Physical Sciences and Mathematics Commons^™

Addressing Specific Safety And Occupational Health Challenges For The Canadian Mines Located In Remote Areas Where Extreme Weather Conditions Dominate, Rachid Halabi, Mustafa Kumral

Journal of Sustainable Mining

The number of mining operations is increasing in the Canadian North, where extreme weather conditions govern. Currently, many mine development projects are also in progress in this region. These mines’ working atmosphere and employment circumstances are highly different from regular mines. One of the main differences is the special safety issues of the Canadian North. The primary sources of these special issues are: the difficulty of finding skilled employees; high employee turnover rate; insufficient training and certification requirements; delicate employment circumstances affecting the psychological well-being of employees; permafrost; mine inspection challenges; inventory and logistic hardship; and the legislative and regulative …

Flow Regime Evolution Of A Major Cave System In The Eastern Alps (Hirlatzhöhle, Dachstein), Lukas Plan, Gottfried Buchegger, Eva Kaminsky, Gabriella Koltai, Tanguy Racine, Jacek Szczygieł

International Journal of Speleology

The 116 km-long and 1560 m-deep Hirlatzhöhle is one of the major cave systems in the Northern Calcareous Alps (NCA; Austria). It is located in the NW part of the Dachstein, an extensive karst massif encompassing 576 km² with its highest point at 2995 m a.s.l. In contrast to most other caves in the NCA, Hirlatzhöhle comprises old (epi)phreatic passages located up to 1 km above the base level as well as two modern major drainage systems. The aim of this study is to define the palaeo- and the active flow conditions in combination with speleogenesis, and the age of …

On Airborne Tire Wear Particles Along Roads With Different Traffic Characteristics Using Passive Sampling And Optical Microscopy, Single Particle Sem/Edx, And Μ-Atr-Ftir Analyses, Zhiqiang Gao, James V. Cizdziel, Kendall Wontor, Carly Clisham, Kaylea Focia, Juanita Rausch, David Jaramillo-Vogel

Faculty and Student Publications

Tire wear particles (TWPs) are a major category of microplastic pollution produced by friction between tires and road surfaces. This non-exhaust particulate matter (PM) is transported through the air and with runoff leading to environmental pollution and health concerns. Here, we collected airborne PM along paved roads with different traffic volumes and speeds using Sigma-2 passive samplers. Particles entering the samplers deposit onto substrates for analysis, or, as we modified it, directly into small (60 ml) separatory funnels, which is particularly useful with high particle loads, where a density separation aids in isolating the microplastics. We quantified putative TWPs (∼10–80 …

Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan

Coal Geology & Exploration

Irregular coal seam mining is easy to cause the problems such as roof stress concentration and abnormal ground pressure behavior. In order to explore the roof fracture law and the structural evolution characteristics of stope with variable length, the roof structure models with four types of boundary conditions were established and analyzed using the small-deflection thin plate bending theory in view of the geometric characteristics and mechanical causes of the abrupt stope with the inclined length of working face changing from small to large in various mining stages. Meanwhile, the roof fracture law and macro-mechanical response were analyzed by MATLAB …

Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale

Coal Geology & Exploration

Permeability is an important parameter to characterize gas flow. In order to ensure the safe and efficient gas drainage, it is necessary to explore the evolution characteristics of coal reservoir gas seepage at different positions from the producing wellbores. However, the effective stress, the gas adsorption/desorption capacity of coal matrix and the temperature of coal reservoir are constantly changing with the gas drainage, and even the drainage damage may occur, which makes the gas migration behavior in coal seam extremely complicated. In order to explore the seepage characteristics of coal reservoir gas during gas drainage, the space-time evolution function of …

Research And Application Progress Of Energy Underground Structures, Wen Jiwei, Hou Junlong, Liu Xinghong, Zeng Xian’En, Xiang Tian

