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Articles 1921 - 1950 of 3546

Full-Text Articles in Sustainability

Research On Key Technologies Of The Zdy25000ldk Intelligent Directional Drilling Equipment, Fang Peng, Yao Ke, Wang Longpeng, Zhang Rui, Meng Rui, Wang Song, Shao Junjie, Liu Pu Jan 2022

Research On Key Technologies Of The Zdy25000ldk Intelligent Directional Drilling Equipment, Fang Peng, Yao Ke, Wang Longpeng, Zhang Rui, Meng Rui, Wang Song, Shao Junjie, Liu Pu

Coal Geology & Exploration

It is the most direct and effective method to extract coalbed methane by drilling along the coal seam and high-level drilling on the roof for comprehensive treatment of coalbed methane in underground coal mines. Improving the drilling speed of directional drilling and the drilling encounter rate in the coal seam of uneven thickness with large fluctuation, reducing the labor intensity of the personnel, enhancing the ability to prevent drilling accidents, and adapting to the intelligent development needs of coal mines, the intelligent drilling equipment for long-distance directional drilling in coal mines are all the important problems to be solved in …

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Development Of A Remote Monitoring System For Coal Mine Automatic Drilling Rigs, Wang Tianlong, Ma Bin, Dong Hongbo Jan 2022

Development Of A Remote Monitoring System For Coal Mine Automatic Drilling Rigs, Wang Tianlong, Ma Bin, Dong Hongbo

Coal Geology & Exploration

According to the policies on the manufacturing of national energy equipment, coal mine robots and intelligent development of coal mines as well as the trend of intelligent development of coal equipment, a remote monitoring system of automatic drilling rigs for coal mines is developed to monitor the automatic drilling rig remotely on the ground by using sensor measurement, software development, virtual reality, network communication, video monitoring and other technologies. The problems of incomplete parameter display, insufficient effective monitoring and inconvenient maintenance of the existing underground coal mine drilling rig are solved. The remote monitoring system includes the main rig, onboard …

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Development And Application Of A Mine-Used Dynamic Azimuth Gamma Instrument While Drilling, Chen Long, Chen Gang, Zhang Jiguan Jan 2022

Development And Application Of A Mine-Used Dynamic Azimuth Gamma Instrument While Drilling, Chen Long, Chen Gang, Zhang Jiguan

Coal Geology & Exploration

Gas drainage borehole along coal seams is the most direct and effective gas control method at present. As a common basis for identifying coal bearing formations, natural gamma can tell whether the borehole trajectory is in the target layer according to the formation radioactivity. However, the existing mine-used gamma logging tools can only carry out sliding drilling measurement, which are not applicable to compound drilling or rotary steering drilling, and cannot meet the working condition of continuous gamma dynamic measurement. On the basis of the analysis of the characteristics of the working conditions of MWD and the principle of gamma …

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Key Technologies And Engineering Practice Of 3d Laser Scanning In Coal Mine Roadways, Wang Haijun, Liu Zaibin, Lei Xiaorong, Han Baoshan, Lu Ziqing Jan 2022

Key Technologies And Engineering Practice Of 3d Laser Scanning In Coal Mine Roadways, Wang Haijun, Liu Zaibin, Lei Xiaorong, Han Baoshan, Lu Ziqing

Coal Geology & Exploration

Intelligent and unmanned mining is an inevitable trend in the development of the coal industry. Precise geological information detection is one of the current key research and development directions in the construction of smart coal mines. The precise detection of information on roadways and the rapid acquisition of three-dimensional roadway models are important data sources for geological transparence. Through a comparative analysis of traditional roadway modeling methods and their advantages and disadvantages, a technical idea of using three-dimensional laser scanning reconstruction technology to construct a high-precision transparent working face roadway model is proposed. On the basis of the analysis of …

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Design And Implementation Of The Geological Guarantee System Architecture Based On Microservices, Li Peng, Cheng Jianyuan Jan 2022

Design And Implementation Of The Geological Guarantee System Architecture Based On Microservices, Li Peng, Cheng Jianyuan

