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Tytuł:
Impact of magnetic particles concentration in ferrooil on its magnetic susceptibility coefficient χ
Autorzy:
Frycz, M.
Anioł, A.
Powiązania:
https://bibliotekanauki.pl/articles/241625.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
magnetic particles concentration
magnetic susceptibility coefficient
Opis:
The purpose of this article is to determine the effect of the concentration of magnetic particles in ferro-oil on the value of its magnetic susceptibility coefficient χ. Determination of the flow and operating parameters of slide journal bearings lubricated with ferro-oils requires, inter alia, designation the first magnetization N and the magnetic induction B vector components, dependent on the magnetic propertis of the lubricant. The fundamental problem lies in the inability to make direct accurate measurement of magnetic induction in the lubricating gap of slide bearing and its solution is to determine it on the analytical and numerical way. A key issue for the accuracy of such solutions is to obtain reasonably accurate values of magnetic susceptibility χ. This article attempts to determine these values and estimate their relationship with the concentration of magnetic particles concentration in ferro-oil being potential lubricant above-mentioned bearings. In this paper, the authors present the characteristic of experimental test benches to determine the coefficients of the magnetic susceptibility. They present method of determining this value from obtained measurement data and analyse the impact of the magnetic particles concentration in ferro-oil on its magnetic susceptibility values. Tests were performed for selected concentrations of magnetic particles in ferro-oil ranging: 2%, 4%, 6% and 8% and the tested ferro-oil was product from Unterensingen FerroTec Company (Germany) which is a mixture of colloidal mineral engine oil LongLife Gold Penzzoil class SAE 15W-40 with addition of Fe3O4 magnetic particles and a surfactant.
Źródło:
Journal of KONES; 2014, 21, 4; 111-117
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Magnetic Particles on the Nematic Droplets Formation in Liquid Crystal
Autorzy:
Majorošová, J.
Gdovinová, V.
Tomašovičová, N.
Juríková, A.
Závišová, V.
Jadzyn, J.
Kopčanský, P.
Powiązania:
https://bibliotekanauki.pl/articles/1032205.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Mm
61.30.Gd
67.30.Hm
Opis:
In this work the thermotropic nematic liquid crystal 4-trans-4'-n-hexyl-cyclohexyl-isothiocyanato-benzene (6CHBT) was dissolved in phenyl-isothiocyanate and doped with spherical magnetic particles with volume concentration ϕ₁=10¯⁴ and ϕ₂=10¯³. The influence of the volume concentration on the phase transitions from isotropic to nematic phase was studied by three experimental methods: optical microscopy, differential scanning calorimetry, and dielectric measurements. The obtained results confirmed the coexistence of isotropic and nematic phase, i.e. nematic or ferronematic droplets in isotropic phase in a wide temperature range between nematic and isotropic phase.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 955-957
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties of Magnetic Nano-Particles
Autorzy:
Lindgård, P. A.
Powiązania:
https://bibliotekanauki.pl/articles/1953165.pdf
Data publikacji:
1997-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Ds
75.40.Gb
76.20.+q
Opis:
The intrinsic thermodynamic magnetic properties of clusters are discussed using spin wave theory for a Heisenberg model, with a fixed magnitude of the spins S$\text{}_{i}$=S and site independent nearest neighbor exchange interaction. The consequences of the more realistic Hubbard model is considered in which we allow for a magnetization profile at T=0 and a structural relaxation, which in turn will give rise to a site dependent exchange interaction. It is concluded that correlation effects among the electrons play a very important role in small clusters, albeit not modifying the thermodynamic properties drastically. The finite cluster size gives foremost rise to a discrete excitation spectrum with a large energy gap to the ground state. The relaxation of the magnetization during the reversal of the external magnetic field is discussed. A first step towards a quantitative understanding of the nonequilibrium statistical mechanics in single-domain ferromagnetic particles is a systematic study of the kinetic Ising model. Results from Monte Carlo simulation and droplet theory are reviewed with particular attention to the effects of various boundary conditions, including a decrease in the number of surface bonds and an addition of surface anisotropy. A new dynamic "outside-in" flip mode is proposed.
Źródło:
Acta Physica Polonica A; 1997, 91, 1; 121-133
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Composites Consisting of High-T$\text{}_{c}$ Superconductor and Fine Magnetic Particles
Autorzy:
Timko, M.
Kopčanský, P.
Kováč, J.
Koneracká, M.
Plecháček, V.
Powiązania:
https://bibliotekanauki.pl/articles/2013009.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.72.Hs
75.50.Tt
Opis:
The composite systems as a mixture of fine magnetic particles of Fe$\text{}_{3}$O$\text{}_{4}$ and superconducting powder such as Bi$\text{}_{1.8}$Pb$\text{}_{0.2}$Sr$\text{}_{2}$Ca$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{10+x}$ were prepared. The influence of internal magnetic field (generated by magnetic particles) on the superconducting properties of prepared composites were studied as a function of concentration of magnetic particles and their magnetic state. The observed data both of the shielding and the Meissner effect were compared with corresponding linear combination of pure signals of magnetite and superconductor, respectively. The large differences were observed for demagnetized samples. It means that result must be discussed in the frame of the distribution of internal magnetic field created by the magnetic particles.
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 389-392
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Anchoring Energy of Liquid Crystal Molecules to Magnetic Particles in HAB-Based Ferronematics
Autorzy:
Tomašovičová, N.
Koneracká, M.
