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Articles 29491 - 29520 of 294628

Full-Text Articles in Physical Sciences and Mathematics

Graphene Aerogels: Part 2 - Derived From Commercial Graphene And Chemically Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken Apr 2024

Graphene Aerogels: Part 2 - Derived From Commercial Graphene And Chemically Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken

Turkish Journal of Chemistry

Graphene aerogels (GAs), the most important class of carbonaceous aerogels, have attracted attention of many researchers due to their superior physical and chemical properties. In this study, commercial graphene (GR) and chemically reduced graphene oxide (RGO) were used as graphene-based precursor materials, unlike graphene oxide (GO), which is widely used in the literature in GA synthesis. GAs were synthesized using the sol-gel technique and dried with supercritical carbon dioxide (SCCO2). In addition, graphene-based materials were used in different ratios and their distribution in the aerogel matrix and its effect on surface properties were investigated. In addition, the synthesized GAs were …

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Evaluation Of P(Hema-Co-Nipam) Hydrogels For Removal Of Methylene Blue From Aqueous Solution:Isotherm, Kinetic, And Thermodynamic Studies, Hayri̇ye Mi̇ne Antep, Müni̇re Nalan Demi̇r, Cevher Gündoğdu Hizliateş, Si̇mge Öztürk, Eli̇f Esen Apr 2024

Evaluation Of P(Hema-Co-Nipam) Hydrogels For Removal Of Methylene Blue From Aqueous Solution:Isotherm, Kinetic, And Thermodynamic Studies, Hayri̇ye Mi̇ne Antep, Müni̇re Nalan Demi̇r, Cevher Gündoğdu Hizliateş, Si̇mge Öztürk, Eli̇f Esen

Turkish Journal of Chemistry

In this study, a novel adsorbent material, poly (2-hydroxyethyl methacrylate-co-N-isopropyl acrylamide) (p(HEMA-co-NIPAM) hydrogel, was synthesized for the purpose of removing methylene blue (MB) from aqueous media. The synthesis of hydrogel was carefully conducted, and its properties were thoroughly examined using techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The adsorption experiments conducted revealed a remarkable affinity of p(HEMA-co-NIPAM) hydrogel towards MB. The highest adsorption was observed when 0.05 g of the adsorbent were utilized, with optimal conditions at a pH of 6.0 and a temperature of 15 °C. This underscores the importance of …

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Investigation Of Benzoic Acid And Sorbic Acid Concentrations In Tomato Paste, Pepper Paste, Ketchup, Mayonnaise, And Barbeque Sauce Samples By Headspace Gas Chromatography-Mass Spectrometry, Orhan Destanoğlu Apr 2024

Investigation Of Benzoic Acid And Sorbic Acid Concentrations In Tomato Paste, Pepper Paste, Ketchup, Mayonnaise, And Barbeque Sauce Samples By Headspace Gas Chromatography-Mass Spectrometry, Orhan Destanoğlu

Turkish Journal of Chemistry

In this study, it was aimed at investigating benzoic acid (BA) and sorbic acid (SoA) concentrations in tomato paste, pepper paste, ketchup, mayonnaise, and barbeque sauce samples by a validated static headspace gas chromatography–mass spectrometry (GC-MS) method. Salicylic acid (SalA) was used as internal standard and the measurements were conducted in the wide linear concentration ranges of BA and SoA which were 2.5–5000 and 12.5–5000, respectively. The limit of detections (LODs) were determined to be 1.5 and 4.5 mg/kg while the limit of quantifications (LOQs) were 2.5 and 12.5 mg/kg for BA and SoA, respectively. The average recovery% values of …

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Construction Of Hyperbranched Imprinted Nanomaterials For Selective Adsorption Of Cadmium (Ii), Sheng Nan Hu, Xinyu Zhang, Ming Guo, Shengchun Wu, Wenjun Lu Apr 2024

Construction Of Hyperbranched Imprinted Nanomaterials For Selective Adsorption Of Cadmium (Ii), Sheng Nan Hu, Xinyu Zhang, Ming Guo, Shengchun Wu, Wenjun Lu

