Engineering Commons^™

Dynamic Disaster Evolution Mechanism Of High Mine Pressure At Hard Roof And Advance Area Prevention And Control Technology, Zheng Kaige, Wang Lintao, Li Bingang, Li Yanjun, Yang Huan, Yang Sen, Dai Nan, Wang Haojie, Wang Zeyang, Xi Jie

Coal Geology & Exploration

The overlying roof on the hard roof working bench is usually not likely to fall off, while tends to form dynamic pressure disaster. The stress evolution characteristics and roof breaking mechanism before and after hard roof weakening were analyzed and revealed using the methods of numerical simulation and theoretical analysis, and the advance area prevention and control technology were proposed and applied in the field practice, for the typical dynamic disaster problem of high mine pressure that was caused by the hard roof against the background of the Buertai Coal Mine in the Shendong Mine Area. As indicated by the …

Enhanced Gas Drainage Technology By Staged Fracturing In Long Bedding Borehole In Hard Coal Bed Of Underground Coal Mine And Its Application, Wang Chenyang, Li Shugang, Zhang Yongtao, Guo Yi, Sun Siqing, Chen Dongdong, Dou Chengyi

Coal Geology & Exploration

In view of the problems of rapid attenuation, long period and low efficiency of gas drainage in hard coal bed, the enhanced gas drainage technology of increasing the permeability of coal bed by staged fracturing in long bedding borehole was put forward for the medium-to-hard coal bed. Herein, research was conducted on No.4 coal bed of Shaanxi Binchang Mining Area. Specifically, the change characteristics of micro-pore structure of coal body before and after hydraulic fracturing were comparatively analyzed by high-resolution electron microscope (SEM) in the laboratory. Meanwhile, the stress characteristics of packer and the stability of borehole were simulated with …

Floor Failure Law Of Extra-Thick Coal Seam In Fully Mechanized Caving Mining, Guo Guoqiang

Coal Geology & Exploration

The coal mining on the high-artesian water body will cause floor disturbance and damage, and lead to the thinner effective waterproof stratum, which enhances the risk coefficient of water bursting at the floor. Grouting modification of the target horizon is an effective governing measure. However, the grouting within the floor damage scope will waste a large amount of grout and affect the project effect. Therefore, it is especially important to carry out the study of the damage depth and regularity of the coal seam floor. Accordingly, the 5105 working bench of the Yushupo Coal Mine in Shanxi was adopted as …

Study Of Constitutive Model Of Frozen Sandstone Damage Based On Weibull Distribution, Yi Ming, Zhao Tao, Ma Feifei, Wang Lei, Yuan Chao

Coal Geology & Exploration

Abstract: The deformation and destruction characteristics of frozen rock is a basic mechanical problem encountered during the construction using the freezing method. Under the action of load, the mechanical characteristics and deformation characteristics are greatly different for the rock with different freezing temperatures, which significantly affects the safety and stability of the freezing wall. Therefore, the study of the damage constitutive relation of the frozen rock is significant for instructing the freezing method design and construction. In order to analyze the whole process of the frozen rock deformation and destruction under load action, the Weibull distribution was adopted to describe …

Analysis On Spatio-Temporal Evolution Law Of Freezing Temperature Field In Eastern Shaft Of Qinan Coal Mine, Huang Shiqing, Rong Chuanxin, Long Wei, Ma Haochen, He Junzhen

Coal Geology & Exploration

Three numerical calculation models of the freezing temperature fields with different soil nature and different burial depths, i.e. the calcareous clay horizon with the burial depth of 218 m, the fine sand horizon with the burial depth of 225 m and the sandy clay horizon with the burial depth of 259 m, were established respectively using the finite element software COMSOL Multiphysics based on the actual forming locations of freezing holes, with the engineering background of using the freezing method in shaft sinking for the eastern air shaft of Qinan Coal Mine Anhui Province and the study object of the …

Experimental Study On Power Matching Of Modular Double Pumping Stations Of Tunnel Drilling Rig, Lu Feifei, Fan Dong, Tian Hongliang

