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Geochemistry Of The Lake Sediments On Robert Island, South Shetland Islands, Antarctica: Implications For Weathering Processes In Polar Areas, Merve Özyurt, Yilmaz Demi̇r, Korhan Özkan, Rai̇f Kandemi̇r

Turkish Journal of Earth Sciences

The preliminary results of geochemical analyses of the surface sediments from 4 lakes on Robert Island, South Shetland, Antarctica, are presented herein. The samples were collected during the Turkish Antarctic Expedition (TAE-II) in 2018. Sediment samples were obtained from the littoral zone (approximately 20 cm) of 4 different lakes exposed on the glacier-free land area on Robert Island. The lake sediments predominantly consist of fine-grained sand, clay, and silt particles. These particles include Fe-shale and graywacke geochemical characteristics. Their plagioclase index of alteration, chemical index of weathering, chemical index of alteration, and other weathering index values, suggest that the studied …

The Petrogenesis Of Analcime In The Coppermine Formation On Robert Island, South Shetland Islands, Antarctica, Rai̇f Kandemi̇r, Yilmaz Demi̇r, Cüneyt Şen, Ufuk Celal Yağcioğlu

Turkish Journal of Earth Sciences

The South Shetland Islands were shaped by island arc volcanism that occurred from the Jurassic to the Quaternary. Robert Island is located in the center of this archipelago, and Coppermine Peninsula, located on the southwestern part of Robert Island, exposures significant rock outcrops of basalts and andesitic-basaltic agglomerates of the Coppermine Formation. The investigated samples were collected during Turkish Antarctic Expedition 2 (TAE-II), in March-April 2018, from the area northeast of Triplet Hill. The volcanic rocks exhibited an amygdaloidal microlithic-porphyritic texture. Subhedral to anhedral phenocrysts of labradorite, augite, and olivine were observed with holocrystalline groundmass composed of plagioclase, pyroxene, and …

Accuracy Investigation Of Gnss-Reflectometry For Sea Level Monitoring On Horseshoe Island, Antarctica: Preliminary Results Of The Turkish Permanent Gnss Station (Tur1), Mahmut Oğuz Selbesoğlu, Hasan Hakan Yavaşoğlu, Mustafa Fahri̇ Karabulut, Özgün Oktar, Vahap Engi̇n Gülal, Hi̇mmet Karaman, Mustafa Ersel Kamaşak

Turkish Journal of Earth Sciences

Antarctica is called a natural laboratory and is highly important for investigating climate change and its evolution over time. Sustainability is a critical concern due to the challenges posed by glacier melting and rising sea levels due to global warming. According to the Intergovernmental Panel on Climate Change, since the industrial age, the global mean sea level has risen by about 20 cm as a result of the increase in the average world temperature by 1 °C. Therefore, long-term observations by satellite-based techniques in and around Antarctica are of great importance for monitoring the impacts of climate change. In the …

Exploring Crowdsourcing Accountability For Mapping Antarctica: A Case Study Using 5 Years Of Social Media Data, Ayşe Gi̇z Gülnerman Gengeç

Turkish Journal of Earth Sciences

The continent of Antarctica is one of the most challenging regions in terms of generating and updating geodata. Extensive research has been conducted on geodata acquisition, primarily focusing on earth observation satellites and local surveys in polar regions. Earth observation satellites offer limited spatial, temporal, and semantic data, while local surveys are constrained by polar regions' size and challenging conditions. This article delves into the crowdsourced data, aiming to significantly enhance geodata contribution in polar regions beyond current methods. To our knowledge, this study is the first of its kind to address social media data, a form of crowdsourcing, specifically …

Effect Of Different Pre-Growth Temperatures On The Survival Kinetics Of Salmonella Enterica And Listeria Monocytogenes In Fresh-Cut Salad During Refrigerated Storage, Avninder Kaur, Veerachandra K. Yemmireddy

