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A Method For Intelligent Identification Of Weak Interlayer Characteristics During The Drilling Of Anchor Boreholes, Gao Dan, Yue Zhongwen, Wang Peng, Yue Xiaolei, Yan Yifei, Zhou Xingyuan, Li Yang Nov 2024

A Method For Intelligent Identification Of Weak Interlayer Characteristics During The Drilling Of Anchor Boreholes, Gao Dan, Yue Zhongwen, Wang Peng, Yue Xiaolei, Yan Yifei, Zhou Xingyuan, Li Yang

Coal Geology & Exploration

Objective The drilling quality of anchor boreholes is significantly influenced by the structural planes of weak interlayers within rock masses. Weak interlayers, tending to be hidden hazards within rock masses, affect the drilling stability and efficiency, further influencing the stability and safety of the whole support structure. Once drilled by drill bits, weak interlayers exhibit significant dynamic responses, which reflect the changes in rock mass structures during the drilling. Methods From the perspective of drilling specific energy, this study conducted digital drilling experiments on rock mass-like specimens bearing weak interlayers using the independently developed measurement while drilling (MWD) system, which …


Biochar/Hydrochar Applications In Disinfection Byproduct Removal For Drinking Water, Ashleu Mussio Marquez, Donna Rouhani, Ismail Abdulraheem, Kers Ung-Watson, Ahmadreza Khatamgooya, Scarlet Nelson, Dr. Jaeyun Moon, Dr. Erica Marti Nov 2024

Biochar/Hydrochar Applications In Disinfection Byproduct Removal For Drinking Water, Ashleu Mussio Marquez, Donna Rouhani, Ismail Abdulraheem, Kers Ung-Watson, Ahmadreza Khatamgooya, Scarlet Nelson, Dr. Jaeyun Moon, Dr. Erica Marti

Undergraduate Research Symposium Posters

This project aims to investigate the process of disinfection byproduct (DBP) removal in drinking water, looking into the applications of biochar and hydrochar, which are low cost and environmentally sustainable adsorbents. These carbon-based adsorbents are derived from agricultural waste biomass, such as walnut shells. These adsorbents will be used to capture and remove contaminants in water, such as DBPs. DBPs are formed when chemical disinfectants react with organic and inorganic substances naturally present in water. The targeted DBPs for adsorption include trihalomethanes, haloacetic acids, haloacetonitriles, and nitrosamines. An example of high concentration DBP formation is during emergency chlorination, where excess …


Characterizing The Mechanical And Visoelastic Properties Of Sodium Alginate, Vesper Evereux Nov 2024

Characterizing The Mechanical And Visoelastic Properties Of Sodium Alginate, Vesper Evereux

Undergraduate Research Symposium Posters

A crucial part of tissue engineering lies in understanding and characterizing the mechanical and viscoelastic properties of various types of biomaterials. Understanding these properties allows better biomaterials to be produced with characteristics more similar to those of the human body and with better biocompatability. In this study, sodium alginate was chemically crosslinked with calcium chloride and subsequently tested for it's instantaneous Elastic Modulus, instantaneous Shear Modulus, and equivalent viscosity using indentation testing methods consisting of a stress-relaxation test and nonlinear curve-fitting analysis. Two and three millimeter indentation tests were performed using a low-cost and portable device built in-lab that resulted …


Emerging Consensus On Net Energy Paves The Way For Improved Integrated Assessment Modeling, Louis Delannoy, Matthieu Auzanneau, Baptiste Andrieu, Olivier Vidal, Pierre -Yves Longaretti, Emmanuel Prados, David J. Murphy, Roger W. Bentley, Michael Carbajales- Dale, Marco Raugei, Mikael Ho¨O¨K, Victor Court, Carey W. King, Florian Fizaine, Pierre Jacques, Matthew Kuperus Heun, Andrew Jackson, Charles Guay- Boutet, Emmanuel Aramendia, Jianliang Wang, Hugo Le Boulzec, Charles A.S. Hal Nov 2024

