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Environmental Sciences

2020

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Articles 31 - 60 of 396

Full-Text Articles in Engineering

Numerical Simulation Of Fractured Water-Conducting Zone By Considering Native Fractures In Overlying Rocks, Li Ruirui, Chen Luwang, Ou Qinghua, Chen Yifei, Wang Yingxin, Ge Rutao, Peng Zhihong Dec 2020

Numerical Simulation Of Fractured Water-Conducting Zone By Considering Native Fractures In Overlying Rocks, Li Ruirui, Chen Luwang, Ou Qinghua, Chen Yifei, Wang Yingxin, Ge Rutao, Peng Zhihong

Coal Geology & Exploration

The intelligent accurate coal mining needs to construct the high-precision and transparent 3D geological model, and the seismic data interpretation integrated into the dynamic roadway data provide data support for the model. The geological model of roadway is established and forward modeling is carried out to analyze the difference of seismic characteristics caused by a roadway. Based on curvature attribute principle, various seismic curvature attributes were applied to seismic data interpretation, guide the roadway recognition in the seismic data. The coal seam 2 of CJT coalfield was selected as the research object, and the high-quality seismic data and various attribute …


Pso-Elm Prediction Model For Surface Deformation Of Mine Slope, Ning Yongxiang, Cui Ximin Dec 2020

Pso-Elm Prediction Model For Surface Deformation Of Mine Slope, Ning Yongxiang, Cui Ximin

Coal Geology & Exploration

During the excavation of the roadway, using reflected in-seam waves detection technique to explore the structure of roadway and accurately interpret the wave impedance interface is of signality for mine production. The method of detecting the position of faults by reflected in-seam waves is usually inaccurate, which is mainly caused by the selected deviation of reflected in-seam waves velocity. In order to reduce the selected deviation of reflected in-seam waves velocity, this paper analyzed the features of reflected in-seam waves velocity of fifteen coal seam in thirteen coal mines and the velocity relationships of reflected in-seam waves, direct in-seam waves …


Discussion On Parameters Of High Density 3d Seismic Exploration Acquisition In Coal Mining Districts, Cheng Jianyuan, Wang Qianyao, Zhu Shujie Dec 2020

Discussion On Parameters Of High Density 3d Seismic Exploration Acquisition In Coal Mining Districts, Cheng Jianyuan, Wang Qianyao, Zhu Shujie

Coal Geology & Exploration

In order to improve the light tar and gas yield, the yield distribution and composition characteristics of pyrolysis products of bituminous coal from Shaanxi Hongliulin in the nitrogen atmosphere and weak oxygen atmosphere were studied in a fixed bed reactor. The results showed that the yield of char and tar were reduced under the weak oxygen atmosphere, and the yield of CO and CO2 increased significantly, leading to the increase of total gas yield. Due to the oxidation combustion reaction, the yield of H2, CH4 and C2-C3 gradually decreased with the increase of …


Technology And Application Of High Efficiency Gas Extraction By Directional Long Borehole Hydraulic Fracturing In Coal Seams Of Medium Hardness And Low Permeability, Guo Chaoqi, Zhao Jizhan, Li Xiaojian, Zhang Jingfei, Wu Shengli, Chen Dongdong, Huang Xingli, Li Baojun Dec 2020

Technology And Application Of High Efficiency Gas Extraction By Directional Long Borehole Hydraulic Fracturing In Coal Seams Of Medium Hardness And Low Permeability, Guo Chaoqi, Zhao Jizhan, Li Xiaojian, Zhang Jingfei, Wu Shengli, Chen Dongdong, Huang Xingli, Li Baojun

Coal Geology & Exploration

Grouting quality test is the key technology for efficient development and utilization of waste land in the goaf of a coal mine, it is of great significance to evaluate the stability of the site and the safety of construction after goaf management. Based on many engineering practices, this paper summarizes the evaluation method of the qualified standards of the grouting quality and the errors existed in the testing work. The results proved that the quality inspection after grouting is a systematic work. The test method could be optimized according to the characteristics of the construction and grouting design requirements, following …


