| 11. |
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| 12. |
- Andersson, L-E, et al.
(författare)
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Some fundamental transmission properties of impedance transitions
- 1984
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Ingår i: Wave motion. - : Elsevier BV. - 0165-2125 .- 1878-433X. ; 6:4, s. 389-406
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Tidskriftsartikel (refereegranskat)abstract
- Reflection and transmission of waves by impedance transitions from a constant input to a constant output characteristic impedence are considered. Several fundamental properties are explored, primarily for impedance transitions with piece-wise constant characteristic impedance in an arbitrary number N of intervals of equal length. For example, the following properties are shown: (i) The relative momentum transmission depends only on the ratio of output to input characteristic impedance. (ii) For a given impedance transition there are at most, and generally exactly, 2N different transitions, including the original one, with identical transmission properties. (iii) For monotoneous impedance transitions the efficiency of energy transmission is minimized by one with an abrupt change in characteristic impedance. (iv) There exists an optimal impedance transition, with a certain antisymmetry, which maximizes the efficiency of energy transmission for a given incident wave of finite duration and energy. Several of the results can be extended to more general classes of impedence transitions. Simple illustrative examples are given.
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| 13. |
- Andersson, Odd E., et al.
(författare)
-
C-axis resistance of HgCl2 intercalated graphite as a function of temperature and pressure
- 1989
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Ingår i: Synthetic Metals volume 34. - Lausanne : Elsevier Sequoia SA. ; , s. 485-490
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Konferensbidrag (refereegranskat)abstract
- The c-axis resistance of stage 3 HgCl2 intercalated graphite has been measured as a function of temperature T and pressure p in the range 40 to 300 K and up to 1 GPa (10 kbar). The absolute resistivity and its T- and p- dependence are all in good agreement with data for other acceptor compounds. The measurements show that a previosly unknown phase transformation occurs above 0.4 GPa. Below 250 K the high pressure phase is metastable down to zero pressure, and an x-ray diffraction analysis of metastable material shows that no stage change occurs. The transition thus probably leads to a different in-plane structure characterized by a more densely packed intercalate layer.
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| 14. |
- Andersson, Odd E., et al.
(författare)
-
Structure, c-axis resistivity, and p-T phase diagram of SbCl5 intercalated graphite
- 1989
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Ingår i: Synthetic Metals volume 34. - Lausanne : Elsevier Sequoia SA. ; , s. 187-192
-
Konferensbidrag (refereegranskat)abstract
- Experimental data are reported for the c-axis resistivity varrhoc of stages n = 3,4,5 and 8 SbCl5 intercalated graphite as a function of T and p, in the range 40 – 300 K and 0-0.5 GPa (5 kbar). varrhoc varied in a systematic way with p, T, and n. Well ordered low-T phases were obtained for all stages; disordering at 200 – 235 K gave rise to well defined multiple anomalies in varrhoc. We also report x-ray diffraction data on the stage 2 compound: evidence was found for large variations in the in-plane structure even for nominally identical samples.
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| 15. |
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| 16. |
- Andersson, P. S., et al.
(författare)
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TISSUE CHARACTERIZATION USING LASER-INDUCED FLUORESCENCE.
- 1987
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Ingår i: Conference on Lasers and Electro-Optics. - 0936659491 ; 14, s. 46-48
-
Konferensbidrag (refereegranskat)abstract
- In cancer tumor detection, tissue autofluorescence and characteristic features of injected hematoporphyrin derivative (HPD) can be utilized. The authors have studied the importance of the excitation wavelength for the achievable contrast between tumor and surrounding tissue using a rat tumor model. They have also compared the relative merits of two HPD preparations for tumor fluorescence detection. The real-time capability of the fluorescence technique is discussed.
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| 17. |
- Andersson, Rolf E, et al.
(författare)
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Antibacterial activity of plantaricin SIK-83, a bacteriocin produced by Lactobacillus plantarum
- 1988
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Ingår i: Biochimie. - : Elsevier BV. - 0300-9084 .- 1638-6183. ; 70:3, s. 381-390
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus plantarum SIK-83 produces a bacteriocin, designated plantaricin SIK-83, which inhibits 66 of 68 lactic acid bacteria from the genera Lactobacillus, Leuconostoc, Pediococcus and Streptococcus. A 500-fold dilution of L. plantarum SIK-83 MRS culture supernatant with phosphate buffer was sufficient to kill 105 cells/ml of Pediococcus pentosaceus within 120s. The killing of a sensitive population followed exponential kinetics. It shown that the bacteriocin binds specifically to sensitive cells but not to nonsensitive lactic acid bacteria, the producer strain or Gram-negative bacteria. Sensitive cells, after exposure to the bacteriocin, could be rescued by treatment with proteolytic enzymes. In buffer, plantaricin SIK-83 was adsorbed to the cell surface almost immediately, and morphological lesions were observed within 2 h after the cells were exposed to the bacteriocin. The lethal mode of action appeared to be due to damage to the cell membrane, resulting in cell lysis, which was detected by electron microscopy and by determination of released intracellular components. © 1988.
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| 18. |
- Andersson, R.E.
(författare)
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Biogenic amines in lactic acid-fermented vegetables
- 1988
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Ingår i: Lebensmittel-Wissenschaft + Technologie. - 0023-6438 .- 1096-1127. ; 21:1, s. 68-69
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Tidskriftsartikel (refereegranskat)abstract
- Lactic acid-fermented vegetables and root crops were analysed with respect to biogenic amines. Cadaverine, histamine, putrescine, spermidine and tyramine were found in concentrations ranging from 1 to 15 mg/kg of product. Dimethylamine, tryptamine, phenylethylamine and spermine were not detected at all in any of the products. Since all the amines found were present in concentrations considerably lower than those known to cause food poisoning, lactic acid-fermented vegetables and root crops should be considered as low-risk products with regard to the presence of biogenic amines. © 1988 Academic Press Limited.
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| 19. |
- Andersson, Rolf E.
(författare)
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Concentration and partial purification of lipase from Pseudomonas fluorescens
- 1980
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Ingår i: Biotechnology letters. - 0141-5492 .- 1573-6776. ; 2:5, s. 247-252
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Tidskriftsartikel (refereegranskat)abstract
- During ultrafiltration in a hollow fiber device 105 liters of lipase frort Pseudomonas fluorescens was concentrated to 4 liters with a yield of 56% of total initial activity. The concentrated lipase solution was lyophilized and purified on a DEAE-cellulose anion exchanger column. The partly purified lipase was found to probably contain carbohydrates. © 1980 Kluwer Academic Publishers.
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| 20. |
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