Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343477
Changyou Li, Q. Zhu, Xiao-xiang He
The electromagnetic properties of fiber-reinforced laminated composite are studied and optimized here, with the fibers in the structure are organized in a periodic way. The laminate is consist of multiple layers with the fibers in each layer periodically arranged and bind together by the matrix which can be epoxy or ceramics etc. A number of fibers are embedded into one periodic cell and bind together to form a fiber bundle for wave absorption enhancement. The electromagnetic wave scattering properties of this composite are studied in detail with different structural and electromagnetic parameters. The constrained optimization by linear approximations is applied for optimization the reflection and transmission properties of the structure. The finite-difference time-domain method is applied in this article for the numerical investigations. Short Gaussian pulse is used as the source for the time domain simulation, and a Fourier transformation is then applied to get the field distribution and the reflection/transmission coefficients in a wide frequency band. Various numerical results are presented with detailed discussions.
{"title":"Electromagnetic properties and optimizations of the laminated composites","authors":"Changyou Li, Q. Zhu, Xiao-xiang He","doi":"10.1109/NEMO49486.2020.9343477","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343477","url":null,"abstract":"The electromagnetic properties of fiber-reinforced laminated composite are studied and optimized here, with the fibers in the structure are organized in a periodic way. The laminate is consist of multiple layers with the fibers in each layer periodically arranged and bind together by the matrix which can be epoxy or ceramics etc. A number of fibers are embedded into one periodic cell and bind together to form a fiber bundle for wave absorption enhancement. The electromagnetic wave scattering properties of this composite are studied in detail with different structural and electromagnetic parameters. The constrained optimization by linear approximations is applied for optimization the reflection and transmission properties of the structure. The finite-difference time-domain method is applied in this article for the numerical investigations. Short Gaussian pulse is used as the source for the time domain simulation, and a Fourier transformation is then applied to get the field distribution and the reflection/transmission coefficients in a wide frequency band. Various numerical results are presented with detailed discussions.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130304674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343566
Wei Lai, Zhi Wang, Minyou Chen, Hongjian Xia, Dan Luo, Yunhai Wei, B. Gao, Yigao Chen
With the extensive investment of wind turbine, it is significant to study the reliability and lifetime estimation model of its core components. Considering the effect of different failure sites on the remaining lifetime, the response of the converter at failure sites is studied. It is found that die attach solder fatigue and DBC (Direct Bonding Copper) solder fatigue, which happen frequently during the serving time, have different effects on thermal loads. A modified Cauer-type thermal model is proposed according to the failure sites. Using a modified lifetime model, Remaining lifetime of the DFIG (Doubly Fed Induction Generator) converter is calculated under different health conditions and failure sites. Reliability analysis is very important to the health management of converter.
{"title":"Reliability Evaluation of IGBT Modules in Wind Power Converter Considering the Effects of Different Failure Sites","authors":"Wei Lai, Zhi Wang, Minyou Chen, Hongjian Xia, Dan Luo, Yunhai Wei, B. Gao, Yigao Chen","doi":"10.1109/NEMO49486.2020.9343566","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343566","url":null,"abstract":"With the extensive investment of wind turbine, it is significant to study the reliability and lifetime estimation model of its core components. Considering the effect of different failure sites on the remaining lifetime, the response of the converter at failure sites is studied. It is found that die attach solder fatigue and DBC (Direct Bonding Copper) solder fatigue, which happen frequently during the serving time, have different effects on thermal loads. A modified Cauer-type thermal model is proposed according to the failure sites. Using a modified lifetime model, Remaining lifetime of the DFIG (Doubly Fed Induction Generator) converter is calculated under different health conditions and failure sites. Reliability analysis is very important to the health management of converter.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125003234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343464
Baichuan Liu, Zhenyu Zhao, Junhong Wang
In this paper, radio wave coverage properties inside a train located in confined space are studied by using Time-Domain Finite Difference method (FDTD). The works in this paper are mainly focused on the effect of materials of train and windows on the radio wave coverage. Calculation results show that metallic train body will cause a loss about 10 dB. When using Fiber Reinforced Plastic (FRP) as train body, the loss reduces significantly. In addition, for windows, using heat-absorbing glazing leads to an extra loss about 1 dB compared to that of dielectric glass. It is concluded that train material and windows have certain impacts on the radio wave coverage inside the train and need to be further studied.