Coal Geology & Exploration

The geological guarantee system is very important for safety production in coal mines. In view of the problems faced by the software development of the system, such as diverse data sources, inconsistent language for integrated development of the geological monitoring system and poor adaptability of the geological support platform in different coal mines caused by customized software development, a three-tier development architecture of the geological support system based on microservices is proposed, which includes an application tier, a platform tier and an infrastructure tier. On the basis of the microservices, the integrated development process of the geological support system is …

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The Adaptive Detection Technology Of Ultrasonic Flow In Mining Boreholes, Dai Chenyu, Zhao Pengpeng, Xu Jing Jan 2022

The Adaptive Detection Technology Of Ultrasonic Flow In Mining Boreholes, Dai Chenyu, Zhao Pengpeng, Xu Jing

Coal Geology & Exploration

For a better flow monitoring at the borehole of underground gas drainage in coal mines, and in response to the influence of factors such as complex composition, poor purity and poor stability of the medium in the pipeline on the measurement accuracy of drainage flow parameters, a set of adaptive detection system of ultrasonic flow for mining boreholes is designed with the time difference method as the measurement principle and the double threshold comparison method as the detection method. The overall scheme of the detection system is designed based on the analysis of the key problems affecting the measurement accuracy …

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Construction And Demonstration Of The Transparent Geological Guarantee System In Tangjiahui Coal Mine, Liu Jiegao, Cheng Jianyuan, Shu Yiguo, Liu Zaibin, Gao Yingui, Gao Yaoquan, Lu Ziqing Jan 2022

Construction And Demonstration Of The Transparent Geological Guarantee System In Tangjiahui Coal Mine, Liu Jiegao, Cheng Jianyuan, Shu Yiguo, Liu Zaibin, Gao Yingui, Gao Yaoquan, Lu Ziqing

Coal Geology & Exploration

The intelligence construction of Tangjiahui Coal Mine is confronted with constrains such as water-conducting faults and pressure of Ordovician limestone water, and how to make the geological conditions transparent has become the technical bottleneck of intelligent mining. Tangjiahui Coal Mine puts emphasize on the prevention and control of water disasters and adopted five advanced technologies, including borehole transient electromagnetic technology, multi-borehole resistivity, seismic while excavating, seismic while mining, microseismic monitoring to build a real-time dynamic transparent geological guarantee system. The system realizes the prevention and control of water disasters, rapid excavation and intelligent mining based on transparent geological models, which …

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Influential Factors Of The Electromagnetic Wave Instrument While Drilling In Coal Seam Horizontal Wells And Resistivity Simulation Calculation, Chen Gang, Zhang Jiguan, Li Quanxin, Liu Zhiyi Jan 2022

Influential Factors Of The Electromagnetic Wave Instrument While Drilling In Coal Seam Horizontal Wells And Resistivity Simulation Calculation, Chen Gang, Zhang Jiguan, Li Quanxin, Liu Zhiyi

Coal Geology & Exploration

In order to figure out the influential factors of the detection by the electromagnetic wave instrument while drilling in coal seam horizontal wells, we studied the impacts of roof and floor surrounding rock resistivity, instrument eccentricity, coal seam borehole collapse and coal seam thickness on the measurement of resistivity through finite element numerical simulation. The resistivity response law of the amplitude ratio and phase difference calculation under the condition of high-resistivity coal rock formation was analyzed. On this basis, a three-layer geological mathematical model was established to simulate the difference between analytical and numerical solutions of the amplitude ratio and …

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Application Research On Dynamic Calibration And Prediction Technology Of Coal Seam In Coalmine Working Face, Liu Wenming, Gao Yaoquan, Jiang Bici, Li Peng, Xue Wuqiang Jan 2022

Application Research On Dynamic Calibration And Prediction Technology Of Coal Seam In Coalmine Working Face, Liu Wenming, Gao Yaoquan, Jiang Bici, Li Peng, Xue Wuqiang

Coal Geology & Exploration

One of the prominent problems of intelligent mining is its inadaptability to geological conditions, especially for the absolute accuracy of coal seam floor and thickness. 3D seismic has a high horizontal resolution and it can control the ups and downs of the coal seam. However, due to the time domain data, the calculation of the coal seam floor elevation is negatively affected by the time-depth conversion point. On the basis of the 3D seismic data of the working face and the coal thickness data during the mining process, the absolute accuracy of the time-depth conversion of the coal seam floor …

