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Sealing Performance Evaluation Criteria And Profile Optimization Of The Volumetric Cavities Of Positive Displacement Motors For Directional Drilling, Kuang Yuchun, Hu Xin, Zhou Jingpei, Luo Jinwu, Liu Yihui, Han Yiwei

Coal Geology & Exploration

Objective Constrained by complex stratigraphic conditions in underground coal mines, directional drilling faces challenges such as low efficiency when encountering medium-hard and hard formations. Positive displacement motors (PDMs) with a diameter of 89 mm are commonly used for directional drilling. Their efficiency is primarily influenced by the sealing performance of their volumetric cavities, which further significantly affects the drilling efficiency. Methods Based on the structural characteristics of the three-dimensional (3D) volumetric cavities of PDMs and the simulation method of two-way fluid-structure interactions, this study proposed the criteria for quantitatively evaluating the efficiency and volumetric cavity performance of PDMs, followed by …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Biogeochemical Mechanisms Behind Water Quality Evolution And Valuable Element Reutilization Of Abandoned Mine Drainage: A Review, Wu Pan, Huang Jiangxun, Li Qingguang, Zhang Ruixue, Li Bo

Coal Geology & Exploration

Background Abandoned mine drainage, also known as acidic mine drainage (AMD), represents a major pollution source in mining areas while also serving as an important carrier of strategic critical metals and underground space utilization. In China, water pollution stemming from coal mining is more severe in the south than in the north. This spatial pattern is jointly shaped by climatic conditions, geological settings, and mining history. Advances From the perspective of the environmental geochemical frontier, this study presents a systematic review of AMD formation and evolution mechanisms, as well as technologies for water pollution prevention and control, resource recovery, and …

Underground Tunnel Drilling Technology And Equipment For Coal Mines In China: A 50-Year Retrospective And Prospects, Tian Hongliang, Li Wangnian, Li Quanxin, Yao Ke, Liu Jianlin, Chang Jianghua

Coal Geology & Exploration

Bcakground Underground tunnel drilling in coal mines represents an indispensable key means for the safe and efficient coal mining, precise disaster prevention and control, and geological transparency of coal mines. This study presents a systematic review of the development history of underground tunnel drilling technology and equipment for coal mines in China over the past 50 years, during which the technology and equipment have evolved from technology introduction to independent innovation and from following to keeping pace with and even to overtaking international counterparts.Advances Initially, this study expatiates on both the important position of coal resources in the national …

Key Techniques And Application Of The Zdy15000ldk High-Power Automatic Directional Drilling Rig, Li Quanxin, Zhang Gang, Fang Peng, Xing Wang, Yao Ke, Zhang Rui, Zhang Boyang, Zhao Xuefeng, Shi Yang, Sun Hanyu, Jia Qian

Coal Geology & Exploration

Objective For deep mining of coal mines, conventional directional drilling rigs face challenges including high labor intensity, limited control accuracy, a low intelligence level, and failure to meet the demand for efficient gas drainage. Meanwhile, high-power automatic drilling rigs encounter technical bottlenecks in automation, control accuracy, and process intelligence in this context. To address these issues, this study proposed an integrated and systematic solution—the ZDY15000LDK high-power automatic directional drilling rig. Methods Using a compact structural layout, a drill rod handling system was developed, consisting of a drill rod loading/unloading manipulator with four degrees of freedom and an automatic drill rod …

Instruments For Simulation Experiments On Coal-Rock Dynamic Disasters In China: Current Status And Key Challenges, Yuan Liang, Tang Haopeng, Ma Yankun, Wu Hua, Zhang Yachao, Jiao Biao, Wang Hao

Coal Geology & Exploration

Background Coal-rock dynamic disasters represent engineering disasters caused by the instability of the multi-phase and multi-field coupling of coal strata under mining disturbances, severely restricting the safe exploitation of deep coal resources. Elucidating the disaster-inducing mechanisms lays the foundation for exploring effective monitoring and early warning, along with prevention and control technologies, while instruments for simulation experiments provide crucial tools for investigating the mechanisms. Gradually increasing scientific and technological level has contributed to the continuous improvement in China's independently developed instruments for simulation experiments on coal-rock dynamic disasters. However, as engineering activities progressively extend toward deep parts, the multi-phase and …

Development History And Prospects Of Geological Guarantee In The Coal Industry: A Review, Liu Feng, Liu Wenming, Dong Shuning, Wang Hao, Cheng Jianyuan, Liu Zaibin, Fan Tao, Ma Liang, An Lin, Chen Baohui, Yan Zicheng, Jiang Bici

Coal Geology & Exploration

Background In China, the coal industry serves as a ballast stone and stabilizer for rapid socio-economic development and national energy security. Despite huge reserves, China’s coal resources are characterized by uneven spatial distribution, diverse coal seams, complex geological structures, and significantly different mining conditions. During coal mining, unclear geological conditions frequently lead to the abandonment of tunneling roadways, poor mining continuity, frequent equipment relocation, and the abrupt onset of concealed geologic hazards. These challenges ultimately result in difficult advancement of mining face, frequent casualties, and considerable economic losses. Geological guarantee represents a crucial foundation and key technology throughout the shaft …

Advances In Geological Guarantee Technologies For Safe, Efficient, And Intelligent Coal Mining In China, Sun Siqing, Miao Yaowu, Jia Lilong

Coal Geology & Exploration

Background Coal mining geology provides the foundation for efficient coal mining, as well as hazard prevention and control. Based on the revision to China’s normative documents entitled Regulations on Geological Work in Coal Mines and Detailed Rules for Geological Work in Coal Mines, the exploration of technologies for coal mining geology, and considerable experience in coal mine production practices, this study systematically reviews the advances in geological guarantee technologies for safe, efficient, and intelligent coal mining in China over the past four decades.Advances Six aspects of advances have been primarily achieved in geological guarantee technologies in China: (1) The …

Mechanisms Underlying Coal Instability During Coal And Gas Outbursts Induced By Deep Mining, Zhang Chaolin, Li Yunfu, Li Zhonghui, Wang Enyuan, Yang Shiji, Chen Jiawei, Wang Meng

Coal Geology & Exploration

Objective The gradual depletion of shallow coal resources drives a shift to the mining of deep coal seams. However, the complex deep mining environment significantly increases the potential risks and severity of coal and gas outbursts. Therefore, there exists an urgent need to investigate the mechanisms underlying the mechanical instability of coals under deep mining, aiming to provide guidance for the safe mining of deep coal mines.Methods By integrating physical experiments, numerical simulations, and theoretical analysis, this study investigated coal and gas outbursts under burial depths of 500 m, 1000 m, and 1600 m and established a multi-field coupling …

Analysis Of Typical Cases And Development Trends Of Coalbed Methane (Coal Mine Gas) Drainage Techniques In Coal Mining Areas, Hao Shijun, Jiang Wenping, Zhang Jing, Du Xinfeng, Mo Haitao, Duan Huijun

Coal Geology & Exploration

Background In the coal mining areas of China, coalbed methane (coal mine gas) occurs under complex conditions, rendering it difficult to achieve its efficient resource exploitation and effective hazard control using a single technique.Advances As indicated by the current state of the research, development, and engineering application of coalbed methane (coal mine gas) drainage techniques in China in recent years, the drainage methods can be classified into three categories according to their spatial arrangements: surface drainage, underground drainage, and surface-underground combined drainage. Furthermore, the surface and underground drainage methods can be subdivided into four types based on their temporal …

Key Techniques For Volume Fracturing Of Deep Coalbed Methane Reservoirs And Their Applications: A Case Study Of The Daning-Jixian Block, Li Shuguang, Xiong Xianyue, Zhen Huaibin, Bai Kunsen, Ji Yuan, Yuan Pu, Li Zhongbai, Zhu Weiping

Coal Geology & Exploration

Background Deep coalbed methane (CBM) reservoirs generally exhibit ultra-low porosity and permeability, high stress, predominance of nanopores, and complex fracture propagation. These characteristics complicate reservoir stimulation, thereby restricting the enhancement in single-well productivity and commercial exploitation. Since 2019, technologies for deep CBM recovery have evolved from volumetric acid fracturing, which highlights the enhancement of matrix permeability, into large-scale volume fracturing focusing on the elevation of both the fracture network scale and proppant efficiency. In 2023, ultra-large-scale volume fracturing aimed at maximizing estimated ultimate recovery (EUR) was further developed. However, the implementation of this novel technique poses challenges such as a …

Damage Evolution Of Coal Reservoirs Under Cyclic Disturbances And Optimization Suggestions For Deep Reservoir Stimulation, Chen Shida, Pu Yifan, Zhao Longmei, Li Xiang, Huang Li, Tang Dazhen, Zhang Yafei, Li Song, Tao Shu

Coal Geology & Exploration

Objectives and Methods During volume fracturing or multi-round hydraulic fracturing of deep coal reservoirs, pressure fluctuations induced by the propagation of fracture tips and fluid accumulation within fractures cause cyclic perturbations to surrounding rocks. To clarify both the mechanical responses of coals and the mechanisms behind fracture evolution within coal reservoirs under such cyclic perturbations, this study conducted triaxial cyclic loading-unloading tests on high-rank coals under varying confining pressures, stress amplitudes, and loading modes. In combination with field engineering data, this study proposed strategies for optimizing deep coal reservoir stimulation. Results and Conclusions The stress-strain curves of coals under cyclic …

Pathways And Modes For Prevention And Control Of Acid Mine Drainage-Induced Pollution In China, Liu Guo, Chen Qian, Gan Xinzhu, Tang Jie, Zhu Mingtan, Fan Jiajun, Ren Shuang

Coal Geology & Exploration

Background Mining activities in polymetallic sulfide mines significantly disrupt regional hydrogeochemical equilibrium, leading to the formation of acid mine drainage (AMD). Consequently, severe pollution of aquatic environments occurs, posing a threat to regional water resource security. To lay the foundation for the prevention and control of AMD-induced pollution, it is necessary to investigate the formation and evolution mechanisms of AMD and establish a low-cost, sustainable risk management and control mode. Methods Based on field sampling and literature research, this study made statistics of the hydrochemical characteristics of AMD from different polymetallic sulfide mining areas across China and elucidated the processes …

Advances In Research On The Quality, Influential Factors, And Contamination Prevention And Control Technologies Of Mine Water In Representative Coal Mining Areas Of China, Xu Guangquan, Zhang Haitao, Liang Miao, Chen Xiaoqing, Li Zixuan, Li Xu, He Jianghui

Coal Geology & Exploration

Background Mine water represents a major type of water body produced during coal mining. Investigating its quality, influential factors, and contamination prevention and control technologies is of great significance for environmental protection and the sustainable utilization of water resources in coal mining areas.Methods Based on field surveys and literature review, this study systematically analyzed the quality and formation mechanisms of mine water in representative coal mining areas of China. Furthermore, it explored the advances and primary challenges in current research on technologies for the prevention and control of mine water contamination and proposed major directions for future research. Advances …

Geophysical Responses And Their Statistical Relationships With Lithium And Kaolinite Contents For Lithium-Rich Coals In The Yangquan Mining Area, Chen Tongjun, Xu Haicheng, Li Wan

Coal Geology & Exploration

Objective China, representing the world's largest consumer of lithium resources, suffers from a limited endowment of conventional lithium resources, rendering it inevitable for China to seek to develop and utilize abundant coal-hosted lithium resources. Through a comparative analysis of coal samples from the lithium-rich No. 8 and the ordinary No. 15 coal seams in the Taiyuan Formation, Yangquan mining area, Shanxi Province, this study explored the statistical relationships between the lithium and kaolinite contents and geophysical responses. Accordingly, the feasibility of the indirect detection of coal-hosted lithium resources using geophysical methods was assessed. Methods First, by testing the lithium content …

Development Path And Prospects Of Technologies For Detecting Hidden Hazards In Coalfield Fire Zones, Deng Jun, Wang Jinrui, Ren Shuaijing, Song Zeyang, Wang Caiping, Li Yaqing, Lu Junhui, Qu Gaoyang

Coal Geology & Exploration

Background Hidden hazards in coalfield fire zones are characterized by limited detectability, rapid evolution, and multi-hazard coupling, posing major challenges to the safe coal mining and related ecological restoration. Methods This study aims to achieve the fine-scale identification and risk control of hidden hazards in coalfield fire zones. Based on a systematic review of the genetic mechanisms and spatial distribution patterns of coalfield fire zones, this study summarizes the characteristics of three primary fire zone types: outcrop/surface fire zones, shallowly buried fire zones, and deeply buried underground burnt-out areas and fire zones within old coal pits. Multi-dimensional hazards caused by …

Stoker-Fired Laboratory Boiler As A Tool For Optimising The Solid Fuel Combustion Process, Przemysław Rompalski, Justyna Guzy-Proc, Mariusz Kieczek

