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Wyszukujesz frazę "magnetic" wg kryterium: Temat


Tytuł:
Distribution system for generating slowly varying magnetic fields
Autorzy:
Zaguła, G.
Puchalski, C.
Czernicka, M.
Bajcar, M.
Saletnik, B.
Powiązania:
https://bibliotekanauki.pl/articles/411311.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
magnetic fields
magnetic stimulation
coils
Opis:
The presented system describes a concept for generating slowly varying signals to stimulate biological objects with magnetic field. The system enables independent control of up to 10 induction coil and it generates changeable signal inducing magnetic fields in the range from 0.1 to 150μT and the frequencies from 0.1 to 100 Hz. The proposed system was applied to investigate the influence of magnetic fields with the aforementioned parameters on physical and chemical properties in selected types of fruits.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2016, 5, 4; 73-78
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic seeding depression in flotation of hematite ore slimes
Autorzy:
Yue, T.
Wu, X.
Powiązania:
https://bibliotekanauki.pl/articles/110503.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnetic seeds
magnetic seeding flotation (MSF)
magnetic seeding agglomeration (MSA)
magnetic seeing depression (MSD)
hematite
Opis:
Magnetic seeding depression (MSD), i.e. adding organic depressant (such as starch) and magnetic seeds and applying a low field intensity pre-magnetization for depressing target mineral in flotation, was investigated in the reverse flotation of hematite ore slimes. Flotation tests found that the iron recovery increased with the addition of magnetic seeds; the depressing ability of starch in flotation was further enhanced by the MSD. The increased adsorption density of starch on target mineral hematite and apparent size enlargement of fine minerals are two reasons for the MSD. Based on FTIR, VSM and AFM measurements it was demonstrated that the starch acted as a bridging adsorption between hematite and magnetic seeds by hydrogen bonding and chemisorption, and resultant coverage of the magnetic seeds and starch on hematite increased the magnetic susceptibility, being beneficial to the agglomeration of hematite fines by reducing the external magnetic intensity needed for agglomeration to take place. The model of the MSD was proposed.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 701-712
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-linear effects of operation temperature on a field-coupled current-controlled inductance
Autorzy:
Schierle, Guido
Meissner, Michael
Hoffmann, Klaus F.
Powiązania:
https://bibliotekanauki.pl/articles/24202733.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
magnetic coupling
magnetic devices
passive component
Opis:
In this publication the effect of the operating temperature on the effective inductance of a controllable inductor is analysed. The main difference compared to a coil with a simple single core lies in the current-controlled inductance-value. This is achieved by a second core implemented perpendicular upon the load-toroid affecting the saturation within a limited shared volume. Corresponding to the presented analysis, the dependencies on the core temperatures are investigated by measurements.
Źródło:
Archives of Electrical Engineering; 2023, 72, 2; 541-553
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method of the magnetic field formation in cyclotron DC-72
Autorzy:
Gulbekian, G.
Ivanenko, I.
Filatov, O.
Franko, J.
Kukhtin, V.
Lamzin, E.
Samsonov, E.
Semchenkov, A.
Semchenkova, O.
Sytchevsky, S. E.
Dmitrev, S. N.
Powiązania:
https://bibliotekanauki.pl/articles/148354.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cyclotron
magnetic field measurements
magnetic field simulations
Opis:
A method of the magnetic field formation in the cyclotron DC-72 model (scale 1:5) is described. The cyclotron is planned to be built in Slovakia. The stages in the shimming of the cyclotron sectors and an automatic system designed for magnetic measurements are described. The data on the magnetic field measurements in the median plane of the cyclotron are presented. A brief description of a computer simulation model and an algorithm of fitting the required sector profiles is presented, as well as the data on the computer simulation of magnetic field distributions. The data on the magnetic field measurements and those on the computer simulations are compared and analyzed. Possible reasons of differences between the measured and simulated data are discussed. The results of the above mentioned computer simulations will be used for building a large facility - the cyclotron DC-72.
