bluuebunny/crossref_metadata_2025 huggingface dataset:
A battery-to-electrolyzer pathway for energy management in a hybrid battery/hydrogen microgrid
Authors: Ahmad Athar , Iamarino Mario , D’Angola Antonio
Published: December 2023

A RES-based microgrid with two simultaneous storage options - battery and hydrogen - is considered. While the battery pack serves as a short-term storage solution, the hydrogen-cycle (consisting of an electrolyzer, a hydrogen pressurized tank and a fuel cell stack) provides for a long-term (seasonal) storage in order to improve the system resilience and to allow off-grid operation for longer time. With respect to the most classical energy management approach, where energy is transferred either from PV to battery (as the priority transfer) or from PV to electrolyzer, the novel strategy adopted in this paper also adds the possibility of a battery-to-electrolyzer energy conversion route. This route is enabled whenever the energy stored in the battery is expected to overcome the estimated short-term energy needs. The novel strategy reveals significant potential to increase the hydrogen production during the summer months, by redirecting to the electrolyzer part of the excess energy that would be otherwise curtailed or transferred to an external grid. Application of the strategy during autumn and winter time reveals on the contrary a clear worsening of the microgrid performance and should be avoided.
Hybrid diagnostic approach for the diagnosis of district heating networks
Authors: Losi E , Manservigi L , Spina P R , Venturini M , Castorino G A M
Published: December 2023

Decarbonization of the heating sector is a mandatory target towards climate neutrality by 2050. In this framework, District Heating Networks (DHNs) do play an important role since the heat carrier is dispatched from a heat source to end-users.

Reliability of DHNs can be affected by several faults, of which the negative consequences can be prevented by employing diagnostic methodologies to evaluate the health state of the DHN and promptly localize the fault cause.

In the literature, DHN faults are usually detected by means of physics-based and data-driven methodologies, but their drawbacks may hinder their application. Thus, this paper proposes a hybrid approach composed of two steps aimed at detecting the most common faults occurring in DHNs, i.e., water leakages as well as anomalous heat and pressure losses. First, a data-driven diagnostic methodology is employed to assess whether a fault is occurring. Then, a physics-based diagnostic approach identifies the health indices of each pipe of the DHN, the fault position, its type and magnitude. In this paper, the hybrid diagnostic approach is applied to the DHN of the campus of the University of Parma, where different faults were artificially implanted.

The diagnostic approach proves to correctly detect and identify the implanted faults, by also correctly estimating their magnitude even in the most challenging scenarios.
Potential Role of green hydrogen as an energy carrier in smart energy system communities
Authors: Mojtahed Ali , Ciancio Alessandro , Sgaramella Antonio
Published: December 2023

Smart energy systems refer to the use of advanced technologies and systems to optimize the generation, distribution, and consumption of energy. The main goal of such a concept is to create an intelligent energy infrastructure based mostly on sustainable solutions namely renewable generations. Notwithstanding, renewable energy resources by their nature are unprogrammable. The main challenge is to balance properly the demand and supply curve To do so, various interventions should be employed to improve the reliability of the system (namely: real-time energy consumption monitoring to optimize energy efficiency and integration of energy storage systems). The final outcome is significant energy saving as well as cost reduction and cutting carbon footprint.

Hydrogen is mostly refers to as ‘future fuel’ due to its marvellous properties. It is an energy carrier that is characterized by water and heat as byproducts of combustion. Furthermore, it can be used in a variety of applications, including transportation, power generation, and industrial processes. It can be used in fuel cells to power electric vehicles or blended directly with natural gas to reduce GHG emissions.

The current work investigates the potential role of Hydrogen inside a smart energy system on a community scale. Various contributions are defined for Hydrogen inside a community featuring power to gas, power to vehicles or blending into NG. The layout is composed of hybrid electric, thermal and cooling power generation which is integrated with storage systems. At the end of the simulation, various scenarios are compared to each other in terms of energy performance, economic indicators and environmental impacts to carry out the best suitable option.
Thermal mapping analysis of a 48V prismatic lithium-ion battery pack with active and passive cooling
Authors: Carlucci Antonio Paolo , Darvish Hossein , Laforgia Domenico
Published: December 2023

This experimental study investigates the thermal behavior of a 48V lithium-ion battery (LIB) pack comprising three identical modules, each containing 12 prismatic LIB cells, during five charge-discharge cycles. A homogeneous liquid cooling system is applied at the bottom of the modules to control the pack temperature when it reaches 40°C (active cooling phase). The initial two cycles represent passive cooling, where the cooling liquid remains stationary. Temperature distribution is measured and analyzed using 27 thermocouples, providing insights into temperature changes in the cells, modules, pack, and cooling system inlet/outlet. Results show that in passive cooling cycles, minimum temperature occurs at pack surfaces due to better convective heat transfer, while maximum temperature is observed in the central LIB cells. The active cooling phase alters the temperature distribution within the pack. One module is found to be more sensitive to high currents, generating more heat and releasing it faster. Additionally, the positive tab temperature is higher than the negative tab temperature within a single cell. The liquid cooling system decreases the temperature rise from 5.8°C to 3.5°C in the discharge cycles with a constant current of -237A. This study emphasizes the significance of evaluating the thermal behavior of individual modules and highlights the complexity of the LIB pack system, as well as the impact of an indirect liquid cooling system on enhancing its thermal performance.
A re-design process of an industrial centrifugal fan through CFD and rapid prototyping
Authors: Piovan Mattia , Pinelli Michele , Suman Alessio , Zanini Nicola , Magnani Giorgia , Zanardi Andrea
Published: December 2023

