Publications associées à Photosensitivity and Luminescence Induced by ArF-Irradiation of Hydrogen Loaded Bi-SiO2 Fiber

Using Complex Hydrides for Hydrogen Storage and Direct Borohydride Fuel Cells for Electricity Production

Hydrogen storage and utilization are the technologies to achieve carbon-neutral energy systems with renewable energy sources. Among the various materials that have been investigated, complex hydrides are a material exhibiting high gravimetric hydrogen dens ...

EPFL2023

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

Printing sub-micron structures using Talbot mask-aligner lithography with a 193 nm CW laser light source

Wilfried Noell, Toralf Scharf, Raoul Kirner, Andreas Vetter

A continuous improvement of resolution in mask-aligner lithography is sought after to meet the requirements of an ever decreasing minimum feature size in back-end processes. For periodic structures, utilizing the Talbot effect for lithography has emerged a ...

2018

Highly selective immobilized bimetallic Ni-Au nanoparticle catalyst for the partial hydrogenation of m-dinitrobenzene

Lioubov Kiwi, Paul Joseph Dyson, Oliver Anthony Beswick, Fernando Cardenas Lizana, Daniel André Samuel Lamey

Transition metal nanoparticles (NPs) are extensively used as catalysts for a wide and diverse range of organic transformations when immobilized on appropriate solid supports. We describe the development of a highly active and highly selective heterogeneous ...

Elsevier Science Bv2017

Stability of Fiber Bragg Gratings Fabricated Using UV Ar+ and ArF Excimer in Bismuth-Aluminum-co-Doped Silica Fibers

Hans Georg Limberger, Georgios Violakis

Continuous annealing of fiber Bragg gratings fabricated using cw and pulsed laser irradiation in Bi-Al-co-doped fibers of different concentrations show activation energy spectra linked to Bi-Al. Thermal stability maps were obtained by their analytical repr ...

2014

Annealing of UV Ar+ and ArF excimer laser fabricated Bragg gratings: SMF-28e fiber

Hans Georg Limberger, Georgios Violakis

Fiber Bragg gratings fabricated in pristine SMF-28e fibers using pulsed ArF-excimer and cw 244-nm Ar+ laser were annealed using tempering rates from 0.0038 to 0.25 K/s. Demarcation energy mapping allowed for the determination of the frequency factors and t ...

Optical Society of America2014

Impact of organic-ligand shell on catalytic performance of colloidal Pd nanoparticles for alkyne gas-phase hydrogenation

Lioubov Kiwi, Fernando Cardenas Lizana, Daniel André Samuel Lamey, Irina Prokopyeva

Monodispersed Pd nanoparticles (NPs) have been prepared by colloidal technique and deposited on a structured support consisting of carbon nanofibers (CNF) grown on sintered metal fibres (SMF). The surface properties of Pd NPs have been fine-tuned by (i) ch ...

Elsevier2014

Dose dependence of luminescence increase in H2-loaded Bi-Al co-doped optical fibers by cw 244-nm and pulsed 193-nm laser irradiation

Hans Georg Limberger, Georgios Violakis

The near infrared luminescence is increased in H2-loaded Bi-Al co-doped optical fibers by irradiation of cw 244-nm or pulsed 193-nm laser light. The dose dependence is different for the two lasers. ...

Ieee2013

Thermal decay of UV Ar+ and ArF excimer laser fabricated Bragg gratings in SMF-28e and Bi-Al-doped optical fiber

Hans Georg Limberger, Georgios Violakis, Pouneh Saffari

Fiber Bragg Gratings were fabricated using a 193-nm-ArF-excimer laser with ac index changes of 0.6×10E-4 and 2.2×10E-4 in pristine and H2-loaded Bi-Al-SiO2 fibers. Thermal annealing of the FBGs was investigated using continuous isochronal annealing. ...

2012

Thermal decay of ArF-excimer-laser fabricated fiber Bragg gratings in Bi-Al-doped optical fibers

Hans Georg Limberger, Georgios Violakis, Pouneh Saffari

Fiber Bragg Gratings were fabricated using a 193-nm-ArF-excimer laser with ac index changes of 0.6×10E-4 and 2.2×10E-4 in pristine and H2-loaded Bi-Al-SiO2 fibers. Thermal annealing of the FBGs was investigated using continuous isochronal annealing. ...

2012

Fabrication of Bragg Gratings in Microstructured Bi:SiO2 Optical Fiber Using an ArF Laser

Hans Georg Limberger, Georgios Violakis

An ArF excimer laser was used to fabricate Bragg gratings in Bi:SiO2 core - microstructured cladding optical fiber. Average and modulated refractive index changes of 2.7 × 10E-4 and 1.0 × 10E-4 were induced in pristine fiber. Fiber luminescence was also me ...

IEEE2012

Fabrication of Bragg gratings in microstructured and step index Bi-SiO2 optical fibers using an ArF laser

Hans Georg Limberger, Georgios Violakis

An ArF excimer laser was used to fabricate Bragg gratings in fibers with Bi-SiO2 core and microstructured or F-doped claddings without fiber presensitization. Average and modulated refractive index changes of 2.7 x 10(-4) and 1.0 x 10(-4) were induced in p ...

Optical Society of America2012

Photosensitivity and stress changes of Ge-free Bi-Al doped silica optical fibers under ArF excimer laser irradiation

Hans Georg Limberger, Christian Ban

The photosensitivity of germanium free Bi-Al-doped silica fibers with different bismuth concentrations was investigated using ArF excimer laser radiation at 193 nm and fiber grating formation. For the fiber with the highest bismuth concentration maximum re ...

Optical Society of America2011

Supported nitrogen-modified Pd nanoparticles for the selective hydrogenation of 1-hexyne

Lioubov Kiwi, Gabor Laurenczy, Paul Joseph Dyson, Rocio Micaela Crespo Quesada, Ryan Dykeman

2,2′-Bipyridine (bipy) and an imidazolium-functionalized bipy ligand were used in the synthesis of palladium nanoparticles in water and in ionic liquid. The function of such ligands was twofold: first, as stabilizing agents to prevent the agglomeration of ...

2011

Hydrogen Storage and Delivery: The Carbon Dioxide – Formic Acid Couple

Gabor Laurenczy

Carbon dioxide and the carbonates, the available natural C-1 sources, can be easily hydrogenated into formic acid and formates in water; the rate of this reduction strongly depends on the pH of the solution. This reaction is catalysed by ruthenium(II) pre- ...

Schweizerische Chemische Gesellschaft2011

Intrinsic Emittance Reduction of an Electron Beam from Metal Photocathodes

Christoph Peter Hauri

Electron beams in modern linear accelerators are now becoming limited in brightness by the intrinsic emittance of the photocathode electron source. Therefore it becomes important for large scale facilities such as free electron lasers to reduce this fundam ...

2010

Infrared Luminescence Enhancement by UV-Irradiation of H2-loaded Bi-Al-doped Fiber

Hans Georg Limberger, Christian Ban

ArF excimer laser irradiation of H2-loaded fibers increases the intensity of both the 1130 and 1390 nm fluorescence in Bi-Al-doped silica fiber by 18 dB and >16 dB. ...

2009

Homogeneous catalytic decomposition of formic acid for high pressure hydrogen generation

Céline Fellay

The main obstacles in the widespread use of hydrogen as energetic alternative to fossil fuels are storage problems intrinsically linked to its extremely light and explosive nature. Since no ideal storage systems currently exist, reversible fixation of hydr ...

EPFL2008