Engineering Commons^™

Another Dangerous Fire Season Is Looming In The Western U.S., And The Drought-Stricken Region Is Headed For A Water Crisis, Mojtaba Sadegh, Amir Aghakouchak, John Abatzoglou

Civil Engineering Faculty Publications and Presentations

Just about every indicator of drought is flashing red across the western U.S. after a dry winter and warm early spring. The snowpack is at less than half of normal in much of the region. Reservoirs are being drawn down, river levels are dropping and soils are drying out.

It’s only May, and states are already considering water use restrictions to make the supply last longer. California’s governor declared a drought emergency in 41 of 58 counties. In Utah, irrigation water providers are increasing fines for overuse. Some Idaho ranchers are talking about selling off livestock because rivers and reservoirs …

Modeling Hydraulic Fracturing Initiation And Propagation In Porous Rock Formationsl, Chang Huang

LSU Doctoral Dissertations

Hydraulic fracturing has long been introduced to the oil and gas industry since the early nineteenth century for both reservoir characterization and reservoir stimulation. Despite the progress made in the last two decades, many challenges still have not been tackled regarding not only the propagation problem but also the initiation problem due to its complexity. The dissertation is divided into two stages, i.e., before and after fracture initiation. The first stage of the research aimed at improving the accuracy in solving the poro-mechanical response of wellbore during fluid injection before a tensile fracture occurs, which is crucial to determine the …

Assessment And Improvement Of Performance Of Septic Systems In Cold Climates (Year 1), Stu Geza, Todd Menkhaus, Lianping Li, Galen Hoogestraat

SDWRI Publications and Reports

Onsite septic systems are used for wastewater treatment for households not connected to sewers. There is a concern about surface and groundwater pollution when effectiveness becomes limited due to soil texture, soil temperature, neighborhood density, and distance to water resources. The goal of this study was to assess treatment performance of local soils and selected treatment media. Lab-scale column experiments were conducted using wastewater from Wastewater Reclamation Facility in Rapid City. The experiments were conducted inside and outside the lab to evaluate the effect of temperature. The columns outside the lab were subject to seasonal variation in temperature. Moisture content, …

Improving Logistics Efficiency Through Collaborative Truck Routing, Patrick Dougherty

Industrial Engineering Undergraduate Honors Theses

The logistics industry is among the world’s largest and most essential. Specifically, trucking is a massive component of the modern logistics system. In 2012, truck transportation carried 68% of all freight tonnage in the U.S. However, trucking currently faces significant problems with efficiency and sustainability. Of all miles driven by trucks yearly in the U.S., 25% are driven with empty loads and 36% are driven with underutilized loads. In addition to this economic inefficiency, the industry faces social and environmental challenges. Driver turnover rates are near 100%, and trucking accounts for a significant level of greenhouse gas emissions. One potential …

Economic Feasibility Of Mixed Plastic Waste Pyrolysis Using Twin Reactor System In Northwest Arkansas, Carol Rogers, Patricia Means, Renato Gonzalez, Kaida Sheets, Hayden Townsend

Chemical Engineering Undergraduate Honors Theses

Plastic waste generation is increasing at an unsustainable rate while recycling solutions remain stagnant. As a chemical means of recycling, mixed plastic waste pyrolysis can generate synthetic oil appropriate for use as fuel in power generation from plastic waste that otherwise accumulates in landfills. With the scaling of a commercial plastic pyrolysis process in Northwest Arkansas (NWA) modeled after an operational sawdust pyrolysis unit in Huntsville, Arkansas, economic analysis resulted in 26.3% internal rate of return. Therefore, construction of a commercial mixed plastic-to-fuel pyrolysis plant is economically justified and should be pursued. To effectively implement the proposed design, NWA must …

Economic And Ecosystem Impacts Of Gm Maize In South Africa, Kristiina Ala-Kokko

Graduate Theses and Dissertations

White maize in South Africa is the only staple crop produced on a widespread commercial basis for direct human consumption using genetically modified (GM) cultivars. Using a combined economic and environmental approach, we estimate the total welfare benefits attributable to GM white maize in South Africa for 2001-2018 are $694.7 million. Food security benefits attributable to GM white maize in South Africa also manifest through an average of 4.6 million additional white maize rations annually. To achieve these additional annual rations using conventional hybrid maize, the additional land required would range from 1,088 hectares in 2001 to 217,788 hectares in …

Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh

Biological and Agricultural Engineering Undergraduate Honors Theses

Global food production must increase to meet the demand associated with increased population growth, so irrigation water use will continue to rise. Therefore, it is important to monitor water usage particularly when an irrigation flowmeter is unavailable. A field water balance was created for a selection of rice fields in East-central Arkansas under observation in 2018 and 2019. From those, irrigation inputs are deduced from the water balance alone. First, each field had sensors that collected water table level (WTL) data. Next, other water inputs and outputs such as precipitation and evapotranspiration (ET) were collected from two modeled sources. The …

Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis

Biological and Agricultural Engineering Undergraduate Honors Theses

Residential adoption of low-impact development (LID) technology can positively impact downstream watershed hydrology by reducing total volumetric discharge from the residential site. This reduction can provide economic, environmental, and social benefits for the residents as well as the community at large. Additionally, homeowners are often affected by stormwater related issues, like flooding or washout, that could be easily mitigated with a sustainably engineered LID structure or network. Engineering for sustainability often includes the blending of several objectives to provide greater overall benefit. This thesis compares the outflow characteristics of three low-maintenance residential LID design scenarios differing in rain garden soil …

Dynamic Analysis Of A Microgrid Powered With An Inverter And Machine-Based Distributed Resources, Brandon William Blackstone

UNLV Theses, Dissertations, Professional Papers, and Capstones

The proliferation of renewable distributed energy resources, particularly photovoltaic (PV) power systems, and the increasing need for a reliable power supply has led to the concept of microgrids, a mini-grid that consists of locally connected power generation units and needs, able to operate connected or disconnected from the utility grid, using controlled and coordinated methods to provide for the users of the microgrid the best possible conditions for their needs. The main technical issues facing microgrids include some of the following, seamless transition from stand-alone to utility grid connected operation, how to preserve frequency and voltage stability, and provide the …

Degradation Of Antibiotics In Aqueous Phase Using Pms Catalytic Decomposition With Zero-Valent Iron Nanoparticles Immobilized In Sba-15, Ahdee Bluma Zeidman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zero-valent iron nanoparticles (nZVI) have been studied as an option for soil remediation and water treatment for many years. The capability of nZVI to produce oxidation/reduction processes, depending on the reaction conditions, has attracted great interest with their major drawback being reactivity loss through agglomeration. The loss in nZVI surface area has been reported to be prevented through immobilization onto a porous media (e.g., SBA-15, MCM-41, or zeolites). In this work, a mesoporous silica structure (SBA-15) is used as an nZVI supporting material to enhance its reactivity and promote peroxymonosulfate (PMS) catalytic decomposition for the degradation of antibiotics in aqueous …

Investigative Study Of Microalgal And Electrochemical Wastewater Treatment Systems And Modeling Of The Wafer-Enhanced Electrodeionization Using Supervised Learning, Humeyra Betul Ulusoy Erol

Graduate Theses and Dissertations

Wastewater has a serious impact on environment and public health due to its high concentration of nutrients and toxic contaminants. Without proper treatment, excess nutrients discharged in wastewater can cause a damage to the ecosystem such as undesirable pH shifts, cyanotoxin production, and low dissolved oxygen concentrations.

Main objectives of this dissertation work were to investigate i) the biofuel potential of P. cruentum when grown in swine wastewater, ii) the influence of four most commonly used ion exchange resins on the system efficiency and selectivity for the removal of sodium, calcium, and magnesium ions, and iii) the modeling of wafer-enhanced …

A Study Of The Frustrated Honeycomb Battery Material Na2ni2teo6, Nathan Christopher Episcopo

Open Access Theses & Dissertations

The P2-type layered hexagonal compound Na2Ni2TeO6 with Ni2+ on a honeycomb lattice was synthesized by the standard solid-state route. Structural characterization chemical phase purity was confirmed by Rietveld refinement of laboratory and synchrotron data. The crystal structure refines well in the P63/mcm space group. Single crystal growth trials using the self-flux-melt method were conducted with limited success. The magnetic transition temperature pertaining to Ni2+ lattice was confirmed by analysis of specific heat capacity to be . The magnetic susceptibility remains largely unchanged in magnetic field of and external pressure of . There is an almost linear response in isothermal magnetization …

Development Of A Cyberinfrastructure For Assessment Of The Lower Rio Grande Valley North And Central Watersheds Characteristics, Linda Isabel Navarro Navarro

