| 1. |
- Aronsson, Gunnar
(författare)
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Construction of singular solutions to the p-harmonic equation and its limit equation for p=∞
- 1986
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Ingår i: Manuscripta mathematica. - 0025-2611 .- 1432-1785. ; 56:2, s. 135-158
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Tidskriftsartikel (refereegranskat)abstract
- Here, all solutions of the form u=rkf(φ) to the p-harmonic equation, div(|∇u|p-2∇u)=0, (p>2) in the plane are determined. One main result is a representation formula for such solutions. Further, solutions with an isolated singularity at the origin are constructed (Theorem 1). Graphical illustrations are given at the end of the paper. Finally, all solutions u=rkf(φ) of the limit equation for p=∞, ux2uxx+2uxuyuxy+uy2uyy=2, are constructed, some of which have a "strong" singularity at the origin (Theorem 2).
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| 2. |
- Aronsson, Gunnar
(författare)
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On certain singular solutions of the partial differential equation ux2uxx+2uxuyuxy+uy2uyy=0
- 1984
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Ingår i: Manuscripta mathematica. - 0025-2611 .- 1432-1785. ; 47:1-3, s. 133-151
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Tidskriftsartikel (refereegranskat)abstract
- The partial differential equation treated here is the formal limit of the p-harmonic equation in R2, for p →∞. Questions related to the smoothness of solutions and the possible existence of stationary points are central for the theory. The singular solutions constructed here bring new light on these questions.
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| 3. |
- Bendix, Tom, et al.
(författare)
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An evaluation of a tiltable office chair with respect to seat height, backrest position and task
- 1986
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Ingår i: European Journal of Applied Physiology and Occupational Physiology. - : Springer Science and Business Media LLC. - 0301-5548 .- 1432-1025 .- 1439-6327. ; 55:1, s. 30-36
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Tidskriftsartikel (refereegranskat)abstract
- The amount of spontaneous movement during seated office work was estimated by analysing the tilting movements of a tiltable office chair. Both movement frequency and amplitude range were considered. The seat inclinations and subjective acceptability were also recorded.The seat was moved more frequently and with a greater range when adjusted 6 cm above popliteal level compared to 1 cm below, or when the backrest was pushed anteriorly or posteriorly compared to a middle position. The greatest acceptability occurred with the highest seat adjustment and the backrest in the middle position. Typing or desk-work influenced movement to a similar extent.
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| 4. |
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| 5. |
- Berglund, S., et al.
(författare)
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Arsenopyrite and sphalerite as T-P indicators in sulfide ores from northern Sweden
- 1980
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Ingår i: Mineralium Deposita. - 0026-4598 .- 1432-1866. ; 15:2, s. 175-187
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Tidskriftsartikel (refereegranskat)abstract
- The compositions of arsenopyrite and sphalerite from five Swedish metamorphosed Cu, Zn-sulfide deposits are related to T and P, according to the methods described by Kretschmar and Scott (1976) and Scott (1973). The As/S ratio of arsenopyrite indicates an equilibrium temperature around 400°C for all the deposits studied, whereas the sphalerite barometer shows pressures between 5 and 7 kb. The mineral assemblages of the bedrocks indicate a similar temperature but a lower pressure. A constant fs2 is probably only effective over distances of millimetres or a few centimetres in the samples studied. The fs2 has always been lower in the surrounding rocks than in the ores as indicated by a higher As/S in arsenopyrite, more FeS in sphalerites and the absence of pyrite.
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| 6. |
- Burström, Lage, et al.
(författare)
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Mechanical energy absorption in human hand-arm exposed to sinusoidal vibration
- 1988
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Ingår i: International Archives of Occupational and Environmental Health. - 0340-0131 .- 1432-1246. ; 61:3, s. 213-216
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Tidskriftsartikel (refereegranskat)abstract
- A possible basis for risk assessment of human exposure to vibration when using hand-held tools may be to determine the amount of mechanical energy that is absorbed by the hand-arm system. The aim of this investigation was to study the absorption of mechanical energy in the human hand-arm system during exposure to sinusoidal vibration within the frequency range of 20 to 1500 Hz. A handle, specially designed for this type of experiments, was used during the measurements. The influence of various experimental conditions, such as three different hand-arm postures, grip force (25–75 N) and vibration levels (27–53 mm/srms), were studied on eight subjects. The outcome clearly shows that the energy absorption properties of the human hand-arm system are more or less dependent on all of the experimental conditions studied, but mainly to the frequency of the vibration stimuli. Furthermore, the results indicate a non-linear relationship between the energy absorbed and all other variables studies.
