Deformation And Collapse Patterns Of Gas Drainage Boreholes And A Precise Monitoring Technology,
2024
School of Safety Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Deformation And Collapse Patterns Of Gas Drainage Boreholes And A Precise Monitoring Technology, Xiao Peng, Huang Xiaosheng, Liu Xiaoxiao, Li Bingkun, Chen Liping, Chen Zixi, Zhang Chao, Cheng Renhui, Zhao Yajie
Coal Geology & Exploration
This study aims to promote the precise and intelligent monitoring of gas drainage boreholes. In the engineering background of a coal mine in Shanxi Province, this study conducted simulation experiments on the plugging of gas extraction boreholes under varying particle size ratios of simulated coal samples using distributed optical fiber monitoring and the Brillouin Optical Time-Domain Analysis (BOTDA). Then, this study established a mathematical model for calculating the borehole plugging rate of the test mine, revealing the deformation and collapse patterns of gas drainage boreholes. Furthermore, this study proposed a precise in-situ monitoring technology for the gas drainage boreholes in …
Exploring Geological Parameters Sensitive To Underground Coal Gasification,
2024
Coal Mine Exploration Bureau of Guizhou Province, Guiyang 550025, China; Guizhou Youchi Energy Technology Co., Ltd., Guiyang 550014, China; Guizhou Provincial Key Laboratory of Fluidized Mining of Coals, Guiyang 550014, China
Exploring Geological Parameters Sensitive To Underground Coal Gasification, Zhou Ze, Yi Tongsheng, Qin Yong, Zhou Yongfeng, Wang Lingxia, Kong Weimin
Coal Geology & Exploration
Compared to ground coal chemical plants, underground coal gasification (UCG) requires gasifiers as geological bodies. Accurately understanding geological conditions is a critical prerequisite for UCG. To minimize the geological risks involved in UCG siting, this study systematically explored the geological parameters sensitive to UCG based on the intricate geological conditions of Guizhou Province, China. By collecting and organizing the exploration data of coal resources in Guizhou, this study established mathematical models for normalized, graded parameter value assignment, the algorithm of parameter weight vectors, and the algorithm of parameter weight product, with the purpose of obtaining the accurate quantitative data of …
A Method For Coal Seam Pressure Relief Based On Steel Cone Impact,
2024
Department of Mining Engineering, Shanxi Engineering Vocational College, Taiyuan 030009, China
A Method For Coal Seam Pressure Relief Based On Steel Cone Impact, Ren Zhimin, Lyu Mengjiao, Wang Fei, Wang Yu, Zhang Guangtai
Coal Geology & Exploration
This study aims to solve the mining safety problems caused by rock bursts in coal mines. With the geological mining conditions of the No.3 coal seam in the Wulihou coal mine in Zuoquan County, Jinzhong City, Shanxi Province as the engineering background, this study proposed a method for coal seam pressure relief based on steel cone impact. Specifically, based on the electromagnetic repulsion generated between energized coils, this study derived the functions of impact force produced when a magnetically driven coil-wound steel cone impacted the coal seam. Combining the theory on elastic mechanics, this study analyzed the stress field distribution, …
Two-Phase Flow Chokeling Results And Control In High-Pressure Gas Wells Producing Water,
2024
School of Mechanical & Automotive Engineering, Qingdao University of Technology, Qingdao 266520, China
Two-Phase Flow Chokeling Results And Control In High-Pressure Gas Wells Producing Water, Liu Xinfu, Liu Chunhua, Li Qingping, Yao Haiyuan, Hao Zhongxian, Liu Yongfei
Coal Geology & Exploration
Prediction and control of two-phase flow chokeling in tight gas wellbores are essential for the normal operation and hydrate control of high-pressure gas wells producing water. The thermodynamic differential equations of energy, kinetic energy and temperature and models of chokeling field for two-phase energy, system heat, mass balance and flow were developed under the conditions of isentropic adiabatic, isobaric heat capacity, constant volume heat capacity, and chokeling energy. A methodology on predicting characteristics and control of two-phase flow before and after chokeling was proposed for gas-water two phase flow. It provided a theoretical basis for optimizing the structural parameters of …
Favorable Factors In Methane Production From Residual Coal Post-Biohydrogen Generation,
2024
Shanxi Key Laboratory of Coal and Coal-measure Gas Geology, Taiyuan 030001, Chin; School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454003, China; Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo 454003, China
Favorable Factors In Methane Production From Residual Coal Post-Biohydrogen Generation, Xia Daping, Liao Jiajia, Chen Zhenhong, Chen Xi, Guo Hongyu, Huang Dan
Coal Geology & Exploration
