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1
Content available Ultrasonic Investigations of Inclusion Complexation of α-Cyclodextrin by DMSO in Pseudo-Binary Aqueous System
Kaczmarek-Klinowska M., Hornowski T., Skumiel A., Jażdżewska M.
Archives of Acoustics
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2015
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Vol. 40, No. 4
569--574
EN
The paper reports the study of the complexation processes in aqueous solution of α-CD and DMSO. Cyclodextrins (CDs) (sometimes called cycloamyloses) are cyclic oligosaccharides formed by glucose units interconnected by α-(1,4) linkages; α-CD is one of three the most common CDs. It consists of six glucopyranose units. The speed of ultrasonic waves has been measured by the resonance method on ResoscanTM System apparatus. Some collateral data, such as density and heat capacity of the system, have also been measured. On the basis of the experimental data the excess adiabatic compressibility was determined. The extremes of the excess adiabatic compressibility function for different mixture compositions allowed us to establish the composition of molecular complexes formed in the solution. The obtained results suggest the formation of the α-CD with DMSO inclusion complexes with chemical stoichiometric ratio value of 1:1.
2
Content available remote Ultradźwięki jako narzędzie badań nanomateriałów
Hornowski T., Józefczak A., Skumiel A.
Postępy Fizyki
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2013
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T. 64, z. 3-6
116--119
PL
Rozchodzeniem się fal ultradźwiękowych i słyszalnych rządzą te same prawa fizyczne, a tym, co je różni, jest przede wszystkim częstotliwość. Ta pozornie drobna różnica ma ogromne konsekwencje praktyczne. Fale sprężyste o dużych częstotliwościach dają sie łatwo kształtować w wąskie wiązki, co umożliwia ich wykorzystanie do kierunkowego sondowania właściwości ośrodka lub aktywnego wpływu na jego stan za pomocą temperatury lub nieliniowych zjawisk w rodzaju kawitacji.
3
Content available remote Turbiny wiatrowe – źródła prądu elektrycznego i hałasu
Preis A., Skumiel A., Makarewicz R.
Postępy Fizyki
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2013
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T. 64, z. 3-6
98--109
PL
Turbiny wiatrowe zamieniają energie wiatru na energie elektryczna. Pisze się i mówi, że elektrownie wiatrowe to „czyste źródła” energii elektrycznej. Jest to prawda, ale tylko połowiczna: faktycznie nie produkują one żadnych związków chemicznych (np. dwutlenku węgla lub metanu), które byłyby szkodliwe dla człowieka i biosfery. Turbina wiatrowa generuje jednak hałas – szczególny rodzaj fal akustycznych. Hałas nie wywiera zgubnego wpływu na stabilność biosfery i nie zagraża przyszłości gatunku ludzkiego, lecz już teraz degraduje życie milionom ludzi w Polsce i na całym świecie.
4
Content available Ultrasonic Properties of Magnetic Nanoparticles with an Additional Biocompatible Dextrane Layer
Dąbek L., Hornowski T., Józefczak A., Skumiel A.
Archives of Acoustics
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2013
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Vol. 38, No. 1
93--98
EN
The temperature dependence of the particle size distribution (PSD) of the magnetic fluid with an additional biocompatible dextran layer was studied using a ultrasonic method. The measurements of the ultrasound velocity and attenuation were carried out as a function of the volume concentration of magnetite particles at temperatures ranging from 15°C to 40°C. In order to extract the PSD from ultrasonic measurements, the theoretical model of Vinogradov-Isakovich was used. The extraction of PSD from the ultrasonic data requires also the measurements the density and viscosity of the ferrofluid samples. The calculated PSD of the magnetic fluid with an additional biocompatible layer shows a greater thermal stability than that of a magnetic fluid with a single surfactant layer.
5
Content available Investigation of Ultrasonic Emulsifying Processes of a Linseed Oil and Water Mixture
Skumiel A., Józefczak A., Heller K., Hornowski T., Wielgusz K.
