Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Cycle du dioxyde de silicium

Publications associées (27)

Modulating the Surface Properties of Lithium Niobate Nanoparticles by Multifunctional Coatings Using Water-in-Oil Microemulsions

Sandrine Gerber, Alessandra Spada, Adrian Stefan Gheata

Inorganic nanoparticles (NPs) have emerged as promising tools in biomedical applications, owing to their inherent physicochemical properties and their ease of functionalization. In all potential applications, the surface functionalization strategy is a key ...

2023

River ecosystem metabolism and carbon biogeochemistry in a changing world

Enrico Bertuzzo, Tom Ian Battin, Luis Gómez Gener

River networks represent the largest biogeochemical nexus between the continents, ocean and atmosphere. Our current understanding of the role of rivers in the global carbon cycle remains limited, which makes it difficult to predict how global change may al ...

NATURE PORTFOLIO2023

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

Unexpectedly minor nitrous oxide emissions from fluvial networks draining permafrost catchments of the East Qinghai-Tibet Plateau

Tom Ian Battin

Streams and rivers emit substantial amounts of nitrous oxide (N2O) and are therefore an essential component of global nitrogen (N) cycle. Permafrost soils store a large reservoir of dormant N that, upon thawing, can enter fluvial networks and partly degrad ...

Nature Research2022

Equal abundance of summertime natural and wintertime anthropogenic Arctic organic aerosols

Julia Schmale

Aerosols play an important yet uncertain role in modulating the radiation balance of the sensitive Arctic atmosphere. Organic aerosol is one of the most abundant, yet least understood, fractions of the Arctic aerosol mass. Here we use data from eight obser ...

2022

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

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

Oliver Kröcher, Alimohammad Bahmanpour, Christophe Jean Baranowski

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

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

Stream Solutes and Particulates Export Regimes: A New Framework to Optimize Their Monitoring

Camille Roland Marie Minaudo

The quantification of solute and sediment export from drainage basins is challenging. A large proportion of annual or decadal loads of most constituents is exported during relatively short periods of time, a “hot moment,” which vary between constituents an ...

Frontiers Media SA (Switzerland)2020

Changing nutrient cycling in Lake Baikal, the world's oldest lake

Sebastiano Piccolroaz

Lake Baikal, lying in a rift zone in southeastern Siberia, is the world's oldest, deepest, and most voluminous lake that began to form over 30 million years ago. Cited as the "most outstanding example of a freshwater ecosystem" and designated a World Herit ...

National Academy of Sciences2020

Adapting the dynamic LakeMab model to simulate seasonal variations of phosphorus concentration in reservoirs: a case study of Lake Bultiere (France)

Camille Roland Marie Minaudo

Controlling phosphorus is fundamental to limit the risk of eutrophication of continental aquatic ecosystems. Integrated modelling of its concentration in the aquatic continuum requires specific tools for water bodies. However, although simple static empiri ...

2020

Ultrafast carbothermal reduction of silica to silicon using a CO2 laser beam

Jaeki Jeong

We report the extraction of silicon via a carbothermal reduction process using a CO2 laser beam as a heat source. The surface of a mixture of silica and carbon black powder became brown after laser beam irradiation for a few tens of seconds, and clear peak ...

NATURE RESEARCH2020

Silicon isotopes in Arctic and sub-Arctic glacial meltwaters: the role of subglacial weathering in the silicon cycle

Tyler Joe Kohler

Glacial environments play an important role in high-latitude marine nutrient cycling, potentially contributing significant fluxes of silicon (Si) to the polar oceans, either as dissolved silicon (DSi) or as dissolvable amorphous silica (ASi). Silicon is a ...

2019

Investigation of subglacial weathering under the Greenland Ice Sheet using silicon isotopes

Tyler Joe Kohler

Subglacial chemical weathering plays a key role in global silicate weathering budgets, contributing to the cycling of silicon (Si) in terrestrial and marine systems and the potential drawdown of carbon dioxide from the atmosphere. Here, we use data from tw ...

2019

High‐resolution spatial sampling identifies groundwater as driver of CO 2 dynamics in an Alpine stream network

Tom Ian Battin, Amber Joy Ulseth, Asa Lovisa Viktoria Horgby, Marta Boix Canadell

Inland waters are major sources of CO2 to the atmosphere. The origin of this CO2 is often elusive, especially in high‐altitude streams that remain poorly studied at present. Here we study the spatial and seasonal variations in streamwater CO2, its potentia ...

2019

Polyphenols as Morphogenetic Agents for the Controlled Synthesis of Mesoporous Silica Nanoparticles

Fabien Sorin, Jialuo Luo

Non-surfactant-induced synthesis of mesoporous silica nanoparticles (MSNPs) is gaining increasing interest because of their low toxicity and simple purification compared to conventional surfactant-based methods. Tannic acid (TA), considered as a glucose-de ...

AMER CHEMICAL SOC2019

In Situ Observation of Coulomb Fission of Individual Plasmonic Nanoparticles

Marcel Drabbels, Ulrich Lorenz, Pavel Olshin, Jonathan Mark Voss, Romain Loïc Charbonnier

Reshaping plasmonic nanoparticles with laser pulses has been extensively researched as a tool for tuning their properties. However, in the absence of direct observations of the processes involved, important mechanistic details have remained elusive. Here, ...

2019

Unexpected large evasion fluxes of carbon dioxide from turbulent streams draining the world’s mountains

Tom Ian Battin, Enrico Bertuzzo, Amber Joy Ulseth, Asa Lovisa Viktoria Horgby, Pier Luigi Segatto

Inland waters, including streams and rivers, are active components of the global carbon cycle.Despite the large areal extent of the world’s mountains, the role of mountain streams forglobal carbonfluxes remains elusive. Using recent insights from gas excha ...

Nature Research2019

Modeling metabolic networks of individual bacterial agents in heterogeneous and dynamic soil habitats (IndiMeSH)

Dani Or, Vassily Hatzimanikatis, Meriç Ataman

Natural soil is characterized as a complex habitat with patchy hydrated islands and spatially variable nutrients that is in a constant state of change due to wetting-drying dynamics. Soil microbial activity is often concentrated in sparsely distributed hot ...

2019