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Full-Text Articles in Engineering

Decision Making For Large-Scale Problems Under Uncertainty And Conflict, Benjamin J. Hamlin May 2026

Decision Making For Large-Scale Problems Under Uncertainty And Conflict, Benjamin J. Hamlin

All Dissertations

Large-scale decision-making problems appear in many areas including long-range forecasting such as energy generation forecasting. Many such problems are subject to conflicting objectives and uncertain data, and can be modeled as linear optimization problems. We study novel theoretical results and algorithms for large-scale linear decision problems under conflict and uncertainty. First, we propose a parametric Benders decomposition algorithm for solving large-scale linear optimization problems with multiple objectives or deterministically uncertain objectives. Second, we extend the parametric Benders decomposition to a multi-stage setting, developing a parametric stochastic dual dynamic programming algorithm, which enables decision-making when conflicts and uncertainty have planning impacts …


Ai Institute Summer Camp Webinar Summary, Dora Nguyen May 2026

Ai Institute Summer Camp Webinar Summary, Dora Nguyen

Paul English Applied Artificial Intelligence (AI) Institute Publications

This report summarizes the AI Institute Summer Camp informational webinar hosted by the Paul English Applied Artificial Intelligence Institute (PEAAII) at the University of Massachusetts Boston. The webinar introduced the structure, curriculum, learning objectives, and student outcomes associated with the 2026 AI Institute Summer Camp. In addition to summarizing the webinar content, this report analyzes participant questions, engagement trends, and areas of audience interest. Findings indicate strong interest in coding accessibility, mentorship opportunities, student outcomes, research experiences, and program flexibility. The report also identifies opportunities for improving future webinar delivery, including expanded eligibility guidance, pre-camp learning resources, enhanced presentation of …


Detecting Sophisticated Cyberattacks On Public Water Infrastructure, Ayrton Purdy May 2026

Detecting Sophisticated Cyberattacks On Public Water Infrastructure, Ayrton Purdy

Graduate Theses and Dissertations (2019 - present)

In recent years there has been an increasing number of cyberattacks on public water generation and distribution systems. Advanced persistent attackers could usurp sensors and control systems to contaminate public drinking water. In order to conceal their malicious activity, they can manipulate sensor data flows to give the appearance of normal activity. The compromised sensors would report normal chemical levels even though unsafe water is entering the distribution system. In response, this research proposes a multi-sensor, cross-comparison approach to anomaly detection. The proposed approach is designed to detect sophisticated cyberattacks which are not easily detectable using traditional cyber tools. The …


Developing A Framework For Microchip Design Recovery, Eric Diep May 2026

Developing A Framework For Microchip Design Recovery, Eric Diep

Graduate Theses and Dissertations (2019 - present)

Due to the increase in diverse chip production over the past decade, reverse engineering has become a difficult and daunting task. This research develops a methodology for microchip design recovery, seeking to validate and reproduce prior approaches to physical reverse engineering using low-cost tools and techniques. We used mechanical hardware abrasion tools and techniques to delayer and capture silicon integrated chip (IC) layout. We focused on the Mifare Classic EVl microchip, commonly implemented in public transit/transportation cards, to extract information for design recovery. The research explores limitations and advantages of mechanical abrasion and optical microscopy in context to modem chip …


Post-Vote Tampering In Nigerian Elections And The Role Of Blockchain-Enabled Electoral Systems, Ransome Chukwubuikem Enechukwu May 2026

Post-Vote Tampering In Nigerian Elections And The Role Of Blockchain-Enabled Electoral Systems, Ransome Chukwubuikem Enechukwu

Electronic Theses and Dissertations

Post-vote tampering during the collation and transmission of election results remains a persistent challenge in Nigerian elections, enabling manipulation of already-cast votes and weakening public trust in electoral outcomes. Existing technological interventions, including biometric voter accreditation and digital result transmission systems, improve voter authentication but do not adequately secure the post-vote result collation process. This thesis proposes a blockchain-enabled framework designed to protect the integrity of election results during the collation and transmission stages. Using a Design Science Research methodology, the study develops a permissioned blockchain framework based on Hyperledger Fabric that records polling-unit results as immutable ledger entries and …


