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Articles 25801 - 25830 of 294494

Full-Text Articles in Physical Sciences and Mathematics

Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty Jul 2024

Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

Transient signals arising from instrumental or environmental factors, commonly referred to as glitches, constitute the predominant background of false alarms in gravitational wave searches with ground-based detectors. Therefore, effective data analysis methods for vetoing glitch-induced false alarms are crucial to enhancing the sensitivity of a search. We present a veto method for glitches that impact matched filtering-based searches for binary inspiral signals. The veto uses unphysical sectors in the space of chirp time parameters as well as an unphysical extension including negative chirp times to efficiently segregate glitches from gravitational wave signals in data from a single detector. Inhabited predominantly …

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Identifying The O’Connell Effect In Eclipsing Binary Stars, Nicholas Paolella Jul 2024

Identifying The O’Connell Effect In Eclipsing Binary Stars, Nicholas Paolella

Computer Science and Information Technology Faculty

Data science techniques have wide-ranging applications throughout scientific explorations. One, is filtering astronomical data to better understand specific populations, such as binary stars. Specifically, binary stars that exhibit the O’Connell effect are worthy of study as this phenomenon is still not well understood. The O’Connell effect can be defined as the asymmetry of maxima in the light curves, as captured by the instrument, while observing the eclipsing binary system in question. There is significant data captured by NASA and curated by Villanova University, which enabled the investigation of eclipsing binary stars and the attributes of which may help identify the …

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Pyrolysis Characteristics And Pore-Fracture Evolutionary Patterns Of Tar-Rich Coals, Geng Jishi, Wang Shuangming, Sun Qiang, Hou Enke, Yang Yuru, Hu Xin, Xue Shengze Jul 2024

Pyrolysis Characteristics And Pore-Fracture Evolutionary Patterns Of Tar-Rich Coals, Geng Jishi, Wang Shuangming, Sun Qiang, Hou Enke, Yang Yuru, Hu Xin, Xue Shengze

Coal Geology & Exploration

Objective Extracting coal-based oil and gas from tar-rich coal through in situ pyrolysis plays a significant role in counteracting the shortage of China's oil and gas resources and enhancing the utilization efficiency of coal resources, representing a new trend for the efficient exploitation of tar-rich coals. During the in situ pyrolysis of tar-rich coals, the internal heat transfer, as well as the migration and production of pyrolysis products, is directly influenced by the oil and gas production characteristics and the characteristics of pores and fractures. Hence, it is particularly critical to identify the pyrolysis characteristics and pore-fracture evolutionary patterns of …

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In-Situ Pyrolysis Of Tar-Rich Coal: Effects On Geological Environments And Geological Guarantee Technology, Xu Shiang, Zhang Pingsong, Cheng Gang, Wu Haibo Jul 2024

In-Situ Pyrolysis Of Tar-Rich Coal: Effects On Geological Environments And Geological Guarantee Technology, Xu Shiang, Zhang Pingsong, Cheng Gang, Wu Haibo

Coal Geology & Exploration

Objective Tar-rich coal, a type of unique unconventional oil and gas resource that integrates coal, oil, and gas, can be transformed into tar, combustible gases, and semi-coke solid fuels with high added value through in-situ pyrolysis. Therefore, the in-situ pyrolysis of tar-rich coal has the potential to meet the challenges in achieving the green exploitation and clean, low-carbon utilization of coals in the traditional coal industry. Furthermore, in terms of how to reduce coal pollution emissions and enhance energy efficiency, this technology offers a new solution for attaining the goals of peak carbon dioxide emissions and carbon neutrality. It also …

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Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, Eli C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval Jul 2024

Variable Radio Emission Of Neutron Star X-Ray Binary Ser X–1 During Its Persistent Soft State, Eli C. Pattie, Thomas J. Maccarone, Alexandra J. Tetarenko, James C. A. Miller-Jones, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval

