Results 51 to 60 of about 4,616 (263)

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

open access: yesMinerals, 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
Bo Wang   +7 more
semanticscholar   +1 more source

Theory and technical system of control of far-near field hard roofs from ground and underground in a large space stope

open access: yesMeitan xuebao, 2023
The stope space, after mining an extra-thick coal seam with hard roofs, is large, and its law of mining pressure is complex. The mechanism of strong mine pressure action for this stope is unclear, and there is a lack of multi-point control technology ...
Bin YU   +7 more
doaj   +1 more source

Compliant Pneumatic Feet with Real‐Time Stiffness Adaptation for Humanoid Locomotion

open access: yesAdvanced Robotics Research, EarlyView.
A compliant pneumatic foot with real‐time variable stiffness enables humanoid robots to adapt to changing terrains. Using onboard vision and pressure control, the foot modulates stiffness within each gait cycle, reducing impact forces and improving balance. The design, cast in soft silicone with embedded air chambers and Kevlar wrapping, offers durable,
Irene Frizza   +3 more
wiley   +1 more source

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

open access: yesMeitan 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   +9 more
doaj   +1 more source

Mechanism and prevention practice of rock burst in thick and hard roof

open access: yesMeikuang Anquan, 2023
Based on the characteristics of thick hard roof and hard coal seam of rock burst mine in Ordos area, the occurrence process of rock burst under the condition of wide coal pillar mining was analyzed. It is revealed that the rock burst in this region is caused by the dynamic system instability in the high stress region of coal body, vibration, stress ...
openaire   +1 more source

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

open access: yesAsia-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   +7 more
wiley   +1 more source

Thick-hard strata movement law and multi-dynamic load mechanism in longwall face with ultra-large cutting height

open access: yesMeitan xuebao
Large mining height technology is characterized by high yield, high efficiency, and high recovery rate. It has become the preferred technology for mining thick coal seams in Yushen mining area.
Jiachen WANG   +6 more
doaj   +1 more source

Mechanism of Support Optimization and Confined Blasting of Thick and Hard Rock with a Wedge-Structure Immediate Roof: A Case Study

open access: yesGeofluids, 2021
Based on the occurrence conditions of a thick and hard main roof and wedge-structure immediate roof in the Zhuxianzhuang Coal Mine, the fracture characteristics and instability migration law of a thick and hard roof (THR) were examined via physical ...
Tong Zhao   +5 more
doaj   +1 more source

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

open access: yesThe 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   +3 more
wiley   +1 more source

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

open access: yesGeomatics, 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   +6 more
doaj   +1 more source

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