Due to the ecological-green transition, it is fundamental to reduce the energy consumption of turbomachines in many fields. In particular, manufacturers of industrial fans are subjected to EU regulation N.327/2011, which indicates the limit for the absorbed power of this kind of machine. New design techniques allow to increase the overall efficiency satisfying the customer’s performance request. Recently, in order to reduce time to market, the manufacturers are very interested in using plastic materials in place of metal in the prototyping phase because they have higher formability, lower costs, and realization time. The aim of the authors is to present the re-design process of a commercial industrial centrifugal fan. The main goal was to change the shape and the number of the blades reducing the separation along the blade-to-blade channel, limiting the leakage flow, and increasing efficiency. Several modifications to the initial geometry were proposed and analyzed through numerical simulations. Three designs were then produced via a rapid prototyping process in plastic material and tested in a standardized rig. Moreover, a comparison between the experimental performances of the actual impeller made in metal sheets and the plastic one will be evaluated in order to view the effects of different roughness and deflation that characterize a plastic component realized using a 3D printing technique.
On the influence of twist and taper of HAWT blades on the rotational augmentation phenomenon: the NREL Phase VI – Phase II comparison
Authors: Mauro Stefano , Lanzafame Rosario , Messina Michele , Brusca Sebastian
Published: December 2023

The physics of 3D flows on rotating blades is currently one of the most important research fields related to wind turbines. Although many authors have studied the phenomenon thoroughly and they have proposed meaningful physical explanation of the mechanism which triggers the onset of the rotational augmentation, a universal correlation between rotor geometry, operating conditions and centrifugal pumping effects has not been derived yet. For instance, all the proposed corrections for rotational stall delay within 1D codes have demonstrated fairly good accuracy but in limited operating range or for specific airfoils or rotor geometries. In the present work the authors applied a consolidated methodology, based on the use of accurate CFD 3D models and of an inverse BEM code, to thoroughly analyze the differences in terms of rotational augmentation effects between the two widely known NREL Phase VI and Phase II HAWTs. This choice was made precisely since both the rotors used the S809 airfoil for the active part of the blade, had equal radial dimensions and the operating conditions were approximately the same. Thus, the substantial difference between the rotors was the fact that the Phase VI blade was twisted and tapered while the Phase II one had constant chord and pitch along the radial direction. In this way, the possible influence due to the twist and taper of the blade on the physics of the centrifugal pumping could be highlighted more easily. The CFD models were developed in Ansys Fluent and validated against experimental measurements available in the literature. The inverse BEM code, already implemented in a previous work, allowed the authors to extrapolate and compare sectional data obtained through the CFD simulations. The post-processing of the results demonstrated the strong influence of the twist and taper of the blade on the dynamics of the rotational augmentation. These results lead the way for a better understanding of the relation between rotor geometry and centrifugal pumping physics.
Design of High Transmission Frequency Circuit for Multiturn Small Loop Transient Electromagnetic Detection
Authors: Yan Fuxue , Sun Yishu , Zhang Yang , Lin Jun
Published: December 2023

Limited by urban road width and other factors, urban TEM detection can only use multiturn small loop as the transmitting coil. The traditional TEM transmitting circuit cannot transmit high frequency repetitive pulse for such large inductance coil. In order to solve this problem, a high transmission frequency circuit is proposed and built in this paper, which can clamp both the rising and falling edges of the emission current, and effectively improve the frequency. The repeated transmission frequency of 250 Hz for 0.73 mH coil at current of 30 A is realized. The circuit effectively improves the strong magnetic field excitation ability, which is of positive significance for the application of multiturn small loop TEM in urban environment.
Research on magnetic gradient method in underground metal pipeline detection
Authors: Wang Shaoqing , Liu Shucai , Qiao Shuai , Jiang Zhihai , Song Lei
Published: December 2023

When the underground metal pipeline is powered by direct current, the magnetic field will be generated around it, and the buried information of the pipeline can be deduced by the change of the magnetic field. Therefore, a method of detecting underground metal pipeline by magnetic gradient is introduced. The mathematical relationship between the magnetic gradient and the buried depth of underground pipeline is derived. The theoretical feasibility of this method is verified by forward simulation, then the physical experiment proves that this method has high detection accuracy.
Influence of Collection Parameters on Lining Detection Results in Comprehensive Wave Field Method
Authors: Wang Yanlong , Yuan Mulin , Hu Xinmin , Xu Dexin
Published: December 2023

