| 1. |
- Carlson, Johan, et al.
(författare)
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A noise-tolerant group delay estimator applied to dispersion measurement in gases
- 2003
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Ingår i: Proceedings, 2003 IEEE Ultrasonics Symposium. - Piscataway, NJ : IEEE Communications Society. - 0780379225 ; , s. 254-257
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Konferensbidrag (refereegranskat)abstract
- In this paper we present a model-based group velocity estimator, that can be used to measure speed of sound in ultrasonic pulse-echo systems as a function of ultrasound frequency. The estimation of group velocities involves numerical differentiation of the phase difference. In the presence of noise, this becomes numerically unstable. The model-based approach presented herein, shows better tolerance to experimental noise. The performance of the estimator is evaluated with simulations as function of pulse bandwidth and SNR. Finally, the estimator applied to real data and compared with other methods for measuring speed of sound in Ethane and Oxygen.
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| 2. |
- Carlson, Johan, et al.
(författare)
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A simple scattering model for measuring particle mass fractions in multiphase flows
- 2002
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Ingår i: Ultrasonics. - 0041-624X .- 1874-9968. ; 39:8, s. 585-590
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present a simple theoretical model of how pulsed ultrasound is attenuated by the particles in a solid/liquid flow. The theoretical model is then used to predict the attenuation of sound, given the mass fraction, the density, and the size distribution of the solid particles. The model is verified experimentally for suspensions of 0–10% (by mass) Dolomite ((Ca,Mg)CO3) particles and water. The experimental results show that the attenuation of sound due to particles varies linearly with mass fraction, and that the proposed theoretical model can be used to predict this attenuation. In all experiments the transmitter and receiver array were clamped onto the pipe wall, thus providing a completely non-invasive and non-intrusive measurement technique.
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| 3. |
- Carlson, Johan, et al.
(författare)
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Exploring interaction effects in two-component gas mixtures using orthogonal signal correction of ultrasound pulses
- 2005
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 117:5, s. 2961-2968
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Tidskriftsartikel (refereegranskat)abstract
- Within Sweden and the EU, an increased use of biogas gas and natural gas is encouraged to decrease emission of carbon dioxide. To support more effective manufacturing, distribution, and consumption of energy gases, new methods for the measurement of the calorimetric value or the gas composition are needed. This paper presents a method to extract and visualize variations in ultrasound pulse shape, caused by interaction effects between the constituents of a two-component gas mixture. The method is based on a combination of principal component analysis and orthogonal signal correction. Pulse-echo ultrasound experiments on mixtures of oxygen and ethane in the concentration range from 20% to 80% ethane show that the extracted information could be correlated with the molar fraction of ethane in the mixture
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| 4. |
- Carlson, Johan, et al.
(författare)
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Projekt: SCOPE Norra
- 2011
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Annan publikation (populärvet., debatt m.m.)abstract
- SCOPE Norra är ett samarbetskonsortium för forskning och utveckling tillsammans med massa- och pappersindustrin i Norrbotten och Västerbotten. Projektet koordineras av centrumbildningen ProcessIT Innovations.Inom SCOPE Norra pågår ett flertal delprojekt, uppdelat på ett antal fokusområden.Huvudfinansiär för konsortiet är Tillväxtverket genom medel från EU:s strukturfonder.
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| 5. |
- Carlson, Johan, et al.
(författare)
-
Ultrasonic measurement of molar fractions in gas mixtures by orthogonal signal correction
- 2004
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Ingår i: 2004 IEEE Ultrasonics Symposium. - Piscataway, NJ : IEEE Communications Society. - 0780384121 ; , s. 821-825
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Konferensbidrag (refereegranskat)abstract
- Within Sweden and the EU, an increased use of biogas and natural gas is encouraged. To support more effective manufacturing, distribution, and consumption of energy gases, new methods for the measurement of the calorimetric value or the gas composition are needed. In this paper, we present a method to quantify variation in ultrasound pulse shape, caused by interaction effects between the constituents of a two-component gas mixture. The method is based on a combination of principal component analysis and orthogonal signal correction. Experiments on mixtures of oxygen and ethane show that the extracted information correlates well with the molar fraction of ethane in the mixture.
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| 6. |
- Martinsson, Pär-Erik, et al.
(författare)
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Investigating the feasibility of using principal component analysis for ultrasonic classification of gas mixtures
- 2003
-
Ingår i: Proceedings, 2003 IEEE Ultrasonics Symposium. - Piscataway, NJ : IEEE Communications Society. - 0780379225 ; , s. 1396-1399
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Konferensbidrag (refereegranskat)abstract
- On-line measurement of the energy content of natural gas is of interest for both industry and customers, since the energy content determines its monetary value. Experiments with pulsed ultrasound show that, in addition to changes in speed of sound and acoustic attenuation, there is also a change in the shape of the sound waveform. In this paper, we investigate the feasibility of using principal component analysis (PCA) to quantify this change in pulse shape. The principle is evaluated for pure oxygen, pure ethane, and mixtures of the two, for different pressures. The results show that by using PCA, it is possible to distinguish between pulses that have propagated through oxygen from pulses in ethane and mixtures of the two.
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| 7. |
- Martinsson, Pär-Erik, et al.
(författare)
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Ultrasonic classification of gases using principal component analysis
- 2003
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Ingår i: 5th world congress on ultrasonics WCU 2003. - Paris : Institut Biomedical des Cordeliers, Université Pierre et Marie Curie. - 2952110506 ; , s. 1129-1132
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Konferensbidrag (refereegranskat)abstract
- On-line measurement of the energy content of natural gas is of interest for both industry and customers, since the energy content determines its monetary value. Experiments with pulsed ultrasound show that, in addition to changes in speed of sound and acoustic attenuation, there is also a change in the shape of the sound waveform. In this paper we investigate the feasibility of using Principal Component Analysis (PCA) to quantify this change in pulse shape. The principle is evaluated for Oxygen and Ethane, for different pressures and different temperatures. The results show that by using PCA, it is possible to distinguish between pulses that have propagated through Oxygen from pulses in Ethane.
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