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Full-Text Articles in Physical Sciences and Mathematics

Environmental Contamination With Clostridioides (Clostridium) Difficile In Vietnam, Peng A. Khun, Long D. Phi, Huong T. T. Bui, Nguyen T. Bui, Quyen T. H. Vu, Luong D. Trinh, Deirdre A. Collins, Thomas V. Riley Jun 2023

Environmental Contamination With Clostridioides (Clostridium) Difficile In Vietnam, Peng A. Khun, Long D. Phi, Huong T. T. Bui, Nguyen T. Bui, Quyen T. H. Vu, Luong D. Trinh, Deirdre A. Collins, Thomas V. Riley

Research outputs 2022 to 2026

AIMS: To investigate the prevalence, molecular type, and antimicrobial susceptibility of Clostridioides difficile in the environment in Vietnam, where little is known about C. difficile. METHODS AND RESULTS: Samples of pig faeces, soils from pig farms, potatoes, and the hospital environment were cultured for C. difficile. Isolates were identified and typed by polymerase chain reaction (PCR) ribotyping. The overall prevalence of C. difficile contamination was 24.5% (68/278). Clostridioides difficile was detected mainly in soils from pig farms and hospital soils, with 70%-100% prevalence. Clostridioides difficile was isolated from 3.4% of pig faecal samples and 5% of potato surfaces. The four …


Drought Stress Responses Of Some Prairie Landscape C4 Grass Species For Xeric Urban Applications, Fatemeh Kazemi, Mansoure Jozay, Farzaneh Salahshoor, Eddie Van Etten, Sahar Rezaie Jun 2023

Drought Stress Responses Of Some Prairie Landscape C4 Grass Species For Xeric Urban Applications, Fatemeh Kazemi, Mansoure Jozay, Farzaneh Salahshoor, Eddie Van Etten, Sahar Rezaie

Research outputs 2022 to 2026

Creating xeric landscapes in lawns and prairies is a significant challenge and practical need in arid urban environments. This study examined the drought resistance of some C4 grass species for constructing urban lawns and prairies. A factorial experiment based on randomized complete block designs with four replications was conducted. Experimental treatments were two irrigation levels (100% and 50% Field Capacity (FC)) and five warm-season grass species (Andropogon gerardii Vitman, Sorghastrum nutans (L.) Nash, Panicum virgatum L., Schizachyrium scoparium (Michx.) Nash, and Bouteloua curtipendula (Michx.) Torr.). The effects of drought on physiological, morphological, and qualitative characteristics of the grass species were …


Iowa Waste Reduction Center Newsletter, June 2023, University Of Northern Iowa. Iowa Waste Reduction Center. Jun 2023

Iowa Waste Reduction Center Newsletter, June 2023, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

In this issue:

--- Save-the-date: Iowa Recycling and Solid Waste Management Conference
--- Save-the-Date: EPA Region 7, Iowa State University
--- EPA Region 7, Iowa State University
--- IWRC and ISU Collaborate to promote sustainable brewing practices
--- From UNI Intern Turned IWRC Professional
--- IWRC Welcomes New Summer Interns
--- Industry News


Characterization Of Boreal-Arctic Vegetation Growth Phases And Active Soil Layer Dynamics In The High-Latitudes Of North America: A Study Combining Multi-Year In Situ And Satellite-Based Observations, Michael G. Brown Jun 2023

Characterization Of Boreal-Arctic Vegetation Growth Phases And Active Soil Layer Dynamics In The High-Latitudes Of North America: A Study Combining Multi-Year In Situ And Satellite-Based Observations, Michael G. Brown

Dissertations, Theses, and Capstone Projects

This dissertation examined the seasonal freeze/thaw activity in boreal-Arctic soils and vegetation physiology in Alaska, USA and Alberta, Canada, using in situ environmental measurements and passive microwave satellite observations. The boreal-Arctic high-latitudes have been experiencing ecosystem changes more rapidly in comparison to the rest of Earth due to the presently warming climatic conditions having a magnified effect over Polar Regions. Currently, the boreal-Arctic is a carbon sink; however, recent studies indicate a shift over the next century to become a carbon source. High-latitude vegetation and cold soil dynamics are influenced by climatic shifts and are largely responsible for the regions …


