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Johannes Tjønnås

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Johannes Tjønnås

Forsker

Johannes Tjønnås
Telefon: +47 408 25 940
Mobil: +47 408 25 940
Avdeling: Mathematics and Cybernetics
Kontorsted: Trondheim

Publikasjoner og ansvarsområder

Publikasjoner

Publikasjon

Control of Reversible Degradation Mechanisms in Fuel Cells: Mitigation of CO contamination

http://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1420615

Fuel Cells are subject to several degradation phenomena where some are reversible and some irreversible. Normally all contribute to a reduced cell voltage, but it may be complicated to discriminate the particular causes. A brief overview is given and a method for modelling and controlling the partic...

Forfattere Tjønnås Johannes Zenith Federico Halvorsen Ivar Johan Klages Merle Scholta Joachim
År 2016
Type Tidsskriftsartikkel
Publikasjon

Towards more autonomous ROV operations: Scalable and modular localization with experiment data.

http://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1396961

Remotely Operated Vehicles (ROVs) are pivotal for subsea inspection, maintenance and repair (IMR) operations. Increased autonomy in such IMR operations may constitute significant improvements in HSE (Health- Safety, Environment) and cost-effectiveness of operations. Localization is an enabling techn...

Forfattere Grøtli Esten Ingar Tjønnås Johannes Azpiazu Lozano Jon Transeth Aksel Andreas Ludvigsen Martin
År 2016
Type Tidsskriftsartikkel
Publikasjon

Dual Control of low concentration CO poisoning by Anode Air Bleeding of Low Temperature Polymer Electrolyte Membrane Fuel Cells

http://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1392386

Fuel impurities, fed to a polymer electrolyte membrane fuel cell, can affect stack performance by poisoning of catalyst layers. This paper describes the dynamic behaviour of a stack, including state-of-the-art membrane electrode assemblies (MEA) of three different manufacturers, at different operati...

Forfattere Klages Merle Tjønnås Johannes Zenith Federico Halvorsen Ivar Johan Scholta Joachim
År 2016
Type Tidsskriftsartikkel
Publikasjon

Well Testing by Sinusoidal Stimulation

http://www.sintef.no/publikasjoner/publikasjon/?pubid=CRIStin+1234775

A new approach to testing of oil and gas wells by means of sinusoidal oscillations in flow and pressure instead of the traditional buildup test is proposed in this article. This approach allows faster testing and simultaneous testing of several wells, with no need for a dedicated test header; it can...

Forfattere Zenith Federico Foss Bjarne Anton Tjønnås Johannes Hasan Agus Ismail
År 2015
Type Tidsskriftsartikkel
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