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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:
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:
Static or dynamic low-frequency magnetic field? A review of literature
Statyczne czy zmienne pole magnetyczne niskiej częstotliwości? Przegląd piśmiennictwa
Autorzy:
Głąb, Grzegorz
Dudek, Jolanta
Klimek, Krzysztof
Skalska-Dulińska, Barbara
Urszula Chrabota, Urszula
Chojak-Fijałka, Katarzyna
Ridan, Tomasz
Glodzik, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1798756.pdf
Data publikacji:
2016
Wydawca:
Akademia Wychowania Fizycznego im. Bronisława Czecha w Krakowie
Tematy:
low-frequency magnetic field
static magnetic field
magnetic field therapy
pole magnetyczne niskiej częstotliwości
stałe pole magnetyczne
magnetoterapia
Opis:
The therapeutic application of magnetic fi elds has experienced signifi cant growth in recent years. A small number of contraindications, as well as the lack of side effects makes both permanent magnets and alternating magnetic fi elds frequently used in physical therapy practice. In a signifi cant number of clinical studies the effi cacy of this physical factor as both an independent method, as well as supporting treatment programs has been confi rmed. In the last few years, a lot of emphasis is put on the fact that all therapeutic methods should have a scientifi c basis and their usage should meet the evidence based medicine criteria (EBM). Therefore, this work will focus on comparison of the use of permanent magnets and alternating low-frequency magnetic fi eld on the basis of the available literature, including mainly, a randomized double-blind trial. Analysis of the available literature on permanent magnet usage has shown clinical effi cacy in many diseases, however, placebo-controlled studies confi rm mainly the analgesic effect in patients after liposuction surgery, with diabetic neuropathy and with chronic pelvic pain. The use of the alternating low-frequency magnetic fi eld also leaves many questions to which scientists have still not found the answer. Randomized double-blind trial proved its therapeutic effi cacy in patients after knee arthroscopy, fractures and delayed bone unions, knee and cervical spine osteoarthritis as well as in case of leg ulceration. Alternating magnetic fi eld application has a wider therapeutic range in comparison to permanent magnets and its effectiveness is much better documented, both in clinical studies as well as randomized double-blind trials. Cite this article as: Głąb G., Dudek J., Klimek K., Skalska-Dulińska B., Chrabota U., Chojak-Fijałka K., Ridan T., Glodzik J. Static or dynamic low-frequency magnetic field? A review of literature. Med Rehabil 2016; 20(2): 31-35.
Terapeutyczne zastosowanie pól magnetycznych wykazuje w ostatnich latach znaczący rozwój. Niewielka liczba przeciwwskazań, jak również brak działań ubocznych przyczyniają się do częstego stosowania tych zabiegów w praktyce fizykoterapeutycznej. W znacznej liczbie prac klinicznych potwierdzono skuteczność tego czynnika fizykalnego zarówno jako samodzielnej metody, jak i wspomagającej w programach terapeutycznych. W terapii stosuje się zarówno magnesy stałe, jak i zmienne pola magnetyczne. W ostatnich latach kładzie się coraz większy nacisk na to, aby wszelkiego rodzaju metody lecznicze miały podstawy naukowe, a ich zastosowanie spełniało kryteria medycyny opartej na faktach (evidence based medicine). Autorzy niniejszej pracy skupią się zatem na omówieniu zastosowania magnesów stałych i zmiennego pola magnetycznego niskiej częstotliwości na podstawie dostępnej literatury obejmującej randomizowane badania na podwójnie ślepej próbie. Analiza dostępnej literatury dotyczącej stosowania magnesów stałych wykazała ich skuteczność kliniczną w wielu schorzeniach, badania z grupą placebo potwierdziły natomiast działanie głównie przeciwbólowe u pacjentów po zabiegach liposukcji, u osób z neuropatią cukrzycową oraz u pacjentek z przewlekłym bólem miednicznym. Zastosowanie zmiennych pól elektromagnetycznych niskiej częstotliwości również pozostawia wiele pytań, na które jak do tej pory naukowcy nie znaleźli odpowiedzi. W badaniach na podwójnie ślepej próbie udowodniono skuteczność terapeutyczną u pacjentów po artroskopii stawu kolanowego, złamaniach i opóźnionym zrostem kostnym, u osób ze zmianami zwyrodnieniowymi stawów kolanowych i kręgosłupa szyjnego, a także w przypadku owrzodzeń podudzi. Działanie pól zmiennych ma w porównaniu z magnesami stałymi znacznie większy zakres terapeutyczny, a skuteczność ich działania jest o wiele lepiej udokumentowana zarówno w badaniach klinicznych, jak i randomizowanych na podwójnie ślepej próbie.
Źródło:
Medical Rehabilitation; 2016, 20(2); 31-35
1427-9622
1896-3250
Pojawia się w:
Medical Rehabilitation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wektorowy gradiometr pola magnetycznego
Magnetic field vector gradiometer
Autorzy:
Wołoszyn, M.
Powiązania:
https://bibliotekanauki.pl/articles/156108.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
gradiometr pola magnetycznego
pole magnetyczne
czujnik magnetyczny
magnetic field gradiometer
magnetic field
magnetic sensor
Opis:
W pracy przedstawiono metodę wyznaczania parametrów wektorowego gradiometru magnetycznego mających istotny wpływ na przybliżony pomiar pochodnych cząstkowych. Wartości pochodnych cząstkowych mierzone są w sposób przybliżony metodą różnicową. Dokładność pomiaru różnicy indukcji magnetycznej zależy od kąta przesunięcia osi czujników magnetycznych, przesunięcia zera i współczynnika skali czujników oraz od odległości między czujnikami. Skuteczność wykrywania obiektów ferromagnetycznych z zastosowaniem wektorowego gradiometru bez informacji o wartościach tych parametrów jest bardzo niska.
Five independent partial derivatives of the magnetic flux density vector are used for detecting ferromagnetic objects by use of vector gradiometers in algorithms of object locating and identifying. This method requires precise measurement of the magnetic flux density gradient (1). A gradiometer built of magnetometers with directional sensitivity characteristics has several parameters, called critical in this paper, that influence the measurement of partial derivatives in a significant way. The gradiometer critical parameters are: angle between the axis of magnetic sensors, offset, accuracy of measurements of separate sensors and the distance between them. The critical parameters values can be determined on a basis of measurements from formulas (4-8). Partial derivatives (1) are determined on a basis of measuring the difference quotient of the magnetic flux density. When choosing the distance sensors, their sensitivity and approximation of partial derivatives by difference quotients should be taken into account.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 12, 12; 1525-1527
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Issues involved in using the direct method for magnetic field strength measurement of electrical steel sheets – review
Problemy pomiaru natężenia pola magnetycznego blach elektrotechnicznych metodą bezpośrednią – przegląd
Autorzy:
Gaworska-Koniarek, D.
Bajorek, J.
Wilczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/159080.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Tematy:
pomiar natężenia pola magnetycznego
czujniki pola magnetycznego
metoda bezpośrednia
magnetic field strength measurements
magnetic field sensor
magnetic field measurement
direct method
Opis:
W artykule, na podstawie dokonanego przeglądu literatury, przedstawiono istniejące problemy pomiaru natężenia pola magnetycznego metodą pośrednią i bezpośrednią w blachach elektrotech-nicznych oraz próby ich rozwiązania. Opisano czujniki składowej natężenia pola magnetycznego stosowane najczęściej do pomiaru natężenia pola magnetycznego w blachach elektrotechnicznych.
The paper presents, based on a review of relevant literature, the existing problems of magnetic field strength measurements of electrical steel sheets by means of the indirect and direct methods. It also describes some attempts to solve these problems. The magnetic field strength sensors most widely used for testing electrical steel sheets are also discussed.
Źródło:
Prace Instytutu Elektrotechniki; 2016, 274; 71-82
0032-6216
Pojawia się w:
Prace Instytutu Elektrotechniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of magnetic field on the corrosion of iron as studied by positron annihilation
Autorzy:
Pietrzak, R.
Szatanik, R.
Powiązania:
https://bibliotekanauki.pl/articles/146285.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
corrosion
magnetic field
positron annihilation
Opis:
Lifetime spectra of positron annihilation in iron corroded in a water solution of HCl and in vapour above its surface have been investigated with emphasis on the effect of corrosion time and environment (solution or vapour) as well as of the presence and orientation of the magnetic field on the measured positron annihilation parameters. All the registered positron lifetime spectra consist of two components. For corroded samples, the intensities of the two components as well as the corresponding values of the mean positron lifetime, differ from those for uncorroded material. The corrosion-induced changes in the positron annihilation parameters depend on the corrosion environment (solution or vapour) and on the presence and direction of external magnetic field.
Źródło:
Nukleonika; 2010, 55, 1; 31-34
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a magnetic field monitoring system for the JAERI AVF cyclotron
Autorzy:
Okumura, S.
Arakawa, K.
Fukuda, M.
Nakamura, Y.
Yokota, W.
Ishimoto, T.
Kurashima, S.
Ishibori, I.
Nara, T.
Agematsu, T.
Nakajima, T.
Powiązania:
https://bibliotekanauki.pl/articles/148733.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
compensation coil
cyclotron
magnetic field
Opis:
We have developed a probe of a nuclear magnetic resonance (NMR) magnetometer for measurement of a fluctuation of an AVF cyclotron field. The stability of the magnetic field of the JAERI AVF cyclotron, measured with the NMR probe, was within 1 × 10-5. A field-measurement accuracy of the order of 1 × 10-6 was achieved using a set of field-compensation coils and optimizing the probe position to obtain enough homogeneity of the magnetic field around the probe for measuring the cyclotron field with a high gradient. To eliminate a major bottleneck in the field measurement inside the cyclotron, the probe was specially produced with the cable shielding against RF noises and proper materials applied.
Źródło:
Nukleonika; 2003, 48,suppl.2; 35-37
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow patterns generated by a strong magnetic field
Wpływ silnego pola magnetycznego na strukturę przepływu
Autorzy:
Fornalik, E.
Powiązania:
https://bibliotekanauki.pl/articles/279226.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
spoke pattern
thermosyphon
magnetic field
Opis:
The influence of a strong magnetic field on a paramagnetic fluid in a cylindrical enclosure of thermosyphon-like geometry was studied. A variety of spoke patterns was experimentally obtained and recorded. The analysis led to some data about the temperature field and, indirectly, about the flow structure. The results related to the heat transfer rate confirmed the conclusions coming from the flow visualization.
Przedstawione zostały badania dotyczące struktury przepływu w geometrii cylindrycznej typu odwrócony termosyfon (tzn. górna część cylindra była grzana, a dolna chłodzona). Naczynie eksperymentalne napełnione cieczą paramagnetyczną zostało umieszczone w przestrzeni badawczej magnesu nadprzewodzącego, generującego silne pole magnetyczne (maksymalna indukcja magnetyczna 5 Tesli). Badano wpływ pola magnetycznego na strukturę przepływu, dokonano wizualizacji pola temperatury przy pomocy ciekłych kryształów oraz pomiaru temperatury za pomocą termopar. Bez pola magnetycznego oraz dla indukcji magnetycznej poniżej 1 Tesli w naczyniu nie obserwowano ruchu konwekcyjnego, a co za tym idzie również żadnej struktury przepływu. Dla indukcji magnetycznej powyżej 1 Tesli w naczyniu eksperymentalnym została zapoczątkowana konwekcja magnetyczna, co objawiło się pojawieniem struktury szprychowej. Struktura szprychowa, typowa dla konwekcji naturalnej w termosyfonie (tzn. górna część cylindra chłodzona, a dolna grzana) uległa zmianie - wraz ze wzrostem indukcji magnetycznej wzrastała liczba płatków, co sugerowało intensyfikację konwekcji. Wyniki wizualizacji zostały potwierdzone przez pomiary termiczne oraz wyznaczoną liczbę Nusselta.
Źródło:
Journal of Theoretical and Applied Mechanics; 2007, 45, 3; 557-568
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reverse reaction magnetic field in two-wire high current busduct
Autorzy:
Piatek, Z.
Kusiak, D.
Szczegielniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/97489.pdf
Data publikacji:
2010
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
high-current busduct
elliptical field
Opis:
Work has shown how a reverse reaction magnetic field influences the whole magnetic field within the conductor and its vicinity. A description of this is presented in formulae for relative field values and parameters taking into account frequency, conductivity and diameter of the conductor. This has shown the field to be an elliptical field.
Źródło:
Computer Applications in Electrical Engineering; 2010, 8; 53-60
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of time-stepping methods for transient magnetic field computations in COMSOL Multiphysics
Autorzy:
Sowa, M.
Typańska, D.
Powiązania:
https://bibliotekanauki.pl/articles/378331.pdf
Data publikacji:
2014
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
time-stepping
COMSOL
transient magnetic field
Opis:
The computations of a transient magnetic field problem are presented. The problem has been constructed and solved in COMSOL Multiphysics which is one of the most popular and versatile commercial programs that allow to deal with solving electromagnetic field problems by means of the finite element method. A simple 2D problem of a coaxial cable has been chosen so that an analytical solution can be used in order to easily compute an error. The main topic of the paper concerns the comparison of the time-stepping methods that are available in COMSOL Multiphysics i.e. the BDF and generalized alpha methods. It is also possible to select various options for these methods, which have an influence on the solution accuracy. These have been also considered in the analysis.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2014, 77; 141-147
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of magnetic field and magnetometers in supporting the air navigation
Autorzy:
Ogórek, I.
Grzegorzewski, M.
Maciejowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/320466.pdf
Data publikacji:
2015
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
magnetic field
air navigation
landing systems
Opis:
At present, the Earth’s magnetic field (geomagnetic field) undergoes considerable variations. The use of towers measuring areal variations in magnetic intensity may provide additional support for aircraft navigation. This paper presents the idea of using magnetometers for supporting GNSS as well as for creating a landing system based on magnetic field variations.
Pole magnetyczne Ziemi (pole geomagnetyczne) podlega znacznym fluktuacjom. Autorzy założyli, że użycie wież mierzących powierzchniowe zmiany intensywności pola magnetycznego w pobliżu lotniska może dostarczyć dodatkowego wsparcia w nawigacji lotniczej. W artykule przedstawiono nowatorski pomysł zastosowania magnetometrów dla wspierania pomiarów GNSS, jak również dla stworzenia systemu wspomagającego lądowanie opartego na sensorach zmian parametrów pola magnetycznego.
Źródło:
Annual of Navigation; 2015, 22; 21-29
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic pollution produced by underground XLPE 220 kV power cable in power plant
Autorzy:
Rezzag Bara, Ilies
Ayad, Ahmed Nour El Islam
Krika, Wafa
Fezazi, Omar
Larouci, Benyekhlef
Powiązania:
https://bibliotekanauki.pl/articles/27313806.pdf
Data publikacji:
2024
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
cables
magnetic field
pollution
power
underground
Opis:
The expansion of the electrical network necessitates the construction of new power plants and the extension of overhead and underground power transmission and distribution systems. However, underground power cables, such as XPLE 220 kV, can cause significant electromagnetic pollution, particularly in urban areas. This paper focuses on the evaluation and prediction of such magnetic emissions using analytical, numerical simulation (the finite element analysis), and experimental measurement. The paper aim is to minimize the magnetic emissions through the adjustment of the horizontal and vertical distances (x, y) of cables, serving as a technical solution. Additionally, the study investigated the impact of faults with varying magnitude and frequency, considering different loads and conditions. The simulation results indicate that several factors contribute to the escalation of magnetic pollution. These factors include a close proximity between cables, faults, and high current intensities.... However, as the distance between cables increases both horizontally and vertically, the strength of the magnetic field decreases, leading to a reduction in magnetic pollution. A comparison was carried out to assess the magnetic emissions of the underground cable, revealing a notable resemblance between the measured and calculated values. Ultimately, the validated simulation model serves as a valuable tool for evaluating, predicting, and mitigating electromagnetic pollution under different fault conditions and positions.
