Can Corporate Sustainability Performance (Csp) Overcome Indonesia's Corporate Debt Problems?, 2024 Sekolah Tinggi Manajemen PPM, Indonesia
Can Corporate Sustainability Performance (Csp) Overcome Indonesia's Corporate Debt Problems?, Johnson Ferry Febrian, Nora Sri Hendriyeni
Jurnal Akuntansi dan Keuangan Indonesia
Based on IMF publications (2022), Indonesian companies have a risky debt level that may cause bankruptcy, so companies are required to make leverage adjustments to return the debt to its optimal level. In recent years, corporate sustainability performance (CSP) practices have been proven to improve performance and overcome financial problems such as debt by integrating sustainability aspects into business processes. Based on stakeholder theory and trade-off theory, this study aims to examine the effect of CSP on leverage adjustment and the role of competitive advantage, equity mispricing, profitability, and firm size in moderating this relationship. This study used a sample …
Bibliography For "Earth Day Display: Planet Vs Plastics: A Book Display Increasing The Awareness Of The Harms Of Plastic In Our Ecosystem", 2024 Chapman University
Bibliography For "Earth Day Display: Planet Vs Plastics: A Book Display Increasing The Awareness Of The Harms Of Plastic In Our Ecosystem", Arianna Tillman, Isabella Piechota, Kalea Brown
Library Displays and Bibliographies
A bibliography created to accompany a display about Earth Day, sustainability, and the harms of plastic during April 2024 at the Leatherby Libraries at Chapman University.
High-Accuracy Reconstruction Of Missing Ground-Penetrating Radar Signals Based On Projection Onto Convex Sets In The Curvelet Domain, 2024 College of Earth Sciences, Guilin University of Technology, Guilin 541004, China
High-Accuracy Reconstruction Of Missing Ground-Penetrating Radar Signals Based On Projection Onto Convex Sets In The Curvelet Domain, Wu Qiming, Wang Honghua, Xi Yuhe, Wang Yucheng
Coal Geology & Exploration
Influence by the acquisition environments and instrument performance, missing signals and destructed channels are inevitable in measured ground-penetrating radar (GPR) profiles. They can cause event discontinuity of reflected and diffracted waves generated by targets, severely impairing the accuracy and resolution of subsequent processing and imaging. Hence, by combining the projection onto convex sets (POCS) algorithm extensively used in image processing with the curvelet transform exhibiting high sparsity, this study proposed a high-accuracy reconstruction method for missing GPR signals based on curvelet-domain POCS. Building on the compressive sensing theory, the objective function for missing signal reconstruction based on discrete curvelet transform …
Application Of The Horizontal Seismic Profiling-Based Advance Detection Technology To The Excavation Of Rock Roadways In Coal Mines Using Tunnel Boring Machines, 2024 College of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, China; Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo 454003, China
Application Of The Horizontal Seismic Profiling-Based Advance Detection Technology To The Excavation Of Rock Roadways In Coal Mines Using Tunnel Boring Machines, Zhang Sheng, Chen Zhao, Lu Song, Yang Zhanbiao, Ji Panjun, He Fei, Lu Yiqiang, Liu Jiawei
Coal Geology & Exploration
With the gradual application of full-face tunnel boring machines (TBMs) to the excavation of rock roadways in coal mines, there is an increasingly urgent need for the accurate and rapid advance prediction of unfavorable geological structures. This study analyzed the characteristics of active-source seismic wave-based advance detection methods and the applicability of the advance detection technology based on TBM seismic while drilling (TSWD) with TBM rock-breaking vibration as a seismic source. Then, by combining the geological and production conditions of coal mine roadways, this study proposed a horizontal seismic profiling (HSP)-based advance detection method applicable to the excavation of roadways …
Positioning Error Compensation Of Drilling Robot Arm For Coal Mine, 2024 CCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, China
Positioning Error Compensation Of Drilling Robot Arm For Coal Mine, Liang Chunmiao, Yao Ningping, Yao Yafeng, Peng Tao
Coal Geology & Exploration
At present, the pose of drilling robots is mostly adjusted by manual remote control and manual retest in combination. Full automatic adjustment has not been achieved. Besides, due to the low precision of open-loop control and inadequate automation capability, the accurate hole positioning and automatic construction of hole groups cannot be realized by drilling robots with water exploration and discharge, outburst prevention and punching prevention in coal mines. Herein, the kinematic model of drilling arm was established by analyzing the structure and action of the drilling robot’s drilling arm. Meanwhile, the dip angle factors such as machining error, body deformation …
Early Warning And Prediction Of Kicks And Lost Circulation Accident During Rescue Drilling Of Mine, 2024 Faculty of Engineering, China University of Geosciences, Wuhan 430074, China; Institute for Natural Disaster Risk Prevention and Emergency Management, China University of Geosciences, Wuhan 430074, China; Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard, Xi’an 710077, China
