| 1. |
- Dave, Göran, 1945, et al.
(författare)
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Biological and toxicological effects of solvent extraction chemicals: Range finding acute toxicity in the rainbow trout (Salmo gairdnerii Rich.) and in the rat (Rattus norwegicus L.)
- 1978
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Ingår i: Hydrometallurgy. - 0304-386X. ; 3:3, s. 201-216
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Tidskriftsartikel (refereegranskat)abstract
- The acute toxicity of twelve solvent extraction chemicals was studied in the albino rat after intraperitoneal injection of the chemicals, and in the rainbow trout (Salmo gairdnerii Rich.) after exposure to the chemicals in the aquaria water. The tested chemicals included the following technical products: one primary aliphatic amine (Primene JM-T), two secondary aliphatic amines (Amberlite LA-1 and Adogen 283), two tertiary aliphatic amines (Adogen 383 and Alamine 336), one quaternary amine (Aliquat 336), two organophosphorus compounds (TBP, tributyl phosphate and HDEHP, di-(2-ethyl)-hexylphosphoric acid), one synthetic carboxylic acid (Versatic 10), one naphthalene-sulphonic acid (NA-SUL AS-50), one substituted oxime (LIX 64N) and one aliphatic alcohol (2-ethylhexanol). The intraperitoneal 96 hours LD 50 in the rat for the tested chemicals varied between less than 50 mg/kg b.w. to more than 5000 mg/kg b.w. Ninety six hours LC 50 in the rainbow trout was not possible to determine for three of the twelve tested chemicals due to their low water solubility. When determined, the LC 50 at 15°C was in the range 0.11–56 mg/l based on the amounts added. The present study discusses the acute toxicity of the chemicals mentioned above, gross pathological changes in the rat and behavioural changes in the fish.
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| 2. |
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| 3. |
- Engquist, Björn, et al.
(författare)
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Difference and finite element methods for hyperbolic differential equations
- 1979
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Ingår i: Computer Methods in Applied Mechanics and Engineering. - : Elsevier BV. - 0045-7825 .- 1879-2138. ; 17-18:3, s. 581-596
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Tidskriftsartikel (refereegranskat)abstract
- In recent years finite element methods have started to be applied to hyperbolic equations. Since modern finite element and finite difference methods for hyperbolic equations look very much alike, new results in the analysis of difference methods are also applicable to element methods. We shall discuss propagation of sharp signals, problems with different time scales and the effect of boundaries on stability and accuracy.
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| 4. |
- Engquist, Björn, et al.
(författare)
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Numerical solution of a PDE system describing a catalytic converter
- 1978
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Ingår i: Journal of Computational Physics. - : Elsevier BV. - 0021-9991 .- 1090-2716. ; 27:3, s. 295-314
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Tidskriftsartikel (refereegranskat)abstract
- Numerical approximations are studied for a large hyperbolic system coupled to a parabolic equation and a system of algebraic equations. The equations, which all are nonlinear, describe nonviscous compressible one-dimensional gas flow in a catalytic converter. Chemical reactions within the gas are included in the model. Well-posedness of the partial differential equations is analyzed together with stability of the numerical models. In particular an investigation is made of the effect of numerical dissipation and different boundary conditions. Numerical results are presented.
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| 5. |
- Engquist, Björn, et al.
(författare)
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Radiation boundary conditions for acoustic and elastic wave calculations
- 1979
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Ingår i: Communications on Pure and Applied Mathematics. - : Wiley. - 0010-3640 .- 1097-0312. ; 32:3, s. 314-358
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Tidskriftsartikel (refereegranskat)abstract
- A technique for developing radiating boundary conditions for artificial computational boundaries is described and applied to a class of problems typical in exploration seismology involving acoustic and elastic wave equations. First, one considers a constant coefficient scalar wave equation where the artificial boundary is one edge of a rectangular domain. By using continued fraction expansions, a systematic sequence of stable highly absorbing boundary conditions with successively better absorbing properties as the order of the boundary conditions increases is obtained. There follows a systematic derivation of a hierarchy of local radiating boundary conditions for the elastic wave equation. A theoretical procedure to guarantee stability at corners of the rectangular domain is worked out. A technique for fitting the discrete radiating boundary conditions directly to the difference scheme itself is proposed.
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| 6. |
- 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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| 7. |
- Blom, Rolf
(författare)
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Bounds on key equivocation for simple substitution ciphers
- 1979
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Ingår i: IEEE Transactions on Information Theory. - : IEEE. - 0018-9448 .- 1557-9654. ; 25:1, s. 8-18
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Tidskriftsartikel (refereegranskat)abstract
- The equivocation of the key for a simple substitution cipher is upper and lower hounded, when the message source is memoryless. The hounds are shown to be exponentially tight. The results are compared with random ciphering. It is observed that the exponential behavior of the equivocation of the key is not determined by the redundancy in the message source, but by the symbol probabilities which are closest in a certain sense.
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| 8. |
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| 9. |
- Dave, Göran, 1945, et al.
(författare)
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Effects of insulin on the fatty acid composition of the total blood plasma lipids in the european EEL, Anguilla anguilla L
- 1979
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Ingår i: Comparative Biochemistry and Physiology A. - 1095-6433. ; 62:3, s. 649-653
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Tidskriftsartikel (refereegranskat)abstract
- 1.1. The fatty acid composition of plasma total lipids in the European eel, Anguilla anguilla L., was studied 3, 10, 24, 96, 168 and 336 hr after i.p. injection of bovine insulin (100 i.u./kg body wt) dissolved in glycine-NaOH buffer solution. Control eels were treated by buffer solution only. 2.2. The insulin-treated eels showed an elevated percentage of palmitoleic acid (16:1) 3 and 336 hr post-injection compared to buffer-treated control eels. 3.3. Insulin caused a significant decrease in the percentage of oleic acid (18:1) 336 hr post-injection. 4.4. Besides the observations mentioned above insulin was not found to have any pronounced effects on the fatty acid composition of total blood plasma lipids.
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| 10. |
- Dave, Göran, 1945, et al.
(författare)
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Metabolic and hematological effects of starvation in the European eel, Anguilla anguilla L.—I. Carbohydrate, lipid, protein and inorganic ion metabolism
- 1975
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Ingår i: Comparative Biochemistry and Physiology A. - 1095-6433. ; 52:3, s. 423-430
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Tidskriftsartikel (refereegranskat)abstract
- 1.The effects of starvation on different metabolities in blood, liver and muscle and the level of cortisol and some inorganic ions in plasma were studied in eels, Anguilla anguilla L., after 11, 47, 96 and 164 days. 2.During the first 96 days the eels apparently used mainly liver and muscle triglycerides and this utilization was accompanied by an increase in water content. 3.Between 47 and 96 days the levels of blood glucose and muscle glycogen increased followed by a decrease. 4.Between 96 and 164 days there was a marked decrease in liver glycogen and plasma protein while the triglyceride and water content of liver and muscle was unaffected. 5.The alterations in cholesterol and phospholipids and the possible role of LCAT (lecithin:cholesterol acyltransferase) in the regulation of these parameters is discussed. 6.During the entire starvation period the level of inorganic phosphate in blood plasma decreased and the level of blood lactate, plasma sodium and plasma cortisol increased. 7.The plasma chloride initially decreased followed by an increase after 96 days. These alterations in plasma chloride are discussed in relation to hematological studies and the level of plasma protein.
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