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2020

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Full-Text Articles in Sustainability

Droughtscape, Summer 2020, National Drought Mitigation Center Jul 2020

Droughtscape, Summer 2020, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Summer 2020


A Survey Of Dairy-Goat Keeping In Zanzibar, Tiffanie Stone, Charles A. Francis, L. O. Eik Jul 2020

A Survey Of Dairy-Goat Keeping In Zanzibar, Tiffanie Stone, Charles A. Francis, L. O. Eik

Department of Agronomy and Horticulture: Faculty Publications

Dairy goats with improved genetics for milk production were recently introduced onto small-scale farms in Zanzibar through governmental and non-governmental projects. These projects were meant to support small-scale farmers by improving both income and household nutrition through milk production. No follow up had been conducted to understand what effects dairy goat keeping had on these small-scale farms, or how they could be improved. A survey of 193 dairy goat farmers in Zanzibar was conducted, including 30% and 60% of all dairy goat farmers on Unguja and Pemba, the two largest islands, respectively. The objective was to understand the impact keeping …


Drivers Of Rural Development Strategies At The Farm Level: A Case Study On Circular Agriculture In The Netherlands, Anna Berger Mulder Jul 2020

Drivers Of Rural Development Strategies At The Farm Level: A Case Study On Circular Agriculture In The Netherlands, Anna Berger Mulder

Graduate Theses and Dissertations

The sustainability of the agricultural sector worldwide is increasingly being pressurized by ecological, economic, and social developments. The Dutch government is promoting enhancing circular agriculture as an important rural development strategy in response to the challenges the sector is facing. All farmers in the country will have to be involved in closed cycles by 2030, but many farmers do not want to or cannot make this transition. This study aims to identify the different factors that influence a farmer’s decision to transition towards circular agriculture. Based on thirteen semi-structured interviews with already transitioned farmers, a policy officer, a consultant, and …


Correlation Analyses Among Soil, Plant, And Environmental Variables And Greenhouse Gas Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil, Diego Della Lunga Jul 2020

Correlation Analyses Among Soil, Plant, And Environmental Variables And Greenhouse Gas Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil, Diego Della Lunga

Graduate Theses and Dissertations

Alternative water management practices for rice (Oryza sativa) production have been developed for water conservation purposes, such as the relatively new furrow-irrigated rice production system, which results in spatially variable volumetric water content (VWC), temperature, and oxidation-reduction (redox) potential. No research has been conducted to relate greenhouse gas (GHG) production to soil and plant properties or environmental factors under furrow-irrigated rice. The objective of this field study was to evaluate correlations between methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) fluxes and emissions and global warming potential (GWP) and near-surface soil properties and environmental factors over two growing seasons …


Economic Determinants Of Energy Intensity: A Country Panel Analysis, Dehdar Fatemeh Jul 2020

Economic Determinants Of Energy Intensity: A Country Panel Analysis, Dehdar Fatemeh

Student Works (2020-2029)

Efforts to lower energy intensity increased initially as a result of rising fuel prices following the first and second oil shocks, which subsequently became serious owing to mounting evidence that fossil fuels are a major cause of climate change and global warming. Energy source is a key problem associated with climate change as oil and gas, and coal constitute major components of fossil fuels. However, the extant literature remains divided on the determinants of energy intensity. For the purpose of filling this gap, this study modeled energy intensity and used panel annual data from 84 countries, (divided to stable and …


Climate Toolkit: A Resource Manual For Science And Action - Version 2.0, Frank Granshaw Jul 2020

Climate Toolkit: A Resource Manual For Science And Action - Version 2.0, Frank Granshaw

PDXOpen: Open Educational Resources

The Climate Toolkit is a resource manual designed to help the reader navigate the complex and perplexing issue of climate change by providing tools and strategies to explore the underlying science. As such it contains a collection of activities that make use of readily available on-line resources developed by research groups and public agencies. These include web-based climate models, climate data archives, interactive atlases, policy papers, and “solution” catalogs. Unlike a standard textbook, it is designed to help readers do their own climate research and devise their own perspective rather than providing them with a script to assimilate and repeat. …


Projected Surface Water For Fruit And Vegetable Irrigation Under A Changing Climate In The Us, Marty Matlock, Greg Thoma, Kieu Ngoc Le, Eric Cummings, Zach Morgan, Andrew Shaw Jun 2020

Projected Surface Water For Fruit And Vegetable Irrigation Under A Changing Climate In The Us, Marty Matlock, Greg Thoma, Kieu Ngoc Le, Eric Cummings, Zach Morgan, Andrew Shaw