Early Warning And Prediction Of Kicks And Lost Circulation Accident During Rescue Drilling Of Mine, Chen Weiming, Wang Jiawen, Fan Dong, Hao Shijun, Zhao Jiangpeng, Qiu Yu
Coal Geology & Exploration
In order to solve the problems such as the difficulty in early warning and prediction of kicks and lost circulation accidents during emergency rescue drilling of mine, a machine learning-based early for warning and prediction model of drilling process was established. Firstly, the accident characterization parameters of the drilling parameters in the early stage of kicks and lost circulation accidents were analyzed. Secondly, the accident characterization parameters were cleaned and processed. On this basis, XGBoost and early warning model was used to carry out the early diagnosis and identification of kicks and lost circulation accidents. Then, the PSO-LSTM accident development …
Coal-Rock Interface Imaging Based On Acoustic Remote Reflection Logging Within Crossing Boreholes Using The Finite Element Method, 2024 School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China
Coal-Rock Interface Imaging Based On Acoustic Remote Reflection Logging Within Crossing Boreholes Using The Finite Element Method, Xu Hongyang, Zhai Cheng, Xia Jigen, Sun Yong, Dong Xingmeng, Lai Yongshuai, Yu Xu, Xu Jizhao, Cong Yuzhou
Coal Geology & Exploration
The presence of small geological structures is the main cause of coal and gas outbursts, making the precise detection of these structures an urgent need. High-precision detection of coal-rock interfaces is essential for identifying small structures and achieving transparent mining faces. The acoustic remote reflection logging technology, with a large detection range, a high resolution, and imaging capability, can accurately identify coal-rock interfaces. In this context, this study proposed a technique for coal-rock interface detection based on acoustic remote reflection logging within crossing boreholes. Specially, by placing acoustic detectors in crossing boreholes, the array waveforms generated by the coal-rock interfaces …
Operation Process Identification For Intelligent Drill Rig Base On Analytic Hierarchy Process, 2024 CCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, Chinа
Operation Process Identification For Intelligent Drill Rig Base On Analytic Hierarchy Process, Zhu Qianxiang, Luo Pengping, Wang Longpeng, Xing Wang, Wang Tianlong
Coal Geology & Exploration
It is very difficult to automatically identify the current process during the intelligent construction of coal mine drill rigs. In response to this, an operation process identification method was proposed, which includes hierarchical modeling of drill rig operation and probability inference of process execution. Firstly, the coupling process among the components of different granularity during the operation of drill rig is described and modeled based on the hierarchical analysis method, which reveals the interactive characteristics between equipment, function and system during the execution of each process. Secondly, Bayesian probabilistic reasoning method is introduced based on the above research to establish …
Development And Application Of An Automatic Online Testing Instrument For The Funnel Viscosity And Density Of Drilling Fluids, 2024 Wuhan Yucheng Qianli Construction Co., Ltd., Wuhan 430051, China
Development And Application Of An Automatic Online Testing Instrument For The Funnel Viscosity And Density Of Drilling Fluids, Xie Hui, Zheng Liqun, Liu Fulin, Liang Mengjia, Liu Xuan, Cai Jihua, Yang Xianyu, Hou Jiwu
Coal Geology & Exploration
In recent years, the research on the automatic performance testing technology for drilling fluids has achieved significant progress both domestically and internationally. However, automatic drilling fluid testing instruments face challenges, such as high costs, complicated structures, and restricted working environments. Given these challenges, this study developed an automatic online testing instrument for the funnel viscosity and density of drilling fluids. The testing instrument consists of mud pumping, testing, cleaning, and control modules, which are built using a programmable logic controller (PLC), an Internet of things (IoT) module, a pressure sensor, an ultrasonic sensor, a peristaltic mud pump, an electric ball …
Analysis On Working Characteristics Of Cam-Roller Impact Mechanism Of Rotary Percussion Drilling Tool, 2024 College of Mechanical Engineering, Yangtze University, Jingzhou 434023, China
Analysis On Working Characteristics Of Cam-Roller Impact Mechanism Of Rotary Percussion Drilling Tool, Sun Yangqing, Yi Xianzhong, Wan Jifang, Ma Jianqi, Wu Jiwei, Yi Jun, Yin Guangpin
Coal Geology & Exploration
Rotary percussion drilling tools can effectively improve their rock breaking efficiency in the deep and hard strata, thus having broad application prospects. The cam-roller is the key mechanism to realize the impact action, but the complex and changeable downhole environment leads to serious damage to the mechanism, which in turn affects the efficiency of rock breaking. Based on the test drilling data of rotary impact drilling tools in several wells, the cam-roller dynamics model was established, the working characteristics under different strokes, speeds and drilling pressures were analyzed by Autodyn (explicit dynamics), and the deformation characteristics of the mechanism were …
