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Articles 1591 - 1620 of 9286

Full-Text Articles in Earth Sciences

Water Inrush Mechanism Of Coal Mine Shaft Fracture Under Fluid-Solid Coupling, Xue Weipei, Shen Lei, Yao Zhishu, Cheng Hua, Rong Chuanxin Oct 2023

Water Inrush Mechanism Of Coal Mine Shaft Fracture Under Fluid-Solid Coupling, Xue Weipei, Shen Lei, Yao Zhishu, Cheng Hua, Rong Chuanxin

Coal Geology & Exploration

The occurrence of coal mine shaft fractures and water inrush accidents is alarmingly frequent, endangering the lives of underground personnel and compromising mine safety. To comprehend the influence of confined groundwater in the process of shaft fracture and the formation mechanism of water inrush channels, a model test was devised using similarity theory and coupled fluid-solid numerical simulation technology. The findings reveal that direct contact between the shaft lining and pressurized water hinders the development of load-bearing and deformation capacities. This is specifically evidenced by the premature appearance of the yield point, a reduction in peak strength and strain, and …

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Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing Oct 2023

Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing

Coal Geology & Exploration

As the weathered bedrock and burned rock aquifers seriously threaten the production safety of mines in the Jurassic coalfield of northern Shaanxi Province, accurate prediction of their waterrichness and water inflow at the working face is of great significance for water control in mines. Aiming at the weathered bedrock and burned rock aquifers with close hydraulic connection, the area where working face 15217 of Shaanxi Hongliulin Coal Mine is located was taken as the study area. Meanwhile, the aquifer thickness, lithological combination index, index of rock burning and weathering degree and core recovery was taken as the evaluation indexes. The …

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Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang Oct 2023

Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang

Coal Geology & Exploration

In order to reveal the mechanism of two-region Darcian and non-Darcian flow induced by constant-head pumping tests in unconfined aquifers, a numerical model of well flow by constant-head pumping underground based on finite difference solution was proposed. In the model, it is assumed that the aquifer is divided into two regions according to the pumping flow characteristics: the finite non-Darcian flow region near the pumping well and the semi-infinite Darcian flow region far away from the pumping well. Specifically, the flow regime in the non-Darcian flow region was simulated by the Izbash’s equation, and the reliability of the proposed solution …

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Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin Oct 2023

Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin

Coal Geology & Exploration

To study the mesoscopic failure characteristics of the layered red shale, uniaxial mechanical experiments were carried out by applying DSTD-1000 electro-hydraulic servo rigid pressure on the red shale with different bedding angles. Meanwhile, SEM and XRD experiments were implemented on debris to obtain its mechanical parameters, failure characteristics, microstructure, and relative content of components. Based on this, models of the red shale with different bedding angles were constructed using the discrete element PFC3D for the uniaxial compression experiments to study the mesoscopic failure characteristics of red shale. The results show that: (1) When the bedding angle θ=30°, 45°, …

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Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun Oct 2023

Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun

Coal Geology & Exploration

In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces. However, coal seams, which have viscoelasticity actually, imposing absorptive and attenuation effects on in-seam waves. To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media, this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation. Using this equation, three-dimensional finite-difference numerical simulation was carried out. The results indicate that (1) for reflected in-seam waves in viscoelastic media, which exhibit high energy attenuation, their propagation and attenuation characteristics are …

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Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang Oct 2023

Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang

Coal Geology & Exploration

In order to improve the support efficiency of coal mine roadway and the automation intelligence of heading face, an anchor drilling robot integrating the cantilever roadheader and the six-degree-of-freedom manipulator was designed, and studied on the anchor drilling sequence planning strategy and the drilling boom trajectory planning method. Firstly, the kinematics model of the manipulator structure was established based on the improved DH method. On this basis, the forward and inverse kinematics solutions were analyzed, and the spatial position and the corresponding joint variable values of the drilling rig were calculated. Secondly, the manipulator space was analyzed based on Monte …

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Book Review: Australian Caves And Karst Systems, John Webb, Susan White, Garry K. Smith, Jo De Waele Oct 2023

Book Review: Australian Caves And Karst Systems, John Webb, Susan White, Garry K. Smith, Jo De Waele

International Journal of Speleology

No abstract provided.

