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1

The use of DSC curves and the Kronmüller theory to study the level of structural defects of Fe-based bulk amorphous alloys

Jeż Bartłomiej, Nabiałek Marcin

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144613

EN

This article presents the results of tests carried out on rapid quenched Fe-based alloys. The alloys were made using an injection-casting method. The actual structure of the alloys was also studied using an indirect method, based on H. Kronmüller's theorem. Based on analysis of the primary magnetization curves, in accordance with the aforementioned theory, it was found that Mo causes a change in internal regions associated with changes in the direction of the magnetization vector. The evolution of the thermal properties with increasing volume of Mo has been confirmed by the DSC curves. Addition of Mo, at the expense of the Nb component, results in changes to the crystallization process (i.e. the crystallization onset temperature and number of stages). The study showed that the addition of Mo at the expense of Nb reduces glass forming ability. Based on the DSC analysis, free volumes were determined for the alloys tested. These values were compared with the analysis of primary magnetization curves. It was found that the DSC curves can be used to indirectly describe the structure of amorphous alloys similar to the theory of the approach to ferromagnetic saturation. This approach is new and can be used by many researchers in this field.

2

Analysis of free volumes and light transmission in hydrogel and silicone-hydrogel polymer contact lenses

Kocela A., Miedzinski R., Filipecka K., Filipecki J.

Optica Applicata

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2016

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Vol. 46, nr 1

35--45

EN

The free volume holes and light transmission of hydrogel and silicone-hydrogel polymer contact lenses were investigated. As the material, the Proclear family (omafilcon A) of hydrogel contact lenses and the Biofinity family (comfilcon A) of silicone-hydrogel contact lenses were used. Positron annihilation lifetime spectroscopy was used to characterize geometrical sizes and fractions of the free volume holes in the investigated samples. There was a clear difference in the size of free volume holes and the fractional free volume between silicone-hydrogel and hydrogel polymer contact lenses. These changes are shown by a thorough analysis of the long-lived component of lifetime of ortho-positronium. At the same time, UV-vis-NIR in the spectral range 200-1000 nm studies were performed on the same samples of contact lenses spectrometry.

3

Analiza porównawcza struktury wewnętrznej implantów hydrofilowych oraz hydrofobowych stosowanych w chirurgii okulistycznej metodą spektroskopii czasów życia pozytonów

Chamerski K.

Technical Issues

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2015

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nr 3

3--10

EN

In presented work internal structures of intraocular lenses were analyzed in terms of defectiveness degree. Studies were conducted by means of positron annihilation lifetime spectroscopy method PALS. The aim of the work was determination of basic parameters describing annihilation centers in research materials, such as positron lifetime in bulk material, mean positron lifetime in the internal structure, positron trapping rate by trapping centers as well as free volumes dimensions. In obtained results differences in free volumes and positron traps concentrations between hydrophilic and hydrophobic materials were noted. Furthermore, comparison of materials with and without blue light chromophores revealed differences in positron trapping rate by multivacancy-like free spaces. Achieved results were referenced for mechanical properties of the studied materials.

4

Studies of unicellular microorganisms Saccharomyces cerevisiae by means of positron annihilation lifetime spectroscopy

Kubicz E., Jasińska B., Zgardzińska B., Bednarski T., Białas P., Czerwiński E., Gajos A., Gorgol M., Kamińska D., Kapłon Ł., Kochanowski A., Korcyl G., Kowalski P., Kozik T., Krzemień W., Niedźwiecki S., Pałka M., Raczyński L., Rajfur Z., Rudy Z., Rundel O., Sharma N. G., Silarski M., Słomski A., Strzelecki A., Wieczorek A., Wiślicki W., Zieliński M., Moskal P.

Nukleonika

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2015

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Vol. 60, No. 4, part 1

749--753

EN

Results of positron annihilation lifetime spectroscopy (PALS) and microscopic studies on simple microorganisms, brewing yeasts, are presented. Lifetime of ortho-positronium (o-Ps) were found to change from 2.4 to 2.9 ns (longer-lived component) for lyophilized and aqueous yeasts, respectively. Also hygroscopicity of yeasts in time was examined, allowing to check how water – the main component of the cell – affects PALS parameters, thus lifetime of o-Ps were found to change from 1.2 to 1.4 ns (shorter-lived component) for the dried yeasts. The time sufficient to hydrate the cells was found below 10 hours. In the presence of liquid water, an indication of reorganization of yeast in the molecular scale was observed. Microscopic images of the lyophilized, dried, and wet yeasts with best possible resolution were obtained using inverted microscopy (IM) and environmental scanning electron microscopy (ESEM) methods. As a result, visible changes to the surface of the cell me mbrane were observed in ESEM images.