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Optimization Of Surface Directional Wells For Water Control Based On Three-Dimensional Seismic Dynamic Geological Modeling, Lu Ziqing, Gao Yaoquan, Guo Yuan Jan 2022

Optimization Of Surface Directional Wells For Water Control Based On Three-Dimensional Seismic Dynamic Geological Modeling, Lu Ziqing, Gao Yaoquan, Guo Yuan

Coal Geology & Exploration

In the treatment of high-pressure Ordovician limestone water in the coal seam floor, the design and construction optimization of surface directional wells mainly relies on two-dimensional AutoCAD geological drawings. For the avoidance of such problems as low drilling rate and off-target in the target area under complex geological conditions, and to improve the effect of precise targeted water hazard control, a technology for optimizing directional wells for water hazard prevention and control based on seismic dynamic modeling is proposed. By comparing and analyzing the current situation and problems of drilling trajectory design and optimization technology, it is pointed out that …

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Development And Application Of Zdy4500lfk Full Automatic Drilling Rig, Dong Hongbo, Fan Qiang, Li Kun, Ma Bin Jan 2022

Development And Application Of Zdy4500lfk Full Automatic Drilling Rig, Dong Hongbo, Fan Qiang, Li Kun, Ma Bin

Coal Geology & Exploration

The ZDY4500LFK full automatic drilling rig was developed and equipped with a surface monitoring and control system to improve the automation of various drilling works and reduce the number of underground workers, then accelerate the intelligent construction of coal mines and meet the demand for the construction of transparent geological security system in mines. In consideration of the key technical problems encountered in the drilling construction of the drilling rig in the transparent geological guarantee system in Tangjiahui Coal Mine of Huaihe Energy West Coal and Electricity Group, such key technologies as row positioning technology and automatic unloading buckle were …

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Prevention And Control Technology Of Ordovician Water In Tangjiahui Coal Mine Based On Transparent Geology, Gao Yaoquan, Gao Yingui, Lu Ziqing, Kong Wanjun Jan 2022

Prevention And Control Technology Of Ordovician Water In Tangjiahui Coal Mine Based On Transparent Geology, Gao Yaoquan, Gao Yingui, Lu Ziqing, Kong Wanjun

Coal Geology & Exploration

The problems of many water diversion faults and, concealed water diversion structure have led to the difficulty of water disaster prevention and control of Ordovician limestone in No.6 coal seam in Tangjiahui Coal Mine. After continuous exploration and practice, a variety of advanced technologies has been introduced to obtain a large number of geological and hydrogeological data, and construct an intelligent geological guarantee system. The technical ideas of “geophysical and drilling exploration, joint grouting treatment up-hole and down-hole, in-hole transient electromagnetic fine exploration, inter-hole resistivity detection of grouting effect, and joint monitoring of coal seam floor by micro-seismic and electromagnetic …

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Construction Method Of Transparent Working Face Based On Borehole Radar, Jiang Bici, Cheng Jianyuan, Li Ping, Liu Wenming, Yu Junhui, Wu Guoqing Jan 2022

Construction Method Of Transparent Working Face Based On Borehole Radar, Jiang Bici, Cheng Jianyuan, Li Ping, Liu Wenming, Yu Junhui, Wu Guoqing

Coal Geology & Exploration

The high-precision detection of coal rock interface is the key and difficult point to construct the three-dimensional geological model of intelligent mining. A method is proposed to construct regional coal rock interface geological model and realize transparent working face by using single hole reflection radar in the hole along coal seam and multi hole detection results. For single borehole radar data, the coal seam radar wave velocity is calculated by using the slope of roadway wave in-phase axis, and the spatial constrained migration imaging is used to realize the accurate calculating of coal seam top/floor reflection interface. Three transparent working …

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Construction Method On Transparent Geological Guarantee Technologies: A Case Study Of Wuhai Mining Area, Gu Baoze, Dai Zhenhua, Li Mingxing, Chen Baohui Jan 2022

