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Resource Security Research In China In The New Era: Evolving Concepts, Paradigm Shifts, And Strategic Pathways, Dong Jiang, Jinwei Dong, Yanzhao Yang, Jingying Fu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Resource security serves as a critical foundation for safeguarding national security and underpinning high-quality socioeconomic development. Major geopolitical conflicts, such as the Russia–Ukraine conflict and the US-Israeli strikes on Iran, have intensified turbulence across global resource supply chains, positioning resource security as a central arena of strategic competition among nations. As a major consumer and trading power in global resource markets, China faces persistently high import dependence for critical mineral resources, and the pressure to ensure resource security amid the pursuit of high-quality development continues to mount. Against this backdrop, resource security is evolving from a narrow focus on supply …

Machine Learning Models For Estimating The Consumed And Remaining Useful Life Of Haul Trucks In An Open-Pit Mine In Peru, Marco Cotrina, Jairo Marquina, Mario Sandoval, Jose Mamani, Johnny Ccatamayo

Journal of Sustainable Mining

The purpose of this study was to develop a machine learning-based model to predict the consumed useful life and estimate the remaining useful life of haul trucks in an open-pit mining operation in Peru. A comparative analysis of multiple machine learning models was conducted, including multiple linear regression (MLR), random forest + PSO, support vector regression (SVR), gradient boosting machine (GBM), decision tree + PSO, and artificial neural networks (ANN-MLP). The models were evaluated using performance metrics such as R², RMSE, and MAE, selecting the optimal model to estimate the remaining useful life based on a theoretical lifespan …

Development Of A Spectral Index And Web Application For Automated Marble Quarry Monitoring: A Sentinel-2 Based Approach For Change Detection And Monitoring, Konstantinos Ntouros, Vasileios Drimzakas - Papadopoulos, Georgios Gkologkinas, Georgios Ntouros, Dimitrios Markou

Journal of Sustainable Mining

This study introduces an automated workflow to monitor marble quarry operations using Sentinel-2 satellite data, providing a cost-effective and efficient tool for regulatory oversight focused on environmental sustainability. At the core of this workflow is the Quarry Change Detection Index (QCDI), a new spectral index specifically developed to leverage the unique spectral characteristics of quarry sites, enhancing the detection of land cover changes associated with quarry expansion. To facilitate practical application, a web-based tool was developed using Google Earth Engine and Streamlit. The user-centric design of this platform features an intuitive interface, allowing users to easily select parameters, visualize data, …

Heavy-Duty Diesel Vehicle Deterioration: Impact Of Vehicle Age And Emission Control Technology On Nox Emissions - Preprint, Amber L. Gurecki Allen, Andrew R. Colman, Max D. Sommer, William D. Waddoups, Darrell B. Sonntag

FEAT Publications

Pre-print manuscript.

Abstract

This study examines the effect of aging and deterioration on NO_x emissions from heavy-duty diesel trucks (HDDTs) with different emission control technologies, including Engine Control only, exhaust gas recirculation (EGR), and selective catalytic reduction (SCR). In-use tailpipe emissions were measured from 12,023 HDDTs from 13 roadside measurement campaigns conducted in California and Utah between 2008 and 2024. Vehicle registration records and the Environmental Protection Agency’s (EPA) engine certification database were used to identify engine NO_x control technology. At younger ages, SCR-equipped HDDTs generally emitted significantly less NO_x than non-SCR-equipped HDDTs. However, after several years …

Bio-Oil Production From Palm Kernel Shell By Pyrolysis: Feedstock Characterization And Potential For Sustainable Transportation Fuel Production, Monday Ejiga, Helen Olayinka Ogunsuyi, Taiwo Mary Oriyomi, Ayodele Adekunle Faiyetole