Kopčanský, P.
Timko, M.
Závišová, V.
Vajda, A.
Fodor-Csorba, K.
Éber, N.
Tóth-Katona, T.
Jadzyn, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813941.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Mm
61.30.Gd
61.30.Hn
Opis:
In this work we describe the magnetic Freedericksz transition in HAB-based (4, 4'-di-n-heptylazoxybenzene) ferronematics. The ferronematic samples were prepared with two different volume concentrations of magnetic particles $φ_1 = 2×10^{-5}$ and $φ_2 = 2×10^{-4}$. The liquid crystal HAB is nematic at the temperatures from ≈53°C to 70°C and smectic A at the temperatures under 53°C. The anisotropy of dielectric permitivity of HAB liquid crystal is positive in nematic phase and negative in smectic A phase. The magnetic Fredericksz transition was studied in nematic phase at temperature 60°C.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 591-594
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Changes in Liquid Crystals Doped with Rod-Like Magnetic Particles Studied by Surface Acoustic Waves
Autorzy:
Bury, P.
Veveričík, M.
Kúdelčík, J.
Kopčanský, P.
Timko, M.
Závišová, V.
Powiązania:
https://bibliotekanauki.pl/articles/1032787.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.30.Gd
75.50.Mm
43.35.Bf
Opis:
The effect of rod-like magnetic particles on liquid crystal (6CHBT) structural changes in electric and weak magnetic fields were studied by means of the attenuation of surface acoustic wave of frequency 30 MHz propagating along ferronematic liquid crystals. Three low volume concentrations (Φ=1×10¯⁵, 1×10¯⁴ and 1×10¯³) of rod-like magnetic particles were added to liquid crystal during its isotropic phase. Several measurements including the investigation of the effects of electrical and magnetic fields applied both separately and in conjunction as well as the influence of temperature on the surface acoustic wave attenuation were performed. The distinctive surface acoustic wave attenuation responses induced by both electric and magnetic fields in studied ferronematic liquid crystals have been observed suggesting both structural changes and the orientational coupling between magnetic moments of magnetic particles and the director of the liquid crystal. Obtained results confirmed the significant influence of the presence of magnetic particles on the structural properties and resulting behavior of 6CHBT liquid crystal.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 913-915
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implantation of superabsorbent polymer by magnetic iron oxide particles
Autorzy:
Grzesiak, Maciej
Szajnecki, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/2079886.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
superabsorbents
hydrogels
magnetic particles
swelling properties
Opis:
The aim of this research was to optimise methods of magnetic particles of iron oxides implantation into superabsorbent polymer based on partially neutralized acrylic acid (SAc/AAc) crosslinked with ethylene glycol dimethacrylate (EGDMA). The structure of the obtained materials was confirmed by infrared spectroscopic analysis (FT-IR/ATR). The quality of implantation process was evaluated on the basis of microscopy images. Swelling properties of the obtained implanted materials were also determined.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2019, 74, 2; 101-113
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of a mixing process induced by a rotating magnetic field with the application of magnetic particles
Autorzy:
Rakoczy, Rafał
Kordas, Marian
Markowska-Szczupak, Agata
Konopacki, Maciej
Augustyniak, Adrian
Jabłońska, Joanna
Paszkiewicz, Oliwia
Dubrowska, Kamila
Story, Grzegorz
Story, Anna
Ziętarska, Katarzyna
Sołoducha, Dawid
Borowski, Tomasz
Roszak, Marta
Grygorcewicz, Bartłomiej
Dołęgowska, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/2086782.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mixing process
alternating magnetic field
magnetic particles
mixing time
Navier–Stokes equation
proces mieszania
zmienne pole magnetyczne
cząstki magnetyczne
czas mieszania
równanie Naviera-Stokesa
Opis:
We demonstrate in this study that a rotating magnetic field (RMF) and spinning magnetic particles using this kind of magnetic field give rise to a motion mechanism capable of triggering mixing effect in liquids. In this experimental work two mixing mechanisms were used, magnetohydrodynamics due to the Lorentz force and mixing due to magnetic particles under the action of RMF, acted upon by the Kelvin force. To evidence these mechanisms, we report mixing time measured during the neutralization process (weak acid-strong base) under the action of RMF with and without magnetic particles. The efficiency of the mixing process was enhanced by a maximum of 6.5% and 12.8% owing to the application of RMF and the synergistic effect of magnetic field and magnetic particles, respectively
Źródło:
Chemical and Process Engineering; 2021, 42, 2; 157--172
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of 6CHBT Liquid Crystal Doped with Ferroelectric or Magnetic Particles to Electric and Magnetic Fields
Autorzy:
Majorošová, J.
Tomašovičová, N.
Timko, M.
Koneracká, M.
Studenyak, I.
Kovalchuk, O.
Kovalchuk, S.
Jadżyn, J.
Kopčanský, P.