Adaptive Artificial Potential Field Guidance And Control For Autonomous Docking With Uncooperative And Unknown Spacecraft, Steven Holmberg May 2026

Adaptive Artificial Potential Field Guidance And Control For Autonomous Docking With Uncooperative And Unknown Spacecraft, Steven Holmberg

Theses and Dissertations

The increasing demand for on-orbit servicing (OOS), active debris removal (ADR), and space domain awareness (SDA) missions has increased the need for autonomous spacecraft rendezvous and proximity operations (RPO) with uncooperative and unknown targets. Traditional guidance and control methods are typically designed for cooperative systems with known geometry and state information. This work builds on previous research to develop and evaluate an artificial potential field (APF)-based control framework capable of autonomous operation with minimal prior target knowledge and applicability to both relatively static and tumbling spacecraft.

The proposed APF formulation incorporates established safety constructs from cooperative docking systems, including an …


Moodify: A Mood-Based Music Recommendation System, Meghana Kagitha May 2026

Moodify: A Mood-Based Music Recommendation System, Meghana Kagitha

Theses and Dissertations

Music has long been recognised as a powerful tool for emotional regulation, yet existing music streaming platforms often fail to align song recommendations with a user's current emotional state. Moodify is a mood-based music recommendation system designed to bridge this gap by delivering personalised playlists that reflect how a user feels in real time.

This project presents the design, development, and evaluation of Moodify, a mobile application that leverages the Circumplex Model of Emotion to capture user mood through an intuitive two-dimensional valence-arousal interface. Rather than relying on text input or manual search, users plot their emotional state directly onto …


A Webcam Eye Tracking Infrastructure For Software Engineering Tasks, Zachary M. Kozak May 2026

A Webcam Eye Tracking Infrastructure For Software Engineering Tasks, Zachary M. Kozak

School of Computing: Dissertations, Theses, and Student Research

Performing eye tracking utilizing commodity webcams has been explored for over a decade, but limited camera quality and sensitivity to head movements have hindered its adoption in research settings. Recent advances in consumer-grade webcams and machine learning methods present an opportunity to improve the accuracy of webcam eye tracking and extend the feasibility of studies beyond controlled laboratory environments.

Current popular webcam eye tracking methods restrict implementations to the browser and rely on continuous user interactions for calibration, limiting the kinds of studies that can be conducted. This thesis presents a feature-based gaze prediction system that incorporates eye geometry and …


Leveraging Code Embeddings To Identify And Address Blind Spots In Benchmark Creation, Charles Moloney May 2026

Leveraging Code Embeddings To Identify And Address Blind Spots In Benchmark Creation, Charles Moloney

School of Computing: Dissertations, Theses, and Student Research

Formal software verification remains critical for early vulnerability detection, yet benchmarking these tools is costly and often reliant on centralized datasets such as SV-COMP. While such repositories enable standardized evaluation, they introduce risks of overfitting and bias, particularly due to first-party benchmark contributions. To address these limitations, we extend ARG-V, our tool for generating SV-COMP-compatible benchmarks from real-world Java code, with a novel approach of using code embedding techniques to selectively sample from mined code. By leveraging Nomic Embed Code and a cosine-based Minimum Hyperspherical Energy (MHE) objective, we systematically select and transform benchmarks from scraped GitHub code that …


Manned Exploration Of Satellites Of The Outer Planets: An Analysis Of Current Technologies And A Discussion Of Advancements Required, Joshua Carson Meador May 2026

Manned Exploration Of Satellites Of The Outer Planets: An Analysis Of Current Technologies And A Discussion Of Advancements Required, Joshua Carson Meador

Theses and Dissertations

The Solar System’s outer planets have many satellites, some of which are known to be the most likely places to find extraterrestrial life in our celestial backyard. Multiple scientific missions have been sent to glean information from these satellites, yet the possibility of a manned expedition has long been exclusive to science fiction stories. This paper intends to collect and analyze the current state of space travel technology to explore the feasibility of such a mission with modern technology and to discuss which future advancements should be the focal point for making such missions a reality. To begin, data on …


Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante May 2026

Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante

Theses and Dissertations

This thesis presents the design and simulation of an 8-tube single-ring anti-resonant hollow-core fiber for sensing applications, with particular emphasis on methane gas detection at the fundamental absorption wavelength of 3.3 µm. Conventional solid-core silica optical fibers exhibit strong multi-phonon material absorption beyond 2.5 µm, rendering them fundamentally unsuitable for efficient light guidance and direct gas sensing at mid-infrared wavelengths. Anti-resonant hollow-core fibers overcome this limitation by guiding light predominantly through an air-filled hollow core via the anti-resonant reflecting optical waveguide mechanism, in which the thin silica glass walls of the cladding tubes act as Fabry-Pérot etalons that confine the …


Conditioning Hierarchical Diffusion Transformers On Rf Circuit Parameters, Ethan Morton May 2026

Conditioning Hierarchical Diffusion Transformers On Rf Circuit Parameters, Ethan Morton

McKelvey School of Engineering Graduate Student Theses & Dissertations

As modern ML techniques have become increasingly advanced, they have begun to be integrated into wireless RF systems for classification, identification, and spectrum management. Deep Neural Networks (DNNs) enable RF system operators and designers to design more flexible systems with greater robustness to errors and attacks. However, neural networks require significant amounts of properly annotated data to train. Current data labeling methods lack the ability to obtain reliable true labels for circuit properties such as carrier frequency offset (CFO), power amplifier (PA) non-linearity, and in-phase/quadrature (IQ) imbalance. This thesis investigates the efficacy of a novel architecture, RF-Diffusion, for generating high-quality …


Consistency-Based Computing Of Fuzzy Eigenvalues And Fuzzy Eigenvectors: Method And Application, Kamala. R. Aliyeva Prof., Nihad Mehdiyev, Shamil Mehdi Apr 2026

Consistency-Based Computing Of Fuzzy Eigenvalues And Fuzzy Eigenvectors: Method And Application, Kamala. R. Aliyeva Prof., Nihad Mehdiyev, Shamil Mehdi

Chemical Technology, Control and Management

The computation of eigenvalues and eigenvectors under uncertainty is a fundamental problem in fuzzy linear algebra and decision analysis. When matrix elements are represented by fuzzy numbers, classical spectral methods cannot be directly applied due to nonlinearity, ambiguity in ordering, and the propagation of uncertainty. Moreover, in many practical applications, particularly those involving pairwise comparison matrices, the reliability of eigenvalue-based results strongly depends on the consistency of the underlying data. This paper proposes a consistency-based framework for computing fuzzy eigenvalues and fuzzy eigenvectors that explicitly integrates consistency analysis into the spectral derivation process. The proposed method preserves the fuzzy structure …


Uncertainty Handling In Stock Market Prediction: A Fuzzy Markov Chain Approach, Alpa Singh Rajput, Arpan Singh Rajput Apr 2026

Uncertainty Handling In Stock Market Prediction: A Fuzzy Markov Chain Approach, Alpa Singh Rajput, Arpan Singh Rajput

Neutrosophic Systems with Applications

Predicting the stock market is never easy because it is influenced by many uncertain and constantly changing factors such as economic conditions, investor behaviour, and global events. Traditional models like the Crisp Markov Chain (CMC) try to predict market movements by using fixed probabilities for different states like bullish, bearish, or stagnant. However, real markets do not behave in such a strict way—they often move gradually between states, which these models fail to capture. To overcome this limitation, this study introduces a Fuzzy Markov Chain (FMC) model, where fuzzy logic is used to handle uncertainty and allow smoother transitions between …


Modeling Agentic Artificial Intelligence Uncertainty In Agriculture Based 6generation: A Hybrid Q-Rung Orthopair Fuzzy Mcdm Methodology, Zekra Sakr, Mona Mohamed Apr 2026

Modeling Agentic Artificial Intelligence Uncertainty In Agriculture Based 6generation: A Hybrid Q-Rung Orthopair Fuzzy Mcdm Methodology, Zekra Sakr, Mona Mohamed