Journal of Bioresource Management

Transportation energy constitutes a substantial share of global energy consumption, and its associated contribution to emissions and, by extension, climate change, necessitates intensified efforts toward the development of sustainable transportation fuels. This study investigated the suitability of Palm Kernel Shell (PKS) biomass for pyrolytic bio-oil production as a potential precursor for transportation biofuels. Laboratory-scale pyrolysis at 450-500 °C produced bio-oil, while proximate analysis (wt.%) showed low moisture (5.59), moderate fixed carbon (20.11), high volatile matter (66.25), and relatively high ash (8.05) contents. Ultimate analysis (wt.%) revealed 49.25 carbon, 5.17 hydrogen, 43.90 oxygen, 0.79 nitrogen, and 0.89 sulphur, with Van Krevelen …

Geotechnical Enhancement Of Noncohesive Coal Mine Overburden Using Microbially Induced Calcite Precipitation And Fly Ash Stabilization For Sustainable Pavement Applications, Atul Gautam, Laxmikant Yadu

Journal of Sustainable Mining

The majority of the waste generated from opencast mining, termed as overburden (OB), is dumped adjacent to the mine boundary and poses long-term stability issues. Various studies have been carried out to assess the risk of dump slope failure, and treatment strategies have been accordingly recommended to strengthen this OB dump. However, scant works are reported to sustainably utilize this OB for construction works. This study aims to quantify the performance of stabilized noncohesive coal mine OB collected from Gondegaon opencast mine (OCM) in India. Stabilization was achieved using two techniques, namely microbially induced calcite precipitation (MICP) through Sporosarcina pasteurii …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Unique Connotation Of Geological-Engineering Dual Sweet Spot Evaluation For Effective Coalbed Methane Exploitation, Luo Pingya, Zhu Suyang

Coal Geology & Exploration

Objective In China, the exploitation of deep and shallow coalbed methane (CBM) still relies on the evaluation approach oriented to the geological-engineering dual sweet spots of unconventional hydrocarbons. However, exemplary CBM production technologies delivered unsatisfactory performance in other blocks and failed to find wide application even in zones with overlapping geological and engineering sweet spots. This issue represents the principal theoretical and technical challenge confronting the comprehensive development of the CBM industry in China. Methods This study aims to elucidate the causes of this issue and provide corresponding solutions, as well as clarifying the conditions for the effective linkage between …

Exploration And Prospects Of Engineering Technologies For Deep Coal Seam Development Based On The Well Factory Mode, Gao Deli, Dong Xuelin, Bi Yansen

Coal Geology & Exploration

Background Given China's energy and mineral resource endowment, the efficient and green development and utilization of deep coal resources are expected to become a significant strategic option for facilitating the country's green energy transition and achieving its goals of peak carbon dioxide emissions and carbon neutrality. This significant demand may be satisfied through development using a structurally complex well factory mode. Method This study introduces the basic concept of a three-dimensional, multi-functional, and precisely controllable underground structurally complex well factory, designed for the efficient and green development of unconventional energy and mineral resources. It then discusses the well factory engineering …

Differential Accumulation Of Coalbed Methane In Medium- To Low-Rank Coal Seams In A Strongly Compressional Tectonic Setting In The Tarim Basin, Liu Honglin, Wang Hongyan, Wang Haichao, Deng Ze

Coal Geology & Exploration

Background The Tarim Basin contains abundant coal and coalbed methane (CBM) resources. However, the geological accumulation patterns of CBM in the basin remain poorly understood. This leads to a relative lack of targeted technologies for the exploration and development of both deep coal reservoirs and steeply dipping coal seams, further rendering it challenging to achieve breakthroughs in CBM development in the basin. Methods Based on test data from 92 coal samples, data on the drilling and production tests of more than 10 exploration wells, and 3D seismic interpretation results, this study systematically investigated the distribution of coal-bearing strata, as well …

Variable-Temperature And Variable-Pressure Adsorption Characteristics Of Deep Coalbed Methane And Their Implications, Jiang Wenping, Sun Siqing, Jin Xianglan, Tian Bofan, Tian Xinjuan

Coal Geology & Exploration

Background Investigating the adsorption characteristics of coalbed methane (CBM) helps bridge key geological information concerning deep CBM, including occurrence state, free gas proportion, and gas-bearing properties, with the gas production potential and commercial exploitation of CBM wells. Such investigation represents a key component of the evaluation, exploration, and exploitation of CBM reservoirs. Methods Using deep coal samples collected from three representative regions, this study designed high-temperature and high-pressure methane isothermal adsorption experiments, together with variable-temperature and variable-pressure methane adsorption experiments, using nuclear magnetic resonance (NMR). The adsorption characteristics of the coal samples derived using the different experimental methods were subsequently …

