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Strona główna » Instytut » Pracownicy » Bożena Jasińska

dr hab. Bożena Jasińska

Zakład

Zakład Metod Jądrowych

Stanowisko:

profesor nadzw.

Kontakt:

pokój: 42A
telefon: (081) 537-62-88
e-mail: bozena.jasinska@umcs.pl

Specjalność naukowa:

fizyka

Funkcje pełnione w IF UMCS:

Zastępca Dyrektora Instytutu Fizyki

Publikacje: Ukryj abstrakty

  1. B. Jasińska, M. Śniegocka, R. Reisfeld, E. Zigansky, Temperature and pressure measurements of PALS spectra in photonic glasses, Material Science Forum, 607(), 2009, 166-168

  2. B. Jasińska, M. Kędzior, M. Śniegocka, A. E. Kozioł, I. Wawrzecka-Gorczyca, Investigation of the free volume in olanzapine by PALS, Physica status solidi c, 6(), 2009, 2432-2434

  3. Jasińska, B. Śniegocka, M. Reisfeld, R. Zigansky, E., Porosity structure in photonic glass, China, Abstract of 9-th International workshop on Positron and , (), 2008, O5.1, 30

  4. Jasińska, B. Kędzior, M. Kozioł, A. Śniegocka, M. Wawrzecka-Gorczyca, I., Free volumes in olanzapine: temperature and pressure dependencies of o-Ps lifetime and intensity, Czech Republic, Praha, Abstract of International workshop, Positron studies in defects, (), 2008, 51

  5. Śniegocka, M. Jasińska, B. Reisfeld, R. Zigansky, E., Temperature and pressure measurements of pores structure in photonic glasses, Czech Republic, Praha, Abstract of International workshop, Positron studies in defects, (), 2008, 52

  6. Jasińska, B. Zaleski, R. Śniegocka, M. Reisfeld, R. Zigansky, E., Testing ETE model, temperature dependences of PALS data, Physica Status Solidi B, 4(), 2007, 3985-3988

  7. Sniegocka, M. Jasinska, B. Goworek, T. Zaleski, R., Temperature dependence of o-Ps lifetime in some porous media. Deviations from ETE model, Chemical Physics Letters, 430(4-6), 2006, 351-354

    Abstract:
    Temperature dependence of ortho-positronium lifetime in some porous materials was investigated. Above the room temperature the extended Tao-Eldrup model works rather well, however at low temperatures one observes in all samples the lifetimes evidently longer than expected. (c) 2006 Elsevier B.V. All rights reserved.

  8. Sniegocka, M. Jasinska, B., Redistribution of o-Ps in porous Vycor glass. Crystallization of silica at high temperatures, Acta Physica Polonica A, 110(5), 2006, 721-727

    Abstract:
    The positron annihilation lifetime spectroscopy was applied to study the porous Vycor glass annealed at the temperatures between 950 and 1050 K. With increased temperature the spectra show significant decrease in o-Ps lifetime and intensity in the pores, while the rise of intensity in the small intermolecular voids is observed. Similar changes are observed as a function of annealing time at fixed temperature depending on the time and temperature of thermal treatment. They can originate from partial crystallization of the silica in the material under study.

  9. Reisfeld, R. Zigansky, E. Jasinska, B. Wodnicka, K., Porosity of sol-gel silica glasses doped by ruthenium bipyridyl as measured by positron annihilation lifetime spectroscopy and nitrogen adsorption, Optica Applicata, 35(4), 2005, 677-689

    Abstract:
    The porous structure of glasses incorporated by ruthenium tris bipyridyl chloride (further Rubpy) and adsorbed by Rubpy is studied by positron annihilation lifetime spectroscopy and liquid nitrogen adsorption method. The first method provides the radius of the pores in the range of 0.6-4 nm and their distribution. The second method provides the radius of the pores in the range of 1-150 nm, their total volumes, size distribution and specific surface area. In the first method both closed and opened pores can be seen when the measurements are made on bulk samples as in this work. When thin films are measured, one has to use a capping material to prevent backscattering. The dimension of the pores can be controlled by the catalyst used for sol-gel formation. When Rubpy is prepared by adding its salt to precursor solution catalyzed by HCl, the pore size increases because of stress exhibited by large molecules. The pore size decreases with adding of Rubpy in precursor solution, catalyzed by HF and HNO3. Glass doped by Rubpy is less sensitive to the type of catalyst, than undoped glasses. A comparative study was performed on undoped glasses prepared by the identical method. We shall discuss the similarities and differences of the two methods.

