Oil, Gas, and Energy Commons^™

Hydrochemical Formation Mechanism And Transmissivity-Impermeability Analysis Of Karst Groundwater On Both Sides Of Fault F104 In Gubei Coal Mine In Huainan, Zheng Zhuyan, Xu Guangquan, Yang Tingting, Yu Shitao, Zhang Haitao

Coal Geology & Exploration

It is of great practical significance for the prevention and control of groudwater hazards in North China type coalfield to judge transmissivity-impermeability of faults by using karst hydrochemical characteristics of two fault walls. Taking karst groundwater of Taiyuan Formation on both sides of fault F₁₀₄ in Gubei coal mine as the research object, and based on the analysis of the hydrogeological conditions of two fault walls, main components sources and water-rock interaction differences were analyzed by using Piper trilinear diagram, ion combination ratio and principal component methods. Reverse hydrochemical simulation of karst groundwater was conducted by using PHREEQC software. …

Mining Response And Dynamic Reinforcement For Narrow Coal Pillar Next To Goaf In Working Face 1402 Of Xin’An Coal Mine, Wang Beifang, Liang Bing, Liu Wei, Zhang Jing, Chi Haibo, Liu Yahui

Coal Geology & Exploration

with the increase of integrating coal mines under national coal de-capacity policy, the mining instability phenomenon of narrow coal pillar next to goaf is increasingly prominent, which has seriously restricted the safety and efficient production in coal mines. Therefore, stability control engineering problem of narrow coal pillar next to goaf, near No.5 drilling field on air return roadway of repeated mining face 1402 in Xin'an coal mine was as study object, a method of combining numerical simulation and theoretical analysis was used to explore the mining disturbance response characteristics of narrow coal pillar stability next to goaf, near No.5 drilling …

Anisotropic Shear Behavior Of Rock Joint Based On 3d Printing Technology, Xu Xunhui, Zhang Guobiao, Bao Han, Yan Changgen

Coal Geology & Exploration

Topography is an important factor affecting the shear behavior of joint. Furthermore, there are certain connections between the anisotropy of topography and the anisotropy of shear behavior. In this study, 3D laser scanning technology and 3D printing technology were used to make molds for simulating the topography of natural joint. Then, the cement mortar samples with dimension of 100 mm×100 mm×150 mm were cast, and shear tests with different shear directions under different normal stresses were conducted. The results indicate that obvious anisotropy has been shown in the joint shear behavior, which is reflected in the peak shear strength and …

Three-Dimensional Stress Evolution And Comprehensive Treatment Technology For Super-Long Working Face Across Abandoned Roadway With Large Section, Wang Yan, Xiong Zuqiang, Zhao Gaobo

Coal Geology & Exploration

In order to solved the problem of super-long working face across abandoned roadway with large section, which is easy to cause rib spalling and roof falling, based on a super-long working face in Chengzhuang mine of Jincheng, a three-dimensional model of abandoned with large section roadway was established. The roof of working face was divided into three parts: coal pillar roof, abandoned roadway roof and mining area roof. The criterion of pillar instability was deduced and the roof stress evolution process of large section abandoned roadway was analyzed by FLAC^3D numerical simulation. The results show that when the W …

Multidimensional Deformation Monitoring Using Insar Technology In Yuxian Mining Area, Du Jiantao, Yan Li, Zhao Chaoying

Coal Geology & Exploration

Yuxian County in Hebei Province is one of the largest mining areas in North China. This area has been suffering serious ground deformation due to underground mining activity, which not only threatens mining safety, but also seriously damages local ecological environment. To obtain the surface deformation map of the overall mining area and to analysis the spatiotemporal evolution features, 61 C-band descending track and ascending track Sentinel-1A/B images from July 2017 to September 2018 were processed based on Interferometric Synthetic Aperture Rader(InSAR) technique. In addition, the two-dimensional deformation time series of Xixizhuang mine were obtained by using the multi-dimensional deformation …

Ruger Approximate Formula-Based Prediction Of Fractured Reservoir, Wu Shanshan, Gao Gang, Gui Zhixian, Wang Peng, Li Chengyi