Emerging Consensus On Net Energy Paves The Way For Improved Integrated Assessment Modeling, Louis Delannoy, Matthieu Auzanneau, Baptiste Andrieu, Olivier Vidal, Pierre -Yves Longaretti, Emmanuel Prados, David J. Murphy, Roger W. Bentley, Michael Carbajales- Dale, Marco Raugei, Mikael Ho¨O¨K, Victor Court, Carey W. King, Florian Fizaine, Pierre Jacques, Matthew Kuperus Heun, Andrew Jackson, Charles Guay- Boutet, Emmanuel Aramendia, Jianliang Wang, Hugo Le Boulzec, Charles A.S. Hal

University Faculty Publications and Creative Works

Extracting, processing, and delivering energy requires energy itself, which reduces the net energy available to society and yields considerable socioeconomic implications. Yet, most mitigation pathways and transition models overlook net energy feedbacks, specifically related to the decline in the quality of fossil fuel deposits, as well as energy requirements of the energy transition. Here, we summarize our position across 8 key points that converge to form a prevailing understanding regarding EROI (Energy Return on Investment), identify areas of investigation for the Net Energy Analysis community, discuss the consequences of net energy in the context of the energy transition, and underline …


Active Tectonics, Erosion Rates, And Topographic Metrics In The Hayword-Calaveras Fault Zone, Simone I. Yeager Nov 2024

Active Tectonics, Erosion Rates, And Topographic Metrics In The Hayword-Calaveras Fault Zone, Simone I. Yeager

Master's Theses

In northern California, the complex geometry of the San Andreas Fault system, and how it steps and propagates across the Earth’s surface, is revealed in the topography. Activity along the Mission and Arroyo Aguague oblique reverse faults, located where the right-lateral Hayward Fault steps to the left of the Calaveras Fault, are manifested in the Diablo Mountain Range. The high topography in the restraining step can be observed in lidar imagery and seismicity studies show these faults are connected at depth. In this study, we investigate active tectonics, erosion rates, and topographic metrics from the southern end of the restraining …


A New Power Airflow Harvester Improves Grass Seed Yield And Quality In Central Queensland, Australia, J H. Wildin, Dingfa Zhou, A Dobson Nov 2024

A New Power Airflow Harvester Improves Grass Seed Yield And Quality In Central Queensland, Australia, J H. Wildin, Dingfa Zhou, A Dobson

IGC Proceedings (1977-2023)

Most perennial tropical grasses produce new seedheads over a period extending up to 4 weeks, Seeds mature and ripen up to 4 weeks after inflorescence emergence. The dilemma for seed producers using one­pass harvesting has been to time the harvesting operation to maxmise. recovery of mature seed, Harvested immature seeds and inert material adversely affect seed purity and germination tests. Light fluffy seeds such as buffel and bluegrasses are generally difficult to harvest with grain crop harvesters, and paddle beater harvesters have been used for simplicity and economy. Over the last 3 years, tractor-mounted brush harvesters using 4 rows of …


Mechanical Harvesting And Processing Of Temperate Zone And Tropical Pasture Seed, J M. Hopkinson, P.T P. Clifford Nov 2024

Mechanical Harvesting And Processing Of Temperate Zone And Tropical Pasture Seed, J M. Hopkinson, P.T P. Clifford

IGC Proceedings (1977-2023)

Temperate zone herbage seed harvesting continues to evolve round combine•harvesters designed principally for large-seeded grain and pulse crops. Most research emphasis has been placed on increasing efficiency of systems for presenting the crop to the auger platform. Timing of harvest, precutting treatment, cutting and pickup alternatives including airblast assistance vary in relation to species and environmental conditions. With the development of drying-cooling systems considerable advantages in the harvesting and processing of grass seed have occurred. An understanding of the range and use of seed cleaning equipment available to meet purity standards is given, along with additional options to meet end.user …


Stratigraphy And Geochronology Of The Eocene Volcanosedimentary Units In The Hekimhan-Darende (Malatya) Region: Implications For The Development Of The Gürün Curl, Emrah Yalçin Ersoy, Osman Candan, İbrahi̇m Uysal Nov 2024