  10. Jasinska, B. Dawidowicz, A. L. Pikus, S., Crystallization process in porous and nonporous Vycor glass, Acta Physica Polonica A, 107(5), 2005, 724-728

    Abstract:
    Three stages of thermal and chemical processing of Vycor glass were carried out. Raw material, the glass with small and big pores was studied. In each stage of study various crystallinity degrees of investigated material were obtained. The relation between crystallinity degree and the intensity of o-Ps components was determined. In nonporous material a high correlation between o-Ps intensity and crystallinity degree was found. In porous material the decrease in total o-Ps intensity can be a measure of the crystallinity degree.

  11. Jasinska, B. Wawryszczuk, J. Zaleski, R., Three-quantum annihilation in porous vycor glass, Acta Physica Polonica A, 107(5), 2005, 821-825

    Abstract:
    Three methods of determination of 3 gamma o-Ps decay intensity are compared. The estimate of 3 gamma fraction obtained from classical lifetime measurements can be distorted due to a higher absorption of the gamma quanta from the continuous spectrum of three-quantum decay, compared to two-quantum one.

  12. Sniegocka, M. Jasinska, B. Wawryszczuk, J. Zaleski, R. Derylo-Marczewska, A. Skrzypek, I., Testing the extended Tao-Eldrup model. Silica gels produced with polymer template, Acta Physica Polonica A, 107(5), 2005, 868-873

    Abstract:
    The temperature dependence of o-Ps lifetime in the pores calculated from extended Tao-Eldrup model was compared to the experimental data, collected for a set of silica gels synthesized using the polymer template technique. For the sample with average pore radii 2.0 nm rather good agreement between the model and experiment was found. For the sample with narrow pores (near 1.0 nm) the lifetime spectrum was complex. Except the range of highest temperatures the lifetimes are far from model calculations.

  13. Reisfeld, R. Saraidarov, T. Jasinska, B., Porous glasses as a matrix for incorporation of photonic materials. Pore determination by positron annihilation lifetime spectroscopy, Optical Materials, 26(2), 2004, 181-189

    Abstract:
    Porous glasses prepared by the sol-gel technique have a variety of applications when incorporated by photonic materials: tunable lasers, sensors, luminescence solar concentrators, semiconductor quantum dots, biological markers. The known methods of pore size determinations, the nitrogen adsorption and mercury porosimetry allow to determine the sizes of open pores. Positron annihilation lifetime spectroscopy (PALS) allows to determine pore sizes also of closed pores. As an example we have performed measurements of non-doped zirconia- silica-polyurethane (ZSUR) ormocer glasses and the same glasses doped with lead sulfide quantum dots. The pore radii range between 0.25-0.38 nm, total surface area 15.5-23.8 m(2)/g. (C) 2003 Elsevier B.V. All rights reserved.

  14. Jasinska, B. Dawidowicz, A. L. Goworek, T. Wawryszczuk, J., Pore size determination by positron annihilation lifetime spectroscopy, Optica Applicata, 33(1), 2003, 7-12

    Abstract:
    Two Vycor glasses were investigated using PALS method. The model of pick-off annihilation in cylindrical free volume was applied to evaluate the pore radii. The o-Ps mean lifetime value in the pores changed from 6.5 to 40 ns in one glass, while from 13 to 51 ns in the other (softer) one. The determined pore radii, using a cylindrical shape model, were from 0.5 to 1.4 nm and from 0.7 to 1.6 nm, respectively.

  15. Jasinska, B. Dawidowicz, A. L., Pore size determination in Vycor glass, Radiation Physics and Chemistry, 68(3-4), 2003, 531-534

    Abstract:
    Pore formation in Vycor glass subjected to annealing at 530degreesC and 550degreesC for different periods of time ranging from 4 to 48 h was studied. The o-Ps lifetime in such a medium was in the range 60-100 ns, while the intensity of this component varied from 20% to 28%. The values of pore radii extracted from PALS data agreed well with those from other porosimetric methods if DeltaR applied in cylindrical model calculations was about 0.18 nm. (C) 2003 Elsevier Science Ltd. All rights reserved.

  16. Jasinska, B. Dawidowicz, A. L. Pikus, S., Application of positron annihilation lifetime spectroscopy in studies of crystallization processes, Physical Chemistry Chemical Physics, 5(15), 2003, 3289-3293

    Abstract:
    This study concerns the crystallization process observed in three-component Vycor glass heated in the temperature range from 875 to 975 K. PALS and X-ray diffraction results confirmed partial crystallization of silica in the studied material depending on the time and temperature of thermal treatment. It is shown that PALS can be treated as a new method for investigation of the crystallinity degree. Increased crystallization degree obtained from X-ray diffraction data is perfectly correlated with o-Ps intensity decrease determined from PALS spectra for each temperature.