Western Kentucky University Stormwater Utility Survey 2023, Warren Campbell, Emily G. Davis Jun 2023

Western Kentucky University Stormwater Utility Survey 2023, Warren Campbell, Emily G. Davis

SEAS Faculty Publications

The main goal of this survey is to identify as many U.S. Stormwater Utilities (SWUs) as possible. Because many stormwater professionals do not have the time to respond to questionnaires, our primary method of identification was Internet searches. We searched key terms such as “stormwater utility”, “stormwater fee”, and “drainage fee”. We scoured online municipal codes such as Municode, AmLegal, Sterling, LexisNexis, General Code, and others. We searched through many city web websitesing to find utilities. We have also had many people contact me to update fees and identify new utilities. However, the data primarily comes from Internet sources and …


Weird Winter Weather In The Anthropocene: How Volatile Temperatures Shape Violent Crime, Christopher Thomas, Kevin T. Wolff Jun 2023

Weird Winter Weather In The Anthropocene: How Volatile Temperatures Shape Violent Crime, Christopher Thomas, Kevin T. Wolff

Publications and Research

Purpose: Current evidence suggests volatile temperatures are becoming more common because of climate change and can be expected to become even more frequent in the future. By focusing on recent temperature variability, we attempt to estimate one important dimension of the impact of climate change on violent crime. We also explore whether sudden upward temperature anomalies have stronger positive impacts on violent crime in the coldest months of the year, as routine activities are likely to change more drastically during this period.

Methods: This study explores the association between sudden temperature anomalies (both upward and downward) and the daily incidence …


Beyond Covid-19: Designing Inclusive Public Health Surveillance By Including Wastewater Monitoring, Rochelle H. Holm, Na'taki Osborne Jelks, Rebecca Schneider, Ted Smith Jun 2023

Beyond Covid-19: Designing Inclusive Public Health Surveillance By Including Wastewater Monitoring, Rochelle H. Holm, Na'taki Osborne Jelks, Rebecca Schneider, Ted Smith

Faculty and Staff Scholarship

Wastewater-based epidemiology is a promising and expanding public health surveillance method. The current wastewater testing trajectory to monitor primarily at community wastewater treatment plants was necessitated by immediate needs of the pandemic. Going forward, specific consideration should be given to monitoring vulnerable and underserved communities to ensure inclusion and rapid response to public health threats. This is particularly important when clinical testing data are insufficient to characterize community virus levels and spread in specific locations. Now is a timely call to action for equitably protecting health in the United States, which can be guided with intentional and inclusive wastewater monitoring.


Scanet: Self-Paced Semi-Curricular Attention Network For Non-Homogeneous Image Dehazing, Yu Guo, Yuan Gao, Ryan Wen Liu, Yuxu Lu, Jingxiang Qu, Shengfeng He, Ren Wenqi Jun 2023

Scanet: Self-Paced Semi-Curricular Attention Network For Non-Homogeneous Image Dehazing, Yu Guo, Yuan Gao, Ryan Wen Liu, Yuxu Lu, Jingxiang Qu, Shengfeng He, Ren Wenqi

Research Collection School Of Computing and Information Systems

The presence of non-homogeneous haze can cause scene blurring, color distortion, low contrast, and other degradations that obscure texture details. Existing homogeneous dehazing methods struggle to handle the non-uniform distribution of haze in a robust manner. The crucial challenge of non-homogeneous dehazing is to effectively extract the non-uniform distribution features and reconstruct the details of hazy areas with high quality. In this paper, we propose a novel self-paced semi-curricular attention network, called SCANet, for non-homogeneous image dehazing that focuses on enhancing haze-occluded regions. Our approach consists of an attention generator network and a scene re-construction network. We use the luminance …


Is Carbon Risk Priced In The Cross Section Of Corporate Bond Returns?, Tinghua Duan, Frank Weikai Li, Quan Wen Jun 2023

Is Carbon Risk Priced In The Cross Section Of Corporate Bond Returns?, Tinghua Duan, Frank Weikai Li, Quan Wen

Research Collection Lee Kong Chian School Of Business

This article examines the pricing of a firm’s carbon risk in the corporate bond market. Contrary to the “carbon risk premium” hypothesis, bonds of more carbon-intensive firms earn significantly lower returns. This effect cannot be explained by a comprehensive list of bond characteristics and exposure to known risk factors. Investigating sources of the low carbon alpha, we find the underperformance of bonds issued by carbon-intensive firms cannot be fully explained by divestment from institutional investors. Instead, our evidence is most consistent with investor underreaction to the predictability of carbon intensity for firm cash-flow news, creditworthiness, and environmental incidents.


