Digital Commons Network^™

Experimental Study On Unloading Confining Pressure Deformation And Damage Failure Of Multi-Source Coal-Based Solid Waste Cemented Backfill, He Xiang, Wei Longqiang, Yang Ke, Zhang Tong, Zhang Cun, Zhang Zilong, Chen Yanjun

Coal Geology & Exploration

Objective The preparation of multi-source coal-based solid waste into filling materials for interval strip filling mining is one of the important means of green coal mining. The deformation and failure law of multi-source coal-based solid waste cemented backfill during strip coal pillar mining directly affects the stability of the stope.Methods Five typical solid wastes were mixed with cement to prepare cemented backfill. The conventional triaxial and constant axial pressure unloading confining pressure stress tests of backfill specimens were carried out. The stress-strain curves and failure characteristics of backfill under two stress loading paths were analyzed. The evolution law of …

Fluoride Ion Removal From Mine Water Via Nucleation Crystallization Pelleting Process, Zhang Xiyu, Dong Shuning, Wang Hao, Jin Pengkang, Wang Xiaodong, Wang Qiangmin, Zhang Tao

Coal Geology & Exploration

Objective The mine water associated with coal mining tends to be rich in fluoride ions. If discharged directly without effective treatment, such water will cause severe pollution to regional ecology, affecting the quality of water resources and the stability of the ecosystem. Methods This study focuses on the challenging treatment of the fluoride pollution caused by coal mining-associated mine water. To overcome the bottlenecks including low efficiency and weak anti-interference of traditional methods for fluoride removal, this study designed a setup for fluoride removal using the nucleation crystallization pelleting (NCP) processing and proposed a novel fluoride removal method—NCP chemical precipitation. …

A Seismic Random Noise Suppression Method Based On Cnn-Mamba, Wei Xiujuan, Liu Xingye, Zhou Huailai

Coal Geology & Exploration

Background Seismic random noise suppression is recognized as a key step to improve the quality of seismic data. Data-driven deep learning provides an intelligent solution for the noise suppression. However, mainstream random noise intelligent methods based on convolutional neural networks (CNNs) are constrained by their local receptive fields. This limitation results in insufficient collaborative optimization between local details and macroscopic structures during denoising, further reducing the noise suppression accuracy. Transformer models, which are widely applied to global feature extraction, can effectively capture long-distance dependencies through the self-attention mechanism, theoretically overcoming the limitations of CNNs in global modeling. However, these models …

Historical Overview, Advancements, And Future Prospects Of Coalfield Structure Research In China, Cao Daiyong, Ju Yiwen, Xia Yucheng, Jiang Bo, Ning Shuzheng, Wei Yingchun, Wang Anmin, Li Xiaoming, Zhan Wenfeng, Li Huantong, Wang Lu, Cai Zhuocheng

Coal Geology & Exploration

Background Coalfield structures represent a basic aspect of coalfield geology. In China, research into this domain has a history of over a century, yielding numerous results after undergoing exploration, learning, and innovation. These results have played a positive role in the long-term, stable coal supply in China. Amidst the ongoing energy structure optimization and the transformation and upgrading of coalfield geology in China, it is both practically and historically significant to review the history of coalfield structure research, summarize relevant experience, and contemplate future directions of the research under emerging circumstances.Methods Based on literature analysis, as well as the …

Mechanisms And Collaborative Prevention And Control Techniques For Various Disasters In Coal Seam Roofs, Zheng Kaige, Zhang Jian, Sun Siqing, Chen Dongdong, Wang Zeyang

Coal Geology & Exploration

Objective The multistage sedimentary and tectonic evolution of coal seams in China has led to the formation of environments with the coexistence of multiple disasters including gas outbursts, water inrushes, and rock bursts. To address the chain evolution of these disasters induced by the coupling of high in situ stress, high water pressure, and intense mining under the condition of deep coal mining, this study systematically investigated the coupling mechanisms and collaborative prevention and control techniques of multiple dynamic disasters in coal seam roofs. Methods Based on the regional tectonic characteristics and the delineation of coal-bearing tectonic units, this study …