Neutrosophic Systems with Applications

In era of advanced intelligent revolutions, the collaboration between intelligent technologies became imperative. For instance, integrating 6G communications with agentic artificial intelligence considered a catalyst to shift agriculture sector into optimized and intelligence sector. This integration resulted in transitioning the sector from static automation to autonomous, agent-based ecosystems. Accordingly, the efficiency roles for artificial intelligence agents (AIAs), deploying and selecting optimal AIA is important. Yet, selection process is still difficult because agricultural criteria are multifaceted and there are inherent environmental uncertainties. To address these challenges and bolster the selection process, this paper suggests a hybrid multi-criteria decision-making (MCDM) that bolstered …


An Improved Logarithmic Ratio-Product Type Estimator For Mean Modeling And Estimation Under Neutrosophic Uncertainty, Anchal Yadav, Mukesh Kumar Apr 2026

An Improved Logarithmic Ratio-Product Type Estimator For Mean Modeling And Estimation Under Neutrosophic Uncertainty, Anchal Yadav, Mukesh Kumar

Neutrosophic Systems with Applications

In classical statistics, population mean estimation generally assumes precise and determinate data along with known auxiliary information. However, in real-world situations where observations are imprecise or expressed in interval form, such as temperature variations or financial market data, classical approaches become less effective. To address this limitation, neutrosophic statistics provide a more flexible framework for handling uncertainty and indeterminacy. This study proposes a neutrosophic logarithmic ratio-product type estimator for estimating the finite population mean using auxiliary information. The bias and mean squared error (MSE) of the proposed estimator are derived using a first-order approximation. Furthermore, performance evaluation is carried out …


Enhanced Parametric Approach For Solving Interval-Valued Trapezoidal Neutrosophic Linear Fractional Programming Problems, Hamiden Abd El- Wahed Khalifa H.A.Khalifa, Moodi Abdulrahman Abdullah Al-Rajeh, Sultan S. Alodhaibi Apr 2026

Enhanced Parametric Approach For Solving Interval-Valued Trapezoidal Neutrosophic Linear Fractional Programming Problems, Hamiden Abd El- Wahed Khalifa H.A.Khalifa, Moodi Abdulrahman Abdullah Al-Rajeh, Sultan S. Alodhaibi

Neutrosophic Systems with Applications

Neutrosophic sets (NSs) generalize the classical versions, by providing a flexible framework capable of representing incomplete, inconsistent, and unclassified data that frequently arises in practical decision frameworks. In this study, a linear fractional programming (LFP) problem with uncertain parameters is investigated. All coefficients in the objective function (OF) as well as the left- and right-hand sides of the constraints are represented using fully trapezoidal neutrosophic numbers (NNs). By employing a suitable score function, the proposed neutrosophic LFP model is transformed into an equivalent scalar LFP problem. Subsequently, a parametric solution procedure is established to regulate the neutrosophic optimum solution. This …


Gauss Elimination Method For Solving The System Of Neutrosophic Linear Equations, Elsayed Badr, Shokry Nada, Saeed Ali, Aya Rabie Apr 2026

Gauss Elimination Method For Solving The System Of Neutrosophic Linear Equations, Elsayed Badr, Shokry Nada, Saeed Ali, Aya Rabie

Neutrosophic Systems with Applications

This paper proposes a unified computational framework for solving linear systems under trapezoidal Neutrosophic uncertainty. The system is formulated as A( I )x = b( I ), where both the coefficient matrix and the right-hand side vector incorporate an indeterminacy parameter I, expressed as A( I ) = A0 + IA1 and b( I ) = b0 + Ib1. A decomposition strategy is developed to separate the model into deterministic and indeterminacy components, yielding a solution of the form x( I ) = x0 + Ix1. The deterministic component is obtained via …


Molecular Catalysts For Electrochemical Nitrogen Activation Toward Sustainable Ammonia Synthesis, Jin-Xiu Han, Hao Xue, Xian-Biao Fu Apr 2026

Molecular Catalysts For Electrochemical Nitrogen Activation Toward Sustainable Ammonia Synthesis, Jin-Xiu Han, Hao Xue, Xian-Biao Fu

Journal of Electrochemistry

Homogeneous electrocatalytic nitrogen reduction reaction (NRR) provides a powerful framework to interrogate molecular nitrogen-fixation pathways under mild conditions. By tuning the metal center, ligand architecture, and reaction medium, these systems enable capturing key intermediates and delivering mechanistic insight at the molecular-level resolution. Nevertheless, advances remain constrained by highly reduced operating potentials, intense competition from the hydrogen evolution reaction (HER), limited durability in turnover, and inadequate long-term stability.