What’S Scope 3 Good For?, Madison Condon Jun 2023

What’S Scope 3 Good For?, Madison Condon

Faculty Scholarship

Opposition to the Securities and Exchange Commission’s (“SEC”) new rule on updated climate risk reporting has focused on one category of disclosures as particularly objectionable: Scope 3 emissions.7 Otherwise known as “supply chain emissions,” Scope 3 emissions have been voluntarily reported by a growing number of companies since the term was invented as part of the Greenhouse Gas Protocol in 2001.8 They include all the emissions both up and downstream of a corporations’ own activities: the emissions of the privately-owned factory that produced the shoes Target sells, as well as the emissions you burn while driving to the …


Planning For A Gnarly Future: Reimagining Planning To Empower Your Community, Elizabeth Sodja Jun 2023

Planning For A Gnarly Future: Reimagining Planning To Empower Your Community, Elizabeth Sodja

All Current Publications

The purpose of this document is to summarize key takeaways and resources from our 5-part online learning series featuring planning solutions to challenges facing Gateway and Natural Amenity Region (GNAR) communities in the west.


Toxicological Effects Assessment For Wildlife In The 21st Century: Review Of Current Methods And Recommendations For A Path Forward, Thomas G. Bean, Val R. Beasley, Philippe Berny, Karen M. Eisenreich, John E. Elliott, Margaret L. Eng, Phyllis C. Fuchsman, Mark S. Johnson, Mason D. King, Rafael Mateo, Carolyn B. Meyer, Christopher J. Salice, Barnett A. Rattner May 2023

Toxicological Effects Assessment For Wildlife In The 21st Century: Review Of Current Methods And Recommendations For A Path Forward, Thomas G. Bean, Val R. Beasley, Philippe Berny, Karen M. Eisenreich, John E. Elliott, Margaret L. Eng, Phyllis C. Fuchsman, Mark S. Johnson, Mason D. King, Rafael Mateo, Carolyn B. Meyer, Christopher J. Salice, Barnett A. Rattner

United States Geological Survey: Staff Publications

Model species (e.g., granivorous gamebirds, waterfowl, passerines, domesticated rodents) have been used for decades in guideline laboratory tests to generate survival, growth, and reproductive data for prospective ecological risk assessments (ERAs) for birds and mammals, while officially adopted risk assessment schemes for amphibians and reptiles do not exist. There are recognized shortcomings of current in vivo methods as well as uncertainty around the extent to which species with different life histories (e.g., terrestrial amphibians, reptiles, bats) than these commonly used models are protected by existing ERA frameworks. Approaches other than validating additional animal models for testing are being developed, but …


Draft Final Annual Operations And Maintenance (O&M) Report Butte Treatment Lagoon (Btl) System – 2022, Pioneer Technical Services, Inc. May 2023

Draft Final Annual Operations And Maintenance (O&M) Report Butte Treatment Lagoon (Btl) System – 2022, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Can Upscaling Ground Nadir Sif To Eddy Covariance Footprint Improve The Relationship Between Sif And Gpp In Croplands?, Genghong Wu, Kaiyu Guan, Chongya Jiang, Hyungsuk Kimm, Guofang Miao, Xi Yang, Carl J. Bernacchi, Xiangmin Sun, Andrew E. Suyker, Caitlin E. Moore May 2023

Can Upscaling Ground Nadir Sif To Eddy Covariance Footprint Improve The Relationship Between Sif And Gpp In Croplands?, Genghong Wu, Kaiyu Guan, Chongya Jiang, Hyungsuk Kimm, Guofang Miao, Xi Yang, Carl J. Bernacchi, Xiangmin Sun, Andrew E. Suyker, Caitlin E. Moore

