Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 20

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Positron Annihilation in and Compressibility of Water-Organic Mixtures. The System Water-Acetamide

100%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
Acta Physica Polonica A
|
1996
|
vol. 90
|
issue 6
1169-1177
EN
The experimental results of positron annihilation experiments in aqueous solutions of acetamide were compared to those of ultrasonic velocity. The system under investigation behaves untypically when changing acetamide concentration. From the point of view of surface tension it interacts with water like normal alcohols, while the positron annihilation and ultrasonic results suggest hydrophilic hydration and lack of hydrophobic interactions.
2
Content available remote

Structure of Carbon Tetrachloride + t-Butanol Mixtures from Positron Annihilation and Ultrasonic Velocity Measurements

100%
Jerie K., Baranowski A., Gliński J.
Acta Physica Polonica A
|
1993
|
vol. 83
|
issue 3
313-320
EN
The densities of and sound velocities in t-butyl alcohol solutions in CCl_{4} were determined in temperature range 25 to 45°C. From these data the adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectrum for this system in room temperature was measured. The results plotted against alcohol concentration suggest that the structural processes occurring in this system are caused by dimerization of the solute molecules.
3
Content available remote

Structure of Aqueous Solutions of Tetramethylammonium Chloride Investigated by Positron Annihilation and Ultrasonic Methods

100%
Jákli G., Jerie K., Baranowski A., Gliński J.
Acta Physica Polonica A
|
1998
|
vol. 93
|
issue 4
649-658
EN
The structure of aqueous solutions of tetramethylammonium chloride was investigated using sound velocity and positron annihilation methods. The results are different than those obtained earlier for systems where hydrophobic hydration occurs, although some evidences for formation of clathrate-like hydrates in liquid phase were observed. The results are interpreted, among others, in terms of competition of different hydrates of tetraalkylammonium cations, hydration of chloride anions, and formation of ionic pairs.
4
Content available remote

Structure of Cyclohexane + t-Butanol Mixtures from Positron Annihilation and Ultrasonic Velocity Measurements

100%
Jerie K., Baranowski A., Gliński J.
Acta Physica Polonica A
|
1993
|
vol. 83
|
issue 3
321-326
EN
The densities of and sound velocities in t-butyl alcohol solutions in cyclohexane were determined in the temperature range 25 to 45°C. From these data adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectra of the solutions were measured at room temperature. The results plotted against alcohol concentration show structural processes, which can be attributed to dimerization of the solute molecules.
5
Content available remote

Positron Annihilation in and Adiabatic Compressibility of Ethylene Glycol Aqueous Solutions

100%
Baranowski A., Jerie K., Gliński J., Orzechowski K.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 1
59-66
EN
The positron annihilation lifetime and ultrasonic velocity in aqueous ethylene glycol solutions were measured. A comparison between the concen­tration and temperature dependences of the above parameters suggests that there is a competition of hydrophobic (interstitial) and hydrophylic (substi­tutional) hydration.
6
Content available remote

Positron Annihilation in and Compressibility of Water-Organic Solutions. The System Water-Pyridine

100%
Jerie K., Baranowski A., Gliński J., Jeżowska-Trzebiatowska B.
Acta Physica Polonica A
|
1992
|
vol. 82
|
issue 3
471-479
EN
The results of positron lifetime and ultrasonic velocity measurements in dilute aqueous pyridine (PYR) solutions show unusual changes in ultrasonic, annihilation data in function of pyridine concentration. The results obtained suggest that strong structural changes occur in the system, in the region of low pyridine concentrations. Liquid clathrate hydrates forming in the system are supposed with unusual stoichiometry and untypical geometry. They are supposed to be very short-living and/or unstable.
7
Content available remote

Structure of Aqueous Solutions of 1,2- and 1,3-Propanediol Investigated by Positron Annihilation and Ultrasonic Methods