Turkish Journal of Chemistry

A hyperbranched ion-imprinted polymer (IIP) material containing multiple selective adsorption sites was synthesized using halloysite nanotubes, methyl acrylate, and ethylenediamine in the presence of a template ion [i.e. Cd (II) heavy metal]. The successful preparation of the Cd-IIP composition was confirmed by FT-IR, XRD, TEM, TGA, and elemental analysis. The polymers exhibited good adsorption of Cd (II) with a maximum adsorption capacity of 64.37 mg·g–1. The imprinting factor (α) for Cd (II) was 2.62 and the selection factor (β) was 1.78, indicating a specific adsorption of Cd (II) ion. The selection coefficients of Cd-IIP for Cd (II)/Pb (II), Cd (II)/Cu …

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Transdermal Delivery System To Release Phthalocyanine Photosensitizers For The Potential Treatment Of Skin Cancer With Pdt, Meryem Çamur Demi̇r, Fatma Kurşun Baysak, Caner Yahya Boyar, Ali̇han Toksoy, Fati̇h Algi Apr 2024

Transdermal Delivery System To Release Phthalocyanine Photosensitizers For The Potential Treatment Of Skin Cancer With Pdt, Meryem Çamur Demi̇r, Fatma Kurşun Baysak, Caner Yahya Boyar, Ali̇han Toksoy, Fati̇h Algi

Turkish Journal of Chemistry

This research aims to examine the transdermal release of water-soluble indium and zinc metallo phthalocyanine (InPc and ZnPc) compounds from the poly(vinyl alcohol) (PVA) membrane and the cytotoxicity effect of these Pcs on normal mouse fibroblasts (L929 fibroblast) and human melanoma (SK-MEL-30) cells. For this purpose, the effects of temperature, pH, drug concentration and membrane thickness on transdermal release were investigated in order to obtain the optimum transdermal release profile by preparing PVA membranes with different thicknesses and crosslinked by heat treatment. Optimum drug release was found to be 85.36% using 6 µm thick PVA membrane at 37 ± 0.5 …

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Preparation Of Cholesterol-Imprinted Polymer For Selective Adsorption Of Cholesterol From Gastrointestinal Mimicking Solution, Veyi̇s Karakoç, Erol Erçağ Apr 2024

Preparation Of Cholesterol-Imprinted Polymer For Selective Adsorption Of Cholesterol From Gastrointestinal Mimicking Solution, Veyi̇s Karakoç, Erol Erçağ

Turkish Journal of Chemistry

The purpose of this study is to synthesize a highly selective adsorbent to remove cholesterol, one of the most important causes of cardiovascular diseases, from the intestinal mimic solution (IMS). For this purpose, cholesterol imprinted polymers were synthesized by suspension polymerization method using the molecular imprinting technique. In the first step, the functional monomer MATyr with hydrophobic character was synthesized. Then, the cholesterol-MATyr monomer precomplex was formed and the polymerization process was carried out by adding cross-linkers with the comonomer HEMA. The synthesized polymer poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-tyrosine methylester) poly(HEMA–MATyr) was characterized by FTIR and SEM. The cholesterol adsorbing behavior of the …

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Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong Apr 2024

Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong

Coal Geology & Exploration

Through 30 years of unremitting explorations, coalbed methane (CBM) wells in China have gradually transitioned from vertical to horizontal wells. However, the lack of basic theories on CBM production using horizontal wells is the main challenge to current CBM development. Compared to shales, coal seams exhibit heterogeneity and a minor presence of foliations and brittle minerals, hindering the formation of volumetric fracture networks. Nevertheless, the roofs and floors of coal seams have high sealing capacities and mechanical strength, creating excellent conditions for hydraulic fracturing. Some fractures in coals are filled with calcite, rendering acidification conducive to the improvement of reservoir …

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Accumulation Characteristics And Exploration Prospects Of Deep Coalbed Methane In The Longtan Formation Of The Nanchuan Block On The Southeastern Margin Of The Sichuan Basin, Guo Tao, Jin Xiaobo, Wu Didi, Xie Fei, Liu Jinxian Apr 2024

Accumulation Characteristics And Exploration Prospects Of Deep Coalbed Methane In The Longtan Formation Of The Nanchuan Block On The Southeastern Margin Of The Sichuan Basin, Guo Tao, Jin Xiaobo, Wu Didi, Xie Fei, Liu Jinxian