Physics & Astronomy Faculty Publications

Ser X–1 is a low-mass neutron star X-ray binary and has been persistently accreting since its discovery in the 1960s. It has always been observed to be in a soft spectral state and has never showed substantial long-term X-ray variability. Ser X–1 has one previous radio observation in the literature in which radio emission was detected during this soft state, which is contrary to the behavior of black hole X-ray binaries. We have recently obtained 10 randomly sampled radio epochs of Ser X–1 in order to further investigate its anomalous soft-state radio emission. Out of 10 epochs, we find 8 …

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Strong Gelfand Pairs Of Some Finite Groups, Joseph E. Marrow Jul 2024

Strong Gelfand Pairs Of Some Finite Groups, Joseph E. Marrow

Theses and Dissertations

Strong Gelfand pairs describe a relation between a group and a subgroup, using a relation between inner products of their characters. We find all strong Gelfand pairs of the dihedral and dicyclic groups, and several of the sporadic groups. We provide some results for the strong Gelfand pairs of the affine linear groups, in addition to the exceptional classical groups $\mathrm{Sp}_4(q)$ for $q$ a power of $2$.

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2024 July 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jul 2024

2024 July 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

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Pilot Experiment For Underground In-Situ Pyrolysis Of Tar-Rich Coal In The Northern Shaanxi Province, Duan Zhonghui, Yang Fu, Wang Zhendong, Ma Li, Duan Xiaoqing, Cao Husheng, Chen Liang Jul 2024

Pilot Experiment For Underground In-Situ Pyrolysis Of Tar-Rich Coal In The Northern Shaanxi Province, Duan Zhonghui, Yang Fu, Wang Zhendong, Ma Li, Duan Xiaoqing, Cao Husheng, Chen Liang

Coal Geology & Exploration

Objective The breakthrough of the pilot experiment for underground in-situ pyrolysis of tar-rich coal in the northern Shaanxi has added new vitality to the research on in-situ conversion of fossil energy such as tar-rich coal and oil shale, and the results have attracted wide attention both inside and outside the industry. The research on underground in-situ pyrolysis of tar rich coal is still in its infancy, lacking systematic research on field engineering data.Methods Based on the pilot experiment, the main geological conditions and engineering difficulties have been clarified, and the progress of underground in-situ pyrolysis has been summarized. The …

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Geological Factors Controlling The Occurrence Of Carboniferous-Permian Tar-Rich Coals In The Ningdong Coalfield, Huang Pengcheng, Guo Weiyong, Ji Xiaoyan, Cai Feifei, Zhang Zhifeng, Huang Kang, Cheng Yunqiang, Liu Zheng, Wang Bei, Chen Rong, Shi Qingmin Jul 2024

Geological Factors Controlling The Occurrence Of Carboniferous-Permian Tar-Rich Coals In The Ningdong Coalfield, Huang Pengcheng, Guo Weiyong, Ji Xiaoyan, Cai Feifei, Zhang Zhifeng, Huang Kang, Cheng Yunqiang, Liu Zheng, Wang Bei, Chen Rong, Shi Qingmin

Coal Geology & Exploration

Objective The Ningdong Coalfield of the Ordos Basin boasts abundant tar-rich coal resources, of which tar-rich coals in the Carboniferous-Permian coal seams exhibit unique occurrence characteristics due to differences in thermal evolution and sedimentary environments. Methods This study analyzed the occurrence characteristics and critical material composition of tar-rich coals in the Hongdunzi and Siguquan mining areas. Based on this, it explored the controlling effects of the degree of coalification and sedimentary environment on the tar yield. Results and Conclusions The results indicate that the Carboniferous-Permian coal seams in the Ningdong Coalfield exhibit average tar yields ranging from 7.15% to 11.07%, …

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Distributions Of Products From The Pyrolysis Of Tar-Rich Coals For Tar Extraction In Northern Shaanxi Province, China, Yu Zunyi, Guo Wei, Yang Panxi, Gao Kun, Yang Fu, Ma Li, Wang Jing, Li Hongqiang, Yang Bolun, Wu Zhiqiang Jul 2024

