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Articles 1861 - 1890 of 294493

Full-Text Articles in Physical Sciences and Mathematics

Error-Tolerant Metric Dimension, Leander Ten Hoff Jul 2026

Error-Tolerant Metric Dimension, Leander Ten Hoff

Master's Theses

Metric dimension is a graph parameter that measures the smallest distance-based unique coordinate system on a graph. Fault-tolerant metric dimension is a variant that requires redundancy. Inspired by this idea, we propose and investigate a new variant we call error-tolerant metric dimension. We first prove some fundamental results to gain familiarity with this more complex variant. Then, we use these tools to study relative behaviors of error-tolerant metric dimension. We prove explicit computations for simple graph families, including bipartite complete graphs and paths. Finally, we extend extremal results from previous papers on metric dimension, including a full correction of an …

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The Characterization Of Bridging Waters And Ions In Protein-Rna Complexes, Leslie Duong Jul 2026

The Characterization Of Bridging Waters And Ions In Protein-Rna Complexes, Leslie Duong

Master's Theses

Here we explore the role of bridging waters and ions in protein-RNA complexes. From an initial set of 33 high-resolution X-ray crystal structures, 17 were identified such that protein-RNA complex and component protein and RNA chains were found within 1 pH unit as indicated by crystallization conditions and their diffraction temperatures meeting one of two ranges: above or below freezing. To define an even more realistic set, 12 unbound-unbound and unbound-pseudo-unbound complexes from the 17-set were studied, showing the large fraction of complexes indicating more protein and RNA water hydrogen bonding in their actual interfacial regions as opposed to those …

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The Relationship Between Foliations Of The Plane, Kaplan Diagrams, And Non-Hausdorff 1-Manifolds, Monique Justine Howe Jul 2026

The Relationship Between Foliations Of The Plane, Kaplan Diagrams, And Non-Hausdorff 1-Manifolds, Monique Justine Howe

Master's Theses

In this paper we seek to explain the relationship between foliations of the plane, Kaplan diagrams, and simply connected non-Hausdorff 1-manifolds with countable basis that are orientable with an ordering on branch points. We will walk the reader through the definitions of all of these objects, and provide examples with a focus on the motivating example of the Reeb foliation. This paper will describe and define the known bijection from the set of foliations of the plane, F, to the set of Kaplan diagrams, K, its inverse, and the one-to-one map from F to the set of simply connected non-Hausdorff …

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Accessibility Fairness Practices In Ai Applications For People With Disabilities, Megan Gross Jul 2026

Accessibility Fairness Practices In Ai Applications For People With Disabilities, Megan Gross

Master's Theses

Advancements in artificial intelligence (AI) improve the lives of people every day with tools like the auto-captioning of videos, improved screen-reader capabilities, and advanced mobility control through speech. However, are all groups of people benefiting from AI or are some being overlooked and left out? Although AI tools made for people with disabilities (PWDs) have improved their lives, AI for the general population generally ignores the experiences of PWDs, making them unable to interact with and benefit from technology. This research evaluates ChatGPT and Gemini in Gmail for usability fairness and analyzes how current regulations and development processes fail to …

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Diagrammatic Methods For Calculating Correlation Functions In Low-Dimensional Quantum Gravity, Nicholas A. Parrilla Jul 2026

Diagrammatic Methods For Calculating Correlation Functions In Low-Dimensional Quantum Gravity, Nicholas A. Parrilla

Master's Theses

This thesis investigates connections between random matrix theory and low-dimensional quantum gravity through the spectral form factor (SFF), a well-studied function that characterizes correlations in the eigenvalue spectrum of an operator. In random matrix ensembles, a feature of the SFF known as the “ramp” is governed by universal spectral correlations, and in Jackiw–Teitelboim (JT) gravity this regime is due to the double-trumpet wormhole geometry. We study the connected correlation functions underlying the SFF using combinatorial, diagrammatic methods from a mathematical formalism known as second-order free probability theory, where they are expressed in terms of annular noncrossing permutations. To access a …

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Rewriting The Calculus 3 Workshop At San José State University, Moorea Lippert Jul 2026

Rewriting The Calculus 3 Workshop At San José State University, Moorea Lippert

Master's Theses

Calculus 3 at San José State University is a very important course for any student pursuing a STEM degree. However, the course is very challenging, so the university offers a supplemental workshop course for Calculus 3 students. Unfortunately, this workshop has not aligned with modern research in math education. This thesis documents efforts to recreate the workshop to better align with this modern research.