In this review, we take electron delivery to the molecular active site as the guiding principle for organizing homogeneous electrochemical N2 activation and transformation. We classify reported systems into direct electron transfer …


Water-Driven Solid Electrolyte Interphase Governs Continuous-Flow Ammonia Electrosynthesis, Peng-Bo Liu, Sheng-Liang Zhai, Ji Huang, Zhong-Shuo Zhang, Jie Zeng, Shao-Feng Li Apr 2026

Water-Driven Solid Electrolyte Interphase Governs Continuous-Flow Ammonia Electrosynthesis, Peng-Bo Liu, Sheng-Liang Zhai, Ji Huang, Zhong-Shuo Zhang, Jie Zeng, Shao-Feng Li

Journal of Electrochemistry

Flow-cell architectures have emerged as a powerful platform for continuous and stable lithium-mediated nitrogen reduction (Li-NRR), enabling ambient-condition electrochemical ammonia synthesis and offering a promising alternative to Haber-Bosch processes. However, Li-NRR is exceptionally sensitive to trace water, and even minor variations in water content can profoundly alter interfacial chemistry. Here, we systematically investigate how initial water concentration affects Li-NRR performance in a continuous-flow cell. Excess water drives the formation of a thick solid electrolyte interphase (SEI) layer, which may impede nitrogen access to metallic lithium and hinder lithium-ion transport. As a result, the ammonia Faradaic efficiency collapses from ~61% to …


Insertion Of Noble Metal Free Cathodic Catalyst Layer With Fe-N-C Catalyst For Boosted Performance Of Pemfc, Shi Zhou, Muhammad Tariq, Asif Nadeem Tabish, Muhammad Salman, Fan-Di Ning, Muhammad Rayyan Tayyab, Ran-Ran Peng, Meng-Geng Hao, Wen-Mu Li, Xiao-Chun Zhou Apr 2026

Insertion Of Noble Metal Free Cathodic Catalyst Layer With Fe-N-C Catalyst For Boosted Performance Of Pemfc, Shi Zhou, Muhammad Tariq, Asif Nadeem Tabish, Muhammad Salman, Fan-Di Ning, Muhammad Rayyan Tayyab, Ran-Ran Peng, Meng-Geng Hao, Wen-Mu Li, Xiao-Chun Zhou

Journal of Electrochemistry

Economical Fe-N-C catalysts are considered as promising alternatives to platinum group metal catalysts for proton exchange membrane fuel cells (PEMFCs). Despite exhibiting robust activity on rotating disk electrodes, their performance within membrane electrode assemblies often experiences limitations, such as decreased O2 diffusion, high H2O2 formation, low proton conduction, and a lower electron transfer number. In this study, key factors, including proton transport, electron conduction, and gas diffusion within air-breathing PEMFCs, have been investigated by adjusting cathode catalyst layer (CCL) compositions. From the experimental results, the optimal peak power density was obtained when the loading of Fe-N-C …


A Comparative Study Of Tin Electrorefining In Molten Licl–Kcl–Cacl₂: Experimental Two-Electrode Current Control And Theoretical Three-Electrode Potential Control, Bryant Johnson, George Ankrah, Ander Fuller, Devin Rappleye Apr 2026

A Comparative Study Of Tin Electrorefining In Molten Licl–Kcl–Cacl₂: Experimental Two-Electrode Current Control And Theoretical Three-Electrode Potential Control, Bryant Johnson, George Ankrah, Ander Fuller, Devin Rappleye

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

Molten salt electrorefining is a mature technology for metal recovery, yet conventional current‑controlled, two‑electrode operation provides limited electrochemical selectivity and restricted insight into electrode‑specific behavior. In this work, a simplified model is developed to compare current‑controlled two‑electrode electrorefining data with a potential‑controlled three‑electrode electrorefining simulation using tin in molten LiCl–KCl–CaCl₂ as a surrogate for plutonium processing. The model examines anodic and cathodic limitations under fixed‑potential operation and evaluates implications for selectivity, efficiency, and runtime relative to experimentally demonstrated two‑electrode performance. Results indicate that independent potential control enables operation closer to thermodynamic selectivity limits, with the potential to suppress impurity oxidation …


