Physical Sciences and Mathematics Commons^™

Effects Of Iron-Nickel Ion Combination On Methane Produced By Lignite Fermentation, Xia Daping, Huang Song, Zhang Huaiwen

Coal Geology & Exploration

In order to study the mechanism of the influence of exogenous optimal iron-nickel ions combination on the gas production process of fermentation, taking Daliuta lignite as an example, experiments were carried out with different contents of iron-nickel ions and the optimal concentration of single ions was elected. The optimal combination concentration of iron-nickel ions were determined by combined design of quadratic regression and common rotation. The fermentation broth of experiment group and blank group(not to added any ions), the coal sample of before and after experiment were analyzed by gas chromatography, X-ray diffraction, Fourier transform infrared spectroscopy, etc. The results …

Origin And Geochemical Characteristics Of Coalbed Methane In Abandoned Coal Mines, Panzhuang Block, Southern Qinshui Basin, Liu Chao, Feng Guorui, Zeng Fangui

Coal Geology & Exploration

In order to analyze the carbon and oxygen composition and origin of the coal seam gas(CSG) in abandoned mines, Panzhuang block, south of Qinshui basin, in this paper, the coalbed methane and produced water samples were collected. The results show that the CSG of abandoned mines is dominated by CH₄, the average is 91.99%, with minor amounts of N₂(6.73%) and CO₂(1.26%). The δ¹³C values of CH₄ range from -31.36‰ to -33.53‰, with an average of -32.25‰, the hydrogen isotope(δD) value is between -182.76‰ and -193.20‰, and the average value …

Mine Water Inrush Rescue Model Based On Optimized Spfa Algorithm, Cai Mingjie, Zhu Xi’An, Liu Demin, Wang Zhangang

Coal Geology & Exploration

Due to the occurrence of coal mine water inrush accidents, it is easy to cause major personnel and property losses. In order to improve the emergency rescue capability of mine water inrush disasters and reduce the water inrush hazard, a mine water inrush rescue route model was proposed. The undirected map and the adjacency list were used to describe and store the mine roadway network. According to the calculation ratio of the height of the water level and the height of underground personnel in roadway, the safety coefficient of the roadway was calculated, and then the equivalent length of the …

Drainage Technology And Test Of Stratified Pressure Control With Four-Channels Of Cbm Well In Double Coal Seams, Pang Tao, Jiang Zaibing, Li Bingang, Du Xinfeng

Coal Geology & Exploration

Aiming at the problems of mutual interference between layers and serious damage in reservoirs in the production process of double-coal CBM wells, a four-channel stratified pressure control drainage technology was proposed, in the process of drainage, two coal seams were controlled in different pressure systems to achieve the purpose of stratified production and CBM well drainage device with four-channel packer, monitoring equipment, multi-channel tubing centralizer, roller sucker rod centralizer and auxiliary communication tube for double coal seams was developed. Field application test shows that the four-channel packer can achieve the isolation effect according to the needs, so that the two …

Optimization Study On Correlation Method Of Multiple Coal Seams, Shu Jiansheng, Ma Liang, Jia Lilong

Coal Geology & Exploration

At present, the development trend of coal mining in China is transferring from the east to the western regions. The Yan'an Formation coal bearing measures middle Jurassic is the most widely distributed in the west, it is of the continental sedimentary environment, which has the characteristics of big change of lithofacies, multiple coal seams, unstable coal seams and less marker, there are difficulties in coal seam correlation, such as lack of basis and multi-solution phenomenon. Based on the wide application of high precision seismic exploration and digital logging technology, the fine correlation of terrestrial multi-coal seams was carried out by …

Simulation Of Seepage Water Inrush Mechanism And Strength Controlling Factors Of Collapse Column, Huo Bingjie, Xie Zhenhua, Fan Zhanglei, Jing Xuedong

Coal Geology & Exploration

In order to study the mechanism and main control factors of seepage water inrush in roadway affected by collapse columns, Darcy, Brinkman and N-S equations were used to describe the linkage system of flow field in aquifer, collapse column and water inrush roadway. Variables such as different parameters and different boundaries were selected to analyze the main factors influencing the seepage water inrush intensity of collapse columns. The results show that under the conditions of constant pressure and flow, the increase of aquifer permeability will lead to the increase of flow velocity in an area where the aquifer meets the …

