Earth Sciences Commons^™

Influencing Mechanism Of Rock Thermal Resistance On Convective Heat Transfer Of Fracture, Wang Yaning, Lu Chuan, Wang Guiling

Coal Geology & Exploration

The convective heat transfer characteristics between high temperature rocks and fluids in Enhanced Geothermal Systems (EGS) have been an important fundamental element of research on Hot Dry Rock (HDR). The thermal resistance of rock has an important influence on the convective heat transfer characteristics of fracture. In order to study its specific influence, two research methods, i.e., the theoretical analysis and the numerical simulation, were used in combination to study the heat transfer law between two parallel smooth flat plates by discussing the analytical solution and establishing the numerical model. The results show that the local Nusselt number Nu_{x …}

Research On Control System Of Drill Pipe Conveying Device Based On Fuzzy Particle Swarm Optimization, Zhang Ning, Liu Qi, Shao Junjie, Chang Jianghua, Luo Pengping, Zou Zujie

Coal Geology & Exploration

In the tripping operation of large-diameter rescue well construction, the drill pipe conveying device used for large-diameter drilling tool transportation and drill string connection. In view of the problem that it is difficult to quickly and accurately lift the drill pipe to the angle of power head for make-up due to its easy vibration in the process of positioning, the structural characteristics and working principle of the drill pipe conveying device were analyzed at first. The kinematic model for the lifting of drill pipe was deduced with the structural relationship, obtaining the mapping relationship in the motion law of the …

Numerical Simulation Of Co2 Storage In Bedded Salt Rock Storage Cavern In Subei Basin, Zong Shi, Liu Shiqi, Xu Hui, Wang Wenkai, Cao Bo, Huang Fansheng

Coal Geology & Exploration

Underground salt cavern is an effective geological body for CO₂ storage. The leakage of CO₂ along the weak interlayer of salt rock and the interface of salt layer and interlayer is the key to restrict the safe storage of CO₂ in underground salt cavern. A fluid-solid coupling mathematical model of CO₂ storage in bedded salt cavern gas storage was established based on the CO₂ salt cavern storage in Jintan area of Subei basin. On this basis, the leakage and migration law of CO₂ in salt rock and mudstone interlayer, as well as its influence …

Lithium And Lithium Isotope Behavior During High Temperature Solid/Fluid Exchanges: Examples From Iceland And The Izu-Bonin Forearc, Alex Maruszczak

USF Tampa Graduate Theses and Dissertations

The development of a method for lithium isotopic measurement was developed using a quadrupole, single-collector ICP-MS. Measured precision was ±1.00‰ 2σ over a 15-month period based on measurements of international rock standards. A 1-hour leach using cold, HCl was sufficient to remove alteration-related Li in minimally to moderately altered seafloor basalts. Measurements on the Holocene ages lavas from the neovolcanic zones of Iceland suggest no systematic Li isotopic variability among the differing Icelandic sources. Felsic samples from Hekla and Pumice contain elevated Li contents of >18ug/g while the tholeiitic and alkaline basalts are <8ug/g Li. Most of the island lies around MORB values of ~+3 to +5‰ with the exception of Western Volcanic Zone samples that show evidence for seawater inputs. The RN-17 drillcore, which penetrates >3000m through a hydrothermal system in the …

Mechanism Of Coal Fine-Bubble Coupling In The Unsaturated Flow Stage Of Coalbed Methane Drainage, Han Wenlong, Li Yong, Chen Xiangsheng, Zhuo Qiming, Wang Yanbin

Coal Geology & Exploration

To reveal the mechanism of interaction between coal fines and gas in the unsaturated flow stage of coalbed methane (CBM) drainage, it is essential to formulate the drainage system and improve the gas production. The effect of air bubbles with different diameters on coal fines with different particle sizes and densities was systematically experimented through the experiment device for microscopic interaction between the air bubble and the coal fines. Meanwhile, the influence of air bubbles on the migration trajectory and velocity of coal fines and the characteristics of coal fine capturing by air bubbles were also analyzed. The results show …