School of Natural Resources: Faculty Publications

Ground solar-induced chlorophyll fluorescence (SIF) is important for the mechanistic understanding of the dynamics of vegetation gross primary production (GPP) at fine spatiotemporal scales. However, eddy covariance (EC) observations generally cover larger footprint areas than ground SIF observations (a bare fiber with nadir), and this footprint mismatch between nadir SIF and GPP could complicate the canopy SIF-GPP relationships. Here, we upscaled nadir SIF observations to EC footprint and investigated the change in SIF-GPP relationships after the upscaling in cropland. We included 13 site-years data in our study, with seven site-years corn, four siteyears soybeans, and two site-years miscanthus, all located …


Draft Final 2023 Residential Metals Abatement Program (Rmap) Racetrack Borrow Submittal, Pioneer Technical Services, Inc. May 2023

Draft Final 2023 Residential Metals Abatement Program (Rmap) Racetrack Borrow Submittal, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Global Projections Of Flash Drought Show Increased Risk In A Warming Climate, Jordan I. Christian, Elinor R. Martin, Jeffrey B. Basara, Jason C. Furtado, Jason A. Otkin, Lauren E. L. Lowman, Eric D. Hunt, Vimal Mishra, Xiangming Xiao May 2023

Global Projections Of Flash Drought Show Increased Risk In A Warming Climate, Jordan I. Christian, Elinor R. Martin, Jeffrey B. Basara, Jason C. Furtado, Jason A. Otkin, Lauren E. L. Lowman, Eric D. Hunt, Vimal Mishra, Xiangming Xiao

School of Natural Resources: Faculty Publications

Flash drought, characterized by unusually rapid drying, can have substantial impact on many socioeconomic sectors, particularly agriculture. However, potential changes to flash drought risk in a warming climate remain unknown. In this study, projected changes in flash drought frequency and cropland risk from flash drought are quantified using global climate model simulations. We find that flash drought occurrence is expected to increase globally among all scenarios, with the sharpest increases seen in scenarios with higher radiative forcing and greater fossil fuel usage. Flash drought risk over cropland is expected to increase globally, with the largest increases projected across North America …


Predicting The Water-Yield Properties Of K2 Limestones Based On Multivariate Lstm Neural Network: A Case Study Of The Poli Mining Area In Yangquan, Shi Suzhen, Shi Guifei, Liu Zuiliang, Li Li, Yao Xuejun, Pei Jinbo, He Yazhou May 2023

Predicting The Water-Yield Properties Of K2 Limestones Based On Multivariate Lstm Neural Network: A Case Study Of The Poli Mining Area In Yangquan, Shi Suzhen, Shi Guifei, Liu Zuiliang, Li Li, Yao Xuejun, Pei Jinbo, He Yazhou

Coal Geology & Exploration

The Taiyuan Formation K2 limestones are the main aquifer in the upper part of the No.15 coal seam in the Poli mining area, Yangquan City. Therefore, determining the water yield properties of K2 limestones is critical to the safe mining of coal seams in the upper and lower formations. To determine the exact distribution of areas with high water-yield properties of the K2 limestones, this study determined the accurate spatial distribution of K2 limestones using the conventional wave impedance inversion firstly. Then, nine optimal seismic attributes were selected using the Pearson correlation coefficient method and the …


Differences In The Adsorption/Desorption Characteristics Of Coal Reservoirs With Different Coal Ranks And Their Effects On The Reservoir Productivity, Wang Qingqing, Meng Yanjun, Yan Taotao, Liu Zhenxing, Xu Guangbo, Li Kunjie, Liu Yanfei May 2023

Differences In The Adsorption/Desorption Characteristics Of Coal Reservoirs With Different Coal Ranks And Their Effects On The Reservoir Productivity, Wang Qingqing, Meng Yanjun, Yan Taotao, Liu Zhenxing, Xu Guangbo, Li Kunjie, Liu Yanfei