Coal Geology & Exploration

Energy geostructure refers to a type of structure equipped with heat exchange pipe in the building foundation element and the underground structure, which has the functions of load bearing and heat exchange. It not only effectively saves the valuable and irreversible underground space resources, but also makes full use of the non-carbon based continuous, stable, safe and clean geothermal energy resources, thus having more advantages than the traditional Ground Source Heat Pump (GSHP). Herein, the concept, advantages, research and application progress of energy geostructure at home and abroad were systematically summarized. Moreover, the current situation of four common energy geostructures, …

Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng

Coal Geology & Exploration

The buried pipeline is the part where the rock mass heat pump system performs direct heat transfer with the ground. The water-bearing structure in the karst area is complex and diverse, which has a significant impact on the heat transfer and storage of the buried pipeline group. Herein, the heat transfer process of a group of 27 vertical buried pipelines in four geological structure types was simulated, including the non-karst structure, fractured karst structure, karst conduit structure and mixed karst structure. Meanwhile, comparison was made for the change of parameters, such as the temperature field in the rock mass, the …

Numerical Simulation On Azimuth Gamma Ray Detection Of Coal And Rock Interface, Chen Gang, Chen Long, Li Quanxin, Liu Zhiyi

Coal Geology & Exploration

In order to meet the requirements of geosteering drilling with LWD azimuth gamma, the response value of gamma ray intensity under different surrounding rock thicknesses and absorption coefficients was studied by numerical simulation. Meanwhile, the variation of special and physical characteristics reflected by API value measured by gamma detector under the radioactive formation conditions was simulated and analyzed. On this basis, the geological model of the three layers of coal, mudstone and limestone of 8-sectors azimuth gamma ray drilling was established to simulate the identification process of roof and floor of coal bed drilled. The simulation results show that the …

Mgrre_Thinsections_05_A_61, Mgrre

Thin Sections

No abstract provided.

Status And Prospect Of Harmless Disposal And Resource Comprehensive Utilization Of Solid Waste Of Coal Gangue, Wang Yutao

Coal Geology & Exploration

A large amount of coal gangue generated during coal production and processing is piled up on the surface, which not only causes land occupation and soil erosion, but also causes geological disasters such as landslides and debris flows. So it has a serious impact on the ecological environment of the mining area. The cumulative stockpile of coal gangue in China has exceeded 6 billion tons, accounting for 13000 hectares of land. In 2020, the output of coal gangue in China is 729 million tons, the comprehensive utilization is 526 million tons, and the comprehensive utilization rate is 72.2%. At present, …

Accelerating Multiparametric Mri For Adaptive Radiotherapy, Shraddha Pandey

USF Tampa Graduate Theses and Dissertations

MR guided Radiotherapy (MRgRT) marks an important paradigm shift in the field of radiotherapy. Superior tissue contrast of MRI offers better visualization of the abnormal lesions, as a result precise radiation dose delivery is possible. In case of online treatment planning, MRgRT offers better control of intratumoral motion and quick adaptation to changes in the gross tumor volume. Nonetheless, the MRgRT process flow does suffer from some challenges that limit its clinical usability. The primary aspects of MRgRT workflow are MRI acquisition, tumor delineation, dose map prediction and administering treatment. It is estimated that the acquisition of MRI takes around …

Utilizing Federated Learning And Meta Learning For Few-Shot Learning On Edge Devices, Kousalya Soumya Lahari Voleti

Theses and Dissertations

The efficient and effective handling of few-shot learning tasks on mobile devices is challenging due to the small training set issue and the physical limitations in power and computational resources on these devices. In this thesis, we propose a solution that combines federated learning and meta-learning to handle independent few-shot learning tasks on multiple devices (or clients) and the server. In particular, we utilize the Prototypical Networks to perform meta-learning on all devices to learn multiple independent few-shot learning models and to combine the models in a centralized data distributed architecture using federated learning which can be reused by the …

