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Geometric modeling of underground ferromagnetic pipelines for magnetic dipole reconstruction-based magnetic anomaly detection

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Petroleum 2020年第2期6卷 189-197页

作者： Dandan Zhao Zhiyong Guo Jian Du Zhongxiang Liu Wei Xu Gaofei Liu School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500China China Petroleum Pipeline Insptection Technologies Co. LtdLangfang065000China

To aid the magnetic anomaly detection(MAD)of underground ferromagnetic pipelines,this paper proposes a geometric modeling method based on the magnetic dipole reconstruction method(MDRM).First,the numerical modeling of basic pipe components such as straight sections,bends and elbows,and tee joints are discussed and the relevant mathematical formulations for these components are ***,after analyzing the function of MDRM and various element division strategies,the sectional division and blocked division methods are introduced and applied to the appropriate pipeline components to determine the volume and center coordinates of each element,establishing the general models for the three typical pipeline components *** resulting volume and center coordinates of each component are the fundamental parameters for determining the MAD forwarding of underground ferromagnetic pipelines using the ***,based on the combination and transformation of the basic pipeline components considered,the visualized geometric models of typical pipeline layouts including parallel pipelines,pipelines with elbows,and a pipeline with a tee joint are *** results demonstrate the feasibility of the proposed method of geometric modeling for the MDRM,which can be further applied to the finite element modeling of these and other components when analyzing MAD ***,the models with output parameters proposed in this paper establish a foundation for the inversion of MAD.

关键词： Magnetic anomaly detection Magnetic dipole reconstruction segmentation method Pipeline detection Geometric modeling

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Rainfall Variability and Trends in West Africa

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Atmospheric and Climate Sciences 2023年第1期13卷 72-83页

作者： Anoumou Réné Tano François-Xavier Djézia Bella Bouo Justin Koffi Kouamé Yao Tchétché Sylvain Djédjé Zézé Bafétigué Ouattara Equipe de la Physique pour l’Environnement Laboratoire de Physique Fondamentale et Appliquée Université NANGUI ABROGOUA Abidjan C&#244 te d’Ivoire Laboratoire de Physique Université de Man Man C&#244 te d’Ivoire

Rainfall variability associated with climate change has enormous impacts on ecosystems, agriculture and people in West Africa but few studies have been devoted to it. Monthly rainfall data from 1901 to 2013, provided by the Global Precipitation Climatology Center dataset, were analyzed using segmentation and empirical modal decomposition (EMD) methods to increase our knowledge on past and recent spatio-temporal rainfall trends and their impacts on the West African region. The results obtained showed that the peak of rainfall during the short rainy season is observed in September in Côte d’Ivoire, Ghana and Liberia. The temporal variability of this rainfall is marked by several breakpoints whose durations range from 2 to 70 years. The periods of change in the rainfall regime, characterized by the appearance of breakpoints, vary from one country to another and are of unequal duration. The main breakpoint appears after 1960. Periods of relative or normal increase or decrease in precipitation are observed before and after 1960. The long-term variability of this rainfall is characterized by a decrease in the amount of rainfall over all West African countries. The results of this study can be used as a tool to help raise awareness among populations for sustainable management of water resources in response to climate change and its adverse effects.

关键词： Rainfall Variability segmentation method Empirical Mode Decomposition method West Africa

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ENERGY HARVESTING USING A CIRCULAR CYLINDRICAL SHELL LAMINATED WITH A SEGMENTED PIEZOELECTRIC LAYER

ENERGY HARVESTING USING A CIRCULAR CYLINDRICAL SHELL LAMINAT...

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2010全国压电和声波理论及器件技术研讨会

作者： Kuochih CHUANG Hornsen(H.S.) TZOU School of Aeronautics and Astronautics Institute of Applied Mechanics StrucTronic Systems and Control LabZhejiang University

Energy harvesting based on the direct piezoelectric effect using the curvature structures is a new endeavor in engineering *** study focuses on energy harvesting from mechanical vibrations through a simply supported circular cylindrical shell laminated with segmented piezoelectric energy harvester patches. The voltage(or modal signal) induced by the modal strains of the piezoelectric patch due to the direct piezoelectric effect can be further converted to modal *** spatially distribution of the modal energy are evaluated and compared in two piezoelectric energy harvester patch sizes.

关键词： Piezoelectricity segmentation method modal energy design

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