Water Systems

Increasing greenhouse gas concentrations in the atmosphere, resulting in climate impacts, are raising concerns over the hydrologic cycle and its effects upon agricultural productivity. If rainfall patterns change, meeting an increased demand for fruits and vegetables will pose a challenge for domestic production regions in the United States (U.S.). Information on potential water supply scarcity in the current production regions provides decision makers with critical information for risk mitigation for future production. We used a hydrologic balance-based model of historic and future water availability to evaluate risk of available irrigation water to support major fruit and vegetable production the US. …


Water Environment Comprehensive Forewarning For Waterlogged Area In Huainan Based On Weber-Fechner Law, Pei Wenming, Zhang Hui, Ju Changhua, Yao Suping, Ren Yongle, Ma Mengxiao, Qiu Kuanbiao Jun 2020

Water Environment Comprehensive Forewarning For Waterlogged Area In Huainan Based On Weber-Fechner Law, Pei Wenming, Zhang Hui, Ju Changhua, Yao Suping, Ren Yongle, Ma Mengxiao, Qiu Kuanbiao

Coal Geology & Exploration

In area with high groundwater level in the east of China, long-time underground coal mining results in a large subsidence water area on the surface. The risk of water environment pollution in subsidence waters is increasing gradually with the influence of human activities. According to Weber-Fisher law, this paper took Panji waterlogged area of Huainan as the research object, selected the water quality evaluation indexes closely related to the water environment of the waterlogged area, analyzed the water environmental conditions of the waterlogged area in different periods, and quantitatively reflected the time and the area of the water environment quality …


Performance Test And Proportioning Optimization Of Loess-Based Grouting Materials In Coal Mining Subsidence Area Of Northern Shaanxi, Cao Xiaoyi, Wang Yutao, Liu Xiaoping, Cao Zubao, Wu Boqiang Jun 2020

Performance Test And Proportioning Optimization Of Loess-Based Grouting Materials In Coal Mining Subsidence Area Of Northern Shaanxi, Cao Xiaoyi, Wang Yutao, Liu Xiaoping, Cao Zubao, Wu Boqiang

Coal Geology & Exploration

Grouting is the main treatment method of mining subsidence area, and the grouting materials have great influence on the grouting effect and cost. Taking the grout mix composed of loess and cement used in northern Shaanxi as the research object, the viscosity, the gelation time, the stone rate and 28 d uniaxial unconfined compressive strength of loess grout were studied by single factor and orthogonal tests. The influencing factors and changing rule of each index were analyzed. Meanwhile, the GA-BPNN prediction model of loess-based grout was established, and the multi-objective global optimization was carried out through GA. The grout ratio …


Stacking Angle Of Slurry-Aeolian Sand Dual-Phase Medium Filling Material, Bai Zhongrong Jun 2020

Stacking Angle Of Slurry-Aeolian Sand Dual-Phase Medium Filling Material, Bai Zhongrong

Coal Geology & Exploration

Stacking angle is an important parameter to describe the spatial accumulation pattern of filling material in the goaf. It has important guiding significance for determining the drilling distance, optimizing the slurry configuration and adjusting the grouting process parameters. In order to grasp the variation law of stacking angle of slurry-aeolian sand dual-phase medium filling material, using self-flow stacking model experiment of tailings and rheological properties experiment, the mixing ratio of aeolian sand was taken as a variable to determine the slurry accumulation parameters and rheological parameters on different conditions of sand ratio. Based on this, Sofra & Boger formula was …


Regional Distribution And Geotectonic Control Of Late Permian Tectonically Deformed Coal In Zhina Coalfield, Zhou Peiming, Gao Wei, Deng Lan, Fu Wei Jun 2020

Regional Distribution And Geotectonic Control Of Late Permian Tectonically Deformed Coal In Zhina Coalfield, Zhou Peiming, Gao Wei, Deng Lan, Fu Wei

Coal Geology & Exploration

In order to find out the tectonically deformed coal distribution law of Zhina coalfield, by sorting out and analyzing the data of more than 200 coal-bearing structural units including Bide syncline, Santang syncline, Zhuzang syncline, Arcong syncline and Guanzhai syncline in Zhina coalfield, Guizhou Province, combined with logging curve analysis, the regional distribution characteristics of coal body structure and structural control factors of No.6, No.16 and No.27 main coal seams are comprehensively analyzed. The study shows that from the west to the east, the proportion of tectonically deformed coal in Zhina coalfield increases gradually. The coal in the western part …