Źródło:
Diagnostyka; 2024, 25, 1; art. no. 2024104
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetothermoelastic vibrations on a viscoelastic microbeam subjected to a laser heat source
Autorzy:
Abouelregal, A. E.
Zenkour, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/38614523.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
thermoviscoelasticity
microbeams
laser pulse
magnetic field
Opis:
The linear theory of viscoelasticity remains an important field of research like most solids and polymer materials when exposed to a vicious dynamic loading effect. This article introduces a new model for describing the behavior of thermoviscoelastic microbeams considering the effects of temperature change and the longitudinal magnetic field. The governing equations in this model are derived based on the Euler–Bernoulli beam theory, Kelvin–Voigt model of viscosity, the generalized thermoelasticity, and the classical Maxwell equations. The two ends of the microbeam are clamped and subjected to the influence of a laser pulse with a temporal intensity profile. The analytical solutions to the physical fields are evaluated using the Laplace transform and its inversion transforms are performed numerically. The thermo-viscoelastic responses of the microbeam are calculated numerically and investigated graphically. The effect of different parameters such as viscosity, laser intensity, and the magnitude of the magnetic field are studied in detail.
Źródło:
Archives of Mechanics; 2021, 73, 1; 3-26
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic field around the screened three-phase high-current busducts
Autorzy:
Szczegielniak, T.
Piątek, T.
Kusiak, D.
Powiązania:
https://bibliotekanauki.pl/articles/97254.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
high current busduct
magnetic field
FEMM
Opis:
This paper presents an analytical method for determining the magnetic field in the three–phase gas–insulated transmission line (i.e., high-current busduct) of circular cross–section geometry. The mathematical model takes into account the skin effect and the proximity effects, as well as the complete electromagnetic coupling between phase conductors and enclosures (i.e., screens). Apart from analytical calculation, computer simulations for high-current busduct system magnetic field were also performed with the aid of the commercial FEMM software, using two–dimensional finite elements.
Źródło:
Computer Applications in Electrical Engineering; 2016, 14; 14-24
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of coaxial magnetocumulative generators
Autorzy:
Wołoszyn, M.
Jakubiuk, K.
Zimny, P.
Kowalak, D.
Powiązania:
https://bibliotekanauki.pl/articles/141467.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
coaxial generator
magnetic field
magnetocumulative generator
Opis:
This paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element.
Źródło:
Archives of Electrical Engineering; 2017, 66, 4; 681-692
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Możliwość zastosowania odczynnika Fentona w procesach usuwania formaldehydu ze ścieków pochodzących z przemysłu drzewnego
Application of Fenton reagent in the process of formaldehyde removal from the timber industry wastewater
Autorzy:
Dębowski, M.
Zieliński, M.
Dudek, M.
Grala, A.
Powiązania:
https://bibliotekanauki.pl/articles/1819294.pdf
Data publikacji:
2012
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
degradation
Fenton's reagent
constant magnetic field
Opis:
The aim of this study was to determine the possibility of degradation of formaldehyde in the effluents from the timber industry with Fenton's reagent. Effluent from the timber industry are characterized by a high concentration of organic compounds and formaldehyde as an obstacle to the purification of wastewater using microorganisms and therefore an alternative to biological methods is the use of solutions based on chemical methods. In recent years, considerable attention is given to testing and implementation of the so-called advanced oxidation methods (Advanced Oxidation Processes - AOPs). A common feature of these systems is that they allow the generation of highly reactive hydroxyl radicals OH center dot with 2,8 V oxidation potential, which react with almost all organic compounds. Fast-paced distribution of impurities, versatility and high efficiency make advanced oxidation methods are now increasingly considered as a promising alternative compared to conventional methods, techniques, wastewater and sludge treatment Wastewater used in the study came from the wood of an industrial plant where the business is the manufacture of chipboard. The study was conducted in three phases with different type of chemical reactants introduced into the technological system. In the first stage reactor was dosed only iron ions Fe3+, H2O2 in the second stage, while the third part of an experiment to test the Fenton reagent treatment was introduced Fe3+ /H2O2. Each stage is divided into five variants. The criterion for division of the variants was the dose of chemical reagents. The study confirmed the applicability of advanced oxidation technologies based on Fenton's reagent in the process of degradation of formaldehyde. It was found that the efficiency of removal of contaminants from wastewater was directly connected with the dose of chemical reagents introduced into the technological system. It was also noted that increasing the dose above the Fenton reagent Fe3+ 0,3 g /l and 3,0 g H2O2/l does not significantly affect the final results of the purification process. The highest results were obtained in the technology used in doses of 0,3 g Fe 3+/l and 3,0 g H2O2 /l to 0,6 g Fe3+/l and 6,0 g H2O2/l. Limiting values of COD in the experimental variants was approximately 70,0% while the concentration of formaldehyde close to 60,0%. If dispensing the water only Fe3+ ions obtained the highest efficiency and reduce the COD concentration of formaldehyde was 28,3% sequentially and 14,5%. The final concentrations of the analyzed indicators of pollution, if only H2O2 dosing were similar to their concentrations in raw wastewater.
Źródło:
Rocznik Ochrona Środowiska; 2012, Tom 14; 587-596
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetorheological fluid damper with radially-shaped gap and contact-less sealing
Tłumik magnetoreologiczny ze szczeliną promieniową i bezstykowym uszczelnieniem tłoka
Autorzy:
Sapiński, B.
Powiązania:
https://bibliotekanauki.pl/articles/281137.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
magnetorheological damper
magnetic field
force response
Opis:
The paper is concerned with design, numerical study of magnetic fluid and experimental testing of a linear magnetorheological damper (MR damper) with radially-shaped gap and contact less sealing. Preferred embodiments for MR dampers development are outlined. The structure, materials used in the main components and operation principle of the damper are described. The magnetic field distribution in the damper in steady states and in transients is numerically studied. Force responses measured for the damper in the experimental setup are provided. Directions for further improvements are suggested.
W artykule przedstawiono projekt, analizę numeryczną pola magnetycznego oraz badania eksperymentalne liniowego tłumika magnetoreologicznego (MR) ze szczeliną promieniową i bezstykowym uszczelnieniem tłoka. Omówiono ogólne zalecenia do konstrukcji tłumików MR. Opisano budowę tłumika, scharakteryzowano materiały konstrukcyjne, z których wykonanojego glówne elementy oraz opisano zasadę działania tłumika. Zamieszczono wyniki obliczeń numerycznych rozkładu pola magnetycznego w tłumiku w stanach ustalonych i nieustalonych. Przedstawiono wyniki pomiarów siły tłumienia na stanowisku badawczym. Sformułowano uwagi dotyczące udoskonalenia konstrukcji opracowanego tłumika.
Źródło:
Journal of Theoretical and Applied Mechanics; 2005, 43, 2; 223-240
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Making of ferromagnetic elliptical shell in transverse magnetic field
Autorzy:
Jakubiuk, K.
Wołoszyn, M.
Zimny, P.
Powiązania:
https://bibliotekanauki.pl/articles/377889.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
ferromagnetic object
magnetic field
ferromagnetic shell
Opis:
A ferromagnetic object, located in the Earth’s magnetic field, changes its distribution. Through measuring such disturbances, one can locate the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, and its task is to eliminate the disturbances in the distribution of the Earth’s magnetic field. A thin walled elliptical shell, made of ferromagnetic material, is examined as the object model. There are coils, placed inside the shell, and their task is to generate a magnetic field, which is eliminating the effect, the shell is making on the distribution of the Earth’s magnetic field in the surrounding area. Such a procedure is called magnetic masking and the winding used for this purpose is called the masking winding. The possibility of building the masking windings for the ferromagnetic elliptical shell, situated in a transverse magnetic field respectively to its major axis, is also examined. The solution of Maxwell’s equations, which are describing the magnetic field distribution caused by the ferromagnetic shell presence in the Earth’s magnetic field, is found. Furthermore, the ability of selecting coils, which are eliminating the perturbations of the magnetic field outside the shell completely, is proven.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2013, 73; 131-136
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of magnetic fields and fertilizers on grass and onion growth on technogenic soils
Autorzy:
Vasilyeva, Maria
Kovshov, Stanislav
Zambrano, Johnny
Zhemchuzhnikov, Maxim
Powiązania:
https://bibliotekanauki.pl/articles/1844328.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
alternating magnetic field
biochar
bioefficiency
biohumus
constant magnetic field
fertilization
physiological parameters of plants
technogenic soils
Opis:
The article deals with effect the use of organic (biohumus) and mineral (biochar) fertilizers based on the products of chicken vital activity on changing the fertility of technogenic sod-podzolic soils exposed to constant and unstable magnetic fields. The germination and growth dynamics of grasses and onions were investigated. The rational rate of introduction of the studied fertilizers into the technogenic soil is determined. Running (RMF) and direct (DMF) magnetic fields were applied in two ways: with fertilizers added and without fertilizers added. It has been established that the effect of preliminary magnetization of technogenic soil has a significant effect on lawn grass germination and the length of onion feathers, which are more than twice the height when exposed to the RMF, as compared with DMF. The effect of RMF on grass germination was also twice as high for DMF, when fertilizers were added. The DMF magnetization and biohumus helps to increase the grass sprout height by 10–20%. Onion sprouts were higher in two cases: DMF and biohumus; RMF and biochar. The influence of the factor of fertilizer type has a significant effect in 30–40% of cases, whilst at a spread rate of more than 5%, significant chemical activity of biochar negatively affects the germination of both grass and onion.
Źródło:
Journal of Water and Land Development; 2021, 49; 55-62
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of ferromagnetic objects by using scalar magnetometers
Autorzy:
Jakubiuk, K.
Wołoszyn, M.
Powiązania:
https://bibliotekanauki.pl/articles/97481.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
magnetization of ferromagnetic object
measurements of magnetic field
scalar magnetometers
detection of ferromagnetic object
Opis:
The paper presents the results of the analysis of the possibility of detecting ferromagnetic objects (ships, submarines, mines, etc.) by using two scalar magnetometers. By using two magnetometers of high sensitivity (in the order of magnitude of pT/Hz0,5) placed at a distance from each other and operating in a differential system, it is possible to detect ferromagnetic objects from a distance. It is necessary to compensate for the error code to synchronize the work of the two magnetometers. Ferromagnetic object’s detection by using two magnetometers requires proper configuration of the devices.
Źródło:
Computer Applications in Electrical Engineering; 2013, 11; 83-91
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of induced magnetic field on MHD mixed convection flow in vertical microchannel
Autorzy:
Jha, B. K.
Aina, B.
Powiązania:
https://bibliotekanauki.pl/articles/265764.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
microchannel
transverse magnetic field
induced magnetic field
velocity slip
temperature jump
pole magnetyczne
skok temperatury
mikrokanał
Opis:
The present work presents a theoretical investigation of an MHD mixed convection flow in a vertical microchannel formed by two electrically non-conducting infinite vertical parallel plates. The influence of an induced magnetic field arising due to motion of an electrically conducting fluid is taken into consideration. The governing equations of the motion are a set of simultaneous ordinary differential equations and their exact solutions in dimensionless form have been obtained for the velocity field, the induced magnetic field and the temperature field. The expressions for the induced current density and skin friction have also been obtained. The effects of various non-dimensional parameters such as rarefaction, fluid wall interaction, the Hartmann number and the magnetic Prandtl number on the velocity, the induced magnetic field, the temperature, the induced current density, and skin friction have been presented in a graphical form. It is found that the effect of the Hartmann number and magnetic Prandtl number on the induced current density is found to have a decreasing nature at the central region of the microchannel.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 3; 567-582
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Eksperymentalne badania czynników zmieniających warunki wspomagania polem magnetycznym
Experimental research on factors that change conditions of aiding by the magnetic field
Autorzy:
Burcan, J.
Sławińska, A.
Bednarek, R.
Powiązania:
https://bibliotekanauki.pl/articles/387463.pdf
Data publikacji:
2009
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
indukcja magnetyczna
pole magnetyczne
magnetic field
magnetic research
Opis:
Streszczenie: W pracy przedstawiono wyniki pomiarów indukcji magnetycznej w otoczeniu czół wysokoenergetycznych magnesów oraz wyniki pomiarów sił oddziaływania między dwoma magnesami. Wykazano, że rozkład wektora indukcji zależy od błędów kształtu magnesów i dokładności ich montażu. Znajomość rozkładu wektora indukcji w funkcji parametrów geometrycznych i materiałowych umożliwia dokładne określenie wartości siły odpychania się współpracujących magnesów. Jest ona niezbędna do poprawnego projektowania łożysk i prowadnic wspomaganych polem magnetycznym.
The study presents the results of magnetic induction measurements in the vicinity of front ends of high-energy magnets as well as the results of forces between two magnets measurements. It has been proved that the distribution of the induction vector is influenced by accuracy of magnets execution and mounting. The knowledge of the course of the induction vector variations as the function of geometry and material parameters enables to determine precisely the variation of the repulsion force value of the co-operating magnets, thus will be helpful when designing pairs unloaded by means of the magnetic field, e.g. bearings or slides.
Źródło:
Acta Mechanica et Automatica; 2009, 3, 1; 27-29
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
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:
Method of estimating the exposure of the natural environment to 50 Hz electric and magnetic fields in power systems with distributed and centralized generations
Autorzy:
Zeńczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/140965.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
distributed generation
electric field
magnetic field
power line
Opis:
The development of a distributed generation will influence the structure of the power transmission and distribution network. Distributed sources have lower power and therefore the lines of lower voltage are used. Therefore, the electric field intensity near such lines is lower. On the other hand magnetic field intensity may prove essential. The main aim of the paper is to present a method estimating the “ballast” of the natural environment at 50 Hz electric and magnetic fields in the power system, with distributed and centralized generation in real operating conditions.
Źródło:
Archives of Electrical Engineering; 2016, 65, 2; 295-304
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using the EMTP/ATP program for calculation of electric and magnetic field distribution under overhead line
Zastosowanie programu EMTP/ATP do obliczania rozkładu pól i elektrycznych i magnetycznych pod linią napowietrzną
Autorzy:
Wiśniewski, J.
Anderson, E.
Karolak, J.
Powiązania:
https://bibliotekanauki.pl/articles/376500.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
electric field
magnetic field
overhead line
EMTP-ATP
Opis:
This paper presents the method of calculation of the electric and magnetic fields under overhead transmission line with any number of circuits, phase positions, voltages and current loads. Calculations of this type usually require specialized and costly programs. The program EMTP/ATP is a royalty free tool to calculate the electric transient and steady states in complex power systems. You can use this program and through appropriate modeling the multi-phase wire system representing the line and measurement device calculate the strength of the electric and magnetic fields. The results of calculations are characterized by a very small error compared to the results obtained by using the specialized program. This method can be used with other popular engineering tools like Matlab/Simulink or PSCad.