Coal Geology & Exploration

Vertical well Y2 in the Nanchuan bloc on the southeastern margin of the Sichuan Basin has yielded daily production of natural flowing gas of 13000 m3, signifying a strategic breakthrough in deep coalbed methane (CBM) exploration on the margin. This study aims to systematically reveal the enrichment and high-yield patterns of CBM in the Nanchuan block. Using data on the regional geology, tests, assays, and production, this study investigated the accumulation characteristic and conducted exploration potential evaluation for deep CBM in the Nanchuan block from the perspective of the quality, pore and fissure characteristics, gas content, and fracability …

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Experimental Study Of The Thermal Cracking Mechanism Of Limestones During Burning, Zhang Weiqiang, Cao Zhicheng, Zhou Qizhong, Wang Zuoquan, Wu Yun Apr 2024

Experimental Study Of The Thermal Cracking Mechanism Of Limestones During Burning, Zhang Weiqiang, Cao Zhicheng, Zhou Qizhong, Wang Zuoquan, Wu Yun

Coal Geology & Exploration

Spontaneous combustion of coal seams will cause different degrees of structural damage to surrounding rocks at different high temperatures, significantly altering their physical and mechanical properties and engineering geological effects. To delve into the structural evolution patterns of rocks during burning, this study investigated the limestones from the floor of a coal mine in Xuzhou. It conducted thermal cracking experiments under different temperatures, exploring the thermal cracking patterns of rocks on multiple scales. Furthermore, this study revealed the genetic mechanism of thermal cracking by combining numerical simulations and microstructure tests. Key findings are as follows: (1) The thermal cracking temperature …

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Semantic Segmentation Of Point Cloud Sequences Using Point Transformer V3, Marion Sisk Apr 2024

Semantic Segmentation Of Point Cloud Sequences Using Point Transformer V3, Marion Sisk

Master's Theses

Semantic segmentation of point clouds is a basic step for many autonomous systems including automobiles. In autonomous driving systems, LiDAR sensors are frequently used to produce point cloud sequences that allow the system to perceive the environment and navigate safely. Modern machine learning techniques for segmentation have predominately focused on single-scan segmentation, however sequence segmentation has often proven to perform better on common segmentation metrics. Using the popular Semantic KITTI dataset, we show that by providing point cloud sequences to a segmentation pipeline based on Point Transformer v3, we increase the segmentation performance between seven and fifteen percent when compared …

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2024 April 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Apr 2024

2024 April 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

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Prediction Of Mine Water Inflow Along Mining Faces Using The Ssa-Cg-Attention Multifactor Model, Ding Yingying, Yin Shangxian, Lian Huiqing, Liu Wei, Li Qixing, Qi Rongrong, Bu Changsen, Xia Xiangxue, Li Shuqian Apr 2024

Prediction Of Mine Water Inflow Along Mining Faces Using The Ssa-Cg-Attention Multifactor Model, Ding Yingying, Yin Shangxian, Lian Huiqing, Liu Wei, Li Qixing, Qi Rongrong, Bu Changsen, Xia Xiangxue, Li Shuqian

Coal Geology & Exploration

Predicting mine water inflow plays an important role in ensuring mine safety, optimizing resource allocation, and improving work efficiency. This study aims to improve the accuracy and stability of the predicted mine water inflow. Given their strong correlations with water inflow, borehole water level and microseismic energy were chosen as multifactor characteristic variables. Using these variables, this study developed the SSA-CG-Attention multifactor prediction model for mine water inflow along mining faces. The new model extracted effective nonlinear local features of data utilizing a new network structure, which was formed by integrating a convolutional neural network (CNN) based on the time …

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Berkely Pit Repository Cost Comparison, Josh Bryson Apr 2024

Berkely Pit Repository Cost Comparison, Josh Bryson

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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Mechanism And Application Of Cross-Interface Fracturing For Permeability Enhancement Through The Roof Blasting Of Tectonic Coal Seams, Gao Kui, Wang Youwei, Qiao Guodong, Tian Yu, Fu Shigui Apr 2024

Mechanism And Application Of Cross-Interface Fracturing For Permeability Enhancement Through The Roof Blasting Of Tectonic Coal Seams, Gao Kui, Wang Youwei, Qiao Guodong, Tian Yu, Fu Shigui

Coal Geology & Exploration

Deep coal mining is challenging due to deteriorating geological conditions. After undergoing multiphase tectonic movements, primary coals have evolved into soft tectonic coal seams with low permeability and high gas content, complicating drilling in coal seams. In this case, the blasting-induced fractures are not well-developed and are prone to be re-compacted. So far, no fundamental breakthrough has been achieved in the key technology of fracturing for permeability enhancement technology through the roof blasting of tectonic coal seams. Given this, this study established test models for similar simulation tests and numerical analysis on the roof blasting of coal seams. By monitoring …

