CENTIGRADE TEMPERATURE SCALE

Keyword(s):  
Universe ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 17
Author(s):  
Nils Andersson

As mature neutron stars are cold (on the relevant temperature scale), one has to carefully consider the state of matter in their interior. The outer kilometre or so is expected to freeze to form an elastic crust of increasingly neutron-rich nuclei, coexisting with a superfluid neutron component, while the star’s fluid core contains a mixed superfluid/superconductor. The dynamics of the star depend heavily on the parameters associated with the different phases. The presence of superfluidity brings new degrees of freedom—in essence we are dealing with a complex multi-fluid system—and additional features: bulk rotation is supported by a dense array of quantised vortices, which introduce dissipation via mutual friction, and the motion of the superfluid is affected by the so-called entrainment effect. This brief survey provides an introduction to—along with a commentary on our current understanding of—these dynamical aspects, paying particular attention to the role of entrainment, and outlines the impact of superfluidity on neutron-star seismology.


1940 ◽  
Vol 11 (6) ◽  
pp. 371-372
Author(s):  
F. G. Brickwedde
Keyword(s):  

2000 ◽  
Vol 284-288 ◽  
pp. 2004-2005 ◽  
Author(s):  
P Mohandas ◽  
D.I Head ◽  
R.L Rusby ◽  
G Schuster ◽  
A Hoffmann ◽  
...  

1997 ◽  
Vol 488 (1) ◽  
pp. 375-396 ◽  
Author(s):  
David S. Finley ◽  
Detlev Koester ◽  
Gibor Basri

2008 ◽  
Vol 25 (11) ◽  
pp. 2046-2054 ◽  
Author(s):  
P. Jonathan Gero ◽  
John A. Dykema ◽  
James G. Anderson

Abstract Spaceborne measurements pinned to international standards are needed to monitor the earth’s climate, quantify human influence thereon, and test forecasts of future climate change. The International System of Units (SI, from the French for Système International d’Unités) provides ideal measurement standards for radiometry as they can be realized anywhere, at any time in the future. The challenge is to credibly prove on-orbit accuracy at a claimed level against these international standards. The most accurate measurements of thermal infrared spectra are achieved with blackbody-based calibration. Thus, SI-traceability is obtained through the kelvin scale, making thermometry the foundation for on-orbit SI-traceable spectral infrared measurements. Thermodynamic phase transitions are well established as reproducible temperature standards and form the basis of the international practical temperature scale (International Temperature Scale of 1990, ITS-90). Appropriate phase transitions are known in the temperature range relevant to thermal infrared earth observation (190–330 K) that can be packaged such that they are chemically stable over the lifetime of a space mission, providing robust and traceable temperature calibrations. A prototype blackbody is presented that is compact, highly emissive, thermally stable and homogeneous, and incorporates a small gallium melting point cell. Precision thermal control of the blackbody allows the phase transition to be identified to within 5 mK. Based on these results, the viability of end-to-end thermometric calibration of both single-temperature and variable-temperature blackbodies on orbit by employing multiple-phase-change cells was demonstrated.


1908 ◽  
Vol 28 ◽  
pp. 615-626
Author(s):  
James G. Gray ◽  
Alexander D. Ross

SUMMARY1. Nickel and the Heusler alloy give “sensitive states” of nearly 2 and about 5 per cent. respectively for a magnetising field of 8 C.G.S. units.2. Steel wire specimens dropped vertically on a stone slab from a height of 1 metre showed a reduction of 37 per cent, in the “sensitive state” for a single fall, 49 per cent, for three falls, 62 per cent, for ten falls, and 73 per cent, for fifty falls.3. After the “sensitive state” has been removed from a specimen by the process of demagnetising by reversals, it cannot be completely restored by reannealing. That is, the specimens exhibit a fatigue effect.4. In the case of one variety of steel, the “sensitive state” had been reduced to less than one-half its original value after seven annealings, and to one-fifth after seventeen.5. No recovery from the fatigue condition was observed in specimens which had been laid aside for fifty-four days.6. Repeated annealings without intermediate magnetic testing showed neither an augmentation of the “sensitive state” nor a fatigue effect.7. Specimens demagnetised at −190° C., heated to room temperature, and cooled again to −190° C., showed a small “sensitive state” at that temperature.8. Larger effects were induced by heating from −190° C. to 15° C., or by cooling from 15° C. to −190° C.9. A “sensitive state” could be induced by any variation of temperature, but not by exposure to a steady temperature, either high or low. The effect is associated solely with change of temperature.10. The amount of “sensitive state” induced by equal temperature alterations varies with the position of the range on the temperature scale and with the material.11. The change from the “sensitive” to the normal condition is unaccompanied by any appreciable change in the specific electrical resistance or elastic constants of the material.


2008 ◽  
Vol 4 (S256) ◽  
pp. 325-336
Author(s):  
Christopher J. Evans

AbstractThe past decade has witnessed impressive progress in our understanding of the physical properties of massive stars in the Magellanic Clouds, and how they compare to their cousins in the Galaxy. I summarise new results in this field, including evidence for reduced mass-loss rates and faster stellar rotational velocities in the Clouds, and their present-day compositions. I also discuss the stellar temperature scale, emphasizing its dependence on metallicity across the entire upper-part of the Hertzsprung-Russell diagram.


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