W artykule przedstawiono metodę obliczeń pól elektrycznych i magnetycznych pod linią wysokiego napięcia o dowolnym układzie faz, liczbie torów, napięciach i obciążeniach. Obliczenia tego typu wymagają zwykle wyspecjalizowanych i kosztownych programów. Program EMTP/ATP jest bezpłatnym narzędziem do obliczania stanów ustalonych i nieustalonych w złożonych układach elektroenergetycznych. Można przy użyciu programu poprzez odpowiednie zamodelowanie układu wieloprzewodowego odwzorować układ pomiarowy pozwalający obliczyć wartość natężenia składowej elektrycznej i magnetycznej pola. Uzyskane wyniki obliczeń charakteryzują się bardzo małym błędem w stosunku do wyników uzyskanych wyspecjalizowanym programem. Metodę tę można stosować przy użyciu także innych szeroko rozpowszechnionych inżynierskich narzędzi jak Matlab/Simulink lub PSCad.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 69; 73-80
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metoda własnego rozproszonego pola magnetycznego do badania szyn kolejowych
Residual magnetic field method (RFM) of railway track inspection
Autorzy:
Juraszek, J.
Powiązania:
https://bibliotekanauki.pl/articles/251224.pdf
Data publikacji:
2015
Wydawca:
Instytut Naukowo-Wydawniczy TTS
Tematy:
pole magnetyczne
szyny kolejowe
Metoda Własnego Rozproszonego Pola Magnetycznego
WRPM
magnetic field
railways
residual magnetic field method
Opis:
W pracy przedstawiono metodę wykrywania uszkodzeń szyn kolejowych za pomocą Metody Własnego Rozproszonego Pola Magnetycznego (MWRPM). Wyznaczono składowe normalne i stacze WRPM oraz ich gradient wzdłuż długości szyny. Metoda umożliwia w szybki i nieinwazyjny sposób identyfikować uszkodzenia szyn kolejowych. Zbudowano specjalną bazę danych magnetogramów uszkodzeń zarejestrowanych na wybranym odcinku szyny kolejowej w zależności od czasu jej eksploatacji.
This paper discussed the evaluation of the railway track state based on the residual magnetic field method measured on the railway track surface. It includes selected problems of the basic of residual magnetism if known, make easier to understand the present issues.
Źródło:
TTS Technika Transportu Szynowego; 2015, 12; 737-740, CD
1232-3829
2543-5728
Pojawia się w:
TTS Technika Transportu Szynowego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Passive loop coordinates optimization for mitigation of magnetic field value in the proximity of a power line
Autorzy:
Książkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/97704.pdf
Data publikacji:
2015
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
power line
magnetic field
optimization
genetic algorithm
Opis:
The paper relates to the distribution of the magnetic field generated by the overhead power line, and it’s reduction in the area of interest using a conductive loop placed in the space near the line. The paper presents results obtained from an original program written in C ++, which implements the procedure for calculating the magnetic field generated by overhead line and a genetic algorithm used to optimize the location and loop compensation factor. Examples of the program are presented for horizontal single-track line and three different shielding loop configurations. The first relates to a single loop (4 to 5 parameters to optimize - 4 position coordinates (y, z) and the compensation factor), the second case involves two loops with one common conductor (6 to 8 parameters - 6 coordinates (y, z) and 0 to 2 compensation factors), the third case concerns two independent loops (8 to 10 parameters - 8 coordinates (y, z) and 0 to 2 of the compensation factors). In addition similar calculations are performed for single-track line with two earth wires.
Źródło:
Computer Applications in Electrical Engineering; 2015, 13; 77-87
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculations of the magnetic field of the three-phase 4-conductor line with rectangular busbars
Autorzy:
Kusiak, D.
Piątek, Z.
Szczegielniak, T.
Jabłoński, P.
Powiązania:
https://bibliotekanauki.pl/articles/1395763.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
rectangular busbar
high-current busduct
Opis:
The paper presents the results of the calculations of the magnetic field for the both shielded and non-shielded 3-phase MR 250 busbar manufactured by Elektromontaż 2 in Katowice, Poland. The busbar magnetic field has been determined by the following methods: analytical method for non–shielded busbar without taking into account the skin and proximity effects, analytical–numerical method based on integral equations, two-dimensional method of finite elements with the use of the commercial FEMM software, measurement method on a test stand. The measurements were performed with the use of a special non-directional magnetic field meter. A satisfactory compliance of the calculations has been obtained.
Źródło:
Computer Applications in Electrical Engineering; 2016, 14; 25-38
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Fields for Electropolishing Improvement: Materials and Systems
Autorzy:
Hryniewicz, Tadeusz
Rokosz, Krzysztof
Rokicki, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/411721.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Magnetic field
Magnetoelectropolishing MEP
Materials
Electrochemical systems
Opis:
The paper aims to present the main objectives for using magnetic fields to improve process of electropolishing (EP), firstly by focusing on materials and electrochemical systems. The general introduction has been concerned on the sample surface treated under pseudopassivity conditions, in the process generally known as magnetoelectropolishing (MEP). Long-term up-to-date experiments have shown profound changes observed on metals and alloys. The advantageous effects gained by applying MEP to metals and alloys cover: improvement of corrosion resistance, bio- and haemocompatibility, roughness by modification of their surfaces. The improvements are also referred to the mechanical properties of metals and alloys treated by MEP namely: removal of hydrogen, fatigue resistance enhancement, etc. Further developments and the effects of magnetic fields on electropolishing of metals and alloys are to be presented in the next publications.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 98-108
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Magnetic Field on Electroless Metallization of 3D Prints by Copper and Nickel
Autorzy:
Kołczyk-Siedlecka, K.
Skibińska, K.
Kutyła, D.
Kwiecińska, A.
Kowalik, R.
Żabiński, P.
Powiązania:
https://bibliotekanauki.pl/articles/353331.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
3D print
metallization
magnetic field
roughness
Opis:
3D printing is a technology with possibilities related to the production of elements of any geometry, directly from a digital project. Elements made of plastic are metalized to give new properties such as conductivity or corrosion resistance. In this work, experimental work related to the electroless deposition of metallic coatings on plastics was carried out. For this purpose, the copper and nickel coatings were catalytically deposited on elements printed using hard-lightened resin. The effect of the metallization time on the properties of copper and nickel coatings was determined. In addition, the process of deposition metals in the magnetic field was analyzed with different direction of magnetic field to the surface of the samples. The coatings were analyzed by XRF, XRD method and morphology of surface was observed by scanning electron microscopy (SEM).
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 17-22
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic field effects on surfactants adsorption on the solid surface as regards of its wettability
Autorzy:
Hołysz, Lucyna
Chibowski, Emil
Terpiłowski, Konrad
Powiązania:
https://bibliotekanauki.pl/articles/1450178.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
surfactants
glass surface
magnetic field
adsorption
hydrophobization
Opis:
The static magnetic field MF (0.44 T) effects on the adsorption of three surfactants: cationic bromide (DTAB) and hexadecyltrimethylammonium bromide (CTAB), and anionic sodium dodecylsulfate (SDS) from their 10-3 M solutions were studied on bare and low-temperature air plasma treated glass plates. The surface properties of the adsorbed surfactants layers were determined via the water advancing and receding contact angles measurements and then calculation of the apparent surface free energy. An optical profilometer was used to determine the structure and topography of the adsorbed layers. The DTAB and SDS concentrations were below their critical micelle concentration and that of CTAB very close to its cmc. The results showed that in the case of DTAB solution (much below its cmc) a small decrease in the contact angle appeared while in CTAB (close to its cmc) an increase in the contact angle value was observed if adsorbed in the MF presence. Quite good reproducibility of the contact angle values was obtained. This was not the case for the SDS solution where the contact angle values were scattered. The reason was that the anionic surfactant did not adsorb homogeneously on the negatively charged glass surface. The contact angles and the calculated values of the work of water spreading clearly show that MF influences the structure of the surfactant adsorbed layer which was also supported by the optical profilometry images.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 6; 101-113
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Repeat Station Network on the Baltic Sea - Why So Needed?
Autorzy:
Welker, E.
Reda, J.
Pałka, A.
Powiązania:
https://bibliotekanauki.pl/articles/320619.pdf
Data publikacji:
2017
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
Earth's magnetic field
marine magnetic repeat stations
secular geomagnetic field changes
Opis:
The development of navigation systems requires more and more accurate base data. Currently, attention is paid to utilization of geophysical fields - gravitational and magnetic ones - for navigation purposes. The Earth’s magnetic field distribution - both onshore and offshore - is complicated and variable in time. Hence, it is essential to precisely know the secular variations in the area of interest. In the case of Baltic Sea, this involves establishing (re-establishing) of a marine network of secular points (repeat stations) and regular magnetic measurements of the three independent components of the Earth’s magnetic field. Such measurements require equipment that ensures not only high stability, but also information about sensors’ orientation in relation to geographic north and to the level. This article presents a new project of the Baltic network of repeat stations and gives a solution for the instruments usable for quasi-absolute magnetic measurements.
Rozwój systemów nawigacyjnych wymaga posiadania coraz dokładniejszych danych. Dotyczy to również znajomości naturalnych pól fizycznych Ziemi, które są postrzegane jako niezwykle użyteczne dla nawigacji, zwłaszcza grawitacyjne oraz magnetyczne. Rozkład pola magnetycznego Ziemi jest bardzo zróżnicowany przestrzennie, a ponadto jest zmienny w czasie - tak na lądzie jak i we wszechoceanie. Stąd tak istotna jest dokładna znajomość jego rozkładu, a także zmian wiekowych. W przypadku Morza Bałtyckiego wymagałoby to ustanowienia (wznowienia) sieci punktów wiekowych na morzu i regularnych pomiarów trzech składowych pola magnetycznego Ziemi w tychże punktach. Tego rodzaju pomiary wymagają odpowiedniego sprzętu, gwarantującego wysoką stabilność czujników, ale również wymagają sensorów zapewniających dokładną orientację urządzenia pomiarowego względem kierunku geograficznego oraz pionu. W artykule przedstawiono projekt Bałtyckiej Sieci Punktów Referencyjnych oraz propozycje rozwiązań technologicznych do budowy urządzeń zapewniających quasi-absolutne pomiary pola magnetycznego na dnie morza.
Źródło:
Annual of Navigation; 2017, 24; 19-30
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the stationary magnetic field on the germination of wheat grain
Autorzy:
Kornarzynski, K.
Pietruszewski, S.
Powiązania:
https://bibliotekanauki.pl/articles/26469.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
magnetic field
wheat
wheat grain
magnetic biostimulation
seed
germination
Źródło:
International Agrophysics; 1999, 13, 4
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electric and magnetic field of different transpositions of overhead power line
Autorzy:
Deltuva, R.
Lukočius, R.
Powiązania:
https://bibliotekanauki.pl/articles/140665.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric and magnetic field strength
linear charge density
electric and magnetic
flux density
electric and magnetic field, power line
transposition
Opis:
In Lithuanian and Polish electric power supply systems, the power transmission lines of 400 kV voltage represent one of the most potential sources of electric and magnetic fields generation. The 400 kV double-circuit overhead power transmission line and its surrounding environment were herby described and simulated through Finite Element Method using COMSOL Multiphysic software package. This study includes magnetic and electric field calculations. The study shows that the values of magnetic field strength and electric field strength present in the vicinity of a 400 kV overhead power transmission line tend to exceed limit values established in the Normative. Measurements are suggested to be taken for the purpose of finding maximum values of magnetic and electric field strength. To reduce these values, it is recommended to increase the height of supports, and restrict human personal and economic activities.
Źródło:
Archives of Electrical Engineering; 2017, 66, 3; 595-605
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dydaktyka elektrotechniki. Magnetyczny Wszechświat
Autorzy:
Przytulski, A.
Powiązania:
https://bibliotekanauki.pl/articles/302397.pdf
Data publikacji:
2018
Wydawca:
Wydawnictwo Druk-Art
Tematy:
przestrzeń międzyplanetarna
pole magnetyczne Ziemi
pole magnetyczne Księżyca
interplanetary space
Earth's magnetic field
magnetic field of the moon
Opis:
Nie tylko Ziemia, ale także Słońce, planety, gwiazdy i całe galaktyki mają własne pola magnetyczne. Już w szesnastym wieku szwajcarsko-austriacki lekarz, alchemik, astrolog, mistyk i filozof Phillippus Aureolus Theophrastus Bombastus von Hohenheim, nazywany od 1529 roku Paracelsusem twierdził, że całe niebo wypełnione jest polem magnetycznym [1]. Jednak rola przypisywana istnieniu sił magnetycznych w tamtym czasie różniła się diametralnie od obecnego stanu wiedzy.
Źródło:
Napędy i Sterowanie; 2018, 20, 10; 108-111
1507-7764
Pojawia się w:
Napędy i Sterowanie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ pola magnetycznego niskiej częstotliwości stosowanego w magnetoterapii na zawartość interleukiny 6 (IL-6) w sercu i mózgu szczura
Influence of low frequency magnetic field used in magnetotherapy on interleukin 6 (IL-6) contents in rat heart and brain
Autorzy:
Ciejka, Elżbieta
Skibska, Beata
Gorąca, Anna
Powiązania:
https://bibliotekanauki.pl/articles/2164072.pdf
Data publikacji:
2017-06-27
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
szczury
mózg
interleukina
pole magnetyczne
terapia polem magnetycznym
serce
rats
brain
interleukin
magnetic field
magnetic field therapy
heart
Opis:
Wstęp Na działanie pól magnetycznych narażona jest coraz większa populacja ludzka. Wynika to zarówno z postępu technicznego i gospodarczego, jak i rozwoju nauk medycznych. Dlatego ważne jest dokładne poznanie i usystematyzowanie wiedzy w zakresie mechanizmów oddziaływania pola magnetycznego na organizmy żywe, dotyczy to zdrowia osób eksponowanych, narażonych na ich działanie. Celem pracy było zbadanie wpływu pola magnetycznego skrajnie niskiej częstotliwości (extremely low frequency magnetic field – ELFMF) na stężenie interleukiny 6 (IL-6) w sercu i mózgu szczura. Materiał i metody Materiał badawczy stanowiły szczury (Sprague-Dawley) podzielone na 3 grupy badawcze: I grupa – kontrolna, bez działania pola magnetycznego; II grupa – poddana działaniu bipolarnego, prostokątnego pola magnetycznego o częstotliwości 40 Hz i indukcji międzyszczytowej 7 mT, czas ekspozycji – 30 min/dzień przez 2 tygodnie; III grupa – poddana działaniu bipolarnego, prostokątnego pola magnetycznego o częstotliwości 40 Hz i indukcji międzyszczytowej 7 mT, czas ekspozycji – 60 min/dzień przez 2 tygodnie. U zwierząt oznaczono stężenia IL-6 po zakończeniu ekspozycji na pole magnetyczne. Wyniki Ekspozycja szczurów w ELFMF o parametrach: częstotliwość 40 Hz, indukcja międzyszczytowa 7 mT, przez 30 min/dzień przez 2 tygodnie spowodowała istotny statystycznie wzrost stężenia IL-6 w sercach w porównaniu z grupą kontrolną (p < 0,05) i nieistotne statystycznie obniżenie stężeń IL-6 w mózgach. Pole magnetyczne stosowane przez 60 min powodowało nieistotny statystycznie wzrost stężeń IL-6 w sercach w porównaniu z grupą kontrolną i istotne statystycznie obniżenie stężeń IL-6 w mózgach (p < 0,05). Wnioski Wpływ pola magnetycznego na stan zapalny w organizmie jest różny w zależności od czasu oddziaływania pola magnetycznego oraz tkanek czy komórek, na które działa. Med. Pr. 2017;68(4):517–523
Background The human population is exposed ever more frequently to magnetic fields (MF). This is due to both technological progress and development of the economy as well as to advances made in medical science. That is why the thorough understanding and systematized knowledge about mechanisms by which MF exerts its effects on living organisms play such an important role. In this context the health of MF-exposed people is the subject of particular concern. The aim of the study was to evaluate the effect of extremely low frequency magnetic field (ELFMF) used in magnetotherapy on the concentration of interleukin 6 (IL-6) in rat heart and brain. Material and Methods The male rats were randomly divided into 3 experimental groups: group I – control, without contact with magnetic field; group II − exposed to bipolar, rectangular magnetic field 40 Hz, induction “peak-to-peak” 7 mT 30 min/day for 2 weeks; and group III − exposed to bipolar, rectangular magnetic field 40 Hz, 7 mT 60 min/day for 2 weeks. Concentration of IL-6 in the heart and brain of animals was measured after MF exposure. Results Exposure to ELFMF: 40 Hz, induction “peak-to-peak” 7 mT 30 min/day for 2 weeks caused a significant IL-6 increase in rat hearts compared to the control group (p < 0.05) and a non-significant IL-6 decrease in rat brain. The magnetic field applied for 60 min resulted in non-significant IL-6 increase in rat hearts compared to the control group and significant IL-6 decrease in rat brain (p < 0.05). Conclusions The influence of magnetic field on inflammation in the body varies depending on the MF parameters and the affected tissues or cells. Med Pr 2017;68(4):517–523
Źródło:
Medycyna Pracy; 2017, 68, 4; 517-523
0465-5893
2353-1339
Pojawia się w:
Medycyna Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wzdłużne pole magnetyczne w szczelinie poprzecznego łożyska ślizgowego
Longitudinal magnetic field in the journal sliding bearing gap
Autorzy:
Frycz, M.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/189916.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
stacjonarne pole magnetyczne
ferrociecz
natężenie pola magnetycznego
obliczenia numeryczne
stationary magnetic field
ferrofluid
magnetic field's intensity
numerical calculations
Opis:
W pracy autorzy przedstawiają analityczno-numeryczną metodę wyznaczania składowych wektora natężenia pola magnetycznego w szczelinie walcowego łożyska ślizgowego. Zagadnienie to staje się istotne, gdy jako czynnik smarowy w łożysku ślizgowym zostanie zastosowana ferrociecz, na którą działa zewnętrzne pole magnetyczne. Wyznaczenie składowych wektora natężenia pola magnetycznego opiera się na analitycznym rozwiązaniu równań Maxwella, a następnie wyznaczeniu stałych całkowania poprzez symulację komputerową. Tak wyliczone numerycznie pole magnetyczne posłuży do dalszych obliczeń numerycznych, między innymi rozkładu ciśnienia hydrodynamicznego i siły tarcia w poprzecznym łożysku ślizgowym smarowanym ferrocieczą.
