Sustainability Commons^™

Mechanism Of Coal Fine-Bubble Coupling In The Unsaturated Flow Stage Of Coalbed Methane Drainage, Han Wenlong, Li Yong, Chen Xiangsheng, Zhuo Qiming, Wang Yanbin

Coal Geology & Exploration

To reveal the mechanism of interaction between coal fines and gas in the unsaturated flow stage of coalbed methane (CBM) drainage, it is essential to formulate the drainage system and improve the gas production. The effect of air bubbles with different diameters on coal fines with different particle sizes and densities was systematically experimented through the experiment device for microscopic interaction between the air bubble and the coal fines. Meanwhile, the influence of air bubbles on the migration trajectory and velocity of coal fines and the characteristics of coal fine capturing by air bubbles were also analyzed. The results show …

Deformation Prediction Of Open-Pit Mine Slope Based On Abc-Grnn Combined Model, Ning Yongxiang, Cui Ximin, Cui Jianguo

Coal Geology & Exploration

Accurate prediction of slope deformation in open-pit mine is an important guarantee for effective disaster early warning of slope. The traditional slope deformation prediction method is unable to characterize and comprehensively analyze the effect of various factors on slope deformation. In view of this, the combined prediction model (ABC-GRNN) of an artificial bee colony algorithm (ABC) and the optimized generalized regression neural network (GRNN) was proposed for slope deformation in open-pit mine. In this prediction model, the following 5 factors affecting the slope deformation of open-pit mine are considered comprehensively: mining disturbance, rainfall, rainfall duration, temperature and humidity. Herein, the …

Optimization Of Cemented Filling Material Ratio Based On Rsm-Bbd Method And Engineering Application, Wang Shushuai, Xu Bin, Li Yang, Yang Zhen

Coal Geology & Exploration

In view of the problems of large stacking of solid waste caused by roof caving method in coal seam mining and imbalance between mining and filling in long-wall cemented backfilling, the No.31 ming area of Chahasu Coal Mine in Inner Monogolia uses continuous mining and filling roadway cemented backfilling mining technology, adopting the “mining at intervals of three” mining method and the “three with high strength filling and one with low strength filling” filling mode. The filling material ratio has an important influence on the filling cost and effect. In order to solve the problems of high cement consumption and …

Mechanical Properties And Mechanism Of Co-Curing Saline Soil With Coal Solid Waste, Dong Chenxi, Wang Nianqin, Li Jiangshan, Chen Xin, Yan Xusheng, Ma Wei

Coal Geology & Exploration

Under the research background of resource utilization of solid wastes in the arid and semiarid regions, a new curing material was developed with the coal wastes (such as the coal gangue (CG) and coal metakaolin (CMK)), the carbide slag (CS) that is a waste material readily available in the arid region, and the ordinary Portland cement (OPC). Besides, its mechanical properties and microscopic change mechanism in curing of saline soil in the arid and semi-arid regions were discussed. Based on the laboratory experiment, the unconfined compressive strength (UCS) characteristics of curing saline soil in different ages were studied by replacing …

Feasibility Study Of Nature Source In-Seam Exploration, Hu Ze’An, Cao Lingkai, Liu Qinjie, Ji Guangzhong, Xi Chaoqiang, Wu Rongxin

Coal Geology & Exploration

The conventional explosive seismic sources are very tightly controlled in high-gas mine, and a novel non-explosive channel wave method is urgently needed as an alternative. Therefore through the theoretical analysis and numerical simulation experiments, we demostrated that the coal seam satisfied the geophysical conditions to develop the nature source in-seam wave. The time-domain numerical simulation experiment of the passive source channel wave was successfully realized by constructing the nature source in-seam wave model with three stochastic terms, including the stochastic spatial position, stochastic initial excitation time and stochastic amplitude of seismic source. We performed frequency dispersion spectrum calculation on the …

Wavefield Separation Of P- And S-Waves Based On Modified Pseudo-Helmholtz Decomposition Operator In Transverse Isotropic Media, Liu Zhaoshun, Du Qizhen, Lyu Wenhao, Zhou Shihao, Fu Liyun