Gas Drainage Technology And Practice Analysis Of Large Diameter High Position Directional Long Borehole, Hao Shijun, Duan Huijun, Mo Haitao, Peng Xu, Peng Dong Dec 2020

Gas Drainage Technology And Practice Analysis Of Large Diameter High Position Directional Long Borehole, Hao Shijun, Duan Huijun, Mo Haitao, Peng Xu, Peng Dong

Coal Geology & Exploration

In order to solve the problem of the high mud content and easy hydration and dispersion of the Cretaceous sedimentary strata in well Songke-2, the bit balling is prone to occur in the water-based drilling fluid environment, which affects the drill bit ROP and induces downhole adhesion stuck, the paper combined the core drilling technology of well Songke-2, systematically analyzed of the causes of bit balling generated by the drill bit in the mudstone and water-based drilling fluid environment, provided a basis for the design of the anti-balling of the drill bit and the formulation of the anti-ball in drilling …


Use Of Image Processing Algorithms For Mine Originating Waste Grain Size Determination, Sebastian Iwaszenko Dec 2020

Use Of Image Processing Algorithms For Mine Originating Waste Grain Size Determination, Sebastian Iwaszenko

Journal of Sustainable Mining

The utilization of mineral wastes from the mining industry is one of most challenging phases in the raw materials life cycle. In many countries, there are piles of mineral waste materials that date back to the previous century. There is also a constant stream of accompanying mineral matter excavated during everyday mine operation. This stream of waste matter is particularly notable for deep coal mining. Grain size composition of waste mineral matter is one of most important characteristics of coal originating waste material. This paper presents the use of image analysis for the determination of grain size composition of mineral …


Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques Dec 2020

Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques

Master's Projects and Capstones

Since discovered and inhabited, the Brazilian Amazon has been explored and impacted negatively by human activities. The conversion of forest to pastureland and farmland, as well as mining activities, road opening, wood and ore extraction and fire are historically the main causes of environmental damages and forest loss in the region. This project overviewed the latest changes in environmental policy and practices towards environmental protection conducted by the Brazilian president Jair Bolsonaro, since he took office in 2019, and analyzed the progress of deforestation in the recent years under the new federal administration. Geographic Information System analysis were used to …


Literature Review: Global Neonicotinoid Insecticide Occurrence In Aquatic Environments, Josephus F. Borsuah, Tiffany L. Messer, Daniel D. Snow, Steve D. Comfort, Aaron R. Mittelstet Dec 2020

Literature Review: Global Neonicotinoid Insecticide Occurrence In Aquatic Environments, Josephus F. Borsuah, Tiffany L. Messer, Daniel D. Snow, Steve D. Comfort, Aaron R. Mittelstet

Biosystems and Agricultural Engineering Faculty Publications

Neonicotinoids have been the most commonly used insecticides since the early 1990s. Despite their efficacy in improving crop protection and management, these agrochemicals have gained recent attention for their negative impacts on non-target species such as honeybees and aquatic invertebrates. In recent years, neonicotinoids have been detected in rivers and streams across the world. Determining and predicting the exposure potential of neonicotinoids in surface water requires a thorough understanding of their fate and transport mechanisms. Therefore, our objective was to provide a comprehensive review of neonicotinoids with a focus on their fate and transport mechanisms to and within surface waters …


Carbon Sequestration By Reforesting Legacy Grasslands On Coal Mining Sites, James F. Fox, J. Elliott Campbell, Peter M. Acton Dec 2020

Carbon Sequestration By Reforesting Legacy Grasslands On Coal Mining Sites, James F. Fox, J. Elliott Campbell, Peter M. Acton

Civil Engineering Faculty Publications

Future carbon management during energy production will rely on carbon capture and sequestration technology and carbon sequestration methods for offsetting non-capturable losses. The present study quantifies carbon sequestration via reforestation using measurements and modeling for recent and legacy surface coal mining grasslands that are re-restored through tree planting. This paper focuses on a case study of legacy coal mining sites in the southern Appalachia the United States. This five million-hectare region has a surface mining footprint of approximately 12% of the land area, and the reclamation method was primarily grassland. The results of the soil carbon sequestration rates for restored …


Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji Dec 2020

Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji

Theses and Dissertations

Wastewater treatment is considered one of the most common forms of pollution control in the united states. Considered as an integral part of the wastewater treatment, the aeration process is the most energy-consuming process among all the processes that take place in any wastewater treatment plant. According to the United States Environmental Protection Agency (EPA), a wastewater treatment plant is expected to remove at least 85% of the suspended solids and dissolved organic compounds from the wastewater before discharging it to a river or a lake. The normal operation of the aeration process is by compressing air continuously to basin …


Developing Highly Reversible Li Metal Anode With Mossy/Dendritic Li Suppression In High Energy Density Batteries, Xi Chen Dec 2020

Developing Highly Reversible Li Metal Anode With Mossy/Dendritic Li Suppression In High Energy Density Batteries, Xi Chen

Theses and Dissertations

Lithium-ion battery technology has wide impact on our daily life. However, most of the commercial batteries with limited energy density are unable to meet the growing demand of electrical vehicles, portable electronic devices and other energy storage systems. Therefore, the development of new electrode materials with high energy density and reliable performance has become a critical mission for researchers. Particularly replacing graphite anode with Li metal is one of most viable approaches to break the limitation of energy density in batteries. Metallic lithium is one of the most promising anode materials, which has a high theoretical specific capacity of 3860 …


Effect Of Citric Acid On Slump, Compressive Strength, And Setting Time Of Belitic Calcium Sulfoaluminate Concrete, Israel Aguilar Rosero Dec 2020

Effect Of Citric Acid On Slump, Compressive Strength, And Setting Time Of Belitic Calcium Sulfoaluminate Concrete, Israel Aguilar Rosero

Graduate Theses and Dissertations

Belitic calcium sulfoaluminate (BCSA) cement has well established advantages related to fast setting time, fast strength gain, long-term strengths, shrinkage, and sustainability. Due to its fast setting and hardening, this type of cement has historically been used to repair concrete structures, highways, and runways. This work provides much needed guidance on establishing mix design criteria for BCSA cement. Guidance is also given on the effects of set retarders on strength, slump, and setting times. Citric acid and a phosphonic acid-based admixture were tested as retarders for different concrete mixtures. Three studies were performed. In the slump study five different water …


Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite Dec 2020

Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite

Theses and Dissertations

The construction industry is facing many challenges. There are growing consumer demands for sustainable building. The construction industry generates a significant portion of the waste going into landfills. The construction industry has failed to keep pace with productivity in the manufacturing industry. Through adoption of Lean management principles, the construction industry can become more sustainable while increasing productivity. The literature was evaluated for three concepts: Lean management principles interaction with sustainability, the current state of sustainability in the construction industry, and the current state of Lean management principles in the construction industry. Lean management philosophies interactions with sustainability has been …


Puerto Rico’S Electric Power System: An Analysis Of Contemporary Failures And The Opportunity To Rebuild A More Resilient Grid, Including The Development Of A Utility-Scale Solar Farm On The Island Municipality Of Culebra, Federico Sotomayor Dec 2020

Puerto Rico’S Electric Power System: An Analysis Of Contemporary Failures And The Opportunity To Rebuild A More Resilient Grid, Including The Development Of A Utility-Scale Solar Farm On The Island Municipality Of Culebra, Federico Sotomayor

International Development, Community and Environment (IDCE)

Puerto Rico’s grid was decimated in 2017 after experiencing back-to-back hurricanes – Maria and Irma. Although the hurricanes caused tremendous damage and hardship to the island, it also created the right circumstances for the local energy landscape to transition toward a more resilient and sustainable model. Through an analysis of recent challenges by the local electric utility PREPA, and subsequent fallout from the hurricanes, we see that they now hold a unique opportunity to redeem themselves by taking advantage of catalyzed resources to rebuild a better system. One region that could greatly benefit from an improved and reimagined grid are …