100%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
|
|
vol. 95
|
issue 4
562-567
EN
The structure of aqueous solutions of 1,2-propanediol and 1,3-propane-diol was investigated using adiabatic compressibility measurements and positron annihilation methods. The experimental results are different than those obtained earlier for systems where hydrophobic hydration dominates. There are some evidences for increased rigidity of the water network, which can arise from the formation of hydrogen bonds between diols and water.
8
Content available remote

Annihilation of o-Positronium in the Vicinity of the Critical Mixing Point

100%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
|
|
vol. 95
|
issue 4
569-574
EN
Positron annihilation spectra were investigated in the critical region close to the consolute point of ethanol + dodecane mixture. The anomalies of the positron lifetimes and intensities were small, nevertheless it was found that the intensity of short-living components of annihilation spectrum seems to increase close to the critical temperature.
9
Publication available in full text mode
Content available

Hydrophobic-Like Solvation in Non-Aqueous Solutions: Positron Annihilation in and Compressibility of Tert-butanol and Tetramethylurea in Ethylene Glycol

100%
Jerie K., Baranowski A., Gliński J., Przybylski J.
Acta Physica Polonica A
|
2001
|
vol. 99
|
issue 3-4
385-392
EN
The pioneer experimental results of positron annihilation experiments in non-aqueous solutions of tetramethylurea and tert-butanol were compared to those of ultrasonic velocity. For tert-butanol, the positron annihilation results exclude existence of hydrophobic-like interactions and formation of weak, labile crystalline-like solvates in solution. For tetramethylurea solute the changes of annihilation parameters with concentration are minor and only limited conclusions can be drawn on this system, while they are stronger for tert-butanol solute. However, all the above is consistent with an assumption that the more hydrophobic solute (tert-butanol) should affect the original glycol structure stronger than that interacting with glycol via hydrogen bondings only. On the other hand, the ultrasonic data for the systems tested, although very precise, hardly confirm formation of any specific structure. It is possible, however, that the solvates do not differ in their compressibility from the pure liquids, and/or are formed only in very small amounts. Thus, usefulness of the positron annihilation method in investigation of liquid structure was proven.
10
Content available remote

Positron Annihilation in and Compressibility of Water-Organic Mixtures. The System Water-Formamide

100%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
Acta Physica Polonica A
|
1994
|
vol. 85
|
issue 3
563-569
EN
The experimental results of positron annihilation experiments in aqueous solutions of formamide were compared to those of ultrasonic velocity. The systems under investigation behave untypically while changing formamide concentration. The results are explained in terms of hydrophilic hydration and lack of hydrophobic interactions.
11
Content available remote

Positron Annihilation in and Adiabatic Compressibility of Water-Organic Solutions. The System Water-Dimethylsulfoxide

88%
Jerie K., Baranowski A., Rozenfeld B., Jeżowska-Trzebiatowska B., Gliński J.
Acta Physica Polonica A
|
1991
|
vol. 79
|
issue 4
507-515
EN
The results of positron lifetime and ultrasonic velocity measurements in dilute aqueous dimethylsulfoxide (DMSO) solutions show the usual extreme characteristic for polar organic solutes. The results obtained suggest that strong structural changes occur in the system, in the region of low DMSO concentrations. Liquid clathrate hydrates forming in the system are supposed, with unusual stoichiometry and untypical geometry of the hydrates.
12
Publication available in full text mode
Content available

Structure of Aqueous Solutions of Acetonitrile Investigated by Acoustic and Positron Annihilation Measurements

88%
Jerie K., Baranowski A., Koziol S., Gliński J., Burakowski A.
Acta Physica Polonica A
|
2005
|
vol. 107
|
issue 5
826-831
EN
We report the results of acoustic and positron annihilation measurements in aqueous solutions of acetonitrile (CH_3CN). Hydrophobicity of the solute is discussed, as well as the possibility of describing the title system in terms of hydrophobic solvation. The concept of Levay et al. of calculating the "ideal positronium lifetimes is applied, basing on the mean volume of cavities (holes) in liquid structure available for positronium pseudoatom. The same calculations performed using the Tao model of annihilation yield very different results. It can be concluded that either acetonitrile forms with water clathrate-like hydrates of untypical architecture, or it is too weak hydrophobic agent to form clathrate-like hydrates at all. The former interpretation seems to be more probable.
13
Content available remote