Determining favorable factors in methane production from residual coal post-biohydrogen production holds great theoretical and practical significance for improving the efficiency of methane production in the second stage of coal-based poly-generation. This study focuses on residual coal after hydrogen generation through anaerobic fermentation. Using coal samples from the Baiyinhua open-pit mine in Inner Mongolia as fermentation substrates, this study explored the dynamic trends of both the methane production and structure of the residual coal under different conditions by altering the aeration conditions and hydraulic retention time (HRT). Key findings are as follows: (1) Among the experiment groups with different atmosphere …
Uranium And Thorium Enrichment Characteristics Of Bauxite In Coal Measure Strata And Their Natural Gamma-Ray Responses,
2024
College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Uranium And Thorium Enrichment Characteristics Of Bauxite In Coal Measure Strata And Their Natural Gamma-Ray Responses, Zhang Xiaohui, Zhang Shangqing, Liu Dongna, Zhao Fenghua, Zhao Jun, Zhong Zhuanghua, Hou Xuqin
Coal Geology & Exploration
Shanxi Province boasts abundant bauxite resources occurring in coal measure strata, with the deep bauxite resources in this province subjected to progressive assessment. This study aims to further determine the endowment of aluminum resources within coals in the province and explore efficient exploration methods. To this end, this study investigated the bauxite layers in Upper Carboniferous coal measure strata in the Xiaoyi area, Shanxi Province. It examined 37 samples from three boreholes using methods such as optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence spectrometry (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). Based on the analysis …
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore,
2024
State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing 100011, China; School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore, Wang Qihang, Li Xu, Guo Qiang, Kuai Dawei
Coal Geology & Exploration
Groundwater flow velocity in wellbore is usually measured by single-well tracking tests or Aqua Vision flow velocity and direction meters to calculate the groundwater flow velocity in the aquifer. Due to the impact of the skin structure, the groundwater flow field near the wellbore changes, causing a difference between the flow velocity in the wellbore and that in the aquifer. In order to investigate the influence of the skin effect on the groundwater flow velocity in the wellbore, a numerical model of groundwater flow that considers the skin effect was established using the COMSOL Multiphysics software. On this basis, the …
Law Governing Variations In Water-Pressure Transmission Rate In Confined Aquifers,
2024
Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China; Key Laboratory of Xinjiang Coal Bearing Resources Exploration and Exploitation, Urumqi 830023, China; Henan Provincial International Joint Laboratory for Landslide Flow Monitoring and Early Warning, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
Law Governing Variations In Water-Pressure Transmission Rate In Confined Aquifers, Wang Wenxue, Wang Bosen, Gao Yanwei, Wu Bing, Nie Tianyu
Coal Geology & Exploration
The water pressure in aquifers is transmitted as energy, with a transmission rate much higher than the migration rate of water particles. The water-pressure transmission rate holds great significance for the safe construction and disaster forecast and prediction of underground engineering under high-pressure water aquifers and bodies. Focusing on the confined aquifers bearing no cohesive soil, this study explored the law governing the changes in the water-pressure transmission rate through theoretical analysis, numerical simulations, field experiments, and laboratory physical model tests. Key findings are as follows: (1) The transmission of water-pressure changes in the aquifers exhibited noticeable hysteresis. The transmission …
Experimental Study On Acoustic Emission Evolution Characteristics And Response Mechanism Of Damaged Rocks,
2024
State Key Laboratory of Water Resources Protection and Utilization in Coal Mining, National Institute of Clean-and-Low-Carbon Energy, Beijing 102211, China; China Energy Investment Group Co., Beijing 100011, China
Experimental Study On Acoustic Emission Evolution Characteristics And Response Mechanism Of Damaged Rocks, Zhang Kai, Zhang Dongxiao, Zhao Yongqiang, Yang Yingming, Guo Weiyao, Sun Peng, Xu Linpeng, Fu Guangsheng
Coal Geology & Exploration
The evolution of rock internal damage is one of the causes of geotechnical engineering disasters, and revealing the response characteristics of key parameters during the rock failure could provide a basis for the identification instability state after rock failure, which is of great importance for the early warning and prevention of rock engineering disasters. Herein, the siltstone specimens with different damage degrees were prepared by cyclic loading-unloading tests, and uniaxial loading tests were carried out with the damaged specimens. On this basis, the relationship between the damage degree of specimen and the wave velocity, as well as the acoustic emission …