In this paper, the authors present analytical and numerical modelling of the components of the vector magnetic field’s induction in the journal sliding bearing gap. This issue becomes important when a lubricating agent containing a ferro-fluid in the journal sliding bearing gap is applied which affects the external magnetic field. Modelling components of the vector magnetic field’s induction is based on the analytical derivation of general solutions of Maxwell's equations, then the determination of the constants of the integration are made by computer simulation. So numerically calculated magnetic field to be used for further numerical calculations include hydrodynamic pressure distribution and friction forces in the journal sliding ferro-fluid lubricated bearings. The paper also presents the geometry of the sliding bearing with a coil that produces an external stationary magnetic field.
Źródło:
Tribologia; 2011, 6; 77-85
0208-7774
Pojawia się w:
Tribologia
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:
Magnetorheological fluids behaviour in oscillatory compression squeeze: experimental testing and analysis
Autorzy:
Horak, Wojciech
Szczęch, Marcin
Sapiński, Bogdan
Powiązania:
https://bibliotekanauki.pl/articles/386608.pdf
Data publikacji:
2019
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
magnetorheological fluid
oscillatory compression
magnetic field
squeeze force
Opis:
This article deals with experimental testing of magnetorheological fluid (MRF) behaviour in the oscillatory squeeze mode. The authors investigate and analyse the influence of excitation frequency and magnetic field density level on axial force in MRFs that differ in particle volume fraction. The results show that, under certain conditions, the phenomenon of self-sealing can occur as a result of the magnetic field gradient and a vacuum in the working gap of the system.
Źródło:
Acta Mechanica et Automatica; 2019, 13, 4; 221-225
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reflection of plane waves from a free surface of a generalized magneto-thermoelastic solid half-space with diffusion
Autorzy:
Singh, B.
Singh, L.
Deswal, S.
Powiązania:
https://bibliotekanauki.pl/articles/282051.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
generalized thermoelasticity
plane waves
reflection
magnetic field
diffusion
Opis:
Green-Naghdi’s theory of generalized thermoelasticity is applied to study the reflection of P and SV waves from the free surface of a magneto-thermoelastic solid half-space. The boundary conditions are satisfied by appropriate potential functions to obtain a system of four non-homogeneous equations in reflection coefficients. The reflection coefficients depend upon the angle of incidence of P and SV waves, magnetic field, thermal field, diffusion parameters and other material constants. The numerical values of the modulus of the reflection coefficients are shown graphically with the angle of incidence of P and SV waves. The effect of magnetic field is observed significantly on various reflected waves.
Źródło:
Journal of Theoretical and Applied Mechanics; 2014, 52, 2; 385-394
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using the EMTP/ATP program for calculation of electric and magnetic field distribution under overhead line
Autorzy:
Wiśniewski, J.
Anderson, E.
Karolak, J.
Powiązania:
https://bibliotekanauki.pl/articles/97319.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
EMTP-ATP program
PSCad
MATLAB Simulink
magnetic field
Opis:
This paper presents the method of calculation of the electric and magnetic fields under overhead transmission line with any number of circuits, phase positions, voltages and current loads. Calculations of this type usually require specialized and costly programs. The program EMTP/ATP is a royalty free tool to calculate the electric transient and steady states in complex power systems. You can use this program and through appropriate modeling the multi-phase wire system representing the line and measurement device calculate the strength of the electric and magnetic fields. The results of calculations are characterized by a very small error compared to the results obtained by using the specialized commercial program. This method can be used with other popular engineering tools like Matlab/Simulink or PSCad.
Źródło:
Computer Applications in Electrical Engineering; 2012, 10; 98-106
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship’s de-perming process using coils lying on seabed
Autorzy:
Wołoszyn, Mirosław
Jankowski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/221088.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic field
ship
de-perming
energy de-perming
Opis:
A ship built from ferromagnetic steel disturbs the uniformity of the Earth’s magnetic field. Changes of ship’s signature are due to the magneto-mechanical interaction of the hull with the Earth’s magnetic field. The ship’s magnetic field can be detected by a magnetic naval mine. For this reason, the vessel has to be demagnetized. There are several methods of ship’s de-perming. The results of experimental and computer simulations of the ship’s de-perming process using coils lying on the seabed are presented in this paper. The simulation of the de-perming process with a hysteresis model of ship’s steel was carried out in Opera-3d 18R2. The laboratory experiments were carried out using a physical ship’s model, several Helmholtz coils, magneto-resistive sensors, etc. The experiments and computer simulations have shown that ship’s de-perming with coils lying on the seabed is possible. The values of coil currents are over dozen times greater than those used in the standard method.
Źródło:
Metrology and Measurement Systems; 2019, 26, 3; 569-579
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study and mathematical modeling of the residence time distribution in magnetic mixer
Autorzy:
Rakoczy, R.
Kordas, M.
Grądzik, P.
Konopacki, M.
Story, G.
Powiązania:
https://bibliotekanauki.pl/articles/778204.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
mixing model
residence time distribution
modelling
magnetic field
Opis:
This study reports on research results in the field of a mixing process under the action of a transverse rotating magnetic field (TRMF). The main objective of this paper is to present the effect of this type of a magnetic field on residence time distribution (RTD) measurements. This paper evaluates the performance of a magnetic mixer by comparing the results of an experimental investigations in a pilot set-up and theoretical values obtained from mathematical model. This model consisting of the set of ideal continuous stirred tank reactors (CSTR) fitted well the experimental data.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 2; 53-60
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Tool Magnetization on Changes in the Surface Layer of Forging Tools
Autorzy:
Zwierzchowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/351493.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot die forging
wear mechanism
magnetic field
durability
Opis:
The paper presents a description of the phenomena occurring on the surface of the forging dies. A detailed analysis was made of 24 pre-forging dies due to the most intensive wear in this operation. To compare the results, new tools were also analysed. The research described in the study showed that the most dangerous factor for the hot forging process analysed is thermal-mechanical fatigue, which causes small cracks, which in turn quickly leads to the formation of a crack network on the entire contact surface of the tool with forged material. The second phenomenon is the tempering of the surface of the material for a long-term temperature effect. The presence of hard iron oxides in the form of scale from forging material is the accompanying phenomenon that intensifies the processes of tool wear. The paper presents the results of the analysis of the presence of residual magnetic field for forging tools and the results of laboratory tests of wear processes of tool steels for hot work in the presence of a magnetic field and in the presence of scale.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 317-324
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Use of Activated Alumina and Magnetic Field for the Removal Heavy Metals from Water
Autorzy:
Szatyłowicz, E.
Skoczko, I.
Powiązania:
https://bibliotekanauki.pl/articles/125318.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
activated alumina
magnetic field
water treatment
heavy metals
Opis:
The objective of this work was to verify the granular activated alumina (AA) sorption properties, during the process of removing copper, lead and cadmium from water, and to monitor the impact of magnetic field (MF) on the effectiveness of removing copper, lead and cadmium from water. Activated alumina adsorption is known to be an effective and inexpensive technology for the removal of selenium and arsenic from water, and was suggested by EPA as a BAT for point-of-use applications. The removal of copper, lead and cadmium from water using AA and impact of magnetic field was reported to a lesser extent. Pilot tests showed that the use of AA sorption materials with MF impact could possibly decrease the copper, lead and cadmium content in the model water. The MF also had a positive effect on the efficiency of removal copper, lead and cadmium on AA. Increasing the efficiency of heavy metals removal in the samples exposed to magnetic field varied from 1.9% to 8.2% compared to the control samples.
Źródło:
Journal of Ecological Engineering; 2018, 19, 3; 61-67
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the residual magnetic field measurement system for early identification of railway defects
Autorzy:
Rucki, Mirosław
Gockiewicz, Anna
Szumiata, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/220497.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
residual magnetic field
measurement
rail inspection
uncertainty
repeatability
Opis:
The paper presents research on the capability of the residual magnetic field (RMF) measurement system to be applied to the railway inspection for the early non-destructive detection of defects. The metal magnetic memory (MMM) phenomena are analysed using normal component Hy of self-magnetic flux leakage (SMFL), and its tangential component Hx, as well as their respective gradients. The measurement apparatus is described together with possible factors that may affect the results of measurement. The Type A uncertainty estimation and repeatability tests were performed. The results demonstrate that the system may be successfully applied to detection of head check flaws.
Źródło:
Metrology and Measurement Systems; 2019, 26, 4; 687-696
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Analysis of the Prospects of the Use of Magnetic Water Treatment in Foundry Engineering
Autorzy:
Dan, Leonid
Trofimova, Larysa
Powiązania:
https://bibliotekanauki.pl/articles/24201265.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
water
magnetic field
magnetic water treatment
molding sand
green strength
Opis:
Scientists are currently focused on creating technologies that produce positive results without affecting the environment. One such technology is magnetic water treatment. In this paper, an analytical review of publications devoted to the application of magnetic treatment of water in various branches of engineering, agriculture, and medicine is carried out. Current views on the structure of water molecules, as well as the theories explaining the influence of the magnetic treatment of water on its properties, are reviewed. The results of studies of the influence of water treated by a magnetic field on the properties of molding sand are analyzed, including those in which the authors of the article took part. It is shown that the magnetic treatment of still water can increase the green strength of the molding sand containing this water from 0.035 to 0.052 MPa, and that of water in motion to 0.075 MPa. Thanks to this, the amount of binder in the molding sand can be reduced. It is concluded that the use of magnetically treated water in foundries is promising.
Źródło:
Journal of Casting & Materials Engineering; 2023, 7, 2; 22--26
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Penetrative convection due to absorption of radiation in a magnetic nanofluid saturated porous layer
Autorzy:
Mahajan, Amit
Sharma, Mahesh Kumar
Powiązania:
https://bibliotekanauki.pl/articles/178577.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnetic nanofluids
penetrative convection
Darcy model
radiation absorption
magnetic field
Opis:
The present study investigates the onset of penetrative convection induced by selective absorption of radiation in a magnetic nanofluid saturated porous medium. The influence of Brownian motion, thermophoresis, and magnetophoresis on magnetic nanofluid treatment is taken into consideration. The Darcy’s model is selected for the porous medium. We conduct a linear stability analysis to examine the onset of instability and evaluate the results for two different configurations, namely, when the layer is heated from below and when the layer is heated from above. The numerical investigations are carried out by applying the Chebyshev pseudospectral method. The effect of the porosity parameter E, parameter Y (represents the ratio of internal heating to boundary heating), Lewis number Le, concentration Rayleigh number Rn, Langevin parameter αL, width of nanofluid layer d, diffusivity ratio η, and modified diffusivity ratio NA is examined at the onset of convection. The results indicate that the convection commences easily with an increase in the value of Y, Le, and NA but opposite in the case with a decrease in the value of E, αL, η and d for both the two configurations. The parameter Rn advances the onset of convection when the layer is heated from below, while delays the onset of convection when the layer is heated from above.
Źródło:
Studia Geotechnica et Mechanica; 2019, 41, 3; 129-142
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the influence of catastrophes on human vital activity
Issledovanie vlijanija katastrof na zhiznedejatel'nost' cheloveka
Autorzy:
Maletkin, V.
Druz, O.
Maletkina, L.
Powiązania:
https://bibliotekanauki.pl/articles/792498.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
vital activity
catastrophe
magnetic field
safety
man
magnetic storm
investigation
Opis:
The analysis of the sources of catastrophes taking place on the Earth and influencing human vital activity has been done in this article.
Рассматриваются проблемы курсовой устойчивости движения автомобиля. В работе анализируется смена свойств управляемости на основе анализа нелинейной велосипедной модели, которая учитывает не линейность сил бокового увода. Получена обобщенная зависимость, определяющая «кривую управляемости». Проанализированы условия потери устойчивости для случая движения с возрастающей скоростью по окружности постоянного радиуса на основе построения бифуркацио нного множества.
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 3
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Miniaturowe, dwuosiowe czujniki pola magnetycznego - z rdzeniami z magnetyków amorficznych
Miniaturized, two axis magnetic field sensors with amorphous alloy cores
Autorzy:
Frydrych, P.
Szewczyk, R.
Salach, J.
Trzcinka, K.
Powiązania:
https://bibliotekanauki.pl/articles/277226.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
czujniki pola magnetycznego
anizotropia magnetyczna
magnetic field sensors
magnetic anisotropy
Opis:
W artykule przedstawiono koncepcję budowy dwuosiowych, transduktorowych czujników pola magnetycznego z rdzeniami z taśmy amorficznej. Jednocześnie przedstawiono nowatorską metodę kształtowania i badania charakterystyk magnesowania rdzeni ramkowych z taśmy amorficznej, wykorzystywanych jako rdzenie badanych czujników. Metoda ta umożliwia pomiar anizotropii magnetycznej rdzenia. Informacja o wartości anizotropii jest niezbędna przy budowie czujników dwuosiowych, a opisane do tej pory metody nie umożliwiały tego typu pomiarów.