Archives of Acoustics
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2013
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Vol. 38, No. 3
297--301
EN
Ultrasonic emulsifying processes of immiscible liquids can be used to obtain stable emulsions. The authors used an ultrasonic sandwich head with an energy concentrator to obtain a suitable value of the energy density necessary for the emerge of ultrasonic cavitation. Two piezoelectric ring (Dext = 50 mm) transducers of Pz-26 type produced by FERROPERM were used to design the ultrasonic sandwich head. The frequency of the ultrasonic wave was 18.4 kHz and the excitation time of the ultrasonic transducer exiting 5 minutes. Visible bubbles during the generation of ultrasonic waves appeared in the mixture after exceeding the cavitation threshold. The authors determined also the cavitation threshold by measuring the electrical voltage conducted to the transducers. To receive long-lasting emulsion, the electrical voltage attained 300 Vpeak. The dispersion dependence on the emulsifying time was determined. The emulsion of linseed oil and water was stable through some months without surfactants.
6
The heating effect of the magnetic fluid APG-832 in an alternating magnetic field
Skumiel A., Łabowski M., Gojzewski H.
Molecular and Quantum Acoustics
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2007
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Vol. 28
229-239
EN
A calorimetric study of the magnetic fluid APG-832 subjected to an alternating magnetic field has been performed. The results have permitted a determination of the specific absorption rat, expressed per the mass unit of the ferrimagnetic contained in the ferrofluid studied. In order to determine the polydispersity of magnetic grains and other parameters of the sample, it was subjected to the measurements by the vibrating sample magnetometer and observations under a transmission electron microscope.
7
The Heating Effect of the Biocompatible Ferrofluidin an Alternating Magnetic Field
Skumiel A., Łabowski M.
Molecular and Quantum Acoustics
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2006
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Vol. 27
233-238
EN
Results of the calorimetric measurements, in the range from 70 kHz up to 1.7 MHz, confirmed the suitability of the use of the ferrofluid studied in magnetic fluid hyperthermia, especially in the frequency range from 600 do 800 kHz. The H2 - law type dependence of the specific absorption rate on the square amplitude of the magnetic field testifies to the presence of superparamagnetic particles in the ferrofluid. The thickness of the surfactant layer was determined on the basis of the magnetic and calorimetric measurements.
8
Determination of Magnetic Particle Size Using Ultrasonic, Magnetic and Atomic Force Microscopy Methods
Zieliński B., Skumiel A., Józefczak A., Vandeweert E.
Molecular and Quantum Acoustics
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2005
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Vol. 26
309-316
9
Temperature Dependence of the Ultrasonic Wave Absorption Coefficient in Ferrofluid Subjected to External Magnetic Field
Józefczak A., Skumiel A., Regulska P.
Molecular and Quantum Acoustics
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2004
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Vol. 25
153-158
10
Investigations of Magnetic Properties of Apg 513a Magnetic Fluid
Hornowski T., Skumiel A., Łabowski M.
Molecular and Quantum Acoustics
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2004
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Vol. 25
115-120
EN
Static magnetic properties of magnetic fluid APG 513A have been measured. The differential magnetic susceptibility was measured as a function of an external magnetic field in the range of 1-200 kA/m, parallel to the direction of the field. The data were analysed using the Langevin equation and taking into account polydispersity of a system. A lognormal function was used as to approximate the distribution function of the size of magnetic particles. On the basis of the least-square fit of the susceptibility data to the Langevin equation the parameters of the distribution function as well as macroscopic parameters of the ferrofluid such as the initial susceptibility, saturation magnetization and particle number density were obtained. In magneto-granulometric analysis of the ferrofluid the mean magnetic diameter and standard deviation of particles were obtained. The agreement between the susceptibility data and the Langevin equation predictions is very good, which suggests the lack of interactions between particles and the absence of agglomerates in the ferrofluid studied.
11
The Frequency Dependance of Ulrtadonic Attenuation in the Water-Based Magnetic Liquid in the Absence of a Magnetic Field
Hornowski T., Łabowski M., Skumiel A.