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Lmcrot: An Enhanced Protein Crotonylation Site Predictor By Leveraging An Interpretable Window-Level Embedding From A Transformer-Based Protein Language Model, Pawel Pratyush, Soufia Bahmani, Suresh Pokharel, Hamid D. Ismail, Dukka Bahadur Apr 2024

Lmcrot: An Enhanced Protein Crotonylation Site Predictor By Leveraging An Interpretable Window-Level Embedding From A Transformer-Based Protein Language Model, Pawel Pratyush, Soufia Bahmani, Suresh Pokharel, Hamid D. Ismail, Dukka Bahadur

Michigan Tech Publications

MOTIVATION: Recent advancements in natural language processing have highlighted the effectiveness of global contextualized representations from Protein Language Models (pLMs) in numerous downstream tasks. Nonetheless, strategies to encode the site-of-interest leveraging pLMs for per-residue prediction tasks, such as crotonylation (Kcr) prediction, remain largely uncharted. RESULTS: Herein, we adopt a range of approaches for utilizing pLMs by experimenting with different input sequence types (full-length protein sequence versus window sequence), assessing the implications of utilizing per-residue embedding of the site-of-interest as well as embeddings of window residues centered around it. Building upon these insights, we developed a novel residual ConvBiLSTM network designed …

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A System Of Communication Between Two Computers Using Novel Frequency Shift Keying Techniques, Jared Reyes Apr 2024

A System Of Communication Between Two Computers Using Novel Frequency Shift Keying Techniques, Jared Reyes

Honors Thesis

Frequency shift keying (FSK) is an old but powerful form of modulation that powered much of the early modems of the 1960’s, and the author felt inspired to make his own version of audio binary FSK modulation. He researched the general history and legacy of the Bell 103, a modem using FSK that defined telecommunication for the next few decades. Using research of the most common English characters of recent emails to determine which English characters should have the shortest bit length, a novel character encoding standard was created using variable bit rate. In addition, he has created a modulation …

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Trip - Transformer Interatomic Potential Predicts Realistic Energy Surface Using Physical Bias, Bryce Eric Hedelius Apr 2024

Trip - Transformer Interatomic Potential Predicts Realistic Energy Surface Using Physical Bias, Bryce Eric Hedelius

Theses and Dissertations

Accurate interatomic energies and forces enable high-quality molecular dynamics simulations, torsion scans, potential energy surface mapping, and geometry optimization. Machine learning algorithms have enabled rapid estimates of energies and forces with high accuracy. Further development of machine learning algorithms holds promise for producing general potentials that support dozens of atomic species. I present my own Transformer Interatomic Potential (TrIP): a chemically sound potential based on the SE(3)-Transformer. TrIP's species-agnostic architecture--using continuous atomic representation and homogenous graph convolutions--encourages parameter sharing between atomic species for more general representations of chemical environments, keeps a reasonable number of parameters, serves as a form of …

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Uconn Baseball Reliever Lane Optimization Tool, Jason Bartholomew Apr 2024

Uconn Baseball Reliever Lane Optimization Tool, Jason Bartholomew

Honors Scholar Theses

The building of a tool to be utilized by UConn’s Division I baseball team that will generate a game plan for when different relievers should be used against different parts of the opponent’s lineup to achieve the lowest total expected value of runs allowed for the remainder of the game based on game situations and matchup probabilities. The tool will also examine and determine situations that may be vital enough to the outcome of the game to bring in a better reliever normally saved for later in the game.