Particle Swarm Optimization-Based Bionic Principle For Solving Hydrodynamic Dispersion Coefficient In Jiang'an Campus, Mei Jie, Li Guangwei, Xia Chengcheng, Liu Yaping, Liu Wen, He Xinyue

Coal Geology & Exploration

Hydrodynamic dispersion coefficient is an important parameter in the study of solute transport in groundwater. In order to understand the transport law of pollutants in groundwater, the particle swarm optimization(PSO) algorithm based on bionic principle is used to solve the hydrodynamic dispersion coefficient of phreatic aquifer under natural flow field in the dispersion test site of Jiang'an Campus of Sichuan University. Compared with the least-square method and the standard curve comparison method, the results show that the results of the standard curve method are subject to subjective influence, and the errors are relatively large. The results of least square method …

Surface Subsidence Law Caused By Fully Mechanized Caving Mining Under Railway, Deng Niandong, Yao Ting, Shang Hui, Liu Donghai

Coal Geology & Exploration

In order to ensure the safe running of the special railway for Guozhuang coal mine, the law of surface movement and deformation in goaf of the coal mine was studied on the basis of the analysis of the actual observation data, the monitoring scheme and control measures of railway under dynamic coal mining conditions were put forward in accordance with that. The results show that the surface movement and deformation are intense, the subsidence value is large, but the subsidence velocity is relatively small on account of fully mechanized caving; Surface subsidence coefficient, the main impact tangent tanβ, …

Deformation Characteristics And Support Timing Of Deep High Stress Roadway, Geng Weile, Dong Ziwen, Guo Shengli, Pi Zikun

Coal Geology & Exploration

The rock occurrence environment and structural characteristics determine its strength criteria, and affects the mechanical and deformation characteristics of surrounding rock. This paper relies on the deep replacement project of a mine in Yunnan, based on the rock strength criteria, and analyzes the mechanics and deformation characteristics of surrounding rock and the reasonable secondary support time of roadway to decrease the influence of the roadway support effect because of the obvious rheological properties present under high ground stress. The results showed that the min-average simulated deviations mf was generalized H-B criterion which was aimed at the sum of deviation absolute …

Nishihara Acceleration Model-Based Experiment Of Creep Characteristics Of Coal, Qu Lina, Li Bo

Coal Geology & Exploration

For conquering limitation that the traditional Nishihara model cannot describe the accelerated creep characteristics of coal body, according to the visco-elastic-plastic flow characteristics of coal in the accelerated creep stage, a nonlinear visco-elastic-plastic model was used to replace the ideal viscoelastic-plastic body in Nishihara model to establish the improved Nishihara acceleration model. And creep equation of the improved model under equal confining pressure triaxial condition was also deduced. Afterwards, the improved accelerated creep model was analyzed by the creep test data of coal specimens in the triaxial creep tests using the method of model identification. The results show that the …

Shear Strength Characteristics Of Slope Soil In Dumping Site In High-Cold Mining Area, Zhou Linhu, Yang Youqing, Hu Xiasong, Li Xilai, Wang Tao, Liu Changyi

Coal Geology & Exploration

The paper aims to study the shear strength characteristics and the influencing factors of the root-soil composite systems of herbs in the dump slope of the high-cold mining area. The dumping site of Jiangcang mining area of Muli Coalfield, located in the northeastern Qinghai-Tibet Plateau, was selected as the study area. For the dump slope which was planted with Elymusnutans Griseb., combined with Poacrymophilakeng, density, moisture content and root content of different depths of root-soil composite systems below the surface of slope were tested; the cohesion and the internal friction angle of soil without roots and root-soil composite systems …

Optimization Of Surface Contact-Based Thermal Conductivity Model Of Cemented Particles, Chen Yuanjiang, Jiang Zhiqiang, Tan Zhiren

Coal Geology & Exploration

In order to explore better the variation law of thermal conductivity of geomaterials, and reduce the thermal damage caused by the problem, according to the structural characteristics of the cemented particles, combined with the effective medium thermal conductivity model and the surface contact thermal conductivity model, the effective thermal conductivity calculation model suitable for the geotechnical cemented particulate material was constructed, and the state of the particulate matter and the cementitious matrix were considered. The transient hot wire method was applied to test the thermal conductivity of the experimental test block, and the predicted values were compared with the measured …