Coal Geology & Exploration

In order to solve the problems of heavy weight, relocation and transportation of the power pumping station of tunnel drilling rigs, it is proposed to divide the pumping station through modular design, and adopt the solution of small-displacement, dual-power and dual-pump confluence, effectively reducing the transportation size and weight of a single pump station. A single-pump station or a double-pump confluence is chosen according to the working conditions to improve the flexibility of the drilling rig and reduce energy consumption. The load-sensing system has the advantages of energy saving, good load adaptability, and convenient speed regulation. However, when the dual-load-sensing …

Study Of Urethane Double-Coated Nylon Membranes For Fluid-Storage Applications, Micah Austin Howell

Masters Theses

Polymer-coated fabrics are used for many fuel and water storage applications, such as in U.S. military field operations. Urethane-double-coated nylon (UDCN) is one such material used in collapsible fluid storage tanks. Research into the mechanical properties of UDCN membranes under different environmental conditions is necessary for substantiating its current operations as well as developing new technologies. Novel modular, closed-loop and scalable pumped-storage hydropower (PSH) systems are one technology that could use UDCN membrane tanks in order to mitigate large costs, risks, environmental impacts, and time-for deployment associated with PSH system construction due to their modular, closed-loop technology. This study focuses …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Experimental Study On The Mechanical Properties Of Coal-Like Materials For Hydraulic Fracturing Simulation, Zhai Cheng, Zheng Yangfeng, Yu Xu, Xu Jizhao, Sun Yong, Cong Yuzhou, Tang Wei, Li Yujie, Zhu Xinyu, Chen Aikun

Coal Geology & Exploration

Simulation experiments on hydraulic fracturing of the coal seam in the laboratory are an effective method to study the mechanism of fracturing and enhancing permeability of coal-rock mass by hydraulic fracturing in coal mines. However, the technology in-situ sampling for large-size coal mass is immature, and the existing large-size coal samples are mostly taken from the stress-relaxation area, which can be further damaged in the transportation and preparation processes, causing large dispersion in test results. Therefore, The use of coal-like materials is a viable option to replace large-size raw coal for hydraulic fracturing simulation experiments. The mechanical properties of coal-like …

High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam, Chen Dongdong, Wang Jianli, Jia Bingyi, Xi Jie

Coal Geology & Exploration

Advanced management of gas enrichment area is an important guarantee to realize safe, efficient and intelligent mining in coal mine. Aiming at the problem of high-efficiency gas drainage in broken and soft coal seam region, taking No.3 coal seam in Hancheng mining area as the research object, a gas drainage mode of comb-shaped long borehole hydraulic fracturing in the roof of coal seam is proposed. The applicability of the model is verified by means of theoretical analysis, numerical simulation and field test, and the fracture propagation law, gas drainage mechanism, and fracturing curve features of comb-shaped borehole in adjacent roof …

Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane, Li Quangui, Wu Xiaobin, Hu Qianting, Liu Le, Shi Jialin, Song Mingyang

Coal Geology & Exploration

The structural plane extensively occurs in coal measures, and is one of the key factors affecting the hydraulic fracturing effect of coal/rock. The fabrication time and filling material types of the structural plane were adjusted to obtain the coal/rock specimens without the filling structural plane, or the coal/rock specimens with the filling structural plane. The physical experiment for hydraulic fracturing was carried out to find out the effect and action mechanism of the structural plane type and injected flow rate on hydraulic fracture extension. As indicated by the result, in the condition of the injected flow rate of 50 mL/min, …

Analysis And Prospect Of Precise Prevention And Control Technical System Ahead Of Large Areas And Time For Gas Disasters In China, Liu Cheng, Sun Dongling, Wu Wenbin, Li Liangwei, Sun Zhongguang

Coal Geology & Exploration

To meet the rapid development of coal mine automation and intelligent production and the urgent need for rapid prevention and regional management outburst, and to promote the development of the gas disaster control technology system in large areas of coal mines, this paper aims to solve the problem of traditional coal seam drilling gas drainage technology, which is “not deep enough to be drilled and cannot be pumped out and cannot be tested.” It analyzes the application effects of technical equipment such as directional drilling, surface wells, staged hydraulic fracturing, deep hole sampling, and detection while drilling in various geological …

