Engineering Commons^™

Evolutionary Mechanisms And Models Of Strain, Porosity, And Permeability Of Compacted Broken Coals, Li Lei, Lu Shouqing, Chu Tingxiang, Zhong Xiaoxing, Liu Chongyang, Ren Ting

Coal Geology & Exploration

Residual coal areas in caving zones of goaves in coal mines serve as primary sites for low-temperature reactions between coal and oxygen. Hence, exploring the evolutionary models of the strain, porosity, and permeability of coals in these areas holds great significance for gaining a deep understanding of the spontaneous combustion process and regularity of coals. Based on the self-developed experimental device for gas seepage in compacted broken coals, this study explored the evolutionary patterns of the strain, porosity, and permeability of compacted coals with single/mixed particle sizes during gas seepage. Furthermore, this study analyzed the variations in the strain, porosity, …

Carbon Microspheres In Natural Coke: Optical Microscopic Characteristics And Their Origin And Implications, An Yanfei, Chen Kaixin, Wang Yaqiao, Cheng Shuo, Huang Jian, He Shuyang, Wang Shengjian

Coal Geology & Exploration

Carbon microspheres (CMs) in natural coke are formed when coal seams undergo magma-induced rapid thermal metamorphism. Analyzing the origin of the optical microscopic characteristics of CMs assists in gaining deep insights into the rapid thermal carbonization and metamorphism of coals. This study examined the natural coke samples rich in CMs from Shitai Coal Mine in Huaibei, Anhui Province. Using experiments like high-resolution reflected polarized light microscopy and scanning electron microscopy (SEM), this study characterized the particle sizes, distribution, optical microscopic characteristics, and ultramicrofabrics of CMs in natural coke, revealing the origin and thermal evolution implications of their optical anisotropy. The …

Botdr-Based Horizontal Deformation Monitoring Of Section Coal Pillars, Chai Jing, Hao Hongru, Yang Jianfeng, Gao Dengyan, Gao Kuiying, Chen Jianhua, Yang Lei, Liu Zeyu

Coal Geology & Exploration

To address potential safety hazards like microcrack initiation, deformation, and failure inside coal pillars, this study monitored the horizontal deformations of coal pillars using the Brillouin optical time-domain reflectometry (BOTDR)—a distributed optical fiber sensing technology. Firstly, this study established a method for converting the axial strain of optical fibers into horizontal deformations based on a theoretical analysis of the failure and bulking characteristics of coal pillars. Secondly, it determined the axial tensile response of metal-based cord-shaped sensing optical fibers by conducting laboratory tests. Then, it corrected the strain coefficient based on the deformation and failure patterns of coal pillars. Finally, …

Exploring A Fly Ash-Based Grouting Material For Toughening Through In Situ Polymerization Of Acrylamide, Zhang Yuehong, Wang Xiaodong, Wang Hai, Wu Boqiang, Ji Zhongkui, Zhu Shibin, Han Le, Feng Longfei

Coal Geology & Exploration

Efficiently controlling the water inflow (loss) of burnt rocks in the roof of coal mining faces requires grouting reinforcement materials with excellent compressive toughness. Silicate cement-based grouting materials, characterized by low costs, have been extensively applied to grouting reinforcement in coal mines. However, their hardened grout is susceptible to deformation, exhibiting poor toughness. By employing the in-situ polymerization of acrylamide (AM) for toughening, this study investigated the effects of AM, cross-linking agent, initiator, and water-cement ratio on the setting time, swelling capacity, compressive strength, and toughness index of the fly ash-based grouting materials. Furthermore, the microstructures of the hardened grout …

Some Reflections On The Application Of Machine Learning To Research Into The Theoretical System Of Mine Water Prevention And Control, Yao Hui, Yin Huichao, Liang Manyu, Yin Shangxian, Hou Enke, Lian Huiqing, Xia Xiangxue, Zhang Jinfu, Wu Chuanshi

