Effect of sinusoidal magnetic field on a rough porous hyperbolic slider bearing with ferrofluid lubrication and slip velocity

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

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A 60-Hz sinusoidal magnetic field induces apoptosis of prostate cancer cells through reactive oxygen species

International Journal of Radiation Biology ◽

10.1080/09553000802460206 ◽

2008 ◽

Vol 84 (11) ◽

pp. 945-955 ◽

Cited By ~ 34

Author(s):

Eui Kwan Koh ◽

Byung-Kyu Ryu ◽

Dong-Young Jeong ◽

Iel-Soo Bang ◽

Myung Hee Nam ◽

...

Keyword(s):

Magnetic Field ◽

Prostate Cancer ◽

Reactive Oxygen Species ◽

Cancer Cells ◽

Reactive Oxygen ◽

Oxygen Species ◽

Prostate Cancer Cells ◽

Sinusoidal Magnetic Field

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Flow Characteristics of a Powder Lubricant in a Slider Bearing

10.1115/imece2001/fed-24914 ◽

2001 ◽

Author(s):

Manjunath Pappur ◽

M. M. Khonsari

Keyword(s):

Slip Velocity ◽

Thrust Bearing ◽

Volume Fraction ◽

Flow Characteristics ◽

Slider Bearing ◽

Systematic Development ◽

Powder Lubrication ◽

Insight Into ◽

Theory And Experiment ◽

Good Agreement

Abstract This paper deals with a systematic development of theory of powder lubrication with the appropriate formalism based on the fundamentals of fluid mechanics. The theory is capable of predicting flow velocity, fluctuation (pseudo-temperature), powder volume fraction, and slip velocity at the boundaries. An extensive set of parametric simulations covering particle size, surface roughness, volumetric flow, load and speed are performed to gain insight into the performance of a powder lubricated thrust bearing. The results of simulations are compared to the published experimental results. Good agreement between the theory and experiment attests to the capability of the model and its potential for design of powder lubricated bearings.

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Influence of a 50 Hz Sinusoidal Magnetic Field on Sea Urchin Embryogenesis

Electricity and Magnetism in Biology and Medicine ◽

10.1007/978-1-4615-4867-6_129 ◽

1999 ◽

pp. 545-547 ◽

Cited By ~ 2

Author(s):

Olga Zeni ◽

Maria Rosaria Scarfì ◽

Marco Della Noce ◽

Francesco La Cara ◽

Ferdinando Bersani ◽

...

Keyword(s):

Magnetic Field ◽

Sea Urchin ◽

Sinusoidal Magnetic Field

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The Magnetoelectric Effect of a Ni0.3Zn0.62Cu0.08Fe2O4 - PbFe0.5Nb0.5O3 Multilayer Composite

Archives of Metallurgy and Materials ◽

10.2478/amm-2014-0169 ◽

2014 ◽

Vol 59 (3) ◽

pp. 1011-1015

Author(s):

P. Guzdek ◽

M. Sikora ◽

Ł. Góra ◽

Cz. Kapusta

Keyword(s):

Magnetic Field ◽

Magnetoelectric Effect ◽

Magnetic Hysteresis ◽

Tape Casting ◽

Casting Process ◽

Layered Composites ◽

Practical Applications ◽

Magnetoelectric Composite ◽

Sinusoidal Magnetic Field ◽

Magnetoelectric Coefficient

Abstract The magnetoelectric effect in multiferroic materials has been widely studied for its fundamental interest and practical applications. The magnetoelectric effect observed for single phase materials like Cr2O3, BiFeO3, and Pb(Fe0.5Nb0.5)O3 is usually small. A much larger effect can be obtained in composites consisting of magnetostrictive and piezoelectric phases. This paper investigates the magnetoelectric effect of a multilayer (laminated) structure consisting of 6 nickel ferrite and 7 PFN relaxor layers. It describes the synthesis and tape casting process for Ni0.3Zn0.62Cu0.08Fe2O4 ferrite and relaxor PbFe0.5Nb0.5O3 (PFN). Magnetic hysteresis, ZFC - FC curves and dependencies of magnetization versus temperature for PFN relaxor and magnetoelectric composite were measured with a vibrating sample magnetometer (VSM) in an applied magnetic field up to 85 kOe at a temperature range of 10 – 400 K. Magnetoelectric effect at room temperature was investigated as a function of a static magnetic field (0.3 - 6.5 kOe) and the frequency of sinusoidal magnetic field (0.01 - 6.5 kHz). At lower magnetic field, the magnetoelectric coefficient increases slightly before reaching a maximum and then decreases. The magnetoelectric coefficient aME increases continuously as the frequency is raised, although this increase is less pronounced in the 1-6.5 kHz range. Maximum values of the magnetoelectric coefficient attained for the layered composites exceed about 50 mV/(Oe cm).

