| 1. |
- Edner, H, et al.
(författare)
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Atmospheric Mercury Mapping In A Cinnabar Mining Area
- 1993
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Ingår i: Science of the Total Environment. - 1879-1026. ; 133:1-2, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- A mobile differential absorption lidar system was used in conjunction with point monitors to study the spatial and temporal distribution of atomic mercury in the atmosphere around an abandoned mercury mine at Abbadia S. Salvatore, Italy. The use of the remote sensing technique allows a fast coverage of large areas both horizontally and vertically with a good temporal resolution. Concentrations exceeding 1000 ng/m3 were measured close to the distillation plant and considerably elevated values also were evident above deposits of roasted cinnabar. Vertical gradients of the mercury concentration in air were established. These showed a very pronounced decrease a few centimeters above the ground.
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| 2. |
- Edner, H, et al.
(författare)
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Differential Absorption Lidar Mapping of Atmospheric Atomic Mercury In Italian Geothermal Fields
- 1992
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Ingår i: Journal of Geophysical Research. - 2156-2202. ; 97:D4, s. 3779-3786
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Tidskriftsartikel (refereegranskat)abstract
- Results from extensive lidar measurements on atmospheric atomic mercury in Italian geothermal fields are reported. A mobile differential absorption lidar system operating on the 254-nm mercury resonance line with a measuring range of about 1 km was used in mineralized as well as nonmineralized areas. Measurements were performed at geothermal power stations and in an unexploited field with natural surface geothermic manifestations. Atomic mercury concentrations ranging from 2 to 1000 ng/m3 were mapped. The high Italian geothermal mercury concentrations are in strong contrast to the recent lidar finding of the absence of atomic mercury in Icelandic geothermal fields.
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| 3. |
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| 4. |
- Edner, H, et al.
(författare)
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Fluorescence Lidar Multicolor Imaging of Vegetation
- 1994
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Ingår i: Optical Society of America. Journal B: Optical Physics. - 0740-3224. ; 33:13, s. 2471-2479
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Tidskriftsartikel (refereegranskat)abstract
- Multicolor imaging of vegetation fluorescence following laser excitation is reported for distances of 50 m. A mobile laser-radar system equipped with a Nd:YAG laser transmitter and a 40-cm-diameter telescope was utilized. The laser light was Raman shifted to 397 nm with pulse energies of approximately 30 mJ. An image-intensified CCD camera with a specially designed split-mirror Cassegrainian telescope was utilized for the simultaneous recording of fluorescence images of leaves and branches in four different spectral bands. Additionally, fluorescence spectra at selected points within the detection area were measured with an image-intensified diode array system. Image processing permits extraction of information related to the physiological status of the vegetation and might prove useful in forest decline research.
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| 5. |
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| 6. |
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| 7. |
- Ferrara, R, et al.
(författare)
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Atmospheric Mercury Emission At Solfatara Volcano (Pozzuoli, Phlegraean Fields, Italy)
- 1994
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Ingår i: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 29:7, s. 1421-1428
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Tidskriftsartikel (refereegranskat)abstract
- Mercury concentrations in air and in condensed steam coming from fumarolic activity at the Solfatara crater (Phlegraean Fields - Italy) were determined. In the condensed steam, mercury was found mainly associated as Hg-S complexes and showed a flux in the range from 0.9 to 4.5 g day(-1). Using the point monitor technique, high values (up to 690 ng m(-3)) of atmospheric mercury levels were observed only close to the main exhaling areas, while background levels (2 ng m(-3)) were measured over the crater area using the lidar technique. An upper limit (<2.4 g day(-1)) for the flux of elemental mercury in air was estimated with the lidar. This remote sensing technique also allowed to assess an upper limit for the SO2 flux (<24 kg day (-1)).
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| 8. |
- Ferrara, R, et al.
(författare)
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Mercury Emissions Into the Atmosphere From A Chlor-alkali Complex Measured With the Lidar Technique
- 1992
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Ingår i: Atmospheric Environment Part A-general Topics. - 0004-6981. ; 26:7, s. 1253-1258
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Tidskriftsartikel (refereegranskat)abstract
- Data are reported on atmospheric mercury flux measured by a lidar system at a chlor-alkali plant located in central Italy. Two mercury sources were identified over the electrolytic cell rooms. A flux value of 36 g h-1 was determined during the daytime while at night the value increase to 56 g h-1. The mercury emitted into the atmosphere was found to be 4 g per 1000 kg of chlorine produced. Atmospheric mercury concentrations were supplemented with some determinations made with the point monitor technique.
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| 9. |
- Ferrara, R, et al.
(författare)
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Vertical Profiles of Atmospheric Mercury Concentration
- 1992
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Ingår i: Environmental Technology. - : Informa UK Limited. - 1479-487X .- 0959-3330. ; 13:11, s. 1061-1068
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Tidskriftsartikel (refereegranskat)abstract
- Vertical profiles of atmospheric mercury concentration determined with a lidar and point monitor systems in the mineralized region of Mt. Amiata (Italy) are reported. Measurements were performed over a large flat area, without arboreal and herbaceous vegetation, constituting a roasted cinnabar deposit which still contains about two parts per thousand of mercury. The determinations carried out with the two techniques yielded comparable results for the working conditions used. Data demonstrate the presence of a vertical gradient of atmospheric mercury concentration, which is particularly large in the layers of air nearest the soil. The highest values (45-1000 ng m-3) were measured a few centimeters from the soil, while background values (2-3 ng m-3) were reached at heights of 10-20 m. The vertical gradient proved to be strongly dependent on ambient temperature.
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| 10. |
- Jarfors, Anders, 1963-, et al.
(författare)
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Reactions during infiltration of graphite fibres by molten Al-Ti alloy
- 1993
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Ingår i: Metallurgical and Materials Transactions. A. - 1073-5623 .- 1543-1940. ; 24:11, s. 2577-2583
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Tidskriftsartikel (refereegranskat)abstract
- The infiltration sequence of graphite fibers with liquid aluminum alloyed with titanium was studied. The titanium concentration was chosen such that a severe reaction occurred between the fibers and the melt. Aluminum carbide and titanium carbide, as well as an aluminide phase were formed. The phenomenon occurring during the infiltration sequence was explained with the aid of the ternary-phase diagram Al-Ti-C. The effect of the reaction on the infiltration height is discussed.
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