Optimization Of Cemented Filling Material Ratio Based On Rsm-Bbd Method And Engineering Application, Wang Shushuai, Xu Bin, Li Yang, Yang Zhen

Coal Geology & Exploration

In view of the problems of large stacking of solid waste caused by roof caving method in coal seam mining and imbalance between mining and filling in long-wall cemented backfilling, the No.31 ming area of Chahasu Coal Mine in Inner Monogolia uses continuous mining and filling roadway cemented backfilling mining technology, adopting the “mining at intervals of three” mining method and the “three with high strength filling and one with low strength filling” filling mode. The filling material ratio has an important influence on the filling cost and effect. In order to solve the problems of high cement consumption and …

Mechanical Properties And Mechanism Of Co-Curing Saline Soil With Coal Solid Waste, Dong Chenxi, Wang Nianqin, Li Jiangshan, Chen Xin, Yan Xusheng, Ma Wei

Coal Geology & Exploration

Under the research background of resource utilization of solid wastes in the arid and semiarid regions, a new curing material was developed with the coal wastes (such as the coal gangue (CG) and coal metakaolin (CMK)), the carbide slag (CS) that is a waste material readily available in the arid region, and the ordinary Portland cement (OPC). Besides, its mechanical properties and microscopic change mechanism in curing of saline soil in the arid and semi-arid regions were discussed. Based on the laboratory experiment, the unconfined compressive strength (UCS) characteristics of curing saline soil in different ages were studied by replacing …

Wavefield Separation Of P- And S-Waves Based On Modified Pseudo-Helmholtz Decomposition Operator In Transverse Isotropic Media, Liu Zhaoshun, Du Qizhen, Lyu Wenhao, Zhou Shihao, Fu Liyun

Coal Geology & Exploration

The separation of P- and S-wave fields is a significant step in elastic reverse-time migration (ERTM), which can effectively eliminate the waveform crosstalk and image artifacts, thus improving the precision of imaging. In anisotropic media, nonstationary spatial filters or low-rank approximation methods are commonly used to separate the wavefields. However, the application of multiple Fourier transforms results in the high computation costs of the above wavefield separation methods. Based on the idea of constructing the isotropic decoupling equations of P- and S- waves with the Helmholtz operator, a modified pseudo-Helmholtz decomposition operator was proposed to eliminate the amplitude distortion. Then, …

Forward Modeling Of Radio-Magnetotelluric Method Based On Julia Acceleration And Study On Effect Of Displacement Current, Mei Zhuxu, Yuan Yuan, Zhou Feng, Zhou Cong, Zhang Lincheng

Coal Geology & Exploration

Radio-magnetotelluric method (RMT) is one of the important tools for shallow surface electromagnetic exploration. Since the exploration frequency band is 10‒300 kHz, the propagation of electromagnetic fields is greatly affected by the dielectric permittivity of the earth. The electromagnetic response calculated with traditional quasi-static conditions severely restricts the accuracy of RMT forward modeling and further affects the resolution of the inversion imaging. In response to this problem, a numerical simulation method of full-current RMT electromagnetic response based on Julia parallel acceleration was proposed. Then, the calculation of each frequency point was sent through the distributed computing in Julia to different …

One Surface Borehole With Multi-Usage Gas Drainage Key Technology For Abandoned Well And Its Application, Fu Junhui

Coal Geology & Exploration

Gas drainage from mining area could be realized through the reconstruction and reuse of abandoned surface gas wells in the coal mine area , which has multiple economic and environmental benefits such as ensuring the safe production of mining, the effective utilization of gas resources, and reducing the pressure of gas escape on the environment. In view of this purpose, the idea of “one surface borehole with multi-usage” gas drainage technology for abandoned wells was proposed based on the characteristics of the surface borehole and the abandoned wells in the mining area. By analyzing the conditions of the mining technology, …

New Understanding Of Coal Seam Distribution Law: Coal Accumulation Model Controlled By Paleoclimate Evolution, Hou Haihai, Chen Hongzhen, Shao Longyi, Pan Zizi