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Research On Tar-Rich Coals: Progress And Prospects, Wang Shuangming, Bao Yuan, Hao Yonghui, Wang Shengquan, Shi Qingmin, Li Dan, Hu Yiliang Apr 2024

Research On Tar-Rich Coals: Progress And Prospects, Wang Shuangming, Bao Yuan, Hao Yonghui, Wang Shengquan, Shi Qingmin, Li Dan, Hu Yiliang

Coal Geology & Exploration

Tar-rich coals are a coal-based oil and gas resource that integrates the properties of coal, oil, and gas. Given China's energy endowment of abundant coal resources but limited oil and gas reserves, exploiting tar-rich coals plays a significant role in alleviating China's tight supply of oil and gas resources and achieving green development and low-carbon utilization of coals. Using tar-rich coals as the keyword, we searched the CNKI and Web of Science databases for academic articles and patents published from 1985 to the end of 2023. Based on the search results, we statistically analyzed the process and main aspects of …

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Exploring The Pore Structure Of Reconstructed Soils And Its Effects On Water And Salt Transport Based On Ct Scanning, Li Huakun, Zheng Liugen, Chen Yongchun, Li Bing, Tao Pengfei, Li Hao Apr 2024

Exploring The Pore Structure Of Reconstructed Soils And Its Effects On Water And Salt Transport Based On Ct Scanning, Li Huakun, Zheng Liugen, Chen Yongchun, Li Bing, Tao Pengfei, Li Hao

Coal Geology & Exploration

Coal gangue serves as a critical material for landfilling and reclamation in the subsidence areas of coal mines. However, due to its rough textures and poor water-holding capacity, soils reconstructed using coal gangue exhibit somewhat different pore structures and water-salt transport from undisturbed soils. To explore the changes in the pore structure of the reconstructed soils and their effects on water and salt transport, this study analyzed the differences in the pore structures between four samples from undisturbed soils, the overburden, mud-gangue mixtures, and gangue using CT scanning and image analysis. Furthermore, an indoor experimental device was designed to simulate …

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Finite State And Sequential Automata, Kriti Gulgulia Apr 2024

Finite State And Sequential Automata, Kriti Gulgulia

Honors Theses

No abstract provided.

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Table Of Contents, The Editors Apr 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun Apr 2024

Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun

Coal Geology & Exploration

In the process of coal mining, mining-induced stress perturbation is a key factor leading to fault activation, which is a primary challenge faced by safe coal mining. Fault activation is prone to induce geological disasters such as rock bursts and floor water inrushes of coal mines. Furthermore, it poses a serious threat to mining safety. Using the Flac3D software for numerical simulations and similar material simulation experiments, this study established a model for faults’ stress-displacement responses under coal mining to analyze the mechanisms behind the evolution of fault structure zones in the process of coal mining. Key findings are …

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Laws Of Changes In The Energy Of Gas Hydrate-Bearing Coals Under Different Confining Pressures And Saturations, Zhu Wei, Gao Xia, Zhang Baoyong, Wu Qiang Apr 2024

Laws Of Changes In The Energy Of Gas Hydrate-Bearing Coals Under Different Confining Pressures And Saturations, Zhu Wei, Gao Xia, Zhang Baoyong, Wu Qiang

Coal Geology & Exploration

Gas hydration for the solidification of coal seams susceptible to outbursts is a novel technology used to prevent coal and gas outbursts by reducing gas pressure and enhancing coal strength. However, an unclear understanding of the failure characteristics and the energy dissipation law of gas hydrate-bearing coals under different confining pressures and saturations leads to the lack of a theoretical basis for the prevention of dynamic disasters such as field coal and gas outbursts in deep mines. Based on the deviatoric stress-strain curves obtained using triaxial compression tests, this study calculated and analyzed the laws of changes in energy of …

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Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi Apr 2024

Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi

Coal Geology & Exploration

Horizontal well perforation and fracturing in complex coal-bearing strata are key to increasing coal seam permeability and enhancing gas extraction efficiency, with the formation structure and perforation location determining fracture propagation. Considering the characteristics of formation structure and perforation locations, a fracturing geological model is established. Based on the finite element method, a numerical model is constructed to study the effects of perforation location, formation conditions, and the difference between vertical stress and horizontal stress on fracture perforation. Engineering verification is conducted, and construction suggestions are proposed. Key findings are as follows: There are three scenarios for the perforation locations: …

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An Intelligent Water Source Discrimination Method For Water Inrushes From Coal Seam Roofs In The Inner Mongolia-Shaanxi Border Region, Wang Hao, Sun Junqing, Zeng Yifan, Shang Hongbo, Wang Tiantian, Qiao Wei Apr 2024

An Intelligent Water Source Discrimination Method For Water Inrushes From Coal Seam Roofs In The Inner Mongolia-Shaanxi Border Region, Wang Hao, Sun Junqing, Zeng Yifan, Shang Hongbo, Wang Tiantian, Qiao Wei