Stratigraphy And Geochronology Of The Eocene Volcanosedimentary Units In The Hekimhan-Darende (Malatya) Region: Implications For The Development Of The Gürün Curl, Emrah Yalçin Ersoy, Osman Candan, İbrahi̇m Uysal

Turkish Journal of Earth Sciences

We present new radiometric (Ar-Ar) age data from the volcanic rocks occurring in the Eocene strata in the Hekimhan and Gürün-Darende (Malaya) regions. The Eocene units in these regions are represented separately by the Tohma and Darende formations, respectively. The two basaltic volcanic interlayers in the Tohma Formation, occurring in the lower and upper parts of the succession yielded Ar-Ar isochron ages of 51.75±0.76 and 42.66±0.43 Ma, respectively, indicating a deposition age of Ypresian-Lutetian interval for the unit. The andesitic volcanic rocks in the basal parts of the Darende Formation yielded an Ar-Ar isochron age of 37.35±0.72 Ma, revealing that …


Anomalous Crustal Structure Beneath The Örenli-Eğiller Depression Zone, Inferred From Magnetotelluric Studies, Western Anatolia, Türkiye, Dornadula Chandrasekharam, Khasi Raju, Prabhala Bhaskhara Venkata Subba Rao, Alper Baba Nov 2024

Anomalous Crustal Structure Beneath The Örenli-Eğiller Depression Zone, Inferred From Magnetotelluric Studies, Western Anatolia, Türkiye, Dornadula Chandrasekharam, Khasi Raju, Prabhala Bhaskhara Venkata Subba Rao, Alper Baba

Turkish Journal of Earth Sciences

In Türkiye, the prevalence of high radiogenic granites makes them ideal locations for initiating enhanced geothermal system (EGS) projects. One such occurrence of these granites is observed in the Kozak area of the Bergama region. To assess the energy potential of this site, a magnetotelluric (MT) survey was conducted, focusing on determining the depth distribution of the intrusive granite.The survey employed dimensionality analysis, utilizing Bahr skew and phase tensor analyses that denote a 2D subsurface nature up to 100 s and beyond that a 3D nature. In the present study, we interpreted MT data up to 100 s. The data …


Processing Of Pinger, Chirp, Boomer, And Parametric Subbottom Profiler Datasets, Aslihan Nasif Nov 2024

Processing Of Pinger, Chirp, Boomer, And Parametric Subbottom Profiler Datasets, Aslihan Nasif

Turkish Journal of Earth Sciences

Subbottom profiler (SBP) systems are commonly employed for geo-hazard analysis in offshore engineering studies. The joint analysis of multi-channel seismic and SBP data also provides additional information for analyzing submarine fluid-flow structures in shallow sediments. Detailed geo-hazard analyses also aim to reveal small-scale changes in the seafloor and the underlying structures. Therefore, the horizontal and vertical resolution of SBP data is a crucial parameter, and obtaining the necessary resolution requires appropriate data processing.This study analyzes the steps and parameters applied in processing pinger, Chirp, boomer, and parametric SBP data, to determine an optimal data processing flow and parameters. Compared to …


Results From A Multi-Laboratory Ocean Metaproteomic Intercomparison: Effects Of Lc-Ms Acquisition And Data Analysis Procedures, Mak A. Saito, Jaclyn K. Saunders, Matthew R. Mcilvin, Erin M. Bertrand, John A. Breier, Margaret Mars Brisbin Nov 2024

Results From A Multi-Laboratory Ocean Metaproteomic Intercomparison: Effects Of Lc-Ms Acquisition And Data Analysis Procedures, Mak A. Saito, Jaclyn K. Saunders, Matthew R. Mcilvin, Erin M. Bertrand, John A. Breier, Margaret Mars Brisbin

