Physical Sciences and Mathematics Commons^™

Within‑Marsh And Landscape Features Structure Ribbed Mussel Distribution In Georgia, Usa, Marshes, William K. Annis, Elizabeth A. Hunter, John M. Carroll

United States Geological Survey: Staff Publications

Ribbed mussels, Geukensia demissa, are marsh fauna that are used in coastal management and restoration due to the ecosystem services they provide. Ribbed mussel restoration efforts may be improved with a greater understanding of the environmental drivers of ribbed mussel distribution at multiple spatial scales to predict areas where restoration could be successful. This study sought to estimate the effects of within-marsh (4 m) and landscape (500 m) factors on ribbed mussel distribution. Ribbed mussel densities were surveyed at 11 sites along the coast of Georgia, USA, and overlaid with spatial data for within-marsh factors (elevation, distance to marsh …

The Mitogenome Relationships And Phylogeography Of Barn Swallows (Hirundo Rustica), Gianluca Lombardo, Nicola Rambaldi Migliore, Giulia Colombo, Marco Rosario Capodiferro, Giulio Formenti, Manuela Caprioli, Elisabetta Moroni, Leonardo Caporali, Hovirag Lancioni, Simona Secomandi, Cristina Cereda, Valerio Carelli, Lauren Gillespie, Yang Liu, Yosef Kiat, Alfonso Marzal, Cosme López-Calderón, Javier Balbontín, Timothy Mousseau, Piotr Matyjasiak, Anders Pape Møller, Et. Al.

Faculty Publications

The barn swallow (Hirundo rustica) poses a number of fascinating scientific questions, including the taxonomic status of postulated subspecies. Here, we obtained and assessed the sequence variation of 411 complete mitogenomes, mainly from the European H. r. rustica, but other subspecies as well. In almost every case, we observed subspecies-specific haplogroups, which we employed together with estimated radiation times to postulate a model for the geographical and temporal worldwide spread of the species. The female barn swallow carrying the Hirundo rustica ancestral mitogenome left Africa (or its vicinity) around 280 thousand years ago (kya), and her descendants …

Nanopore Structure And Surface Roughness In Brittle Tectonically Deformed Coals Explored By Atomic Force Microscopy, Zhang Ningyuan, Yao Suping

Coal Geology & Exploration

The pore structure of coal is the key to coalbed methane (CBM) exploration and exploitation, and coal mining safety. Compared to primary coals, tectonically deformed coals (TDCs) have stronger heterogeneity and are of great importance in coal reservoir study. Here, the pore structure and surface roughness of brittle TDCs were obtained with atomic force microscopy (AFM) and NanoScope Analysis and Gwyddion software. The results show that tectonic deformation generally promotes the pore development in brittle TDCs, but the extent of tectonic impact varies greatly among different brittle TDCs. As a result, two stages in brittle TDCs were identified: weak brittle …

Preliminary Investigation Of Uranium Resource Evaluation Method Based On Natural Gamma Logging Data：A Case Study Of The Pengyang Uranium Deposit In Ordos Basin, Yu Reng’An, Sun Dapeng, Zhou Xiaoxi, Deng Fan, Si Qinghong, Hu Yongxing

Coal Geology & Exploration

“Coal and uranium exploration” and “oil and uranium exploration” are current research hotspots. Using logging data of coal and oilfield drilling to further evaluate uranium resources remains a difficult problem. Taking the Pengyang uranium deposit in the Ordos Basin as an example, this article explores the method of evaluating uranium resources based on natural gamma logging data. According to the remarkable features of the natural gamma anomaly response in the sandstone-type uranium reservoirs in the study area, the natural gamma logging regression model of the quantitative gamma logging value of the uranium deposit in the Pengyang area was studied by …

Temperature Field Analysis Of New Pipe Curtain Freezing Method In River Embankment Anti Seepage Reinforcement, Zhou Yuxuan, Hu Jun, Xiong Hui, Ren Junhao, Zhan Jianjian, Wang Zhixin

Coal Geology & Exploration

In order to explore whether the new pipe curtain freezing method can effectively strengthen the river embankment, this paper uses the finite element software to study the application of the new pipe curtain freezing method in anti-seepage and embankment reinforcement based on the temperature field, and sets up four analysis paths to deeply analyze the basic situation of the frozen soil curtain and the freezing effect characteristics of each path. The results show that the frozen soil curtain spreads around after it is formed at the freezing pipe. From the 8th day, the development of the frozen soil curtain on …