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Hydrus Modeling Of A Sahelian Agroforestry System: An Investigation Of Local Water Balance, Nicole A. Butler Jul 2026

Hydrus Modeling Of A Sahelian Agroforestry System: An Investigation Of Local Water Balance, Nicole A. Butler

Master's Theses

Effects of drought can devastate agricultural productivity in the West African Sahel. Climate complexities, such as lower-than-average rainfall and high winds, can lead to crop failure and low yields, thereby creating food security issues. Agriculture in the Sahel is primarily rainfed, and the rain is becoming increasingly unpredictable due to the changing climate. The method of intercropping groundnut (Arachis hypogea) and pearl millet (Pennisetum glaucum) with the shrub species Piliostigma reticulatum can combat the effects of climate change and restore degraded soil. Intercropping can increase water availability and crop yield when compared to crops grown in the absence of shrubs. …

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Monoids With K-Strictly Local Geodesic Languages, William M. Hong Jul 2026

Monoids With K-Strictly Local Geodesic Languages, William M. Hong

Master's Theses

A paper by Gilman, Hermiller, Holt and Rees (2011) prove that a group G finitely generated by X is virtually free if and only if the language of geodesics words in G over X is k-strictly local if and only if the word problem is context-free. If M is a monoid finitely generated by X, we define Γu(M,X) to be the underlying, undirected graph of Γ(M,X). We prove that if the language of geodesics in Γu(M,X) based at the identity is k-strictly local, then the monoid and semi-group word problems are context-free.

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Probabilistic Metric Dimension, Kyle Worley Jul 2026

Probabilistic Metric Dimension, Kyle Worley

Master's Theses

The metric dimension of a graph G is the smallest number of unique vertices (often called “marked vertices” or “landmarks”) such that each vertex has a unique distance to the marked vertices. If a set of vertices S ⊆ V (G) when marked gives all vertices unique distances, it is called a resolving set. Hence if G is a graph with a resolving set S, then for all v, u ∈ V (G) there exists s ∈ S such that d(v, s) ̸= d(u, s). The metric dimension dim(G) = min(|S|). Two widely studied variants exist, one where edges are …

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Rational Non-Euclidean Triangles And Elliptic Curves, Tyler Morales Jul 2026

Rational Non-Euclidean Triangles And Elliptic Curves, Tyler Morales

Master's Theses

We say a triangle △ is rational if its side lengths are rational. For a geometry of constant curvature κ, we say △ is a rational triangle if the generalized tangents of its side lengths are rational. We are able to parameterize rational triangles having the same inradius and semiperimeter on an plane curve, write a bijection between the rational points on this curve and triples of side lengths, and show that this curve is an elliptic curve. Then, we write a general transformation for our plane curve to short Weierstrass form to compute ranks and add points easily using …

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Hybrid Microbial-Enzymatic Electrosynthesis For De Novo Decanoic Acid Production From Co2, Yongze Wang, Wenjin Dong, Meijing Wei, Su Song, Zhiqing Huang, Yaojie Liu, Shelley D. Minteer, Hui Chen Jul 2026

Hybrid Microbial-Enzymatic Electrosynthesis For De Novo Decanoic Acid Production From Co2, Yongze Wang, Wenjin Dong, Meijing Wei, Su Song, Zhiqing Huang, Yaojie Liu, Shelley D. Minteer, Hui Chen