Powiązania:
https://bibliotekanauki.pl/articles/1368661.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Mm
61.30.Gd
64.70.Md
Opis:
Introduction of ferroelectric or magnetic nanoparticles into nematic liquid crystal is a promising method for the improvement of the electro-optic or magneto-optic properties of different nematic liquid crystals by non-chemical way. This work is devoted to the study of composite systems of liquid crystal with spherical ferroelectric or magnetic particles with the aim to study their sensitivity to electric and magnetic fields. The nematic 4-(trans-4'-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT) liquid crystal was doped with SbSI ferroelectric particles or with $Fe_{3}O_{4}$ magnetic particles. The structural transitions in ferronematic samples were indicated by capacitance measurements in a capacitor made of ITO-coated glass electrodes in combined electric and magnetic fields. The obtained results showed the increase of the shift in critical voltage with increasing magnetic field in both kinds of samples.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 260-261
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fully coupled multi-physics modeling of the multi-type magnetic particles dynamic behavior in low intensity magnetic separator
Autorzy:
Wang, Feiwang
Zhao, Hongming
Dai, Huixin
Du, Wuxing
Powiązania:
https://bibliotekanauki.pl/articles/109730.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
multi-physics model
low-intensity magnetic separator
magnetic particles
dynamic behaviour
Opis:
Studying the dynamic behavior of magnetic particle suspensions in the low intensity magnetic separator has important implications for various mineral beneficiation processes. A new approach for fully coupled multi-physics modeling of the dynamic behavior of multi-type magnetic particles (MTMPs) is developed in the study. In this model, the particle tracing module is employed to identify and determine individual particle trajectories in the fluid and magnetic field, which are modelled through the COMSOL Multiphysics. The results show that the different arrangements of the permanent magnet assembly and the volume percentage of interlocked particles affect the dynamic behavior of MTMPs and the efficiency of the separation. The model is compared with experiments and the particle capture theory and the correctness of the solution obtained from COMSOL is demonstrated. The model gives new possibilities to control, optimise, and develop the process of LIMS.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 163-172
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The ferro-oils viscosity depended simultaneously on the temperature and magnetic oil particles concentration η = η(t,ϕ). Part 2
Autorzy:
Frycz, M.
Powiązania:
https://bibliotekanauki.pl/articles/243733.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
Opis:
The purpose of this article is to determine and describe the viscosity characteristics of the ferro-oils at context of temperature changes depend on different concentrations of magnetic particles. These characteristics were determined for the following test conditions: atmospheric pressure, constant shear rate and absent of an external magnetic field. In Part I of the paper there was determined and described four mathematical-physical models of fittings of the viscosity characteristics: exponential, fourth-degree polynomial and two homographic models – second- and third-degree. In present Part II of the paper above mentioned models have been developed. That has been done their depending on parameter of concentrations of magnetic particles ϕ in ferro-oil. There have been also undertaken comparison of the accuracy of estimation of reached results by selected mathematical models as well as these results have been rated according to their compliance with theoretical assumptions. Tests were performed for selected concentrations of magnetic particles in ferro-oil ranging: 1%, 2%, 4%, 6% and 8%. Tested ferro-oil was product from Unterensingen FerroTec Company (Germany) which is a mixture of colloidal mineral engine oil LongLife Gold Pennzoil class SAE 15W-40 with addition of Fe3O4 magnetic particles and a surfactant. Analysis of the results, identifying and fitting of characteristics has been made by means of software StatSoft STATISTICA ver. 9.1. The obtained characteristics going to be used by author in his future work to build mathematical models of viscosity changes of ferro-oils in the aspect of changes of parameters such as temperature, pressure, shear rate and the value of the external magnetic field. The determined parameters of physical properties will be used in analytical and numerical studies of flow and operating parameters of slide journal bearings lubricated with ferro-oils.
Źródło:
Journal of KONES; 2016, 23, 3; 127-134
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The ferro-oils viscosity depended simultaneously on the temperature and magnetic oil particles concentration η = η(t,ϕ). Part 1
Autorzy:
Frycz, M.
Powiązania:
https://bibliotekanauki.pl/articles/243457.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
Opis:
The purpose of this article is to determine, identify and describe the viscosity characteristics of the ferro-oil with different concentrations of magnetic particles at context of temperature changes. These characteristics were determined for the following test conditions: atmospheric pressure, constant shear rate and absent of an external magnetic field. Tests were performed for selected concentrations of magnetic particles in ferro-oil ranging: 1%, 2%, 4%, 6% and 8%. Tested ferro-oil was product from Unterensingen FerroTec Company (Germany) which is a mixture of colloidal mineral engine oil LongLife Gold Penzzoil class SAE 15W-40 with addition of Fe3O4 magnetic particles and a surfactant. Analysis of the results, identifying and fitting of characteristics has been made by means of software StatSoft STATISTICA ver.9.1. There has been also undertaken comparison of the accuracy of estimation of reached results by selected mathematical models as well as these results have been rated according to their compliance with theoretical assumptions. Moreover, the waveform parameters of functions have been determined and their assessed quality has been done also. The obtained characteristics going to be used by author in his future work to build mathematical models of viscosity changes of ferro-oils in the aspect of changes of parameters like temperature, pressure, shear rate and the value of the external magnetic field. The determined parameters of physical properties will be used in analytical and numerical studies of flow and operating parameters of slide journal bearings lubricated with ferro-oils.
