scholarly journals Geochemical fingerprints of brannerite (UTi2O6): an integrated study

2020 ◽  
Vol 84 (2) ◽  
pp. 313-334 ◽  
Author(s):  
Marion Turuani ◽  
Flavien Choulet ◽  
Aurélien Eglinger ◽  
Philippe Goncalves ◽  
Julie Machault ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Ore Deposits ◽  
Raman Spectrometry ◽  
Element Abundances ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Refractory Mineral ◽  
Definition Of

AbstractBrannerite (UTi2O6) is among the major uranium-bearing minerals found in ore deposits, however as it has been long considered as a refractory mineral for leaching it is currently disregarded in ore deposits. Brannerite is found in a variety of geological environments with the most common occurrences being hydrothermal and pegmatitic. On the basis of scanning electron microscopy observations coupled with electron probe micro-analyses and laser ablation inductively-coupled plasma mass spectrometer analyses, this study describes the morphological features and the major- and trace-element abundances of brannerite samples from five hydrothermal and five pegmatitic localities across the world. Mineral compositions are also compared with observations from transmission electron microscopy and Raman spectrometry showing that brannerite is amorphous. Significant results include the definition of substitution trends and REE patterns, which are characteristics of either an occurrence or genetic type (hydrothermal and pegmatitic). Hence, in combination, it is possible to obtain reliable constraints for establishing a geochemical classification of brannerite. Inferred fingerprints have direct implications for forensic science and the exploration industry; they also contribute to a better understanding of metallogenic processes and to optimising the extraction of uranium.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

scholarly journals Antimony and Nickel Impurities in Blue and Green Copper Pigments

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1236
Author(s):  
Sylwia Svorová Pawełkowicz ◽  
Barbara Wagner ◽  
Jakub Kotowski ◽  
Grażyna Zofia Żukowska ◽  
Bożena Gołębiowska ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Ore Deposits ◽  
Copper Ore ◽  
Inductively Coupled ◽  
Parish Church ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Quantitative Analyses ◽  
First Time

Impurities in paint layers executed with green and blue copper pigments, although relatively common, have been studied only little to date. Yet, their proper identification is a powerful tool for classification of paintings, and, potentially, for future provenance studies. In this paper, we present analyses of copper pigments layers from wall paintings situated in the vicinity of copper ore deposits (the palace in Kielce, the palace in Ciechanowice, and the parish church in Chotków) located within the contemporary borders of Poland. We compare the results with the analyses of copper minerals from three deposits, two local, and one historically important for the supply of copper in Europe, i.e., Miedzianka in the Holy Cross Mountains, Miedzianka in the Sudetes, and, as a reference, Špania Dolina in the Slovakian Low Tatra. Optical (OM) and electron microscopy (SEM-EDS), Raman spectroscopy, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have been used for a detailed investigation of the minute grains. Special attention has been devoted to antimony and nickel phases, as more unusual than the commonly described iron oxides. Analyses of minerals from the deposits helped to interpret the results obtained from the paint samples. For the first time, quantitative analyses of copper pigments’ impurities have been described.

scholarly journals Towards Reconfigurable Electronics: Silicidation of Top-Down Fabricated Silicon Nanowires

2019 ◽  
Vol 9 (17) ◽  
pp. 3462 ◽  
Author(s):  
Muhammad Bilal Khan ◽  
Dipjyoti Deb ◽  
Jochen Kerbusch ◽  
Florian Fuchs ◽  
Markus Löffler ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silicon Nanowires ◽  
Inductively Coupled Plasma ◽  
Density Functional ◽  
Field Effect Transistors ◽  
Density Functional Theory Calculations ◽  
Silicide Phase ◽  
Top Down ◽  
Inductively Coupled ◽  
Transmission Electron

We present results of our investigations on nickel silicidation of top-down fabricated silicon nanowires (SiNWs). Control over the silicidation process is important for the application of SiNWs in reconfigurable field-effect transistors. Silicidation is performed using a rapid thermal annealing process on the SiNWs fabricated by electron beam lithography and inductively-coupled plasma etching. The effects of variations in crystallographic orientations of SiNWs and different NW designs on the silicidation process are studied. Scanning electron microscopy and transmission electron microscopy are performed to study Ni diffusion, silicide phases, and silicide–silicon interfaces. Control over the silicide phase is achieved together with atomically sharp silicide–silicon interfaces. We find that {111} interfaces are predominantly formed, which are energetically most favorable according to density functional theory calculations. However, control over the silicide length remains a challenge.

