| 41. |
- Carlsson, J., et al.
(author)
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Application of optical fluorescence spectroscopy to paper production
- 1999
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In: TAPPI INTERNATIONAL PAPER PHYSICS CONFERENCE. - Atlanta : Tappi Press. - 0898529549 ; , s. 429-436
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Conference paper (peer-reviewed)abstract
- Fluorescence light emitted from paper following the absorption of either ultraviolet or visible light has a wavelength distribution determined by the chemical composition of the paper. This can be used both for laboratory measurements of paper characteristics and for on-line monitoring of the paper during production. Such measurements can be performed non-intrusively at sampling rates high enough to give a sub-millimetre resolution in the machine direction in a paper machine or rerewinder. In this project two types of fluorescence monitors have been constructed. They are operating at different wavelengths and thereby they monitor different substances in the paper. The monitors have been tested at newsprint producing paper mills together with an optical speedometer. The measurements in the production environment have shown that the equipment is capable of indirectly monitoring paper quality parameters which affect the local abundance of lignin. Examples of such parameters are the number of shives in the paper and wire marks. A fluorescence based method for scanning cross-directional newsprint profiles in the laboratory has been developed. From these measurements the relative shrinkage of the paper during drying can be calculated using time-frequency analysis.
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| 42. |
- Chu, H.S., et al.
(author)
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VLBI observations of the puzzling BL Lacertae object 0235+164
- 1996
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In: Astronomy and Astrophysics. - : Springer. - 0004-6361 .- 1432-0746. ; 307:1, s. 15-20
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Journal article (peer-reviewed)abstract
- For over 20 years, many models have been proposed to explain the variability of AO0235+164. Among them, the most favorable has been micro-lensing. We have made a series of VLBI observations on this source in order to better understand its nature. The resultant maps indicate dramatic changes in the position angle of the jet between observations as well as a correlation between the intensity of the VLBI core and flux outbursts which occurred between the observing sessions. These characteristics, in conjunction with other arguments, suggest that the source variability is intrinsic, i.e. microlensing is of minor importance. We suggest two models: 1) a model in which the jet starts at a very small angle to the line of sight and then curves away to become about 6deg at about 1 mas from the core; and 2) a CME (Coronal Mass Ejection) model that also may explain the violent variability in intensity, polarization position angle, and jet direction in AO0235+164.
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| 43. |
- Collin, Sven-Olof, et al.
(author)
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Market Segmentation in Scientific Publications : Research Patterns in American vs European Management Journals
- 1996
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In: British Journal of Management. - Chichester : Wiley-Blackwell. - 1045-3172 .- 1467-8551. ; 7:2, s. 141-154
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Journal article (peer-reviewed)abstract
- Ideal science should conform to certain criteria or goals, among them the goals of universalism and commonality. Realization of these goals may be limited, however, through the dividing up of researchers in terms of geographical borders. In this study the general hypothesis is tested that there is a segmentation of the society of management researchers into a North American (US) and a European (E) segment, a segmentation which is furthered by differences in incentive schemes and in paradigms. Four leading management journals from North America and from Europe, respectively, and the 242 articles they contained published in 1993 were selected to represent the different geographical segments. The results provide: support for the existence of two such segments; support for differences in incentive schemes influencing the articles; support for their being paradigm differences between the two segments; and support for a paradigm effect being stronger in US-journals than in E-journals, US-authors are more willing, however, to conform to the E-paradigm than vice versa. We argue for methodological pragmatism in order to reduce the presumed counter-productive effects of paradigmatic rigidity.
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| 44. |
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| 45. |
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| 46. |
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| 47. |
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| 48. |
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| 49. |
- D'Hertefeldt, Tina, Universitetslektor, 1965-, et al.
(author)
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Physiological integration of the clonal plant Carex arenaria and its response to soil-borne pathogens
- 1998
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In: Oikos. - Chichester : Wiley-Blackwell. - 0030-1299 .- 1600-0706. ; 81:2, s. 229-237
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Journal article (peer-reviewed)abstract
- We test the hypothesis that the expansive horizontal clonal growth of Carex arenaria may provide a method of escape from soil-borne pathogens (fungi and nematodes) by growing away from the site of infection. Plants were grown in non-sterilized or sterilized dune sand, i.e., with or without soil-borne pathogens. The effects of soil-borne pathogens were studied on the whole genet, on the mother alone, and on the first primary rhizome. Genets with the mother plant infected produced less total biomass and had less biomass allocated to roots than genets with uninfected mothers. Infected genets had fewer primary rhizomes and lower total rhizome length, but rhizome specific weight or the distance between shoots did not decrease in infected plants. In C. arenaria, uninfected mothers with an infected first primary rhizome produced shorter and fewer rhizomes than uninfected genets. The infected first rhizome continued to grow at the same speed as uninfected rhizomes, probably by support from the uninfected mother plant. However, secondary rhizome branching was affected only by direct exposure to soil pathogens and not by the status of the mother plant. The results provide evidence that clonal growth may facilitate escape from soil-borne pathogens. The rhizome explores a patchy environment by supporting the growth of young tillers when passing pathogenic patches.
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| 50. |
- Dimmler, Martin, et al.
(author)
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On-line arithmetic for real-time control of microsystems
- 1999
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In: IEEE/ASME transactions on mechatronics. - Piscataway, NJ : IEEE Press. - 1083-4435 .- 1941-014X. ; 4:2, s. 213-217
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Journal article (peer-reviewed)abstract
- The integration of microcontrollers within mechanical systems is a current trend. However, decreasing the size of the system and satisfying higher precision requirements make it necessary to reevaluate the common signal processing techniques for controller implementations, because limited controller size, computation speed, and power consumption become major topics. In this paper, we demonstrate that serial computations with the most significant digits first, that is, on-line arithmetic, offer an important potential for real-time control. They enable a combination of traditional functions, such as analog-to-digital converters and control data computations. This leads to very efficient controller implementations with small size, high speed, and low power consumption. After a brief description of the requirements and challenges of microsystem controller design, the use of on-line arithmetic for real-time control is proposed. A short introduction to on-line arithmetic is given and control-specific implementation guidelines are presented and finally applied to a simple test system.
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