Ultramarine, Lazurite and Sodalite Studied by Positron Annihilation and EPR Methods

88%
Baranowski A., Dębowska M., Jerie K., Jezierski A., Sachanbiński M.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 1
29-41
EN
Studies of positron annihilation accompanied by EPR technique were undertaken for sodalite and lazurite and their synthetic counterparts (syn­thetic sodalite and ultramarines). Results of measurements performed by two techniques of positron annihilation spectroscopy (angular correlation of annihilation radiation, ACAR, and positron annihilation lifetime) revealed the undoubted influence of free radicals on positron annihilation mechanism but both inhibition of positronium formation by them and the effect of filling cages ought to be taken into account. The distinct differences between ACAR curves for sodalites, lazurites and ultramarines probably reflect the presence of different radicals in their cages and chemical heterogeneity as well as the disorder in Al, Si-site ordering in case of ultramarines. Comparison of the results of ACAR measurements with the ones of the EPR studies indicates that there is correspondence between them. Similarly to three families of the ACAR curves, different likes of EPR lines were obtained for three groups of samples; sodalites, lazurites and ultramarines. It is possible that the an­nihilation of positrons takes place mainly with unpaired electrons recorded by the EPR technique.
14
Publication available in full text mode
Content available

Structure of Aqueous Solutions of 1,2-, 1,3- and 1,4-Butanediol Investigated by Positron Annihilation and Ultrasonic Methods

88%
Jerie K., Baranowski A., Gliński J., Orzechowski K., Przybylski J.
Acta Physica Polonica A
|
2001
|
vol. 99
|
issue 3-4
393-398
EN
The structure of aqueous solutions of 1,2-, 1,3- and 1,4-butanediol was investigated using adiabatic compressibility measurements and positron annihilation methods. In the case of 1,2-butanediol the experimental results are very similar to those obtained earlier for systems where hydrophobic hydration dominates. In other cases there are evidences for increased rigidity of the water network, which arises from formation of hydrogen bonds between diols and water. Usefulness of both the methods applied in investigating the structure of liquid solutions was proved.
15
Content available remote

Positron Annihilation in Chloropolystyrenes

76%
Baranowski A., Dębowska M., Jerie K., Mirkiewicz G., Rudzińska-Girulska J., Sikorski R.
Acta Physica Polonica A
|
1993
|
vol. 83
|
issue 3
239-249
EN
Results of angular correlation of annihilation radiation and positron annihilation lifetime measurements are presented for atactic polystyrene and chloropolystyrenes. The inhibition of positronium formation follows the chlorine introduction as the decrease in intensities of the narrow component in angular correlation of annihilation radiation curves and of the longest-lived component in positron annihilation lifetime spectra prove. In general, the chlorine "activity" towards positrons seems to depend on its position in the polymer structure. The annihilation rate distribution as well as the radius and volume distributions of free-volume sites where positronium is assumed to be formed obtained with the use of CONTIN program for the raw sample in the 2nd series are given additionally.
16
Content available remote

Positron Annihilation Studies of Styrene-N-X-Phenylmaleimides

76%
Baranowski A., Dębowska M., Jerie K., Rudzińska-Girulska J., Pawełka Z., Sikorski R. T.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 1
51-57
EN
Results of angular correlation of annihilation radiation and positron an­nihilation lifetime measurements are presented for five styrene copolymers: poly(co-styrene-phenylmaleimide) and its three derivatives with chlorine as well as for one with the OH group substituted in the benzene ring. It occurs that the chlorine substituted in three different positions in the benzene ring poly(co-styrene-o (or -m, -p)-chlorophenylmaleimide) inhibits the formation of the positronium to different extent. The greatest effect is observed in case of the chlorine atoms substituted in the benzene ring at ortho-position towards the nitrogen atom. In addition, electric dipole moments were measured for N-X-phenylmaleimide units, to check whether their magnitude influences the positron annihilation parameters. On the basis of the present results no correlation between the positron annihilation parameters and the electric dipole moments of the units was noticed.
17
Content available remote