Coal Geology & Exploration

The separation of P- and S-wave fields is a significant step in elastic reverse-time migration (ERTM), which can effectively eliminate the waveform crosstalk and image artifacts, thus improving the precision of imaging. In anisotropic media, nonstationary spatial filters or low-rank approximation methods are commonly used to separate the wavefields. However, the application of multiple Fourier transforms results in the high computation costs of the above wavefield separation methods. Based on the idea of constructing the isotropic decoupling equations of P- and S- waves with the Helmholtz operator, a modified pseudo-Helmholtz decomposition operator was proposed to eliminate the amplitude distortion. Then, …

Inversion Of Self-Potential Data Based On Improved Sparrow Search Algorithm, Lang Jianxiang, Tang Hongzhi, Ai Hanbing

Coal Geology & Exploration

Self-potential (SP) method is a natural source geophysical prospecting technology with low cost and simple operation for field observation. Generally, the inversion of SP data has the characteristics of ill-posedness and non-linearity. The conventional inversion algorithms are classified into the types of local optimization and global search. However, it is hard for the gradient-based local optimization algorithm to obtain the global optimal solution, and the inversion results are dependent on the construction of initial model. The traditional global search algorithm has the disadvantages of low convergence rate, insufficient ability of escaping local minima and instability. Thus, a new global optimization …

Forward Modeling Of Radio-Magnetotelluric Method Based On Julia Acceleration And Study On Effect Of Displacement Current, Mei Zhuxu, Yuan Yuan, Zhou Feng, Zhou Cong, Zhang Lincheng

Coal Geology & Exploration

Radio-magnetotelluric method (RMT) is one of the important tools for shallow surface electromagnetic exploration. Since the exploration frequency band is 10‒300 kHz, the propagation of electromagnetic fields is greatly affected by the dielectric permittivity of the earth. The electromagnetic response calculated with traditional quasi-static conditions severely restricts the accuracy of RMT forward modeling and further affects the resolution of the inversion imaging. In response to this problem, a numerical simulation method of full-current RMT electromagnetic response based on Julia parallel acceleration was proposed. Then, the calculation of each frequency point was sent through the distributed computing in Julia to different …

A Fault Diagnosis Method Of Rescue Lifting Vehicle Based On Spectral Clustering, Li Lijing, Chang Dashuai, Li Lei, Chai Junfei

Coal Geology & Exploration

In allusion to the characteristics of complex structure of rescue lifting vehicle, the poor independence of working condition and fault data, and the difficulty in fault diagnosis, we proposed a fault diagnosis algorithm of rescue lifting vehicle with the semi-supervised support vector machine in this paper. In the algorithm, the information on hidden features of the original fault data was mined with the idea of spectral clustering, to effectively distinguish the independent structural features of the fault information in the component system with different degrees of coupling. Firstly, a fault map was established based on the original input data. Then, …

Projected Long-Term Climate Trends Reveal The Critical Role Of Vapor Pressure Deficit For Soybean Yields In The Us Midwest, Wenguang Sun, David Fleisher, Dennis Timlin, Chittaranjan Ray, Zhuangji Wang, Sahila Beegum, Vangimalla Reddy

Nebraska Water Center: Faculty Publications

Extreme climate events including heat waves and droughts are projected to become more frequent under future climate change conditions. However, the mechanisms between soybean yields and climate factors, specifically involving variable rainfall and high heat episodes, are still unclear, particularly with respect to spatial trends in the United States (US) Midwest. A recently modified version of the model GLYCIM was used to evaluate rainfed soybean production across 12 states at a 10 km spatial resolution for three time periods (2011–2020, 2051–2060, 2091–2099) under Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5. Results showed that except for the northernmost Midwest counties, …

Strategies For Achieving Agriculture Carbon Peak And Carbon Neutrality In China Based On View Of Biogeochemical Cycle, Shiqi Yang, Xin Yan

Bulletin of Chinese Academy of Sciences (Chinese Version)

Biogeochemical cycle is the basic theory of matter (elements) flow among atmosphere, hydrosphere, biosphere and lithosphere, which provides important guidance to achieving the national goal of agriculture carbon peak (ACP) and agriculture carbon neutrality (ACN). As a basic industry, agriculture has large-scale temporal and spatial influence on the greenhouse effect, hence great importance should be attached to ACP and ACN in order to assist the overall strategy of achieving national carbon peak and neutrality. Based on the view of biogeochemical cycle and connotations of ACP and ACN, this article analyzes the paths to achieve ACP and ACN, and discusses the …