Paper presents new conception of two-axis, fluxgate magnetic field sensors for measurements of Earth's magnetic field. Developed sensors utilizes soft amorphous alloys. Moreover paper presents new methodology of shaping and testing of magnetic characteristics of frame-shaped amorphous alloys cores utilized in such sensors. Presented methodology of testing enables direct measurements of magnetic anisotropy of amorphous alloy, what is required for development of two-axis fluxgate sensors.
Źródło:
Pomiary Automatyka Robotyka; 2011, 15, 2; 766-773
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multisource model of ship electric field
Autorzy:
Jakubiuk, K.
Zimny, P.
Wołoszyn, M.
Powiązania:
https://bibliotekanauki.pl/articles/97439.pdf
Data publikacji:
2011
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field of the ship
mine protection
BEM
Opis:
A steel-hulled ship in sea water produces an electric field around itself. The source of this field are electrochemical processes and ship’s cathodic protection. The analysis of the electric field around the ship is important by the reason of the ship’s identification and counter-mine protection. The paper presents a simplified model of the ship’s multisource electric field, which allows to calculate the electric field distribution in the so-called distant zone around the ship in an approximate way using a PC, during time lasting from few up to several dozen of minutes.
Źródło:
Computer Applications in Electrical Engineering; 2011, 9; 78-84
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of the finite element method equations conditioning for the magnetic field-circuital problems
Autorzy:
Gołębiowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/141457.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic field-circuital problem
condition number
iterative method
Opis:
The presented systems with magnetically coupled windings are solved with the finite element method. If the issue of voltage supply is analyzed, a system of linear equations with a partially skew-symmetric sparse matrix is obtained. Iterative methods used to solve a system of equations are particularly effective for symmetric matrices. Resultant equations can be reduced to this symmetrical form by using the method known from the literature [1]. The ratio of the maximum to the minimum eigenvalue of the main matrix of this circuit, which is the condition number, is however very high. This means that the problem is ill-conditioned and leads to a very long iterative solution process. The method presented in the article allows for a direct solution of a system of equations on its part, corresponding to high eigenvalues of the system matrix. The remaining part of the system of equations is solved by iterative methods. This part has much better condition number, and therefore the computational process is fast. The proposed iterative process depends on multiplication of a sparse matrix by vectors. It is not necessary (and possible) to store the entire matrix. This is especially important for larger sizes of a matrix.
Źródło:
Archives of Electrical Engineering; 2017, 66, 2; 325-337
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stiffness and damping characteristics of MR fluid-based sandwich beams: experimental study
Autorzy:
Romaszko, M.
Sapiński, B.
Powiązania:
https://bibliotekanauki.pl/articles/281768.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
magnetorheological fluid
beam
magnetic field
vibration
stiffness
damping
Opis:
The study investigates the behaviour of three-layered cantilever sandwich beams filled with magnetorheological fluids (MRFs) differing in the iron particle content by volume. Outer layers are made of aluminium, the space between them is sealed with silicone rubber. Two types of beams are considered: fully filled beams and partially filled beams, subjected to the magnetic field. The aim of the study is to determine stiffness and damping characteristics in relation to the magnetic field strength and the actual location where the magnetic field acts upon the beam. For this purpose, measurements have been taken of the beam free vibration response for various magnetic field strength levels and for various positions of the electromagnet located along the beam axis. Basing on the developed measurement data processing algorithm, the influence of the vibration amplitude on the natural frequency and a dimensionless damping coefficient have been determined. Finally, the equivalent natural frequency and the dimensionless damping coefficient have been derived accordingly, and the stiffness and damping ratio have been determined in function of the magnetic field strength, the electromagnet position and the MRF iron particle content by volume.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 3; 571-583
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of the Pulsed High Magnetic Field on Fusarium culmorum (W.G. Smith) Sacc
Wpływ impulsowego, wysokiego pola magnetycznego na Fusarium culmorum (W.G. Smith) Sacc
Autorzy:
Gorczyca, A.
Janas, P.
Kasprowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/388653.pdf
Data publikacji:
2011
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
impulsowe pole magnetyczne
F. culmorum
pulsed magnetic field
Opis:
The aim of the investigations was an assessment of the impact of the pulsed high magnetic field on a concentrated spore suspension of F. culmorum fungus, which is a dangerous pathogen of many crops. 5, 10, 15 and 20 pulses of 9 Tesla induction were applied. The pulsed magnetic field limited germination of the tested strain. A significant difference was found for 15 and 20 pulses. Mycelial linear growth was also reduced, as was found both for the inoculation and logarithmic phase of growth in Petri dish culturing, however, no limited mycelium sporulation was observed. There is a potential for the application of the tested physical method – the pulsed high magnetic field to limit the development and harmfulness of F. culmorum.
Celem przeprowadzonych badań była ocena wpływ impulsowego, wysokiego pola magnetycznego na skoncentrowaną zawiesinę zarodników grzyba F. culmorum, groźnego patogena wielu roślin uprawnych. Zastosowano 5, 10, 15 i 20 impulsów pola magnetycznego o indukcji 9 Tesli. Impulsowe pole magnetyczne ograniczyło kiełkowanie badanego szczepu. Istotną różnicę stwierdzono dla 15 i 20 impulsów. Wzrost liniowy grzybni również ulegał ograniczeniu, co stwierdzono zarówno dla inokulacji, jak i fazy logarytmicznej wzrostu w hodowli szalkowej. Nie zaobserwowano jedynie ograniczenia sporulacji grzybni. Istnieje możliwość wykorzystania testowanej metody fizycznej - impulsowego wysokiego pola magnetycznego - do ograniczania rozwoju i szkodliwości F. culmorum.
Źródło:
Ecological Chemistry and Engineering. A; 2011, 18, 11; 1477-1484
1898-6188
2084-4530
Pojawia się w:
Ecological Chemistry and Engineering. A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic field simulation in the central region of the VINCY Cyclotron
Autorzy:
Vorojtsov, S.
Vorozhtsov, A.
Nešković, N.
Ristić -Durović, J.
Ćirković, S.
Vujović, V.
Powiązania:
https://bibliotekanauki.pl/articles/148735.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cyclotron
central region
magnetic field
plug
beam dynamics
Opis:
The VINCY Cyclotron is under construction at the Vinca Institute of Nuclear Sciences, Laboratory of Physics, Belgrade, Serbia and Montenegro. One of the most difficult problems to solve is the magnetic field shaping in the central region of the machine in a wide range of field levels. The latest measurements showed a very large magnetic field depression in the central region. The following shimming elements are used for the field shaping in the central region: a central plug and a spacer ring between the sectors and the median pole plate. These elements should both release enough vertical space for the inflector and the RF electrodes and produce a field bump in the very center of the machine. Concerning this region, one has to mention the following facts: sectors are absent or very reduced, and the small gap between the sectors restricts remarkably the possibilities of producing a field bump. Therefore, the design of these elements is the most critical one. Optimization of the central plug gap affects both the vertical sparking probability and the beam dynamics at higher harmonic modes. The redesign of the magnetic structure of the central region relied solely on the detailed 3-dimensional calculations to speed up the experimental shimming procedure. The desired calculated magnetic field shapes, which include the influence of the plug, have been produced and confirmed
Źródło:
Nukleonika; 2003, 48,suppl.2; 39-44
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Separation of Ho3+ in Static Magnetic Field
Autorzy:
Kołczyk, K.
Wojnicki, M.
Kutyła, D.
Kowalik, R.
Żabiński, P.
Cristofolini, A.
Powiązania:
https://bibliotekanauki.pl/articles/355096.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rare earth metals
REE
recycling
separation
magnetic field
Opis:
The rare earths elements (REE) belong to the group of critical metals and they are achieving more and more interest due to their special properties. However, there occur some problems connected with their production. The most difficult phase is separation of REE. It includes a necessity to intensify currently applied processes and looking for new solutions. The present work introduces an idea to use differences in physical properties of the REE ions to get them separated. In the experimental part of the work some efforts were undertaken to analyse results presenting changes of holmium ions concentration under an influence of the magnetic field gradient. There was determined the gradient of magnetic field and concentration of Ho3+ ions depending on initial concentration of the solution and time. A simulation of changing the concentration of holmium ions in the solution under an influence of the magnetic field gradient was performed to compare the mathematical model with the obtained results.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 1919-1924
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transduktorowe czujniki pola magnetycznego - przegląd rozwiązań i prace własne
Magnetic field fluxgate-based sensors - survey of solutions and own works
Autorzy:
Moskowicz, S.
Powiązania:
https://bibliotekanauki.pl/articles/157104.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
czujnik transduktorowy
pole magnetyczne
fluxgate
magnetic field sensors
Opis:
Transduktorowe czujniki pola magnetycznego wykorzystuje się do pomiarów słabych stałych i wolnozmiennych pól magnetycznych od lat dwudziestych XX wieku. W ich ponad osiemdziesięcioletniej historii opracowano i opracowuje się nadal wiele różnych konstrukcji czujników. W artykule, w oparciu literaturę i badania własne, przedstawiono przegląd stosowanych rozwiązań oraz współczesne konstrukcje czujników.
Magnetic field fluxgate-based sensors have been used to measure weak, constant and slowly varying magnetic fields since the 1920s. Many different constructions of these sensors have been worked out up to now. Basing on the literature and the research work performed by the author, the paper presents a survey of the employed solutions and modern constructions of the sensors.
Źródło:
Pomiary Automatyka Kontrola; 2008, R. 54, nr 12, 12; 839-841
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrochemical deposition of cobalt-nickel coatings in a constant magnetic field
Autorzy:
Miękoś, Ewa
Klepka, Tomasz
Zieliński, Marek
Sroczyński, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/2146891.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cobalt-nickel coatings
constant magnetic field
electrochemical deposition
Opis:
The electrochemical deposition of Co-Ni coatings on gold-disc electrode with and without of constant magnetic field (CMF) has been investigated using cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The EDX results showed that CMF applied during the electrodeposition of Co-Ni coatings affects their composition. In particular, an increase by 17% in the content of cobalt in coating, i.e. the main component, with a simultaneous decrease of nickel content has been observed when magnetic induction B of 1200 mT was applied compare to this without of CMF. Moreover, it has been supposed that the increase of internal stresses in electrodeposited Co-Ni coatings under CMF can be attributed to a decrease in their thickness.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 2 (Special issue - selected papers conference: Physicochemistry of interfaces - instrumental methods); art. no. 146066
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Establishing and characterizing a permanent magnet system for the prototype of NISs Kibble balance
Autorzy:
Emira, Sayed
Shaaban, E. R.
Rashad, M. M.
Gelany, Shaker A.
Powiązania:
https://bibliotekanauki.pl/articles/2203366.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Kibble balance
Planck constant
magnet system
magnetic field
Opis:
The Kibble balance experiment is used to redefine the kilogram as a unit of mass based on the Planck constant. To demonstrate and understand the basic principle of the Kibble balance, the National Institute of Standards (NIS)-Egypt has constructed a prototype Kibble balance that can measure gram-level masses with 0.01% relative uncertainty. Through the construction of this prototype, the challenges can be studied and addressed to overcome the weaknesses of NIS’s prototype. This study presents the design and construction of the prototype Kibble balance. It also focuses on the design and performance of the magnetic system, which is a crucial element of the Kibble balance. Analytical modeling and finite element analysis were used to evaluate and improve the magnet system. Several other aspects were also discussed, including the yoke’s material and enhancing the magnetic profile within the air gap of the magnet system. Over a vertical distance of 30 mm inside the air gap, the magnetic flux density was found to be 0.3 T, and the uniformity was found to be 8 x 10-5.
Źródło:
Metrology and Measurement Systems; 2023, 30, 1; 3--16
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximate BEM analysis of time-harmonic magnetic field due to thin-shielded wires
Przybliżona analiza harmonicznego pola magnetycznego od przewodów umieszczonych w cienkościennej osłonie za pomocą zhybrydyzowanej metody elementów brzegowych
Autorzy:
Jabłoński, P.
Powiązania:
https://bibliotekanauki.pl/articles/376630.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
time-harmonic magnetic field
electromagnetic field
BEM
boundary element method
Opis:
Analysis of electromagnetic field of filamentary parallel wires with time-harmonic currents enclosed with a thin conductive shield is considered in this paper. The model uses the boundary element method (BEM), but the thin shell is treated specially by using an approximate quasi-analytical solution. Such an approach allows avoiding some numerical troubles connected with the small thickness of the layer, and leads to a system of equations with fewer unknowns when compared to the conventional BEM. Numerical tests confirm its usability in the considered class of problems.
Praca dotyczy analizy harmonicznego pola magnetycznego od długich, równoległych, cienkich przewodów umieszczonych w cienkościennej przewodzącej osłonie. Zaproponowany model wykorzystuje metodę elementów brzegowych (MEB), ale pole w cienkiej osłonie modelowane jest w sposób przybliżony za pomocą zależności półanalitycznej. Takie podejście pozwala uniknąć pewnych kłopotów numerycznych związanych z małą grubością warstwy, a ponadto prowadzi to układu równań z mniejszą liczbą niewiadomych w porównaniu z tradycyjną MEB. Numeryczne testy potwierdzają jego użyteczność w rozpatrywanej klasie zagadnień.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 69; 57-64
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Equation of the magnetic field distribution of dynamo sheets taking into account crystallographic structure
Autorzy:
Mazgaj, Witold
Szular, Zbigniew
Sierżęga, Michał
Szczurek, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/140486.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
crystallographic texture
dynamo steel sheet
iron crystal
magnetic anisotropy
magnetic field
Opis:
The main purpose of the paper is to present a method which allows taking into account the anisotropic properties of dynamo steel sheets. An additional aim is to briefly present anisotropic properties of these sheets which are caused by occurrences of some textures. In order to take into account textures occurring in dynamo sheets, a certain sheet sample is divided into elementary segments. Two matrix equations, describing changes of the magnetic field, are transformed to one non-linear algebraic equation in which the field strength components are unknown. In this transformation the flux densities assigned to individual elementary segments are replaced by functions of flux densities of easy magnetization axes of all textures occurring in the given dynamo sheet. The procedure presented in the paper allows determining one non-linear matrix equation of the magnetic field distribution; in this equation all textures occurring in a dynamo sheet are included. Information about textures occurring in typical dynamo sheets may be used in various approaches regarding the inclusion of anisotropic properties of these sheets, but above all, the presented method can be helpful in calculations of the magnetic field distribution in anisotropic dynamo sheets.
Źródło:
Archives of Electrical Engineering; 2019, 68, 1; 185-194
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geophysical cartography in Poland : an overview
Autorzy:
Krzywiec, P.
Nawrocki, J.
Polechońska, O.
Wróblewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/2065895.pdf
Data publikacji:
2005
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
geophysical cartography
seismic data
magnetic field
gravity field
thermal field
petrophysical parameters
Opis:
Regional analysis and mapping of various geophysical data has been recognized as an important — even crucial — element of geological studies for many years. Due to rapid development of advanced numerical tools it is presently possible to construct, maintain and comprehensively analyse even very large geo-databases, including seismic, gravity, magnetic, geothermal and other geophysical data. In many countries, national geological surveys, commercial companies and research institutions are involved in mapping projects focused on spatial representation of geophysical data that could later be used for various studies. Recently, new policy of the Polish Ministry of Environment regarding geological cartography in years 2005–2020 has been declared (cf. Ber & Jezierski, 2004). In this document, geological cartography is used as a rather wide term that includes also other geo-disciplines like geoenvironmental studies or surface geochemistry. Among them, mapping of geophysical data is also mentioned. In this paper, short overview of the current state-of-the-art of selected aspects of regional geophysical mapping in Poland is given, with some remarks regarding potential directions of future work.