Open Multi-Agent Systems: The Free-Range-Zoo Framework And Moasei Competition, Ceferino J. Patino Iv Apr 2026

Open Multi-Agent Systems: The Free-Range-Zoo Framework And Moasei Competition, Ceferino J. Patino Iv

School of Computing: Dissertations, Theses, and Student Research

The field of multi-agent reinforcement learning (MARL) has made significant strides in addressing sequential decision-making problems under uncertainty. However, traditional MARL frameworks assume closed-world settings with fixed agent sets, static task distributions, and unchanging environment dynamics. This thesis presents two complementary contributions that advance the state of open-world multi-agent systems research: (1) the free-range-zoo framework, an open-source environment suite for MARL in open environments featuring dynamic agent populations, evolving task sets, and changing operational frames; and (2) the MOASEI Competition, an international benchmarking event that leverages free-range-zoo to evaluate how artificial agents handle openness in complex, partially observable domains. The …


2026 - The Thirtieth Annual Symposium Of Student Scholars Apr 2026

2026 - The Thirtieth Annual Symposium Of Student Scholars

Symposium of Student Scholars Program Books

The full program book from the 30th Annual Symposium of Student Scholars, held on April 22-24, 2026. Includes abstracts from the presentations and posters.


Strategic Layout And Optimization Paths Of The Standard System For The Exploration And Exploitation Of Deep Coalbed Methane, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Ye Jincheng, Zhang Jiaqi, Wang Tianyun Apr 2026

Strategic Layout And Optimization Paths Of The Standard System For The Exploration And Exploitation Of Deep Coalbed Methane, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Ye Jincheng, Zhang Jiaqi, Wang Tianyun

Coal Geology & Exploration

Objective In China, the deep coalbed methane (CBM) industry has emerged as a key sector for the reserve growth and production addition of natural gas. However, the current CBM technical standard system, which was developed based on shallow CBM practices, is incompatible with the demands for the exploration and development of deep CBM. To address this challenge, this study proposes the optimization paths of the current standard system, aiming to provide standardization support for large-scale exploitation of deep CBM.Methods Deep CBM reservoirs exhibit complex geological conditions of high temperature, pressure, and in-situ stress, as well as the CBM occurrence …


Parameter Optimization And Field Application Of Roof Volume Fracturing Using Horizontal Wells For Coalbed Methane Extraction From Broken-Soft Coal Seams, Zhang Qingli, Sun Siqing, Li Haozhe, Wu Xiaoxuan, Yang Fan, Zheng Yuqi, Li Wenbo Apr 2026

Parameter Optimization And Field Application Of Roof Volume Fracturing Using Horizontal Wells For Coalbed Methane Extraction From Broken-Soft Coal Seams, Zhang Qingli, Sun Siqing, Li Haozhe, Wu Xiaoxuan, Yang Fan, Zheng Yuqi, Li Wenbo

Coal Geology & Exploration

Objective and Method To achieve rapid coalbed methane (CBM) extraction from broken-soft coal seams using surface horizontal wells, this study proposed a volume fracturing technology for coal seam roof using horizontal wells. Focusing coal seam 4-1 in a mining area, this study established a numerical model using finite element analysis (FEA) software Abaqus Using this model, the impacts of in-situ stress on the cross-layer propagation characteristics of multiple fractures were investigated. Through true triaxial hydraulic fracturing experiments, the multi-fracture propagation patterns under varying injection rates of fracturing fluids, perforation cluster numbers, and cluster spacings were analyzed. Using 3D fracturing design …


Structural Design And Parameter Optimization Of A Vibration Absorber For Rescue Casing-While-Drilling Rigs, Liu Pu, Yao Ningping, Zou Zujie, Fan Dong, Wei Hongchao, He Binjie Apr 2026

