 TsuchidanaFujisawa.Kanagawa 252-0881.Japan

In this paper,we consider the fuel economy optimization problem for a mild hybrid electric vehicle(HEV)using hierarchical model predictive *** the proposed algorithm,two problems are addressed:eco-driving and torque *** the eco-driving problem,vehicle speed was *** the reduction in fuel consumption and NOx emissions,the torque required to follow the target speed was ***,in the torque distribution problem,the distribution between the engine and motor torques were *** this phase,engine characteristics were *** problems differ in terms of time scales;therefore,a hierarchical model predictive control is ***,the numerical simulation results demonstrated the efficacy of this research.

关键词： Mild HEV Energy management Model predictive control Hierarchical control

Diagnosis and therapeutic strategies for small bowel vascular lesions

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World Journal of Gastroenterology 2019年第22期25卷 2720-2733页

作者： Eiji Sakai ken Ohata Atsushi Nakajima Nobuyuki Matsuhashi Department of Gastroenterology NTT Medical Center TokyoTokyo 141-8625Japan Division of Gastroenterology and Hepatology Yokohama City University School of MedicineYokohama 236-0004Japan

Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be venous lesions, they usually manifest as a chronic, well-compensated condition. Subsequent to video capsule endoscopy, deep enteroscopy can be applied to control active bleeding or to improve anemia necessitating blood transfusion. Despite the initial treatment efficacy of argon plasma coagulation (APC), many patients experience re-bleeding, probably because of recurrent or missed AEs. Pharmacological treatments can be considered for patients who have not responded well to other types of treatment or in whom endoscopy is contraindicated. Meanwhile, a conservative approach with iron supplementation remains an option for patients with mild anemia. DL and AVM are considered to be arterial lesions;therefore, these lesions frequently cause acute life-threatening hemorrhage. Mechanical hemostasis using endoclips is recommended to treat DLs, considering the high re-bleeding rate after primary APC cauterization. Meanwhile, most small bowel AVMs are large and susceptible to re-bleeding therefore, they usually require surgical resection. To achieve optimal diagnostic and therapeutic approaches for each type of small bowel lesion, the differences in their epidemiology, pathology and clinical presentation must be understood.

关键词： Angiodysplasia Angioectasia Dieulafoy's lesion Arteriovenous malformation Obscure gastrointestinal bleeding Video capsule endoscopy Deep enteroscopy Argon plasm coagulation

Semiconductor steady state defect effective Fermi level and deep level transient spectroscopy depth profiling

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Journal of Semiconductors 2016年第9期37卷 26-32页

作者： ken K.Chin Zimeng Cheng Department of Physics and CNBM New Energy Materials Research Center New Jersey Institute of Technology (NJIT)

The widely used deep level transient spectroscopy（DLTS） theory and data analysis usually assume that the defect level distribution is uniform through the depth of the depletion region of the n–p junction. In this work we introduce the concept of effective Fermi level of the steady state of semiconductor, by using which deep level transient spectroscopy depth profiling（DLTSDP） is proposed. Based on the relationship of its transition free energy level（TFEL） and the effective Fermi level, the rules of detectivity of the defect levels are listed. Computer simulation of DLTSDP is presented and compared with experimental data. The experimental DLTS data are compared with what the DLTSDP selection rules predicted. The agreement is satisfactory.

关键词： Fermi level deep level transient spectroscopy Schottky junction

RECENT PROGRESS OF NANO-MECHANICAL MAPPING

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Chinese Journal of Polymer Science 2009年第1期27卷 37-47页

作者： Toshio Nishi Sae Nagai So Fujinami ken Nakajima WPI Advanced Institute for Materials Research Tohoku University 2-I-1KatahiraAoba-kuSendaiMiyagi 980-8577Japan

Nano-mechanical mapping by atomic force microscopy has been developed as an useful application to measure mechanical properties of soft materials at nanometer *** date,the Hertzian theory was used for analyzing force- distance curves as the simplest model among several contact mechanics between elastic ***,the preexisting methods based on this theory do not consider the adhesive interaction in principle,which cannot be neglected in the ambient condition.A new analytical method was introduced...

关键词： Atomic force microscopy Nano-mechanical mapping Force-distance curve JKR theory

Fast-moving bimorph actuator based on electrochemically treated millimeter-long carbon nanotube electrodes and ionic liquid gel

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International Journal of Smart and Nano Materials 2012年第4期3卷 263-274页

作者： kentaro Yamato ken Mukai kenji Hata Kinji Asaka Health Research Institute National Institute of Advanced Industrial Science and Technology(AIST)1-8-31 MidorigaokaIkedaOsaka 563-8577Japan Nanotube Research Center National Institute of Advanced Industrial Science and Technology(AIST)Central 51-1-1 HigashiTsukubaIbaraki 305-8565Japan

The development is described of an electromechanical bimorph actuator composed of ionic liquid gel sandwiched by electrochemically treated millimeter-long single-walled carbon nanotubes(SG-SWNT).Electrochemical doping of the SG-SWNT and electrochemical polymerization of polypyrrole on the surface of the SG-SWNT improved the performance of a previously reported actuator using non-treated *** conductivity of the SG-SWNT sheets treated at the anodic potential(doped)was found to be three times larger than that of the original *** generated strain of the actuator prepared from the doped SG-SWNT sheets was increased compared to that prepared from non-doped ***,the generated strain of the actuator from the doped SG-SWNT sheets swelled with ionic liquid(IL)was increased to twice that without *** electropolymerization of pyrrole on the surface of the SG-SWNT sheet was carried *** conductivity of the SG-SWNT was seven times larger after the *** generated strain of the SG-SWNT actuator prepared from the SG-SWNT sheets with electropolymerization was twice as large as that without the electropolymerization at low *** higher frequency,both actuators provide almost the same *** actuators exhibit mechanical resonance at about 100 Hz.

关键词： carbon nanotube polypyrrole electrochemical doping ionic liquid bimorph actuator

Atypical causes of cholestasis

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World Journal of Gastroenterology 2014年第28期20卷 9418-9426页

作者： ken D Nguyen Vinay Sundaram Walid S Ayoub Department of Internal Medicine Cedars Sinai Medical CenterLos AngelesCA 90048United States Department of Gastroenterology and Hepatology Multi Organ Transplant CenterCedars Sinai Medical CenterLos AngelesCA 90048United States

Cholestatic liver disease consists of a variety of disorders. Primary sclerosing cholangitis and primary biliary cirrhosis are the most commonly recognized cholestatic liver disease in the adult population, while biliary atresia and Alagille syndrome are commonly recognized in the pediatric population. In infants, the causes are usually congenital or inherited. Even though jaundice is a hallmark of cholestasis, it is not always seen in adult patients with chronic liver disease. Patients can have “silent” progressive cholestatic liver disease for years prior to development of symptoms such as jaundice and pruritus. In this review, we will discuss some of the atypical causes of cholestatic liver disease such as benign recurrent intrahepatic cholestasis, progressive familial intrahepatic cholestasis, Alagille Syndrome, biliary atresia, total parenteral nutrition induced cholestasis and cholestasis secondary to drug induced liver injury.

关键词： Cholestasis Benign recurrent intrahepatic cholestasis Progressive familial intrahepatic cholestasis Alagille syndrome Biliary atresia Total parenteral nutrition Drug induced liver injury