For hydraulic tunnel lining detection, a comprehensive wave field method is presented for the detection of hydraulic tunnel lining in this paper, and a 1:1 hydraulic tunnel model is built according to the actual engineering situation. The effects of source, sampling rate, offset and group interval on the detection results are analyzed through experiments, a set of parameters suitable for hydraulic tunnel lining detection is finally derived, which can effectively improve the efficiency and accuracy of lining defect detection in the subsequent work.
Application of Borehole Geophysical Prospecting Method in Pile Foundation Detection of Existing Buildings
Authors: Wang Jianli , Hou Dongmei , Huang Ming
Published: December 2023

It is particularly important to find out the pile foundation of existing buildings for building safety protection and engineering construction safety during the development and utilization of urban underground space. As a non-destructive, efficient and economic method, the borehole geophysical techniques such as magnetic gradient method, ground penetrating radar method and parallel seismic test method are used to detect the pile foundation of existing buildings, which have obvious advantages. According to the combined abnormal characteristics such as "strong magnetic anomaly, electromagnetic wave in-phase axis change and diffraction wave anomaly at the pile end, P-wave velocity variation", the pile foundation length can be judged.
Application of Shallow Reflection Seismic Exploration in The Investigation of Active Faults in Guanzhong Basin
Authors: Li Pei , Li Fengying , Wang Xiaojiang , Zhang Kai , Rong Lixin , Jiang Chunxiang , Wang Tong
Published: December 2023

Active fault detection is an important part of site selection of major projects in urban construction. In order to find out the distribution of active faults in Xixian New District of Guanzhong Basin, high-resolution shallow reflection seismic detection is carried out in the area. The optimal observation system parameters and vibrator excitation parameters are determined through a number of technical tests and the processing parameters are selected in the process of data processing to ensure to obtain high-quality seismic profiles. According to the detection test results, the distribution of the main active faults and the distribution characteristics of underground space in the area are found out, the buried depth of the bottom interface of the Quaternary is inferred and interpreted and the internal strata of the Quaternary are divided in detail.
Experiment on Interference Factors of High-precision Gravity Detection in Urban Underground Space
Authors: Lu Han , Bi Dong , Zhou Mingxia , Sun Hailong , Jiang Hong
Published: December 2023

The traditional geophysical methods in urban underground space detection suffer from many interference factors, and cannot obtain effective detection data. The high-precision gravity method has few interference factors. For human activities and other interference sources, reasonable research work arrangements can be made through preliminary experimental analysis, and these interference factors can be avoided in actual work to obtain effective gravity observation data and interpretation results. The author studies the theoretically affected factors in urban detection and conducts experimental detection and analysis. The high-precision gravity method has a good effect on the detection of urban underground space.
Application of High-density Resistivity Method in Fine Division of Quaternary Geological Structure in the Starting Area of Xiongan New Area
Authors: Guo Shujun , Sun Sheng , Cheng Zhengpu , Wang ChunHui , Xie Xinglong
Published: December 2023

In the starting area of Xiongan New Area, the high-density resistivity method is used for fine detection of the deep-lying strata 0m ∽ 200m in the study area. The stratigraphic and lithologic framework of 0 m-200 m depth has been established. The results show that the middle and Late Pleistocene strata are rich in fine sand, and no hidden ground fissures have occurred. It is proved that the high-density resistivity method is effective and feasible in urban planning and construction geological exploration, and it can provide data support for the further construction of Xiongan New Area.
High Frequency Passive Surface Wave Dispersion Extraction by Linear Seismic Array Aligned with Noise Source Azimuth
Authors: Gao Ji , Zha Huasheng , Zhang Haijiang
Published: December 2023

Due to the uneven spatial and temporal distribution of noise sources, the dispersion data extracted from high-frequency (>1Hz) ambient noise data would be contaminated and biased. Based on the azimuth analysis of the noise sources, we propose a linear array data acquisition strategy that considers the noise source direction to get high quality dispersion data.
Critical Technical Problems of 3D GPR Road Cavity Detection Based on Vast Field Experiment Data Analysis
Authors: Ling Jianyu , Qian Rongyi
Published: December 2023

Utilizing 3D GPR to conduct road cavity detection can well prevent the occurrence of collapse. However, the problems existing in the application of 3D GPR in road cavity detection are not very clear. Hence, we have carried out more than 1000 km road cavity detection work and summarized the main points of data acquisition, processing and interpretation in engineering applications. The main points we found are related to the complexity of the pavement environment and the diversity of above and below ground interference sources, which are difficult to obtain in laboratory experiments. Then the solutions and ideas are put forward, aiming at accelerating the development of 3D GPR cavity detection technology in the field of engineering application.
Void Detection Behind Shield Tunnel Segments Using Ground Penetrating Radar: A Laboratory Experiment
Authors: Lai Sicong , Yue Yunpeng , Meng Xu , Liu Hai
Published: December 2023