Structural Design And Parameter Optimization Of A Vibration Absorber For Rescue Casing-While-Drilling Rigs, Liu Pu, Yao Ningping, Zou Zujie, Fan Dong, Wei Hongchao, He Binjie

Coal Geology & Exploration

Objective Rescue drilling rigs undergo intense vibration at borehole mouths when operating in a confined underground space of coal mines. To address this issue, this study designed a compact multi-directional, passive dynamic vibration absorber, aiming to improve the operational stability and safety of the rigs. Methods Based on the spring-mass-damping system theory, a stepwise optimization design method was proposed for the longitudinal and transverse dynamic models of the vibration absorber. For the longitudinal vibration model, the particle swarm optimization (PSO) algorithm was applied for multi-objective parameter optimization. In contrast, for the transverse vibration model, the fixed point theory was employed …


Exploring The Vertical Heterogeneity Of Extremely Thick Aquifers In Coal Mines Through Layered Fine-Scale Pumping Tests, Guo Xiaoming Apr 2026

Exploring The Vertical Heterogeneity Of Extremely Thick Aquifers In Coal Mines Through Layered Fine-Scale Pumping Tests, Guo Xiaoming

Coal Geology & Exploration

Objective Extremely thick aquifers in mining areas typically exhibit strong heterogeneity and high water yield. Therefore, they are prone to cause severe water inflow in mines and induce water disasters, representing a major factor affecting the mining safety of numerous mines in China. However, the vertical heterogeneity of these aquifers remains poorly understood, emerging as a primary bottleneck in the prevention and control of such water hazards. Methods To scientifically reveal the vertical heterogeneity characteristics of extremely thick aquifers, this study investigated the extremely thick Luohe Formation aquifer in a coal seam roof of a representative coal mine in the …


Optical Mechanisms Behind Vitrinite Reflectance Suppression Caused By Strong Anisotropy: A Case Study Of Contact Metamorphic Coals, An Yanfei, He Shuyang, Chen Kaixin, Gao Junhan Apr 2026

Optical Mechanisms Behind Vitrinite Reflectance Suppression Caused By Strong Anisotropy: A Case Study Of Contact Metamorphic Coals, An Yanfei, He Shuyang, Chen Kaixin, Gao Junhan

Coal Geology & Exploration

Objective For vitrinite with weak anisotropy, which proves uniaxial and optically negative, replacing random vitrinite reflectance (Rran) with the maximum vitrinite reflectance (Rmax) allows for the accurate correction of vitrinite reflectance suppression induced by anisotropy. However, as its anisotropy intensifies, vitrinite exhibits increasingly complex optical properties, rendering it challenging to reflect the thermal metamorphic temperature of vitrinite using Rmax. Methods This study investigated the strongly anisotropic vitrinite in coals and natural coke subjected to magma intrusion in the Shitai coal mine, Huaibei City, Anhui Province. Using a reflected-polarized light microscope (R-PLM), an …


Mechanisms Behind Thermal Evolution Of The Structural Alignment Of Polycyclic Aromatic Hydrocarbons In Coals: Implications For Structural Transition Of Coal Macromolecules, Song Yu, Jiang Bo, Cheng Guoxi, Zheng Sijian, Li Ming, Ge Yao, Dai Yan, Wang Qian, Feng Guangjun Apr 2026

Mechanisms Behind Thermal Evolution Of The Structural Alignment Of Polycyclic Aromatic Hydrocarbons In Coals: Implications For Structural Transition Of Coal Macromolecules, Song Yu, Jiang Bo, Cheng Guoxi, Zheng Sijian, Li Ming, Ge Yao, Dai Yan, Wang Qian, Feng Guangjun

Coal Geology & Exploration

Objective Coals are highly sensitive to variations in temperature and pressure conditions. The structural evolution of coal macromolecules, driven by tectono-thermal processes, is the key to understanding coal rank transition and geological evolution. The structural alignment of polycyclic aromatic hydrocarbons (PAHs) in coals represents a critical indicator for characterizing coal rank transition and geological evolution. However, due to limited studies, there is a lack of systematic experimental demonstration and theoretical support for the structural alignment and microstructural characteristics of PAHs in coals, as well as their intrinsic relationships with the structural transition of coal macromolecules, during pyrolysis. Methods This study …