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Characterization Of Environmental Levels Of Pesticide Residues In Household Air And Dust Samples Near A Bioenergy Plant Using Treated Seed As Feedstock, Jabeen Taiba, Eleanor G. Rogan, Daniel D. Snow, Chandran Achutan, Muhammad Zahid Oct 2023

Characterization Of Environmental Levels Of Pesticide Residues In Household Air And Dust Samples Near A Bioenergy Plant Using Treated Seed As Feedstock, Jabeen Taiba, Eleanor G. Rogan, Daniel D. Snow, Chandran Achutan, Muhammad Zahid

Nebraska Water Center: Faculty Publications

Exposure to neonicotinoid insecticides is associated with adverse human health outcomes. There is environmental contamination in Saunders County, Nebraska, due to the accumulation of fungicides and insecticides from a now-closed ethanol plant using seed corn as stock. A pilot study quantified environmental contamination in nearby houses from residual pesticides by measuring dust and air (indoor/outdoor) concentrations of neonicotinoids and fungicides at the study site (households within two miles of the plant) and control towns (20–30 miles away). Air (SASS® 2300 Wetted-Wall Air Sampler) and surface dust (GHOST wipes with 4 × 4-inch template) samples were collected from eleven study …

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Does Drought Stress Eliminate The Benefit Of Elevated Co2,/Sub> On Soybean Yield? Using An Improved Model To Link Crop And Soil Water Relations, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy Oct 2023

Does Drought Stress Eliminate The Benefit Of Elevated Co2,/Sub> On Soybean Yield? Using An Improved Model To Link Crop And Soil Water Relations, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Daugherty Water for Food Global Institute: Faculty Publications

Crop simulation models are indispensable tools that facilitate studies to assess climate impacts and adaptation responses, but have not been adequately tested in terms of accurately predicting crop growth and water stress responses to high carbon dioxide concentrations [CO2]. The soybean model, GLYCIM, previously modified with a coupled leaf-level gas exchange – energy balance model, was integrated with a two-dimensional convectivediffusive root growth module which linked soil and leaf water potentials with the regulation of stomatal conductance. We evaluated the accuracy of this modified GLYCIM using experimental data from a Free-Air CO2 Enrichment (FACE) site, SoyFACE, and …

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Leaching Performance Of Nanotechnology-Induced High-Arsenic-Bearing Tooeleite-Like Mineral Nanowaste, Arindam Malakar, Sanjit Das, Samirul Islam, Rajneesh Singh, Sugata Ray Oct 2023

Leaching Performance Of Nanotechnology-Induced High-Arsenic-Bearing Tooeleite-Like Mineral Nanowaste, Arindam Malakar, Sanjit Das, Samirul Islam, Rajneesh Singh, Sugata Ray

Nebraska Water Center: Faculty Publications

For arsenic decontamination from groundwater, arsenic crystallization is becoming adopted due to its sustainability and economic benefits. However, arsenic crystallization technology is a two-step process, which makes it complex and generates hazardous waste. Successful efforts toward making it a single-step process are presented here. The addition of nanorods and ball-milled zinc sulfide nanoparticles to arsenic-contaminated water result in highly monodispersed and higharsenic- containing mineralized nanowaste with a crystalline structure similar to the mineral Tooeleite ((Fe3+6(As3+O3)4SO4(OH)4•4H2O)). This study reports the results of a short-term stability test …

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Nutritional Challenges Of Substituting Farmed Animals For Wild Fish In Human Diets, Sebastian A. Heilpern, Rafael M. Almeida, Kathryn J. Fiorella, Alexander S. Flecker, Demetra Williams, Peter B. Mcintyre Oct 2023

Nutritional Challenges Of Substituting Farmed Animals For Wild Fish In Human Diets, Sebastian A. Heilpern, Rafael M. Almeida, Kathryn J. Fiorella, Alexander S. Flecker, Demetra Williams, Peter B. Mcintyre

School of Earth, Environmental, & Marine Sciences Faculty Publications

Wild fisheries provide billions of people with a key source of multiple essential nutrients. As fisheries plateau or decline, nourishing more people will partially rely on shifting consumption to farmed animals. The environmental implications of transitions among animal-sourced foods have been scrutinized, but their nutritional substitutability remains unclear. We compared concentrations of six essential dietary nutrients across >5000 species of wild fishes, aquaculture, poultry and livestock species, representing >65% of animals consumed globally. Wild fishes are both more nutrient-dense and variable than farmed animals; achieving recommended intake of all nutrients with farmed species could require consuming almost four times more …