Chemistry Faculty Research & Creative Works

The steady increase in atmospheric CO2 levels is a key driver of anthropogenic climate change, prompting widespread global concern. In this context, the sustainable conversion of CO2 into value-added chemicals represents an attractive route toward carbon-neutral manufacturing and green chemistry. Here, we developed a proof-of-concept hybrid microbial-enzymatic electrosynthesis system that combines microbial electrosynthesis (MES) and enzymatic electrosynthesis (EES) to convert CO2 into decanoic acid under ambient conditions, using electrical energy. In the MES module, CO2 was converted to acetate via the Wood–Ljungdahl pathway of Clostridium ljungdahlii, using H2 produced by electrochemical water splitting as the electron …

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Fermat's Last Theorem Over Quadratic Number Fields, Richie Tay Jul 2026

Fermat's Last Theorem Over Quadratic Number Fields, Richie Tay

Master's Theses

Fermat’s Last Theorem states that the equation xn + yn = zn has no nontrivial integer solutions for n ≥ 3. While the rational case is completely solved, the situation over quadratic number fields is not as straightforward. For some exponents nontrivial solutions exist, while for others they do not. This thesis studies Fermat-type equations over quadratic number fields, combining classical methods with more modern techniques from the theory of elliptic curves. The thesis first reviews the rational cases n = 2, n = 3, n = 4, then develops the necessary background on quadratic number fields, including rings of …

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Math 141 Calculus I (Queens College), Anisha Clarke Jul 2026

Math 141 Calculus I (Queens College), Anisha Clarke

Open Educational Resources

This syllabus provides the outline for a calculus one course using OpenStax Calculus Volume I and no graphing calculator.

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Deep Neural Networks: A Formulation Via Non-Archimedean Analysis, Wilson A. Zuniga-Galindo Jul 2026

Deep Neural Networks: A Formulation Via Non-Archimedean Analysis, Wilson A. Zuniga-Galindo

School of Mathematical & Statistical Sciences Faculty Publications

We introduce a new class of deep neural networks (DNNs) with multilayered tree-like architectures. The architectures are codified by using numbers in the ring of integers of non-Archimedean local fields. These rings have a natural hierarchical organization as infinite rooted trees. Natural morphisms on these rings allow us to construct finite multilayered architectures. The new DNNs are robust universal approximators of real-valued functions defined on the mentioned rings. We also show that the DNNs are robust universal approximators of real-valued square-integrable functions defined in the unit interval.

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Inferring Host Environment Properties And Gravitational-Wave Decay Time From The Eccentricity Measurement Of Dynamically Captured Binaries, A. Vincent Paul, Parthapratim Mahapatra, Marc Favata, K. G. Arun Jul 2026

Inferring Host Environment Properties And Gravitational-Wave Decay Time From The Eccentricity Measurement Of Dynamically Captured Binaries, A. Vincent Paul, Parthapratim Mahapatra, Marc Favata, K. G. Arun

Department of Physics and Astronomy Faculty Scholarship and Creative Works

Dynamical capture in dense stellar environments is a promising channel for producing eccentric compact binary mergers. Although there have been no confident detections of eccentric mergers to date, a few candidates show indications of nonnegligible in-band eccentricity upon reanalysis of the data. By assuming an observed eccentric event originates from a dynamical gravitational-wave (GW) capture, we show that it is possible to identify the host environment using the eccentricity and mass posteriors. In particular, the eccentricity posterior can be mapped to posteriors on key capture parameters, such as the relative velocity at infinity and the impact parameter. By comparing these …

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Reskilling And Retraining The Water Technology Workforce: An Agentic Generative Ai Framework For Water Purification, Nano‑Mems, And Curriculum Development, Satyadhar Joshi, Noor Zulfiqar Jul 2026

Reskilling And Retraining The Water Technology Workforce: An Agentic Generative Ai Framework For Water Purification, Nano‑Mems, And Curriculum Development, Satyadhar Joshi, Noor Zulfiqar