Projecting Water Available For Irrigation Use And Identifying Water Supply Stress Under Climate Change Scenarios In Selected U.S. Fruit And Vegetable Production Regions, Andrew Shaw Dec 2020

Projecting Water Available For Irrigation Use And Identifying Water Supply Stress Under Climate Change Scenarios In Selected U.S. Fruit And Vegetable Production Regions, Andrew Shaw

Graduate Theses and Dissertations

Climate change affects water resources differently across geospatial regions in the United States (U.S). There is a concern of how water availability will be affected by changes in long-term temperature and precipitation patterns, specifically in major production regions for eight fruit and vegetable crops. The effects on surface water available for irrigation use and supply stress in five regions containing 31 Agricultural Statistics Districts (ASDs) were assessed. The Water Supply Stress Index Model was used and modified to project water available for irrigation use across nine climate scenarios driven by historical data, five General Circulation Models, two population scenarios, and …


Assessing Grassed Waterway Implementation Using Acpf And Swat Models, Kirsten Schaefer Dec 2020

Assessing Grassed Waterway Implementation Using Acpf And Swat Models, Kirsten Schaefer

MSU Graduate Theses

Agriculture is the most significant contributor of nonpoint source pollutants in US waterways, with sediment being the most prevalent cause of impairments. Sediment loss mitigation occurs through Best Management Practices (BMPs), such as grassed waterways. Federal and state agencies incentivize the implementation of BMPs through cost-share programs for farmers. The investment of public funds has increased pressure to demonstrate the effectiveness and value of individual projects, necessitating the development of strategies for prioritizing projects based on the sensitivity of sites to sediment erosion and optimal locations for implementation. This study has three primary objectives: (i) document existing locations of grassed …


Potential Of Hemp (Cannabis Sativa L.) For Paired Phytoremediation And Bioenergy Production, Hanah T. Rheay, Emmanuel C. Omondi, Catherine E. Brewer Nov 2020

Potential Of Hemp (Cannabis Sativa L.) For Paired Phytoremediation And Bioenergy Production, Hanah T. Rheay, Emmanuel C. Omondi, Catherine E. Brewer

Agricultural and Environmental Sciences Faculty Research

Hemp (Cannabis sativa L.) is a multi-use crop that has been investigated for its potential use in phytoremediation of heavy metals, radionuclides, and organic contaminants, and as a feedstock for bioenergy production. A review of research literature indicates that hemp is a suitable crop for phytoremediation, and a competitive option for bioenergy. Coupling phytoremediation and bioenergy production from a single hemp crop is a potential solution to overcoming the economic constraints of phytoremediation projects. The current challenge is ensuring that the extracted contaminants are not introduced into the consumer marketplace. After several decades of limited research on hemp in the …


The Utilization Of Shared Energy Storage In Energy Systems: Design, Modeling And Optimization, Rui Dai Nov 2020

The Utilization Of Shared Energy Storage In Energy Systems: Design, Modeling And Optimization, Rui Dai

USF Tampa Graduate Theses and Dissertations

Energy storage (ES) plays a significant role in modern smart grids and energy systems. With the advances of ES technologies, efficiently applying ES to energy systems has become the bottleneck for achieving the benefits of ES. The traditional approach of utilizing ES is the so-called distributed framework in which there is a separate ES for each individual user. Due to the inherent limits in the distributed framework such as cost inefficiency and space limitations, many studies have promoted to utilize a shared ES in energy systems to further exploit the potentials of ES. However, current studies always focus on maximizing …


Improvement Of The Effectiveness Of Greywacke Crushing Process By Applying An Impact Crusher In Quarry For The Production Of Railway Ballast, Krzysztof Kurus, Karolina Jąderko-Skubis Nov 2020

Improvement Of The Effectiveness Of Greywacke Crushing Process By Applying An Impact Crusher In Quarry For The Production Of Railway Ballast, Krzysztof Kurus, Karolina Jąderko-Skubis

Journal of Sustainable Mining

The production of aggregates in rock mining requires an optimal system of crushers, separators and conveyors. Proper machine selection allows to obtain aggregates with appropriate technical parameters and increase the output of required fractions with a given unit cost. The usage of rock raw materials for the production of railway ballast used in the railway track superstructure is connected with the necessity to meet strictly defined quality requirements.