Preparation and Characterization of Nickel(Ni)-Silver(Ag) Core-Shell Nanoparticles for Conductive Pastes

2012 ◽  
Vol 531 ◽  
pp. 211-214 ◽  
Author(s):  
Jun Jie Jing ◽  
Ji Min Xie ◽  
Hui Ru Qin ◽  
Wen Hua Li ◽  
Ming Mei Zhang
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Water Solution ◽  
Average Diameter ◽  
Core Shell ◽  
Ni Nanoparticles ◽  
Shell Nanoparticles ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Nickel(Ni)-silver(Ag) core-shell nanoparticles with different shell thickness were synthesized with Ni nanoparticles by liquid phase reduction technique form water solution. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and inductively coupled plasma spectroscopy (ICP). The results showed that the Ni nanoparticles are in sphere shape and the average diameter is 104nm , the nickel(Ni)-silver(Ag) core-shell nanoparticles has good crystallinity and the thinkness of Ag nanoshells could be effectively controlled by changing the concentration of silver nitrate. The product can be used for nickel-based conductive paste preparation because of the surface character of Ag and the magnetic property of Ni

A multimethodic approach for the characterization of manganiceladonite, a new member of the celadonite family from Cerchiara mine, Eastern Liguria, Italy

2017 ◽  
Vol 81 (1) ◽  
pp. 167-173
Author(s):  
G. O. Lepore ◽  
L. Bindi ◽  
F. Di Benedetto ◽  
E. Mugnaioli ◽  
C. Viti ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Paramagnetic Resonance ◽  
Oh Groups ◽  
International Mineralogical Association ◽  
Cell Parameters ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Plasma Mass Spectrometry

AbstractIn the manganesiferous ores associated with the metacherts of the ophiolitic sequences at the Cerchiara mine, Eastern Liguria (Italy), a new Mn-bearing mineral belonging to the mica group has been recently found and characterized. High resolution transmission electron microscopy and electron diffraction tomography studies confirm that the mineral belongs to the mica group. Unit-cell parameters from the powder diffraction pattern are:a= 5.149(1),b= 8.915(1),c= 10.304(1) Å, β = 102.03(1)°, space groupC2 orC2/m. On the basis of the electron paramagnetic resonance spectroscopic results, the Mn4+content represents a very subordinate fraction of the total Mn, the remaining occurring as Mn3+. The Raman spectrum clearly indicates the presence of OH groups in the structure. Laser-ablation inductively-coupled-plasma mass-spectrometry measurements assess the presence of considerable amounts of Li.Assuming all Mn as Mn3+and 22 negative charges, the empirical formula can be expressed as: (K0.83□0.17)(Mn1.143+Mg0.80Li0.20Fe0.023+)(Si3.89Al0.10)O10[(OH)1.92F0.08] with the sum of the octahedral cations indicating a 'transitional' character between a di- and a tri-octahedral structure. This formula corresponds ideally to the Mn3+analogue of celadonite, thus expanding the range of solid solution in the celadonite family. The ideal end-member formula KMn3+MgSi4O10(OH)2can be easily related to celadonite by the homovalent substitutionVIMn3+→VIFe3+. The mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association, (IMA 2015-052).

scholarly journals Carbon supported manganese(IV)–cobalt(II/III) oxides nanoparticles for high-performance electrochemical supercapacitors

Chemija ◽  
2020 ◽  
Vol 31 (2) ◽  
Author(s):  
Jolita Jablonskienė ◽  
Dijana Šimkūnaitė ◽  
Jūratė Vaičiūnienė ◽  
Giedrius Stalnionis ◽  
Audrius Drabavičius ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Performance ◽  
Optical Emission ◽  
Spherical Shape ◽  
High Specific Capacitance ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
One Step ◽  
Shape Of Nanoparticles

The carbon supported manganese(IV)–cobalt (II/III) oxides nanoparticles labelled as MnO2–Co3O4/C nanocomposites have been prepared by a simple one-step microwave-assisted heating method using different precursor materials. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) have been used for the characterization of morphology, structure and composition of the synthesized nanocomposites, whereas the electrochemical performance of the prepared nanocomposites has been evaluated by using cyclic voltammetry (CV). It was determined that the use of different precursor materials for the synthesis of the carbon supported MnO2 and Co3O4 nanocomposites results in a different morphology of the prepared substances. A high specific capacitance (Cs) of 658.8 F g−1 at a scan rate of 10 mV s−1 in a 1 M Na2SO4 solution has been obtained for the MnO2–Co3O4/C-2 nanocomposite that has a spherical shape of nanoparticles. Moreover, it significantly outperforms the MnO2–Co3O4/C-1 nanocomposite that has a lamellar shape of nanoparticles.

