1,721,080 research outputs found
Critical current hysteresis in a ferromagnet-superconductor device
No full textWe investigated the electrical properties of a thin film device composed of a superconducting Nb channel (5 μm wide) and a ferromagnetic superimposed structure (a square Ni80Fe20 dot of 20 μm in size) which is magnetized by a small external magnetic field. A hysteretic dependence of the critical current of the superconducting channel on the applied field is observed. This behavior is attributed to the stray field generated by the magnetized ferromagnetic dot. The strength of the effect and the small size make the device attractive as a switching element in modern low-critical-temperature superconducting circuits, all based on Nb technolog
A three-arm current comparator bridge for two terminal-pair impedance comparisons over the complex plane
No full textA three-arm current comparator impedance bridge is here presented. This bridge is digitally-assisted, and allows comparisons among three unlike impedances, defined as two terminal-pair standards. Its scope is the calibration of impedances having arbitrary phase angles, against calibrated nearly-pure impedances. Preliminary tests, the measurement of an air-core inductor and of an RC network versus decade resistance and capacitance standards, at kHz frequency, are presented; the relative deviations respect to well-established calibration methods are in the 10−5 to 10−6 range, with potential for improvements
A Multiphase Direct-Digital-Synthesis Sinewave Generator for High-Accuracy Impedance Comparison
No full textStudy on the traceability of salinity measurements in seawater
No full textINRIM Measurement Report, EUROMET Electrochemical Analysis WG Project 91
A focused magneto-optical Kerr magnetometer for Barkhausen jump observations
No full textWe describe a modified version of a magneto-optical Kerr magnetometer which allows measuring the hysteresis loop of a specific portion of the sample surface. The diameter of the sampled area can be optically tuned from several mm down to 15 μm. High quality hysteresis loops can be measured in a few seconds. Strong fluctuations are observed when the spot diameter is reduced to a few hundred microns or less. These fluctuations are related to the well-known Barkhausen noise here investigated for the first time in a systematic way using optical techniques. Preliminary data for epitaxial Fe grown on MgO are presented. © 2000 American Institute of Physics
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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