Theses and Dissertations

Due to an increase in urbanization in the Lower Rio Grande Valley (LRGV), there have been substantial modifications to hydrology causing a decline in water quality to the Laguna Madre watershed. The major concern is the inflow of freshwater from the North and Central waterways released to the Lower Laguna Madre which is designated as an impaired watershed for high concentrations of bacteria and low dissolved oxygen. The objective of this study is to perform a watershed characterization to determine potential pollution sources of each watershed by developing a cyberinfrastructure and collect a wide inventory of data. The objective will …

Drinking Water: Iron And Manganese, Bruce I. Dvorak, Becky Schuerman

Department of Civil and Environmental Engineering: Faculty Publications

Iron and manganese are two naturally occurring drinking water contaminants that can cause poor taste and odor issues, and be associated with discoloration that leads to staining of fixtures, dishes, and laundry. They are primarily found in Eastern Nebraska groundwater and most people mention these issues when iron levels exceed 300 micrograms per liter (µg/L) and manganese levels exceed 50 µg/L. Levels of iron can be much higher and are not associated with health concerns but manganese concentrations above 300 µg/L may pose a health issue for rice or soy formula-fed infants. Higher levels, over 1,000 µg/L, may pose a …

Surface Modified Polypropylene Membranes For Treating Hydraulic Fracturing Produced Waters By Membrane Distillation, Tharaka Hawpe Gamage

Graduate Theses and Dissertations

Membrane distillation is an emerging technology for treating hydraulic fracturing flowback and produced waters. Suppression of membrane fouling by inorganic and polar and non-polar organic compounds is a challenge. Here polyhydroxyethyl methacrylate, polyacrylic acid, polvinylallyl imidazolium bromide and polyvinylhexyl imidazolium bromide chains have been grafted from the membrane surface. Fouling is initially due to adsorption of organic compounds followed by scale formation. When challenged with produced water, membranes modified with polvinylallyl imidazolium bromide chains provided the greatest resistance to fouling. For EC pretreated produced water and synthetic produced water that contained mainly inorganic species, the flux decline was much less.

Challenges And Opportunities In Precision Irrigation Decision-Support Systems For Center Pivots, Jingwen Zhang, Kaiyu Guan, Bin Peng, Chongya Jiang, Wang Zhou, Yi Yang, Ming Pan, Trenton Franz, Derek M. Heeren, Daran R. Rudnick, Olufemi P. Abimbola, Hyungsuk Kimm, Kelly Caylor, Stephen Good, Madhu Khanna, John Gates, Yaping Cai

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigation is critical to sustain agricultural productivity in dry or semi-dry environments, and center pivots, due to their versatility and ruggedness, are the most widely used irrigation systems. To effectively use center pivot irrigation systems, producers require tools to support their decision-making on when and how much water to irrigate. However, currently producers make these decisions primarily based on experience and/or limited information of weather. Ineffective use of irrigation systems can lead to overuse of water resources, compromise crop productivity, and directly reduce producers’ economic return as well as bring negative impacts on environmental sustainability. In this paper, we surveyed …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Progress Of Coal Fines Agglomeration And Settlement Mechanism Based On High Efficiency Coalbed Methane Drainage, Li Yong, Han Wenlong, Wang Yanbin, Meng Shangzhi, Wu Xiang, Wang Zhuangsen, Ma Zhentao, Liu Du, Zhao Shihu

Coal Geology & Exploration

Significant low-yield and inefficient wells seriously hinder the development of China’s coalbed methane (CBM) industry, and the coal fractures and production pipes blocking caused by the coal fines settlement are the key influencing factors. This paper systematically investigates the latest research progress in the composition, generation mechanism, suspension transport and output control of coal fines produced by coalbed methane wells at home and abroad, summarizes the control mechanism and key issues of coal fines agglomeration-settlement and dispersion behavior, and proposes research prospects. The coal fines problem accompanies the entire process of CBM exploration and development, involving all aspects of geological …

Geological Unit Division And Development Countermeasures Of Deep Coalbed Methane In Southern Yanchuan Block, Chen Zhenlong

