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Weave geometry generation avoiding interferences for mesoscale RVEs

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Journal of Materials Science & Technology 2019年第12期35卷 2869-2882页

作者： Daniel Höwer Shengkai Yu Trenton M.Ricks Brett A.Bednarcyk Evan J.Pineda Bertram Stier Stefanie Reese jaan-Willem Simon Institute of Applied Mechanics RWTH Aachen University52074 AachenGermany NASA Glenn Research Center ClevelandOH 44135USA Collier Research and Development Corporation Newport NewsVA 23606USA

An algorithm which allows the generation of representative volume elements(RVEs) for complex woven and warp-interlaced fiber-reinforced composite topologies while avoiding unphysical tow intersections is presented. This is achieved by extending an existing RVE generation strategy in two significant ways:(1) the local cross section shape of the tow is adjusted depending on the local tow curvature in a way that preserves the cross sectional area of the tow, and(2) the elementary crimp interval is separated into a planar and a transition region. The modifications facilitate the generation of a wide range of elaborate textile topologies without tow intersections, which are present without the proposed modifications unless complex tow to tow contact models are introduced. The mechanical properties of plain weaves were predicted based on the topology generated with the proposed algorithm as well as based on RVEs which were constructed based on actual micrographs, i.e. a "digital twin" of the actual microstructure. A comparison of the predicted mechanical properties based on finite element and Multiscale Generalized Method of Cells techniques shows close agreement. However, some differences exist with respect to experimentally determined material parameters due to the finite dimensions of the specimens. Lastly,mechanical properties of multilayered weaves are predicted with the finite element method. The considered material systems are carbon fiber in epoxy matrix as well as C/C-SiC. However, the procedure is applicable to a wide range of material systems.

关键词： RVE generation Multiscale analysis Composites

Power Quality Issues Concerning Photovoltaic Generation and Electrical Vehicle Loads in Distribution Grids

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Smart Grid and Renewable Energy 2015年第6期6卷 164-177页

作者： jaan Niitsoo Paul Taklaja Ivo Palu Joni Klüss Department of Electrical Power Engineering Tallinn University of Technology Tallinn Estonia Department of Electrical Engineering and Automation Aalto University Helsinki Finland

The high utilization level of renewable generation including residential photovoltaic (PV) systems together with the uncontrolled charging of electric vehicles (EVs) can have a significant impact on load characteristics in distribution networks. Harmonic content of PV generation, EV charging loads, and their influence on power quality indicators in residential distribution networks are discussed in this paper. For investigating likely power quality scenarios, PV generation and EV charging measurement results including current harmonic amplitude and phase angle values are used and compared with present load characteristics. Different modelling scenarios are analysed and a simplified model of harmonics in PVs and EVs is offered. The results of the study show moderate additional harmonic distortion in residential load current and voltage distortion at the substation’s busbar when PV generation and EV loading are added. The scenarios presented in this paper can be further used for modelling the actual harmonic loads of the PVs and EVs in distribution networks.

关键词： Current Measurement Distributed Generation Electric Vehicles Load Modelling Photo Voltaic Power Quality Power System Harmonics

Different Pathogenetic Impact of Oxidative Stress and Inflammation on Vascular Endothelium and Arterial Stiffness

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Different Pathogenetic Impact of Oxidative Stress and Inflam...

Long-term rare giant sialolithiasis for 30 years:A case report and review of literature

第14届国际自由基学术大会

作者： Jaak Kals Priit Kampus jaan Eha Mihkel Zilmer Department of Biochemistry National and European Center of Excellence of Molecular and Clinical Medicine University of Tartu 19 Ravila Street Tartu 50411 Estonia Department of Cardiology University of Tartu 8 Puusepa Street Tartu 51014 Estonia

＜正＞Background: Inflammation and oxidative stress （OxS） play key roles in atherogenesis, however, their causal relationship is yet incompletely understood. Much attention has been given to the possibility that inflammation is a primary process of atherosclerosis and OxS may be a by-product of the inflammatory process. We hypothesized accordingly

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World Journal of Clinical Cases 2023年第22期11卷 5382-5390页

作者： Jit-Swen Mao Yu-Chien Lee Jessie Chao-Yun Chi Wan-Ling Yi Yung-An Tsou Chia-Der Lin Chih-jaan Tai Liang-Chun Shih Department of Otorhinolaryngology-Head and Neck Surgery China Medical University HospitalTaichung 400Taiwan Department of Otorhinolaryngology Head and Neck SurgeryTaichung HospitalMinistry of Health and WelfareTaichung 404Taiwan Department of Otorhinolaryngology-Head and Neck Surgery Asia University HospitalTaichung 404Taiwan School of Medicine China Medical UniversityTaichung 404Taiwan

BACKGROUND Sialolithiasis is one of the most common salivary gland disorders,most commonly affecting the submandibular *** sialolithiasis can be treated using non-invasive conservative measures and invasive *** selection was based on the ductal system anatomy and the size and location of the *** study aimed to review the updates on sialolithiasis treatment and compare the different management strategies of the *** SUMMARY This report presents a case of a long-term,rare,and giant sialolithiasis within the submandibular gland parenchyma for 30 years in an older *** patient presented with painless right submandibular *** tomography revealed a calcified mass measuring 35 mm×20 mm within the right submandibular *** this case,the infection and fibrosis of the affected gland and size of the stone did not provide us with other alternatives except for the excision of the involved ***,right submandibular sialoadenectomy was performed via the transcervical *** the surgery,the patient recovered without any complaints,side effects,or *** Tailored management is important for preserving gland function,maintaining low risk,and reducing patient discomfort.