Numerical Calculation Of Heat Transfer In Single Medium-Deep Geothermal Well, Shang Hongbo, Zhao Chunhu, Jin Dewu, Xu Shuanhai, Wang Xiaodong, Zhang Weidong, Han Yongliang

Coal Geology & Exploration

Medium-deep geothermal single well heat transfer is a technology of developing geothermal energy to "obtain heat without extracting groundwater". This technology has the advantages of not damaging the groundwater environment and taking more heat. However, there are few studies on the numerical calculation of single well heat transfer above 3000m depth. In this paper, based on the geothermal geological conditions in Xi'an, the numerical method was used to calculate the heat transfer of a medium-deep geothermal single well with different well structures (L-shaped directional wells and cluster directional wells) under the scenario of continuous operation of a heating season. The …

Fluid Factor Of Fracture And Seismic Velocity Response In Anisotropic Coal Beds, Li Qin, Ma Suibo, Zhao Bin

Coal Geology & Exploration

The storage and transport of gas and water in coal seam are related to the density, strike and filler of cracks. Research on the identification and prediction of coal seam cracks will be helpful to prevent and control disastrous accidents in coal mines, such as water inrush and gas outburst. It plays an important role in the safety evaluation of coal mining. Based on the theory of fracture equivalent model, the variation characteristics of fluid factor in coal seam crevices with different fillings and fracture weaknesses parameters(fracture density, aspect ratio, volume modulus, shear modulus, Lamé parameters) are analyzed by combining …

Influencing Factors Of Azimuth Electromagnetic Wave Roof And Floor Detection While Drilling Along Coal Seam, Chen Gang, Fan Yiren, Li Quanxin

Coal Geology & Exploration

Aiming at the problems of poor detection accuracy and low efficiency of roof and floor interface in horizontal well drilling in coal mine, the design idea of explosion-proof azimuth electromagnetic wave logging tool while drilling in coal mine is put forward. In order to suit the working environment of underground coal seam, the influence of instrument parameters such as source distance, transmitting frequency and coil installation angle on signal response was obtained by forward simulation. The results show that the received signal strength of the azimuth electromagnetic wave instrument while drilling increases with the increase of transmitting frequency, coil distance …

Research And Application Of Casing Milling And Fishing Technology In Floor Comb-Shaped Directional Borehole, Guan Qiangsheng, Wei Hongchao

Coal Geology & Exploration

In order to solve the problem that using the conventional strong-force rotary drawing process for borehole sticking accident in comb-shaped directional borehole in floor is not ideal, and using reverse thread drill pipe or strong twist cause big time and economic loss, through the calculation and analysis of the passing capacity of casing milling and fishing pipe in the curved hole, the technical parameters of casing milling and fishing, the sticking accident of floor comb-shaped directional borehole with the depth of 344 m in a coal mine in Henan Province was successfully solved. The application results show that the maximum …

Csamt Phase Correction And Its Application In Detection Of Water-Accumulating Area Of Goaf In Coal Mine, Su Chao, Hou Yanwei, Wang Cheng, Li Dan

Coal Geology & Exploration

Magnetic field data of controlled source audio magnetotelluric method(CSAMT) is vulnerable to electromagnetic interference, and will lead to serious degradation of phase data quality. The affected phase data are corrected by referring to the high quality phase data of adjacent measuring points and combining the least squares fitting and interpolation method. Through forward simulation analysis, it is found that cubic polynomial interpolation is effective, not only can restore the variation characteristics of phase curve more accurately, but also involve the corrected phase data in the inversion calculation, so that the inversion results are more accurate and reliable. The method is …

Test Of Water Absorbent Resin For Disposal Of Waste Mud, Wei Meng, Qi Jinhui, Zhang Ningxin, Wen Jun

Coal Geology & Exploration

In the course of engineering construction, a lot of abandoned mud is produced. How to properly handle these mud has received extensive attention. In this paper, the application of absorbent resin in waste mud treatment is studied by series of experiments. Compared with the common flocculants, the flocculation effect of absorbent resin is better, and the separation speed of waste mud solid liquid can be accelerated obviously. The water absorption rate of absorbent resin in the mud reaches 46.33 g/g, which can be incorporated into the mud to greatly reduce the water content and fluidity of the mud within 30 …

