Ultrasonic measurements of molecular relaxation in ethane and carbon monoxide

Martinsson, Pär-Erik; Delsing, Jerker

doi:10.1109/ultsym.2002.1193454

Cited by 9 publications

(16 citation statements)

References 9 publications

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“…8 and 9) and it will not be possible to discriminate their contributions since measurements at only one frequency were made. Martinsson and Delsing (2002) give measurements of the attenuation of (pure) ethane at 600 kHz/bar (i.e. the condition of the 1 MHz measurement at 1.5 bar) of 30-40 np/m.…”

Section: Temperature Environment and Candidate Gas Evolutionmentioning

confidence: 99%

Silence on Shangri-La: Attenuation of Huygens acoustic signals suggests surface volatiles

Lorenz

Leese

Hathi

et al. 2014

Planetary and Space Science

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a b s t r a c tObjective: Characterize and understand acoustic instrument performance on the surface of Titan. Methods: The Huygens probe measured the speed of sound in Titan's atmosphere with a 1 MHz pulse time-of-flight transducer pair near the bottom of the vehicle. We examine the fraction of pulses correctly received as a function of time.Results: This system returned good data from about 11 km altitude, where the atmosphere became thick enough to effectively transmit the sound, down to the surface just before landing: these data have been analyzed previously. After an initial transient at landing, the instrument operated nominally for about 10 min, recording pulses much as during descent. The fraction of pulses detected then declined and the transmitted sound ceased to be detected altogether, despite no indication of instrument or probe configuration changes. Conclusions: The most likely explanation appears to be absorption of the signal by polyatomic gases with relaxation losses at the instrument frequency, such as ethane, acetylene and carbon dioxide. These vapors, detected independently by the GCMS instrument, were evolved from the surface material by the warmth leaking from the probe, and confirm the nature of the surface materials as 'damp' with a cocktail of volatile compounds. Some suggestions for future missions are considered. Practice implications: None.

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Section: Temperature Environment and Candidate Gas Evolutionmentioning

confidence: 99%

Silence on Shangri-La: Attenuation of Huygens acoustic signals suggests surface volatiles

Lorenz

Leese

Hathi

et al. 2014

Planetary and Space Science

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“…Both of these are frequency dependent. They depend on the details of underlying physics [3], [4], [9], [10]. Good physical models are crucial for the understanding of the problem, so that proper instrumentation can be designed.…”

Section: B Theorymentioning

confidence: 99%

Measurement of methane Ccontent in upgraded biogas using pulse-echo ultrasound

Carlson¹,

Martinsson²,

Nordenvaad³

2007

Proceedings of the Interntional Congress on Ultrasonics

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In this paper we present an ultrasonic pulseecho technique for estimating the methane (CH 4 ) content in binary mixtures of CH 4 and carbon dioxide (CO 2 ). The method is based on parametric estimation of phase velocity and frequency dependent attenuation in combination with Partial Least-Squares Regression (PLSR). The technique is verified using experiments on mixtures with a volume fraction of CO 2 in the range of 0 % -10 %. The experiments show that the CH 4 content can be accurately estimated with high repeatability.

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“…Hence, both these properties can help to monitor changes in experimental conditions. This has recently been studied in both theory and experiments by Dain and Lueptow, 4,5 Martinsson, 6 and Townsend and Meador. 7 The frequency dependence of the attenuation is fairly easy to measure, but the speed of sound is much more difficult.…”

Section: Introductionmentioning

confidence: 97%

Exploring interaction effects in two-component gas mixtures using orthogonal signal correction of ultrasound pulses

Carlson

Martinsson

2005

The Journal of the Acoustical Society of America

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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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Ultrasonic measurements of molecular relaxation in ethane and carbon monoxide

Cited by 9 publications

References 9 publications

Silence on Shangri-La: Attenuation of Huygens acoustic signals suggests surface volatiles

Silence on Shangri-La: Attenuation of Huygens acoustic signals suggests surface volatiles

Measurement of methane Ccontent in upgraded biogas using pulse-echo ultrasound

Exploring interaction effects in two-component gas mixtures using orthogonal signal correction of ultrasound pulses

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