{"title":"Research on Radio Wave Coverage inside Train in Confined Space","authors":"Baichuan Liu, Zhenyu Zhao, Junhong Wang","doi":"10.1109/NEMO49486.2020.9343464","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343464","url":null,"abstract":"In this paper, radio wave coverage properties inside a train located in confined space are studied by using Time-Domain Finite Difference method (FDTD). The works in this paper are mainly focused on the effect of materials of train and windows on the radio wave coverage. Calculation results show that metallic train body will cause a loss about 10 dB. When using Fiber Reinforced Plastic (FRP) as train body, the loss reduces significantly. In addition, for windows, using heat-absorbing glazing leads to an extra loss about 1 dB compared to that of dielectric glass. It is concluded that train material and windows have certain impacts on the radio wave coverage inside the train and need to be further studied.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131536438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343499
Liyang Chen, Wei Zheng, Yanhui Liu
An iterative spatiotemporal Fourier transform (STFT) method is proposed to synthesize a wideband scannable frequency-invariant (FI) pattern for a uniformly spaced linear antenna array. This method applies a modification-and-projection iteration to continuously update the synthesis results. An example for synthesizing a scannable FI pattern with uniform sidelobe level (SLL) is provided to verify the effectiveness and efficiency of the proposed method.
{"title":"Efficient Scannable Frequency-invariant Pattern Synthesis Using Iterative Spatiotemporal Fourier Transform","authors":"Liyang Chen, Wei Zheng, Yanhui Liu","doi":"10.1109/NEMO49486.2020.9343499","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343499","url":null,"abstract":"An iterative spatiotemporal Fourier transform (STFT) method is proposed to synthesize a wideband scannable frequency-invariant (FI) pattern for a uniformly spaced linear antenna array. This method applies a modification-and-projection iteration to continuously update the synthesis results. An example for synthesizing a scannable FI pattern with uniform sidelobe level (SLL) is provided to verify the effectiveness and efficiency of the proposed method.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131549309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343572
Zi-Jian Han, Yong-Xin Zhou, R. Pan, Song Yue, Xiang Li, Chuanbing Wang, X. Qi, K. Shi, Xiangjun Song
A broadband and high-gain circularly polarized antenna based on electromagnetic band gap (EBG) structures is proposed by analyzing the influence of EBG layouts on antenna performances. Compared with the reference circularly polarized antenna, the impedance bandwidth, the axial ratio bandwidth and the broadside gain of the proposed EBG antenna are significantly improved. In addition, the method of optimizing the layout of EBG structures provides a general strategy for designing broadband and high-gain EBG antenna.
{"title":"Broadband and High-Gain Circularly Polarized Antenna by Using EBG Structures","authors":"Zi-Jian Han, Yong-Xin Zhou, R. Pan, Song Yue, Xiang Li, Chuanbing Wang, X. Qi, K. Shi, Xiangjun Song","doi":"10.1109/NEMO49486.2020.9343572","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343572","url":null,"abstract":"A broadband and high-gain circularly polarized antenna based on electromagnetic band gap (EBG) structures is proposed by analyzing the influence of EBG layouts on antenna performances. Compared with the reference circularly polarized antenna, the impedance bandwidth, the axial ratio bandwidth and the broadside gain of the proposed EBG antenna are significantly improved. In addition, the method of optimizing the layout of EBG structures provides a general strategy for designing broadband and high-gain EBG antenna.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132368677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343551
Xu Wang, Mengjie Li, Z. Li
Terahertz (THz) detectors have shown attractive prospects in the areas of THz sensing and imaging. This paper presents the multi-physics modeling of an on-chip octagonal ring antenna loaded with a polysilicon resistor coupled with a sensitive proportional to absolute temperature (PTAT) sensor using a 55 nm CMOS process, leading to an uncooled monolithic resonant CMOS fully integrated THz thermal detector. The theoretical analysis, multi-physics modeling, and experimental verification of the detector are presented in detail. The maximum responsivity is 38.04 V/W with a noise equivalent power (NEP) of 2.89 μW/Hz0.5 at 2.58 THz for the THz source and an existing atmospheric window, and it has the natural scalability to focal plane arrays, showing great potentials for uncooled, compact, low-cost, easy- integration, and mass-production THz detection systems.
