نتایج جستجو برای: weak partings
تعداد نتایج: 140830 فیلتر نتایج به سال:
this paper gives an overview of the difficulties associated with the design of hard rock pillars in south african mines. recent examples of large scale pillar collapses in south africa suggest that these were caused by weak partings which traversed the pillars. currently two different methods are used to determine the strength of pillars, namely, empirical equations derived from back analyses o...
This paper gives an overview of the difficulties associated with the design of hard rock pillars in South African mines. Recent examples of large scale pillar collapses in South Africa suggest that these were caused by weak partings which traversed the pillars. Currently two different methods are used to determine the strength of pillars, namely, empirical equations derived from back analyses o...
The C 1 coal of Latest Permian during mass extinction in eastern Yunnan was studied to reveal the terrestrial paleoenvironment and influence geological events on coal-formation extinction. An analysis Rare Earth Elements (REEs) conducted from Yantang Mine Xuanwei, Province, which deposited latest Permian. A total 24 samples coals, partings, roofs floors were taken fresh face underground mine. r...
This paper reports the mineralogical compositions of super-low-sulfur (Yueliangtian 6-upper (YLT6U)) and high-sulfur (Yueliangtian 6-lower (YLT6L)) coals of the Late Permian No. 6 coal seam from the Yueliangtian coal mine, Guizhou, southwestern China. The mineral assemblages and morphology were detected and observed by X-ray diffractogram (XRD), optical microscopy and field-emission scanning el...
In a study of a sediment core from the US Atlantic Coastal Plain (Ocean Drilling Program Site 174X-Millville), Wright and Schal-ler (1) claim to have resolved the onset of the Paleocene/Eocene carbon isotope excursion (CIE) across 13 y. Such a rapid change would require an enormous and instantaneous release of isotopically light carbon into the ocean/atmosphere, implicating comet impact. The cl...
An investigation was conducted in the Aberdeen area on wives of oil men working either off-shore or on-shore. No differences were found in measures of general health; but 'off-shore wives' were shown to experience mood and behavioural changes, linked to the pattern of swiftly recurring partings and reunions. While a majority of such wives appeared to tolerate or even thrive on their style of li...
in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...
Sediments of Late Jurassic to Early Cretaceous age, overlying a continental gneissic basement, were sampled in fifteen cores at Site 330, Falkland Plateau. Thin limestone bands occur at intervals throughout much of the succession represented by Cores 3 through 14. Many of the limestones, which vary in thickness from two or three centimeters to several tens of centimeters, are characterized by s...
argillite, interbedded basalt and abundant diabase sills. More specifically, the rhodonite is located above a section of grey, black and pale green chert and argillite at the base of the unit [IIPPvs( I ) on Figure 2-15-21 and about 50 metres below an upper section of brightly coloured, maroon, red, green and grey chert and argillite [Unit IIPPvs(2) on Figure 2-15-21, This stratigraphic positio...
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