Mechanisms And Equation Improvement For Gas Seepage In Coal Seams Around Boreholes Subjected To High-Pressure Co2 Foam Fracturing, Pang Mingkun, Zhang Tianyu, Pan Hongyu, Song Xianfeng, Wu Shan, Zhang Tianjun

Coal Geology & Exploration

Objective The special low-porosity, low-permeability structures of high-gas-content coal seams restrict efficient gas drainage. To address this issue, this study accurately determined the seepage parameters of annularly fractured coals around boreholes subjected to CO₂ foam fracturing to enhance both the design accuracy of boreholes for gas pre-drainage from coal seams and gas drainage efficiency. Methods Using an independently developed apparatus for gas seepage experiments on fractured coals around boreholes, this study investigated the coals with pores and fractures distributed in an annular pattern around boreholes from the perspective of varying initial pore structures. Specifically, this study analyzed the evolutionary …

Classification-Based Point Cloud Denoising And 3d Reconstruction Of Roadways, Chen Denghong, Pang Ning, Nie Wen, Feng Juqiang, Kan Jiliang, Zhang Jinjing

Coal Geology & Exploration

Objective The point cloud denoising and 3D reconstruction of roadways serve as a key step in the digital modeling and analysis of roadways. However, the conventional algorithm based on single filtering fails to effectively remove the noise at varying scales from point clouds. Meanwhile, the existing 3D reconstruction algorithms suffer from low modeling accuracy and high susceptibility to distortion. These necessitate developing methods and technologies to obtain high-quality point cloud data and construct high-accuracy 3D models for roadways. Methods This study proposed an adaptive classification-based point cloud denoising algorithm using neighborhood radius (R), minimum neighborhood point number ( …

Dominant Geological And Engineering Factors Controlling The Productivity Of Horizontal Wells For Deep Coalbed Methane In The Southern Shenfu Block, Guo Guangshan, Liu Yancheng, Zhao Gang, Chen Zhaohui, Li Chen, Kang Lifang, Wang Yuchuan, Wang Jianan

Coal Geology & Exploration

Objective The southern Shenfu block along the eastern margin of the Ordos Basin hosts one of the rare gas fields with reserves of over 100 billion cubic meters (bcm) in China, serving as a pilot demonstration area for the exploration and production of deep coalbed methane (CBM) conducted by the China National Offshore Oil Corporation (CNOOC). In this block, the gas production of horizontal wells is 2-10 times that of vertical wells. However, the horizontal wells are challenged by significantly different and rapidly declining gas production. Determining dominant factors controlling the productivity of horizontal wells for deep CBM is the …

Impacts Of The Hydrochemical Characteristics Of Coal Seam Water On The Structures And Metabolic Functions Of Microbial Communities, Wang Gaohao, Duan Shengjie, Wang Bei, Niu Guobin, Liang Yongping, Yu Feilong, Ma Kai, Zhao Weizhong

Coal Geology & Exploration

Background The core of coalbed methane (CBM) bioengineering is to inject bio-fracturing fluids rich in efficient methanogenic bacteria into coal reservoirs to promote the conversion of coals to methane. However, the relationships of the hydrochemical characteristics of coal seam water with the structures and metabolic functions of microbial communities remain unclear. Methods This study investigated coal seam water from 12 typical mining areas in Ningxia. Based on microbial classification and sequencing, as well as statistical analysis, this study explored the relationships of pH, anions, cations, and chemical oxygen demand (COD) of coal seam water with the structures and metabolic functions …

Construction And Application Of A Model For Drainage Via Directional Boreholes Against Water Hazards In Deep Vertical Shafts, Zhao Chunhu, Zhu Mingcheng, Ji Yadong, Wang Shidong, Zhang Wenzhong, Zhu Kaipeng, Liu Yingfeng, Shang Hongbo, Li Chaofeng, Fan Min, Li Kai