Coal Geology & Exploration

It is very important for coal and coal-measure gas exploration to correctly understand the distribution law of coal seam and its main control factors in different coal accumulation models. Based on the review of the theories and models of paleogeographic coal control, coal accumulation in sequence stratigraphy, allochthonous coal accumulation and multiple coal accumulation theoretical system, a new coal accumulation model under the control of climatic revolution was proposed through the analyses of the Jurassic coal-bearing strata in the southern margin of Junggar Basin. The paleotemperature and paleohumidity during Badaowan Formation(coal accumulation period), Sangonghe Formation, Xishanyao Formation (coal accumulation period) …

A New Model Of Surface And Underground Integrated Three-Dimensional Prevention And Control Of Rock Burst In Binchang Mining Area, Wu Xueming, Ma Xiaohui, Lyu Dazhao, Zheng Kaige, Wang Dongjie

Coal Geology & Exploration

With the continuous increase of coal mining intensity, the mine gradually moves to the deep, bringing about increasingly serious rock burst hazard. The deep rock burst mines often have one or more layers of hard and thick rock strata. These hard roofs are thick and strong integrity. When they suddenly rupture, they can release a large amount of elastic energies, which can easily to cause rock burst accidents and seriously restrict the safety of mine production. Herein, appropriate treatment measures were put forward for the special situation of deep burial depth of coal seam and general presence of many kinds …

Co2-Ecbm Simulation Study Considering Klinkenberg Factor State, Sa Zhanyou, Wu Jingbo, Yang Yongliang, Zhang Xin, Lu Shouqing, Liu Jie, Wang Hao

Coal Geology & Exploration

In order to explore the role of Klinkenberg effect and Klinkenberg factor in different states in the process of CO₂-Enhanced Coal Bed Methane (CO₂-ECBM), the effects of Klinkenberg factor of zero, fixed Klinkenberg factor and dynamic Klinkenberg factor on CO₂-ECBM were simulated and analyzed by COMSOL finite element software. The dynamic changes of CH₄ and CO₂ pressure with this factor were studied, and the CH₄ gas production was compared with the engineering practice. The results show that the effective permeability of CH₄ and CO₂ increases slowly at first, then …

Study On The Time Law Of Water-Rock Interaction In Coal Mine Groundwater Reservoir, Zhang Kai, Liu Shuyu, Cao Zhiguo, Gao Ju, Chen Xiangyu, Yan Jiayu

Coal Geology & Exploration

The retention time of mine water in the coal mine underground reservoir will affect the ion concentration of effluent, but the time law of water-rock interaction during operation of the reservoir is still unclear. In order to reveal the occurrence type and intensity of water-rock interaction in different operation stages of coal mine underground reservoir, two groups of static simulation tests of water-rock interaction were designed based on the test and analysis on-site samples, namely the fine sandstone-mine water (S-K) and mudstone-mine water (N-K). The types of water-rock interaction were analyzed from two aspects: the change of rock composition and …

Deformation Prediction Of Open-Pit Mine Slope Based On Abc-Grnn Combined Model, Ning Yongxiang, Cui Ximin, Cui Jianguo

Coal Geology & Exploration

Accurate prediction of slope deformation in open-pit mine is an important guarantee for effective disaster early warning of slope. The traditional slope deformation prediction method is unable to characterize and comprehensively analyze the effect of various factors on slope deformation. In view of this, the combined prediction model (ABC-GRNN) of an artificial bee colony algorithm (ABC) and the optimized generalized regression neural network (GRNN) was proposed for slope deformation in open-pit mine. In this prediction model, the following 5 factors affecting the slope deformation of open-pit mine are considered comprehensively: mining disturbance, rainfall, rainfall duration, temperature and humidity. Herein, the …

Influence Of Coal Mining Disturbance On Soil Physiochemical Properties And The Response Mechanism Of Microbial Community, Song Ziheng, Liu Gang, Sun Liping, Wang Fei, Guo Junting