Źródło:
Journal of KONES; 2016, 23, 2; 113-120
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sources of Magnetic Particles from Air Pollution in Mountainous Area
Źródła cząstek magnetycznych z zanieczyszczeń powietrza w obszarach górskich
Autorzy:
Kantor, Pavel
Raclavska, Helena
Matysek, Dalibor
Raclavsky, Konstantin
Svedova, Barbora
Kucbel, Marek
Powiązania:
https://bibliotekanauki.pl/articles/318939.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
podatność magnetyczna
mikroanaliza
zanieczyszczenie gleby
osadzanie atmosferyczne
emisje z hutnictwa
magnetic susceptibility
microanalysis
soil pollution
atmospheric deposition
emissions from metallurgy
Opis:
Measurement of magnetic susceptibility of topsoil represents a very useful tool for the detection of atmospherically deposited magnetic particles. The samples of forest soils from the Moravian-Silesian Beskydy Mountains (the Czech Republic) were used for identification of emissions sources of particles with magnetic ordering. Magnetic susceptibility was measured at bulk samples of grain size class under 2 mm. Microanalysis using electron microscope with an energy dispersive X-ray spectrometer was used for the determination of particles in the magnetic fraction. The samples of dust from the sintering plant of the Iron Works in the town of Třinec were analysed. The values of magnetic susceptibility of forest soils in the Třinec region are increased. In the relatively near vicinity of the industrial area, the average value for Javorový Mount was 7.90×10-6 m3/kg, for Ostrý Mount it was 6.69×10-6 m3/ kg. It was proved that they were higher than the average values from the Beskydy Mountains (4.64×10-6 m3/kg). The concentrations of lead and magnetic susceptibility in soils showed significant correlation dependence (rs = 0.85). The iron and steel industry represent the primary source of the pollution load in forest soils of the studied area. Statistically, significant dependences between the organic matter content and the lead and zinc concentrations as well as between the magnetic susceptibility values and the iron concentrations in forest soils were found. It was confirmed that the airborne particles are deposited on vegetation and accumulated in the organic horizon of forest soils.
Pomiar podatności magnetycznej wierzchniej warstwy gleby stanowi bardzo przydatne narzędzie do wykrywania osadzonych z atmosfery cząstek magnetycznych. Próbki gleb leśnych z Beskidu Morawsko-Śląskiego (Czechy) wykorzystano do identyfikacji źródeł emisji cząstek o właściwościach magnetycznych. Podatność magnetyczną mierzono w próbkach zbiorczych w klasie ziarnowej poniżej 2 mm. Mikroanaliza z użyciem mikroskopu elektronowego ze spektrometrem dyspersyjnym energii rentgenowskiej została użyta do oznaczenia frakcji magnetycznej cząstek. Przeanalizowano próbki pyłu ze spiekalni Huty Żelaza w Trzyńcu. Stwierdzono wzrost wartość podatności magnetycznej gleb leśnych w regionie Trzyńca. W stosunkowo bliskim sąsiedztwie obszaru przemysłowego Javorový Mount średnia wartość wynosiła 7,90 × 10-6 m3/kg, w przypadku Ostrý Mount 6,69 × 10-6 m3/kg. Wykazano, że były one wyższe niż średnie wartości dla Beskidów (4,64 × 10-6 m3/kg). Zawartość ołowiu i podatność magnetyczna w glebach wykazały istotną korelację (rs = 0,85). Hutnictwo żelaza i stali stanowi główne źródło ładunku zanieczyszczeń w glebach leśnych badanego obszaru. Stwierdzono statystycznie istotne zależności między zawartością materii organicznej a stężeniem ołowiu i cynku, a także między wartościami podatności magnetycznej a stężeniami żelaza w glebach leśnych. Potwierdzono, że zawieszone w powietrzu cząstki osadzają się na roślinności i gromadzą się w organicznym horyzoncie gleb leśnych.
Źródło:
Inżynieria Mineralna; 2019, 21, 1; 47-52
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The friction force and friction coefficient in the journal sliding bearing ferrofluid lubricated with different concentrations of magnetic particles
Autorzy:
Frycz, M.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/247265.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic pressure
capacity
friction force
friction coefficient
ferrofluid
numeric calculation
Opis:
There is an important operational parameter in the case of sliding bearings are friction forces and coefficient of friction. It depends on how much proportions of heat in the gap of the oil film from the value of the friction force. Ferrofluid lubricated sliding bearings have specific structure and are suitable only for use in specific cases. We may use them in the absence of gravity, vacuum, or in case of strong magnetic fields or radioactive. Maintenance of lubricant in the oil-gap as well as the viscosity change occurs through controlling of the external magnetic field. Change of the value of viscosity and mass forces (magnetic forces) in the equation of momentum depends on the concentration of magnetic particles and the intensity of external magnetic field. The aim of this paper is to present the influence of concentration of magnetic particles on the friction force value and coefficient of friction. The numerical calculations of friction forces and friction coefficient have been performed before setting the hydrodynamic pressure and a lift force from the Reynolds-type equation. Reynolds-type equation has been derived from basic equations, ie equations of momentum and equations of stream's continuity. There have been also used Maxwell's equations for the ferrofluid in the case of stationary magnetic field's existence. It has been assumed stationary and laminar flow of lubricant liquid and the isothermal model for lubrication of slide bearings. As the constitutive equation has been used Rivlin-Ericksen one. The cylindrical journal bearing of finite length with the smooth sleeve of whole angle of a belt has been taken into consideration. In a thin layer of oil film has been assumed constancy of the oil density with temperature changes and the independence of the oil's thermal conductivity coefficient from thermal changes. The viscosity of the oil depends mainly on the magnetic field.
Źródło:
Journal of KONES; 2011, 18, 4; 113-120
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vorticity transport analysis in magnetic viscoelastic fluid
Autorzy:
Kumar, P.
Mohan, H.
Hoshoudy, G.