Silvopastoral Agroforestry In Upland And Lowland Uk Grassland: Tree Growth And Animal Performance,
2024
Institute of Grassland and Environmental Research, UK
Silvopastoral Agroforestry In Upland And Lowland Uk Grassland: Tree Growth And Animal Performance, W R. Eason, R Lavender, R O. Clements, C Duller, E Gill, M Hislop
IGC Proceedings (1997-2023)
Trees, individually protected from herbivore damage using plastic shelters, were planted at two densities (100 and 400 stems/ha) into sheepgrazed pasture in upland and lowland UK grassland sites in 1988. Tree and animal performance were compared with conventional forestry (no sheep) and pasture (no tree) systems. Effects on tree growth and survival are highly species and site dependent although some treatment effects did emerge. Tree shelters encouraged rapid early height growth compared to forestry controls although in some cases tree form was also adversely affected. Generally tree performance within agroforestry treatments was better at the higher planting density. Eight years …
Use Of Annual Self-Reseeding Legumes In An Oak Forest In Central Italy,
2024
Universita di Firenze, Italy
Use Of Annual Self-Reseeding Legumes In An Oak Forest In Central Italy, P Talamucci, G Argenti, A Pardini, S Piemontese, N Stagliano
IGC Proceedings (1997-2023)
A trial has been carried out for three years in an oak coppice geometrically thinned out of Mediterranean Central Italy, about the functioning of a pastoral system made by four different resources: native pasture, subterranean clover (Trifolium brachycalycinum Katzn. et Morley) in pure stand, strips thinned out and firebreaks improved with oversown subclover, all grazed by sheep. Subclover increased the forage yield and improved the palatabilty of the pasture and the regularity of grazing; the higher biomass intake by animals reduced the quantity of dried biomass in summer and contributed to keep low either fire hazards or flame diffusion …
The Effects Of Shelterbelts On Adjacent Pastures And Soils In A Temperate Climate,
2024
AgResearch, Palmerston North
The Effects Of Shelterbelts On Adjacent Pastures And Soils In A Temperate Climate, A G. Gillingham, M F. Hawke
IGC Proceedings (1997-2023)
Two trials were conducted to differentiate the direct (exposure) from the indirect (modified soil fertility due to nutrient transfer by grazing animals) effects of farm shelterbelts on associated pasture growth.Soil from close to “unmanaged”shelterbelts with dense shelter to ground level had relatively high potassium (K) levels and, in a glasshouse situation, provided more pasture growth than soil from further distances, or from adjacent to “managed” shelterbelts. Pasture grown in boxes of a common soil implanted at increasing distances from a shelterbelt also produced highest growth rates close to shelter. These results generally explain the pattern of resident pasture growth, except …
Temperate Pasture And Sheep Performance Under Radiata Pine And In Open Pasture,
2024
Lincoln University, NZ
Temperate Pasture And Sheep Performance Under Radiata Pine And In Open Pasture, K M. Pollock, R J. Lucas, D B. Pownall, S E. Thomson
IGC Proceedings (1997-2023)
Forage production from years 4 to 6 of an agroforestry system at 400-600 trees per ha and pasture alone were compared for a temperate sub-humid environment. Forage production was best for lucerne pasture followed by phalaris/clover and cocksfoot/clover, and least for ryegrass/clover and the ryegrass only pastures. Total pasture production in the agroforest relative to the open pasture was from 10% more for phalaris to 20% less for lucerne. Sheep carrying capacity over all pastures was 14.6 sheep/ha in the open and 11.8 sheep/ha in the agroforest and varied by ±15% according to the pasture types.
Grazing Management Of Tagasaste (Chamaecytisus Proliferus) For Sheep And Cattle Production In Southern Australia,
2024
The University of Western Australia
Grazing Management Of Tagasaste (Chamaecytisus Proliferus) For Sheep And Cattle Production In Southern Australia, N J. Edwards, G M. Allen, D M. Mcneill, C M. Oldham
IGC Proceedings (1997-2023)
Direct grazing of hedgerows of tagasaste (Chamaecytisus proliferus) by sheep or cattle appear to be very robust systems. Tagasaste persists under a continuous grazing regime with cattle such that plant regrowth maintained between 5 and 10 cm in length produces in excess of 215 kg of animal liveweight/ha/year. This level of production is also sustained within a rotational grazing regime. Under both grazing systems cattle production within a year is highly seasonal, with liveweight gains from young cattle peaking at 1.0-1.5 kg/head/day in winter and spring, but dropping to maintenance only by late summer-autumn. Sheep, like cattle, can …
Shrub Palatability To Rusa Deer (Cervus Timorensis Russa) In New Caledonia,
2024
Centre de CoopÈration Internationale en Recherche Agronomique pour le DÈveloppement
Shrub Palatability To Rusa Deer (Cervus Timorensis Russa) In New Caledonia, C Corniaux, S Le Bel, J M. Sarrailh
IGC Proceedings (1997-2023)