Coal Geology & Exploration

The theoretical system of mine water prevention and control encompasses three fundamental aspects: disaster-causing mechanisms, risk evaluation, and disaster prediction. This theoretical system, having undergone rapid development over the past 20 years, aims to gain insights into the behavior characteristics of mine water and predict its evolutionary trend, thus serving the prevention and control of water disasters in mining areas. Applying machine learning, a powerful tool for data analysis and mining in the era of big data, to research into the theoretical system has garnered considerable attention. This study focuses on the specific applications of machine learning to the three …

Water Inrush Mechanism And Water-Conducting Fractured Zone’ Developmental Patterns Of A Typical Ultra-Thick Coal Seam In The Huanglong Coalfield During Fully Mechanized Mining, Yan Heping, Li Wenping, Duan Zhonghui, Yang Yugui

Coal Geology & Exploration

The mining of thick coal seams in the Huanglong Jurassic coalfield has led to the formation of high water-conducting fractured zones, which are prone to connect the extremely thick sandstone aquifers of the overlying Cretaceous Luohe Formation. Qinggangping Coal Mine in the coalfield exhibits the typical characteristics of pulsed water inrushes during coal mining, posing a severe threat to safe mining. This study investigated the fully mechanized mining face 42105 in Qinggangping Coal Mine. Using 3DEC discrete element simulation, flushing fluid leakage in boreholes, integrated geophysical exploration, and borehole TV, this study examined the developmental patterns of the water-conducting fractured …

Construction And Analysis Of A Method For Grading Long-Term Vegetation Carbon Sink In Waste Dumps Of An Open-Pit Coal Mine, Yang Fei, Cui Kuankuan, Zhang Chengye, Li Jun, Wang Jinyang, Du Tianmeng, Zhang Haoran

Coal Geology & Exploration

Vegetation carbon sink serves as a crucial indicator for the ecological assessment of an open-pit coal mine. The accurate inversion and grading of vegetation carbon sink play a significant role in exploring the ecological restoration of coal mines. This study proposed a method for grading vegetation carbon sink of an open-pit coal mine based on the particle swarm optimization (PSO) algorithm. Specifically, using a light use efficiency (LUE) model, this study first determined the spatio-temporal distributions of the 2005‒2020 vegetation carbon sink in the waste dumps of the Shengli No.1 open-pit coal mine through inversion based on Landsat images and …

Weight And Resistance Reduction Mechanism Of Drilling Rods For Drilling In Soft Coal Seam And Its Application, Wang Yonglong, Guo Jiakuan, Yu Zaijiang, Du Kang, Sun Yuning

Coal Geology & Exploration

Gas drainage boreholes during construction is a necessary means to control gas hazards. In response to the issues such as high drilling resistance, low drilling efficiency, and high labor intensity caused by the significant self-weight of the drilling rod in drilling into the soft coal seams, a research approach of reducing the self-weight and lowering the drilling resistance by optimizing the drilling rod structure was proposed. Thus, a four-winged concave grooved drilling rod was designed to address both of its advancing resistance and rotating torque losses. Meanwhile, a drilling resistance model for the drilling rod was established. On this basis, …

Impact Of Student Beliefs And Self-Efficacy On Performance In Higher Education Stem Courses, Lauren Nicole Fogg

Doctoral Dissertations

In engineering education, students often face feelings of inadequacy, leading to academic struggles and potential dropout. This dissertation investigates the impact of interactive course materials on students' confidence and self-efficacy in problem-solving, focusing on an Engineering Materials class at Louisiana Tech University. Over four quarters, involving seven sections and 218 students, a 13-question Likert scale survey was administered repeatedly, alongside demographic data and textbook usage surveys. The study aims to compare students’ attitudes and beliefs when not using a textbook versus when using an interactive web-native book. Hypotheses suggest that the interactive book will enhance problem-solving beliefs, confidence, and grades. …

Phase Interface Dynamics And Heat Transfer Mechanisms In Evaporating Droplet And Pool Boiling Processes, Md Tanbin Hasan Mondal