As a recognized non-destructive testing (NDT) method, ground penetrating radar (GPR) has been applied for void detection in shield tunnel. However, due to the complex structures of shield segment with double-layer rebar meshes inside, the GPR responses of voids behind shield segment are still not clear. This paper presents a series of laboratory experiments to analyze and characterize the radar responses of voids based on a platform which is composed of two 1:1 scale shield segment. Results preliminarily show that the low-frequency radar signals from the near-segment voids are less obvious than the high-frequency signals. For the voids which are far away from the segment, the radar reflections appear as multi hyperbolas.
A GPR Resolution Enhancement Method Based on Weakly Supervised Learning
Authors: Zhou Mei , Wang Xiaokai , Shi Zhengsheng , Chen Wenchao
Published: December 2023

Ground penetrating radar (GPR) is mainly used to detect underground structures in archaeology, military and other fields. In practice, the detection depth and resolution of GPR data are often difficult to balance. Therefore, it is vital to develop a method that can obtain both deeper distance and higher resolution. In this paper, a weakly supervised method for improving the resolution of GPR data based on the Cycle-Consistent Adversarial Network (Cycle-GAN) is proposed, which improves the quality of GPR data by learning the mapping relation between low-resolution and unpaired high-resolution data. The actual data is used to verify the validity and feasibility of the proposed method. Experimental results have shown that our method is able to recover detailed high-frequency components and the resolution is effectively improved.
Deep Learning Inversion of Multi-processed GPR Data to Characterize Subsurface Defects
Authors: Wang Yuanzhen , Qin Hui , Tang Yu , Zhang Donghao , Zhang Lin , Yao Yao
Published: December 2023

Ground penetrating radar (GPR) is highly recommended for investing defects in concrete structures, yet interpreting GPR data is hindered by the fact that the images primarily display reflected electromagnetic waves rather than the actual shapes of the defects. In this paper, we introduce a deep learning network that aims to convert GPR B-scan images into permittivity maps of subsurface structures. This network takes three types of data as inputs and outputs the distribution of permittivity. These three types of data are the original data, the data obtained after applying migration to the original data, and the data obtained after processing the original data using a neural network. Each type of data is processed using different methods and contains distinct information, which is collectively used for inverting data. In this study, we validate the effectiveness of the proposed network by the finite-difference time-domain (FDTD) forward modeling data.
ES-MDA Method for Inverting SIP Data Based on Cole-cole Model Parameters
Authors: Su Peng , Wang Hui , Huang Zitong , Yang Jin
Published: December 2023

SIP reflects the characteristics of charge storage in underground media. IP parameters such as polarizability and relaxation time are correlated with minerals, pores and other physical properties of rocks, so when establishing the relationship between SIP and other petrophysical parameters, it is necessary to accurately estimate SIP parameters and quantify the uncertainty of estimation. In this paper, the ES-MDA method is used to inverse the synthetic SIP data based on the dual cole-cole model, and the uncertainty of the inversion results is quantified while estimating the parameters. The results show that the ES-MDA method can accurately estimate the SIP parameters, and the sample parameter set of the inversion results has less uncertainty.
Seismic Data Interpolation via Improved cGAN Network
Authors: Huang Zhen , Gao Jianjun , Li Fan , Li Chao Lin
Published: December 2023

The seismic data are always spatially undersampled during filed acquisition, limited by the natural environment and economic conditions. Irregularly missing seismic traces can affect the subsequent processing of seismic data, ultimately impacting the imaging and inversion results. Therefore, seismic data regularisation and interpolation are particularly necessary and have become an important step for data pre-processing. This abstract presents an improved GC algorithm with partial convolution layers and spectral normalization and applies it on 2D seismic data reconstruction. Compared with the traditional cGAN reconstruction method, The proposed method can effectively enhance the generative capability of the cGAN algorithm. Both synthetic and field data experiments demonstrate that the reconstruction performance of the improved cGAN method is better than the conventional cGAN method.
Description of Random Heterogeneity and Characteristic Analysis of Wave Field in Near-surface Medium
Authors: Fan Xiunan , Sun Zhangqing , Han Fuxuan , Wang Ruihu , Liu Yaguan , Lu Jipu , Cen Wenpan , Gao Zhenghui
Published: December 2023

Random heterogeneity of near surface medium is caused by weathering layer, desert and gravel layer etc. For seismic exploration in this complex area, it is helpful to improve the exploration effect that detailed description of this heterogeneity and in-depth analysis the characteristics of seismic wave field in this medium. In order to figure out the above-mentioned issue, firstly, a regional multi-scale disturbance random medium modeling method in complex topographical conditions is proposed to describe the random heterogeneity of near-surface medium. Secondly, in the condition of undulating earth’s surface, the finite difference method (FDM) of wave equation numerical simulation is used to simulate the seismic wave field. Finally, some seismic wave characteristics in near-surface random heterogeneity are obtained by analyzing seismic snapshots and gathers.
Forward Modeling Analysis of Cross-hole Resistivity Tomography (ERT) Using Unstructured Grids
Authors: Cai Yumei , Liu Zhengyu , Dong Zhao , Liu Benchao , Pang Yonghao , Liu Jiawen
Published: December 2023