5

PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix

Wieczorek A., Zgardzińska B., Jasińska B., Gorgol M., Bednarski T., Białas P., Czerwiński E., Gajos A., Kamińska D., Kapłon Ł., Kochanowski A., Korcyl G., Kowalski P., Kozik T., Krzemień W., Kubicz E., Niedźwiecki S., Pałka M., Raczyński L., Rudy Z., Rundel O., Sharma N. G., Silarski M., Silarski A., Strzelecki A., Wiślicki W., Zieliński M., Moskal P.

Nukleonika

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2015

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Vol. 60, No. 4, part 1

777--781

EN

The polystyrene doped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenyl)benzoxazole as a wavelength shifter prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260, 283, and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.

6

Comparison of the free volume sizes and shapes determined from crystallographic and PALS data

Tydda M., Jasińska B.

Nukleonika

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2015

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Vol. 60, No. 4, part 1

771--775

EN

Two different classes of molecular crystals were investigated. The first group was benzenediols, which are characterized by the same chemical composition but a different organization of their crystallographic structures; all of the compounds from this group have only one kind of free volumes. The second class was represented by olanzapine, which has more complex chemical composition and two kinds of free volumes in the structure. The o-Ps lifetime values determined from positron annihilation lifetime spectroscopy (PALS) measurements agree quite well with those calculated for sizes found from crystallographic data for benzenediols (agreement within 10% of the lifetime values). For olanzapine, a good agreement is observed in the case of cuboidal free volumes, while for the other kind of void, the agreement is less satisfactory. Positronium diffusion coefficient determined from o-Ps redistribution in olanzapine agrees with these found for polymers.

7

Positrons in naphthalene : critical remarks on the relation between o-Ps lifetime and void size

Goworek T., Zgardzińska B., Wawryszczuk J.

Nukleonika

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2013

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Vol. 58, No. 1

183-187

EN

Lowering the temperature or applying high pressure leads to elimination of positronium component in the e+ lifetime spectrum in solid naphthalene. Disappearance of positronium means reaching the free volume size limit at which there is no energy level in the potential well. It allows to estimate that size, which is found inconsistent with predictions of the popular Tao-Eldrup model. The range of applicability of that model is discussed. The dependence of the free e+ decay constant on pressure indicates that positronium is formed not only in the blob processes, but during the whole free positron life. The lifetime of free positrons begins to rise with temperature earlier than Ps intensity.

8

PALS investigation of resorcinol under high pressure

Tydda M., Jasińska B., Pieniążek A.

Nukleonika

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2013

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Vol. 58, No. 1

195-198

EN

Two kinds of measurements were conducted with resorcinol at high pressure : the first one with the use of a mechanical press and the second one with the use of a gaseous compressor. In the second case, due to some gas penetrating the material structure, the lifetime spectra obtained were difficult to analyze. The free volumes in resorcinol were influenced both by high pressure and the gas coming into the crystallographic structure.

9

Zastosowanie teorii bilansów w termodynamice stanów nieustalonych

Wrzesiński Z.

Prace Naukowe Politechniki Warszawskiej. Mechanika

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2012

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z. 241

3-90

PL

W pracy zastosowano wyniki teorii bilansów w termodynamice stanów nieustalonych, na przykładzie zjawiska strzału w broni lufowej. Rozpatrzono dwa przypadki: pierwszy - gdy pole przekroju poprzecznego komory nabojowej równe jest polu przekroju poprzecznego lufy (układ KLP) oraz drugi - gdy pola przekroju poprzecznego komory nabojowej i lufy nie są sobie równe (układ KSLP). Zdefiniowano pojęcia mieszaniny gazowo-prochowej (MGP) i masowej gęstości zasobu energii łącznej oraz sformułowano referencjalne i substancjalne bilanse zasobu masy, pędu i energii łącznej MGP. Następnie, przy użyciu pojęć pierwotnych i aksjomatów, tworzących teorię balistyki wewnętrznej oraz substancjalnych równań bilansowych zasobu masy, pędu i energii łącznej, sformułowano balistyczne równania bilansowe zasobu masy, pędu i energii łącznej we współrzędnych Eulera i Lagrange'a. Bilanse te wraz z warunkami początkowo-brzegowymi utworzyły zamknięty układ równań, spełniający warunki konieczny i wystarczający do rozwiązania problemu głównego balistyki wewnętrznej (PGBW) układu KLP oraz KSLP. W ostatniej części pracy zdefiniowano parametry zredukowane balistycznych równań bilansowych i przy ich wykorzystaniu sformułowano bezwymiarowe balistyczne bilanse zasobu masy, pędu i energii łącznej MGP, które wraz z bezwymiarowymi warunkami początkowo-brzegowymi utworzyły zamknięty układ równań spełniający warunki konieczny i wystarczający dla rozwiązania PGBW bezwymiarowych układów KLP oraz KSLP.