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The Public's Perception Of An Earthquake Early Warning System: A Study On Factors Influencing Continuance Intention, Marion Lara L. Tan, Lauren J. Vinnell, Alvin Patrick M. Valentin, Raj Prasanna, Julia S. Becker Oct 2023

The Public's Perception Of An Earthquake Early Warning System: A Study On Factors Influencing Continuance Intention, Marion Lara L. Tan, Lauren J. Vinnell, Alvin Patrick M. Valentin, Raj Prasanna, Julia S. Becker

Quantitative Methods and Information Technology Faculty Publications

This paper investigates the perceptions of the New Zealand public towards the Android Earthquake Alert (AEA) system, a public-facing earthquake early warning system. Specifically, it examines the public’s continuance intention towards the AEA system and the influencing factors of satisfaction, confirmation, perceived usefulness, and perceived trust. To gather insights into the public’s perceptions regarding the AEA system, this study distributed online surveys following two separate earthquake alert events on 12 October and 22 October 2021. A total of 524 and 671 participants responded to the two events’ surveys, providing valuable data for analysis and exploration. Structural Equation Modelling of the …

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Use And Effectiveness Of Wildlife Exits Designed For Ocelots And Other Mesocarnivores On A South Texas Highway, Zarina N. Sheikh, Jamie E. Langbein, Kevin W. Ryer, Md Saydur Rahman, Christopher A. Gabler, John H. Young Jr., Richard Kline Oct 2023

Use And Effectiveness Of Wildlife Exits Designed For Ocelots And Other Mesocarnivores On A South Texas Highway, Zarina N. Sheikh, Jamie E. Langbein, Kevin W. Ryer, Md Saydur Rahman, Christopher A. Gabler, John H. Young Jr., Richard Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Movement is a key component of survival and reproduction, often causing wildlife to cross heavily trafficked highways, resulting in road mortalities by oncoming vehicles. Fencing and crossing structures are commonly regarded as effective mitigation structures to reduce these mortalities. In south Texas, ten wildlife exits (WE) were installed along State Highway 100 in conjunction with existing mitigation structures to provide the US endangered ocelot (Leopardus pardalis), a medium-sized spotted wild cat, a safe option to escape the right of way (ROW). The objectives of this study were to determine the effectiveness and species usage and to estimate the …

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Widespread Dominance Of Methane Ebullition Over Diffusion In Freshwater Aquaculture Ponds, Renske J. E. Vroom, Sarian Kosten, Rafael M. Almeida, Raquel Mendonça, Ive S. Muzitano, Icaro Barbosa, Jonas Nasário, Ernandes S. Oliveira Junior, Alexander S. Flecker, Nathan Barros Oct 2023

Widespread Dominance Of Methane Ebullition Over Diffusion In Freshwater Aquaculture Ponds, Renske J. E. Vroom, Sarian Kosten, Rafael M. Almeida, Raquel Mendonça, Ive S. Muzitano, Icaro Barbosa, Jonas Nasário, Ernandes S. Oliveira Junior, Alexander S. Flecker, Nathan Barros

School of Earth, Environmental, & Marine Sciences Faculty Publications

An ever-increasing demand for protein-rich food sources combined with dwindling wild fish stocks has caused the aquaculture sector to boom in the last two decades. Although fishponds are potentially strong emitters of the greenhouse gas methane (CH4), little is known about the magnitude, pathways, and drivers of these emissions. We measured diffusive CH4 emissions at the margin and in the center of 52 freshwater fishponds in Brazil. In a subset of ponds (n = 31) we additionally quantified ebullitive CH4 fluxes and sampled water and sediment for biogeochemical analyses. Sediments (n = 20) were …

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Cross-Scale Urban Land Cover Mapping: Empowering Classification Through Transfer Learning And Deep Learning Integration, Zhe Wang, Chao Fan, Xian Min, Shoukun Sun, Xiaogang Ma, Xiang Que Oct 2023

Cross-Scale Urban Land Cover Mapping: Empowering Classification Through Transfer Learning And Deep Learning Integration, Zhe Wang, Chao Fan, Xian Min, Shoukun Sun, Xiaogang Ma, Xiang Que