Molecular and Quantum Acoustics
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2003
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Vol. 24
41-46
EN
The measurements of ultrasonic attenuation in a water-based magnetic fluid EMG-605 as a function of frequency are presented. Experimental results are analyzed using two-phase model of magnetic liquid. A good agreement between experimental data and the predictions of theoretical model was obtained.
12
The Effect of Duration of Magnetic Field Application and Temperature of Velocity and Absorption Coefficient of Ultrasound Wave in a Magnetic Fluid
Hornowski T., Józefczak A., Łabowski M., Skumiel A.
Molecular and Quantum Acoustics
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2003
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Vol. 24
31-40
13
Magnetic and Acoustic Properties of Water-Based Ferrofluids
Skumiel A., Soczkiewicz M.
Molecular and Quantum Acoustics
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2003
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Vol. 24
149-160
EN
The fundamental magnetic and acoustic properties of the magnetic grain on the basis of the low-frequency measurements of magnetic susceptibility os proposed and its tesults are compared with those obtained by transmission electrone microscope (TEM). The acoustic part is devoted to analysis of the anisotropy of absorption coefficient of the ultrasonic wave in ferrofluids of different concentrations of the solid phase. On the basis of the fit of the Taketomi function to the experimental data some information on the ferrofluid structure in a magnetic field have been obtained. Structural changes in the ferrofluid upon formation and decay of magnetic clusters can be traced on the basis fo results of measurements of ultrasound absorption coefficient and propagation velocity in a slowly changing magnetic field.
14
Effects of Magnetic Field Decay Time on the Hysteresis of Ultrasonic Wave Attenaution on Ferrofluid
Józefczak A., Skumiel A.
Molecular and Quantum Acoustics
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2003
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Vol. 24
89-96
EN
Acoustic properities of a ferrofluid subject to an external magnetic filed depend on the sweep rate. The magnetic filed determines the mode and degree of aggregations of the magnetic particles and their association into chain-like clusters. After the removal of the filed the ferrofluid does not return to the original state as indicated by the ultrasound wave propagation study, in particular by changes in the ultrasonic wave absorption coefficient. A hysteresis of the ultrasonic wave absorption coefficient has been observed. The hysteresis depends on the rate of the magnetic field intensity decay. The effect of the hysteresis on the acoustic properities of the ferrofluid has been studied.
15
Ultrasonic and Magnetic Study of Physiology Based Magnetic Fluid
Józefczak A., Skumiel A., Łabowski M., Timko M., Gierczyk N.
Molecular and Quantum Acoustics
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2002
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Vol. 23
193-199
16
The Effect of the Concentration of Ferroparticles in a Magnetic Fluid on its Acoustic and Magnetic Properties
Skumiel A., Józefczak A., Hornowski T., Kaczmarek M.
Molecular and Quantum Acoustics
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2002
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Vol. 23
389-396
17
Magnetic and Ulrtrasonic Studies of Gel-Like Magnetic Systems
Hornowski T., Skumiel A., Józefczak A., Kaczmarek M.
Molecular and Quantum Acoustics
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2001
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Vol. 22
107-12
EN
The paper presents results of experimental studies of magnetic susceptibility and ultrasonic properties of ferrogel in the presence of magnetic field. The results are discussed in terms of theoretical predictions, and some magnetic as well as elastic parameters of studied system are obtained.
18
Determination on the Magnetic Susceptibility Anisotropy, Propagation Velocity and Absorption Coefficient of an Ultrasonic Wave in a Magnetic Fluid
Skumiel A., Hornowski T., Józefczak A., Łabowski M.
Molecular and Quantum Acoustics
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2001
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Vol. 22
221-230
19
An Investigation of the Magnetic Properties of Ferrofluids
Skumiel A., Hornowski T., Józefczak A., Łabowski M.
Molecular and Quantum Acoustics
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2001
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Vol. 22
231-238
20
Investigation of Ferrofluids by Magnetic and Acoustic Methods
Skumiel A., Hornowski T., Łabowski M.
Molecular and Quantum Acoustics
|
2000
|
Vol. 21
251-259
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