Coal Geology & Exploration

Background Vertical shafts are typically employed in the deep mining areas of Jurassic coalfields in western China. However, the direct exposure of extremely thick Cretaceous aquifers frequently leads to significant water inflow in shafts. Meanwhile, the continuous sand-carrying water inflow and scouring in vertical shafts pose serious safety hazards to the overall quality of shaft walls. Methods In underground water exploration and discharge boreholes, water outlets are below the floors of aquifers to be drained. This allows unpowered water discharge. In other words, water can flow out naturally. By fully leveraging this advantage, combined with the favorable condition of spatial …

Diffusion Mechanisms Of Power-Law Grouts In Water-Rich Sand Layers During Permeation Grouting, Xie Bao, Cheng Hua, Wang Xuesong, Li Mingjing, Liu Xiangyang, Han Xueyu

Coal Geology & Exploration

Objective This study aims to clarify the spherical diffusion patterns of power-law grouts in water-rich sand layers during permeation grouting and their influential factors. To this end, permeation grouting experiments were conducted to gain insights into the quantitative impacts of varying grouting parameters on grout diffusion.Methods Using model experiments on spherical diffusion during permeation grouting, this study analyzed the macroscopic diffusion morphologies and microscopic infilling effects of grouts, as well as the trends of permeation and soil pressures during grouting. Then, based on the spherical diffusion equations for permeation grouting that consider multi-effect coupling, this study analyzed the factors …

A Method For Efficient Virtual-Physical Synchronization Of The Digital Twin System Of An Excavation-Supporting Robot Cluster Targeting Coal Pillars Between Mining Faces, Mao Qinghua, Sima Junlei, Ma Hongwei, Wang Chuanwei, Chen Yanzhang, Guo Wenjin, Cui Wenda, Cheng Jiashuai

Coal Geology & Exploration

Objective Virtual models for excavation-supporting robot clusters targeting coal pillars between mining faces encounter challenges like a large data size and anomalies in data transmission, which lead to poor virtual-physical synchronization. This study proposed a method for efficient virtual-physical synchronization of the digital twin (DT) system of an excavation-supporting robot cluster using 3D model lightweighting and a trajectory prediction and correction model. Methods Fit-controlling vertices were defined, and their collapse cost factor was introduced to improve the quadratic error metric (QEM) algorithm and to constrain the lightweighting process of the 3D model of an assembly while maintaining fits between components. …

An Improved Mp-Nmo Correction Method Based On Multiparameter Fitting And Its Application, Yang Xiaohui, Yu Pengfei, Zhang Jiawei

Coal Geology & Exploration

Objective and Methods Normal moveout (NMO) correction is a core step in seismic data processing. However, the conventional NMO correction method tends to cause wavelet stretching when processing wide-angle or large-offset seismic data, leading to degraded stacking quality and distorted amplitude variation with offset (AVO) attributes. Although the matching pursuit (MP)-NMO correction method can mitigate the stretching effect, it will cause lateral discontinuity due to overlapping seismic events. Therefore, this study developed an improved MP-NMO correction method based on multiparameter fitting. Specifically, during MP decomposition, cubic polynomial fitting was applied to the amplitude, frequencies, and phases of wavelets from the …

Draft Final 2024 Residential Metals Abatement Program (Rmap): Walkerville Park (Walkerville Drive & Ryan Road) Soil Remedial Action Construction Completion Report, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Final Multi-Pathway Residential Metals Abatement Program (Rmap) Plan (Dated March 27, 2025), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Draft Final 2025 Residential Metals Abatement Program (Rmap) Rock Creek Cattle Company Borrow Submittal #1, Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Re: Comment Letter For Draft Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed Sites Ur-05 Remedial Action Work Plan (Rawp) (Dated March 14, 2025), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

The Future Of The Us Marine Seafloor And Subseafloor Sampling Capabilities, Future 2024 Pi-Team, Olga Libman‐Roshal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Recent changes in US oceanographic assets are impacting scientists' ability to access seafloor and sub-seafloor materials and thus constraining progress on science critical for societal needs. Here we identify national infrastructure needs to address critical science questions. This commentary reports on community-driven discussions that took place during the 3-day FUTURE of US Seafloor Sampling Capabilities 2024 Workshop, which used an “all-hands-on-deck” approach to assess seafloor and sub-seafloor sampling requirements of a broad range of scientific objectives, focusing on capabilities that could be supported through the US Academic Research Fleet (US-ARF) now or in the near future. Cross-cutting issues identified …