School of Earth, Environmental, & Marine Sciences Faculty Publications

Metaproteomics is an increasingly popular methodology that provides information regarding the metabolic functions of specific microbial taxa and has potential for contributing to ocean ecology and biogeochemical studies. A blinded multi-laboratory intercomparison was conducted to assess comparability and reproducibility of taxonomic and functional results and their sensitivity to methodological variables. Euphotic zone samples from the Bermuda Atlantic Time-series Study (BATS) in the North Atlantic Ocean collected by in situ pumps and the autonomous underwater vehicle (AUV) Clio were distributed with a paired metagenome, and one-dimensional (1D) liquid chromatographic data-dependent acquisition mass spectrometry analysis was stipulated. Analysis of mass spectra from …


Assessing Climate Change-Induced Drought In Abu Dhabi, Salem Anwar Alblooshi Nov 2024

Assessing Climate Change-Induced Drought In Abu Dhabi, Salem Anwar Alblooshi

Thesis/ Dissertation Defenses

This thesis examines trends of drought related to climate change in a region within the Abu Dhabi Emirate through advanced remote sensing and statistical trend analysis techniques. To analyze long-term trends in temperature, precipitation, evapotranspiration, and groundwater levels, we use Google Earth Engine (GEE) as our primary data extraction and analysis tool, covering the years from 2002 to 2016. Evaluation of MODIS Land Surface Temperature data indicated a statistically significant warming trend each month, with rates reaching as high as 0.1°C/year. Although precipitation patterns revealed significant variability without any major trends, evapotranspiration values showed a predictable increase, especially during the …


A Decade Of Monitoring Reveals A Dynamic Fish Assemblage On A Substantial Artificial Reef In The Texas Gulf Of Mexico, David Hicks, Ethan T. Getz, Richard Kline, Carlos E. Cintra-Buenrostro Nov 2024

A Decade Of Monitoring Reveals A Dynamic Fish Assemblage On A Substantial Artificial Reef In The Texas Gulf Of Mexico, David Hicks, Ethan T. Getz, Richard Kline, Carlos E. Cintra-Buenrostro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Fish communities on artificial reefs have rarely been monitored over long periods to evaluate success of reef deployment. Here, we used roving diver surveys to assess changes in fish assemblages on a large, reefed vessel during 2008–2017. Multivariate analyses revealed a dynamic community that stabilized after 5 years. Species richness increased and species dominance decreased during 2008–2017. The fish community shifted toward reef-associated species such as hogfish and pufferfish. Species composition shifted, but trophic structure was relatively stable, which suggested that functional groups may not reflect larger community shifts. Our results indicate that fish communities on artificial reefs are temporally …


Evaporation Basins For Salinity Management, Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Evaporation Basins For Salinity Management, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

An evaporation basin is an engineered earth structure designed to safely store and evaporate saline water discharged from drainage or pumping, while protecting high-value agricultural land, natural assets or built infrastructure.

DPIRD recommends that evaporation basins should form part of an integrated water and salinity management program. Information on this page is a guide only.

It is recommended that landholders seek expert advice plus engineering design and related support from qualified contractors.


Shallow Relief Drains In Western Australia, Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Shallow Relief Drains In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Shallow relief drains are easy to construct and a cost-effective way to:

  • remove accumulated surface water from depressions and low-lying land
  • divert run-off from land that is prone to inundation or flooding
  • remove surface water to a safe disposal area, to reduce the length of time the land is inundated or flooded
  • reduce the potential for localised recharge and the development of secondary salinity
  • improve the continuity of flow within the catchment along the valley floor.


Measuring Soil Salinity, Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Measuring Soil Salinity, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

To make sound decisions on managing saline sites, you need to know the source of salt, how salinisation is occurring, the landscape context, and most importantly, the actual salt concentration of the soil.

The most common 'measures' of salt concentration are actually estimates based on electrical conductivity of a soil and water solution. Soil salt content can be measured in a laboratory by measuring the total dissolved solids in a sample. In the field, salt concentration can also be estimated using electromagnetic induction-based soil sensors.