Pan-Arctic Soil Moisture Control On Tundra Carbon Sequestration And Plant Productivity, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Beniamino Gioli, Barbara Bailey, George Burba, Eugénie S. Euskirchen, Jennifer D. Watts, Kyle A. Arndt, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Albertus J. Dolman, Roisin Commane, Charles E. Miller, Josh Hashemi, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Elyn R. Humphreys, Oliver Sonnentag, Gesa Meyer, Gabriel H. Gosselin, Philip Marsh, Walter C. Oechel

Daugherty Water for Food Global Institute: Faculty Publications

Long-term atmospheric CO₂ concentration records have suggested a reduction in the positive effect of warming on high-latitude carbon uptake since the 1990s. A variety of mechanisms have been proposed to explain the reduced net carbon sink of northern ecosystems with increased air temperature, including water stress on vegetation and increased respiration over recent decades. However, the lack of consistent long-term carbon flux and in situ soil moisture data has severely limited our ability to identify the mechanisms responsible for the recent reduced carbon sink strength. In this study, we used a record of nearly 100 site-years of eddy covariance …

Exploring International Rare Earth Industry Landscape Changes And China’S Strategic Responses, Yiding Wu, Zilong Peng, Dan Lai, Shen Zhao, Lu Wang, Weiqiang Chen, Peng Wang

Bulletin of Chinese Academy of Sciences (Chinese Version)

Rare earth elements are widely identified as critical raw materials to underpin high-end technological innovation and the development of emerging industries, which makes them as important strategic minerals deserved by key international great powers. Since 2011, the United States and other developed nations are quickly fostering the development of their supply chains and industrial ecosystems of rare earth out of China's engagement. Consequently, the new diversified supply pattern of rare earth has been formalizing at global level. Under this full supply chain view, this study performs a deep-dive analysis of international rare earth industry landscape changes in the key stage …

Importance Of Snowmelt On Soil Nitrate Leaching To Groundwater – A Model Study, Sahila Beegum, Arindam Malakar, Chittaranjan Ray, Daniel D. Snow

Nebraska Water Center: Faculty Publications

The movement of nitrate to surface water bodies during snow accumulation and melting has been extensively studied, but there are only limited studies on the influence of snow processes on nitrate leaching to groundwater. The present study investigated the impact of snow processes on nitrate leaching to groundwater based on a simulation modeling approach using HYDRUS-1D. HYDRUS-1D model has a temperature threshold-based snow model in addition to water, solute, and heat simulation components. The snow component in HYDRUS-1D was previously not applied to snow simulation studies since the method does not consider a detailed physical and process-based representation of snow …

Time Domain Reflectometry Waveform Interpretation With Convolutional Neural Networks, Zhuangji Wang, Shan Hua, Dennis Timlin, Yuki Kojima, Songtao Lu, Wenguang Sun, David Fleisher, Robert Horton, Vangimalla R. Reddy, Katherine Tully

Nebraska Water Center: Faculty Publications

Interpreting time domain reflectometry (TDR) waveforms obtained in soils with non-uniform water content is an open question. We design a new TDR waveform interpretation model based on convolutional neural networks (CNNs) that can reveal the spatial variations of soil relative permittivity and water content along a TDR sensor. The proposed model, namely TDR-CNN, is constructed with three modules. First, the geometrical features of the TDR waveforms are extracted with a simplified version of VGG16 network. Second, the reflection positions in a TDR waveform are traced using a 1D version of the region proposal network. Finally, the soil relative permittivity values …

Globally Scalable Approach To Estimate Net Ecosystem Exchange Based On Remote Sensing, Meteorological Data, And Direct Measurements Of Eddy Covariance Sites, Ruslan Zhuravlev, Andrey Dara, André Luís Diniz Dos Santos, Oleg Demidov, George Burba