I-GUIDE Forum

Urban land cover mapping is essential for effective urban planning and resource management. Thanks to its ability to extract intricate features from urban datasets, deep learning has emerged as a powerful technique for urban classification. The U-net architecture has achieved state-of-the-art land cover classification performance, highlighting its potential for mapping urban trees at different spatial scales. However, deep learning approaches often require large, labeled datasets, which are challenging to acquire for specific urban contexts. Transfer learning addresses this limitation by leveraging pre-trained deep learning models on extensive datasets and adapting them to smaller urban datasets with limited labeled samples. Transfer …

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Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian Oct 2023

Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian

I-GUIDE Forum

Given multi-model ensemble climate projections, the goal is to accurately and reliably predict future sea-level rise while lowering the uncertainty. This problem is important because sea-level rise affects millions of people in coastal communities and beyond due to climate change's impacts on polar ice sheets and the ocean. This problem is challenging due to spatial variability and unknowns such as possible tipping points (e.g., collapse of Greenland or West Antarctic ice-shelf), climate feedback loops (e.g., clouds, permafrost thawing), future policy decisions, and human actions. Most existing climate modeling approaches use the same set of weights globally, during either regression or …

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How Sensitive Are Catchment Runoff Estimates To On-Farm Storages Under Current And Future Climates?, David E. Robertson, Hongxing Zheng, Jorge L. Pena-Arancibia, Francis H S Chiew, Santosh Aryal, Martino E. Malerba, Nicholas J. Wright Oct 2023

How Sensitive Are Catchment Runoff Estimates To On-Farm Storages Under Current And Future Climates?, David E. Robertson, Hongxing Zheng, Jorge L. Pena-Arancibia, Francis H S Chiew, Santosh Aryal, Martino E. Malerba, Nicholas J. Wright

Climate Science Research Articles

Storage of water in farm dams is important to support irrigation, stock requirements and domestic uses when reticulated water is unavailable. Farm dams that fill by intercepting landscape runoff change the total volume and seasonality of catchment streamflow, potentially impacting water policy outcomes. While numerous studies have quantified how climate change and farm dams independently change streamflow characteristics, few studies have investigated their interactions. This study investigates the interactions between farm dams and climate change in the Murray-Darling Basin of southern and eastern Australia. We use hydrological modelling that explicitly represent farm dams and remotely sensed data describing historical farm …

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Causes And Effects Of Shisper Glacial Lake Outburst Flood Event In Karakoram In 2022, Sandeep Kumar Mondal, Vatsal D. Patel, Rishikesh Bharti, Ramesh P. Singh Oct 2023

Causes And Effects Of Shisper Glacial Lake Outburst Flood Event In Karakoram In 2022, Sandeep Kumar Mondal, Vatsal D. Patel, Rishikesh Bharti, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Karakoram Himalayas are vulnerable to glacial lake outburst floods (GLOFs), which cause catastrophic floods in the surrounding areas. The increasing natural and anthropogenic activities, especially in the Indo-Gangetic Plains at the southern flank of the towering Himalayas, could be the cause of climate change affecting the frequency of the natural hazards in the Himalayas. In the present study, a detailed analysis of the Shisper Lake breach of 7 May 2022 is carried out using satellite remote sensing. A decreasing trend in the glacial mass balance is observed between 2017 and 2021; in this period, frequent GLOF episodes occurred. A pronounced …

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The Influence Of Effluent: Exploring How Wastewater Effluent Impacts Ísafjörður, Iceland, Madi Bennett-Wells Oct 2023

The Influence Of Effluent: Exploring How Wastewater Effluent Impacts Ísafjörður, Iceland, Madi Bennett-Wells

Iceland: Climate Change and The Arctic

Wastewater effluent is of growing concern in communities without proper wastewater treatment plans in place. This study examines the effects that wastewater discharge has on water quality in various communities through field research and an accompanying literature review. Water quality parameters (pH and temperature) were used to determine the impact effluent has on the local harbor, Pollurinn, in Ísafjörður, Iceland. Results showed that there was a statistical significance between pH and the area of study, while temperature was more varied; these results signify that effluent has the biggest impact on the area immediately surrounding the effluent pipe. The literature review …

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Assessing The Performance Of Agricultural Systems In The Inland And Coastal Regions Of Northern Portugal Using Indicators: Establishing The Foundation Towards Better Agricultural Practices, Genevieve Gehlken Oct 2023

Assessing The Performance Of Agricultural Systems In The Inland And Coastal Regions Of Northern Portugal Using Indicators: Establishing The Foundation Towards Better Agricultural Practices, Genevieve Gehlken