Physical Simutation Experiment Investigation On Hydraulic Fracture Propagation In High-Dip Coal Seam, Jiang Wei, Zhang Jun, Zhong Jie, Zhao Chen, Tang Zhuyun, Lu Haibing, Yi Xinbin, Wang Hai Jun 2020

Physical Simutation Experiment Investigation On Hydraulic Fracture Propagation In High-Dip Coal Seam, Jiang Wei, Zhang Jun, Zhong Jie, Zhao Chen, Tang Zhuyun, Lu Haibing, Yi Xinbin, Wang Hai

Coal Geology & Exploration

In order to study the hydraulic fracture geometry in high-dip coal seam, a large-scale true triaxial fracturing simulation system was used to carry out physical simulation experiments, and the hydraulic fracture geometry of the maximum horizontal principal stress along the strike direction and along the dip direction-in 60° dip coal seam were investigated respectively. Experimental results of the maximum principal stress direction along the strike direction show that: hydraulic fracture initiation is easily; fracture height is limited in the whole time; fracture connectivity is good; fracture propagates mainly along bedding and natural fracture, vertical fracture is formed; the influence of …


Surface Efficient Gas Extraction Mode Based On Full Coverage Of Working Face, Fang Jiawei, Han Baoshan, Zhou Jiajia, Wang Zhengxi, Zhang Dingliang, Liu Jia, Xu Jianjun Jun 2020

Surface Efficient Gas Extraction Mode Based On Full Coverage Of Working Face, Fang Jiawei, Han Baoshan, Zhou Jiajia, Wang Zhengxi, Zhang Dingliang, Liu Jia, Xu Jianjun

Coal Geology & Exploration

Aiming at the problems of soft and broken coal seam, low permeability, difficulty in gas extraction and low drainage efficiency in working face, a full-coverage mode for gas extraction in working face through the horizontal well group with staged fracturing roof at both ends is proposed. Taking a mine in Suxian mining area of Huaibei coalfield as an example, based on the characteristics of in-situ stress and working face distribution, combined with the analysis of gas geological conditions and coal seam mechanical properties in the area, the cross section dipole sonic logging method was used to optimize the orientation of …


Practice And Understanding Of Multi-Layer Drainage Of Cbm Wells In Liupanshui Area, Liu Jiang, Sang Shuxun, Zhou Xiaozhi, Bi Caiqin, Jin Jun, Shan Yansheng Jun 2020

Practice And Understanding Of Multi-Layer Drainage Of Cbm Wells In Liupanshui Area, Liu Jiang, Sang Shuxun, Zhou Xiaozhi, Bi Caiqin, Jin Jun, Shan Yansheng

Coal Geology & Exploration

To improve the effect of drainage and extraction of coalbed methane wells, it is necessary to divide the drainage and production stages reasonably and formulate corresponding control measures. Based on the previous exploration and trial production of coalbed methane in Liupanshui area, this paper analyzed the geological characteristics of coalbed methane and the development characteristics of coal reservoirs in the area, and studied the drainage effect of the combined layers of two wells comparatively. The research shows that the area has several basic characteristics, including many coal seams, thin single-layer thickness, high gas content, high reservoir pressure, low coal seam …


Application Of Time Series Model In Water Inflow Prediction Of Working Face, Shi Longqin, Wang Yaru, Qiu Mei, Gao Weifu Jun 2020

Application Of Time Series Model In Water Inflow Prediction Of Working Face, Shi Longqin, Wang Yaru, Qiu Mei, Gao Weifu

Coal Geology & Exploration

In practical production of mines, the prediction of mine water inflow is of great significance for mine water prevention and control. Taking working face 1301 of Yuncheng coal mine as the research object, and without considering the influence of seasonal factors, ARIMA-the time series analysis model-is used to establish the functional relationship between mine water inflow and time, which proves that the time series of water inflow in working face 1301 of Yuncheng coal mine is affected by seasonal factors. Then, based on the principle of addition and decomposition of time series, the long-term trend, seasonal indexes, circulating factors and …


Fractal Theory-Based Seepage Model Of Hershel-Bulkley Fluid In Porous Medium, Yang Xian, Lu Wei, Jin Xin, Chen Juan, Feng Xingfa Jun 2020

Fractal Theory-Based Seepage Model Of Hershel-Bulkley Fluid In Porous Medium, Yang Xian, Lu Wei, Jin Xin, Chen Juan, Feng Xingfa