Sustainability In The Cruising Industry: Innovations In Air Quality, Energy Efficiency, And Waste Management, Fikret Durmus, Mi Ran Kim

ICHRIE Research Reports

The cruise industry, a cornerstone of the global hospitality and tourism sector, faces increasing scrutiny over its environmental impact. As passenger numbers grow, so does the industry's responsibility to adopt sustainable practices. This report examines key innovations in air quality management, energy efficiency, and waste management, highlighting the industry's transition from historically high emissions and waste production to advanced sustainability initiatives. Key focus areas include evolving maritime regulations, adopting cleaner propulsion technologies, integrating energy-efficient solutions, and improving waste treatment practices. Findings indicate that industry leaders are investing in liquefied natural gas engines, exhaust gas cleaning systems, and onshore power supply …

Decarbonized Shipping: Is It The Best Sustainable Shipping Solution?, Olivia Akers

Sustainable Supply Chain Management

In the era of globalization and the fourth industrial revolution, the maritime shipping industry has grown exponentially in the twenty-first century. In fact, 90% of today’s goods travel across the ocean before reaching the end consumer, meaning that ocean transportation of goods contributes significantly to overall environmental impacts on the ocean. Awareness of this impact has increased as humans strive to eliminate unsustainable practices in an effort to protect the long term health of our planet. Decarbonized shipping has been proposed as a possible solution for unsustainable shipping practices, and the goal of this chapter is to evaluate this solution …

Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Bres No. 158 Site Evaluation Summary Report (Dated February 24, 2025), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Re: Comment Letter For The Butte Priority Soils Operable Unit (Bpsou) Insufficiently Reclaimed Sites Bres No. 158 – Waste Rock Dump Remedial Action Work Plan (Rawp) (Dated March 28, 2025), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

The State Of Municipal Scale Highest Use Urban Wood Reclamation Projects, Bradley C. Almond

Graduate Liberal Studies Theses and Dissertations

Millions of urban trees are downed annually for various reasons, such as storms, disease, or development. We are all witnesses to the loss of trees as we see the piles of woody waste assembled on the curbside, ready for public works pickup. Today, most urban wood waste ends up in landfills, mulching/chipping facilities, or firewood production. Each of these alternatives results in the release of sequestered carbon back into the atmosphere.

The initial research led to successful diversion from landfills to mulch and firewood operations. Then, the research shifted to converting urban wood waste for its best use, which outlined …

Investigating The Microbial Communities In Freshwaters Of Northern Sweden, Maizy Wilcox

Undergraduate University Honors Capstones

Climate change is shifting the stability of sensitive ecosystems in the Arctic region due to global warming, with widespread impacts on permafrost regions, including the Stordalen Mire region of Sweden. Due to climate change, the Stordalen Mire is composed of thawing permafrost shifting into a wetland (V onk et al., 2015). As permafrost thaws, the landscape transforms due to changing water environmental conditions, causing lower pH changes and higher temperatures in the water, impacting the underlying soil chemistry and biology, vegetation, and microbial communities (Webb et al., 2022). The increased temperature can enhance methanogenic microbial growth by expanding the groundwater …

Enhancing Water Supply Resilience & Sustainability: Potential Solutions To Address Water Scarcity In Bogotá, Colombia, Sophia Alvarez Wong

Master's Projects and Capstones

Municipal water utilities are in urgent need of adapting to the intensifying impacts of climate change and population growth—key drivers of urban water scarcity worldwide. In rapidly expanding cities like Bogota, Colombia, these pressures have contributed to a severe water crisis driven by prolonged droughts, ecosystem degradation, increasing water demands, and overdependence on limited water sources. This study explores potential adaptation and management strategies that utilities can implement to sustainably strengthen supply system resilience and enhance water security, in the context of low- to middle-income regions. A series of comparative and case study analyses were conducted to assess the feasibility …