Numerical Simulation Of Azimuth Electromagnetic Wave Response Of Complex Geological Model Of Horizontal Hole In Coal Mines, Zhang Yi, Kang Zhengming, Feng Hong, Han Xue, Chen Gang

Coal Geology & Exploration

The advance and accurate identification of the coal-rock interface is one of the key technologies to realize automatic tunneling and intellectualization of coal mines. Azimuth electromagnetic wave tool has a large detection range and can distinguish the lithologic interface and interface orientation. It has been successfully applied in oilfield logging, but there are few researches on the coal mine measurement environment. In order to study the detection performance of azimuth electromagnetic wave logging in the complex 3D model of coal mines, the finite element numerical simulation method is used to investigate the influence of the drilling fluid in the borehole …

Study And Application On Multi Branch Point Sampling Drilling Technology Of Coal Seam Floor Borehole, Chu Zhiwei, Long Weicheng, Jia Bingyi, Liu Fei

Coal Geology & Exploration

According to the technical requirements of long-distance gas parameter measurement, gas extraction borehole design guidance, and extraction evaluation for broken soft coal seam, the multi branch point sampling drilling method of coal seam floor borehole was proposedand its sampling drilling process was formulated on the basis of analyzing existing problems of sampling and drilling technology. Furthermore, the key drilling technologies such as accurate drilling trajectory control and “mechanical + hydraulic” efficient slag removal were developed. The equipment of drilling and sealed sampling were introduced. The application test was carried out in a coal mine in Suzhou, Anhui Province, in which …

Geological Structure Detection With Tunnel Transient Electromagnetic Kirchhoff 2d Migration Imaging, Qi Zhipeng, Guo Jianlei, Sun Naiquan, Li Xiu, Fan Yanan

Coal Geology & Exploration

The green construction of tunnel requires not only predicting disaster anomalies such as water inrush and mud inrush in front of tunnel face, but also identifying geological structure to support disaster warning and prevention. The traditional transient electromagnetic interpretation method can only provide resistivity information, which not meet the requirements of tunnel geological disaster management. Therefore, virtual wavefield imaging technology is introduced into the tunnel detection to achieve comprehensive interpretation of the electrical information and structures of disaster anomalies. Firstly, transient electromagnetic data is transformed into virtual wave field. Then, the resistivity imaging method was used to calculate the resistivity …

Powder Discharge Characteristics Of Pneumatic Double Pipe Directional Drilling In Broken Soft Coal Seams And Its Application, Nie Chao, Wang Yi, Yao Yafeng, Hong Jianjun

Coal Geology & Exploration

To study the influence of casing, casing bit size and casing rotational speed on pulverized coal discharge in double pipe directional drilling technology, three kinds of casing and casing bits in different sizes are designed respectively against the background of pneumatic double pipe directional drilling in the broken soft coal seam, the changes of the discharge rate and outlet velocity of pulverized coal under different combinations are analyzed, and the influence law of different casing rotational speeds on the suspension rate and conveying trajectory of pulverized coal are obtained. The numerical simulation results show that the ø120/96 mm casing with …

Failure Analysis Of Deep Coal Seam Floor Considering Strain Softening Of Surrounding Rock And Formation Contact In Goaf, Yin Shangxian, Meng Haopeng, Qian Shuangbin

Coal Geology & Exploration

In order to study the failure mode of the floor in deep coal seam mining, we proposed a FLAC^3D finite difference numerical method considering the strain softening of surrounding rock and the contact of goafs .Through the qualitative analysis of Rankine’s earth pressure theory, the failure of the deep coal seam floor is studied based on the measured water conducting fracture zone of the floor in working face 2023 of Linxi Mine. The results show that the mechanical state of surrounding rock after plastic failure can be described more accurately by using the strain-softening constitutive relationship instead of the …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Specific Properties And Combustion Characteristics Of Natural Coke From Adjacent Areas Of Jiangsu, Shandong, Henan And Anhui Provinces, Qin Yunhu, Wang Shuangmei, Zhu Shifei, Wu Guoqiang, Quan Jutao, Mao Lixin

Coal Geology & Exploration

It is particularly important to improve resource utilization efficiency against the background of carbon peak and carbon neutrality, but the natural coke has not been paid enough attention for a long time. The natural coke is abundant in China and is often found in the mining of coal mines in neighboring areas of Shandong, Henan and Anhui provinces. Due to the intrusion of magmatic rock, the original coal seam is baked and transformed into natural coke. In this study, samples of natural coke from various areas were collected to study its macroscopic and microscopic characteristics. The industrial analysis, geochemical parameters, …