Źródło:
Przegląd Geologiczny; 2005, 53, 10/2; 967-972
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear stability analysis for ferromagnetic fluids in the presence of magnetic field, compressibility, internal heat source and rotation through a porous medium
Autorzy:
Kumar, K.
Singh, V.
Sharma, S.
Powiązania:
https://bibliotekanauki.pl/articles/279562.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
ferrofluids
rotation
magnetic field
porous medium
heat source
compressibility
Opis:
The effects of magnetic field and heat source strength on thermal convection of a compressible rotating ferromagnetic fluid through a porous medium are investigated theoretically using linear stability theory. A normal mode analysis method is employed to find solutions for the fluid layer confined between parallel planes with free boundaries. The cases of stationary and oscillatory instabilities are discussed. For the stationary state, compressibility, medium porosity and temperature gradient due to heat source have destabilizing effects, whereas rotation and ratio of magnetic permeability delay the onset of convection. The magnetic field and medium permeability have both stabilizing and destabilizing effects under certain conditions. The variations in the stationary critical thermal Rayleigh number and neutral instability curves in (Ra1, x)-plane for various values of physical parameters are shown graphically to depict the stability characteristics. The sufficient conditions for the non-existence of overstability are obtained and the principle of exchange of stabilities holds true in the absence of magnetic field and rotation under certain conditions.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 4; 1067-1081
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:
The effect of Ti content on α martensite phase transformation, and magnetic properties by Mössbauer spectroscopy in Fe-30%Ni-x%Ti (wt%) alloys
Autorzy:
Yaşar, E.
Erdem, U.
Akif Tuna, M.
Armağan, O.
Kırındı, T.
Powiązania:
https://bibliotekanauki.pl/articles/1050927.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
martensitic transformation
Mössbauer spectroscopy
isomer shift
internal magnetic field
Opis:
In this study, the influence of Ti content on the microstructure of the martensite bcc α'), which was formed by thermal effect, was investigated by scanning electron microscope and transmission electron microscope observations, in Fe-30Ni-xTi (x=0.8, 1.8, 2.6) alloys. The crystallographic orientation relationship between austenite fcc (γ) and thermally induced bcc (α') martensite was found to be as (111)_{γ}/(011)_{α} (Kurdjumov-Sachs (K-S)), by the electron diffraction analysis. The martensitic transformation temperature (M_{s}) of α' martensite was determined as -41°, -62°, and -76 ° in the alloys with 0.8%, 1.8%, and 2.6% Ti concentration, respectively. The Mössbauer spectrometer analysis has been revealed by a paramagnetic character for the austenite phase and magnetically order character for α' martensite phase. Hyperfine magnetic field, isomer shift and volume fractions of phases were determined by the Mössbauer spectroscopy.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1165-1169
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza oddziaływań indukcyjnych pola magnetycznego na ekrany torów wielkoprądowych w układzie płaskim
Analysis of the induction of the magnetic field on the screens of large current tracks in the flat arrangement
Autorzy:
Leśniak, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2031412.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
pole magnetyczne
model
tor prądowy
magnetic field
current paths
Opis:
W artykule dokonano graficznej interpretacji pola magnetycznego w żyłach powrotnych wybranego kablowego toru prądowego, przy wykorzystaniu oprogramowaniu komercyjne Ansoft Maxwell. W aspekcie omawianej problematyki, wyznaczenie rozkładu pola magnetycznego w modelu odwzorowującym przekrój prostokątny toru prądowego - w skrócie „PTP”, warunkuje prawidłowy opis skorelowanych z nim zjawisk wtórnych. Zaliczamy do nich m.in. naprężenia cieplne lub mechaniczne, przyspieszające proces starzenia, powodujący powstawanie strat w przesyle energii elektrycznej lub uszkodzenia kabli elektroenergetycznych. W artykule odzwierciedlono ważne aspekty poruszanej problematyki w sposób poglądowy, tzn. na przykładzie obliczeniowym. Z uwagi na obszerność poruszanego zagadnienia, na tym etapie pominięto jego analityczny aspekt.
The paper deals with effects of three phase current flow in screened high-current tracks. The problems related to the analysis of separate phase magnetic field and its influence on the screening elements of the configuration have been considered. Special attention has been paid to the modeling of magnetic field in the screens of flat configuration. The results of quantitative field analysis have been presented and the graphical interpretation of these results has been performed. Some more significant observations have been specified.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2021, 73; 53--56
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of laser and variable magnetic field simulation on amaranth seeds germination
Autorzy:
Dziwulska-Hunek, A
Kornarzynski, K.
Matwijczuk, A.
Pietruszewski, S.
Szot, B.
Powiązania:
https://bibliotekanauki.pl/articles/26336.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
laser
magnetic field
simulation
amaranth
seed germination
germination temperature
Źródło:
International Agrophysics; 2009, 23, 3; 229-235
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of magnetic field irradiation on broccoli seed with accelerated aging
Wpływ działania pola magnetycznego na przyspieszenie starzenia się nasion brokuła
Autorzy:
Martinez, F.R.
Pacheco, A.D.
Aguilar, C.H.
Pardo, G.P.
Ortiz, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/36962.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
magnetic field
irradiation
broccoli
seed
aging
physiological quality
biostimulation
Opis:
In order to improve the physiological quality of aged broccoli seed (Brassica oleracea var. Waltham29), in this study a variable magnetic field (VMF) of 3.6 mT, 60 Hz by 5min was used as pre-sowing treatment. The accelerated aging treatment was applied for 0, 48 and 72 h (AA0h, AA48h and AA72h) and then the VMF treatment, under a randomised complete block design with 4 replications of 30 seeds. For seeds aged for 72 h a final germination of 20% was obtained, whereas without magnetic stimulation it was null. However, the magnetic bio-stimulation in 48 h aged seeds was significantly negative, reducing the final germination by 45.83% compared to the treatment without magnetic field, while the VMF effects in unaged seed were zero. The variable magnetic field effects depended on the seed aging time, resulting in positive, negative and null outcomes (responses) in vigour variables.
W celu uzyskania poprawy właściwości fizjologicznych nasion brokuła (Brassica oleracea var. Waltham 29) poddanych przyspieszonemu starzeniu, zastosowano przedsiewne zmienne pole magnetyczne (VMF) o wartości 3,6 mT, 60 Hz przez 5 min. Proces przyspieszonego starzenia prowadzono przez 0, 48 and 72 h (AA0h, AA48h i AA72h), po czym nasiona poddawano działaniu VMF. Badanie prowadzono metodą bloków losowych w 4 powtórzeniach po 30 nasion. Przyspieszone starzenie przez 72 godziny spowodowało wzrost wskaźnika kiełkowania nasion o 20%, podczas gdy dla próby bez działania pola magnetycznego wynik był zerowy. W przypadku nasion poddanych starzeniu przez 48 godzin efekt stymulacji magnetycznej był negatywny, powodując spadek końcowego wskaźnika kiełkowania o 45,83% w porównaniu do wariantu bez pola magnetycznego. Dla nasion niepoddawanych starzeniu wpływ działania VMF był zerowy. Wpływ działania zmiennego pola magnetycznego na nasiona był uzależniony od czasu starzenia nasion, powodując pozytywne, negatywne lub zerowe zmiany w wartościach wskaźników ich wigoru.
Źródło:
Acta Agrophysica; 2014, 21, 1
1234-4125
Pojawia się w:
Acta Agrophysica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the screen thickness on the total magnetic field of a double-pole bifilar high-current busduct
Autorzy:
Kusiak, D.
Piątek, Z.
Szczegielniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/97205.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
tubular screen
high-current busduct
magnetic field
tubular conductor
Opis:
In the paper shown the impact of the screen thickness on the total magnetic field of a double-pole bifilar line in the screen and its immediate vicinity. The resultant magnetic field in the high-current busduct of this type has two components of different amplitudes and initial phases. As a consequence this field is elliptical. This phenomenon has been described with the formulas relevant to the relative values of the field and the parameters allowing the frequency, conductivity, and the cross-section dimensions of screen. Into account was taken skin, internal and external proximity effects. These phenomena have a strong impact on the magnetic field in the environment of two-conductor shielded highcurrent busduct and should be taken into consideration also for the industrial frequency of phase currents.
Źródło:
Computer Applications in Electrical Engineering; 2013, 11; 73-82
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature error of Hall-effect and magnetoresistive commercial magnetometers
Autorzy:
Nowicki, M.
Kachniarz, M.
Szewczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/141287.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic field measurement
magnetometers
Hall-effect
magnetoresistive
temperature error
Opis:
The paper presents a special measurement system for investigation of temperature influence on the indication of commercially available sensors of the magnetic field. Utilizing the developed system, several magnetoresistive and Hall-effect sensors were investigated within the temperature range from –30°C to 70°C. The obtained results indicate that sensitivity of most of the investigated sensors is unaffected, except the basic magnetoresistive device. However, Hall-effect sensors exhibit considerable temperature drift, regardless of the manufacturer.
Źródło:
Archives of Electrical Engineering; 2017, 66, 3; 625-630
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of coefficients of multivariable power series approximating magnetic nonlinearity of AC machines
Autorzy:
Sobczyk, T. J.
Warzecha, A.
Powiązania:
https://bibliotekanauki.pl/articles/141620.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetism
magnetic field co-energy
mathematical modelling
parameters estimation
Opis:
Energy based approach was used in the study to formulate a set of functions approximating the magnetic flux linkages versus independent currents. The simplest power series that approximates field co-energy and linked fluxes for a two winding core of an induction machine are described by a set of common unknown coefficients. The authors tested three algorithms for the coefficient estimation using Weighted Least-Squared Method for two different positions of the coils. The comparison of the approximation accuracy was accomplished in the specified area of the currents. All proposed algorithms of the coefficient estimation have been found to be effective. The algorithm based solely on the magnetic field co-energy values is significantly simpler than the method based on the magnetic flux linkages estimation concept. The algorithm based on the field co-energy and linked fluxes seems to be the most suitable for determining simultaneously the coefficients of power series approximating linked fluxes and field co-energy.
Źródło:
Archives of Electrical Engineering; 2015, 64, 3; 379-389
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The onset of thermal convection in couple-stress fluid in hydromagnetics saturating a porous medium
Autorzy:
Rana, G. C.
Powiązania:
https://bibliotekanauki.pl/articles/201216.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
couple stress fluid
magnetic field
porous medium
thermal convection
Opis:
In this paper, the effect of magnetic field on thermal convection in couple-stress fluid saturating a porous medium is considered. By applying linear stability theory and the normal mode analysis method, a mathematical theorem is derived which states that the viscoelastic thermal convection at marginal state, cannot manifest as stationary convection if the thermal Rayleigh number R, the medium permeability parameter Pι the couple-stress parameter F and the Chandrasekher number Q, satisfy the inequality R ≤4π2/Pl (1 + 2π2F + PlQ/2ε) the result clearly establishes the stabilizing character of couple-stress parameter and magnetic field whereas destabilizing character of medium permeability.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 2; 357-362
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magneto-thermoelastic problem in the context of four theories under influence of laser pulse and gravity field
Autorzy:
Abo-Dahab, Sayed
Abd-Alla, Abdelmooty
Alqarni, Abdelkalk
Powiązania:
https://bibliotekanauki.pl/articles/240083.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
generalized thermoelasticity
gravity
laser pulse
magnetic field
half-space
Opis:
The paper is devoted to study the effect of gravity, magnetic field and laser pulse on the general model of the equations of generalized thermoelasticity for a homogeneous isotropic elastic half-space. The formulation is applied under four theories of generalized thermoelasticity: the coupled theory, Lord-Schulman theory, Green-Lindsay theory as well as Green-Naghdi theory. By employing normal mode analysis, the analytical expressions for the displacement components, temperature and the (mechanical and Maxwell’s) stresses distribution are obtained in the physical domain. These expressions are also calculated numerically and corresponding graphs are plotted to illustrate and compare the theoretical results. The effect of gravity, magnetic field and laser pulse are also studied and displayed graphically to show the physical meaning of the phenomena. A comparison has been made between the present results and the results obtained by the others. The results indicate that the effects of magnetic field, laser pulse and gravity field are very pronounced.
Źródło:
Archives of Thermodynamics; 2020, 41, 1; 31-66
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of single- and multi-step shear stress relaxations of isotropic magnetorheological elastomer using fractional derivative viscoelastic models
Autorzy:
Nam, T. H.
Petríková, I.
Marvalová, B.
Powiązania:
https://bibliotekanauki.pl/articles/38695689.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
magnetorheological elastomer
stress relaxation
fractional viscoelastic
model
magnetic field
Opis:
The paper presents numerical simulations of single- and multi-step shear stress relaxations of isotropic magnetorheological elastomer (MRE) using fractional derivative Maxwell and Kelvin–Voigt viscoelastic models. The isotropic MRE has been fabricated by filling micro-sized carbonyl iron particles in silicone rubber. Fractional derivative Maxwell and Kelvin–Voigt viscoelastic models were used to fit the experimental data of the isotropic MRE measured by single- and multi-step relaxation tests at different constant strains and external magnetic fields. The fractional Maxwell viscoelastic model showed a relatively large difference between the measured and calculated results. The fractional Kelvin–Voigt model was fitted well with the experimental data of the isotropic MRE at various constant strain levels under different magnetic fields in both single- and multi-step shear stress relaxations. The calculated shear stress with the long-term prediction is in excellent agreement with the measured one. Therefore, the fractional derivative Kelvin–Voigt viscoelastic model is applicable to predict the long-term stress relaxation of the isotropic MRE.
Źródło:
Archives of Mechanics; 2022, 74, 4; 251-266
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power line magnetic field mitigation using a passive loop conductor
Autorzy:
Budnik, K.
Machczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/376311.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
electric field
electric power lines
Fourier transform
loop conductor
Opis:
The paper presents in a tutorial manner methods of the calculation of magnetic fields in vicinity of overhead electric power lines without and with passive mitigation loops. Exact and simplified methods of the determination of the magnetic field of a straight overhead conductor based on the Fourier transform technique are presented. The mitigation effects due to the passive loop are also investigated, whereas the mitigation loop can be treated as a rectangular loop (two-conductor closed mitigation loop) horizontal located under the power line. The decomposition of the magnetic fields in two components: magnetic field obtained in free space from the Biot-Savart law and the magnetic field produced by earth current shows that in practical cases the effects from earth currents can be neglected as compared with effects from line currents.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2013, 73; 137-145
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic field of tubular screened phase conductor in a system with grounded or shorted shield
Autorzy:
Kusiak, D.
Piątek, Z.
Szczegielniak, T.
Jabłoński, P.
Powiązania:
https://bibliotekanauki.pl/articles/97359.pdf
Data publikacji:
2014
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
tubular screen
tubular conductor
high-current busduct
Opis:
In the paper discusses the influence of grounding or shorting of the screen on the magnetic field of screened phase conductor. This phenomenon has been described with the formulas relevant to the relative values of the field and the parameters allowing the frequency, conductivity, and the cross-section dimensions of screen. Into account was taken skin, internal and external proximity effects. Components of this field were expressed through modified Bessel’s functions as a function r and & of cylindrical coordinates. As a consequence this the magnetic field is a rotating elliptical field.