Hydrochemical Characteristics And Source Analysis Of Deep Groundwater In Qianyingzi Coal Mine, Chen Kai, Liu Qimeng, Liu Yu, Peng Weihua, Wang Zitao, Zhao Xiang

Coal Geology & Exploration

The shallow coal resources in China have been gradually depleted. Under the condition that the deep coal exploitation has been started, the threat from the high-artesian limestone water at the coal seam floor is greater. Deep understanding of the hydrochemical composition control mechanism in the aquifer of the mine area is an important scientific precondition for pertinently carrying out water hazard prevention and control. In order to find out the qualitative and quantitative sources of the conventional ions which in the deep ground water of the Anhui Qianyingzi Coal Mine, the 22 conventional ion concentrations in limestone water were analyzed …

Abnormal Response Characteristic Simulation During Transient Electromagnetic Detection In Mine Borehole, Zhang Jun

Coal Geology & Exploration

Conventional mine transient electromagnetic advance detection method is greatly influenced by the condition outside of the mine, which leads to the inaccurate location in anomalous body detection. In order to solve this problem, an advance detection method for measuring the three-component signals of the transient electromagnetic field in the down-hole borehole was proposed to carry out numerical simulation for the abnormal response characteristics from the different locations of the plane where the receiving coil is located and the different orientations of the anomalous body. The principle of borehole transient electromagnetic detection was analyzed, and the test design and construction design …

Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes, Huang Zhongzheng, Jiang Guoqing, Wang Jun, Cheng Jiulong, Ma Zhi, Tian Chuxiao, Xin Chengtao

Coal Geology & Exploration

Closed poor boreholes connect aquifers at some degree to form well concealed water diversion channels, which poses a water hazard threat on either tunneling or working bench recovery. In order to discuss the effectiveness of using the transient electromagnetic method in the advance detection of closed poor boreholes for the mine, the 3D geologic-geophysical model of the closed poor boreholes in front of the tunneling working bench was established based on the full-space transient electromagnetic theory to simulate and study the response characteristics of the full-space transient electromagnetic field in the influence area model of closed poor boreholes. As indicated …

Experimental Study On Nondestructive Testing Of Anchor Cable In Pumped Storage Power Station, Yan Liangping, Zhou Liming, Cui Botao, Wang Bolin, Lu Jiangang

Coal Geology & Exploration

In order to demonstrate the effect of elastic wave reflection method, the nondestructive testing test of anchor cables was carried out at the bank slope of Fukang Pumped Storage Power Station in Xinjiang. On the basis of the basic theory of elastic wave reflection method, the anchor cable sensor is embedded, and the data acquisition, signal excitation position and wave velocity of anchor body in the process of nondestructive testing of anchor cable are systematically studied. The following results are obtained: When the receiving sensor position is fixed and the excitation part is the steel strand where the receiving sensor …

Development And Application Of A Retractable Slip Overshot In Underground Coal Mines, Wu Tao

Coal Geology & Exploration

The stuck and buried drills in underground coal mines often lead to accidents of broken drill pipes in the holes. At present, the success rate of the commonly used fishing methods of male and female fishing tap buckle is low, which not only consumes a lot of manpower and material resources, but also affects the production progress of coal mining. Based on this, a retractable slip overshot with the structural design of the cooperation between the slips and the outer cylinder through the wedge-shaped spiral surface has been proposed, which converts the pull-out force of the drill rod into a …

Modelling The Thermoelectric Properties Of Cement-Based Materials Using Finite Element Method And Effective Medium Theory, Lorenzo Stella, Conrad Johnston, Javier Troncoso, Piotr Chudzinski, Esther Orisakwee, Jorge Kohanoff, Ruchita Jani, Niall Holmes Dr., Brian Norton, Xiaoli Liu, Ming Qu, Hongxi Yin, Kazuaki Yazawa

Conference papers

Because of the thermoelectric (TE) effect (or Seebeck effect), a difference of potential is generated as a consequence of a temperature gradient across a sample. The TE effect has been mostly studied and engineered in semiconducting materials and it already finds several commercial applications. Only recently the TE effect in cement-based materials has been demonstrated and there is a growing interest in its potential. For instance, a temperature gradient across the external walls of a building can be used to generate electricity. By the inverse of the TE effect (or Peltier effect), one can also seek to control the indoor …