School of Earth, Environmental, & Marine Sciences Faculty Publications

The effect of the pre-growth temperature of bacterial cultures on their subsequent survival kinetics in fresh-cut produce during refrigerated storage was investigated in this study. Three-strain cocktails of Listeria monocytogenes and Salmonella enterica, cultured at different growth temperatures (4, 21, and 37 °C) were inoculated on fresh-cut mixed salad and on individual produce in the mixed salad. The inoculated samples were stored at 4 °C and 80 ± 2% relative humidity (RH) for up to 72 h and the growth, survival, or death kinetics were determined at regular intervals. The results indicate that depending upon the type of pathogen …

Numerical Simulations Of Enhancing Permeability And Gas Extraction Of Thick Coal Seams Through Static Fracturing, Wang Xinfeng, Liu Wengang, Wang Long, Wei Youyu, Zhang Qiao

Coal Geology & Exploration

This study seeks to improve the underground operation efficiency and optimize the borehole arrangement parameters for static fracturing of coal seams. To this end, this study conducted tests in the belt roadway of the No. 12316 fully mechanized mining face in the Wangjialing Coal Mine, China Coal Huajin Group. By combining the equations for coal seams’ deformation and failure, gas diffusion and seepage, and coal seams’ permeability evolution, this study constructed a model of the damage and permeability evolution of coal seams. Based on the numerical simulations of the process of static fracturing and permeability enhancement of coals, as well …

Genetic Type And Gas-Generating Potential Of Coalbed Methane In The Bayanhua Sag, Erlian Basin, Meng Qin, Li Ling, Li Jie, Tian Wenguang, Lin Haitao, Li Heng

Coal Geology & Exploration

The Bayanhua Sag in the Erlian Basin is a critical experimental area for coalbed methane (CBM) development from low-rank coals in Inner Mongolia. However, the relatively low exploration level and the limited understanding of the CBM origin in the sag restrict the CBM exploration and development to some extent. This study tested the gas components, stable isotopes and hydrochemistry of the gas and water samples from CBM wells in the Bayanhua Sag. It also conducted radioisotopic dating for these samples. By combining the classic charts for the identification of natural gas origin, this study clarified the gas origins, further analyzed …

A Simulation Study On The Suspension And Transport Patterns Of Proppants In Long Distance Pipelines For Integrated Well And Ground Fracturing, Li Haozhe, Jiang Zaibing, Sun Siqing, Zhu Chuanyong, Fan Yao, Guo Yong, Cheng Bin

Coal Geology & Exploration

Integrated well and ground fracturing is a developmental trend for the staged fracturing of underground long boreholes in coal mines. Using the integrated fracturing technology, the fracturing fluids, after being pressurized using a ground fracturing pump, enter long boreholes in underground coal mines through ground penetrating wells and long distance pipelines, aiming to achieve fracturing with high injection rates of fracturing fluids. The suspension and transport patterns of proppants in long distance pipelines hold critical significance for optimizing parameters related to proppant adding and avoiding sand plugging in pipelines. This study evaluated the rheological properties and proppant carrying capacity of …

Dynamic Prediction Method Of Tunnel Water Inflow Based On Detailed Depiction Of Complex Geological Bodies, Du Yajun, Li Qingbo, Wan Weifeng, Yang Fengwei, Li Yazhe, Qian Hui

Coal Geology & Exploration

It is a challenge to accurately characterize the irregular geological bodies and underground structures such as inclined faults and inclined tunnels during the numerical simulation of tunnel water inflow prediction, and the prediction generally assumes that the tunnel excavation is completed instantaneously without considering the construction progress. A dynamic prediction method for tunnel water inflow based on precise characterization of complex geometric bodies was proposed by addressing the non-self-intersection and watertight issues required in the coupling process of three-dimensional (3D) geological models and 3D groundwater numerical models. Specifically, a sealed boundary interface of inclined tunnels, shafts, inclined faults and irregular …

A Method For Evaluating Aquiclude Stability In The Water Conservation-Based Mining Of Shallowly Buried Coal Seams In Ecologically Vulnerable Areas In Northwest China, Li Heng, He Tao, Guo Bin