Źródło:
Nukleonika; 2003, 48, 4; 207-210
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conception of Magnetic Memory Switched by Time Dependant Current Density and Current Electron Spin Polarization
Autorzy:
Steblinski, Paul
Blachowicz, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/227198.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spintronics
magnetic logic
BPM memories
magnetic simulations
Opis:
In this article the magnetic memory model with nano-meter size made from iron cells was proposed. For a purpose of determining the model specifications, the magnetic probes group with different geometrical parameters were examined using numeric simulations for the two different time duration of transitions among quasi-stable magnetic distributions found in the system, derived from the energy minimums. The geometrical parameters range was found, for which the 16 quasi–stable energetic states exist for the each probe. Having considered these results the 4 bits magnetic cells systems can be designed whose state is changed by spin-polarized current. Time dependent current densities and the current electron spin polarization directions were determined for all cases of transitions among quasi-stable states, for discovered set of 4 bits cells with different geometrical parameters. The 16-states cells, with the least geometrical area, achieved the 300 times bigger writing density in comparison to actual semiconductor solutions with the largest writing densities. The transitions among quasi-stable states of cells were examined for the time durations 10⁵ times shorter than that for up to date solutions.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 2; 309-312
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculations of macroscopic eddy current losses in ferromagnetic materials considering hysteresis loop
Autorzy:
Bereźnicki, M.
Jabłoński, P.
Powiązania:
https://bibliotekanauki.pl/articles/378369.pdf
Data publikacji:
2018
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
eddy current power losses
magnetic hysteresis
magnetic nonlinearity
Opis:
The paper presents an algorithm for calculation of eddy current power losses caused by macroscopic eddy currents in ferromagnetic materials considering non-linearity of magnetization characteristics and magnetic hysteresis. The results of calculations are presented for a typical non-oriented steel sheet with silicon content of 6.5%. It has been found that inclusion of hysteresis loop and non-linearity of magnetization for the analyzed material has little effect on the calculated eddy current losses. Restrictions on the use of the algorithm are primarily due to the assumption of average values of the flux in the cross section of the sample, numerical problems when converting B → H and H → B for large increases in the induction, and the lack of regularity of the shape of the hysteresis loop measurements.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2018, 93; 205-214
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nuclear magnetic precession measured with SQUIDs
Autorzy:
Burghoff, M.
Powiązania:
https://bibliotekanauki.pl/articles/156431.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
SQUID
nuclear magnetic precession
low magnetic field measurement
Opis:
We have developed a superconducting quantum interference devices (SQUID) system measuring nuclear magnetic precession at very low magnetic fields with a spectral resolution beyond the natural line width of liquids. A coil system applies a magnetic polarization field and a perpendicular static detection field to the sample. The detection system for the very weak magnetic field generated by the processing nuclei consists of LTc-SQUID sensors in a liquid helium cryostat. We measured the 'H precession signal of benzene, distilled water and chloroform samples at various detection fields. With our set-up. broad band detection of the nuclear magnetic resonance of the investigated liquids with a very high resolution is possible. Benzene showed the narrowest natural resonance line width of 0.12 Hz followed by chloroform of about 0.17 Hz. The observed line widths increased linearly with the detection field with a slope independent of the investigated sample. This increase is attributed to the inhomogeneity of the detection field, rather than to intrinsic properties of the investigated liquids, and thus describes the properties of our measurement system. Reliable low field NMR and MRI depend strongly on field homogeneity of the detection field coils and the residual field inside the agnetically shielded room. At such low fields, high demands on the absolute homogeneity of the static field correspond to very moderate requirements on its relative homogeneity 111. Reduction of these system parameters and its influence is the prerequisite for a good frequency and spatial resolution. Here, we investigated our SQUID measurement system and estimated all main system parameters at very low fields below a microtesla.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 9 bis, 9 bis; 17-20
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on buildup of fine weakly magnetic minerals on matrices in high gradient magnetic separation
Autorzy:
Zheng, X.
Wang, Y.
Lu, D.