Comprehensive Review Of Heat Transfer Correlations Of Supercritical Co2 In Straight Tubes Near The Critical Point: A Historical Perspective, Nicholas C. Lopes, Yang Chao, Vinusha Dasarla, Neil P. Sullivan, Mark Ricklick, Sandra Boetcher

Publications

An exhaustive review was undertaken to assemble all available correlations for supercritical CO2 in straight, round tubes of any orientation with special attention paid to how the wildly varying fluid properties near the critical point are handled. The assemblage of correlations, and subsequent discussion, is presented from a historical perspective, starting from pioneering work on the topic in the 1950s to the modern day. Despite the growing sophistication of sCO2 heat transfer correlations, modern correlations are still only generally applicable over a relatively small range of operating conditions, and there has not been a substantial increase in predictive capabilities. Recently, …

Autonomous Unmanned Aerial Vehicle Navigation Using Reinforcement Learning: A Systematic Review, Fadi Almahamid, Katarina Grolinger

Electrical and Computer Engineering Publications

There is an increasing demand for using Unmanned Aerial Vehicle (UAV), known as drones, in different applications such as packages delivery, traffic monitoring, search and rescue operations, and military combat engagements. In all of these applications, the UAV is used to navigate the environment autonomously --- without human interaction, perform specific tasks and avoid obstacles. Autonomous UAV navigation is commonly accomplished using Reinforcement Learning (RL), where agents act as experts in a domain to navigate the environment while avoiding obstacles. Understanding the navigation environment and algorithmic limitations plays an essential role in choosing the appropriate RL algorithm to solve the …

Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

This study interprets the observed behavior of solvent extraction of lignin from hardwoods by adapting the framework of the FLASHCHAIN theory (Niksa and Kerstein, 1991; Niksa, 2017). A constitution submodel specifies distributions of molecular weight and reactive sites for native lignin. The model simulates delignification as depolymerization of lignin macromolecules into fragments small enough to be soluble. This process competes with intrachain condensation that consumes labile bridges without forming new fragments, and with recombination that forms larger chains and inhibits further depolymerization. After the soluble fragments are transported from the particle into the bulk solvent, all chemistry continues as long …

Cellular Bioenergetics: Experimental Evidence For Alcohol-Induced Adaptations, Liz Simon, Patricia E. Molina

School of Medicine Faculty Publications

At-risk alcohol use is associated with multisystemic effects and end-organ injury, and significantly contributes to global health burden. Several alcohol-mediated mechanisms have been identified, with bioenergetic maladaptation gaining credence as an underlying pathophysiological mechanism contributing to cellular injury. This evidence-based review focuses on the current knowledge of alcohol-induced bioenergetic adaptations in metabolically active tissues: liver, cardiac and skeletal muscle, pancreas, and brain. Alcohol metabolism itself significantly interferes with bioenergetic pathways in tissues, particularly the liver. Alcohol decreases states of respiration in the electron transport chain, and activity and expression of respiratory complexes, with a net effect to decrease ATP content. …

Parametric Design Of A Manifold For A Hollow Micropillar Evaporator For Use In High Heat Flux Applications, Alex Dutton

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the failure of Dennard Scaling and changes in electronics packaging leading toward 2.5 and 3D packages, the current methods of thermal management are failing to keep up with rising heat fluxes. In order to manage these rising heat fluxes, engineers and scientists are looking towards two phase cooling and microchannel flows.

Many forms of novel thermal management are currently being investigated as means to address the thermal challenges present in modern microelectronics, including flow boiling, pool boiling, and direct liquid cooling. One technology of interest is evaporative cooling using continuously fed micro-droplets. High evaporation rates can be achieved by …

Speeding Up The Quantification Of Contrast Sensitivity Functions Using Multidimensional Bayesian Active Learning, Shohaib Shaffiey

McKelvey School of Engineering Graduate Student Theses & Dissertations

No abstract provided.

