13 research outputs found
Magnetization reversal process and nonlinear magneto-impedance in Cu/NiFe and Nb/NiFe composite wires
The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC
current is studied. The frequency spectrum of a voltage induced in a pick-up
coil wound around the wire is analyzed. The frequency spectrum is shown to
consist of even harmonics within a wide range of AC current amplitudes and
longitudinal DC magnetic fields. The strong dependencies of the harmonic
amplitudes on the DC field are found. The results obtained may be of importance
for the design of weak magnetic field sensors.Comment: 8 pages, 4 figures, publishe
Current distribution and giant magnetoimpedance in composite wires with helical magnetic anisotropy
The giant magnetoimpedance effect in composite wires consising of a
non-magnetic inner core and soft magnetic shell is studied theoretically. It is
assumed that the magnetic shell has a helical anisotropy. The current and field
distributions in the composite wire are found by means of a simultaneous
solution of Maxwell equations and the Landau-Lifshitz equation. The expressions
for the diagonal and off-diagonal impedance are obtained for low and high
frequencies. The dependences of the impedance on the anisotropy axis angle and
the shell thickness are analyzed. Maximum field sensitivity is shown to
correspond to the case of the circular anisotropy in the magnetic shell. It is
demonstrated that the optimum shell thickness to obtain maximum impedance ratio
is equal to the effective skin depth in the mahnetic material.Comment: 23 pages, 7 figure
Localization corrections to the anomalous Hall effect in a ferromagnet
We calculate the localization corrections to the anomalous Hall conductivity
related to the contribution of spin-orbit scattering into the current vertex
(side-jump mechanism). We show that in contrast to the ordinary Hall effect,
there exists a nonvanishing localization correction to the anomalous Hall
resistivity. The correction to the anomalous Hall conductivity vanishes in the
case of side-jump mechanism, but is nonzero for the skew scattering. The total
correction to the nondiagonal conductivity related to both mechanisms, does not
compensate the correction to the diagonal conductivity.Comment: 7 pages with 7 figure
Preterm Infants’ Follow-Up Program at a Public Hospital in Buenos Aires: Two-Decade Study
Objectives: To analyze temporal trends of mortality, morbidity, growth and neurodevelopment until 2 years of corrected age (CA) of very low birth weight infants (VLBWI) born between 1986- 2005 in Ramon Sardá Maternal Infant Hospital (RSMIH).
Methods: Descriptive temporal trend study divided in 5 quinquenniums.1255 VLBWI were born at RSMIH between 1986-2005; 46 were excluded (genetic syndromes, major congenital malformations, confirmed intrauterine infections), 84 were referred out and 1125 were studied. Birth weight (BW), gestational age (GA); morbidity; growth; neurodevelopment at 1 and 2 years of CA; neurological and sensorial disorders, antenatal steroids use, breastfeeding; rehospitalizations; mothers´ age and years of schooling and Unsatisfied Basic Needs Index (UBNI) were recorded.
Results: Survival rates increased during the last two periods, especially in <1000g BW infants despite the decrease in GA and BW. Children receiving surfactant (Sf), parenteral nutrition (PN) and antenatal steroids (AS) in the last quinquennium obtained better results in growth (40 weeks GA and 1 CA). The use of these therapies increased greatly in the last decade. Also breastfeeding at 40 weeks GA and 4 months tended to be better. Bronchopulmonary dysplasia (BPD) increased. Rehospitalizations (majorly attributable to lower tract infections) and UBNI stayed equal all along. Mothers’ years of schooling increased a little in the last two quinquenniums.
Conclusion: In the last quinquennium children tended to be smaller in GA and BW due to an increase in the survival rate as a result of higher technology and appropriate interventions such as AS, PN, Sf, etc
Electrical properties of ferromagnetic-insulator nanocomposites
Analysis of experimental studying of electrical properties of ferromagnetic-insulator nanocomposites is presented in the paper
Electrical properties of ferromagnetic-insulator nanocomposites
Analysis of experimental studying of electrical properties of ferromagnetic-insulator nanocomposites is presented in the paper
Magnetorefractive effect in magnetophotonic crystals
Materials Research Society Symposium Proceedings834115-120MRSP
Giant magnetoimpedance in composite wires with insulator layer between non-magnetic core and soft magnetic shell
10.1016/j.jmmm.2005.10.149Journal of Magnetism and Magnetic Materials3001e63-e66JMMM