EN

Indie study the results of the balance theory in the thermodynamics of unstable states have been applied, as exemplified by the shot of a barrel gun. Two cases have been analyzed, the first one when the cross-section of the chamber is equal to the cross-section of the barrel (KLP system) and the second one when the cross-sections of the chamber and the barrel are not equal (KSLP System). The notion of a powder gas mixture (MGP) has been defined, as well as that of mass density of joint energy capacity, referential and substantive balances of mass momentum and joint energy of MGP. Next, with primitive notions and axioms constituting the theory of internal ballistics and substantive balance equations of mass momentum and energy capacity, a ballistic balance equation of mass momentum and joint energy has been formulated in terms of Euler and Lagrange coordinates. The above balances together with initial boundary conditions formed a closed system of equations fulfilling the necessary and sufficient condition to solve the main problem of inner ballistics (PGBW) of the KLP and KSLP systems. In the last part of the study reduced parameters of ballistic balance equations have been defined and by their application, dimensionless ballistic balances of mass momentum and joint energy of MGP have been formulated, which, combined with dimensionless initial boundary conditions, formed a closed system of equations fulfilling the necessary and sufficient condition for solving PGBW of dimensionless KLP and KSLP systems.

10

Free volume effect on behavior of polymer liquids in shear flows

Steller R.

Polimery

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2012

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T. 57, nr 7-8

562-570

EN

Rheological properties of polymers such as non-Newtonian viscosity and non-zero normal stress differences during the shear flow of polymeric liquids were interpreted from the point of view of the free volume theory. It was shown that the shear viscosity variations result from the changes of the total free volume, while the normal stress differences stem from the anisotropy of the free volume distribution in a polymer liquid subjected to the shearing flow. Theoretical predictions were compared with literature data for PE-LD melt (known as IUPAC melt A) and polyisobutylene (PIB) solution in 2,6,10,14-tetramethylpentadecane (NIST standard reference material). Good agreement between theory and the experiment was found.

PL

Reologiczne właściwości polimerów, w tym lepkość nienewtonowską oraz niezerowe różnice naprężeń normalnych w przepływie ścinającym zinterpretowano na gruncie teorii objętości swobodnej. Wykazano, że zmiany lepkości wynikają ze zmian całkowitej objętości swobodnej, podczas gdy niezerowe różnice naprężeń normalnych są wywołane anizotropią rozkładu objętości swobodnej w cieczy polimerowej poddanej przepływowi ścinającemu. Teoretyczne przewidywania porównano z danymi literaturowymi dotyczącymi stopionego PE-LD (znanego jako stop IUPAC A) i roztworu poliizobutylenu (PIB) w 2,6,10,14-tetrametylopentadekanie (wzorcowy materiał odniesienia NIST). Stwierdzono dobrą zgodność między teorią a doświadczeniem.

11

Influence of low temperature on the free volume in polyethylene by positron annihilation

Osoba W.

Nukleonika

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2010

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Vol. 55, No. 1

69-72

EN

Positron lifetime measurements were performed as a function of temperature in thermo-shrunken, modified polyethylene. Mean volume of free volume cavities in the investigated polymer was estimated from the results of the measurements. This mean volume turned out to be a smooth function of temperature (from room temperature to 8.5 K). The effect of trapping of free electrons, produced during positron irradiation, was observed at lowered temperature.

12

Biodegradable polyester blend and copolyesters studied by positron annihilation and other methods

Dębowska M., Rudzińska-Girulska J., Serwadczak M., Kiersnowski A., Pigłowski J.

Nukleonika

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2010

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Vol. 55, No. 1

57-64

EN

Two polyesters, i.e. an aromatic one: poly(butylene terephthalate) – PBT and an aliphatic one: poly(ĺ- -caprolactone) – PCL were mixed in melt to obtain a biodegradable product. DSC, 1H NMR, SEM, WAXS, SAXS, BOD and PALS measurements were performed to study the homopolymers as well as their physical blend and copolyesters. The latter were obtained due to the transesterification reaction. Ortho-positronium (o-Ps) annihilation lifetimes were used to create the distributions of free volume. The progressive changes in probability density function of free volume, i.e. increase in large free volume holes contribution to the total free volume, appearing when going from the homopolymers to the blend and then to the copolyesters reflect the influence of: the addition of aliphatic polyester, the weight fraction of it in the composition and transesterification. The higher contribution of larger free volume holes corresponds well with the reduced crystallinity of compositions revealed in X-ray diffraction and the worsening of the regularity of structure of the macromolecules involved in formation of crystals, deduced from the 1H NMR.

