Engineering Commons^™

Physical And Mechanical Properties Of Thermal Insulation Materials For In-Situ Temperature-Preserved Coring Of Deep Rocks, Xue Shouning, He Zhiqiang, Li Cong, Yu Bo, Lu Xuelian, Liu Wenyue, Yang Jianping, Wei Zijie

Coal Geology & Exploration

High temperature affects deep coal mining and other engineering activities. However, conventional coring methods for terrestrial hard rocks lack temperature-preserved measures, ignoring the effects of temperature on the physical and mechanical properties of rocks. Consequently, the parameters obtained are subjected to distortion, affecting the safe and efficient mining of resources such as deep coals. To make breakthroughs in the development of in-situ temperature-preserved coring technologies for deep rocks, this study proposed using the hollow glass microsphere/epoxy resin (HGM/EP) as thermal insulation materials and the physical and mechanical properties. The results are as follows: (1) With an increase in the HGM …

Research Advances On The In-Situ Pressure-Preserved Coring And Gas Parameter Determination For Deep Coal Seams, Xie Heping, Cui Pengfei, Shang Delei, Fan Dong, Chen Ling, Yang Mingqing, Du Lin, Gao Mingzhong

Coal Geology & Exploration

The in-situ gas pressure and content of coal seams are critical for the safe production of deep coal mines and the accurate evaluation of coalbed methane resources. To address the technical challenges of accurately determining in-situ gas content in deep coal seams, this study proposed brand-new principles of in-situ pressure coring and the tests of in-situ gas content and pressure. It also derived a calculation method for in-situ gas content in coal seams and a method for determining the in-situ gas pressure while considering the effects of moisture content and multiple gas components. Given the in-situ stress environment deep in …

A Preliminary Study Of Pressure-Preserved Coring Calculation Principle And Method For In-Situ Pressure In Deep Coal Seams, Cui Pengfei, Gao Mingzhong, Shang Delei, Li Jianhua, Chu Peng, Song Jie, Li Yongcheng, Hao Haichun

Coal Geology & Exploration

The accurate acquisition of in-situ gas pressure in coal seams is a key link in the chain of the prevention and control of gas disasters. Presently, it is still necessary to explore accurate, low-cost, and time-saving methods for determining gas pressure. Based on the in-situ pressure-preserved coring for deep coal seams, this study proposed a calculation method for in-situ gas pressure in deep coal seams and developed the calculation process. Using the constructed numerical model of the gas pressure evolution in the pressure-preserved space, this study verified the reliability of the proposed method by comparison with the theoretical and numerical …

Influence Of Gas Components On The Determination Of Gas Pressure In Coal Seams Under In-Situ Pressure-Preserved Coring, Chu Peng, Shang Delei, Li Jianhua, Ma Shaoming, Zhu Guodong, Cui Pengfei

Coal Geology & Exploration

Determining the pressure and content of coal seam gas based on pressure-preserved coring is an effective method for quickly and accurately calculating gas parameters. Coal seam gas is a multi-component gas mixture dominated by methane. Given that coals show different adsorption capacities for different gases and that the components in the mixed gas exhibit different partial pressures, the proportions of gas components can influence the calculation results of the content and pressure of coal seam gas. To accurately determine the in-situ gas pressure in coal seams based on the pressure-preserved coring, this study investigated the influence of gas components on …

Exploring The Wetting Mechanism Of Surfactants For Coals Based On Molecular Simulations, Tong Yanjun, Yang Zundong, Song Jie, Li Yongcheng, Liu Yiting

Coal Geology & Exploration

With a gradual increase in the depth and mechanization degree of coal mining, secondary explosions of gas and coal dust have become increasingly severe. Chemical dust suppressants such as surfactants can reduce these explosions by effectively inhibiting the generation and diffusion of coal dust. To explore the inhibition mechanism of nonionic surfactants for hydrophobic coal dust, this study analyzed the basic physicochemical properties of typical hydrophobic coal dust at a depth of 1050 m using FT-IR, XRF, and XRD. This study built a molecular structure model of coal dust by combining test techniques such as EA, XPS, and ¹³C …

Sealing Performance Analysis And Structure Optimization Of Pressure-Preserved Controller For Pressure-Preserved Coring In Deep Coal Mine, Wang Tianyu, Li Jianan, Zhang Yiwei, Li Ju, Xie Heping