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| 7. |
- Edman, Anne-Christine, et al.
(författare)
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Structural diversity in muscle fibres of chicken breast
- 1988
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 251:2, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- hicken breast muscle is usually considered to be a relatively homogeneous white muscle and has therefore been widely used for studies of muscle proteins. In a previous study, however, we have found different M-region structures in different fibres from this muscle. Because of this result, we have now carried out a combined histochemical and ultrastructural survey of this muscle. In particular, we have made use of large transverse cryo-sections that include most of the muscle cross-section. Although the white region is fairly homogeneous in fibre content according to normal histochemical criteria (mATPase), we have found that there is a gradation of fibre structure across the muscle. The bulk of the muscle stains conventionally for Type-II fibres according to mATPase tests (the "white" part) but, in the small "red" part of the muscle, there are also Type-I fibres together with the Type-II fibres. Superimposed on this division into Type-I and Type-II fibres are variations in fibre size, oxidative and glycolytic staining properties, and variations of Z-band width and M-band structure; there is no strict correlation among any of these parameters. The apparently uniform staining across most of the muscle when tested for myofibrillar ATPase may be a misleading indicator of fibre properties.
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| 8. |
- Lexell, Jan, et al.
(författare)
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Morphological detection of neurogenic muscle disorders : how can statistical methods aid diagnosis?
- 1987
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Ingår i: Acta Neuropathologica. - 0001-6322 .- 1432-0533. ; 75:2, s. 109-115
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Tidskriftsartikel (refereegranskat)abstract
- The light microscopical observation of groups of histochemically similar muscle fibres, referred to as fibre-type grouping, is commonly considered to be evidence of a denervation and reinnervation process affecting the spinal motor neurons or the peripheral nerves. It can be difficult to assess whether such groups have occurred by chance or are due to a slowly progressive pathological process in an early stage of development. Consequently, there is a need for one or more objective methods for assessing the fibre-type arrangement in healthy and diseased human muscles. The purposes here are to review the methods for the detection of fibre-type grouping that have been published in the last two decades, to describe some unsolved problems, and to indicate some likely lines of development
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| 9. |
- Loberg, Bengt E.H., et al.
(författare)
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Ferride geochemistry of Swedish Precambrian iron ores
- 1983
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Ingår i: Mineralium Deposita. - 0026-4598 .- 1432-1866. ; 18:3, s. 487-504
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Tidskriftsartikel (refereegranskat)abstract
- Chemical analysis for major and trace elements have been performed on 30 Swedish Precambrian iron ores and on some from Iran and Chile. The Swedish ores consist of apatite iron ores, quartz-banded iron ores, skarn and limestone iron ores from the two main ore districts of Sweden, the Bergslagen and the Norrbotten province. Some Swedish titaniferous iron ores were also included in the investigation. The trace element data show that the Swedish ores can be subdivided into two major groups: 1. orthomagmatic and exhalative, 2. sedimentary. Within group 1 the titaniferous iron ores are distinguished by their high Ti-contents. From the ferride contents of the Kiruna apatite iron ores, the ores are considered to be mobilization products of skarn iron ores from the Norbotten province.
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| 10. |
- Romer, Rolf, et al.
(författare)
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Interpretation of lead isotope data from the uraniferous Cu-Fe-sulfide mineralizations in the proterozoic Greenstone Belt at Kopparasen, northern Sweden
- 1988
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Ingår i: Mineralium Deposita. - 0026-4598 .- 1432-1866. ; 23:4, s. 256-261
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Tidskriftsartikel (refereegranskat)abstract
- The polymetamorphic Early Proterozoic basic metavolcanites of the Kopparasen greenstone belt, northern Sweden, contain U mineralizations which are confined to Cu-Fe-sulfide mineralizations in mylonitized zones within basic metatuffs and graphite-bearing mica schists. Tracelead isotope data from sulfides indicate contamination of the sulfide lead with two different lead components at ca. 430 Ma. One lead component was leached from rocks with a 232Th/238U ratio of 3.0-3.2, while the other lead component had evolved in a environment with a lower 232Th/238U ratio (0.0-0.05). The source for this latter lead component underwent a U-Th separation, probably in relation to the formation of the U mineralizations. If this lead component was leached from the U mineralizations, these mineralizations have a 207Pb/206Pb model age of ca. 1,780 Ma, which is less than the least radiogenic lead model age of the supracrustal belt (ca. 2,050 Ma). A possible genetic model for the uranium mineralizations includes the transport of U with an oxidized metamorphic fluid, which was channelled into the permeable zones, and the local reduction of the fluid by sulfides, which caused the precipitation of U.
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