Doctoral Dissertations

Despite the significant importance and widespread use of phase-change cooling techniques, there are still fundamental questions about the microscopic processes that govern the heat transfer mechanisms. In order to gain a better understanding of the underlying physics involved, it is essential to have information at the microscale regarding the surface temperature distribution with time as well as the location and speed of the moving contact line (MCL). A comprehensive understanding of heat transfer mechanisms and phase-interface behavior during phase-change cooling is crucial for improving heat transfer models, optimizing surface engineering, and maximizing overall effectiveness. Firstly, this dissertation presents a capacitance-based …

Dynamic Simulations And Applicability Evaluation Of Novel Perforation Techniques, Bi Gang, Yuan Peijie, Han Fei, Fu Shuaishuai, Wu Jiemin, Ma Ying

Coal Geology & Exploration

The development and improvement of perforated completion techniques hold great practical significance and value for efficient testing and exploitation of oil and gas fields. However, conventional shaped-charge perforation for well completion of low-permeability reservoirs (e.g., low-permeability coal seams) suffered high seepage resistance and reduced productivity due to the presence of compaction damage zones. To achieve enhanced exploitation efficiency of low-permeability reservoirs, novel perforation techniques, including self-cleaning and after-effect perforation, have been proposed. However, their perforation performance and applicability remain ambiguous. Based on the explicit time integration algorithm and fluid-structure interaction mechanism of LS-DYNA, this study proposed a method for finite …

A Simulation Study Of Mechanisms Behind Water Inrush From Fault-Bearing Floors Of Ultra-Thick Coal Seams Under Loading And Unloading At Significantly Variable Amplitude, Li Hao, Zhu Kaipeng, Guo Guoqiang, Zhou Yang, Kang Zhiqin

Coal Geology & Exploration

Ultra-thick coal seams feature large stope spaces and extensive disturbance ranges. Significantly variable amplitude loading and unloading are prone to cause the fault rupture of floors of ultra-thick coal seams, inducing water disasters. Numerical simulation serves as a critical method for revealing the fault reactivation and water inrush mechanisms at the floors of ultra-thick coal seams. The key of this method is to accurately inflect the coupling characteristics of rock mass rupture and fissure water under significantly variable amplitude loading and unloading. This study determined the correlations of the damage variable with plastic strain and stress, deriving the equations for …

Intelligent Identification Method Of Drilling Fluid Rheological Parameters Based On Machine Learning, Liu Changye, Yang Xianyu, Cai Jihua, Wang Ren, Wang Jianlong, Dai Fanfei, Guo Wanyang, Jiang Guoshe, Feng Yang

Coal Geology & Exploration

The rheology of drilling fluid, which characterizes its flow and deformation, is vital for transporting and suspending rock cuttings as well as for enhancing the drilling rate. Precise control of drilling fluid rheological parameters is essential to ensure borehole cleanliness and efficient drilling. This paper proposes an intelligent identification method for drilling fluid rheological parameters based on Convolutional Neural Networks (CNNs). The method employs magnetic stirring to generate stable images of drilling fluid flow, uses various data augmentation methods to increase the number of images and create a database, thereby enhancing the model’s robustness and generalization capabilities. The AlexNet CNN …

Dynamic Mechanisms Of Coal And Gas Outbursts Based On A Multi-Zone Combined Coal Model, Li Feng, Wang Chenchen, Wang Bo, Jing Yadong, Yan Zhengxu, Zhang Minbo

Coal Geology & Exploration

Coal and gas outbursts (hereafter referred to as outbursts) severely affect coal mining safety. However, many scientific problems underlying the outbursts remain unsolved. To minimize the influence of anisotropy in the mechanical properties of coals on research into outbursts, this study constructed a multi-zone combined coal model. Based on the stress distribution of overlying strata and the stress wave propagation mechanisms, this study located the weak zone of coals, shrinking the research object from the outburst center to the weak zone. Given that outbursts are triggered by the disturbance of external dynamic load, this study examined the propagation patterns of …

