| 1. |
- Andersson, Göran, et al.
(author)
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Electrical resistivity measurements under hydrostatic conditions up to 10 GPa
- 1984
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In: Journal de Physique Colloques vol. 45. - : EDP Sciences. - 0449-1947. ; , s. 379-382
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Conference paper (peer-reviewed)abstract
- A large scale Bridgman anvil system has been designed. Steel gaskets permit compression of a methanol-ethanol medium over a volume of 500-250 mm3. Up to 12 wires have been used to contact specimens. The system has so far served up to 7.5 GPa, with anvils made of ASP tool steel. The transition Bi III-V was found to occur at a lower pressure than the recommended average. The electrical resistance of copper was measured up to 6 GPa under hydrostatic conditions.
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| 2. |
- Andersson, Per, et al.
(author)
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Thermal conductivity of orientationally-disordered crystals under high pressure
- 1983
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In: Thermal conductivity 17. - New York : Plenum Publishing. - 0306411776 ; , s. 527-536
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Conference paper (peer-reviewed)abstract
- The transient hot-wire method was used to study the effects of temperature and pressure on the thermal conductivity, λ, of several molecular substances showing varying degrees of disorder in molecular orientation. Molecular solids both in the plastic and normal crystal state were investigated as well as a clathrate hydrate. The measurements were made in the temperature range 100 - 450 K and at pressures up to 2.5 GPa. The conductivity results for the different types of crystal studied are discussed in terms of the simple Debye formula. We discuss the unusual glass-like behaviour of λ(T) for the clathrate hydrate in some detail.
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| 3. |
- Andersson, Per, et al.
(author)
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Thermal resistivity of ice Ih near the melting point
- 1980
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In: Journal of Physics C: Solid State Physics. - : Institute of Physics Publishing (IOPP). - 0022-3719 .- 1747-3802. ; 13:4, s. L73-L76
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Journal article (peer-reviewed)abstract
- The thermal resistivity r(T) of ice Ih has been re-measured from 120K to as close as practicable to melting. Measurements were made under isobaric conditions at a pressure of 0.07 GPa, and corrected to isochoric conditions. The resultant deviation from the simple theoretical prediction, r/T=constant, has been plausibly accounted for by interaction between optic and acoustic phonons. Thermal resistivity arising from the presence of point defects has been shown to be of negligible importance.
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| 4. |
- Bohlin, Leif, et al.
(author)
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Cone-plate instrument for stress relaxation measurements
- 1980
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In: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 73:1, s. 61-65
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Journal article (peer-reviewed)abstract
- An instrument for the measurement of stress relaxation in shear is described. The force is detected by a sensitive piezoresistive pressure transducer. The requirement of constant strain can be fulfilled within less than 1%. Preset values of shear strain can be imposed on the sample within 0.1 sec. This instrument is suitable for soft solids and elastic liquids with a lower limit of ∼ 1 sec for the relaxation time. Results are given for wheat flour dough, a gelatinous deoxycholate complex and a gelatin gel. The instrument is simple, robust, and reliable, as well as inexpensive.
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| 5. |
- Brydsten, Ulf, et al.
(author)
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Hot strip determination of the thermal conductivity tensor and heat capacity of crystals
- 1983
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In: International journal of thermophysics. - : Plenum Publishing. - 0195-928X .- 1572-9567. ; 4:4, s. 369-387
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Journal article (peer-reviewed)abstract
- A method of determining the principal thermal conductivities and the specific heat capacity for an anisotropic crystal is presented, tested, and discussed. Two parallel metal strips are deposited onto a plane face of the specimen. One strip serves as a heater, the other as a temperature sensor. A pulse of constant dc power is applied to the heater, and the response at the sensor is measured by means of an ac bridge, monitored by a lock-in amplifier. The experiment is on-line with a PDP-11/34 computer system. The expression for the temperature rise in case of infinitely long strips is fitted to the sensor temperature data. In the isotropic case one experiment yields both thermal conductivity and heat capacity. In an anisotropic case experiments have to be performed with two or three different strip orientations, if all principal thermal conductivities are to be determined. A precision of 0.1% is readily obtained, and the method is thus valuable in cases where small changes in thermal conductivity are to be determined. We estimate that the accuracy generally obtainable is about 2% as regards thermal conductivity and heat capacity. The accuracy in determining thermal diffusivities is mainly limited by geometrical factors and may ultimately be better than 1%. Results are given for isotropic CaF2 and anisotropic SiO2 at 300 K.
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| 6. |
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| 7. |
- Brydsten, Ulf, et al.
(author)
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Thermal conductivity of single-crystal NaCl under uniaxial compression
- 1983
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In: Journal of Physics C: Solid State Physics. - : Institute of Physics Publishing (IOPP). - 0022-3719. ; 16:1, s. 143-146
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Journal article (peer-reviewed)abstract
- The variation of the thermal conductivity of single-crystal NaCl under uniaxial compression is investigated by the dynamic hot-strip method. Over a stress range of 0-1.0 MPa no effect whatsoever is found. The relative change in thermal conductivity under uniaxial compression must be smaller than 1.5*10-9 Pa-1, contrary to the result of an earlier investigation.
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| 8. |
- Bäckström, Gunnar
(author)
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A rational system of music notation
- 1981
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In: Annales Academiae regiae scientiarum Upsaliensis : Kungl. Vetenskapssamhällets i Uppsala årsbok. - Stockholm : Almqvist & Wiksell. - 0504-0736. ; 24, s. 16-22
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Journal article (pop. science, debate, etc.)
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| 9. |
- Bäckström, Gunnar
(author)
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Determination of thermal properties using a shielded thermocouple
- 1982
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In: Journal of Physics E: Scientific Instruments. - : Institute of Physics Publishing (IOPP). - 0022-3735. ; 15:10, s. 1049-1053
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Journal article (peer-reviewed)abstract
- A new version of the hot-wire method for measuring thermal conductivity is proposed. The sheath of a differential Thermocoax wire is heated by an electric current and the temperature is recorded before, during and after heating. An on-line desk computer fits the theoretical expression for the temperature to the data. Thermal conductivity as well as heat capacity for a fluid or plastic medium surrounding the wire may be determined.
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| 10. |
- Bäckström, Gunnar
(author)
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Smid medan trycket är högt
- 1983
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In: Forskning och framsteg. - Stockholm. - 0015-7937. ; :2, s. 22-28
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Journal article (pop. science, debate, etc.)
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