Powiązania:
https://bibliotekanauki.pl/articles/281534.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Rivlin-Ericksen viscoelastic fluid
suspended magnetic particles
vorticity
Opis:
Results of investigation on the transport of vorticity in Rivlin-Ericksen viscoelastic fluid in the presence of suspended magnetic particles is presented here. Equations governing the transport of vorticity in Rivlin-Ericksen viscoelastic fluid in the presence of suspended magnetic particles are obtained from the equations of magnetic fluid flow. From these equations it follows that the transport of solid vorticity is coupled with the transport of fluid vorticity. Further, we find that because of thermokinetic process, fluid vorticity may exist in the absence of solid vorticity, but when fluid vorticity is zero, then solid vorticity is necessarily zero. A two-dimensional case is also studied and found that the fluid vorticity is indirectly influenced by the temperature and the magnetic field gradient.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 1; 127-133
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution of hydrodynamic pressure in the interspace of lateral sliding bearings lubricated by ferrofluid with different concentrations of magnetic particles
Autorzy:
Frycz, M.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/245424.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic pressure distributions
capacity
ferrofluid
magnetic field
numeric calculation
Opis:
This paper presents the numerical results of hydrodynamic pressure distributions and capacity in the gap of ferrofluid-lubricated slide bearing with different concentrations of magnetic particles. Ferrofluid is a colloidal mixture of dispersing agent (base) and diffused (magnetic particles). The most common distracted factors are Fe3O4, Ge2O2 or NiO. Scattering factor is mostly water, mineral oil, synthetic oil. In addition, the magnetic particles are coated with a surfactant in the form of long chains of molecules or electrostatic coating. Reynolds-type equation has been derived from the equations of momentum and continuity equation for laminar, steady and isothermal flow. Viscoelastic model Rivlin-Ericksen type of lubricant has been adopted. It has been adopted also that the dynamic viscosity depends generally on the magnetic field. The equations of momentum, continuity and Maxwell's equation with a constitutive equation were made dimensionless, and then them small units of higher order have been omitted (units of the order of the relative radial clearance: i//=0.001). Such estimated system of equations of motion was divided into two subsystems by the small parameter method. The basic system of differential equations which consider the effect of the magnetic field has been received and the additional system which takes into account influences of non-Newtonian properties as well. Integrating the appropriate momentum equations and imposing boundary conditions the velocity vector components and the Reynolds-type equation have been obtained. While computer simulations of the magnetic field were assumed that the longitudinal component of magnetic induction vector does not change with the length of the bearing. Reynolds-type equation by which the hydrodynamic pressure distributions can be determined has been solved numerically using Mathcad and ourselves calculation procedures. The paper presents results of numerical calculations of hydrodynamic pressure distribution and lift force for the simulated values of the magnetic field and ferrofluid's dynamic viscosity and for different relative eccentricities and dimensionless length of the bearing. The results presented in the paper are the solutions of a basic system.
Źródło:
Journal of KONES; 2011, 18, 3; 83-89
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Immobilizacja naringinazy z Penicillium decumbens na magnetycznych nośnikach polisacharydowych
Immobilization of naringinase from Penicillium decumbens on polysaccharide-coated magnetic particles
Autorzy:
Bodakowska-Boczniewicz, Joanna
Garncarek, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/582579.pdf
Data publikacji:
2018
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
naringinaza
immobilizacja enzymów
polisacharydy
naringinase
enzyme innobilization
polysaccharides
Opis:
Naringinaza z Penicillium decumbens została unieruchomiona na aktywowanych nośnikach polisacharydowych o właściwościach magnetycznych. W badaniach wykorzystano gumę guar, karobową, tragakantową, ksantanową oraz karagenianin. Nośniki otrzymano poprzez pokrycie mikrocząsteczek magnetytu (Fe3O4) polisacharydem, a następnie aktywując je aldehydem glutarowym lub polietylenoiminą. Celem niniejszej pracy była immobilizacja naringinazy z P. decumbens na magnetycznych nośnikach polisacharydowych oraz charakterystyka otrzymanego biokatalizatora. Najwyższą aktywność enzymu uzyskano poprzez immobilizację naringinazy na nośniku otrzymanym na bazie gumy karobowej aktywowanej polietylenoiminą. Immobilizacja naringinazy na tak otrzymanym nośniku wpływała na zmniejszenie optymalnej wartości pH oraz optymalnej temperatury aktywności badanego enzymu. Immobilizacja powodowała zwiększenie wartości stałej Michaelisa oraz zmniejszenie maksymalnej szybkości reakcji w porównaniu z enzymem wolnym.
Naringinase from Penicillium decumbens was immobilized on activated polysaccharide supported with magnetic properties. Magnetic microparticles were prepared by coating a magnetite (Fe3O4) with a polysaccharide followed by activating with glutaraldehyde or polyethyleneimine. Guar gums, locust bean, tragacanth, xanthan and carrageenan were used in the research. The main goals of this work were the immobilization of naringinase on magnetic polysaccharide carriers and the characterization of such immobilized enzyme. The naringinase immobilized on a carrier obtained on the basis of carob gum activated with polyethyleneimine had the highest activity. The immobilization of the naringinase on the carrier thus obtained influenced the reduction of the optimal pH value and the optimal temperature. Immobilization increased the Michaelis constant value and decreased the maximum reaction rate, as compared to the free enzyme.
