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Luis Nuño - One of the best experts on this subject based on the ideXlab platform.
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magnetic complex permeability Imaginary Part dependence on the microstructure of a cu doped ni zn polycrystalline sintered ferrite
Ceramics International, 2020Co-Authors: A Barba, Carolina Clausell, J. C. Jarque, Luis NuñoAbstract:Abstract In this study, the effective complex magnetic permeability-Imaginary Part ( μ e f f ' ' ) of a Cu doped-NiZn polycrystalline ferrite used as EMI suppressor has been quantitatively related to microstructural parameters. It has been observed that μ e f f ' ' strongly depends on average grain size ( G ) of the compact, but also on its relative density ϕ : the higher grain size and density the higher μ e f f ' ' . A mathematical relationship between μ e f f ' ' and average grain size and densification has been proposed and tested, accurately reproducing the experimental results. The use of densification concept allows to compare the wide range of microstructures tested and includes a lower value of relative density (estimated around 0,56) below which μ e f f ' ' is virtually zero. The grain boundary thickness ( δ ) has been estimated around 2 nm which is in agreement with experimental results reported in this work and with those found in literature.
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effect of average grain size and sintered relative density on the Imaginary Part µ of the complex magnetic permeability of cu0 12ni0 23zn0 65 fe2o4 system
Ceramics International, 2016Co-Authors: Carolina Clausell, Antonio Barba, Luis Nuño, J. C. JarqueAbstract:Abstract The influence of the sintered microstructure on the electromagnetic properties of Cu-doped NiZn ferrites were investigated. Two of the main variables of the thermal cycle have been modified: the maximum sintering temperature and the dwell time at that temperature, or sintering time. The evolution of the Imaginary Part – µ ″ of the complex magnetic permeability was studied as a function of relative density, grain size and amplitude of the grain size distribution of the sintered pieces. The results show that µ ″ depends on the sintered microstructure and that there is a limiting value of the average grain size (~20–25 µm) from which the electromagnetic properties of these kinds of materials worsened significantly.
J. C. Jarque - One of the best experts on this subject based on the ideXlab platform.
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magnetic complex permeability Imaginary Part dependence on the microstructure of a cu doped ni zn polycrystalline sintered ferrite
Ceramics International, 2020Co-Authors: A Barba, Carolina Clausell, J. C. Jarque, Luis NuñoAbstract:Abstract In this study, the effective complex magnetic permeability-Imaginary Part ( μ e f f ' ' ) of a Cu doped-NiZn polycrystalline ferrite used as EMI suppressor has been quantitatively related to microstructural parameters. It has been observed that μ e f f ' ' strongly depends on average grain size ( G ) of the compact, but also on its relative density ϕ : the higher grain size and density the higher μ e f f ' ' . A mathematical relationship between μ e f f ' ' and average grain size and densification has been proposed and tested, accurately reproducing the experimental results. The use of densification concept allows to compare the wide range of microstructures tested and includes a lower value of relative density (estimated around 0,56) below which μ e f f ' ' is virtually zero. The grain boundary thickness ( δ ) has been estimated around 2 nm which is in agreement with experimental results reported in this work and with those found in literature.
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effect of average grain size and sintered relative density on the Imaginary Part µ of the complex magnetic permeability of cu0 12ni0 23zn0 65 fe2o4 system
Ceramics International, 2016Co-Authors: Carolina Clausell, Antonio Barba, Luis Nuño, J. C. JarqueAbstract:Abstract The influence of the sintered microstructure on the electromagnetic properties of Cu-doped NiZn ferrites were investigated. Two of the main variables of the thermal cycle have been modified: the maximum sintering temperature and the dwell time at that temperature, or sintering time. The evolution of the Imaginary Part – µ ″ of the complex magnetic permeability was studied as a function of relative density, grain size and amplitude of the grain size distribution of the sintered pieces. The results show that µ ″ depends on the sintered microstructure and that there is a limiting value of the average grain size (~20–25 µm) from which the electromagnetic properties of these kinds of materials worsened significantly.
Carolina Clausell - One of the best experts on this subject based on the ideXlab platform.
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magnetic complex permeability Imaginary Part dependence on the microstructure of a cu doped ni zn polycrystalline sintered ferrite
Ceramics International, 2020Co-Authors: A Barba, Carolina Clausell, J. C. Jarque, Luis NuñoAbstract:Abstract In this study, the effective complex magnetic permeability-Imaginary Part ( μ e f f ' ' ) of a Cu doped-NiZn polycrystalline ferrite used as EMI suppressor has been quantitatively related to microstructural parameters. It has been observed that μ e f f ' ' strongly depends on average grain size ( G ) of the compact, but also on its relative density ϕ : the higher grain size and density the higher μ e f f ' ' . A mathematical relationship between μ e f f ' ' and average grain size and densification has been proposed and tested, accurately reproducing the experimental results. The use of densification concept allows to compare the wide range of microstructures tested and includes a lower value of relative density (estimated around 0,56) below which μ e f f ' ' is virtually zero. The grain boundary thickness ( δ ) has been estimated around 2 nm which is in agreement with experimental results reported in this work and with those found in literature.