Harrisburg University Other Works

The rapid digitalization of water infrastructure is bringing artificial intelligence, advanced sensing, and membrane materials science into routine water treatment practice. At the same time, utilities, regulators, and training institutions face a persistent workforce challenge: many operators, engineers, and managers are being asked to adopt data-driven tools without a coherent educational pathway that links AI literacy to real treatment workflows. This article synthesizes recent literature on agentic generative AI, reinforcement learning, smart sensing, nano-enabled membranes, and digital twins for water systems, then translates those developments into a structured reskilling model for the water sector. The proposed framework is organized around …

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Construct Overlap Inflates Apparent Economic-Capacity Alignment: Evidence From A Hebei City Panel, 2014–2023, Shuo Pang, Jianguang Hou, Danlin Yu Jul 2026

Construct Overlap Inflates Apparent Economic-Capacity Alignment: Evidence From A Hebei City Panel, 2014–2023, Shuo Pang, Jianguang Hou, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Index-based urban sustainability studies often ask whether urban resilience and economic development evolve harmoniously, but the answer is unreliable when the two constructs contain the same economic indicators. A targeted audit of recent Chinese coupling studies shows that economic variables are commonly embedded in urban-resilience systems without a reported construct-overlap weight check. Using Hebei, China, as a measurement-validity test rather than as another provincial economic-growth case, this study analyzes a balanced 2014–2023 panel of 11 prefecture-level cities. Duplicated economic concepts account for 44.4% of the baseline resilience-index entropy weight and 88.2% of the baseline economic-index weight, indicating substantial mechanical exposure …

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Oregon State Rank Assessment For Alpine Smelowskia (Smelowskia Ovalis), Lindsey K. Wise Jul 2026

Oregon State Rank Assessment For Alpine Smelowskia (Smelowskia Ovalis), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Alpine smelowskia (Smelowskia ovalis) using NatureServe methodology, 2026.

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Developing And Testing Visualization Simulations For The Gamma-Ray Energy Tracking Array (Greta), Blake Mcnulty Jul 2026

Developing And Testing Visualization Simulations For The Gamma-Ray Energy Tracking Array (Greta), Blake Mcnulty

Physics and Astronomy Summer Fellows

GRETA is a recently-completed Department of Energy-funded project to construct an array of 120 gamma-ray detectors for use in nuclear physics experiments. The Gretina Array was the successful pilot project to construct 48 of the eventual 120 detectors that would be used in the array. UCGretina is a program that is used to simulate the GRETA array for the purposes of planning experiments and analyzing measurements. My job for this summer, with the advent of the full GRETA system, was to implement the new modular mounting structure for the full GRETA array in the simulation code. This involves creating the …

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History, Current Status, And Implications Of The Exploration And Exploitation Of Coal Resources In Guangxi, China, Wang Hui, Han Xiaozhong, Peng Zhilong, Li Huoying, Qin Baojian, Lu Ankang, Qin Xiaoyan, Peng Feifei, Xu Huiheng, Lan Bingui Jul 2026

History, Current Status, And Implications Of The Exploration And Exploitation Of Coal Resources In Guangxi, China, Wang Hui, Han Xiaozhong, Peng Zhilong, Li Huoying, Qin Baojian, Lu Ankang, Qin Xiaoyan, Peng Feifei, Xu Huiheng, Lan Bingui

Coal Geology & Exploration

Objective Based on a comprehensive review of the history and current status of coal exploration and exploitation, this study presents an analysis of both the endowment characteristics and the exploration and research levels of coal resources in Guangxi Zhuang Autonomous Region. From the perspective of coal self-sufficiency capacity and energy security guarantee, this study proposes several recommendations for the exploration and exploitation of coal resources in the region. Methods The exploration level, current status of exploitation, and supply-demand imbalance of coal resources in Guangxi are determined through a systematic literature review, surveys of coal mine enterprises, and exchanges with relevant …

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Research And Practice Of Four-Dimensional In-Situ Stress Fields For Deep Coalbed Methane Production: A Case Study Of The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Chen Yiyu, Gao Deli, Zhao Haifeng, Chen Gaojie Jul 2026