Coal Geology & Exploration

Adsorption/desorption parameters are critical to the evaluation of the reserves and productivity potential of coalbed methane (CBM). Moreover, the law governing the desorption process is closely related to the productivity of CBM wells. This study aims to investigate the adsorption/desorption characteristics of coal reservoirs with different coal ranks and their effects on the productivity of the reservoirs. Based on the data of the coal macerals, coal quality, gas content, and isothermal adsorption experiments of 49 coal core samples from the Fanzhuang and Anze blocks in the southern Qinshui Basin and the Baode and Liulin blocks in the eastern Ordos Basin, …


Temporal And Spatial Variation Characteristics Of Water Conservation Function Of Upper Danjiang River Basin In Qinling Mountains And Its Influencing Factors, Yang Jingyu, Shu Zunyun, Yang Fu, Fu Deliang, Ma Li, Zhang Liwei, Xue Yuze May 2023

Temporal And Spatial Variation Characteristics Of Water Conservation Function Of Upper Danjiang River Basin In Qinling Mountains And Its Influencing Factors, Yang Jingyu, Shu Zunyun, Yang Fu, Fu Deliang, Ma Li, Zhang Liwei, Xue Yuze

Coal Geology & Exploration

Effective water conservation function can regulate the regional hydrological cycles and ensure the regional ecological security, which are closely related to human production and life. For this reason, the way to accurately evaluate the water conservation function has become a research hot topics in current ecohydrology. Herein, the temporal and spatial variation rules of water conservation in Upper Danjiang River Basin in Qinling Mountains from 2010 to 2020 were analyzed based on the Distributed Hydrology Soil Vegetation Model (DHSVM) and the water balance method, and the effects of changes in climate and land use on the water conservation function of …


Image Sharpening Method Of Automatic Loading And Unloading Drill Pipe Target In Underground Coal Mine, Yao Ningping, Liang Chunmiao, Yao Yafeng, Song Haitao May 2023

Image Sharpening Method Of Automatic Loading And Unloading Drill Pipe Target In Underground Coal Mine, Yao Ningping, Liang Chunmiao, Yao Yafeng, Song Haitao

Coal Geology & Exploration

Due to the space limitation of underground roadway in coal mine, the drilling robot is designed with two independent systems, i.e., the drilling system and the drilling pipe loading and unloading system, which are in flexible layout. Using the monocular visual identification based on cooperative target, the drilling system is associated with the drilling pipe loading and unloading system for the cooperative operation of the two systems to deliver the drill pipe. However, there are problems such as borehole cinder, cooperative target polluted by sewage, high dust concentration, low visibility, low luminance of artificial light source, uneven illumination resulting in …


Application Of Pillar-Free Self-Formed Roadway Technology Under The Influence Of Reserse Faults: Strata Behavior Law And Surrounding Rock Control, Zhang Wenjie, He Manchao, Wang Jiong, Ma Zimin, Cheng Manjiang, Niu Shaokun May 2023

Application Of Pillar-Free Self-Formed Roadway Technology Under The Influence Of Reserse Faults: Strata Behavior Law And Surrounding Rock Control, Zhang Wenjie, He Manchao, Wang Jiong, Ma Zimin, Cheng Manjiang, Niu Shaokun

Coal Geology & Exploration

To explore the influence of reverse fault activation on the stability of the application of the pillar-free self-formed roadway technology, this study systematically investigated the influencing scope and mechanisms of the reverse fault activation through theoretical analysis, numerical simulations, engineering practice, and field monitoring. The results show that, under the combined action of horizontal tectonic stress and dead weight stress, reverse faults have a significant influence on both the advanced abutment pressure of working faces and the pressure on the roadway roof after coal mining. The reverse fault was locally activated when the working face was close to the reverse …


Influencing Mechanisms Of Sc-Co2 Extraction On The Microstructures Of High-Rank Tectonic Coals, Zhang Xiaodong, Zhang Yu, Zhang Shuo, Li Guizhong, Li Xianzhong May 2023

Influencing Mechanisms Of Sc-Co2 Extraction On The Microstructures Of High-Rank Tectonic Coals, Zhang Xiaodong, Zhang Yu, Zhang Shuo, Li Guizhong, Li Xianzhong