Coal Geology & Exploration

The azimuthal anisotropy of pre-stack P-wave is the most widely used method to detect fracture. This method mainly uses the long-axis and minor axis information of the ellipse fitted by the AVAZ seismic data to evaluate the fracture. When applying it in practice, it is considered that the variation of AVAZ response characteristics in the fractured reservoirs is just determined by the anisotropic parameters, and the influence of non-anisotropic parameters is not taken into account, which leads to the multi-solution of fracture evaluation. In order to improve the accuracy of this fracture evaluation technology, we started with the model analysis, …

Application Of Far And Near Trace Attributes For Avo Analysis In Deep Water Area In Qiongdongnan Basin, Liu Shiyou, Zhang Yingzhao, Li Yangsen, Yan Anju, Zhang Haiyang

Coal Geology & Exploration

For prestack seismic data with low signal-to-noise ratio(SNR), the effect of traditional AVO rendezvous analysis and intercept gradient product attribute(P×G attribute) may not be ideal. In order to extract the information of AVO attribute effectively, this paper starts from the prestack partial superposition body, according to the relative relation of the far and near track part superposition body, the far and near attribute factor similar to the P×G attribute was constructed, in which the near track stack reflects the intercept attribute, and the near-far stack difference reflects the intercept attribute, which is similar to the …

Application Of Small Scale Curvature In Small And Micro-Structure Interpretation Of Coal Field, Cheng Yan

Coal Geology & Exploration

The interpretation and delineation of small and micro-structure which acts as one of the main disaster sources in coal mine is an important guarantee for safe and efficient production of coal mines. However, it can't satisfy the geological guarantee for precise mining by only using the traditional seismic exploration methods to solve this problem. Therefore, in this paper, we reconstruct the seismic data by extracting the components above 60 Hz from the 3D seismic data, and then extract minimum negative curvature to interpret and analyze the small and micro-structures in study areas. By comparing the revealed micro-structures and explained results …

Application Of Mine-Hole Joint Microseismic Technology In Monitoring The Damage Depth Of Working Face Floor, Duan Jianhua, Yan Wenchao, Nan Hanchen, Zhang Qingqing, Fan Xin

Coal Geology & Exploration

Accurate prediction of the mining damage depth of floor is a key problem in the prevention and control of mining floor water hazard especially in the case with confined water. It is very important for developing the strategy of water control. According to the geological characteristics and working face layout of Baode coal mine, Shaanxi Province, a high-precision microseismic monitoring system consisting of well and hole arrays was deployed to detect the floor damage depth in working face 81307 in real time. The velocity model was calibrated and the location accuracy was verified by hammering method. It is proved that …

Forward Response Analysis Of Shield Advanced Detection With Moving Array Electrode, Zhao Shuanfeng, Bai Yunrui, Huang Tao, Wei Mingle

Coal Geology & Exploration

Aiming at problems of serious electromagnetic interference, difficult application in TBM(Tunnel Boring Machine) tunnel construction and so on, a method of shield advanced detection based on moving array electrodes is adopted. Using Comsol Multiphysics finite element simulation software to establish geoelectric model, forward response analysis is carried out for various geological conditions. The results show that adding the protective electrodes can obviously enlarge the voltage distribution range, which means the detection range increases. In order to improve the detection effect, it is necessary to add protective electrodes. Changes in the size, shape and position of the anomalous body will exhibit …

Frequency Dispersion Mechanism Of Complex Resistivity Of Coal, Guo Yuehui, Zhang Yugui, Li Jian, Zhou Meng

Coal Geology & Exploration

In order to study the physical mechanism of frequency dispersion of complex resistivity of coal at 0-200 kHz, the amplitude-frequency and phase-frequency of complex resistivity of coal are measured under variable frequency of constant current. Using the Fourier inverse transform to convert the frequency domain data of complex resistivity of coal into time domain data; Using the Cole-Cole model, the complex resistivity dispersion data are fitted; Drawing on the electric double layer deformation hypothesis theory, the dispersion mechanism of complex resistivity of coal is studied by comparing the frequency dispersion of sandstone. The results show that in the current frequency …

The Key Technology For Drilling Horizontal Well In Coal Seam Roof In Qianbei Mining Area, Hu Xinpeng, Zhao Yongzhe, Xu Kanshe, Wang Linjie, Li Peng, Duan Huijun