Accumulation Mode Of Middle-Low Rank Coalbed Methane In Houxia Basin，Xinjiang, Tu Zhimin, Che Yanqian, Li Peng, Lin Wenji

Coal Geology & Exploration

There are successful cases of large-scale CBM development of low-rank coal abroad. Though China is rich in low-rank CBM resources, their exploration and development progress is slow. Considering the low exploration degree and for the purpose of further understanding the accumulation conditions of medium-low rank CBM and guiding exploration practice in Houxia Basin, seismic and geological analysis, as well as coal petrography analysis and drainage production data of drilled wells are carried out in the study area. The results show that the coal seams are characterized by complex structure, large thickness (4.1-24.3 m), stable development, large difference in gas content …

3d Forward Modeling Of Dc Resistivity Method Based On Finite Element With Mixed Grid, Wang Xinyu, Wang Cheng, Mao Yurong, Yan Liangjun, Zhou Lei, Gao Wenlong

Coal Geology & Exploration

The DC resistivity method is widely used in the mineral resources exploration and geological survey industries because of its high efficiency and low cost, such as non-ferrous metals and coal fields. However, in the process of borehole–to–surface and surface–to–borehole resistivity method exploration, the influence of borehole factors (borehole fluid resistivity and borehole diameter) on the apparent resistivity response in different exploration modes is unclear, and whether it will affect the interpretation of apparent resistivity data is an issue worth exploring. Therefore, we proposed a mixed grid finite element method to realize the 3D forward modeling of DC resistivity. Then we …

A Review：Geological Feasibility And Technological Applicability Of Underground Coal Gasification, Jiang Xiuming, Wu Caifang

Coal Geology & Exploration

Underground coal gasification (UCG) is a potential new method of coal utilization, which is of great significance for alleviating China’s energy crisis, ensuring national energy security, and achieving carbon peaking and carbon neutrality goals. It has always been valued by countries all over the world. On the suitability of UCG resource conditions, the feasibility of process and technology, and the controllability of environmental impact, this paper summarizes the development status of UCG technology, and clarifies the coal resource reserves suitable for UCG technology, different standards of geological area selection and location selection technology, the development history and applicable conditions of …

Optimization Calculation Of The Width Of Waterproof Coal Pillars In Fault Zones Based On Spatial Relationship Between Coal Strata And Fault, Wu Bin, Xie Daolei, Han Jing, Chen Qiang, Zhang Huide

Coal Geology & Exploration

The appropriate setting width of the waterproof coal pillars is an important measure to prevent water inrush hazard during near fault mining. The working face 123_up01(south) of Jining No.3 Coal Mine in Shandong Province is adjacent to F8 fault in the west. The fall of F8 fault is large, which may be conducted with the Ordovician limestone aquifer at the bottom. To ensure the safe mining in the working face, it is necessary to calculate the size of waterproof coal pillars of fault F8. In view of the actual occurrence of coal strata, the spatial relationship between fault …

Spatial Distribution Of Harmful Trace Elements In Chinese Coals, Cao Qingyi, Ren Wenying, Liang Chaoming, Zhang Yufei, Yang Liu

Coal Geology & Exploration

The potential impact of harmful trace elements in coal on the ecological environment and human health is one of the hot topics in the fields of geochemistry and energy environment. Geochemical mapping plays an important role in the deep understanding of geochemical processes and their changing laws. However, previous studies have not provided the national geochemical maps of harmful trace elements in Chinese coals. In this study, the content data of 1 167 Be, 1 315 Co, 1 406 Cu, 1 191 Mo, 1 247 Th, and 1 390 Zn in Chinese coal samples are analyzed, and their average contents …

Eefficient Fracturing Technology And Fine Drainage System Of Ultra-Deep Coalbed Methane In Southeast Chongqing：A Case Study Of Ny1 Well, Fang Dazhi, Cheng Zehu, Li Jiaxin

Coal Geology & Exploration

According to the results of China’s new round of coalbed methane (CBM) resource evaluation, the CBM development mainly focuses on medium and shallow coal seams, and the geological conditions of deep-ultra deep coal reservoirs are more complicated. Thus, the reservoir fracturing technology and drainage management technology are two major factors in the development of CBM wells for deep coal reservoirs. In the area of southeast Chongqing, the coal seam of Longtan Formation is as deep as nearly 2 000 m, and there is no experience in ultra-deep CBM well development in this area. The NYI well is taken as an …