Topography And Wildfire Jointly Mediate Postfire Ecosystem Multifunctionality In A Chinese Boreal Forest, Jianjian Kong, Zifan Ding, Wenhua Cai, Jiaxing Zu, Bo Liu, Jian Yang Nov 2024

Topography And Wildfire Jointly Mediate Postfire Ecosystem Multifunctionality In A Chinese Boreal Forest, Jianjian Kong, Zifan Ding, Wenhua Cai, Jiaxing Zu, Bo Liu, Jian Yang

Earth and Environmental Sciences Faculty Publications

Both topography and wildfire can exert significant influences on ecosystem processes and functions during boreal forest successions. However, their impacts on ecosystem multifunctionality (EMF) remain unclear. A mega-fire burned an area of 8700 hectares in the Great Xing’an Mountains in 2000, creating a wide range of fire severity levels across various topographic positions. This provided a unique opportunity to explore the impacts of mixed-severity fire disturbance in boreal forests. We evaluated the effect pathways of wildfire and topography on aboveground multifunctionality (AEMF), soil multifunctionality (SEMF), and overall multifunctionality (OEMF). We found that high-severity burning resulted in lower AEMF, SEMF, and …


Saltland Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Saltland Pastures In Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Saltland pastures are associations of salt and waterlogging-tolerant plants that produce fodder for grazing animals from saline and waterlogged soils. Saltland pastures can improve production from saltland sites, reduce salt movement from the site, and improve soil structure.

The Department of Primary Industries and Regional Development recommends that saltland management is part of a whole-farm, and preferably whole-catchment, plan.


Using Convolutional Neural Network To Determine Time Window For Analyzing Local Shear-Wave Splitting Measurements, Yanwei Zhang, Stephen S. Gao Nov 2024

Using Convolutional Neural Network To Determine Time Window For Analyzing Local Shear-Wave Splitting Measurements, Yanwei Zhang, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The time window for analyzing local shear-wave splitting (SWS) phases significantly affects the quality of measurements, revealing a noteworthy domain influence. In this study, an approach using convolutional neural network (CNN) is applied to determine the end of time window (e), which has a similar idea of the phase-picking CNNs. The start of time window is 0.5 s before e. Our data set contains 803 human-labeled measurements, recorded from three stations located in Ridgecrest, California. These measurements are foreshocks and aftershocks of an M 7.1 earthquake on 6 July 2019. After 21 times shifting on each measurement, 90% of the …


Roaded Catchments In Wa, Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Roaded Catchments In Wa, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Roaded catchments are earthwork structures designed to increase the amount of run-off from the catchment above a receiving farm dam.

Roaded catchments are lined with clay and compacted to make a smooth surface that reduces infiltration and increases run-off. Roaded catchments should discharge into a silt trap and then into a dam (excavated earth tank). This combined structure should be fenced to exclude livestock.

The Department of Primary Industries and Regional Development recommends that roaded catchments are part of an integrated water and salinity management program.

The information in this page is only a guide – seek expert advice before …


Managing Subsurface Water In Wa, Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Managing Subsurface Water In Wa, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

The Department of Primary Industries and Regional Development (DPIRD) recommends that subsurface water management is part of an integrated water and salinity program. An integrated program can help to lower water tables and alleviate problems with waterlogging, rising salinity, and infrastructure damage.


Excavated Tanks (Farm Dams), Department Of Primary Industries And Regional Development, Western Australia Nov 2024

Excavated Tanks (Farm Dams), Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Guidelines and information for planning, legal requirements, design, construction and management of excavated tanks for water storage on farm.

Excavated tanks (farm dams) provide effective water storage wherever surface water run-off can be harvested for livestock, crop spraying, irrigation and domestic use on rural properties.

Excavated tanks for rainfall storage are common in the southern agricultural areas of WA.

Well-designed and constructed dams are farm assets, safe and require little maintenance.

Poor design and construction can lead to poor water harvesting and storage, excessive costs, downstream erosion and risks to property and people.