13

Speed Of Ultrasound And Thermodynamic Properties Of 1-Butanol In Binary Liquid Mixtures At 293.15 K

Bebek K.

Molecular and Quantum Acoustics

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2005

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Vol. 26

7-13

EN

The speeds of ultrasound in and densities of binary solutions of 1-butanol in hexane and cyclohexane were measured on the whole concentration range at 293.15 K. The experimental results in connection with literature data were used to calculate the isothermal compressibility coefficients and isochoric molar heat capacities for the pure components, as well as the excess molar volumes, excess adiabatic compressibilities, free volumes and the free intermolecular lengths for the binaries under test. The dependences of the excess properties on the mixture composition were compared and discussed in terms of the free intermolecular length and other factors affecting the solvation and self-association effects.

14

Acoustic and Volu,E Effects Of Self-Association Of 3-Methylpyrazole In Cyclohexane

Bebek K., Filosek G., Ernst S.

Molecular and Quantum Acoustics

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2004

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Vol. 25

23-28

EN

The speeds of ultrasound in and densities of 3-methylopyrazole with cyclohexane mixtures were measured in the whole concetration range at 293.15 and 313.15 K. The Excess molar volumes, free volumes excess volumes and diabatic copressibilty coefficients, as well as the free intermolecular lenghts were determinated for the binaries. The dependance of the excess molar volumes and excess free volumes on the mixture composition were compared and discussed in terms of the free intermolecular lenght and other factors affecting the self-association of 3-methylopyrazole and structural changes of the non-polar solvent. Search Site

15

Ultrasonic and Volumetric Effects of Self-Association of Aliphatic Alcohols in Cyclohexane

Bebek K.

Molecular and Quantum Acoustics

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2003

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Vol. 24

17-22

EN

The speed of ulrtasound in and densities of binary solutions of ethanol, propan-2-ol and 2-methylopropan-2-ol in cyclohexane were measured on the whole concentration range at 293.15K. The excess molar volumes, free volumies, excess free volumes and adiabatic cmpressibility coeffcients, as well as the free intermolecular lenghts were determined for binaries. The dependance of the excess molar volumes and excess free volumes on the mixture composition were compared and discussed in terms of the intermolecular lenght and other factors afecting the self-association of alcohols and structural changes od the solvent.

16

Influence of the free volume and chain flexibility on transport properties of membranes

Danch A., Osoba W.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Śląska

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2002

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z. 47

19-28

EN

The results of positron annihilation lifetime spectroscopy, calorimetric measurements and mechanical spectroscopy are presented for the chosen membranes. The concept of the two amorphous fractions in the semicrystalline system is applied, as the first attempt, in order to better explain the transport phenomenon. New formula, for the relaxation time evaluation (tau), is proposed. Some correlation between the transport parameters and the tau values was found.

PL

Przedstawiono wyniki badań objętości swobodnych metodą anihilacji pozytonów oraz ruchliwości segmentów łańcucha polimerowego w wybranych membranach. W celu wyjaśnienia transportu, dla procesu dyfuzji przez membranę substancji lotnych, poddaje się pod dyskusję możliwość zastosowania koncepcji zakładającej istnienie dwóch obszarów amorficznych. Zaproponowanie nowego równania dla czasu relaksacji (tau) pozwoliło określić korelację pomiędzy parametrami transportowymi, a strukturą nadcząsteczkową membrany.

17

Bean cotyledons microporosity under hydration conditions

Golonka P., Dryzek J., Kluza M.

Nukleonika

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2002

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Vol. 47, nr 4

137-140

EN

Positron Annihilation Spectroscopy (PAS), proton Nuclear Magnetic Relaxation (NMR) and hydration kinetics measurements were applied to study the free volume formation process in the initial stages of bean cotyledons imbibition. These methods allowed us to analyse the behaviour of bound water in the bean cotyledon molecular structure, and to observe free volume regions formed there. They also made it possible to describe their dimensions and concentration quantitatively. Good correlation was found between the increase of the free volume radius and the amount of water bound to the bean cotyledon solid matrix.