Daugherty Water for Food Global Institute: Faculty Publications

Despite a rapid development of Nature-Based Solutions (NBS) for carbon removal in recent years, the methods for evaluating NBS still have certain gaps. We propose an approach based on a combination of remote sensing data and meteorological variables to reconstruct the spatiotemporal variation of net ecosystem exchange from eddy-covariance stations. A Lagrangian particle dispersion model was used for upscaling satellite images and flux towers. We trained data-driven models based on kernel methods separately for each selected land-cover class. The results suggest that the proposed approach to quantifying carbon exchange on a medium-to-large scale by blending eddy covariance flux data with …

Role Of Social Determinants Of Health In Differential Respiratory Exposure And Health Outcomes Among Children, Jagadeesh Puvvula, Jill A. Poole, Yeongjin Gwon, Eleanor G. Rogan, Jesse E. Bell

Daugherty Water for Food Global Institute: Faculty Publications

Background Attributes defining the Social Determinants of Health (SDoH) are associated with disproportionate exposures to environmental hazards and differential health outcomes among communities. The dynamics between SDoH, disproportionate environmental exposures, and differential health outcomes are often specific to micro-geographic areas.

Methods This study focused on children less than 20 years of age who lived in Douglas County, Nebraska, during 2016–2019. To assess the role of SDoH in differential exposures, we evaluated the association between SDoH metrics and criteria pollutant concentrations and the association between SDoH and pediatric asthma exacerbations to quantify the role of SDoH in differential pediatric asthma outcomes. …

Droughtscape, Winter 2023, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2023

Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson

Scripps Senior Theses

We are experiencing a climate crisis that must be confronted with strategic mitigation. Pomona College contributes to the climate crisis through its emissions for which there is a baseline record. However there is no baseline record of the climate mitigation currently performed by the trees on Pomona’s campus through carbon storage. This study seeks to determine a current baseline quantity of carbon stored and sequestrated by Pomona’s trees as well as possible courses of climate mitigation for Pomona College to take. Initial information gathering was conducted through interviews with several stakeholders. This study was conducted using data collected prior to …

Estimating Evapotranspiration And Analyzing Soil Moisture And Heat Flux Parameters At Taneum Creek, Central Washington, Edward Vlasenko

All Master's Theses

In the past two decades, stream restoration work, primarily in the form of wood emplacement, has been undertaken in the Taneum Creek watershed, resulting in increased channel-floodplain connectivity. One of the goals of stream restoration was to boost dry season groundwater storage in the shallow floodplain aquifer. However, any gains in groundwater due to increased connectivity may be nullified by increased evapotranspiration (ET) losses because of denser floodplain vegetation. Within the floodplain aquifer budget, ET is a major flow of water out of the system and is not well quantified.

In order to quantify ET, a monitoring site was established …

Labile Carbon And Soil Texture Control Nitrogen Transformation In Deep Vadose Zone, Lidong Li, Jordan Shields, Daniel D. Snow, Michael Kaiser, Arindam Malakar

Daugherty Water for Food Global Institute: Faculty Publications

Understanding transient nitrogen (N) storage and transformation in the deep vadose zone is critical for controlling groundwater contamination by nitrate. The occurrence of organic and inorganic forms of carbon (C) and nitrogen and their importance in the deep vadose zone is not well characterized due to difficulty in sampling and the limited number of studies. We sampled and characterized these pools beneath 27 croplands with different vadose zone thicknesses (6–45 m). We measured nitrate and ammonium in different depths for the 27 sites to evaluate inorganic N storage. We measured total Kjeldahl nitrogen (TKN), hot-water extractable organic carbon (EOC), soil …

Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer

Cal Poly Humboldt theses and projects

A growing interest in sustainable waste management and the implementation of new policies have prompted a shift towards alternative resource recovery methods for organic waste, including food waste. To effectively assess alternative food waste treatment scenarios, it is important to evaluate the life cycle impacts associated with each scenario. The storage phase of food waste, encompassing its accumulation in kitchens, and storage in bins for collection and transportation, has been overlooked as a source of greenhouse gases in previous studies. This investigation aimed to identify the greenhouse gases emitted during the initial five-day period of low-oxygen storage. An open dynamic …

Land Systems, Soils And Vegetation Of The Southern Goldfields And Great Western Woodlands Of Western Australia - Volume 1, Peter-Jon A. Waddell, Paul Galloway