Evaluation Method And Application Of Fracturing Effect Based On Dynamic Permeability Change Of Coal Reservoir Hydraulic Fracturing, Shan Tuo, Sun Changyan, Wang Qian, Xie Xiangjun, Fan Yigang

Coal Geology & Exploration

The fracturing construction curve is considered to be an important basis for reflecting the fracturing effect, while the dynamic change of reservoir permeability in the fracturing stage can more intuitively reflect the effect of fracture formation. In this paper, a quantitative evaluation method for reservoir dynamic permeability in fracturing stage was established based on the principle of well testing. Then, the method was applied to evaluate the fracturing effect of two coalbed methane (CBM) wells in a block in southern Junggar Basin, and the dynamic permeability curve of reservoir during fracturing stage is obtained. Meanwhile, the G-function method was …

Ground Development Technology And Engineering Application Of Cbm In Coal Mine Goafs： A Case Study Of Jincheng Mining Area In Qinshui Basin, Zhou Xianjun, Li Guofu, Li Chao, Wang Zheng, Li Jiangbiao

Coal Geology & Exploration

There are still rich CBM resources in goafs after coal mining, and the resource evaluation, development and utilization have dual significance of environmental protection and resources. In recent years, ground drilling has been actively explored in Jincheng, Xishan and Yangquan mining areas in Shanxi Province to extract CBM in the goafs. However, in the process of ground development of CBM, due to water accumulation in the goafs, confined water gushing from overlying strata and other reasons, there is no gas production or low gas extraction from ground drilling. Taking Yuecheng Coal Mine in Jincheng, Shanxi as an example, this paper …

Efficient Treatment Technology Of Incrementally Open Water Gushing Channel Under Dynamic Water Conditions, Pu Zhiguo, Ding Xiang, Li Zhe, Ji Zhuochen, Yan Xin, He Xiaolang, Ma Jianguo

Coal Geology & Exploration

In Yushen mining area of Shaanxi Province, a blasting expansion fissure on the eastern side of the Xiwan Open-pit Coal Mine communicates the water-bearing body of burnt rock outside the pit, and an incrementally open water gushing channel with a length greater than 65 m is formed. The water volume gushing from burnt rock stabilizes at about 400 m³/h and the flow velocity is as high as 0.36 m/s, resulting in a series of problems in ecology, environmental protection, economy and safety. To block the water gushing channel and solve the problem as soon as possible, a quick …

Identification Of Burning Temperature Of Burnt Rocks In Northern Shaanxi Based On Thermoacoustic Emission Technology, Sun Qiang, Wang Shaofei, Ge Zhenlong, Wei Shaoni, Ding Xiaoying

Coal Geology & Exploration

The identification of the burning temperature of burnt rocks has important guiding significance for the formation and evolution of burnt rocks. Based on the thermal Kaiser effect, the threshold temperature of burnt rock in Zhangjiamao, Shenmu, Northern Shaanxi Province is predicted through the acoustic emission (AE) acumulated energy and the changes of parameters RA (rise time/amplitude) and AF (average frequency) during heat treatment. The results show that the thermoacoustic emission characteristics of burnt rocks can effectively identify the burning temperature of burnt rocks, and it is basically consistent with the petrographic analysis of the temperature experienced by the burnt rocks. …

Simplified Internal Variable Gradient Model For Zonal Disintegration Of Rocks In Circular Underground Tunnels, He Ziguang, Zhao Fasuo, Chen Haoxiang, Wu Bo, Zhou Jingjing

Coal Geology & Exploration

As one of the typical nonlinear phenomena of deep level surrounding rock masses, zonal disintegration has captured many attentions of geotechnical engineers in the past years. On the basis of the internal variable theory, the closed-form analytical solutions to stress, strain and displacement fields near circular tunnels are obtained. The gradient-dependent solutions are compared with the results of the classical elasticity theory, and the effects of microstructures on the stresses and deformation fields are investigated as well. It is noted that the stress and deformation fields derived from the gradient model show remarkable quasi-periodicity and fluctuation, which is consistent with …

Searches For Gravitational Waves From Known Pulsars At Two Harmonics In The Second And Third Ligo-Virgo Observing Runs, R. Abbott, H. Abe, F. Acernese, Teviet Creighton, M. G. Benjamin, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