Coal Geology & Exploration

Deep coalbed methane resources have great potential, accounting for 62.8% of the total resources. However, effective development faces many challenges such as strong heterogeneity, high geostress, difficult process matching and low production capacity. Taking the deep coalbed methane in Southern Yanchuan Block as an example, the key parameters are overlaid and analyzed, the development geological units of the gas field are finely divided according to the five controlling factors of “sedimentation coal-control, tectonic influenced accumulation, hydrodynamic gas-control, geostress seepage-control, physical property production-control”. The key geological attributes and development constraints of each development geological unit are clarified, and the differentiated development …

Optimization On Particle Size Fraction Of Lightweight Coated Ceramsite Proppant In Coal Reservoir, Chang Xiaoliang, Lyu Runsheng, Wang Peng, Li Bing, Gao Lin

Coal Geology & Exploration

Hydraulic fracturing is currently one of the main technical measures for enhancing coal reservoirs permeability. The spreading range and transportation distance of proppants in the fracture is an important indicator of hydraulic fracturing to evaluate fracturing effect. According to the characteristics of coal reservoirs in Lu’an mining area, physical experiments and numerical simulation methods are used to compare and analyze the effects of fracture conductivity, sand spreading range, particle size combination and other factors on conductivity of coalbed methane wells, and the best proppants particle size and particle size ratio are selected. The research results indicate that the fracture conductivity …

Causes For Low Cbm Production Of Vertical Wells And Efficient Development Technology In Northern Zhengzhuang Block In Qinshui Basin, Jia Huimin, Hu Qiujia, Fan Bin, Mao Chonghao, Zhang Qing

Coal Geology & Exploration

In order to realize the efficient development of deep CBM in the north of Zhengzhuang block in Qinshui Basin, firstly, the geological conditions and development data of coal reservoir are deeply analyzed, and the development data of shallow CBM are compared. Secondly, based on the evaluation of gas content, the difficulty of coalbed methane recovery is evaluated by comprehensive evaluation of reservoir permeability, reservoir-desorption pressure difference, coal structure and in-situ stress state-Finally, the reasons for low production of CBM wells in the northern Zhengzhuang Block are clarified, and the adaptive technology for efficient development is put forward. The results show …

Numerical Simulation And Test Of Gas Drainage With Water Jet Layered Pressure Relief And Permeability Enhancement In Soft Coal Seam, Liu Xiao, Li Yong, Xuan Dequan, Hu Shixiong, Jing Tianxiang, Xu Sen

Coal Geology & Exploration

Hydraulic punching is the main technical measure to enhance permeability and drainage of coal seam gas. The pressure relief effect is mainly evaluated by the coal output. However, there are some problems such as large coal output, uneven pressure relief and easy stress concentration. Therefore, this paper puts forward the soft coal interlayer water jet layered pressure relief and permeability increasing gas drainage technology. Considering the influence of gas pressure compression and coal matrix adsorption gas expansion on the coal mass deformation, a multiphysics theoretical model under the coupling condition of stress field, fracture field and seepage field was established. …

The Enrichment And High Yield Law Of Cbm In Yanjiao Syncline In Zhijin Block, Guizhou Province, Guo Tao

Coal Geology & Exploration

In view of the problems such as the large number of coal seams, the thin single layer, the complex structure, much mylonite coal and hard to evaluate favorable area in southern China, this paper makes use of the exploration achievements and tests data of Zhijin Block to study the reservoir-forming conditions of multiple coal seam CBM. The results show that the enrichment and high yield CBM in south China is characterized by “sedimentation storage-control, preservation gas-control, geostress coal structure control production”. The thickness, number and quality of coal are controlled by sedimentation, which determines the resource base of coal bed …

Practice Of Enhanced Gas Extraction By Staged Fracturing With Comb-Shaped Long Hole In Coal Mine Roof, Jia Bingyi, Chen Dongdong, Wu Jie, Sun Siqing, Wang Jianli, Zhao Jizhan, Zhang Jie

Coal Geology & Exploration

In order to solve the problems of drilling construction difficulty, low gas drainage concentration, poor drainage effect and inability to realize the predrainage of large area, based on the existing directional drilling technology and hydraulic fracturing technology in coal mines, combined with the previous research results, the staged hydraulic fracturing technology of comb-shaped long borehole in roof was proposed, and the field test was carried out in Sangshuping No.2 well in Hancheng mining area.The test results show that the main hole length of comb-shaped hole in roof was 588 m, including 8 branch holes, the total drilling footage was 1 …

Different-Source Prediction Of Gas Emission Based On Sapso-Elm And Its Application, Ren Haifeng, Yan Youji, Wu Qinghai