Źródło:
Computer Applications in Electrical Engineering; 2014, 12; 65-81
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of magnetic field from a power line using a passive loop conductor
Autorzy:
Budnik, K.
Machczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/97443.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
overhead power line
earth return
passive loop
Opis:
The study presents in a tutorial manner methods of the calculation of magnetic fields in vicinity of overhead electric power lines without and with mitigation loops. Exact and simplified methods of the determination of the magnetic field of a straight overhead conductor based on the Fourier transform technique are presented. The decomposition of the magnetic fields in two components: magnetic field obtained in free space from the Biot-Savart law and the magnetic field produced by earth current is discussed. It is shown that in practical cases the effects from earth currents can be neglected as compared with effects from line currents. Moreover the mitigation effects due to the passive loop are also investigated, whereas the mitigation loop can be treated as a rectangular loop (two-conductor closed mitigation loop) located near the power line horizontal or non-parallel to the earth surface.
Źródło:
Computer Applications in Electrical Engineering; 2013, 11; 46-63
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined treatment technology for storm runoff and circulating waters from vehicle transport enterprises
Autorzy:
Kvartenko, Oleksandr
Lysytsya, Andriy
Kovalchuk, Nataliya
Prysiazhniuk, Ihor
Pletuk, Oksana
Powiązania:
https://bibliotekanauki.pl/articles/1841973.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
circulating waters
combined reagents
magnetic field
vehicle transport enterprises
Opis:
The development of transport infrastructure strengthens the technogenic burden on the environment. Waste, thaw and rain waters from vehicle transport enterprises, such as car-washing installations, petrol stations, and car service stations may pollute ground and surface waters, and adjacent landscapes. The article presents quality parameters and suggests a number of measures permitting to minimize the harmful impact on the environment. The purpose is to improve the reagent treatment technology applicable to surface runoff from vehicle transport enterprises and the reuse of circulating waters by improving well-known methods with original technological procedures and chemical reagents. Research methods include the use of potentiometry, titrometry, and gravimetry. The investigation has shown the possibility to increase the efficiency of runoff treatment and removal of suspended particles and dissolved organic matter by 20–30%. This can be achieved by the application of a permanent magnetic field of 30–40 mT and the subsequent processing by the solution of aluminum chlorohydrate. Optimum parameters have been determined regarding magnetic field and processing conditions. It has been proven that the use of aluminum chlorohydrate in combination with polyhexamethyleneguanidine hydrochloride simplifies substantially the technological cycle. A better treatment can be achieved in comparison with the usual coagulant by 25%. Heavy metal ions are removed from water and the method includes microbiological disinfection and preservation of water in storage reservoirs. The improved technological scheme suggests the reagent treatment of storm and circulating waters for their repeated use.
Źródło:
Journal of Water and Land Development; 2021, 50; 180-186
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation and reflection of magneto-elastic plane waves at the free surface of a rotating micropolar fibre-reinforced medium with voids
Autorzy:
Anya, Augustine Igwebuike
Khan, Aftab
Powiązania:
https://bibliotekanauki.pl/articles/279185.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
rotation
micropolar fibre-reinforced
voids
reflection coefficients
magnetic field
Opis:
This work investigates rotational effects on propagation and reflection of waves at the free surface of a micropolar fibre-reinforced medium with voids under magnetic fields. When the P-wave is incident on the free surface, there exist four coupled reflected plane waves traveling in the medium; quasi-longitudinal displacement (qLD) wave, quasi-transverse displacement (qTD) wave, quasi-transverse microrotational (qTM) wave and a wave due to voids. Normal mode analysis is adopted in concomitant with Snell’s laws, and appropriate boundary conditions in determination of the solution. Amplitude ratios which correspond to reflected waves in vertical and horizontal components are presented analytically and graphically.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 869-881
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of the beam made of magnetorheological elastomer bending in the magnetic field
Autorzy:
Miedzińska, D.
Sławiński, G.
Boczkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/245981.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
magnetorheological elastomer
smart materials
numerical modelling
magnetic field influence
Opis:
Magnetorheological elastomers (MREs) belong to the group of so-called smart materials, which respond to an external stimulus by changing their viscoelastic properties. Magnetorheological (MR) material can be fluid, gel or solid like material, such as elastomer. The mechanical properties of the MR materials change when subjected to an external magnetic field. The MREs are interesting candidates for the active stiffness and vibration control of structural systems. In the paper the verification process of the applied FE modelling method is presented. The verification is based on the three point bending experiment. The results of that experiment were used to evaluation of the correction on numerical model and analysis. The model was based on the assumption that MRE behaves like an orthotropic material with the material properties o f MRE on the direction along the iron chains - and of a pure elastomer - on the other directions. Such an assumption can be made for the small deformations of a sample, what took place in the considered experiment. The FE modelling method was considered to be correct. On the base of the verified method a FE element model of the MRE beam bending was developed. Such MRE beams are used as "smart" switches that react under the changeable magnetic field.
Źródło:
Journal of KONES; 2010, 17, 1; 261-265
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for Canceling the Power Frequency Magnetic and Electric Fields at Pre-Specified Points on the Lines’ Corridors
Autorzy:
Saied, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/262789.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
power transmission lines
magnetic field
electrostatic interference
mitigation
shielding
Opis:
Methods are presented for the cancellation of the power line’s magnetic and electric fields at pre-specified points close to the line corridor. For canceling the magnetic field, three auxiliary conductors constituting two mitigating loops are used. Their configuration should be geometrically similar to the arrangement of the 3-phase power line’s conductors, with respect to the point at which a zero magnetic field is required. A procedure is suggested for the optimal selection of the scaling factor relating the power conductors’ and the mitigating conductors’ geometrical dimensions. In a case study, the magnetic field reduction varies between 100% near the zero-field point to 35% to the right of that point, with an optimal scaling factor of 0.15. Similar procedure can be used for cance¬ling the electric field at a pre-specified point. The three auxiliary conductors should carry charges proportional to those on the active conductors, but of opposite signs. Results show that the field at the specified point will be exactly zero, instead of the original value of 2.6kV/m. The three voltages required to supply the auxiliary conductors are 76.62, 62.53 and 51.50kV, with almost equal phase angles. The fact that the potentials of the three auxiliary conductors are almost in phase suggests the possibility of using one transformer with appropriate taps to supply them.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 2; 13-19
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of frequent magnetic field on chlorophyll content in leaves of sugar beet plants
Autorzy:
Rochalska, M.
Powiązania:
https://bibliotekanauki.pl/articles/147808.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
magnetic field
chlorophyll
nitrogen
seed quality improvement
sugar beet
Opis:
Chlorophyll content in plant leaves is correlated with the yield and nitrogen content in plants. Non-destructive investigations of chlorophyll content in leaves of 3 varieties of sugar beet grown from seeds revealed that a low frequent magnetic field, acting independently or in combination with other methods of seed improvement, increased chlorophyll content in leaves of the investigated plants. The treatment with the magnetic field increased nitrogen content in the examined plants. The effect was not connected with environmental conditions during vegetation seasons.
Źródło:
Nukleonika; 2005, 50,suppl.2; 25-28
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biochemical and cellular properties of Gluconacetobacter xylinus cultures exposed to different modes of rotating magnetic field
Autorzy:
Fijałkowski, K.
Drozd, R.
Żywicka, A.
Junka, A. F.
Kordas, M.
Rakoczy, R.
Powiązania:
https://bibliotekanauki.pl/articles/779565.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
bacterial cellulose
bioprocess
Gluconacetobacter xylinus
rotating magnetic field
optimization
Opis:
The aim of the present study was to evaluate the impact of a rotating magnetic field (RMF) on cellular and biochemical properties of Gluconacetobacter xylinus during the process of cellulose synthesis by these bacteria. The application of the RMF during bacterial cellulose (BC) production intensified the biochemical processes in G. xylinus as compared to the RMF-unexposed cultures. Moreover, the RMF had a positive impact on the growth of cellulose-producing bacteria. Furthermore, the application of RMF did not increase the number of mutants unable to produce cellulose. In terms of BC production effi cacy, the most favorable properties were found in the setting where RMF generator was switched off for the fi rst 72 h of cultivation and switched on for the further 72 h. The results obtained can be used in subsequent studies concerning the optimization of BC production using different types of magnetic fields including RMF, especially.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 2; 107-114
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geomagnetic detection method for pipeline defects based on ceemdan and WEP-TEO
Autorzy:
Zhang, Tao
Wang, Xinhua
Chen, Yingchun
Shuai, Yi
Ullah, Zia
Ju, Haiyang
Zhao, Yizhen
Powiązania:
https://bibliotekanauki.pl/articles/220762.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
geomagnetic detection
pipeline defects
magnetic field
filtering
data processing
Opis:
This paper presents a geomagnetic detection method for pipeline defects using complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and wavelet energy product (WEP) - Teager energy operator (TEO), which improves detection accuracy and defect identification ability as encountering strong inference noise. The measured signal is first subtly decomposed via CEEMDAN into a series of intrinsic mode functions (IMFs), which are then distinguished by the Hurst exponent to reconstruct the filtered signal. Subsequently, the scale signals are obtained by using gradient calculation and discrete wavelet transform and are then fused by using WEP. Finally, TEO is implemented to enhance defect signal amplitude, completing geomagnetic detection of pipeline defects. The simulation results created by magnetic dipole in a noisy environment, indoor experiment results and field testing results certify that the proposed method outperforms ensemble empirical mode decomposition (EEMD)-gradient, EEMD-WEP-TEO, CEEMDAN-gradient in terms of detection deviation, peak side-lobe ratio (PSLR) and integrated side-lobe ratio (ISLR).
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 345-361
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Magnetic Field on the Germination Process of Tosca Bean Seeds (Phaseolus Vulgaris L.)
Autorzy:
Broszkiewicz, Anna
Detyna, Jerzy
Bujak, Henryk
Powiązania:
https://bibliotekanauki.pl/articles/2199699.pdf
Data publikacji:
2018-12-20
Wydawca:
Instytut Hodowli i Aklimatyzacji Roślin
Tematy:
biostimulation
germination process
magnetic field
plant,
plant growth stimulation
Opis:
The experiment was aimed at determining, whether exposure to static magnetic fields of intensities (1T,  2.5T, and 5T) stimulates the growth of Tosca bean seeds (Phaseolus vulgaris L.). Each treatment group in the  experiment underwent exposure to the magnetic field for a specific period of time, that is: 900s, 1800s, or  3600s. The measurements of root volumes were taken every 24 hours. The first measurement was taken after  96 hours since the beginning of germination. The collected data was analyzed using statistical methods.  The experiment allowed to determine that the magnetic field had a significant influence on the lowering of  bean seeds germination rate. The extent of this influence was dependent on the combination of factors: magnetic  field force- time of exposure.
Źródło:
Plant Breeding and Seed Science; 2018, 77; 103-116
1429-3862
2083-599X
Pojawia się w:
Plant Breeding and Seed Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza wpływu wirującego pola magnetycznego na produkcję ferrocieczy
Experimental study of ferrofluid production exposed to a rotating magnetic field
Autorzy:
Rakoczy, R.
Masiuk, S.
Grądzik, P.
Powiązania:
https://bibliotekanauki.pl/articles/2071138.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ferrociecz
magnetyczne ferrocząstki
wirujące pole magnetyczne
ferrofluid
magnetic nanoparticles
rotating magnetic field
Opis:
Celem prezentowanej pracy jest wyznaczenie wpływu wirującego pola magnetycznego na reakcję chemiczną, której produktem jest koloidalna zawiesina magnetyt o cząstkach charakteryzujących się wymiarem rzędu -10 nm. W pracach badawczych przeanalizowano wpływ zmian natężenia pola magnetycznego oraz objętości dodawanej wody amoniakalnej na otrzymywaną ilość magnetytu. Otrzymane wyniki zostały porównane z masą osadu uzy-skanąz reakcji prowadzonej bez obecności wirującego pola magnetycznego. Uzyskane rezultaty zostały opracowane w formie zależności analitycznej.
Fe3O4 magnetic nanoparticles (ferrofluid) were prepared by Fe2+ and Fe3+ co-precipitation using NH4OH under rotating magnetic field to enhance the crystallization of Fe3O4 ferrofluid. It was found that the mass of Fe3O4 ferrofluid depended on the applied volume of NH4OH and magnetic field intensity. In addition, the analytical dependence describing mass variation of Fe3O4 ferrofluid is proposed.
Źródło:
Inżynieria i Aparatura Chemiczna; 2010, 3; 101-102
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibile Applications of Magnetic Microwires in Aviation
Autorzy:
Draganová, K.
Blažek, J.
Praslička, D.
Kmec, F.
Powiązania:
https://bibliotekanauki.pl/articles/97841.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
aviation
magnetic microwires sensors
magnetic field sensors
mechanical stress sensors
temperature sensors
Opis:
Magnetic microwires have been rediscovered due to a number of the unusual magnetic properties and their potential applications. The paper concerns glass-coated magnetic microwires composed of a ferromagnetic metallic core with a diameter of 0.6 – 30 μm and of a glass coat with a thickness of 2 – 20 μm. The fabrication process and magnetic properties of these microwires are described. Due to their unique properties microwires can be used as a sensing element of sensors. Microwire-based sensors can be used in a wide range of aviation applications as magnetic field sensors, tensile stress sensors or temperature sensors. The main advantages of microwire-based sensors are associated with their small dimensions and weight, which play a very important role in aviation.
Źródło:
Fatigue of Aircraft Structures; 2013, 5; 12-17
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
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:
Sposób oceny małoczęstotliwościowego pola magnetycznego na statkach morskich
The way of assessment of low frequency magnetic field on board of ships
Autorzy:
Pałczyńska, B.
Spiralski, L.
Wyszkowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/153580.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
pomiary pola elektromagnetycznego
natężenie pola magnetycznego
electromagnetic field measurement
magnetic field intensity
Opis:
Przedstawiono sposób pomiaru natężenia pola magnetycznego w zakresie małych częstotliwości. Opisano komputerowy system pomiarowy, który umożliwia izotropowy pomiar wartości skutecznej oraz rejestrację przebiegów czasowych natężenia pola magnetycznego, a następnie metodą off-line dokonuje analizy częstotliwościowej sygnału pomiarowego. Przedstawiono wybrane wyniki pomiarów laboratoryjnych oraz przeprowadzonych w siłowni okrętowej statku badawczo-szkoleniowego.
The way of magnetic field measurement in low frequency range is presented. The computer measurement system, that allows isotropic measurement of magnetic field intensity RMS value and recording its waveforms and than off-line time-frequency analysis of the measured signal is described. Some selected results of the measurements, that were carried out in a laboratory and in the engine room of the research-training vessel are presented.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 9 bis, 9 bis; 687-690
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of electric and magnetic field intensities in proximity of power lines using genetic and particle swarm algorithms
Autorzy:
Król, K.
Machczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/141588.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power line
electric field
magnetic field
optimization
genetic algorithm
particle swarm algorithm
Opis:
The paper presents optimization of power line geometrical parameters aimed to reduce the intensity of the electric field and magnetic field intensity under an overhead power line with the use of a genetic algorithm (AG) and particle swarm optimization (PSO). The variation of charge distribution along the conductors as well as the sag of the overhead line and induced currents in earth wires were taken into account. The conductor sag was approximated by a chain curve. The charge simulation method (CSM) and the method of images were used in the simulations of an electric field, while a magnetic field were calculated using the Biot–Savart law. Sample calculations in a three-dimensional system were made for a 220 kV single – circuit power line. A comparison of the used optimization algorithms was made.
