| 1. |
- Bengtsson, Magnus, et al.
(författare)
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Lidar fluorescence measurements of algal growth on electrical insulators
- 2003
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Ingår i: 2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666). - 0780377346 ; , s. 473-473
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Konferensbidrag (refereegranskat)abstract
- Fluorescence measurements using lidar techniques have been shown to be useful for monitoring of algal growth on e.g. historical monuments. In this experiment similar measurements were performed on electrical insulators to examine the correlation between algal growth and the quality of the insulator, a factor of importance in the high-voltage grid management
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| 2. |
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| 3. |
- Dernfalk, Andreas, 1975, et al.
(författare)
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Laser-induced fluorescence spectroscopy for detection of biological contamination on composite insulators
- 2003
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Ingår i: In Proc. 13th International Symposium on High Voltage Engineering, Delft, Netherlands.
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Konferensbidrag (refereegranskat)abstract
- A new technique for remote detection of biological contamination on high-voltage outdoor insulators has been investigated. The technique, which is based on laser-induced fluorescence (LIF) spectroscopy, has been applied to study surfaces of real silicon rubber insulators from a distance of approximately 60 m. Measurements were performed outdoors on a number of clean, as well as, biologically contaminated insulators. Several types of biological contamination were included, as five of the studied insulators had become covered when installed in Sweden, and another three had been contaminated by fungal growth in laboratory. Fluorescence spectra obtained from the surfaces of the described insulators are presented and the applicability of the technique is discussed and compared with photographic methods.
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| 4. |
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| 5. |
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| 6. |
- Larsson, A, et al.
(författare)
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In-situ diagnostics of HV outdoor insulators using laser-induced fluorescence spectroscopy
- 2002
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Ingår i: IEEE Transactions on Dielectrics and Electrical Insulation. - : Institute of Electrical and Electronics Engineers (IEEE). - 1070-9878. ; 9:2, s. 274-281
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Konferensbidrag (refereegranskat)abstract
- A new method for remote and non-intrusive diagnostics and surveillance of high-voltage insulators and insulation materials is presented, in particular pertinent to outdoor insulation. The method is based on laser-induced fluorescence (LIF) spectroscopy. The relationship between the LIF-spectrum and different materials and surface characteristics of silicone rubber samples are studied. These characteristics include hydrophobicity, filler content and biological growth. Furthermore, real insulators that have been naturally aged have also been studied. We conclude that laser-induced fluorescence has a significant potential to become a highly useful technique for contact-free and non-intrusive monitoring of the status of insulator materials in high-voltage systems.
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| 7. |
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| 8. |
- Larsson, A, et al.
(författare)
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Laser-triggered electrical breakdown in liquid dielectrics - Imaging of the process by the shadowing technique
- 2001
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Ingår i: IEEE Transactions on Dielectrics and Electrical Insulation. - : Institute of Electrical and Electronics Engineers (IEEE). - 1070-9878. ; 8:2, s. 212-219
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Tidskriftsartikel (refereegranskat)abstract
- Electric breakdown in transformer oil subjected to a quasi-uniform de electric field has been triggered by a focused laser pulse and prebreakdown discharge phenomena were imaged by the shadowing technique. Extensive data were recorded of the prebreakdown phenomena, such as streamers and gas bubble growth, from the initiation of the laser plasma to the disruptive discharge. The data was used to qualitatively and semi-quantitatively describe these phenomena. The image material also was used to improve and modify the qualitative description of the laser-triggered breakdown process previously presented by Sunesson et al.
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| 9. |
- Mohan, R. K., et al.
(författare)
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Photon-echo amplification and regeneration for optical data storage and processing
- 2000
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Ingår i: Journal of Luminescence. - 0022-2313. ; 86:3-4, s. 383-390
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Tidskriftsartikel (refereegranskat)abstract
- Optical data storage devices and erasable memories with storage densities in the range of terabits/cm2, all-optical devices for communication like optical bit-rate converters, routers and image processors can become a reality with photon-echo-based frequency-selective materials. In photon-echo-based optical data storage and data processing the photon-echo-output intensity generally is about 0.1–1% of the input intensity. Many devices, such as processors would require that the photon-echo output is used as an input to a new photon-echo process and hence the amplification of photon-echo signals is necessary. In this paper we describe the development of a fibre amplifier for amplifying photon-echo data. Requirements and performance for the fibre amplifier are discussed. Some examples of our initial experiments, where photon-echoes amplified by the fibre amplifier are used to generate secondary photon-echoes, are also presented.
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| 10. |
- Moiseev, S. A., et al.
(författare)
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Complete reconstruction of the quantum state of a single-photon wave packet absorbed by a Doppler-broadened transition
- 2001
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Ingår i: Physical Review Letters. - 1079-7114. ; 87:17, s. 173601-173604
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Tidskriftsartikel (refereegranskat)abstract
- An idea for how to reconstruct the quantum state of a nonstationary single-photon wave packet absorbed in a macroscopic medium with inhomogeneously broadened lines is presented. An analytical treatment of the problem is performed and the requirements on the proposed scheme for complete recovery of the recorded nonstationary quantum state with a probability close to unity is described. The physical nature of the present scheme is also discussed.
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