Coal Geology & Exploration

In order to improve the accuracy of gas emission prediction, in view of the multiple correlations and complexity of the influencing factors of gas emission, principal component analysis and separated source prediction theory were combined, the gas emission data of the mining layer, adjacent layer, and goaf were respectively subjected to principal component analysis to reduce dimensionality, and the predictor was obtained. Aiming at the problem that the input weight matrix and hidden layer threshold of the extreme learning machine were generated randomly, the simulated annealing particle swarm optimization algorithm was used to optimize the parameters of the extreme learning …

Mechanism And Control Of Strong Ground Pressure In Fully Mechanized Mining Face, Zhang Yin, Zhao Yi, Li Hao

Coal Geology & Exploration

In order to ensure the safe use of the withdrawal roadway in the fully mechanized mining face of thick coal seam, taking the strong ground pressure behavior of the withdrawal roadway in 31102 working face of Nalinhe No.2 well as the method of combination of field monitoring and theoretical analysis, the strong ground pressure behavior of the withdrawal roadway in the mining process of fully mechanized mining face in thick coal seam was studied. The results show that: the strong ground pressure behavior of withdrawal roadway in fully mechanized mining face of thick coal seam is mainly the result of …

Multi-Level Fuzzy Mathematics-Based Comprehensive Evaluation Model Of Cbm Well Productivity, Feng Yulong, Zhou Linyuan, Wang Qian, Liu Chengrui

Coal Geology & Exploration

To accurately predict the productivity of CBM wells, a multi-level fuzzy mathematics method was used to establish a comprehensive evaluation model including 3 secondary evaluation parameters(i.e. resource conditions, development conditions, and transformation processes) and 10 tertiary evaluation parameters. Combined with the data of reservoir parameters and stimulation technologies of 15 coalbed methane target blocks in China, the comprehensive evaluation work was carried out using the model. Finally, the actual production of each block was collected to verify the evaluation results, and the corresponding relationship between the evaluation results and the production was obtained. The results show that, the average daily …

Characteristics Of Shale Gas Reservoir In Upper Paleozoic Coal Measures In Yangquan Block, Qinshui Basin, Li Yangyang, Li Xianqing, Zhang Xueqing, Xiao Xianming, Yu Zhenfeng, Wang Baoyu

Coal Geology & Exploration

Shale reservoir characteristics are the basic content of shale gas storage capacity evaluation. In order to explore the properties of high-evolved coal-measures shale gas reservoirs and optimize favorable reservoirs, various experimental methods of rock pyrolysis, X-ray diffraction, scanning electron microscopy, high-pressure mercury intrusion, low-temperature N₂ and CO₂ gas adsorption were applied to the Qinshui Basin. Reservoir characteristics were studied with core samples of coal-measure shale core from the Upper Paleozoic in Yangquan Block. The results show that the Upper Paleozoic coal-measures shale in Yangquan Block of the Qinshui Basin has a high content of organic carbon(average TOC is …

Prediction Of Coal Seam Gas Content Based On Abc-Bp Model, Zang Zijing, Wu Haibo, Zhang Pingsong, Dong Shouhua

Coal Geology & Exploration

It is valuable to exploit the coalbed-methane which is rich in our country. The prediction of gas content in coalbed methane reservoir is a key step in the early stage of development and utilization. In recent years, BP neural network algorithm has been often used in coalbed methane prediction, but the model has some shortcomings in the training process, such as slow convergence speed, sensitive to initial value and easy to fall into local minimum value. Therefore, this paper proposed an improved BP neural network prediction model characterized by artificial bee colony algorithm. Firstly, R-type cluster analysis was used to …

Comprehensive Exploration Of Collaps Column And Three-Dimensional Construction Technology Of Water Plug Based On Directional Horizontal Drilling, Tian Gan, Nan Shenghui, Lin Xudong, Fan Juan

Coal Geology & Exploration

The Ordovician limestone water inrush from floor caused by water-conducted collapse columns is the main water hazard threat in Tashan Mine of Tongmei Group. Water inrush from collapse columns once happened in the roadway excavation of 8228 working face. On the basis of comprehensive geophysical exploration above and below the well, the development boundary, the influence zone, the cementation of the fractured body and the distribution characteristics of the water flowing subsided column are found out by means of multi-layer and multi-branch surface directional horizontal drilling speed logging, drilling fluid leakage, cuttings logging and logging while drilling, and combined with …