  17. Goworek, T. Jasinska, B. Wawryszczuk, J. Zaleski, R. Suzuki, T., On possible deviations of experimental PALS data from positronium pick-off model estimates, Chemical Physics, 280(3), 2002, 295-307

    Abstract:
    The sources of possible inconsistency between the models of trapped positronium annihilation and experimental data are discussed. There are two such sources: excessive simplifications in the models of pick-off process and appearance of other processes not accounted in the models. In the case of the smallest traps, the penetration depth of ortho- positronium (o-Ps) wavefunction into the bulk can be larger than usually assumed. In traps of sizes exceeding I run the population of excited levels in the well has to be taken into account. For such large voids the sources of divergence of the experiment and model predictions can be: escape of o-Ps from open pores to outside, chemical interaction of o-Ps with pore surfaces (adsorbate layers), the presence of impurities inside free volumes. (C) 2002 Elsevier Science B.V. All rights reserved.

  18. Goworek, T. Jasinska, B. Suzuki, T., Ortho-Ps in bi-dispersional porous glass, Positron Annihilation - Icpa-12, (), 2001, 316-318

    Abstract:
    PAL spectra in porous Vycor glass with average pore radius approximate to 0.9 nm were measured as a function of temperature. Two long-lived components reflect the existence of two maxima in the pore radii distribution Relative intensities of these components drastically change with temperature.

  19. Jasinska, B. Dawidowicz, A. L., Pore formation in Vycor glasses studied by PAL method, Positron Annihilation - Icpa-12, (), 2001, 371-373

    Abstract:
    Pore formation in two Vycor glasses of different sodium and boron oxide content was investigated. At higher initial content of these oxides the pore growth and transformation appears at lower temperatures. Generally, at higher Na and B content (a softer glass) the observed o-Ps lifetime is larger.

  20. Jasinska, B. Dawidowicz, A. L. Radkiewicz, S., Liquation of vycor glasses - Study by positron annihilation lifetime method, Acta Physica Polonica A, 99(3-4), 2001, 379-384

    Abstract:
    Two Vycor glasses of different percentages of the components were liquated between 725 K and 950 K and leached in order to produce pores. Little intermolecular voids characterized by ortho-positronium lifetime value tau (2) approximate to 1.5 ns were observed simultaneously. At the first stage of pore formation the intensity I-2 decreased considerably for both glasses, while at liquation temperatures higher than 825 K it increased again. The increase in I-2 resulted from changes in the properties of the bulk material. The growth of tau (2) in this range of temperatures was also observed.

  21. Goworek, T. Jasinska, B. Wawryszczuk, J. Ciesielski, K. Goworek, J., Mesopore characterization by positron annihilation, Characterization of Porous Solids V, (), 2000, 557-564

    Abstract:
    The model of a particle in a rectangular potential well, commonly used in positron studies of free volume distribution in polymers, was extended to larger voids, like pores. by taking into account the effects of positronium annihilation from the excited levels. The average lifetime calculated in this way (for room temperature) agrees quite well with the experimental data for various porous materials (silica gels, Vycor glass, porous polymers). The parameter DeltaR describing the penetration of positronium wavefunction into the bulk needs to be slightly enlarged in relation to that in small spherical voids.

  22. Goworek, T. Ciesielski, K. Jasinska, B. Wawryszczuk, J., Temperature variations of average o-Ps lifetime in porous media, Radiation Physics and Chemistry, 58(5-6), 2000, 719-722

    Abstract:
    Modification of the Tao-Eldrup model is proposed in order to extend its usefulness to the case of porous media. The modification consists in the transition from spherical to capillary geometry and in inclusion of pick-off annihilation from the excited states of a particle in the well. Approximated equations for pick-off constant in these states are given. The model was tested by observing the temperature dependences of o- Ps lifetime in various media. In the case of silica gels and Vycor glass with narrow pores, the model seems to work well, while for larger pores in Vycor unexpectedly long lifetimes appear in the range of lowest temperatures. (C) 2000 Elsevier Science Ltd. All rights reserved.