Powiązania:
https://bibliotekanauki.pl/articles/109662.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle buildup
force equilibrium
magnetic matrices
magnetic separation
Opis:
Buildup of magnetic mineral particles on matrices determines the saturated deposit volume of minerals, which is of great importance in the high gradient magnetic separation (HGMS) systems. In this paper buildup of fine weakly magnetic minerals on the matrix is studied with a force equilibrium model. Elaborate rules of particle buildup on the matrix are presented. An imaginary sector ring is used to approximately quantify the volume of saturated particle buildup. The influence of the particle size, magnetic induction, fluid viscosity and velocity as well as matrix size on saturated particle buildup is investigated and discussed. With the same matrix size, the saturated buildup volume decreases with the decrease of the particle size, applied magnetic induction and increase of the fluid viscosity and velocity. The saturated buildup volume normalized by the matrix volume, and the ratio of particle deposit volume to the matrix volume (Vd/Vm) decreases with the increase of the matrix size. Under the same matrices packing fraction, the total mineral deposit volume, when adopting small size matrices, is larger than that when adopting large size matrices. Only small size matrices can be used for recovery of minerals in size of several micrometers. Based on performed analyses, the ore feeding time in a cycle for a cyclic HGMS system and the rotation speed of the swivel for a continuous HGMS system under different circumstances are also discussed.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 94-109
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selective agglomeration of magnetite in entlandite-serpentine system and implication for their separation
Autorzy:
Lu, J.
Yuan, Z.
Liu, J.
Li, L.
Wang, N.
Meng, Q.
Powiązania:
https://bibliotekanauki.pl/articles/110411.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
serpentine
pentlandite
magnetite
selective magnetic agglomeration
magnetic separation
Opis:
In nickel sulfide processing, magnesium silicates (serpentines) can easily form slime coatings or hetero-aggregation on pentlandite surfaces, and hence decrease the pentlandite flotation rate and recovery. In this work, magnetic separation of pentlandite from serpentine using selective magnetic coating through adding magnetite fines as magnetic seeds was investigated. Interactions of magnetite-pentlandite and magnetite-serpentine were calculated by the DLVO (Derjaguin-Landau-Verwey-Overbeek) theory. The results show that the interaction of magnetite-pentlandite was obviously stronger than that of magnetite-serpentine with an external weak magnetic field (4776 A/m-1). Therefore, fine magnetite fractions selectively adhered to the pentlandite surfaces and enhanced its magnetism, resulting in being separated from serpentine by magnetic separation, which was further verified by magnetic coating-magnetic separation and SEM observations.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 943-955
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical investigations and optimisation of grain-oriented silicon steel mechanical cutting process
Autorzy:
Patyk, Radosław
Bohdal, Łukasz
Gontarz, Szymon
Powiązania:
https://bibliotekanauki.pl/articles/2204588.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
magnetic materials
shear slitting
sheared edge
magnetic properties
Opis:
The process of mechanical cutting of magnetic materials has many advantages in the form of high efficiency with reduced process costs in relation to other cutting technologies; no thermal stresses in the material, which significantly deteriorate the magnetic properties; or the possibility of shaping materials taking into account long cutting lines. In industrial practice, it is very difficult to ensure appropriate conditions for the cutting process and its proper control. Currently, there are no data on the selection of technological parameters of the mechanical shear slitting process of grain-oriented silicon steel in terms of the obtained cutting surface quality and the obtained magnetic properties of the workpiece. The article presents the possibilities of forecasting the characteristic features of the cut edge and selected magnetic properties of grain-oriented silicon steel. For this purpose, proprietary numerical models using FEA (Finite Element Analysis) were used. Then, experimental studies were carried out, and the optimisation task was developed. The developed results enable the correct selection of technological parameters of the process, ensuring the appropriate quality of the cut edge of steel and minimal interference with the magnetic properties.
Źródło:
Acta Mechanica et Automatica; 2022, 16, 3; 292--300
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematica implementation of BEM model for magnetic field analysis in parallel conductors with time-harmonic currents
Implementcaja w Mathematice modelu MEB do analizy harmonicznego pola magnetycznego układu równoległych przewodów z prądem sinusoidalnym
Autorzy:
Jabłoński, P.
Powiązania:
https://bibliotekanauki.pl/articles/376039.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
time-harmonic magnetic field
magnetic field
BEM
conductors
Opis:
This paper presents a computational model for time-harmonic magnetic field analysis in a configuration of any number of long parallel conductors carrying currents or exposed to an externally applied transverse magnetic field. The model is based on the Boundary Element Method (BEM) and implemented in Mathematica by effective use of its built-in functions and algorithms. The cross-sections of the conductors can have any shapes, with or without holes. In addition, it is possible to add any number of filamentary currents. The model allows finding magnetic field at a given point, powers transmitted across the boundaries of the wires, and the matrix of self and mutual impedances of the considered set of wires. Examples of its use are presented.