This paper presents an example of the use of an impact crusher in a selected quarry for the purpose of obtaining the correct parameters of railway ballast and a suitable grain curve. …


Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman Nov 2020

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce …


Enhancing The Visibility Of Vernier Effect In A Tri-Microfiber Coupler Fiber Loop Interferometer For Ultrasensitive Refractive Index And Temperature Sensing, Fangfang Wei, Dejun Liu, Zhe Wang, Zhuochen Wang, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova Nov 2020

Enhancing The Visibility Of Vernier Effect In A Tri-Microfiber Coupler Fiber Loop Interferometer For Ultrasensitive Refractive Index And Temperature Sensing, Fangfang Wei, Dejun Liu, Zhe Wang, Zhuochen Wang, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

In this paper a Vernier effect based sensor is analyzed and demonstrated experimentally in a tri-microfiber coupler (Tri-MFC) and polarization-maintaining fiber (PMF) loop interferometer (Tri-MFC-PMF) to provide ultrasensitive refractive index and temperature sensing. The main novelty of this work is an analysis of parameters of the proposed Tri-MFC-PMF with the objective of determining the conditions leading to a strong Vernier effect. It has been identified by simulation that the Vernier effect is a primary factor in the design of Tri-MFC-PMF loop sensing structure for sensitivity enhancement. It is furthermore demonstrated experimentally that enhancing the visibility of the Vernier spectrum in …


Saudi Regime For Ships Source Oil Spill In The Arabian Gulf Preparedness And Response, Abdullah M. Almutairi Nov 2020

Saudi Regime For Ships Source Oil Spill In The Arabian Gulf Preparedness And Response, Abdullah M. Almutairi

World Maritime University Dissertations

No abstract provided.


Compliance Assessment Of The National Oil Spill Contingency Plan Of The Philippines On 1990 International Convention On Oil Spill Preparedness, Response And Co-Operation Using Retos, Godofredo Garcia Vagilidad Nov 2020

Compliance Assessment Of The National Oil Spill Contingency Plan Of The Philippines On 1990 International Convention On Oil Spill Preparedness, Response And Co-Operation Using Retos, Godofredo Garcia Vagilidad

World Maritime University Dissertations

No abstract provided.


Assessing Oil Spill Management In Senegal Using The Iso 31000:2018 Standard As A Risk Management Framework, Abdou Aziz Diouf Nov 2020

Assessing Oil Spill Management In Senegal Using The Iso 31000:2018 Standard As A Risk Management Framework, Abdou Aziz Diouf

World Maritime University Dissertations

No abstract provided.


A Comparative Study Of The Implementation Of Oil Spill Contingency Planning In Promoting Ocean Sustainability And Governance : A Case Study Of Ghana And Canada., Marvin Bang-Gesina Ayoo Nov 2020

A Comparative Study Of The Implementation Of Oil Spill Contingency Planning In Promoting Ocean Sustainability And Governance : A Case Study Of Ghana And Canada., Marvin Bang-Gesina Ayoo

World Maritime University Dissertations

No abstract provided.


Global Air Quality Trekkers: Nandi Clean Kitchen Study, Samantha Dykhuis, Stephanie Schiavo, Avalin Senefeld Oct 2020

Global Air Quality Trekkers: Nandi Clean Kitchen Study, Samantha Dykhuis, Stephanie Schiavo, Avalin Senefeld

Purdue Journal of Service-Learning and International Engagement

Indoor air pollution is a widespread environmental health challenge sub-Saharan Africa and is the leading cause of premature death in many sub-Saharan African countries. This pollution is primarily caused by the burning of biomass fuels inside an enclosed kitchen in order to provide heat for cooking. Global Air Quality Trekkers is an undergraduate engineering team within the EPICS department at Purdue that began in fall 2016. Our objective is to create a kitchen design that utilizes natural ventilation to mitigate the amount of air pollutants present in these kitchens, specifically in the Nandi community of Western Kenya. This year, our …


