1. |
- Andersson, Per, et al.
(författare)
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Pressure dependence of the thermal conductivity, thermal diffusivity, and specific heat of some polymers
- 1975
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Ingår i: Journal of Polymer Science Polymer Physics Edition. - : Wiley. - 1542-9385 .- 0098-1273. ; 13:2, s. 243-251
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Tidskriftsartikel (refereegranskat)abstract
- The pressure dependence of the specific heat of poly(methyl methacrylate), polystyrene, and atactic and isotactic polypropylene was determined from simultaneous measurements of thermal conductivity and diffusivity in a cylindrical geometry at 300°K and in the pressure range 0-37 kbar. The thermal conductivity and the diffusivity both increase strongly with pressure, while the specific heat decreases. The pressure dependencies are most pronounced at low pressures. The results are compared with other experimental results and with theoretical calculations.
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2. |
- Sundqvist, Bertil, et al.
(författare)
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The thermal properties of an epoxy resin at high pressure and temperature
- 1977
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Ingår i: Journal of Physics D. - Bristol : Institute of Physics. - 0022-3727 .- 1361-6463. ; 10:10, s. 1397-1403
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Tidskriftsartikel (refereegranskat)abstract
- The thermal conductivity lambda , thermal diffusivity and heat capacity per unit volume has been measured for an epoxy resin, Araldite AW 106, with hardener HV 953 U. Measurements have been carried out at room temperature up to 2.5 GPa and between 300 and 430K at 0.11 and 0.27 GPa. The glass transition temperature and its pressure (P) dependence have been determined. The quantity delta lambda / delta P was found to change abruptly in the temperature region of the glass transition.
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3. |
- Sundqvist, Bertil, et al.
(författare)
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Thermal conduction of metals under pressure
- 1976
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics. - 0034-6748 .- 1089-7623. ; 47:2, s. 177-182
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Tidskriftsartikel (refereegranskat)abstract
- It is shown that the original Ångström method of determining the thermal diffusivity of metals is not valid in the case of a specimen surrounded by a solid medium, and an appropriate modification is described. Several simplifications of this method are also presented and criteria for their validity given. An electronic system has been developed for automatic sampling and analysis of the temperature data. The new method has been applied to Cu under pressure, and the results show that the thermal conductivity rises by 6.4% up to 2.5 GPa (25 kilobar).
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4. |
- Sundqvist, Bertil, et al.
(författare)
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Thermal conductivity of copper under high pressure
- 1977
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Ingår i: High Temperatures-High Pressures. - London : Pion Ltd. - 0018-1544 .- 1472-3441. ; 9:1, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- The thermal diffusivity, a, of copper has been measured at room temperature up to a pressure of 2.5 GPa (25 kbar) by means of a method recently developed. In this pressure range the diffusivity increases linearly with a slope of (1/a)da/dp = 2.7x10-2 GPa-1. As the density and specific heat of copper are known as functions of pressure, this result can be used to obtain the pressure dependence of the thermal conductivity, lambda, with the result (1/lambda)d(lambda)/dp = 3.1x10-2 GPa-1. This value is shown to agree well with theoretical calculations of this slope. However, a comparison between this result and the pressure dependence of the electrical conductivity shows deviations from the Wiedemann-Franz law.
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5. |
- Sundqvist, Bertil, et al.
(författare)
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Thermal conductivity of gold and silver at high pressures
- 1978
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Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier B.V.. - 0022-3697 .- 1879-2553. ; 39:10, s. 1133-1137
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Tidskriftsartikel (refereegranskat)abstract
- The thermal diffusivities of gold and silver have been measured under pressure up to 2.5 GPa at room temperature. From the measured data the pressure dependence of the thermal conductivity, λ, has been calculated. The values found for the pressure coefficient λ−1 δλ/δP were 3.9 × 10−2GPa−1 for gold and 4.0 × 10−2 GP silver at atmospheric pressure. The results are compared to theoretical predictions of the pressure dependence and also to previous experimental results for copper and aluminium. For the noble metals, small angle or “vertical” scattering of electrons is shown to have a stronger volume dependence than “horizontal” scattering.
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6. |
- Sundqvist, Bertil, et al.
(författare)
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Measurement of the pressure dependence of the electron-phonon interaction in aluminium
- 1979
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Ingår i: Journal of Physics F: Metal Physics. - Bristol : Institute of Physics. - 0305-4608. ; 9:9, s. L161-L166
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Tidskriftsartikel (refereegranskat)abstract
- The authors report measurements of the electrical resistance of aluminium in the temperature range 30-40 degrees C and the pressure range 0.2-1.0 GPa. From these experiments the pressure dependence of the electron-photon interaction lambda is evaluated. With p in GPa the result is lambda (p)= lambda 0 exp(-0.0467p+4.7*10-4 p2). This expression for lambda describes accurately the observed pressure dependence of the superconducting Tc for pressures up to about 4 GPa.
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7. |
- Malmhäll, Roger, et al.
(författare)
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Hall effect in Metglas 2826A and 2826 - dependence on temperature and pressure
- 1977
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Ingår i: Proceedings of International Conference on Magnetism, ICM 76. - : Elsevier. - 072040732X - 9780720407327 ; 86-88, s. 796-798
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Konferensbidrag (refereegranskat)abstract
- The Hall resistivity, ρH, of Metglas 2826A is measured for 0.6 ≤ T/Tc ≤ 1.9. Below To (∼255 K), the extraordinary Hall coefficient R1 is constant at +4.24 x x10-8 m3/As. The magnetic susceptibility, derived from our data, exhibits a Curie-Weiss behaviour above 350 K and varies as (T - Tc)-1.75 for (T - Tc) < 90 K. In 2826 at 300 K ρH drops linearly with increasing pressure.
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8. |
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9. |
- Alm, Ove, et al.
(författare)
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A multiple coaxial wire for pressure calibration
- 1974
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 45:4, s. 594-595
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Tidskriftsartikel (refereegranskat)abstract
- A single wire containing several metals suitable for pressure calibration has been produced by extrusion. Coaxial combinations of Ce-Bi-TI and Ce-Bi-Ba have been prepared by the procedure described.
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10. |
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