Źródło:
Prace Naukowe Uniwersytetu Ekonomicznego we Wrocławiu; 2018, 542; 9-24
1899-3192
Pojawia się w:
Prace Naukowe Uniwersytetu Ekonomicznego we Wrocławiu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of magnetic particles concentration in ferro-oil on values of friction force and coefficient of friction of slide journal bearing
Autorzy:
Frycz, M.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/243124.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
friction force
friction coefficient
lepkość dynamiczna
stężenie cząstek magnetycznych
siła tarcia
współczynnik tarcia
Opis:
This article has been focused on the analysis of changes in friction force as well as coefficient of friction of slide journal bearing in terms of the concentration of magnetic particles in the lubricating ferro-oil. There has been present an analytical and numerical calculation model based on experimentally determined physical quantities describing the dependence of ferro-oil’s viscosity on fundamental parameters such as temperature, pressure or external magnetic field in the paper. Numerical calculations of the dimensionless friction force as well as the dimensionless friction coefficient were performed by solving the Reynold’s type equation using the finite difference method using Mathcad 15 and own calculation procedures. The obtained results has been presented in the form of a series of graphs that take into account: the influence of external magnetic field, corrections related to the influence of pressure changes, corrections related to the influence of temperature changes and finally corrections related to non-Newtonian ferro-oil properties. An analysis of the obtained characteristics has been made so the observations and conclusions were drawn regarding optimum magnetic particle content in the ferro-oil lubricating the sliding journal bearing.
Źródło:
Journal of KONES; 2017, 24, 1; 143-150
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The program of experimental research regarding concentration of magnetic particles Fe3 O4 in ferrofluid for slide journal bearing lubrication
Autorzy:
Miszczak, A.
Frycz, M.
Powiązania:
https://bibliotekanauki.pl/articles/246352.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrostatic bearings
ferrofluid
position of test bearings
measuring the force of friction
magnetic field
hydrodynamic bearings
temperature distribution
Opis:
This paper presents the project of the test stand to determine the friction force, the relative eccentricity and temperature distribution m the slide journal bearing during the lubrication with ferrofluid or classic oil. The test stand is built on the basis of TUM 25 lathe's corps. There is the shaft with a diameter of journal d = 100 mm supported on two supports attached to the lathe's body. There is a sleeve in the housing with the electromagnets installed in the centre of this shaft. The housing of sleeve is loaded bv a transverse force with hydrostatic supports (cylindrical and flat one). Measurement of friction force is made by strain gauge force sensor Friction force is measured on the body shells. At the same time is performed measurement of both sleeve and journal displacements by four inductive displacement's sensor s and four whirl-stream ones to determine the relative eccentricity and displacement of sleeve axis towards oj the shaft axis. The slide bearing is supplied bv the ferrofluid which is thermatly stabilized in ultrathermostat. In the paper is shown particular plan for experimental research. These studies are intended to demonstrate the changes of relative eccentricity and temperature distribution in the bearing. Additionally are presented the changes of friction forces caused by the bearing surfaces shape and ferrolubricant with different concentrations of magnetic particles Fe3O4. The gap of slide bearing can be affected by the external longitudinal magnetic field with different ralues of magnetic field strength. The bearing may by loaded a transverse force varying stepwise, or continuously with values from a few to several thousand Newton. A/so, the rotational velocitv of Journal can be changed stepwise, or continuously from 0 to 6000 rpm using a programmable inverter.
Źródło:
Journal of KONES; 2010, 17, 2; 321-325
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Models of viscosity characteristics η=η(b) of ferro-oil with different concentration of magnetic particles in the presence of external magnetic field
Autorzy:
Frycz, M.
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/244776.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
external magnetic field
Opis:
The purpose of this article is to determine, identify and describe the viscosity characteristics of the ferro-oil with different concentrations of magnetic particles in the presence of an external magnetic field interaction. These characteristics are defined in the context of magnetic induction changes. These rheological tests were performed on a Physica MCR 301 rheometer. It was used a measuring system ‘plate to plate’ type which was armed with magneto-rheological research system MRD 180/1T. The tests were performed for the selected temperature of the medium i.e. 90°C, the shear rate θ changes were carried from 0 to 1000 1/s. Changes of the magnetic field intensity value were ranged from 0 to 500 mT. The selected concentrations of magnetic particles in a ferro-oil were 1%, 2%, 4%, 6% and 8% and the tested ferro-oil was product of FerroTec of Unterensingen (Germany), which is a mixture of colloidal mineral motor oil Penzzoil’s LongLife Gold's SAE 15W-40 with Fe3O4 magnetic particles and the surfactant. Analyses of the results, identify and matching characteristic were calculated using STATISTICA software. It has been proposed three categories of functions mapping the waveforms of the results obtained experimentally: the exponential function, logarithmic with basis of the normal and the polynomial function.
Źródło:
Journal of KONES; 2014, 21, 4; 119-126
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the magnetic particles concentration on the ferro-oil’s dynamic viscosity in presence of an external magnetic field in the aspect of shear rate’s variations
Autorzy:
Frycz, M.
Horak, W.