Synthetic Pseudo-Spin-Hall Effect In Acoustic Metamaterials, Matthew Weiner, Xiang Ni, Andrea Alù, Alexander B. Khanikaev

Advanced Science Research Center

While vector fields naturally offer additional degrees of freedom for emulating spin, acoustic pressure field is scalar in nature, and it requires engineering of synthetic degrees of freedom by material design. Here we experimentally demonstrate the control of sound waves by using two types of engineered acoustic systems, where synthetic pseudo-spin emerges either as a consequence of the evanescent nature of the field or due to lattice symmetry. First, we show that evanescent sound waves in perforated films possess transverse angular momentum locked to their propagation direction which enables their directional excitation. Second, we demonstrate that lattice symmetries of an …

Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo

Coal Geology & Exploration

To solve the problems of poor application flexibility and non-adjustable performance of the current fracturing fluid system in unconventional natural gas of coal measures, an integrated fracturing fluid system is researched. In this study, the experimental evaluation was performed for the viscosity increase, drag reduction, sand suspension, temperature and shear resistance, gel breaking, additive compatibility, anti-swelling and surface tension of the integrated fracturing fluid system based on three kinds of integrated thickeners in combination with the field clay stabilizer, cleanup additive and gel breaker. Meanwhile, the field application effect of integrated fracturing fluid was analyzed. The results show that: the …

Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun

Coal Geology & Exploration

At present, there is no fixed way to predict the sensitive zones of subsidence disaster development in underground coal mining areas, and the prediction result of sensitive zones has a great uncertainty. Herein, the subsidence disaster in Xishan area of Taiyuan City, Shanxi Province was taken as the research object. Totally 4 types of kernel SVM based prediction model for sensitivity zoning of subsidence disaster were constructed with the methods of GIS spatial analysis, statistical analysis and Support Vector Machine (SVM) in combination, taking the subsidence disaster data checked and recorded in 2012 and 2014 as the modeling and verification …

A Cluster Structure On The Coordinate Ring Of Partial Flag Varieties, Fayadh Kadhem

LSU Doctoral Dissertations

The main goal of this dissertation is to show that the (multi-homogeneous) coordinate ring of a partial flag variety C[G/P_K^−] contains a cluster algebra for every semisimple complex algebraic group G. We use derivation properties and a canonical lifting map to prove that the cluster algebra structure A of the coordinate ring C[N_K] of a Schubert cell constructed by Goodearl and Yakimov can be lifted, in an explicit way, to a cluster structure \hat{A} living in the coordinate ring of the corresponding partial flag variety. Then we use a minimality condition to prove that the cluster algebra \hat{A} is equal …

Synthesis Of Carbon Nanohoops And Macrocycles Via Alkyne Metathesis, Xin Zhou

LSU Doctoral Dissertations

Cycloparaphenyleneacetylene (CPPA) and cycloparaphenylene (CPP) are called carbon nanohoops; they are fully conjugated macrocycles with radially oriented aromatic groups. Though many syntheses of CPPA and CPP were reported, in the macrocyclization step, the yields were usually not satisfying, as the reactions were irreversible. Our group utilizes alkyne metathesis to address this problem. Chapter 1 provides backgrounds and an introduction to the carbon nanohoops and alkyne metathesis.

Chapter 2 details the synthesis of the [3]CPP⁴A and [3]CPP⁵A, with good macrocyclization yields via alkyne metathesis. This study showed the error-correction ability of alkyne metathesis, especially with nonsymmetric substrates. …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying

Coal Geology & Exploration

The coal measure fault zone generated by the superimposition of the polytropic movement and multiple structure has important effects on the coal seam gas occurrence. The method of combining the geologic analysis, COMSOL Multiphysics numerical simulation and field data monitoring was adopted to analyze the interaction relations between the stress distribution characteristics and faults of the normal fault zone in the coal measure, study the coal seam permeability variation characteristics influenced by the normal fault zone in the coal measure, and simulate the gas migration status and concentration distribution condition after the formation of the normal fault zone. The coal …

Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei

Coal Geology & Exploration

Lithium (Li) is an important energy metal, and the global demand for Li has grown rapidly in recent years. The discovery of coal-associated Li deposits in China proves that coal mines may serve as a potential alternative of Li resources. No.20 coal seam in Pu’an mining area in Guizhou province of China was selected as the study object. The basic properties, mineral composition, elemental composition, and occurrence modes of Li of the raw coal and six density-graded samples (obtained through a float-sink test) were determined by using coal proximate analysis, optical microscope, X-Ray fluorescence spectroscopy (XRF), inductively coupled plasma mass …

Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang

Coal Geology & Exploration

Crossing ditch mining of shallow coal seam is common in northern Shaanxi mining area, which seriously threatens the safe production and the sound ecological development. The mining-induced overburden fractures and surface cracks are developed as a result of the extension and expansion of microcracks in rock mass. In order to more systematically study the evolution law of overburden microcracks in crossing ditch mining of shallow coal seam, a numerical model of particle flow in coal mining was established with the Particle Flow Code (PFC) numerical simulation platform according to the field ditch profile and borehole data under the background of …

Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie

Coal Geology & Exploration

Stress relaxation often occurs in the saturated soft clay with poor water permeability under the actual working condition at fast construction speed (fast loading rate), which brings huge hidden dangers to the safe operation of engineering practice. Herein, the unconsolidated undrained triaxial shear test was performed based on the soft dredger fill in Tianjin Binhai using the WF stress path triaxial instrument, and the influence law of such factors as the different initial strain, confining pressure, shear rate, sampling depth and structural properties of the soft dredger fill on its stress relaxation characteristics was analyzed accordingly. According to the test …

Spatial Variation Characteristics Of Soil Heavy Metal Speciation And Bioavailability In Coal Gangue Accumulation Area—Taking Fengfeng Mining Area As An Example, Sun Tao, Song Shijie, Chang Qing, Wang Chenchen, Zhang Yanjie, Peng Ruisi, Wang Yi

Coal Geology & Exploration

The surface accumulation of coal gangue is a typical form of ecological environment destruction in the eastern coal mining area of China, and the prevention and control of heavy metal pollution in the soil in the accumulation area has become a hot spot in the current research. Taking the shallow soil (with a vertical depth of 40 cm and below) around a coal gangue mountain (within a radius of 300 m) in use in the Fengfeng mining area of Hebei as the research object, the active state, iron manganese oxidation state, organic state and residue state of four kinds of …

Effect Of Initial Adhesion On Shear Strength And Deformation Characteristics Of Interfaces In Heterogeneous Soils, Zhu Yanbo, Yang Fanfan, Miao Shuaisheng, Li Futong, Zhang Yuxuan

Coal Geology & Exploration

In the Loess Plateau of China, the interface between the Loess and Hipparion Red Clay is widely distributed. The initial adhesion between this interfaces plays an important role in its shear strength. To investigate the effect of initial adhesion on shear strength and deformation characteristics of the interfaces, we firstly performed a series of direct shear experiments. Then, we discussed the effects of initial adhesion on failure mode, shear deformation and shear strength of interfaces. The results indicate that the failure modes of interfaces with initial adhesion and interfaces without initial adhesion are different. The initial adhesion improves the sliding …

Time-To-Depth Conversion Accuracy Analysis And Improvement Method For Inclined Coal Bed, Wang Huifeng, Fu Chao, Li Guo, Chen Tongjun