We present a targeted search for continuous gravitational waves (GWs) from 236 pulsars using data from the third observing run of LIGO and Virgo (O3) combined with data from the second observing run (O2). Searches were for emission from the l = m = 2 mass quadrupole mode with a frequency at only twice the pulsar rotation frequency (single harmonic) and the l = 2, m = 1, 2 modes with a frequency of both once and twice the rotation frequency (dual harmonic). No evidence of GWs was found, so we present 95% credible upper limits on the strain amplitudes …

Transformative Ecoliteracy Development In Postsecondary Education: Cultivating Intentional Relationships Through Garden-Based Learning, Shevawn Armstrong

Dissertations and Theses

Education can play a critical role in empowering learners to address the global, complex, and interconnected sustainability problems humanity currently faces. Ecoliteracy, as an educational aim, may support the cultivation of values, attitudes, and skills required for the development of sustainability solutions and our collective ability to design regenerative ways of living. However, empirical research that explores and supports the development of ecoliteracy in adults is limited. This grounded theory action research study aimed to contribute to this body of knowledge. This study explored how adult ecoliteracy and practical gardening skills may be cultivated through an intentionally designed, holistic, garden-based …

Raytheon Technologies Corporation: An Analysis Of Leadership, Ethics, And Social Responsibility, Jarett Monterio

Journal of Global Awareness

The purpose of this analysis is to examine Raytheon Technologies Corporation (RTC) in the context of its leadership structure, ethical issues and practices, stakeholder relationships, and position within the social responsibility realm. Undertaking an analysis of an aerospace and defense company such as RTC is perhaps timelier than ever. We live in a world of increasing global competition and confrontation. Simultaneously, we are experiencing unprecedented technological development. Combined, this has created a situation where the boundaries of conventional warfare have been redrawn. The questions of what appropriate offensive and defensive tactics are and how governments, and increasingly private sector companies, …

Contextualizing The Impact Of Faculty-Led Short-Term Study Abroad On Students’ Global Competence: Characteristics Of Effective Programs, Colleen Fisher, Laurel Iverson Hitchcock, Ashley Neyer, Stacy C. Moak, Sarah Moore, Scott Marsalis

Journal of Global Awareness

Short-term faculty-led study abroad programs are high-impact pedagogical practices designed to enhance students' global competency. However, there is a gap in our understanding regarding the specific educational components of short-term faculty-led study abroad programs that promote global competency. This systematic review examined nearly two decades of research on such programs (n=86) to assess the educational components associated with increases in students' global competencies using Steinberg's (2017) educational components as a framework. Results indicated that the educational components included in global competency-building education abroad courses varied substantially across programs and global regions. The components most strongly supporting enhanced global competency were …

Notes From The Editor, Jay Nathan

Journal of Global Awareness

No abstract provided.

Modeling Empirical Stock Market Behavior Using A Hybrid Agent-Based Dynamical Systems Model, Daniel A. Cline, Grant T. Aguinaldo, Christian Lemp

Northeast Journal of Complex Systems (NEJCS)

We describe the development and calibration of a hybrid agent-based dynamical systems model of the stock market that is capable of reproducing empirical market behavior. The model consists of two types of trader agents, fundamentalists and noise traders, as well as an opinion dynamic for the latter (optimistic vs. pessimistic). The trader agents switch types stochastically over time based on simple behavioral rules. A system of ordinary differential equations is used to model the stock price as a function of the states of the trader agents. We show that the model can reproduce key stylized facts (e.g., volatility clustering and …

Cysteine Metallochemistry And Metal Binding: Quantification Of The Thermodynamic Foundations Of Cellular Homeostasis, Matthew R. Mehlenbacher

Dartmouth College Ph.D Dissertations

Metals are required for life. Many metalloproteins contain cysteine in their metal-binding site (MBS) and cysteines are unique in that they are reactive, and strongly bind certain metals, which aid in metal selectivity and specificity. Using isothermal titration calorimetry (ITC), the thermodynamic foundation for metal binding, cellular protection, and transcriptional regulation, which all utilize cysteines in their MBS, are quantified.

In bacteria there are metalloprotein pathways that actively uptake mercury, which are regulated by the metalloregulatory protein MerR. MerR de-represses the transcription of these mer proteins in a metal-dependent manner. Using ITC, the thermodynamic foundation of the negative allosteric coupling …