Independent Study Project (ISP) Collection

This study conducts a comprehensive evaluation of agricultural systems in the distinct coastal and inland regions of Northern Portugal. Employing key indicators, including soil erosion, nitrogen surplus, irrigation practices, Agricultural Gross Domestic Product (GDP), and crop yield, the analysis reveals statistically significant disparities and unique challenges in each region. The coastal areas, marked by higher agricultural GDP, exhibit distinct economic dependencies on agriculture, while the inland regions face challenges related to water scarcity, soil erosion, and rural isolation. The looming threat of climate change adds complexity to these dynamics, further highlighting the need for region-specific, sustainable agricultural practices. In the …

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More Than Energy: Coal As A Mineral Resource, University Of North Dakota. Energy And Environmental Research Center Oct 2023

More Than Energy: Coal As A Mineral Resource, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Brochure on Carbon Ore, Rare Earth, and Critical Minerals (CORE-CM) Initiative, an Energy & Environmental Research Center and U.S. Department of Energy project. Explores the benefits of utilizing lignite coal from the Williston Basin.

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Carbon Storage Monitoring, Verification, And Accounting (Mva), University Of North Dakota. Energy And Environmental Research Center Oct 2023

Carbon Storage Monitoring, Verification, And Accounting (Mva), University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about carbon storage monitoring, verification, and accounting (MVA). Includes background on MVA, the Energy & Environmental Research Center, and Plains CO2 Reduction (PCOR) Partnership plans for MVA strategy development.

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General Brochure, University Of North Dakota. Energy And Environmental Research Center Oct 2023

General Brochure, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Information about the Energy & Environmental Research Center (EERC). Includes information on the EERC’s expertise, research priorities, facilities, and employment statistics.

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Poor Water Quality Persists In Diverse Urban Communities, Rae Cade, Danlin Yu, Kyle Whyte, Pankaj Lal, Cortni Borgerson Oct 2023

Poor Water Quality Persists In Diverse Urban Communities, Rae Cade, Danlin Yu, Kyle Whyte, Pankaj Lal, Cortni Borgerson

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

While humans need water to survive, water can also efficiently transmit microbial diseases and heavy metals to consumers. Over 50,000 water violations occurred in 2020 and such burdens were not borne equally amongst consumers. Yet, the factors that drive such variation remain unclear. We examined the interactions between water quality and inherited equity gaps in one of the most diverse urban areas in the United States. We used publicly available drinking water datasets to determine which contaminant was most prevalent between 2010–2020 and who was significantly more likely to be affected by this contamination. We found that a lack of …

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Public Perceptions Of Water Quality In The Lake Bunyonyi Sub-Catchment, Western Uganda, Alex Saturday, Thomas J. Lyimo, Siajali Pamba, Susan Kangume, Jeniffer Turyatemba Sep 2023

Public Perceptions Of Water Quality In The Lake Bunyonyi Sub-Catchment, Western Uganda, Alex Saturday, Thomas J. Lyimo, Siajali Pamba, Susan Kangume, Jeniffer Turyatemba

Tanzania Journal of Science

Lake Bunyonyi ecosystem plays vital roles in water resource conservancy and tourism. Nevertheless, the rapid increase in human population and the unrelenting human activities are threatening the values, functions, and ecological integrity of the lake. In this study, the public perceptions of drinking water quality and its health implications in the Lake Bunyonyi Sub-catchment, Western Uganda are presented. A closed-ended questionnaire was administered to 267 respondents living within one Kilometre away from the lake shores. Besides, observation and interview methods were used to complement data collected by the questionnaire method. Results indicate that the prominent activities around the lake are …

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Self-Organization For Community Resilience In An Invisible Agricultural Community, Anna Erwin, Chelsea A. Silva, Zhao Ma Sep 2023

Self-Organization For Community Resilience In An Invisible Agricultural Community, Anna Erwin, Chelsea A. Silva, Zhao Ma

School of Earth, Environmental, & Marine Sciences Faculty Publications

This study investigates how self-organizing efforts by residents of informal settlements, primarily migrant and informal farmworkers, shape community resilience in Majes, a water-scarce irrigation district in the Atacama Desert of Peru. We collected 45 semi-structured interviews with residents and authorities in Majes and analyzed findings through a framework of self-organizing. Analyses revealed that self-organizing by residents of informal settlements incorporated the three components of White’s theory of Community Agency and Community Resilience, which contends that marginalized communities increase resilience by fostering a commons praxis, practicing a prefigurative politics, and developing opportunities for economic autonomy. We also found …

