نتایج جستجو برای: rare earth elements ree

تعداد نتایج: 590324  

2007
Stephen W. Parman Nobumichu Shimizu Timothy L. Grove Jesse C. Dann

The trace element compositions of igneous augite preserved in metamorphosed komatiite samples from the lower Komati Formation, Barberton Mountainland, South Africa (3.49 Ga), were analyzed in order to estimate the pre-metamorphic bulk composition of the samples. The chemical effects of metamorphism are evaluated by calculating the trace element (TE) composition of a hypothetical augite in equil...

Mohammadi, , Yari, , Zarrinkoub, ,

The study area is located about 105 kilometers east of Sarbisheh in Southern Khorasan and in the Sistan suture zone. The magmatic rocks of this area are exposed as intrusive and sub volcanice including diorite, quartz diorite, porphyry quartz diorite and porphyry diorite with Oligocene- Miocene age. These rocks have granular, porphyry with fine- grained matrix, ophitic, intergranular and glomer...

2018
Jingyao Xu Joan Carles Melgarejo

The sequence of replacement in groundmass perovskite and spinel from SK-1 and SK-2 kimberlites (Eastern Dharwar craton, India) has been established. Two types of perovskite occur in the studied Indian kimberlites. Type 1 perovskite is found in the groundmass, crystallized directly from the kimberlite magma, it is light rare-earth elements (LREE)-rich and Fe-poor and its ∆NNO calculated value is...

1999
Jaegwan Chung Junghwan Park Byung-Hee Choi

We studied the electronic structure of rare-earth ditelluride (ReTe2: Re = La, Pr, Sm, and Gd) using photoemission spectroscopy. From the x-ray photoelectron spectroscopy (XPS) study of the 3d core levels of rare-earth elements, we found that all the rare earth elements are trivalent. We have also made theoretical calculations using the Gunnarsson and Schönhammer approximation and multiplet cal...

Journal: :Ironmaking & Steelmaking 2022

Different alloying concepts to trace deoxidation products, mainly aluminium oxides, using rare earth elements (REEs), were tested on the laboratory scale by melting trials with a high-frequency remelting furnace. Lanthanum and Cerium, which belong group of light REEs, used for these experiments. The formed multiphase inclusions characterized scanning electron microscopy energy dispersive spectr...

ژورنال: علوم آب و خاک 2016
خسرویانی, دولت , داودیان دهکردی, علیرضا , شیبی, مریم , گیوی, جواد,

The concentrations of rare-earth elements (REEs) were determined with the aim of investigating the behavior of these elements in granitic rock, granitic soils and soils between rock and lichen in Shir-kuh of Yazd province. Rare earth element patterns of the P-rich granite were determined by the mixture of Eu-enriched feldspars, middle REEs to heavy REEs-enriched apatite and Light REEs-enriched ...

Journal: :Journal of Petrology 2023

Abstract Alkaline-peralkaline igneous systems are promising sources of Rare Earth Elements (REE). Preservation bias has resulted in a gap the geological record for alkaline-peralkaline magmatic systems, with hypabyssal plumbing system linking magma chambers to extrusive volcanic rocks poorly represented. Large plutonic varieties these often proposed have fed (now eroded) volcanoes, and current ...

Journal: :Circular Economy and Sustainability 2022

Abstract Rare earth elements (REEs) are often referred to as the industrial vitamins and key drivers of industry 4.0 revolution. The current global supply chain REEs for green high-tech applications with more than 220 metric kilotons per year involves a huge environmental impact (backpack) well piling up radioactive by-products about 1.5 times amount produced. E-wastes municipal solid waste str...

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