Journal of Sustainable Mining

This paper presents the results of quality testing performed on a stoker-fired laboratory boiler to present the technical potential of the boiler as a tool for optimising the combustion process of prepared solid fuels (granulate, energy blend) in the context of current demands related to the decarbonisation policy. The comprehensive testing of such fuels at a laboratory scale makes it possible to gain deep insights into the quality parameters of the fuel, flue gas and combustion waste, as well as to determine the combustion process parameters before the fuel is introduced for combustion in broader power engineering and household boilers. …

Comparative Analysis Of Transportation Emissions And Policy In Lahore And Los Angeles, Laiba Rehman

Master's Projects and Capstones

In 2023, exposure to air pollution killed 7.9 million people globally, becoming the second leading cause of death worldwide. Transportation emissions are among the primary drivers of this burden especially in rapidly urbanizing cities where vehicle fleets are growing faster than regulatory frameworks respond. This study examines the contribution of transportation emissions to urban air quality, public health and climate change in Lahore, Pakistan and Los Angeles, California. First, it employs a secondary data analysis of PM_2.5 and ozone concentrations and vehicle fleet composition in each city, followed by an analysis of emission inventories. Second, it evaluates the regulatory …

Deforestation Dynamics In The Amazon: Impacts, Socio-Environmental Drivers And Restoration Pathways, Maria Natalia Rodriguez

Master's Projects and Capstones

The Amazon, which is the largest tropical rainforest in the world, experienced 542,581 km² of forest loss between the years 2000 and 2020. The process of deforestation endangers the ecological system results which maintain ecosystem connectivity and the Earth's climate system. The Amazon rainforest supplies essential ecological services which include maintaining soil fertility, storing carbon, purifying water and climate stability. The fundamental ecosystem of this area faces new threats because of increasing forest destruction. The research study adopts a combined methodology that uses Geographic Information Systems (GIS) with a comprehensive literature review to study Amazon deforestation patterns and its driving …

Productive Armature, Gabriel Ofem Peter

Masters Theses

What if water was all you had, what if your only source of survival was a body of water? I shudder to think that some people get to be put in this situation in the world we live in. As I understand the importance of water to survival, it is obvious that water can be the only lifeline of survival for a community. This is the experience for residents of Makoko, Lagos. Their survival depends on the Lagos Lagoon, a large body of water flowing in from the Atlantic Ocean. This research looks beyond the surface of what this community …

Somatic Prosthetics For Planetary Resonance, Disha Dharesh Kumar R

Masters Theses

This thesis investigates how industrial design can transcend extractive technological paradigms in favor of relational interfaces that foster planetary attunement. Framing the climate crisis as a 'crisis of imagination', the research challenges the Western bifurcation of nature and culture by drawing on Indic cosmologies- which recognize stones, plants, and ecosystems as conscious at different levels and participants in a shared cosmic field. By synthesizing research in Biosemiotics, Quantum Information Pansycishm, and Neuroscience, the project redefines intelligence as a distributed, more-than-human phenomenon.

The research materializes as a speculative design artifact: a device that functions as a somatic prosthetic for planetary resonance. …

Characterization Of Mixed Metal Biogenic Manganese Oxide Materials For Catalysis And Rare Earth Element Sequestration, Elisa Morales, Jeremy Brown, Chloe Runge, Madeline York, Genesis Dennis, Cole Johnson, Anthony M. Baudino, Norman Paz-Ramirez, John Rey A. Romal, Kari Stone, Sarah E. Shaner

Chemistry Department Faculty Articles

This study explores the potential of utilizing biogenic manganese oxides (BMOs) produced by Mn-oxidizing Pseudomonas putida MnB1 to facilitate metal cation uptake for rare earth element (REE) sequestration and the synthesis of novel materials. Previous studies have shown that P. putida MnB1 efficiently oxidizes environmental Mn(II) to Mn(IV)-oxides, producing BMOs with unique physicochemical properties. Unlike their abiotic counterparts, BMOs exhibit high surface area, reactivity, and amorphous, poorly crystalline structures, making them promising platforms for adsorbing metal cations. This research study, building on the prior work, demonstrates the incorporation of ten different main group, transition, and rare earth metals into the …

Innovation Strategies For Small And Medium-Sized Construction Companies In Nigeria, Olabode Akinkunmi Akindele

Walden Dissertations and Doctoral Studies

No abstract provided.