Research And Practice Of Four-Dimensional In-Situ Stress Fields For Deep Coalbed Methane Production: A Case Study Of The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Chen Yiyu, Gao Deli, Zhao Haifeng, Chen Gaojie

Coal Geology & Exploration

Background Deep coalbed methane (CBM) reservoirs are characterized by well-developed microstructures and natural fractures, along with highly heterogeneous rock mechanical properties and in-situ stress field distribution. The CBM production of the reservoirs tends to cause constantly evolving formation pressure and in-situ stress within the control ranges of CBM wells, further enhancing the complexity of stress distribution. Additionally, severe fracturing channeling can be observed between new and old wells. This phenomenon is primarily triggered by in-situ stress variations induced by large-scale fracturing and CBM production. Therefore, accurately assessing the dynamic evolutionary patterns of in-situ stresses in reservoirs after fracturing and during …

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Enrichment Mechanisms Of U And Th Elements In The Bauxite Rock Series Of The Benxi Formation, Lower Carboniferous, Central North China Block, Bian Yukang, Zhang Xiaoyang, Chen Jinfeng, Lyu Dawei, Zhu Dongya, Liu Quanyou, Meng Qingqiang, Shen Xiaoli, Li Qing, Kong Weijiang, Dou Yunfei Jul 2026

Enrichment Mechanisms Of U And Th Elements In The Bauxite Rock Series Of The Benxi Formation, Lower Carboniferous, Central North China Block, Bian Yukang, Zhang Xiaoyang, Chen Jinfeng, Lyu Dawei, Zhu Dongya, Liu Quanyou, Meng Qingqiang, Shen Xiaoli, Li Qing, Kong Weijiang, Dou Yunfei

Coal Geology & Exploration

Objective Uranium (U) and thorium (Th) in rocks and minerals are the material basis for the generation and release of crust-derived helium. Methods The enrichment characteristics and mechanisms of U and Th are key to understanding the accumulation of crust-derived helium reservoirs. Taking the bauxite series of the Benxi Formation in the central North China Block as the research object, this study reveals the enrichment mechanisms of U and Th in the bauxite series and calculates the helium generation rate by means of petrogeochemical and chronological research methods, combined with detrital zircon dating, sedimentary environment identification, and mass balance calculation. …

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Sand Tank Experiments On The Seepage And Water Pressure Distribution During Single-Well Dewatering At The Bottom Of A Confined Aquifer, Wang Wenxue, Zhang Mengying, Li Yang, Fang Yuan, Zhao Shuli, Shen Mengjun Jul 2026

Sand Tank Experiments On The Seepage And Water Pressure Distribution During Single-Well Dewatering At The Bottom Of A Confined Aquifer, Wang Wenxue, Zhang Mengying, Li Yang, Fang Yuan, Zhao Shuli, Shen Mengjun

Coal Geology & Exploration

Background Depressurization through dewatering using inclined wells arranged at the aquifer bottom represents a crucial technical approach to the prevention and control of water-sand inrush disasters during coal mining beneath aquifers. However, the mechanisms underlying seepage-pressure interactions and water-preserved depressurization remain poorly understood. Methods Based on the water-yield properties of confined aquifers and the distribution characteristics of inclined wells for dewatering, this study developed a fan-shaped sand tank experimental system for simulating dewatering and seepage from confined aquifers. Using the experimental system, this study carried out seepage experiments using a partially penetrating well at the bottom of a confined aquifer …

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Load Sharing Patterns And Their Key Influencing Factors For The Composite Structure Of A Lined Hard Rock Cavern For Compressed Air Energy Storage, Hu Lihua, Zhou Qiming, Zhang Kai, Yu Liyuan, Liang Xin, Sun Qiang, Wu Yun, Hu Chengguo, Li Wei Jul 2026

Load Sharing Patterns And Their Key Influencing Factors For The Composite Structure Of A Lined Hard Rock Cavern For Compressed Air Energy Storage, Hu Lihua, Zhou Qiming, Zhang Kai, Yu Liyuan, Liang Xin, Sun Qiang, Wu Yun, Hu Chengguo, Li Wei