Coal Geology & Exploration

Slurry is a kind of widely-used engineering fluid. Slurry will seeps into the formation in the process of construction, which has a certain impact on the project. In order to make deeper study on the seepage mechanism of slurry, the formation is simulated as porous medium, the slurry is simulated as Hershel-Bulkley fluid which can more comprehensively reflect its rheological properties, and the seepage model of Hershel-Bulkley fluid in porous medium was established based on Fractal theory. Based on the calculation results of seepage model, the effect of pressure gradient, flow index, consistency coefficient and porosity on the instantaneous average …


Test Of Mechanical Properties Of Limestone Under Hydraulic Pressure-Stress Coupling, Tian Shukun Jun 2020

Test Of Mechanical Properties Of Limestone Under Hydraulic Pressure-Stress Coupling, Tian Shukun

Coal Geology & Exploration

To study the mechanical properties of limestone with water-rich saturated circumstance under water pressure-stress coupling, compression failure tests of limestone samples with different water pressure were carried out by using a self-developed permeability test device, the device can realize uniaxial compression test. Then, the stress-strain characteristics of limestone, the effect of hydraulic pressure on uniaxial compressive strength, the elastic modulus and the deformation modulus, and the correlation between breaking characteristics and hydraulic pressure were tested. The results show that the increased hydraulic pressure has a significant influence on the stress-strain curve and strength characteristics. With the increase of hydraulic strength, …


Development Characteristics Of Water Conducted Fracture Zone Based On Overburden Structural Effect, Cao Zubao, Wang Qingtao Jun 2020

Development Characteristics Of Water Conducted Fracture Zone Based On Overburden Structural Effect, Cao Zubao, Wang Qingtao

Coal Geology & Exploration

In order to study the roof water disaster caused by coal mining in Huanglong coalfield, taking mining failure of layered overburden as research object, four typical composite structural models for coal-soft rock-hard rock-soft rock-hard rock(combination I), coal-soft rock-soft rock-hard rock-hard rock(combination Ⅱ), coal-hard rock-soft rock-hard rock-soft rock(combination Ⅲ) and coal-hard rock-hard rock-soft rock-soft rock(combination IV) were generalized. Numerical simulation and theoretical calculation were used to analyze the mining failure characteristics of different overburden combinations and correlation between water conducting fissures and lithologic combination structure of overburden. The law of the effect of overburden structure on the development height of water …


The Law Of Soaking Infiltration And Collapse Deformation In Typical Loess-Paleosol Series, Zhao Jingang, Lyu Yuanqiang, Chao Jun, Yang Zhe, Xia Meng Jun 2020

The Law Of Soaking Infiltration And Collapse Deformation In Typical Loess-Paleosol Series, Zhao Jingang, Lyu Yuanqiang, Chao Jun, Yang Zhe, Xia Meng

Coal Geology & Exploration

In order to investigate the law of moisture migration and collapse deformation of the typical loess-paleosol series, on the basis of water immersion test of the large test pits of Xi’an North-airport intercity rail transit in the loess tableland of Weibei, the real-time in-site observation was adopted, the soaking infiltration and collapse deformation of collapsible soil layer under conditions of non water seepage hole were traced and tested. The results show that: The movement of water immersion is dominated by vertical movement in the early stage. The whole form is like a continuous increase of “weight” shape. As the water …


Numerical Calculation Of Temperature Field Of Freeze-Sealing Pipe Roof Method In Gongbei Tunnel, Long Wei, Rong Chuanxin, Duan Yin, Guo Ke Jun 2020

Numerical Calculation Of Temperature Field Of Freeze-Sealing Pipe Roof Method In Gongbei Tunnel, Long Wei, Rong Chuanxin, Duan Yin, Guo Ke

Coal Geology & Exploration

This paper took the Gongbei tunnel in the Zhuhai Connection Section of the Hong Kong-Zhuhai-Macao Bridge as an example to study the development of the temperature field of the Freeze-Sealing Pipe Roof Method. Based on the heat transfer theory of two-dimensional porous media, the FEM software COMSOL was used to numerically analyze the actual working conditions of the active freezing period, the numerical calculation was verified by field measurement. The development and distribution of the temperature field before and after the opening of the special-shaped freezing pipes was studied. The results showed that: when freezing for 30 days, the concrete …


Influence Factors And Formation Properties Of Temperature Field In The Frozen Wall Of Double Ring Pipes, Li Huaixin, Lin Bin, Wang Peng Jun 2020

