Results 41 to 50 of about 4,083 (232)

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

Meikuang 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

Effect of Thick–Hard Main Roof Fracturing on the Spatiotemporal Evolution of Overburden Fractures

Applied Sciences
Gas gushing and the co-mining of coal and gas outbursts are common disasters in coal mines. The weakening of thick–hard main roof fracturing can effectively alleviate the gas overrun in the initial mining stage. Four numerical simulation schemes were designed to determine the optimal fracturing treatment scheme for the gas overrun problem in the ...
Jinfeng Ju, Chengen Qi, Zhu Li
openaire   +2 more sources

Drop‐Location‐Insensitive Droplet‐Based Electricity Generator Using Polydimethylsiloxane Slippery Covalently Attached Liquid Coatings

Advanced Science, EarlyView.
Drop‐location sensitivity remains a key barrier to practical droplet‐based electricity generators (DEGs). Here, a polydimethylsiloxane slippery covalently attached liquid (PDMS‐SCAL)‐coated interface promotes droplet sliding instead of splitting or bouncing, allowing stable electricity generation from randomly falling raindrops. The resulting PDMS‐SCAL‐
Jung Bin Yang, Donghyeon Yoo, Hideaki Teshima, Donghan Lee, Dongwhi Choi, Dong Rip Kim, Nenad Miljkovic   +6 more
wiley   +1 more source

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

Geofluids, 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, Peilin Gong, Kaan Yetilmezsoy, Majid Bahramian, Changyou Liu, Xiaofei Gong   +5 more
doaj   +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

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

Structural quantification of multi-thick hard roof and strong ground pressure control in large mining height stope: a case study

Geomechanics and Geophysics for Geo-Energy and Geo-Resources
The mining of deep large-height longwall faces leads to frequent occurrences of strong ground pressure, at the same time, there are multi-thick hard rock strata in the roof of the longwall face, therefore, it is important to master the fracture ...
Yangbo Lu, Shaohong Yan, Kunyou Zhou, Chenxi Zhang, Yi Zhou   +4 more
doaj   +1 more source

Evolution of roof treatment processes from blasting to hydraulic fracturing to prevent rockburst in thick-hard roof coal mines in Xinjiang, China

Frontiers in Earth Science
Rockburst prevention poses a major challenge in coal mining, with thick and hard roof strata being the primary cause of rockbursts. To analyze the feasibility and effectiveness of using hydraulic fracturing as an alternative to blasting methods for ...
Kunlun Liu, Taotao Du, Taotao Du, Yuhai Wu, Hongping Li, Xu Yang, Jiang Liu, Hongbao Liang, Jianqi Wang   +8 more
doaj   +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

The coelurosaur theropods of the Romualdo formation, early Cretaceous (Aptian) of Brazil: Santanaraptor placidus meets Mirischia asymmetrica

The Anatomical Record, EarlyView.
Abstract The upper carbonate concretion levels of the Romualdo Formation (Aptian, Brazil) have yielded several theropod dinosaur remains, including spinosaurids and the coelurosaurs Santanaraptor placidus and Mirischia asymmetrica, the phylogenetic affinities of which are controversial.
Rafael Delcourt, Orlando Nelson Grillo, Christophe Hendrickx, Maximilian Kellermann, Max Cardoso Langer   +4 more
wiley   +1 more source