Construction Method On Transparent Geological Guarantee Technologies: A Case Study Of Wuhai Mining Area, Gu Baoze, Dai Zhenhua, Li Mingxing, Chen Baohui

Coal Geology & Exploration

Coal geological guarantee technologies are applied in the whole life cycle of the coal industry. The technologies are the basis and premise of realizing safe, efficient, intelligent and green mining of coal resources, and plays a key role in disaster prevention, hidden disaster-causing factor detection and intelligent mining of coal. Without any doubt, geological transparency is the crucial task to improve the ability of intelligent analysis and decision-making, automatic and precise control, and efficient coal mining. For the purpose of solving the problems faced by Wuhai Mining Area in the construction of coal mine intellectualization, such as complex geological conditions …

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Feasibility Study Of The Metaverse Technology In Coal Mine Emergency Training And Drills, Guo Yangyang Jan 2022

Feasibility Study Of The Metaverse Technology In Coal Mine Emergency Training And Drills, Guo Yangyang

Coal Geology & Exploration

Coal mine safety training and emergency drills are effective measures to prevent disasters and accidents. At this stage, however, there are problems such as the boring training content, drills emphasizing “performance” rather than “practice”, and formalism. Metaverse technology integrates VR, AR, 3D, blockchain, Internet of things, AI, digital twin and other technologies, therefore, it is characterized by intuitiveness, strong interaction and high knowledge conversion rate in coal mine safety training and emergency drills, which can well solve the above problems. Now the metaverse technology is increasingly mature from hardware, software to various supporting facilities, while it is still faced with …

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Modeling Vapor Transfer In Soil Water And Heat Simulations: A Modularized, Partially-Coupled Approach, Zhuangji Wang, Dennis Timlin, David Fleisher, Wenguang Sun, Sahila Beegum, Sanai Li, Ya Chen, Vandimalla R. Reddy, Katherine Tully, Robert Horton Jan 2022

Modeling Vapor Transfer In Soil Water And Heat Simulations: A Modularized, Partially-Coupled Approach, Zhuangji Wang, Dennis Timlin, David Fleisher, Wenguang Sun, Sahila Beegum, Sanai Li, Ya Chen, Vandimalla R. Reddy, Katherine Tully, Robert Horton

Nebraska Water Center: Faculty Publications

Coupled water and heat transfer models are widely used to analyze soil water content and temperature dynamics, evaluate agricultural management systems, and support crop growth modelling. In relatively dry soils, vapor transfer, rather than liquid water flux, becomes the main pathway for water redistribution. However, in some modularized soil simulators, e.g., 2DSOIL (Timlin et al., 1996), vapor transfer is not included, which may induce errors in soil water and heat modelling. Directly embedding vapor transfer into existing water and heat transfer modules may violate the modularized architecture of those simulators. Therefore, the objectives of this study are to design a …

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The Use Of Microalgal Sourced Biodiesel To Help Underground Mines Transition To Battery Electric Vehicles, Corey A. Laamanen, Kyle Moreau, Sabrina M. Desjardins, Shannon H. Mclean, John A. Scott Jan 2022

The Use Of Microalgal Sourced Biodiesel To Help Underground Mines Transition To Battery Electric Vehicles, Corey A. Laamanen, Kyle Moreau, Sabrina M. Desjardins, Shannon H. Mclean, John A. Scott

Journal of Sustainable Mining

The use of fossil fuel sourced diesel underground has various associated health and environmental hazards, and additional energy demand and costs associated with necessary ventilation. One way to reduce these impacts is by utilizing a biodieselblend, which generates lower levels of harmful emissions from underground equipment and can be produced regionally, reducing the impact of transportation. Furthermore, this would help allow use of existing machinery during transition towards more widespread electrification underground. Therefore, the concept of an integrated supply and use chain within the mining industry is examined based on biodiesel from acidophilic photosynthetic microalgae cultivated using CO 2 in …

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Investigating The Effectiveness Of A Ground Support System Implemented On Block A: A Case Study Of Southern Africa Metalliferous Mine, Kamogelo Manyelo, Peter Kolapo Jan 2022