Influence Factors And Formation Properties Of Temperature Field In The Frozen Wall Of Double Ring Pipes, Li Huaixin, Lin Bin, Wang Peng

Coal Geology & Exploration

In order to research the change law of the temperature field of the frozen wall of double-circle pipes, an auxiliary shaft in Huainan coalmine was taken as the research object, the FLAC3D software was used to numerically simulate the formation process of the temperature field of the frozen wall of double-circle pipes and the influence of different factors on average temperature of frozen wall based on the relevant geological parameters. The research results show that temperature of the soil in the double-circle pipes is the lowest, and temperature on both sides increases gradually, the interval between frozen holes is …


Detection Technique And Application Of Transmission In-Seam Wave In Thin Coal Seam, Yang Hui Jun 2020

Detection Technique And Application Of Transmission In-Seam Wave In Thin Coal Seam, Yang Hui

Coal Geology & Exploration

Aiming at the problem of serious attenuation of channel wave in thin seam and its limited distance of propagation, a method of restricted CT imaging was proposed by using the furthest in-seam wave propagation distance. Firstly, the variation of in-seam wave frequency with different thickness of coal seam was studied by theoretical derivation. Taking a 1.5m thin seam as the main research object, the attenuation characteristics of channel wave were simulated by forward modeling, and the effective propagation distance of channel wave was determined. The actual data of No. 15 coal seam in a coal mine in Shandong Province shows …


Influence Of Parting In Composite Coal Seam On Interpretation Of Fault Throw By Channel Wave Seismic Exploration, Su Xiaoyun Jun 2020

Influence Of Parting In Composite Coal Seam On Interpretation Of Fault Throw By Channel Wave Seismic Exploration, Su Xiaoyun

Coal Geology & Exploration

The channel wave seismic exploration technology has achieved relatively reliable result in detection of faults, collapse columns and the change of coal thickness in working faces, now becomes the preferred method for detection of underground geological structures. But for detection of geological structures in partings of composite coal seams the method has still certain problems. In order to study the influence of partings in composite coal seams on detection of channel wave seismic exploration, various models were built by changing thickness, lithology of parting in composite coal seams and experimenting with channel wave seismic detection in Shanxi to study how …


Suppression Of Multiple Reflected Refraction In Shallow Low-Velocity Zones By Vertical Combination Of Seismic Sources, Fu Yanning, Chang Suoliang, Zhang Sheng, Liu Zuiliang, Yang Yong, Chen Qiang, Liu Bo, Xu Yuying Jun 2020

Suppression Of Multiple Reflected Refraction In Shallow Low-Velocity Zones By Vertical Combination Of Seismic Sources, Fu Yanning, Chang Suoliang, Zhang Sheng, Liu Zuiliang, Yang Yong, Chen Qiang, Liu Bo, Xu Yuying

Coal Geology & Exploration

A special type of multiple reflected refraction often appears in seismic records in areas with low-velocity structures. It seriously affects the closed reflection wave, which causes the distortion of the reflection wave shape and affects the correct interpretation of the seismic data. Based on the forward simulation of the multiple reflected refraction equation, the generation mechanism of multiple reflected refraction in the shallow low-velocity zones was set forth. A method of suppressing multiple reflected refraction by vertically combined dual sources was proposed. The formation parameters(formation thickness and velocity)are obtained according to the methods of small refraction and micro logging in …


Seismic Impedance Inversion Of Coal Field With Reflectivity Method Based On Bayesian Theory, Yang Zhen, Gao Zhenyu, Liu Xingye Jun 2020

Seismic Impedance Inversion Of Coal Field With Reflectivity Method Based On Bayesian Theory, Yang Zhen, Gao Zhenyu, Liu Xingye

Coal Geology & Exploration

Seismic inversion can reflect the morphology of subsurface formation and facies information more intuitively. Seismic impedance inversion can directly produce elastic information of underground media, providing reliable information for subsequent coal identification, water channel prediction and collapse column distinguishing. A Bayesian-based inversion of reflectivity method was developed. It can consider the various propagation effects of seismic waves and solve the objective function nonlinearly, which can more accurately calculate the impedance and improve the inversion resolution. The method is applied to the actual data from Buertai coal mine and satisfactory results are output, which effectively verifies the feasibility and effectiveness of …


Research On Electronically Controlled Automation Technology Of Underground Drilling Rig For Coal Mine, Dong Hongbo, Yao Ningping, Ma Bin, Liao Jiangnan Jun 2020