Coal Geology & Exploration

Water conservation and coal mining are both critical to Northwest China. Water conservation-based coal mining is an important technology for the coordinated development of coal and water resources in this region. In this technology, the evaluation of aquiclude stability is critical. Due to the shallow depth of coal seams, intense topographic cutting, and complex changes in near-surface aquifers in the ecologically vulnerable areas in Northwest China, there exist large errors between traditional methods for aquiclude evaluation and the actual hydrological observations in these areas. To address this challenge, this study develops using the 3D geological modelling combined with numerical simulation …

Micp Restoration Law Of Coal Mining Induced Ground Fissures And Its Influencing Factors, Li Tao, Gao Ying, Yan Jingwang, Zhang Jiarui, Kou Guigui, Ma Tengfei, Mei Aoran

Coal Geology & Exploration

The coal mining induced ground fissures in the loess covered area of northwest China cause shallow groundwater resource leakage and soil instability. Therefore, the experimental study was conducted on Microbial Induced Carbonate Precipitation (MICP) restoration of coal mining induced ground fissures in the loess covered area. Specifically, the characteristics of mining induced ground fissures were observed and their development characteristics were revealed based on Ningtiaota Coal Mine in northern Shaanxi. The coal mining induced ground fissures in loess were classified with consideration to the observed mine pressure. Based on the classification and characteristics of coal mining induced ground fractures, the …

Experimental Study On Proportioning Of Ultra-High Strength Similar Materials For Large Similarity Ratio Model Tests, Zhan Xinyu, Gao Lin, Zhao Fanghao, Wang Yongyin, Liu Ping, Han Sen

Coal Geology & Exploration

Similar simulation of physical material is a common research method in the field of geotechnical engineering. Selecting appropriate similar materials and determining their proportions is the key to successfully simulating the prototype project. Existing similar materials are mostly developed for similar simulation with small geometric similarity ratio (1∶250-1∶25). These materials generally have low strength (0.2-7.6 MPa), making it difficult to meet the requirements of large similarity ratio model. Therefore, in order to prepare an ultra-high strength similar material with a strength of more than 10 MPa suitable for large similarity ratio model, river sand, barite, gypsum, and cement with different …

Mechanical Properties And Strength Deterioration Mechanism Of Soil In Inner Dump Of Open-Pit Coal Mine Under The Action Of Freeze-Thaw Cycles, Zhang Heyong, Wang Xuedong, Zhu Yongdong, Wang Haipeng, Qi Lihui

Coal Geology & Exploration

In order to investigate the influence mechanism of freeze-thaw cycles on the structure and mechanical properties of soil, the typical clay soil in the inner dump of Yuanbaoshan open-pit coal mine in Inner Mongolia was taken as the research object, and the simulation analysis of the internal temperature, moisture and stress fields of the soil was carried out through laboratory freeze-thaw cycle tests and MatDEM numerical simulation. The results show that: freeze-shrinkage occurs to the soil in the dump after the freeze-thaw cycles, and the stress-strain curve shows the trend of strain softening at low confining pressure for shear failure, …

Detection Of Small Objects In Open-Pit Coal Mine Stopes Using Uav Remote Sensing Images, Liu Mingrui, Che Ben, Dong Hongbo, Zhu Ruoli

Coal Geology & Exploration

Open-pit coal mine stopes witness frequent vehicle accidents due to their complex terrains. Therefore, accurately positioning vehicles in the stopes is critical to safe coal mining. To overcome the inaccurate positioning of small targets in the mining areas using Unmanned aerial vehicle (UAV) remote sensing images, this study proposed an improved YOLOv7 model for object detection. First, to expedite the reasoning of the YOLOv7 network, the ELAN module in the original YOLOv7 model was improved by introducing partial convolution. Based on this, the eSE channel attention mechanism was combined to form the PConv-eSE convolution attention module. The purpose is to …

Intelligent Optimization Method For Tunnel Rotary Drilling Based On Drill String Status Estimation, Yao Ningping, Wei Hongchao, Zhang Jinbao, Lu Chengda, Li Hao, Yao Yafeng, Ke Yougang, Zhang Youzhen