Coal Geology & Exploration

As the pressure-preserved controller is a core component of the deep coal in-situ pressure-preserved coring device, its sealing design plays a decisive role in the effect of pressure-preserved coring. In order to obtain the optimal sealing structure, a two-dimensional axisymmetric nonlinear contact model was established for the sealing structure of the pressure-preserved controller. On this basis, the effects of different groove design, cone angle selection and friction coefficient on the sealing performance were analyzed by orthogonal test method. Meanwhile, the stress changes of the sealing ring under different closing stages and medium pressures were studied. The results show that: the …

Pressure Relief Mechanisms And Effects Of Liberation Seam Mining In 1000-M-Deep Coal Mines: A Case Study Of The Huafeng Coal Mine In Tai’An, China, Gao Yanan, Zhang Yao, Zhang Defei, Zhang Yudong, Zhao Weidong, Yu Liyuan

Coal Geology & Exploration

Liberation seam mining serves as an important approach to the prevention of deep dynamic disasters such as coal and gas outbursts, as well as rock bursts. Based on the Nos. 2613 and 2412 mining faces of a 1000-m-depth coal mine in the Huafeng Coal Mine in Tai’an, Shandong, this study investigated the engineering scientific issues such as the pressure relief mechanisms and effect evaluation of liberation seam mining through physical and numerical simulations. As a result, it determined the movement law of overburden strata and the characteristics of underground pressure after the mining of the liberation seam and ascertained the …

Remote Sensing And Gis Based Approach To Evaluate The Impact Of Stone Quarrying And Crushing Activities On Land Resources, R. S. Chaurasia, S. N. Mohapatra

Journal of Sustainable Mining

The land is one of the most treasures to support life, like food, fibre, medicine, and minerals, etc. Stone quarrying is one of the key elements which supports socio-economic development and industrial expansion. RS and GIS play an important role in environmental assessment to monitor the stone quarries and related activities for time to time. The present study was carried out to evaluate the impact of stone quarrying and crushing activities (SQCA) on land resources. Therefore, matrix change analysis of 2021, 2015, 2008 and 2003 were used for change detection. High-resolution Google Earth Pro images were used for the assessment …

Predictive Model Of Seismic Vibrations’ Peak Value Induced By Multi-Face Blasting, Krzysztof Fuławka, Lech Stolecki, Piotr Mertuszka, Marcin Szumny, Arkadiusz Anderko

Journal of Sustainable Mining

The seismicity level induced by blasting in the Polish copper mines is very important inlight of the efficiency of active rockburst prevention and safe conduct of blasting operations in the vicinity of the mining infrastructure such as shafts, workings, or function chambers (e.g., workshops, storages, etc.). Knowledge of the seismic vibrations’ peak value might be the basis for designing blasting works in a way that ensures desired seismic effect. However, current experiences show that Peak Particle Velocity prediction models developed so far do not apply to multi-face blasting, where there are many vibrations’ sources at the same time dotted across …

Managing The Rock Mass Destruction Under The Explosion, Maksym Kononenko, Oleh Khomenko, Ivan Sadovenko, Valeriy Sobolev, Yuliya Pazynich, Adam Smoliński

Journal of Sustainable Mining

Using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis of the mechanism of the destruction of a solid medium under the action of an explosion, analytical modelling of the parameters of the formation of crumpling zones and crushing of the rock mass around the charging cavity during its explosive loading was carried out. Analytical models of the radii of the crumpling, intensive fragmentation and fracturing zones formed around the charging cavity in the rock mass during its explosive loading, taking into account the pressure of the explosion products, the limit of tensile-compressive strength of the rocks, …

Application Geological Strength Index (Gsi) Quantification Method On The Characterization Of Carbonate Rock Mass, Singgih Saptono, Danu Mirza Rezky

Journal of Sustainable Mining

Determining GSI as a representation of the presence of rock mass in slope analysis continues to develop. The development of the quantitative GSI method was carried out because the basic (qualitative) GSI values were deemed too subjective so the results from the use of the quantitative GSIwere expected to be more objective and accurate. The method used is to combine 3 GSI quantitative methods to find GSI based on surface conditions and joint structure. The results showed that the Quantitative GSI value was smaller than the GSI predictive value (qualitative). The GSI approach with RQD and UCS parameters is also …

Design Of Stormwater Bmps For Surface And Groundwater Protection Based On Site-Scale Soil Properties: Phase I, Kelly Kibler, Lisa Chambers, Melanie Beazley

Florida DOT

Much of Earth’s nutrient cycling takes place in soils. Characteristics of soils control physical, chemical, and biological processes that determine rates of nutrient fluxes, storage, or transformation. As remediation of excess nutrients in stormwater runoff is one function of stormwater Best Management Practices (BMPs), the soil profile constitutes one of the most important factors of BMP design. Variation observed in BMP effectiveness (e.g., why one BMP design works effectively in one place and not another) can often be explained by variations in the soil profile, either through direct means or by a soil’s influence on hydraulics of stormwater flow through …