Research On Electronically Controlled Automation Technology Of Underground Drilling Rig For Coal Mine, Dong Hongbo, Yao Ningping, Ma Bin, Liao Jiangnan

Coal Geology & Exploration

In order to conform to the development direction of automation and intelligence of underground equipment in coal mines, a set of electronically controlled system of drilling rig has been developed according to the characteristics of underground drilling rigs in coal mines. The functions such as remote control, parameter monitoring, working condition judgment and safe interlocking were realized in the drilling rig. On the basis of single-acting control of the drilling rig, the technology of automatic drilling and automatic trip-out of the drilling rig was studied, which greatly improved the automation of underground drilling rig in coal mine. The functional experiments …


Design And Numerical Simulation Of Multi-Layer Bit With Extra-High Matrix, Sun Qibin, Shen Lina, Yang Gansheng, Tian Guoliang, Ruan Hailong, Chen Xi Jun 2020

Design And Numerical Simulation Of Multi-Layer Bit With Extra-High Matrix, Sun Qibin, Shen Lina, Yang Gansheng, Tian Guoliang, Ruan Hailong, Chen Xi

Coal Geology & Exploration

Aiming at the problem that the life of the diamond bit is limited by the height of the bit matrix, an optimized design scheme of an impregnated diamond bit with extra-high multi-layer matrix was proposed. In the design of the bit, eccentric staggered cutting teeth, alternate waterways and water baffles were introduced to ensure the cooling and effective drilling of the bit. Through strength and hydraulic flow field simulation, the strength of the drill bit was checked, the rationality of the waterway structure was verified, and the finished product of the drill bit was further realized. The drill bit breaks …


Analysis Of Paleoclimatic Cycles In The Ultra Thick Coal Seam Of Yan'an Formation In The Southern Ordos Basin, Dong Guoqi, Wang Dongdong, Liu Haiyan, Mao Qiang, Yin Lusheng Jun 2020

Analysis Of Paleoclimatic Cycles In The Ultra Thick Coal Seam Of Yan'an Formation In The Southern Ordos Basin, Dong Guoqi, Wang Dongdong, Liu Haiyan, Mao Qiang, Yin Lusheng

Coal Geology & Exploration

Coal is a climate-sensitive sediment that contains abundant paleoclimate information. In order to find out the paleoclimate information contained in the coal seam and the evolution of its controlling factors, the No.4 thick coal seam in the first member of Yan’an Formation in the south of Ordos basin was studied. Based on the intensive sampling of the thick coal seam, the information of organic macerals, major and trace elements, and stable carbon isotopes of organic matter were systematically tested. By using the macerals, characteristic elements and carbon isotopes of coal and rocks, four cycles of paleoclimate with alternation of warm-wet …


Change Law Of Adsorption/Desorption Energy Of Coal With Different Water Content Under The Action Of Far Infrared, Ma Kai, Ma Qianqian, Shi Yongtao Jun 2020

Change Law Of Adsorption/Desorption Energy Of Coal With Different Water Content Under The Action Of Far Infrared, Ma Kai, Ma Qianqian, Shi Yongtao

Coal Geology & Exploration

The essence of coal gas adsorption/desorption process is the process of interaction between gas molecules and molecules or atoms on the surface of the coal matrix, and the nature of the interaction is energy change. In order to deeply study the coalbed gas adsorption/desorption rules and energy change rules under the action of far infrared, the self-developed device was used to perform CO2 adsorption/desorption experiments on coal samples with different water contents under the action of far infrared. Then, the experimental results are calculated using the adsorption/desorption energy change model obtained from the principle of far-infrared thermal radiation, and …


Acoustic Emission Characteristics And Damage Evolution Of Coal-Rock Under Different Confining Pressures, Yu Jie, Liu Xiaohui, Hao Qijun Jun 2020

Acoustic Emission Characteristics And Damage Evolution Of Coal-Rock Under Different Confining Pressures, Yu Jie, Liu Xiaohui, Hao Qijun

Coal Geology & Exploration

Using PCI-2 acoustic emission(AE) system, the AE experiments of different confining pressures (0, 8, 16, 5 MPa) were carried out in Baijiao coal mine in Furong, Sichuan Province, in order to reveal the change rule of ringing count rate, the temporal and spatial distribution of AE, b value of AE and damage characteristics of damaged coal-rock under different confining pressures, and to provide a theoretical basis for prediction of coal-rock damage. The results show that the AE phenomenon can reflect the crack propagation of coal-rock and the confining pressure can restrain the damage of coal-rock. With the increase of confining …