Coal Geology & Exploration

To address the issue in existing research where it is difficult to obtain bottom-hole drilling parameters while drilling, and to overcome the problem of low accuracy and insufficient improvement when optimizing rotary drilling operational parameters using only borehole data, an intelligent optimization method for near-horizontal tunnel rotary drilling based on drill string status is proposed. This involves constructing an in-hole state observer to estimate bottom-hole drilling parameter information. Firstly, the characteristics of rotary drilling in underground coal mine tunnels are analyzed, considering the constraints of actual drilling, and an optimization target evaluation method for mechanical drilling speed and drill bit …

On-Line Compensation For Geomagnetic Error While Drilling Based On Magnetic Inertial Slime Mould Algorithm, Yang Jinxian, Cai Jipeng

Coal Geology & Exploration

In response to the serious distortion of the azimuth angle of the drilling tool caused by the large measurement error of strap-down micro-electro-mechanical-system (MEMS) magnetometer on the drilling tool in the measurement-while-drilling (MWD) environment, an online compensation method for the geomagnetic error of the drilling tool based on the magnetic-inertial slime mould algorithm (MISMA) was proposed. Firstly, the geomagnetic measurement error compensation model of the drilling tool was established through the analysis on the output error of the magnetometer, and the magnetometer error parameters were sorted into solution vectors. Then, the objective function of the ideal magnetic output data, the …

Obstacle-Avoidance Trajectory Planning Of Mine Drilling Robot During Drill Pipe Loading And Unloading, Yao Yafeng, Yao Ningping, Peng Tao, Liang Chunmiao, Peng Guangyu

Coal Geology & Exploration

The position of drill pipe loading and unloading by mine drilling robot will change with the attitude adjustment of the host machine, and obstacles are present in the loading and unloading path of drill pipe. Therefore, there is a problem of obstacle-avoidance trajectory planning with variable targets in the loading and unloading of drill pipe. For this reason, the DH parameter table was created according to the performance parameters of the explosion-proof 6-DOF manipulator, and the function relation of the change in loading and unloading position of drill pipe before and after the attitude adjustment of the 3-DOF host machine …

Stress Field Of High-Temperature Wellbore Under Spray Cooling For Underground Coal Gasification, Tang Yang, Xie Na, Xiong Haoyu, He Yin, Huang Shunxiao

Coal Geology & Exploration

As a supplement to traditional physical coal mining technology, underground coal gasification (UCG) is a new generation of chemical coal mining technology. During the gasification, the wellbore of UCG production wells is subjected to the combined action of high temperature and internal pressure loads. Targeting the structural characteristics of the wellbore of UCG production wells, this study, based on the heat transfer theory, established a calculation model for the transient temperature of the wellbore under the cooling through annular spray water injection. By combining the wellbore pressure model, as well as the elasticity theory and the wall cylinder theory, this …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Numerical Simulations Of The Effects Of Bedding Planes On Hydraulic Fracture Propagation Law In Oil Shale, Li Yanwei, Zhu Chaofan, Zeng Yijian, Shui Haoche, Fan Cunhan, Guo Wei

Coal Geology & Exploration

Hydraulic fracturing serves as a major technical means for the exploitation of oil shale reservoirs presently, and the hydraulic fracture morphology in oil shales is primarily affected by differences in the characteristics of bedding planes. However, current studies mostly focus on the influence of the developmental degree of bedding planes on fracture propagation, overlooking the effects of the bedding plane thickness itself on hydraulic fracture propagation. This study delves into the oil shale in the Xunyi area, Ordos Basin. Based on the theory of linear elastic fracture mechanics, this study developed a stress-damage-seepage model of hydraulic fracture propagation. Using the …

Vertical Variability Of Hydrogeological Characteristics Of Luohe Formation By Double Packer System Pumping Test, Li Chaofeng, Liu Yexian, Zhang Jinkui, Ren Dengjun, Hou Tao, Liu Zengping, Xu Xinqi, Ma Ji, Wang Qingzhen, Duan Xiliang, Xing Jiebo, Li Yang