California Kelp Forests: An Analysis Of Macrocystis Pyrifera And Nereocystis Luetkeana Restoration After Decades Of Decline, Gabrielle K. Farrer

Master's Projects and Capstones

California’s kelp forests are some of the most biodiverse and productive ecosystems on the planet. Centuries of anthropogenic degradation via habitat destruction and climate change have culminated in decreased kelp forest habitat at an accelerated rate since at least the 1850s (Scarborough et al. 2022; Rogers-Bennett & Catton, 2019; Kumagai et al. 2024; Smith et al. 2023). This study synthesizes major threats, past and present, to California’s kelp forests, including the overharvesting of multiple species, pollution from coastal development, and climate change impacts. I also examine current management practices regarding kelp forests such as the use of marine protected areas …

A Roadmap For Greywater Reuse At The University Of San Francisco Hilltop Campus: A Financial, Regulatory, And Technical Feasibility Study, Apama'bo Anand Oszkar

Master's Projects and Capstones

Abstract

Water scarcity is increasing in California, so we need strategies to reduce potable water demand. Decentralized greywater systems offer promising solutions to this problem. This study provides a roadmap for successfully implementing greywater reuse at the University of San Francisco (USF) by addressing financial, technical, and regulatory considerations. By deploying a mixed-methods approach that combines qualitative expert interviews and quantitative water usage analysis, policy review, cost analysis, and case studies, this study established USF’s annual recycled water demand as 8 million gallons, with two primary uses: irrigation, which accounts for 67% of the demand, and toilet-urinal flushing, which represents …

Trade-Off Between Limonene & Geraniol-Based Reprocessable And Non-Reprocessable Epoxy Thermosets: Role Of Aliphatic Diamines In Polymer Networks Design, Priyankkumar Kanubhai Patel

Electronic Theses & Dissertations

The growing demand for sustainable materials, driven by environmental concerns and the rapid depletion of fossil fuels, has garnered significant attention in the fabrication of bio-based epoxy thermosets as renewable alternatives to petroleum-derived thermosetting polymers. The present study focuses on the synthesis and characterization of epoxy prepolymer resins derived from limonene and geraniol via a two-step process, followed by the fabrication of thermally cross-linked flexible epoxy thermoset films using various traditional aliphatic diamine curing agents, namely 1,2-ethylenediamine (EDA), 1,4-butylenediamine (BDA), and 1,6-hexamethylenediamine (HDA). Additionally, the incorporation of cystamine, a disulfide-containing diamine, enabled the formation of a covalent adaptable network through …

Effectiveness Of Urban Composting And Waste Management In The San Francisco Bay Area, Elijah Ashiagbor

Master's Projects and Capstones

The increasing food waste epidemic contributes to environmental degradation through amplified GHG emissions, notably CH4, from MSW landfills. Addressing this challenge is essential for public health and environmental sustainability. This research reviews municipal composting initiatives within the San Francisco Bay Area, evaluating effectiveness, efficiency, and sustainability. Utilizing data from CalRecycle and local municipalities, this study analyzes different composting processes, regulatory compliance with California’s Senate Bill 1383, and factors affecting waste diversion rates. Key discoveries indicate that in-vessel composting shows better efficiency and compost quality compared to windrow methods, particularly suitable for urban counties with space limitations. However, participation rates in …

Analyzing Ballast Water Treatments, Invasive Species, And Pathogens, And A Decade-Long Analysis On The San Francisco And Baltimore Ports, Jasmin Ibarra-Cortes

Master's Projects and Capstones

Installation of advanced technologies to treat ballast water on ships is necessary to meet current ballast water management standards and reduce the secondary spread of invasive species during intracoastal voyages. This research includes a literature review on non-native aquatic species, particularly diapausing eggs, and available treatment methods for installation. A comparative analysis from 2014 - 2024 on bulker, tanker, and container vessels arriving coastwise to the ports of San Francisco and Baltimore was performed to evaluate treatment installation trends, traffic patterns, and the effectiveness of treatment(s) on targeting diapausing eggs. Use of ultraviolet (UV) radiation combined with filtration has increased …