The cross-hole electrical resistivity tomography (ERT) method has advantages in obtaining deep geological information and can accurately image complex underground structures. However, it is usually difficult to fit complex boundaries using structured grids in the modeling process. The accuracy of forward modeling is affected by the meshing of the model. The unstructured grids may describe the irregular complex model more effectively. Therefore, we study cross-hole ERT forward modeling, using unstructured grids to analyze the forward characteristics of complex underground structures. The effectiveness of the unstructured grids in cross-hole ERT has been revealed in this work.
Application of Non-negative Matrix Factorization in Processing Self-potential Signals Caused by Geo-microbe
Authors: Zhang Lijuan , Cui Yi-An , Luo Yijian , Xie Jing , Guo Youjun
Published: December 2023

Microorganisms play a significant role in the evolutionary process of the Earth and are closely related to the modification and evolution of the Earth’s surface circles at different spatial and temporal scales. Given geological microbiology in the self-potential signal data can be represented with non-negative matrix, which makes use of non-negative matrix factorization method to deal with the data become possible. This paper introduces the basic principle of non-negative matrix factorization method, based on non-negative matrix factorization method is discussed to isolate the self-potential signal data in geological microbes may and effect. By separating two natural potential signals containing noise with blind sources, the separation effect is good and the non-negative matrix factorization method is found to be an effective method for extracting their self-potential signal data. Although this numerical simulation is the self-potential signal is introduced in the work of geological microbiology, but this method also has reference significance for other signal data processing, can also be used to other geophysical data processing, the implementation of the research on environmental protection, to improve the cognitive complex biological geological process of shallow earth environment has important significance.
The Magnetotellurics Inversion with a Tree Based Bayesian Framework
Authors: Tian Shengqi , Guo Rongwen , Yang Gangqiang
Published: December 2023

Bayesian inversion offers a valuable means of estimating uncertainty, allowing us to evaluate the impact of inversion. However, tackling Bayesian inversion in high-dimensional spaces remains a crucial area of research. Building upon Hawkins’ work, we have developed a tree-based Bayesian inversion scheme specifically designed to address the challenges posed by the magnetotellurics inversion problem. By employing the cdf9/7 wavelet as our basis function, we conducted a numerical simulation of a low-resistance abnormal body, yielding highly accurate inversion results.
Assimilating Seismic Data And Soil Basic Information to Predict Near-surface Permeability And Water Content
Authors: Song Zhengyi , Zhang Yu
Published: December 2023

Soil permeability plays a key role in the study of earth sciences for agriculture and forestry. Because the traditional laboratory measurement is time-consuming and laborious, and only discrete profile data can be obtained. In this paper, a simple and efficient method using soil transfer function (PTFs), is proposed to estimate permeability and other parameters indirectly by seismic wave observation. Based on Biot’s theory establishing the relationship between shear-wave velocity and permeability, and the basic soil information in the study area, including land survey, logging and drilling data, using the PTFs constraint to estimate saturated hydraulic conductivity, soil components, saturated water content and residual water content may favor the physical corrections of the PTFs. The results show that there are three distinct layers of permeability in the study area, consistent with the velocity structure. The measured basic information further verifies the accuracy of the saturated permeability coefficient estimation, which shows the reliability of the improved PTFs. The established near surface permeability estimation method by integrating seismic wave observation and soil basic information may provide further assimilation for parameter estimation combining geophysical observation and hydrogeographic statistics.
A Multi-resolution Approach to 3D Controlled-source Electromagnetic Modeling
Authors: Li Jian , Liu Jianxin , Guo Rongwen , Wang Yongfei , Xu Jingdao
Published: December 2023

We have introduced a multi-resolution sampling approach for 3D finite-difference controlled-source electromagnetic forward modeling. Inside this scheme, the discrete operators are constructed based on the original sampling points. At the same time, the algorithm reduces the number of discrete electromagnetic fields instead of the number of cells. To avoid the deterioration of the condition number of the coefficient matrix caused by multiplying by different levels of sparse operators, we introduce a novel technique to optimize the condition number of the coefficient matrix. The results show that the new approach improves computational efficiency without compromising the accuracy of the solution.
Two-Dimensional Magnetotelluric Forward Modeling in Space-wavenumber Mixed Domain
Authors: Li Wei , Liu Jianxin , Guo Rongwen , Ji Hang
Published: December 2023

In magnetotelluric exploration, if you want to do 2D or 3D numerical modelling, what you need in the computational and memory requirements are potentially enormous. In order to get efficient and precise forward simulation results, we propose a new 2D numerical modelling method in space-wavenumber mixed domain. This method uses the one-dimensional Fourier transform in the horizontal directions, so the two-dimensional partial differential equations in the spatial domain can be transformed into a set of independent one-dimensional differential equations with different wave numbers. Then we can use the finite different method to solve the one-dimensional equations. In this article, the COMMEMI-2D1 model was used to verify the accuracy of the algorithm. We compare our results with the traditional finite different method in TE mode, indicating that the algorithm improves computational efficiency.
3D Electromagnetic Forward Modeling in Anisotropic Medium Using the Secondary Field Formula
Authors: Xu Jingdao , Liu Jianxin , Guo Rongwen , Li Jian
Published: December 2023