Coal Geology & Exploration

Water hazard on the coal seam proof induced by high-intensity coal mining are increasingly prominent in the Inner Mongolia-Shaanxi border region. The effective, accurate water-source discrimination of the water inrushes is the key to water hazard prevention. This study investigated three typical mines in the Inner Mongolia-Shaanxi border region. To this end, principal component analysis (PCA) was employed to extract principal components from 80 groups of groundwater samples. Then, with inorganic indicators K++Na+, Ca2+, Mg2+, Cl−, SO4 2−, HCO3 − and TDS and organic indicators UV254 …

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Sulphate Contamination In An Abandoned Coal Mine In Light Of Mining Effects, Qi Yueming, Zhou Pei, Zhou Lai, Jiang Dan, Yang Yuqing, Liu Yanzhuo Apr 2024

Sulphate Contamination In An Abandoned Coal Mine In Light Of Mining Effects, Qi Yueming, Zhou Pei, Zhou Lai, Jiang Dan, Yang Yuqing, Liu Yanzhuo

Coal Geology & Exploration

Abandoned high-sulfur coal mines will become deeply buried acid-producing contamination sites, posing hazards to adjacent aquifers and surrounding environments. Furthermore, mining effects and the complex spatial distribution of abandoned mines complicate the assessment of the contamination processes and degrees in adjacent aquifers. Focusing on a certain abandoned coal mine, this study examined the migration characteristics of SO4 2− pollution in acid mine drainage using numerical simulations by taking sulfate (SO4 2−) as the characteristic contaminant and considering the effects of the fractures formed by the mining of multiple coal seams on the aquifer structure. Furthermore, it analyzed …

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Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong Apr 2024

Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong

Coal Geology & Exploration

The ground-based transient electromagnetic method (TEM), with unique advantages, has been extensively applied for hydrogeological exploration in coal mines. However, in field exploration, complex terrains tend to cause variations in geometric shapes of transmitting sources and deviations in signals received, reducing exploration accuracy. Hence, by integrating theoretical analysis and numerical simulations with the analysis of actual terrain data, this study systematically investigated the response characteristics of electrical- and magnetic-source TEM fields under complex terrains. Using the vector finite-element electromagnetic forward modeling technique based on second-order backward Euler discretization, this study delved into the laws of influence of peak and valley …

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Exploring The Detection Performance Of Different Array Configurations For Multi-Electrode Resistivity Method Tomography Using A 2.5d Finite Element Method, Zhao Rongchun, Lyu Yuzeng, Zhang Zhi, Wei Liuye, Pan Hongxu Apr 2024

Exploring The Detection Performance Of Different Array Configurations For Multi-Electrode Resistivity Method Tomography Using A 2.5d Finite Element Method, Zhao Rongchun, Lyu Yuzeng, Zhang Zhi, Wei Liuye, Pan Hongxu

Coal Geology & Exploration

Multi-electrode resistivity method is equipped with various electrode array configurations. Due to their different electrode arrangements, various electrode array configurations tend to exhibit significantly varying detection effects under different survey environments. Hence, to achieve satisfactory detection effects using high-resolution electrical resistivity tomography, it is necessary to explore the strategy for choosing appropriate array configurations targeting different objects in practical work. Given the high applicability of the method, its forward and inversion calculations remain a critical task. Based on the differential equations to be satisfied by the point source potential in a three-dimensional structure, this study derived the variational problem to …

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Research On Path Planning Methods For Underground Roadheader Robots, Zhang Xuhui, Zheng Xili, Yang Wenjuan, Li Yuyang, Ma Bing, Dong Zheng, Chen Xin Apr 2024

Research On Path Planning Methods For Underground Roadheader Robots, Zhang Xuhui, Zheng Xili, Yang Wenjuan, Li Yuyang, Ma Bing, Dong Zheng, Chen Xin

Coal Geology & Exploration

In order to solve the problems of difficulty and low efficiency in the movement of robotic roadheaders under conditions of non-full-section roadways in coal mines, the characteristics of unstructured environments in coal mines and the motion characteristics of robotic roadheaders were analyzed, and a path planning method for robotic roadheaders based on deep reinforcement learning was proposed. The tunnel environment was constructed in real time using depth cameras, a virtual model for detecting roadheader-tunnel collisions was established, collision detection was performed in a virtual environment using the hierarchical bounding box method, and an obstacle avoidance strategy under the restrictions of …

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