Coal Geology & Exploration

The ecological problems caused by coal mining in Yellow River Basin are becoming more serious. In order to explore the influence characteristics of coal mining disturbance on soil factors and microbial community in Yellow River Basin, and to clarify the differences in soil microbial communities between the marginal coal mining subsidence area and the unmined area, equidistant sampling was performed from the marginal subsidence area, the start point (HD), to the unmined area in the study area of Shangwan Mine in Inner Mongolia. Specifically, sampling points at 150 (D1), 300 (D2), 450 (D3), 600 (D4) and 750 m (D5) from …

Feasibility Study Of Nature Source In-Seam Exploration, Hu Ze’An, Cao Lingkai, Liu Qinjie, Ji Guangzhong, Xi Chaoqiang, Wu Rongxin

Coal Geology & Exploration

The conventional explosive seismic sources are very tightly controlled in high-gas mine, and a novel non-explosive channel wave method is urgently needed as an alternative. Therefore through the theoretical analysis and numerical simulation experiments, we demostrated that the coal seam satisfied the geophysical conditions to develop the nature source in-seam wave. The time-domain numerical simulation experiment of the passive source channel wave was successfully realized by constructing the nature source in-seam wave model with three stochastic terms, including the stochastic spatial position, stochastic initial excitation time and stochastic amplitude of seismic source. We performed frequency dispersion spectrum calculation on the …

Inversion Of Self-Potential Data Based On Improved Sparrow Search Algorithm, Lang Jianxiang, Tang Hongzhi, Ai Hanbing

Coal Geology & Exploration

Self-potential (SP) method is a natural source geophysical prospecting technology with low cost and simple operation for field observation. Generally, the inversion of SP data has the characteristics of ill-posedness and non-linearity. The conventional inversion algorithms are classified into the types of local optimization and global search. However, it is hard for the gradient-based local optimization algorithm to obtain the global optimal solution, and the inversion results are dependent on the construction of initial model. The traditional global search algorithm has the disadvantages of low convergence rate, insufficient ability of escaping local minima and instability. Thus, a new global optimization …

Development Of Storage Equipment Of Continuous Cable Pipe For Borehole Rescue, Gao Ke, Niu Xin, Zhao Yan, Qin Xiaolin, Lyu Xiaoshu, Xie Xiaobo

Coal Geology & Exploration

The double-bit bionic self-balancing continuous drilling technology has the advantages including requiring no drilling rig, high drilling speed and slight disturbance to the borehole wall. It is one of the key potential technologies for constructing the security and rescue passages against mine disasters. In this technology, as there are passages for power supply, signal, chip removal and other aspects that are built in the continuous cable pipe, it is required that there shall be no such interference, extrusion or arrangement of dynamic/static conductive electric conduction link as in using the existing drum hoist to store continuous pipes during storage. Therefore, …

A Fault Diagnosis Method Of Rescue Lifting Vehicle Based On Spectral Clustering, Li Lijing, Chang Dashuai, Li Lei, Chai Junfei

Coal Geology & Exploration

In allusion to the characteristics of complex structure of rescue lifting vehicle, the poor independence of working condition and fault data, and the difficulty in fault diagnosis, we proposed a fault diagnosis algorithm of rescue lifting vehicle with the semi-supervised support vector machine in this paper. In the algorithm, the information on hidden features of the original fault data was mined with the idea of spectral clustering, to effectively distinguish the independent structural features of the fault information in the component system with different degrees of coupling. Firstly, a fault map was established based on the original input data. Then, …

Trait-Based Assembly Of Arbuscular Mycorrhizal Fungal Communities Determines Soil Carbon Formation And Retention, Caitlyn C. A. Horsch, Pedro M. Antunes, Catherine Fahey, A. Stuart Grandy, Cynthia M. Kallenbach

Faculty Publications

Fungi are crucial for soil organic carbon (SOC) formation, especially for the more persistent mineral-associated organic C (MAOC) pool. Yet, evidence for this often overlooks arbuscular mycorrhizal fungi (AMF) communities and how their composition and traits impact SOC accumulation.