W pracy przedstawiono model obliczeniowy dla pola EM w dowolnym układzie długich równoległych przewodów wiodących prądy sinusoidalne lub poddanych działaniu zewnętrznego poprzecznego pola magnetycznego. Model wykorzystuje metodę elementów brzegowych (MEB) i jest zaimplementowany w Mathematice, co pozwala na efektywne wykorzystanie wielu wbudowanych w nią funkcji i algorytmów. Przewody mogą mieć dowolne przekroje poprzeczne, pełne lub wydrążone. Można także dodać dowolną liczbę przewodów nieskończenie cienkich. Model pozwala na obliczanie pola magnetycznego w dowolnym punkcie, mocy wnikającej do obszarów przewodzących oraz macierzy impedancji własnych i wzajemnych. Zaprezentowano przykłady jego zastosowania.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 69; 65-72
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of the Force Function Distribution in the Workplace of the Magnetic Disc Type Separator Intended for the Cleaning of Bulk Substances from the Ferromagnetic Impurities
Autorzy:
Shvedchykova, Iryna
Melkonova, Inna
Powiązania:
https://bibliotekanauki.pl/articles/411225.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
permanent magnet
force function
magnetic system
magnetic separator
Opis:
The paper deals with the magnetic system of the disk separator with permanent magnets. It is shown that the developed magnetic system can be used to purify finely dispersed friable substances from unwanted ferromagnetic inclusions. The main advantage of the magnetic system is the ability to self-clean the surface of a non-magnetic rotating discharging disk. The research of the distribution of the force function acting on multi-domain ferromagnetic particles in the working zone of the disk separator was carried out. To solve the main tasks of the study, a finite element method was implemented, realized in the COMSOL Multiphysics software environment. It is shown that when changing the air gap or the effective length of the poles, the distribution of the force function over the height of the working zone, as well as the magnitude of force, varies. The rational size of the air interpolar gap, which provides the maximum value of power force, was determined.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2019, 8, 3; 3-10
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Operating point resolved loss computation in electrical machines
Autorzy:
von Pfingsten, G.
Ruf, A.
Steentjes, S.
Hombitzer, M.
Franck, D.
Hameyer, K.
Powiązania:
https://bibliotekanauki.pl/articles/141566.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
efficiency maps
material degradation
magnetic losses
magnetic material
behaviour
soft magnetic materials
electrical machines
Opis:
Magnetic circuits of electromagnetic energy converters, such as electrical machines, are nowadays highly utilized. This proposition is intrinsic for the magnetic as well as the electric circuit and depicts that significant enhancements of electrical machines are difficult to achieve in the absence of a detailed understanding of underlying effects. In order to improve the properties of electrical machines the accurate determination of the locally distributed iron losses based on idealized model assumptions solely is not sufficient. Other loss generating effects have to be considered and the possibility being able to distinguish between the causes of particular loss components is indispensable. Parasitic loss mechanisms additionally contributing to the total losses originating from field harmonics, non-linear material behaviour, rotational magnetizations, and detrimental effects caused by the manufacturing process or temperature, are not explicitly considered in the common iron-loss models, probably even not specifically contained in commonly used calibration factors. This paper presents a methodology being able to distinguish between different loss mechanisms and enables to individually consider particular loss mechanisms in the model of the electric machine. A sensitivity analysis of the model parameters can be performed to obtain information about which decisive loss origin for which working point has to be manipulated by the electromagnetic design or the control of the machine.
Źródło:
Archives of Electrical Engineering; 2016, 65, 1; 73-86
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hard magnetic material measurements in a pulsed field magnetometer considering coating and eddy current effects
Autorzy:
Kern, Alexander
Leuning, Nora
Hameyer, Kay
Powiązania:
https://bibliotekanauki.pl/articles/24202740.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
eddy current effects
hard magnetic materials
magnetic property measurement
Opis:
Rare-earth permanent magnets are coated in order to avoid corrosion. When considering the rated geometrical properties of a sample, the coating thickness has to be known precisely as it wrongly enlarges the magnetically active volume which in turn affects the accuracy of the measured magnetic properties. In this work, the sensitivity of hard magnetic material property measurements regarding the consideration of different coating thicknesses is evaluated. Moreover, the impact of eddy current effects on the magnetic properties is studied when measuring in an open circuit. Additionally, an outlook for a measurement-based determination of the electric conductivity of permanent magnet samples is given.
Źródło:
Archives of Electrical Engineering; 2023, 72, 2; 407--414
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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