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effect of average grain size and sintered relative density on the Imaginary Part µ of the complex magnetic permeability of cu0 12ni0 23zn0 65 fe2o4 system
Ceramics International, 2016Co-Authors: Carolina Clausell, Antonio Barba, Luis Nuño, J. C. JarqueAbstract:Abstract The influence of the sintered microstructure on the electromagnetic properties of Cu-doped NiZn ferrites were investigated. Two of the main variables of the thermal cycle have been modified: the maximum sintering temperature and the dwell time at that temperature, or sintering time. The evolution of the Imaginary Part – µ ″ of the complex magnetic permeability was studied as a function of relative density, grain size and amplitude of the grain size distribution of the sintered pieces. The results show that µ ″ depends on the sintered microstructure and that there is a limiting value of the average grain size (~20–25 µm) from which the electromagnetic properties of these kinds of materials worsened significantly.
Patrick J Mcdonald - One of the best experts on this subject based on the ideXlab platform.
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gravitational redshift and other redshift space distortions of the Imaginary Part of the power spectrum
Journal of Cosmology and Astroparticle Physics, 2009Co-Authors: Patrick J McdonaldAbstract:I extend the usual linear-theory formula for large-scale clustering in redshift-space to include gravitational redshift. The extra contribution to the standard galaxy power spectrum is suppressed by kc−2, where kc = ck/aH (k is the wavevector, a the expansion factor, and H = /a), and is thus effectively limited to the few largest-scale modes and very difficult to detect; however, a correlation, ∝kc−1, is generated between the real and Imaginary Parts of the Fourier space density fields of two different types of galaxy, which would otherwise be zero, i.e., the cross-power spectrum has an Imaginary Part: Pab(k,μ)/P(k) = (ba+fμ2)(bb+fμ2)−i(3/2)Ωm(μ/kc)(ba−bb)+(kc−2), where P(k) is the real-space mass-density power spectrum, bi are the galaxy biases, μ is the cosine of the angle between the wavevector and line of sight, and f = dln D/dln a (D is the linear growth factor). The total signal-to-noise of measurements of this effect is not dominated by the largest scales — it converges at k ~ 0.05 h Mpc−1. This gravitational redshift result is pedagogically interesting, but naive in that it is gauge dependent and there are other effects of similar form and size, related to the transformation between observable and proper coordinates. I include these effects, which add other contributions to the coefficient of μ/kc, and add a μ3/kc term, but don't qualitatively change the picture. The leading source of noise in the measurement is galaxy shot-noise, not sample variance, so developments that allow higher S/N surveys can make this measurement powerful, although it would otherwise be only marginally detectable in a JDEM-scale survey.
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gravitational redshift and other redshift space distortions of the Imaginary Part of the power spectrum
arXiv: Cosmology and Nongalactic Astrophysics, 2009Co-Authors: Patrick J McdonaldAbstract:I extend the usual linear-theory formula for large-scale clustering in redshift-space to include gravitational redshift. The extra contribution to the standard galaxy power spectrum is suppressed by k_c^{-2}, where k_c=c k/a H (k is the wavevector, a the expansion factor, and H=\dot{a}/a), and is thus effectively limited to the few largest-scale modes and very difficult to detect; however, a correlation, \propto k_c^{-1}, is generated between the real and Imaginary Parts of the Fourier space density fields of two different types of galaxy, which would otherwise be zero, i.e., the cross-power spectrum has an Imaginary Part: P_{ab}(k,\mu)/P(k)=(b_a+f\mu^2)(b_b+f\mu^2) -i(3\Omega_m/2)(\mu/k_c)(b_a-b_b)+\mathcal{O}(k_c^{-2}), where P(k) is the real-space mass-density power spectrum, b_i are the galaxy biases, \mu is the cosine of the angle between the wavevector and line of sight, and f=dlnD/dlna (D is the linear growth factor). The total signal-to-noise of measurements of this effect is not dominated by the largest scales -- it converges at k~0.05 h/Mpc. This gravitational redshift result is pedagogically interesting, but naive in that it is gauge dependent and there are other effects of similar form and size, related to the transformation between observable and proper coordinates. I include these effects, which add other contributions to the coefficient of \mu/k_c, and add a \mu^3/k_c term, but don't qualitatively change the picture. The leading source of noise in the measurement is galaxy shot-noise, not sample variance, so developments that allow higher S/N surveys can make this measurement powerful, although it would otherwise be only marginally detectable in a JDEM-scale survey.
C Avila - One of the best experts on this subject based on the ideXlab platform.
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the ratio ρ of the real to the Imaginary Part of the forward elastic scattering amplitude at tev
Physics Letters B, 2002Co-Authors: C Avila, W F Baker, R Desalvo, D P Eartly, C Guss, H Jostlein, M R Mondardini, J Orear, S M Pruss, R RubinsteinAbstract:Abstract We have measured ρ, the ratio of the real to the Imaginary Part of the p p forward elastic scattering amplitude, at s =1.8 TeV. Our result is ρ=0.132±0.056; this can be combined with a previous measurement at the same energy to give ρ=0.135±0.044.
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measurement of rho the ratio of the real to the Imaginary Part of the p barp forward elastic scattering amplitude at sqrt s 1 8 tev
Physical Review Letters, 1992Co-Authors: Norman A Amos, C Avila, W F Baker, D P Eartly, M Bertani, M M Block, D A Dimitroyannis, R W Ellsworth, G Giacomelli, B GomezAbstract:We have measured {rho}, the ratio of the real to the Imaginary Part of the {ital {bar p}p} forward elastic-scattering amplitude, at {radical}{ital s} =1.8 TeV. Our result, {rho}=0.140{plus minus}0.069, is compared with extrapolations from lower-energy data based on dispersion relations, and with the UA4 value at {radical}{ital s} =546 GeV.
