The Experts below are selected from a list of 27471 Experts worldwide ranked by ideXlab platform
Junjiang Guo - One of the best experts on this subject based on the ideXlab platform.
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fabrication of fesibpnb amorphous powder Cores with high dc bias and excellent soft Magnetic properties
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Junjiang Guo, Yaqiang Dong, Qikui Man, Chuntao Chang, Xinmin WangAbstract:Abstract Fe-based amorphous Magnetic alloy powders with a composition of (Fe0.76Si0.09B0.1P0.05)99Nb1 were first prepared by water atomization, and then amorphous Magnetic powder Cores were produced from a mixture of the amorphous alloy powders with diameters of below 75 μm and different volume of insulation and bonding materials by mold compacting with a compact pressure of 2200 MPa at room temperature. The amorphous Magnetic Cores exhibit superior DC-bias properties and excellent soft Magnetic properties after appropriate heating treatment. The DC-bias properties of the present amorphous Magnetic Cores just decrease 15% as the external field increases to 100 Oe. Meanwhile, it also exhibits a high permeability of 56 at 1 MHz and a low core loss of 451 W/kg at Bm=0.1 T and f=100 kHz. The present Fe-based amorphous Magnetic powder Cores with superior DC-bias properties are a potential candidate for a variety of industrial applications.
Alexander Wei - One of the best experts on this subject based on the ideXlab platform.
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plasmon resonant nanoparticles and nanostars with Magnetic Cores synthesis and magnetomotive imaging
ACS Nano, 2010Co-Authors: Hyonmin Song, Qingshan Wei, Quy Khac Ong, Alexander WeiAbstract:Plasmon-resonant gold nanostars (NSTs) with Magnetic Cores were synthesized by a multistep sequence from superparaMagnetic Fe3O4 nanoparticles (NPs) and evaluated as optical contrast agents under magnetomotive (MM) imaging conditions. Core−shell Fe3O4@Au NPs were prepared in nonpolar organic solvents with nanometer control over shell thickness and with good epitaxy to the Fe3O4 surface. Anisotropic growth was performed in micellar solutions of cetyltrimethylammonium bromide (CTAB) under mildly reducing conditions, resulting in NSTs with physical features similar to those produced from colloidal gold seeds. NSTs could be produced below 100 nm from tip to tip, but seed size had a significant impact on growth habit, with larger seed particles producing submicrometer-sized “morning stars”. Both NSTs and aggregated core−shell NPs are responsive to in-plane Magnetic field gradients and can provide enhanced near-infrared (NIR) contrast under MM conditions, but do so by different mechanisms. NSTs can modulate pol...
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gyroMagnetic imaging dynamic optical contrast using gold nanostars with Magnetic Cores
Journal of the American Chemical Society, 2009Co-Authors: Qingshan Wei, Hyonmin Song, Quy Khac Ong, Alexei P Leonov, Jacob Hale, Ken Ritchie, Alexander WeiAbstract:Plasmon-resonant nanoparticles with optical scattering in the near-infrared (NIR) are valuable contrast agents for biophotonic imaging and may be detected at the single-particle limit against a dark background, but their contrast is often limited in environments with high noise. Here we consider gyroMagnetic imaging as a dynamic mode of optical contrast, using gold nanostars with superparaMagnetic Cores. The nanostars exhibit polarization-sensitive NIR scattering and can produce a frequency-modulated signal in response to a rotating Magnetic field gradient. This periodic “twinkling” can be converted into Fourier-domain images with a dramatic reduction in background. We demonstrate gyroMagnetic imaging of nanostars inside of tumor cells, using broadband excitation: while their time-domain signals are obscured by incoherent scattering, their Fourier-domain signals can be clearly resolved in less than a second. The gyroMagnetically active nanostars do not cause a loss in viability, and can even have a mild s...
Charles R. Sullivan - One of the best experts on this subject based on the ideXlab platform.