Coal Geology & Exploration

This study aims to reveal the influencing patterns of supercritical CO2 (SC-CO2) on the microstructures of tectonic coals during the injection of CO2 into deep coal seams. The study conducted SC-CO2 extraction experiments on two types of high-rank coal samples with different damage degrees, namely the lean coal samples from the Daping coal mine in Shanxi Province and the anthracite samples from the Zhenxing coal mine in Guizhou Province. Accordingly, this study compared the parameters of pore structures and aromatic carbon stacking structures in the coal samples before and after the extraction experiments. Finally, this …


Technology Of Raising Upper Limit Of Mining By Grouting Reconstruction In Thick Water-Bearing Sand Layer And Its Application, Xing Maolin, Zheng Shitian, Shi Zhiyuan, Zhao Shaolei, Du Botao, Cui Siyuan May 2023

Technology Of Raising Upper Limit Of Mining By Grouting Reconstruction In Thick Water-Bearing Sand Layer And Its Application, Xing Maolin, Zheng Shitian, Shi Zhiyuan, Zhao Shaolei, Du Botao, Cui Siyuan

Coal Geology & Exploration

In order to set anti-collapse coal (rock) pillars in the thick loose water-bearing sand layer to raise the upper limit of mining, the grouting transformation technology of thick water-bearing sand layer was studied. Aiming at raising the upper limit of mining in the fourth aquifer in working face 1010-1 of Wugou Coal Mine in Huaibei, Anhui. The analysis is conducted through theoretical calculation, experiments on of grouting materials ratio, and in-situ grouting test, with a focus on the scope and horizon of transformation, the applicability of grouting materials, the mix ratio of grout at different depths, the arrangement of drilling …


Table Of Contents, The Editors May 2023

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Experimental Study On Compressive Strength Characteristics Of Coal-Rock Combinations Influenced By Number Of Bedding Surfaces, Zheng Jianwei, Wang Shuwen, Li Haitao, Yang Guoqiang, Lyu Dazhao, Liu Biao, Fu Yukai, Li Xiaopeng, Lei Guorong May 2023

Experimental Study On Compressive Strength Characteristics Of Coal-Rock Combinations Influenced By Number Of Bedding Surfaces, Zheng Jianwei, Wang Shuwen, Li Haitao, Yang Guoqiang, Lyu Dazhao, Liu Biao, Fu Yukai, Li Xiaopeng, Lei Guorong

Coal Geology & Exploration

The layering effect of the coal seam roof poses major influence on the mechanical behavior of the coal-rock system. Herein, the coal seam roof was simplified into coal-rock combinations with different number of bedding planes in the rock unit, and on this basis, uniaxial compression tests were conducted. Then, the stress-strain characteristics, the evolution law of surface strain field and the acoustic emission characteristics during the test were collected and analyzed using the stress monitoring system, the digital image correlation (DIC) method, and the acoustic emission (AE) system. The test shows that: the stress-strain process of the coal-rock combinations can …


Reliability Analysis And Compressibility Correction Of Mercury Intrusion Porosimetry Experiments For Low-Medium-Rank Coals, Song Dangyu, Zhao Yuwei, Li Yunbo, Yu Zhen May 2023

Reliability Analysis And Compressibility Correction Of Mercury Intrusion Porosimetry Experiments For Low-Medium-Rank Coals, Song Dangyu, Zhao Yuwei, Li Yunbo, Yu Zhen

Coal Geology & Exploration

Low-medium-rank coals are soft and exhibit significant compressibility under high pressure. Therefore, it is debatable whether the pore structure of low-medium-rank coals can be reliably determined using mercury intrusion porosimetry (MIP) experiments. In this study, MIP experiments were conducted on four samples of low-medium-rank coals. By comparing the mercury injection curves of samples with different particle sizes, as well as the macroscopic and microscopic characteristics of the samples before and after mercury injection, this study established a correction method for the mercury injection volume at the high-pressure stage and investigated the reliability of MIP experiments in determining the pore structure …


A Simulation Study On The Formation Mechanisms Of Gas Hydrates In Pores Of Gas Hydrate-Bearing Sediments In The South China Sea, Zheng Mingming, Zhou Kerui, Wu Zurui, Liu Tianle, Yan Shichun, Zeng Guo’Ao May 2023