Occurrence Pattern Of Adsorbed And Free Gas In Deep Coal Seams Under The Control Of Pore Structure: A Case Study Of The No. 8 Coal Seam In The Daning-Jixian Block Along The Eastern Margin Of The Ordos Basin, Bian Liheng, Shen Jian, Shi Rui, Zhang Wei, Ma Zhuang, Liang Xuemin, Dong Jiying, Zhu Peipei, Ma Tianyu

Coal Geology & Exploration

Background Deep coalbed methane (CBM) holds an important strategic position in China's unconventional natural gas system. However, concerning deep CBM occurrence, there remains a lack of systematic quantitative understanding of the underlying mechanisms and the controlling effects of pore structure. Methods This study investigated high-rank coal samples collected at a burial depth of approximately 2000 m from the No. 8 coal seam in the Daning-Jixian block along the eastern margin of the Ordos Basin. Using multiscale pore characterization techniques, including low-temperature liquid nitrogen adsorption, high-pressure mercury injection, and low-temperature CO₂ adsorption, the full-scale pore size distribution of the coal …

Controlling Effects Of Ash Yield On The Adsorption-Desorption Behavior And Production Potential Of Methane In Deep Coal Reservoirs, Huang Daojun, Liu Xinshe, Chen Shida, Sun Wen, Jiao Pengshuai, Wang Huaichang

Coal Geology & Exploration

Objective The lithotype and quality characteristics of coals significantly affect the reservoir permeability and production potential of coalbed methane (CBM). However, there remains a lack of clear understanding of the controlling effects of ash yield on the gas-bearing properties and methane adsorption-desorption behavior of coal seams under comparable thermal maturity. Focusing on coal samples obtained through continuous sealed coring from the No. 8 coal seam in well M172 in the east-central part of the Ordos Basin, this study aims to clarify the impacts of ash yield on the pore structure, adsorption capacity, desorption process, and resource recoverability. This effort is …

Components And Isotope Fractionation Of Deep Coalbed Methane And Their Geological Implications In The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Zhang Yun, Wang Hongna, Chen Yiyu, Chen Gaojie, Wang Jun, Liu Lingqi, Li Panxue, He Hongcheng, Li Wenbiao

Coal Geology & Exploration

Objective The components of deep coalbed methane (CBM), along with its isotopic composition and fractionation patterns, hold great significance for revealing the genetic types, occurrence characteristics, flow, and production patterns of CBM. Methods This study investigated the Shanxi and Benxi formations in the Daning-Jixian block, Ordos Basin. A range of analyses and tests were conducted, including field CBM desorption experiments on coal samples from the deep parts of both formations, continuous monitoring of wellhead gas from two production wells, physical property tests on the samples, organic petrological experiments, and geochemical analysis. Furthermore, this study analyzed the components and isotopes of …

Investigating The Mechanisms Controlling Gas Flow In Coal Reservoirs Based On Multi-Scale Digital Rocks, Han Lei, Huang Dongxiang, Zhang Xiaodong, Shen Jian, Zhang Shuo, Ni Xiaoming, Liu Xiao

Coal Geology & Exploration

Background Deep coal reservoirs exhibit highly heterogeneous pore-fracture structures. However, limited by a single imaging resolution, conventional digital rock techniques struggle to characterize complex pore-fracture networks across multiple scales. This poses significant scientific challenges for the fine-scale characterization of deep coal reservoirs and the investigation of their seepage mechanisms. Methods This study investigated deep coalbed methane (CBM) reservoirs in the north-central Qinshui Basin. The pore-fracture structures of coal samples were characterized by integrating X-ray computed tomography (CT), mercury injection capillary pressure (MICP), and scanning electron microscopy (SEM). Digital rock models incorporating multi-scale pores and fractures were then constructed by integrating …