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microfabricated racetrack inductors with thin film Magnetic Cores for on chip power conversion
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018Co-Authors: Daniel V. Harburg, Alex J. Hanson, Christopher G. Levey, David M. Otten, Bradley A Reese, Jizheng Qiu, John Ranson, Charles R. SullivanAbstract:This paper presents design methods and electrical performance measurements for microfabricated racetrack power inductors. Magnetic components with sputtered Co–Zr–O thin-film Magnetic Cores are demonstrated in a multimegahertz dc–dc converter for solid-state lighting applications. The high-power-density and high-efficiency dc–dc converter is designed to transfer 25 W of power at switching frequencies between 1 and 30 MHz. Utilizing our Magnetic components, the converter achieves a 90% conversion efficiency at 4 MHz with an inductor power density of 1 W/mm2 of substrate area. Small-signal measurements of the inductors are compared with modeled predictions to validate the design optimization approach. Fabricated components achieved inductance values of 1.2 $\mu \text{H}$ and peak quality factors of 15.1 at 8.3 MHz.
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On-chip RF power inductors with nanogranular Magnetic Cores using prism-assisted UV-LED lithography
2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors Actuators and Microsystems (TRANSDUCERS & EUROSENSORS X, 2013Co-Authors: Daniel V. Harburg, Christopher G. Levey, Rezwan G. Khan, Florian Herrault, Jungkwun Kim, Charles R. SullivanAbstract:This paper presents a CMOS-compatible microfabrication process for on-silicon racetrack power inductors using prism-assisted lithography with an ultraviolet light-emitting diode (UV-LED) array as a light source. This combination of lithographic techniques was applied in making 60-μm-tall SU-8 structures with 45° sidewalls to achieve high performance from a sputtered nanogranular Magnetic core material, Co-Zr-O. Microfabricated Magnetic components with Co-Zr-O Cores were designed, built, and tested for use in a 25-W dc-dc power converter operating at a switching frequency between 5-30 MHz. Fabricated inductors achieved a peak quality factor of 18 and an inductance of 660 nH at 15 MHz.
Nicola Femia - One of the best experts on this subject based on the ideXlab platform.
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Transformer Design for Isolated Switching Converters Based on Geometric Form Factors of Magnetic Cores
IEEE Transactions on Industrial Electronics, 2013Co-Authors: Antonietta De Nardo, Giulia Di Capua, Nicola FemiaAbstract:This paper discusses issues related to the transformer design for switch-mode power supplies based on the use of geometric form factors (GFFs) of Magnetic Cores. It is shown that GFFs allow a straightforward and reliable transformer design complying with loss and size constraints. It is also proved that inherent assumptions underlying the application of previous design methods based on some geometric constants can be penalizing if the effects of specific combinations of GFFs of Magnetic Cores are not properly considered. Examples regarding the design of transformers for forward converters are presented and discussed.
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A novel approach to transformers design based on acceptability boundary curves of Magnetic Cores
2010 IEEE 12th Workshop on Control and Modeling for Power Electronics (COMPEL), 2010Co-Authors: Giulia Di Capua, Nicola FemiaAbstract:A novel approach to the design of transformers for switching power supplies is presented. The complete model of the transformer, including thermal properties of core and windings, is solved by means of numerical computation to determine Acceptability Boundary Curves (ABCs). The ABCs allow to identify Magnetic Cores suitable for the realization of transformers complying with given power handling specifications and with loss, temperature and maximum flux density constraints. The paper shows how to determine windings turns number enabling the use of a certain core. A case study is discussed to prove the efficacy of the ABC concept in practical design.
W. Wilczynski - One of the best experts on this subject based on the ideXlab platform.
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Influence of Magnetic circuit production for their Magnetic properties
Journal of Materials Science, 2003Co-Authors: W. WilczynskiAbstract:Punching and packing in the process of production of Magnetic Cores for electrical machines result in the most significant deterioration of their Magnetic properties. Specific total losses increase and Magnetic polarization curve steepness decreases. This article presents a method that lets measure Magnetic properties of Cores following different methods of core packing. The effect has been shown of some technological operations in the production process of Magnetic Cores for electrical machines on their Magnetic properties.