DPIRD recommends that excavated tanks should be …


Accumulation Of Road Salt In A Calcareous Fen: Kampoosa Bog, Western Massachusetts, Wayne Ndlovu, Andrew J. Guswa, Amy L. Rhodes Oct 2024

Accumulation Of Road Salt In A Calcareous Fen: Kampoosa Bog, Western Massachusetts, Wayne Ndlovu, Andrew J. Guswa, Amy L. Rhodes

Geosciences: Faculty Publications

Road salt poses a threat to the quality of soils and water resources. Wetlands located in salt contaminated areas are at risk of experiencing lower plant and animal species diversity. Therefore, it is critical to understand how modifications to salt application rates and hydrological events impact wetland water quality. Here, we use chloride mass flux, discharge, groundwater chloride concentration, meteorological, and salt application data from 2012– 2020 to estimate chloride accumulation and outflux rates in the Kampoosa Bog subwatersheds, located in Stockbridge and Lee, Massachusetts, and bordered by major highways (Interstate-90 and U.S. Route 7). We also investigate the correlation …


Effects Of Longitudinal Training Walls On Two-Dimensional Flow Structure, Sediment Transport, And Bed Aggredation Using Numerical Methods And Sediment Core Analyses In Grand River, Michigan, Sumaiya Tul Siddique Oct 2024

Effects Of Longitudinal Training Walls On Two-Dimensional Flow Structure, Sediment Transport, And Bed Aggredation Using Numerical Methods And Sediment Core Analyses In Grand River, Michigan, Sumaiya Tul Siddique

LSU Doctoral Dissertations

Longitudinal training walls (LTWs) are structures oriented parallelly with the main flow and separate the channel into two sub-channels. One channel acts as the main navigational channel and the other is considered a secondary side channel. The long-term effects of the LTWs on morphodynamics and deposition remain poorly understood. This study investigated the long-term effects of the LTWs on flow, sediment transport and long-term deposition of the Grand River using numerical approaches and sediment core analysis. The effects of LTWs on 2D flow dynamics and sediment transport were investigated by using numerical approaches. The long-term deposition under the influence of …


A Dynamic Damage Rate-Based Constitutive Model For Rock Damage, Meng Xiangzhen, Zhang Huimei, Li Yugen, Yuan Chao, Chen Shiguan Oct 2024

A Dynamic Damage Rate-Based Constitutive Model For Rock Damage, Meng Xiangzhen, Zhang Huimei, Li Yugen, Yuan Chao, Chen Shiguan

Coal Geology & Exploration

Objective A constitutive model is identified as the most effective method for describing the deformations and failure characteristics of rocks and characterizing their mechanical behavior. Developing the equation and constitutive model for the dynamic damage evolution of rocks based on changes in their damage rates under loading is an important part of rock mechanics. Methods To further investigate the whole process of rock deformations and failure under loading, rocks were divided into the damaged and undamaged parts via abstraction, with the latter bearing effective stress and the former bearing residual stress. This study established the equation and constitutive model based …


Mechanisms And Control Of Rock Bursts In Goaf-Side Roadways Under The Condition Of Thick And Hard Roofs In The Xinjie Mining Area, Inner Mongolia, Liu Wenchao, Zhao Yixin, Guo Jihong Oct 2024

Mechanisms And Control Of Rock Bursts In Goaf-Side Roadways Under The Condition Of Thick And Hard Roofs In The Xinjie Mining Area, Inner Mongolia, Liu Wenchao, Zhao Yixin, Guo Jihong

Coal Geology & Exploration

Objective and Methods Rock bursts in mining roadways in deep coal mines under the condition of thick and hard roofs severely threaten the safe coal mining of the mining face. To meet this threat, this study, focusing on the No.3-1103 mining face auxiliary transport roadway, a goaf-side roadway, in a typical deep mine of the Xinjie mining area, Inner Mongolia, analyzed the external dominant factors and internal driving sources for frequent rock bursts in the goaf-side roadway. Assuming the mechanical characteristics of the rock beam-foundation system, this study constructed mechanical models under loading before roof fracturing based on …


Effect Of Cadmium-Free Filler Metal On Mechanical Properties And Microstructure Of Pdc Cutters, Zhang Suhui, Yao Ningping, Liu Qingxiu, Liu Huan, Wang Dechuan Oct 2024

Effect Of Cadmium-Free Filler Metal On Mechanical Properties And Microstructure Of Pdc Cutters, Zhang Suhui, Yao Ningping, Liu Qingxiu, Liu Huan, Wang Dechuan