Distributions Of Products From The Pyrolysis Of Tar-Rich Coals For Tar Extraction In Northern Shaanxi Province, China, Yu Zunyi, Guo Wei, Yang Panxi, Gao Kun, Yang Fu, Ma Li, Wang Jing, Li Hongqiang, Yang Bolun, Wu Zhiqiang

Coal Geology & Exploration

Objective Tar-rich coals stand as a special type of coal resource that integrates coal, oil, and gas properties. These coals, boasting abundant hydrogen-rich structures such as side chains and bridge bonds with aliphatic structures, are prone to crack and produce tar and gas during pyrolysis. These establish tar-rich coals as ideal raw materials that produce oil and gas through thermal conversion. Presently, the research into tar extraction from tar-rich coals through pyrolysis remains in its initial stage, and exploring the impacts of technological conditions, including heat carrier, heating type, and pyrolysis temperature, on the pyrolysis process holds critical significance for …

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Simulation Of The Pyrolysis Process Of Tar-Rich Coals In An H2O Atmosphere Based On The Reactive Force Field Molecular Dynamics, Huang Zibo, Liu Qianru, Liu Hong, Zhou Wenjing, Wei Jinjia Jul 2024

Simulation Of The Pyrolysis Process Of Tar-Rich Coals In An H2O Atmosphere Based On The Reactive Force Field Molecular Dynamics, Huang Zibo, Liu Qianru, Liu Hong, Zhou Wenjing, Wei Jinjia

Coal Geology & Exploration

Objective Tar-rich coal resources, abundant in China, can be converted into energy products (e.g., chemicals and gas/liquid fuels) through pyrolysis, thus alleviating the country’s dependence on oil and gas imports. A thorough understanding of the product evolution and reaction mechanisms of the pyrolysis of tar-rich coals is crucial to research into the clean and efficient conversion processes of coals. Methods Based on the reactive force field molecular dynamics (ReaxFF MD), this study simulated the pyrolysis process of tar-rich coals (long-flame coals) and explored the impacts of the H2O atmosphere on the distribution of pyrolytic products, along with the …

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Spatiotemporal Distributions Of Typical Contaminants From The In-Situ Pyrolysis Of Tar-Rich Coals, Tian Hua, Zhang Ruolin, Wang Qianji, Wu Xiaoyu, Zhang Lei, Zhang Lingru, Fang Siyuan Jul 2024

Spatiotemporal Distributions Of Typical Contaminants From The In-Situ Pyrolysis Of Tar-Rich Coals, Tian Hua, Zhang Ruolin, Wang Qianji, Wu Xiaoyu, Zhang Lei, Zhang Lingru, Fang Siyuan

Coal Geology & Exploration

Objective and Methods Under high temperatures, oil and gas produced from the in situ pyrolysis of tar-rich coals will migrate toward and accumulate in the overburden strata after passing through the fracture zones on the coal seam roof, causing potential contamination risks for the underground environment. To understand the release and distribution characteristics of typical contaminants generated from the underground pyrolysis of tar-rich coals, this study investigated the typical tar-rich coals from the Shenfu mining area of the Jurassic coalfield in northern Shaanxi Province. Based on data on the stratigraphic structures and lithology and using the self-developed equipment for similarity …

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Downhole Heaters For In-Situ Pyrolysis Of Tar-Rich Coals：A Review And Prospects, Wang Zhendong, Duan Zhonghui, Yang Fu, Ma Li Jul 2024

Downhole Heaters For In-Situ Pyrolysis Of Tar-Rich Coals：A Review And Prospects, Wang Zhendong, Duan Zhonghui, Yang Fu, Ma Li

Coal Geology & Exploration

Significance China boasts abundant tar-rich coal resources, which prove to be potential coal-based oil and gas resources capable of ensuring China's energy security. Extracting hydrogen while preserving carbon through the in-situ pyrolysis of tar-rich coals has developed into a trend in the clean and low-carbon utilization of coal resources. Downhole heaters serve as critical equipment for the efficient in-situ pyrolysis of tar-rich coals. Advances Based on investigations and the systematic collection of relevant information and data, this study offers a brief introduction of the currently used methods for in-situ convection heating, focusing on the present situation of the research and …

