| 1. |
- Blomqvist, Jan Einar, 1936-
(författare)
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Innovation engineering : Pedagogic strategy of Halmstad University
- 1992
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Ingår i: Product development in engineering education. - Halmstad : Halmstad University. - 9163011034 ; , s. 11-18
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Konferensbidrag (refereegranskat)abstract
- At small Halmstad University we have, for the past 13 years, a unique educational program in innovation engineering. The three-year educational program provides the candidates with a broad technical and economical education with special emphasise on handling the innovation process and running new product development projects. An optional fourth year, entitled innovation management, focuses on leadership, innovation, and the choices of technology in multinational companies. This is the summing up of 13 years of experience, during which 286 innovation engineers received an education (even if 22% left with one or two unwritten exams).
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| 2. |
- Borkowski, Kazimierz M., et al.
(författare)
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Determination of the Toruń Antenna Position from VLBI Observations
- 1992
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Ingår i: Acta Astronomica. - Warsaw : Fundacja Astronomii Polskiej im. Mikolaja Kopernika / Copernicus Foundation for Polish Astronomy. - 0001-5237. ; 42, s. 371-375
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Tidskriftsartikel (refereegranskat)abstract
- Four strong radio sources were observed over a 12-hr session in March, 1990 between radio telescopes at Onsala and Torun at wavelength of 6 cm in the standard VLBI Mark II setup for the purpose of improving the coordinates of the Torun 15-meter antenna. The Cartesian coordinates of the antenna derived from the presented measurements are (in meters): 3638609.62 +/- 0.19, 1221773.23 +/- 0.54 and 5077024.50 +/- 1.66 in the x, y, and z directions, respectively.
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| 3. |
- Brönmark, Christer, et al.
(författare)
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Indirect effects of fish community structure on submerged vegetation in shallow, eutrophic lakes : an alternative mechanism
- 1992
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Ingår i: Hydrobiologia. - Dordrecht : Springer Netherlands. - 0018-8158 .- 1573-5117. ; 243/244:1, s. 293-301
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Tidskriftsartikel (refereegranskat)abstract
- The loss of submerged macrophytes during eutrophication of shallow takes is a commonly observed phenomenon. The proximate reason for this decline is a reduction of available light due to increasing phytoplankton and/or epiphyton biomass. Here we argue that the ultimate cause for the transition from a macrophyte-dominated state to a phytoplankton-dominated state is a change in fish community structure. A catastrophic disturbance event (e.g. winterkill) acting selectively on piscivores, cascades down food chains, eventually reducing macrophyte growth through shading by epiphyton, an effect that is reinforced by increasing phytoplankton biomass. The transition back from the phytoplankton to the macrophyte state depends on an increase in piscivore standing stock and a reduction of planktivores. A conceptual model of these mechanisms is presented and supported by literature data and preliminary observations from a field experiment. © 1992 Kluwer Academic Publishers.
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| 4. |
- Bååth, L.B. 1948-
(författare)
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A closer look at active galactic nuclei — the great engines of the universe
- 1992
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Ingår i: Physica scripta. T. - Stockholm, Sweden : Kungliga Vetenskapsakademien. - 0281-1847. ; T43, s. 57-66
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Tidskriftsartikel (refereegranskat)abstract
- The intensive radio emission from powerful radio galaxies and quasars Make these attractive candidates to become "standard candles" to probe the Universe. This paper discusses this possibility and the physics of the radio sources.
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| 5. |
- Bååth, L.B. 1948-
(författare)
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High resolution images of Blazar cores
- 1992
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Ingår i: Variability of Blazars. - Cambridge, UK : Cambridge University Press. - 0521413516 ; , s. 196-204
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Konferensbidrag (refereegranskat)
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| 6. |
- Bååth, L.B. 1948-, et al.
(författare)
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IMAGES OF THE BL LACERTAE OBJECT 1749+701 AT 5 GHZ
- 1992
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Ingår i: Astronomy and Astrophysics. - Les Ulis, France : EDP Sciences. - 0004-6361 .- 1432-0746. ; 262:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents images of 1749+701 from data obtained between 1980 and 1983 as a part of our VLBI programme to monitor a subsample of BL Lac objects at 5GHz. Our images show that this source has a complex structure with a jet pointing towards the north-west at a position angle of about -65-degrees. The brightest component is growing in extension along this position angle. We suggest this to be the core and that the growing extension was caused by a shock generated during an outburst and moving out along the jet. From the extension rate, we obtain an angular separation speed of 0.18 mas yr-1, which corresponds to an apparent transverse speed of 5c. The distances and position angles of two outer components seem remarkably constant. The phenomenon can be understood through a model in which a relativistic jet bends such that its axis is very close to the line of sight in two points. We also deduce that the Lorentz factor must be 4.5 less-than-or-equal-to gamma less-than-or-equal-to 6.5 and that the viewing angle must be 5-degrees less-than-or-equal-to theta less-than-or-equal-to 10-degrees. In this paper, we also present two images obtained from 5GHz MERLIN and combined MERLIN-VLBI data respectively. These maps show that there is a weak component located at a distance of 0.42 arcsec from the core at p.a -155-degrees.