{"title":"Multiphysics Modeling of CMOS Fully Integrated 2.58 THz Thermal Detector","authors":"Xu Wang, Mengjie Li, Z. Li","doi":"10.1109/NEMO49486.2020.9343551","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343551","url":null,"abstract":"Terahertz (THz) detectors have shown attractive prospects in the areas of THz sensing and imaging. This paper presents the multi-physics modeling of an on-chip octagonal ring antenna loaded with a polysilicon resistor coupled with a sensitive proportional to absolute temperature (PTAT) sensor using a 55 nm CMOS process, leading to an uncooled monolithic resonant CMOS fully integrated THz thermal detector. The theoretical analysis, multi-physics modeling, and experimental verification of the detector are presented in detail. The maximum responsivity is 38.04 V/W with a noise equivalent power (NEP) of 2.89 μW/Hz0.5 at 2.58 THz for the THz source and an existing atmospheric window, and it has the natural scalability to focal plane arrays, showing great potentials for uncooled, compact, low-cost, easy- integration, and mass-production THz detection systems.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133430225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present in this paper a well-scaling parallel approach of the finite element-domain decomposition method (FEM-DDM) for solving large scale 3D scattering problems on many-core SW26010 processors. In this parallel approach, the whole solution domain is first decomposed in a two-level hierarchical way to minimize the inter process communication. Then the FEM matrix of each unit-level subdomain to be solved in the iterative solution of the interface problem from FEM-DDM, is solved via another sparse approximate inverse (SPAI) preconditioner accelerated iterative solver. This inner–outer iteration scheme is further accelerated by exploring many-core parallelization, with specially designed sparse matrix vector multiplications to improve the data access efficiency. The performance achievements are investigated in terms of accuracy, speed up, and scalability.
{"title":"A Well-Scaling Parallel FEM-DDM Algorithm for Electromagnetic Simulation on SW26010 Many-core Processor","authors":"Jiandong Lai, Rui-Qing Liu, Wei-Jia He, Wen Wang, Ming-lin Yang, X. Sheng","doi":"10.1109/NEMO49486.2020.9343550","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343550","url":null,"abstract":"We present in this paper a well-scaling parallel approach of the finite element-domain decomposition method (FEM-DDM) for solving large scale 3D scattering problems on many-core SW26010 processors. In this parallel approach, the whole solution domain is first decomposed in a two-level hierarchical way to minimize the inter process communication. Then the FEM matrix of each unit-level subdomain to be solved in the iterative solution of the interface problem from FEM-DDM, is solved via another sparse approximate inverse (SPAI) preconditioner accelerated iterative solver. This inner–outer iteration scheme is further accelerated by exploring many-core parallelization, with specially designed sparse matrix vector multiplications to improve the data access efficiency. The performance achievements are investigated in terms of accuracy, speed up, and scalability.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116619894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343460
Jun Dai, Yikun Ding, C. Ruan
Compact, cost-effective, high-power and broadband radiation sources are required for terahertz (THz) spectroscopy and communication applications. In this paper, we present a new terahertz photomixer using a planar antenna integrated vacuum photodiode. The photocathode of the photodiode can be excited to emit high-density THz electron beams corresponding to the illuminating laser beat frequency. The electron beams can be accelerated and transported through a micron scale vacuum channel to feed an integrated broadband antenna generating continuous THz radiation into free space. The vacuum channel enables high current density operation and carrier mobility, which makes the photomixer capable of radiating high output power of milliwatt level within 0.1-2.0 THz. The latest development in the schematic design of the vacuum photomixer, design and analysis of the vacuum transistor and the broadband antenna is reviewed and discussed. Further research works will be focused on the analytical framework of the photomixer that involves photocathode modeling, charged sheets transportation in the micron scale vacuum channel, and impedance match.
