| 11. |
- Pers, Charlotta, et al.
(författare)
-
Changes in apparent oxygen removal in the Baltic proper deep water
- 2000
-
Ingår i: Journal of Marine Systems. - 0924-7963 .- 1879-1573. ; 25:3-4, s. 421-429
-
Tidskriftsartikel (refereegranskat)abstract
- By developing a steady state diagnostic model for a stratified deep-water mass, one is able to quantify both the mass flows and apparent oxygen removal in the Baltic proper deep water. The model is based on continuity of the assumed conservative observable volume, salinity and temperature. Second degree polynomials are fitted to observed vertical profiles of temperature as well as oxygen concentration to give a functional correspondence with the used spatial variable salinity. These relations are used in the model that calculate the water flows, oxygen flows and oxygen removal during four periods between 1959 and 1997. The model forms a boundary value problem, which is solved with a finite difference scheme. The model seems to give reasonable estimates of the flows. The oxygen removal is mainly balanced by inflow of oxygen with incoming water. The oxygen consumption is 4-8 ╡1 O2 1-1 day -1, which corresponds to a degradation of organic matter in the range 30-60 g C m-2 year-1. (C) 2000 Elsevier Science B.V.
|
|
| 12. |
- Björn, Lars Olof, et al.
(författare)
-
Evolution of UV-B regulation and protection in plants
- 2002
-
Ingår i: Advances in Space Research. - 1879-1948 .- 0273-1177. ; 30:6, s. 1557-1562
-
Konferensbidrag (refereegranskat)abstract
- Plants have evolved under the influence of UV-B radiation and have acquired systems for monitoring it and investing appropriate resources for protection against it, i.e., filters, quenchers of radicals and reactive oxygen species, and repair systems. An hypothesis for how plants monitor radiation has been presented.
|
|
| 13. |
- Ivchenko, Nickolay V., et al.
(författare)
-
Current singularities observed on Astrid-2
- 2002
-
Ingår i: Advances in Space Research. - 0273-1177 .- 1879-1948. ; 30:7, s. 1779-1782
-
Tidskriftsartikel (refereegranskat)abstract
- Swedish microsatellite Astrid-2 carried out,electric and magnetic field measurements at 1000 km altitude during its operation in January-July, 1999. At a number of occasions sharp gradients in the magnetic field were observed by the satellite. If interpreted as spatial gradients they imply current densities of hundreds muA/m(2). Occurrence of such 11 current singularities is studied. The nature of the events is discussed.
|
|
| 14. |
- Kosenko, D. I., et al.
(författare)
-
Time-dependent thermal X-ray afterglows from GRBS
- 2004
-
Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 34, s. 2705-2710
-
Tidskriftsartikel (refereegranskat)abstract
- Time-dependent thermal X-ray spectra are calculated from physically plausible conditions around GRB. It is shown that account for time-dependent ionization processes strongly affects the observed spectra of hot rarefied plasma. These calculations may provide an alternative explanation to the observed X-ray lines of early GRBs afterglows (such as GRB 011211). Our technique will allow one to obtain independent constraints on the GRB collimation angle and on the clumpiness of circumstellar matter.
|
|
| 15. |
- Kosenko, D. I., et al.
(författare)
-
X-ray emission of young SN Ia remnants as a probe for an explosion model
- 2004
-
Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 33, s. 392-397
-
Tidskriftsartikel (refereegranskat)abstract
- We present results of hydrodynamical simulations of young supernova remnants. To model the ejecta, we use several models (discussed in the literature) of type Ia supernova explosions with different abundances. Our hydro models are one-dimensional and spherically symmetrical, but they take into account ionization kinetics with all important processes. We include detailed calculations for the X-ray emission, allowing for time-dependent ionization and recombination. In particular, we compare the computed X-ray spectra with recent XMM-Newton observations of the Tycho supernova remnant (SNR). Our goal is to find the most viable thermonuclear SN model that gives good fits to both these X-ray observations and typical SN Ia light curves.
|
|
| 16. |
- Waligórski, M P R, et al.
(författare)
-
Cellular parameters for track structure modeling of radiation hazard in space.
- 2004
-
Ingår i: Adv Space Res. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 34:6, s. 1378-82
-
Tidskriftsartikel (refereegranskat)abstract
- Based on irradiation with 45 MeV/u N and B ions and with Co-60 c rays, cellular parameters of Katz’s track structure modelhave been fitted for the survival of V79-379A Chinese hamster lung fibroblasts. Cellular parameters representing neoplastictransformations in C3H10T/1/2 cells after their irradiation with heavy ion beams, taken from earlier work, were also used to modelthe radiation hazard in deep space, following the system for evaluating, summing and reporting occupational exposures proposed in1967 by a subcommittee of NCRP. We have performed model calculations of the number of transformations in surviving cells, aftera given fluence of heavy charged particles of initial energy 500 MeV/u, penetrating thick layers of cells. We take the product of celltransformation and survival probabilities, calculated along the path lengths of charged particles using cellular survival and transformationparameters, to represent a quantity proportional to the ‘‘radiation risk factor’’ discussed in the NCRP document. The‘‘synergistic’’ effect of simultaneous charged particle transfers is accounted for by the ‘‘track overlap’’ mode inherent in the model ofKatz.
|
|
| 17. |
- Eriksson, Lars Torsten, et al.
(författare)
-
Mind Map Marketing : A Creative Approach in Developing Marketing Skills
- 2004
-
Ingår i: Journal of Marketing Education. - : SAGE Publications. - 0273-4753 .- 1552-6550. ; 26:2, s. 174-187
-
Tidskriftsartikel (refereegranskat)abstract
- In this conceptual article, the authors describe an alternative course structure that joins learning key marketing concepts to creative problem solving. The authors describe an approach using a convergent-divergent-convergent (CDC) process: key concepts are first derived from case material to be organized in a marketing matrix, which is then used as the platform for creation of a marketing plan through various forms of creativity resulting in four maps developed through mind mapping, the technique of focus for divergent thinking in this article. Finally, the matrix format returns to summarize the key concepts, models, and major decisions identified during the first two phases. The student benefits from theCDCprocess in learning marketing both through the (re)discovery of what is well-established marketing knowledge and also through creative learning to solve practical problems continually in flux.
|
|