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| 7. |
- Bååth, L.B. 1948-
(författare)
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New millimetric VLBI results
- 1992
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Ingår i: Extragalactic radio sources - from beams to jets. - Cambridge : Cambridge University Press. - 0521416027 ; , s. 137-144
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Konferensbidrag (refereegranskat)
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| 8. |
- Bååth, L.B. 1948-
(författare)
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Varying gamma in 3C273
- 1992
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Ingår i: Variability of Blazars. - Cambridge : Cambridge University Press. - 0521413516 ; , s. 229-233
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Konferensbidrag (refereegranskat)
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| 9. |
- Bååth, L.B. 1948-, et al.
(författare)
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VLBI observations of active galactic nuclei at 3 MM
- 1992
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Ingår i: Astronomy and Astrophysics. - Les Ulis : EDP Sciences. - 0004-6361 .- 1432-0746. ; 257:1, s. 31-46
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Tidskriftsartikel (refereegranskat)abstract
- Recent improvements in data analysis and receiver techniques have allowed us to produce maps of the 100 GHz emission from the compact cores of active galactic nuclei with the unsurpassed resolution of 50-mu-as (microarcseconds). We present here hybrid maps of a set of compact radio sources observed at two epochs with a global VLBI array. The high resolution enables us to show details of active galactic nuclei on size scales of 10(16)-10(17) cm. Jets are shown to be more curved in these inner parts than further out in the areas mapped with VLBI at lower frequencies. Our maps of the quasar 3C345 show that the curvature seen with lower resolution instruments continues very close to the core. New components are seen separating from the cores of 3C84 and BL Lac. We observe a component in 3C84 separating from the core with an apparent speed approximately 21000 km sec-1. The radio source OJ287 is still unresolved with our array, having a core size of less-than-or-similar-to 10(17) cm. There is no indication of any compact component in 3C279 which would be associated with the outburst in integrated flux density which happened some months before our observation. The flux density of the most compact component we observe in 3C279 agrees well with that of the quiet core as extrapolated from its radio spectrum at lower frequencies. The inner part of the radio jet of the giant elliptical galaxy M87 also shows a continuation of the structure on a larger size scale, with a structure we interpret as parts of a helical pattern. No fringes were found for 4C39.25 or Sgr A.
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| 10. |
- Graneli, Wilhelm, et al.
(författare)
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Rhizome dynamics and resource storage in Phragmites australis
- 1992
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Ingår i: Wetlands Ecology and Management. - Dordrecht, Netherlands : Springer Netherlands. - 0923-4861 .- 1572-9834. ; 1:4, s. 239-247
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal changes in rhizome concentrations of total nonstructural carbohydrates (TNC), water soluble carbohydrates (WSC), and mineral nutrients (N, P and K) were monitored in two Phragmites australis stands in southern Sweden. Rhizome biomass, rhizome length per unit ground area, and specific weight (weight/ length ratio) of the rhizomes were monitored in one of the stands. Rhizome biomass decreased during spring, increased during summer and decreased during winter. However, changes in spring and summer were small (< 500 g DW m-2) compared to the mean rhizome biomass (approximately 3000 g DW m-2). Winter losses were larger, approximately 1000 g DW m-2, and to a substantial extent involved structural biomass, indicating rhizome mortality. Seasonal changes in rhizome length per unit ground area revealed a rhizome mortality of about 30% during the winter period, and also indicated that an intensive period of formation of new rhizomes occurred in June. Rhizome concentrations of TNC and WSC decreased during the spring, when carbohydrates were translocated to support shoot growth. However, rhizome standing stock of TNC remained large (> 1000 g m-2). Concentrations and standing stocks of mineral nutrients decreased during spring/ early summer and increased during summer/ fall. Only N, however, showed a pattern consistent with a spring depletion caused by translocation to shoots. This pattern indicates sufficient root uptake of P and K to support spring growth, and supports other evidence that N is generally the limiting mineral nutrient for Phragmites. The biomass data, as well as increased rhizome specific weight and TNC concentrations, clearly suggests that "reloading" of rhizomes with energy reserves starts in June, not towards the end of the growing season as has been suggested previously. This resource allocation strategy of Phragmites has consequences for vegetation management. Our data indicate that carbohydrate reserves are much larger than needed to support spring growth. We propose that large stores are needed to ensure establishment of spring shoots when deep water or stochastic environmental events, such as high rhizome mortality in winter or loss of spring shoots due to late season frost, increase the demand for reserves. © 1992 SPB Academic Publishing.
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