Geochemical Characteristics And Influencing Factors Of Deep Coalbed Methane In The Linxing-Shenfu Block, Wu Peng, Hu Weiqiang, Li Yangbing, Ma Litao, Li Yong, Zhao Fei, Niu Yanwei, Chen Jianqi, Li Panpan, Liu Zaizhen, Li Chenchen, Cao Di, Liu Cheng

Coal Geology & Exploration

Identifying the origin and geochemical characteristics of deep coalbed methane (CBM) is critical for its exploration and production. This study examined the desorbed gas from deep-CBM parameter wells in the Linxing-Shenfu block on the eastern margin of the Ordos Basin. It systematically tested the composition, content, and carbon isotopes of CBM in coal seams Nos. 8 and 9. In combination with the degree of thermal evolution, gas-bearing properties, coal seam burial depths, geological structures, and hydrogeologic conditions, it delved into the geochemical characteristics and influencing factors of deep CBM. The results show that the deep CBM in the study area …

Anti-Channeling Methods For Coalbed Methane Production Using L-Type Horizontal Wells, Liu Zhan, Zhang Qunxia, Geng Yuxin, Luo Dan, Wang Minggang

Coal Geology & Exploration

Coalbed methane (CBM) production using L-type horizontal wells can yield stable single-well production of up to above 8 000 m³/d. However, due to the lack of sand settling pockets, L-type horizontal wells fail to achieve gas-water separation under the action of gravity. Consequently, gas channeling from tubing is prone to occur, significantly decreasing pumping efficiency and restricting further drainage and pressure reduction. By optimizing the lifting process for production in the early stage, the gas channeling from tubing has been somewhat alleviated. However, the anti-channeling effects remain unsatisfactory in low-fluid-pressure and high-yield gas wells. This study examined L-type …

Technologies For Water Hazard Prevention And Control In Burnt Rock Aquifers Within Concealed Burnt Areas, Wang Hai

Coal Geology & Exploration

Burnt rocks are extensively distributed in northwestern China, featuring well-developed pores and fractures and abundant water, emerging as primary aquifers in this region. The burnt rocks in concealed burnt areas in this region show inconspicuous surface remains, complicating their identification. Penetrating burnt rock aquifers in coal mining will lead to water hazard and destroy water resources in these aquifers. To prevent and control water hazard in burnt rocks within concealed burnt areas and preserve water resources in burnt rock aquifers, this study analyzed the distributions of burnt rocks in China and the effects of water in them on coal mining. …

Development Of Remote Control System For Automatic Drilling Rig Used In Coal Mine, Dong Hongbo, Yao Ningping, Wang Tianlong, Ma Bin, Peng Guangyu

Coal Geology & Exploration

In response to the problems of high labor intensity and great safety risk of drilling rig under the complex construction environment, a set of remote monitoring system for automatic drilling rig of coal mine was developed using the electronic circuit, measurement sensing, remote control, video monitoring and big data technologies. The system, based on ZDY4500LFK coal mine drilling rig, has implemented the three control modes: in-line-of-sight control, underground centralized control and ground remote monitoring. Besides, a cloud automatic drilling rig management and control platform was established. Specifically, the in-line-of-sight monitoring is used to realize the accurate operation of drilling rig …

Research On Digital Twin-Driven Tracking, Positioning And Collision Detection Method Of Excavating And Anchoring Equipment, Yang Wenjuan, Zhao Dian, Zhang Xuhui, Chen Xin, Zheng Xili, Liu Yanhui, Zhang Ran, Wan Jicheng

Coal Geology & Exploration

The automation of excavating and anchoring operation is critical for intelligent excavation of coal mine roadway. Aiming at the challenges of relative pose measurement and collision detection during the alternating operation of the current excavating and anchoring equipment, a digital twin-driven tracking, positioning and collision detection method was proposed. Firstly, in order to overcome the influence of low illumination, high dust and complex background interference in the underground excavating face, the multi-point infrared LED target is taken as the information source, the infrared LED feature point image is collected by industrial camera, the center of the spot is extracted using …