Investigating The Effectiveness Of A Ground Support System Implemented On Block A: A Case Study Of Southern Africa Metalliferous Mine, Kamogelo Manyelo, Peter Kolapo

Journal of Sustainable Mining

This study aims to investigate the effectiveness of the ground support systems that are planned to be implemented on Block A, which will be excavated through the Marikana fault zone. The block of ground being prepared for mining has been physically affected by the presence of the Marikana fault and is therefore geomechanically and geotechnically weaker than the normal stoping conditions on the rest of the shaft. Joint mapping conducted in Block A raiselines indicated that there is a high concentration of shallow dipping joints which are dipping in opposite directions. Such conditions present special challenges in the planned excavations …

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Application Of Entropy Method For Estimating Factor Weights In Mining-Method Selection For Development Of Novel Mining-Method Selection System, Elsa Pansilvania Andre Manjate, Mahdi Saadat, Hisatoshi Toriya, Fumiaki Inagaki, Youhei Kawamura Jan 2022

Application Of Entropy Method For Estimating Factor Weights In Mining-Method Selection For Development Of Novel Mining-Method Selection System, Elsa Pansilvania Andre Manjate, Mahdi Saadat, Hisatoshi Toriya, Fumiaki Inagaki, Youhei Kawamura

Journal of Sustainable Mining

Mining-method selection (MMS) is one of the most critical and complex decisionmaking processes in mine planning. Therefore, it has been a subject of several studies for many years culminating with the development of different systems. However, there is still more to be done to improve and/or create more efficient systems and deal with the complexity caused by many influencing factors. This study introduces the application of the entropy method for feature selection, i.e., select the most critical factors in MMS. The entropy method is applied to assess the relative importance of the factors influencing MMS by estimating their objective weights …

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Sources And Techniques Of Domestic Heating Within Tritia Region, Malgorzata Wysocka, Krystian Skubacz, Krzysztof Samolej Jan 2022

Sources And Techniques Of Domestic Heating Within Tritia Region, Malgorzata Wysocka, Krystian Skubacz, Krzysztof Samolej

Journal of Sustainable Mining

The paper presents the balance of energy consumption for domestic heating in Opole and Silesian Voivodship (Poland), divided into various media. The report was based on an analysis of approximately 250 documents containing low-carbon economy plans for individual municipalities (gminas). The authors compared the current situation in these voivodships and their districts with the structure of the heating system in Poland as a whole, based on data from the Central Statistical Office of Poland. The data demonstrate that the use of coal-based energy media has not changed significantly over the years and around 55-60% of households with individual heating systems …

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Modelling The Throttle Effect In A Mine Drift, Rickard Hansen Jan 2022

Modelling The Throttle Effect In A Mine Drift, Rickard Hansen

Journal of Sustainable Mining

The throttle effect is a phenomenon, which may occur during a fire underground, causing unforeseen smoke spread. This paper focuses on the modelling of the throttle effect in a mine drift, using a CFD software. The aim of the paper is to investigate whether the CFD tool is able to predict and reproduce the throttle effect for fire scenarios underground. Experimental data from fire experiments in a model-scale mine drift and modelling results from a CFD model were used during the analysis. It was found that the CFD model was not able to fully reproduce the throttle effect for fire …

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Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray Jan 2022

Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Improvement of nutrient use efficiency and limiting trace elements such as arsenic and uranium bioavailability is critical for sustainable agriculture and food safety. Arsenic and uranium possess different properties and mobility in soils, which complicates the effort to reduce their uptake by plants. Here, we postulate that unsaturated soil amended with ferrihydrite nanominerals leads to improved nutrient retention and helps reduce uptake of these geogenic contaminants. Unsaturated soil is primarily oxic and can provide a stable environment for ferrihydrite nanominerals. To demonstrate the utility of ferrihydrite soil amendment, maize was grown in an unsaturated agricultural soil that is known to …

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Developing An Open Database To Support Forensic Investigation Of Disasters In South East Asia: Forinsea V1.0, Andres Payo, Raushan Arnhardt, Angelo Carlo R. Galindo, Pham Van Dong, Ma. Aileen Leah G. Guzman, Yasmin O. Hatta, Andrew Bevan, Jose Claro N. Monje Jan 2022