A Simulation Study On The Formation Mechanisms Of Gas Hydrates In Pores Of Gas Hydrate-Bearing Sediments In The South China Sea, Zheng Mingming, Zhou Kerui, Wu Zurui, Liu Tianle, Yan Shichun, Zeng Guo’Ao

Coal Geology & Exploration

The formation of high-quality gas hydrates in the pores of the sediment matrix serves as the premise and material basis for experimental research on gas hydrates, thus providing theoretical guidance for the exploration of deep-water hydrocarbons and gas hydrates in China. Based on the geological conditions of gas hydrate-bearing sediments in well GMGS2-07 in the South China Sea, this study conducted numerical simulations and laboratory experiments using the TOUGH+HYDRATE code and a self-developed device for gas hydrate reactions and generation, respectively. Firstly, this study verified the accuracy and reliability of the numerical simulation method. Then, it investigated the quality of …


In-Situ Stress Calculation For Coal Reservoirs Based On Log Parameters: A Case Study Of The Southern Yanchuan Block, Chang Chuang, Li Song, Tang Dazhen, Feng Peng May 2023

In-Situ Stress Calculation For Coal Reservoirs Based On Log Parameters: A Case Study Of The Southern Yanchuan Block, Chang Chuang, Li Song, Tang Dazhen, Feng Peng

Coal Geology & Exploration

In-situ stress affects the permeability of coal reservoirs throughout the extraction of coalbed methane (CBM) and further influences the migration and output of CBM. To explore the effective methods for calculating the in-situ stress in coal seams, this study investigated the southern Yanchuan block at the eastern margin of the Ordos Basin. Based on the logs and well test data of the major coal seams in the study area, as well as the calculation results of parameters including the coal rock Poisson's ratio, modulus of elasticity, and reservoir pressure of coals, this study built a calculation model for the in-situ …


Construction And Experimental Verification Of A Damage Constitutive Model Of Rocks Under Uniaxial Compression Considering Seepage Pressure, Song Zhanping, Wang Jiahui, Pan Hongwei, Yang Pengtao, Yang Tengtian, Tian Song May 2023

Construction And Experimental Verification Of A Damage Constitutive Model Of Rocks Under Uniaxial Compression Considering Seepage Pressure, Song Zhanping, Wang Jiahui, Pan Hongwei, Yang Pengtao, Yang Tengtian, Tian Song

Coal Geology & Exploration

The construction of tunnels and underground projects in a water abundance environment is subjected to increasingly frequent construction accidents arising from the surrounding rock instability caused by groundwater infiltration. Therefore, establishing a damage constitutive model of rocks under uniaxial compression while considering seepage pressure is of great significance for guiding field construction. To characterize the stress-strain relationships in the process of uniaxial compression damage of rocks, this study introduced concepts such as the deformation model of porous rocks, pore aspect ratio, and self-consistent model and theories such as hydrochemical damage and Weibull distribution-based statistical damage into the original constitutive models …


Analysis On Water Loss Characteristics Of Roof Aquifer And Borehole Hydraulic Curtain Protection In Deep Coal Mining In Inner Mongolia‒Shaanxi Mining Area, Zhao Chunhu, Wang Shidong, Ji Zhongkui, Zhu Kaipeng, Yang Jian, Xu Feng, Yu Bo May 2023

Analysis On Water Loss Characteristics Of Roof Aquifer And Borehole Hydraulic Curtain Protection In Deep Coal Mining In Inner Mongolia‒Shaanxi Mining Area, Zhao Chunhu, Wang Shidong, Ji Zhongkui, Zhu Kaipeng, Yang Jian, Xu Feng, Yu Bo

Coal Geology & Exploration

The geological and hydrogeological characteristics of the main mined coal seams in the deep Inner Mongolia‒Shaanxi Mining Area vary greatly from that of the shallow area. Herein, the relevant research results on the geological and hydrogeological characteristics, as well as the mining-induced water-flowing fracture, were analyzed systematically for the main mined coal seams in the deep mining areas, such as Hujierte, Taigemiao and Xinjie. On this basis, it is summarized that a typical indirect water loss (inrush) mode could be formed easily under the drive of coal mining, with the protection of key weak water barrier layer of Jurassic Anding …