Table Of Contents, 2024 China Coal Technology and Engineering Group (CCTEG)
An Experimental Study Of Factors Influencing Gas Seepage In Confined Broken Anthracite, 2024 College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China; State Key Laboratory of Green and Low-carbon Development of Tar-rich Coal in Western China, Xi’an University of Science and Technology, Xi’an 710054, China
An Experimental Study Of Factors Influencing Gas Seepage In Confined Broken Anthracite, Li Zhen, Yu Yirui, Wang Hongwei, Feng Guorui, He Fulian, Wang Dezhang, Zhou Jinhui, Liu Luyan, Han Xinlei
Coal Geology & Exploration
The void structure evolution of broken coals in a caving zone directly affects the gas seepage characteristics of the zone, further influencing the gas migration and enrichment patterns in abandoned coal mine goaves. With the second generation of compaction-seepage-CT scanning experimental system for broken coals independently designed and developed, this study performed 162 sets of permeability experiments on broken anthracite samples with five particle size ranges under varying gas pressures, axial stresses, and void fractions. Key findings are as follows: (1) When gas migrated in broken anthracite, its pressure and flow rate kept dynamically changing until the adsorption equilibrium was …
Deformation And Collapse Patterns Of Gas Drainage Boreholes And A Precise Monitoring Technology, 2024 School of Safety Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Deformation And Collapse Patterns Of Gas Drainage Boreholes And A Precise Monitoring Technology, Xiao Peng, Huang Xiaosheng, Liu Xiaoxiao, Li Bingkun, Chen Liping, Chen Zixi, Zhang Chao, Cheng Renhui, Zhao Yajie
Coal Geology & Exploration
This study aims to promote the precise and intelligent monitoring of gas drainage boreholes. In the engineering background of a coal mine in Shanxi Province, this study conducted simulation experiments on the plugging of gas extraction boreholes under varying particle size ratios of simulated coal samples using distributed optical fiber monitoring and the Brillouin Optical Time-Domain Analysis (BOTDA). Then, this study established a mathematical model for calculating the borehole plugging rate of the test mine, revealing the deformation and collapse patterns of gas drainage boreholes. Furthermore, this study proposed a precise in-situ monitoring technology for the gas drainage boreholes in …
Exploring Geological Parameters Sensitive To Underground Coal Gasification, 2024 Coal Mine Exploration Bureau of Guizhou Province, Guiyang 550025, China; Guizhou Youchi Energy Technology Co., Ltd., Guiyang 550014, China; Guizhou Provincial Key Laboratory of Fluidized Mining of Coals, Guiyang 550014, China
Exploring Geological Parameters Sensitive To Underground Coal Gasification, Zhou Ze, Yi Tongsheng, Qin Yong, Zhou Yongfeng, Wang Lingxia, Kong Weimin
Coal Geology & Exploration
Compared to ground coal chemical plants, underground coal gasification (UCG) requires gasifiers as geological bodies. Accurately understanding geological conditions is a critical prerequisite for UCG. To minimize the geological risks involved in UCG siting, this study systematically explored the geological parameters sensitive to UCG based on the intricate geological conditions of Guizhou Province, China. By collecting and organizing the exploration data of coal resources in Guizhou, this study established mathematical models for normalized, graded parameter value assignment, the algorithm of parameter weight vectors, and the algorithm of parameter weight product, with the purpose of obtaining the accurate quantitative data of …
A Method For Coal Seam Pressure Relief Based On Steel Cone Impact, 2024 Department of Mining Engineering, Shanxi Engineering Vocational College, Taiyuan 030009, China
A Method For Coal Seam Pressure Relief Based On Steel Cone Impact, Ren Zhimin, Lyu Mengjiao, Wang Fei, Wang Yu, Zhang Guangtai
Coal Geology & Exploration
This study aims to solve the mining safety problems caused by rock bursts in coal mines. With the geological mining conditions of the No.3 coal seam in the Wulihou coal mine in Zuoquan County, Jinzhong City, Shanxi Province as the engineering background, this study proposed a method for coal seam pressure relief based on steel cone impact. Specifically, based on the electromagnetic repulsion generated between energized coils, this study derived the functions of impact force produced when a magnetically driven coil-wound steel cone impacted the coal seam. Combining the theory on elastic mechanics, this study analyzed the stress field distribution, …
Two-Phase Flow Chokeling Results And Control In High-Pressure Gas Wells Producing Water, 2024 School of Mechanical & Automotive Engineering, Qingdao University of Technology, Qingdao 266520, China
Two-Phase Flow Chokeling Results And Control In High-Pressure Gas Wells Producing Water, Liu Xinfu, Liu Chunhua, Li Qingping, Yao Haiyuan, Hao Zhongxian, Liu Yongfei