Powiązania:
https://bibliotekanauki.pl/articles/246160.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
rheometer
slide journal bearings
Opis:
The purpose of this study is to determine the effect of changes in the concentration of magnetic particles in ferrooil to change its physical properties, in particular the dynamic viscosity in a constant external magnetic field in terms of changes in shear rate and changes in the intensity of that field. Rheological studies were carried out on Physica MCR 301 rheometer in the “plate -plate” measurement system with an adapter to magneto-rheological studies MRD 180/1T. The applied adapter enable to obtain almost homogeneous distribution of magnetic field strength. Thermal stabilization was carried out by a water jacket in a closed chamber and controlling the nature of the magnetic field was conducted by current’s changes. Tests were performed for shear rate’s changes from 0 to 1000 1/s as regards changes an external magnetic field intensity 0–700 mT. The selected concentrations of magnetic particles in a ferro-oil were 1, 2, 4, 6 and 8% and the tested ferrofluid was product of FerroTec of Unterensingen (Germany), which is a mixture of colloidal mineral motor oil Penzzoil’s LongLife Gold's SAE 15W-40 with Fe3O4 magnetic particles and the surfactant. The paper presents, in the form of graphs, the changes of ferro-oil’s dynamic viscosity as a function of shear rate and concentration of magnetic particles in the aspect of external magnetic field’s intensity changes. The results of research were also subjected to analysis. The obtained characteristics of ferro-oil’s viscosity show clear evidence of non-Newtonian properties of the liquids. There is observed progression of these properties with increasing of magnetic particles concentration. This fact indicates the essential effect of the addition mentioned particles to the change of the ferro-oil’s viscosity characteristics.
Źródło:
Journal of KONES; 2013, 20, 3; 139-144
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the magnetic particles concentration on the ferro-oil’s dynamic viscosity in presence of an external magnetic field in the aspect of temperature changes
Autorzy:
Czaban, A.
Frycz, M.
Horak, W.
Powiązania:
https://bibliotekanauki.pl/articles/247080.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
temperature changes
external magnetic field
Opis:
There is presented an effect of the changes of the concentration of magnetic particles included in the ferro-oil on its dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. The authors assume that the concentration of magnetic particles in ferro-oil can significantly affects its basic physical properties as dynamic viscosity, as well as the operational properties of journal sliding bearings ferro-oil’s lubricated. The equally significant as the above mentioned properties may affect the external environmental conditions of operation, especially temperature changes. In this context, an important technique’s issue appears to determine the principles of selection of optimal concentration of above mentioned particles according to the existing environmental conditions of its operation, or the expectations laid against the operation of the devices. Rheological studies were carried out on Physica MCR 301 rheometer in the “plate-to-plate” measurement system with an adapter to magneto-rheological studies MRD 180/1T. Thermal stabilization was carried out by a water jacket in a closed chamber and controlling the nature of the magnetic field was conducted by current’s changes. Tests were performed for four selected temperature range of 60º, 70º, 80º and 90ºC as regards changes an external magnetic field intensity 0-700 mT. The selected concentrations of magnetic particles in a ferro-oil were 1, 2, 4, 6 and 8%.
Źródło:
Journal of KONES; 2013, 20, 2; 55-60
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanokompozyt poly(ε-kaprolakton)/tlenki żelaza dla zastosowań medycznych
Poly(ε-caprolactone)/iron oxides nanocomposite for medical applications
Autorzy:
Świętek, M.
Gwizdała, J.
Tokarz, W.
Menaszek, E.
Błażewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/285834.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
magnetyczne nanokompozyty
polimery
magnetyt
cząstki magnetyczne
magnetic nanocomposites
polymer
magnetite
magnetic particles
Opis:
Nanokompozyty polimerowe stanowią szeroką grupę materiałów znajdujących zastosowanie zarówno w wielu gałęziach przemysłu, jak i w medycynie. Fenomen nanokompozytów związany jest z łatwością modyfikacji ich cech materiałowych będących pochodną właściwości zarówno samego polimeru, jak i zastosowanego nanododatku. Pozwala to na projektowanie oraz wytwarzanie materiałów o określonej charakterystyce, adresowanych do konkretnych potrzeb. Celem niniejszej pracy było otrzymanie oraz charakterystyka polimerowych nanokompozytów o właściwościach magnetycznych. Jako osnowę polimerową wykorzystano biozgodny i bioresorbowalny poli(ε-kaprolakton), do którego wprowadzono cząstki magnetytu znajdujące się w dyspersji nanometrycznej. Do przygotowania materiałów zastosowano prostą metodę odlewania filmu/odparowania rozpuszczalnika. W celu zbadania wpływu zawartości nanododatku na właściwości nanokompozytu przygotowano serię materiałów różniących się od siebie ilością wprowadzonych do matrycy polimerowej cząstek magnetycznych (0; 0,5; 1 oraz 2%). Charakterystyka nanokompozytów obejmowała badania własności magnetycznych i powierzchniowych materiałów oraz ocenę ich degradacji oraz biozgodności. Pętle histerezy wprowadzonego do matrycy polimerowej nanododatku oraz otrzymanych nanokompozytów wykazywały przebieg typowy dla multidomenowych materiałów ferrimagnetycznych. Zaobserwowano, że istnieje korelacja pomiędzy wartością namagnesowania nasycenia oraz remanencją, a zawartością cząstek magnetycznych w nanokompozycie. Na podstawie obserwacji mikroskopowych stwierdzono, że część wprowadzonych cząstek magnetycznych ulega aglomeracji, reszta zaś pozostaje w dyspersji nanometrycznej. Wytworzone materiały nie wykazały toksycznego wpływu na komórki (Normal Human Osteoblast), co pozwala sądzić, że otrzymane nanokompozyty mogłyby zostać wykorzystane w medycynie.