Hydrological Dynamics Of Surface-Groundwater Interactions Between Major Springs Of Mammoth Cave And The Green River, Kentucky, Usa, Matthew Cecil

Masters Theses & Specialist Projects

Mammoth Cave is an iconic example of the cave and karst systems that underlie over 50% of the United States and provide around 13% of the world’s population with water resources. These environmental features are vulnerable to drought, pollution, and human impacts. The complex hydrological regime of the Mammoth Cave system has been studied in the past, but there are improvements and updates that can be made to the past research. The dynamics of the surface-groundwater system, particularly reversals of the Green River and how it backfloods into the cave, are some examples. Echo River and River Styx Springs provide …

Adaptation Of Nirtrifiers And Heterotrophs To Low Dissolved Oxygen In An Activated Sludge Biological Nutrient Removal Pilot Plant, Shashank Khatiwada

Civil & Environmental Engineering Theses & Dissertations

Low dissolved oxygen (DO) operation is one of the innovative technologies in biological nutrient removal (BNR) processes that is being investigated due to the potential to reduce aeration requirements, reduce a treatment plant’s carbon footprint, and to lower costs associated with chemical addition to promote denitrification. These benefits are achieved through development of micro-zones, within aerated basins where simultaneous nitrification and denitrification (SND) can occur. In this study, an activated sludge BNR pilot was run in an anerobic/aerobic (A/O) configuration at a controlled temperature and constant flow to observe microorganism-driven transformations of nitrogen and phosphorus at varying low DO conditions. …

Design And Development Of Transition Metal-Based Electrocatalysts For Environmentally Friendly And Efficient Hydrogen Evolution Reactions (Her), Navid Attarzadeh

Open Access Theses & Dissertations

Hydrogen fuel is a clean energy source primarily because it emits no carbon dioxide (CO2). Sustainable energy alternatives have attracted the scientific community and policymakers as concerns over global warming and depletion of fossil fuels have increased significantly. Substituting H2 gas as a primary source for our daily energy consumption under the guideline of the hydrogen economy concept has not progressed as anticipated because of inadequate efficiency associated with the generation (electrolyzer) and utilization (fuel cell) devices. However, there are challenges associated with hydrogen that must be overcome for it to become a truly sustainable and widespread energy source. The …

Evaluating The Feasibility Of Using Strain Measured During Sinusoidal Rate Pumping Tests To Characterize An Aquifer, Riley Blais

All Theses

Pumping tests with sinusoidal variation in pumping rate have been proposed as a method for improving aquifer characterization. These tests can interrogate a larger aquifer volume than slug tests and they can be more sensitive to small variations in drawdown. Current methods of using sinusoidal variations of rate are based on measuring pressure signals from the reservoir or aquifer, which requires access to monitoring wells. An alternative approach has been developed that measures the strain in the vadose zone instead of pressure in the reservoir. An instrument has been developed at Clemson University that can measure small strains using optical …

Phase Distribution Of Nickel, Chromium, And Cobalt In Seawater At Olivine-Enriched Beaches: Implications For Carbon Capture By Enhanced Silicate Weathering, Nathaniel J. Padrnos

Master's Theses

The application of olivine to coastal areas is a proposed method of removing carbon dioxide from the atmosphere for climate change mitigation. Olivine is abundant and dissolves relatively fast, but it contains trace amounts of nickel (Ni), chromium (Cr), and cobalt (Co) which may be toxic to marine biota in cases of widespread coastal olivine spreading. Prior studies have suggested that Ni concentrations in marine sediments and/or the overlying water column due to olivine dissolution could be a limiting factor for its carbon capture potential. Therefore, it is critical to understand and model the processes affecting trace metal bioavailability after …

Towards Sustainable Water Management: Soil Analysis, Modeling, And Sensor Implementation On A Micro-Basin Chile's Los Lagos Region, Tammy N. Huynh

Civil Engineering ETDs

The Los Lagos region of Chile is experiencing ecological and socioeconomic challenges because of climate change. Despite efforts by the agricultural sector to understand and manage water resources, the lack of basic water quantification data affects their ability to effectively plan and implement water management strategies. This research aims to address this critical issue through three key objectives. First, characterize soil properties related to texture and structure in a micro-basin of the Los Lagos region. Secondly, it aims to investigate the hydrologic budget of the micro-basin with an emphasis on soil moisture using the Soil Moisture Routing model (SMR). Lastly, …