Coal Geology & Exploration

To investigate the hydrogeological conditions of the thick Luohe Formation in Ordos Basin and quantitatively evaluate vertical variation characteristics of its aquifer’ s water-rich, proposes the method of using the coefficient of transmissibility to evaluate the water-rich of the aquifer, and give the seven level classification standard of water-rich by the method of determining coefficient of transmissibility. The double-packer system was used to carry out the pumping tests of 10 vertical sections of fixed thickness of the Luohe Formation in the DJ1 and DJ2 boreholes in the Gaojiabao mine field, shaanxi, and the hydrogeological parameters were calculated. Using the comprehensive …

Characteristics And Genetic Mechanism Of Low Sulfate In High-Salt Groundwater Of Permian Sandstone In Fudong Mining Area, Huainan, Jiang Chunlu, Huang Wendi, Fu Xianjie, Zheng Liugen, Cheng Shigui, Shan Chonglei

Coal Geology & Exploration

Hydrogeochemistry research of groundwater in coal mining areas is of great significance to the prevention and control of mine water and the comprehensive utilization of water resources. In terms of the low surfate of Permian sandstone water in Fudong mining area, Anhui Huainan Coalfield, the hydrochemical characteristics, water-rock interaction and low sulfate genesis of sandstone water were studied through water sampling and test by multivariate statistical method, in combination with the hydrogeological condition analysis and the sulfur and oxygen isotope technology. The results show that the Permian sandstone water in the study area is weakly alkaline, with an average TDS …

Evaluation Of Water Quality And Identification Of Pollution Factors In Mining Subsidence Area With High Phreatic Water Level, Hu Lin, Chen Yongchun, Xu Yanfei, Li Bing, Wang Jin, An Shikai, Chen Chen, Sun Hongjie, Miao Wei

Coal Geology & Exploration

Huainan mining area is characterized by a high phreatic water level, as well as a wide range and large area of coal mining subsidence areas, with the water quality monitoring data missing and prominent water environment. Therefore, the evaluation of water quality monitoring and identification of pollution factors in large subsidence area is of great significance to regional water environmental governance. Specifically, the water quality of the subsidence area was evaluated with the Nemerow pollution index method by testing the water samples collected from 175 sampling points in the study area. Meanwhile, the eutrophication state of water bodies was evaluated …

Rate-Of-Penetration (Rop) Prediction Model Based On Formation Characteristics Of Extremely Thick Plastic Mudstone In South China Sea, Zeng Xiaolong, Li Qian, Wei Hongchao, Chen Jiahao, Zhu Haiyan

Coal Geology & Exploration

In terms of petroleum and gas resources, South China Sea is the important energy replacement area in China. However, most of the reservoirs are buried deep, and the strong plasticity of the formation under high confining pressure and the complex geological environment seriously affect the drilling efficiency. It is also very difficult to accurately predict the ROP. Hence, a set of intelligent ROP prediction model was established for the extremely thick mudstone formation with unique viscoelastic and strong plastic characteristics in South China Sea. The model took the actual data of 10 wells in an area of South China Sea …

Emerging Sensing, Imaging, And Computational Technologies To Scale Nano-To Macroscale Rhizosphere Dynamics – Review And Research Perspectives, Amir H. Ahkami, Odeta Qafoku, Tiina Roose, Quanbing Mou, Yi Lu, Zoe G. Cardon, Yuxin Wu, Chunwei Chou, Joshua B. Fisher, Tamas Varga, Pubudu Handakumbura, Jayde A. Aufrecht, Arunima Bhattacharjee, James J. Moran

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The soil region influenced by plant roots, i.e., the rhizosphere, is one of the most complex biological habitats on Earth and significantly impacts global carbon flow and transformation. Understanding the structure and function of the rhizosphere is critically important for maintaining sustainable plant ecosystem services, designing engineered ecosystems for long-term soil carbon storage, and mitigating the effects of climate change. However, studying the biological and ecological processes and interactions in the rhizosphere requires advanced integrated technologies capable of decoding such a complex system at different scales. Here, we review how emerging approaches in sensing, imaging, and computational modeling …