关键词： Huge sialolithiasis Submandibular gland Treatment Complications Case report

Power Quality Issues Concerning Photovoltaic Generation in Distribution Grids

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Smart Grid and Renewable Energy 2015年第6期6卷 148-163页

作者： jaan Niitsoo Marek Jarkovoi Paul Taklaja Joni Klüss Ivo Palu Department of Electrical Power Engineering Tallinn University of Technology Tallinn Estonia Department of Electrical Engineering Tallinn University of Technology Tallinn Estonia Department of Electrical Engineering and Automation Aalto University Helsinki Finland

Unregulated utilization of renewable generation including residential photovoltaic (PV) systems can have a significant impact on load characteristics in distribution networks. For improving PV generation capabilities, power quality aspects have to be coordinated with present load characteristics. This paper discusses the harmonic content of PV generation and the influence to power quality indicators in residential distribution networks. PV generation measurement results including current harmonic amplitude and phase angle values are presented. Results of different modelling scenarios are analysed and a simplified model of harmonics in PVs is offered. The results of the study showed a moderate additional harmonic distortion in residential load current and voltage distortion at the substation’s busbar when PVs were added. Novelty of the paper is that harmonic current values at higher orders are presented and analysed. The results pointed out in this paper could be further used for modelling the actual harmonic loads of the PVs in distribution networks.

关键词： Current Measurement Load Modelling Photo Voltaic Power Quality Power System Harmonics

波罗的海的半石化软体动物壳中氧和碳的同位素成分作为一种古盐度的指示标志

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地质科学译丛 1990年第1期7卷 29-33页

作者： jaan-MatiPunning 王薇薇

软体动物壳中的δ^(13)C和δ^(13)O同位素成分,主要通过水和被溶解的碳酸氢盐同位素成分测定.水的δ^(13)O值表现出与波罗的海含盐度的明显相关性.根据半石化(subfossil)壳中碳酸盐骨骼的δ^(13)O值,可利用这种相关性作为恢复古盐度和... 详细信息

软体动物壳中的δ^(13)C和δ^(13)O同位素成分,主要通过水和被溶解的碳酸氢盐同位素成分测定.水的δ^(13)O值表现出与波罗的海含盐度的明显相关性.根据半石化(subfossil)壳中碳酸盐骨骼的δ^(13)O值,可利用这种相关性作为恢复古盐度和划分海洋沉积物的一种基础.壳中的δ^(13)C值主要是通过陆相成因的碳酸氢盐的同位素成分测定的,尤其是通过生活于近临滨海带的Lymnaea bal-thica碳酸钙骨骼中的同位素成分测定.根据δ^(13)O资料,调查区(爱沙尼亚的西部和西北部沿海带)的盐度在Littorina阶为最高(大约9～11‰)。通常Limnaea阶的含盐度与现代的含盐度相似,但在某些情况下可能还超过现代的2～3‰.

关键词：软体动物壳同位素古盐度标志

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个案研究:一次失败的医院并购

中国卫生产业 2004年第7期1卷 84-86页

作者： jaan sidorov 张本良孟璞

1999年11月,Hershey医疗中心(HMC:Hershey Medical Center)与Geisinger健康系统(Geisinger:Geisinger Health System)宣布他们之间的并购失败.前车之鉴,后事之师.通过这次失败,我们应该注意到以下四个在医疗机构并购中须加以重视的因素:

关键词：个案研究医院并购并购失败公司制管理并购原因组织结构

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波罗的海沿岸三国环境政策制订的驱动力

AMBIO－人类环境杂志 2001年第7期30卷 443-449页

作者： Andres Kratovits jaan-Mati Punning 刘林群塔林师范大学地生态系

本文详尽阐述了国际环境体制和多边环境协议在波罗的海沿岸三国(爱沙尼亚、拉脱维亚和立陶宛)制订本国环境政策过程中所起的作用。将污染物排放趋势与环境状况变化参照国际环境体制进行对比后可以得出结论,正式加入环境公约与环境领域... 详细信息

本文详尽阐述了国际环境体制和多边环境协议在波罗的海沿岸三国(爱沙尼亚、拉脱维亚和立陶宛)制订本国环境政策过程中所起的作用。将污染物排放趋势与环境状况变化参照国际环境体制进行对比后可以得出结论,正式加入环境公约与环境领域所发生的变化之间并没有明显的联系。这三个波罗的海沿岸国家的做法是,先加入涉及全球性或区域性环境安全的国际环境体制,尔后才接受对于解决其自身环境问题比较重要的协议并加入相关的体制。因此,可以断定,这三个国家在制订自身环境政策过程中把国际法律文件看作是预防性的,而非整治性的。另一方面,它们认为,积极参与多边环境协议,对于在其环境政策方面采取下一个步骤,即接受欧盟的环境政策("欧亚体经验规范")(Acquis Communautaire),将起着巨大推动作用。

关键词：波罗的海沿岸环境政策制订国际环境体制环境协议

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群体饲养可使母猪处于低应激状态

国外畜牧学（猪与禽） 2009年第2期29卷 40-41页

作者： jaan Jourquin 陈杰（译）夏彦斌（译）文谦（校）比利时Beerse市Janssen动物保健公司不详

在经过从母猪的单只圈养转变为群体饲养的初期阵痛后,许多养猪场在母猪生产上找到了新的平衡点,但是其他猪场似乎仍处于苦苦的挣扎之中。为了要取得良好的繁殖性能,使母猪远离应激是至关重要的。

关键词：应激状态群体饲养母猪繁殖性能养猪场平衡点圈养仔猪