Coal Geology & Exploration

Objective Compressed air energy storage (CAES) in a lined hard rock cavern holds great prospects. However, the load sharing mechanisms of the cavern’s composite structure, comprising a sealing layer, lining, and surrounding rocks, remain poorly understood.Methods Based on the elastic analytical solutions of stress fields, this first study derived the radial load equilibrium equations for the composite structure of a lined hard rock cavern for CAES. Accordingly, a novel method for calculating the load sharing ratios of the composite structure was developed. Then, an analysis scheme for the load sharing ratios was designed. Using this scheme, this study investigated …

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Cnn-Based Assessment Of The Degrees Of Fracture Development In Bedrocks And Classification Of Bedrock Weathering Zones, Lei Jian, Lu Haifeng, Fan Yufei Jul 2026

Cnn-Based Assessment Of The Degrees Of Fracture Development In Bedrocks And Classification Of Bedrock Weathering Zones, Lei Jian, Lu Haifeng, Fan Yufei

Coal Geology & Exploration

Background Bedrock weathering zones exhibit distinct vertical gradational characteristics. Accurately identifying the degrees of fracture development in the zones is critical to the safe production of mines in shallowly buried coal seams covered by thick water-bearing unconsolidated layers. Methods Focusing on the Qinan coal mine in Anhui Province, this study proposed a hybrid convolutional neural network (CNN) model, which enabled feature extraction using a synergistic architecture consisting of conventional convolutional layers and inception modules. Specifically, based on conventional log data and calculated shale content and fracture development index, combined with core observations, this study constructed a dataset containing labels that …

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Three-Dimensional, Collaborative Detection Approach For Fire Zones In Shallowly Buried Coal Seams And Its Application, Fan Kaixiang, Hu Xiangming, Hong Haibo, Dong Hao, Yu Shijian, Wei Zhengrong, Guo Yongxiang Jul 2026

Three-Dimensional, Collaborative Detection Approach For Fire Zones In Shallowly Buried Coal Seams And Its Application, Fan Kaixiang, Hu Xiangming, Hong Haibo, Dong Hao, Yu Shijian, Wei Zhengrong, Guo Yongxiang

Coal Geology & Exploration

Objective Fire zones in shallowly buried coal seams have long restricted safe and efficient coal mining due to their considerably hidden and hazardous nature. However, individual methods for fire source detection are susceptible to geological conditions and ambient noise, suffering from limited detection dimensions and the presence of technical blind spots. Therefore, they fail to accurately localize hidden fire sources in shallow coal seams. Methods This study proposes a three-dimensional, collaborative multi-source detection approach that combines the self-potential (SP) method, the radon measurement (Rn) method, electrical resistivity tomography (ERT; also referred to as high-density resistivity method), and the transient electromagnetic …

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A Machine Learning Approach For Water Quality Assessment In The Lower Rio Grande Valley Watershed, Saika Nowshin Nowrin, Chu-Lin Cheng, Jungseok Ho, Jinwoo An, Fatemeh Nazari Jul 2026

A Machine Learning Approach For Water Quality Assessment In The Lower Rio Grande Valley Watershed, Saika Nowshin Nowrin, Chu-Lin Cheng, Jungseok Ho, Jinwoo An, Fatemeh Nazari

Civil Engineering Faculty Publications

Water quality analysis plays an essential role in maintaining the health and sustainability of river ecosystems, especially in semi-arid regions like the Arroyo Colorado Watershed in South Texas. Since the river is a vital source of water supply for local communities, agriculture, and wildlife, it faces significant challenges and pollution from land use changes, climate variation, and agricultural runoff. Continuous monitoring and assessment of water quality parameters and their temporal variability are essential to ensure the drinking water supply and aquatic ecosystem health. However, comprehensive laboratory-based water quality investigations are often constrained by higher costs, logistical complexity, and limited manpower. …

