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Concept

Quartz

Related publications (24)

Phase Transformation-Induced Interfacial Debonding of Silica Inclusions in Iron

Andreas Mortensen, Alejandra Inés Slagter, David Hernandez Escobar, Julie Nathalie S Gheysen

We document that in unstressed, undeformed, samples of pure iron containing silica inclusions precipitated by melt deoxidation, the iron matrix and a small fraction of the silica inclusions are locally separated at room temperature by a void. Thermal cycli ...

Springer2023

Iron Reduction in Profundal Sediments of Ultraoligotrophic Lake Tahoe under Oxygen-Limited Conditions

Meret Aeppli

Increased periods of bottom water anoxia in deep temperate lakes due to decreasing frequency and depth of water column mixing in a warming climate may result in the reductive dissolution of iron minerals and increased flux of nutrients from the sediment in ...

2023

Excitonic devices with van der Waals heterostructures: valleytronics meets twistronics

Andras Kis, Ahmet Avsar, Alberto Ciarrocchi, Fedele Tagarelli

2D semiconducting transition metal dichalcogenides comprise an emerging class of materials with distinct properties, including large exciton binding energies that reach hundreds of millielectronvolts and valley-contrasting physics. Thanks to the van der Wa ...

2022

Effect of different ions on dissolution rates of silica and feldspars at high pH

Karen Scrivener, Mahsa Bagheri

The dissolution kinetics of silica-containing minerals in aggregates influences strongly the process of ASR in concrete. In this paper, the effect of different ions on the dissolution rates of SiO2 (amorphous and quartz) and feldspars at high pH values was ...

Pergamon-Elsevier Science Ltd2022

Abnormal temperature dependent elastic properties of fused silica irradiated by ultrafast lasers

Yves Bellouard, Pieter Vlugter

Materials with thermal-invariant elastic properties are of interest for resonant device frequency and dimensional stability of precision devices. Here, we demonstrate that the temperature coefficient of elasticity (TCE) of amorphous silica can be locally r ...

2022

Effect of femtosecond laser-induced high pressure on fused silica polymorphism

Arunkrishnan Radhakrishnan

High-pressure studies in silica are of great interest to earth and planetary sciences. Highpressure phases are rarely found in nature as a result of shock events like meteorite impacts or volcanic events in nature. Recreating these phases remains a challen ...

EPFL2022

Direct Visualization of Atomic-Scale Heterogeneous Structure Dynamics in MnO2 Nanowires

Kangning Zhao

Manganese oxides are attracting great interest owing to their rich polymorphism and multiple valent states, which give rise to a wide range of applications in catalysis, capacitors, ion batteries, and so forth. Most of their functionalities are connected t ...

AMER CHEMICAL SOC2021

Inorganic and Metal-Organic Heterogeneous Catalysts for Hydrogen Energy Applications

Fatma Pelin Uran

The main focus of this thesis is the exploration of inorganic and metal-organic heterogeneous catalysts for hydrogen (H2) energy applications. In particular, we investigated metal nanoparticles (NPs) and metal-organic frameworks (MOFs) for their employment ...

EPFL2021

Aggregate dissolution in different pore solutions

Mahsa Bagheri

The occurrence of cracking due to alkali silica reaction (ASR) affects the service life of concrete structures. The dissolution of silica-containing minerals within aggregates causes the formation of ASR products, which fill macroscopic cracks and cause th ...

EPFL2021

Yielding of a quartz sand from saturated to dry state

Alessio Ferrari

The paper presents the results of an experimental work where we analyse the behaviour of an unsaturated quartz sand in a wide range of degree of saturation (from saturated to dry state). The possibility of anticipating the hydro-mechanical behaviour of the ...

E D P SCIENCES2020

The impact of synthetic amorphous silica (E 551) on differentiated Caco-2 cells, a model for the human intestinal epithelium

Heinrich Hofmann

For several decades, food-grade synthetic amorphous silica (SAS) have been used as a technological additive to reduce caking of food powders. Human exposure is thus inevitable and safety concerns are taken seriously. The toxicity of silica in general and S ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Dry-pressed anodized titania nanotube/CH3NH3PbI3 single crystal heterojunctions: The beneficial role of N doping

László Forró, Bálint Náfrádi, Endre Horvath, Konrad Domanski, Márton Kollár, Pavao Roko Andricevic

Highly ordered, anodically grown TiO2 nanotubes on titanium supports were annealed in ammonia atmosphere in order to incorporate nitrogen doping (

2019

FVPM numerical simulation of the effect of particle shape and elasticity on impact erosion

François Avellan, Ebrahim Jahanbakhsh, Audrey Paulette Solange Maertens, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

The erosion of hydraulic machines by solid particle impacts is a widespread problem that leads to outage for expensive repairs, efficiency reduction, and cavitation enhancement. Numerical simulations can be used to study the phenomenon, provided they featu ...

ELSEVIER SCIENCE SA2019

Hydro-mechanical response of Opalinus Clay shale: dependency on composition and burial depth

Eleonora Crisci

Shales are sedimentary formation currently studied for their involvement in many geo-energy related applications, such as radioactive waste disposal, CO2 sequestration, oil and gas extraction. In Switzerland the Opalinus Clay shale has been selected has ho ...

EPFL2019

Variations in elastic and electrical properties of crustal rocks with varying degree of microfracturation

Marie Estelle Solange Violay, Lucas Xan Pimienta, Luis Felipe Orellana Espinoza

This work aims at investigating the effect of varying degrees of microfracturing on the joint elastic and electrical transport properties of rocks. Different crustal rocks were subjected to Thermal Treatment, expected to induce microfracturing, up to diffe ...

2019

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes

Kumar Varoon Agrawal, Guangwei He, Deepu Joseph Babu

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and non-porous supports (polymer, ceramic, metal, carbon, and graphene). We developed a novel crystallization t ...

JOURNAL OF VISUALIZED EXPERIMENTS2018

Compression testing spherical particles for strength: Theory of the meridian crack test and implementation for microscopic fused quartz

Andreas Mortensen, Václav Pejchal, Raphaël Charvet, Cyril Henri Dénéréaz, Goran Zagar

We show that uniaxial compression testing of spherical particles can give unambiguous access to their tensile strength as governed by surface flaws if one uses pairs of elasto-plastic platens, tailoring their hardness in order to control the relative area ...

2017

Geochemistry, geothermometry and influence of the concentration of mobile elements in the chemical characteristics of carbonate-evaporitic thermal systems. The case of the Tiermas geothermal system (Spain)

The Tiermas low temperature geothermal system, hosted in the Paleocene-Eocene carbonates of the Jaca-Pamplona basin, has been studied to evaluate the geochemistry and the temperature of the waters in the deep reservoir. These waters are of chloride-sodium ...

Elsevier Science Bv2017

{225} habit planes in martensitic steels: from the PTMC to a continuous model

Roland Logé, Cyril Cayron, Annick Pauline Baur

Fine twinned microstructures with {225}γ habit planes are commonly observed in martensitic steels. The present study shows that an equibalanced combination of twin-related variants associated to the Kurdjumov-Sachs orientation relationship is equivalent to ...

Nature Research2017

Short magmatic residence times of quartz phenocrysts in Patagonian rhyolites associated with Gondwana breakup

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner, Susanne Seitz

A key parameter in the study of magma evolution is the time scale on which magmatic processes occur. Using nanoscale secondary ion mass spectrometry (NanoSIMS), SIMS, and cathodoluminescence (CL) analyses, we have measured titanium (Ti) diffusion profiles ...

Geological Society of America2016