  23. Jasinska, B. Dawidowicz, A. L. Goworek, T., Positron lifetimes at the initial stage of pore formation in Vycor glass, Radiation Physics and Chemistry, 58(5-6), 2000, 723-726

    Abstract:
    The formation of narrow pores during leaching of Vycor glass by sulphuric acid was investigated using the positron lifetime technique. During the leaching process the pore diameter remained roughly constant (except for the case of cold leaching). The time of processing changed the total length of capillaries, but not their number; at the temperature 50 degrees C during 20 min of leaching the average leaching depth was 24 mu m. (C) 2000 Elsevier Science Ltd. All rights reserved.

  24. Jasinska, B. Dawidowicz, A. L. Goworek, T. Radkiewicz, S., Processes during liquation of Vycor glass studied by positron annihilation lifetime spectroscopy, Physical Chemistry Chemical Physics, 2(14), 2000, 3269-3274

    Abstract:
    This study concerns Vycor glass subjected to liquation in the temperature range 725-950 K and leached in hot acid in order to produce pores. Three stages of pore creation were observed with increasing liquation temperature: The initial structure of nanopores with a radius of about 0.5 nm (like in the nonliquated glass) disappears, giving way to the next group, dominant at 875 K, whose average radius is 1.15 nm, independently of the liquation time. The spread of these radii is narrow, 0.15 nm. At the highest temperatures, the intensity of this component decreases rapidly (down to 1%), and large pores begin to grow; the specific surface area diminishes. About 900 K, the total positronium formation probability decreases significantly, which can be ascribed to the partial crystallization of silica.

  25. Jasinska, B. Koziol, A. E. Goworek, T., Void shapes and o-Ps lifetime in molecular crystals, Acta Physica Polonica A, 95(4), 1999, 557-561

    Abstract:
    The size and shape of the free volume in molecular crystals was estimated from crystallographic data. The o-Ps lifetime values were calculated from respective models and compared with the experimental data. The best agreement for channel-like voids has been obtained for the value of DR parameter equal 0.19 nm. The threshold value of radius allowing Ps trapping in the void was found to be (0.12-0.13) nm.

  26. Ciesielski, K. Dawidowicz, A. L. Goworek, T. Jasinska, B. Wawryszczuk, J., Positronium lifetimes is porous Vycor glass, Chemical Physics Letters, 289(1-2), 1998, 41-45

    Abstract:
    The ortho-positronium lifetimes in porous Vycor glass were measured in a wide range of pore radii. A good correlation of the most probable lifetime with the model accounting for the population of upper levels of a particle in the potential well was observed. For channel-like voids (capillaries in porous media) a new value of the empirical parameter, Delta R, entering in the semi-empirical Eldrup equation, is proposed: Delta R = (0.191 +/- 0.007) nm; it explains some of the discrepancies previously found in crystalline solids. (C) 1998 Elsevier Science B.V. All rights reserved.

  27. Goworek, T. Ciesielski, K. Jasinska, B. Wawryszczuk, J., Positronium states in the pores of silica gel, Chemical Physics, 230(2-3), 1998, 305-315

    Abstract:
    The lifetime spectra of positrons annihilating in silica gels with pore radii from 2 to 10 nm were measured, and the results compared with the predictions made by the Tao-Eldrup model extended to include the annihilation of positronium from the excited states in the potential well. The long-lived parts of the spectra were analysed as a sum of 1-3 components with continuous lambda distributions (gaussian in the logarithmic scale). The Ip state population in Si40 is demonstrated; the decay constant of ortho-Ps in it agrees quite well with the model estimate and the growth of intensity with temperature resembles that expected from the Boltzmann distribution. In one-component fit the lifetimes at the maximum of lambda distribution at a room temperature for various pore radii were found also to be very close to the calculated lifetime averaged over all states of the positronium particle in the rectangular potential well. (C) 1998 Elsevier Science B.V. AII rights reserved.

  28. Goworek, T. Ciesielski, K. Jasinska, B. Wawryszczuk, J., Lifetimes of o-Ps in the pores of silica gel, Positron Annihilation, (), 1997, 296-298

    Abstract:
    An attempt to extend the popular Tao-Eldrup model (TEM) toward large voids is presented. The lifetimes of o-Ps in various states of the particle in the spherical and cylindrical wells have been calculated. The existence of o-Ps in excited well state("1p-like" state) is demonstrated.

  29. Jasinska, B. Koziol, A. E. Goworek, T., Free volumes in perfect molecular crystals and o-Ps lifetime, Positron Annihilation, (), 1997, 308-311

    Abstract:
    The size of free volume in molecular crystals was estimated from crystallographic data. The threshold value of free volume radius allowing Ps formation was found to be (0.12 - 0.13) nm. The lifetime estimates were compared with experimental data for 13 crystalline solids.

