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Tonni Franke Johansen

Research Scientist

Tonni Franke Johansen

Research Scientist

Tonni Franke Johansen
Phone: 404 72 793
Email:
Department: Connectivity Technologies and Platforms
Office: Trondheim

Publications and responsibilities

Publication
https://www.sintef.no/en/publications/publication/?pubid=1631977

Ultrasonic tools are being used for imaging in a large variety of fields, spanning from medical applications in a hospital to applications deep down in oil and gas wells. When applying ultrasonic imaging techniques to image through elastic materials, such as steel, one of the main challenges these...

Authors Andreas Sørbrøden Talberg Tonni Franke Johansen Svein-Erik Måsøy Tarjei Rommetveit Svein Brekke Hefeng Dong
Year 2018
Type Academic article
Publication
https://www.sintef.no/en/publications/publication/?pubid=1660031

Sealing of new wells, and the increasing need of plug and abandonment (P&A) of old wells, has triggered research and development of new methods for saving time at this operation. Shale has proven to seal off the annulus in longer well sections; however, the detection and qualification of the...

Authors Tore Lie Sirevaag Tonni Franke Johansen Idar Larsen Rune Martin Holt
Year 2018
Type Academic lecture
Publication
https://www.sintef.no/en/publications/publication/?pubid=1457451

Dual-frequency band probes are needed for ultrasound (US) reverberation suppression and are useful for image-guided US therapy. A challenge is to design transducer stacks that achieve high bandwidth and efficiency at both operating frequencies when the frequencies are widely separated with a...

Authors Ola Finneng Myhre Tonni Franke Johansen Bjørn Atle J. Angelsen
Year 2017
Type Academic article
Publication
https://www.sintef.no/en/publications/publication/?pubid=1512031

Verification of annular barriers is essential for well integrity, with ultrasonic methods being central in well integrity testing for many decades. By doing ultrasonic pitch-catch measurements on a bench top laboratory setup developed to replicate an oil well casing, we were able to show that the...

Authors Andreas Sørbrøden Talberg Tonni Franke Johansen Idar Larsen
Year 2017
Type Academic chapter/article/Conference paper
Publication
https://www.sintef.no/en/publications/publication/?pubid=1404384

Current methods for ultrasonic pitch-catch well logging use two receivers to log the bonded material outside a single casing. For two casings separated by a fluid, we find by simulation that increasing the number of receivers provides a better picture of the effect of the bonded material outside the...

Authors Erlend Magnus Viggen Tonni Franke Johansen Ioan Alexandru Merciu
Year 2017
Type Academic article
Publication
https://www.sintef.no/en/publications/publication/?pubid=1416168

This paper presents a bonding technique based on gold-tin (Au-Sn) intermetallics to bond an active layer to a backing material in a piezoelectric ultrasonic transducer stack. The bonding process was performed at 310°C. The temperature ramping rate was found to play an important role to the bond...

Authors Tung Manh Hoang-Vu Nguyen Ahn Duy Le Knut Eilif Aasmundtveit Lars Hoff Trym Eggen Tonni Franke Johansen Frederic Lanteri Jean-François Gelly
Year 2016
Type Academic article
Publication
https://www.sintef.no/en/publications/publication/?pubid=1319026

Anatomic orientation in transsphenoidal surgery can be difficult, and residual tumors are common. A major limitation of both direct microscopy and endoscopic visualization is the inability to see below the surface of the surgical field to confirm the location of vessels, nerves, tumor remnants, and...

Authors Ole Solheim Tonni Franke Johansen Johan Cappelen Geirmund Unsgård Tormod Selbekk
Year 2016
Type Academic article