We grew sudangrass with AMF communities representing different traits conserved at the family level: competitors, from the Gigasporaceae family; ruderals, from the Glomeraceae family; or both families combined. We labeled sudangrass with 13C-CO2 to assess AMF contributions to SOC, impacts on SOC priming, and fungal biomass persistence in MAOC.

Single-family AMF communities decreased total SOC by 13.8%, likely due to fungal …

Potential Effect Of Phlorotannins In Brown Algae For Antidiabetic Therapy: Molecular Docking Approach, Melani Sinastri Renagupita, Rahadianto Rahadianto, Efyluk Garianto, Herin Setianingsih

Makara Journal of Science

This study aims to manifest the effect of the active compound phlorotannins in brown algae on decreasing insulin resistance by analyzing the predicted interaction between phlorotannins and protein tyrosine phosphatase 1B (PTP 1B) and estimating the pharmacokinetics and toxicity of the active compound for type 2 diabetes mellitus (DM) therapy. This type of research uses an in silico study to test the effect of using phlorotannins as an active compound in brown algae against PTP 1B inhibition. Starting from preparing materials, i.e., downloading the three-dimensional structure of phlorotannins via PubChem and PTP 1B via RSCB PDB (PDB 1A5Y), molecular docking …

Diketopiperazine Cyclo-(S-Pro-R-Leu) Produced By Periconia Pseudobyssoides K5 Isolated From Toona Sureni (Meliaceae) And Its Heme Polymerization Inhibition Activity, Azmi Azhari, Desi Harneti, Asri Peni Wulandari, Yeni Mulyani, Sari Purbaya, Aprilia Permata Sari, Galih Bayu Pratama, Unang Supratman, Yoshihito Shiono

Makara Journal of Science

Fungi endophytes are living microorganisms colonizing inside the internal tissue of a plant and provide ecological benefits for their host. Endophytes provide various metabolites for plant adaptation toward biotic and abiotic stresses and have tremendous pharmacological activities. Toona sureni (T. sureni) (Meliaceae) belongs to the Toona genera and is reported to have antimalarial activity. To determine the compounds produced by the endophytic fungus from this plant, we isolated a compound from Periconia pseudobyssoides (P. pseudobyssoides) K5 endophytes from the stem bark of T. sureni. Diketopiperazine cyclo-(S-Pro-R-Leu), a non-ribosomal peptide, was isolated from brown …

The Potency Of Citrus Aurantiifolia Swingle And Sea Salt Solution As A Cleansing Agent For Edible Bird’S Nests, Siti Gusti Ningrum, Adhitya Yoppy Ro Candra, Hana Cipka Pramuda Wardhani

Makara Journal of Science

The present study aimed to evaluate the potency of Citrus aurantiifolia Swingle and sea salt solution as a promising cleansing agent for edible bird’s nests (EBNs). Ascorbic acid, sodium, and chloride analyses of the C. aurantiifolia Swingle and sea salt solution were conducted using HPLC, ICP-OES, and titrimetry, respectively. The characteristics of physical samples and hydrogen peroxide detection were examined in this study. The reduction activity of the Citrus aurantiifolia Swingle and sea salt solution on the nitrite of 120 white EBNs was studied. This nitrite reduction activity was compared with the available method (standard), drinking water method, 6% C. …

Synthesis And Study Of Anticancer And Antioxidant Activities Of 2-Oxoquinoline Hydrazide Derivatives, Marwa Khalil Mohamed, Ezzeldin Mohamed S. Salem, Ibrahim Ahmed I. Ali

Makara Journal of Science

In this work, hydrazone, thiosemicarbazide, diamide, and dipeptide derivatives were prepared from the glycine and β-alanine hydrazide of 4-hydroxy-2-oxoquinoline. The desired derivative resulted from substitution, hydrazinolysis, condensation, and azide coupling reactions. The fabricated derivatives were screened for anticancer characteristics toward human’s colon carcinoma (HCT-116) cell line using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide viability assay, while antioxidant property was examined using an in vitro H₂O₂ scavenging method. The β-alanine hydrazide derivative 3a showed a remarkable IC₅₀ value of 18.8 μg/mL, whereas its corresponding thiosemicarbazide 5b exhibited moderate activeness with an IC₅₀ value of 26.89 μg/mL. Conversely, …