  30. Goworek, T. Ciesielski, K. Jasinska, B. Wawryszczuk, J., Positronium in large voids. Silicagel, Chemical Physics Letters, 272(1-2), 1997, 91-95

    Abstract:
    The lifetime spectra of positrons annihilating in a porous medium (silicagel) were measured as a function of temperature. In the low temperature limit the lifetime of o-Ps in the pores agrees rather well with the popular Tao-Eldrup formula. With the rise of temperature the second long-lived component grows; that component was identified as o-Ps annihilation from the Ip- like state in the potential well. The lifetimes of o-Ps in various states of the spherical well have been calculated. The experimental value of the lifetime for the Ip state is in good agreement with the model calculation. (C) 1997 Elsevier Science B.V.

  31. Goworek, T. Jasinska, B. Wawryszczuk, J. Ciesielski, K., Positronium formation in dihydroxybenzenes, Journal of the Chemical Society-Faraday Transactions, 93(8), 1997, 1573-1578

    Abstract:
    Lifetime spectra of positrons in solid dihydroxybenzenes have been investigated over a wide range of temperatures. The variation of Ps formation probability with temperature and relative permittivity is an argument in favour of spur model concepts in the description of Ps formation in solids. An attempt to estimate the average excess electron-positron distance in the spur is undertaken. Detailed analysis of the e(+) lifetime spectrum in hydroquinone indicates that the long- lived part of that spectrum can be a continuous distribution of lifetimes, not a discrete component.

  32. Goworek, T. Jasinska, B. Wawryszczuk, J. Ciesielski, K., Positrons in benzenediols, Journal of Radioanalytical and Nuclear Chemistry-Articles, 210(2), 1996, 441-449

    Abstract:
    Temperature dependence of positronium formation probability P was measured for catechol, resorcinol and hydroquinone. The variations of P with temperature and relative permittivity can be explained in the framework of spur reaction mode. It seems that the spur processes are important at the first stage of Ps formation, the final value of P depends also on free volume availability and trapping efficiency.

  33. Jasinska, B. Koziol, A. E. Goworek, T., Ortho-positronium lifetimes in nonspherical voids, Journal of Radioanalytical and Nuclear Chemistry-Articles, 210(2), 1996, 617-623

    Abstract:
    Experimental values of o-Ps lifetime were compared with model calculations, approximating the voids in a solid by spheres or cuboids. In the case of resorcinol the model of spherical voids is well consistent with the experimental data. For channel-like free volumes the formula, analogous to that for spheres, gives systematically the values of o-Ps lifetime too large. No positronium is found in anthracene, although the radius of free volume is larger than 0.97 Angstrom at which the Ps binding energy should be zero.

  34. Goworek, T. Jasinska, B. Wawryszczuk, J. Ciesielski, K., Positrons in resorcinol, Journal of the Chemical Society-Faraday Transactions, 92(9), 1996, 1573-1578

    Abstract:
    The temperature dependence of parameters describing the positron lifetime spectrum in resorcinol has been investigated. It was found that the solid phase transition point is located near 353 K, but over several K the transition is very slow, its rate lies in the range of days. The dimensions of positronium traps (free volumes) were estimated from crystallographic data. In spite of the non-spherical shape of these free volumes the o-Ps lifetime and its temperature dependence calculated from the popular Tao-Eldrup formula are relatively consistent with the experimental values. The main features of the temperature dependence of the positronium formation probability can be explained in the framework of the spur model. The increase in probability in the region below the transition point may be the result of ion-molecule reactions in the spur, or of the dependence of the Ps trapping probability on the trap size.

  35. Goworek, T. Jasinska, B. Wawryszczuk, J., Positrons in benzenediols - Does the spur model work in a solid?, Abstracts of Papers of the American Chemical Society, 211(), 1996, 34-NUCL

  36. Halas, S. Jasinska, B., Platinized magnesium as reducing agent for hydrogen isotope analysis, Isotopes in Environmental and Health Studies, 32(1), 1996, 105-109

    Abstract:
    Platinized magnesium has recently been proposed as a new reducing agent for the conversion of small quantities of water to hydrogen in a dame-sealed borosilicate glass tube at 400 degrees C for isotopic analysis. The reagent, Mg-Pt, in contrast to zinc can be prepared in every laboratory by coating a magnesium granulate with a thin layer of platinum by reaction with H2PtCl6 . 6H(2)O dissolved in acetone-ether mixture. Excellent reproducibility of the isotope ratios in hydrogen gas prepared from water samples has been obtained using 4 mu l of water and 120 mg of the reagent.


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