نتایج جستجو برای: hard rocks

تعداد نتایج: 168880  

Journal: :Minerals 2021

The paper presents the results of research on rare earth elements (REY) and selected radionuclides in barren rocks deposited a heap at mine belonging to Polish Mining Group (the largest producer hard coal EU countries). maximum concentration REEs determined silstones was 261.6 mg/kg sandstones 221.2 mg/kg. average uranium thorium content 6.8 11.6 mg/kg, respectively. On other hand, samples burn...

2016
L. Kissick F. Butcher P. Donnelly J. D. Piercy J. L. Vago D. Loizeau L. Lorenzoni P. M. Grindrod

Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. Introduction: We present preliminary work to characterize surface rock abundance at ExoMars Rover landing site candidates. A challenge in quantifying the a...

1999
Brian Evans David L. Kohlstedt

1.1. Strategy and Techniques For a rock of given mineralogy and microstructure, the variables important in determining strength are pressure, temperature, strain, strain history, strain rate, pore fluid pressure, grain size, fugacities of water and other volatiles, and chemical activities of the mineral components. Although earth scientists may now duplicate pressures and temperatures appropria...

2011
Alessandro Iannace

Sedimentary rocks are one component of the modern threefold classification of rocks. They derive from the lithification of sediments, which are produced in basically two ways: by the mechanical deposition of grains derived from the alteration of other rocks (detrital or clastic rocks), or as chemical precipitates or grains formed organically or inorganically from an aqueous solution. The whole ...

2000
Bernard BONIN

105 Abstract: Origin of A-type alkali feldspar granites is currently the subject of a world-wide debate. Contrasting hypotheses have been proposed, which range from an entirely crustal origin to an almost complete mantle derivation. A-type alkali feldspar granites belong to either unimodal granite (rhyolite)-dominated association, or bimodal gabbro (basalt)-granite (rhyolite) suite. It is argue...

2015
Zizhen Wang Ruihe Wang Tianyang Li Hao Qiu Feifei Wang

Underground rocks usually have complex pore system with a variety of pore types and a wide range of pore size. The effects of pore structure on elastic wave attenuation cannot be neglected. We investigated the pore structure effects on P-wave scattering attenuation in dry rocks by pore-scale modeling based on the wave theory and the similarity principle. Our modeling results indicate that pore ...

2006
G. R. PARSLOW

SINCE Cross, Iddings, Pirsson, and Washington 09o3) first published their system of deriving normative minerals from chemical analyses, the CIPW norm has been successfully used to identify, compare, and classify trends in igneous rocks with similar or differing mineral compositions. The norm has been used for metamorphic rocks and rocks of somewhat uncertain mode of origin (Bowes, ~967). Variou...

2006

Basement rocks in the 17,000-square-mile region of southern Oklahoma crop out in the Wichita and Arbuckle Mountains and have been studied in subsurface samples from 175 wells. The rocks are divided into two contrasting provinces, each completely different from the other in age and petrologic character. Each province has played a different role in guiding the stratigraphic and structural evoluti...

Journal: :The European respiratory journal 2011
S Duong-Quy P Dao T Hua-Huy C Guilluy P Pacaud A T Dinh-Xuan

Endothelial dysfunction is one of the main consequences of the toxic effects of cigarette smoke on the vascular system. Increasing evidence suggests that the small G-protein RhoA and its downstream effectors, the Rho-kinases (ROCKs), are involved in systemic endothelial dysfunction induced by cigarette smoke. This study aimed to evaluate the role of the RhoA/ROCKs pathway in pulmonary artery en...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2016
Nicole M Foley Mark S Springer Emma C Teeling

Most molecular phylogenetic studies place all placental mammals into four superordinal groups, Laurasiatheria (e.g. dogs, bats, whales), Euarchontoglires (e.g. humans, rodents, colugos), Xenarthra (e.g. armadillos, anteaters) and Afrotheria (e.g. elephants, sea cows, tenrecs), and estimate that these clades last shared a common ancestor 90-110 million years ago. This phylogeny has provided a fr...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید