Results 61 to 70 of about 139,365 (154)
Adjoint functors and triangulated categories
, 2007 We give a construction of triangulated categories as quotients of exact categories where the subclass of objects sent to zero is defined by a triple of functors. This includes the cases of homotopy and stable module categories. These categories naturally
Grime, Matthew
core +2 more sources
Energies, 2018 The movements of overburden induced by mining a thick coal seam with a hard roof extend widely. The effects of breakages in the hard strata on the strata behaviors might vary with the overlying strata layers.
Yiwen Lan +3 more
doaj +1 more source
Scientific ReportsThick-hard roof fracturing presents a significant challenge for disaster prevention in longwall mining. This study investigates the 15,311 south working face and develops a mechanical model to analyze energy release during both initial and cyclic roof ...
Rui Wang +4 more
doaj +1 more source
Journal of Rock Mechanics and Geotechnical EngineeringDuring fully mechanized caving mining of thick coal seams, a large amount of strain energy accumulates in the roof, especially when the roof is thick and hard, making it difficult for the roof to collapse naturally.
Qi Wang +5 more
doaj +1 more source
Preliminary Report on a Stratified Late Archaic-Woodland Era Rockshelter in Rogers County, Oklahoma [PDF]
, 1995 In northeastern Oklahoma, very little is known about the transition from the Late Archaic to the Woodland period (Wyckoff and Brooks, 1983: 55). To date, most of the archeological evidence documenting this time period has been derived from sites with ...
Hill, Kiven C. +3 more
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矿业科学学报, 2016 It is difficult to determine the first roof weighting interval of hard roof on fully mechanized caving face.Based on the working face 8301 of Dongzhouyao coal mine, a model of two edges fixed in thick and hard roof was established by using energy method ...
Cheng Zhanbo, Kong Dezhong, Yang Jinghu
doaj
A Roof of One\u27s Own: Widow Walking in the Anthropocene [PDF]
, 2018 A nonfiction work that explores widow\u27s walks in a time of climate change on the coasts.
Mullen, Anna C
core +1 more source
Energies, 2017 In extra-thick coal seams, mining operations can lead to large-scale disturbances, complex overburden structures, and frequent and strong strata behavior in the stope, which are serious threats to mine safety. This study analyzed the overburden structure
Jingxuan Yang, Changyou Liu, Bin Yu
doaj +1 more source
Study on disaster mechanism of thick and hard overhanging roof and top cutting control technology
Gong-kuang zidonghuaTo address the challenges of significant deformation and high instability risks in the surrounding rock of unsupported roadways beneath a laterally thick and hard overhanging roof, this study focused on the 3810 working face transport roadway in ...
GENG Ming, SUN Jing
doaj +1 more source
The Baptist Church in Warren: Rehabilitation and Preservation Report [PDF]
, 2013 The Baptist Church in Warren is located in the Warren Waterfront Historic National Register District. Warren also has a Voluntary Historic District. Both the National Register Nomination and the Voluntary Historic District have regulations which pertain ...
Bambara, Lauren +4 more
core +1 more source