Combining Semi-Continuous And Discrete Water Quality Data To Characterize Solute Transport, Biogeochemical Processes, And Wildfire Disturbances In Fluvial Systems, Justin Rae Nichols

Civil Engineering ETDs

In the past decade, high-frequency water quality sondes have become more abundant in watersheds across North America and Europe and are gaining a foothold in Asia and South America. In this dissertation, three relevant topics associated with high-frequency data are investigated, i.e., the impact of winter’s precipitation on surface water quality and stream metabolism, the longitudinal propagation of wildfire disturbances through a fluvial network, and the use of machine learning with high-frequency data to estimate fluvial nutrient processing. First, we found that significant snow precipitation can cause surface water anoxia and declines in stream metabolism. Second, our data illustrate that …

Integrating Sensor Development, Risk Assessment, And Community Engagement To Support Environmental Justice In The Rural Community Of El Tiple, Colombia, David Bahamon Pinzon

All Dissertations

In Colombia, ethnic communities have traditionally been responsible stewards of natural resources. They recognize the importance of these resources for their livelihood, as well as their ancestral and cultural heritage. El Tiple, a rural Afro-Colombian community, has been affected by the incursion of private corporations that promoted the expansion of sugarcane monocrops in their territory. Since the introduction of the monoculture industry, local freshwater sources have been depleted due to intensive water use for irrigation of the sugarcane crops. Additionally, the intensive usage of agrochemicals has been linked with loss of native flora, damages to family farms, and pollution of …

How Active Rainwater Harvesting May Help Reduce Nuisance Flooding: Flood Analysis And Social Barriers To Adoption, Isabel Lopez

Open Access Theses & Dissertations

As urbanization continues to expand, fewer pervious surfaces are available to help reduce stormwater runoff from rainfall. The impacts of urbanization are becoming evident through sunny day flooding - flooding that occurs in areas not designated by the Federal Emergency Management Agency (FEMA) as flood zones. Nevertheless, water accumulates in low-lying areas and compromises street intersections and other parts of neighborhoods. Some methods can help alleviate the impacts of unexpected heavy rains, such as passive and active rainwater harvesting. As a pilot study, in a selected area in the northeast of El Paso, the level of adoption (e.g., what percentage …

Performance Evaluation Of A Coupled Photovoltaic-Thermal Solar Powered Desalination Pilot System, Martin Chavarin

Open Access Theses & Dissertations

A pilot scale coupled photovoltaic-thermal solar powered desalination system was evaluated at the Brackish Groundwater National Desalination Research Facility (BGNDRF). The pilot system consisted of a 3-kW photovoltaic-thermal (PVT) solar panel array and a 2.3 kW photovoltaic (PV) array coupled with a 4 gal/min single-stage 4 membrane reverse osmosis (RO) desalination system. A heat exchange system was in place to provide simultaneous cooling for the PVT system and heating to the RO system feed water. This system was evaluated with three objectives in mind. The first objective was to identify whether cooling of the PVT panels resulted in a significant …

Characterization Of Mechanically Recycled Polylactic Acid (Pla) Filament For 3d-Printing By Evaluating Mechanical, Thermal, And Chemical Properties And Process Performance, Mahsa Shabani Samghabady

All Theses

Polylactic acid (PLA) is a biopolymer made from renewable resources such as sugar and corn. PLA filament is a popular material used in Fused Deposition Modeling (FDM) 3D-printing. While this material has many advantages, all the failed parts, support structures, rafts, nozzle tests, and the many prototype iterations during the 3D-printing process contribute to the plastic pollution and release of greenhouse gases. Although PLA is biodegradable, it can take years to degrade in landfills. Instead of throwing away PLA waste and buying new filaments, PLA can be recycled. Amongst the different recycling technologies, mechanical recycling is the most environmentally friendly. …

A Hybrid Lateral Flow Sand Filter Wastewater Treatment System: An Evaluation On The Treatment And Disposal Capabilities Of A Modified Sand Filter, Harry Mccaskill Iv

Graduate Theses and Dissertations (2019 - present)

Decentralized wastewater treatment exists primarily in suburban and rural areas where centralized treatment is not an option. Traditional on-site treatment systems usually include the use of a septic tank and a drain field. This orthodox method works well when implemented into environments that are accommodating for the infiltration of effluents, and thus allowing for soil treatment. Unfortunately, there are some circumstances that prevent traditional systems from working such as impermeable soil conditions. The Wastewater Treatment System analyzed in this thesis was created to overcome such inhospitable environments. More specifically, this system is catered towards the rural residences of The Alabama …

