Publications associées à Fiber optics opens window on stream dynamics

Quench Detection and Temperature Measurement With Fiber Optic Sensors

Davide Uglietti, Kamil Sedlák, Christoph Müller

For the EU DEMO conductor testing, a temperature sensor based on Fiber Bragg Grating (FBG) optical fiber is studied at the EPFL Swiss Plasma Center. The SULTAN test facility has been upgraded to use fiber optic sensor for temperature monitoring and quench ...

IEEE Institute of Electrical and Electronics Engineers2024

Lotic-SIPCO2: Adaptation of an open-source CO2 sensor system and examination of associated emission uncertainties across a range of stream sizes and land uses

Andrew Lean Robison

River networks play a crucial role in the global carbon cycle, as relevant sources of carbon dioxide (CO2) to the atmosphere. Advancements in high-frequency monitoring in aquatic environments have enabled measurement of dissolved CO2 concentration at tempo ...

Association for the Sciences of Limnology and Oceanography (ASLO)2024

The microbial genomics of glacier-fed streams: adaptations to an extreme ecosystem

Massimo Bourquin

Glacier-fed streams are the cold, ultra-oligotrophic, and unstable streams that are fed by glacial meltwater. Despite these extreme conditions, they harbour a diverse and abundant microbial diversity that develops into biofilms, covering the boulders and s ...

EPFL2024

Winter post-droughts amplify extreme nitrate concentrations in German rivers

Jana Freiin von Freyberg

Hydrological extremes can affect nutrient export from catchments to streams, posing a threat to aquatic ecosystems. In this study, we investigated the effects of hydrological drought on nitrate concentrations in the streamflow of 182 German catchments from ...

Iop Publishing Ltd2024

High energy-density electrostatic actuators for soft robotics

Sylvain Thomas Schaller

This thesis reports high energy-density electrostatic actuators for use in soft robotics. This thesis has two main parts: a) a detailed study of electro-adhesion using microfabricated electrodes, and b) a flexi-ble fiber-shaped linear motor. Electro-adhesi ...

EPFL2024

The cost of adaptability: resource availability constrains functional stability under pulsed disturbances

Hannes Markus Peter

Global change exposes ecosystems to changes in the frequency, magnitude, and concomitancy of disturbances, which impact the composition and functioning of these systems. Here, we experimentally evaluate the effects of salinity disturbances and eutrophicati ...

Amer Soc Microbiology2024

Treeline displacement may affect lake dissolved organic matter processing at high latitudes and altitudes

Hannes Markus Peter

Climate change induced shifts in treeline position, both towards higher altitudes and latitudes induce changes in soil organic matter. Eventually, soil organic matter is transported to alpine and subarctic lakes with yet unknown consequences for dissolved ...

Nature Portfolio2024

At what spatial scale does natural selection operate? Using multiscale frameworks to calibrate the effects of environmental factors across landscape continuums

Annie Sandrine Guillaume

Patterns in nature arise from processes interacting across a continuum of spatial scales, where new relationships emerge at each level of investigation. These patterns are nested features encompassing fine-scale local patterns, such as topography and geolo ...

EPFL2024

Space-time wave packets with reduced divergence and tunable group velocity generated in free space after multi-mode fiber propagation

Tobias Kippenberg, Hao Song, Maxim Karpov, Xinzhou Su

Previously, space-time wave packets (STWPs) have been gen-erated in free space with reduced diffraction and a tunable group velocity by combining multiple frequency comb lines each carrying a single Bessel mode with a unique wave num-ber. It might be poten ...

Optica Publishing Group2023

Humidity-insensitive optical fibers for distributed sensing applications

Luc Thévenaz, Tiago Filipe Pimentel Das Neves

Humidity is a critical environmental factor in various applications, and its temperature dependence must be considered when developing thermo-hygrometer fiber sensors. The optical fibers that constitute the sensor must have a temperature reference, which s ...

2023

Tunable pump compression and fast modulation for pulsed THz generation

Ileana-Cristina Benea-Chelmus, Shima Rajabali, Yazan Lampert Almahmoud, Alessandro Tomasino

We demonstrate tunable dispersion compensation of femtosecond pulses at telecom wavelengths for broadband Terahertz generation in 7.5-meter fiber link using a Silicon prism pair. The prism pair enhances the amplitude of the THz E-field in InGaAs photocondu ...

IEEE2023

Atlas Narratives of Anthropogenic Transformations across the Vietnamese Mekong Delta's Urban-Rural Territories: Water Ecosystems as Subject for the Social Ecological Transition

Sylvie Tram Nguyen

Well beyond the impact of climate change, anthropogenic modifications of the Vietnam Mekong Delta's ecosystems have resulted in environmental degradation and subsequent loss in ecosystems. The environmental impacts include but are not limited to accelerate ...

EPFL2023

Use of an unmanned aerial-aquatic vehicle for acoustic sensing in freshwater ecosystems

Mirko Kovac, Raphael Zufferey

Freshwater ecosystems are endangered, underfunded and understudied, making new methods such as passive acoustic monitoring (PAM) essential for improving the efficiency and effectiveness of data collection. However, many challenges are still to be addressed ...

Wiley2023

Clogging of riverbed substrates by fine sediment

Romain Maxime Dubuis

Riverbeds represent the habitat of numerous aquatic species. Exchanges between the groundwater, the hyporheic zone and the surface flow are also essential for river ecosystems. Fine sediment transported by rivers deposits inside or on top of the bed and mo ...

EPFL2023

Process development of pre-impregnated hybrid thin-ply composites

Alexios Argyropoulos

Thin-ply composites, obtained with recently developed fiber spreading techniques, rapidly gained industrial interest because they offer a large composite design freedom, and lead to a composite tensile strength that is close to that of the individual fiber ...

EPFL2023

Study on the possibility of Φ-OTDR sensing in hollow-core fibres

Luc Thévenaz, Malak Mohamed Hossameldeen Omar Mohamed Galal, Yuting Yang

The backscattering process in hollow core fibres shows a large similarity with Rayleigh scattering, offering the potential to be exploited for distributed sensing. A classical Φ-OTDR implementation is used to observe the backscattering signal from the surf ...

SPIE2023

Integrated silicon photonic MEMS

Niels Quack, Hamed Sattari, Alain Yuji Takabayashi

Silicon photonics has emerged as a mature technology that is expected to play a key role in critical emerging applications, including very high data rate optical communications, distance sensing for autonomous vehicles, photonic-accelerated computing, and ...

SPRINGERNATURE2023

Food web structure and energy flux dynamics, but not taxonomic richness, influence microbial ecosystem functions in a Sphagnum-dominated peatland

Alexandre Buttler, Edward Mitchell, Vincent Eric Jules Jassey

Soil microbial communities are vital for multiple ecosystem processes and services. In particular, soil microbial food webs are key determinants of soil biodiversity, functioning and stability. Unclear, however, is how struc-tural features of food webs, su ...

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER2023

A Survey of Industrial N-nitrosamine Discharges in Switzerland

Florian Frédéric Vincent Breider, Caroline Gachet Aquillon, Urs von Gunten

N-nitrosamines are formed during different industrial processes and are of significant concern due to their carcinogenic and mutagenic properties. This study reports concentrations of N-nitrosamines in eight different industrial wastewater treatment plants ...

2023

A Kilometre-range Distributed Relative Humidity Fibre Sensor

Tiago Filipe Pimentel Das Neves

Fibre optics sensors have been identified as very good candidates for environmental monitoring inside the silicon detectors operated at CERN's Large Hadron Collider. The objective of this dissertation is the development of a Relative Humidity (RH) distribu ...

EPFL2022