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Exploring The Pyrolysis Of Tar-Rich Coals Under The Catalysis Of Cerium-Modified Magnetic Core-Shell Hzsm-5, Zhou Anning, Zhang Zhi, Chen Yongan, Zhang Huaiqing, Bai Zhuangwei, Shi Zhiwei, He Xinfu Jul 2024

Exploring The Pyrolysis Of Tar-Rich Coals Under The Catalysis Of Cerium-Modified Magnetic Core-Shell Hzsm-5, Zhou Anning, Zhang Zhi, Chen Yongan, Zhang Huaiqing, Bai Zhuangwei, Shi Zhiwei, He Xinfu

Coal Geology & Exploration

Objective Tar-rich coals are valuable resources integrating coal, tar, and gas properties. Catalytic pyrolysis serves as a significant approach for achieving green and low-carbon development of tar-rich coals. However, the research and development of efficient and recyclable catalysts for the pyrolysis of tar-rich coals remains highly challenging. Methods With HZSM-5@SiO2@MgFe2O4 (HSMF) as the raw material, this study prepared HZSM-5@SiO2@MgFe2O4 (mHSMF) with a hierarchical porous structure using the hydrothermal method and alkali modification, followed by the preparation of cerium-modified mHSMF (5-CeO2/mHSMF) using the precipitation method. Employing a fixed-bed reactor, …

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Information Geometric Approaches To Optimal Experimental Design And Reduced-Order Modeling In Ocean Acoustics, Jay C. Spendlove Jul 2024

Information Geometric Approaches To Optimal Experimental Design And Reduced-Order Modeling In Ocean Acoustics, Jay C. Spendlove

Theses and Dissertations

This thesis demonstrates the application of information geometry to problems in underwater acoustics. Information geometry combines the fields of information theory and differential geometry by interpreting a multiparameter model as a Riemannian manifold in an ambient data space. Information geometry tools are especially powerful in context of problems of experimental design and model selection in ocean acoustics. The application area specifically considered in this research is geoacoustic inversion, where seabed parameter values are inferred from acoustical data. Chapter 2 contains a paper submitted to the Journal of Theoretical and Computational Acoustics, which introduces information geometry tools such as the model …

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Documentation Of Norm Negotiation In A Secondary Mathematics Classroom, Michelle R. Bagley Jul 2024

Documentation Of Norm Negotiation In A Secondary Mathematics Classroom, Michelle R. Bagley

Theses and Dissertations

While previous mathematics education research has shown that norms can change in mathematics classrooms, little research has closely documented the struggles, concessions, and compromises involved in the negotiation process. Negotiating norms is a complex process entailing deliberate teacher moves intended to promote norms, often met with misunderstandings or resistance from students. This thesis documented the negotiation process that occurred when a teacher attempted to require conceptual explanations from students who had not previously been accustomed to doing so. I recorded six days of instruction in a 9th grade algebra unit, transcribed the class discussions, and inferred norms "at play" for …

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Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones Jul 2024

Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones

Aerospace Sciences Student Publications

Cyberattacks on space assets are often portrayed in vague terms of doubt and mystery. Several claims depict satellites being compromised or attacked, but little corroboration has been published or made publicly available. As the commercial space industry grows, increased concern with space cybersecurity will prompt commercial satellite decision-makers to analyze the often-undefined risk of cyberattacks against satellites. This article identifies and characterizes the nature of cybersecurity risks to space assets and postulates why space professionals might not prioritize cybersecurity. Additional information was captured from a decadal survey of space professionals conducted in 2012 and 2022. The results show a rise …

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Table Of Contents, The Editors Jul 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Strategic Value And Scientific Exploration Of In-Situ Pyrolysis Of Tar-Rich Coals, Wang Shuangming, Shi Qingmin, Sun Qiang, Cui Shidong, Kou Bingyang, Qiao Junwei, Geng Jishi, Zhang Lei, Tian Hua, Jiang Pengfei, Cai Yue, Liu Lang Jul 2024

