1. |
- Alm, Ove, et al.
(author)
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A multiple coaxial wire for pressure calibration
- 1974
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In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 45:4, s. 594-595
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Journal article (peer-reviewed)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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2. |
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3. |
- Andersson, Per, et al.
(author)
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Electrical resistance of Evanohm under pressure
- 1975
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In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 46:9, s. 1292-1293
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Journal article (peer-reviewed)abstract
- The electrical resistance of Evanohm wire has been determined as a function of hydrostatic pressure. A Teflon cell with a novel type of electrical feedthrough was used to contain the fluid medium. The resistance was found to decrease approximately linearly by 0.3% up to 27 kilobar. The remarkably small variation of its resistance with temperature and pressure makes Evanohm a suitable material for strain measurements under pressure.
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4. |
- Andersson, Per, et al.
(author)
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Pressure dependence of the thermal conductivity of an epoxy resin
- 1973
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In: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 44:2, s. 705-707
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Journal article (peer-reviewed)abstract
- The pressure dependence of the thermal conductivity of Araldite has been determined in a cylindrical geometry at 300 K. The pressure coefficient was found to be independent of the percentage of hardener, the conductivity at 25 kbar being higher by the factor 1.75 ± 0.05 than at atmospheric pressure.
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5. |
- Andersson, Per, et al.
(author)
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Pressure dependence of the thermal conductivity, thermal diffusivity, and specific heat of polyethylene
- 1973
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In: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 44:6, s. 2601-2605
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Journal article (peer-reviewed)abstract
- The pressure dependence of the specific heat of high‐density polyethylene was determined from simultaneous measurements of thermal conductivity and diffusivity in a cylindrical geometry at 300 K and in the pressure range 0–25 kbar. The thermal conductivity and the diffusivity both increase strongly with pressure, the values at 25 kbar being higher by factors of 2.75 and 2.77, respectively, than those at atmospheric pressure. The specific heat decreases, most strongly so at low pressures, and its value at 25 kbar is 0.80 times that at atmospheric pressure. The thermal conductivity of low‐density polyethylene was determined as a function of pressure. Its value at 25 kbar was found to be 2.19 times that at atmospheric pressure. The difference in conductivity response to pressure between the two varieties is given a simple theoretical interpretation.
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6. |
- Andersson, Per, et al.
(author)
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Specific heat of solids at high pressures from simultaneous measurements of thermal conductivity and diffusivity
- 1972
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In: High Temperatures-High Pressures. - 0018-1544 .- 1472-3441. ; 4:1, s. 101-109
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Journal article (peer-reviewed)abstract
- A method of determining the specific heat of solids at high pressures, from simultaneous measurements of thermal conductivity and diffusivity in a cylindrical geometry, is described. Results are reported for polytetrafluoroethylene (Teflon) in the range 0-30 kbar at 300 K. With increasing pressure both the thermal conductivity and diffusivity increase strongly and approximately linearly, while the specific heat decreases, most strongly at low pressures.
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7. |
- Andersson, Per, et al.
(author)
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Thermal conductivity of solids under pressure by the transient hot wire method
- 1976
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In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 47:2, s. 205-209
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Journal article (peer-reviewed)abstract
- An electronic circuit has been constructed which delivers constant power to a nickel wire also functioning as a resistance thermometer. The temperature increase versus time, t, is linear in ln t, and the coefficient of slope directly yields the thermal conductivity of the medium surrounding the wire. Systematic errors due to finite time, wire length, and lateral extension of the medium and due to plastic deformation of the wire are analyzed. Temperatures are sampled automatically, and the digital data are reduced by means of an on-line desk calculator. The thermal conductivities of AgCl and polytetrafluoroethylene have been measured up to 10 kilobar.
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8. |
- Andersson, Per, et al.
(author)
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Thermal conductivity of Teflon at high pressures
- 1975
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In: High Temperatures-High Pressures. - 0018-1544 .- 1472-3441. ; 7:5, s. 551-553
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Journal article (peer-reviewed)abstract
- The thermal conductivity of different qualities of polytetrafluoroethylene, in the form of cylindrical specimens, was measured up to 3 GPa at room temperature by a steady-state method. A transient hot-wire method was also employed at pressures up to 1 GPa. With the exception of a recent investigation, reasonable agreement with previous work was obtained.
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9. |
- Ross, Russell George, et al.
(author)
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Effects of H and D order on the thermal conductivity of ice phases
- 1978
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In: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 68:9, s. 3967-3972
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Journal article (peer-reviewed)abstract
- Thermal conductivities (λ) of nine ice phases were determined by the transient hot wire method in a temperature range of 100–300 K and under pressures up to 2.2 GPa. Pure D2O as well as D2O–H2O mixtures were found to have values of λ close to those of pure H2O, except in phase VIII. For this phase λ was found to be about 9% lower in the case of pure D2O as well as in 1:1 and 1:3 mixtures of D2O:H2O. The hydrogen ordered phases systematically exhibit higher λ than the disordered ones, and in particular the presence of ice VI′ could be detected by a change of slope at low T in the curve of ln λ versus ln T for phase VI. If the results are fitted to the function λ=CT−n, the values of n fall into two groups. One group with n<1 contains only paraelectric phases, whereas the other group, having higher values of n, contains antiferroelectric phases and phase Ih. The latter phase is exceptional in that λ has a negative pressure coefficient. The results are interpreted in terms of dynamic decoupling of the hydrogen atoms from the lattice and in terms of induced oxygen disorder.
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10. |
- Ross, Russell G., et al.
(author)
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Thermal conductivity and heat capacity of benzene, naphthalene and anthracene under pressure
- 1979
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In: Molecular Physics. - : Taylor & Francis. - 0026-8976 .- 1362-3028. ; 38:2, s. 527-533
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Journal article (peer-reviewed)abstract
- Using the transient hot-wire method the thermal conductivity and the heat capacity per unit volume have been measured for solid naphthalene and anthracene, and further measurements have been made for phase II of benzene. Measurements were made in the temperature range 110 K to 480 K, and at pressures up to 2.3 GPa. The results for benzene, naphthalene and anthracene are discussed in relation to available theoretical models for the temperature and density dependence of the thermal properties.
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