Understanding Marsh Elevation And Accretion Processes And Vulnerability To Rising Sea Levels Across Climatic And Geomorphic Gradients In California, Usa, Karen M. Thorne, Mckenna L. Bristow, Lyndsay L. Rankin, Katya E. Kovalenko, Justine A. Neville, Chase M. Freeman, Glenn R. Guntenspergen

State & Federal Reports and Publications

Tidal marshes build elevations by below- and aboveground organic and mineral soil processes. Marsh elevation and accre- tion data can be used to determine if marshes are keeping pace with sea-level rise. Using a network of 54 deep rod surface elevation tables with paired feldspar marker horizon plots, we tracked elevation and accretion trends across 16 marshes in California, USA. All sites had overall positive gains across years that included severe drought conditions and extreme rain events. Marsh elevation relative to tidal datum (z*) was the key predictor for elevation and accretion rates, with higher change rates at lower z* …

Tidal Bed Stress Asymmetry And Sediment Transport In Estuaries, Austin Scott Hudson

Dissertations and Theses

Rivers and estuaries provide numerous ecological, economic, and cultural resources. The value of these resources is greatly influenced by sediment transport processes, which can be affected by human activities and climate variability. A key driver of sediment transport in tidal rivers and estuaries is tidal asymmetry of velocity and bed stress, which can manifest from both non-linear tidal interactions and linear interactions among astronomical tidal constituents.

In this study, an analytical framework is developed to examine and describe the dynamics of bed stress asymmetry in semidiurnal, diurnal, and mixed-tide estuaries (Chapter 1). While tidal velocity asymmetry has been previously analyzed, …

The Seasonal Origins And Ages Of Water Provisioning Streams And Trees In A Tropical Montane Cloud Forest, Emily Burt, Gregory R. Goldsmith, Roxanne M. Cruz-De Hoyos, Adan Julian Ccahuana Quispe, A. Joshua West

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Determining the sources of water provisioning streams, soils, and vegetation can provide important insights into the water that sustains critical ecosystem functions now and how those functions may be expected to respond given projected changes in the global hydrologic cycle. We developed multi-year time series of water isotope ratios (δ¹⁸O and δ²H) based on twice-monthly collections of precipitation, lysimeter, and tree branch xylem waters from a seasonally dry tropical montane cloud forest in the southeastern Andes mountains of Peru. We then used this information to determine indices of the seasonal origins, the young water fractions …

Ortho-Fluoro Or Ortho Effect? Oxidative Addition Of Zerovalent Nickel Into The C–Cn Bond Of Substituted Benzonitriles, Tülay Ateşin, William D. Jones, Abdurrahman C. Atesin

School of Earth, Environmental, & Marine Sciences Faculty Publications

A recent study of the oxidative addition of zerovalent Ni to the C–CN bond of F-substituted benzonitriles showed significantly increased stabilization of the C–CN oxidative addition products with o-F groups (−6.6 kcal/mol per o-F) compared to m-F groups (−1.8 kcal/mol per m-F). To answer the question of whether this is an o-F effect or an ortho effect, in this study the effect of CF3 and CH3 groups on the oxidative addition of the [Ni(dmpe)] fragment [dmpe = 1,2-bis(dimethylphosphino)ethane] to the C–CN bond of benzonitriles has been studied. A density functional theory study of the reaction …

Brachiaria Spp. (Syn. Urochloa Spp.) Cv. Mulato Ii (Convert Hd364) Mass Production Under Continuous Grazing In The Water/Dry Transition Period, A. L. A. Castro, A. C. Prado, M. C. Silva Júnior, M. S. Soares, M. V. Teixeira

IGC Proceedings (1977-2023)

In the transition period between the rainy and dry seasons there is decreased water, temperature and luminosity, reducing forage production and quality. Because of this variability in forage mass production, it is essential to quantify forage mass for use in planning and decision making about pastures management. The objective was to evaluate Brachiaria spp. (Syn. Urochloa spp.) cv. Mulato II (Convert HD364) growth, biomass production managed under continuous grazing with steers fed with protein supplement feed in-trough and on-ground during the seasonal transition period. The experiment was carried out in the Beef Cattle Sector of Jatai Federal University …