Strategic Value And Scientific Exploration Of In-Situ Pyrolysis Of Tar-Rich Coals, Wang Shuangming, Shi Qingmin, Sun Qiang, Cui Shidong, Kou Bingyang, Qiao Junwei, Geng Jishi, Zhang Lei, Tian Hua, Jiang Pengfei, Cai Yue, Liu Lang

Coal Geology & Exploration

Background Given China's significant demand shortfall of oil and gas, numerous constraints on oil and gas supply, an arduous task of green and low-carbon energy transition of coals, tar-rich coals, a type of coal resource integrating the properties of coal, oil, and gas, have great potential for increasing the oil and gas supply of the country. Advances Despite the successful engineering test conducted in Yulin, Shaanxi Province, in-situ pyrolysis of tar-rich coals remains in its exploratory stage. This technology holds great strategic value in two aspects: (1) It enables reduced demand shortfall of oil and gas in China to enhance …

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Numerical Simulations Of The Evolutionary Patterns Of Multi-Physical Fields During The In-Situ Pyrolysis Of Tar-Rich Coals, Yang Fu, Cheng Xiangqiang, Li Mingjie, Wu Zhiqiang, Wei Jinjia, Cao Husheng Jul 2024

Numerical Simulations Of The Evolutionary Patterns Of Multi-Physical Fields During The In-Situ Pyrolysis Of Tar-Rich Coals, Yang Fu, Cheng Xiangqiang, Li Mingjie, Wu Zhiqiang, Wei Jinjia, Cao Husheng

Coal Geology & Exploration

Objective The in-situ pyrolysis of tar-rich coals, an emerging technology for coal resource utilization characterized by cleanliness, high efficiency, and safety, is still in its initial development stage. This technology is greatly influenced by the evolutionary patterns of multi-physical fields and critical process parameters. Methods A numerical simulation model involving multi-physical fields was established by coupling fluid flow, heat transfer, and chemical reactions, and its reliability was verified by comparing the numerical simulation results with the pyrolysis experimental results of cylindrical coal samples. Based on the pilot test conditions, the impacts of permeability, heat-carrier flow rate, and fracture zone height …

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Impacts Of The Caking Property Of Tar-Rich Coals On Their Pore Structure Evolution And Seepage During Pyrolysis, Chang Zhibing, Wang Chuchu, Kuang Wenhao, Tang Ying, Wu Xiaodan, Liu Shuqin Jul 2024

Impacts Of The Caking Property Of Tar-Rich Coals On Their Pore Structure Evolution And Seepage During Pyrolysis, Chang Zhibing, Wang Chuchu, Kuang Wenhao, Tang Ying, Wu Xiaodan, Liu Shuqin

Coal Geology & Exploration

Objective The in-situ pyrolysis of tar-rich coals stands as a technique whereby coal seams are heated underground to produce tar and gas products. During the in-situ pyrolysis, the injection of heating media and the production of tar and gas are affected by the pore structure and permeability of coal seams. Since pyrolysis of caking tar-rich coals is accompanied by the formation of colloids, the pore structure and permeability of caking tar-rich coals differ from those of non-caking tar-rich coals. Methods Caking tar-rich coals were pyrolyzed at 300, 400, 500, and 600 ℃. During the pyrolysis, the pore parameters of the …

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Identification Of Tar-Rich Coal Based On The True Density And Natural Gamma Ray Response Of Coals, Shi Qingmin, Geng Xuhu, Wang Shuangming, Cai Yue, Han Bo, Wang Shengquan, Zhang Zhehao, He Yufei Jul 2024

Identification Of Tar-Rich Coal Based On The True Density And Natural Gamma Ray Response Of Coals, Shi Qingmin, Geng Xuhu, Wang Shuangming, Cai Yue, Han Bo, Wang Shengquan, Zhang Zhehao, He Yufei