Developing An Open Database To Support Forensic Investigation Of Disasters In South East Asia: Forinsea V1.0, Andres Payo, Raushan Arnhardt, Angelo Carlo R. Galindo, Pham Van Dong, Ma. Aileen Leah G. Guzman, Yasmin O. Hatta, Andrew Bevan, Jose Claro N. Monje

Electronics, Computer, and Communications Engineering Faculty Publications

This article describes the development of a bespoke database, FORINSEA1.0, created to address the need for a systematic curation of information needed for the descriptive phase of the FORIN approach and its application to two study areas in the South East Asia region. FORINSEA1.0 allows researchers, for the first time, to explore and make use of subnational, geocoded data on major disasters triggered by natural hazards (flooding, earthquake, landslide and meteorological hazards) since 1945 until 2020 in the hydrological catchment of the Red River in Vietnam and the Marikina Basin in the Philippines. FORINSEA1.0 also contains relevant subnational information on …

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Combining Green Metrics And Digital Twins For Sustainability Planning And Governance Of Smart Buildings And Cities, Casey R. Corrado, Suzanne M. Delong, Emily G. Holt, Edward Y. Hua, Andreas Tolk Jan 2022

Combining Green Metrics And Digital Twins For Sustainability Planning And Governance Of Smart Buildings And Cities, Casey R. Corrado, Suzanne M. Delong, Emily G. Holt, Edward Y. Hua, Andreas Tolk

VMASC Publications

Creating a more sustainable world will require a coordinated effort to address the rise of social, economic, and environmental concerns resulting from the continuous growth of cities. Supporting planners with tools to address them is pivotal, and sustainability is one of the main objectives. Modeling and simulation augmenting digital twins can play an important role to implement these tools. Although various green best practices have been utilized over time and there are related attempts at measuring green success, works in the published literature tend to focus on addressing a single problem (e.g., energy efficiency), and a comprehensive approach that takes …

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Comparison Effect On Biogas Production From Vegetable And Fruit Waste With Rumen Digesta Through Co-Digestion Process, Anika Tasnim, Muhammad Rashed Al Mamun, Md Anwar Hossen, Md Towfiqur Rahman, Md Janibul Alam Soeb Jan 2022

Comparison Effect On Biogas Production From Vegetable And Fruit Waste With Rumen Digesta Through Co-Digestion Process, Anika Tasnim, Muhammad Rashed Al Mamun, Md Anwar Hossen, Md Towfiqur Rahman, Md Janibul Alam Soeb

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Biogas is the best renewable energy as it can be produced from any biomass for example any plant or living organism. The purpose of this research was to produce biomethane from co-digestion of vegetable and fruit waste with rumen digesta through anaerobic digestion process. In this research, two trials of experiment were conducted. Each trial has three different sample with different mixing ratios. Raw materials used in the experiment was rumen digesta of goat and cow, potato, capsicum, cucumbers, onions, radish, cauliflower, carrot, leafy vegetables, apple, banana, and papaya. In each sample, 1200 gram of raw materials were used. Hydraulic …

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Fish And Invertebrate Use Of Restored Vs. Natural Oyster Reefs In A Shallow Temperate Latitude Estuary, Jonathan H. Grabowski, Christopher J. Baillie, Adam Baukus, Rachael Carlyle, F. Joel Fodrie, Rachel K. Gittman, A. Randall Hughes, David L. Kimbro, Juhyung Lee, Hunter S. Lenihan, Sean P. Powers, Kevin Sullivan Jan 2022

Fish And Invertebrate Use Of Restored Vs. Natural Oyster Reefs In A Shallow Temperate Latitude Estuary, Jonathan H. Grabowski, Christopher J. Baillie, Adam Baukus, Rachael Carlyle, F. Joel Fodrie, Rachel K. Gittman, A. Randall Hughes, David L. Kimbro, Juhyung Lee, Hunter S. Lenihan, Sean P. Powers, Kevin Sullivan