Coal Geology & Exploration

The average-velocity method is the most commonly-used time-to-depth conversion technology for the seismic survey of coalbed. But for the steeply-inclined coalbed, the average velocity changes rapidly laterally, and the interpretation accuracy varies greatly, so that the intelligent coal mining could not be assured effectively. Herein, the accuracy of various average-velocity-interpolation methods was discussed by analyzing a steeply-inclined coalbed model and a practical 3D seismic mining area and appropriate improvement methods were proposed accordingly. The calculation results of a forward model show that the bottom elevation accuracy of coalbed is greatly affected by the locations of interpolation points in the case …

Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei

Coal Geology & Exploration

In borehole enlarge drilling, it is necessary to adjust the flow of mud pump to switch drilling and borehole enlarging state, and the control effect is not ideal. To improve the precision of the borehole enlarging technology while drilling machinery control, a pump-free double channel mechanical borehole enlarging drill bit was developed, which equiped with dual channel to form a complete set of double channel drill pipe and double channel water device. Two sets of individual waterways were designed, annulus water way for cooling bit and carry out rock powder, and center water way is used to control the opening …

Air-Driven Directional Drilling Technology And Equipment In Soft Coal Seam Of Huainan Mining Area, Tian Hongliang, Chen Jian, Zhang Jie, Cheng Heyu, Dong Ruigang, Du Limeng, Liu Degui, Guan Qiangsheng

Coal Geology & Exploration

Aiming at Huainan mining area using bedding directional drilling to eliminate gas outburst in strip coal seams of working face and adjacent roadways, we put forward a technical idea of using pneumatic long directional drilling hole to eliminate gas outburst by one hole. On the basis of the previous pneumatic screw directional drilling technology test, we developed a narrow-body full-section remote directional drilling rig with a width of only 1.1 m, the spindle angle can be stepless adjusted from −90° to 90°, and maximum remote distance of 50 m. The ø73/82 mm screw pneumatic screw drill was optimized, with maximum …

Influencing Factors Of Increasing The Signal Strength Of The Em-Mwd By Applying Insulation Coating Outside The Casing, Shao Chun, Hu Chuang, Xu Lin, Chen Minghua, Long Xiaoping

Coal Geology & Exploration

Applying insulation coating outside the casing can reduce the attenuation of Electromagnetic measurement-while-drilling (EM-MWD) signals in low resistivity formations and increase the transmission depth of EM-MWD signals. For the purpose of obtaining the resistivity range of the formation applicable to the insulation coating and the influence of the coating characteristics on the received signal strength, a simulation model is established based on the finite element method, and simulation experiments are carried out on the application effect of the insulation coating applied to the casings of different resistivity formations and the influence regularity of the coating resistivity, thickness and length on …

Research On Drill Pipe Pose Recognition Technology Based On Monocular Vision, Ma Bin, Peng Guangyu

Coal Geology & Exploration

As a key technology in the field of intelligent drilling equipment, automatic drill pipe loading and unloading technology restricts the automation and intelligent development of underground drilling equipment in coal mines. The existing drill pipe automatic loading and unloading system mainly relies on the mechanical structure and proximity switches for positioning, which has the problem of poor positioning accuracy and low automation. To solve this problem, a drill pipe pose recognition algorithm based on monocular vision technology was proposed. The camera was used to capture the image containing the cooperative target, and the relative distance and posture between the camera …

Redevelopment Strategy Of Closed Coal Mine Industrial Plaza: A Case Study Of Fenghuangshan Mine In Jincheng, China, Wang Jingxiang, Chang Jiang, Deng Yuanyuan, Lin Yan, Wu Haoran

Coal Geology & Exploration

With the effective implementation of China’s policy on cutting the overcapacity of coal, a number of mines with exhausted resources and backward production capacity have been shut down and abandoned. Thus, the traditional independent industrial and mining areas become silent, and the industrial plazas serving coal production and workers’ lives are faced with the problems such as function loss and idle land. Therefore, excavating the value of the closed coal mine industrial plazas and giving it new functions is the key to revitalize the existing resources and stimulate the vitality of independent industrial and mining areas. Herein, research was conducted …