{"title":"Design and Analysis of High Power, Broadband Terahertz Vacuum Photomixer Device","authors":"Jun Dai, Yikun Ding, C. Ruan","doi":"10.1109/NEMO49486.2020.9343460","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343460","url":null,"abstract":"Compact, cost-effective, high-power and broadband radiation sources are required for terahertz (THz) spectroscopy and communication applications. In this paper, we present a new terahertz photomixer using a planar antenna integrated vacuum photodiode. The photocathode of the photodiode can be excited to emit high-density THz electron beams corresponding to the illuminating laser beat frequency. The electron beams can be accelerated and transported through a micron scale vacuum channel to feed an integrated broadband antenna generating continuous THz radiation into free space. The vacuum channel enables high current density operation and carrier mobility, which makes the photomixer capable of radiating high output power of milliwatt level within 0.1-2.0 THz. The latest development in the schematic design of the vacuum photomixer, design and analysis of the vacuum transistor and the broadband antenna is reviewed and discussed. Further research works will be focused on the analytical framework of the photomixer that involves photocathode modeling, charged sheets transportation in the micron scale vacuum channel, and impedance match.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"239 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116419348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343594
Yan Li, Yang Shi, Zhi-yi Gao, Hao-Nan Zhou, Chuang-Chuang Fang, W. Tian
In this paper, the mechanism of passive intermodulation on the metal contact surface is analyzed. According to the roughness contact model, the corresponding equivalent circuit model is established. The influence of metal contact surface roughness, contact area, mechanical loading, and excitation electromagnetic field strength on passive intermodulation power is studied with numerical simulation using ADS. The suppression measures to reduce passive intermodulation products in engineering applications are proposed.
{"title":"Simulation of Third-order Inorganic Intermodulation on a Rough Contact Surface","authors":"Yan Li, Yang Shi, Zhi-yi Gao, Hao-Nan Zhou, Chuang-Chuang Fang, W. Tian","doi":"10.1109/NEMO49486.2020.9343594","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343594","url":null,"abstract":"In this paper, the mechanism of passive intermodulation on the metal contact surface is analyzed. According to the roughness contact model, the corresponding equivalent circuit model is established. The influence of metal contact surface roughness, contact area, mechanical loading, and excitation electromagnetic field strength on passive intermodulation power is studied with numerical simulation using ADS. The suppression measures to reduce passive intermodulation products in engineering applications are proposed.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115557723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-07DOI: 10.1109/NEMO49486.2020.9343434
Yinfei Weng, Zachary Su
The article introduces an automatic synthesis method for on-chip transformer from electromagnetic (EM) simulations. Using this method, a transformer library, parametric layout and scalable model are generated quickly, then a fast search through the transformer space produces an optimal design. We used this method to design transformer for common wireless application. The synthesis method of transformer includes various constraints such as inductance, quality factors, and coupling coefficients to ensure that the synthesis results meet expectations, and the accuracy deviation is within 5%.
{"title":"Automatic Synthesis for On-chip Transformer","authors":"Yinfei Weng, Zachary Su","doi":"10.1109/NEMO49486.2020.9343434","DOIUrl":"https://doi.org/10.1109/NEMO49486.2020.9343434","url":null,"abstract":"The article introduces an automatic synthesis method for on-chip transformer from electromagnetic (EM) simulations. Using this method, a transformer library, parametric layout and scalable model are generated quickly, then a fast search through the transformer space produces an optimal design. We used this method to design transformer for common wireless application. The synthesis method of transformer includes various constraints such as inductance, quality factors, and coupling coefficients to ensure that the synthesis results meet expectations, and the accuracy deviation is within 5%.","PeriodicalId":305562,"journal":{"name":"2020 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114651201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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