Źródło:
Archives of Electrical Engineering; 2018, 67, 4; 829-843
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of a pulsed magnetic field on selected polymer implant materials
Autorzy:
Szponder, Tomasz
Stodolak-Zych, Ewa
Polkowska, Izabela
Sobczyńska-Rak, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/306606.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pole magnetyczne
biomateriały
implant ortopedyczny
magnetic field
biomaterials
orthopaedic implants
Opis:
Physiotherapy with the use of pulsed magnetic fields is one of the methods of activating the processes of bone healing and regeneration. Exposing materials serving as membranes in guided bone regeneration (GBR) or guided tissue regeneration (GTR) to magnetic fields is an effective model that allows to monitor changes in the material under the influence of the magnetic field. Methods: Materials engineering methods were used to verify the extent of material degradation resulting from magnetic field exposure in an aqueous environment. Changes in surface morphology were observed under an optical microscope and a scanning electron microscope (SEM). Changes in surface wettability were analysed in relation to the direct contact angle. Chemical structural changes were verified with the use of infrared spectroscopy (FTIR-ATR). Results: The PCL-based membrane materials underwent relatively moderate surface degradation (altered contact angle, changes in surface morphology), but the absence of observable FTIR-ATR spectral shifts evidenced material stability under the influence of magnetic field. More extensive degradation processes were observed in the case of PLDLA-based materials, whose surface character changed from hydrophilic to hydrophobic. The spectra revealed enhanced intensity of the chain terminal groups, provided that modifiers (nanometric SiO2 and TCP (water reservoir)) were present in the polymer matrix. Conclusions: The extent degradation in the polymer membrane was primarily dependent on the presence of aqueous environment, while the influence of the magnetic field on the analysed membrane materials was negligible. Therefore, GBR/GTR membrane implants can be considered to remain stable during rehabilitation with the use of alternating magnetic field.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 1; 87-96
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Efficient Inductive Coil Link Design for Wireless Power Transfer to Visual Prostheses
Autorzy:
Celik, M.
Aydin, E.
Powiązania:
https://bibliotekanauki.pl/articles/1031436.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
wireless power transfer
inductive link
magnetic field
telemetry
visual prosthesis
Opis:
Powering therapeutic devices plays a crucial role in the design phase of implantable electronic units. Batteries could not provide sufficient charge storage, used for the lifetime of the device, considering the space available for them. As sophisticated surgical procedures are required with the possible trauma to the patient such as material discrepancy and tissue damage, replacement is quite risky and not an option. Thus, therapeutic devices, especially visual prostheses, receive power wirelessly through inductive coil links which are connected to a battery outside the body. An inductive link is based on the main principle that there are two components such as primary and secondary units. Although primary unit includes the battery outside the body, power transmitter, and control unit, secondary unit under the skin contains amplifier, rectifier regulators, and power control unit. In this study, an inductive coil link is modelled to evaluate fundamental design specifications for visual prostheses. Inductive coil link parameters are quantitatively investigated so that maximum power transfer efficiency and miniaturization, which are critically important for electronics placed in intraocular region, are provided. Considering 20 mm distance, it is concluded that the separation and the size of the coil pair, loop diameter, frequency have a major role to determine the system performance.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 535-537
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie i analiza pola magnetycznego w nietypowych układach współrzędnych
Modeling and analysis of magnetic field untypical coordinate systems
Autorzy:
Skowron, M.
Powiązania:
https://bibliotekanauki.pl/articles/408525.pdf
Data publikacji:
2013
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
pole magnetyczne
równanie Laplace'a
magnetic field
Laplace’s equations
Opis:
Prezentowany artykuł zawiera rozwiązanie równania Laplace’a dla układu współrzędnych sferoidy spłaszczonej oraz obliczenia rozkładu pola magnetycznego wewnątrz sferoidy spłaszczonej umieszczonej w jednorodnym polu magnetycznym. Modelowana sferoida ma paramagnetyczne właściwości magnetyczne. Umieszczenie sferoidy spłaszczonej o takich właściwościach powoduje zniekształcenie rozkładu pola magnetycznego, największe odkształcenia są na granicach ośrodków. Wielkość tych zmian zależy od ułożenia modelowanej sferoidy względem polaryzacji pola.
The paper presents solution of the Laplace equation for the oblate spheroid coordinate system and calculation of the magnetic field distribution inside the oblate spheroid placed in a uniform magnetic field. Modeled spheroid is paramagnetic. The oblate spheroid with such properties deformation the magnetic field distribution, the biggest deformation on borders of resorts. The magnitude of these changes depends on the pose spheroids modeled the polarization field.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2013, 1; 47-48
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coil design with litze wire for magnetic particle spectrometry
Konstrukcja cewki z wykorzystaniem lica do spektrometrii cząstek magnetycznych
Autorzy:
Wróblewski, P.
Smolik, W.
Powiązania:
https://bibliotekanauki.pl/articles/408864.pdf
Data publikacji:
2017
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
magnetic field
nanoparticles
coils
spectroscopy
pole magnetyczne
nanocząstka
cewka
spektroskopia
Opis:
The design of an excitation coil for magnetic particles spectrometer (MPS) was described. It was assumed that the spectrometer should measure the spectra of particles of diameter in the range 10-100 nm. To measure the amplitude and phase angle spectra of magnetic nanoparticles it is required to generate sinusoidal alternating spatially homogeneous magnetic field of magnitude of 20 mT. The work volume of the designed spectrometer was 202020 mm allowing measurement of small samples. The estimation of magnetic properties of magnetic nanoparticles is crucial in Magnetic Particles Imaging. In this paper we described the excitation coil design which minimizes power losses on the coil related to heat emission. The resonance circuit operating on 20 kHz frequency was applied. Optimal litze wire configuration was proposed to negate skin and proximity effects. The numeric simulations for the optimal and commercially available suboptimal litze wire configurations were performed. The comparison of the results was shown and discussed.
W artykule tym została opisana konstrukcja cewki pobudzającej do wykorzystania w spektroskopii cząstek magnetycznych. W projekcie złożono, że spektrometr, którego częścią będzie cewka, będzie w stanie mierzyć widma odpowiedzi nanocząsteczek o średnicy od 10 d0 100 nm. Do skutecznego pomiaru widm amplitudowych i fazowych cząstek magnetycznych potrzebne jest pobudzenie ich sinusoidalnie zmiennym w czasie, ale przestrzenie jednorodnym polem magnetycznym o amplitudzie powyżej 20 mT przy częstotliwości 20 kHz. Robocza objętość projektowanego spektrometru została ustalona na 202020 mm, co pozwala na pomiar małych próbek. Estymacja parametrów magnetycznych nanocząsteczek jest niezwykle ważna do prawidłowego odtworzenia obrazu w tomografii nanocząsteczek magnetycznych. Opisana w artykule konstrukcja cewki pobudzającej pozwala na minimalizacje strat mocy na cewce i związanego z tym przegrzewania się układu. Zaproponowana optymalna konfiguracja lica pozwala skutecznie zmniejszyć wpływ efektu naskórkowego i efektu zbliżenia. Zastosowano również układ rezonansowy pracujący przy częstotliwości 20 kHz. Przeprowadzono symulacje numeryczne pola generowanego przez cewki z wykorzystaniem zarówno optymalnych rozwiązań, jak i dostępnych na rynku konfiguracji drutu lica. W artykule zaprezentowano oraz omówiono wyniki części tych symulacji.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2017, 7, 1; 150-153
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of a static magnetic field on Saccharomyces cerevisiae growth in wastewater containing phenol and p-chlorophenol
Autorzy:
Rutkowska-Narożniak, Anna
Pajor, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/2174350.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
p-chlorophenol
phenol
proliferation
Saccharomyces cerevisiae
static magnetic field
wastewater
Opis:
The effect of a static magnetic field (MF) of 7 mT with phenol (P) or p-chlorophenol (p-chP) concentrations of 100 mg∙dm-3 on the proliferation of Saccharomyces cerevisiae yeast was investigated. The abundance of the microorganism was determined under static culture conditions on a YPG medium with or without the addition of P or p-chP and exposed or unexposed to the MF over 48 h of the experiment. A static MF of 7 mT was shown to have a stimulating effect on S. cerevisiae cell proliferation after 24 h. It was proved that P and p-chP were used as an additional carbon source by yeasts. The greatest stimulation of the growth of the studied microorganisms was observed under the simultaneous effect of an MF and in presence of either P or p-chP. It was generally about 2 times higher at the time of the study than in the control. Statistical analysis of the results was carried out using, among other things, analysis of variance (ANOVA). A statistically significant difference in the growth of the tested microorganisms was observed. The study results indicate the possibility of applying an MF of 7 mT to enhance the process of phenol and p-chlorophenol removal from industrial wastewater.
Źródło:
Journal of Water and Land Development; 2022, 55; 178--184
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does the magnetic field improve the quality of radish seeds?
Czy pole magnetyczne wpływa na poprawę jakości nasion rzodkiewki?
Autorzy:
Krawiec, M.
Kornarzńnski, K.
Palonka, S.
Kapłan, M.
Baryła, P.
Kiczorowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/11542460.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Tematy:
magnetic field
Raphanus sativus
seed quality
radish
seed
germination
emergence
Opis:
The use of high quality sowing material is the fundamental condition for good yielding of crop plants. One of new, unconventional methods of seed quality improvement is low-frequency variable magnetic field. It has been found that this physical factor has a favourable effect on seed germination, emergence and growth of many crop plants. The objective of the study was to determine the effect of low-frequency magnetic field (LFMF) on the germination of radish seeds, with particular emphasis on old seeds. The experimental material were seeds of 7 lots of radish cv. ‘Mila’, with germination capacity of 66.5–92.5%. The age of the seeds was from 1 to 8 years. Seeds from all the lots were treated with variable magnetic field with frequency of 50 Hz, at 3 doses of magnetic induction as follows: 0 (control), 30 and 60 mT for 30 seconds. Then, the seed germination energy and capacity were determined, as well as the length of the hypocotyl and of the radicle of the seedling, dry weight of seedling, and emergence and mean time of emergence. The low frequency magnetic field exposure (30 and 60 mT) improved radish seed germination energy and capacity of every old seed lot. The increase of germination energy of old seeds amounted to 12.3–19.2%, and the increase of germination capacity was 5.8–10%. Magnetic field stimulation caused the increase of germination energy for 3 out of 4 seed lots of high quality but did not affect the improvement of germination capacity of those lots. No significant effect of magnetic field of seeds on the hypocotyl and radicle elongation was observed with the exception of 1 out of the 7 seed lots. For the 2 old seed lots out of the 3 total, magnetic field treatment caused the increase of emergence by 4.4–13.0%.
Stosowanie materiału siewnego wysokiej jakości jest podstawowym warunkiem dobrego plonowania roślin uprawnych. Jedną z nowych, niekonwencjonalnych metod uszlachetniania nasion jest zmienne pole magnetyczne niskiej częstotliwości. Stwierdzono korzystny wpływ tego czynnika fizycznego na kiełkowanie nasion, wschody i wzrost wielu roślin uprawnych. Celem badań było określenie wpływu pola magnetycznego niskiej częstotliwości na kiełkowanie nasion rzodkiewki, ze szczególnym uwzględnieniem nasion starych. Materiałem do badań były nasiona 7 partii rzodkiewki odmiany ‘Mila’ o zdolności kiełkowania 66,5–92,5%. Wiek nasion wynosił 1–8 lat. Nasiona wszystkich partii traktowano zmiennym polem magnetycznym o częstości 50 Hz w 3 dawkach indukcji magnetycznej: 0 (kontrola), 30 i 60 mT przez 30 s. Następnie określono energię i zdolność kiełkowania nasion, długość hypokotylu i korzenia siewki, suchą masę siewki oraz wschody i średni czas wschodów. Traktowanie nasion polem magnetycznym o indukcji 30 i 60 mT poprawiło energię i zdolności kiełkowania nasion starych. Wzrost energii i zdolności kiełkowania tych nasion wynosił odpowiednio 12,3–19,2% i 5,8–10%. Stymulacja nasion polem magnetycznym spowodowała wzrost energii kiełkowania 3 z 4 badanych partii nasion wysokiej jakości, ale nie wpłynęła na poprawę ich zdolności kiełkowania. Istotny wpływ traktowania nasion polem magnetycznym na wydłuĪenie hypokotylu i korzenia siewki stwierdzono jedynie w 1 spośród 7 badanych partii. W przypadku 2 na 3 partie nasion starych traktowanie ich polem magnetycznym spowodowało poprawę wschodów siewek o 4,4–13%.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2013, 12, 6; 93-102
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On thermal instability of Kuvshiniski fluid with suspended particles saturated in a porous medium in the presence of a magnetic field
Autorzy:
Singh, M.
Powiązania:
https://bibliotekanauki.pl/articles/265476.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
thermal convection
Kuvshiniski fluid
suspended particles
magnetic field
porous medium
Opis:
The thermal instability of a Kuvshiniski viscoelastic fluid is considered to include the effects of a uniform horizontal magnetic field, suspended particles saturated in a porous medium. The analysis is carried out within the framework of the linear stability theory and normal mode technique. For the case of stationary convection, the Kuvshiniski viscoelastic fluid behaves like a Newtonian fluid and the magnetic field has a stabilizing effect, whereas medium permeability and suspended particles are found to have a destabilizing effect on the system, oscillatory modes are introduced in the system, in the absence of these the principle of exchange of stabilities is valid. Graphs in each case have been plotted by giving numerical values to the parameters, depicting the stability characteristics. Sufficient conditions for the avoidance of overstability are also obtained.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 4; 981-994
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal convection in a ferromagnetic fluid layer with magnetic field dependent viscosity: a correction applied
Autorzy:
Prakash, J.
Kumar, R.
Kumari, K.
Powiązania:
https://bibliotekanauki.pl/articles/178325.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ferromagnetic convection
magnetic field dependent viscosity
stationary convection
Rayleigh number
Opis:
The effect of magnetic field dependent (MFD) viscosity on thermal convection in a horizontal ferromagnetic fluid layer has been investigated numerically. A correction is applied to Sunil et al. [24] which is very important in order to predict the correct behavior of MFD viscosity. Linear stability analysis has been carried out for stationary convection. The MFD viscosity parameter δ as well as the measure of nonlinearity of magnetization M3, both have a stabilizing effect on the system. Numerical results are also obtained for large values of magnetic parameter M1 and predicted graphically.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 3; 39-46
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Manufacturing of ZrO2-Ni graded composites via centrifugal casting in the magnetic field
Autorzy:
Wachowski, M.
Kosturek, R.
Winkler, H.
Miazga, A.
Lada, P.
Kaszuwara, W.
Konopka, K.
Zygmuntowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/200807.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ZrO2-Ni
ceramic matrix composites
FGM
microstructure
magnetic field
Opis:
The paper presents the possibility of fabricating ceramic-metal composites by an innovative method of centrifugal slip casting in the magnetic field. It was examined whether the use of this method would allow obtaining a gradient concentration of metal particles in the ceramic matrix. In the applied technique, the horizontal rotation axis was used. The study investigated the effect of solid phase content on the properties and microstructure of the products. Water-based suspensions with 35, 40, 45 and 50 vol.% of solid-phase content were prepared with 10 vol.% additional of nickel powder. The viscosity of prepared slurries was considered. The gradient distribution of nickel particles in the zirconia matrix was observed on SEM. Vickers hardness of ZrO2-Ni composites has been measured. The research revealed that the physical properties depend on the volume fraction of solid content and increase as the volume of solid content increases.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 539-545
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-100 z 401

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