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Comparison of the Influences of Surface Texture and Boundary Slip on Tribological Performances

Mathematical Problems in Engineering ◽

10.1155/2015/126824 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Qiyin Lin ◽

Baotong Li

Keyword(s):

Surface Texture ◽

Slip Velocity ◽

Structure Parameters ◽

Textured Surfaces ◽

Slider Bearing ◽

Boundary Slip ◽

Surface Textures ◽

Slip Surfaces ◽

Texture Structure ◽

The Relationship

Close attentions have been widely paid to the engineering textured and slip surfaces for improving bearing tribological performances. Comparison studies on the tribological characteristics of slip and textured surfaces are carried out in this work. The analysis results point out that the influences of surface texture and boundary slip on tribological performances of slider bearing are strongly similar. For the determinate surface textures, there is one and only value of slip velocity to make the tribological performances of textured and slip surfaces in agreement. The corresponding relation between the slip velocity and the texture structure parameters is also obtained, and the size of slip velocity is directly related to the texture geometry parameters including its position parameters. This study will help us to further understand the relationship between boundary slip and surface texture and also the slip phenomenon.

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Sinusoidal magnetic field stimulates magnetosome formation and affects mamA, mms13, mms6, and magA expression in Magnetospirillum magneticum AMB-1

Canadian Journal of Microbiology ◽

10.1139/w08-095 ◽

2008 ◽

Vol 54 (12) ◽

pp. 1016-1022 ◽

Cited By ~ 1

Author(s):

Xiaoke Wang ◽

Likun Liang ◽

Tao Song ◽

Longfei Wu

Keyword(s):

Magnetic Field ◽

Geomagnetic Field ◽

Biomedical Applications ◽

Magnetic Particles ◽

Industrial Sector ◽

Magnetic Pole ◽

Variable Intensity ◽

New Approach ◽

Sinusoidal Magnetic Field ◽

Magnetospirillum Magneticum

Magnetic particles are currently one of the most important materials in the industrial sector, where they have been widely used for biotechnological and biomedical applications. To investigate the effects of the imposed magnetic field on biomineralization in Magnetospirillum magneticum AMB-1 and to suggest a new approach that enhances formation of magnetosomes, cultures inoculated with either magnetic or nonmagnetic precultures were incubated under a sinusoidal magnetic field or geomagnetic field. The results showed that the sinusoidal magnetic field up-regulated mms6 expression in the cultures inoculated with magnetic cells, and magA, mms6, and mamA expression in the cultures inoculated with nonmagnetic cells. The applied sinusoidal magnetic field could block cell division, which could contribute to a decrease in the OD600 values and an increase in the coefficient of magnetism values of the cultures, which could mean that the percentage of mature magnetosome-containing bacteria was increased. The linearity of magnetosome chains was affected, but the number of magnetic particles in cells was increased when a sinusoidal magnetic field was applied to the cultures. The results imply that the variable intensity and orientation of the sinusoidal magnetic field resulted in magnetic pole conversion in the newly forming magnetic particles, which could affect the formation of magnetic crystals and the arrangement of the adjacent magnetosome.

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Peristaltic Motion of Micropolar Fluid With Slip Velocity in A Tapered Asymmetric Channel in Presence of Inclined Magnetic Field and Thermal Radiation

Sohag Journal of Mathematics ◽

10.18576/sjm/080102 ◽

2021 ◽

Vol 8 (1) ◽

pp. 9-22

Keyword(s):

Magnetic Field ◽

Thermal Radiation ◽

Micropolar Fluid ◽

Slip Velocity ◽

Inclined Magnetic Field ◽

Asymmetric Channel ◽

Peristaltic Motion

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Ferrofluid lubrication of circular squeeze film bearings controlled by variable magnetic field with rotations of the discs, porosity and slip velocity

Royal Society Open Science ◽

10.1098/rsos.170254 ◽

2017 ◽

Vol 4 (12) ◽

pp. 170254

Author(s):

Rajesh C. Shah ◽

Rajiv B. Shah

Keyword(s):

Magnetic Field ◽

Slip Velocity ◽

Magnetic Particles ◽

Reynolds Equation ◽

Variable Magnetic Field ◽

Squeeze Film ◽

Design System ◽

Porous Region ◽

Different Shapes ◽

Bearing Design

Based on the Shliomis ferrofluid flow model (SFFM) and continuity equation for the film as well as porous region, modified Reynolds equation for lubrication of circular squeeze film bearings is derived by considering the effects of oblique radially variable magnetic field (VMF), slip velocity at the film–porous interface and rotations of both the discs. The squeeze film bearings are made up of circular porous upper disc of different shapes (exponential, secant, mirror image of secant and parallel) and circular impermeable flat lower disc. The validity of Darcy's Law is assumed in the porous region. The SFFM is important because it includes the effects of rotations of the carrier liquid as well as magnetic particles. The VMF is used because of its advantage of generating maximum field at the required active contact area of the bearing design system. Also, the effect of porosity is included because of its advantageous property of self-lubrication. Using Reynolds equation, general form of pressure equation is derived and expression for dimensionless load-carrying capacity is obtained. Using this expression, results for different bearing design systems (due to different shapes of the upper disc) are computed and compared for variation of different parameters.

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