University Faculty and Staff Publications

Coastal marine habitats continue to be degraded, thereby compelling largescale restoration in many parts of the world. Whether restored habitats function similarly to natural habitats and fully recover lost ecosystem services is unclear. In estuaries, oyster reefs have been degraded by multiple anthropogenic activities including destructive fishing practices and reduced water quality, motivating restoration to maintain oyster fisheries and other ecosystem services, often at relatively high cost. We compared fish and invertebrate communities on recently restored (0–1 year post-restoration), older restored (3–4 years post-restoration), and natural oyster reefs to determine if and when restored reefs support functionally similar faunal communities. …

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Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia Jan 2022

Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia

College of Graduate Studies: Theses & Dissertations

An investigation was conducted on the optimal engine parameters for facilitating lower NOX and soot emissions of PCCI combustion with either ethanol or n-butanol. The PFI fuels selected were tested at loads of 3, 4, and 5 Bar IMEP for a total of 28 total combustion tests with variations made to the EGR% and boost pressure for each test in order to find the optimal emissions strategy. A Mie-scattering spray fuel analysis was also conducted on the three fuels to gain insight on their influence on combustion/emissions characteristics. It was found that ethanol had a greater average Sauter Mean Diameter …

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Techno-Economic Feasibility Of Electrifying Food Markets In Nigeria With Biogas Hybrid Mini-Grids, Demi Temitope Ogunwo Jan 2022

Techno-Economic Feasibility Of Electrifying Food Markets In Nigeria With Biogas Hybrid Mini-Grids, Demi Temitope Ogunwo

Cal Poly Humboldt theses and projects

This thesis explored the feasibility of electrifying a food market in an urban city in Nigeria with a hybrid biogas-powered mini-grid. Under the Energizing Economies Initiative of the Rural Electrification Agency of Nigeria, nine markets in the country currently receive constant access to electricity via hybrid mini-grid systems. As a majority of these systems are diesel-solar-battery systems, this thesis explored the use of biogas generators as a substitute for diesel generators in hybrid mini-grids for food markets. A fruit and vegetable market in Ketu, Lagos was used as a case study for the research. The research for this thesis was …

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Calcite Depression In Bastnaesite-Calcite Flotation System Using Organic Acids, Emmy Muhoza Jan 2022

Calcite Depression In Bastnaesite-Calcite Flotation System Using Organic Acids, Emmy Muhoza

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bastnaesite is the primary source of light REEs, namely cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd), to name a few. Bastnaesite is typically concentrated using the froth flotation beneficiation method. Flotation of bastnaesite suffers from high reagent consumption due to the similar surface characteristics of bastnaesite and associated gangue minerals, including calcite. Additionally, complex stages of high-temperature conditioning are often required to suppress the detrimental impact of dissolved calcium ions on the flotation of bastnaesite. This research seeks to investigate the capabilities of organic acids in the bastnaesite-calcite flotation systems to selectively depress calcite minerals and effectively chelate calcium …

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Saxs-Based Nano-Scale Pore Structure Characteristics Of Coals With Different Metamorphic Degrees, Zhang Yu, Li Yong, Wang Yanbin, Wang Zhuangsen, Zhao Shihu, Han Wenlong Dec 2021

Saxs-Based Nano-Scale Pore Structure Characteristics Of Coals With Different Metamorphic Degrees, Zhang Yu, Li Yong, Wang Yanbin, Wang Zhuangsen, Zhao Shihu, Han Wenlong

Coal Geology & Exploration

In order to reveal the characteristics of nano-scale pores in coals with different metamorphic degrees, the small-angle X-ray scattering method (SAXS) is used to obtain the porosity, pore size distribution, specific surface area and fractal dimension of 15 samples whose vitrinite reflectance Rmax is 0.31%-6.24%, and the low temperature CO2 and N2 adsorption DFT model results are used to verify the pore size distribution. The results show: during coalification process, when Rmax is < 0.5%, the porosity and the specific surface area of coal increase with the increase of metamorphic degree, the micropores(< 2 nm) content increases seldomly, the mesoporous(2-50 nm) and microporous(50-100 nm) content increase greatly, and the surface of coal is gradually smooth. When Rmax=0.5%-1.4%, the porosity and the specific surface area decrease, and each type of pore content is reduced, and the surface of …

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