Analysis of Pt-Nanoparticles Embedded on Crystalline TiO2 Studied by Transmission Electron Microscopy

2000 ◽  
Vol 638 ◽  
Author(s):  
Jordi Arbiol ◽  
Ana Ruiz ◽  
Albert Cirera ◽  
Francisca Peiró ◽  
Albert Cornet ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Inductively Coupled Plasma ◽  
Surface Density ◽  
Reaction Rate ◽  
Gas Sensing ◽  
Pt Nanoparticles ◽  
Inductively Coupled ◽  
Transmission Electron

AbstractIn this work, we studied the Pt particles embedded on crystalline TiO2 nanopowders. As it is well known, metal nanoparticles distributed on TiO2 surface can improve dramatically the reaction rate and selectivity of reaction in gas sensing. We prepared a wide set of TiO2 samples with different nominal Pt concentration. The aim of this study was to analyse the Pt distribution on TiO2 surface (density of Pt, particle size distribution, etc.), as well as the Pt phases existing in our samples. We used High Resolution Transmission Electron Microscopy (HRTEM) as a powerful tool to study Pt particles morphology. The HRTEM images were compared with computer simulations to confirm the results obtained. The chemical composition of the material has been also investigated by Inductively Coupled Plasma (ICP).

The nature and origin of non-marine 10 Å clay from the Late Eocene and Early Oligocene of the Isle of Wight (Hampshire Basin), UK

Clay Minerals ◽  
2001 ◽  
Vol 36 (3) ◽  
pp. 447-464 ◽  
Author(s):  
J. M. Huggett ◽  
A. S. Gale ◽  
N. Clauer
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Late Eocene ◽  
X Ray Diffraction ◽  
Wetting And Drying ◽  
Wet Chemistry ◽  
X Ray ◽  
Inductively Coupled ◽  
Early Oligocene ◽  
Transmission Electron

AbstractVariegated palaeosols, which formed from weathering of clays, silts and brackish to freshwater limestones, are present in the Late Eocene–Early Oligocene Solent Group of the Hampshire Basin, southern UK. The composition and origin of the clay in three segments of the lower part of the Solent Group have been investigated by X-ray diffraction, microprobe analysis, inductively coupled plasma-mas spectrometry, K/Ar dating, high resolution scanning electron microscopy, analytical transmission electron microscopy and wet chemistry. The detrital clay mineral suite is dominated by illite and smectite with minor kaolinite and chlorite. Seasonal wetting and drying in gley soils has resulted in replacement of smectite by Fe-rich, or illite-rich illitesmectite. Illite has also formed with gypsum and calcite in ephemeral hypersaline alkaline lakes that periodically dried out. This illite may have precipitated directly from solution. X-ray diffraction data and probe analyses indicate that the neoformed illite is Fe-rich. The K and Fe for the illitization are thought to be derived from weathered glauconite reworked from the underlying Bracklesham Group and Barton Beds.

scholarly journals The Role of Continental Crust in the Formation of Uraninite-Based Ore Deposits

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 136 ◽  
Author(s):  
Stefanie R. Lewis ◽  
Antonio Simonetti ◽  
Loretta Corcoran ◽  
Stefanie S. Simonetti ◽  
Corinne Dorais ◽  
...  
Keyword(s):  
Trace Element ◽  
Inductively Coupled Plasma ◽  
Ore Deposits ◽  
Source Attribution ◽  
Rock Composition ◽  
Isotopic Signatures ◽  
Element Abundances ◽  
Inductively Coupled ◽  
Spatially Resolved ◽  
Icp Ms

This study reports trace element abundances and Pb, Sr, and U isotopic signatures of uraninite from a variety of ore deposits in order to establish baseline forensic information for source attribution of raw, natural U-rich samples. Trace element concentrations, reported here, provide insights into uraninite crystal substitution mechanisms and possible crustal sources of U, including mobility of trace elements between pristine versus altered fractions. Spatially resolved laser ablation (LA) multicollector (MC) inductively coupled plasma mass spectrometry (ICP-MS) analyses were used to determine secondary 207Pb-206Pb isochron ages, and these were validated by corroborative results obtained by solution mode (SM) MC-ICP-MS for the same sample. Secondary Pb-Pb isochron ages obtained, in this study, indicate that uraninite alteration occurs shortly after ore mineralization. Initial 87Sr/86Sr values correlate in general with host craton age, and therefore suggest that uraninite ore formation is closely linked to the nature of the bedrock geology. The δ238U values are explained by invoking multiple physicochemical conditions and parameters such as temperature, nuclear field shift, oxidation, and source rock composition. The δ234U values indicate that the uraninites, investigated here, have undergone recent alteration, but the latter has not perturbed the Pb-Pb secondary isochron ages.

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