Technical Bulletins

This technical bulletin defines and maps the land resources of the southern Goldfields region of Western Australia (WA). The southern Goldfields region, as featured in this bulletin, covers 151,753 km². The western and eastern borders are variable because they align with various cadastral boundaries. The western survey border, which in part follows the WA State Barrier Fence, demarcates cleared agricultural land from the intact, western extent of the Great Western Woodlands. The eastern border abuts the westernmost Nullarbor pastoral lease boundaries, except for the north-easternmost and south-easternmost edges which continue into Crown land. Major towns are Coolgardie, Kalgoorlie …

Land Systems, Soils And Vegetation Of The Southern Goldfields And Great Western Woodlands Of Western Australia - Volume 2, Peter-Jon A. Waddell, Paul Galloway

Technical Bulletins

This technical bulletin defines and maps the land resources of the southern Goldfields region of Western Australia (WA). The southern Goldfields region, as featured in this bulletin, covers 151,753 km². The western and eastern borders are variable because they align with various cadastral boundaries. The western survey border, which in part follows the WA State Barrier Fence, demarcates cleared agricultural land from the intact, western extent of the Great Western Woodlands. The eastern border abuts the westernmost Nullarbor pastoral lease boundaries, except for the north-easternmost and south-easternmost edges which continue into Crown land. Major towns are Coolgardie, Kalgoorlie …

Shallow Water Coral Distribution And Its Response To Climate Change, Amaury De Jesus

Dissertations and Theses

Shallow water corals are one of the main reef-building organisms that secrete carbonates as their skeletons, and therefore, are one of the major sinks of CO2 in the ocean. These reef builders are also very crucial to marine environments and human society. As the global energy demand continues rising, fossil fuel burning increases at a faster pace despite the increase in energy supply using clean and renewable energy. The increase of CO2 in the atmosphere has been shown to exacerbate global warming and may cause ocean acidification, threatening the habitat of shallow-water corals. Many recent observations show alarming signs of …

Bibliography, Leslie North

Faculty/Staff Personal Papers

Bibliography of publications by Leslie North.

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Winter Dynamics Of Storm Water Management Ponds And Winter Tolerance In Three Aquatic Plant Species, Patrick Strzalkowski

Theses and Dissertations (Comprehensive)

The vast majority of the research into the performance of stormwater management ponds (SWMPs) has been performed in warm regions or during the warmer seasons in temperate regions. It is presumed that SWMPs are inactive in the winter as any potential stormwater is trapped in snow and ice. The main goal of this thesis was to test this presumption and to study the dynamics and performance of three SWMPs during the winter. Remote water level loggers were installed into the three SWMPs and daily grab samples from the influents and effluents were taken and analyzed for total phosphorus (TP), chloride, …

Middle Savannah River: An A/R/Tographic Ecopedagogical Ethnography Experimenting With Rhizomatic Perspectives, Lisa Augustine-Chizmar

College of Graduate Studies: Theses & Dissertations

This research is an experiment in perspective. Using the four commonplaces (Schwab, 1978), I practiced letting the Savannah River teach me what there is to know about the water, the land, the people, and the other entities that depend on ki through artistic, ethnographic, and ecopedagogical lenses. The ethnographic findings describe the social actors that depend on ki and give a voice to the River. The a/r/tographic findings display the River on a canvas map through two hundred years using paint, clay, photography, video, abstract acrylics, and fabric. Together, these methods contribute to a unique ecopedagogical journey. This word cloud …

Influence Of Thick Sandstone On Development Of Overburden Mining Fissures In Northern Shaanxi Coal Mining Area Of Yellow River Basin And Suggestions On Water-Preserved Coal Mining, Wang Shuangming, Wei Jiangbo, Song Shijie, Wang Shengquan, Sun Tao

Coal Geology & Exploration

The change of geological conditions of coal seam roof overburden and the development of mining fissures caused by coal mining activities are the direct causes of damage to the key underground aquifers, and also the root causes of ecological environment degradation in the mining area. As a typical geological condition, the thick sandstone developed in the overburden structure of the coal seam roof has an important impact on the development law of mining fissures in the overburden. Therefore, the influence of the thickness and location of different thick sandstones on the development morphology and height of overburden mining fractures was …