The Year The West Was Burning: How The 2020 Wildfire Season Got So Extreme, Mojtaba Sadegh, Ata Akbari Asanjan, Mohammad Reza Alizadeh Oct 2020

The Year The West Was Burning: How The 2020 Wildfire Season Got So Extreme, Mojtaba Sadegh, Ata Akbari Asanjan, Mohammad Reza Alizadeh

Civil Engineering Faculty Publications and Presentations

More than 4 million acres of California went up in flames in 2020 – about 4% of the state’s land area and more than double its previous wildfire record. Five of the state’s six largest fires on record were burning this year.

In Colorado, the Pine Gulch fire broke the record for that state’s largest wildfire, only to be surpassed by two larger blazes, the Cameron Peak and East Troublesome fires.

Oregon saw one of the most destructive fire seasons in its recorded history, with more than 4,000 homes destroyed.

What caused the 2020 fire season to become so extreme?


Evaluation And Analysis Of Paleoenvironments Of The Neogene Oil Shale Of Zhangcun Formation, Qinshui Basin, Liu Yanhai, Li Kunjie, Liu Dongna, Xue Shubin, Liu Yangfe, Chu Yonghui Oct 2020

Evaluation And Analysis Of Paleoenvironments Of The Neogene Oil Shale Of Zhangcun Formation, Qinshui Basin, Liu Yanhai, Li Kunjie, Liu Dongna, Xue Shubin, Liu Yangfe, Chu Yonghui

Coal Geology & Exploration

In order to deeply analyze the indication of oil shale development characteristics on paleoenvironments and provide theoretical guidance for oil shale resource evaluation, the organic geochemistry and elemental geochemistry characteristics of the Neogene Zhangcun Formation oil shale in the central part of the Qinshui basin were analyzed by Rock-Eval and TOC and the paleoclimate and paleogeographic environments of the depositional period were discussed as well. The results show that the oil shale of Zhangcun Formation has the low oil content which Tar=4.15%, higher hydrocarbon potential, kerogen is of sapropel type(I1), which has relatively shallow burial depth. The element …


Pyrolysis Characteristics And Pyrolysis Product Composition Of Bituminous Coal Under Weak Oxidizing Atmosphere, Zang Libin, Cui Hufeng, Li Qingchun Oct 2020

Pyrolysis Characteristics And Pyrolysis Product Composition Of Bituminous Coal Under Weak Oxidizing Atmosphere, Zang Libin, Cui Hufeng, Li Qingchun

Coal Geology & Exploration

In order to improve the light tar and gas yield, the yield distribution and composition characteristics of pyrolysis products of bituminous coal from Shaanxi Hongliulin in the nitrogen atmosphere and weak oxygen atmosphere were studied in a fixed bed reactor. The results showed that the yield of char and tar were reduced under the weak oxygen atmosphere, and the yield of CO and CO2 increased significantly, leading to the increase of total gas yield. Due to the oxidation combustion reaction, the yield of H2, CH4 and C2-C3 gradually decreased with the increase of …


Progressive Gas Extraction Technology In Broken Soft Coal Seam Of Qinglong Coal Mine, Guizhou Province, Liang Daofu, Cao Jianming, Dai Mao, Chu Zhiwei, Zhang Lei Oct 2020

Progressive Gas Extraction Technology In Broken Soft Coal Seam Of Qinglong Coal Mine, Guizhou Province, Liang Daofu, Cao Jianming, Dai Mao, Chu Zhiwei, Zhang Lei

Coal Geology & Exploration

Aiming at the problems of uncontrollable trajectory, shallow borehole depth and poor gas extraction effect in gas treatment drilling of broken soft coal seam in Qinglong coal mine, the regional progressive gas extraction technology in broken soft coal seam based on compressed-air directional drilling was proposed, on the basis of analyzing the technical bottleneck of existing gas extraction borehole with rotary drilling. The principle and advantage of the technology was expounded, the technology of directional drilling by compressed-air, the technology of long distance in-seam drilling, and the technology of compound slag discharge by double power were integrated. The field test …