نتایج جستجو برای: weak partings

تعداد نتایج: 140830  

Journal: :Advances in Space Research 2016

Journal: :int. journal of mining & geo-engineering 2012
d.f. malan

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...

Journal: :Frontiers in Earth Science 2023

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...

2016
Panpan Xie Hongjian Song Jianpeng Wei Qingqian Li

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...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
Paul N Pearson Christopher J Nicholas

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...

Journal: :The British journal of psychiatry : the journal of mental science 1985
J K Morrice R C Taylor D Clark K McCann

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ولی عصر (عج) - رفسنجان - دانشکده ریاضی 1389

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...

2006
John Tarney

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...

2002
JoAnne Nelson

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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