Coal Geology & Exploration

Objective Tar yield, derived from the Gray-King assay, serves as the sole metric for evaluating tar-rich coal. However, insufficient exploration data hinder its effective application in the fine-scale evaluation of extensive tar-rich coal. Methods Based on binary classification, this study proposed the optimal thresholds for tar-rich coal identification using true density (ρ) and natural gamma-ray (GR) log. Moreover, this study elucidated the intrinsic mechanisms behind the significant petrophysical parameter responses of tar-rich coal. Results and Conclusions Key findings are as follows: (1) Coals with various metamorphic grades differ in identification threshold. For instance, long-flame tar-rich coal, the optimal …

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A Log-Based Method For Evaluating The Tar Yield Of Tar-Rich Coal, Tian Han, Li Ning, Wang Shuangming, Wu Hongliang, Feng Zhou, Wang Kewen, Wang Guiwen Jul 2024

A Log-Based Method For Evaluating The Tar Yield Of Tar-Rich Coal, Tian Han, Li Ning, Wang Shuangming, Wu Hongliang, Feng Zhou, Wang Kewen, Wang Guiwen

Coal Geology & Exploration

Objective As a kind of coal-based oil and gas resource, tar-rich coal is significant for the supply of oil and gas resources, as well as the clean and efficient utilization of coals. Presently, the identification of tar-rich coals primarily depends on the Gray-King assay. In contrast, there is a lack of studies on the accurate identification and evaluation of tar-rich coal using geophysical methods. Methods This study investigated coals in the Jurassic Xishanyao and Badaowan Formations in Santanghu Basin, Xinjiang. Based on petrophysical experiments, as well as the typical log response characteristics of tar-rich coal, this study developed a new …

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A Method For Predicting The Tar Yield Of Tar-Rich Coals Based On The Bp Neural Network Using Multiple Indicators Of Coal Petrography And Coal Quality, Qiao Junwei, Wang Changjian, Zhao Hongchao, Shi Qingmin, Zhang Yu, Fan Qi, Wang Duo, Yuan Dandan Jul 2024

A Method For Predicting The Tar Yield Of Tar-Rich Coals Based On The Bp Neural Network Using Multiple Indicators Of Coal Petrography And Coal Quality, Qiao Junwei, Wang Changjian, Zhao Hongchao, Shi Qingmin, Zhang Yu, Fan Qi, Wang Duo, Yuan Dandan

Coal Geology & Exploration

Objective Tar yield, the most important coal quality parameter for coal utilization through low-temperature pyrolysis, determines the clean utilization of tar-rich coals. However, various constraints result in limited test data on tar yield in the geological exploration stage of coals, substantially restricting the fine-scale assessment and efficient utilization of tar-rich coals. Methods To achieve more scientific and accurate fine-scale tar-rich coal assessments, this study examined 1073 sets of lithotype and coal quality data obtained previously from a Jurassic coalfield in northern Shaanxi. From these data, 141 sets with 20 lithotype and coal quality parameters regarding macerals, proximate analysis, ultimate analysis, …

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Performance Of Carbon Foams Based On Heavy Tar Produced By Tar-Rich Coal Pyrolysis, Zhang Lei, Liu Chunjiang, Song Ruikang, Wang Qi, Chen Ya, Huang Pengcheng Jul 2024

Performance Of Carbon Foams Based On Heavy Tar Produced By Tar-Rich Coal Pyrolysis, Zhang Lei, Liu Chunjiang, Song Ruikang, Wang Qi, Chen Ya, Huang Pengcheng

Coal Geology & Exploration

Objective Preparing graphitized foam materials using heavy tar produced by the pyrolysis of tar-rich coals plays a significant role in the high-value utilization of tar-rich coal resources. Methods This study aims to prepare high-performance carbon foam materials by investigating the relationships between various reaction conditions and carbon foam performance. First, using mesophase asphalt prepared with heavy tar as the precursor, carbon foams were developed via the high-temperature self-foaming method. Then, the effects of different reaction temperatures, heating rates, and reaction pressures on the performance of coal tar-based carbon foams were examined. Finally, quadratic multinomial regression equations were established using Box-Behnken …