Free Volume in Epoxy-Coal Resins Studied by Positron Annihilation

76%
Baranowski A., Dębowska M., Jerie K., Kurzeja L., Hennek K., Rudzińska-Girulska J.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 1
43-49
EN
In this paper the macroscopic properties of the tetrafunctional epoxy resin (N, N'-tetraglycidyl ether of diaminodiphenylmethane) cured by 4, 4'-diaminodiphenylmethane, were studied. For the system the influence of various curing conditions on the glass temperature was investigated. Results obtained for two compositions: an unmodified one and a modified with coal were compared with information on the free volume given by the positron annihilation technique.
18
Publication available in full text mode
Content available

Positron Annihilation Lifetime Spectroscopy and Dielectric Measurements of Natural Kaolinite and Kaolinite Intercalated by Potassium Acetate

76%
Leluk K., Orzechowski K., Jerie K., Baranowski A., Słonka T., Głowiński J.
Acta Physica Polonica A
|
2006
|
vol. 110
|
issue 5
621-629
EN
Intercalation of clay minerals consists in inserting of guest molecules into interlayer area. It results in expanding the interlayer distance and changes of physical and chemical properties of the material. Dielectric spectroscopy, positron annihilation lifetime experiments, X-ray, and thermoanalysis were jointly applied to investigate the structural changes accompanying intercalation.
19
Publication available in full text mode
Content available

Investigation of Sol-Gel Glasses Doped with Lanthanide Ions by Spectroscopic, Acoustic, and Positron Annihilation Methods

76%
Jerie K., Baranowski A., Legendziewicz J., Guzik M., Burakowski A., Gliński J.
Acta Physica Polonica A
|
2006
|
vol. 110
|
issue 5
583-591
EN
The results of optical spectroscopic (UV-Vis, absorption, and emission), acoustic (sound velocity of precursor solutions, the solvation numbers of ions in these solutions), and positron annihilation of glasses are presented and discussed for silica glasses obtained by the alcoholic sol-gel technique, doped with selected lanthanides and with some addition of ethylene glycol. The aim of these investigations was the determination of the local structure of glass close to lanthanide ions and its influence on the optical properties of the material. The results show that the existence of alcohol-glycol solvates in glasses decrease the number of empty voids in its structure as well as the size of the remaining ones. One can suppose that this is caused by cooperative interactions of glycol molecules with the network of hydrogen bonds of the glass.
20
Content available remote

Liquid Crystalline Polyurethanes Studied by Positron Annihilation Method

64%
Baranowski A., Dębowska M., Jankowski A., Jerie K., Penczek P., Rudzińska-Girulska J., Szczepaniak B., Wolińska-Grabczyk A.
Acta Physica Polonica A
|
1995
|
vol. 88
|
issue 1
21-27
EN
A series of liquid crystalline polyurethanes of different both flexible spacer length and mesogenic group content was studied by means of positron annihilation method. The investigated polymers were targeted on the sep­aration of aromatic hydrocarbons from their mixtures with aliphatic ones. The effect of modification of the liquid crystalline polyurethane chain on the polyurethane free volume size and free volume distribution was determined on the basis of the positron annihilation lifetime spectra. In the positron annihilation lifetime spectra measured for the samples under study two long com­ponents of several nanoseconds, characteristic of o-Ps decaying by pick-off, occurred. The correlation of the values of the o-Ps lifetime with the size of the free volume region allowed to recover the free volume distributions with the use of the method employing the numerical Laplace inversion technique. The obtained results were compared with the diffusion data on the mobility of liquid hydrocarbons in the liquid crystalline polyurethanes enabling the correlations between polymer structure and its transport properties to be evaluated.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.