Performance Of Co2-Cured Alkali-Activated Blast-Furnace Slag Incorporating Magnesium Oxide, Yubin Jun, Seong Ho Han, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigated characteristics of alkali-activated slags incorporating magnesium oxide (MgO) subjected to CO₂ curing. The samples were prepared by adding 2%, 5%, and 10% MgO to the total binder mass. The mixture was activated with potassium hydroxide (KOH) and cured in a CO₂ incubator for 3 days. The compressive strength of the MgO-incorporated CO₂-cured alkali-activated slag was higher than that of the conventional alkali-activated slag at all ages up to 28 days. No reduction in the strength was observed over time. The enhanced strength was independent of MgO content. Combined X-ray diffraction with thermogravimetric analysis …

Development Of Quantum True Random Number Generators And Implementation On Ibm Cloud Lab, Vaishnavi K

Theses and Dissertations

Random numbers are the lifeline of any cryptographic operation in modern computing. Quantum mechanics has the intrinsic ability to generate truly random numbers, making it an ideal alternative for scientific applications that require high-quality randomness. Quantum True Random Number Generators (QTRNGs) can yield real random data to replace random-looking periodic sequences. To construct such a random number generator, this work uses the IBM Q Experience platform called Qiskit.

This research focuses on the development and analysis of quantum-based TRNGs along with their prime characteristics. Qubits and quantum gates are the predominant sources of true randomness on quantum platforms. These inherent …

Dna G-Quadruplexes As Targets For Natural Product Drug Discovery, Kai-Bo Wang, Yingying Wang, Jonathan Dickerhoff, Danzhou Yang

Purdue University Libraries Open Access Publishing Fund

DNA guanine (G)-quadruplexes (G4s) are unique secondary structures formed by two or more stacked G-tetrads in G-rich DNA sequences. These structures have been found to play a crucial role in highly transcribed genes, especially in cancer-related oncogenes, making them attractive targets for cancer therapeutics. Significantly, targeting oncogene promoter G4 structures has emerged as a promising strategy to address the challenge of undruggable and drug-resistant proteins, such as MYC, BCL2, KRAS, and EGFR. Natural products have long been an important source of drug discovery, particularly in the fields of cancer and infectious diseases. Noteworthy progress has recently been made in the …

Rheological Properties And 3d Printing Behavior Of Pcl And Dmso2 Composites For Bio-Scaffold, Jae-Won Jang, Kyung-Eun Min, Cheolhee Kim, Chien Wern, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

The significance of rheology in the context of bio three-dimensional (3D) printing lies in its impact on the printing behavior, which shapes material flow and the layer-by-layer stacking process. The objective of this study is to evaluate the rheological and printing behaviors of polycaprolactone (PCL) and dimethyl sulfone (DMSO₂) composites. The rheological properties were examined using a rotational rheometer, employing a frequency sweep test. Simultaneously, the printing behavior was investigated using a material extrusion 3D printer, encompassing varying printing temperatures and pressures. Across the temperature range of 120–140 °C, both PCL and PCL/DMSO₂ composites demonstrated liquid-like behavior, …

Artificial Neural Network-Based Modelling For Yield Strength Prediction Of Austenitic Stainless-Steel Welds, Sukil Park, Cheolhee Kim, Namhyun Kang

Mechanical and Materials Engineering Faculty Publications and Presentations

This study aimed to develop an artificial neural network (ANN) model for predicting the yield strength of a weld metal composed of austenitic stainless steel and compare its performance with that of conventional multiple regression and machine learning models. The input parameters included the chemical composition of the nine effective elements (C, Si, Mn, P, S, Ni, Cr, Mo, and Cu) and the heat input per unit length. The ANN model (comprising five nodes in one hidden layer), which was constructed and trained using 60 data points, yielded an R² value of 0.94 and a mean average percent error …