The electromagnetic (EM) method is an essential geophysical method to detect underground geological structures. With the increasing requirements for the reliability of data interpretation, we need an accurate anisotropic forward algorithm, which is applied several times in the inversion. At the same time, modeling the anisotropic response is an advantageous method for designing actual survey lines. In this paper, we utilize the quadratic field formulation in anisotropic media to derive the governing equations for electromagnetic fields. The governing equation is discretized using the finite difference method. Experimental results indicate that our algorithm is able to accurately model both the magnetotelluric (MT) and the controlled-source electromagnetic (CSEM) response.
Magnetotelluric Forward Modeling in Spherical Coordinate System Under Non-planar Wave Field Source
Authors: Hou Sheng , Guo Rongwen , Liu Jianxin , Li Ruiqing , Wang Yongfei , Cao Xun
Published: December 2023

In the traditional magnetotelluric forward modeling, the spherical earth model is typically stretched into the rectangular coordinate system using geographical projection, inevitably producing modeling errors especially for cases with large-scale data coverage. In these cases, the earth can not be considered as be flat, and the external source is not laterally uniform. In this paper, we developed a MT modeling algorithm in the spherical coordinate system based on the use of the spherical harmonic function

P

1

0

for the source. A model with public solutions is used to verify our algorithm. A more realistic model is designed to show the application of our algorithm.
3D Inversion of Grounded-source Transient Electromagnetic Data
Authors: Qi Yanfu , Li Xiu , Qi Zhipeng , Zhou Jianmei , Sun Naiquan , Liu Wentao
Published: December 2023

The grounded-source transient electromagnetic method has the characteristics of convenient installation of emission source and large emission power, and is being widely used. To get a fine interpretation of observation data, we introduce a three-dimensional inversion algorithm for the grounded-source transient electromagnetic data. Firstly, the unstructured time-domain finite-element method is used to calculate the electromagnetic response, and then the quasi Newton method is used for data inversion. Finally, the reliability of this algorithm is verified by applying it to the theoretical model.
3D Simulation of Semi-airborne Magnetometric Resistivity Data for the Monitoring of Water-rich Fracture Zones
Authors: Chen Zhongchang , Yang Dikun
Published: December 2023

Fracture zones, which are commonly saturated with water, pose significant risks during underground construction and the ongoing maintenance of infrastructure projects. Detecting such objects and monitoring their stability usually require surface geophysical methods over rough terrains that are slow and expensive, sometimes even impractical if the fracture zone is underwater. In this work, we propose using the semi-airborne magnetometric resistivity (SA-MMR) method to monitor the water content in the fracture zone rapidly. SA-MMR combines the advantages of efficiency from drone-borne geophysics and high data quality because of the measurements of a steady-state magnetic field by high-precision total-field magnetometers. We design our model based on an actual water gushing accident during the tunnel construction. The accident happened when the water from a reservoir above the route gushed into the tunnel through a weathered fault zone. In our synthetic survey, we utilize a set of electrodes that act as current sources, strategically placed along the strike of the fault; the total-field magnetometer, which is suspended 5 meters above the terrain using a drone that covers the entire survey area; two identical surveys are carried out before and after the fault’s water content increases. Our 3D forward modeling indicates that despite the low-resistivity water layer above the fracture zone, the SA-MMR data anomaly can be as large as 16 nT for a 10 A source current. The magnitude of the detected anomaly in question surpasses the noise level of contemporary airborne total-field magnetometers by multiple orders of magnitude, and our study has shown that SA-MMR has great potentials in quickly and economically mapping the variation of water content in water-rich fracture zones.
BSR Characteristics and Gas Hydrate Accumulation Mechanism in Qiongdongnan Basin
Authors: Fang Xiaoyu , Zhang Jinfeng , Luo Junsheng , Xiong Pengfei , Liao Jin , Yao Zhe , Li Xushen , Zhu Jitian
Published: December 2023

This paper makes full use of the high-precision three-dimensional seismic data in this area, combined with the differences in the source supply, migration and accumulation mode and occurrence characteristics of hydrate gas, analyzes and summarizes the gas hydrate migration and accumulation reservoir forming model in Qiongdongnan Basin. The hydrate migration and accumulation reservoir forming models in Qiongdongnan Basin are preliminarily divided into three categories: lower-generation and upper-storage type, self-generation and self-storage type and compound mixed type. The first two categories are further divided into five sub categories, of which the lower-generation and upper-storage types are divided into four sub categories: gas chimney dominated type, mud diapir dominated type, micro-fracture dominated type and fault dominated type. The self-generation and self-storage type can be regarded as: shallow in-situ migration and accumulation type.
Detection of Seepage Paths in Dam by Electrical Resistivity Tomography
Authors: Guo Youjun , Cui Yi-An , Xie Jing , Luo Yijian , Guan Junfeng
Published: December 2023

