Equivalence of Measurements on Soft Magnetic Materials in the U.K. and Measurements for Operational Conditions
Measurements on soft magnetic materials were made to determine the measurement capabilities available to the partners of a government-funded collaborative research project, with 16 partners from industry and academia. One of the objectives of this project was the development of advanced magnetic materials for novel electrical machines for use in harsh environments such as gas turbines. To establish the measurement confidence necessary to deliver this project objective, an equivalence study was undertaken. A reference core of soft magnetic material that has been measured over a period of many years at the National Physical Laboratory (NPL) was distributed and the dc and ac properties were measured. The measurement systems of the three laboratories are independent and this ensured that no correlations that could skew the results existed. In the analyses, the measurements at NPL were used as the baseline. With the core capabilities established, it was possible to develop the new measurements required to deliver the overall project objectives. At NPL, a standard permeameter method was modified for the measurement of strips. This was incorporated into a stress machine to measure the dc properties of the soft magnetic materials used by the partners, at stress levels of up to 700 MPa. The results for seven materials are presented and the changes in the properties with applied stress compared to establish which materials exhibit favorable properties.
Magnetic anisotropy of plastically deformed low-carbon steel
Macroscopic hysteresis and local Barkhausen noise techniques were used for the comprehensive magnetic investigation of structural low-carbon steel subjected to uniaxial plastic tension. Scattering of the measured magnetic parameters was substantial within the Lüders band region with stabilization at higher strains. Compressive residual stresses in the deformation direction formed a hard magnetization axis with intriguing two-phase remagnetization. The magnetic parameters had the highest sensitivity to strain in this direction. They changed as cos2 with rotation to the perpendicular easy magnetization axis, where the magnetic sensitivity was the lowest. The relation between the deformed steel microstructure (dislocation and residual stress patterns) and the obtained magnetic behaviour is interpreted. The applicability of the examined techniques for the non-destructive characterization of steel degradation is discussed.
Do Potential People Have Moral Rights?
By a potential person I shall mean an entity which is not now a person but which is capable of developing into a person, given certain biologically and/or technologically possible conditions. This is admittedly a narrower sense than some would attach to the term ‘potential'. After all, people of the twenty-fifth century, if such there will be, are in some sense potential people now, even though the specific biological entities from which they will develop, i.e. the particular gametes or concepti, do not yet exist. For there do exist, in the reproductive capacities of people now living and in the earth's resources, conditions adequate to produce these future people eventually, provided of course that various possible catastrophes are avoided. Indeed, in some sense of ‘potential’ there have been countless billions of potential people from the beginning of time. But I am concerned not with such remote potentialities but with currently existing entities that are capable of developing into people.