Investigating The Characteristics Of Ch4 Adsorption In Coal Reservoirs Based On Interpretable Machine Learning, Chen Ruibin, Zhou Sandong, Zhang Weixin, Yan Detian, Wang Hua

Coal Geology & Exploration

Objective Accurately predicting methane (CH₄) adsorption capacity in coal reservoirs is critical to the efficient exploration and exploitation of coalbed methane (CBM). Existing studies largely rely on experimental data from a small number of samples and theoretical adsorption models such as Langmuir. However, these studies exhibit time-consuming and laborious processes, as well as conclusions with limited generalizability, posing challenges to their widespread applications across different basins. Methods Based on 1150 sets of experimental data on CH₄ adsorption in coals, this study investigated five machine learning models, namely artificial neural network (ANN), support vector machine (SVM), K-nearest neighbor …

Mechanical Anisotropy And Depth Effects Of Deep Coal Seams, Mei Xiaofan, Wang Cong, Wang Kaifeng, Tang Shuheng, Zhang Songhang, Xi Zhaodong

Coal Geology & Exploration

Objective The mechanical properties of coal seams determine the stability, fracability, and fracturing performance of deep coal reservoirs. Since the in situ stress applied to coal increases with burial depth, deep coal differs from its shallow counterpart in damage behavior, key mechanical parameters, and failure mechanism. Furthermore, deep coal exhibits pronounced mechanical anisotropy.Methods Focusing on the No. 9 coal seam in the Linxian area along the eastern margin of the Ordos Basin, this study carried out triaxial compression tests at 60℃ under different confining pressures to determine the mechanical anisotropy of deep coal. By comparing the full stress-strain curves, …

An Improved Brittleness Characterization Method For Deep Coalbed Methane Reservoirs And Its Application To Well Logs, Huang An’Er, Gong Fei, Peng Suping, Zou Guangui, Zhang Zhaoji, Wu Yiquan, Rong Zhihong, Li Qingrun

Coal Geology & Exploration

Background Deep coalbed methane (CBM) reservoirs are characterized by high pressure, low porosity, and low permeability. Therefore, large-scale volume fracturing is required for their commercial development. As an important engineering sweet spot parameter for selecting optimal fracturing targets, the brittleness index can reflect the difficulty in generating complex fracture networks during fracturing. However, existing brittleness characterization methods are largely applicable to strata with high brittle mineral content, such as shales and sandstones, while methods for characterizing the brittleness of deep CBM reservoirs with high organic matter content and low brittle mineral content are lacking. Methods Rock physics experiments on 20 …

A Fault Identification Method For Deep Coalbed Methane Reservoirs Based On An Improved Transunet, Gao Congshun, Wu Haibo, Liu Lei, Wang Zijian, Huang Xuanyu, Jia Lilan, Xu Aiguo

Coal Geology & Exploration

Objective Small-scale faults in deep coalbed methane (CBM) reservoirs significantly affect CBM enrichment and the deployment of development wells. However, deep seismic data tend to suffer from low signal-to-noise ratios (SNRs) and poor continuity of reflection events, while conventional methods are likely to miss small-scale faults. To address these limitations, this study proposes a fault identification method based on an improved TransUNet. Methods The proposed method is developed based on the R50-ViT-B_16 TransUNet architecture. A coordinate attention (CA) module is introduced before the skip connections enter the decoder to enhance the feature representation of the locations and directional continuity of …

Petrophysical Model-Driven Seismic Inversion For Physical Property Parameters Of Deep Coalbed Methane Reservoirs, Chen Yang, Guo Qiang, Ba Jing

Coal Geology & Exploration

Objective Deep coalbed methane (CBM) reservoirs typically exhibit complex pore-fracture structures, as well as strong nonlinear and non-unique corresponding relationships between elastic and physical property parameters. In this context, this study develops a seismic petrophysical inversion method that accounts for pore structure variations. Methods This study investigated deep CBM reservoirs along the eastern margin of the Ordos Basin. First, a petrophysical model based on variable pore aspect ratios was established, and the corresponding linearized forward operator was derived. Then, the pore aspect ratios were estimated using near-borehole log data. Meanwhile, the multimodal prior distributions of reservoir physical property parameters were …