The stability of the dam can be compromised by water erosion and seepage, which primarily affect the resistivity distribution underground. Seepage pathways in the dam are detected through electrical resistivity tomography (ERT), utilizing variations in resistivity for delineation. The 2D profiles show that the resistivity structure of the dam is relatively higher resistivity values (100~400Ωm), while the seepage paths exhibit significantly lower resistivity values (10–50 Ω m). it can outline five seepage paths.
Application Prospect of Airborne Electromagnetic Method in Engineering Exploration
Authors: Wang Peijian , Niu Yu , Wang Lai
Published: December 2023

Airborne electromagnetic method has developed rapidly since the twentieth century and has been maturely applied to uranium and polymetallic mineral exploration and railroad engineering survey in China. Engineering survey is an important foundation to guarantee the construction of cities and infrastructure in China, Further exploration of the introduction of airborne electromagnetic method in engineering survey can greatly promote the process of engineering construction in China and guarantee the strategic needs of national key projects.
Audio Magnetotelluric Imaging of a Concealed Mineral Deposit: A Case Study of Carbonate Hosted Zhugongtang lead-zinc Deposit, NW Guizhou Province, China
Authors: Pitiya Regean , Lu Mao , Chen Rujun , Nong Guanhai , Chen Siwen , Yao Hongchun , Shen Ruijie , Jiang Enhua
Published: December 2023

Non-intrusive geophysical exploration methods play a major role in ore deposit detection. This study aimed to characterize the subsurface electrical resistivity structure across the recently discovered super-large Zhugongtang lead-zinc deposit in north-western Guizhou province of China, using audio magnetotellurics (AMT) method. The results of this procedure were compared with available geological information. The estimated geoelectrical strike by impedance tensor invariants ranged between N285°E and N315°E. This range is consistent with known NW-SE trending structures in the Zhugongtang mining area. The obtained 2D inversion models revealed the presence of formations with an exceptionally low resistivity (< 15 Ωm), which corresponded to the known location of lead-zinc bearing formations. Moderate to low resistivity anomalies (< 63 Ωm) were observed at both shallow and greater depths. These anomalies were interpreted as indicative of geological formations composed of shale, sandstone, claystone, and silty mudstone. In addition, the resistivity models also revealed widespread high resistivity anomalies (> 1000 Ωm). These anomalies were thought to represent dolomite and limestone lithologies. In summary, the results presented in this study make a valuable contribution to the existing body of literature on the Zhugongtang deposit.
Three-Dimensional Profiling of Drilled Shafts Based on Four-Point Ultrasonic Measurement
Authors: Wang Jinchao , Wang Chuanying , Han Zengqiang , Wang Yiteng
Published: December 2023

Drilled piles are one of the most important foundation systems, and the shapes of the shafts prior to casting have a significant impact on their quality. In order to better obtain geometrical information on the shafts, this study proposes a profiling approach based on four-point ultrasonic measurement. First, data from horizontal sections are fitted using least squares to obtain sectional contour curves. Vertical contours are generated by iterative fitting to ensure the smoothness of the curves. Data-processing software is then used to merge the horizontal sectional curves and the vertical curves into a three-dimensional image that approximates the actual contours of the shaft.
Research and Application of 3D High Density Electrical Method
Authors: Han Yalu , Wang Yanlong , Tan Chun , Du Lizhi
Published: December 2023

3D high-density electrical method is a kind of artificial underground stable flow field established by setting electrodes on the ground, which is used to analyze the underground distribution of geological bodies, so as to predict or solve the problems in the planning, design and construction of projects. However, 3D high-density electrical method still has its limitations. In order to study the resolution ability of 3D high-density electrical method in actual underground cavity investigation, a comparative test of two-pole device and dipole device was established in this paper. The results show that the two-pole device can detect large depth but low resolution, while the dipole device is more affected by depth and has better effect in the measurement of low resistance abnormal body.
3D Inversion of Transient Electromagnetic Data for Concealed Karst Cavern Detection
Authors: Li Shicong , Liu Yajun , Peng Ronghua , Guo Peng , Yu Gang
Published: December 2023

The karst cavern is common undesirable geological body in limestone areas, which can bring great safety hazards to the construction and operation of tunnels, bridges and highways. Transient electromagnetic method (TEM) can effectively detect hidden karst structures based on the difference in electrical property between the karst cavern and the surroundings. Traditionally, 1D inversion is commonly used for the interpretation of TEM data due to its high efficiency. However, this may lead to artifacts due to 2D or 3D effects in practical surveys. In this study, we present a Gaussian-Newton approach to 3D inversion of TEM data for karst cavern detection. The numerical test on synthetic TEM data demonstrates that 3D inversion can effectively delineate the location and geometry of concealed karst cavern compared to the 1D inversion results.
Study on Geoelectrical Structure Based on Audio Magnetotelluric Inversion in Gudui, Tibet
Authors: Yan Jiahe , Zeng Zhaofa , Zhou Shuai , Ming Yuanyuan , Wang Lingxu , Zhao Jianwei
Published: December 2023