Coal Geology & Exploration
Prediction and control of two-phase flow chokeling in tight gas wellbores are essential for the normal operation and hydrate control of high-pressure gas wells producing water. The thermodynamic differential equations of energy, kinetic energy and temperature and models of chokeling field for two-phase energy, system heat, mass balance and flow were developed under the conditions of isentropic adiabatic, isobaric heat capacity, constant volume heat capacity, and chokeling energy. A methodology on predicting characteristics and control of two-phase flow before and after chokeling was proposed for gas-water two phase flow. It provided a theoretical basis for optimizing the structural parameters of …
Favorable Factors In Methane Production From Residual Coal Post-Biohydrogen Generation, 2024 Shanxi Key Laboratory of Coal and Coal-measure Gas Geology, Taiyuan 030001, Chin; School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454003, China; Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo 454003, China
Favorable Factors In Methane Production From Residual Coal Post-Biohydrogen Generation, Xia Daping, Liao Jiajia, Chen Zhenhong, Chen Xi, Guo Hongyu, Huang Dan
Coal Geology & Exploration
Determining favorable factors in methane production from residual coal post-biohydrogen production holds great theoretical and practical significance for improving the efficiency of methane production in the second stage of coal-based poly-generation. This study focuses on residual coal after hydrogen generation through anaerobic fermentation. Using coal samples from the Baiyinhua open-pit mine in Inner Mongolia as fermentation substrates, this study explored the dynamic trends of both the methane production and structure of the residual coal under different conditions by altering the aeration conditions and hydraulic retention time (HRT). Key findings are as follows: (1) Among the experiment groups with different atmosphere …
Uranium And Thorium Enrichment Characteristics Of Bauxite In Coal Measure Strata And Their Natural Gamma-Ray Responses, 2024 College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Uranium And Thorium Enrichment Characteristics Of Bauxite In Coal Measure Strata And Their Natural Gamma-Ray Responses, Zhang Xiaohui, Zhang Shangqing, Liu Dongna, Zhao Fenghua, Zhao Jun, Zhong Zhuanghua, Hou Xuqin
Coal Geology & Exploration
Shanxi Province boasts abundant bauxite resources occurring in coal measure strata, with the deep bauxite resources in this province subjected to progressive assessment. This study aims to further determine the endowment of aluminum resources within coals in the province and explore efficient exploration methods. To this end, this study investigated the bauxite layers in Upper Carboniferous coal measure strata in the Xiaoyi area, Shanxi Province. It examined 37 samples from three boreholes using methods such as optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence spectrometry (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). Based on the analysis …
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore, 2024 State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing 100011, China; School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore, Wang Qihang, Li Xu, Guo Qiang, Kuai Dawei
Coal Geology & Exploration
Groundwater flow velocity in wellbore is usually measured by single-well tracking tests or Aqua Vision flow velocity and direction meters to calculate the groundwater flow velocity in the aquifer. Due to the impact of the skin structure, the groundwater flow field near the wellbore changes, causing a difference between the flow velocity in the wellbore and that in the aquifer. In order to investigate the influence of the skin effect on the groundwater flow velocity in the wellbore, a numerical model of groundwater flow that considers the skin effect was established using the COMSOL Multiphysics software. On this basis, the …
Law Governing Variations In Water-Pressure Transmission Rate In Confined Aquifers, 2024 Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China; Key Laboratory of Xinjiang Coal Bearing Resources Exploration and Exploitation, Urumqi 830023, China; Henan Provincial International Joint Laboratory for Landslide Flow Monitoring and Early Warning, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
Law Governing Variations In Water-Pressure Transmission Rate In Confined Aquifers, Wang Wenxue, Wang Bosen, Gao Yanwei, Wu Bing, Nie Tianyu
Coal Geology & Exploration
The water pressure in aquifers is transmitted as energy, with a transmission rate much higher than the migration rate of water particles. The water-pressure transmission rate holds great significance for the safe construction and disaster forecast and prediction of underground engineering under high-pressure water aquifers and bodies. Focusing on the confined aquifers bearing no cohesive soil, this study explored the law governing the changes in the water-pressure transmission rate through theoretical analysis, numerical simulations, field experiments, and laboratory physical model tests. Key findings are as follows: (1) The transmission of water-pressure changes in the aquifers exhibited noticeable hysteresis. The transmission …