Browsing NTNU Open by Author "Johansen, Tonni Franke"
Now showing items 1-19 of 19
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A Study of the Ultrasonic Measurements for Logging Behind a Steel Pipe: Expanding the proessing to improve the differentiation between heavy fluids and light solids
Sirevaag, Tore Lie (Doctoral theses at NTNU;2019:375, Doctoral thesis, 2020)In petroleum applications using acoustic wave theory, the most used practice can be found in borehole geophysical methods, where acoustic logging has long been the foremost source for cement evaluation. Due to stricter ... -
Analysis of acoustic impedance matching in dual-band ultrasound transducers
Myhre, Ola Finneng; Johansen, Tonni Franke; Angelsen, Bjørn Atle J. (Journal article; Peer reviewed, 2017)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 ... -
Analysis of acoustic impedance matching in dual-band ultrasound transducers
Myhre, Ola Finneng; Johansen, Tonni Franke; Angelsen, Bjørn Atle J. (Journal article; Peer reviewed, 2017)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 ... -
Auralization using headphones
Eide, Ingebjørg Nordstoga (Master thesis, 2012)In this report various techniques used to estimate head related impulse responses are compared. The purpose is to investigate the effectiveness of presenting auralization via the QuietPro system's earplugs, and see if sound ... -
Characterization of medical piezoelectric ultrasound transducers using pulse echo methods.
Mylvaganam, Janani (Master thesis, 2007)In this thesis, a measurement set-up has been developed to characterize high frequency medical ultrasound transducers using a pulse echo set-up. This work is a continuation of an earlier project. The aim of this project ... -
Demping av maskinstøy for mikrofon montert på utsiden av kjøretøy
Mølmshaug, Torstein (Master thesis, 2012)Målinger, analyse og filtrering av maskinstøy fra et militært kjøretøy, der hovedfokuset i oppgaven er å skape best mulige forhold for forståelse av tale. -
Design, Fabrication and Testing Highly Sensitive Single Element Doppler Transducers
Bolstad, Per Kristian; Hoff, Lars; Torp, Hans; Johansen, Tonni Franke (Journal article; Peer reviewed, 2018)Three common piezoelectric materials have been studied for use in pulsed wave Doppler ultrasound, where high sensitivity is required, while bandwidth is less important. A large transducer aperture, 80 mm 2 , results in a ... -
Directive under-water transducer design for Doppler velocity log
Tesaker, Andreas (Master thesis, 2019)En 1 MHz direktiv undervannstransduser for bruk i DVL er designet, simulert, konstruert og testet gjennom målinger i denne oppgaven. Designet følger teorien for en piezoelektrisk disk som opererer i tykkelsesmodi, omsluttet ... -
Effect of bubble size on ultrasound backscatter from bubble clouds in the context of gas kick detection in boreholes
Indimath, Shivanandan; Fiorentini, Stefano; Bøklepp, Bjarne Rosvoll; Avdal, Jørgen; Johansen, Tonni Franke; Måsøy, Svein-Erik (Peer reviewed; Journal article, 2023)Early detection of gas influx in boreholes while drilling is of significant interest to drilling operators. Several studies suggest a good correlation between ultrasound backscatter/attenuation and gas volume fraction (GVF) ... -
Finite Element Modeling of Piezoelectric Ultrasonic Transducers
Nygren, Morten Wollert (Master thesis, 2011)The optimization of piezoelectric ultrasonic transducers has tradisionally been done through trial and error, somewhat guided by one-dimentional simulations. This can often be a very time-consuming and expensive process, ... -
Implementation and Evaluation of a Dispersion Compensation Algorithm for Acoustic Touch Localization
Iversen, Vegard Stornes (Master thesis, 2023)Denne avhandlingen undersøker og implementerer en dispersjons kompensasjons algoritme for akustisk berøringslokalisering på isotrope plater. Studien bygger på en tidligere prosjektoppgave som utforsket berøringslokaliser ... -
Laboratory experiments on ultrasonic logging through casing for barrier integrity validation
Talberg, Andreas Sørbrøden; Johansen, Tonni Franke; Larsen, Idar (Chapter, 2017)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 ... -
Pyintegrity: An Open-Source Toolbox for Processing Ultrasonic Pulse-EchoWell Integrity Log Data
Viggen, Erlend Magnus; Diez, Anja; Johansen, Tonni Franke (Journal article, 2024)Many companies offer similarly designed wireline tools using ultrasonic pulse-echo measurements toevaluate barrier integrity in cased-hole wells. While these tools provide very similar data, differentcompanies process their ... -
Touch Localization by Estimating the Direction of Arrivals of Plate Edge Reflections
Strømsnes, Niklas (Master thesis, 2023)Dette prosjektet utforsker muligheten for berøringslokalisering ved bruk av metoder for estimering av ankomstvinkler (direction-of-arrival (DOA)) på Lamb-bølger som reflekteres fra kantene på en plate. Det foreslås en ... -
Transmit Beams Adapted to Reverberation Noise Suppression Using Dual-Frequency SURF Imaging
Näsholm, Sven Peter; Hansen, Rune; Måsøy, Svein-Erik; Johansen, Tonni Franke; Angelsen, Bjørn Atle J. (Peer reviewed; Journal article, 2009)A method that uses dual-frequency pulse complexes of widely separated frequency bands to suppress noise caused by multiple scattering or multiple reflections in medical ultrasound imaging is presented. The excitation pulse ... -
Ultrasonic focusing through a steel layer for acoustic imaging
Talberg, Andreas Sørbrøden; Dong, Hefeng; Johansen, Tonni Franke; Måsøy, Svein-Erik; Brekke, Svein; Rommetveit, Tarjei (Journal article; Peer reviewed, 2018)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 ... -
Ultrasonic Imaging through Solids
Samuelsen, Elly (Master thesis, 2016)Ultrasonic testing is a widely used method, in the industry, for non destructive inspection of materials. The most commonly used technique is the pulse-echo technique where ultrasound is introduced into a test object and ... -
Ultrasonic pulse-echo dataset from numerical modelling for oil and gas well integrity investigations
Diez, Anja; Viggen, Erlend Magnus; Johansen, Tonni Franke (Peer reviewed; Journal article, 2025)The ultrasonic pulse-echo (PE) measurement is a crucial measurement technique to determine the integrity of oil and gas wells. Oil companies use various analysis techniques and corrections to derive the pipe thickness and ... -
Ultrasonic well integrity logging using phased array technology
Johansen, Tonni Franke; Buschmann, Philip Erik; Røsberg, Knut Marius; Diez, Anja; Viggen, Erlend Magnus (Chapter, 2023)Ultrasonic well integrity logging is an important and common procedure for well completion and plug-and-abandonment operations. Typical logging tools employ single-element ultrasound transducers. In medical ultrasound ...