Developing Optical Devices And Projects For Teaching Engineering, Nathan D. Lemke, John Mccauley, Tristan E. Noble, Grace Riermann, Ellesa St. George, Nathan C. Lindquist, Keith R. Stein, Karen Irene Rogers

Physics and Engineering Faculty Publications

We are creating a suite of tools and techniques based on optics to be used for teaching a variety of engineering topics. Each tool is intended for non-expert use and without the need for high-end equipment such as vibration-free optical tables. Here we report progress on three such tools: image-plane digital holography for measuring mechanical deformation; schlieren imaging of convective flows using a smart phone; and a simple optical communication protocol using LabVIEW. We will present the designs of the tools and preliminary results from teaching engineering labs and projects with these tools. Specific courses impacted to date include Fluid …

Improving The Reliability Of Visual Inspections Conducted By Environmental Health And Safety Professionals, On A Hyperscale Data Centre Construction Site, Alex A. Schouten, Victor Hrymak

Conference papers

The conduct of visual inspections on construction sites is of crucial importance for workplace safety. This is because visual inspection is the primary method by which construction site hazards are routinely observed, monitored and controlled. However, there is no consensus guidance as to how such visual inspections should be conducted. This is resulting in many observable hazards going unseen and therefore not being appropriately managed on construction sites worldwide. In an attempt to improve the reliability of visual inspection, this study presents results from an innovative method called systematic visual inspection which utilises an iterative set eye scan pattern during …

Navigating The Virtual Landscape: Implementing A Pedagogical Framework In A Virtual Summer Engineering Course To Enhance Students' Academic Development, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this evidence-based practice paper, the recently established CIRE educational model was incorporated, and modified, to establish an alternative pedagogical framework for a virtual, fast-paced summer engineering course in a private university in Texas. Transitioning to fully online courses in the wake of COVID-19 required a rapid modification of traditional pedagogical methods to overcome challenges such as the lack of academic resources and established campus practices, while simultaneously ensuring the academic and social development of students. In this regard, a pedagogical framework known as the CIRE model – which is the acronym for Communication, Initiation, Reduction, and Extension – was …

Midterm Oral Exams Add Value As A Predictor Of Final Written Exam Performance In Engineering Classes: A Multiple Regression Analysis, Minju Kim, Celeste Pilegard, Huihui Qi, Curt Schurgers, Marko Lubarda, Saharnaz Baghdadchi, Alex Phan

Psychology Faculty Articles and Research

What is gained when midterm oral exams are implemented in the undergraduate engineering classroom? This research paper examines whether midterm oral exam scores add value above and beyond midterm written exam scores in predicting students’ final written exam scores. The purpose of this study is to evaluate the potential utility of oral exams as formative assessments: if oral exam scores provide additional information beyond written exam scores, they may add meaningful value for students and instructors. The current study investigates this question using data from 10 undergraduate engineering classes (N = 925), representing 6 different courses and 5 different instructors. …

In-Person Instruction Or Remote Learning?: Understanding Students' Learning Experiences During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Research attests that student success in engineering education is cultivated largely due to classroom environments, academic inclusion, and engagement in undergraduate research. It is further revealed that the social and academic fabric of the institution such as academic advising, peer tutoring, disability services, and outdoor recreational programs is essential towards fostering well-being, recruitment, retention, and student success. However, these studies were conducted in a period in which students experienced traditional face-to-face instruction. In the wake of COVID-19, most institutions responded by terminating in-person instruction, mandating to seek off-campus housing, and shifting to a fully remote context. As such, educators were …

Do Agrivoltaics Improve Public Support For Solar? A Survey On Perceptions, Preferences, And Priorities, Alexis Pascaris, Chelsea Schelly, Mark Rouleau, Joshua Pearce

Michigan Tech Publications, Part 1

Agrivoltaic systems integrate agricultural production with solar photovoltaic electricity generation. Given the proven technical, economic, and environmental co-benefits provided by agrivoltaic systems, increased proliferation is anticipated, which necessitates accounting for the nuances of community resistance to solar development on farmland and identifying pathways for mitigation. Minimizing siting conflict and addressing agricultural communities’ concerns will be key in continued deployment of agrivoltaics, as localized acceptance of solar is a critical determinant of project success. This survey study assessed if public support for solar development increases when energy and agricultural production are combined in an agrivoltaic system. Results show that 81.8% of …