Ecological Interest Theory Of “Lucid Waters And Lush Mountains Are Invaluable Assets” And Its Application In The Yellow River Basin, Guangqian Wang, Deyu Zhong

Bulletin of Chinese Academy of Sciences (Chinese Version)

To address the core challenges of quantifying ecological value and converting it into economic gains, this study proposes a theoretical framework of ecological interest (EI) based on the principle that “lucid waters and lush mountains are invaluable assets”. Three fundamental origins of ecological interest are explained, including the temporal value discount, the spatial ecological compensation, and the civilizational occupation-compensation balance. These three dimensions establish the logical connection between ecological and economic values. Setting a 5% annual simple interest rate as the benchmark and adopting “Lucid Waters and Lush Mountains” green certificates as the standardized ecological assets for property rights delineation …

Butte Priority Soils Operable Unit Butte Reduction Works Smelter Area Intermediate 60% Remedial Design Submittal, Pioneer Technical Services, Inc., Atlantic Richfield Company

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Unquaint Pigs’ Stakeholder Perspectives On Wild Swine In Central Western Florida, Tyler Koerner

USF Tampa Graduate Theses and Dissertations

The Anthropocene presents important questions for how to address the continuous transferal of new species into new spaces and the cascading impacts of environmental transformations. Novel ecosystems present one such outline for conservation that acknowledges the modification of historic ecosystems and the social entanglements that arrive with new species. I argue that novel ecosystems can benefit from further anthropological integrations that aid in describing the entanglements of introduced species and the pursuit of best managerial outcomes. For wild swine in Florida, the adoption of a novel approach is especially relevant because of entanglements with historic and modern Floridian stakeholders and …

An Analytical Framework For Quantifying Urban And Community Resilience To Natural Hazards From Cell-Phone Gps-Location And Traffic-Flow Data, Georgios Chatzikyriakidis

Civil and Environmental Engineering Theses and Dissertations

Urban areas are increasingly exposed to natural hazards while accommodating a growing share of the global population, yet a consistent science-based framework for quantifying urban and community resilience remains lacking. This dissertation develops a physics-based analytical framework grounded in statistical mechanics and the quantitative theory of Brownian motion. A city is conceptualized as a complex medium in which citizens move analogously to Brownian particles within a viscoelastic environment, influenced by socioeconomic interactions and infrastructure functionality.

A central premise is that urban resilience, interpreted as engineering resilience (an outcome), can be quantified through a single metric: the mean-square displacement MSD=⟨r²(t)⟩, of …

Quantifying Co2 And Ch4 Fluxes In A Semi-Arid Floodplain: Assessing Spatial And Temporal Drivers, Miles E. Kelsey

Earth and Planetary Sciences ETDs

Rivers transport sediment and carbon across Earth’s surface, and their floodplains can store carbon over decades to millennia, making them important to terrestrial carbon management. While soil carbon can persist long term, it may be released as greenhouse gases through processes like methanogenesis and heterotrophic respiration. Environmental controls on these fluxes remain poorly constrained across floodplains in different climate and geomorphic setting, but especially in semi-arid systems where measurements are limited. To address this gap, we quantified CO₂ and CH₄ fluxes along the Middle Rio Grande (New Mexico, USA) using 227 chamber measurements collected May to November 2025 at three …

Saving The Great Basin: Creating Places For The Birds, Bees And Beyond, Carlos Gomez

Hospitality Design Graduate Student Capstones

This project looks at how vacant and underused parcels along the Truckee River in Reno, Nevada, can be rethought as part of a larger ecological system. Rather than treating these parcels as empty leftover spaces, the project sees them as opportunities to create small habitat patches that can support native species, improve stormwater function, and strengthen the river corridor over time. The work focuses on three sites along the Truckee River: California Avenue, Island Avenue, and Commercial Row. Each site responds to a different condition along the urban transect, from a sloped residential river edge to a tighter urban parcel …

The Biowell System: An Integrative Framework That Connects Ecological Sustainability And Mental Wellbeing Through The Regenerative Processes Of Bioswales, Nathan A. Bussa

Hospitality Design Graduate Student Capstones

The Biowell System is an evaluative framework that connects ecological sustainability and mental well-being through the regenerative processes of bioswales.