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Research On Three-Stage Automatic Hole Packer For Gas Extraction Drilling In Underground Coal Mine, Wang Qingfeng, Shi Shuhan, Xin Dezhong, Chen Hang, Zhang Shitao Sep 2023

Research On Three-Stage Automatic Hole Packer For Gas Extraction Drilling In Underground Coal Mine, Wang Qingfeng, Shi Shuhan, Xin Dezhong, Chen Hang, Zhang Shitao

Coal Geology & Exploration

In view of the requirements of hole sealing during gas extraction drilling in underground coal mine for manual packer installation and sealing material injection, as well as the low automation level of hole sealing technology, a three-stage automatic hole packer for gas extraction drilling in underground coal mine was developed, with the appearance similar to the drill pipe. The hole packer could be mechanized into the drilling hole by an automatic drilling machine, and realize the automatic injection of sealing material. Herein, the Mooney-Rivlin hyperelastic constitutive model was used to represent the strain energy function by the finite element analysis …

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Intelligent Optimization And Control Technology For Drilling Process Of Coal Mine Tunnels, Yao Ningping, Wu Min, Chen Luefeng, Lu Chengda, Fan Haipeng, Zhang Youzhen, Li Wangnian, Yao Ke Sep 2023

Intelligent Optimization And Control Technology For Drilling Process Of Coal Mine Tunnels, Yao Ningping, Wu Min, Chen Luefeng, Lu Chengda, Fan Haipeng, Zhang Youzhen, Li Wangnian, Yao Ke

Coal Geology & Exploration

The harsh environment for drilling construction of coal mine tunnel, complex coal seam structure and complicated operation procedures can cause low drilling efficiency and high drilling cost. For this reason, it is imperative to carry out studies on the optimization and control technology for the drilling process of coal mine tunnel. Herein, study was conducted from intelligent identification of lithology of coal-bearing formation, intelligent optimization of drilling parameters and their intelligent control, focusing on the key technology for control of drilling process of coal mine tunnel. First, in order to accurately determine the type of coal-bearing formation, an intelligent identification …

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Continuous And Discontinuous Numerical Simulation Of The Rock Breaking Process Of Pdc Drill Bit Under Composite Impact, Qin Chengshuai, Sun Hongbin, Li Liping, Liu Xuegang, Liu Zhihui, Feng Chun, Sun Zizheng Sep 2023

Continuous And Discontinuous Numerical Simulation Of The Rock Breaking Process Of Pdc Drill Bit Under Composite Impact, Qin Chengshuai, Sun Hongbin, Li Liping, Liu Xuegang, Liu Zhihui, Feng Chun, Sun Zizheng

Coal Geology & Exploration

Composite impact drilling is a novel rock-breaking technique that combines both axial and torsional impacts. To address the issues of complex failure mechanisms and unclear rock-breaking mechanisms under the axial-torsional impacts on rock by Polycrystalline Diamond Compact (PDC) drill bits, a FEM-DEM rock model based on shared nodes was established using the Continuous Discontinuous Element Method (CDEM), and the rationality of this computational model was verified through laboratory uniaxial compression experiments. Besides, a composite impact motion model for single drill bit was built through the secondary development of JavaScript, and the composite impact rock-breaking process of single PDC drill bit …

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Application Of Intelligent Direct Push Measurement While Drilling Device For Environmental Geological Surveys, Sun Pinghe, Zhou Shengwei, Cao Han, Gao Qiang, Cheng Gongbi, Zhang Hui Sep 2023

Application Of Intelligent Direct Push Measurement While Drilling Device For Environmental Geological Surveys, Sun Pinghe, Zhou Shengwei, Cao Han, Gao Qiang, Cheng Gongbi, Zhang Hui

Coal Geology & Exploration

In order to solve the technical challenges of inaccuracy and poor credibility of contaminant survey results due to the low accuracy of drilling trajectories in environmental geological surveys, the structural and functional characteristics of the existing direct-push drilling tools were analyzed. On this basis, the method of near-bit measurement while drilling using single-action combination was proposed. An intelligent measurement-while-drilling (MWD) device was developed, a laboratory platform monitoring module was established, a set of monitoring software was developed, and the stability and reliability of the intelligent MWD device was analysed. Then, verification tests have been carried out on the laboratory platforms …

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