Concealed Riprap Detection Technology In Pile Foundation Engineering, Li Junjie, Ge Longjin, Zhang Honggang, Li Jianmin, Zhu Honglei, Li Guanhao

Coal Geology & Exploration

It is often necessary to use pile foundation to deal with soft soil foundation for the newly built gate station near the seawall. If there is a concealed riprap layer in the construction area, it will affect the construction progress of pile foundation and increase the construction cost. Furthermore, the spatial distribution characteristics of riprap also play a decisive role in the selection of pile foundation construction technology. In view of the blindness problem in using the drilling method to investigate the irregular concealed riprap, we adopt the comprehensive investigation technology combining the ground penetrating radar with the high density …

Supporting Technology Of Roadway Crossing Fractured Zone Of Fault Under Dynamic And Static Load, Song Weihua, Di Chunlei, Deng Zhaorui

Coal Geology & Exploration

The gateway 5303 encountered multiple normal faults during the driving in Changping mine of Jinmei Group. For the purpose that the gateway can pass through the faults safely and rapidly and ensure applicative methods and scope of supporting. So based on the principle of maximum principal stress and fracture damage mechanics of rock, the paper analyzes the crushing mechanism of the normal fault zone under dynamic and static load from macroscopic and microscopic perspectives. Then, the plastic failure model of fault zone was established, the normal fault sliding mechanism and supporting theory were combined to derive the expression of the …

Fault Identification Technology Of Ant Attribute Optimization, Li Hongwei, Bai Xuelian, Cui Jingbin, Wan Zhonghong, Yuan Shihong, Chu Wanchang

Coal Geology & Exploration

In the field of seismic geological exploration, the ant attributes is more and more widely used for rapid identification of fault system, and in the process of practical application, ant attributes based on 3D seismic data extraction are displayed either along strata slice(plan) or in section, the features of fault system and distribution characteristics of seismic events is not corresponding to the actual situation, the application effect is poorer, fault interpretation work is given priority to with manual interpretation backbone profile, unable to realize fault automatic tracking. In view of this widespread situation, this paper studies and analyzes the actual …

Analysis Of Factors Affecting The Automatic High-Frequency Induction Brazing Strength Of Pdc, Dai Yongbo

Coal Geology & Exploration

With the development of automation and intelligentization in manufacturing industry, the research on PDC bit brazing automation is one of the key development directions of bit production technology. In order to study the influencing factors and adaptation methods of welding strength in PDC automatic brazing process, PDC high frequency induction welding and shear strength comparison test were carried out by using PDC and alloy pillar as the base material through special tooling and test conditions. Combined with the shear strength experiment and the morphology of brazing surface of PDC high-frequency induction brazing, the effect of brazing filler alloys, fluxes, surface …

Combined Cbm Production Behavior And Development Strategy Of Multiple Coal Seams In Zhijin Block, Guo Tao, Gao Xiaokang, Meng Guixi, Xiao Cui

Coal Geology & Exploration

Aiming at the problems that the CBM layers are numerous and thin, it is difficult to develop it effectively in south China, on the basis of the actual production data of CBM wells in Zhijin block, the production characteristics and the influencing factors of gas production of the directional wells for co-extraction of different seams and the horizontal wells for thin seams were analyzed, and corresponding suggestions for CBM development were put forward. The analysis indicated that the gas production of co-extraction of different seams was quite different, was influenced by the liquid-supplying capacity of formation, the height of desorbing …

Comprehensive Evaluation Technology And Application Of Grouting Reinforcement Effect For Broken Coal And Rock Mass, Wang Xiaolei, Ji Zhigang, Luo Wenqiang

Coal Geology & Exploration

Grouting reinforcement of broken coal and rock mass plays an important role in controlling the stability of surrounding rocks, and the grouting effect detection is an important link to ensure the grouting engineering to meet the requirements. The evaluation index was quantitatively analyzed by slurry filling rate method, mechanical parameter method, segmented water injection method, geological radar method, drilling television method and core inspection method. The comprehensive evaluation form of grouting effect was put forward, and the application research was carried out. The results show:The rate of filling slurry and coring was more than 90%; After grouting, the compressive strength …

Application Of High Precision Gravity Survey In Detecting Mined-Out Areas Of Fushun Coal Mine, Huan Hengfei, Gao Tie, Zhao Haiqing, Zhao Weijun, Guo Canwen, Shi Bin

Coal Geology & Exploration

In order to find out the location, depth and distribution range of the mined-out areas in Fushun coal mine, and comprehensively considering the factors affecting the geophysical methods in the cities, the method of high-precision gravity survey was firstly used to study the mined-out areas in the area. Firstly, by analyzing the physical differences of the mined-out areas, a theoretical model was established for forward calculation and preliminarily studied on applicability of the gravity method. Then, a large-scale work of high-precision gravity survey was arranged in the study area, and through potential field separation,3D apparent density inversion and boundary identification …

Agronomic Or Contentious Land Change? A Longitudinal Analysis From The Eastern Brazilian Amazon, Stephen Aldrich, Cynthia S. Simmons, Eugenio Arima, Robert T. Walker, Fernando Michelotti, Edna Castro

Department of Earth and Environmental Systems

Since 1984, nearly 1,000 people have been killed in the Brazilian Amazon due to land conflicts stemming from unequal distribution of land, land tenure insecurity, and lawlessness. During this same period, the region experienced almost complete deforestation (< 8% forest cover by 2010). Land conflict exacts a human toll, but it also affects agents’ decisions about land use, the subject of this article. Using a property-level panel dataset covering the period of redemocratization in Brazil (1984) until the privatization of long-term leases in the eastern Amazon (2010), we show that deforestation is affected by land conflict, particularly in cases of expropriation of property for agrarian reform settlement formation. Deforestation on these settlements is much greater when soils are poor for agriculture and when the land has been the object of past conflict. Deforestation and conflict are episodic, and both agronomic drivers and contentious drivers of land change are active in the region. Ultimately, the outcome of these processes of contentious and agronomic land change is substantial deforestation, regardless of who was in possession and control of the land.

Green Strategic Planning Approach For International Shipping Activities, Xiaofang Wu, Luoping Zhang, Huan Feng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Sustainability is a long-term and ultimate goal for international shipping, although it is slowly making progress. The shipping perspective that moves away from “port-to-port” operations to “door-to-door” services also requires international shipping to take a long-term and holistic view instead of fragmented efforts. How to achieve the long-term sustainability goal becomes a key issue for door-to-door international shipping. Hence, green strategic planning for door-to-door international shipping was proposed with green development that puts forward the eco-centric point of view as its basic theory for sustainability. This study used a strategic decision-making approach, a so-called multi-dimensional decision-making (MDDM), coupled with the …

Student Sustainability Leadership Development At Portland State University: Developing Holistic Sustainability Leaders, Megan Suzanne Schneider

Dissertations and Theses

In order to address the myriad of social, economic, and environmental challenges the world is facing, we need to be able to engage in leadership that fosters collective action towards sustainable solutions. Higher education is an institution that can equip people with the abilities to engage in sustainability leadership. This master's thesis research explores how students develop sustainability leadership through their college experience. Nine students, who had been identified as sustainability leaders through their participation in the Student Sustainability Center (SSC), a co-curricular sustainability program at Portland State University, were selected to be part of this grounded theory research project. …

On The Frontlines - The Fishermen Of Ibrahim Hyderi, Muhammad Haris Aslam Khan

MSJ Capstone Projects

Climate change has become a matter of recent debate for much of the world. According to a report published by a German watch, a non-governmental organization, in 2019, Pakistan among the five countries at severe risk of climate change disasters.

During the last two decades, Pakistan saw more than 141 extreme climatic catastrophes. Only in 2016, more than 566 people died due to these conditions.

A report published by Asian Development Bank in 2017 indicates Pakistan’s climate change profile. It states that more than 1,600 people have lost their lives in the super flood of 2010 alone. A loss of …

How To Promote Education For Sustainable Development? Vision Of The Educational Situation And Its Contribution To Sustainable Development., Khalid Aada

Writing and Language Studies Faculty Publications and Presentations

During the last decade, the importance of leaving a rational paradigm, debtor of functionalist and utilitarian models, towards another more congruent with the preservation of natural resources, and therefore of life, has been widely discussed. In the same way, different voices have been raised, pointing out the urgency of inserting these precepts into the educational field, hoping to achieve the true cultural transformation that is needed to consolidate the change. Multiple International Entities promote sustainability in Education as an initiative that should be ambitious, complex and reforming character, given the global scope of the social, economic and environmental situation affecting …