| Partner: M. Zduniak |
Ostatnie publikacje
| 1. | Rostocki A.J.♦, Siegoczyński R.M.♦, Kiełczyński P., Szalewski M., Balcerzak A., Zduniak M.♦, Employment of a novel ultrasonic method to investigate high pressure phase transitions in oleic acid, HIGH PRESSURE RESEARCH, ISSN: 0895-7959, Vol.31, No.2, pp.334-338, 2011 Streszczenie: In this work, the variation of sound velocity with hydrostatic pressure for oleic acid is evaluated up to 350MPa. During the measurement, we identified the phase transformation of oleic acid and the presence of the hysteresis of the dependence of sound velocity on pressure. From the performed measurements, it can be seen that the dependence of sound velocity on pressure can be used to investigate phase transformations in natural oils. Ultrasonic waves were excited and detected using piezoelectric LiNbO3(Y-36 cut) 5MHz transducers. The phase velocity of the longitudinal ultrasonicwaveswas measured using a cross-correlation method to evaluate the time of flight. Słowa kluczowe: Sound velocity, oleic acid, high pressure, phase transition Afiliacje autorów:
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Prace konferencyjne
| 1. | Kiełczyński P., Szalewski M., Rostocki A.J.♦, Zduniak M.♦, Siegoczyński R.M.♦, Balcerzak A., Investigation of High-Pressure Phase Transitions in Vegetable Oils by Measuring Phase Velocity of Longitudinal Ultrasonic Waves, IUS 2009, IEEE International Ultrasonics Symposium, 2009-09-20/09-23, Rzym (IT), DOI: 10.1109/ULTSYM.2009.5441766, pp.1563-1566, 2009 Streszczenie: Monitoring and studying the pressure effect on liquid properties are becoming increasingly important in food, chemical, cosmetic and pharmaceutical industry as well as in laboratory practice. Accurate thermodynamic data in liquids as a function of pressure are required for studies the structure of liquids as well as for various engineering applications. Direct measurement of thermodynamic parameters is very difficult. The velocity of sound is related to many thermodynamic parameters and can be measured relatively simple. In this work the variation of sound velocity and isothermal compressibility with hydrostatic pressure for triolein is evaluated up to 650 MPa. During the measurement we stated the phase transformation of triolein and the presence of the hysteresis of the dependence of sound velocity on pressure. To the authors' knowledge, the measurement of the sound velocity of liquids under high pressure during the phase transition is the novelty. From the performed measurements it results that the dependence of sound velocity on pressure can be used to investigate phase transformations in natural oils. Słowa kluczowe: Vegetable oils, Velocity measurement, Phase measurement, Ultrasonic variables measurement, Thermodynamics, Liquids, Pressure measurement, Chemical industry, Monitoring, Pressure effects Afiliacje autorów:
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