Results 51 to 60 of about 7,991 (237)

Dynamic failure and stability model analysis of thick and hard rock with wedge-structure immediate roof occurrence

, 2021
To eliminate roof-control disasters typicallyencountering in mines with thick and hard rock strata, fracturecharacteristics, instability mechanism and prevention methods were investigatedin the study.
Zhao, Tong, Gong, Peilin, Liu, Changyou, Bahramian, Majid, Yetilmezsoy, Kaan   +4 more
core   +1 more source

System and application of regional fracking of coal seam roof on and under the ground to prevent rockburst

Meitan kexue jishu, 2023
To solve the problems of small local relief range, low continuity and high operational risk of rockburst, regional hydro-fracking and burst prevention system and engineering application research were carried out within thick and hard roof of a coal seam ...
PAN Junfeng, LU Chuang, MA Xiaohui, XIA Yongxue, XIE Fei, XU Gang, DOU Guidong, LYU Dazhao, SUN Xiaodong, MA Wentao   +9 more
doaj   +1 more source

Mechanical properties and acoustic emission characteristics of thick hard roof sandstone in Shendong coal field

International Journal of Coal Science & Technology, 2017
The mechanical properties and acoustic emission characteristics of thick hard roof sandstone were investigated. Samples were taken from the 30.87-m thick sandstone roof in a mine in the Shengdong coal field, China. Firstly, the composition and microscopic characteristics were analyzed by XRD and FE-SEM, respectively. Moreover, the indirect tensile test,
Li, Huigui, Li, Huamin
openaire   +1 more source

Thermal Calculations for Co‐Firing of Hydrogen/Ammonia and Coal in 660‐MW Coal‐Fired Boilers

Asia-Pacific Journal of Chemical Engineering, EarlyView.
ABSTRACT To achieve a clean energy transition under the dual carbon goals, blending hydrogen/ammonia into pulverized coal boilers represents a key technological pathway. Different hydrogen/ammonia co‐firing ratios (5%–50%) are investigated for their impact on the thermodynamic characteristics of 660‐MW supercritical boiler at 100% and 20% boiler ...
Yaodong Da, Nana Hou, Weipeng Wang, Yongqiang Chang, Xin Liu, Feng Pan, Defu Che, Lei Deng   +7 more
wiley   +1 more source

Functional morphology of the pharyngeal teeth of the ocean sunfish, Mola mola

The Anatomical Record, EarlyView.
Abstract Many fish use a set of pharyngeal jaws in their throat to aid in prey capture and processing, particularly of large or complex prey. In this study—combining dissection, CT scanning, histology, and performance testing—we demonstrate a novel use of pharyngeal teeth in the ocean sunfish (Mola mola), a species for which pharyngeal jaw anatomy had ...
Benjamin Flaum, Michael J. Blumer, Mason N. Dean, Laura J. Ekstrom   +3 more
wiley   +1 more source

Rock burst mechanism induced by stress anomaly in roof thickness variation zone: a case study

Geomatics, Natural Hazards & Risk, 2022
The variation of hard roof thickness is an essential contributor in triggering rock bursts during longwall mining. Case analysis and numerical modeling were used to study the stress and energy characteristics of the coal and rock mass and its fracture ...
Xianxi Bai, Anye Cao, Wu Cai, Yingyuan Wen, Yaoqi Liu, Songwei Wang, Xuwei Li   +6 more
doaj   +1 more source

A Composite Pressure Relief Method Based on Roof Cutting and Fracturing Expansion for Thick Hard Roofs in Large Mining Heights

International Journal of Geomechanics
Abstract In coal mining, thick and hard roof strata are widely distributed, posing significant hazards that easily lead to various issues such as extensive deformations of the surrounding rock and failure of support systems due to strong mining pressure, resulting in frequent safety incidents.
Jun Yang, Hongxu Song, Yubing Gao, Qiang Fu, Jianning Liu, Yuxuan Liu, Hongyu Jin   +6 more
openaire   +1 more source

Study on the Mechanism and Prevention of Frequent Mine Seismic Events in Goaf Mining under a Multi-Layer Thick Hard Roof: A Case Study

, 2023
Mine seismic events are an inevitable dynamic phenomenon occurring in deep mines. A scientific and rational method is needed to evaluate and understand mine seismicity and its induced disasters. In the Ordos mining area of North China, multiple groups of
Junpeng Ma, Jinwen Bai, Zhongxiang Gao, Sitao Zhu, Zhu Li, Bo Wang, Guorui Feng, Wenda Wu   +7 more
core   +1 more source

Osteological correlates of the respiratory and vascular systems in the neural canals of Mesozoic ornithurines Ichthyornis and Janavis

The Anatomical Record, EarlyView.
Abstract In birds, the neural canal houses a variety of anatomical structures including the spinal cord, meninges, spinal vasculature, and respiratory diverticula. Among these, paramedullary diverticula and the extradural dorsal spinal vein may leave behind osteological correlates in the form of pneumatic foramina and fossae, and a bilobed geometry of ...
Jessie Atterholt, M. Grace Burton, Mathew J. Wedel, Juan Benito, Ellen Fricano, Daniel J. Field   +5 more
wiley   +1 more source

Functional anatomy, jaw mechanisms, and feeding behavior of Dunkleosteus terrelli (Placodermi, Arthrodira)

The Anatomical Record, EarlyView.
A new musculoskeletal reconstruction and revision of the cranio‐mandibular anatomy of the Devonian arthrodire placoderm Dunkleosteus terrelli from a comparative and functional anatomical perspective. Dunkleosteus is a specialized arthrodire with many specializations for feeding on large vertebrates, and many of its features are part of broader ...
Russell K. Engelman, Robert K. Carr, Kate Trinajstic, Zerina Johanson, Oleg A. Lebedev   +4 more
wiley   +1 more source