Two Heads Are Better Than One: Single Pilot Operation Threatens The Safety Of The Friendly Skies, Alexandria E. Rook

Arkansas Law Review

Boeing’s Maneuvering Characteristics Augmentation System (“MCAS”), an automated piloting system, is only supposed to handle aircraft operations in very specific circumstances. Despite devasting results with MCAS, Boeing has another automated piloting system on the horizon that poses even more grave risks: Single Pilot Operation (“SPO”). Boeing—along with Airbus—wants to replace one of the pilots in the cockpit of commercial airline flights with the new SPO technology it is developing. The FAA should not allow SPO technology to be implemented because it is premature, motivated by financial gain to the detriment of safety, and ignores the importance of professional judgment in …

Combinatorial Studies Of Noble Metal Catalysts For Carbon Utilization, Natalie Leong Page

Theses and Dissertations

Electrocatalysts demonstrate significant promise for sustainable processes like carbon capture and generating recycled carbon fuels which are needed to achieve net zero carbon emissions. However, the commercialization of these processes is limited by several factors, one of which is the high cost of catalysts. The discovery and development of cheaper alternatives has been difficult due to constraints in experimental methodologies, scalability limitations, and a lack of understanding of reaction mechanisms. Within this dissertation is the development of a novel scanning electrochemical system and its implementation for high-throughput data generation from combinatorially sputtered material libraries. Combinatorial Pd-Au alloys were investigated for …

Raditation Test Report: Characterization Of Fairchild Imaging Cis2521 Cmos Focal Plane Array, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

This report documents the results of radiation testing of Fairchild CIS2521 CMOS imaging sensor. Proton radiation measurements (both transient and total ionizing dose) were performed at the Crocker Nuclear Laboratory (CNL) of the University of California, Davis (UC Davis). Latchup characterization using Heavy Ion radiation was performed at the Texas A&M University Cyclotron Institute, Radiation Effects Facility.

Design And Test Of Asynchronous Systems Using The Link And Joint Model, Ebelechukwu Esimai

Dissertations and Theses

Asynchronous circuits offer numerous advantages, including low energy consumption and good composability and scalability. However, they remain meagerly adopted in the mainstream semiconductor industry. One reason is the limited number of design tools available to help designers navigate design complexity, particularly the myriad of asynchronous implementation styles.

This dissertation focuses on managing the myriad of asynchronous implementation styles by utilizing a circuit-neutral model, called Links and Joints, and embedding this Link-Joint approach into a design flow. Although years of past work have already laid the groundwork, the work in this dissertation identifies and addresses key missing pieces.

First, the …

A Computational Investigation Of Wood Selection For Acoustic Guitar, Jonah Osterhus

Senior Honors Theses

The acoustic guitar is a stringed instrument, often made of wood, that transduces vibrational energy of steel strings into coupled vibrations of the wood and acoustic pressure waves in the air. Variations in wood selection and instrument geometry have been shown to affect the timbre of the acoustic guitar. Computational methods were utilized to investigate the impact of material properties on acoustic performance. Sitka spruce was deemed the most suitable wood for guitar soundboards due to its acoustic characteristics, strength, and uniform aesthetic. Mahogany was deemed to be the best wood for the back and sides of the guitar body …

Communication—The Development Of A Stable And Practical Saturated Reference Electrode For Molten Chloride Salt Systems, J. Marvin Torrie, Ranon Fuller, Devin Rappleye

Faculty Publications

A simply constructed, stable, Ni/Ni²⁺ saturated reference electrode (SRE) has potential to measure thermodynamic behavior of molten chloride salts more reliably. Like the Ag/Ag⁺ reference electrode (RE), the Ni/Ni²⁺ SRE is made of commercially available materials. Initial experiments in molten CaCl2 and LiCl show the Ag/Ag⁺ RE potential drifting two times faster than the SRE. Furthermore, experiments show the replicability of SREs by comparing two Ni/Ni²⁺ SREs with different compositions of NiCl₂ which is supportive of saturated phase behavior.