Coal Geology & Exploration

primary ways to develop the soft coal seam CBM. Aiming at the complex geological conditions and reservoir conditions in Qianbei mining area of Guizhou Province, in order to solve the problems of horizontal well leakage, well trajectory control and solid completion in the horizontal well drilling of coal seam roof, the key technology of horizontal well drilling of coal seam roof in Qianbei mining area, with the accurate control of trajectory as the core, and the technology of preventing leakage, eccentricity and solid completion are combined. Combined with on-site drilling practice, the problems of difficulties in horizontal well drilling were …

Effect Of Temperature On The Performance Of Pdc Cutters With Different Shape, Zhang Suhu, Wang Chuanliu, Dai Yongbo

Coal Geology & Exploration

In order to explore the performance of PDC cutters at different temperatures to adapt to different brazing temperatures, and to reasonably select the shape to improve efficiency. Based on the several main parameters affecting the quality of polycrystalline diamond compacts (PDC), such as wear resistance, grinding time, stationarity and impact toughness, the performance of PDC sheets from different manufacturers and different shapes was tested. The performance of PDC before or after heating and at different temperatures was obtained. At the same time, the performance of flat sheets, micro-arcs sheets and arcs sheets was compared. The results show that with the …

Senior Project Scientist George Hagerman Discusses Wind Turbines On Coast Live, News @ Odu

News Items

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Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …

Computational Assessment Of Aortic Valve Function And Mechanics Under Hypertension, Saurav Kadel

Browse all Theses and Dissertations

Calcific aortic valve disease (CAVD), the most common valvular heart disorder, is associated with complications such as stroke, heart attack, aortic aneurysm, left ventricular hypertrophy, and ultimately death. While hypertension has been identified as a major risk factor for CAVD, the mechanisms by which it may promote calcification are still unknown. Given the sensitivity of valvular tissue to mechanical stress alterations, the hemodynamic abnormalities linked to hypertension may play a role in the development of CAVD. Further, the effects of hypertension on the left ventricular functionality and coronary flow resistance remain largely uninvestigated. Hence, the objectives of this thesis were …

Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri

Wayne State University Dissertations

Solid electrolytes including ceramics and polymers are considered to be the ultimate substitute for organic liquid electrolytes currently used in commercialized lithium ion batteries to address the safety concerns due to Li dendrite growth and internal short circuiting. However, low ionic conductivity due to high grain boundary resistance in ceramics and semi-crystalline nature of polymers has held back the solid electrolytes from being used in Li-ion batteries. Polyethylene oxide (PEO), complexed with a Li-salt, is a well-studied polymer electrolyte showing ionic conductivity properties at room temperature. However, the coexistence of amorphous and crystalline regions at room temperature (< Tm, the melting temperature) has

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Heigh-Ho, They Blow, Husker Balloons Have Got To Go, Zowie Vincent

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

One petition, one billboard, one lawsuit, and a 52% majority vote. Multiple attempts have been made to challenge the balloon releases at Memorial Stadium. Though there are mild surges of advocacy against this action during the football season and the annual spring semester vote, this issue, despite numerous attempts, continues to fall on deaf ears.

Lincoln’S Brightest Policy On Solar Energy, Jerin Tekolste

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

The push towards renewable energy is ubiquitous, with reasons varying from greater independence from foreign energy markets to environmental considerations or sustainable futures. Many countries, states, and cities all around the world are pursuing different ways to better their energy generation and Lincoln is no different. The current policy provides some incentive towards residential solar power but can be improved upon. There are typically three mechanisms used for residential photovoltaic (PV) solar generation: Feed-In Tariffs (FITs), Net Metering, and Net Purchase and Sale. This paper will compare the options Lincoln could use and will conclude with what would be the …

Save The Tax Break, Megan Bilstein

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Saving 26% on inputting a clean form of energy sounds pretty good to me. According to the U.S. Department of Energy by inputting a solar panel into your house, property, or shop you could have 30% of the cost to install a solar panel system deducted from your federal income taxes, that was in 2019. Come 2020 it decreased to 26% and 22% in 2021 then completely gone in 2022. Unless something is done to save the tax credit this form of renewable energy may be completely forgotten about or put to the side in Nebraska while other forms will …