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Molecular Modeling Of Tar-Rich Coals From Northern Shaanxi And Their Molecular Dynamic Characteristics In The Process Of Pyrolysis For Tar Extraction, Guo Wei, Yang Panxi, Yu Zunyi, Yang Fu, Wang Jing, Ma Li, Li Hongqiang, Yang Bolun, Wu Zhiqiang Jul 2024

Molecular Modeling Of Tar-Rich Coals From Northern Shaanxi And Their Molecular Dynamic Characteristics In The Process Of Pyrolysis For Tar Extraction, Guo Wei, Yang Panxi, Yu Zunyi, Yang Fu, Wang Jing, Ma Li, Li Hongqiang, Yang Bolun, Wu Zhiqiang

Coal Geology & Exploration

Objective The pyrolysis process and mechanism of tar-rich coals remain unclear due to their complex structures. Therefore, it is necessary to investigate the structure-activity relationship between their structure and the distributions of their pyrolytic products and determine the mechanism behind their pyrolysis for tar extraction. Methods Focusing on typical tar-rich coals from northern Shaanxi Province, this study calculated and constructed the molecular model of the coals using characterization methods such as carbon-13 nuclear magnetic resonance (13C NMR), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), determining the molecular formula at C444H380O74 …

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Advances In Research On Hydrogenation Saturation Of Polycyclic Aromatic Hydrocarbons In Coal Tar, He Xinfu, Gao Fan, Wu Hongju, Zhang Xiaoqin, Ma Tao, Shi Zhiwei, Zhou Anning, Zhang Yating Jul 2024

Advances In Research On Hydrogenation Saturation Of Polycyclic Aromatic Hydrocarbons In Coal Tar, He Xinfu, Gao Fan, Wu Hongju, Zhang Xiaoqin, Ma Tao, Shi Zhiwei, Zhou Anning, Zhang Yating

Coal Geology & Exploration

Significance Polycyclic aromatic hydrocarbons (PAHs), a predominant component in coal tar, can be used to produce jet fuels with high energy density and thermal stability through hydrogenation saturation. Based on the characteristics of the PAH hydrogenation process, this study proposed that primary challenges in PAH hydrogenation saturation include the resonance energy of PAHs themselves, the spatial site resistance of hydrogenation intermediates, and the competitive adsorption of feedstocks and intermediates on active sites in the catalysts. Progress Based on the review of research progress in catalysts for PAH hydrogenation saturation in recent years, this study analyzed the substantial factor influencing the …

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Synthesis Of Portions Of An Acinetobacter Baumannii Lipooligosaccharide (Los), Brandon Conrad Jul 2024

Synthesis Of Portions Of An Acinetobacter Baumannii Lipooligosaccharide (Los), Brandon Conrad

LSU Doctoral Dissertations

Glycoconjugate vaccines have become an effective strategy for protection against an array of globally persistent diseases resulting from pathogenic bacteria such as Haemophilus influenzae type b (Hib), Neisseria meningitidis, and Salmonella enterica serotype Typhi. Comprised of a carbohydrate (referred to as glycan) covalently inked to a carrier protein, these vaccines can initiate adaptive immunity by inducing B and T cell responses once in the lymphatic system. This is particularly relevant for infants two years of age and younger whose immune systems are not fully developed. A continuously emerging threat in clinical settings, Acinetobacter baumannii is a Gram-negative bacterium …

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Rfc-Berkeley Pit Wpp-2024-02, Mark Thompson, Loren Burmeister Jul 2024

Rfc-Berkeley Pit Wpp-2024-02, Mark Thompson, Loren Burmeister

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco Jul 2024

The Arbitrariness Of Symmetry In Mathematical Proofs, Melisa Vivanco

Philosophy Faculty Publications

Symmetry is not an inherent characteristic of mathematical proofs; instead, it is a property that arbitrarily manifests in different modes of presentation. This arbitrariness leads to the conclusion that symmetry cannot be part of the defining or essential properties that characterize proofs. Consequently, contrary to some authors’ claims, symmetry does not significantly contribute to the validity, accuracy, or soundness of mathematical proofs. What is more, it does not even play any critical role in heuristic aspects such as explanatory power. The examples developed in this paper constitute compelling evidence supporting these claims.

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