Gudui geothermal field in Shannan, Tibet has great potential for geothermal energy development. The main purpose of our geophysical investigation is to study the geothermal structure in this region. Therefore, 363 stations were deployed around the intersection region of numerous faults to measure AMT observe data. The 2D and 3D inversion were carried out by optimal inversion method. The result shows that the geothermal reservoir under the three springs areas combine together and the source of this reservoir comes from a deeper geothermal reservoir.
Exploration of Undercurrent Path for Hot Springs in Tibet by UAV-based Frequency Electromagnetic Induce Method
Authors: Cheng QinBo , Tan MengXin , Liu Jintao , Zhang Zhicai
Published: December 2023

Hot springs are useful resources for a wide range of fields, including tourist industry and power generation. In this study, an UAV-FDEM instrument is proposed, which use the unmanned aerial vehicle (UAV) to carry a multi-coil Frequency Electromagnetic induce (FDEM) instrument for scanning survey in the field. We exploit the new method to investigate the electrical conductivity (EC) distribution around the hot springs in the Yangbajing, Tibet. The results clearly present the boundary of high and low EC zones, and indicate the undercurrent path of hot spring based on the measured EC values. These discoveries by UAV-FDEM are confirmed by the electric resistivity tomography (ERT) measurements. Our investigations also reveal the causes of hot spring formation i.e., the exposure of shallow groundwater or the eruption of deep conduit hot water.
Assessment of Salinity in Fresh and Saline Aquifers in the Coastal Area of Jiangsu Province
Authors: Shang Tongxiao , Guan Yixiao , Xu Zhengwei , Hao Shefeng , Gong Xulong , Mei Rong , Liu Xiaoyu
Published: December 2023

Within the littoral alluvial expanse of the Yangtze River Delta, the phreatic zone encompassing the aquifer represents a prolific ecosystem, which has been subjected to an enduring epoch of marine sediment deposition, and is conspicuously susceptible to the escalating phenomenon of urbanization. The prodigious abstraction of the groundwater reserves has engendered a recent encroachment of seawater and leakage of connate saline water, culminating in the salinization of freshwater sources. For an incisive comprehension of the gradations of salinity (viz., fresh, brackish, and saline) and to execute evaluations of the groundwater’s quality, the spatial distributions of the total dissolved solids (TDS) were interpolated employing bifurcate power functions that establish a relationship between the Vertical Electrical Sounding (VES)-predicated transformation average resistivity and the assayed TDS from the systematically sampled boreholes corresponding to the aquifer stratum. The scrutiny of the groundwater’s physicochemical attributes is of paramount significance to efficaciously steer the exploitation and management of hydric resources within the area under investigation.
The CSEM Response in Horizontal Steel Casing for Geological Advance Forecast
Authors: Li Jintai , Liu Jianxin , Zhang Zihao , Liu Rong
Published: December 2023

Water inrush is a prevalent geological hazard that poses a significant threat to human safety and property in underground mining operations. As deep mines are being rapidly exploited through tunnel construction, accurately predicting and detecting water inrush has become increasingly crucial. The land-based controlled source electromagnetic method (CSEM) is commonly employed to identify water-bearing structures. In order to enhance its sensitivity, we have proposed a novel measurement approach for CSEM, which involves deploying electromagnetic sensors within horizontally positioned steel-cased wells embedded in the coal seam. To evaluate the feasibility of this new approach, numerical modeling was conducted using COMSOL to address the challenges posed by the casing. The influence of the steel casing was investigated, and the results demonstrated that it has minimal impact on the measured magnetic field amplitude. Moreover, the magnetic field distribution along the horizontal casing well provided straightforward indication of any anomalous bodies surrounding the coal seam. Through numerical simulations, we have validated the proposed method as a viable and effective technique for detecting water-bearing structures during deep mineral exploration.
Analysing the Relationship Between the Fault’s Distribution and the Earthquake Actives Near Gongxian China Based on Gravity Data
Authors: Xu Menglong , Yang Yabin , Sun Chengye , Chen Liang , Qiu Gengen
Published: December 2023

Huaying Mountain fault zone, the largest fault zone in the Sichuan Basin, is playing an important role to geological studies, such as the characterization of structural features, earthquakes occurrence, oil and gas reservoir distribution. However, the complexity and lack of consensus on deformation mechanisms necessitate further investigation of fold and thrust belts in the SB. Therefore, based on the real areal gravity exploration data and magneto-telluric (MT) data, it characterizes the spatial distribution of HMFZ in this region. Further, it gives the analysis combining the gravity anomaly, fault distribution data, and frequent earthquake activity around the study area, which provides insights that can be exploited for the evaluation of seismogenic tectonics in this region.