Pva-Sansevieria Trifasciata Fraction Films As Absorbers Of Electromagnetic And Thermal Radiation On Smartphones, Nabiila Rahmani, Gustini Syahbirin, Akhiruddin Maddu, Purwantiningsih Sugita, Auliya Ilmiawati

Makara Journal of Science

Technological developments have prompted the production of highly advanced smartphones. However, various advanced features cause smartphones to heat up quickly and emit more electromagnetic radiation, which harms human health. Smartphone protection is needed to solve these issues. This study aims to create a film from the S. trifasciata plant based on polyvinyl alcohol (PVA) to reduce electromagnetic and thermal radiation on smartphones. S. trifasciata plants were macerated with acetone and partitioned with n-hexane, dichloromethane, ethyl acetate, and water. The films were made by mixing PVA with the four fractions. Among the four layers of film, the PVA + water …

Pollen-Mediated Gene Flow From Genetically Modified Herbicide Resistant Creeping Bentgrass, L. S. Watrud, E. H. Lee, A. Fairbrother, C. Burdick, J. R. Reichman, M. Bollman, M. Storm, G. King, P. K. Van De Water

IGC Proceedings (1977-2023)

Approximately 162 ha of multiple experimental fields of creeping bentgrass (Agrostis stolonifera L.) genetically modified for resistance to Roundup ®herbicide, were planted in central Oregon in 2002. When the fields flowered for the first time in the summer of 2003, a unique opportunity was presented to evaluate methods to monitor potential pollen-mediated gene flow from the experimental GM crop fields to compatible sentinel and resident plants that were located in surrounding, primarily non-agronomic areas.

Assessing The Risk Posed By Transgenic Virus-Resistant Trifolium Repens To Native Grasslands In Southeast Australia, R. C. Godfree, P. W. G. Chu, A. G. Young

IGC Proceedings (1977-2023)

In Australia, comprehensive environmental risk assessments must be performed on transgenic plants (GMOs) prior to their commercial release. A key element is the determination of whether the release of a particular GMO poses any weediness threat to the environment or other agricultural systems, which can occur by means of direct invasion or by introgression of transgenes into wild populations of the same or closely related species. For transgenic pasture plants this question could be of added importance because many of these species have been selected for traits encouraging long-term persistence and competitiveness in complex plant communities (Godfree et al., …

Belowground Meristem Populations As Regulators Of Grassland Dynamics, Harmony J. Dalgleish, D. C. Hartnett

IGC Proceedings (1977-2023)

Studies of plant populations are critical for linking organism to ecosystem-level phenomena and for understanding mechanisms driving responses to global change. In perennial grasslands, the below-ground population of meristems (the bud bank) plays a fundamental role in local plant population recruitment, persistence and dynamics. We explore two aspects of the bud bank in North American grasslands. It has been hypothesized that low variability in arid biomes is explained by meristem limitation, which constrains responses to pulses of high resource availability. Our research tests this hypothesis by comparing bud-bank populations across six sites in the United States that vary 3-fold in …

The Impact Of Vegetation Structure And Spatial Heterogeneity On Invertebrate Biodiversity Within Upland Landscapes, L. Cole, M. L. Pollock, D. Robertson, J. P. Holland, D. I. Mccraken

IGC Proceedings (1977-2023)

Livestock grazing influences vegetation structure and composition at both the patch and wider landscape scale (Milne et al., 1998), and this may have effects on upland invertebrate communities, which in turn influence bird abundance and distribution (Fuller & Gough, 1999; Cole et al., 2002). Of particular importance are open grasslands and wet flushes where invertebrates are abundant and more accessible to birds. However, there have been few studies of invertebrates associated with upland habitats, and most of these have focused on heather moorland, blanket bog, or very fine-scaled structure within grasslands (Dennis et al. 1997; 1998; 2001). This …