Polymer nanocomposites are a wide group of materials which have applications in many branches of industry as well as in medicine. The phenomenon of nanocomposites is associated with simplicity of modification of their features, which are derived from properties of both the polymer matrix and the nanoadditive. This property enables to design and fabricate materials with strictly defined characteristics, addressed to specific needs. The aim of the presented studies was fabrication and characterization of polymer nanocomposites with magnetic properties. As a polymer matrix, a biocompatible and bioresorbable poly(ε-caprolactone) was used. Magnetite powder with nanometer-sized grain fraction was introduced into the polymer matrix as a magnetic nanoadditive. As a fabrication method casting film/solvent evaporation was applied. In order to examine how amount of magnetic nanoadditive influences the properties of nanocomposites, the series of materials with various concentrations of magnetic particles was prepared (0, 0.5, 1 and 2%). Characterization of materials included magnetic and surface properties investigations as well as evaluation of degradability, and biocompatibility of the fabricated materials. Magnetic hysteresis loops of both the nanoadditive itself and the nanocomposite demonstrate curves typical for multi-domain ferromagnetic materials. Existence of the correlation between the values of magnetic saturation and remanence, and the content of magnetic particles has been observed. Microscopic evaluations have shown that small part of magnetic particles has tendency to agglomerate but the rest remains in nanometric dispersion. For the fabricated materials no cytotoxic influence on the cells was observed (Normal Human Osteoblast). This suggests that obtained nanocomposites could find application in medicine.
Źródło:
Engineering of Biomaterials; 2014, 17, 127; 22-32
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Eksperymentalna metoda wyznaczenia współczynników podatności magnetycznej χ ferroolejów o różnym stężeniu cząstek magnetycznych
Experimental method of determining the magnetic susceptibility coefficient χ for ferro-oils with different concentrations of magnetic particles
Autorzy:
Frycz, M.
Anioł, P.
Powiązania:
https://bibliotekanauki.pl/articles/187774.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ferroolej
współczynnik podatności magnetycznej
stężenie cząstek magnetycznych
ferro-oil
magnetic susceptibility coefficient
magnetic particles concentration
Opis:
W niniejszym artykule została zaprezentowana budowa stanowiska badawczego do eksperymentalnego wyznaczenia współczynników podatności magnetycznej χ ferroolejów o różnym stężeniu cząstek magnetycznych oraz została przedstawiona analiza wyników pozyskanych tą metodą. Zewnętrzne, jednorodne, stałe pole magnetyczne uzyskano za pomocą dwóch płytek stałych magnesów umieszczonych równolegle, a zmiany wartości pola zadawano poprzez możliwość kontrolowanego przemieszczania tych magnesów względem siebie. Pomiędzy magnesami umieszczona została próbka badanego oleju, a wartości natężenia pola magnetycznego pomierzono z użyciem miernika indukcji pola magnetycznego Smart Magnetic Sensor SMS 102. Badaniom poddano ferrooleje o wybranych stężeniach cząstek magnetycznych, tj.: 8%, 6%, 4% oraz 2% objętościowo.
This paper presents the construction of an experimental test bench to determine the magnetic susceptibility coefficients χ of ferro oils with different concentrations of magnetic particles, and also the analysis of the results that were obtained by this method. The outer, homogeneous, constant magnetic field was obtained by means of the two plates of permanent magnets arranged in parallel, and changes the field value were carried out by the possibility of controlled movement of the magnets relative to each other. Samples of lubricants were placed between the magnets, and the magnetic field strength was measured by using the magnetic induction SMS Smart Magnetic Sensor 102. Ferro oils with selected concentrations of magnetic particles of 8%, 6%, 4%, and 2% were studied.
Źródło:
Tribologia; 2014, 3; 29-38
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Haemocompatibility and cytotoxic studies of non-metallic composite materials modified with magnetic nano and microparticles
Autorzy:
Szymonowicz, M.
Rybak, Z.
Fraczek-Szczypta, A.
Paluch, D.
Rusak, A.
Nowicka, K.
Blazewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/306490.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
nanokompozyty
cząstki magnetyczne
hemoliza
żywotność komórkowa
koagulacja
nanocomposite
magnetic particles
polysulfone
haemolysis
cell viability
coagulation systems
Opis:
Purpose: Preventing the formation of blood clots on the surface of biomaterials and investigation of the reasons of their formation are the leading topics of the research and development of biomaterials for implants placed into the bloodstream. Biocompatibility and stability of a material in body fluids and direct effect on blood cell counts components are related both to the structure and physico-chemical state of an implant surface. The aim of this study was to determine haemocompatibility and cytotoxicity of polysulfone-based samples containing nano and micro particles of magnetite (Fe3O4). Methods: The polysulfone-based samples modified with nanometric and micrometric magnetite particles were examined. Physicochemical properties of the composites were determined by testing their wettability and surface roughness. The action of haemolytic, activation of coagulation system and cytotoxicity of composites was evaluated. Results: Wettability and roughness of materials were correlated with nanoparticles and microparticles content. In the tests of plasma coagulation system shortening of activated partial thromboplastin time for polysulfone with nano magnetite and with micro magnetite particles was observed in comparison with pure polysulfone. Prothrombine time and thrombine time values as well as fibrinogen concentration were unchanged. Haemolysis values were normal. Morphology and viability of cells were normal. Conclusions: Composites made from polysulfone modified with nanoparticles and microparticles of magnetite cause neither haemolytic nor cytotoxic reaction. These composites evoke plasma endogenous system activation.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 3; 49-58
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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