Publications associées à Silice précipitée

High-Density Immobilization of TCEP on Silica Beads for Efficient Disulfide Reduction and Thiol Alkylation in Peptides

Tris-(2-carboxyethyl)phosphine (TCEP) linked to agarose beads is widely used for reducing disulfide bridges in proteins and peptides. The immobilization of TCEP on beads allows efficient removal after reduction to prevent its reaction with alkylating reage ...

2023

Micromechanics of oxide inclusions in ferrous alloys

Alejandra Inés Slagter

Oxide inclusions are inevitably present in steel as a direct consequence of the steelmaking process; as a result, a cubic centimetre of modern steel will generally contain about a million of these hard and brittle micrometre-sized ceramic particles. Inclus ...

EPFL2023

Data-driven optimization tool for the functional, economic, and environmental properties of blended cement concrete using supplementary cementitious materials

Hisham Tarek Mohamed Hafez

The need to produce more sustainable concrete is proving imminent given the rising environmental concerns facing the industry. Blended cement concrete, based on any of the prominent supplementary cementitious materials (SCMs) such as fly ash, ground granul ...

ELSEVIER2023

Strong silicon oxide inclusions in iron

Andreas Mortensen, Léa Deillon, Alejandra Inés Slagter, Joris Pierre Everaerts

Oxide inclusions are ubiquitous in steel and are known to affect, generally in a negative sense, the mechanical performance of steel products. Micromechanical properties of those phases are therefore important, yet they have remained largely unexplored. We ...

2022

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

Pre-bcc: A novel integrated machine learning framework for predicting mechanical and durability properties of blended cement concrete

Hisham Tarek Mohamed Hafez

Partially replacing ordinary Portland cement (OPC) with low-carbon supplementary cementitious materials (SCMs) in blended cement concrete (BCC) is perceived as the most promising route for sustainable concrete production. Despite having a lower environment ...

ELSEVIER SCI LTD2022

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

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri, Mahdieh Shakoorioskooie

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

The effect of paste composition, aggregate mineralogy and temperature on the pore solution composition and the extent of ASR expansion

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri

The reaction kinetics of the alkali silica reaction depends on the composition of the pore solution. The evolution of the pore solution composition in different cement pastes and concretes was studied. Pastes containing silica fume or metakaolin had the lo ...

SPRINGER2022

Characterization of water sorption cycle in the cement microstructure of controlled oxide composition

Monisha Rastogi

This thesis investigates the water vapour sorption behaviour of samples with maximized calcium-silicate-hydrate (C-S-H) content. Primarily, the role of heterogeneous and homogeneous cavitation has been studied during the drying of cementitious materials. C ...

EPFL2022

Grafting of Alkali Metals on Fumed Silica for the Catalytic Dehydrogenation of Methanol to Formaldehyde

Oliver Kröcher, Alimohammad Bahmanpour, Christophe Jean Baranowski, Jack Brandon

Water free, non-oxidative catalytic dehydrogenation of methanol to formaldehyde is an important process for the formation of anhydrous, molecular formaldehyde (FA). Sodium or sodium-containing salts were shown to catalyze the reaction, but their reaction m ...

Wiley-VCH Verlag2021

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

Advances in heterogeneous catalysis for the synthesis of polyoxymethylene dimethyl ethers

Christophe Jean Baranowski

Our society is engaged in a major shift towards more sustainable industries. The required transition from fossils to renewable resources with low greenhouse gas emission is specifically challenging in the transportation sector where high thermal efficiency ...

EPFL2020

Structural and microstructural studies on SiC-SiO2 ceramic composites

Ho-Yun Lee

In this study, SiC ceramic substrates were prepared with 99.5% silicon carbide powders which were came from waste silicon mud during the manufacturing process of solar cells. It is found that a SiO2 layer with 50 nm in thickness is present on the SiC surfa ...

2019

Tensile response of low clinker UHPFRC subjected to fully restrained shrinkage

Emmanuel Denarié, Mohamed Abdul Hafiz, Amir Hajiesmaeili

This paper addresses the tensile response of Strain Hardening Ultra High Performance Fiber Reinforced Concretes (SH-UHPFRC) subjected to restrained autogenous shrinkage deformations under full and partial restraint conditions, right after casting and until ...

Pergamon-Elsevier Science Ltd2019

Effect of replacement of silica fume with calcined clay on the hydration and microstructural development of eco-UHPFRC

Karen Scrivener, Mohammadhadi Kazemi Kamyab, Wei Sun, Wei Huang

In this paper, the replacement of high cost silica fume with calcined clay was investigated in UHPFRC mixes. The impact of two grades of calcined clay on the hydration and microstructural development of UHPFRC matrices was investigated, where 54% of the ce ...

Elsevier Sci Ltd2017

Application of micro X-ray diffraction to investigate the reaction products formed by the alkali–silica reaction in concrete structures

Gervais Chapuis, Alla Arakcheeva, Philip Pattison

Alkali-silica reaction (ASR) is one of the most important deterioration mechanisms in concrete leading to substantial damages of structures worldwide. Synchrotron-based micro-X-ray diffraction (micro-XRD) was employed to characterize the mineral phases for ...

Pergamon-Elsevier Science Ltd2016

Carboxylic Acid Functionalized Clathrochelate Complexes: Large, Robust, and Easy-to-Access Metalloligands

Rosario Scopelliti, Kay Severin, Kurt Schenk, Philip Pattison, Euro Solari, Mathieu Jérémie Marmier, Matthew David Wise

Polycarboxylate ligands are among the most important building blocks for the synthesis of metal–organic frameworks (MOFs). The ability to access these ligands in an efficient way is of key importance for future applications of MOFs. Here, we demonstrate th ...

2016

Composition of C-S-H in pastes with increasing levels of silica fume addition

Karen Scrivener, John Espen Rossen, Barbara Lothenbach

New results show that the microstructure development of cement–silica fume blends is very different from plain cement. Portlandite (CH) tends to precipitate as platelets and even around clinker grains as “CH rims” and is consumed by pozzolanic reaction wit ...

Pergamon-Elsevier Science Ltd2015

Influence of silica fume on the microstructure of cement pastes: New insights from H-1 NMR relaxometry

Karen Scrivener, Arnaud Charles Albert Muller

H-1 NMR has been used to characterise white Portland cement paste incorporating 10 wt.% of silica fume. Samples were measured sealed throughout the hydration without sample drying. Paste compositions and C-S-H characteristics are calculated based on H-1 NM ...

Pergamon-Elsevier Science Ltd2015

Solution-Controlled Dissolution of Supplementary Cementitious Material Glasses at pH 13: The Effect of Solution Composition on Glass Dissolution Rates

Ruben Anton Snellings

Supplementary cementitious materials (SCMs) are widely used to partially replace portland clinker in blended cements. Reducing clinker contents further without compromising the development of early strength necessitates a better assessment and enhancement ...

Wiley-Blackwell2013