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Evaluation Of Deep High-Quality Reservoirs Based On The Fuzzy Analytic Hierarchy Process And The Entropy Weight Method: A Case Study Of The No. 8 Coal Seam In The East-Central Ordos Basin, Yan Ronghui, Xu Hao, Hu Jianling, Li Xiaotian, Jiao Pengshuai, Huang Daojun, Chen Shida, Wu Xiaozhuo Jul 2026

Evaluation Of Deep High-Quality Reservoirs Based On The Fuzzy Analytic Hierarchy Process And The Entropy Weight Method: A Case Study Of The No. 8 Coal Seam In The East-Central Ordos Basin, Yan Ronghui, Xu Hao, Hu Jianling, Li Xiaotian, Jiao Pengshuai, Huang Daojun, Chen Shida, Wu Xiaozhuo

Coal Geology & Exploration

Objective Significant breakthroughs have been achieved in the exploration and exploitation of coalbed methane (CBM) in the deep No. 8 coal seam within the east-central Ordos Basin. However, a comprehensive quantitative evaluation system at the regional scale is yet to be established for reservoirs in the No. 8 coal seam. Methods Based on logs, coal quality, and measured physical property data from over 270 wells in the east-central Ordos Basin, this study developed a comprehensive evaluation system for deep coal reservoirs using the fuzzy analytic hierarchy process combined with the entropy weight method. Specifically, the evaluation system consisted of nine …

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Co2 Fracturing Stimulation Technology For Low-Yield Directional Coalbed Methane Wells And Its Applications, Zhang Junsheng, Cao Yunxing, Wang Li, Wang Zhongbin, Yang Baige, Shi Bin, Cao Yongsen, Xu Fengyi Jul 2026

Co2 Fracturing Stimulation Technology For Low-Yield Directional Coalbed Methane Wells And Its Applications, Zhang Junsheng, Cao Yunxing, Wang Li, Wang Zhongbin, Yang Baige, Shi Bin, Cao Yongsen, Xu Fengyi

Coal Geology & Exploration

Background In China, low-yield coalbed methane (CBM) wells represent a high proportion of approximately 57% (over 12400 wells), generally encountering challenges such as low pressure, dry reservoirs, and near-wellbore formation damage and blockage. Conventional hydraulic fracturing is prone to induce water blocking damage, while treatments such as acidification offer only limited blockage-removing radii. Therefore, existing techniques are insufficient to achieve blockage removal and permeability enhancement while avoiding reservoir damage. Exploring efficient waterless stimulation technologies suitable for these low-yield wells is of great significance for increasing CBM production and advancing the CBM industry. Methods This study investigated directional wells PXC-03 and …

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Water Hazards In Thick Floor Aquicludes For Coal Mining Above Confined Aquifers In North China-Type Coalfields: Patterns, Mechanisms, And Prevention And Control, Meng Haopeng, Yin Shangxian, Lian Huiqing, Yin Huichao, Hou Enke, Zhang Yi’An, Wang Zhuo, Jin Zidong, Cai Xiangjun, Cao Min, Wang Jianguang Jul 2026

Water Hazards In Thick Floor Aquicludes For Coal Mining Above Confined Aquifers In North China-Type Coalfields: Patterns, Mechanisms, And Prevention And Control, Meng Haopeng, Yin Shangxian, Lian Huiqing, Yin Huichao, Hou Enke, Zhang Yi’An, Wang Zhuo, Jin Zidong, Cai Xiangjun, Cao Min, Wang Jianguang

Coal Geology & Exploration

Background Water hazards in coal seam floors represent a core challenge restricting the exploitation of deep coal resources in North China-type coalfields. As coal mining extends to greater depths, previous studies and experience exhibit limited applicability in the pattern classification, mechanism interpretation, and prevention and control of water hazards in thick floor aquicludes. Therefore, there is an urgent need to make breakthroughs and improvements in these three aspects.Methods Using several methods, including case-based induction, theoretical analysis, numerical simulation, and technical summary, this study developed a classification system based on parallel multiple criteria for floor water hazards by combining available …

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