Coal Geology & Exploration

Objective PDC bits are critical components of geological support equipment and play a vital role in advancing technology and improving efficiency in the coal industry. Currently, PDC bits are brazed using silver filler metals containing cadmium, a toxic and polluting element. This study introduces the use of environmentally friendly, cadmium-free filler metals for brazing PDC bits. Methods The study investigates the wetting mechanism between brazing filler metals and base materials, utilizing Ag-Cu-Zn series brazing filler metals containing high silver and Sn, Mn and Ni, and only Ni for flame brazing of PDC cutters and steel. The shear strength of different …


Rock Burst Hazard Evaluation Of Coal Mining Face Based On A Gaussian Mixture Model, Cui Feng, Li Yifei, Jia Chong, Lu Changliang, He Shifeng, Zhang Suilin, Tian Mengqi Oct 2024

Rock Burst Hazard Evaluation Of Coal Mining Face Based On A Gaussian Mixture Model, Cui Feng, Li Yifei, Jia Chong, Lu Changliang, He Shifeng, Zhang Suilin, Tian Mengqi

Coal Geology & Exploration

Objective Deep insights into the probabilistic information contained in the energy distribution of acoustic emission (AE) or microseismic events are significant for the rock burst hazard evaluation of coal mining face. Methods This study investigated No.40111 mining face of the No.4 coal seam at the Dafosi Coal Mine in Shaanxi Province. Using physical simulation experiments with similar materials, theoretical analysis, and on-site monitoring, this study investigated the evolutionary patterns of AE monitoring data during coal mining and illustrated the physical meaning of fluctuations in the probability distribution of AE energy. Accordingly, this study proposed an index model for the rock …


Advances In Research On The Evolution Of Trans-Scale Discontinuous Structures During The Creeps Of Strongly Disturbed Coals, Zhang Liang, Wang Laigui, Ren Ting, Li Xiangchun, Gao Ke, Li Haitao, Zhao Shankun Oct 2024

Advances In Research On The Evolution Of Trans-Scale Discontinuous Structures During The Creeps Of Strongly Disturbed Coals, Zhang Liang, Wang Laigui, Ren Ting, Li Xiangchun, Gao Ke, Li Haitao, Zhao Shankun

Coal Geology & Exploration

Objective and Methods Disasters associated with surrounding rocks in roadways, such as time-dependent deformation failure and creep-induced rock bursts, severely threaten deep mines in China. These disasters, coupled with the impacts of deep mining and structural changes, render it urgent to explore the evolutionary patterns of trans-scale discontinuous structures during the creeps of strongly disturbed coals. This study systematically reviews the scale effects of coals' mechanical properties, the discontinuous structures and multi-physics field effects of coals, and the long-term stability, creep evolutionary patterns, and mechanical models of coals. It highlights the close correlation between discontinuous structures (including their fractures and …


Sedimentary Environments, Mechanical Properties, And Rock Burst Risk Identification Of Overburden In Deep Mines, Qiao Wei, Cheng Xianggang, Dou Linming, He Hu, Meng Xiangsheng, Ren Yangyang, Xiao Chong, Cai Jin Oct 2024

Sedimentary Environments, Mechanical Properties, And Rock Burst Risk Identification Of Overburden In Deep Mines, Qiao Wei, Cheng Xianggang, Dou Linming, He Hu, Meng Xiangsheng, Ren Yangyang, Xiao Chong, Cai Jin

Coal Geology & Exploration

Objective Disaster risk identification and prediction serve as a prerequisite for disaster control. An engineering geological environment is identified as the fundamental condition inducing dynamic disasters like rock bursts in mines. Exploring the sedimentary genetic mechanisms of engineering geological environments holds great significance for predicting rock burst risks. Methods With the Gaojiapu Coal Mine in the Binchang mining area, Shaanxi Province, as a case study, this study analyzed the engineering geological characteristics of rock masses under different sedimentary microfacies. Furthermore, it explored the deformation and failure characteristics of rocks in different sedimentary environments, along with the energy release patterns of …