High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman

All Dissertations

Atmospheric carbon dioxide (CO₂) concentrations have been increasing at an accelerating rate for the past two centuries, profoundly impacting global climate change. Atmospheric CO₂ concentrations are influenced by the global carbon cycle through physical and biogeochemical pathways. Tidal wetland environments play a vital role in the global carbon cycle by offsetting atmospheric CO₂ concentrations through their natural physiochemical processes of high autotrophic productivity, allochthonous organic matter deposition, anoxic soils, and continuous accretion which promotes carbon sequestration with long-term storage at the land-ocean margin. The Intergovernmental Panel on Climate Change (IPCC) and United States Global Change Research …

Development And Characterization Of Lead & Lead-Free Perovskite Solar Cell Materials, Rubaiya Murshed

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years, perovskite photovoltaic technology has offered enormous viability and dimensionality in solar cell research. As a light-harvesting active layer, Perovskite generated remarkable development in device efficiency of 25.7% for the single-junction solar cell, and over 33% for the perovskite/silicon tandem solar cell. Also, perovskite-perovskite tandem solar cell (also called all-perovskite tandem solar cell) shows great potential in device performance and achieved a power conversion efficiency (PCE) of 26.4%. Transitioning photovoltaic technology from the laboratory to commercial products, high PCE, low cost, long lifetime, and low toxicity are some of the critical factors to consider during material selection. Pb-halide …

Evaluating Direct Filtration As An Alternative To Conventional Carbon-Based Advanced Treatment For Indirect Potable Reuse, Savannah M. Flemmer

Civil & Environmental Engineering Theses & Dissertations

Hampton Roads Sanitation District (HRSD) is recharging purified wastewater into the Potomac Aquifer via the Sustainable Water Initiative for Tomorrow (SWIFT) project. Conventional SWIFT treatment applies coagulation, flocculation, sedimentation, ozonation, biofiltration, granular activated carbon (GAC) adsorption, and ultraviolet disinfection to secondary effluent to produce water that meets drinking water standards for managed aquifer recharge. HRSD is considering implementing direct filtration as an alternative to conventional treatment for two additional SWIFT facilities. Direct filtration presents an opportunity for significant cost savings by eliminating sedimentation, shortening flocculation detention time, and reducing coagulant usage. Without upstream removal of solids and organics, however, biofilters …

Biocrude Production From Lignin In Hydrothermal Medium: Effect Of Rapid Heating And Short Residence Time, Kyoko Hirayama

Civil & Environmental Engineering Theses & Dissertations

This study aims to address knowledge gaps in the production of valuable products from waste streams generated during lignocellulosic biofuel production. The primary objective is to develop a process that converts lignin, a byproduct of bioethanol refineries, into a sustainable biolubricant.

The first chapter examines recent advancements in synthesizing biolubricants and investigates their scalability. It explores innovative materials, catalysts, chemical modification approaches, and additives that have emerged in the field. A particular hurdle is the oxidative stability of biolubricants derived from plant oils, which are prone to autooxidation due to their C=C bonds. To overcome this, the study aims to …

Nickel Recovery From Low-Grade Laterites: Study Of Thermal Pre-Treatments To Improve The Efficiency Of The Hydrometallurgical Process, Johana Borda, Robinson Torres

Journal of Sustainable Mining

The processing of lower-grade laterites to obtain nickel has increased due to the gradual depletion of higher-grade sulphide ore reserves. However, the extraction from laterites has been limited because conventional technologies imply a considerable expense of energy or reagents. In this document, the effect of thermal pre-treatments on a laterite sample is demonstrated to improve nickel leaching under moderate conditions. The influence of agents such as coke, coal and NaCl in the heat treatment was also studied. With the results it is presumed that part of the nickel occluded in the goethite migrates to the iron oxides surface during the …

European Feedback On Post-Mining Seismicity, Isabelle Contrucci, Dalija Namjesnik, Peter Niemz, Paloma Primo, Andrzej Kotyrba, Grzegorz Mutke, Petr Konicek, Pascal Dominique, Tobias Rudolph, Stefan Möllerherm, Jannes Kinscher, Emmanuelle Klein, Simone Cesca

Journal of Sustainable Mining

Following the Paris Agreement adopted in 2015, Europe has committed to reducing its greenhouse gas emissions. In this context, the abandonment of coal as an energy source, both in terms of consumption and production, will lead to the closure of many mines in the years to come.

Mine closure guidelines to manage residual mining risks already exist in European countries. However, they do not include post-mining seismic risk management due to a lack of sufficient studies and knowledge on this subject. After mining closure, the flooding of the mining works leads to hydromechanical loading of the underground and, in the …