The objective of this study was to determine a palatability scale of five shrub legumes to rusa deer during the dry season in New Caledonia. Acacia ampliceps and Samanea saman remain low in acceptability. Gliricidia sepium is more palatable but quite less than Leucaena leucocephala (native cultivar) and Calliandra calothyrsus (San Ramon). Therefore, since the regression of Leucaena leucocephala population, Calliandra calothyrsus could be very promising to replace it in the deer diet. On the other hand, Acacia ampliceps seems to be the most interesting shrub legume to plant in the west coast, where soil erosion, due to successive droughts …
Soil Nutrient Redistribution Pattern About The Tree In A Silvopastoral System,
2024
University of Aberdeen
Soil Nutrient Redistribution Pattern About The Tree In A Silvopastoral System, L C. Nwaigbo, H G. Miller, A R. Sibbald, G Hudson
IGC Proceedings (1997-2023)
The objective of this paper is to report the effect of animal-tree interactions on soil nutrient redistribution pattern in a grazed silvopastoral experiment site at Glensaugh, in NE Scotland. Scots pine (Pinus sylvestris L) tree species were planted in square lattice arrangements at 5 m x 5 m, spacing (400 stems/ha) on plots replicated over three blocks in Randomized Complete Block design on a predominantly rye grass (Lolium perenne L) pasture which was grazed by sheep yearly from April to October. Included in the design were grazed pasture plots without trees (Control). Soil samples were collected from around …
Trees For Shelter: The Implications In Agroforestry System,
2024
University of Aberdeen
Trees For Shelter: The Implications In Agroforestry System, L C. Nwaigbo, A R. Sibbald, G Hudson
IGC Proceedings (1997-2023)
The objective of this study was to determine the horizontal and vertical variations in soil penetration resistance (PR) observed at tree-scale in silvopastoral plots that were grazed by sheep with and without trees. Sycamore trees (Acer pseudoplatanus L) were planted in the spring of 1988 at 10 m x 10 m spacing (100 stems/ha) at Glensaugh NE of Scotland on plots replicated over three blocks in Randomized Complete Block design on a predominantly rye grass (Lolium perenne L) pasture. Included in the design were pasture plots without trees (Control). The experiment is grazed by sheep yearly from April to …
A Silvopastoral System In The North Atlantic Zone Of Costa Rica: Combining Indigenous Timber Species With Dairy Pasture Swards,
2024
North Carolina State University
A Silvopastoral System In The North Atlantic Zone Of Costa Rica: Combining Indigenous Timber Species With Dairy Pasture Swards, A Moulaert- Quiros, J P. Mueller, M Villarreal, R Piedra, L Villalobos
IGC Proceedings (1997-2023)
The objective of this study was to design, establish and monitor a silvo pastoral experiment on a dairy farm in the northern Atlantic region of Costa Rica. Indigenous timber species, Vochysia guatemalensis and Hyeronima alchorneoides were used together with or without the tropical pasture legume, Arachis pintoi in a split plot design with a 4 x 2 x 2 factorial arrangement. First year establishment was good for the tree component (2.3 to 10 % mortality) but poor for A. pintoi (4 to 5 % of sward). Poor legume establishment was attributed to lax grazing management and excess competition from existing …
Productivity Of Three Tree Legumes Grazed By Cattle,
2024
The University of Queensland, Australia
Productivity Of Three Tree Legumes Grazed By Cattle, R C. Gutterridge
IGC Proceedings (1997-2023)
Three tree legumes Albizia chinensis, Leucaena leucocephala K 636 and Tipuana tipu were grown in conjunction with the grass Brachiaria decumbens and grazed by weaner cattle at a stocking rate of 2.5 animals per hectare for a total of 447 days. Albizia was best adapted to this acidic, poorly drained site in south east Queensland giving the highest yields of edible dry matter, high survival rate and moderate liveweight gains of 0.45 kg/head/day. The productivity of L. leucocephala K 636 was always poor but it gave the highest liveweight gains of all treatments in the first 280 days of grazing, …
Morphological And Physiological Response Of Planeleaf Willow (Salix Planifolia Pursh.) To Simulated Browsing,
2024
North Dakota State University--Fargo
Morphological And Physiological Response Of Planeleaf Willow (Salix Planifolia Pursh.) To Simulated Browsing, L Xu, J L. Dodd, M A. Smith, Q D. Skinner, W A. Laycock
IGC Proceedings (1997-2023)
Morphological and physiological responses of planeleaf willow (Salix planefolia Pursh.) to simulated browsing were studied under controlled conditions. The treatments consisted of every combination of three clipping intensities (30%, 60% and 90% of current twigs length removal) and three clipping timings (late winter, early spring and mid-summer). Increased clipping intensity stimulated bud activation; increased total leaf area and leaf size and increased the length of current year’s twigs. Mid-summer browsing increased the total number of leaves, the number of current twigs and decreased the length of current twigs. Higher browsing intensity resulted in higher photosynthetic rate of recently matured …
