Results 71 to 80 of about 399,174 (293)

Analysis of the Influence Characteristics of the Support Stability of a Fully Mechanized Coal Mining Face under the Hard Roof Mining Pressure

Shock and Vibration, 2021
The conditions of the hard roof in my country vary greatly, ranging from a few meters to tens of meters or even hundreds of meters in thickness. The coal reserves under the hard roof account for about one-third of the total reserves.
Jiaxin Dang, Min Tu, Xiangyang Zhang, Qingwei Bu   +3 more
doaj   +1 more source

Optimization Analysis of Advanced Support for Thick and Hard Roof

International Journal of Natural Resources and Environmental Studies
Based on the geological conditions of 1033 working face in Yuandian No.1 Coal Mine, this paper studies the support distance and support strength of hydraulic support in the advanced section of roadway roof. Through numerical simulation analysis, the advance support range of the advance roadway is 5m, 10m, 15m, 20m and 25m four kinds of distance plastic
Yongkun Zhang, Kaiwei Wang
openaire   +1 more source

Utilization of hard rock dust with red clay to produce roof tiles [PDF]

Journal of Asian Ceramic Societies, 2015
AbstractUtilization of rock dust to produce roof tiles and its effects on properties of tiles, mixed with red clay collected from Naogaon district of Bangladesh were investigated. After proper characterization of the raw materials, tiles were prepared with different percentages of rock dust (10-50%) mixed with clay sintered from 850-1100°C temperature.
Sultana, Mst. Shanjida, Ahmed, Aninda Nafis, Zaman, Mohammad Nazim, Rahman, Md. Aminur, Biswas, Pradip Kumar, Nandy, Pranab Kumar   +5 more
openaire   +2 more sources

Revisiting a long‐overlooked skull: Implications for the distribution of Dinodontosaurus brevirostris (Kannemeyeriiformes) in the Brazilian Triassic

The Anatomical Record, EarlyView.
Abstract Dicynodonts (Anomodontia: Dicynodontia) were one of the main groups of terrestrial tetrapods in Permian and Triassic faunas. In Brazil, the genus Dinodontosaurus is one of the most common tetrapod taxon in the Triassic Santa Maria Supersequence. This genus has a complex taxonomic history and is represented in the Triassic of both Argentina and
Julia Lara Rodrigues de Souza, João Lucas Da Silva, Voltaire D. P. Neto, Arielli Fabrício Machado, Juan A. Escobar, Felipe L. Pinheiro   +5 more
wiley   +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

Deformation and Fracture Mechanisms of Thick Hard Roofs in Upward Mining Coalfaces: A Mechanical Model and Its Validation

Applied Sciences
The safety and efficiency of underground coal mining are threatened by thick hard roofs characterized by large overhang areas, problematic spontaneous caving, and high dynamic load upon their breakage.
Wei Zhang, Linchao Cao, Dongsheng Zhang, Yang Hu, Jingyu Chang, Zhenying Zhang   +5 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

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

Meitan 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, Zhaohui WANG, Wenchao SUN, Meng LI, Xin ZHANG, Jialong LI, Dongxin HOU   +6 more
doaj   +1 more source

Jack of all trades? Product diversification in nonfinancial firms [PDF]

While financial firms keep searching for the secret formula to make profits out of providing multiple financial services under one roof, nonfinancial firms seem headed in the opposite direction.
Mitchell Berlin
core  

Poultry Housing [PDF]

, 1935
PDF pages ...
Cray, R. E., Twitchell, H. P.
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