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Influence of Positron Irradiation on Positronium Formation in n-Alkanes

100%

Pietrow M., Zgardzińska B.

Acta Physica Polonica A

2006

vol. 110

issue 5

641-648

Positronium formation probability was investigated as a function of irradiation time and temperature for some long-chain saturated hydrocarbons (alkanes). Intensity of ortho-positronium component in the lifetime spectrum depends on the concentration of trapped excess electrons, but also on concentration of radicals and ions acting as electron scavengers. The results indicate the existence of two kinds of electron traps; those which are not emptied by thermal treatment disappear after several days of positron irradiation.

Ortho-Positronium in Some n-Alkanes; Influence of Temperature and Pressure

81%

Zgardzińska B., Pietrow M., Goworek T., Wawryszczuk J.

Acta Physica Polonica A

2006

vol. 110

issue 5

747-753

Positron lifetime spectra were measured for a series of odd-numbered n-alkanes from C_{11}H_{24} to C_{19}H_{40} as a function of temperature and pressure. The ortho-Ps lifetimes in the rotator phase and the increase in intensity at the transition to that phase can be explained by location of Ps in the vicinity of kink-type conformers. The relation between o-Ps lifetime and molecule length can be described in the framework of extended Tao-Eldrup model. One can eliminate the effect of intensity rise in time by sample illumination or by application of high pressure. A decrease in temperature by 1 K is equivalent to an increase in pressure by about 4 MPa.

Human Tissue Investigations Using PALS Technique - Free Radicals Influence

27%

Jasińska B., Zgardzińska B., Chołubek G., Pietrow M., Gorgol M., Wiktor K., Wysogląd K., Białas P., Curceanu C., Czerwiński E., Dulski K., Gajos A., Głowacz B., Hiesmayr B., Jodłowska-Jędrych B., Kamińska D., Korcyl G., Kowalski P., Kozik T., Krawczyk N., Krzemień W., Kubicz E., Mohammed M., Pawlik-Niedźwiecka M., Niedźwiecki S., Pałka M., Raczyński L., Rudy Z., Sharma N., Sharma S., Shopa R., Silarski M., Skurzok M., Wieczorek A., Wiktor H., Wiślicki W., Zieliński M., Moskal P.

Acta Physica Polonica A

2017

vol. 132

issue 5

1556-1558

The positron annihilation lifetime spectroscopy was applied to the samples of the human uterine leiomyomas and the normal myometrium tissues taken from the selected place of the uterus during a surgery. The method indicated differences in values of the measured positron annihilation lifetime spectroscopy parameters (lifetimes and intensities) between healthy and diseased tissue samples. The additional measurements were performed either in darkness or in presence of visible light which influenced the free radicals present in both kind of tissues and, as a result, made changes in free annihilation and o-Ps decay lifetime and intensity values.

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Influence of Positron Irradiation on Positronium Formation in n-Alkanes

Ortho-Positronium in Some n-Alkanes; Influence of Temperature and Pressure

Human Tissue Investigations Using PALS Technique - Free Radicals Influence